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SCIENCE  PROGRESS 

IN  THE  TWENTIETH   CENTURY 

A  QUARTERLY  JOURNAL  OF 

SCIENTIFIC    WORK 

&    THOUGHT 


VOL.  VIII 
NO.   29.    JULY    191 3 


EDITOR 


SIR    RONALD    ROSS,    K.C.B.,    F.R.S.,    D.Sc, 
LL.D.,    M.D.,   F.R.C.S. 


LONDON 
JOHN   MURRAY,   ALBEMARLE    STREET,   W. 

*9J3 


NOTICE 

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CONTENTS 

PAGE 

i.     VERTEBRATE   PAL/EONTOLOGY    IN    1912;    With   Note 

on  Giant  Tortoises  and  their  Distribution  i 

R.  Lydekker,  F.R.S. 

2.  TEMPERATURE   AND   THE   PROPERTIES   OF   GASES  .       26 

Francis  Hyndman,  B.Sc. 
{Illustrated) 

3.  LENARD'S   RESEARCHES   ON   PHOSPHORESCENCE       .       54 

E.  N.  Da  C.  Andrade,  B.Sc,  Ph.D. 
{Illustrated) 

4.  THE  CORROSION   OF   IRON 72 

H.  E.  A. 

{Illustrated) 

5.  RECENT  WORK  ON  VOLCANOES 85 

Professor  E.  H.  L.  Schwarz,  F.G.S. 

6.  A  CONTRIBUTION  TO  THE  BIONOMICS  OF  ENGLISH 

OLIGOCH^TA. — Part  I.     British  Earthworms   .        .       99 

The  Rev.  Hilderic  Friend,  F.L.S.,  F.R.M.S. 

7.  ENZYMES  AS  SYNTHETIC  AGENTS.— Part  I.    In  Carbo- 

hydrate Metabolism 113 

Professor  J.  H.  Priestley,  B.Sc,  F.L.S. 

8.  SCIENTIFIC   NATIONAL   DEFENCE I22 

Colonel  Charles  Ross,  D.S.O. 

9.  WOMAN'S   PLACE   IN   NATURE 133 

I.     M.  S.  Pembrey,  M.A.,  M.D. 
II.     O.  A.  Craggs,  D.Sc 

iii 


iv  CONTENTS 


PAGE 


10.  THE   SEATS  OF   THE   SOUL   IN   HISTORY    .         .        .145 

David  Fraser  Harris,  M.D.,  B.Sc.  (Lond.) 

11.  THE   OUTLOOK   FOR   HUMAN   HEALTH        .         .         .153 

Bernard  Houghton,  B.A.,  I.C.S. 

12.  REVIEWS,   BOOKS   RECEIVED,   AND   NOTES. 

Thomas  Preston,  "The  Theory  of  Light."  (Macmillan)  .  .  168 
Arthur  Holmes,  "  The  Age  of  the  Earth."     (Harper's  Library 

of  Living  Thought) 168 

Marcus  Hartog,  "Problems  of  Life  and  Reproduction."     (John 

Murray)     .         .         .         .         .         .         .         .         .         .170 

E.  H.  Ross,  "Reduction  of  Domestic  Flies."     (John  Murray)     172 

Books  Received 173 

Notes.     Prof.  Nathaniel  Henry  Alcock,  M.D.,  D.Sc.  .         .         .175 
The  University  of  Bristol 175 

NOTICE.     The  Emoluments  of  Scientific  Workers     .         .         .     176 


SCIENCE    PROGRESS 

VERTEBRATE     PALAEONTOLOGY    IN     1912 

By  R.  LYDEKKER,  F.R.S. 

By  far  the  most  striking  event  of  the  year,  so  far  as  verte- 
brate palaeontology  is  concerned,  is  the  discovery  by 
Mr.  Charles  Dawson,  in  a  shallow  bed  of  high-level  gravel 
at  Piltdown,  in  the  parish  of  Fletching,  Sussex,  of  portions  of 
a  cranium  and  lower  jaw  which  indicate  a  being  inter- 
mediate in  many  respects  between  man  and  the  man-like  apes. 
In  describing  these  specimens  at  the  meeting  of  the  Geological 
Society  held  on  December  18,  191 2  {Abstracts  Proc.  Geol.  Soc. 
No.  932,  Dec.  28,  1912),  Dr.  A.  Smith  Woodward  referred  to 
these  remains  as  "  human  "  ;  but  as  they  are  regarded  as  repre- 
senting a  distinct  generic  type,  it  may  be  a  question  whether 
they  have  any  right  to  that  title  ;  it  is  perhaps  better  to  refer 
to  them  as  man-like. 

Mr.  Dawson  states  that  the  skull  was  broken  up  by  the 
workmen  who  found  it  and  most  of  the  fragments  thrown 
away.  On  the  other  hand,  Sir  E.  R.  Lankester,  in  an  article 
in  the  Daily  Telegraph  of  December  19,  19 12,  asserts  that  it  was 
broken  when  discovered  and  that  the  fractured  parts  had  been 
slightly  worn  before  entombment  in  the  gravel.  The  lower 
jaw  was  dug  up  by  Mr.  Dawson  in  an  undisturbed  patch  of 
gravel  a  short  distance  away  from  the  spot  where  the  skull 
was  found.  Although  certain  doubts  were  expressed  at  the 
meeting  whether  the  skull  and  lower  jaw  belonged  to  the 
same  individual,  there  can  be  no  hesitation  in  regarding  them 
as  associated  and  there  are  some  reasons  for  believing  them  to 
pertain  to  a  female. 

The   gravel,  which   lies   at    a    height   of  80   ft.   above    the 

Ouse,  also  yielded  more  or  less  imperfect  teeth  of  an  elephant, 

a  mastodon,  a  horse,  a  hippopotamus  and  a  beaver,  as  well  as 

a  fragment  of  the  antler  of  a  red  deer  and  Palaeolithic  imple- 

1 


2  SCIENCE   PROGRESS 

ments  of  the  Chellean  type.  Messrs.  Dawson  and  Woodward 
conclude  that  the  gravel-bed  is  of  the  same  age  as  the  embedded 
Chellean  implements,  which  are  less  water-worn  than  most 
of  the  associated  flints;  but  that  the  teeth  of  the  elephant 
(which  is  of  a  Pliocene  type)  and  mastodon  are  derived  from 
older  (Pliocene)  gravels,  while  the  skull  and  jaw  belong  to  the 
period  of  the  bed  in  which  they  were  found.  The  remoteness 
of  that  period  is  indicated  by  the  subsequent  excavation  of  the 
Ouse  valley  to  a  depth  of  80  ft.  On  the  other  hand,  Sir  E.  R. 
Lankester,  after  first  committing  himself  to  the  statement  {Daily 
Telegraph,  Dec.  19,  1912)  that  the  skull  and  jaw  "were  probably 
embedded  for  the  first  time  in  the  existing  gravel  and  not 
washed  out  of  a  previous  deposit,"  subsequently  shifted  his 
ground  and  asserted  {op.  cit.  Jan.  6,  19 13)  that  the  specimen 
"  was  undoubtedly  washed  into  the  gravel  where  it  was  found 
from  a  previous  deposit." 

The  skull,  which  lacks  the  bones  of  the  face,  and  is  other- 
wise imperfect,  is  stated  by  Dr.  Smith  Woodward  to  exhibit 
all  the  essential  features  of  that  of  modern  man  {Homo)  and 
has  a  brain-capacity  of  at  least  1070  c.c.  It  is,  however, 
remarkable  for  the  excessive  thickness  of  the  bones  of  the 
roof,  which  averages  10  mm.  and  in  one  spot  reaches  12  mm. 
The  forehead  is  steeper  than  in  skulls  of  the  Neanderthal 
type  but  shows  only  slight  development  of  the  brow-ridges 
and  also  affords  evidence  that  the  plate  of  bone  (tentorium) 
dividing  the  cerebral  hemispheres  from  the  cerebellum  occupies 
the  same  relative  position  as  in  modern  man.  Viewed  from 
the  back,  the  skull  is  remarkably  low  and  broad,  with  relatively 
small  mastoid  processes. 

Of  the  lower  jaw,  the  right  half  or  ramus  is  nearly  com- 
plete, with  the  exception  of  the  loss  of  the  articular  condyle, 
as  far  forward  as  the  middle  of  the  bond  of  union  or  symphysis 
with  its  fellow  of  the  opposite  side.  Unfortunately,  however, 
only  two  teeth,  the  first  and  second  molars,  remain,  although 
the  socket  of  the  third  is  preserved.  In  place  of  the  thickened 
and  rounded  posterior  border  of  the  symphysis  and  the  promi- 
nent chin  of  man,  this  portion  of  the  jaw  slopes  regularly 
upwards  towards  the  position  which  would  be  occupied  by 
the  bases  of  the  front  teeth.  In  fact,  whereas  a  modern  human 
jaw,  when  viewed  from  below,  has  the  appearance  of  a  horseshoe- 
like arch,  the  Sussex  jaw  has  a  contour  recalling  that  of  a  pair 


VERTEBRATE  PALAEONTOLOGY   IN    1912  3 

of  pliers  when  closed.  In  these  respects  the  jaw  is  essentially 
that  of  a  chimpanzi.  The  two  molars,  which  are  essentially 
human  in  structure,  "  have  been  worn  perfectly  flat  by  masti- 
cation, a  circumstance  suggesting  that  the  canines  resembled 
those  of  man  in  not  projecting  sensibly  above  the  level  of  the 
other  teeth."  Thus  writes  Dr.  Woodward.  On  the  other 
hand,  Sir  E.  R.  Lankester  expresses  the  opinion  {D.T.  Dec.  19, 
1912)  that  the  Sussex  jaw  "had  almost  certainly  great  canines 
and  large  front  teeth."  It  should  be  added  that  in  the 
shallowness  of  the  notch  separating  the  articular  condyle  from 
the  coronoid  process  the  Sussex  jaw  approximates  to  the 
Pleistocene  Heidelberg  jaw,  which,  however,  is  of  a  much 
more  massive  type,  and,  although  lacking  a  prominent  chin, 
has  a  comparatively  short  symphysis. 

Perhaps  the  most  remarkable  feature  of  the  Sussex  "  man  " 
is  the  association  of  a  distinctly  human  type  of  cranium  with 
an  equally  marked  simian  form  of  lower  jaw.  This,  however, 
according  to  Dr.  Elliot  Smith,  who  contributed  an  appendix 
to  the  original  description,  is  no  matter  for  surprise,  as  in- 
creasing brain-development  in  the  forerunners  of  man  must 
have  involved  more  rapid  growth  and  change  in  the  cranium 
than  in  other  parts  of  the  skeleton.  Special  interest  also 
attaches  to  a  remark  by  the  same  observer  that  the  region 
of  the  brain  believed  to  be  associated  in  man  with  the  power 
of  speech  is  but  poorly  developed  in  the  Sussex  skull.  Not 
improbably,  therefore,  the  half-man  and  half-ape  of  the  Sussex 
Weald  was  devoid  of  the  power  of  articulate  speech. 

Be  this  as  it  may,  it  is  evident,  to  quote  the  words  of 
Sir  E.  R.  Lankester,  that  these  remains,  in  spite  of  their 
imperfection,  "are  of  extreme  importance,  and  constitute  a 
new  step  in  the  acquirement  of  solid,  tangible  knowledge  as 
to  the  development  of  man  from  ape-like  ancestors.  This  half 
of  a  lower  jaw  from  Sussex  furnishes  .  .  .  evidence  of  a  man- 
like creature  really  intermediate  between  man  and  ape.  It 
comes  nearer  to  the  realisation  of 'the  missing  link'  than  any- 
thing yet  discovered." 

In  the  published  abstract  of  the  original  description  no 
scientific  designation  was  given  to  this  missing  link;  but  in 
the  full  text  of  the  paper,  published  in  vol.  lxix.  of  the  Quarterly 
Journal  of  the  Geological  Society  (pp.  1 17-51),  the  new  generic 
and  specific  title   of  Eoanthropus  dawsoni  is  proposed. 


4  SCIENCE  PROGRESS 

Compared  with  the  foregoing,  the  rest  of  the  year's  work  on 
fossil  mammals  appears  insignificant ;  as  a  matter  of  fact,  it  is 
distinctly  below  the  average  in  interest  and  importance. 

As  standing  on  the  border-land  between  zoology  and 
palaeontology,  brief  reference  may  be  made  to  the  handsome 
volume  by  Messrs.  Rio,  Breuil,  and  Sierra  on  the  mural 
sketches  of  animals  from  Spanish  caves,  published  under  the 
auspices  of  the  Prince  of  Monaco.  In  connexion  with  this  may 
be  noticed  the  identification  by  Mr.  E.  P.  Newberry  (Klio,  vol.  xii. 
pp.  397  et  seq.)  of  "  the  animal  of  Set "  or  Typho,  so  frequently 
represented  in  ancient  Egyptian  frescoes,  with  the  wart-hog 
(Phacochoerus  africanus).  Many  previous  attempts  at  the 
identification  of  the  animal  in  question — which  has  been  con- 
sidered to  represent  the  okapi — have  been  made,  but  the 
controversy  now  seems  to  be  finally  decided. 

Hitherto  there  has  been  a  gap  in  our  knowledge  of  the 
forms  of  the  horse  existing  between  the  modern  period  and 
the  early  metal  age.  This  is  to  some  extent  filled  by  the  dis- 
covery of  a  skeleton  in  the  superficial  formations  of  Neukolln 
(formerly  Rixdorf),  near  Berlin.  According  to  Dr.  Max 
Hilzheimer  {Zool.  Anz.  vol.  xl.  pp.  105-17),  this  skeleton 
indicates  a  small  but  well-formed  breed  of  the  western  type 
akin  to  the  existing  so-called  "  Reitpferd." 

The  same  author  also  describes  {Zeits.  Morph.  u.  Anthrop. 
vol.  xv.  pp.  229-46)  remains  of  a  dog  and  other  domesticated 
animals  from  a  stratum  of  the  third  or  fourth  century  at 
Paulinenaue,   Mark. 

The  Vienna  University  recently  sent  an  expedition  to  collect 
fossil  mammals  from  the  well-known  deposits  of  Pikermi, 
Attica ;  a  report  on  the  results  is  contributed  by  Dr.  O.  Abel  in 
the  Verh.  Zool.-Bot.  Ges.  PVien,  vol.  lxii.  pt.  2,  pp.  61-3 

The  same  author,  it  may  be  mentioned  here,  has  published 
{Zool.  Jahrb.  191 2,  suppl.  15,  Bd.  i.  pp.  597-609)  notes  on 
adaptation  in  extinct  animals. 

The  Miocene  mammalian  fauna  of  Venice  is  reviewed,  with 
a  number  of  illustrations,  by  Mr.  Stefanini  in  the  first  part  of 
a  new  serial,  Mem.  1st.  Geol.  Padova,  vol.  i.  pp.  267-318. 

In  Australia  Mr.  Glauert  (Rec.  W.  Austral.  Mus.  vol.  i. 
pp.  37-46)  gives  a  list  of  the  fossil  mammals  found  in  the 
miscalled  Mammoth  Cave;  while  Mr.  J.  Mahony  {Victoria 
Naturalist,    vol.    xxix.   pp.    43-6)    records    the    occurrence    of 


VERTEBRATE  PALEONTOLOGY  IN    1912  5 

remains  of  the  Tasmanian  devil  (Sarcophilus  ursinus)  on  the 
mainland  in  association  with  those  of  various  extinct 
marsupials. 

The  latest  of  Dr.  Stehlin's  valuable  contributions  to  our 
knowledge  of  the  extinct  mammalian  fauna  of  Switzerland 
{Abh.  schweiz.  pal.  Ges.  vol.  xxxviii.  pp.  1 165-1298)  relates  to  the 
osteology  and  dentition  of  the  lemuroid  genus  Adapis,  of  which 
a  new  species  is  described.  As  the  result  of  his  studies,  the 
author  confirms  the  opinion  that  Adapis  should  be  included  in 
the  Lemuroidea  and  that  its  affinities  are  probably  nearer  to  the 
Lemurince  than  to  either  the  Indrisince  or  Chiromyince.  The 
genus  cannot  however  be  regarded  as  ancestral  to  any  of 
the  existing  or  Pleistocene  representatives  of  the  group  but 
represents  a  completely  extinct  collateral  branch. 

The  cave-lion  (Felis  leo  fossilis),  as  exemplified  by  remains 
from  the  neighbourhood  of  Heidelberg,  forms  the  subject  of 
a  memoir  by  Mr.  A.  Wurm  in  the  Jahrcsbcr.  oberrhein.  Geol. 
Ges.  ser.  2,  1912,  pp.  77-102. 

Two  other  noteworthy  papers  on  fossil  Carnivora  have 
appeared  during  the  year.  In  the  first  of  these  Prof.  Sidney 
Reynolds  reviews  the  British  Pleistocene  Mustelidce  in  the 
Palaeontographical  Society's  volume  for  191 1,  published  in 
February  1912.     No  new  forms  are  described. 

In  the  second  Dr.  J.  Merriam  {Mem.  Univ.  California,  vol.  i. 
No.  2)  describes  the  skeletons  and  teeth  of  wolves  and  other 
Canidce  from  the  Pleistocene  asphalt-beds  of  Rancho  La  Brea, 
California.  Many  of  these  belong  to  the  great  extinct  wolf  for 
which  the  late  Prof.  Leidy  proposed  the  name  of  Canis  dims  ; 
they  serve  to  show  that  this  species,  although  near  akin  to  the 
existing  so-called  timber-wolf,  was  bigger  than  any  other  known 
member  of  the  group,  not  even  excluding  the  great  black 
Alaskan  wolf  (C.  pambasileus).  Two  other  species,  C.  milleri 
and  C.  andersoni,  are  likewise  regarded  as  extinct ;  the  former 
being  related  to  the  timber-wolf,  which  is  stated  to  present 
certain  resemblances  to  the  coyote  or  prairie  wolf.  Yet  other 
kinds  are  regarded  as  representing  extinct  races  of  existing 
American  Canidce. 

In  another  article  (Univ.  California  Pub.,  Bull.  Dep.  Geol. 
vol.  vii.  pp.  37-46)  the  writer  last  mentioned  records  the 
occurrence  in  the  La  Brea  asphalt  of  bears  referable  to  the 
extinct  genus  Arctotherium  and  the  modern  Ursus,  as  well  as  of 


6  SCIENCE  PROGRESS 

a  puma  nearly  related  to  one  of  the  living  races  of  that  widely 
spread  species. 

If  the  identification  be  correct,  considerable  interest  attaches 
to  a  premolar  tooth  from  the  Tongrien  horizon  near  Rennes 
described  by  Mr.  Maurice  Leriche  (Ann.  Soc.  Ge'ol.  Nord, 
vol.  xxxix.  pp.  369,  370,  1910)  as  a  new  generic  type  of  seal, 
under  the  name  of  Palceotaria  henriettce.  As  indicated  by  its 
designation,  the  animal  to  which  this  tooth  pertained  is  con- 
sidered to  be  most  nearly  allied  to  the  eared  seals  {Otariidce), 
while  it  is  likewise  claimed  to  be  the  earliest  known  member  of 
the  Pinnipedia. 

Miss  Dorothy  Bate,  who  has  done  so  much  to  increase  our 
knowledge  of  the  natural  history  of  the  Mediterranean  Islands, 
has  discovered  in  the  superficial  deposits  of  Crete  the  remains 
of  a  gigantic  rat,  described  (Geol.  Mag.  decade  5,  vol.  ix.  pp.  4-6) 
as  Mus  catreus.  It  is  the  largest  known  member  of  its  genus 
(including  Epimys)  and  rivals  in  size  the  great  African  Cricetomys 
gambianus. 

Considerable  interest  attaches  to  Mr.  M.  A.  C.  Hinton's 
identification  (Q.  J.  Geol.  Soc.  vol.  lxviii.  p.  249)  of  remains 
of  an  extinct  lemming  (Dicrostonyx  henseli)  from  a  Pleistocene 
Arctic  bed  near  Ponder's  End.  The  same  species  occurs  in 
the  fissures  at  Ightham,  Kent. 

A  new  race  of  the  extinct  wild  ox  or  aurochs  (Bos  primi- 
genius  italics)  from  the  Pleistocene  of  the  Roman  district  and  a 
second  (B.  p.  sicilice),  remarkable  for  its  small  size,  from  that  of 
Sicily,  are  recorded  by  Dr.  Hans  Pohlig  in  the  Bull.  Soc.  beige 
Geol.  vol.  xxvi.  Proc.  Verb.  pp.  311—17. 

The  most  elaborate  memoir  published  during  the  year  on 
fossil  ungulates  is  one  by  Dr.  R.  Kowarzik  (Denks.  K.  Ak.  Wiss. 
Wien,  vol.  lxxxvii.  pp.  1-62),  on  remains  of  musk-oxen  from  the 
diluvial  deposits  of  Europe  and  Asia,  in  which  it  is  concluded 
that  these  animals  were  natives  of  the  Arctic  regions  in  late 
Tertiary  times  but  were  driven  southwards  during  the  glacial 
period.  The  glacial  representative  of  the  animal  is  regarded 
as  a  distinct  species  (Ovibos  fossilis,  Rat.  =  Prceovibos  priscus, 
Staud.),  which  at  the  close  of  the  cold  period  found  its  way 
from  England  to  the  Arctic  barred  by  the  disappearance  of  a 
former  land-bridge.  Continental  herds  wandered,  however,  by 
way  of  Russia,  Siberia,  and  Bering  Strait,  to  N.  America, 
where  they  gave  rise  to  Q.  mackenzianus,  the  form   now   in- 


VERTEBRATE   PALEONTOLOGY   IN    1912  7 

habiting  the  area  west  of  the  watershed  between  the  Atlantic 
and  Arctic  Oceans.  Here  it  may  be  mentioned  that  in  a  paper 
published  in  the  Zool.  Anzeiger  for  191 1  (vol.  xxxvii.  p.  107) 
the  same  writer  has  taken  the  extraordinary  course  of  proposing 
the  new  generic  term  Bosovis — Bovovis  it  should  be — for  Ovibos 
moschatus  and  restricting  Ovibos  to  O.  mackenzianus,  apparently 
oblivious  of  the  fact  that  the  former  is  the  type  of  Ovibos. 

During  the  last  two  or  three  years  a  new  contributor— Mr. 
J.  Chomenko  (J.  Khomenko) — to  our  knowledge  of  the  mam- 
malian palaeontology  of  the  Russian  empire  has  published 
several  papers  on  the  Pliocene  and  Miocene  faunas  of  Bessarabia. 
In  three  of  these,  published  in  Trd.  Obsc.  jest.,  Kisinev,  19 10, 
191 1  and  1912,  the  author  describes  remains  of  the  beaver,  of 
the  giraffe-like  Helladotherium  of  the  Pikermi  beds  of  Attica, 
and  of  an  extinct  camel ;  the  last  being  referred  to  in  the  title 
of  the  paper  as  Camelns  bessarabiensis,  although  it  is  stated  in 
the  text  that  this  is  not  meant  to  be  a  specific  name  !  In  another 
serial,  the  title  of  which  I  am  unable  to  transliterate,  the  same 
writer  describes  a  jaw  from  Bessarabia  identified  with  Cervus 
ramosus  of  Croizet,  a  deer  typically  from  the  French  Pliocene. 

In  a  fourth  communication  Mr.  Chomenko  {Ann.  Geol.  et 
Min.  de  la  Russie,  vol  xiv.  pp.  148-66)  describes  mastodon 
teeth  from  the  Upper  Pliocene  of  Southern  Bessarabia,  which 
he  regards  as  representing  a  new  race  of  Mastodon  arvernensis, 
under  the  name  of  precursor.  Reference  may  also  be  made  to 
a  paper  by  Mr.  G.  Pontier  {Ann.  Soc.  Geol.  Nord,  vol.  xxxix. 
PP-  303-7»  l9l°)  on  a  last  lower  molar  of  the  South  American 
M.  andium  remarkable  for  carrying  five,  in  place  of  the  normal 
four,  ridges  on  the  crown,  thus  showing  an  approximation  to 
the  so-called  tetralophodont  mastodons,  in  which  the  number 
of  ridges  on  this  tooth  is  always  five. 

Hitherto  such  remains  of  fossil  elephants  as  have  been 
discovered  in  Africa  appear  to  have  been  more  or  less  nearly 
related  to  the  existing  Elephas  africanus ;  but  in  the  Geological 
Magazine  (decade  5,  vol.  ix.  pp.  1 10-13)  Dr.  C.  W.  Andrews 
describes  a  fragmentary  molar  from  the  Nile  near  Khartum 
which  indicates  a  species  akin  to  the  European  Elephas 
meridionalis  but  with  taller  plates  to  the  molars. 

The  phylogeny  and  ancestry  of  the  Proboscidea — from  the 
primitive  forms  of  the  Fayum  Tertiary  onwards — is  reviewed  by 
Dr.  Gunther  Schlesinger  at  considerable  length  in  the  Jahrbuch 


8  SCIENCE  PROGRESS 

of  the  Austrian  Geological  Survey,  vol.  lxii.  pp.  87-182.  The 
same  subject,  as  exemplified  by  the  affinities  of  the  Pleistocene 
European  E.  antiquus,  forms  the  subject  of  an  article  by  Mr. 
Zuffardi  in  Atti.  R.  Ac.  Lincei,  ser.  2,  vol.  xxi.  pp.  298-304. 

In  191 1  Dr.  Schlesinger  provisionally  referred  an  elephant's 
tooth  from  Lower  Austria  to  the  Siwalik  E.  planifrons ;  this 
determination  he  confirms  in  a  later  paper  published  in  Verh. 
Zool.-Bot.  Ges.  Wien,  vol.  lxii.  pt.  2,  p.  55.  Two  unusually  fine 
skeletons  of  the  mammoth  have  recently  been  placed  on  exhibi- 
tion. The  first  of  these,  which  is  in  the  Museum  at  Stuttgart, 
is  reported  to  be  the  largest  known,  and  was  found  at  Steinheim, 
in  Swabia,  in  the  summer  of  1910.  The  tusks  are  of  no  very 
great  size,  measuring  7^  ft.  ;  but  the  skeleton  is  remarkable  for 
the  great  relative  length  of  the  legs,  especially  the  front  pair,  as 
well  as  for  the  unusual  width  of  the  molars.  The  second 
skeleton,  which  has  been  set  up  in  the  Volkerkunde  Museum  at 
Leipzig,  is  nearly  complete  and  has  been  described  by  Dr.  J. 
Felix  in  the  Veroffentlichungen  der  Stddt.  Mus.  fiir  Volkerkunde 
for  191 2.  In  was  discovered  in  December  1908  under  a  con- 
siderable thickness  of  sand  and  clay,  near  Borna,  its  presence 
being  revealed  by  the  tip  of  one  of  the  tusks.  This  skeleton 
stands  3*20  metres  in  height. 

Brief  notice  will  suffice  for  a  paper  by  Dr.  A.  Andreuxi 
(Riv.  Ital.  Pal.  vol.  xviii.  pts.  2  and  3,  pp.  88-90)  on  remains  of 
E.  meridionalis  from  the  Italian  Pliocene;  and  to  a  second,  by 
Dr.  Pohlig  {Bull.  Soc  beige  Ge'ol.  vol.  xxvi.  Proc.  Verb.  pp. 
187-93),  on  a  lower  jaw  of  the  American  Mastodon  americanus 
with  the  left  permanent  tusk  in  situ.  Dr.  Pohlig  appears  to  be 
of  opinion  that  this  specimen  is  unique  in  this  respect ;  but  an 
example  with  the  right  tusk  was  recorded  in  1886  by  the  present 
writer  {Cat.  Foss.  Mamm.  Brit.  Mus.  pt.  iv.  p.  21). 

Another  mummified  carcase  of  a  rhinoceros  has  been  dis- 
covered in  the  ozokerit  beds  of  Starunia,  Galicia,  which  has 
been  described  by  Dr.  Abel  in  the  Verh.  Zool.-Bot.  Ges.  Wien, 
vol.  lxii.  pts.  2,  3,  pp.  79-82  ;  the  species  in  this  instance  being 
the  woolly  Rhinoceros  antiquitatis. 

During  the  year  Mr.  Ivar  Sefve  has  made  a  further  contribu- 
tion to  our  knowledge  of  the  extinct  Equida?  of  South  America, 
in  a  memoir  published  in  the  K.  Svenska  Vet.-Ak.  Handlinger  (vol. 
xlviii.  No.  6).  Among  the  groups  recognised  are  Hyperhippidium 
and  Parahipparion ;  a  new  species  of  the  latter  being  named  in 


VERTEBRATE  PALEONTOLOGY   IN    1912  9 

honour  of  the  late  Prof.  Burmeister,  the  pioneer  of  Argentine 
palaeontology. 

The  titanotheres  of  the  Uinta  beds  of  Utah  have  engaged 
the  attention  of  Mr.  E.  S.  Biggs,  who,  in  addition  to  naming  a 
new  genus  and  several  species  {Field  Mus.  Geo/.  Pub/,  vol.  iv. 
pp.  17-41),  comments  on  the  rapid  evolution  and  short  life  of 
some  of  the  groups  of  these  perissodactyles. 

Turning  to  marine  mammals,  it  may  be  mentioned  that  in 
the  group  of  Sirenia  the  scapula  of  Halitherium  schinzi  was 
described  in  191 1  by  Mr.  O.  Schmidtgen  (Centralblatt  fur  Mineral, 
191 1,  pp.  221-3);  and  also  that  during  the  year  under  review 
Dr.  R.  Issel  {Mem.  R.  Ac.  Lincei,  ser.  5,  vol.  ix.  pp.  119-25)  has 
contributed  a  note  on  the  corresponding  bone  of  the  allied  genus 
Felsinotherium.  The  first-named  writer  has  likewise  recorded 
{Zool.  Jahrbuch,  191 2,  suppl.  15,  vol.  ii.  pp.  449-95)  some  new 
observations  with  regard  to  the  structure  of  the  pelvis  and 
hind-limb  of  Halitherium. 

Fossil  whales  akin  to  the  modern  rorquals  and  tinners  form 
the  subject  of  an  article  by  Prof.  F.  W.  True  in  vol.  lix.  No.  6 
of  the  Smithsonian  Miscellaneous  Collections,  which  mainly 
consists  of  a  summary  of  a  paper  in  Danish  by  Dr.  H.  Winge. 
Both  writers  consider  that  among  a  multitude  of  generic 
divisions  which  have  been  proposed,  Aulocetus,  Cetotherium, 
Herpetocetus,  and  Plesiocetus  are  valid  ;  and  of  these,  as  well 
as  of  the  two  allied  existing  genera,  Balcenoptera  and  Megaptera, 
diagnoses  based  on  osteological  characters  are  appended. 

It  is  gradually  becoming  evident  that  the  South  American 
freshwater  dolphins  of  the  family  Iniidoe,  now  represented  by 
the  genera  Inia  and  Pontoporia,  each  with  a  single  species,  had 
numerous  forerunners  during  Tertiary  times.  The  latest 
addition  to  the  list  is  Hesperocetus  californicus,  a  genus  and 
species  established  by  Prof.  True  {Smithson.  Misc.  Collect. 
vol.  Ix.  No.  n)  on  the  evidence  of  an  imperfect  lower  jaw,  with 
teeth,  from  the  Californian  Tertiaries.  This  genus,  which  is 
provisionally  referred  to  the  Iniidcv,  is  remarkable  for  the  length 
of  the  symphysis  of  the  lower  jaw  and  the  large  size  of  the 
teeth,  which  recall  those  of  the  extinct  Delphinodon,  classed  by 
the  author  with  the  Delphinidce.  Other  extinct  Iniida:  are 
Saurodelphis,  Pontoplanodcs  and  Ischyrorhynchus,  all  exclusively 
American. 

In  a  second  article,  Dr.  True  {Journ.  Ac.  Nat.  Sci.  Philadelphia, 


io  SCIENCE  PROGRESS 

ser.  2,  vol.  xv.  pp.  165-93)  describes,  with  numerous  illustrations, 
the  skeleton  of  a  porpoise  from  the  Miocene  of  Maryland,  which 
is  referred  to  a  new  species  of  the  Tertiary  genus  Delphinodon, 
with  the  name  D.  dividum.  Although  referable  to  the  family 
Dclphinidce,  the  extinct  genus  differs  from  existing  forms  by  the 
lack  of  union  of  the  axis  with  the  atlas  vertebra  and  the  dis- 
tinctly tuberculate  character  of  the  hind  cheek-teeth.  "  The 
most  striking  primitive  characters  of  the  species,"  observes 
Dr.  True,  "  are  the  rugosity  of  the  enamel-layer  of  the  teeth  and 
the  presence  of  anterior  and  posterior  ridges  and  accessory 
cusps.  The  teeth  of  recent  typical  delphinoids,  with  the 
exception  of  Steno,  have  smooth  crowns.  .  .  .  This  peculiarity 
in  a  genus  which  otherwise  presents  the  characters  of  a  typical 
delphinoid  points  to  affinity  with  the  fossil  genus."  It  is  added 
that  accessory  cusps  occur  in  the  teeth  of  the  white  whale 
(Delphinapterus),  which  Dr.  True  regards  as  representing  a 
family  distinct  from  the  Delphinidce. 

In  the  Atti  Ac.  Lincei,  Mem.  ser.  5.  vol.  ix.  pp.  35-8,  Messrs. 
Bassani  and  Misuri  describe  and  figure  the  skull  of  a  long- 
snouted  dolphin  from  the  Miocene  of  Lecce,  Otranto,  which 
is  identified  with  a  species  previously  described  by  Mr.  Del 
Piaz  as  Ziphiodelphis  abeli. 

Leaving  cetaceans  for  edentates,  it  may  be  mentioned  in 
the  first  place  that  so  long  ago  as  the  year  1874  two  Spanish 
engineers,  Messrs.  Cuataparo  and  Ramirez,  described,  under 
the  name  of  Glyptodon  mexicanus,  the  carapace  and  skull  of 
a  large  glyptodont,  or  giant  armadillo,  from  a  superficial  deposit 
in  Mexico.  This  specimen,  which  is  in  the  Mexican  National 
Museum,  and  another  specimen  from  Mexico  in  the  American 
Museum  of  Natural  History,  form  the  subject  of  an  article 
by  Mr.  Barnum  Brown  {Bull.  Amer.  Mus.  Nat.  Hist.  vol.  xxxi. 
pp.  i6y-yy)  in  which  they  are  referred  to  the  new  genus 
Brachyostracon,  under  the  respective  names  of  B.  mexicanus  and 
B.  cylindricus,  the  latter  constituting  the  generic  type.  In  the 
relatively  simple  form  of  the  first  two  lower  cheek-teeth  the 
genus  is  stated  to  approximate  to  the  South  American 
Sclerocalyptus  (Hoplophorus)  and  Panochthus,  although  the 
absence  of  lateral  prolongations  of  the  sides  of  the  carapace 
and  the  mode  of  arrangement  of  the  plates  in  the  head-shield 
suggest   relationship   to   the   typical    Glyptodon,      The    author 


VERTEBRATE  PALEONTOLOGY   IN    1912  11 

arranges  the  glyptodonts  in  three  families  —  Glyptodontidce, 
Scleroscalyptidce,  and  Doedicuridce — but  it  may  be  suggested  that 
sub-family  rank  appears  amply  sufficient  for  these  groups. 

A  paper  by  Dr.  J.  Richter  on  the  armature  of  the  genus 
for  which  the  author  retains  the  name  Hoplophorus  appeared  in 
the  Palceontographica  for  191 1  (vol.  lvii.  pp.  257-84,  pts.  xxii.  and 
xxiii.)  but  was  omitted  from  my  review  of  that  year's  work. 
Another  omission  was  a  paper  by  Dr.  Smith  Woodward  in  the 
Quart.  Journ.  Geol.  Soc.  (vol.  lxvii.  pp.  278-81,  191 1)  on  three 
mammalian  teeth  from  the  Wealden  of  Hastings.  Two  of  these 
are  referred  to  a  previously  described  species,  Plagiaulax 
dawsoni;  the  third  has  been  provisionally  assigned  to  an 
American  Cretaceous  genus  with  the  new  specific  name  of 
Dipriodon  valdensis.  All  three  belong  to  the  group  of  Multi- 
tuberculata,  which  is  included  by  some  palaeontologists  in  the 
marsupials  while  by  others  it  is  considered  to  be  more  nearly 
related  to  the  monotremes. 

Birds,  as  usual,  have  attracted  little  attention  but  there  is  a 
memoir  by  Mr.  Koloman  Lambrecht  on  the  fossil  birds  of  the 
Borsoder  Bukh-Gebirges  and  Hungary  originally  published  in 
Aquila,  vol.  xix.  pp.  270-320.  The  remains,  however,  are  for 
the  most  part  from  Pleistocene  deposits  and  referable  to  ex- 
isting species.  They  indicate  the  existence  in  Hungary  during 
the  Pleistocene  of  Arctic  steppe-like  and  tundra-like  conditions ; 
the  occurrence  of  ptarmigan  in  the  fauna  being  specially  note- 
worthy. 

A  review  of  the  bird-faunas— chiefly  Pleistocene — of  the 
Pacific  coast  of  North  America  is  contributed  by  Mr.  L.  H.  Miller 
to  the  Bulletin  of  the  Department  of  Geology  of  the  University  of 
California.  The  chief  faunas  reviewed  are  those  of  the  Potter's 
Creek  and  Samwell  Caves  and  the  asphalt  beds  of  Rancho  la 
Brea ;  special  attention  being  directed  to  their  bearing  on  the 
past  and  present  geographical  distribution  of  generic  groups. 

The  first  paper  relating  to  fossil  reptiles  for  notice  is  one 
by  Mr.  F.  Broili  (Zeits.  deutsch.  geol.  Ges.  vol.  lxiv.  pp.  492-500) 
on  a  remarkably  well-preserved  skeleton  of  Pterodactylus 
microynx  discovered  in  the  Kimeridgian  Lithographic  Stone  of 
Eichstadt,  Bavaria,  of  which  an  illustration  is  given.  The 
structure  of  the  wing  of  pterodactyles  is  discussed  by  Prof. 
S.  W.  Williston  in  a  paper  published  in  the  Journal  of  Geology, 


12  SCIENCE  PROGRESS 

Chicago,  for  191 1  (vol.  xix.  pp.  696-745)  but  not  noticed  in  my 
review  of  the  work  of  that  year.  This  same  paper  also  contains 
a  restoration  of  Nyctosaurus. 

In  connexion  with  the  above  may  be  noticed  a  very  in- 
teresting article  by  Messrs.  E.  and  A.  Harle,  published  in  Bull. 
Soc.  Ge'ol.  France,  vol.  xi.  pp.  n  8-21,  on  the  means  by  which  the 
giant  pterodactyles  of  the  American  Cretaceous  were  enabled 
to  fly.  For  permission  to  reproduce,  in  a  somewhat  condensed 
form,  the  following  abstract  of  this  most  interesting  article,  I 
am  indebted  to  the  editor  of  The  Field. 

Some  of  these  pterodactyles  had  a  wing-expanse  of  at  least 
from  21  to  24  ft.,  whereas  the  largest  flying  birds  of  the  present 
day,  such  as  the  albatrosses,  condors,  lammergeiers,  and  mara- 
bout  storks,  have  not  more   than   about  half  the  bulk  of  the 
former,  although   they   have   probably  attained   the   maximum 
size  compatible,  under  present  physical   conditions,  with   the 
power  of  flight.     For  studies  of  the  flight  of  birds  and  insects 
in  connexion  with  the  theory  of  aeroplanes  have  demonstrated 
that  the  power  necessary  to  propel  animals   through   the   air 
varies  per  unit  of  weight  approximately  as  the  sixth  root  of 
the  weight ;  that  is  to  say,  as  the  square  root  of  their  dimensions. 
Accordingly,  the  power  required  increases  more  rapidly  than 
the  weight  and  the  dimensions.     If,  for  instance,  the  dimensions 
be  quadrupled  a  power  is  required  per  unit  of  weight  equal  to 
that  originally  sufficient  multiplied  by  the  square  root  of  four  ; 
that  is  to  say,  the  power  must  be  doubled  per  unit  of  weight. 
From  this  it  is  evident  that  a  limit  to  the  weight,  and  conse- 
quently to  the  size,  of  animals  capable  of  flight  must  be  reached. 
But  the  pterodactyles  of  the  Cretaceous  greatly  exceeded  these 
limits,  yet,  from   the   situations   in  which   their  skeletons   are 
found  in  Kansas,  it  is  evident  that  they  were  able  to  fly  dis- 
tances of  at  least   100  miles  from   the    shore.     Probably  they 
performed    skimming    flights    above   the   waves   in   pursuit   of 
surface-swimming  fish,  for  the  capture  of  which  the  structure 
of  the  skull  and  beak  seems  adapted.     Again,  if  we  go  back  in 
time  to  the  Carboniferous  period  of  France,  we  find  gigantic 
dragon-flies  with  a  wing-expanse  of  from  28  to  32  in.,  which  it 
is  certain  would  be  unable  to  fly,  from  lack  of  sufficient  pro- 
pelling power,  under  present  physical  conditions,  as  they  are 
fully  three    times   the   size   of   the    biggest   of   their    existing 
relatives. 


VERTEBRATE  PALEONTOLOGY  IN    1912  13 

How,  then,  were  these  giants  capable  of  flight  ?    One  sug- 
gestion is  that  the  attraction  of  gravity,  owing  to  the  diameter 
of  the  earth  having  been  greater,  was  less  in  past  epochs  than 
at  the  present  day.     But  an  increase  in  the  earth's  radius  of 
some  60  miles,  which  is  the  maximum  that  could  be  allowed, 
would  cause  but  slight  diminution  in  the  pull  of  gravity.     On 
the  other  hand,  an  increase  in  atmospheric  pressure  would  have 
much  more  effect  on  the  flying  capacity  of  animals.     Suppose, 
for  example,  an  animal  flying  by  wing-beats  (and  it  is  certain 
that  pterodactyles  did  not  glide  from  trees  or  cliffs  in  aeroplane- 
fashion),   in  which   the  wing-expanse  was   double   that   of  the 
largest  modern  birds.     From   the  formula   given  above   it  will 
be  evident  that  under  existing  conditions  such  an  animal  would 
require,  per  unit  of  weight,  a  power  equal  to  that  of  our  largest 
birds   multiplied  by  the  square  root  of  four   (in  other   words, 
doubled),  which  would  manifestly  be  impossible  to  realise.     But 
if  the   atmospheric    pressure  were  four   times   as   great   as   at 
present,  flight  would   be  possible  with  the  power   diminished 
by  one-half.     And,  as  a  matter  of  fact,  the  necessary  power, 
per  unit  of  weight,  being  doubled  in  one  way  and  halved   in 
another,  would  remain  the  same  and  be  no  greater  than  in  the  case 
of  existing  birds.     Accordingly,  an  augmentation  in  atmospheric 
pressure  in  the  proportion  of  one  to  four  would  compensate  a 
similar  increase  in  the  size  of  the  animal.     So  that  we  have  the 
general  rule  that  all  increase  in  the  size  of  the  animal  would 
be  compensated  by  a   proportional  augmentation  of  pressure. 
Thus  in  the  case  of  the  largest  known  pterodactyles,  of  which 
the  wing-expanse  was  about  double  that  of  the  biggest  living 
birds,  the  impossibility  of  flight  on  account  of  their  size  would 
be  annulled  by  a  double  atmospheric  pressure.     If  the  tempera- 
ture were  higher  than   at   the  present   day  there  would    be   a 
further  slight  increase  in  the  pressure.      The  fact,  then,  that 
giant  reptiles  which  could  not  fly  under  present  conditions  did 
do  during  the  Cretaceous,  coupled  with  the  similar  case   pre- 
sented by  the  giant  dragon-flies  of  the  Coal  period,  leads  the 
authors  to  regard  (so  far  as  conclusions  of  this  kind  have  any 
value  and  always  bearing  in  mind  the  possibility  that  nature 
may  have  utilised  means  of  which  we  have  no  cognisance)  an 
increased  atmospheric  pressure  during  geological  time  as  the 
most  plausible  and  probable  explanation  of  the  problem. 

During  the  past  few  years  the  dinosaurian  quarries  of  Tenda- 


i4  SCIENCE  PROGRESS 

guru,  German  East  Africa,  have  been  worked  with  great 
energy  and  a  vast  number  of  gigantic  bones  transported  to 
Berlin.  An  account  of  the  excavations  and  descriptions  of 
some  of  the  bones,  by  Mr.  Janensch  and  others,  will  be  found  in 
Sitzber.  Ges.  natfor.  Freunde  for  191 2.  According  to  this,  the 
biggest  of  the  Tendaguru  dinosaurs  is  remarkable  for  the  huge 
dimensions  of  the  scapula  and  humerus,  which  are  propor- 
tionately much  larger  than  in  other  species  and  actually  bigger 
than  any  other  known  specimens.  The  biggest  humerus 
measures  rather  more  than  6  ft.  6  in.  in  length.  Of  this 
enormous  bone  a  cast  has  been  acquired  by  the  Natural 
History  Museum.  The  dinosaur  to  which  this  great  bone 
belonged  is  believed  to  be  near  akin  to  Diplodocus  but  with 
a  relatively  as  well  as  actually  larger  scapula  and  fore-limb. 
Another  paper,  by  Dr.  E.  Hennig,  on  the  possible  occurrence 
of  the  Tendaguru  deposits  in  other  districts  appears  in  the 
same  journal  (pp.  493-7). 

To  the  Memoirs  of  the  American  Museum  of  Natural 
History,  ser.  2,  vol.  i.  pt.  1,  Prof.  H.  F.  Osborn  contributes 
an  illustrated  account  of  the  skull  of  the  gigantic  theropod 
dinosaur  Tyrannosaurus  rex,  from  the  Upper  Cretaceous  of 
Montana,  together  with  notes  on  the  skulls  of  Allosaurus  and 
the  Theropoda  in  general.  The  skull  of  Tyrannosaurus, 
which  is  furnished  with  a  formidable  armature  of  teeth  of 
the  megalosaurian  type,  is  not  only  the  largest  in  the  theropod 
order,  but  also  the  most  powerful  and  massive  among  reptiles 
as  a  whole ;  as  may  be  verified  by  the  inspection  of  a  cast 
exhibited  in  the  Natural  History  Museum.  A  noteworthy 
feature  of  the  skull  is  the  fusion  of  the  vomers  into  a  single 
diamond-shaped  plate,  articulating  posteriorly  by  a  long  style 
with  the  pterygoids,  since  a  practically  identical  structure 
exists  in  the  ostrich  and  its  relatives.  As  an  adaptive  modifi- 
cation correlated  with  the  powerful  dentition,  attention  is 
specially  directed  to  the  antero-posterior  shortening  of  the 
skull  and  the  reduction  of  the  number  of  pairs  of  teeth  from 
twenty  (in  Allosaurus)  to  sixteen.  This  abbreviation  of  the 
skull  is  paralleled  among  modern  cats  and  certain  extinct  dog- 
like carnivores.  The  homology  of  certain  bones  of  the  thero- 
pod skull  is  also  discussed.  A  second  article  in  the  same 
issue  is  devoted  to  the  description,  by  Prof.  Osborn,  of  the 
"  mummified "    skin    of    Trachodon    annectans,    an    iguanodont 


VERTEBRATE  PALEONTOLOGY   IN   1912  15 

dinosaur  from  the  Upper  Cretaceous  of  Wyoming.  As  this 
wonderful  specimen  was  noticed  and  an  illustration  of  a 
portion  of  the  skin  was  given  in  my  last  year's  article,  further 
mention  is  unnecessary. 

The  structure  of  the  fore-foot  of  the  genus  Trachodon  is 
discussed  fully  in  the  Bull.  Amer.  Mus.  Nat.  Hist.  vol.  xxxi. 
pp.  105-7,  by  Mr.  Barnum  Brown,  who  shows  that  there  are 
four  toes,  of  which  the  two  corresponding  with  the  second 
and  third  in  the  typical  pentadactyle  series  are  furnished  with 
hoofs.  Unlike  the  European  Iguanodon  and  its  American  repre- 
sentative Champtosaitrus,  the  trachodonts  were  unable  to  make 
any  use  of  their  fore-limbs  in  progression. 

In  a  second  article  in  the  volume  last  quoted  (pp.  13 1-6)  the 
same  author  gives  a  preliminary  description  of  a  new  genus  and 
species  of  trachodont  dinosaur  {Saurolophus  osborni)  from  the 
Cretaceous  of  Edmonton,  Alberta,  characterised  by  the  develop- 
ment of  a  tall  crest  immediately  above  the  eye-sockets.  It  is 
also  shown  that,  in  common  with  other  members  of  the  tracho- 
dont group,  these  dinosaurs  had  a  ring  of  bones  in  the  sclerotic 
of  the  eye. 

Bare  mention  will  suffice  for  an  article  by  Prof.  R.  S.  Lull 
on  a  restoration  of  the  skeleton  and  external  form  of  the 
armoured  dinosaur  Stegosaurus,  published,  during  the  year 
under  review,  in  Verhandlungen  des  VIII.  Internal.  Zool.  Kon- 
gress  zu  Graz  of  1910.  In  connexion  with  this  may  be  men- 
tioned an  article  by  Prof.  G.  R.  Wieland  {Science,  vol.  xxxvi. 
pp.  287-8)  on  the  analogy  between  the  bony  plates  of  the 
armoured  dinosaurs  and  the  shells  of  the  chelonians ;  an 
analogy  first  suggested  by  the  same  writer  in  191 1.  In  the 
present  article  this  idea  is  further  developed,  the  author  ex- 
pressing the  opinion  that  "  dinosaurs,  instead  of  eventually 
confining  extensive  dermal  development  to  a  single  nether 
layer  covering  the  body-region  only,  as  in  the  turtles,  tended 
to  develop  both  the  nether  and  outer  layers  in  the  body  or 
skull  or  both.  And  this  is  only  another  but  definite  way  of 
saying  that  dermal  armature  was  variously  developed  in  the 
Dinosauria  or  that  it  tended  to  assume  bizarre  patterns." 

An  armoured  dinosaur,  Stegopelta  landerensis,  from  the 
Cretaceous  of  Wyoming,  forms  the  subject  of  a  short  paper 
by  Dr.  R.  S.  Moodie  published  in  191 1  in  the  Kansas  Science 
Bulletin,  ser.  2,  vol.  v.  pp.  257-73. 


16  SCIENCE   PROGRESS 

Finally,  a  general  review  of  the  distribution  of  Cretaceous 
dinosaurs  by  Dr.  Lull  in  the  Bull.  Geol.  Soc.  America,  vol.  xxiii. 
pp.  208-12,  contains  a  considerable  amount  of  new  and  interesting 
information  on  this  subject. 

Two  new  South  African  genera  and  species  referred  to  the 
Parasuchia  (or  Thecodontia),  as  typified  by  the  European 
Phytosaurus  (Belodon),  are  described  by  Mr.  D.  M.  S.  Watson 
in  the  second  volume  of  the  Records  of  the  Albany  Museum, 
under  the  names  of  Mesosuchus  browni  and  Eosuchus  colletti. 
They  appear  to  be  more  or  less  nearly  related  to  the  gigantic 
Erythrosuchus,  which,  like  the  two  new  forms,  occurs  in  the 
South  African  Karu  formation. 

In  an  article  on  the  remains  of  crocodilians  from  the  Upper 
Tertiaries  of  Parana,  published  in  vol.  xxi.  of  Anales  del  Museo 
National  de  Buenos  Aires,  Mr.  C.  Rovereto  refers  two  out  of 
three  species  to  Alligator,  with  the  proviso  that  they  may 
belong,  as  they  almost  certainly  do,  to  the  South  American 
genus  Caiman.  The  third  species,  which  was  described  by 
Burmeister  as  Rhamphostoma  neogceum,  is  referred  to  the 
existing  Indian  genus  Garialis,  a  reference  which  is  less  re- 
markable than  it  might  appear,  seeing  that  crocodilians  of 
the  same  generic  type  occur  in  the  Cretaceous  and  Eocene  of 
Europe. 

From  a  distributional  point  of  view  considerable  interest 
attaches  to  the  description  by  Prof.  L.  Dollo,  in  the  science 
section  of  the  Bull.  R.  Ac.  Set.  Beige,  1912,  No.  1,  pp.  8-9,  of  a 
freshwater  tortoise  of  the  genus  Podocnemis,  from  the  Lower 
Eocene  of  the  Enclave  de  Cabinda,  Congo  State.  Although 
now  restricted  to  tropical  South  America  and  Madagascar,  the 
genus  is  represented  in  the  Eocene  of  England,  India,  the 
Fayum,  and  the  Congo. 

The  paddles  and  other  remains  of  certain  North  American 
Jurassic  plesiosaurs  form  the  subject  of  an  article  by  Mr.  M. 
G.  Mehl  in  the  Journal  of  Geology,  vol.  xx.  pp.  344-52.  One 
remarkably  fine  limb  is  tentatively  assigned  to  the  European 
genus  Murcenosaurus,  under  the  name  M.  reedii.  Possibly  the 
imperfect  specimen  described  by  another  writer  as  Plesiosaurus 
shirleyensis,  which  certainly  does  not  belong  to  the  genus  to 
which  it  is  referred,  may  represent  an  allied  type.  Finally, 
the  so-called  Cimoliosaurus  laramiensis  is  considered  to  be  not 
improbably   referable    to    Tricleidus,    a    genus    established    by 


VERTEBRATE  PALEONTOLOGY  IN   1912  17 

Dr.  C.  W.  Andrews  for  a  plesiosaur  from  the  Oxford  Clay  of 
Peterborough. 

The  lower  jaw  of  a  gigantic  ichthyosaur  discovered  in  the 
Trias  of  Aust  Cliff  in  1877  and  preserved  in  the  museum  at 
Bristol  is  discussed  by  Prof,  von  Huene  in  Centralbl.  fur  Mm. 
Geol.  it.  Pal.  1912,  pp.  61-3,  by  whom  it  is  considered  to  be 
related  to  Mixosaurus  and  Merriamia. 

At  the  conclusion  of  a  memoir  on  the  structure  of  the  skull 
of  that  very  remarkable  Triassic  reptile  Placodus,  whose  bean- 
like teeth  seem  evidently  adapted  for  crushing  the  shells  of 
molluscs  or  crustaceans,  Mr.  F.  Broili  (Palceontographica, 
vol.  lix.  pp.  147-55)  remarks  that  the  skull-roof  possesses  no 
sign  of  those  bony  ridges  and  rugosities  seen  on  the  skull  of 
Placochelys  but  is,  on  the  contrary,  entirely  smooth.  From  this 
it  is  inferred  that  Placodus  probably  did  not  possess  a  bony 
carapace,  as  such  a  structure  was  very  likely  associated  with 
a  roughened  skull ;  this  being  confirmed  by  the  absence  of 
direct  evidence  that  bony  plates  have  been  found  in  association 
with  the  skeleton.  On  the  other  hand,  there  may  have  been 
a  horny  plastron.  The  alleged  relationship  to  Placochelys  is 
therefore  not  borne  out  by  the  available  evidence. 

Passing  to  the  mammal-like  groups  of  early  reptiles 
reference  may  be  made  first  to  an  article  by  Prof.  S.  W. 
Wilhston  {Amer.  Journ.  Set.  vol.  xxxiv.  pp.  457-68)  on  the 
restoration  of  the  cotylosaurian  genus  Limnoscelis,  from  the 
Permo-Carboniferous  of  New  Mexico.  To  repeat  the  author's 
summary  of  the  osteological  characters  of  the  genus  would  be 
out  of  place  and  it  must  suffice  to  mention  that  this  primitive 
reptile,  which  attained  a  length  of  about  seven  feet  and  had 
remarkably  short  limbs,  probably  frequented  the  borders  of 
swamps  and  marshes. 

To  the  Journal  of  Morphology  for  1912  the  same  writer 
contributes  an  account  of  the  Cotylosauria,  the  group  to  which 
Limnoscelis  belongs.  In  a  third  communication,  published  in 
the  Journal  of  Geology  for  191 1  (vol.  xix.  pp.  233-7), 
Dr.  Wilhston  gives  a  restoration  of  Seymouria,  a  relative  of 
Limnoscelis,  although  regarded  as  typifying  a  family  by  itself. 
It  may  be  added  that  much  interesting  information  with  regard 
to  these  and  kindred  forms  may  be  found  in  an  article  by  the 
same  palaeontologist  in  the  Journal  of  Morphology,  vol.  xxiii. 
PP-  637-66,  on  primitive  reptiles  in  general. 
2 


18  SCIENCE  PROGRESS 

European  Triassic  Cotylosauria  are  discussed  by  Prof,  von 
Huene  in  the  Paloeontographica,  vol.  lix.  pp.  69-102,  pis.  v.-ix. 
Telerperton  and  Sclerosaurus  are  referred  to  this  group ;  the 
former,  which  has  very  generally  been  classed  among  the 
Rhynchocephalia,  being  regarded  as  a  near  relative  of  the  South 
African  Procolophon.  A  new  genus  and  species,  Koiloskiosaurus 
coburgense,  is  established  on  the  evidence  of  a  skeleton  from 
the  Bunter  of  Coburg. 

Here  may  be  appropriately  noticed  a  paper  by  Mr.  D.  M.  S. 
Watson  (A tin.  Mag.  Nat.  Hist.  ser.  8,  vol.  x.  pp.  573-87)  on  the 
homology  and  relationships  of  the  elements  of  the  lower  jaw 
in  the  mammal-like  reptiles.  However,  the  subject  is  one  of  an 
extremely  technical  nature,  which  it  would  be  useless  to 
attempt  to  review  without  the  aid  of  diagrams. 

Mention  may  likewise  be  made  of  a  second  paper  by  the 
same  author  (op.  cit.  vol.  viii.  pp.  294-330),  published  in  191 1  but 
not  referred  to  in  my  review  of  that  year's  work,  on  the  skull 
of  the  South  African  Diademodon,  with  notes  on  the  same  part 
of  the  skeleton  in  other  members  of  the  cynodont  group. 

A  nearly  complete  skeleton  of  the  South  African  dicynodont 
genus  long  known  as  Ptychognathus  but  now  termed  Lystrosaurus 
forms  the  subject  of  an  article  by  Mr.  Watson  in  the  Records 
of  the  Albany  Museum,  vol.  ii.  pp.  287-95.  Lystrosaurus  appears 
to  have  been  of  aquatic  habits  and  also  to  have  used  its 
powerful  pair  of  upper  tusks  for  digging.  It  probably  dug  with 
its  mouth  open,  scooping  up  food  with  the  lower  jaw.  "  It  is 
natural  to  suppose  that  Lystrosaurus  was  a  vegetable-feeder, 
as  the  absence  of  [cheek]  teeth  and  the  presence  of  a  horny 
beak  are  more  adapted  to  such  a  diet  than  to  a  carnivorous  one. 
The  extraordinary  massiveness  of  the  jaws,  however,  is  rather 
difficult  to  reconcile  with  the  softness  of  most  aquatic  plants 
and  suggests  some  additional  food." 

To  the  Annals  of  the  South  African  Museum,  vol.  vii.  pt.  5, 
Dr.  R.  Broom  contributes  no  less  than  five  articles  on  reptiles 
of  the  Trias  and  Permian  of  South  Africa.  In  the  first  of  these, 
after  describing  a  new  species  of  Propappus,  he  gives  reasons  for 
believing  that  its  well-known  bigger  relative  Pariasaurus  stood 
higher  on  its  limbs  than  is  generally  supposed.  Both  these 
reptiles  appear  to  have  been  tortoise-like  in  habits  and  probably 
protected  themselves  by  digging  in  the  ground.  In  the  second 
paper   the   author  describes  a  new  mosasaurian  of  the  genus 


VERTEBRATE  PALEONTOLOGY  IN   1912  19 

Tylosaurus  and  in  the  third  a  new  cynodont  from  the  Storm- 
berg  beds.  More  important  are  certain  observations  in  the 
fourth  paper  on  the  structure  of  the  dicynodont  skull,  where  it 
is  stated  that  the  bone  in  which  the  pineal  foramen  (that  is  to 
say,  the  aperture  for  the  pineal  eye)  is  pierced  is  probably  a 
special  development  in  this  group,  the  paired  bones  behind  this 
representing  the  parietals. 

These  early  South  African  reptiles  form  the  subject  of 
another  paper  by  Dr.  Broom,  published  in  the  Proceedings  of 
the  Zoological  Society  for  191 2  (pp.  859-76).  The  remains 
described  are  referred  to  no  less  than  seven  new  generic 
types  as  well  as  to  a  number  of  species  included  in  previously 
known  genera.  Although  several  of  these  are  of  consider- 
able interest,  none  requires  special  notice  on  the  present 
occasion. 

In  an  earlier  portion  of  the  Zoological  Society's  Proceedings 
(pp.  419-25)  Dr.  Broom  discusses  the  structure  of  the  internal 
ear  in  dicynodonts  and  the  much-disputed  homology  of  the 
mammalian  auditory  ossicles.  As  regards  the  latter,  he  reverts 
to  the  old  view  that  the  incus  corresponds  to  the  reptilian 
quadrate ;  the  removal  of  that  element  from  the  mandibular 
articulation  being  foreshadowed  in  the  Permian  African  genus 
Cynognathus,  in  which  it  has  partially  slipped  out  from  the 
joint. 

Next  to  Eoantliropns,  perhaps  the  most  important  discovery 
of  the  year  in  the  branch  of  science  under  discussion  is  the 
identification  of  a  toad  from  the  Jurassic  of  Wyoming.  So  long 
ago  as  1887  the  late  Prof.  O.  C.  Marsh  announced  that  he  had 
evidence  of  the  occurrence  of  a  tailless  batrachian  in  the  Como 
beds  of  the  Montana  Jurassic  and  proposed  for  it  the  new 
generic  and  specific  designation  Eobatrachus  agilis.  The  two 
specimens  were  never  properly  .described  or  figured  and  the 
genus  has  consequently  been  ignored  by  palaeontologists. 
Recently  the  types  have  come  into  the  hands  of  Dr.  R.  L. 
Moodie,  who  expresses  himself  perfectly  satisfied  {Amer.  Journ. 
Sci.  vol.  xxx.  pp.  286-8)  as  to  the  general  correctness  of  the 
original  diagnosis  and  raises  no  doubts  with  regard  to  the 
horizon  from  which  the  specimens  were  obtained.  He  adds 
that  the  Como  batrachian  appears  to  be  a  toad,  probably 
referable  to  the  family  Bufonida?  and  possibly  even  to  the 
existing    genus    Bufo.       In   stating  that     the    earliest    tailless 


26  SCIENCE  PROGRESS 

batrachians  hitherto  known  date  from  the  Oligocene  or  Eocene, 
the  author  has  overlooked  the  description  in  1902  by  Mr.  L.  M. 
Vidal  {Mem.  R.  Ac.  Cienc.  Barcelona,  ser.  3,  vol.  iv.  p.  203) 
of  a  frog  from  the  reputed  Kimeridgian  of  Montsech,  north- 
eastern Spain,  under  the  name  of  Palceobatrachus  gaudryi;  the 
genus  being  typically  from  the  European  Miocene  and  Oligocene. 
This  putting-back  of  the  clock  in  regard  to  the  geological  age 
of  frogs  and  toads  upsets  current  ideas  on  the  subject  of 
batrachian  evolution. 

In  a  communication  on  the  skulls  of  large  Coal  Measure 
labyrinthodonts  preserved  in  the  Museum  at  Newcastle  {Man- 
chester Mem.  vol.  lviii.  No.  1),  Mr.  D.  M.  S.  Watson  records  a 
morphological  observation  which,  although  somewhat  technical, 
is  of  such  importance  as  to  deserve  quotation  in  full  : 

"  Examination  of  these  primitive  and  extremely  well-pre- 
served skulls  seems  to  show  that  the  ordinary  idea  of  the 
autostylism  of  the  Tetrapoda  is  incorrect  in  postulating  a 
connexion  between  the  pterygo-quadrate  cartilage  and  the 
otic  region.  It  is,  I  think,  quite  certain  that  there  never  was 
such  a  connexion  in  primitive  forms,  except  through  the  dermal 
bones  of  the  temporal  region.  The  lower  attachment  with  the 
basisphenoid  I  have  shown  to  exist  in  crossopterygians,  which 
are  hence  '  amphistylic '  in  a  different  way  to  Notidanus" 

In  this  connexion  may  be  noticed  a  long  paper  by  Dr.  J. 
Versluys  {Zoo/.  Jahrb.  191 2,  suppl.  xv.  2nd  vol.  pp.  545-719) 
on  the  problem  of  streptostylism  and  the  mobility  of  the  palate 
in  extinct  and  living  reptiles.  The  subject  is,  however,  of  such 
a  complicated  nature  that  it  would  be  impossible  to  do  justice 
to  it  in  the  space  at  my  disposal. 

Reverting  to  the  Stegocephalia,  it  has  to  be  added  that 
Prof,  von  Huene  has  communicated  to  the  Anatomischer 
Anzeiger,  vol.  xli.  pp.  98-104,  an  article  on  the  skull  of  the 
American  genus  Eryops,  in  which  the  relationships  and 
homology  of  the  constituent  bones  of  the  occipital  and  basi- 
cranial  regions  are  clearly  indicated. 

In  this  place  reference  may  be  made  conveniently  to  an 
article  by  Dr.  Moodie  in  the  serial  already  quoted  (pp.  277-85) 
on  the  amphibian  fauna  of  the  Permian  shales  of  Mazon  Creek, 
Illinois.  Ten  species,  referred  to  eight  genera,  are  now  known 
from  this  horizon ;  their  systematic  positions  being  indicated  in 
a  table  of  classification. 


VERTEBRATE  PALEONTOLOGY  IN   1912  21 

In  regard  to  literature  relating  to  fossil  fishes  the  writer 
may  take  the  opportunity  of  mentioning  that  authors  do  not 
send  him  copies  of  papers  on  this  subject  to  nearly  the  same 
extent  as  they  do  those  on  higher  vertebrates.  Consequently  his 
reviews  on  this  section  contain  more  omissions  than  is  the  case 
in  other  groups. 

Such  notice  as  I  can  give  may  commence  with  mention  of 
an  article  by  Dr.  C.  R.  Eastman  on  Mesozoic  and  Caenozoic 
fishes  published  in  the  Bulletin  of  the  Geological  Society  of 
America,  vol.  xxiii.  pp.  228-32.  After  alluding  to  the 
general  lines  on  which  piscine  evolution  appears  to  have  taken 
place  during  past  epochs,  the  author  raises  the  question  whether 
the  fish-fauna  of  the  ocean  abysses  has  been  driven  to  its 
present  haunts  as  a  refuge  against  foes  and  competition.  The 
question  is  answered  in  the  affirmative,  the  author  remarking 
that,  according  to  palaeontological  evidence,  this  "refuge  was 
not  inhabited  to  any  great  extent  by  fishes  prior  to  the  latter 
part  of  the  Cretaceous.  But,  beginning  during  this  period  and 
steadily  proceeding  until  the  present  day,  a  gradual  migration 
of  certain  groups  of  fishes  into  great  depths  of  the  ocean  has 
been  in  progress,  coincident  with  remarkably  striking  changes 
in  the  anatomical  structure  of  the  emigrant  outcasts.  As  a 
result  of  recent  researches,  more  especially  of  the  late  Cretaceous 
and  Eocene  deep-sea  fish-faunas,  we  are  enabled  to  note  the 
gradually  changing  constitution  of  these  abyssal  assemblages 
from  the  close  of  the  Mesozoic  onward  to  our  own  day."  The 
paper  concludes  with  notices  of  recent  work  on  fossil  fishes. 

A  large  series  of  remains  of  fishes  from  the  Upper  Tertiary 
and  Secondary  deposits  of  France  form  the  subject  of  two 
papers  by  Mr.  F.  Priem,  published  in  Bull.  Soc.  Ge'ol.  France, 
ser.  4,  vol.  xii.  pp.  213-45  and  250-71  ;  a  few  species  being 
described  as  new.  In  a  third  article  the  same  author  {op.  cit. 
pp.  246-9)  describes  and  figures  certain  fish-otoliths  from  the 
French  and  English  Eocene.  A  supplement  to  his  account  of 
the  fishes  of  the  Paris  Basin  was  also  published  by  Mr.  Priem  in 
191 1  {Ann.  Palceont.  vol.  vi.  pp.  1-44). 

In  the  Mem.  Soc.  ital.  Sci.  ser.  3,  vol.  xvii.  pp.  182-245,  Messrs. 
Bassani  and  d'Erasmo  discuss  the  Cretaceous  fish-fauna  of  Capo 
d'Orlando,  near  Naples ;  all  the  specimens  being  referred  to 
previously  known  species.  Another  paper  on  the  Italian  fish- 
fauna,  namely  that  of  the  Pliocene  of  Imolese,  by  Mr.  G.  de 


22  SCIENCE  PROGRESS 

Stefano,  appeared  in  Boll.  Soc.  Geol.  Hal.  vol.  xxix.  pp.  381-402, 
1911. 

Two  memoirs  on  fossil  fishes  have  been  issued  during  the 
year  by  the  Palaeontographical  Society  (in  the  volume  for  191 1). 
In  the  first  of  these  Dr.  R.  H.  Traquair — whose  recent  death 
is  a  great  loss  to  fossil  ichthyology — continues  his  account  of  the 
British  Carboniferous  Palceoniscidce,  describing  one  species  of 
Canobius  as  new.  In  the  second  Dr.  Smith  Woodward  com- 
pletes his  account  of  the  fishes  of  the  English  Chalk,  dealing, 
apart  from  a  supplement,  with  the  well-known  genus  PtycJiodus, 
of  which  he  figures  a  remarkably  fine  series  of  associated  teeth 
obtained  by  Mr.  Willett  near  Brighton.  The  author  concludes 
with  the  remark  that  the  English  Cretaceous  fish-fauna  is  of  a 
much  more  modern  type  than  the  contemporary  reptilian  and 
mammalian  faunas,  thereby  indicating,  at  any  rate  in  the  case 
of  the  acanthopterygian  teleosteans,  a  remarkably  rapid  process 
of  evolution.  The  distribution  of  Ptychodus  teeth  in  the  English 
Chalk,  as  well  as  the  teeth  themselves,  form  the  subject  of  a 
paper  by  G.  E.  Dibley  in  the  Quart.  Journ.  Geol.  Soc.  vol.  lxvii. 
pp.  263-77,  1911- 

The  following  papers  by  Mr.  M.  Leriche  published  during 
191 1  may  also  be  mentioned  here:  Note  sur  les  Poissons 
stampiens  du  Bassin  de  Paris,  Ann.  Soc.  Geol.  Nord,  vol.  xxxi. 
pp.  324-36 ;  Sur  quelques  Poissons  du  Cretace  du  Bassin  de 
Paris,  Bull.  Soc.  Geol.  France,  ser.  4,  vol.  x.  pp.  455-71  ;  Note  sur 
les  Poissons  Neogenes  de  la  Catalogue,  ibid.  pp.  471-4;  and  Un 
Pycnodontoide  aberrant  du  Senonien  du  Hainault — Acrotemnus 
splendens,  de  Kon.,  Bull.  Soc.  Beige  geol.  vol.  xxv.  Proc.  Verb.  pp.  162-8. 

Brief  notice  must  also  suffice  for  two  papers  on  Cretaceous 
fishes,  of  which  the  first,  by  Dr.  G.  d'Erasmo  (Riv.  Hal.  Paleont. 
vol.  xviii.  fasc.  2  and  3),  deals  with  certain  species  from  Monte 
Libano.  In  the  second  Dr.  E.  Henning  (Sitzber.  Ges.  natfor. 
Freunde,  191 2,  pp.  483-93)  discusses  the  rapid  evolution  of 
teleostean  fishes  in  the  short  period  between  the  Upper  and 
Middle  Cretaceous  and  the  question  whether  this  implies  poly- 
phyletic  origin  from  several  distinct  groups  of  ganoids.  The 
fish-faunas  of  a  number  of  Cretaceous  horizons  are  contrasted 
with  one  another. 

Of  more  general  interest  is  certain  new  evidence  as  to  the 
community  of  type    existing   between   the  Tertiary   faunas   of 


VERTEBRATE  PALAEONTOLOGY  IN    1912  23 

Western  Africa  and  Eastern  South  America  furnished  in  a  paper 
by  Dr.  Eastman  (Ann.  Carnegie  Mus.  vol.  viii.  pp.  376-8)  on 
remains  of  freshwater  fishes  from  Guinea.  The  most  important 
of  these  are  referable  to  a  species  of  double-armoured  herring 
belonging  to  the  Tertiary  genus  Diplomystus  and  closely  allied 
to  one  from  the  Brazilian  Tertiaries.  "  It  is  an  interesting  and 
significant  fact,"  remarks  the  author,  "  that  species  of  the  same 
genus,  or  at  least  of  very  closely  allied  genera,  should  occur 
respectively  in  the  freshwater  deposits  of  the  eastern  coast  of 
South  America  and  western  coast  of  Africa,  the  presumption 
being  that  the  strata  are  approximately  contemporaneous — that 
is  to  say,  early  Tertiary.  This  coincidence  points  to  a  simi- 
larity of  the  freshwater  fish-faunas  of  the  two  continents 
extending  as  far  back  as  the  dawn  of  Tertiary  time  and  also 
suggests  a  correspondence  of  geological  history  between  the 
land-masses  on  either  side  of  the  Atlantic." 

The  author  then  proceeds  to  discuss  the  bearing  of  the  dis- 
covery on  the  theory  of  a  land-connexion,  by  means  of 
"  Helenis,"  between  Africa  and  South  America ;  such  hypo- 
thetical continent  having  been  regarded  as  the  original  home 
of  the  Lepidosirenidae,  Characinidce,  Cichlidce,  and  Siluridce.  As 
the  genus  Diplomystus  also  occurs  in  the  Lower  Tertiaries  of 
Europe  and  Western  Asia,  its  distribution  is  not  very  dis- 
similar to  that  of  the  Chelonian  genus  Podocnemis  (supra), 
which  may  have  followed  the  same  lines  of  migration,  whatever 
these  may  have  been. 

In  a  second  communication  (op.  cit.  pp.  182-7)  Dr.  Eastman 
describes  the  skeletons  of  two  European  Jurassic  fishes  within 
the  ribs  of  each  of  which  are  contained  the  remains  of  a  lizard. 
In  one  case  the  reptile,  which  had  doubtless  been  swallowed  as 
food,  appears  to  be  a  species  of  the  contemporary  rhyncho- 
cephalian  genus  Homceosaurus,  whilst  in  the  second  instance  the 
prey  may  have  belonged  to  the  same  or  a  nearly  allied  genus. 

"  The  Soft  Anatomy  of  Cretaceous  Fishes  "  appears  a  some- 
what strange  title  for  a  palaeontological  paper,  but  Dr.  Moodie 
(Kansas  Sci.  Bull.  ser.  2,  vol.  v.  pp.  277-87,  191 1)  has  obtained 
material  which  enables  him  to  record  certain  details  on  this 
point.  In  the  same  article  he  also  describes  a  new  species  of 
Thrissopater  from  the  Cretaceous  of  Texas. 

The  affinities  of  Saurorhamphus  freyeri,  a  fish  first  described 
by  Heckel  in  1849  from  the  Cretaceous  bituminous  schists  of 


24  SCIENCE  PROGRESS 

Carso  Triestino,  are  discussed  by  Dr.  d'Erasmo  in  Boll.  Soc. 
Adriat.  Set.  Nat.  vol.  xxvi.  pp.  45-88,  in  a  manner  chiefly 
interesting  to  systematists.  The  same  remark  applies  in  an 
even  greater  degree  to  a  paper  by  Mr.  L.  Neumayer  in  the 
Palceontographica  (vol.  lix.  pp.  251-88)  on  the  comparative 
anatomy  of  the  skull  in  Eocene  and  modern  Siluridce. 

Two  papers  have  been  published  during  the  year  on  the 
nature  of  those  remarkable  flat  spiral  structures,  armed  on  the 
convex  border  with  powerful  teeth,  described  under  the  names 
of  Edestus,  Helicoprion,  etc,  which  have  long  been  a  puzzle  to 
ichthyologists,  some  of  whom  have  regarded  them  as  highly 
modified  dorsal  spines  of  sharks,  whilst  others  consider  that 
they  pertain  to  the  mouth.  The  first  of  these  is  an  English 
translation  of  a  paper  by  Mr.  A.  Karpinsky  in  Bull.  Ac.  Sci. 
St.  Pe'tersbourg,  191 1,  pp.  1 105-21,  briefly  mentioned  in  my 
review  for  that  year.  The  main  object  of  this  paper,  of  which 
the  translation  is  published  in  Verh.  K.  Min.  Ges.  St.  Pe'tersbourg, 
vol.  xlix.  pp.  69-94,  is  to  show  that  the  view  held  by  Dr.  O.  P. 
Hay  and  others  that  these  organs  are  dorsal  spines  is  untenable 
and  that  they  are  really  appendages  of  the  mouth.  To  this 
view  Dr.  Hay  {Proc.  U.S.  Nat.  Mus.  vol.  xlii.  p.  31)  is,  how- 
ever, himself  a  convert,  as  the  result  of  the  examination  of  a 
specimen  discovered  about  eighteen  years  ago  in  the  Coal 
Measures  of  Iowa.  This  specimen,  which  is  double,  comprises 
an  upper  and  a  lower  element,  both  of  which  are  bilaterally 
symmetrical  and  appear  to  have  been  produced  in  front  of  the 
mouth  of  the  shark  in  such  a  manner  that  one  worked  against 
the  other.  Their  shafts  seem  to  have  been  developed  by  the 
consolidation  and  fusion  of  a  median  row  of  teeth,  which 
gradually  become  worn  away  in  the  fore  part  of  the  series  in 
the  usual  shark-fashion  but  the  bases  of  which  form  the  shaft.1 


NOTE:  GIANT  TORTOISES  AND  THEIR 
DISTRIBUTION 

In  my  article   on   "Giant   Tortoises   and   their    Distribution," 
Science  Progress,  October    19 10,  vol.  v.  pp.  302-17,  reference 

1  Since  this  article  was  set  up,  several  other  palaeontological  papers  and 
memoirs  have  come  to  hand  (notably  a  continuation  of  Prof.  W.  B.  Scott's  des- 
cription of  the  Santa  Cruz  fauna),  which  it  was  found  impossible  to  notice. 


GIANT  TORTOISES  AND  THEIR  DISTRIBUTION   25 

was  made  to  a  giant  land  tortoise  then  living  in  Ceylon,  at 
Matara,  near  Galle.  At  the  time  of  writing  I  had  some  doubt 
as  to  whether  this  specimen  was  distinct  from  the  Colombo 
tortoise  referred  to  in  Dr.  Giinther's  Catalogue  of  Gigantic 
Tortoises  in  the  British  Museum  as  having  been  living  at 
Uplands,  in  Mutwal,  near  Colombo,  in  1870.  From  a  letter 
communicated  to  Spolia  Zeylanica  for  December  1910  by  Mr. 
Joseph  Pearson,  director  of  the  Colombo  Museum,  I  learn  that 
the  Colombo  tortoise  was  found  in  Ceylon  when  the  island  was 
taken  over  by  the  British  in  1796,  and  that  it  died  in  1894, 
within  a  week  of  its  removal  from  Uplands  to  Victoria  Park, 
Colombo.  It  is  now  preserved  in  the  museum  at  Colombo, 
and  is  referred  by  Mr.  Pearson  to  Testudo  gigantea.  Its  shell 
measures,  in  a  straight  line,  40  inches  in  length. 

This  being  so,  it  is  clear  that  the  Matara  tortoise,  of  which 
a  photograph  appeared  in  my  article,  represents  a  second 
giant  tortoise  imported  into  Ceylon  ;  as,  indeed,  is  indicated 
at  the  close  of  Mr.  Pearson's  letter.  This  tortoise  I  have 
referred  to  T.  gigantea  ;  and  it  may  be  that  the  measurement 
given  in  my  article  may  refer  to  that  specimen.  I  regret, 
however,  that  I  cannot  recall  where  I  obtained  this  measure- 
ment, or  the  information  as  to  a  tortoise  having  been  imported 
into  Ceylon  from  the  Seychelles  in  1797  or  1798.  Mr.  Pearson 
states  that  he  is  endeavouring  to  obtain  further  information 
with  regard  to  the  Matara  tortoise,  of  which  the  very  existence 
might  apparently  have  remained  unknown  to  naturalists  had 
it  not  been  for  the  photograph  by  Mr.  Stanley  Mylius, 
published  in  Country  Life  of  July  9,  1910. 

R.  Lydekker. 


TEMPERATURE    AND    THE    PROPERTIES 

OF   GASES 

By   FRANCIS   HYNDMAN,   B.Sc. 

In  every  branch  of  human  activity  there  are  distinct  periods 
which  are  marked  either  by  some  new  discover}''  or  by  the 
termination  of  a  definite  line  of  work.  The  study  of  the 
thermodynamic  properties  of  gases  and  the  relation  of  the 
gaseous  to  the  other  states  of  matter  has  now  reached  the  con- 
clusion of  such  a  period.  It  may  be  said  that  the  modern  study 
and  theory  of  gases  dates  from  the  publication  at  Leiden  in  1873, 
by  J.  D.  van  der  Waals,  of  his  famous  treatise  on  the  continuity 
of  the  liquid  and  gaseous  states.  Since  that  time  a  large  army  of 
workers  have  been  occupied  in  striving  to  reduce  the  then 
unliquefied  gases  to  the  liquid  and  ultimately  to  the  solid  state, 
and  in  determining  the  various  constants  which  define  them. 
The  honour  of  conquering  the  last  of  the  known  gases  which 
remained  unliquefied  owing  to  the  extremely  low  temperature 
required  has  fallen  to  Prof.  H.  Kamerlingh  Onnes  of  Leiden, 
who  has  been  for  twenty-five  years  building  up  the  most 
perfect  and  efficient  cryogenic  laboratory  in  the  world. 

This  gas,  helium,  which  was  unknown  fifteen  years  ago 
except  spectroscopically  in  the  sun,  has  now  been  found  to  occur 
in  minute  quantities  in  every  radioactive  portion  of  the  earth's 
crust  which  has  been  tested,  with  one  or  two  trifling  exceptions. 
Its  presence  is  closely  connected  with  the  radioactivity  which 
nearly  all  substances  possess,  and  it  appears  to  be  one  of  the 
decomposition  products  of  radium  and  of  similar  substances.  It 
occurs  in  the  atmosphere  but  in  very  small  quantity,  and  is 
obtained  in  practice  by  heating  certain  minerals,  preferably 
monazite  sand.  It  is  hence  a  very  remarkable  substance,  besides 
being  the  gas  which  is  the  most  difficult  to  liquefy.  As  all 
the  known  gases  have  now  been  liquefied,  this  line  of  work  must 
stand  still  until  the  chemists  discover  some  other  and  possibly 
even  more  refractory  gas. 

It  is   interesting  to  note  that  Prof,  van  der  Waals  retired 

26 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  27 

from  his  chair  at  Amsterdam  just  at  the  time  when  this 
result  was  obtained,  which  so  brilliantly  confirmed  his  pre- 
diction that  all  substances  which  do  not  decompose  could  be 
brought  under  suitable  conditions  of  pressure  and  temperature 
into  the  states  of  solid,  liquid,  vapour,  or  gas  respectively. 

With  the  latter  states,  and  probably  with  solids  also,  the 
whole  thermodynamic  condition  of  a  substance  is  known  with 
the  determination  of  two  sets  of  data.  One,  the  relation  between 
the  volume  and  the  pressure  at  any  possible  temperature,  is 
commonly  spoken  of  as  the  determination  of  the  equation  of 
state  for  the  substance.  The  second,  the  relation  between  the 
change  of  temperature  of  the  substance  and  the  amounts  of  heat 
required  to  produce  that  change  of  temperature  under  different 
conditions,  is  known  as  the  determination  of  the  specific  heat. 
It  may  be  said  at  once  that  with  no  substance  is  there  a  complete 
knowledge  of  the  equation  of  state  or  of  the  variations  of  the 
specific  heat  covering  even  two  out  of  the  four  states  of  matter 
mentioned  above.  On  the  other  hand,  small  ranges  are  known 
for  various  substances  with  more  or  less  accuracy,  and  these  can 
be  pieced  together,  by  the  aid  of  a  principle  which  will  be 
considered  later,  into  equations  of  state  which  represent  an  ideal 
substance  which  occupies  an  average  position  among  the  varia- 
tions of  actual  substances. 

This  subject  has  to  be  attacked  from  two  different  sides,  one 
that  of  thermodynamics,  which  enunciates  general  propositions 
to  which  all  substances  in  any  state  must  agree,  but  which 
is  sometimes  only  applied  to  actual  substances  with  difficulty 
owing  to  the  want  of  knowledge  of  some  of  the  data  which  are 
requisite.  On  the  other  hand,  an  attempt  can  be  made  to  build 
up  a  theory  which  will  account  satisfactorily  for  the  behaviour 
of  matter  by  considering  its  constitution  and  attempting  to 
arrive,  by  as  nearly  strict  mathematical  paths  as  possible,  at  the 
probable  behaviour  of  matter  with  the  constitution  which  has 
been  supposed.  We  will  not  consider  the  various  constitutions 
which  have  been  suggested,  nor  any  one  in  detail,  but  shall 
merely  outline  the  fundamental  conceptions  on  which  the  one 
most  commonly  used — the  kinetic  theory — has  been  based.  The 
conceptions  on  which  this  theory  are  grounded  have  enabled 
progress  to  be  made  in  other  branches  of  science  also,  and 
the  assistance  derived  from  these  in  return  has  helped  to  con- 
firm the  validity  of  the  conceptions  of  the  kinetic  theory. 


28  SCIENCE  PROGRESS 

As  we  assume  that  any  actual  gas  can  be  ultimately  brought 
into  the  solid  state  through  all  the  others,  we  may  discuss  the 
relations  of  quantities  in  the  gaseous  state  as  the  least  compli- 
cated, without  any  loss  of  generality.  The  kinetic  theory 
assumes  that  all  pure  gases  consist  of  a  vast  number  of  particles 
which  are  exactly  similar  in  volume  (5),  shape,  and  mass  (m)  to 
one  another,  and  that  they  are  all  striving  to  move  in  straight 
lines  with  velocities  which  are  continually  varying  about  a 
certain  mean  value  («)•  These  particles  or  molecules  are 
known  to  be  exceedingly  small ;  so,  where  the  gas  is  in  a  com- 
paratively rarefied  condition  and  the  size  of  the  molecules  is  very 
small  compared  with  the  average  distance  between  them,  it  is 
possible,  as  a  first  approximation,  to  neglect  the  size  of  the 
molecules  and  to  treat  them  as  if  they  were  only  mathematical 
points  without  any  action  on  one  another,  and  merely  endowed 
with  mass  and  velocity,  that  is,  with  kinetic  energy.  The 
molecules  are  continually  striking  against  the  walls  of  the 
containing  vessel  with  blows  the  force  of  which  depends  upon 
their  kinetic  energy,  and  hence  on  their  velocity.  If  we  call  the 
combined  effect  of  these  blows  the  pressure,  and  measure  it  as 
a  distributed  force  applied  to  every  square  centimetre  of  the  wall, 
it  is  easily  found  that 

( 1 ) p  =  §  .  n  .  \  mu*  =  \du- 

where  («)  is  the  number  of  molecules  per  cubic  centimetre, 
(u)  has  the  value  given  above,  and  d  is  the  density  =  ijv, 
where  v  is  the  volume  of  the  gas.  Hence  we  have  pv  =  %u2. 
Comparatively  rough  experiments  with  air  or  similar  gases 
under  moderately  small  pressures  made  by  the  early  experi- 
menters, or  more  accurate  experiments  made  more  recently 
at  really  small  pressures,  have  shown  that  as  a  first  approxima- 
tion the  relation 

(2) pv=  R/„(i+a/)  =  RT 

holds  for  gases,  where  R  and  a  are  constants,  and  /  is  the 
temperature  centigrade.  The  value  of  T  is  then  clearly 
determined  when  the  value  of  a  is  known. 

This  relation  is  known  as  the  Boyle-GayLussac-Avogadro 
law,  and  is  the  most  simple  equation  of  state.  By  comparing 
the  two  values  for  pv,  it  will  be  seen  that  %u2  =  RT,  and  hence 
that  the  temperature  and  the  mean  velocity  are  very  closely 
related.    Also  that,  where  T  =  /0(i  -f  at)  =  0,  u  would  be  zero,  and 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  29 

hence  there  would  be  no  motion.  If  we  could  suppose  this 
equation  to  hold  until  that  condition  were  reached,  the  state 
of  no  motion,  beyond  which  it  would  logically  seem  impossible 
to  go,  would  be  reached  at  a  temperature  /  =  i/a. 

From  the  comparatively  rough  measurements  mentioned 
above,  a  was  found  to  have  a  mean  value  of  2rs>  and  hence,  with 
the  limitations  stated  above,  2730  would  be  the  temperature 
below  zero  centigrade  at  which  all  motion  would  cease  and 
matter  would  be  quiescent.  This  point  has  been  called  the 
absolute  zero,  and  although  the  value  given  to  it  now  is  not 
exactly  —  2730  C,  it  is  sufficiently  near  this  for  any  difference 
to  be  considered  in  the  light  of  a  correction.  It  was  also 
shown  by  Lord  Kelvin  that  the  value  of  the  absolute  zero 
could  be  obtained  from  a  study  of  the  cycle  of  a  perfect  engine, 
that  the  thermodynamic  temperature  which  enters  into  this  is 
very  nearly  273  +  f  C,  and  that  its  zero  value  is  identical 
with  the  temperature  at  which  motion  would  cease  with  a 
perfect  gas.  In  consequence  of  the  great  importance  of  this 
work,  it  is  common  to  call  temperatures  on  the  absolute  scale 
temperatures  Kelvin,  so  that  zero0  C.  =  2730  K.1 

As  indicated  above,  this  ideal  gas  state  is  found  to  exist 
to  a  very  near  approximation  when  the  density  of  real  gases 
is  very  small,  and  it  is  assumed  that  it  would  apply  strictly 
at  exceedingly  small  densities  near  to  zero  density.  The 
coefficient  of  expansion  a,  found  under  these  conditions,  will 
then  be  the  inverse  of  the  absolute  temperature,  and  this  is  the 
principal  means  by  which  an  estimate  is  arrived  at  of  the  real 
value  of  this  temperature. 

If  the  molecules  of  a  gas  have  no  attractions  for  one  another, 
no  work  will  be  done  on  allowing  the  gas  to  expand  into  a 
vacuum.  It  was  at  first  thought  that  air  and  other  similar 
gases  conformed  with  this,  but  the  experiments  of  Joule  and 
Kelvin  showed  that  real  gases  were  in  general  either  heated 
or  cooled  when  allowed  to  expand  in  this  way,  excepting  under 
certain  definite  conditions  of  temperature  and  initial  pressure 
which  vary  for  each  gas,  and  at  which  there  is  no  change.  A  per- 
fect gas  would,  under  all  conditions,  be  in  the  condition  so  that 

« *(&)--  (f)E-« 

E  =  Total  Energy 


1  As  will  be  explained  later,  the  best  value  at  present  is  273'oc). 


30  SCIENCE  PROGRESS 

would  hold,  whereas  with  real  gases  the  states  at  which  zero 
values  for  the  Joule-Kelvin  effect  are  found  only  occur  under 
certain  definite  relations  between  pressure  and  temperature 
for  each  gas  (see  curve  d,  fig.   i,  p.  38). 

Some  difficulty  is  found  in  the  application  of  equation  (3) 
to  experimental  results,  as  it  is  strictly  only  derived  for 
infinitesimal  changes  of  temperature,  and  the  total  energy  (E) 
is  supposed  to  remain  constant.  This  makes  its  employment 
to  reduce  experiments,  in  which  the  changes  of  temperature  and 
pressure  are  not  very  small,  a  somewhat  difficult  task,  which  is 
also  increased  by  the  difficulty  of  excluding  other  effects  which 
tend  to  mask  the  one  sought,  and  which  sometimes  allow  a 
considerable  fall  in  pressure  to  take  place  with  no  change  of 
temperature. 

A  gas  which  at  the  same  time  obeys  the  equation  of  state  (2) 
and  which  exhibits  no  Joule-Kelvin  effect  may  strictly  be  called 
a  perfect  gas,  but,  as  pointed  out,  a  gas  may  obey  one  without 
necessarily  obeying  the  other,  at  least  over  a  certain  range. 

Experimental  investigation  at  even  moderate  accuracies  soon 
showed  that  gases  obeyed  these  laws  to  a  greater  or  less  degree, 
and  it  was  noted  that  the  greatest  deviations  were  found  with 
gases  such  as  carbon  dioxide,  sulphur  dioxide,  and  ethylene, 
which  are  comparatively  easily  liquefied.  With  the  class  which 
Faraday  called  the  "  permanent  gases  "  because  he  was  unable 
to  liquefy  them,  such  as  nitrogen,  oxygen,  and  hydrogen,  the 
deviations  are  much  smaller.  Still  greater  deviations  are  found 
with  vapours  of  liquids  such  as  water,  etc.,  just  above  their 
boiling  points.  The  extended  kinetic  theory  as  applied  to  real 
substances  takes  cognisance  of  both  the  size  of  the  molecules 
and  their  attraction  to  one  another,  but  has  not  been  made 
to  include  as  yet  the  internal  energy  of  the  molecule  and  the 
way  in  which  this  changes  with  temperature  and  pressure.  It  is 
clear  that  the  molecules  must  have  something  of  the  nature  of  real 
extension,  as  shown  by  the  increasing  difficulty  of  compression, 
as  certain  limits  are  approached,  and  by  such  phenomena  as 
effusion,  and,  on  the  other  hand,  a  real  molecular  attraction  as 
shown  in  such  phenomena  as  capillarity.  Also  these  character- 
istics are  even  more  marked  in  the  solid  state.  Molecules 
are  known  from  observations  of  the  density  of  gases  to  consist 
in  most  cases  of  two  or  more  separate  and  distinct  atoms, 
among  which  there  must  be  a  certain  amount  of  internal  energy 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  31 

of  motion  which  can  be  measured  by  observations  on  the  specific 
heats.  Without  considering  the  historical  development  of 
knowledge  in  this  direction,  the  modern  position  may  be 
summed  up  as  follows,  leaving  out  of  account  considerations 
of  electrons  which  can  only  make  very  small  percentage  changes 
in  these  relations. 

(1)  All  chemically  elementary  substances,  and  many  com- 
pounds, are  capable  of  existing  in  the  conditions  of  solid,  liquid, 
vapour  or  gas  under  specific  conditions  of  pressure  and 
temperature. 

(2)  All  pure  gases  consist  of  a  very  large  number  (n  =  about 
io20  per  cubic  centimetre  under  normal  conditions)  of  similar 
molecules. 

(3)  These  molecules  are  moving  in  straight  lines  for  distances 
depending  on  the  density  of  the  gas  and  known  as  the  free  path, 
the  mean  value  being  of  the  order  of  io-4  mm.  at  ordinary 
temperature  and  pressure ;  they  move  with  velocities  which 
are  changing  at  each  collision,  but  continually  varying  about 
some  mean  value,  the  square  of  which  is  proportional  to  the 
absolute  temperature.  These  velocities  are  of  the  order  of 
1   kilometre  per  second  at  the  ordinary  temperature. 

(4)  All  molecules  of  any  given  pure  gas  consist  of  the  same 
number  of  one  or  more  atoms,  these  being  the  smallest  particles 
of  the  substance  which  can  exist  without  loss  of  identity  alone 
or  in  combination.  Each  atom  occupies  a  definite  volume  under 
definite  conditions  of  temperature  and  pressure,  and  each  mole- 
cule of  more  than  one  atom  another  volume  which  is  not  the  sum 
of  the  atomic  volumes.  There  is  in  each  case  a  limiting  volume 
which  would  only  be  reached  at  the  lowest  temperatures  and 
highest  pressures.  Each  molecule  occupies  an  effective  space 
which  is  some  small  multiple  of  its  real  volume  and  is  usually 
denoted  by  (b). 

(5)  Complex  molecules  at  any  rate  have  some  internal  motion  ; 
and  possibly  atoms  also,  though  to  a  smaller  extent. 

(6)  The  molecules  exert  an  attraction  on  one  another  which 
varies  very  little  with  the  pressure,  but  which  decreases  as  the 
temperature  decreases.  It  is  probable  that  the  law  of  attraction 
varies  with  a  much  higher  power  than  the  square  (that  of 
gravitation  and  simple  electric  or  magnetic  attraction),  some 
index  of  the  order  of  6  being  indicated,  and  hence  it  is  only 
effective  when  the  molecules  are  very  close  together. 


32  SCIENCE  PROGRESS 

A  very  slight  consideration  of  the  above  conditions  which 
would  have  to  be  satisfied  by  an  equation  of  state  show  that 
it  must  necessarily  be  very  complex  if  it  is  to  express  them 
exactly.  Suitable  equations  can  be  obtained  as  the  result  of 
careful  experiment  under  known  conditions  and  over  a  definite 
range  for  certain  given  substances,  but  such  measurements  are 
difficult  and  lengthy,  and  the  values  found  are  only  strictly 
applicable  to  the  conditions  under  which  they  are  made. 

These  measurements,  although  of  the  utmost  importance  in 
special  cases,  would  be  of  little  assistance  in  the  general  question 
without  a  guiding  principle.  The  utility  of  this  can  be  best 
illustrated  by  an  example.  Consider  some  hydrogen  and  some 
carbon  dioxide  at  the  ordinary  temperature  and  under  the 
atmospheric  pressure.  For  small  changes  of  pressure  and 
temperature,  both  will  behave  very  similarly.  Suppose,  how- 
ever, that  they  are  strongly  compressed.  It  will  be  found  that 
at  1 50  C.  the  carbon  dioxide  will  become  a  liquid  under  a 
pressure  of  51  kilogrammes  per  sq.  cm.,  whereas  the  hydrogen 
will  become  very  dense,  but  will  still  remain  a  gas  even  under 
the  enormous  pressure  of  5,000  kilogrammes  per  sq.  cm.  as 
found  by  actual  experiment,  and  as  we  know  now  under  any 
pressure  which  could  be  applied  at  this  temperature.  The 
former  is  called  a  vapour,  the  latter  a  gas  at  this  temperature, 
and  to  bring  hydrogen  into  the  condition  of  a  vapour  it  is 
necessary  to  go  down  to  the  temperature  of  about  —  2400  C. 

It  is  found  that  there  is  some  particular  temperature  for 
every  gas,  below  which  it  must  be  cooled  before  it  can  be 
liquefied,  and  which  is  known  as  the  critical  temperature  (Tc) 
while  the  necessary  pressure  to  liquefy  at  this  temperature  is 
the  critical  pressure  {pc).  The  significance  of  this  point  will 
be  further  illustrated  by  a  consideration  of  the  result  of  heating 
a  liquid  and  the  vapour  above  it  in  a  space  where  pressure 
can  be  applied.  At  any  temperature  there  is  a  definite  vapour 
pressure  under  these  conditions  which  is  independent  of  the 
volume  of  liquid  and  vapour  until  there  is  either  all  liquid 
or  all  vapour.  As  the  boiling  point  is  that  at  which  the  vapour 
pressure  of  the  liquid  is  the  same  as  the  pressure  above  it, 
it  follows  that  as  the  pressure  on  a  liquid  is  reduced  from  the 
normal  boiling  point  under  atmospheric  pressure  the  liquid  will 
boil  at  continually  lower  temperatures  until,  in  the  natural 
course,  the  freezing  point  is  reached,  when  it  changes  to  the  solid 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  33 

state.  Suppose,  however,  that  the  temperature  is  raised  above  the 
boiling  point  and  the  pressure  increased  enough  to  preserve  some 
liquid.  The  vapour  pressure  will  rise  with  the  temperature 
until  a  point  is  reached  at  which  the  liquid  meniscus  vanishes 
suddenly  with  a  very  small  increase  of  temperature  and  cannot 
be  re-obtained  by  any  increase  of  pressure.  The  liquid  has 
passed  to  the  gaseous  state  through  the  critical  point. 

The  investigation  of  the  exact  behaviour  of  substances  at 
this  point  and  the  means  of  determining  the  exact  values  of  the 
constants  are  questions  of  great  interest,  but  we  are  concerned 
for  the  moment  with  the  values  of  these  quantities  only. 
Suppose  we  have  these  for  some  series  of  substances  and  we 
divide  the  pressure  volume  and  temperature  of  these  under  any 
conditions  by  the  critical  values.  The  result  is  known  as  the 
"  reduced  "pressure  (-zr),  volume  (</>),  and  temperature  (0),  so  that 
7r  =  p/pc,  etc.  Thus  far  everything  is  the  result  of  experiment, 
and  we  may  turn  to  the  guiding  principle  mentioned  above. 
This  was  enunciated  by  J.  D.  van  der  Waals  as  the  deduction 
from  the  theoretical  equation  of  state  deduced  by  him  in  1873. 
This  equation  will  be  duly  considered,  but  the  great  principle 
deduced  from  it  and  known  as  the  "  law  of  corresponding  states  " 
is  of  wider  application.  It  may  be  said  to  generalise  matter,  to 
reduce  everything  to  one  substance  under  different  conditions,  as 
it  states  that  "  All  substances  have  the  same  properties  at  the  same 
reduced  pressure,  volume,  and  temperature.11 

When  one  takes  into  consideration  the  great  complexity  of 
many  molecules  and  the  extraordinary  range  of  properties  ex- 
hibited, from  helium  with  a  melting  point  of  less  than  30  K.  to 
such  a  substance  as  iodobenzene,  which  is  one  of  those  which 
have  a  high  critical  point  which  has  been  determined  with 
some  accuracy  (Tc  =  721  K.),  it  is  remarkable  that  the  coinci- 
dence should  be  as  good  as  it  is.  However,  even  with  sub- 
stances which  are  chemically  elementary  and  in  which  there 
is  no  association  of  vapour  molecules  on  approaching  the 
liquid  state,  there  are  many  differences  which  appear  to  be 
connected  with  chemical  properties,  as  substances  of  similar 
chemical  characters  fall  into  classes  in  which  the  divergences 
may  be  exceedingly  small.  In  most  cases  the  divergences  are 
unexplained :  probably  there  are  not  at  present  sufficient 
accurate  data  on  which  any  more  comprehensive  generalisation 
could  be  based.     The  successful  solution  of  this  further  prob- 

3 


34  SCIENCE   PROGRESS 

lem  awaits  some  one  who  is  able  to  systematise  the  enormous 
mass  of  data  which  is  being  obtained.  Something  in  the 
shape  of  a  further  generalisation  has  been  obtained  by  the 
application  of  the  thermodynamic  reasoning  of  J.  Willard  Gibbs 
to  the  relations  of  the  solid  to  the  other  states  ;  but  this  rather 
extends  the  former  results  of  van  der  Waals  to  states  which  he 
did  not  consider,  than  increases  the  general  accuracy  with  which 
the  experimental  data  are  systematised  and  new  relations  deduced. 

One  of  the  main  difficulties  in  this  subject  is  the  great  experi- 
mental difficulty  which  is  encountered  directly  really  accurate 
data  at  any  other  temperatures  than  the  normal  are  required. 
Even  at  the  normal  temperature  it  is  only  by  the  very  greatest 
care  at  every  step  that  values  are  obtained,  which  are  more 
accurate  than  to  0*02  per  cent.  The  vast  majority  of  measure- 
ments of  compressibility  at  constant  temperature,  the  deter- 
mination of  isothermals,  are  hardly  accurate  to  o'2  per  cent.,  while 
very  few  critical  data  are  accurate  to  i  per  cent. 

It  is  very  rarely  that  the  same  observer  makes  measurements 
on  the  three  critical  data,  so  that  the  results  are  often  not  very 
comparable,  and  in  any  case  the  values  given  are  in  units  which 
are  not  always  self-evident.  It  is  unfortunate  that  a  really 
strict  system  of  units  has  not  been  generally  recognised,  as  all 
three  units  of  pressure,  volume,  and  temperature  are  liable  to 
some  ambiguity.  Pressure  is  usually  expressed  in  atmospheres, 
the  value  of  which  depends  upon  the  latitude  of  the  experimental 
station  at  which  the  determinations  are  made,  but  which  are 
sometimes  mean  atmospheres  reduced  to  latitude  450.  If  all 
observers  deduced  their  results  to  the  C.G.S.  unit  of  a  mega- 
dyne  per  sq.  cm.,  which  is  very  nearly  an  atmosphere,  it  would 
be  much  clearer.  The  same  is  true  of  the  volumes  which  are 
sometimes  given  in  the  unit  known  as  the  normal  volume,  the 
volume  of  the  quantity  of  gas  under  experiment  at  zero0  C.  and 
under  the  unit  of  pressure  employed.  Others  express  the 
volumes  in  terms  of  the  mass  of  the  gas,  which  is  easily 
converted  to  the  first  mentioned,  if  the  law  of  Avogadro  is 
assumed  to  hold  strictly.  However,  as  will  be  explained  later, 
this  law  is  not  strict,  and  if  a  correction  is  applied  so  that 
equal  volumes  of  different  gases  shall  contain  equal  numbers 
of  molecules,  a  unit  is  obtained  which  is  known  as  the  "  theo- 
retical normal  volume  "  and  which  makes  results  on  different 
gases  strictly  comparable.     There  is  less  ambiguity  about  the 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  35 

scale  of  temperature  which  is  either  centigrade  or  Kelvin,  and 
between  which  there  is  a  relation  which  is  now  almost  exactly 
known.  However,  temperatures  are  sometimes  given  in  the 
scales  of  a  particular  gas  thermometer. 

The  difficulties  experienced  in  the  determination  of  the  exact 
values  of  the  critical  constants  are,  as  mentioned  above,  very- 
great,  and  this  from  two  causes.  In  the  first  place  their  value 
varies  very  much  with  the  presence  of  only  small  traces  of 
impurities,  traces  which  would  hardly  affect  any  other  physical 
constant ;  and  in  the  second  place  the  critical  state  is  so  evanes- 
cent and  so  exact  with  pure  substances  that  it  is  absolutely 
necessary  to  have  the  meniscus  under  view  during  the  whole 
time  until  it  disappears  with  a  minute  rise  of  temperature  while 
the  pressure  is  kept  constant,  or  still  better  is  increased  very 
slowly,  so  that  no  heating  due  to  compression  can  take  place. 
It  is  clear  that  these  conditions  are  not  easily  attained  in  practice, 
and  hence  the  differences  between  the  results  given  by  even  the 
most  careful  workers  can  be  understood. 

However,  the  attainment  of  these  data  to  a  high  degree  of 
accuracy  is  only  a  matter  of  time,  and  a  number  are  now  known 
to  a  sufficient  accuracy  to  make  deductions  drawn  from  their 
use  right  in  principle  if  not  in  actual  value. 

In  attacking  a  subject  such  as  this  with  the  desire  of  de- 
ducing some  general  laws,  there  are  always  two  main  lines  of 
advance  open,  both  of  which  can  be  usefully  followed  as  each 
gives  the  possibility  of  arriving  at  some  conclusion  which  would 
not  have  been  deducible  from  the  other.  Thus  the  simple 
relation  of  equation  (2)  has  been  of  immense  value,  and  really 
embodies  the  results  of  the  deductive  and  the  empirical  lines  of 
argument  in  their  simplest  form.  The  next  step  on  the  de- 
ductive side  was  made  by  J.  D.  van  der  Waals  in  1873,  who 
from  kinetic  and  thermodynamical  reasoning  obtained  the  well- 
known  form : 

(4) (^ +  £)(«/-*)  =  RT  =  (1 +«)<-i-*)T 

in  which  a  and  b  are  functions  of  the  attraction  and  of 
the  volume  occupied  by  the  molecules  respectively,  and  are 
supposed  to  be  invariable  with  temperature  and  pressure.  It  is 
clear  from  the  propositions  formulated  above  that  these  as- 
sumptions are  not  correct,  and  many  attempts  have  been  made 
by   Clausius,   Batelli,   Berthelot,    Boltzmann,   Reinganum,   and 


36  SCIENCE  PROGRESS 

others  to  obtain  a  closer  agreement  with  the  experimental 
results  either  by  the  inclusion  of  an  additional  constant  or 
better  by  making  them  functions  of  the  temperature  and  per- 
haps of  pressure.  Probably  the  most  satisfactory  of  these  is 
that  due  to  Reinganum 

(5) ('+5)^-" 

where  a1  and  bl  are  functions  of  both  v  and  T.  It  is  certainly  very 
exact  for  comparatively  small  densities,  gives  a  good  agreement 
for  higher  densities,  and  is  capable  of  easy  manipulation. 

The  other  main  line  of  development  is  more  empirical,  al- 
though many  points  have  to  be  considered  before  the  best  form 
is  reached.  It  is  clear  that  the  corrections  to  (2)  which  are 
given  by  (4)  or  (5)  could  be  covered  by  a  convergent  series  in 
powers  of  the  density  in  which  the  coefficients  of  the  various 
terms  were  determined  from  experimental  data.  There  is  much 
to  be  said  for  expressing  the  product  pv  as  a  series  of  increas- 
ing powers  of  d  or  -.     The  series  developed  by  H.  K.  Onnes 

principally  from  the  experimental  results  of  Amagat  is 

(6)  .     .     .     .    pv  =  A  +  B/v  +  C/v*  +  D/v4  +  Ejv*  +  etc. 

in  which  p  and  v  are  most  conveniently  expressed  in  mega- 
dynes  and  theoretical  normal  volumes,  at  constant  temperature. 
It  is  found  that  with  the  highest  pressures  used  by  Amagat 
(about  3,000  At)  when  the  density  is  about  io3  the  F  term  is  the 
last  that  is  necessary. 

For  every  substance  it  is  clearly  possible  to  obtain  such 
a  series  with  some  accuracy,  if  the  measurements  cover  a 
sufficiently  wide  range,  thus  enabling  the  relations  between 
p  and  v  to  be  known  at  certain  given  temperatures.  To  obtain 
the  change  with  temperatures  a  number  of  isothermals  at  differ- 
ent temperatures  are  required,  the  change  of  coefficient  between 
any  two  being  sufficient  to  give  the  relation  over  that  particular 
range. 

However,  it  is  the  combination  of  these  relations  with  the 
principle  of  corresponding  states  which  makes  their  use  parti- 
cularly instructive.  The  equation  (4)  can  be  put  into  the 
reduced  form  in  which  the  pressure  volume  and  temperature 
are  generalised  and  a  and  b  vanish  by  noting  that,  as  it  is  a 
cubic  equation  in  v,  it  will   have  three  roots,  which  must  all 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  37 

coincide    at    the    critical    point.     Without   going   through    the 
process  it  follows  from  this  that 

(7) (* +  |)  (30-0  =  80 

is  the  reduced  equation. 

On  the  other  hand  equation  (6)  can  only  be  put  into  the 
reduced  form  by  making  some  general  assumption  with  regard 
to  the  relations  of  the  critical  data.  One  which  is  very  nearly 
true  in  a  large  number  of  cases,  and  may  be  found  to  be  strictly 

true  in  some,  is  that  s— —  =  a  constant  =  A,  say,  and  then  the 

equation  will  appear  as 

(8)  .     .     .     .     \v(f>  =  A'  +  B'/0\  +  C'A£!X2  +  D'/<£4\*  +  etc. 

in  which  A'  B'  etc.,  are  functions  of  the  reduced  temperature  6 
of  the  form 

(9) B'  =  6x6  -{■  b2  +  6J6  +  btJ6*  +  b>!6\ 

In  using  this  equation  it  is  not  necessary  to  give  a  value 
to  \  if,  as  is  very  useful,  the  values  of  pv/T  at  given  values 
of  p,  v   and  t  are  wanted,  for  we  get  X  ir^\d  =  A"  +  B"/(f)\  + 

C'7<£2\2  +  etc.,  and  hence /z//T  =  A"+  BvQf)  +  C'W2^)2  +  etc; 

where  B"  etc.  =  by  +  b2/0  +  b3/6~  +  bx\8'  +  bbj6\  The  value  of  Tcjpc 
is  much  more  accurately  known  than  \  and  is  usually  between 
2  and  4  (see,  however,  Table  III.).  For  general  deductions  a 
value  of  A,  can  be  taken  and  the  reduced  form  ir<f>  obtained 
for  some  special  values  of  cf>  and  6. 

Either  from  (7)  or  (8)  or  any  other  reduced  equation  it  is 
hence  possible  to  calculate  relations  between  ir,  4>  and  6  which 
apply,  at  any  rate  up  to  the  practical  limits  of  these,  to  a  fair 
approximation  for  any  given  substance,  when  the  values  of  the 
critical  constants  are  inserted. 

In  fig.  1  the  system  of  values  obtained  from  equation  (7) 
by  plotting  irfyjd  against  1/$  =  8  as  rectangular  co-ordinates  is 
shown,  but  it  must  be  clearly  understood  that  the  numerical 
values  can  only  be  taken  as  an  approximation  to  the  results  of 
experiment,  although  the  main  principles  are  correct. 

It  will  be  noticed  that  there  are  two  clearly  defined  limits, 
where  §  =  3  and  at  high  temperatures.  As  far  as  the  first  is 
concerned,  Amagat  found   at   his   highest   pressures  values   of 


38 


SCIENCE  PROGRESS 


8  of  about  2  and  the  compressibility  was  very  sensibly  decreas- 
ing. On  the  other  hand  the  lowest  critical  temperature  known 
being  that  of  helium  at  say  5°  K.,  it  follows  that  a  value  of 
6  =  iooo  makes  T  =  5ooo°  K.,  a  value  far  above  any  at  which  iso- 


I  I 


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r-.r  o  7f  <  o 


Fig.  i. 


thermal  measurements  are  possible  under  present  conditions. 
As  the  critical  temperature  of  hydrogen  is  about  six  times  as 
great,  it  follows  that  even  with  6  =  ioo  the  practical  limits  are 
reached  with  this  gas  and  hence  with  all  others,     There  are 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  39 

two  special  points,  A  where  i/<j>  =  o  and  -k$\Q  —  8/3,  at  which  all 
the  isotherms  converge,  and  B  which  is  the  critical  point. 

This  diagram  of  7r<£/0  is  particularly  interesting  and  con- 
venient for  showing  the  whole  range  in  consequence  of  these 
limits.  It  is  to  be  noticed  that  the  change  of  7n/>/0  obtained 
in  passing  along  an  isotherm  is  a  change  of  entropy  with 
change  of  density  (—  dty/dv),  which  is  very  important  in  many 
theoretical  discussions. 

By  the  usual  process  of  finding  minimum  values  it  will  be 
found  that  the  minima  of  irfyjd  are  given  by 

(10) <t>\27  -  80)  -  1 80  +  3  =  o 

for  various  values  of  6,  the  limiting  values  to  give  real  solutions 
being  6  =  -2f  and  -s\  where  irfyjQ  —  %  and  zero  respectively  (fig.  1, 
curve  c).  We  shall  see  later  also  that  values  of  7r</>/0  =  pv/T\ 
are  of  considerable  interest  in  the  treatment  of  the  variability 
of  certain  quantities  such  as  the  specific  heats. 

It  has  been  mentioned  above  that  one  of  the  criteria  of  a 
perfect  gas  is  that  it  shall  not  be  heated  or  cooled  in  expanding 
through  a  small  orifice  under  a  small  difference  of  pressure. 
Now  it  is  found  in  practice  that  nearly  all  gases  are  cooled  on 
expansion  and  that  at  the  ordinary  temperature  only  helium 
and  hydrogen  will  be  heated  among  the  known  gases.  The 
effect  with  helium  has  not  yet  been  observed  directly,  that  with 
hydrogen  being  measured  with  some  uncertainty  by  Joule  and 
Kelvin  in  their  famous  experiments.  All  that  one  can  justly 
deduce  from  their  results  with  hydrogen  is  that  the  change  was 
very  small,  but  towards  a  heating  rather  than  a  cooling  effect. 

The  general  equation  given  by  Lord  Kelvin  reduces  when 
there  is  no  heating  to  (3),  and  if  this  is  applied  to  the  reduced 
equation  (7)  the  following  relation  is  obtained 

("5 02(27-40)-i8<H-3  =  o, 

which  is  the  same  equation  as  (10)  if  6  has  twice  the  value  it 
has  there. 

The  values  obtained  from  this  are  shown  in  curve  d,  fig.  1. 
Hence  at  all  values  inside  the  curve  there  will  be  cooling  and 
at  all  values  outside  heating.  The  maximum  temperature 
according  to  equation  (1 1)  at  which  the  inversion  will  take  place 
will  be  6  =  675,  at  which  it  will  occur  at  zero  density.  Con- 
sidering the  case   of  hydrogen  and  assuming  Tc  =  30  K.,  pc  = 


4o  SCIENCE  PROGRESS 

15  At,  and  taking  B  =  o*i  and  hence  7r=r5  atmospheres,  then 
0  =  6*3 1  which  makes  T  =  189*3  K.  From  this  to  about  0  =  2  the 
inversion  occurs  at  nearly  the  same  values  of  7r<f>/0,  the  pressures 
rising  to  77  =  8*95,  which  with  hydrogen  =  134  At.  This  is  not  very 
different  from  the  results  found  by  Olszewski  at  Cracow  using 
a  method  which  is  not  strictly  carried  out  on  the  principles 
on  which  the  Kelvin  equation  is  deduced.  Also  it  is  known 
from  practical  experience  that  hydrogen  experiences  a  sensible 
cooling  when  expanded  through  a  fine  jet  at  pressures  of  about 
100  atmospheres  at  the  temperature  of  liquid  air,  which  is 
about  83  K.,  as  this  has  been  used  to  effect  the  liquefaction  of 
hydrogen  in  combination  with  the  regenerative  process  as  used 
by  Linde  originally  for  air. 

This  limiting  value  for  helium,  with  a  Tc  =  5*1  and  pc  =  2*3 
about,  will  be  T  =  32*2  K.  with  &  =  o*i.  This  result  is  again  to 
some  extent  substantiated  by  experiment,  as  the  isothermal 
determinations  of  H.  K.  Onnes  at  Leiden  showed  that  the 
minimum  value  />v/T  would  be  at  about  18°  K.  for  very  small 
densities,  and,  as  has  been  pointed  out  above,  the  relations 
expressed  by  equations  (10)  and  (n)  make  this  temperature  just 
half  that  of  the  inversion  point  for  the  same  density. 

By  using  a  temperature  of  150  K.  obtained  by  means  of  liquid 
hydrogen  boiling  under  reduced  pressure,  H.  K.  Onnes  was 
able  to  liquefy  helium  with  ease.  As  a  contrast  is  the  case  of 
oxygen,  in  which  Tc  =  1 55°  K.  and  pc  =  50  At.  at  a  density  of 
0*02,  which  would  be  equivalent  to  a  pressure  of  about  1 
atmosphere  0  =  6'6,  whence  T  =  1023  K.  =  7500  C,  while,  where 
8  =  1*5;  7T  =  5  '9 ;  so  that  at  a  temperature  of  —  400  C,  the  pressure 
at  which  inversion  would  occur  would  be  about  300  kg.  and 
hence  quite  within  measurable  limits. 

It  should  again  be  emphasised  that  the  results  obtained  by 
the  use  of  equation  (7),  or  indeed  any  other  theoretical  equation, 
are  not  to  be  taken  as  numerically  accurate,  but  only  as  indicat- 
ing the  probable  course  of  the  relation.  If  anything  were 
wanted  to  make  this  clear,  it  would  be  a  consideration  of  the 
limiting  temperatures  found  by  the  use  of  the  various  equations 
of  state  and  equation   (8).      Some   of  the   more  important   are 

Clausius  3*182  V  1  +  —  tc,  Berthelot  4*24  tc,  Reinganum   5*36  tc 

in  place  of  the  6*75  tc  found  with  the  v.d.  Waals  equation.     On 
the  other  hand,  the   empirical  equation  (8)  gives  a  value  just 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  41 

under  5  when  the  density  is  taken  as  vanishingly  small,  and  in 
this  case  it  is  not  necessary  to  make  any  assumptions  about  the 
value  of  X,  so  it  is  probably  not  very  far  from  the  truth.  It  is 
hoped  that  a  more  detailed  consideration  of  this  relation  will 
be  published  shortly  elsewhere ;  but  the  subject  is  painfully 
lacking  in  data,  those  of  Thompson  and  Joule  made  in  1854 
being  almost  the  only  series  available,  although  there  are  a  few 
other  measurements  by  Olszewski,  as  mentioned  above,  and 
others  which  are  more  or  less  capable  of  mathematical  treat- 
ment over  a  small  range. 

It  would  be  exceedingly  important  for  the  whole  gas  theory 
to  have  a  series  of  accurate  measurements  on  one  or  more 
gases  for  considerable  ranges  of  temperature  and  determining 
not  only  the  sign  but  the  value  of  the  Joule-Kelvin  effect,  as  a 
function  of  initial  temperature  and  of  initial  density. 

One  of  the  most  important  applications  of  the  study  of  the 
isothermals  of  gases  is  in  the  corrections  to  be  applied  to  the 
gas  thermometer  to  give  temperatures  on  the  absolute  scale. 
This  involves  two  problems — the  evaluation  of  the  difference 
between  the  centigrade  and  Kelvin  scales,  which  depends  partly 
on  strictly  thermodynamic  reasoning  and  partly  on  the  deduc- 
tions to  be  drawn  from  the  properties  of  various  gases.  For 
ordinary  thermometric  purposes,  however,  it  is  more  important 
to  know  the  point-to-point  differences  between  the  scales  of 
any  given  gas  used  for  thermometric  purposes  and  the  absolute 
scale,  that  is,  the  correction  which  must  be  applied  to  the 
temperature  as  read  by  the  thermometer  to  get  the  real  temper- 
ature at  any  point  of  the  scale. 

Until  helium  became  known  and  reasonably  obtainable, 
standard  thermometry  may  be  said  to  have  been  confined  to 
the  use  of  two  gases,  as  no  one  gas  is  practically  available  over 
the  whole  range  of  temperatures  measurable  by  the  gas 
thermometer. 

For  temperatures  from  ioo°  C.  upwards  to  the  highest  point 
which  the  reservoir  will  stand,  nitrogen  is  still  the  most  suitable 
gas,  as  the  corrections  are  comparatively  small ;  it  does  not 
penetrate  the  walls  of  the  reservoir  like  hydrogen,  or  still  more 
helium,  nor  attack  mercury  like  oxygen  at  high  temperatures. 
There  is  every  reason  to  suppose  that  argon  will  be  a  still 
more  suitable  gas  when  its  thermodynamic  properties  are 
sufficiently    well    known.      For    temperatures    below    ioq°   C- 


42  SCIENCE   PROGRESS 

hydrogen  has  been  up  to  quite  recently  the  standard,  as  its  very 
low  critical  point  (30  K.)  makes  the  corrections  quite  small  until 
temperatures  only  obtained  by  liquid  hydrogen  are  reached. 
Now  that  helium  is  available  with  a  critical  point  of  about  5*1  K. 
and  a  small  very  simple  molecule,  which  makes  divergences 
extremely  small,  there  is  no  doubt  that  it  is  the  most  suitable 
gas  for  low  temperatures,  as  the  corrections  are  even  small  at 
the  temperature  of  solid  hydrogen,  the  lowest  temperature 
obtainable  without  the  aid  of  helium  itself.  Thus  quite  shortly 
we  may  expect  standard  gas  thermometry  to  be  confined  to 
helium  thermometers  up  to  1009  C.  and  argon  thermometers  from 
about  o°  C.  upwards,  there  being  a  region  of  150  to  200°  over 
which  the  two  scales  can  be  compared.  However,  for  practical 
purposes  the  hydrogen  and  nitrogen  scales  will  continue  to 
be  used,  and,  if  the  absolute  corrections  are  known,  readings 
made  with  them  are  as  accurate  as  if  made  with  a  standard 
thermometer  with  the  same  care. 

The  evaluation  of  the  absolute  scale  is  due  to  Lord  Kelvin  in 
1847  from  the  theory  of  heat  engines.  Heat  is  taken  in  at  a 
temperature  T  and  given  out  at  a  temperature  T!,and  the  theory 
says  that  the  amounts  of  heat  are  proportional  to  the  absolute 
temperatures  with  a  perfect  reversible  engine.  As  the  most 
perfect  working  substance  is  a  perfect  gas  and  as  certain  actual 
gases  approach  very  nearly  to  the  standard  of  perfection,  they 
are  clearly  the  most  suitable  substances  to  determine  the  value 
of  the  difference  between  the  Kelvin  and  centigrade  scales. 

It  is  rather  remarkable  that  the  original  value  of  —  273-1  C, 
which  was  derived  from  gases  whose  properties  were  observed  at 
considerable  distances  from  the  absolute  zero,  should  be  almost 
exactly  the  value  which  the  most  recent  and  careful  determina- 
tions would  indicate.  From  time  to  time  lengthy  papers  have 
been  published  making  estimations  of  the  absolute  zero  derived 
from  measurements  on  the  Joule-Kelvin  effect  which  are  known 
not  to  be  very  accurate.  It  is  not  to  be  wondered  at  that  there 
should  have  been  a  considerable  discrepancy  between  the  results 
obtained,  but  they  at  least  all  indicated  that  the  value  of  the 
Kelvin  zero  on  the  centigrade  scale  would  be  more  than  —273 
and  less  than  —273*5.  Much  more  accurate  information  is, 
however,  obtained  from  a  strict  investigation  of  accurate 
isothermals,  and  it  will  only  be  necessary  to  consider  the  results 
furnished  by,  say,  nitrogen,  hydrogen,  and  helium  with  critical 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  43 

points  at  about  127  K.,  20  K.,  and  5  K.  respectively,  as  they 
practically  cover  the  range  of  exact  measurements  0=  1  to  0=  10. 
For  the  first  gas  the  values  of  Amagat  are  used,  for  the  second 
those  of  Onnes  and  Braak,  for  the  third  those  of  Onnes,  and  in 
each  case  the  empirical  expression  of  actual  results  by  means  of 
equation  (6)  will  be  used,  as  these  coincide  with  the  actual 
isotherms  within  the  limits  of  experimental  error.  The 
hydrogen  results  are  the  most  important  on  account  of  their 
accuracy  and  the  wide  range  of  temperature  covered,  so  that 
both  the  Kelvin  zero  and  the  variations  from  the  Kelvin  scale 
can  be  obtained  from  the  same  set  of  measurements. 

There  are  two  types  of  standard  thermometers  used — those  at 
constant  volume  and  constant  pressure  ;  but  as  the  latter  is  less 
simple,  and  in  most  cases  the  corrections  are  larger,  the  constant 
volume  thermometer  is  used  more  frequently,  excepting  at  high 
temperatures.  With  an  initial  pressure  of  760  mm.  or  1  atmo- 
sphere at  zero  C.  it  is  known  as  the  normal  hydrogen,  helium,  or 
other  gas  thermometer  as  the  case  may  be,  and  with  an  initial 
zero  pressure  of  1,000  mm.  as  the  international  thermometer. 
With  these  small  densities  all  terms  above  the  third  in  equation 
(6)  become  vanishingly  small,  and  even  the  third  has  very  small 
influence,  so  that  obtaining  the  corrections  at  these  pressures 
resolves  itself  into  the  problem  of  measuring  the  value  of  B  as 
accurately  as  possible. 

The  value  of  the  absolute  zero  is  usually  obtained  by 
correcting  the  pressure  coefficient  at  one  of  the  standard 
temperatures  mentioned  above  to  a  zero  density  by  the  aid  of 
the  second  and  third  terms  of  equation  (6),  which  gives  the 
deviations  from  the  perfect  gas  state  of  equation  (2).  This 
deduction  depends  on  the  assumption  that  at  limitingly  low 
pressures  any  gas  will  be  in  a  state  where  its  deviations  from 
the  Boyle-GayLussac-Avogadro  law  expressed  by  equation  (2) 
may  be  neglected.  With  a  constant  volume  thermometer  the 
pressure  coefficient  is  the  change  of  pressure  with  a  given 
known  interval  of  temperature,  which  is  usually  taken  to  be 
zero0  C.  to  ioo°  C,  as  these  points  are  obtainable  with  very  great 
accuracy,  or  rather  the  exact  value  of  the  boiling  point  of  water 
(although  usually  not  exactly  ioo°  C.)  is  easily  determinable  at 
the  time   of  the   experiment.      Hence   the   pressure   coefficient 

t-  t  —  T '  an<^  ^  we  0Dtam  ^is  relation  with  equation  (1) 


44 


SCIENCE  PROGRESS 


we  find  that 


p-po  _  R 


p 

T0 


=  —  —  ^-  and   hence 


As 


a  con- 


T-T0      v0      T0  """  -      T0 

sequence,  if  the  perfect  gas  state  can  be  assumed  at  very  small 
pressures  and  densities,  the  absolute  value  of  zero0  C.  is  given 
by  the  inverse  of  the  coefficient  of  expansion  from  o*o°  C. 
to  some  temperature  which  is  not  only  ioo°  C.  most  suitably 
for  the  reason  given  above,  but  also  because  this  is  the  standard 
interval  of  the  centigrade  scale. 

In  the  following  table  are  collected  the  values  for  a  few 
gases  used  for  thermometric  purposes  in  which  the  value  of  B  is 
known  to  a  sufficiently  high  degree  of  accuracy  to  make  the 
calculation  of  any  real  value. 

The  curvature  of  the  isotherms  is  so  small  that  the  C  term 
does  not  enter  into  the  result  except  for  the  purpose  of  obtaining 
the  theoretical  normal  volume. 

If  the  critical  data  were  known  with  sufficient  accuracy,  it 
would  be  possible  to  derive  these  results  by  substitution  in  the 
reduced  form,  but  at  present  the  errors  are  far  too  great  to  make 
this  method  of  any  real  value. 

Table  I.     Absolute  Zero 


Data. 

Helium. 

Hydrogen. 

Nitrogen. 

IO3  Bioo  . 

+  0-673 

+  0-86316 

+  0*44303 

IO3  B„     . 

+  0*512 

+  0-5800I 

-037215 

io6  Co     . 

+  OI2 

+  0-670 

+  2-62170 

o:.    . 

0*0036616 

0*0036629 

0-0036744 

At  pressure/. 

1000 

1090 

1000 

av  limit  .... 

o"oo366i7 

0-0036617 

00036618 

1    -T 

1  a   .              .              . 

-  273-10  C. 

-  273'io 

-  273'09 

<1V1 

According  to  Berthelot,  who  has  carefully  reviewed  the 
whole  of  the  data  available,  the  most  probable  value  for  absolute 
zero  is  —  273-09°  C,  while  the  above  results  for  hydrogen  and 
helium,  which  were  obtained  subsequently,  give  273*1.  Thus  it 
is  probable  that  the  uncertainty  has  now  been  reduced  to  a 
hundredth  of  a  degree  centigrade. 

There  is  a  much  greater"  degree  of  uncertainty  in  the 
evaluation  of  the  divergences  of  the  gas  scales  from  the  absolute, 
if  the  values  given  by  different  workers  are  given  an  equal 
weight.     However,  it  is  most  probable  that  the  values  calculated 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  45 

from  actual  isotherms  by  Kamerlingh  Onnes  and  Braak  for 
hydrogen  and  helium  are  to  be  taken  with  much  greater  con- 
fidence than  those  obtained  by  wide  extrapolation  of  experi- 
mental values  or  from  theoretical  considerations,  using  some 
equation  of  state.  In  each  case  the  differences  between  real 
and  absolute  may  be  expressed  by  means  of  a  series,  if  the 
observations  are  sufficiently  numerous  and  accurate  to  allow 
the  coefficients  to  be  obtained.  For  hydrogen  this  is  the  case, 
and  in  a  series  of  the  form 


(12) 


A/  =  a f-  b 

100 


VIOO/  \IOO/  MOO/ 


the  coefficients  have  the  following  values  in  the  range  +  ioo°  C. 
to  —  217-4°  C. 

a  =  -  0-0143307 
b  =  +  0*00669 1 6 
c  —  +  0-0049175 
d  —   +  0*0027297. 

Similar  differences  can  be  obtained  for  other  gases  by 
correspondingly  careful  measurements. 

The  following  table  gives  values  calculated  from  the  above 
equation  for  hydrogen  and  from  experimental  isotherms  for 
helium,  where,  however,  the  values  have  been  interpolated  in 
the  experimental  range.  Those  in  square  brackets  are  extra- 
polated. 


Table  II.     Corrections  to  Absolute  Scale,  International 

Thermometer 


Temperature  read. 

Helium. 

Hydrogen. 

loo°C. 

O'O 

O'O 

5° 

— 

—  0*0047 

0 

O'O 

O'O 

-  150 

— 

+  0*0082 

—  100 

-  0*004 

+  00187 

-  150 

+  0*0014 

+  0*0337 

—  200 

+  0*004 

+  0*0593 

-  250 

" 

[+  01076] 

These  values  appear  to  be  as  accurate  as  it  is  possible  to 
obtain  them  at  the  present  time,  except  by  a  direct  measurement 
of  the  values  of  B  and  C  at  the  temperature  concerned,  which 
is  naturally  more  likely  to  give  a  correct  value. 


46  SCIENCE   PROGRESS 

It  is  not  the  purpose  of  this  article,  however,  to  derive  the 
most  accurate   corrections  or  to  discuss  the  relative  merits  of 
the   various   methods   by   which   such    corrections    have    been 
obtained,  but  to  indicate  the  most  approved  modern  lines  along 
which  such  investigations  proceed.     One  very  striking  fact  is 
the  extreme  accuracy  of  such  measurements,  even  at  tempera- 
tures such  as  +  5000  C.   or  —  250°  C.      Tenths    of  degrees  are 
capable  of  exact  determination,  and  at  the  latter  temperatures 
even  hundredths  of  degrees  are  determinable  with  certainty,  with 
carefully  prepared  and  calibrated  instruments.     This  accuracy 
is  really  necessary  at  low  temperatures,  on  account  of  the  much 
higher  proportion  of  the  temperature  which  one-hundredth  of 
a  degree  has  at,  say,  50  K.  than  at  300  K.     It  is  clear  that  such 
an  accuracy  is  only  obtainable  when  every  possible  precaution 
is  taken,  and,  in  particular,  when  the  temperature  of  the  gas 
which    is    being    measured    is    kept    constant    to    about    one- 
hundredth  of  a  degree.    For  all  isothermal  work  at  low  tempera- 
tures the  reservoir  of  gas  is  immersed  in  a  liquid  which  is  caused 
to  boil  at  the   required  temperature  by  adjusting  the  pressure 
on  it.     The  vapour  pressure  of  a  pure  liquid  diminishes  with  the 
temperature  according  to  the  relation  expressed  by  the  border- 
curve   between   liquid   and   vapour,  which  can   be  deduced  by 
corresponding  states  from  one  accurate  series  of  measurements, 
or,  better,  by  direct  measurement  in  each  case. 

As,  however,  in  practice  it  is  impossible  to  keep  gases  quite 
pure,  the  liquefied  gas  will  be  more  or  less  a  mixture,  and  the 
temperature  at  which  it  boils  under  a  given  pressure  will 
change  as  the  more  volatile  component  boils  away.  Such  a 
condition  is  very  well  exhibited  by  the  boiling  of  liquid  air. 
Here  the  normal  boiling  points  of  oxygen,  freshly  condensed  air, 
and  nitrogen  are  respectively  90  K.,  82  K.,  and  79  K.,  hence  that  of 
air  is  very  nearly  obtained  by  the  sum  of  the  proportions  of 
liquid  oxygen  and  nitrogen  contained  in  it.  When  the  air  is 
boiled,  the  more  volatile  nitrogen  boils  away,  so  that  the  liquid 
becomes  continually  richer  in  oxygen  and  the  temperature  rises 
until  a  steady  state  is  reached  at  which  the  mixture  boils  as 
a  simple  substance.  Hence  it  is  clearly  not  possible  to  keep  a 
temperature  constant  by  boiling  liquid  air  at  constant  pressure, 
and  this  is  true  of  all  gases  used  for  such  work,  although,  where 
the  amount  of  impurity  is  small,  the  total  change  of  temperature 
may  be  small  also.     It  is  necessary  to  have  an  elaborate  system 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  47 

by  which  the  gas  is  boiled  under  a  pressure  which  can  be  kept 
constant  when  required  or  changed  very  slowly  to  coincide 
with  the  slow  change  in  temperature,  which  is  indicated  by  some 
delicate  and  sensitive  thermoscope,  while  a  thermometer  is  used 
to  make  the  actual  measurements  of  temperature  when  this  has 
been  constant  for  a  sufficient  time  for  a  steady  state  to  have 
been  reached  in  the  gas  reservoir  and  adjacent  parts.  Although 
the  gas  thermometer  is  the  invariable  standard,  subject  to  the 
corrections  considered  above,  it  is  hardly  ever  used  for  the 
actual  measurements,  partly  because  a  standard  gas  thermo- 
meter is  a  valuable  instrument  which  might  be  damaged  in  the 
course  of  the  experiments,  and  partly  because  the  work  of 
reading  the  pressure  and  volume  and  of  keeping  all  the  condi- 
tions suitable  for  obtaining  the  best  results  is  so  laborious  and 
complicated  that  the  temperatures  are  better  obtained  by  means 
of  resistance  or  thermoelectric  thermometers  which  have  been 
carefully  calibrated  in  the  neighbourhood  of  the  experimental 
points  by  comparison  with  a  standard  gas  thermometer.  These 
electric  methods  have  also  the  great  advantage  that  the  measure- 
ments can  take  place  in  another  room  in  quiet. 

What  has  been  said  about  low  applies  equally  to  high 
temperatures,  only  here  the  gas  reservoir  is  sometimes  immersed 
in  the  vapour  of  a  boiling  liquid  ;  but  very  few  isothermal  measure- 
ments have  been  made  at  high  temperatures  except  at  the 
comparatively  low  pressures  of  gas  thermometery. 

There  is  some  reason  for  this,  as  there  are  only  a  few 
substances  where  high  temperature  measurements  are  likely  to 
give  any  very  important  result.  Of  these,  mercury  is  pro- 
bably the  most  manageable,  although  other  substances,  such  as 
zinc  and  cadmium,  which  also  have  monatomic  vapours  would 
be  of  great  interest.  There  are  at  the  present  time  many 
measurements  on  vapour  pressures,  but  these  give  only  very 
meagre  information  in  comparison  with  that  obtained  when  the 
volume  is  measured  also.  The  normal  boiling  point  is  only  a 
special  vapour  pressure  which  occurs  at  different  reduced 
temperatures,  as  the  pressure  of  1  atmosphere  is  a  varied 
fraction  of  the  critical  pressure.  It  is  not  without  interest 
to  consider  the  relation  between  the  boiling  point  and  the 
critical  data  of  all  the  mono-,  di-,  and  tri-atomic  substances  for 
which  reasonably  accurate  data  are  available,  as  collected  in 
Table  III. 


48  SCIENCE  PROGRESS 

Table  III.     Data  of  Change  of  State 


Substance. 

Molecule. 

Density. 

Tc 

TB 

TK 

pc 

Tc/pc 

TB/T, 

Helium  . 

He 

2 

5'i 

4"5 

<3 

2'3 

2"22 

o-88 

Hydrogen 

H, 

I 

1  r 
J)3 

20 

14 

II'O 

— 

o'57 

Nitrogen 

N2 

14 

127 

77 

63 

35"o 

3'63 

o'oi 

Carbon  monoxide  . 

CO 

14 

133 

83 

69 

35'5 

375 

C62 

Argon 

A 

20 

153 

87 

85 

51-0 

2-95 

0-57 

Oxygen  . 

o„ 

16 

155 

90 

— 

5o"o 

3*1° 

o"6o 

Nitric  oxide    . 

NO 

15 

179 

130 

120 

71-0 

2'52 

°'73 

Krypton. 

Kr 

41 

2IO 

160 

121 

74'o 

3-89 

076 

Xenon     . 

Xe 

64 

288 

164 

123 

57'° 

4'53 

o'57 

Carbon  dioxide 

co2 

22 

304 

(195  sub] 

imes  I  At) 

77-0 

5  "34 

064 

Nitrous  oxide. 

N.,6 

22 

312 

193 

171 

77'5 

4 '02 

o'6i 

Hydrogen   chloride 

HC1 

I7-8 

325 

— 

— 

83-0 

3'92 

— 

Hydrogen  bromide 

HBr 

40-5 

304 

Hydrogen  sulphide 

H,S 

"7 

373 

I90 

187 

9o'o 

4'i5 

C56 

Carbon  oxysulphide 

COS 

30 

378 

• — 

— 

65*0 

5-82 

— 

Hydrogen  selenide 

H,Se 

40' 5 

411 

232 

209 

9i"o 

4-5i 

o'57 

Chlorine 

CI, 

35-5 

419 

239 

171 

93*5 

4'5~ 

0-57 

Hydrogen  iodide     . 

HI 

64 

424 

236 

223 

[        ] 

[       ] 

C56 

Sulphur  dioxide 

SO., 

32 

429 

263 

200 

79-0 

5 '44 

061 

Carbon  disulphide  . 

CS, 

38 

549 

319 

163 

74'o 

7*4 

0-58 

[Fluorbenzene 

C6HSF 

48 

560 

358 

— 

447-0 

1-25 

0-63] 

Bromine 

Br, 

80 

575 

336 

266 

[132] 

[4-3] 

0-58 

Water     . 

H,0 

9 

638 

393 

273 

200'0 

3'2o 

0*62 

Mercury 

Hg 

100 

[1065] 

630 

234 

[95] 

[M-2] 

[o'59] 

The  density  is  that  in  the  vapour  state,  and  is  half  the 
molecular  weight.  Tc,  TB,  TF  are  the  absolute  values  of  the 
critical,  boiling  and  freezing  point  temperatures,  and  pc  is 
the  critical  pressure  in  atmospheres.  Tc/pc  =  vc/\  and  is  seen 
to  increase  with  increasing  density  more  than  with  temperature 
or  molecular  complexity.  Indeed,  with  more  complex  molecules 
of  the  type  of  fluorbenzene,  which  is  given  as  an  example,  as  it 
is  well  studied  and  normal,  this  ratio  appears  to  be  little  more 
than  half  the  lowest  value  otherwise  found  in  the  table,  and  thus 
among  simple  substances.  No  doubt  the  meaning  is  a  variation 
in  the  critical  volume  which  cannot  be  satisfactorily  investigated 
for  want  of  sufficient  reliable  data.  The  last  column  is  the 
reduced  normal  boiling  point,  and  the  mean  of  the  values 
given  is  0*62  or  very  nearly  2/3,  which  is  a  rough  and  useful 
approximation  to  this  ratio.  It  may  be  noted  that  there  is  much 
less  regularity  in  the  relation  of  the  freezing  point  to  the 
others,  as  would  be  anticipated  from  the  complex  molecular 
conditions  which  appear  at  and  near  the  solid  state. 

By  making  use  of  the  principle  that  equally  reduced  vapour 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  49 

pressures  correspond  to  equally  reduced  temperatures,  it  is 
possible  to  arrive  at  the  values  of  some  of  the  gaps  in  the  table. 
A  value  for  the  critical  pressures  of  bromine  found  thus  is 
pc  =  132.  To  arrive  at  approximate  values  for  mercury,  it  is 
necessary  to  make  an  independent  estimate  for  either  pc  or  Tc. 
Since  the  ratio  TB/Tc  is  also  available,  and  taking  this  as  0-59, 
Tc  appears  as  1065,  and  then  from  the  known  vapour  densities 
the  critical  pressure  comes  out  at  95  atmospheres  only.  This  is 
remarkably  low,  and  makes  the  ratio  Tc/pc  very  large,  thus 
showing  probably  that  vc  is  large.  However,  as  has  been 
mentioned  above,  the  data  are  still  wanting  to  enable  any 
generalisations  to  be  made  with  elementary  substances  and 
simple  compounds. 

To  have  complete  knowledge  of  the  thermodynamic  condition 
of  a  substance,  it  is  necessary  to  know  the  quantity  of  heat  which 
will  be  required  to  raise  a  known  mass  of  it  a  known  difference 
of  temperature.  In  the  case  of  solids  and  liquids,  the  mass  is  kept 
under  constant  conditions  of  pressure  and  the  volume  allowed 
to  increase  with  increase  of  temperature,  so  that  the  applied 
heat  does  external  work  in  producing  this  increase  of  volume, 
in  addition  to  that  which  would  be  required  to  change  its 
temperature  at  constant  volume.  If  we  call  Cp  the  atomic  heat 
at  constant  pressure  and  Cv  that  at  constant  volume,  they  will 
mean  the  number  of  calories  required  to  raise  the  atomic  weights 
of  any  substance  one  degree  centigrade  under  these  conditions. 
However,  to  make  the  definition  quite  exact,  it  is  necessary 
to  define  the  calorie  used,  as  there  is  still  unfortunately  an 
ambiguity  owing  to  the  existence  of  several  calories  which  differ 
by  as  much  as  1  per  cent.  There  is  so  much  in  favour  of  the 
mean  calorie,  the  hundredth  part  of  the  heat  require  to  raise  one 
gramme  of  water  from  zero  to  ioo°  C,  that  it  is  becoming  more 
generally  accepted  as  the  standard.  We  have,  then,  as  p  is 
constant 

(13) Cp-  Cv=p{vl-  v)  =  $pv 

where  ft  is  the  coefficient  of  expansion  at  constant  pressure. 

With  solids  and  liquids  Cp  and  fi  can  be  measured,  and  Cv 
can  be  deduced  from  them,  as  it  is  exceedingly  difficult  to  measure 
it  direct. 

With  gases  and  vapours,  however,  there  is  no  difficulty  in 
keeping  the  volume  constant,  so  that  the  two  quantities  Cp  and 

4 


50  SCIENCE  PROGRESS 

Cv  can  be  measured  independently,  or  their  difference  and  their 
ratio  can  be  determined  experimentally  and  their  values  be 
thus  obtained. 

The  earlier  experimenters,  whose  values  were  not  very  accur- 
ate and  who  mostly  used  the  permanent  gases  for  their  measure- 
ments, concluded  that  Cp  and  Cv  varied  little  with  temperature, 
and  that  Cv  at  any  rate  did  not  vary  with  the  volume.  Such 
conclusions  are  quite  in  accord  with  deductions  to  be  drawn 
from  a  consideration  of  ideal  gases  obeying  equation  (2),  with 
which  the  difference  of  the  specific  heats  will  be  a  constant 
from  equation  (13). 

However,  experiment  shows  that  both  specific  heats  not  only 
vary  considerably  with  change  of  temperature,  but  with  change 
of  density  also.  There  are  not  many  substances  on  which 
experiments  have  been  made  in  several  states,  but  the  general 
trend  of  change  is  indicated  by  what  is  known. 

In  the  solid  state  the  majority  of  the  elements  have  atomic 
heats  approximating  to  6*5,  even  hydrogen  being  5*88  as  deduced 
from  the  results  of  the  change  in  the  specific  heat  of  palladium 
by  occluded  hydrogen  ;  in  the  gaseous  state  it  is  3*4  at  o°  C.  If 
we  assume  that  the  molecular  heat  is  strictly  additive,  as  it 
appears  to  be  in  a  large  number  of  cases,  we  can  compare  the 
heats  of  simple  compounds  such  as  water,  which  is  particularly 
interesting  because  it  is  the  standard  calorimetric  substance. 
It  will  be  convenient  to  give  molecular  heats  to  avoid  any 
question  about  the  atomic  heats  in  the  molecule,  and  to  assume 
the  simple  molecule  in  all  states  for  this  purpose,  although  it 
is  certainly  more  complex  in  many  liquids  and  solids.  We  have 
not  always  both  specific  heats  at  the  different  temperatures  of  the 
vapour  and  gas,  so  must  assume  that  the  difference  is  equal  to 
2  gramme  calories,  which  is  very  nearly  the  value  for  an  ideal 
gas.  Taking  then  the  constant  pressure  value  throughout,  we 
find  for  ice  at  o'o°  C.  9/36  and  decreasing  with  the  temperature, 
for  water  at  about  160  C,  18  ;  for  steam  at  100,  6*35  +  2  =  8*35  ;  for 
water  vapour  at  1,000,  u'52  +  2  =  13*52,  assuming  that  the  same 
law  holds  as  at  lower  temperatures. 

The  changes  here  shown  appear  to  be  general.  Starting 
from  the  minimum  at  absolute  zero,  the  value  grows  until  it 
reaches  a  maximum  at  some  temperature  coinciding  with  the 
liquid  state  at  moderate  pressures,  then  again  decreases  to  a 
second   minimum   at  a  temperature    corresponding    with    the 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  51 

vapour  state  at  moderate  pressures,  again  increasing  with  the 
temperature  very  rapidly,  and  in  some  cases  passing  the  first 
maximum  at  easily  attainable  temperatures.  The  molecular 
heats  of  gases  at  constant  pressure  appear  to  be  given  by  a 
formula  as  follows : 

(14) Cp  =  &s  +  zT 

where  z  is  a  coefficient  which  increases  with  the  complexity  of 
the  gas. 

In  the  above  no  mention  has  been  made  about  density,  as  it 
is  always  assumed  that  the  density  was  small.  However,  in 
some  of  the  experiments  which  determined  the  best  values  we 
have,  the  density  was  certainly  very  high,  and  we  may  consider 
shortly  the  effect  of  density ;  but  the  measurements  are  very 
contradictory,  and  unfortunately  the  results  which  have  been 
deduced  as  yet  from  theoretical  grounds  do  not  appear  to  be 
reconcilable  with  the  best  experimental  evidence. 

If  an  easily  manageable  equation  of  state  were  to  hand,  which 
were  true  over  a  large  range,  there  should  be  no  difficulty  in 
deducing  the  changes  of  both  Cp  and  Cv  from  the  well-known 
relations 


(15) 


8Q_  -&£ 
dv  :=      8/» 


Putting  these  equal  to  zero  respectively  should  then  give  the 
temperatures  at  which  the  maximum  and  minimum  values  of 
Cv  and  Cp  occur  at  various  densities  (pressures).  However, 
with  either  (2)  or  (4)  Cv  appears  as  a  constant,  and  with  (8)  it 
appears  to  only  show  maxima  between  very  narrow  limits  of 
density.  This  subject  is  now  under  consideration  with  improved 
coefficients.  It  is  known  that  Cv  increases  with  increase  of 
density  with  all  gases,  excepting  hydrogen,  which  have  been 
tried.  In  the  case  of  hydrogen  it  decreases,  and  hence,  as  the 
reduced  temperature  of  hydrogen  at  ordinary  experimental 
temperatures  is  much  higher  than  that  attainable  with  the  other 
permanent  gases  which  were  tried,  one  is  naturally  led  to  the 
supposition  that  the  maximum  value  will  occur  for  hydrogen 
at  some  lower  temperature  with  moderate  pressures. 

The  maximum  value  of  Cv  appears   to  increase  with   the 
density,  so  that  at  very  high  pressures  it  is  possible  that  the 


52  SCIENCE   PROGRESS 

change  with  hydrogen  would  be  the  same  as  with  other  gases. 
If  these  conclusions  are  correct  the  results  should  be  intensified 
in  the  case  of  helium,  which  has  a  much  lower  critical  tempera- 
ture and  pressure. 

It  appears  to  be  probable  also  that  at  temperatures  below  the 
critical  Cp  —  Cv  may  be  negative,  in  which  case  K  =  Cp/Cv  would 
further  be  less  than  unity.  If  this  should  be  substantiated  by 
investigation  it  will  throw  some  doubt  upon  the  deductions 
which  are  customarily  made  about  the  connection  between  k 
and  the  total  and  external  energy  of  the  molecule.  Certainly 
the  main  conclusions  are  justified,  and  the  deduction  that  k  would 
have  its  maximum  value  with  monatomic  molecules  has  been 
abundantly  demonstrated,  first  with  mercury  vapour  and  subse- 
quently with  the  gases  of  the  argon  group,  where  the  experi- 
mental results  all  show  values  differing  very  little  from  5/3.  In 
the  liquid  state  the  molecular  heat  of  mercury  is  about  67 
and  in  the  solid  64,  which  would  appear  to  indicate  that  even 
in  the  solid  state  it  is  monatomic,  as  this  value  coincides  with 
the  general  value  of  the  atomic  heat  of  solid  elements. 

However,  the  elements  with  simple  molecules  in  the  gaseous 
state  are  still  very  little  studied  in  the  liquid  and  solid  states, 
partly  owing  to  the  low  temperatures  at  which  they  would  have 
to  be  observed  and  partly  because  the  importance  of  these 
measurements  is  not  very  generally  recognised  except  among 
those  who  are  fully  occupied  with  these  and  similar  questions. 
There  are  three  separate  lines  of  experimental  research  which 
are  all  very  fruitful  and  which  are  at  present  only  connected 
together  in  a  very  imperfect  way  theoretically  owing  to  the 
want  of  sufficient  data.  The  accurate  study  of  isothermals, 
which  is  the  absolutely  necessary  foundation  for  an  advance 
in  the  theory  of  coincident  condition,  and  the  possibility  of 
arriving  at  a  generally  applicable  equation  of  state  can  receive 
most  important  assistance  from  the  study  of  the  Joule-Kelvin 
effect  and  the  specific  heats.  It  must,  however,  be  emphasised 
that  the  preliminary  and  pioneer  stages  are  past,  and  that  unless 
measurements  are  exact  they  have  really  very  little  value  or  are 
actually  harmful  because  they  form  the  basis  of  false  con- 
clusions. 

In  isothermal  work  it  is  possible  at  about  the  ordinary  tem- 
perature to  arrive  at  an  accuracy  of  about  0*02  per  cent,  mean 
error  in  the  determinations.     As  lower  temperatures  are  used, 


TEMPERATURE  AND  THE  PROPERTIES  OF  GASES  53 

not  only  does  the  proportional  error  become  of  more  importance, 
but  at  the  same  time  the  difficulties  become  greater.  It  may 
hence  be  said  that  an  accuracy  of  o*i  per  cent,  is  about  the  limit  of 
usefulness  in  isothermal  determinations  even  at  very  low  tem- 
peratures. Such  accuracies  can  now  be  attained  at  the  tempera- 
ture of  boiling  hydrogen  and  should  be  attainable  even  in 
boiling  helium,  so  that  the  properties  of  helium  as  a  gas  and 
everything  else  as  a  solid  can  be  investigated  at  very  nearly  the 
absolute  zero,  that  is,  at  and  about  50  K. 

At  any  temperature  where  the  system  of  isotherms  is  ac- 
curately known  it  should  not  be  difficult  to  determine  experi- 
mentally both  BCv/8v  and  hCpjhp  by  enclosing  the  gas  in  a 
comparatively  athermanous  envelope  and  causing  a  small  change 
of  temperature  by  electrical  means  in  the  gas,  keeping  this  at 
one  time  at  constant  volume  and  at  another  at  constant 
pressure.  The  energy,  and  therefore  heat,  absorbed  would  be 
known,  so  that  all  the  data  would  be  present  to  calculate  the 
above  values  by  starting  with  volumes  or  pressures  which 
were  increased  by  a  small  proportion.  The  isothermals  would 
only  be  required  for  correction  to  standard  value  and  the 
results  would  be  much  more  accurate  than  any  deductions 
from  the  isotherms  themselves,  as  these  involve  the  second 
differential  coefficients  with  the  temperature  (see  15).  It 
would  be  necessary  to  have  the  thermometer  in  the  gas,  which 
might  introduce  some  difficulty  in  the  construction ;  or,  if  the 
isothermals  were  sufficiently  accurately  known,  the  temperature 
change  could  be  deduced  from  the  changes  in  p  or  v  when  the 
other  variable  was  kept  constant. 

From  what  has  been  said  it  will  be  seen  that  the  subject  has 
reached  a  stage  at  which  it  is  clear  that  much  new  light  cannot 
be  obtained  without  either  many  accurate  data  or  some  unlooked- 
for  discovery.  To  obtain  the  former,  lengthy  experiments  with 
complicated  apparatus  are  necessary,  but  the  results  would  well 
repay  the  labour,  if  such  labour  were  possible.  However,  in 
spite  of  the  growing  importance  of  the  subject  from  every  point 
of  view,  it  is  strictly  true  that  there  is  only  one  place  in  this 
country  where  such  measurements  are  at  all  possible,  although 
they  form  the  only  real  foundation  of  a  kinetic  theor}'  of  matter 
and  its  connection  with  practical  thermodynamics. 


LENARD'S    RESEARCHES    ON 
PHOSPHORESCENCE 

By  E.  N.  DA  C.  ANDRADE,  B.Sc,  Ph.D. 

In  the  following  pages  a  brief  account  is  given  of  the  chief 
phenomena  of  phosphorescence  known  in  E.  Becquerel's  time 
together  with  a  description  of  the  more  recent  work  of  Lenard 
and  his  co-workers,  whose  labours  have  contributed  largely  to 
the  solution  of  the  problems  underlying  the  emission  of  light 
by  the  atom  or  molecule. 

When  ordinary  bodies  are  heated,  they  begin  to  emit  visible 
light  at  a  definite  temperature,  which  is  the  same  whatever  the 
substance  may  be  (about  5000  C.) ;  it  is  to  such  radiation,  due 
to  temperature  alone  and  usually  referred  to  as  temperature 
radiation,  that  KirchofPs  law  applies,  though  W.  Wien  {Nobel- 
Vortrag,  191 1,  p.  5)  imagines  that  it  may  be  possible  to  extend 
the  law  to  other  radiations  by  an  extension  of  the  conception 
of  temperature  ;  he  admits,  however,  that  at  present  it  is  impos- 
sible to  state  how,  for  example,  a  phosphorescent  body  can 
fall  into  equilibrium  with  the  radiation.  In  certain  cases  light 
may  be  emitted  at  a  temperature  far  below  that  at  which 
temperature  radiation  sets  in  ;  such  cases  are  classed  together 
as  luminescence  phenomena  ;  these  are  variously  grouped  under 
the  headings  triboluminescence,  lyoluminescence,  crystallo- 
luminescence,  chemical  luminescence  and  phosphorescence, 
fluorescence  and  thermoluminescence.  The  first  three  names 
are  given  respectively  to  the  emission  of  light  which  takes 
place  on  rubbing  or  breaking  certain  substances  (a  well-known 
case  being  that  of  sugar),  to  the  emission  of  light  observed 
when  certain  solid  substances  are  dissolved,  and  to  the  emission 
of  light  attending  the  crystallisation  of  salts — for  instance, 
sodium  or  potassium  sulphate.  It  is  probable  that  the  two 
latter  cases  are  only  examples  of  triboluminescence,  the  light 
being  attributable  to  the  friction  and  breaking  of  the  crystals 
which  take  place  on  dissolution  and  crystallisation  :  apparently 

54 


LENARD'S  RESEARCHES  ON  PHOSPHORESCENCE  55 

the  bodies  which  exhibit  the  phenomena  in  question  are  all 
triboluminescent.1  Chemical  luminescence  is  the  form  of 
luminosity  accompanying  certain  chemical  actions,  such  as  slow 
oxidations  :  the  so-called  "  phosphorescence  "  of  phosphorus  and 
of  putrefying  organic  matter  are  cases  in  point. 

The  term  phosphorescence  is  properly  applied  to  the  power 
which  many  bodies  possess  of  emitting  light  after  excitation 
by  radiations.  This  excitation  can  be  effected  not  only  by  visible 
and  invisible  (ultra-violet)  light  but  also  by  cathode  and  canal 
rays  and  by  Rontgen  rays ;  irradiation  of  some  kind  is  neces- 
sary, however,  in  all  cases  of  true  phosphorescence. 

In  phosphorescence,  the   emission   of  light  continues  after 
the  exciting  radiations  have  ceased  ;   if  the  emission  does  not 
persist  during  a   measurable   time   the   phenomenon  is  termed 
fluorescence.      In  the  case  of  solids  there  is  no  true  fluorescence, 
although  the  term  is  often  used  in  speaking  of  the  phosphores- 
cence of  very  short  duration  which  is  exhibited  by  many  solids  : 
in  the  case  of  gases  and  liquids  the  duration  of  the  period  of 
after-glow  is  inappreciable  and  we  may  speak  of  fluorescence. 
But  there  is  little  point   in   attempting  to   distinguish    rigidly 
between  the  two  terms,  though  it  is  possible  that  more  refined 
measurement  would  show  a  very  short  after-glow  even  in  the 
case  of  gases.    Thermoluminescence,  so-called  by  E.  Wiedemann, 
who  first  observed  it,  is  the  property  of  selective  light-emission 
which  certain  artificial  substances  exhibit  on  being  heated   to 
a   temperature    far    below  that   which   conditions   temperature 
radiation  ;   it  is  necessary  to   excite   the    substance  previously 
by  certain  radiations,  which  do  not,  however,  cause  the  emission 
of  light  at  ordinary  temperatures.      This  is  only  a  particular 
case  of  phosphorescence,  the  exciting  energy  being  stored  at 
the   lower   temperature  and  only  liberated  as  the  transformed 
radiation  at  the  higher  :  all  the  phosphoroids — as  we    shall  in 
future   call    phosphorescent  solids — prepared    by    Lenard  can 
be  caused  to  show  such  a  storage  of  energy.     Hence  we  shall 
include  the  so-called  fluorescence  of  solids  and  thermolumines- 
cence under  the  general  term  phosphorescence. 

Some  of  the  first  observations  of  true  phosphorescence 
seem  to  have  been  made  on  gems  :  for  instance,  Boyle  and 
afterwards    Wolf   observed    the    phenomenon   in   the  case    of 

1  See  Kayser,  Handbuch  der  Spektroscopie,  p.  678,  where  a  detailed  account  of 
the  results  of  various  experimenters  will  be  found. 


56  SCIENCE  PROGRESS 

diamonds,  which  are  really  phosphorescent l ;  and  subsequently 
Dufay  showed  that  a  fresh  exposure  to  light  would  again  render 
the  stone  and  other  phosphoroids  phosphorescent  after  their 
power  of  emitting  light  had  been  destroyed  by  heating.  The 
first  artificial  phosphoroid  was  prepared  by  Peter  of  Bologna, 
the  "Bologna  stone"  (about  1602).  This  is  barium  sulphide 
containing  traces  of  foreign  metals,  which,  as  we  shall  see  later, 
are  essential  for  the  phosphorescence.  With  the  aid  of  this 
phosphoroid  Zanotti,  using  the  solar  spectrum,  established  the 
important  fact  that  the  colour  of  the  emitted  phosphorescent 
light  is  independent  of  the  colour  of  the  exciting  light ;  Dufay, 
using  coloured  glasses,  established  the  same  fact  for  diamonds 
and,  as  already  stated,  recognised  that,  in  the  case  of  phosphores- 
cence consequent  on  heating,  a  previous  excitation  was  necessary. 
Later  on  Wilson  showed  that  a  great  number  of  phosphorescent 
shells  each  emitted  light  of  a  fixed  colour,  whatever  the  colour 
of  the  exciting  light.  The  next  fundamental  observation,  that 
the  red  and  infra-red  rays  extinguish  a  glowing  phosphoroid — 
i.e.  cause  the  parts  on  which  they  fall  to  lose  their  luminosity 
much  faster  than  the  other  parts — was  first  made  at  the  begin- 
ning of  the  nineteenth  century  by  Ritter,  though  the  first  easily 
accessible  reference  is  to  be  found  in  the  poet  Goethe's  scientific 
works  (Farbenlehre,  §  678).  This  phenomenon  was  rediscovered 
by  E.  Becquerel,  who  noticed  also  that  when  infra-red  light  was 
first  thrown  on  the  phosphoroid  a  momentary  increased  lumino- 
sity was  noticeable,  which  was  followed  by  the  rapid  decay  of 
intensity  just  mentioned,  so  that  the  parts  of  a  phosphorescent 
sheet  struck  by  infra-red  radiations  first  become  brighter  than 
the  other  parts  but  soon  afterwards  become  much  darker.  He 
observed  that  the  effect  of  light  was  similar  to  that  produced 
by  directly  heating  the  phosphoroid  and  used  these  properties 
in  investigating  the  infra-red  solar  spectrum.  He  also  made 
an  extensive  series  of  observations  on  the  spectra  of  phos- 
phorescent  substances   by  throwing  a  spectrum  on   to   plates 

1  It  was  generally  thought  by  the  ancients  and  in  mediaeval  times — Pliny, 
Solinus,  Isidor  of  Seville— that  the  ruby  and  carbuncle  shone  in  the  dark  ;  though 
no  phosphorescence  of  any  duration  is  obvious  in  the  case  of  these  stones,  the 
ruby  shows  the  phosphorescence  of  very  short  duration  usually  called  fluorescence  ; 
in  fact,  the  genuineness  of  the  stone  may  be  tested  by  exposing  it  to  blue  light, 
when  the  true  ruby— which  may,  however,  be  synthetic— emits  red  light  ;  a  paste 
imitation  only  reflects  the  blue. 


LENARD'S  RESEARCHES  ON  PHOSPHORESCENCE  57 

covered  with  the  powdered  phosphors  and  observing  the 
luminosity  produced  in  various  parts  of  the  spectrum ;  he 
found,  as  previous  observers  had  done,  that  the  nature  of  the 
emitted  light  was  independent  of  the  wave-length  of  the 
exciting  light.  Becquerel  also  made  important  observations  on 
the  temperature  effects  and  the  law  of  decay  of  the  phosphores- 
cent light  with  time  which  will  be  dealt  with  later  on ;  by 
systematically  using  the  spectroscope  in  this  work  he  placed 
the  study  of  the  whole  question  on  a  new  footing.  But  he  did 
not  put  forward  any  general  theory  of  phosphorescence. 

At  this  time,  the  latter  half  of  the  nineteenth  century,  one 
of  the  chief  obstacles  in  the  way  of  the  study  of  the  subject  was 
the  difficulty  of  preparing  artificial  phosphoroids  which  would 
behave  in  a  definite  way :  for  instance,  calcium  sulphide  could 
be  prepared  so  that  it  would  phosphoresce  either  yellow  or 
green.  A  first  step  in  the  direction  of  a  solution  of  this  problem 
was  made  by  Lecoq  de  Boisbaudran,  who  showed  that  certain 
substances,  which  did  not  phosphoresce  in  the  cathode  rays 
when  pure,  were  rendered  phosphorescent  by  the  addition  of 
traces  of  foreign  metals ;  that,  for  instance,  the  luminosity 
of  many  substances  was  due  to  traces  of  manganese.  About 
this  time,  Crookes,  working  on  the  rare  earths,  showed  that 
their  presence,  for  example  in  salts  of  calcium,  gave  rise  to 
definite  phosphorescence  spectra  under  the  influence  of  cathode 
rays ;  both  he  and  Lecoq  de  Boisbaudran  did  much  work  on 
these  phosphorescent  spectra.  Verneuil  traced  the  phos- 
phorescence of  calcium  sulphide  to  the  presence  of  traces  of 
bismuth.  It  is  at  this  point  that  the  researches  of  Lenard 
begin,  to  whose  work  I  shall  now  devote  special  attention. 

Lenard,  in  conjunction  with  Klatt,  first  stated  in  detail  the 
conditions  to  be  observed  in  preparing  phosphoroids  from  the 
alkaline  earths  and  systematically  prepared  a  large  number  of 
substances  of  this  class,  which  includes  nearly  all  those  which 
remain  luminous  during  a  considerable  period  after  the  exciting 
light  has  ceased  ;  a  form  of  luminosity  which  it  is  convenient  to 
call  the  after-glow.  Three  components  are  necessary :  the 
sulphide  of  an  alkaline  metal ;  a  small  quantity — generally  less 
than  a  ten-thousandth  of  the  whole — of  a  foreign  metal ;  and 
a  fusible  component  or  flux.  The  action  of  the  flux,  which 
may  be  any  one  of  a  large  number  of  colourless  fusible  salts, 
sodium  sulphate  for  instance,  is  principally  to  bind  the  loose 


58  SCIENCE  PROGRESS 

mass  together ;  it  has  also  an  influence  on  the  intensity  of 
the  emitted  light  which  will  be  further  referred  to. 

The  specific  character  of  the  phosphorescent  light  is  de- 
pendent on  the  presence  and  nature  of  the  traces  of  foreign  metal. 
Lenard  and  Klatt  were  able  to  attribute  the  phosphorescence  of 
calcium  sulphide  previously  investigated  by  Lommel  definitely 
to  traces  of  particular  metals.  To  each  metal  corresponds  a 
series  of  emission  bands,  the  phosphorescent  light  being  always 
resolved  by  the  spectroscope  into  bands  having  a  maximum  of 
intensit}'  at  a  given  wave-length  fading  off  into  darkness  on 
both  sides  of  this  maximum.  The  bands  are  referred  to  by  the 
wave-length  at  which  they  have  their  maximum  intensity  ;  and 
uncertainty  as  to  the  identity  of  a  given  band,  which  might  arise 
in  the  discussion  of  the  displacement  of  a  band  by  influences  to 
be  mentioned  later,  is  avoided  by  the  definition  of  a  band  as  a 
complex  of  emitted  wave-lengths  which  possess  common 
properties  in  respect  of  temperature,  excitation  by  light  of  a 
particular  wave-length,  and  rate  of  decay  after  the  exciting  light 
has  been  cut  off.  These  tests  also  serve  to  separate  superposed 
bands.  The  spectral  position  of  the  bands  is  peculiar  to  the 
given  active  metal,  but  their  intensity  and  period  of  decay 
depend  to  some  extent  on  the  fusible  component.  A  pure 
phosphoroid  is  defined  as  consisting  of  one  alkaline  sulphide 
together  with  traces  of  an  active  foreign  metal  and  a  flux.  The 
pure  sulphides  do  not  phosphoresce,  but  an  addition  of  o'oo2  per 
cent,  of  bismuth  will  render  barium  sulphide  strongly  phos- 
phorescent. The  colour  of  the  phosphorescent  light  varies 
markedly  with  the  temperature  of  the  phosphoroid,  the  shade 
obvious  to  the  naked  eye  being  made  up  of  different  bands 
which  all  vary  in  intensity  independently  of  one  another  with 
temperature.  In  the  case  of  each  phosphoroid,  there  is  a 
temperature  above  which  it  cannot  be  excited,  but  there  seems 
to  be  no  lower  limit  in  this  respect. 

The  investigation  of  phosphorescence  has  been  greatly 
facilitated  by  Lenard's  method  of  plotting  the  distribution  of 
the  exciting  and  excited  light  in  the  spectrum.  As  long  as  the 
phosphorescent  glow  was  treated  as  a  whole,  the  complexity 
of  the  observed  phenomena  baffled  interpretation,  but  the 
behaviour  of  the  individual  bands  is  not  so  incomprehensible. 
To  observe  the  distribution  of  excitation,  in  other  words,  the 
relation  between  the  wave-length  of  the  exciting  light  and  the 


LENARD'S  RESEARCHES  ON  PHOSPHORESCENCE  59 


intensity  of  the  incited  light,  a  spectrum  is  allowed  to  fall  upon 
a  screen  covered  with  the  given  phosphoroid,  the  exciting  light 
from  a  Nernst  lamp  or  mercury  vapour  lamp  being  passed 
through  a  quartz  prism  in  order  to  obtain  the  ultra-violet 
portion  strong  and  well  dispersed.  The  parts  of  the  spectrum 
which  are  most  effective  in  exciting  the  phosphorescent  light 
were  then  at  once  observable.  On  examining  the  incited  light 
through  a  prism,  using  the  method  of  crossed  spectra,  it  is 
resolved  into  its  component  bands,  the  relative  intensity  of  the 
different  parts  of  which  can  be  estimated.  Stokes's  law,  that 
the  incited  light  is  of  longer  wave-length  than  the  exciting  light, 
is  always  obeyed  by  phosphoroids.      As  a  first  result  of  this 


Co.  L-u    ci 

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method,  it  appeared  that  to  each  band  ol  emitted  light 
correspond  definite  ranges  of  wave-lengths  which  are  capable 
of  exciting  it ;  these  selective  groups  of  wave-lengths  will  be 
referred  to  as  the  exciting  spectrum.  The  composition  of  this 
spectrum  depends  only  on  the  nature  of  the  active  metal  and  of 
the  alkaline  sulphide.  Further,  there  are  no  bands  common  to 
different  metals,  either  of  excitation  or  emission.  In  fig.  1  the 
spectral  distribution  of  the  exciting  and  incited  light  is  set  out 
according  to  Lenard's  method  in  the  case^  of  the  two  phos- 
phoroids calcium  sulphide  containing  copper  as  the  active 
metal  denoted  by  CaCu  and  strontium  sulphide  containing 
copper  denoted  by  SrCu.  The  sharp  unshaded  curves  indicate 
the  distribution  of  the  exciting  light,  the  abscissae  representing 
the  wave-length  of  the  light,  the  ordinates  the  efficiency  of  each 


60  SCIENCE  PROGRESS 

wave-length  in  exciting  the  particular  band  of  phosphorescent 
light  in  question — that  is  to  say,  the  intensity  of  the  incited 
light.  The  distribution  of  the  intensity  of  the  incited  light 
according  to  wave-length  is  represented  by  the  shaded  curves. 
The  first  phosphoroid  gives  three  bands  of  emitted  light;  these  are 
represented  separately,  as  there  is  a  different  exciting  spectrum 
corresponding  to  each  band ;  the  three  spectra  are  denoted 
by  a,  /8,  7.  The  second  has  two  bands,  a  and  #,  represented  in 
the  same  manner.  It  will  be  observed  that  the  bands  are  best 
excited  by  very  narrow  groups  of  wave-lengths  and  that  in 
general  more  than  one  exciting  band — usually  three — corre- 
spond to  each  band  of  emitted  light.  The  dotted  curve  gives 
the  distribution  of  exciting  light  corresponding  to  the  momentary 
process,  to  be  referred  to  subsequently.  The  intensities  of  the 
different  bands  in  the  diagram  are  not  drawn  to  scale,  but  they 
are  all  represented  as  having  the  same  maximum  intensity ;  this 
is  done  because,  though  all  the  bands  have  perfectly  definite 
spectral  positions,  their  relative  intensities  vary  with  the  fusible 
component,  the  temperature  and  the  manner  in  which  the 
phosphoroid  is  prepared.  Hence  such  a  diagram  can  only  give 
the  general  course,  the  position  of  the  maximum  intensity,  and 
the  range  of  each  band. 

The  behaviour  of  a  band  with  regard  to  temperature  is  such 
that  it  is  possible  to  discriminate  between  three  different  states 
of  the  phosphoroid.  In  the  coldest  state,  which  Lenard  calls 
the  lower  momentary  state,  each  particular  band  rapidly  reaches 
its  maximum  intensity  when  incited,  and  on  the  cessation  of  the 
exciting  light  as  rapidly  decays — it  being  a  general  rule  that 
a  band  which  is  easily  incited  dies  out  quickly,  and  that  one 
which  is  slowly  incited  dies  out  slowly.  The  light  emitted 
at  this  stage  is  often  very  feeble,  sometimes  not  noticeable  ;  as 
the  temperature  of  the  phosphoroid  is  raised,  the  second  or 
"  resting"  state  is  reached,  in  which  light  energy  is  both  emitted 
and  at  the  same  time  stored  up ;  when  the  exciting  illumination 
is  cut  off,  the  stored-up  energy  is  liberated  as  the  after-glow,  the 
intensity  of  the  bands  gradually  diminishing  with  time.  On 
raising  the  temperature  still  further  the  third  temperature  state, 
the  upper  momentary  state,  is  reached,  in  which,  as  in  the  lower 
state,  there  is  no  after-glow,  but  a  rapid  excitation  followed  by 
a  rapid  emission  of  light.  It  is  necessary,  however,  to  dis- 
tinguish clearly  between  the  upper  and  the  lower  momentary 


LENARD'S  RESEARCHES  ON  PHOSPHORESCENCE  61 

states.  In  the  lower  state,  besides  the  rapid  emission,  which  is 
usually  feeble,  there  is  always  an  invisible  storage  of  light- 
energy  proceeding  simultaneously,  the  which  energy  is  liberated 
as  a  strong  after-glow  when  the  temperature  of  the  phosphoroid 
is  raised  to  that  of  the  permanent  state  without  subjecting  it  to 
further  excitation.  The  energy  thus  stored  in  the  lower  state, 
which  does  not  give  rise  to  any  luminosity  so  long  as  the 
temperature  is  below  that  of  the  permanent  state,  can  be  pre- 
served during  an  extraordinarily  long  time,  extending  into 
months.  The  bands  which  appear  at  a  given  temperature  are 
those  which  are  permanent  bands  at  that  temperature.  All 
luminosities  which  were  observed  by  early  experimenters  to 
appear  in  phosphoroids  on  heating  were  due  to  energy  having 
been  stored  in  this  way  in  the  cold  state  of  the  given  substance : 
after  they  had  once  been  made  luminous  by  warming,  a  fresh 
excitation  was  necessary  before  luminosity  could  be  again  so 
produced.  Thus  heat  cannot  act  as  an  exciter  of  phosphorescence, 
but  only  as  a  liberator  of  light-energy  already  supplied  and 
stored  during  the  lower  momentary  state.  During  the  upper 
momentary  state,  there  is,  however,  no  storage  of  energy.  The 
two  momentary  states  constitute  what  is  sometimes  referred  to 
as  fluorescence,  but,  as  already  stated,  it  is  proposed  to  restrict 
this  term  to  gases  and  liquids  in  which  the  duration  of  the  after- 
glow is  at  least  so  short  that  it  has  never  been  measured. 

Besides  the  two  momentary  and  the  permanent  state,  there 
is  a  fourth  process  of  lesser  importance,  on  which  not  much 
work  has  been  done,  to  which  only  passing  reference  can  be 
made.  Lenard  found  that  the  shorter  ultra-violet  rays  can 
excite  a  luminosity  of  medium  duration  falling  between  that 
of  the  momentary  and  the  permanent  state  ;  it  is  most  intense  in 
the  extreme  ultra-violet,  and  gradually  grows  fainter  with  in- 
creasing wave-length,  becoming  unnoticeable  in  the  visible  violet. 
This  form  of  incitation  he  called  the  ultra-violet  process ;  it  is  of 
account  only  if  the  exciting  light  be  of  very  short  wave-length. 
It  has  not  the  definite  excitation  distribution  of  the  other 
processes,  but  seems  to  be  more  nearly  allied  to  the  permanent 
than  to  the  momentary  states. 

In  Lenard's  researches  in  conjunction  with  Pauli  and  Kam- 
merlingh  Onnes  at  low  temperatures,  and  subsequent  work  with 
improved  apparatus,  the  fact  has  been  clearly  established  that 
there  are  different  exciting  spectra  corresponding  to  the  momen- 


62  SCIENCE  PROGRESS 

tary  and  permanent  bands.  These  regions  of  exciting  wave- 
length for  the  two  phases  largely  overlap,  so  that  in  general  a 
given  wave-length  may  induce  both  processes  simultaneously ; 
but  some  of  the  shorter  wave-lengths  of  the  exciting  light  induce 
only  the  momentary,  some  of  the  longer  only  the  permanent 
process.  In  fig.  i  the  exciting  spectrum  corresponding  to  the 
momentary  process  is  indicated  by  the  broken  line.  Thus  in 
the  permanent  state  the  energy  is  at  the  same  time  in  part  stored 
and  in  part  used  for  the  immediate  emission  of  transformed 
radiation  ;  but,  while  that  of  some  wave-lengths  is  used  for  both 
processes,  certain  small  spectral  regions  are  only  available  for  the 
one  process,  certain  other  regions  only  for  the  other.  By  going 
to  a  low  enough  temperature,  the  three  states  have  been  observed 
in  all  phosphoroids.  Each  band  stores  its  own  energy,  as  can  be 
found  by  observing  the  exciting  spectrum  in  the  lower  state. 

As  regards  the  exciting  spectrum,  the  character  of  this  for 
the  momentary  is  somewhat  different  from  that  for  the  per- 
manent state,  as  can  be  seen  in  the  figure.  The  distribution,  in 
the  case  of  the  latter,  consists  of  well-defined  bands,  there  being 
in  general  more  than  one  exciting  band  corresponding  to  each 
emission  band.  The  most  frequent  case  is  that  of  three  sharp, 
nearly  equal  maxima  of  exciting  intensity  separated  by  regions 
in  which  the  light  produces  no  permanent  glow.  The  distribu- 
tion in  the  case  of  the  momentary  bands  is  not  nearly  so  sharp  ; 
there  is  only  one  band  of  exciting  light  corresponding  to  each 
emission  band,  and  this  is  ill-defined  and  lies  largely  in  the 
ultra-violet :  the  position  of  the  less  refrangible  edge  of  the 
band  is  characteristic  of  that  band,  however. 

The  theory  which  Lenard  has  developed  to  explain  the 
properties  of  the  bands  just  described— for  the  bands  are  the 
fundamental  things — attributes  the  phenomena  to  a  photo- 
electric action  *  of  the  light,  which  liberates  electrons  from  the 
metallic  atoms  in  the  "  centres "  from  which  the  emission  of 
light  proceeds  present  in  all  phosphorescent  substances.  These 
centres  are  complex  molecules  having  as  essential  components 
an  atom  of  the  active  metal,  together  with  the  alkali  metal  and 
sulphur,  and  they  are  distributed  singly  and  separately  through- 
out the  mass  of  inactive  material  which  forms  the  bulk  of  the 

1  The  liberation  of  negative  electricity — electrons — which  takes  place  when 
light  of  short  wave-length  falls  upon  metals  and  many  other  substances  is  called 
the  photo-electric  effect. 


LENARD'S  RESEARCHES  ON  PHOSPHORESCENCE  63 

phosphoroid.  They  must  be  fibrous  in  structure  in  different 
directions,  as  the  phosphorescence  is  destroyed  by  crushing  the 
phosphoroid.  To  each  emission  band  must  correspond  one 
kind  of  centre,  the  various  kinds  functioning  independently  of 
one  another  ;  as  a  pure  phosphoroid  usually  shows  more  than 
one  band,  the  same  active  metal  and  alkaline  sulphide  must 
be  capable  of  forming  different  kinds  of  centre.  Again,  a  single 
band  in  a  pure  phosphoroid  has  often  three  definite  correspond- 
ing bands  in  the  exciting  spectrum  of  the  permanent  phase 
{i.e.  three  wave-lengths  particularly  capable  of  exciting  it),  so 
that  there  must  be  secondary  differences  among  the  centres 
which  emit  one  band,  enabling  them  to  resonate  to  different 
exciting  wave-lengths.  Furthermore,  each  centre  must  be 
capable  of  three  periods  of  oscillation,  namely  those  corre- 
sponding to  the  emission,  the  excitation,  and  the  extinction 
by  the  action  of  infra-red  light  to  which  reference  has  been 
made  in  the  introduction,  of  which  details  are  given  later. 
The  centres  which  Lenard  hypothecates  to  satisfy  these  con- 
ditions are  of  two  kinds,  the  "  momentary"  and  the  "  permanent " 
centres.  The  permanent  centres  are  systems  consisting  of  atoms 
of  the  active  metal,  the  alkali  metal  and  sulphur  (say  Cax  Cuy  Sz, 
x,  y,  z  being  whole  numbers)  so  arranged  that  both  the  metals 
are  held  by  the  valency  bands  of  the  sulphur  atom,  the  difference 
between  the  various  emission  bands  which  are  given  by  a  pure 
phosphoroid  being  conditioned  by  the  number  of  valencies  of  the 
active  metallic  atom  by  which  the  connection  with  the  sulphur 
atom  is  effected.  In  support  of  this  view  we  have  the  fact  that 
the  number  of  bands  is  never  greater  than  the  number  of  valencies 
of  the  active  metal,  and  that  the  different  bands  have  widely 
different  intensities,  corresponding  to  a  greater  facility  of  forma- 
tion of  certain  bondages  such  as  is  to  be  expected.  The  different 
excitation  bands  may  correspond  to  different  space  arrangements 
of  the  metallic  atom  with  respect  to  the  sulphur  atom. 

The   permanent   process   is   most   marked   in   phosphoroids 
containing   sulphur,1  and   hence   the    assumption  is    made  that 

1  Hirsch  (Heidelberg  Dissertation,  1912)  has  recently  prepared  phosphoroids  of 
moderate  duration  which  do  not  contain  sulphur,  an  oxide  or  carbonate  of  the 
alkali  metal  being  substituted  for  the  sulphide  ;  these  have  not  been  much  studied, 
but  show  that  sulphur  is  not  absolutely  necessary  for  the  production  of  permanent 
bands.  Phosphoroids  without  sulphur  had,  of  course,  been  previously  prepared, 
notably  by  Crookes,  Lecoq  de  Boisbaudran,  and  Goldstein. 


64  SCIENCE  PROGRESS 

in  these  phosphoroids  the  sulphur  atom  is  responsible  for  the 
storage  of  the  light  energy ;  correspondingly  the  momentary 
centres  would  seem  to  be  free  from  sulphur.  In  these,  oxygen 
may  very  well  take  the  place  of  sulphur,  as  oxides  containing 
traces  of  active  metal  were  long  ago  shown  by  Lecoq  de 
Boisbaudran  and  Crookes  to  give  a  phosphorescence  of  short 
duration. 

On  Lenard's  theory  the  light  is  emitted  by  the  atom  of 
active  metal  on  the  return  of  an  electron  previously  photo- 
electrically  liberated  by  the  exciting  light.  In  the  unexcited 
state,  the  atom  possesses  its  normal  complement  of  electrons; 
in  the  excited  state  all  the  electrons  which  can  be  liberated 
from  the  atom  by  the  action  of  light  or  cathode  rays  escape 
from  it  to  other  parts  of  the  centre ;  whilst  the  intermediate 
condition,  in  which  the  electrons  return  to  the  atom,  is  the 
occasion  of  the  light-emissions.  In  the  excited  state,  the 
escaping  electrons  are  probably  stored  in  the  sulphur  atom  in 
the  case  of  the  sulphide  phosphoroids. 

The  broad  bands  of  which  the  emitted  light  is  made  up  are 
formed  by  the  superposition  of  spectral  lines  of  varying  position, 
as  it  may  be  supposed  that  the  period  of  the  emitted  light  will 
vary  within  limits,  both  from  centre  to  centre  and  from  time  to 
time  in  the  same  centre,  in  consequence  of  the  variation  in  the 
immediate  surroundings  of  the  different  centres  in  amorphous 
substances  and  the  molecular  agitation.  In  support  of  this 
view,  it  has  been  observed  that  on  decreasing  the  molecular 
movements  by  lowering  the  temperature  of  the  phosphoroid, 
the  bands  become  much  narrower.  By  cooling  with  liquid 
and  solid  hydrogen — to  about  140  absolute — Lenard  and  his 
collaborators  have  succeeded  in  getting  the  bands  very  sharp  : 
they  still  remained  bands,  however,  whose  intensity  would  not 
support  a  strong  dispersion.  A  line  spectrum  could,  perhaps, 
hardly  be  expected  even  at  these  low  temperatures  in  amorphous 
substances,  owing  to  the  above-mentioned  local  variations  in 
the  arrangement  of  the  molecules  surrounding  the  centres ; 
there  seems  more  likelihood  of  such  an  emission  spectrum  in 
crystalline  substances.  The  influence  of  the  immediate  sur- 
roundings of  the  centres  on  the  period  of  the  light  emitted 
by  them  has  been  beautifully  demonstrated  in  Lenard's  experi- 
ments on  the  spectral  position  of  a  given  emission  band  in 
phosphoroids  made  with  sulphides  of  the  different  alkali  metals. 


LENARD'S  RESEARCHES  ON  PHOSPHORESCENCE  65 

For  if  similar  phosphoroids  be  prepared  with  the  same  active 
metal,  but  with  different  sulphides  as  bases,  we  get,  passing 
from  one  to  the  other,  a  series  of  bands  which  are  in  every  way 
analogous  to  one  another,  but  having  maxima  which  are  dis- 
placed relatively  in  such  a  manner  that  the  wave-lengths  of  the 
band  maximum,  divided  by  the  square-root  of  the  specific 
inductive  capacity  of  the  phosphoroid,  gives  a  number  which 
is  roughly  constant  in  all  the  phosphoroids.  But  this  is  what 
theory  says  would  be  the  case  for  a  Hertzian  ^electro-magnetic 
oscillator  vibrating  in  media  of  different  inductive  capacities,  so 
that  it  is  to  be  inferred  that  the  electron  which  causes  the 
emission  of  the  light  vibrates  in  and  has  its  period  controlled 
by  the  nature  of  the  immediate  surroundings  of  the  atom  to 
which  it  belongs.  This  leads  to  the  assumption  that  the  forces 
which  bind  the  photo-electric  electron  to  its  atom  extend  out 
so  far  into  the  surroundings  of  the  atom  that  the  mean  com- 
position of  these  controls  its  period ;  or  it  may  be  supposed 
that  the  electron  moves  on  the  surface  of  the  atom  and,  in  the 
oscillations  which  it  performs  on  its  return,  swings  outside  the 
atom  while  stimulating  the  emission  of  light  from  it— that  is  to  say, 
from  other  electrons  contained  in  it.  This  picture  is  supported 
by  the  results  of  other  experiments  on  the  photo-electric  effect. 

Very  strong  confirmation  of  this  view,  which  attributes  the 
phosphorescence  to  the  photo-electric  action  of  the  light  on 
the  atoms  of  active  metal  in  certain  "  centres "  within  the 
phosphoroid,  has  been  obtained  in  direct  experiment  on  the 
photo-electric  effect  in  phosphoroid,  performed  by  Lenard  in 
collaboration  with  Saeland.  As  phosphoroids  are  good  insu- 
lators, as  the  centres  lose  negative  electricity  under  the  action  of 
light,  they  acquire  a  positive  charge  ;  finally,  they  are  raised  to 
such  a  positive  potential  that  the  negative  electricity  can  no 
longer  escape.  On  calculating  from  the  capacity  of  the  phos- 
phorescent sheet  and  the  known  initial  velocity  of  the  photo- 
electrically  liberated  electrons,  the  charge  required  to  raise  the 
phosphoroid  to  the  necessary  potential,  it  is  found  that,  in  order 
that  the  positive  charge  actually  acquired  may  be  sufficient  to 
stop  the  escape  of  electrons,  only  a  fraction  of  the  surface  can  be 
charged  by  it :  this  is  strongly  in  favour  of  the  theory  that  there 
are  certain  centres  which  alone  take  part  both  in  the  phos- 
phorescent and  photo-electric  action  of  the  phosphoroid. 
Further,  it  has  been  shown  by  experiment  that  the  two  effects 
5 


66  SCIENCE  PROGRESS 

are  excited  by  light  of  the  same  wave-lengths  and  that  the  wave- 
lengths which  are  inactive  in  respect  of  the  one  are  inactive  in 
respect  of  the  other  phenomenon  ;  again,  separate  components  of 
the  phosphoroid  which  show  no  phosphorescence  also  show  no 
photo-electric  effect.  From  the  close  connection  of  the  two  effects, 
the  theory  that  the  photo-electrically  liberated  electron  causes 
the  emission  of  phosphorescent  light  seems  well  established. 

J.  Becquerel  has  carried  out  some  very  interesting  experi- 
ments, partly  in  collaboration  with  H.  Becquerel  and  Kammer- 
lingh  Onnes,  on  the  phosphorescence  of  uranyl  salts.  The 
bands  of  the  spectrum  of  the  emitted  light  became  very  narrow 
at  low  temperature,  but  a  magnetic  field  did  not  appear  to 
influence  the  emitted  light ;  Lenard  had  likewise  looked  for  a 
magnetic  effect  in  the  phosphoroids  of  the  alkaline  earths  and 
failed  to  find  it.  A  noteworthy  point  is  that  in  the  uranyl  salts 
no  traces  of  foreign  metal  condition  the  phosphorescence,  which 
must  be  attributed  to  the  uranium  itself.  Experiment  indicates 
that  the  "  centres  "  of  light  emission  are  present  only  in  relatively 
very  small  numbers,  as  in  the  phosphoroids  hitherto  discussed, 
only  a  very  few  of  the  uranium  atoms  being  active  at  a  time. 
The  experimenters  suggest  a  possible  connection  between  the 
light-emission  and  the  radioactivity  of  the  uranium  atom, 
the  atoms  being  assumed  to  be  active  only  while  they  are 
breaking  down.  The  fact  that  the  intensity  of  the  emitted 
light  does  not  decrease  when  the  temperature  is  lowered  even 
to  140  absolute  offers  some  support  to  this  theory,  which  is, 
however,  not  very  strongly  upheld. 

We  now  pass  on  to  the  extinction  of  phosphorescence  by 
means  of  red  and  infra-red  light  of  which  mention  has  already 
been  made.  The  effect,  although  most  marked  with  these  rays, 
is  not  confined  to  the  infra-red  region  of  the  spectrum,  as 
Fommel  found  a  short  wave  region  (384-96  up)  which  could 
also  extinguish  phosphorescence.  Further  work  by  Dahms  has 
shown  that  light  of  certain  wave-lengths  which  can  extinguish 
the  emission  of  a  phosphoroid  already  excited  can  also  excite 
an  unexcited  phosphoroid,  which  shows  that  there  is  no  essential 
difference  between  rays  which  excite  and  those  which  extinguish; 
if  light  of  a  given  wave-length  and  intensity  falls  on  a  phos- 
phoroid, an  equilibrium  is  finally  set  up.  Thus  a  piece  of  spar 
excited  by  the  ultra-violet  showed  extinction  to  the  edge  of 
the  ultra-violet,  but,  if  previously  unexcited,  was  excited  by  the 


LENARD'S  RESEARCHES  ON  PHOSPHORESCENCE  67 

whole  spectrum  up  to  the  infra-red.  The  experiments  of  Dahms 
referred  to  the  whole  of  the  emitted  light,  as  at  the  time  of  his 
work  little  was  known  of  the  separate  bands  of  which  this  light 
is  made  up. 

Lenard,  studying  the  effect  of  infra-red  illumination  in  ex- 
tinguishing the  bands,  found  that  it  was  in  all  respects  similar 
to  that  produced  by  heat.  As  already  observed  by  Becquerel, 
when  the  phosphoroid  is  exposed  to  the  extinguishing  light, 
it  first  of  all  lights  up  brilliantly  during  a  short  time  and  then 
rapidly  loses  in  intensity,  the  light  becoming  extinct.  The 
effect  of  both  infra-red  light  and  heating  is  thus  to  accelerate 
the  emission  of  the  stored  energy  and  consequently  the  phos- 
phoroid becomes  non-luminous  more  rapidly.  Recent  measure- 
ments by  Lenard  have  shown  that  the  light-total — the  time  sum 
of  the  light  energy  emitted  as  the  after-glow  of  a  given  band — 
is  the  same  whatever  the  rate  at  which  the  light  is  emitted, 
whether  normally  or  accelerated  by  heating  or  irradiation  by 
the  red  rays.  Another  example  in  which  the  irradiation  by 
the  "extinguishing"  rays  has  the  same  effect  as  heating  the 
whole  phosphoroid  is  supplied  by  the  effect  called  by  Lenard 
the  "  actinodielectric  effect."  It  is  found,  namely,  that  if  a 
phosphoroid  be  subjected  to  the  infra-red  rays,  its  conductivity 
is  temporarily  improved,  an  effect  which  is  also  produced  by 
heating  the  phosphoroid. 

After  quenching  by  heat,  infra-red  radiation  can  produce 
no  further  momentary  illumination,  and  vice  versa.  The  effect 
of  rise  of  temperature  is  to  bring  out  each  permanent  band 
as  the  temperature  of  the  permanent  state  for  that  band  is 
reached :  the  bands  then  emit  very  rapidly  and  die  out :  if 
the  initial  temperature  be  above  that  of  the  permanent  state, 
neither  heating  nor  infra-red  produce  any  effect.  The  thermo- 
metric  temperature  of  the  phosphoroid  is  not  appreciably  raised 
by  infra-red  radiation,  but  we  may  assume  that  the  local  molecular 
temperature  1  of  the  centres  rises  and  that  this  produces  the 
same  effect  on  the  light-emission  as  heating  the  whole  phos- 
phoroid. The  conception  of  a  raised  local  temperature  is  quite 
reasonable  if  we  consider  the  excited  centres  as  resonating  to 

1  It  is  doubtful  if  it  be  altogether  advisable  to  refer  to  a  local  agitation  of  this 
kind  as  temperature  ;  as  the  vibrations  are  forced,  there  is  a  regularity  about  them 
which  is  essentially  lacking  in  true  temperature  agitations.  However,  in  this 
particular  case  it  is  hoped  that  confusion  is  avoided. 


6S  SCIENCE  PROGRESS 

the  infra-red  rays  so  that  they  acquire  a  considerable  local 
kinetic  energy.  The  effect  of  the  local  agitation  is  probably  to 
bring  the  sulphur  atom  which  stores  the  electrons  emitted 
from  the  active  metal  atom  intermittently  nearer  to  the  metallic 
atom,  so  that  the  latter  "  by  action  at  small  distances  "  regains 
its  electrons  and  so  emits  its  light  sooner  than  it  would  other- 
wise have  done.  The  temperature  insulation  of  the  centres 
must  be  very  good,  as  on  cutting  off  the  infra-red  radiation  its 
effect  continues,  just  as  if  the  centres  remained  at  their  high 
temperature  for  some  time.  If,  however,  the  phosphoroid  be 
first  subjected  to  infra-red  radiation  and  then  excited,  the  pre- 
liminary irradiation  has  no  effect  on  the  light-emission,  which 
shows  that  the  period  of  the  excited  and  unexcited  centres  is 
different,  the  latter  not  resonating  to  the  infra-red  rays.  This 
is  as  might  be  expected,  as  the  centres  are  in  a  different  electrical 
state  in  the  two  cases.  An  interesting  fact  is  recorded  by  Pauli, 
who  investigated  the  ultra-violet  and  infra-red  light  emitted  by 
phosphoroids — namely,  that  no  phosphoroid  which  exhibits  a 
marked  and  prolonged  after-glow  ever  gives  infra-red  bands ; 
such  bands,  if  present,  presumably  accelerate  the  extinction  of 
the  visible  bands  of  the  phosphoroid. 

The  resonating  system  is  probably  the  oppositely  charged 
or  polarised  couplet  formed  by  the  sulphur  atom  and  the  active 
metallic  atom;  and,  the  extinction  spectrum,  which  gives  the 
efficacy  of  the  different  wave-lengths  in  accelerating  the  emission 
of  light,  will  give  by  its  maximum  the  free  period  of  the  polarised 
couplet.  This  accords  with  the  theory  of  dispersion,  which 
shows  that  the  slowest  free  periods  of  the  molecules  correspond 
not  to  vibrating  electrons,  but  to  whole  atoms  or  groups  of 
atoms  in  the  molecule,  which  must  be  electrically  charged  or 
polarised  as  has  been  imagined.  The  experimentally  found 
extinguishing  spectrum  shows  that  the  extinguishing  power 
has  a  sharp  boundary  as  we  go  further  into  the  infra-red. 
Each  active  metal  seems  to  have  the  same  distribution  in  this 
respect,  whatever  the  alkaline  metal  of  the  sulphide,  although 
the  distribution  of  excitation  of  the  different  bands  is  different. 
This  accords  well  with  the  hypothesis. 

It  has  been  already  mentioned  that  Lenard  has  shown  that 
the  total  amount  of  light  energy  emitted  by  a  given  phosphoroid 
is  the  same  whether  the  emission  be  accelerated  by  heating  so 
as  to  last  only  a  few  seconds  or  whether  it  takes  place  normally. 


LENARD'S  RESEARCHES  ON  PHOSPHORESCENCE  69 

In  the  same  paper  he  also  describes  experiments  demonstrating 
that  the  light  total  has  a  limit  to  which  it  tends  with  increasing 
intensity  and  duration  of  excitation  ;  this  limit  is  independent 
of  the  nature  of  the  excitation.1  When  this  limit  is  reached  the 
phosphoroid  is  said  to  be  fully  excited  by  two  different  wave- 
lengths separately,  and  if  a  band  have  two  different  light  totals 
corresponding  to  these  excitations,  these  light  totals  are  not 
added  together  when  the  phosphoroid  is  excited  by  both  wave- 
lengths at  once  ;  the  emission  in  this  case  is  of  the  same  intensity 
as  that  excited  by  one  alone  ;  this  shows  that  there  can  only  be 
one  kind  of  centre  capable  of  emitting  the  particular  band 
which  can  resonate  to  both  exciting  periods.  Whilst  this  is  true 
of  the  permanent  bands,  the  momentary  bands,  as  Hausser  has 
shown,  have  no  limit  of  emission  intensity ;  in  this  case  the 
intensity  increases  steadily  with  the  intensity  of  excitation,  and 
an  addition  of  the  two  emissions  excited  by  different  wave- 
lengths is  effected  when  these  are  used  simultaneously. 

In  comparing  the  light  total  caused  by  excitation  by  cathode 
rays  and  excitation  by  light,  a  difficulty  arises  owing  to  the 
fact  that  the  cathode  rays  cannot  penetrate  and  so  excite  as 
thick  a  layer  of  the  phosphoroid  as  the  light  rays :  the  emitted 
light  increases  with  the  thickness  of  the  phosphorescent  sheet 
used  until  this  is  about  1  mm.  in  the  case  of  excitation  by  light ; 
but  with  the  thinnest  sheets  which  can  be  prepared  the  cathode 
rays  already  excite  their  maximum  of  emitted  energy.  How- 
ever, the  depth  of  penetration  of  the  cathode  rays  can  be 
calculated  from  their  known  coefficient  of  absorption  :  from  such 
calculations  Lenard  arrives  at  the  conclusion  that  the  total  of 
emitted  light  is  the  same  whether  the  exciting  agent  be  light  or 
cathode  rays. 

The  laws  of  the  decay  of  intensity  of  the  emitted  light  were 
first  considered  by  Becquerel,  who,  however,  investigated  the 
whole  of  the  light  emitted  from  impure  phosphoroids  and  not 
the  separate  bands.  Since  the  different  bands  due  to  one  metal 
die  out  at  different  rates,  it  is  not  astonishing  that  the  empirical 
formula  which  he  proposed  represented  observation  only  very 
roughly.  Subsequently  Nicholls  and  Merrit  and  also  Werner 
put  forward  as  the  law  of  decay  of  the  permanent  process  the 

formula  I  =  — — — —2,  in  which  1  is  the  intensity  of  the  light, 
\C  -f-  at)" 

1  Which  may  be  light  or  cathode  rays, 


70  SCIENCE  PROGRESS 

t  the  time,  and  a  and  c  are  constants  ;  a  formula  of  this  kind  had 
already  been  used  by  Becquerel.  This  seemed  to  give  a  fair 
representation  within  the  observed  limits,  the  time  of  observa- 
tion being  about  thirty  minutes.  Recently  Lenard  and  Hausser 
have  attacked  the  problem  in  great  detail  and  have  shown  that, 
inasmuch  as  according  to  the  conditions  of  excitation  the  decay 
can  take  place  in  different  ways,  so  that  under  certain  conditions 
curves  of  decay  can  be  obtained  for  the  same  band  which  cut 
one  another,  no  law  can  be  given  without  considerable  further 
discussion  of  the  circumstances  preceding  the  after-glow. 
This  is  due  to  a  non-homogeneity  of  the  centres,  to  be  mentioned 
again  shortly.  They  investigate  the  behaviour  of  the  separate 
bands.  Their  experiments  on  the  effect  of  the  amount  of  active 
metal  present  in  a  pure  phosphoroid  show  that  the  total  of 
emitted  light  per  unit  volume  of  the  phosphoroid — the  reduction 
to  unit  volume  follows  from  experiments  made  on  phosphorescent 
sheets  of  different  thickness — rises  first  of  all  proportionally 
with  the  increase  of  metal  in  the  phosphoroid,  but  then 
turns  and  becomes  constant,  provided  that  the  phosphoroid  be 
fully  excited  in  all  cases.  The  law  of  decay,  and  therefore  to 
some  extent  the  light  total,  depends  upon  the  amount  of  excita- 
tion, if  this  be  insufficient  to  excite  the  phosphoroid  fully  :  the  first 
falling  off  in  intensity  is  relatively  greater  for  a  brief  excitation. 
These  and  other  observations  lead  to  the  assumption  of  the 
simultaneous  presence  of  permanent  centres  of  different 
duration  :  those  of  small  duration  will  be  quickly  excited  and 
will  quickly  decay,  whilst  the  more  durable  will  have  a  slow 
excitation  corresponding  to  their  slow  falling  off.  This  assump- 
tion accounts  for  the  observed  influence  of  the  duration  of  the 
excitation  on  the  law  of  decay,  as  in  the  case  of  brief  excitation 
a  relatively  much  larger  number  of  quickly  decaying  centres  are 
excited  than  by  a  longer  excitation.  As  regards  the  amount  of 
metal  present,  if  this  be  small,  only  more  permanent  centres  are 
formed  in  the  phosphoroid  ;  as  it  is  increased,  the  number  of 
such  centres  increases  until  a  stage  is  reached  when  all  that 
are  possible  are  formed,  and  then  the  less  persistent  "  per- 
manent "  centres  are  produced.  After  this,  the  addition  of 
active  metal  does  not  increase  the  number  of  permanent 
centres,  as  experiment  shows.  The  metal  then  goes  to  form 
"momentary"  centres,  the  intensity  of  the  momentary  process 
being  exceedingly  small  for  small   metal  content.     Hirsh  has 


LENARD'S  RESEARCHES  ON  PHOSPHORESCENCE  71 

shown  that  for  a  large  number  of  bands  the  intensity  of  the 
momentary  process  continually  increases  with  the  amount  of 
active  metal,  whilst,  as  stated,  the  number  of  permanent  centres 
soon  reaches  a  limit.  He  has  also  shown  that  a  higher 
temperature  is  needed  to  prepare  phosphoroids  of  pronounced 
after-glow,  which  falls  in  with  the  hypothesis,  as  other  considera- 
tions show  that  the  centres  of  long  duration  must  be  very  large 
atomic  complexes  which  would  take  some  time  to  form,  the 
production  of  which  would  accordingly  be  much  facilitated  by 
the  increased  diffusion  consequent  on  a  higher  temperature  in 
the  preparation.  Short  heating  at  comparatively  low  tem- 
perature will  give  rise  to  a  phosphoroid  which  shows  a 
good  momentary  process  and  only  a  very  faint  permanent 
process. 

Some  account  has  now  been  given  of  the  work  carried  out 
on  the  phosphorescence  of  pure  phosphoroids  of  known  com- 
position which  seem  to  offer  by  far  the  best  opportunity  of 
obtaining  a  true — or  perhaps  one  should  say  useful * — insight 
into  the  mechanism  of  phosphorescence.  The  information  so 
obtained  is  particularly  helpful  in  the  study  of  the  emission  of 
light  in  general,  as  we  are  dealing  with  single  widely  separated 
centres  of  emission  provided  by  the  atoms  of  the  active  metal. 
A  great  amount  of  interesting  work  has  been  done  on  the 
phosphorescence  of  substances  of  doubtful  composition,  especi- 
ally for  excitation  with  fast  cathode  rays,  which  excite  a  short 
phosphorescence  in  nearly  all  substances.  It  is  hard  to  give 
a  condensed  account  of  this  work,  consisting,  as  it  largely 
does,  of  observations  under  imperfectly  known  conditions  of  very 
complex  phenomena :  the  lack  of  any  broad  theoretical  basis 
for  the  class  of  experiments  referred  to  renders  generalisation 
as  to  many  very  interesting  but  apparently  independent 
phenomena  which  have  been  observed  almost  impossible.  I 
have  therefore  and  from  considerations  of  space  confined  myself 
to  the  long  series  of  connected  experiments  made  by  Lenard 
and  his  collaborators  and  to  the  other  experiments  known  to 
me  which  bear  directly  on  the  questions  under  discussion. 
May  this  brief  description  of  systematic  labours  and  able 
theorising  help  to  demonstrate  the  significant  and  far-reaching 
results  to  which  the  careful  study  of  a  single,  apparently 
insignificant,  phenomenon  may  lead. 

1  A  distinction  without  a  difference,  according  to  the  pragmatists, 


THE    CORROSION    OF    IRON 

By  H.  E.  A. 

In  the  first  of  the  series  of  articles  on  this  subject  in  this 
journal !  reference  was  made  to  a  number  of  experiments  on 
the  rusting  of  iron  carried  out  by  Messrs.  Lambert  and  Thomson 
with  very  special  care,  and  exception  was  taken  to  their 
conclusions  in  the  following  terms : 

"  There  can  be  little  doubt  that  although  Lambert  and 
Thomson  were  successful  in  carrying  the  purification  of  iron 
very  far,  they  were  not  sufficiently  careful  to  secure  the  removal 
of  carbon  dioxide  from  their  apparatus.  In  view  of  the  results 
obtained  by  others,  it  is  inconceivable  that  they  would  have 
arrived  at  results  such  as  they  describe  had  they  done  so.  And 
it  is  not  difficult  to  see  where  they  went  astray.  Whilst  they 
took  great  care  to  prepare  oxygen  free  from  acid  impurity  by 
electrolysing  a  solution  of  baryta  and  all  water  introduced  into 
the  apparatus  was  carefully  distilled  from  an  alkaline  solution, 
they  evidently  were  not  alive  to  the  difficulty  of  removing 
carbon  dioxide  entirely  from  glass  surfaces,  although  this  has 
long  been  recognised  ;  a  very  large  area  of  glass  was  exposed 
within  their  apparatus,  especially  in  the  vessel  in  which  the 
oxygen  was  stored." 

Mr.  Lambert  has  continued  the  inquiry  and  has  described 
his  later  work  in  a  communication  to  the  Chemical  Society 
published  in  October  last ;  he  has  also  discussed  the  subject 
in  an  article  published  in  the  Chemical  News  of  April  13. 

In  repeating  his  experiments,  he  has  used  practically  the 
same  apparatus  as  before  but  has  introduced  a  variety  of 
additional  refinements  and  precautions.  The  conclusion  he 
arrives  at  is  as  follows  : 

"  The  results  go  to  show  that  none  of  the  criticisms  is  valid 
and  that  the  claim  which  is  founded  on  the  experiments  is 
substantially  accurate — namely,  that  commercial  forms  of  iron 
will  undergo  corrosion  quite  readily  in  contact  with  pure  water 

1  Science  Progress,  No.  20,  April  191 1.— See  also  S.  P.,  October  191 1  and 
January  1912. — Ed. 

72 


THE  CORROSION   OF  IRON 


73 


and'  pure  oxygen  under  conditions  such  that  carbonic  acid  (or 
any  other  acid)  can  neither  be  present  nor  be  formed  during  the 
reaction." 

The  only  possible  comment  on  this  is  that  Mr.  Lambert 
cannot  read,  that  is  to  say,  interpret,  his  own  observations.  The 
apparatus  used  by  him  is  shown  in  the  figure.  The  oxygen 
vessel  to  which  reference  is  made  above  is  that  marked  D  in  the 
figure.  In  the  earlier  experiments,  carbon  dioxide  was  removed 
by  merely  exhausting  the  apparatus  of  which  parts  only  had 
been  subjected  to  the  cleansing  action  of  steam  ;  while  in  the 
later  series  the  exhaustion  was  proceeded  with,  the  temperature 
of  the  part  between  H  and  L  was  raised  "  by  heating  a  large 
metal  plate  fixed  under  the  apparatus,  with  a  hood  of  sheet 
asbestos   covering   the   parts   above   it.      The   oxygen   storage 


vessels  and  other  parts  which  could  not  be  heated  thus  were 
heated  by  means  of  a  large  blowpipe  flame."  At  once  it  may 
be  asked  :  Were  the  thick  glass  taps  E  and  F  thus  heated  ?  It 
stands  to  reason  that  they  were  not :  so  that  the  "  other  parts 
which  could  not  be  heated  thus  "  were  not  all  heated  thus  but 
only  some  of  them  ;  and  in  the  case  of  those  that  were  heated 
the  heating  could  not  have  been  carried  to  more  than  a  moderate 
temperature. 

Now  what  are  the  facts  reported  ?  Experiment :  The  vacuum 
was  examined  by  means  of  the  discharge  produced  by  a  large 
coil  in  the  Plucker  tube  T.  Observation :  "  During  the  last 
stages  of  this  first  exhaustion,  whilst  the  glass  surfaces  zvere 
being  heated  (my  italics),  the  spectrum  of  carbon  dioxide  was  seen 
but  it  disappeared  after  some  time,  etc."  Inference:  Carbon 
dioxide  was  present  in  the  first  series  of  experiments  criticised 
in  the  former  article  in  this  journal.    Therefore,  far  from  none 


74  SCIENCE  PROGRESS 

of  the  criticisms  being  valid,  as  Mr.  Lambert  asserts  in  the 
passage  quoted  above,  the  one  of  major  consequence  zs  justified 
by  his  own  admission.  Moreover,  the  criticism  is  still  applicable 
to  his  later  work,  as  he  cannot  possibly  have  heated  the  entire 
surface  of  his  apparatus,  and  the  degree  to  which  he  heated 
parts  of  it  must  have  been  such  that  it  is  not  likely  that  he 
did  more  than  drive  off  the  major  part,  let  us  say,  of  the  carbon 
dioxide  condensed  on  and  within  the  glass,  thereby  reaching  an 
equilibrium,  perhaps,  but  never  removing  the  whole  of  the  gas. 

In  order  that  there  may  be  no  misunderstanding,  let  me  say 
that  I  hold  it  to  be  impossible  to  obtain  valid  results  with  an 
apparatus  of  so  complicated  a  character,  in  which  so  large  a 
surface  of  glass  is  exposed,  as  that  used  by  Mr.  Lambert ; 
infinite  opportunity  is  given  in  such  an  apparatus  for  the 
retention  of  carbon  dioxide  at  the  glass  surfaces. 

Mr.  Lambert's  views  are  summarised  in  the  statement : 

"The  glass  walls  of  all  the  vessels  with  which  the  water 
and  oxygen  came  in  contact  had  been  subjected  to  the  exhaustive 
treatment  described  above  and  so  it  may  be  said  to  be  proved 
beyond  any  reasonable  doubt  that  oxygen  and  water — both  of 
the  highest  obtainable  purity — have  the  power,  of  themselves, 
of  causing  commercial  iron  to  rust. 

"  Further,  the  rusting  seemed  to  take  place  as  quickly  as  it 
does  in  ordinary  air  or  oxygen  and  so  it  cannot  any  longer  be 
maintained  that  carbon  dioxide  or  any  other  acid  is  the  '  dominant 
factor  in  the  atmospheric  corrosion  of  iron,'  where  commercial 
forms  of  the  metal  are  meant." 

Reading  back  we  learn  what  is  here  meant,  by  "commercial 
forms  of  the  metal  "  : 

"  Three  different  kinds  of  commercial  iron  were  used,  one 
in  each  vessel — namely,  (i)  a  pure  commercial  electrolytic  sheet 
iron  ;  (2)  Kahlbaum's  pure  iron  foil ;  and  (3)  a  cylinder  of  iron 
turned  from  a  large  nail  taken  from  the  roof  of  Merton  College 
library  while  repairs  were  being  carried  out.  This  nail  was 
made  of  very  soft  iron  and  was  more  than  two  hundred  years 
old. 

"  The  iron  in  each  case  was  carefully  polished  with  fine 
carborundum  and  then  with  Swedish  filter  paper.  The  results 
in  all  three  cases  were  the  same  and  did  not  differ  in  any  respect 
from  the  results  obtained  with  other  good  specimens  of  com- 
mercial iron  used  in  earlier  experiments.  Corrosion  was  visible 
in  a  few  hours  and  a  considerable  quantity  of  rust  had  formed 
within  a  few  days." 

Mr.   Lambert   took  none  of  the  precautions  to  cleanse   the 


THE  CORROSION   OF   IRON  75 

surface  of  the  "  commercial  iron,"  such  as  Moody  and  Friend 
have  shown  to  be  necessary,  without  which,  as  a  rule,  iron 
rusts  even  under  the  conditions  these  workers  adopted — con- 
ditions which  involved  the  exclusion  of  carbon  dioxide,  if  not 
absolutely,  to  an  extent  far  beyond  that  attained  to  by  Lambert. 

Mr.  Lambert's  second  series  of  experiments,  like  the  first,  there- 
fore, afford  no  proof  of  the  validity  of  his  contention  that  iron, 
both  highly  purified  and  commercial,  can  rust  in  the  absence 
of  an  acid  electrolyte. 

In  the  latter  part  of  his  account  he  has  much  to  say  of  the 
properties  of  the  so-called  pure  iron  which  he  prepared — not 
a  few  of  his  statements  are  self-evident  propositions,  though 
valuable  and  interesting  as  bringing  out  the  influence  impurities 
exercise  in  conditioning  change. 

Apparently  the  highly  purified  iron  at  his  disposal  was  not 
so  entirely  exceptional  as  he  implies  ;  although  it  did  not  rust 
perceptibly  on  exposure  to  water  and  air,  the  rust  test  is 
probably  a  far  less  delicate  test  of  purity  than  the  acid  test. 
It  was  attacked  slowly  by  a  cold,  very  dilute  solution  of  chlor- 
hydric  acid  and  dissolved  readily  in  chlorhydric,  nitric  and 
sulphuric  acids  on  warming.  It  seems  therefore  to  have  been 
less  highly  purified  than  the  zinc  prepared  by  Reynolds  and 
Ramsay,  as  this  latter  was  scarcely  attacked  by  acid. 

Pieces  of  the  iron  which  had  been  pressed  by  an  agate 
pestle  in  an  agate  mortar  were  found  to  rust  readily  over  the 
compressed  part,  whilst  the  uncompressed  pieces  remained 
bright.  Mr.  Lambert  attributes  the  difference  in  behaviour  to 
the  difference  in  "  solution  pressure  "  but  it  is  sufficient  probably 
to  assume  that  the  conductivity  of  the  metal  is  increased  by 
compression  and  that  the  influence  of  such  negative  impurity 
as  is  present  is  thereby  enhanced  if  no  other  explanation  be 
forthcoming. 

The  object  of  Mr.  Lambert's  communication  to  the  Faraday 
Society  is  to  show,  he  says — 

"that  a  simple  and  natural  development  of  the  ideas  of 
Faraday  on  electrolysis  will  give  us  the  beginnings  of  a  satis- 
factory theory  of  the  corrosion  of  iron — a  theory  incomplete 
as  yet,  owing  to  the  lack  of  experimental  facts,  but  one  which 
is  quite  in  accordance  with  well-established  facts  and  which 
is  not  affected  by  the  question  whether  iron  is  soluble  to  any 
appreciable  extent  in  pure  air-free  water." 


76  SCIENCE  PROGRESS 

He  then  proceeds  to  sketch  a  "  theory,"  but  the  terms  used 
are  those  used  in  the  previous  articles  in  this  journal.  Evidently 
he  has  assimilated  a  good  deal  since  the  publication  of  his  first 
communication  to  the  Chemical  Society  and  will  soon  be 
quite  an  orthodox  exponent  of  electrolytic  doctrine.  I  venture 
to  think,  however,  that  we  have  long  had  a  satisfactory  theory 
of  the  corrosion  of  iron — at  all  events,  our  "  theory  "  of  the 
process  is  certainly  not  incomplete  owing  to  the  lack  of 
experimental  facts  but  because  of  the  general  lack  of  appre- 
ciation of  the  facts,  owing  to  the  long-continued  failure  of 
chemists  to  take  notice  of  a  few  fundamental  principles.  If, 
moreover,  a  simple  and  natural  development  of  the  ideas 
of  Faraday  will  give  us  the  beginnings  of  a  satisfactory  theory 
of  corrosion,  why,  it  may  be  asked,  have  Mr.  Lambert  and  others 
been  so  slow  in  assimilating  them  ?— they  have  simply  never 
made  the  attempt  until  persistent  hammering  at  the  truth  has 
forced  them  at  last  to  pay  some  attention  to  it.  But  it  is  often 
and  well  said  :  better  late  than  never.  We  may  be  thankful  that 
some  appreciation  of  the  value  to  chemists  of  Faraday's  teaching 
is  at  last  being  shown.  That  the  tendency  should  become  mani- 
fest even  in  a  centre  of  feudalism  such  as  that  in  which 
Mr.  Lambert  works  bodes  well  for  the  future.  Faraday's  work 
was  done  only  about  seventy-five  years  ago,  and  therefore  has 
not  the  crusted  authority  of  Greek  masterpieces. 

At  all  events,  Mr.  Lambert  now  recognises  that  the  presence 
of  an  electrolyte  is  an  essential  feature  in  rusting — he  sees  that 
otherwise  there  can  be  no  change.  As  he  says,  "No  part  of 
the  metal  can  dissolve  unless  an  electric  current  actually  passes 
through  the  electrolyte."  Moreover,  he  implies,  if  he  does  not 
assert,  that  iron  pure  and  simple,  if  in  contact  with  a  relatively 
electronegative  conductor,  will  be  attacked  by  water  in  the 
entire  absence  of  acid.  He  speaks  of  water,  however,  as 
the  electrolyte  water  and  everything  turns  on  this. 

When  he  can  show  that  water  is  an  electrolyte,  no  one  will 
hesitate  to  agree  with  him:  but  he  cannot:  both  the  evidence 
and  theory  go  to  show  that  it  would  not  be,  if  it  were  obtain- 
able. To  quote,  as  almost  every  one  does,  Kohlrausch's 
experiments  made  many  years  ago  in  very  ordinary  glass  as 
proof  that  water  is  an  electrolyte  is  absurd  ;  Kohlrausch  never 
had  water  to  deal  with,  and  any  one  who  seeks  to  refine  on  his 
experiments  would  only  carry  the  purification  a  stage  further 


THE  CORROSION   OF  IRON  7; 

and  observe  a  still  lower  degree  of  conductivity  without  ever 
arriving  at  water  pure  and  simple. 

It  is  worth  while,  however,  to  analyse  Mr.  Lambert's  state- 
ments with  regard  to  the  case  of  a  piece  of  ordinary  commercial 
iron  in  contact  with  the  electrolyte  water  ;  they  are  as  follows  : 

"  Whenever  we  have  two  metals  (or  two  modifications  of 
the  same  metal)  which  are  electrically  different,  that  is,  have 
different  solution  pressures  and  they  are  placed  in  metallic 
contact  in  an  electrolyte,  then  the  relatively  electropositive 
part  will  dissolve  with  the  production  of  an  electric  current 
flowing  through  the  electrolyte  from  the  electropositive  to  the 
electronegative  pole  and  in  the  opposite  direction  through 
the  metal. 

"The  rate  of  such  a  reaction  depends  (a)  on  the  magnitude 
of  the  difference  of  electric  potential — that  is,  the  difference  of 
solution  pressure  between  the  two  metals,  and  (b)  on  the 
resistance  offered  by  the  electrolyte  to  the  passage  of  the  electric 
current. 

"  No  part  of  the  metal  can  dissolve  unless  an  electric  current 
actually  passes  through  the  electrolyte.  The  rate  of  the  re- 
action may,  however,  be  so  infinitesimal  that  the  amount  of 
metal  passing  into  solution  will  not  be  sufficient  to  respond  to 
chemical  tests  even  after  long  periods. 

"  Let  us  consider,  in  this  light,  the  case  of  a  piece  of 
ordinary  commercial  iron  in  contact  with  the  electrolyte  water. 

"  Such  a  piece  of  iron  is  impure  and  not  homogeneous — 
there  are  some  parts  of  it  which  have  a  different  solution 
pressure  from  other  parts  and  so  when  it  is  placed  in  contact 
with  the  electrolyte  water  we  have  all  the  conditions  for  the 
production  of  an  electric  current. 

"  If  the  conditions  are  such  that  an  appreciable  electric 
current  can  pass  between  the  two  electrically  different  parts 
of  the  iron,  the  metal  will  dissolve  at  the  relatively  electro- 
positive parts.  The  fact  that  iron  is  practically  insoluble  in 
pure  water  (in  the  absence  of  oxygen),  shows  that  the  current 
which  actually  does  pass  is  so  infinitesimal  that  the  amount 
of  iron  dissolved  cannot  be  detected,  even  after  long  periods, 
by  chemical  means. 

"  This  may  be  due  to  two  causes,  namely  (a)  the  small  magni- 
tude of  the  electromotive  force,  owing  to  the  small  differences 
of  potential  between  the  electrically  different  parts  of  the  metal 
and  (b)  the  great  resistance  offered  to  the  passage  of  an  electric 
current  by  the  electrolyte. 

"The  writer's  experiments  seem  to  be  generally  accepted  as 
proving  beyond  any  doubt  that  commercial  forms  of  iron  will 
undergo  corrosion  quite  readily  in  contact  with  pure  water  and 
pure  oxygen  in  the  complete  absence  of  carbonic  acid  or  any 


78  SCIENCE  PROGRESS 

other  acid — that  the  only  essentials  for  the  corrosion  of  ordinary 
iron  are  water  and  oxygen.  It  is  generally  believed  that  iron 
must  pass  through  a  process  of  solution  before  rust  is  produced, 
and  so,  whilst  the  metal  is  practically  insoluble  in  pure  water 
alone,  it  must  be  soluble  in  the  presence  of  oxygen.  It  follows, 
then,  that  oxygen  must  bring  about  some  alteration  in  the 
conditions  of  the  '  voltaic  circle  ' — commercial  iron  and  water — 
in  such  a  way  that  a  greatly  increased  electric  current  passes 
between  the  electrically  different  parts  of  the  iron." 

Firstly,  it  may  be  noted  that  Mr.  Lambert  here  admits  that 
iron  is  practically  insoluble  in  pure  water;  he  means,  of  course, 
water  such  as  he  has  prepared,  which  cannot  have  been  pure. 
It  may  well  be  argued,  therefore,  that  as  it  has  been  shown  to 
be  practically  insoluble  in  Lambertian  water,  iron  would  be 
insoluble  in  pure  water. 

Secondly,  that  he  attributes  very  special  influence  to  oxygen 
— of  which  more  presently — inasmuch  as  he  holds  that  pure 
water  plus  pure  oxygen  can  attack  iron  in  absence  of  acid. 

According  to  Mr.  Lambert,  the  current  passing  between 
electrically  different  parts  of  a  piece  of  commercial  iron  in 
(Lambertian)  water  may  be  small  because  of  the  small 
differences  of  potential  existing  between  the  electrically  dif- 
ferent parts  of  the  metal.  This  argument  may  at  once  be 
disposed  of,  as  graphite  and  probably  other  impurities  in 
commercial  iron  are  just  as  effective  as  platinum  would  be. 

That  a  great  resistance  would  be  offered  by  the  electrolyte 
to  the  passage  of  the  current  is  beyond  question.  And  as  even 
Lambertian  water  offers  great  resistance,  water  would  offer 
infinite  resistance  ;  therefore  there  would  be  no  current  and  no 
action  if  water  alone  were  used. 

It  is  necessary  therefore  to  consider  what  are  the  alterations 
in  the  conditions  which  may  be  brought  about  by  oxygen  and 
whether  these  be  such  that  iron  would  be  attacked  when 
subjected  to  the  conjoint  action  of  oxygen  and  water.  According 
to  Mr.  Lambert — 

"  Oxygen  must  do  one  of  two  things — it  must  in  some  way 
or  other  increase  the  electrical  differences  between  the  parts  of 
the  metal  and  so  increase  the  electromotive  force  or  it  must 
reduce  the  resistance  of  the  circuit.  When  a  piece  of  com- 
mercial iron  is  put  into  water  in  a  vacuum,  iron  strives  to  pass 
into  solution  at  the  relatively  electropositive  part  of  the 
metallic  surface,  but  hydrogen,  produced  by  the  electrolysis  of 


THE  CORROSION   OF  IRON  79 

the  water,  is  deposited  at  the  relatively  electronegative  part. 
This  film  of  hydrogen,  forming  almost  instantaneously  and 
covering  up  the  negative  pole,  introduces  an  enormous  resist- 
ance into  the  circuit  and  reduces  the  electric  current  to  an 
almost  negligible  strength,  so  that  the  rate  at  which  the  iron 
passes  into  solution  is  infinitely  small. 

"  Oxygen  dissolved  in  the  water  probably  acts  by  oxidising 
the  hydrogen  thus  deposited  at  the  negative  pole — destroying 
the  polarisation — and  so  allowing  a  greater  current  to  pass 
between  the  electrically  different  parts  of  the  metal. 

"  If  this  argument  is  true,  then  commercial  iron  ought  to 
pass  into  solution,  in  the  absence  of  oxygen,  if  it  is  placed  in  an 
electrolyte,  such  as  copper-sulphate  solution,  where,  instead  of 
the  non-conducting  hydrogen  film,  there  would  be  a  conducting 
film  of  metallic  copper  produced  at  the  relatively  electro- 
negative pole.  Experiment  shows  this  to  be  true.  Commercial 
iron,  when  brought  into  contact  with  a  solution  of  pure  copper 
sulphate  in  a  vacuum,  causes  the  immediate  deposition  of 
copper  on  the  iron  just  as  readily  as  when  the  experiment  is 
conducted  in  the  presence  of  air ;  in  short,  all  the  copper  is 
removed  from  the  solution  and  iron  takes  its  place." 

Inasmuch  as,  ex  hypothesi  and  in  point  of  fact,  oxygen  and 
water  are  non-conductors  both  singly  and  when  conjoined,  the 
conditions  are  such,  when  only  these  are  present,  that  an 
appreciable  electric  current  cannot  pass.  But  waiving  this 
argument,  the  fact  remains  that  we  have  no  reason  to  suppose 
that  oxygen  can,  in  any  way,  reduce  the  resistance  of  a  circuit — 
all  substances  which  can  do  this  are  of  the  class  commonly 
known  as  electrolytes,  though  in  reality  they  only  become 
electrolytes  when  used  in  conjunction  with  water.  It  can  only 
act  as  a  depolariser — but  Mr.  Lambert  must  pursue  his  studies 
of  Farada}^  and  perhaps  of  later  writers  also  a  little  further  in 
order  that  he  may  understand  the  office  of  the  depolariser— that 
it  not  only  exercises  the  cleansing  effect  to  which  he  refers  and 
also  puts  a  stop  to  all  back  action  but,  which  is  far  more 
important,  throws  energy  into  the  circuit.  Over  and  over 
again,  this  has  been  pointed  out ;  but  it  is  not  yet  part  of  "  the 
simple  and  natural  development  of  the  ideas  of  Faraday  "  now 
in  progress.  However,  we  may  hope  that  the  doctrine  may 
soon  become  the  belief  of  pioneers  like  Mr.  Lambert. 

Apparently  the  part  played  by  hydrogen  polarisation  is 
vastly  exaggerated.  We  know  perfectly  well  how  small  a  part 
relatively  it  plays  in  an   ordinary  simple   fluid   cell   and   how 


80  SCIENCE  PROGRESS 

fluctuating  is  the  influence  it  exercises ;  neither  does  it  reduce 
the  current  to  an  almost  negligible  strength,  though  it  renders 
it  aggravatingly  inconstant,  nor  has  it  such  an  effect  that  the 
rate  at  which  the  metal  passes  into  solution  is  infinitely  small. 

Copper  sulphate  not  only  prevents  any  deposition  of 
hydrogen  on  the  negative  surface  but  by  exchanging  copper 
for  hydrogen  contributes  energy  to  the  circuit :  at  the  same 
time,  owing  to  the  deposition  of  copper,  the  resistance  is 
greatly  lowered,  so  that  the  action  takes  place  more  rapidly, 
both  because  the  electromotive  force  is  raised  and  at  the  same 
time  the  resistance  is  lowered. 

But  the  changes  pictured  can  only  take  place  in  an 
electrolytic  circuit  and  such  a  circuit  is  only  possible  when  iron 
is  in  contact  not  only  with  water  and  oxygen  but  also  with  an 
electrolyte;  attack  by  water  and  oxygen  alone  is  impossible. 

In  any  case,  the  illusion  under  which  Mr.  Lambert  rests, 
"that  his  experiments  are  generally  accepted  as  proving  beyond 
any  doubt  that  the  only  essentials  for  the  corrosion  of  ordinary 
iron  are  water  and  oxygen,"  should  be  dispelled  by  the  above 
statements. 

But  there  are  other  points  of  interest  in  his  communication 
which  deserve  attention.  He  not  only  contends  that  he  has 
prepared  chemically  pure  iron  but  states  that  such  iron  can  be 
exposed  to  the  action  of  oxygen  and  water  (even  tap  water) 
during  an  apparently  indefinite  time  without  showing  any  signs 
of  corrosion.  Chemical  purity  is  not  the  only  essential, 
however,  as  will  be  obvious  from  the  following  statement : 

<(  In  the  preparation  of  pure  iron  by  the  writer's  method  the 
same  sample  of  ferric  nitrate,  treated  in  exactly  the  same 
manner  throughout  its  conversion  into  iron,  will  not  always 
give  like  specimens  of  the  metal. 

"  One  batch  of  iron  will  rust  quite  readily,  whilst  another 
batch  can  be  exposed  for  many  months  to  the  action  of  air  and 
water  without  showing  any  signs  of  corrosion.  All  the  pieces 
of  the  same  batch  behave,  as  a  rule,  in  a  precisely  similar 
manner.  Now,  any  difference  between  the  batches  cannot  be 
due  to  differences  in  chemical  composition.  The  only  possible 
variable  factors  are  temperature  of  reduction  and  rate  of  cooling, 
and  so  differences  in  the  product  must  be  of  a  physical  and  not 
of  a  chemical  character. 

"  It  is  a  very  striking  fact  that  the  pieces  of  iron  which  will 
not  rust  can  also  be  put  in  solutions  of  copper  sulphate  or 


THE  CORROSION   OF  IRON  81 

copper  nitrate  of  any  strength,  without  causing  copper  to  be 
deposited  on  the  iron,  whilst  pieces  from  a  batch  of  iron  which 
rusts  always  cause  the  deposition  of  copper  from  the  same 
solutions  of  copper  salts.  Sometimes  the  copper  is  deposited 
quickly,  whilst  at  other  times  several  hours  may  elapse  before 
the  deposition  of  copper  takes  place.  The  metal  is  always 
attacked  at  one  or  more  points  and  the  deposition  of  copper 
spreads  from  these  points  over  the  whole  surface  in  a  very 
short  time. 

"  It  is  clear  from  these  experiments  that  physical  differences 
in  iron  of  the  same  high  state  of  chemical  purity  can  cause  most 
profound  differences  in  its  behaviour. 

"  If  the  theory  is  true,  we  should  expect  such  results.  In  the 
case  of  the  iron  which  does  not  rust  and  is  unaffected  by  solu- 
tions of  copper  sulphate  or  copper  nitrate,  the  metal  is  probably 
physically  homogeneous,  at  any  rate  on  the  surface.  There 
would,  therefore,  be  no  differences  of  solution  pressure — no 
electrically  different  parts — on  the  surface  of  the  metal,  and  so 
no  tendency  for  the  metal  to  pass  into  solution  by  electrolytic 
action  when  the  metal  was  put  into  an  electrolyte.  Since  iron 
could  not  therefore  pass  into  solution,  we  should  not  expect 
rusting  to  take  place,  nor  should  we  expect  the  deposition  of 
copper  on  the  iron  from  solutions  of  copper  salts." 


Mr.  Lambert  states  further  that  when  pieces  of  metal  which 
had  been  exposed  during  several  months  to  the  action  of  air 
and  water  without  corroding  were  pressed  upon  by  an  agate 
pestle  in  an  agate  mortar  and  again  exposed,  they  rusted  in  the 
course  of  a  few  hours,  rust  forming  first  at  the  edges  which  had 
not  been  pressed,  while  the  pressed  portions  remained  bright. 
In  the  same  way,  copper  was  precipitated  immediately  when  the 
pressed  pieces  were  placed  in  a  solution  of  copper  sulphate, 
deposition  commencing  at  the  unpressed  edges.  He  assumes 
that  the  difference  in  physical  state  was  the  cause  of  the 
difference  in  the  behaviour  of  the  iron  before  and  after  it  was 
subjected  to  pressure.    But  this  explanation  is  not  good  enough. 

In  the  first  place,  it  is  open  to  question  whether  two  parts  of 
a  plate  composed  of  a  homogeneous  material  would  be  at 
different  potentials  after  the  one  had  been  subjected  to  pressure 
if  pressure  had  no  effect  in  altering  the  chemical  nature  of  the 
material  and  merely  changed  the  electrical  resistance  of  the  one 
relatively  to  the  other. 

In  the  second  place,  it  is  improbable  that  different  specimens 
of  iron  prepared  by  reducing  oxidised  iron  in  hydrogen — the 
6 


82  SCIENCE  PROGRESS 

method  adopted  by  Mr.  Lambert — should  so  differ  physically 
that  one  would  corrode  and  the  other  would  not. 

The  facts  point  to  the  conclusion  that  the  inactive  samples 
obtained  by  Mr.  Lambert  consisted  of  iron  which  in  some  way 
had  been  rendered  passive  and  that  the  effect  of  pressing  with 
an  agate  pestle  was  to  remove  a  protecting  layer.  The  deposi- 
tion of  copper  at  the  unpressed  edges  of  the  pieces  is  in 
accordance  with  this  explanation  ;  as  Moody  has  shown,  rust 
does  not  form  initially  in  the  iron  itself,  but  separates  from  the 
solution,  so  that  the  position  taken  up  by  the  rust  has  no 
special  significance. 

Mr.  Lambert,  it  should  be  stated,  has  foreseen  the  possibility 
of  the  formation  of  a  protective  film  on  the  surface  of  the  metal 
— either  of  an  oxide  or  of  a  hydride — but  he  has  rejected  the 
explanation.  As  it  is  not  likely  either  that  a  hydride  would  be 
formed  or  that  it  would  be  effective  if  formed,  it  is  only 
necessary  to  take  the  formation  of  a  coating  of  oxide  into 
account.  Mr.  Lambert  contemplates  the  possible  formation  of 
such  a  film  by  the  reversible  decomposition  of  small  traces  of 
water  in  the  hydrogen  used  for  the  reduction  of  the  iron  ;  he 
therefore  dried  the  hydrogen  used  in  reducing  the  iron  oxide  by 
passing  it  over  phosphoric  oxide,  so  as  to  remove  all  but  the 
most  minute  traces  of  water  ;  then  the  iron  which  was  produced 
was  brought  into  contact  with  copper  sulphate  solution  while  it 
was  still  in  the  atmosphere  of  hydrogen.  As  there  was  no 
deposition  of  copper,  he  came  to  the  conclusion  that  the  in- 
activity of  the  metal  would  not  be  accounted  for  by  the  presence 
of  a  protective  film  of  oxide.  But  drying  the  hydrogen  so 
thoroughly  in  such  a  case  can  only  have  been  a  work  of 
supererogation  during  the  greater  part  of  the  operation,  as 
water  is  one  of  the  products  of  change;  it  could  only  be  effective 
towards  the  close.  In  view  of  the  affinity  of  iron  and  oxygen, 
taking  the  behaviour  of  iron  into  account,  it  is  more  than 
probable  that  in  some  of  Mr.  Lambert's  experiments  the  metal 
produced  was  superficially  coated  with  oxide,  perhaps  in 
consequence  of  the  introduction  of  a  little  oxygen  together 
with  the  hydrogen. 

It  would  seem  therefore  that  the  argument  used  against 
Moody,  which  was  shown  by  him  in  advance  to  be  untenable, 
is  actually  applicable  to  Mr.  Lambert's  work  :  his  results,  in 
fact,  appear  to  be  open  to  doubt  on  more  grounds  than  one. 


THE  CORROSION   OF  IRON  83 

As  pointed  out  in  the  third  of  these  articles,  Dunstan  in 
particular  has  called  attention  to  the  manner  in  which  various 
agents  inhibit  rusting,  and  has  sought  to  show  that  the  con- 
clusions arrived  at  by  Moody  and  Friend  are  invalidated  by 
their  having  used  such  substances  in  their  experiments. 

It  has  been  shown  by  Friend  that  the  inhibiting  effect  of 
alkalies  is  due,  in  all  probability,  to  the  retention  of  a  certain 
amount  of  alkali  at  the  surface  of  the  metal ;  this  appears  to 
be  in  some  degree  porous,  so  that  the  alkali  can  be  removed 
only  by  long-continued  washing — a  precaution  which  Friend 
adopted  in  his  ingeniously  simple  experiments  referred  to  in  the 
first  of  these  articles. 

The  wonderful  efficiency  of  the  film  formed  on  slightly 
heated  steel  in  protecting  it  against  corrosion  is  well  known. 
Next  in  protective  efficiency  comes  that  which  is  formed  when 
the  metal  is  rendered  passive  in  nitric  acid.  But  other  oxi- 
dising agents  appear  to  act  only  so  long  as  they  are  in  contact 
with  the  metal ;  I  have  often  had  occasion  to  observe  of  late 
that  they  cease  to  be  effective  very  soon  after  the  iron  is 
withdrawn  from  their  influence. 

It  is  to  be  regretted  that  Mr.  Lambert  did  not  take  advice 
before  continuing  his  experiments,  particularly  before  publishing 
the  account  of  his  further  work  :  had  he  taken  the  opinion 
of  those  who  have  given  special  consideration  to  such  matters, 
he  would  probably  have  carried  out  the  inquiry,  if  not  in  a  more 
effective  manner,  at  least  more  circumspectly,  so  that  the  time 
spent  would  not  have  been  largely  wasted  in  asking  questions 
in  such  a  way  that  the  answers  are  of  little  avail.  The  possible 
flaws  in  his  arguments  would  have  been  indicated. 

Subjects  so  intricate  need  to  be  dealt  with  comprehen- 
sively, in  the  light  of  a  mature  experience;  and  the  inquirer 
should  ever  be  mindful  of  the  pitfalls  which  threaten  each  step 
he  takes. 

At  present,  instead  of  seeking  counsel  of  one  another,  we  too 
often  affect  secrecy  and  resent  all  criticism. 

Individualism  is  undoubtedly  the  very  breath  of  science, 
but  it  now  needs  to  be  tempered  judiciously  with  collectivism. 
Our  present  failure  to  discuss  and  dispute  is  largely  the  cause 
of  the  absence  of  understanding  which  now  overshadows 
scientific  workers. 


84  SCIENCE  PROGRESS 

Bodies  such  as  the  Chemical  Society  in  the  near  future  will 
need  to  be  more  alive  to  their  responsibilities  to  their  members 
and  no  longer  confine  themselves  to  the  perfunctory  performance 
of  their  duties  as  publishing  organisations.  The  practice  which 
prevails  in  several  academies  of  submitting  the  more  important 
communications  they  receive  to  the  opinions  of  referees  and  of 
publishing  the  reports  that  are  given,  might  with  great  advantage 
be  extended  ;  such  reports  would  serve  to  guide  readers,  and 
inform  them  to  what  extent  the  opinions  advanced  were  open 
to  criticism  at  the  moment.  We  are  now  undertaking  tasks 
of  extraordinary  difficulty  and  it  behoves  us  collectively  to 
discover  some  means  of  promoting  the  efficiency  of  our  in- 
dividual efforts. 


RECENT    WORK    ON    VOLCANOES 

By  E.  H.  L.  SCHWARZ,  F.G.S., 

Professor  of  Geology,  Rhodes  University  College,  Grahams  town,  S.  Africa 

The  volcanic  regions  of  the  globe  have  long  been  known  and 
most  volcanoes  have  been  described  in  detail,  so  that  it  is  to 
be  expected  that  a  certain  definiteness  would  have  been  reached 
as  to  the  nature  of  volcanism.  As  to  the  cause,  that  is  another 
matter — but  just  what  volcanoes  are  and  what  happens  when 
they  become  active,  surely  that  ought  to  have  been  settled 
now  beyond  question.  This  is  not  the  case.  The  investigations 
into  the  West  Indian  eruptions  of  1902  threw  a  flood  of  light 
on  the  subject,  in  which,  however,  there  are  still  many  lacunae. 
Dr.  Albert  Brun's  daring  work  in  Java  and  elsewhere  has 
opened  up  an  entirely  new  chapter,  whilst  Reek's  work  in 
Iceland  and  Russell's  on  the  Snake  River  Plains  of  Idaho 
has  so  largely  increased  our  knowledge  that  it  can  hardly  be 
maintained  that  we  have  really  known  anything  about  the 
subject  of  volcanoes  till  quite  recently.  I  propose  in  this 
article  to  review  this  recent  work  briefly,  confining  myself 
to  actual  observations  in  the  field  or  the  laboratory,  and 
picking  out  only  those  points  which  are  fundamentally  new. 

I  will  begin  with  the  West  Indian  eruptions,  more  especially 
dealing  with  Mont  Pelee.  I  need  not  enter  into  general  details, 
as  these  have  been  so  adequately  described  by  Lacroix  (1), 
Flett  (2),  Anderson  (2),  Russell  (3),  and  Heilprin  (4),  whilst 
an  exceedingly  interesting  collection  of  letters  from  eye- 
witnesses has  been  published  by  Flammarion  (5).  Mont  Pelee, 
which  but  once,  in  185 1,  has  been  known  to  show  signs  of 
activity  and  then  only  by  throwing  out  a  harmless  shower  of 
ashes,  commenced  its  eruption  on  April  25,  1902.  Excursionists 
immediately  ascended  the  mountain  and  found  that  the  bowl- 
shaped  hollow  at  its  summit,  called  L'Etang  Sec,  was  being 
filled  up  with  boiling  mud  from  which  sulphurous  vapours 
were  being  given  off.  Eight  days  later,  ashes  were  ejected, 
and  on  May  5  an  aValanche  of  incandescent  mud  rushed  down 

85 


86  SCIENCE  PROGRESS 

the  valley  of  the  Riviere  Blanche  and  overwhelmed  the  sugar 
factory  of  M.  Guerin,  burying  the  owner  and  his  wife  and 
twenty-five  employees.  On  May  8,  at  ten  minutes  to  eight 
in  the  morning,  a  blast,  blown  as  if  from  a  funnel,  and  directed 
immediately  on  to  the  town  of  Saint  Pierre,  scorched  and  killed 
every  living  being,  with  the  exception  of  two  men,  who  was 
within  the  city,  to  the  number  of  twenty-six  thousand.  The  area 
of  total  destruction  was  quite  narrow,  but  all  the  country  to  the 
west  and  south  was  scorched,  though  many  people  escaped  who 
were  within  this  outer  zone.  Other  eruptions  occurred  on 
May  26,  June  9,  July  9  and  11.  On  August  30,  after  a  period 
of  quiet  during  which  the  residents  around  the  mountain  were 
beginning  to  become  reassured  and  the  fugitives  to  return,  a 
second  blast,  as  sudden  and  fierce  as  the  first,  was  blown  out, 
directed  this  time  to  the  south  and  east,  which  destroyed  a  new 
area  of  country.  Heilprin  had  actually  visited  the  crater  on  the 
previous  day  and  was  on  the  margin  of  the  cloud  when  the  blast 
occurred.  It  is  the  nature  of  this  blast  which  is  of  the  utmost 
interest ;  the  shower  of  ashes  which  preceded  it  and  the 
torrential  rain  due  to  the  violent  disturbance  of  the  atmo- 
sphere, which  washed  down  this  ash  and  covered  everything 
with  a  slimy  coating  of  grey  ash,  are  phenomena  which  are 
well  known  from  other  volcanoes  in  their  explosive  stage. 

Pliny,  Epistola  XX.,  describes  a  similar  blast  in  the  eruption 
of  Vesuvius  in  79  a.d.,  an  eruption  of  a  volcano  likewise  starting 
activity  after  a  lengthy  period  of  quiescence :  "  Ab  altero  latere 
nubes  atra  et  horrenda  ignei  spiritus  tortis  vibratisque  discursibus 
rnpta  in  longas  flammarum  figuras  dehiscebat ;  fulguribus  illce 
et  similes  et  majores  erant,"  which  we  may  translate,  with  the 
accounts  of  the  eye-witnesses  of  the  Mont  Pelee  eruption  to 
guide  us  :  "  From  the  other  side  a  black  and  terrible  cloud — 
the  spirit  of  fire— belched  forth  with  whirling  and  quivering 
offshoots,  and  rent  with  long  trails  of  flame  like  flashes  of 
lightning,  only  broader."  Earl  Orrery  in  his  translation  renders 
spiritus  ignei  as  "  charged  with  combustible  matter,"  but  the 
sense  seems  to  be  more  the  "essence"  or  "soul  of  fire";  the 
descriptions  of  those  who  breathed  this  "spirit  of  fire"  and 
the  condition  of  the  bodies  both  at  Pompeii  and  Saint  Pierre 
seems  to  point  to  something  more  than  combustible  matter  or 
even  heat. 

Two  people  escaped  from  the  area  of  all  but  total  destruction. 


RECENT  WORK  ON  VOLCANOES  87 

Of  these,  Leon  Compere-Leandre,  a  shoemaker,  was  sitting  on  his 
doorstep  at  the  time  of  the  blast ;  he  rushed  indoors  and 
sheltered  himself  under  the  table.  Four  others  came  running 
into  the  room,  one  of  whom,  a  child  of  ten  years,  dropped  dead 
and  the  others  fled.  He  himself  came  out  from  under  the 
table  and  went  into  another  room,  where  he  found  an  old  man 
who  had  fallen  dead  on  his  bed ;  the  corpse  was  blue  and 
swollen,  but  the  clothes  were  intact.  After  finding  the  rest  of 
the  people  in  the  house  were  dead,  he  threw  himself  on  his  bed 
and  lost  consciousness.  At  the  end  of  an  hour  he  woke  up 
to  find  the  roof  burning ;  then,  covered  with  burns,  he  fled  and 
reached  Fond-Saint-Denis,  three  miles  distant,  where  he  was 
attended  to.  He  said  that  he  had  not  felt  a  sensation  of  suffoca- 
tion nor  was  there  a  want  of  air,  only  that  the  air  was  burning. 

The  other  man  who  escaped  was  Auguste  Ciparis,  a  negro, 
who  was  shut  up  in  a  cell  in  the  prison  without  a  window  and 
only  a  narrow  grating  in  the  door.  He  was  waiting  for  his 
usual  breakfast  on  the  8th  when  it  suddenly  became  dark ; 
immediately  afterwards  hot  air  entered  his  cell  through  the 
grating.  It  came  gently  but  fiercely.  There  was  no  smoke 
nor  noise  nor  odour  to  suggest  burning  gas,  but  it  burnt  his 
flesh  ;  he  was  clad  in  his  hat,  shirt,  and  trousers,  but  these  did 
not  take  fire,  yet  beneath  his  shirt  his  back  was  terribly  burned. 
The  water  in  his  jug  was  not  affected  and  this  was  all  the 
nourishment  he  had  till  he  was  rescued  three  days  later. 

Most  of  the  victims  seemed  to  have  succumbed  instanta- 
neously, as  if  from  a  blast  of  choke-damp.  Some  were  burned 
internally,  having  as  the  coal  miners  say,  "  swallowed  fire  " ; 
in  some  instances  their  heads  burst ;  others  were  scorched  all 
over.  A  doctor's  carriage  stood  ready  before  the  house  with 
the  charred  body  of  the  horse  in  its  place  before  the  carriage ; 
the  metal  parts  remaining  showed  that  it  had  not  moved  and 
the  coachman  was  by  its  side.  Clothing  was  never  burned, 
but  the  victims  in  the  streets  had  their  clothes  torn  off  them 
by  the  rush  of  the  blast,  as  happens  sometimes  in  a  severe 
tornado  in  America.  People  in  the  outer  zone  who  were 
rescued  fell  into  two  classes  :  those  who  were  burned  internally 
— that  is  to  say,  the  upper  part  of  the  respiratory  canal  was 
destroyed  ;  these  all  died.  Of  the  others,  some  were  singed 
all  over,  whilst  some  again  were  burned  on  the  face  and  on 
their  hands,  and  these  mostly  recovered  quickly. 


88  SCIENCE  PROGRESS 

The  evidence  seems  to  point  to  the  blast  having  been  made 
up  of  an  intensely  hot  heavy  gas.  Sulphurous  vapours  were 
given  out  before  the  blast  but  did  not  accompany  it.  M.  Molinar, 
who  observed  the  whole  occurrence  from  Mont  Parnasse, 
relates  that  the  volcano  vomited  fire  during  a  quarter  of  an 
hour  and  then  became  completely  quiet ;  at  eleven  o'clock,  lava 
and  smoke  began  to  pour  out.  Had  the  blast  been  water- 
vapour,  there  should  have  been  some  clouds  due  to  the  con- 
densing vapour,  but  though  the  wind  was  blowing  away  from 
where  M.  Molinar  stood  and  the  view  was  perfectly  clear,  no 
clouds  were  seen  to  form.  The  statements  at  any  rate  establish 
the  fact  that  a  volcano  can  discharge  a  mass  of  gas  downwards 
and  that  this  gas  is  like  that  of  a  mine  explosion.  It  desiccates, 
as  witness  the  trees  in  the  outer  zone  which  were  rendered 
sapless,  but  the  leaves  still  hung  from  the  brittle  twigs  ;  and 
it  is  certainly  not  water-vapour.  What  this  gas  is  can  only  be 
guessed  from  Brun's  researches. 

Dr.  Brun  commenced  his  work  in  1901  and  finished  his  field 
observations  in  1910(6).     During  this  time  he  had  visited  the 
Italian  volcanoes,  those  of  the  Canary  Islands,   Java  and   the 
Hawaiian  Islands.      His  laboratory  work  consisted    in    deter- 
mining the  melting-points  of  rocks  and  rock-forming  minerals, 
especially  those  of  volcanic  origin,  and   the  analysis  of  gases 
collected  from  actual  volcanoes  either  in  the  explosive  stage  or 
driven  out  of  lavas   in  which   they  had   become   dissolved   or 
occluded  during  cooling.     Brun's  method   in   the  field   may  be 
gathered   from   his  account  of  the   ascent   of   Mount   Semeroe 
in  Java.     Having  watched  the  crater  in  eruption  from  a  distance 
for  some  time,  Brun   desired  to  look   down  into   the  working 
chimney.     Profiting,  then,  by  an  interval  between  two  explosions 
he  rapidly  approached  and  stood  on  the  actual  rim  of  the  crater. 
He  was  able   to  snap  three   photographs  one  after   the  other. 
Hardly  had  he  finished  when  an  explosion  burst  out— still  he 
could  photograph,  though  incandescent  blocks  fell  all  around. 
He  observes  that  investigations  made  overlooking  the  volcanic 
orifices  during  the  paroxysmal  stage  are  very  rare  and  to  profit 
by  them  one  must  have  complete  control  over  oneself  and  know 
beforehand   on   what    one    must    concentrate    one's    attention. 
When  he  arrived  at  the  rim  of  the  crater  the  western  chimney 
of  the  three  that  were  filled  with  liquid  lava  was  belching  forth 
gas  and  bluish  smoke ;  little  masses  of  lava  were  being  gently 


RECENT  WORK  ON   VOLCANOES  89 

lifted  and  from  the  resulting  crack  gas  was  being  vigorously 
expelled,  rising  with  a  violent  whirling  motion  like  that  of  a 
water-spout.  The  gas  and  fumes  were  insoluble  in  air.  At  the 
moment  of  the  explosion  not  much  could  be  seen,  but  from  the 
number  and  velocity  of  the  ejected  blocks  it  was  evident  that 
the  nearest  chimney  had  entirely  emptied  itself.  The  rim  on 
which  he  stood  was  swept  with  fumes,  but  there  was  no  con- 
densation of  moisture  on  the  cool  surface  of  the  rocks.  On 
another  occasion  Brun  thrust  his  geological  hammer  into  the 
uprushing  stream  of  gas  and  no  water  was  condensed  on  the 
bright  metallic  surface. 

In  a  neighbouring  volcano,  Bromo,  the  continued  explosions 
prevented  Brun  from  looking  down  into  the  crater.  So  he 
caused  a  little  platform  to  be  cut  in  the  loose  cinders  just  under 
the  rim  on  the  outside ;  on  this  he  established  his  battery  of 
thermometers,  barometers  and  hygrometers,  and  also  a  little 
pump  which  had  attached  to  it  a  long  train  of  glass  tubes 
connected  by  indiarubber  joints,  which  was  dangled  into  the 
crater.  When  an  explosion  took  place  the  hygrometer  showed 
no  excess  of  moisture  in  the  air.  I  can,  however,  find  no 
account  of  an  analysis  of  the  gas  thus  collected  directly  from 
the  throat  of  the  volcano  by  the  pump.  Elsewhere  Brun  relies 
on  the  gases  occluded  in  the  lavas ;  these  are  expelled  on 
heating  the  rock  to  a  certain  temperature  above  the  melting- 
point.  Plutonic  rocks  and  lavas  which  have  been  in  existence 
for  long  geological  periods  are  "  dead,"  and  do  not  contain,  or 
have  lost,  occluded  gases.  Recent  lavas  when  heated  to  their 
explosion-point  suddenly  give  off  with  tremendous  violence 
large  quantities  of  chlorides — magnesium,  iron,  and  silicon — 
together  with  ammonium  chloride,  carbon  dioxide,  carbon 
monoxide,  marsh  gas,  chlorine,  hydrogen  chloride,  and  less 
frequently  sulphur  dioxide  and  sulphuretted  hydrogen,  and 
lastly,  hydrogen  and  nitrogen,  but  neither  oxvgen  nor  water. 
Gautier  (7)  points  out,  however,  that  the  gases  of  fumaroles  are 
generally  hydrous.  But  then  fumaroles  belong  to  a  late  stage 
of  the  volcano,  when  the  activity  is  dormant  and  water  from 
the  surrounding  rocks  can  percolate  and  attain  to  the  hot  centre  of 
the  volcano  and  thence  be  driven  up  to  the  surface  of  the  earth. 

Fouqu6's  analyses  of  the  gases  from  Santorin  in  1866  (8), 
although  collected  from  the  surface  of  sulphurous  water  in  a 
fissure,  contained  only  traces  of  oxygen  but  nearly  30  per  cent. 


90  SCIENCE  PROGRESS 

of  hydrogen,  nitrogen  and  carbon  dioxide  practically  making  up 
the  rest.  Specimens  of  the  gas  taken  in  later  stages  show  a 
progressive  increase  in  oxygen  and  in  carbon  dioxide.  The  fact 
that  chlorides  of  magnesium  and  iron  are  deposited  on  cinders 
around  the  crater  again  proves,  according  to  Brun,  that  the 
exhalations  of  volcanoes  are  anhydrous.  The  "  steam "  of 
volcanoes  consists  of  volatile  chlorides,  mostly  ammonium 
chloride.  If  the  "steam"  had  been  water-vapour,  it  would 
dissolve  in  air  and  soon  disappear.  The  white  cloud,  on  the 
contrary,  remains  suspended  during  long  periods  over  the 
volcano  and  the  wind  may  carry  it  many  miles  to  leeward. 
The  most  positive  evidence  Brun  advances  is  his  measurement 
of  the  humidity  of  the  cloud  given  off  from  the  pit  of  Kilauea  in 
eruption  relatively  to  the  humidity  of  the  air  outside.  In  a  long 
series  of  observations,  he  found  that  there  was  less  moisture  in 
the  cloud  than  outside  it,  and  consequently  he  inferred  that 
there  was  no  water-vapour  in  the  exhalation.  On  the  other 
hand,  the  cloud  of  the  fumaroles  on  the  north  of  the  pit,  in 
action  at  the  same  time  as  the  volcano,  contained  much  water- 
vapour.  Gautier  found  from  62  to  77  per  cent,  of  water-vapour  in 
the  fumaroles  of  Vesuvius  after  the  eruption  of  1906  ;  but  in  view 
of  Brun's  work  in  Hawaii,  one  is  not  justified  in  maintaining  that 
the  gases  of  the  central  chimney  must  equally  be  hydrous. 
Moissan's(9)  analyses  of  the  gases  of  the  Mont  Pelee  fumaroles, 
interesting  from  the  fact  that  considerable  quantities  of  argon 
were  discovered  in  them,  show  large  amounts  of  oxygen  and 
water-vapour.  It  will  be  remembered,  also,  that  in  the 
beginning  water  was  pumped  up  into  L'£tang  Sec  and  caused 
the  mud-rush  which  overwhelmed  the  Usine  Guerin.  That  is 
to  say,  when  a  volcano  begins  to  work  after  a  period  of 
quiescence,  the  volcanic  gases  drive  before  them  the  water 
contained  in  the  crevices  and  pores  of  the  rocks  ;  then,  when  the 
eruption  ceases,  the  same  water  from  the  surface  seeks  to 
penetrate  again  into  the  cracks  which  it  previously  occupied. 
As  the  pressure  of  the  volcanic  vapours  grows  less  and  less, 
the  surface  water  advances  more  and  more  into  the  heated  area, 
till,  coming  at  last  into  the  neighbourhood  of  the  cooling  molten 
rock,  it  is  driven  forth  in  the  form  of  aqueous  vapour  mixed 
more  or  less  with  volcanic  products. 

The  elements  of  water,  it  is  true,  are  found  in  the  volcanic 
exhalations,  but  combined  with  carbon,  chlorine,  or  nitrogen. 


RECENT  WORK  ON  VOLCANOES  91 

The  combined  nitrogen  appears  to  be  the  result  of  the  action 
of  hydrogen  on  metallic  nitrides.  Silvestri  (10)  actually  found 
nitride  of  iron  on  the  surface  of  lava  from  Etna.  Metallic 
nitrides,  when  heated  with  hydrogen  or  water-vapour,  yield 
ammonia,  and  this  would  readily  form  sal-ammoniac  with  the 
hydrogen  chloride  of  the  exhalations. 

So  far  for  the  gases  given  off  from  volcanoes  ;  the  types  of 
volcanoes  that  yield  them  are  those  that  have  been  known  since 
the  earliest  times.     In  Iceland  and  in  the  Snake  River  Plains  of 
Idaho,   there   are   types   that    are    entirely    new    to    scientific 
literature.      The    commonly   known    types    are   mostly  those 
connected    with    the    folding    in    the    earth's    crust.      In    the 
Mediterranean   and  West   Indies   the   volcanoes   lie   uniformly 
at  the  back  of  the  great  folds ;  in  the  JEgean  and  in  Mount 
Ararat,  the  volcanoes  lie  in  a  "Schaarung"  or  knot  where  two 
systems  of  folds  meet.     In  Kasbek  and  Elbruz  the  cones  lie  in 
the  centre  axis  of  the  folds,  while  in  the  Andes  they  are  related 
at  any  rate  to  the  folds  in  that  they  follow  lines  of  weakness 
determined  for  them  by  the  curvature  of  the  strata.     In  Iceland 
and  in  Idaho,  the  whole  country  for  thousands  of  square  miles 
has  been  a  seething  mass  of  lava  and  the  vents  rise  through  it 
as  if  drilled  by  gases  that   have   come   through   a   semi-viscid 
magma  without  any  sort  of  order.     The   special   types   repre- 
sented here  are  the  explosion  rings,  the  slag  craters,  and  the 
buckler  cones;  then  there  are  the  fissure  eruptions  which  are 
well  known  and  the  volcanoes  of  block-uplift  which  are  new  to 
science.      Although  the  description  of  these  is  due  principally 
to  Dr.  Hans  Reck  from  examples  in  Iceland,  they  were  being 
investigated  by  Walther  von  Knebel  at  the  time  of  his  death. 
The    latter    with    two    companions    had    ascended    the    most 
wonderful  of  all  volcanoes,  the  Askja,  camping  on  the  shores  of 
the  lake  that  lies  in  the  south-eastern  corner  of  the  caldera  on 
top.     On  the  fatal  day,  July  10,  1907,  he  and  his  artist  friend 
Rudloff  had  taken  a  collapsible  boat  and  had  gone  for  a  row  ; 
when  the  third  member  of  the  party  returned  to   camp   there 
was  no  sign  of  the  others.     A  relief  party  was  immediately  sent 
out,  but  nothing  could  be  found  of  the  missing  ones.     Dr.  Reck 
the   following  year  visited   the   place   and   spent   eleven    days 
searching  for  a  clue  to  the  mystery;  the  only  result  was  the 
surmise  that  an  avalanche  of  rocks  had  overwhelmed  the  frail 
boat  and  its  freight. 


92  SCIENCE  PROGRESS 

Iceland  is  an  elevated  portion  of  a  plateau  of  basalt  and 
pelagonite  tuff  that  at  one  time  stretched  in  a  continuous  field 
from  Antrim  in  the  north  of  Ireland  to  Greenland,  a  distance  of 
a  thousand  miles.  The  Faroe  Islands  are  an  isolated  remnant 
of  this  plateau  ;  all  the  rest  has  sunk  beneath  the  sea.  The  first 
of  the  lavas  rests  on  the  topmost  beds  of  the  Cretaceous  system 
in  Scotland,  so  that  presumably  the  eruptions  commenced  in 
Eocene  times  and  are  still  going  on  at  the  present  day  in  the 
northern  part  of  the  area. 

On  the  other  side  of  the  Atlantic,  in  Oregon,  Washington, 
California,  Idaho,  and  Montana,  an  extent  of  country  larger 
than  France  and  Great  Britain  combined  has  been  flooded  with 
basalt ;  the  previous  topography  has  been  buried  under  lava 
2,000  ft.  thick  and  in  some  places  3,700  ft.  thick,  the  surface  of 
which  is  a  level  plain  like  that  of  a  lake-bottom.  In  the  Snake 
River  Plains,  a  part  of  the  larger  area,  the  lava  rolls  up  to  the 
base  of  the  hills  on  the  north  and  on  the  east  and  follows  the 
sinuosities  of  their  margin  as  the  waters  of  a  lake  follow  its 
promontories  and  bays.  The  basalt  rests  on  beds  of  lapilli 
which  may  reach  180  ft.  in  thickness,  and  these  in  turn  rest  on 
lacustrine  deposits.  I  follow  I.  C.  Russell's  description  of 
this  area  (11). 

Explosion  Rings. — These  are  the  more  primitive  forms  of 
what  Judd  calls  crater  rings,  of  which  many  examples  occur  in 
Italy,  such  as  the  hollows  in  which  lie  the  lakes  of  Bolseno, 
Bracciano,  Albano,  Nemi,  and  Frascati.  The  simplest  of  all 
occur  in  Idaho  near  Cleft,  where  there  are  two  circular  holes 
drilled  through  the  basalt  without  any  elevated  rings.  Their 
diameters  are  1,100  and  800  ft. ;  the  encircling  cliffs  rise  200  ft. 
above  the  floor,  which  is  composed  of  fine  yellow  soil.  In 
Iceland  (13)  we  find  a  slight  development;  the  type  is  the 
Hrossaborg,  near  Akureyri,  the  capital  of  North  Iceland.  Here 
the  plains  consist  of  doleritic  lava  overlying  pelagonite  tuff,  and 
the  volcanic  eruption  has  lifted  up  a  portion  in  the  form  of 
a  circular  hill  with  a  crater,  some  800  yards  in  diameter,  on  top. 
The  only  products  of  the  volcano  were  gases  which  have  drilled 
the  circular  chimney  and  elevated  the  rocks  around.  The  inner 
walls  of  the  crater  are  120  ft.  high,  and  on  all  sides  the  rocks 
slope  outwards.  It  is  a  typical  crater  of  elevation  according  to 
Leopold  von  Buch,  only  unfortunately  we  cannot  apply  this 
term  to  this  type  now,  as  the  original  name  was  used  erroneously 


RECENT  WORK  ON   VOLCANOES  93 

for  the  ordinary  strato-volcanoes  which  are  built  up  of  successive 
layers  of  ash  and  lava-flows  from  the  actual  chimney  that  they 
surround  ;  in  the  Hrossaborg  the  lava  and  ashes  are  older,  and 
came  from  other  volcanic  vents  or  fissures. 

From  these  explosion  rings,  or  Gasmaare,  as  Beck  calls 
them,  we  pass  to  the  well-known  crater  rings  surrounded  with 
low  crater  walls  formed  of  tuff  and  lava  ejected  from  the  volcano. 
Many  examples  occur  in  Iceland  and  Idaho,  but  no  special 
mention  of  these  is  necessary  here,  unless  to  point  out  that 
in  Idaho  vast  streams  of  lava  issued  from  them.  These  heads 
of  the  lava  columns  are  covered  with  scoriaceous  and  ropy  lava, 
which  makes  them  look  like  the  tops  of  great  springs  of  water 
suddenly  congealed.  In  one  case,  a  particular  lava-flow  had  its 
origin  in  two  such  pools,  and  a  mile  from  its  source  it  was 
joined  by  a  still  larger  river  of  lava.  The  united  streams  flowed 
some  thirty  miles,  descending  about  a  thousand  feet,  more  than 
half  of  the  fall  being  in  the  first  ten  miles,  so  that  the  distal 
portions  flowed  on  a  gradient  of  i  in  200.  Other  streams  have 
flowed  for  fifty  miles  in  the  same  area  in  rivers  of  molten  rock 
one  to  three  miles  across  and  300  ft.  in  thickness. 

Slag  Craters. — Two  volcanoes  of  this  type  are  described 
by  Russell  from  Idaho.  Blanche  Crater  rises  about  60  ft. 
above  the  plains,  and  has  a  perfect  crater  on  top ;  the  conical 
pile  is  composed  of  thin  cakes  of  highly  vesicular  lava,  which 
have  been  blown  out  in  a  plastic  or  liquid  condition.  It  is  of 
quite  recent  origin,  as  it  lies  in  a  canyon  excavated  500  ft.  in 
the  older  lava.  The  other  example  is  the  Martin  Butte,  like- 
wise a  conical  pile  of  scoriaceous  lava.  In  Iceland,  slag  cones 
are  extremely  common  and  form  the  most  weird  objects  in  the 
landscape,  as  the  viscid  lava  has  built  up  piles  of  all  shapes, 
resembling  towers,  organ-pipes,  needles,  or  gigantic  skittles  (12). 
They  vary  from  150  ft.  in  height  to  quite  small  hornitos  or 
blowing  and  driblet  cones.  They  are  often  assembled  in 
swarms,  as  if  a  great  mass  of  gas  had  pierced  a  viscid  covering 
along  a  number  of  independent  channels.  They  frequently 
form,  also,  the  caps  of  the  next  type  of  volcano. 

Buckler  Cones. — One  example  has  been  described  from 
Idaho,  the  Black  Butte;  it  rises  300  ft,  with  a  base  two  miles 
in  diameter.  It  is  built  up  of  successive  layers  of  highly 
scoriaceous  lava,  which  flowed  away  in  all  directions,  and  there 
is  no  evidence  at  all  of  lapilli  or  cinders.    There  is  no  crater 


94  SCIENCE  PROGRESS 

on  top,  the  last  lava-flow  having  filled  it  up.  In  Iceland  this 
form  is  very  common,  some  nineteen  "  Dyngjen  "  being  known, 
but  owing  to  the  low  angle  of  the  cone,  the  slope  varying  from 
6°  to  8°,  they  are  easily  overlooked,  especially  in  the  snow- 
covered  area.  One  such  buckler  cone,  the  Skjaldbreid,  is  3,000  ft. 
high,  and  seven  miles  in  diameter  at  the  base;  it  has  a  small 
crater  on  top,  but  others  may  have  very  large  ones.  In  the 
Kalotta  Dyngja,  a  post-volcanic  fissure  has  cut  through  the 
cone,  and  it  is  therefore  possible  to  study  its  internal  structure. 
Mauna  Toa,  in  Hawaii,  belongs  to  this  type,  although  the  great 
spreading  base  is  concealed  beneath  the  ocean. 

Fissure    Eruptions. — Iceland   has   long  been    known    as    the 
typical  locality  of  this  type  of  volcano.     The  eruption  of  Laki, 
or  Skapta  Jokiill,  occurred  in   1783.     The  first  eruption  took 
place  on  June  8,  and  was  accompanied  by  tremendous  detona- 
tions and  earthquake  shocks.     A  great  black  bank  of  ash  was 
thrown  into  the  air,  in  which  several  up-rushing  columns  could 
be  seen ;  that  is  to  say,  the  explosions  occurred  at  several  places 
along  the  fissure.    Later  on,  the  explosive  stage  became  confined 
to  the  southern  half,  while  the  northern  half  poured  out  lava, 
as   was   evident   from   the   reflection   of  the  glowing   mass  in 
the  overhanging  canopy  of  cloud.     On  June  12  a  lava  stream, 
200  yards  wide,  had  flowed  nine  miles  down  the  bed   of  the 
Skapta  River.     The  lava  in  this  part  is  covered  with  hornitos, 
little   blowing  cones,  whose   origin  is  ascribed   to  the   escape 
of  water-vapour  which  the  lava  had  absorbed  from  the  river 
water.     Towards  the  end  of  June  the  eruptions  ceased  for  a 
time,  but  in  the  beginning  of  August  activity  was  renewed,  and 
stream  after  stream  of  lava  flowed  down  the  river-beds,  destroy- 
ing all  the  meadow  land   adjoining.     After   a   period   of  rest, 
the   eruptions   started   again   on   October   25,  when  the   entire 
plain  in  the  neighbourhood  became   a  glowing  lake   of   lava, 
and  the  molten  rock  continued  to   flow   during  the  whole   of 
November.      All   this   time   the   air   was   filled   with    ash    and 
sulphurous  vapours,  and   the  vegetation  over  a  large  part  of 
the   island   was   killed ;   half  the   animals   perished,   and    5,000 
people,  out  of  a  total  population  of  50,000,  died  of  famine  or 
disease.   Iceland  is  full  of  such  fissures,  as  also  in  all  probability 
was  the  whole  basaltic  plateau  of  which  it  is  part.     The  effect 
of  fissure   and   other  eruptions  occurring  more  or  less  simul- 
taneously over  an    area   little  short  of  a  million  square  miles 


RECENT  WORK  ON  VOLCANOES  95 

must  have  had  a  far-reaching  influence  on  the  climate  of  the 
world ;  one  can  almost  assert  that  it  was  this  which  was  the 
cause  that  enabled  a  tropical  flora  to  flourish  in  the  Eocene 
period  close  to  the  North  Pole,  and  that  the  epidemics  con- 
sequent on  the  pollution  of  the  air  were  a  factor  at  any  rate  in 
the  extermination  of  the  Mesozoic  types  of  animals.  Not  only 
in  North  Europe  and  America  were  these  volcanic  outbursts 
active,  but  in  India  the  Deccan  traps  were  extruded  at  about 
the  same  time,  and  also  probably  the  lavas  of  the  Mawi 
plateau  in  Central  Africa.  Contemporaneously  with  these 
eruptions  the  crumpling  of  the  earth's  crust,  which  gave  rise 
to  the  Alps-Himalayan  chains  and  the  folds  of  the  east  of  the 
Pacific,  was  also  started  ;  the  vast  dislocations  of  the  earth's 
crust  and  the  floods  of  lava  which  issued  from  it  in  certain 
parts,  bring  up  the  question  whether  this  solid  earth  can  con- 
tain within  itself  such  terrific  forces  of  disruption ;  or  whether 
it  is  not  more  reasonable,  seeing  that  we  have  recently  had 
visitors  from  celestial  space  such  as  the  planetoids  Eros  and 
M.T.,  which,  had  they  fallen  upon  the  earth,  would  have  caused 
just  such  disturbances,  to  ascribe  the  early  Cainozoic  eruptions 
and  crumplings  to  causes  operating  from  without. 

Volcanoes  of  Block-Uplift. — Reck  (13)  calls  these  Tafelberg- 
horste,  but  in  Iceland  they  always  have  a  volcano  on  top.  The 
question  whether  they  are  horsts,  that  is,  blocks  from  which 
the  neighbouring  country  has  been  faulted  away,  or  whether 
they  owe  their  origin  to  vertical  uplift,  is  a  matter  very  difficult 
to  decide.  In  the  Utah  and  Colorado  plateaux,  the  whole 
country  is  parcelled  out  in  long  strips  and  the  difficulty  of 
explaining  the  occurrence  here  is  as  great  one  way  as  the 
other.  If  the  valleys  between  the  long  plateaux  had  been 
faulted  down,  how  could  the  strips  between  have  been  sus- 
tained, with  the  earth's  crust  all  shattered  around  them?  It  is 
like  the  case  of  a  pancake  laid  on  a  gridiron,  but  then  the  rods 
of  the  gridiron  are  here  represented  by  narrow  slips  of  rock 
fifty  or  more  miles  long,  and  these  are  not  strong  enough  to 
allow  of  suspension  from  the  ends.  Masses  of  igneous  rock 
pumped  up  by  hydraulic  pressure  would  supply  an  elevatory 
force  for  the  plateaux,  and  this  seems  a  more  reasonable 
explanation ;  hence  these  Colorado  and  Utah  plateaux  are  still 
called  mountains  of  block-uplift.  In  the  Ries  (14)  in  Germany, 
again,   there    is   a   circular    depression    some   fifteen    miles   in 


96  SCIENCE  PROGRESS 

diameter;  it  is  surrounded  by  Jurassic  strata  resting  on 
granite,  whilst  in  the  depression,  whose  floor  is  the  same  granite, 
the  level  of  this  rock  is  above  that  in  the  surrounding  country, 
where  it  is  covered  with  sedimentary  beds.  The  Ries  granite, 
then,  is  a  gigantic  plunger  which  has  been  elevated  by  volcanic 
forces,  and  the  balance  of  evidence  seems  to  indicate  that  the 
fault-blocks  of  Iceland  have  been  elevated  in  a  similar  manner, 
although  they  are  bounded  by  quadrilateral  and  not  circular 
faults. 

The  simplest  example  of  a  volcano  of  block-uplift  is  the 
Herdubreid  in  the  lava  desert  of  the  Odadahraun.  The  cliffs 
surrounding  the  block  are  some  i, 800  ft.  high,  300  ft.  of  which 
are  concealed  under  tabus  heaps.  The  rock  comprising  them  is 
brown  pelagonite  tuff,  covered  on  top  with  the  basalt,  which 
flowed  from  the  central  chimney.  The  volcano  is  of  the  buckler 
type,  with  a  deep  central  crater,  from  which  lava  poured  out  in 
a  symmetrical  low  angle  cone.  It  is  5,450  ft.  high  and  rises 
some  4,000  ft.  above  the  plain.  The  walls  of  the  pedestal  on 
which  the  lava  rests  are  kept  quite  fresh  by  the  enormous 
weathering  that  goes  on  in  such  regions  ;  there  is  no  sign  of 
any  fissure  traversing  them  by  which  the  volcanic  gases  could 
have  risen  to  form  the  chimney.  The  block  has  been  driven 
upwards  between  two  sets  of  crossing  faults  and  an  escape 
vent  has  been  drilled  in  the  centre  through  the  solid  rock. 

To  the  south-west  of  the  Herdubreid  lies  the  much  larger 
Dyngjufjoll  block,  with  the  square  caldera  of  Askja  at  its 
summit.  The  lava  desert,  with  its  surface  so  scoriaceous  and 
rent  with  chasms  that  it  is  all  but  impossible  to  traverse,  is 
here  covered  with  pumice  thrown  out  by  the  Rudloff  crater 
which  lies  in  the  Askja.  A  narrow  gorge,  the  Askja  Op,  leads 
up  to  the  top  at  the  north-eastern  corner.  On  entering  the 
Askja,  one  finds  oneself  in  a  wide,  level  plain  filled  with  slaggy 
lava  and  surrounded  on  all  sides  by  steep  hills,  whose  crests 
turn  round  at  right  angles  and  enclose  the  square  caldera. 
The  area  of  the  depressed  lava-field  is  about  sixteen  square 
miles.  The  surrounding  hills  rise  from  it  1,000  to  1,200  ft., 
but  from  the  outside  the}'  rise  from  2,000  to  2,500  ft.  The  outer 
dimensions  of  the  block  are,  roughly,  fifteen  miles  on  all  four 
sides.  The  remarkable  fact  about  the  Askja  is  that  the  boundary 
hills  are  made  of  the  older  pelagonite  tuff  of  the  same  nature  as 
that  forming  the   pedestal   on   which  the   Herdubreid  volcano 


RECENT  WORK  ON   VOLCANOES  97 

stands.  In  the  Askja  the  volcano  was  formed  in  the  same  way, 
but  towards  the  end  of  its  activity  the  mass  of  lava  collapsed, 
leaving  a  rim  of  the  pelagonite  tuff  standing  all  round. 

In  the  south-eastern  corner  lie  the  two  crater  lakes,  the  von 
Knebel  and  the  Rudloff  lakes.  The  former  is  much  the  larger ; 
it  lies  against  the  marginal  hills  which  rise  1,500  ft.  above  the 
level  of  the  water  in  step-like  or  vertical  cliffs.  On  the  north 
and  west  the  walls  are  made  of  the  Askja  basalt  in  which  the 
lake  is  sunk  180  ft.  Owing  to  the  great  steepness  of  the  sides, 
there  is  a  continual  falling  of  stones,  some  of  which  shoot  out  a 
couple  of  hundred  feet  into  the  lake.  Along  the  southern  shore 
there  are  a  great  number  of  solfataras. 

The  Rudloff  lake,  so  named  after  the  artist  who  was  with 
von  Knebel  when  he  met  his  death,  is  of  much  more  recent 
origin.  It  was  formed  in  the  eruption  of  1875,  and  the  pumice 
thrown  out  of  this  small  orifice  still  covers  all  the  eastern  side 
of  the  island.  There  is  a  small  crater  ring  round  it,  rising  some 
35  ft.  above  the  Askja  lava,  but  the  level  of  the  lake  is  180  ft. 
below  it.  The  water  is  milky  white  and  still  steaming,  while 
from  the  surrounding  walls  solfataras  gush  forth,  covering  the 
rocks  with  sulphur  and  gypsum  crystals. 

The  Dyngjufjoll  with  its  Askja  caldera  stands  isolated  and 
almost  in  the  centre  of  eastern  Iceland.  No  vegetation  grows 
upon  it  and  there  is  none  within  many  miles ;  all  around  are 
the  plains  of  bare,  black  lava,  covered  in  places  with  the  grey 
pumice  of  the  Rudloff  crater.  The  ponies  carrying  supplies 
have  to  be  driven  back  to  grazing-ground  immediately  they  have 
been  off-loaded,  and  should  an  expedition  be  cut  off  by  storms 
or  by  other  mishap  from  relief  from  outside,  it  would  be  quite 
impossible  for  the  members  of  the  expedition  to  reach  safety. 
Caldera  are  now  known  from  many  examples,  such  as  the  above- 
mentioned  case  of  the  Ries  in  Swabia,  and  there  is  an  excellent 
instance  of  one  in  Glen  Coe  in  Scotland  (15).  These  types 
simply  show  a  central  plunger  with  crush  zones  and  volcanic 
products  round  the  rim.  In  the  Hegau(i4),  not  far  from  the 
Ries,  we  have  an  example  where  the  floor  of  the  depression  is 
flooded  with  lava.  All  these  are  circular  pits ;  it  was  not  till  the 
Icelandic  occurrences  were  described  that  the  relationship 
between  the  caldera  and  faulting  became  clear.  In  the  Askja, 
in  addition,  we  have  two  sets  of  faults :  an  outer  set  by  which 
the  block  was  elevated  either  relatively  to  the  surrounding 
7 


98  SCIENCE  PROGRESS 

country  or  absolutely ;  these  were  not  connected  with  volcanic 
outbursts.  Then  followed  a  collapse,  and  along  the  faults  thus 
developed  inside  and  parallel  to  the  old  ones  lava  was  extruded 
and  explosive  volcanoes,  like  the  Rudloff  crater,  broke  out. 
The  two  blocks  fit  into  one  another  like  the  joints  of  a  telescope, 
and  the  last  stage  of  the  Askja  volcano,  judging  from  the  Ries 
and  other  caldera,  will  be  that  the  inner  core  will  rise  through 
the  outer  rim  and  finally  settle  as  an  elevated  block. 

Bibliography 

i.  A.  Lacroix,  "La  Montagne  Pele*e  et  ses  Eruptions,"  Paris,  1904. 

2.  Tempest  Anderson  and  John  S.  Flett,  Report  on  the  Eruptions  of  the 

Soufriere  in  St.  Vincent  in  1902,  and  on  a  Visit  to  Montagne  Pelde  in 
Martinique,  Phil.  Trans.  A.,  vol.  200,  p.  353,  1903 ;  and  vol.  208,  p.  275, 
1908. 

3.  I.  C.  Russell,  Volcanic  Eruptions  in  Martinique  and  St.  Vincent,  Smithsonian 

Inst.,  Ann.  Rept.for  1902,  Washington,  1903. 

4.  Angelo  Heilprin,  "Mont  Petee,"  Philadelphia,  1903. 

5.  Camille  Flammarion,  "Les  Eruptions  Volcaniques,"  Paris. 

6.  Albert  Brun,  "  Recherches  sur  l'exhalaison  volcanique,"  Geneva,  191 1. 

7.  A.  GAUTIER,  Comptes  Rendus,  vol.  148,  1909,  p.  1705  ;  vol.  149,  1909,  p.  84. 

8.  F.  Fouque,  "Santorin  et  ses  Eruptions,"  Paris,  1879. 

9.  H.  Moissan,  Comptes  Rendus,  vol.  135,  1902,  p.  1085  ;  vol.  138,  1904,  p.  36. 

10.  O.  Silvestri,  Poggendor/'s  Annalen,  vol.  157,  1876,  p.  165. 

11.  I.  C.  Russell,  Geology  and  Water  Resources  of  the  Snake  River  Plains  of 

Idaho,  Bull.  U.S.  Geol.  Survey,  p.  199,  1902. 

12.  R.  Sapper,  Uber  islandische  Lavaorgeln  und  Hornitos,  Zeitschr.  d.  Deutsch. 

Geol.  Gesel.,  1910,  p.  214. 

13.  Hans  Reck,  Das  vulkanische  Horstgebirge  Dyngjufjoll  mit  den  Einbruchs- 

kalderen  der  Askja  und  des  Knebelsees  sowie  dem  Rudloff  Krater  in 
Zentral  Island,  Anhang  z.  d.  Abh.  Kgl.  Preuss.  Akad.  d.  Wiss.,  1910 ; 
W.  von  Knebel  and  H.  Reck,  "Island,"  Stuttgart,  1912;  H.  Reck, 
Islandische  Masseneruptionen,  Geol.  u.  Pal.  Abhandl.  Koke?t.  Neue  Folge, 
ix.,  1910. 

14.  W.  Branco,  Schwabens  125  Vulcan  Embryonen,  Stuttgart,  1894. 

15.  C.  T.  Clough,  H.  B.  Maufe,  and  E.  B.  Bailey,  On  the  Cauldron  Subsi- 

dence of  Glen  Coe,  Quart.  Journ.  Geol,  Soc,  vol.  55,  1909. 


A  CONTRIBUTION   TO  THE  BIONOMICS 
OF  ENGLISH  OLIGOCH^TA 

PART  I.    BRITISH   EARTHWORMS 

By  THE  REV.  HILDERIC  FRIEND,  F.L.S.,  F.R.M.S. 
no,   Wilmot  Road,  Swadlincote,  Burton-on-Trent.     April  10,  1913 

Scope  of  the  Inquiry. — The  annelids  fall  into  two  great  orders, 
which  are  known  respectively  as  Polychaets  and  Oligochsets. 
The  former  are  marine,  the  latter  terrestrial.  Polychaets  are 
so  named  on  account  of  the  large  number  of  bristles,  chaetae 
or  setae,  which  are  a  characteristic  of  many  of  the  species  ; 
while  the  Oligochaets  are  marked  by  the  comparative  fewness 
of  the  setae.  It  is  true  that  some  Polychaets  have  few  setae, 
and  some  Oligochaets  have  many,  but  that  simply  shows  that 
Nature  is  not  bound  by  human  laws,  or  that  no  system  of 
classification  is  perfect.  It  is  not  proposed  in  this  paper  to 
inquire  into  the  bionomics  of  the  Polychaets,  the  other  great 
order  being  more  than  sufficient  for  our  present  study.  The 
Oligochaets  fall  into  various  groups,  and  each  is  worthy  our 
most  careful  investigation.  But  in  order  that  we  may  gain  an 
accurate  knowledge  of  our  subject  it  is  necessary  to  restrict 
ourselves  to  those  species  which  are  indigenous  ;  and  as  these 
again  are  arranged  in  different  families,  each  of  which  has  its 
own  peculiarities,  the  inquiry  will  in  the  present  instance  be 
limited  to  the  largest  forms  of  terrestrial  annelids  found  in 
Great  Britain.  These  are  popularly  known  as  Earthworms, 
and  thus  we  are  reminded  of  that  interesting  and  instructive 
volume  by  Darwin  entitled  Vegetable  Mould  and  Earthworms. 

In  spite  of  the  splendid  lead  which  that  volume  gave  to  a 
subject  of  supreme  importance,  it  is  surprising  how  indifferent 
the  public  has  remained  to  the  life-history  and  economics  of 
this  class  of  animals.  Many  thousand  copies  of  the  work  were 
sold,  and  doubtless  hundreds  of  readers  opened  their  eyes  in 
amazement  as  they  read.  Then  the  book  was  closed,  and  the 
eyes  as  well,  never  to  be  reopened  except  in  the  case  of  one 

99 


ioo  SCIENCE  PROGRESS 

or  two  enthusiasts,  who  have  quietly  carried  on  the  work 
during  the  intervening  quarter  of  a  century,  with  very  amazing 
results.  The  time  has  now  come  when  it  is  possible  once  more 
to  survey  the  subject,  and  create  a  new  point  of  departure. 

The  Number  of  Species. — As  our  inquiry  is  limited  to  the 
British  Lumbricidae,  the  question  naturally  arises,  How  many 
species  of  Earthworm  are  there  in  the  British  Isles  ?  It  will 
be  instructive,  in  answer  to  that  query,  to  look  a  little  into 
the  history  of  the  subject.  In  1865  Dr.  G.  Johnston  compiled 
A  Catalogue  of  British  Worms,  based  on  the  collection  then 
found  in  the  British  Museum.  The  number  of  Lumbricidae 
there  recorded  is  eleven,  about  half  of  which  are  satisfactory, 
while  the  remainder  are  doubtful.  Under  one  or  two  headings 
we  find  more  than  one  species  confused,  while  in  other  cases 
the  same  species  appears  under  more  than  one  name. 

Darwin  does  not  allude  to  Johnston's  catalogue.  He  remarks 
that  "The  British  species  of  Lumbricus  have  never  been  carefully 
monographed ;  but  we  may  judge  of  their  probable  number 
from  those  inhabiting  neighbouring  countries.  In  Scandinavia 
there  are  eight  species,  according  to  Eisen  ;  but  two  of  these 
rarely  burrow  in  the  ground,  and  one  inhabits  very  wet  places 
or  even  lives  under  the  water.  Hoffmeister  says  that  the  species 
in  Germany  are  not  well  known,  but  gives  the  same  number 
as  Eisen,  together  with  some  strongly  marked  varieties." 

When  Dr.  Rosa  published  his  Revisione  dei Lumbricidi  in  1893 
he  enumerated  six  species  of  Lumbricus,  forty-nine  of  Allolobo- 
phora,  and  six  of  Allurus.  Thus  the  number  of  European  Lum- 
bricidae had  been  raised  to  upwards  of  sixty  species.  Beddard 
two  years  later  issued  his  Monograph  of  the  Order  Oligochceta 
(1895),  and  allowed  three  species  of  Allurus  with  Tetragonurus, 
fifty-two  of  Allolobophora,  and  seven  of  Lumbricus  known  to 
science.  The  following  year  (1896)  de  Ribaucourt's  Etude  sur 
la  Faune  Lombricide  de  la  Suisse  appeared,  and  no  fewer  than 
forty-four  species  of  Allolobophora  were  recorded  for  Switzer- 
land alone,  in  addition'  to  seven  species  of  Lumbricus  and  five 
of  Allurus.  Passing  over  the  work  of  Vaillant,  Oerley,  and 
others,  we  arrive  at  the  year  1900,  which  marked  the  appearance 
of  Michaelsen's  volume  on  Oligochceta  (Das  Tierreich,  x.),  in  which 
the  number  of  species  has  grown  beyond  all  bounds. 

My  own  researches  commenced  in  1890,  and  it  was  then 
assumed  that  our  native  Earthworms  numbered   half  a  score, 


THE   BIONOMICS  OF  ENGLISH   OLIGOCH^TA    101 

or  at  most  a  dozen  species.  To-day  the  figure  stands  at  forty 
and  upwards,  and  there  are  doubtless  still  several  discoveries 
to  be  made  in  our  gardens,  islands,  and  mountains.  It  is  with 
these  forty  species  that  we  are  immediately  concerned. 

Rarity  and  Frequency. — It  must  not  be  assumed  that  they 
are  all  generally  distributed  over  the  British  Isles.  In  a  few 
instances  the  species  is  represented  by  a  solitary  specimen, 
and  in  others,  while  the  number  of  specimens  is  unlimited, 
they  are  at  present  known  in  only  one  locality.  While  many 
are  common  throughout  the  country,  as  well  as  in  Europe, 
others  have  a  range  which  is  very  instructive.  Let  us  take 
a  few  examples.  In  1892  I  wrote  to  Dr.  Rosa  of  Turin  to  the 
effect  that  a  new  worm  (Lumbricus  papillosus  Friend)  had  turned 
up  in  Ireland.  He  alludes  to  it  in  an  appendix  to  the  genus 
Lumbricus  (op.  cit.  27),  and  notes  incidentally  that  the  name 
had  already  been  appropriated  by  O.  F.  Muller.  On  this 
account  Cognetti  afterwards  changed  it  to  Lumbricus  friendi. 
This  species  has  been  sought  unceasingly  in  every  part  of 
England,  Scotland,  and  Wales  without  a  trace  being  found, 
yet  I  no  sooner  landed  in  Dublin  in  March  last  and  began  my 
researches  than  it  turned  up  in  plenty.  In  1890  Michaelsen 
placed  it  in  his  list  of  species,  and  recorded  it  for  Switzerland, 
while  Southern  has  more  recently  remarked  that  "  L,  friendi 
is  common  in  the  south  of  Ireland.  On  the  Continent  it  is 
markedly  alpine  in  its  range,  and  is  only  found  at  considerable 
elevations  in  the  Pyrenees  and  the  Alps."  In  the  light  of 
Taylor's  recent  paper  on  "  Dominancy  in  Nature"  this  is  most 
instructive. 

We  may  compare  with  this  the  distribution  of  another  of 
our  British  Lumbricidae,  which,  so  far  as  I  am  aware,  has  never 
been  studied  by  any  other  investigator  but  myself.  In  1910 
I  was  spending  Easter  at  Bridlington,  and  found  a  solitary 
specimen  of  Octolasium  gracile  Oerley.  It  was  new  to  Britain, 
and  would  seem  to  be  gradually  working  towards  the  west. 
Up  till  the  present  it  has  never  been  found  in  Ireland,  Wales, 
or  the  West  of  England,  and  in  Scotland  and  the  Midlands  is 
very  rarely  seen.  Yet  in  the  autumn  of  191 1  it  was  the  dominant 
Lumbricid  at  Sutton  Broad  in  East  Anglia,  and  in  Epping 
Forest  and  elsewhere  in  the  south  and  east  it  is  quite  gre- 
garious. Unfortunately  Michaelsen  confuses  it  with  O.  lacteum, 
from  which,  in  England  at  least,  it  is  absolutely  distinct ;  and 


io2  SCIENCE  PROGRESS 

thus  we  are  unable  at  present  to  give  its  Continental  distribution 
with  certainty.  Oerley  found  it  near  Budapest  and  Vlissingen. 
He  also  found  it,  or  a  variety,  alike  in  Hungary  and  at  Woolwich. 
I  cannot  distinguish  the  Epping  Forest  forms  from  that  named 
O.  rubidum  Oerley.  Mons.  de  Ribaucourt  regarded  O.  gracile 
as  a  subspecies  of  O.  profugum,  and  records  it  as  such  for 
Switzerland.  Is  it  possible  that  in  England  it  has  developed 
along  definite  lines,  and  so  become  a  well-marked  species,  while 
in  Europe  its  affinities  with  O.  lacteum  Oerley  {=  O.  profugum 
Rosa)  are  still  clearly  marked  ? 

Some  curious  facts  relate  to  the  genus  Allurus.  It  was 
recorded  as  British  by  Johnston,  and  rediscovered  about  1890 
in  Dorsetshire  and  Devonshire.  The  type  {A.  tetrcedrus)  is  now 
known  to  be  one  of  our  commonest  worms.  It  occurs  in  every 
part  of  the  British  Isles  by  streams,  water-courses,  ditches, 
ponds,  and  water  generally.  The  type,  moreover,  is  very 
constant  in  this  country.  I  have  found  one  or  two  varieties 
in  different  parts  of  England,  but  they  have  been  marked  chiefly 
by  variations  in  colour  (as  var.  luteus,  etc.).  But  a  study  of 
monographs  will  reveal  the  fact  that  Allurus  is  not  a  simple 
species,  and  when  the  subject  has  been  more  carefully  studied 
its  lessons  will  be  very  instructive.  On  the  one  hand  we  find 
that  a  number  of  pigmy  species  are  found  in  the  Swiss  Alps, 
while  A.  hercynius  Mich,  has  once  been  found  in  Scotland, 
A.  tetragonurus  Friend  at  Bangor  in  Wales,  and  A.  macrurus 
Friend  at  Malahide,  near  Dublin.  Following  out  these  hints, 
we  conclude  that  A.  tetrcedrus  is  dominant,  and  that  the  allies 
have  been  forced  into  outlying  districts,  where  a  careful  search 
would  probably  be  rewarded  by  the  discovery  of  other  interesting 
forms.  If  the  West  of  England,  Wales,  and  Scotland  were 
explored  with  care  it  might  be  possible  to  gain  much  light 
on  some  of  the  problems  which  such  facts  as  these  suggest. 

Again  we  have  one  record  only  for  an  alpine  species  of 
Lumbricid  {Eisenia  alpina  Rosa),  although  we  certainly  ought  to 
find  others  in  the  highlands  of  Scotland  if  not  in  other  localities. 
1  shall  have  occasion  under  another  heading  to  speak  of  certain 
garden  worms  found  in  various  parts  of  the  country,  but  it  will 
be  well  to  observe  here  that  one  worm  {Octolasium  intermedium 
Friend)  has  hitherto  been  found  in  Oxford  Botanic  Gardens  only, 
Dendrobcena  merciensis  Friend  only  in  leaf  mould  in  Derbyshire, 
Hdodrilus  elongatus  Friend  (a  species  which  has  not  yet  been 


THE   BIONOMICS   OF   ENGLISH   OLIGOCH^ETA    103 

described)  in  a  garden  in  Cornwall,  to  say  nothing  of  certain 
more  or  less  well-known  species  which  occur  in  Kew  Gardens. 
During  the  spring  of  the  present  year  Allolobophora  antipce  Mich, 
was  found  by  me  at  Blenheim  Palace,  A.  norvegica  Eisen  and 
possibly  other  species  new  to  Britain  being  discovered  about 
the  same  time  in  Dublin.  All  these  have  a  bionomic  value  which 
is  unique,  and  suggest  the  need  of  a  much  more  systematic 
examination  than  has  ever  yet  been  undertaken. 

Having  referred  in  the  foregoing  section  to  those  species 
which  are  of  rare  occurrence  or  limited  range,  it  may  be  well  to 
add  that  a  certain  number  of  species  are  everywhere  to  be  met 
with.  Lumbricus  terrestris  L.  and  Allolobophora  longa  Ude  are 
the  dominant  types.  L.  rubellus  Hoff.  and  L.  castaneus  Savigny 
abound  in  meadows ;  L.  festivus  Sav.  being  less  common. 
A.  chlorotica  is  always  to  be  found  in  damp  places,  under  stones, 
and  near  the  haunts  of  cattle,  where  A.  caliginosa  (which  includes 
turgida  and  trapezoides)  is  also  frequently  discovered.  The 
brandling  and  gilt-tail,  to  be  mentioned  again  later,  are  ubiquit- 
ous, the  curious  tree  worms  are  fairly  common  in  old  tree  trunks, 
and  in  road  scrapings  one  is  pretty  sure  to  meet  with  D.  mam- 
malis.  In  gardens  and  fields  one  finds  two  species  of  Octolasium 
pretty  generally  distributed,  and  E.  rosea  is  another  of  the  widely 
known  species.  Having  just  completed  a  report  on  the  distribu- 
tion of  earthworms  in  England  I  may  refer  the  interested  reader 
to  the  pages  of  the  Zoologist  for  further  details. 

Habits  and  Habitats. — We  may  naturally  pass  on  to  a  little 
fuller  study  of  some  details  in  the  life-history  of  our  indigenous 
earthworms.  Is  it  possible  to  tell  where  certain  species  may  be 
found?  Can  one  judge  by  the  locality  what  species  are  likely 
to  occur  ?  The  answer  is  in  the  affirmative.  Thus  if  one  sees 
a  decaying  tree  trunk  in  a  moist  condition  he  may  be  pretty 
certain  that  he  will  not  look  in  vain  for  such  species  as  D.  arborea, 
D.  subrubicunda,  L.  castaneus,  B.  eiseni,  and  somewhat  rarely 
D.  octcedra.  Several  of  these  also  occur  in  leaf  mould,  along  with 
D.  merciensis,  L.  rubellus,  and  Eisenia  rosea,  veneta  or  foetida. 
The  latter  (E.  foetida  Sav.),  which  is  popularly  known  as  the 
Brandling,  is  the  first  to  attach  itself  to  stable  manure.  It  will 
thrive  in  such  material  long  before  any  other  species  can  find  a 
subsistence  in  the  strong  pungent  mass.  When  decomposition 
has  set  in,  however,  L.  terrestris,  L.  rubellus,  and  D.  subrubicunda 
will  become  common,  along  with  large  quantities  of  Enchytrceus 


104  SCIENCE   PROGRESS 

albidus  Henle.  Later  still  one  finds  A.  chlorotica,  A.  caliginosa, 
E.  rosea  and  other  forms.  Ditches  are  frequented  by  A  Hums 
tetrcedrus,  A. chlorotica,  D  .subrubicunda ,  D .  merciensis  and  O.gracile. 
And  here  it  may  be  remarked  that  the  other  species  of  Octolasium 
found  in  England  rarely  occur  in  such  situations,  but  prefer 
gardens  and  ploughed  fields.  Another  difference  will  be  indi- 
cated hereafter. 

In  many  parts  of  the  country  it  is  the  custom  for  the  roadmen 
to  place  their  sweepings  and  scrapings  in  heaps  either  by  the 
roadside  or  in  a  field  or  waste  plot.  For  a  time  no  signs  of  life 
will  be  found  here ;  then  various  Fridericias  and  other  Enchy- 
traeids  begin  to  abound,  and  with  these  one  will  nearly  always 
find  such  earthworms  as  B.  eiscni,  B.  constrictus,  L.  castaneus, 
E.  rosea,  and  D.  mammalis.  If  a  fork  is  inserted  in  the  soil  of 
pastures  and  worked  to  and  fro,  L.  castaneus,  L.  rubellus,  and 
L.  festivus  may  readily  be  obtained.  In  some  places  the  same 
means  will  be  successful  in  bringing  out  A.  tonga,  A.  caliginosa, 
E.  rosea,  and  one  or  two  others.  It  thus  appears  that  a  certain 
number  of  species  have  well-defined  habitats  and  definite  habits, 
such  forms  as  Allurus  never  being  taken  save  where  moisture 
is  found,  and  the  Octolasiums  being  found  either  in  ditches 
(O.  gracile)  or  in  gardens  and  fields.  Nearly  all  our  native 
species  love  moisture,  but  they  frequently  perish  in  great 
numbers  in  times  of  continued  flood. 

Slime  and  Mucus. — One  has  not  to  study  the  Lumbricidae  long 
before  becoming  aware  of  great  differences  in  relation  to  the 
matter  which  is  given  off  under  irritation.  All  our  earthworms 
are  provided  with  dorsal  pores,  and  from  these  we  frequently 
find  an  exudation  of  one  kind  or  another.  In  the  case  of  the 
different  species  of  Lumbricus  there  is  a  watery  discharge  quite 
distinct  from  the  slime  which  is  one  of  their  chief  characteristics. 
This  fluid  is  best  seen  when  the  worms  are  partially  dried.  They 
seem  then  to  pour  it  out  from  the  dorsal  region  with  a  view  to 
moistening  their  surroundings  and  thus  making  progress  possible. 
It  must  be  observed  that  the  native  Lumbrici  (of  which  we  have 
four  species  in  England,  and  a  fifth  in  Ireland)  never  give  off 
a  coloured  or  foetid  liquid.  In  this  respect  Allurus,  B.  eiseni, 
A.  longa  and  one  or  two  other  Allolobophoras  are  in  agreement 
with  the  Lumbrici.  With  reference  to  the  Allolobophoras 
(including  therein  Allolobophora,  Octolasium,  Aporrectodea, 
Dendrobaena  and  other  genera)  there  is  a  great  deal  of  diversity 


THE   BIONOMICS  OF  ENGLISH   OLIGOCH^TA    105 

in  the  matter  of  secretion.  Some  exude  it  from  the  entire 
length  of  the  body,  others  from  the  head  or  tail,  or  from  special 
segments.  Nor  is  the  appearance  and  smell  the  same  in  the 
different  cases.     Let  us  examine  a  few  of  the  principal. 

In  the  Brandling  {Eisenia  fcetida  Sav.)  we  find  a  very  profuse 
exudation  of  a  yellow  colour  and  pungent  odour  from  almost 
the  entire  length  of  the  body.  To  some  the  smell  resembles 
garlic,  to  others  the  liquor  from  boiled  cabbage.  It  leaves  a 
good  deal  of  powdery  matter  behind  when  dry,  but  I  am  not 
able  to  recall  any  memoir  dealing  with  its  chemical  constituents. 
Next  to  it,  so  far  as  volume  of  output  goes,  we  may  place 
A.  chlorotica  Sav.,  often  known  as  the  green  worm.  It  is  very 
sluggish  as  a  rule,  and  one  would  suppose  the  secretion  serves 
to  keep  off  enemies.  It  is  similar  in  colour  to  the  last,  and 
may  be  poured  off  from  any  part  of  the  body.  Eisenia  rosea  Sav. 
and  Eophila  icterica  Mich,  also  act  in  a  similar  way,  but  the  fluid, 
particularly  in  the  case  of  the  former  (which  was  once  known  as 
Alio,  mucosa),  leaves  a  white  chalky  sediment.  D.  submbicunda 
has  a  yellowish  tail,  and  it  frequently  happens  that  a  large 
quantity  of  gold-coloured  secretion  exudes  therefrom.  Then 
from  O.  cyaneum  and  O.  profugum  a  yellow  exudation  may  be 
obtained  from  the  region  of  the  sexual  organs  and  from  the 
caudal  segments.  Thus,  without  giving  further  details,  it  is  very 
clear  that  much  variety  prevails,  and  it  seems  very  desirable  that 
a  careful  study  of  the  subject  should  be  undertaken  with  a  view 
to  determining  the  exact  nature  and  composition  of  the  various 
kinds  of  fluid,  and  the  exact  purposes  for  which  the  fluid  exists. 
The  slime  seems  to  be  almost  purely  lubricative,  the  white  and 
yellow  fluids  preservative. 

Helodrilus  oculatus  Hoffmeister. — As  illustrating  some  of  the 
problems  in  bionomics  which  the  study  of  the  Oligochaets 
raises,  it  may  be  well  to  take  one  particular  species ;  and  I 
select  for  the  purpose  H.  oculatus.  The  name  is  well  chosen. 
Helodrilus  means  the  worm  found  by  low  marshy  ground  (&V09) 
on  the  sides  of  rivers,  while  oculatus  refers  to  the  presence 
at  certain  periods  of  a  couple  of  eye-spots.  This  is,  I  believe, 
the  only  species  of  Lumbricidae  in  which  eye-spots  have  been 
discovered,  and  is  of  interest  because  such  spots  are  not  un- 
known in  Naididae  on  the  one  hand  and  Polychaeta  on  the  other. 
Helodrilus  was  first  described  by  Hoffmeister  in  1843.  No 
adult  was  known,  and  the  description  was  therefore  incomplete; 


106  SCIENCE  PROGRESS 

and  for  many  years  it  was  lost  to  sight.  It  was  rediscovered 
in  1890,  but  as  the  connection  was  not  then  recognised 
Michaelsen  named  it  Allolobophora  hermanni.  In  1896  de 
Ribaucourt  gave  a  full  description  of  it  as  found  by  him  in 
company  with  Lumbricus  michaelseni  in  extremely  humid  soil. 
He  remarks  that  by  its  form  and  manner  of  life  it  appears  to 
be  a  link  between  the  terricolous  and  the  limicolous  species. 
But  as  yet  the  connection  between  the  two  had  not  been 
suspected.  Rosa,  in  1893,  had  given  Michaelsen's  A.  hermanni 
place  in  his  Revisione,  but  does  not  allude  to  Helodrilus,  and 
in  1895  Beddard  has  the  following  note:  "  H.  oculatus  Hoffm. : 
This  is  an  extremely  mysterious  species,  neglected  by  Rosa  in 
his  recent  revision  of  the  Lumbricidae,  and  therefore  probably 
not  believed  by  him  to  be  a  Lumbricid.  Its  most  remarkable 
structural  peculiarity  is  a  pair  of  eye-spots  on  the  buccal  seg- 
ment. There  are  four  pairs  of  setae  in  each  segment,  which 
are  straight  instead  of  curved,  and  said  to  be  black  ;  the  male 
pores  are  upon  the  fifteenth  segment.  The  body  is  elongate 
and  pink  in  colour;  the  length  at  most  135  mm.  It  occurs  on 
the  seashore  in  pools  more  or  less  dried  up."  Beddard  adds 
that  "  Vaillant  suggests  that  this  worm  is  probably  a  Tubificid, 
on  account  of  the  presence  of  eye-spots,  and  because  of  its 
habitat.  The  black  setae  are  very  suggestive  of  what  I  have 
myself  observed  in  Tubifex  rivulorum.  But  it  does  not  seem 
to  me  that  we  are  justified  in  relegating  the  genus  to  any  family 
at  present." 

When,  in  1900,  Das  Tierreich  :  Oligocholia  appeared,  Michael- 
sen  put  the  matter  right.  He  showed  that  H.  oculatus  Hoffm. 
and  Allolobophora  hermanni  were  one  and  the  same,  and  gave 
Germany,  Switzerland,  and  Italy  as  its  distribution.  In  the 
course  of  time  England  was  added  to  the  list  of  habitats.  As 
I  was  exploring  the  pond  in  the  Cambridge  Botanic  Garden 
in  July  1907,  I  found  several  adult  specimens  of  the  worm,  and 
sent  an  account  of  it  to  the  Gardeners'  Chronicle  some  time  later. 
Next  it  was  found  by  Mr.  Evans  near  Edinburgh,  and  at  the 
same  time  I  found  the  immature  forms  at  Malvern,  with  the 
eye-spots  distinctly  visible.  But  though  I  kept  it  under  obser- 
vation for  two  years,  I  was  never  able  to  find  an  adult.  During 
the  past  three  years  I  have  taken  H.  oculatus  from  mud  on  the 
banks  of  the  Thames  at  Kew,  near  the  sea  at  Hastings,  by  the 
dykes  in  Pevensey  Marsh,  by  streams  and  ditches  in  Derbyshire 


THE   BIONOMICS  OF   ENGLISH   OLIGOCH^TA    107 

and  Notts,  by  the  Dodder  at  Ballsbridge,  Dublin,  and  by  the 
stream  at  Swords ;  and  have  received  it  from  Epping  Forest. 
The  forms  at  Kew  were  large,  with  correspondingly  large 
cocoons,  while  those  at  Malvern  were  small  with  small  cocoons. 
It  is  in  many  ways  a  most  curious  worm,  and  seems,  like 
O.  gracile,  to  be  gradually  working  westward. 

Constancy  and  Variation. — This  reference  to  the  two  forms  of 
H.  oculatus  Hoffm.  leads  me  naturally  to  some  remarks  on  the 
tendency  to  change  in  some  worms,  and  the  evidences  of 
stability  in  others.  The  most  stable  English  worms  are  the 
four  species  of  Lumbricus  and  the  three  species  of  Octolasium. 
Out  of  the  thousands  of  specimens  which  I  have  examined 
during  the  past  quarter  of  a  century,  it  has  rarely  been  my  lot 
to  see  any  varieties  of  either.  Some  years  ago  I  recorded  a 
short-tailed  form  of  Lumbricus  for  Calverley  near  Leeds,  and 
some  Continental  writers  affirm  that  the  girdle  of  L.  terrestris 
extends  over  more  than  six  segments,  but  I  have  never  seen  a 
single  case  of  this  kind  in  England. 

It  might  here  be  remarked  that  normally  the  girdle  in  the 
genus  Lumbricus  extends  over  six  segments,  while  the  tubercula 
pubertatis  occur  as  a  band  on  the  innermost  four.  Further, 
there  is  a  regular  gradation  in  the  matter  which  is  peculiarly 
interesting.  This  may  be  shown  by  the  following  chart,  in 
which  the  figures  show  the  segments  covered  by  the  tubercula : 


1.  L.  rubellus  Hoffm.        .     28,  29,  30,  31. 

29,  3°,  3i,  32. 


2.  L.  castaneus  Sav. , 

3.  L.  melibceus  Rosa 

4.  L.  tyrtaeus  ?  . 

5.  L.  studeri  de  R. 

6.  L.  terrestris  L. 

7.  L.  papillosus  Friend 


3°.  3i»  32,  33- 

31,  32,  33,  34- 
32,  33,  34,  35- 
33,  34,  35,  36. 
34,  35,  36,  37- 


8.  L.  festivus  Sav.  (=  rubescens  Friend)  35,  36,  37,  38. 

No.  4  is  doubtful,  but  in  view  of  the  regularity  here  displayed 
it  seems  impossible  to  believe  that  there  is  not  a  true  form  to 
fit  the  niche.  But  while  the  tubercula  are  constant  it  is  curious 
to  observe  that  the  girdle  is  variable  in  one  or  two  instances, 
and  these  become  instructive  accordingly.  Why  is  it,  for 
example,  that  the  Irish  worm  L.  papillosus  has  only  five  girdle 
segments  instead  ot  six,  and  has  a  pair  of  large  papillae  on  each 
side?    L.  melibceus  similarly  has  only  five  girdle  segments. 

The  three  species  of  Octolasium  found  in  England  are  like 


io8  SCIENCE   PROGRESS 

the  Lumbrici  in  this  respect :  they  each  have  six  girdle  seg- 
ments ;  but  while  two  of  them  have  the  tubercula  extending 
over  the  four  innermost  girdle  segments,  the  third  (O.  gracile) 
has  the  band  along  the  whole  six.  Along  with  this  peculiarity 
we  have  also  a  difference  of  colour,  habit,  and  habitat.  Octolasium 
gracile  Oerley  is  somewhat  flesh-coloured,  emits  no  turbid 
fluid,  and  is  found  in  wet  places ;  while  O.  cyaneum  and 
O.  lacteum  have  steel-blue  bodies,  clay-coloured  girdles,  and 
yellow  tails,  from  which  coloured  fluid  exudes,  and  are  found 
in  gardens  and  fields,  chiefly  in  ground  which  is  under 
cultivation. 

Among  the  Allolobophoras  the  most  constant  seems  to  be 
A.  longa,  which  shares  with  L.  terrestris  the  dominancy  among 
British  Earthworms.  The  two  are  readily  distinguishable  by 
the  position  of  the  girdle,  the  colour,  and  the  shape  of  the 
prostomium,  but  were  until  quite  recently  constantly  mistaken 
the  one  for  the  other.  In  the  case  of  almost  all  the  other 
species  of  Allolobophora  variation  constantly  occurs.  Thus 
A.  caliginosa  has  two  forms,  which  are  sometimes  so  well 
marked  that  they  might  pass  for  different  species  ;  hence  the 
name  turgida  applied  to  one,  and  that  of  trapezoides  to  the  other. 
The  green  worm  is  exceedingly  variable.  Sometimes  it  is  an 
intense  green  and  very  sluggish,  so  that  it  might  be  mistaken 
for  a  grub.  At  other  times  {forma  cambrica  Friend)  it  is  just  as 
active,  and  has  a  colour  resembling  that  of  caliginosa.  The 
mucous  worm  {Eisenia  rosea  =  mucosa)  has  well-marked  varieties, 
one  of  which  (macedonica)  occurs  in  England  and  on  the 
Continent,  and  might  almost  pass  for  a  subspecies  at  times. 
So  among  the  Dendrobenes  we  have  subriibiciinda  and  arborea, 
which  have  similar  peculiarities  to  those  found  in  the  foregoing 
species ;  and  while  at  times  they  are  perfectly  distinct,  at  other 
times  it  is  impossible  for  an  expert  to  say  whether  a  given 
specimen  is  truly  one  or  the  other.  If  any  one  wishes  to  pursue 
this  subject  further  he  will  find  that  Michaelsen,  Rosa,  Beddard, 
Eisen,  Cognetti,  De  Ribaucourt,  Vejdovsky,  and  others  abound 
in  illustrations  and  supply  abundant  material  for  the  most 
critical  biologist. 

Allusion  was  made  above  to  the  genus  Allurus,  and  a  further 
reference  may  be  permitted  under  this  heading.  In  July  of  last 
year  (1912),  while  I  was  collecting  at  Hastings,  I  had  the  good 
fortune  to  find  quite  a  number  of  Oligochaets  which  were  either 


THE  BIONOMICS  OF  ENGLISH  OLIGOCH^ETA    109 

new  to  science  or  to  Britain.  Among  these  was  a  fragile 
creature  flourishing  in  alga  at  Ecclesbourne,  near  where  the 
little  stream  falls  into  the  sea.  About  a  dozen  specimens  were 
collected  and  taken  home  for  examination.  These,  however, 
perished  almost  immediately,  before  I  was  able  to  prepare  a 
description.  It  was  necessary,  therefore,  to  get  a  fresh  supply 
if  possible,  and  preserve  them  forthwith.  This  was  done,  and 
notes  were  taken  both  of  the  living  and  the  preserved  forms. 
In  no  case  was  an  adult  specimen  to  be  found,  and  for  the 
present  one  is  obliged  to  speak  cautiously  ;  but  the  evidence 
clearly  pointed  to  a  new  species  of  British  Oligochseta,  and  the 
creature  has  been  named  provisionally  Allurus  mollis.  Just  as 
the  dominant  type  has  driven  some  species  to  the  Alps  and 
others  to  the  borderlands  of  Wales  and  Ireland,  so  it  is  possible 
that  in  this  case  a  tender  form  has  been  compelled  to  find  refuge 
in  algae,  to  take  to  the  boats  indeed,  just  as  the  Tanka  people 
on  the  Chinese  rivers  have  done  in  escaping  from  the  oncoming 
Celestials  of  more  robust  and  over-mastering  character. 

As  a  final  illustration  of  the  extent  to  which  variation  may 
run  (without  alluding  to  internal  structure  and  the  work  of 
Woodward,  Bateson,  and  others),  one  may  take  that  most  poly- 
morphic of  all  Allolobophoras,  Eisenia  veneta  Rosa.  Its  history 
is  one  of  great  interest,  and  may  be  read  in  the  pages  of  Rosa 
and  in  my  own  contributions  to  annelid  study.  I  first  found  it 
many  years  ago  in  Dr.  Scharff's  garden,  Dublin,  and  named  it 
A.  kibernica,  not  knowing  that  it  had  also  been  found  in  Venice. 
In  March  of  this  year  I  found  it  again  in  Dublin,  in  a  neighbour- 
ing locality.  After  the  lapse  of  some  years  a  second  British 
form  turned  up  at  Oxford,  which  I  named  Tepidaria.  This  has 
not  yet  been  found  elsewhere,  so  far  as  I  am  aware ;  but  it  is 
a  striking  variety.  I  failed  to  obtain  it  again  during  a  recent 
visit  to  the  Oxford  Botanic  Garden.  In  1909,  while  collecting 
in  some  gardens  at  Malvern,  I  came  across  two  new  forms,  one 
of  which  was  very  robust  (E.  robusta  Friend),  while  the  other 
was  like  a  dendrobene  (E.  dendroida  Friend).  A  variety  found 
in  Cornwall  has  not  yet  been  named,  but  Southern  has  taken  a 
further  form  in  Ireland  which  is  similar  to  Michaelsen's  variety 
zebra,  and  yet  another  variety  is  named  hortensis.  It  is  such 
facts  as  these  which  make  the  study  of  our  Earthworms  full  of 
interest  to  the  biologist.  They  are  but  samples  of  the  kind  of 
material  which  an  extended  investigation  has  enabled  one  to 


no  SCIENCE  PROGRESS 

bring  together;  and  the  examination  of  our  Enchytraeids  and 
other  Oligochaets  supplies  us  with  further  material  of  an  equally 
instructive  character.* 

List  of  British  Earthworms. — At  last  the  Lumbricidae  of  Great 
Britain  have  been  fairly  well  investigated,  and  the  reproach  that 
they  "  have  never  been  carefully  monographed  "  may  be  wiped 
away.  Southern  and  1  have  done  our  best  to  make  the  list 
complete,  and  although  we  shall  probably  be  able  in  time  to 
make  a  few  further  additions,  when  the  gardens  connected  with 
our'  old  mansions  have  been  explored,  and  the  highlands  and 
islands  have  been  investigated,  yet  we  cannot  hope  to  find 
many  new  species.  The  following  list  will  be  of  service  for 
future  workers,  and  supplies  sufficient  information  for  working 
purposes. 

Allurus  (Eisen)  =  Eiseniella  (Michaelsen) 

i.  A.  tetraedrus  Sav.     Dominant.     Very  widely  distributed. 

Var.   luteus   Friend.     Carlisle,  Calverley,  Newark,  and 
elsewhere. 

2.  A.  tetragonurus  Friend.     Bangor  in  Wales. 

3.  A.  macrurus  Friend.     Malahide,  near  Dublin. 

4.  A.  hercynius  Michaelsen.     Scotland. 

5.  A.  mollis  Friend.     Hastings  and  Burton  Joyce. 

Eisenia  (Malm.  em.  Michaelsen) 

6.  E.  foetida  Savigny.     Everywhere  in  manure  and  rich  soil. 

7.  E.  veneta  Rosa.     Represented  by  the  varieties  named. 

Var.  hibernica  Friend.     Dublin. 

Var.  tepidaria  Friend.     Oxford  Botanic  Garden. 

Var.  robusta  Friend.     Gardens  at  Malvern. 

Var.  dendroida  Friend.     Gardens  at  Malvern. 

Var.  zebra  Michaelsen.     Ireland. 

Var.  unnamed.     Gardens  in  Cornwall. 

8.  E.  alpina  Rosa.     Perthshire,  Scotland. 

9.  E.  rosea  Sav.     Widely  distributed. 

Var.  macedonica  Rosa.     In  gardens  :  Kew,  Chelsea. 
Var.  unnamed.     Cambridge  Botanic  Garden. 

Allolobophora  (Eisen  em.  Rosa) 

10.  A.  georgii  Michaelsen.     Valencia,  Ireland. 

11.  A.  caliginosa  Sav.     Widely  spread.     Two  forms: 

Var.  turgida  Eisen.     Common. 
Var.  trapezoides  Duges.     Common. 

12.  A.  longa  Ude.     Everywhere  dominant. 

.13.  A.  relictus  Southern.    Clare  Island,  Ireland. 


THE  BIONOMICS  OF  ENGLISH  OLIGOCR£TA    in 

Aporrectodea  (Oerley) 

14.  A.  chlorotica  Sav.     Very  widely  distributed. 

Var.  cambrica  Friend.     Wales,  Cambridge. 

15.  A.  similis  Friend.     Kew  Gardens. 

Dendrob^ena  (Eisen  em.  Rosa) 

16.  D.  rubidus  Sav.     Under  two  forms  : 

Var.  subrubicunda  Eisen.     Very  widely  spread. 
Var.  arborea  Eisen.     In  decaying  tree-trunks. 

17.  D.  mammalis  Sav.     Frequent  in  road  scrapings,  etc. 

18.  D.  merciensis  Friend.     Derbyshire,  England. 

19.  D.  octaedra  Sav.     Local  and  somewhat  rare. 

20.  D.  submontana  Vejd.     Kew  Gardens. 

Helodrilus  (Hoffm.  em.  Mich.) 

21.  H.  oculatus  Hoffm.     Sussex,  Surrey,  Essex,  Notts,  Derby- 

shire; also  Dublin  and  Swords,  in  Ireland;  Scotland. 

22.  H.  ictericus  Sav.     Kew,  Chelsea,  Cambridge,  etc. 

23.  H.  elongatus  Friend.     Pencarrow,  Cornwall. 

Bimastus  (Moore) 

24.  B.  beddardi  Mich.     Ireland. 

25.  B.  eiseni  Levinsen.     England,  Ireland,  Wales,  Isle  of  Man, 

and  Scotland. 

26.  B.   constrictus    Rosa.     Not    very    common,   but   somewhat 

widely  distributed. 

Octolasium  (Oerley  em.  Rosa) 

27.  O.  cyaneum  Sav.     In  cultivated  ground. 

28.  O.   lacteum   Oerley  (=  profugum   Rosa).     Pretty  generally 

distributed,  in  cultivated  ground. 

29.  O.  gracile  Oerley.     In  ditches  and  wet  places,  chiefly  in  the 

East  of  England. 

30.  O.  intermedium  Friend.     Oxford  Botanic  Garden. 

31.  O.  rubidum  Oerley.     Reported  by  the  discoverer  as  found  at 

Woolwich,  but  not  confirmed  hitherto. 

Genus  not  yet  Determined 

32.  Allolobophora  antipae  Mich.     Blenheim  Palace,  191 3. 

33.  Allolobophora  norvegica  Eisen.     Dublin,  March  191 3. 

34.  Allolobophora  (doubtful).     Dublin,  March  191 3. 

35.  Allolobophora  (doubtful).     Dublin,  March  1913. 


ii2  SCIENCE  PROGRESS 

Lumbricus  (Linnaeus  em.  Eisen) 

36.  L.  rubellus  Hoffm.     Universally  distributed  in  Britain. 

37.  L.  castaneus  Sav.     Similar  distribution  to  last. 

38.  L.  festivus  Sav.     Less  common  than  the  foregoing. 

39.  L.    papillosus    Friend    (=  L.    friendi    Cognetti).     South   of 

Ireland. 

40.  L.  terrestris  Linn.     Widely  distributed. 

This  list  shows  a  total  of  forty  species,  with  about  a  dozen 
forms  and  varieties,  some  of  which  have  been  given  specific  rank 
by  one  or  other  of  our  leading  authorities.  I  have  pleasure  in 
gratefully  acknowledging  a  grant  from  the  Government,  through 
the  courtesy  of  the  Royal  Society,  to  enable  me  to  carry  out 
this  research  into  Annelid  Bionomics  and  Economics. 

Bibliography 

Beddard,  A  Monograph  of  the  Order  Oligochasta,  1895. 

Friend,    Many   contributions  in  Joicrn.   Linn.  Society,  Proc.  R.I.  Acad.,  Irish 

Naturalist,  Zoologist,  Naturalist,  and  elsewhere. 
MlCHAELSEN,  "  Oligochaeta,"  Das  Tierreich,  1900. 
Oerley,  A  magyarorszdgi  Oligochaetak  Faunaja,  etc. 
Ribaucourt,  de,  Etude  sur  la  Faune  Lombricide  de  la  Suisse,  1896. 
ROSA,  Revisione  dei  Lumbricidi,  1893. 
Southern,  Proc.  R.I.  Acad.  vol.  xxvii.  1909. 


ENZYMES   AS   SYNTHETIC   AGENTS 

I.   IN   CARBOHYDRATE   METABOLISM 

By  J.  H.  PRIESTLEY,  B.Sc,  F.L.S. 

Professor  of  Botany,  Leeds 

Introduction 

In  the  present  state  of  our  knowledge,  the  constructive  syntheses 
in  the  plant  that  precede  the  formation  of  the  protoplasmic 
complex,  present  a  peculiarly  difficult  problem. 

The  activity  of  organic  chemistry  has  brought  to  light  so 
many  possible  compounds  and  reactions  that  may  form  links  in 
the  numerous  syntheses  required,  that  it  is  difficult  for  the 
biologist  to  decide  what  lines  best  admit  of  experimental  attack. 
In  this  quandary  it  is  very  desirable  that  some  thread  of  guid- 
ance should  be  obtained  through  the  labyrinth  of  possibilities, 
and  such  a  thread  is  perhaps  provided  in  the  idea  that  the  plant 
may  employ  enzymes  as  catalysts  to  such  synthetic  chemical 
reactions.  As  the  number  of  available  enzymes  present  in  an 
organism  is  presumably  limited  and  as  their  powers  as  a  rule 
seem  strictly  limited,  this  narrows  the  field  of  inquiry  in  relation 
to  metabolic  synthesis,  and  it  is  perhaps  worth  while  considering 
what  light  is  thrown  upon  the  problem  when  it  is  considered 
from  this  standpoint. 

Since  Croft  Hill  first  announced  the  synthesis  of  maltose  by 
the  use  of  the  maltase  (glucase)  extracted  from  yeast,  a  number 
of  investigators  have  experimentally  attempted  to  use  enzymes 
as  catalysts  to  synthetic  reactions.  The  idea  underlying  these 
experiments  is  simple. 

Most  of  the  reactions  catalysed  by  enzymes  are  of  a  reversible 
nature,  as  is  indicated  by  the  way  in  which  the  reactions  grad- 
ually slow  up  and  ultimately  come  to  an  equilibrium  point  if  the 
products  of  the  reaction  are  allowed  to  accumulate.  Thus  if 
a  reaction  of  the  general  type  be  expressed  by  the  formula 
A  +  B  ^tC  +  D,  then  the  arrows  indicate  that  at  any  time  this 
reaction  is  going  in  either  direction  and  the  resultant  effect  of 
8  113 


114  SCIENCE  PROGRESS 

these  dual  reactions  depends  upon  the  extent  to  which  either 
A  4-  B  or  C  +  D  are  present  in  excess  of  equilibrium  concentra- 
tion. If  A  +  B  are  present  in  excess  of  equilibrum  concentration, 
then  the  reaction  will  be  proceeding  more  rapidly  in  the  direction 
from  left  to  right,  and  this  will  continue  to  be  the  case  until  so 
much  C  +  D  has  been  formed  that  the  reverse  conversion 
C  +  D-»A  +  Bis  going  on  as  rapidly  as  the  conversion  A  +  B 
into  C  +  D.  This  is  the  equilibrium  point  of  the  reaction  and, 
for  a  definite  reaction,  at  a  definite  temperature,  is  a  quite 
definite  point  that  can  be  expressed  in  terms  of  the  concentration 
of  the  reacting  bodies. 

Now  if  an  enzyme  behaves  as  an  ordinary  catalyst  its 
addition  should  make  no  difference  to  the  position  of  this 
equilibrum,  but  only  shorten  the  time  in  which  this  equilibrium 
point  is  attained.     In  such  a  reaction  as 

CuHaOu  +  H„0  t  2C,H12Os 

(maltose)  (glucose) 

if  the  reaction  proceeds  from  right  to  left  it  will  be  of  a  synthetic 
nature.  Realising  this,  Croft  Hill  attempted  to  obtain  con- 
centration conditions  such  that  the  reaction  should  tend  to  go 
from  right  to  left  to  attain  equilibrium,  and  in  this  way  managed 
with  the  use  of  an  enzyme  catalyst  to  synthesise  maltose.  So 
far,  then,  experiment  seems  to  be  in  agreement  with  theory,  but 
a  closer  acquaintance  with  the  literature  suggests  a  number  of 
fresh  problems  of  great  importance  to  the  biologist. 

These  it  is  proposed  to  consider  briefly  and  by  no  means 
exhaustively  in  so  far  as  they  touch  the  two  main  types  of 
synthesis  with  which  the  biologist  is  particularly  concerned, 
viz.  carbohydrate  synthesis  and  protein  synthesis. 

Synthesis  of  Carbohydrates 

It  is  possible  that  in  the  many  problems  that  this  subject 
presents,  the  study  of  reversible  chemical  action  as  catalysed  by 
enzymes  offers  us  the  best  experimental  method  of  attack  under 
"  in  vitro  "  conditions  because  it  may  thus  be  possible  to  realise 
the  essential  conditions  in  regard  to  stereo-isomerism.  Emil 
Fischer,1  in  his  Faraday  lecture  to  the  Chemical  Society,  referring 

1  "Synthetical  Chemistry  in  its  Relation  to  Biology,"  Transactions  of  Chemical 
Society ■,  1907,  vol.  91. 


ENZYMES  AS  SYNTHETIC  AGENTS  115 

to  the  attempts  that  had  been  made  to  synthesise  sugars  from 
carbon  dioxide  and  water,  pointed  out  that  in  addition  to  the 
small  yields  obtained  by  these  chemical  methods  they  also  failed 
to  realise  the  condition  of  producing  only  optically  active 
sugars.  Since  then  in  more  recent  experiments  (Stoklasa, 
Sebor  and  Zdobnicky  l)  the  yields  have  been  improved  by  the 
use  of  the  ultra-violet  rays  of  the  quartz  mercury  vapour 
lamp,  but  the  difficulty  of  producing  the  right  optically  active 
sugar  still  remains.  All  the  naturally  occurring  sugars  in  the 
plants  are  optically  active,  having  different  powers  of  rotating 
the  plane  of  polarised  light,  and  all  are  what  are  termed  d  forms, 
that  is  of  the  same  general  type  of  constitution  as  the  sugar  that 
Fischer  has  termed  (^-glucose.  The  difference  in  the  power  of 
rotating  polarised  light  is  traced  to  the  different  arrangement 
of  the  asymmetric  carbon  atoms  within  the  isomeric  sugars. 
The  problem  then  is  to  produce  in  vitro  not  only  a  sugar  but 
the  sugar  with  the  natural  arrangement  of  the  asymmetric  carbon 
atoms,  not  merely  an  isomer  of  this  sugar  but  the  correct  stereo- 
isomer, as  it  is  called. 

Enzymes,  themselves  probably  asymmetric  organic  bodies, 
are  in  most  cases  extremely  restricted  in  reference  to  the 
reactions  they  can  accelerate  and  can  usually  only  react  with  a 
certain  class  of  stereo-isomer.  This  fact,  which  is  of  great 
biological  significance,  is  probably  to  be  traced  to  the  method  in 
which  they  produce  their  accelerating  effect;  they  are  usually 
regarded  as  combining  with  the  reacting  substances,  and  if  these 
are  asymmetric,  then  in  all  probability  this  temporary  combina- 
tion is  facilitated  by  their  own  asymmetric  constitution.  The 
same  fact  should  hold  good  in  relation  to  their  activities  in 
synthesis,  and  they  should  therefore  produce  optically  active 
bodies  instead  of  inactive  mixtures  containing  equal  quantities 
of  both  stereo-isomers.  They  therefore  provide  a  possible  agent 
by  which  this  necessary  asymmetry  should  be  introduced  in  the 
course  of  the  process  of  synthesis  known  as  photosynthesis. 
The  starting-point  for  this  synthesis  is,  of  course,  carbon  dioxide, 
but  when  the  substance  has  diffused  into  the  chloroplast  the  next 
substance  in  the  transition  to  carbohydrate  is  still  a  matter  for 
speculation. 

Considerable,  but  not  conclusive,  evidence  has  accumulated 
that  formaldehyde  is  produced  within  the  plant,  and  the  passage 
1  Biochem.  Zeitschr.  1912,  vol.  41,  p.  333. 


n6  SCIENCE  PROGRESS 

from  formaldehyde  to  a  glucose  is  then  a  step  which  can  be 
produced  in  the  test  tube  by  the  use,  for  instance,  of  various 
inorganic  reagents  such  as  calcium  hydrate.1  But  in  some  very 
important  papers2  in  which  the  evidence  to  be  obtained  from  the 
distribution  of  sugars  within  the  leaf  is  considered,  the  con- 
clusion is  reached  that  the  first  sugar  in  the  series  of  up-grade 
sugars  is  the  di-saccharose  cane  sugar,  a  conclusion  which  is 
more  difficult  to  reconcile  with  the  statement  that  formaldehyde 
is  the  first  detectable  compound  in  the  transition  from  carbon 
dioxide. 

Considering  the  question  from  our  present  specialised  view- 
point, light  may  be  thrown  on  the  contradiction  if  we  consider  that 
the  series  of  sugar  transitions  are  probably  reversible  reactions 
and  attempt  to  obtain  light  upon  the  up-grade  series  by  consider- 
ing the  well-established  steps  in  the  hydrolysis  of  the  starch 
molecules  with  the  aid  of  enzymes  as  it  occurs  under  in  vitro 
conditions. 

The  stages  in  the  process  are  represented  in  the  following 
scheme : 

(by  diastase  [amylase]) 

Starch  >  dextrin 

(by  diastase  [dextrinase]) 

dextrin >  maltose 

(by  maltase) 
maltose — >  glucose 

It  will  be  seen  that  cane  sugar  does  not  figure  in  this  series 
at  all ;  cane  sugar,  a  di-saccharose,  is  itself  broken  down  by 
the  action  of  sucrase  (or  invertase)  into  the  mono-saccharoses 
glucose  and  fructose.  Beyond  ^-glucose  the  catalytic  reactions 
by  which  the  sugar  is  split  up  into  simpler  molecules  are  still 
unknown  owing  to  the  difficulty  in  carrying  out  the  process 
away  from  the  plant  tissues.  Glucose  can  be  split  up  into 
carbon  dioxide  and  water,  it  is  true,  by  the  action  of  three  purely 
inorganic  catalysts  acting  in  series,3  but  this  affords  no  proof 
that  the  reactions  in  the  plant  proceed  in  the  same  manner. 

Zymase  will  give  alcohol  and  carbon  dioxide  when  in  contact 

1  Fischer,  loc.  cit.,  p.  3. 

2  Brown  and  Morris,  "  A  Contribution  to  the  Chemistry  and  Physiology  of 
Foliage  Leaves,"  /.  Chem.  Soc,  1893,  63,  p.  604;  Parkin,  Biochemical  Journal, 
vol.  vi.  p.  1. 

3  See  Euler,  General  Chemistry  of  Enzymes,  Eng.  trans,  by  Pope  (pub.  Wiley 
&  Sons),  p.  52. 


ENZYMES  AS  SYNTHETIC  AGENTS  117 

with  glucose,  but  the  intermediate  stages  in  what  is  undoubtedly 
a  complex  process  are  still  in  dispute,1  and  in  any  case  zymase 
is  not  at  present  regarded  as  an  important  factor  in  the  decom- 
position of  sugar  in  the  aerobic  tissues  of  the  plant,  though  it 
apparently  occurs  in  the  higher  plants  and  especially  in  massive 
ill-aerated  tissues.  It  is  to  oxidases  that  the  catalysis  of  the 
sugar  in  the  aerobic  tissues  is  generally  ascribed,  and  as  the 
details  of  this  process  have  never,  I  think,  been  followed  in  vitro, 
stages  in  this  return  from  sugar  to  carbon  dioxide  and  water  are 
still  quite  obscure. 

This  being  so,  we  can  only  suggest  from  our  present  standpoint 
that  if  formaldehyde  be  the  first  formed  product,  a  ^-glucose 
would  be  the  first  sugar  likely  to  be  formed,  and  we  may  now 
proceed  to  consider  whether  any  light  is  thrown  upon  the  next 
step,  if  it  is  considered  as  a  condensation  of  two  molecules  of 
dextrose  to  give  maltose,  the  process  being  accelerated  by  the 
enzyme  maltase. 

I  fear  that  in  the  present  state  of  the  literature  of  the  subject 
our  conclusion  will  be  that  though  the  idea  may  be  suggestive, 
the  subject  is  too  full  of  contradictions  to  enable  one  to  reach 
any  hypothesis  with  a  satisfactory  decisiveness. 

It  was  previously  pointed  out  that  Croft  Hill  described  the 
synthesis  of  maltose  from  glucose  by  the  aid  of  the  enzymes  of 
an  extract  of  yeast  which  contained  considerable  quantities  of 
maltase.  But  a  difficulty  arose  when  it  was  subsequently 
pointed  out,  and  the  statement  confirmed  later  by  E.  F.  Arm- 
strong, that  the  di-saccharose  formed  was  an  isomer  of  maltose 
and  termed  iso-maltose.  This  point  has  since  become  of  consider- 
able importance  as  the  actions  of  enzymes  have  been  more  fully 
investigated  and  their  properties  become  more  strictly  defined. 

It  is  realised  that  the  molecule  glucose,  containing  several 
asymmetric  carbon  atoms,  can  exist  in  a  large  number  of  isomeric 
forms,  and  that  moreover  the  dextro-isomer,  ^-glucose  can  itself 
exist  in  two  stereo-isomeric  forms  which  can  pass  over  into 
one  another  through  an  intermediate  modification.2 

1  For  a  review  of  recent  literature,  see  Harden,  "Alcoholic  Fermentation," 
Monographs  on  Biochemistry. 

a  More  probably  a  stable  equilibrium  point  exists  between  the  two  forms  when 
in  solution  (Lowry).  For  a  clear  account  of  these  problems  of  sugar  constitution, 
see  E.  F.  Armstrong,  "  The  Simpler  Carbohydrates  and  the  Glucosides,"  Mono- 
graphs on  Biochemistry. 


n8  SCIENCE  PROGRESS 

These  two  forms,  the  a  and  the  /3,  will  give  recognisably 
different  glucose  compounds,  the  a  and  /3  glucosides,  and 
maltose  is  such  a  glucose  compound,  maltose  itself  being  the 
a-glucose-glucoside,  iso-maltose  the  /3-glucose-glucoside. 

Translated  into  terms  of  this  nomenclature,  the  maltose 
synthesised  in  Croft  Hill's  experiments  was  the  /3-maltose,  and 
it  was  presumably  synthesised  through  the  agency  of  the  maltase 
present  in  the  yeast  extract. 

But  if  the  matter  be  tested,  maltase  will  be  found  to  be 
without  action  upon  the  /3-maltose,  and  will  only  hydrolyse 
the  a-maltose,  the  substance  formed  during  the  hydrolysis  of 
starch. 

This  is  accepted  as  a  statement  of  the  facts  by  some  writers,1 
and  it  is  regarded  as  marking  a  distinction  between  the  ordinary 
catalyst  and  the  behaviour  of  the  enzyme  catatyst. 

But  such  a  distinction  is  so  vital,  and  renders  the  whole 
interpretation  of  enzyme  action  so  uncertain  if  accepted,  that  any 
alternative  explanations  need  serious  consideration.  Bayliss,3 
while  pointing  out  the  obvious  difficulty  that  if  the  enzyme  is 
synthesising  a  sugar  it  is  incapable  of  hydrolysing,  the  equili- 
brium point  of  the  reaction  must  be  affected,  indeed  abolished, 
suggests  that  another  possible  explanation  is  that  the  synthesis 
of  /3-maltose  may  have  been  due  to  the  presence  of  another 
enzyme.  Yeast  extract  would  certainly  contain  many  enzymes, 
and  in  some  yeasts  Henry  and  Auld  have  detected  appreciable 
quantities  of  emulsin.  Emulsin,  the  enzyme  usually  associated 
with  the  breaking  down  of  the  glucoside  amygdalin,  is  capable 
of  attacking  /3-glucosides,  indeed  amygdalin  itself  is  really  a 
/3-glucose-glucoside,  from  which  the  emulsin  (or  the  amygdalase 
portion  of  it,  it  is  really  again  a  group  of  enzymes  that  is  included 
under  this  name  3)  splits  off  one  molecule  of  glucose,  leaving  the 
mandelo-nitrite  glucoside  to  be  still  further  broken  down.  If 
then  the  yeast  extract  contained  emulsin,  this  might  be  expected, 
in  the  presence  of  excess  of  glucose,  to  synthesise  the  /3-maltose. 

The  difficulty  in  the  way  of  accepting  this  explanation  lies  in 
the  fact  that  it  is  difficult  to  explain  the  preponderance  of  the  /3 
synthetic  compound,  bearing  in  mind  the  relative  preponderance 

1  See  for  instance,  Abderhalden,  Physiological  Chemistry y  Trans.  Hall,  p.  481 
(1908). 

3  Bayliss,  "  The  Nature  of  Enzyme  Action,"  Monographs  on  Biochemistry. 
3  For  review  of  recent  literature,  see  Euler,  loc.  cit.,  p.  23. 


ENZYMES  AS  SYNTHETIC  AGENTS  119 

of  maltase  in  the  yeast  extract  which  experience  of  yeast  extracts 
would  lead  investigators  to  expect. 

As  E.  F.  Armstrong1  has  also  shown  that  emulsin  synthesises 
the  o.-maltose,  again  the  opposite  form  to  the  one  it  attacks,  the 
difficulty  is  here  complete,  and  needs  apparently  to  be  worked 
out  upon  the  line  of  these  suggestions.  But  unless  the  difficul- 
ties can  be  traced  to  impurities  in  the  enzyme  preparations  it 
seems  that  whatever  suggestion  is  made  to  get  over  the  difficulty 
must  involve  a  new  interpretation  of  the  nature  of  an  enzyme  as 
an  organic  catalyst.2  We  need  not  yet  give  up  the  hope  of 
seeing  the  knot  unravelled  upon  the  lines  of  the  simpler  interpre- 
tation of  enzyme  nature,  as  Bourquelot  and  Bridel 3  have  recently 
announced  the  synthesis  of /3-methyl-glucoside  from  an  alcoholic 
solution  of  glucose  by  the  aid  of  emulsin — a  fact  that  suggests  a 
normal  behaviour  for  this  enzyme  at  any  rate  under  certain 
circumstances.  In  later  papers  they  attribute  this  synthetic 
activity  to  a  lactase  present  in  the  extract  of  emulsin.4 

With  this  discussion  of  the  present  state  of  our  knowledge  of 
the  transition  from  glucose  to  maltose  in  vitro  we  may  briefly 
consider  the  process  in  the  tissues  of  the  leaf.  Here  we  are  at 
once  met  with  the  surprising  difficulty  that  maltase  has  not  been 
described  as  usually  present  in  the  tissues  of  the  leaf.  This  is 
astonishing  in  view  of  the  nightly  conversion  of  starch  into 
maltose,  and  presumably  the  further  change  of  some  of  the 
maltose  into  mono-saccharose  sugars,  although  carbohydrates 
may  apparently  leave  the  leaf  as  maltose.5  The  absence  of 
reports  as  to  its  occurrence  may  be  due  to  difficulties  in  the 
way  of  extraction.  Students  working  with  me  have  on  one  or 
two  occasions  obtained  indications  of  hydrolysis  of  maltose 
when  studying  the  enzymic  activity  of  extracts  of  dried  and 
powdered  leaves,  but  certainly  such  activity  is  often  not  recog- 
nisable. The  point  seems  well  worthy  of  further  investigation, 
especially  as  the  curious  facts  as  to  the  distribution  of  storage 
carbohydrates  in  leaves  may  possibly  find  some  explanation  in 

1  E.  F.  Armstrong,  toe.  cit.,  p.  75  (1st  ed.). 

3  For  instance,  the  suggestion  of  the  existence  and  synthetic  activity  of  anti- 
enzymes.     See  Euler,  loc.  cit.,  p.  266. 

3  Compte  Rendus,  1912,  t.  155,  p.  319. 

4  See,  for  instance,  Comptes Rendus,  1912, 155,  p.  1553.  Synthesis  of  a-glucosides 
by  another  enzyme  have  now  also  been  recorded.  See  Comptes  Rendus,  1913,156, 
pp.  168,  491  and  1493. 

*  See  Mangham,  Science  Progress,  New  Series,  Nos.  18  and  19. 


120  SCIENCE   PROGRESS 

this  direction.  In  leaves  such  as  the  snowdrop,  where  cane 
sugar  seems  to  be  stored  to  the  complete  exclusion  of  starch,1 
the  enzyme  disastase  is  yet  present,  and  leaf  extracts  exert 
a  rapid  hydrolytic  action  on  starch.  No  maltase  however 
can  be  extracted,  and  possibly  in  the  absence  of  this  enzyme 
no  maltose  can  be  formed,2  and  therefore  no  starch.  In  cases 
where  maltose  is  presumably  freely  formed,  that  is,  on  this 
view,  in  all  cases  where  starch  is  subsequently  formed,  it  is 
difficult  to  know  at  present  whether  the  often  reported  presence 
of  emulsin  in  such  leaves  may  or  may  not  have  significance. 

From  starch  to  maltose  the  down-grade  stages  are  by  no 
means  clear.  As  was  suggested  in  the  scheme  given  earlier,  the 
process  probably  takes  place  in  two  main  stages,  associated  with 
different  enzymes  or  more  probably  groups  of  enzymes.  At 
present  it  is  perhaps  only  worth  pointing  out  that  the  statements 
in  the  older  literature  3  as  to  a  portion  of  the  starch  molecule 
incapable  of  complete  hydrolysis,  arose  from  a  mistaken  inter- 
pretation of  an  equilibrium  point  which  is  very  definitely 
obtained  in  the  hydrolysis  of  dextrin  to  maltose.4 

It  is  not  unnatural  that  it  should  have  proved  impossible  as 
yet  to  form  starch  granules  by  merely  reversing  the  enzyme 
mechanism  in  vitro,  seeing  that  the  process  in  the  plant  is 
apparently  so  complicated  that  it  never  occurs  but  in  association 
with  a  controlling  plastid.  Everything  points  to  a  complicated 
process  involving  the  use  of  a  series  of  enzymes  under  close 
protoplasmic  control,  and  presumably  held  to  definite  places  in 
the  internal  surfaces  of  the  solid  phase  of  the  granule — indeed, 
so  carefully  controlled  apparently  that  they  are  not  liberated  in 
death,  so  that  I  do  not  think  it  has  ever  been  found  possible  to 
detect  appreciable  disappearance  of  starch  from  the  plastid  after 
death  produced  by  chloroform  or  other  anaesthetic,  although  the 
diastatic  activity  of  an  aqueous  extract  of  such  a  leaf  seems  to 
be  fully  adequate  to  the  hydrolysis  of  the  amount  of  starch 
present.5 

In  view  of  these  facts  one  has  to  interpret  very  tentatively 

1  Parkin,  loc.  cit. 

1  The  statements  as  to  the  distribution  of  enzymes  in  the  snowdrop  leaf  are 
based  on  work  done  in  this  laboratory,  but  not  yet  published. 
3  See  for  instance,  Reynolds  Green,  Fermentation. 
*  Bayliss,  loc.  cit.,  Chap.  VI.,  p.  55  (1st  ed.). 
5  See  Brown  and  Morris,  loc.  cit.,  p.  651,  discussion  of  Wortman's  results. 


ENZYMES  AS  SYNTHETIC  AGENTS  121 

such  statements  as  those  of  Fernbach  and  Wolff1  as  to  the 
existence  of  a  coagulating  diastase,  and  to  suspend  judgment 
upon  statements  as  to  the  production  of  starch  from  sugars 
within  the  cell  upon  concentration  of  the  sap  by  plasmolysis.2 

Possibly  light  may  be  thrown  upon  the  question  by  the 
similar  but  perhaps  simpler  problem  of  the  synthesis  of  glycogen,3 
upon  which  Cremer  and  others  have  conducted  investigations. 

While  progress  may  be  slow,  recent  work  on  the  chemical 
constitution  of  starch  seems  to  hold  out  much  hope,  in  suggesting 
that  the  molecules  of  the  substance  are  perhaps  more  simply 
constituted  than  one  has  dared  to  hope;4  in  this  case  their 
ultimate  synthesis  will  be  an  experimental  problem  admitting 
more  readily  of  the  construction  of  the  hypotheses  which  lead 
to  the  laboratory. 

(Note. — If  it  proves  possible  to  utilise  physical  methods  on  a 
sufficiently  large  scale,  new  methods  may  possibly  be  provided 
to  the  physiologist  enabling  him  gently  to  break  up  his  unwieldy 
molecules  into  more  recognisable  constituents.  Ultra-violet 
radiation  seems  likely  to  be  largely  employed  as  a  tool  in  such 
investigations ;  see  for  instance  the  recent  investigations  of 
Berthelot  and  Gaudechon  5  and  many  others.  Professor  Bragg, 
in  drawing  my  attention  to  recent  work  on  these  lines,  in  which 
X-rays  were  used,6  suggested  to  me  that  in  these  cases  we  may 
have  in  a  large  molecule  more  than  one  collision  resulting  from 
the  passage  of  the  /3-particle  through  its  constituent  atoms  ;  there 
will  then  result  two  or  more  charges  of  the  same  sign  upon 
the  molecule,  and  inevitably  disturbance  of  the  distribution 
of  its  surface  energy  will  follow,  probably  accompanied  by 
the  disruption  of  the  molecule.7) 

1  Comptes  Rendus,  1903,  137,  p.  718. 

3  Overton,  Vierteljahrsschr .  d.  natur.  Ges  in  Zurich,  1899,  44,  P-  88. 

3  Chem.  Ber.,  1899,  32,  p.  2062. 

4  See  note  in  Science  Progress,  October  1912,  referring  to  recent  work  of 
Pringsheim. 

8  Comptes  Rendus.     See  also  Bierry,  Henri,  and  Rane,  Comptes  Rendus,  151, 
p.  316,  etc. 

6  Colwell  and  Russ,  Nature,  vol.  90,  p.  531. 

7  See  also  Bragg,  Nature,  vol.  90-,  p.  531. 


SCIENTIFIC   NATIONAL   DEFENCE 

By  COLONEL  CHARLES   ROSS,    D.S.O. 

Autlwr  of  "  Representative  Government  and    War" 

The  National  Defence  problem  has,  of  late  years,  obtruded 
itself  with  no  little  force  on  the  attention  of  the  surprised  and 
indignant  British  Citizen.  Since  the  downfall  of  the  great 
Napoleon  he  has  come  to  regard  himself  as  perfectly  secure  in 
his  island  home.  Guarded  by  his  unassailable  fleet  and  the 
jealousies  of  continental  powers,  he  has  been  able  to  devote 
himself  to  problems  of  internal  politics,  to  colonisation,  com- 
merce, and  sport.  From  time  to  time  the  sudden  advent  of 
hostilities  in  some  far-distant  colony,  a  royal  review  at  Alder- 
shot,  or  the  outbreak  of  war  between  foreign  powers,  has 
recalled  to  his  mind  that  he  possesses  an  army,  in  which, 
however,  he  has  never  taken  any  very  great  or  intelligent 
interest.  When  he  comes  to  think  of  it,  he  remembers,  with  a 
sense  of  considerable  gratification,  that  this  army  enjoys  an 
unrivalled  record  of  past  victories  in  every  quarter  of  the  globe. 
But  the  British  Citizen  has  always  been  somewhat  hazy  as  to 
the  reasons  for  the  existence  of  this  army.  He  supposes  that 
it  is  really  in  the  nature  of  an  Imperial  police  force,  and  cannot 
quite  grasp  why  it  should  have  interfered  in  other  people's 
quarrels  on  the  Continent  in  the  times  of  Napoleon  and  Marl- 
borough. But  that  was  in  the  "  good  old  days,"  when  the 
British  people  were,  probably,  rather  harebrained  ;  and  no  one 
would,  of  course,  venture  to  suggest  that  anything  of  the  sort 
should  be  done  in  these  days  of  business  and  hard  common  sense. 
On  the  other  hand,  he  was  profoundly  convinced  of  the  vital 
importance  of  the  navy.  It  had  always  been  evident  to  him 
that,  so  long  as  he  held  command  of  the  sea,  he  would  be  safe 
from  serious  attack  in  his  own  home ;  and  he  had  held  this 
sea-supremacy  for  so  many  years  that  he  had  come  to  believe 
that  some  special  dispensation  of  Providence  had  placed  him 
in  his  sea-girt  isle  in  order  that  he  might  march  securely  in 

122 


SCIENTIFIC  NATIONAL  DEFENCE  123 

the  van  of  progress  and  bear  the  banner  of  civilisation  to  the 
uttermost  ends  of  the  earth. 

Such  had  always  been  his  simple  creed  of  national  defence. 

A  partial  awakening— so  to  speak,  a  yawning  and  a  stretching 
— occurred  in  1899,  when  he  was  quite  suddenly  and  unex- 
pectedly attacked  by  the  Boers.  To  his  profound  astonishment, 
not  only  did  the  Boers  care  nothing  at  all  for  his  navy,  but  that 
navy  itself  proved  to  be  practically  helpless.  For  the  moment 
the  citizen  was  seriously  disturbed  ;  he  feared  that  all  was  not 
well  with  a  navy  which  could  fail  him  in  his  crisis.  But  he 
cheered  up  when  he  heard  that  some  naval  guns  had  been 
very  cleverly  transported  to  Ladysmith  by  sailors,  on  carriages 
designed  by  sailors  ;  and  that,  at  the  very  first  shot — or  was  it 
the  second  shot?— the  matter  is  unimportant— had  struck  a  Boer 
gun  full  on  the  nose.  His  navy  had  retrieved  its  reputation. 
Later  on,  he  found  that  his  navy  had  done  him  great  service ;  for 
its  overwhelming  power  had  rendered  intervention  by  certain 
neutral  powers  impracticable.  His  army  proved  to  be  altogether 
too  small  to  execute  its  task  ;  and  he  passed  through  his  "  black 
week."  But,  to  his  delight,  the  Empire  and  the  Volunteers  rose 
to  the  occasion  ;  money  was  poured  out  like  water  ;  recruits  were 
enlisted  wherever  they  could  be  found  ;  and,  once  more,  the 
Briton  triumphed. 

A  further  awakening  occurred  in  1904,  when  the  struggle 
between  the  Russians  and  the  Japanese  commenced ;  and  the 
Press  teemed  with  descriptions  of  bloody  and  desperate  con- 
flicts of  a  type  which  the  British  citizen  had  thought  to  be  long 
since  obsolete.  The  savagery  of  it  shocked  him.  It  was  an 
interesting  war,  because  a  nation  of  islanders  was  fighting  for 
its  existence  against  a  powerful  continental  State.  The  citizen 
watched  it  with  keen  interest,  and  with  keen  sympathy  for  the 
islanders.  He  foretold  that  they  would  defeat  the  continental 
power  on  the  sea,  because  they  were  islanders  whose  blood 
was  partly  composed  of  ozone,  and  that  the  breath  of  the  sea 
kills  all  but  the  hardiest.  It  may  yet  be  proved  that  there  is 
a  certain  substratum  of  truth  in  his  reasoning,  or  instinct.  He 
was  inclined  to  regard  himself  as  something  of  a  prophet  when 
his  forecast  came  true.  He  was  somewhat  astonished,  however, 
when  the  islanders,  not  content  with  having  defeated  their 
enemy  on  the  sea,  proceeded  to  disembark  large  armies  on  the 
mainland  and  attack  the  Russian  armies.    They  beat  the  conti- 


i24  SCIENCE  PROGRESS 

nentals — that  goes  without  saying — because  they  were  islanders; 
but  were  they  altogether  wise  in  carrying  the  war,  in  this 
fashion,  on  to  the  mainland  ?  Where  was  their  common  sense  ? 
But,  after  all,  they  were  mere  tyros  at  this  sort  of  thing ;  we 
must  all  live  and  learn. 

Nevertheless,  in  spite  of  his  complacency,  there  lingered  a 
certain  doubt  in  his  own  infallibility.  The  Germans  had  set 
to  work  in  a  very  calm  and  deliberate  fashion  to  construct  a 
fleet.  They  had  expressed  the  intention  of  becoming  lords  of 
the  Atlantic.  They  had  shaken  a  mailed  fist  in  the  air.  At 
the  outset  he  was  inclined  to  regard  this  exhibition  with  some 
amusement.  He  knew,  of  course,  that  the  Germans,  situated 
as  they  were  in  the  midst  of  possible  enemies,  were  obliged 
to  maintain  a  vast  and  very  efficient  army ;  and  he  did  not 
consider  it  possible  that  a  nation  would  make  the  necessary 
sacrifices  to  be  strong  on  the  sea  as  well  as  on  the  land.  But, 
as  time  went  on,  and  the  German  navy  steadily  increased, 
his  amusement  gave  place  to  wonderment,  then  to  gravity, 
finally  to  no  little  consternation.  It  dawned  upon  him  slowly, 
very  slowly,  that  a  great  continental  State  was  about  to  fly  in 
the  face  of  Providence  and  actually  challenge  his  sea-supremacy. 
His  consternation  was  accentuated  by  the  attitude  of  his 
Government.  The  latter,  far  from  accepting  the  challenge 
boldly  and  building  ships  and  recruiting  additional  men,  and 
all  the  other  things  that  are  necessary  to  ensure  naval  supremacy, 
sought  to  induce  the  Germans  to  change  their  mind  ;  with  the 
result,  as  was  only  to  be  foreseen  by  every  man  of  common 
sense,  that  they,  believing  the  British  to  be  afraid  of  them, 
built  ships  more  rapidly,  and  in  greater  numbers,  than  before. 

The  citizen  commenced  to  regard  his  Government  with 
great  contempt.  One  good  had,  however,  resulted  from  its 
action,  or  lack  of  action.  The  Empire,  as  a  whole,  had  been 
convinced  that  the  Germans  were  the  aggressors;  and  the 
Dominions  were  displaying  a  very  pronounced  inclination  to 
support  the  Mother  Country.  The  citizen  had  visions  of 
Canadians  and  Australians  and  New  Zealanders  and  even  of 
Boers  and  Indians  marching  shoulder  to  shoulder  against  the 
common  foe;  but  whether  the  march  was  to  take  place  on 
the  Continent  or  in  his  own  country  he  did  not  stop  to  consider. 

It  was  about  this  time  that  his  business  called  for  a  rapid 
visit  to  Australia.     During  the  long  and  wearisome  voyage  he 


SCIENTIFIC   NATIONAL  DEFENCE  125 

learned  many  things.  First  and  foremost  he  grasped  the  fact 
that,  while  Australia  is  a  very  long  distance  away  from 
England,  Germany  is  very  close  to  it ;  and  that  there  would 
be  ample  time  for  the  German  Army,  or  a  small  portion  of  it, 
to  over-run  England,  before  ever  a  single  Australian  could 
reach  the  country  to  help  in  its  defence.  His  visions  of  an 
Imperial  army  marching  to  victory  vanished. 

There  were  several  soldiers  on  board  the  ship,  and  the 
citizen  heard  many  interesting  discussions.  These  men,  he 
found,  regarded  the  subject  from  a  totally  different  standpoint 
to  his  own.  Their  talk  was  all  of  force — the  stronger  force  and 
the  weaker  force,  and  how  the  latter  might  hope  to  beat  the 
former.  He  had  always  held  the  view  that  the  conscripts  of  the 
Continent  were,  in  reality,  slaves,  and  that  one  free-born  Briton 
would  be  more  than  a  match  for  any  three  of  them.  When, 
with  some  diffidence,  he  suggested  this  view,  a  curious  silence 
reigned.  Finally,  one  said  that  continental  armies  were  not 
slaves,  that  they  were  composed  of  very  fine  and  well-trained 
troops,  and  that  they  had  always  fought  with  the  utmost 
gallantry  and  devotion.  He,  the  speaker,  while  fully  confident  in 
the  capacity  of  his  own  men  to  beat  equal  numbers  of  any  troops 
in  the  world,  would  be  sorry  to  "take  on"  three  times,  or  even 
double,  his  own  numbers.  For  his  part,  he  was  in  favour  of 
universal  service ;  and  this  remark  evidently  expressed  the  view 
of  most,  if  not  all,  of  those  present.  The  citizen  was  greatly 
astonished,  for  he  had  always  understood  that  the  volunteer  was 
equal  to  three  pressed  men. 

It  was  gradually  impressed  on  him  that  it  was  a  great  thing 
to  possess  superior  numbers,  for  that  these  would  make  up 
for  a  multitude  of  sins.  If  possible,  one  should  bring  double 
numbers  to  bear  against  the  enemy;  because  even  the  great 
Napoleon  had  never  been  able  to  withstand  double  his  own 
numbers.  The  citizen  rather  took  exception  to  this  statement, 
for  had  not  Clive  and  other  British  heroes  constantly  beaten 
double  and  even  treble  their  own  numbers?  He  pointed  to  the 
battles  of  Crecy,  Poictiers,  Agincourt.  It  was  explained  to  him 
that  such  battles  had  been  fought  against  undisciplined — that  is, 
inefficient — troops,  and  that  no  superiority  of  numbers  could 
make  up  for  inefficiency.  He  asked  what  it  was  which  con- 
stituted this  "efficiency,"  and  was  told  that  it  consisted  of  many 
things ;  that,  before  troops  could  be  termed  efficient,  they  must 


i26  SCIENCE  PROGRESS 

be  thoroughly  well  trained  and  able  to  act,  both  by  day  and 
night,  in  any  and  every  sort  of  country;  that  they  must  be 
thoroughly  disciplined,  the  rank  and  file  having  perfect  con- 
fidence in  their  officers  and  in  their  own  prowess,  and  the 
officers  having  perfect  confidence  in  their  men,  in  their  leaders, 
and  in  themselves  ;  that,  in  addition,  they  must  be  well  organised, 
the  arrangements  for  supplying  the  troops  with  food,  ammuni- 
tion, clothing,  and  everything  they  required,  for  tending  sick 
and  wounded,  being  almost  perfect.  Weakness  in  any  one  of 
these,  and  in  numerous  other  items  which  it  was  impossible  to 
remember  offhand,  would  result  in  a  loss  of  efficiency. 

But   the    matter    did    not    stop   here.     The   most   perfectly 
organised,  trained,  and   disciplined  troops  would  probably  be 
beaten  if  badly  led.     This  made  him  ask  questions  relative  to 
this  leading.     He  was  told  that  the  principle  of  the  thing  was 
"to   concentrate   superior   force    at    the   decisive   point   at   the 
decisive  moment."     He  thought  this  sounded  very  pretty,  and 
he  rather  believed  that  he  had  heard  the  expression  before,  but 
he  was  not  quite  certain  of  the  exact  meaning  of  it.     After  some 
little  hesitation  he  was  told   that   the  battle  was  the  decisive 
point,  and  that  the  moment  at  which  the  battle  was  fought  was 
the   decisive   moment.     He    pointed    out,    however,   that   there 
were  many  battles  in  each  war,  and  that  they  could  not  all  be 
decisive  points.     He  was  told  that  they  were;  or  that,  if  they 
were  not,  then  the  first  battle  was  the  decisive  point ;  and  that, 
if  that  one  was  not,  then  the  next  one  would  be;  or  it  might  be 
that  the  last  battle  would  prove  to  be  the  decisive  point.     He 
said  it  seemed  to  him  very  difficult,  and  was  told  that  it  was 
difficult ;  that  the  average  man  found  it  sufficiently  hard  to  say 
which  had  been  the  decisive  point  in  a  war  after  it  had  been 
fought,  and  that  it  was  one  secret  of  success  to  be  able  to  fore- 
cast the  decisive  point  and  another  to  prepare  the  superior  force 
in  peace  time;  for,  unless  that  were  done,  it  was  unlikely  that 
superior   force   would   be   available   at   the   first   battle.     Then 
followed  a  discussion  as  to  the  consequences  of  losing  the  first 
battle,  and  the  general  consensus  of  opinion  was  that,  in  modern 
war,  it  would  almost  certainly  prove  disastrous.     The  reason 
seemed  to   be  that  defeat   led   to  demoralisation.     The  citizen 
found  it  difficult  to  believe  that  men  could  be  downcast  by  a 
single  beating ;  but  he  was  assured  that,  judging  from  history, 
it  was  undoubtedly  the  case,  only,  of  course,  the   better  the 


SCIENTIFIC  NATIONAL  DEFENCE  12; 

troops  the  better  would  they  stand  up  under  defeat.  It  was 
impressed  upon  him  that,  with  superior  numbers  and  superior 
efficiency,  a  nation  could  make  almost  certain  of  winning  a  war; 
and  he  was  also  told  that  some  German  general  had  written  that, 
as  it  was  impossible  to  make  certain  of  superior  efficiency,  it 
became  necessary  to  aim  at  superior  numbers  by  training  every 
man  in  a  nation  to  arms. 

On  another  occasion  the  conversation  turned  on  the  Russo- 
Japanese  War,  and  how  the  Japanese  had  very  cleverly 
attacked  the  Russians,  without,  in  the  first  instance,  declaring 
war,  and  inflicted  what  proved  to  be  a  wound  from  which  the 
Russians  could  never  recover.  It  appeared  that  the  great  thing 
to  aim  at  was  to  surprise  the  enemy,  and  that  the  most  disas- 
trous form  of  surprise  was  that  in  which  a  nation  was  caught 
napping — that  is,  unprepared  for  war — and  suddenly  attacked. 
Such  an  idea  seemed  to  the  citizen  to  be  perfectly  monstrous ; 
and,  in  spite  of  the  illustrations  of  the  Boer  and  the  Russo- 
Japanese  Wars,  he  refused  to  believe  that  nations  could  act 
in  so  dastardly  a  manner.  He  recognised,  however,  that  if  that 
form  of  making  war  did  come  into  fashion,  it  would  be  a  poor 
look-out  for  a  nation  which  was  not  perfectly  prepared ;  and  he 
also  recognised  that,  if  a  nation  refused  to  act  in  that  fashion,  it 
must  endeavour  to  compensate  for  its  exemplary  behaviour  by 
making  itself  stronger  than  any  possible  enemy.  He  found  that 
a  certain  pessimism  reigned  as  regards  a  possible  struggle 
between  Great  Britain  and  Germany  :  simply  for  this  very 
reason,  that  it  was  thought  that  the  Germans,  having  made  their 
preparations,  would  attack  at  their  own  convenience,  suddenly 
and  unexpectedly,  when  Great  Britain  was  least  ready  to  meet 
the  attack;  and  that  there  were  no  signs  that  the  British  people 
were  even  aware  of  such  a  possibility,  or  were  making  any 
efforts  to  prepare  for  it.  The  citizen  was  half  convinced,  the 
exponents  of  these  views  evidently  being  so  very  much  in 
earnest;  nevertheless,  he  drew  consolation  from  the  fact  that, 
in  the  Russo-Japanese  War,  it  was  the  fleet  of  the  island  power 
which  had  surprised  its  adversary  in  so  effective  a  fashion,  and 
if  the  Japanese  fleet  could  accomplish  it,  assuredly  the  British 
fleet  could  do  likewise.  It  was  pointed  out  to  him,  however, 
that  he  was  optimistic,  for  that  it  was  not  the  sailors  or  the 
admirals  who  decided  when  it  was  time  to  attack  an  enemy,  but 
the  statesmen ;  and  he  was  asked  whether  he  had  sufficient  faith 


128  SCIENCE  PROGRESS 

in  British  statesmen  to  believe  that  they  would  order  the  fleet 
to  go  and  surprise  the  enemy.  As  his  political  views  were 
pronouncedly  opposed  to  those  of  the  Government,  he  felt  that 
there  was  but  little  hope  until  after  the  next  General  Election. 
Nevertheless,  on  thinking  matters  over,  he  refused  entirely  to 
believe  that  a  modern  civilised  nation  would  suddenly  attack  an 
unsuspecting  neighbour. 

He  had  but  just  arrived  at  this  conclusion  when  the  Austrians 
suddenly,  without  warning,  seized  two  Turkish  provinces. 
Shortly  afterwards  the  Italians,  again  without  warning,  attacked 
the  Turks  and  seized  Tripoli;  and,  while  the  Turks  were  still 
at  war  with  the  Italians,  they  were,  again  without  warning, 
attacked  by  the  allied  Balkan  States.  So  unsuspected  had  been 
the  existence  of  this  alliance  and  so  rapid  the  collapse  of  the 
Turkish  power,  that  the  citizen  was  obliged,  against  his  will,  to 
discard  his  previous  conviction  and  admit  to  himself  certain 
fundamental  truths : 

That  wars  are  won  by  superior  force,  wisely  employed. 

That  superior  force  consists  of  superior  numbers  combined 
with  superior  efficiency. 

That  the  first  battle  is  all-important. 

That  the  best  way  to  win  it  is  to  attack  the  enemy  before  he 
is  ready. 

That  modern  wars  are,  accordingly,  won  by  peace  pre- 
paration. 

While,  however,  he  admitted  to  himself  that  this  was  the 
scientific  method  of  conducting  war,  yet  he  refused  to  believe 
that  the  great  British  nation  would  ever  be  guilty  of  such 
methods.  Such  being  the  case,  it  became  evident  to  him  that 
the  nation  would  do  wisely  to  organise  and  train  every  available 
source  of  fighting  strength,  in  the  hope  of  successfully  repelling 
a  sudden  and  unexpected  attack. 

He  had  always  belived  that  the  Government  would  make  the 
necessary  arrangements  to  assure  the  security  of  the  nation  ; 
and,  being  of  a  tractable  disposition,  with  plenty  of  work  of  his 
own,  he  was  entirely  content  that  it  should  be  so — always  pro- 
vided, of  course,  that  he  was  not  overtaxed.  He  recalled  to 
mind,  however,  that  after  the  Boer  War  the  Government  had 
disclaimed  all  responsibility  for  neglect  to  prepare  for  it ;  and 
had  asserted  that  the  defence  of  the  country  was  the  business  of 
the  people  themselves,  that  is,  of  the  British  citizen.     Evidently, 


SCIENTIFIC  NATIONAL  DEFENCE  129 

it  behoved  him  to  devote  the  most  earnest  attention  to  this 
problem  of  the  national  security.  He  determined  to  study  the 
whole  matter  on  strictly  scientific,  or  business,  lines.  But  he 
found  it  difficult  to  commence;  the  whole  business  was  an 
unknown  quantity  to  him ;  there  were  no  known  quantities  at 
all,  except  these  two  horrible  ideas,  of  superior  force  and 
attacking  the  enemy  when  he  was  unprepared.  Where  was  he 
to  turn  to  gain  knowledge  ? 

Though  quantities  of  literature  had  been  produced  on  the 
subject,  yet  such  of  it  as  he  had  read  arrived  at  conclusions 
which  were  hopelessly  conflicting.  Some  were  in  favour  of  one 
thing;  some  in  favour  of  another;  some  in  favour  of  nothing; 
but  most  people  were  apparently  stoutly  opposed  to  the  views  of 
everybody  else.  He  began  to  think  that,  perhaps,  Lord  Roberts 
was  not  altogether  wrong  in  his  strenuous  advocacy  of  national 
service ;  but,  on  the  other  hand,  "  militarism  "  was  said  to  be 
(by  those  who  knew  what  it  meant)  a  fell  disease.  Besides,  it 
had  been  said  by  a  member  of  the  Government,  a  man  in  whom 
everybody  had  the  utmost  faith,  that  there  were  two  descriptions 
of  strategy,  one  which  controlled  armies  in  the  field  and  one 
which  constructed  them  in  peace  time ;  and  that  Lord  Roberts, 
though  a  master  of  the  former,  was  ignorant  of  the  latter. 
Then  there  were  assertions  that  the  field  gun  and  rifle  of  the 
army  were  not  all  that  could  be  desired,  that  the  cavalry  were 
short  of  horses  and  that  the  army  would  be  seven  thousand  short 
of  officers  on  mobilisation.  This  seemed  a  large  number.  On 
the  other  hand,  the  reassuring  official  statement  had  been  made 
that  the  army  was  better  than  it  ever  had  been.  That  was  very 
consoling.  At  the  same  time,  one  must  evidently  compare  an 
army,  not  with  what  it  has  been  in  the  past,  but  with  those 
armies  against  which  it  might  have  to  fight  in  the  future.  The 
state  of  the  navy  was  also  disturbing.  There  were  men  who 
could  hardly  be  termed  either  pessimists  or  alarmists,  who 
questioned  both  the  efficiency  and  sufficiency  of  the  navy. 
It  was  said  that  there  were  not  enough  cruisers  and  not  enough 
men  to  man  the  navy  when  mobilised.  On  the  other  hand,  the 
citizen  had  been  officially  told  to  sleep  peacefully  in  his  bed. 
But  he  had  already  slept  for  nearly  a  century  on  this  matter  of 
defence ;  surely,  it  was  time  to  be  up  and  doing.  He  began  to 
doubt  this  official  optimism.  It  had  been  clearly  proved,  so  he 
understood,  that  the  naval  superiority  of  160  per  cent,  over  the 

9 


130  SCIENCE  PROGRESS 

next  strongest  navy  which  he  had  enjoyed  a  few  years  ago  had 
now  been  reduced  to  a  mere  60  per  cent. ;  the  two-to-one 
standard  had  not  been  maintained.  The  Mediterranean,  more- 
over, had  certainly  been  practically  evacuated  by  his  fleet ;  and 
he  had  read  somewhere,  at  one  time  or  another,  that  the 
Mediterranean  was  the  strategical  pivot  of  manoeuvre,  or 
strategical  centre  of  gravity — he  could  not  quite  remember 
which  ;  but,  at  all  events,  it  was  something  of  first  importance. 

These  official  statements  did  not  ring  true.  The  citizen 
religiously  read  all  the  debates  in  both  Houses  of  Parliament; 
and  he  had  been  struck  by  the  very  unconvincing  answers  to 
certain  questions.  Some  of  the  official  statements,  moreover, 
were  rather  conflicting  ;  while  some  of  the  statesmen  appeared  to 
have  changed  their  minds  whenever  it  suited  their  convenience. 
He  had  gained  a  temporary  increase  of  confidence  when  he  read 
that  the  official  views  were  supported  by  the  General  Staff  and 
by  the  Committee  of  Imperial  Defence.  But,  within  a  few  days, 
the  statesman  concerned  had  modified  his  assertion  ;  and  every- 
body had  gathered  that  the  General  Staff  had  raised  some 
objection.  He  had  asked  a  soldier  friend  of  how  many  officers 
the  General  Staff  consisted ;  and  had  been  told  that  he  was  not 
quite  certain,  but  that  he  supposed  there  might  be  some  two  or 
three  hundred  scattered  about  in  various  parts  of  the  world. 
The  citizen  ruminated,  asking  himself,  were  all  these  officers 
unanimous  on  this  tremendous  problem  of  national  defence  ? 
He  also  made  inquiries  as  to  composition  of  the  Committee  of 
Imperial  Defence ;  and  this  body  seemed  to  consist  chiefly,  if 
not  entirely,  of  members  of  the  Government.  The  citizen  had 
lately  been  reading  Dickens  aloud  to  his  family  after  dinner; 
and  all  had  been  hugely  amused  at  the  cleverness  of  Sairey 
Gamp  in  putting  the  closure  on  an  argument  by  quoting  the 
opinion  of  the  non-existent  but  expert  Mrs.  Harris.  It  seemed 
to  the  citizen  as  though  the  Committee  of  Imperial  Defence  and 
the  General  Staff  were  being  used  by  statesmen  as  political 
Mrs.  Harrises. 

The  citizen  did  not  at  all  like  it.  His  suspicion  was  accen- 
tuated by  the  fact  that,  while  he  had  been  asleep,  or,  rather, 
while  he  had  been  in  the  act  of  yawning  and  stretching, 
neighbouring  nations  had  left  him  far  behind  in  the  matter  of 
aerostatics.  Here  was  a  patent  danger.  Of  what  value  was  the 
command  of  the  sea  if  the  command  of  the  air  were  lost?     He 


SCIENTIFIC  NATIONAL  DEFENCE  131 

had  visions  of  bombs,  literally  bolts  from  the  blue,  bursting  on 
his  devoted  head  in  the  middle  of  the  night.  Clearly  he  should 
awake  and  work  to  make  up  lost  ground  ;  but  he  trembled  to 
think  what  it  would  mean  to  him  if  war  broke  out  while  he  was 
still  unprepared.  It  was  this  that  taught  him,  more  than  any- 
thing else,  that,  during  all  these  years  of  sleep,  the  business  of 
war,  like  everything  else,  had  progressed  and  become  more 
scientific;  and  that  the  conduct  of  war,  which  he  had  fondly 
believed  to  be  an  art  to  be  left  to  the  genius  of  the  artist  who 
should  appear  when  the  occasion  arose,  had  become  a  science  in 
which  forethought  and  preparation  would  play  a  dominant, 
possibly  a  decisive  part. 

But  what  was  he  to  do  ?  He  knew  nothing  of  the  subject, 
not  even  the  rudiments  of  it.  Who  was  he  to  believe  ?  Was 
Lord  Roberts  right;  or  were  the  politicians  right?  What  did 
the  General  Staff,  or  those  responsible  for  it,  really  think  ?  What 
did  the  Naval  General  Staff  think?  After  all,  these  were 
probably  the  men  who  knew  most  about  it ;  and  it  struck  him, 
for  the  first  time,  as  an  absurdity  that  the  men  who  knew  most 
about  so  vital  a  matter  as  national  defence  should  be  the  only 
men  who  were  not  allowed  to  express  any  opinions. 

He  must  find  time  to  study  the  matter  for  himself;  but  how 
should  he  begin  ?  To  maintain  forces,  aerial,  sea,  and  land, 
superior  to  those  of  any  possible  combination  of  enemies 
would  necessitate  taxation  which  he,  for  one,  was  by  no  means 
prepared  to  pay.  It  was  also  a  counsel  of  perfection  unless 
the  nation  possessed  resources,  both  in  men  and  money,  far 
superior  to  anything  which  other  nations  enjoyed,  and  also 
unless  the  men  of  the  nation  were  prepared  to  pay  a  tax  of 
one,  two,  or  three  years'  personal  service  as  well  as  a  mere 
money  tax.  That  the  navy  and  the  aerial  force  should  be 
stronger  than  those  of  any  possible  enemy,  or  even  probable 
combination  of  enemies,  he  was  quite  prepared  to  admit.  But 
why  should  the  army  be  stronger  than  that  of  a  possible 
opponent?  He  considered  and  discussed  this  question;  and 
finally  concluded  that  it  was  necessary  to  maintain  an  army  of 
such  size  and  efficiency  as  would  enable  it  to  safeguard  the 
over-sea  possessions  and  home  territory  in  all  eventualities  and 
assure  allies  in  the  event  of  European  complications. 

He  had  hesitated  to  admit  this  last ;  but  he  had  now  learned 
that  Great  Britain  had,  in  the  past,  been  constantly  obliged  to 


132  SCIENCE  PROGRESS 

intervene  in  Europe  in  order  to  maintain,  or  restore,  the  balance 
of  power,  because  no  nation  had  ever  established  its  supremacy 
on  the  Continent  but  it  immediately  sought  to  compass  the 
downfall  of  the  British  power. 

What  size  army  was,  then,  required?  And  what  plane  of 
efficiency  ?  It  was  evident  to  him  that  the  highest  efficiency 
was  necessary ;  and  that  it  was  excessively  foolish  and  ex- 
travagant to  maintain  anything  in  the  nature  of  an  inefficient 
armed  force.  But  the  size  of  the  army  proved  to  be  a  great 
stumbling-block.  Expert  opinion  seemed  to  differ  in  the  most 
remarkable  fashion  from  an  army  numbering  millions,  obtained 
by  European  compulsory  methods,  to  a  small  voluntary  army. 

The  citizen  has  not  yet  made  up  his  mind  as  to  the  strength 
of  the  army  he  requires,  or  whether  voluntarism  is  sufficient  or 
compulsion  necessary.  He  is,  however,  inclined  to  think  that 
the  voluntary  system  is  incapable  of  producing  an  army  of  the 
required  numbers  or  efficiency,  and  that  the  men  of  the  nation 
must  be  prepared  to  pay  a  tax,  not  only  of  money,  but  of  personal 
service.  One  view  he  has  heard,  however,  which  has  given  him 
food  for  thought.  Can  a  nation,  he  was  asked,  which  is  content 
to  train  but  a  very  small  portion  of  its  men  to  arms,  hope  to 
compete  with  success  in  preparation  for,  and  in  the  conduct  of, 
war,  whether  on  land,  sea,  or  air,  against  one  which  trains  every 
able-bodied  man  ?  In  the  one  case  you  have  a  general  ignorance 
of  military  matters  ;  in  the  other  a  general  knowledge.  That,  it 
appeared  to  him,  was  the  scientific  problem  of  the  future ;  and  it 
also  appeared  to  him  that  the  British  nation  was  determined  to 
try  the  experiment  of  her  voluntary  systems  against  the  modern 
system  of  the  nation  in  arms. 

Another  point  impressed  him  greatly.  He  was  assured  that 
it  requires  twelve  years  in  which  to  convert  a  voluntary  system 
into  an  efficient  modern  system. 


WOMAN'S    PLACE    IN    NATURE 

I.— By  M.  S.  PEMBREY,  M.A.,  M.D. 

The  present  time  is  one  of  unrest;  and  one  of  the  signs,  the 
violent  agitation  in  pursuit  of  the  so-called  "rights  of  women," 
is  worthy  of  consideration  as  a  problem  of  biology.  As  such  the 
movement  has  both  a  physiological  and  pathological  aspect,  and 
there  are  many  indications  that  a  frank  discussion  on  these  lines 
is  needed.  The  problem  is  not  a  simple  one.  The  agitation  is 
not  supported  but  resisted  by  a  majority  of  the  women  of  this 
country  ;  in  the  ordinary  sense  of  the  word  it  is  not  political,  for 
the  militants  of  the  so-called  "  woman's  movement"  will  support 
alike  Tories,  Liberals,  Radicals,  and  Socialists,  provided  that 
they  will  cry  "Votes  for  Women."  It  is  a  movement  supported 
by  a  limited  number  of  women  and  men,  whose  views  may  be 
in  advance  of  civilisation  or  may  on  the  other  hand  be  an 
expression  of  the  pathological  effects  of  over-civilisation. 

It  is  often  forgotten  that  men  and  women  are  subject  to 
biological  laws.  The  effects  of  civilisation  upon  the  character- 
istics which  they  have  shared  with  animals  for  unknown  ages 
are  very  small  and  are  not  necessarily  progressive.  Public 
opinion  in  this  country  has  been  greatly  influenced  by  the 
advances  and  theories  of  biological  science.  The  belief  in  the 
Bible  as  a  guide  to  conduct  has  been  undermined,  but  the 
practical  application  of  the  theory  of  evolution  has  not  taken 
its  place.  Even  among  scientific  men  the  pressure  exerted  by 
public  opinion  is  so  strong  that  conventional  views  on  morality 
are  often  more  effective  than  the  teaching  of  science.  Public 
opinion  upon  what  is  right  and  what  is  wrong  varies  from  time  to 
time,  and  at  any  time  is  a  question  of  geography.  The  biological 
basis  of  a  true  morality  must  be  eternal,  the  same  at  all  times 
and  in  all  places  and  for  all  mankind. 

If  the  subject  of  woman's  place  in  nature  is  examined  from 
the  biological  standpoint,  it  will  be  found  that  there  is  no 
support  for  the  doctrine  of  equality.  Biology  shows  that 
differentiation  in  structure  and  division  of  labour  go  together, 

133 


134  SCIENCE  PROGRESS 

Man  and  woman  can  never  be  equal.  The  only  way  to  bring 
about  an  approximate  equality  is  to  unsex  both.  Such  a  level- 
ling process  the  primitive  instincts  of  healthy  women  and  men 
will  prevent.  Nevertheless  it  must  be  admitted  that  too  much 
attention  has  been  given  to  the  views  of  those  in  whom  these 
healthy  instincts  are  not  properly  developed.  Signs  are  not 
wanting  that  some  men  and  women,  who  think  that  they  have  a 
public  mission,  look  upon  their  animal  characteristics  as  an 
obstacle  to  the  attainment  of  what  they  call  the  higher  intellectual 
and  spiritual  life.  They  have  lost  or  never  fully  possessed  the 
natural  instincts  which  serve  as  a  guide  to  life.  They  do  not 
know  what  or  how  much  to  eat  or  drink,  when  to  work  or  when 
to  rest  or  when  to  marry,  and  vainly  seek  for  rules  of  life  ;  they 
have  overlooked  the  fact  that  excesses  of  intellectuality  and 
spirituality  as  often  lead  to  wayward  conduct,  illness,  and 
degeneration  as  the  more  common  vices.  Sexual  antagonism 
is  the  special  mission  of  other  extremists.  The  words  of  our 
national  marriage  service,  which  has  long  been  cherished  by 
many  generations  of  women,  are  declared  to  be  offensive  and 
indecent.  The  widespread  decline  in  the  birth-rate  has  shown 
that  marriage  has  been  debased  from  the  position  which  it 
should  occupy  according  to  the  teachings  of  religion  and 
biology. 

The  old-fashioned  view  of  woman's  place  in  nature  is  the 
one  supported  by  biological  knowledge.  Woman's  sphere  was 
the  home  and  family,  for  there  she  found  ample  opportunities 
for  the  exercise  of  her  special  gifts  of  patience,  kindness,  and 
love  of  offspring.  Her  influence  in  the  State  was  indirectly 
as  great  as  that  of  man,  for  apart  from  the  control  she  exercised 
upon  man,  she  held  in  her  hands  the  training  of  her  sons  and 
daughters  in  those  early  years  during  which  character  is  most 
easily  moulded.  The  responsibility  of  a  family  prevented  her 
from  becoming  too  much  interested  in  herself  or  in  intellectual 
problems.  As  a  young  woman  she  looked  upon  marriage  as 
the  aim  of  life,  and  as  an  experienced  matron,  with  every  wish 
for  the  happiness  of  her  daughters,  she  kept  the  same  ideal 
before  them.  The  term  "  old  maid  "  was  one  of  reproach  ;  a 
childless  marriage  was  a  calamity,  a  reflection  upon  one  or  other 
or  both  partners;  the  marriage  of  a  young  man  and  an  old 
woman  was  an  unnatural  condition  to  be  explained  only  by 
sordid  motives.     All  of  these  prejudices  had  a  true  biological 


WOMAN'S   PLACE   IN   NATURE  135 

basis,  and,  although  it  may  sound  harsh  in  these  days,  served  a 
good  purpose  in  maintaining  a  true  ideal.  Even  the  feminine 
fashions  and  adornments  were  a  recognition,  often  unconscious 
it  is  true,  of  the  importance  of  secondary  sexual  characteristics. 
The  mind  and  the  body  react  upon  each  other  ;  mental  conditions 
influence  the  internal  secretions,  and  as  is  well  known,  the 
internal  secretions  have  a  profound  effect  upon  the  mind.  The 
woman  who  was  afraid  of  a  mouse  gladly  braved  the  risks 
of  childbirth  and  bore  her  pains  without  the  use  of  anaesthetics. 
The  restrictions  imposed  upon  her  activity  by  bearing  and 
suckling  her  children  were  not  deplored  as  unfair  limitations 
of  her  career,  but  were  accepted  either  with  joy  as  a  holy  duty 
or  as  a  matter  of  course.  It  would  have  been  an  insult  to  suggest 
that  she  lacked  in  the  least  degree  the  maternal  instincts  so 
well  developed  in  many  of  the  lower  animals.  The  true  mother 
toiling  for  her  husband  and  children  did  not  deplore  her  lot 
or  consider  herself  a  slave  or  martyr  any  more  than  the  sailor 
or  miner  regards  himself  as  a  hero  in  running  risks  of  ship- 
wreck or  explosion.  She  was  not  worried  by  ideas  of  equality 
with  man ;  she  knew  full  well  that  in  many  respects  she  was 
superior,  and  as  such  claimed  and  obtained  exceptional  treat- 
ment and  respect.  Her  womanly  charm  was  more  effectual 
than  reason  in  influencing  man  in  her  favour ;  her  natural  tact 
and  intuition  were  more  useful  than  a  logical  argument.  The 
fact  that  she  was  educated  and  trained  along  special  lines  was 
no  reflection  upon  her  mental  or  physical  capacity ;  it  was  a 
recognition  of  the  ideal  division  of  life's  labour  and  purpose. 
The  limitation  of  the  means  of  earning  a  living  was  not  a 
grievance,  for  domestic  service,  teaching,  and  nursing  were 
responsible  duties  which  formed  the  best  training  for  a  woman 
whose  future  was  in  married  life. 

On  all  these  points  a  biological  defence,  if  defence  be  needed, 
can  be  offered,  and  there  is  little  doubt  that,  even  if  the  new 
women  increase  in  influence  by  obtaining  votes,  the  majority  of 
women  will  maintain  their  position  by  those  qualities  which 
have  served  them  so  well  in  the  past.  The  old-fashioned  ideal 
is  not  debased  because  it  is  sexual  and  has  an  origin  in  animal 
instincts.  The  slur  cast  upon  our  Victorian  mothers  has  not 
been  properly  resented.  It  is  true  that  they  did  not  glory  in 
competing  in  mental  and  physical  contests  with  men,  but  they 
could  and  did  bear  and  rear  large  and  healthy  families.    The 


1 36  SCIENCE   PROGRESS 

possession  of  a  baby  is  of  more  value  to  the  State  than  a  first- 
class  in  classics  or  a  silver  trophy  for  sport.  The  peasant 
woman  gazing  with  longing  eyes  upon  her  child  at  her  breast 
has  an  experience  of  the  purpose  of  life  which  the  highest 
intellectual  gifts  alone  cannot  supply. 

It  may  now  be  asked  why  with  such  an  ideal  before  them  is 
there  a  revolt  among  certain  classes  of  women  ?  What  are  the 
causes  and  how  are  they  to  be  removed  ?  It  seems  clear 
that  the  chief  cause  of  the  unrest  is  modern  education,  which  has 
been  artificially  forced  and  encouraged  along  wrong  lines.  Too 
much  stress  has  been  laid  upon  intellectual  attainments  and 
pleasures,  and  it  has  been  loudly  proclaimed  that  the  education 
of  the  two  sexes  should  be  the  same  and  that  a  woman  should 
not  be  debarred  from  entering  any  profession  or  occupation  she 
may  choose.  It  is  maintained  that  a  woman  is  a  better  mother 
if  she  be  well  educated.  Even  if  this  statement  be  admitted,  it 
depends  upon  the  definition  of  a  good  education.  The  natural 
instincts  of  healthy  women  have  for  ages  guided  her  in  the 
performance  of  the  duties  of  a  daughter,  wife,  and  mother,  and 
there  is  little  doubt  that  an  unsuitable  or  bad  education  by 
suppressing  or  blunting  those  instincts  will  make  her  less 
efficient  in  these  services  which  are  of  fundamental  importance 
to  the  race.  The  effects  of  education  and  of  a  specialised  pro- 
fession or  occupation  are  obvious  even  in  a  man ;  his  body  and 
mind  are  moulded  to  type.  The  effects  upon  woman  would  be 
greater  especially  if  the  occupation  were  continued  for  life  ;  her 
sexual  life  begins  early  and  ends  early,  and  under  natural 
conditions  makes  a  great  demand  upon  the  resources  of  the  body. 
Even  if  she  can  perform  more  efficiently  than  man  any  of  the 
work  generally  done  by  men,  the  race  will  lose  thereby,  if  at  the 
same  time  she  becomes  unfitted  for  those  very  duties  which 
man  can  never  assume. 

It  is  difficult  to  obtain  data,  but  there  is  general  agreement 
that  the  more  highly  educated  people  are  the  less  fertile.  There 
is  both  a  comic  and  a  pathetic  side  in  the  meetings  of  learned  men 
and  women  to  discuss  the  subject  of  eugenics ;  it  would  not  be 
an  unduly  rash  calculation  to  say  that  the  average  number  of 
offspring  of  the  married  members  at  most  meetings  is  not  more 
than  two. 

The  extension  of  the  old  doctrine  of  internal  secretions  by 
the  modern  work  upon  the  functions  of  the  ductless  glands  has 


WOMAN'S  PLACE   IN   NATURE  137 

shown  that  bodily  and  mental  health  are  a  complex  interaction 
of  all  the  organs  performing  their  functions  in  proper  sequence. 
The  distinctive  organs  of  the  two  sexes  are  no  exception  to  this 
rule,  and  no  one  with  common  sense  and  a  belief  in'either  design 
or  evolution  will  maintain  the  contrary. 

The  intrusion  of  women  into  the  occupations  formerly  occu- 
pied by  men  has  made  them  independent  but  at  the  same  time 
has  deprived  men  of  employment.  Every  healthy  man  is  a 
potential  husband.  Now  the  woman's  demand  is  "  equal  wages 
for  equal  work."  It  is  impossible  for  any  woman,  however  able 
she  may  be,  to  carry  out  the  duties  of  a  profession  and  at  the 
same  time  bear  and  rear  numerous  and  healthy  children.  By 
the  very  nature  of  things,  and  by  no  means  due  to  man-made 
laws,  the  woman  is  not  in  a  position  of  equality.  Even  if  she 
removed  these  obstacles  by  practising  celibacy,  she  would  not 
be  entitled  to  equal  wage  for  equal  work  ;  a  man's  duty  to  him- 
self, to  woman,  and  to  the  race  is  to  marry,  and  the  State  should 
recognise,  as  it  is  beginning  to  do  in  greater  measure,  that  the 
fulfilment  of  this  duty  entitles  the  man  to  better  pay  or  less 
taxation.  The  celibate  woman,  who  performs  for  the  State  no 
duty  which  a  man  cannot  equally  well  do,  is  not  entitled  to 
greater  pay  than  her  sister  who  is  forced  by  the  claims  of  mother- 
hood to  retire  for  a  time  from  the  same  kind  of  work. 

The  higher  education  of  women  and  their  employment  in 
posts  which  might  be  filled  by  men  has  brought  about  a  post- 
ponement of  marriage  to  such  a  late  stage  that  often  half  the 
period  of  the  woman's  sexual  life  is  already  past.  Late  marriages 
are  bad  for  the  health  and  morals  of  both  sexes  and  bad  for 
the  State,  for  the  offspring  will  be  less  numerous  and,  as  the 
evidence  goes,  less  vigorous.  The  idea  that  a  smaller  number 
of  children  born  to  parents  no  longer  young  will  grow  up  into 
better  citizens  owing  to  a  better  environment  has  no  biological 
support.  The  only  child  lacks  the  beneficial  effect  of  the  struggle 
for  existence  in  the  family,  the  mutual  education,  the  discipline 
and  the  hardening  of  both  body  and  mind  produced  by  the  clash 
of  its  interests  with  those  of  numerous  brothers  and  sisters.  A 
woman  should  experience  the  joys  and  trials  of  a  family  when 
she  is  young  and  able  to  adapt  herself  to  circumstances  and  play 
with  her  children  ;  she  should  look  forward  to  spending  her  old 
age  not  with  her  children  around  her,  but  with  her  grandchildren 
or  great-grandchildren. 


138  SCIENCE  PROGRESS 

The  so-called  higher  education  of  women  is  not  a  good  ideal 
for  either  woman,  man,  or  the  State.  Education  at  a  University 
for  three  or  four  years  makes  a  considerable  demand  upon  the 
bodily,  mental,  and  pecuniary  resources  of  the  woman,  and  there 
is  little  doubt  that  these  would  be  more  useful  to  all  concerned 
if  they  were  devoted  to,  or  reserved  for,  marriage.  There  is  no 
evidence  that  the  middle-aged  intellectual  woman  makes  a  better 
wife  or  mother.  The  indications  are  all  the  other  way.  The 
mental  training  causes  the  woman  to  be  self-centred  and  more 
sensitive  to  any  discomfort  or  pain  associated  with  child-bearing 
and  distracts  her  attention  from  those  domestic  duties  which 
mean  so  much  for  the  health  and  training  of  her  children.  So 
little  is  known  of  the  conditions  determining  the  transmission  of 
intellectual  capacity  that  an  anticipation  of  the  propagation  of 
intelligence  or  genius  by  the  marriage  of  the  highly  intellectual 
is  even  less  justified  than  the  prediction  of  mediocrity  or  insanity. 
The  woman  who  is  married  for  her  services  as  a  cheap  secretary 
or  assistant  in  her  husband's  intellectual  pursuits  is  as  much 
degraded  as  the  wife  who  is  valued  only  as  a  cheap  housekeeper 
and  cook.  The  physiological  test  of  woman's  efficiency  is 
motherhood. 

To  all  these  arguments  it  may  be  objected  that  marriage  as 
a  career  is  not  open  to  all  women,  because  there  are  about  a 
million  and  a  half  more  women  than  men  in  this  country. 
Why,  if  it  is  maintained  that  women  are  equal  to  men,  should 
not  women  take  their  share  in  building  up  the  Empire  by 
emigration  to  the  Colonies,  where  there  is  a  dearth  of  women  ? 
In  Australia  and  New  Zealand  they  might  obtain  both  husbands 
and  votes,  and  might  reintroduce  the  old-fashioned  morality  of 
family  life.  In  these  Colonies  where  the  women  have  the  vote, 
the  artificial  and  immoral  limitation  of  offspring  has  resulted 
in  a  decline  of  about  30  per  cent,  in  the  birth-rate.  Some 
details  of  the  opportunities  for  marriage  in  Canada  were  given 
at  the  recent  meeting  of  the  Central  Emigration  Board  ;  a  lady, 
who  had  spent  the  greater  part  of  the  last  four  years  in  the 
Dominion,  is  reported  x  to  have  said  that  "  if  a  woman  went  out 
to  the  West  she  married  almost  inevitably.  She  had  had  seven 
proposals  in  seven  weeks.  She  did  not  know  even  the  names 
of  some  of  the  men,  one  of  whom  was  a  cook  in  a  Canadian 
Pacific  Railway  train.     A  party  of  forty-five  girls  went  from 

1  The  Daily  Telegraph,  May  2,  19 13,  p.  15. 


WOMAN'S   PLACE   IN   NATURE  139 

Vancouver  to  Montreal.  Forty  of  them  got  married  on  the  way, 
and  only  five  arrived  at  their  destination." 

A  further  remedy  is  to  be  sought  in  a  return  to  a  simpler 
standard  of  living.  Limited  pecuniary  resources  are  no  obstacle 
to  a  happy  and  healthy  family,  and  it  is  notorious  that  many  of 
the  greatest  men  have  been  the  sons  of  poor  parents  in  humble 
positions.  A  true  biological  ideal  is  necessary :  early  marriage, 
numerous  offspring,  and  a  healthy  struggle  for  existence. 
Women,  even  without  votes,  have  more  than  their  share  of 
influence  in  moulding  public  opinion.  Let  them  recognise  that 
conventional  morality,  which  allows  and  even  preaches  the 
prevention  of  conception  and  the  induction  of  early  abortion, 
is  wicked,  degrading,  and  injurious,  especially  for  the  woman. 
Let  them  admit  that  the  servant  girl  who  gives  birth  to  an 
illegitimate  child  is  more  moral,  even  if  she  is  less  educated, 
then  the  woman  who,  from  the  day  of  her  marriage,  openly 
sanctified  by  a  religious  ceremony,  takes  measures  to  prevent 
motherhood.  From  a  biological  standpoint  an  illegitimate  child 
is  a  testimony  that  a  woman  is  more  moral  than  her  sisters  who 
have  taken  preventive  measures.  A  decline  in  the  number  of 
illegitimate  children  is  no  evidence  that  a  country  is  more 
moral.  This  truth  appears  to  have  received  little  recognition 
from  women,  but  judges  and  juries,  knowing  the  bitterness  of 
the  persecution  of  women  by  women,  always  show  a  sympathetic 
attitude  to  women,  even  when  they  are  guilty  of  infanticide. 

The  prevention  of  conception,  voluntary  abortion,  and  pros- 
titution have  no  analogy  among  the  lower  animals  ;  they  are 
not  physiological,  but  pathological.  These  evils  are  not  due 
to  man-made  laws,  but  to  the  absence  of  a  true  sexual  instinct 
in  many  women.  They  are  not  due  to  low  wages,  and  it  is  the 
grossest  insult  to  women  to  say  that  poverty  is  a  bar  to  true 
virtue.  Twenty  or  thirty  years  ago  domestic  servants  had  low 
wages,  but  there  is  no  evidence  that  they  were  less  virtuous 
than  the  servants  of  the  present  day,  who,  without  the  aid  of 
any  trade  union  or  votes,  have  raised  their  wages  by  about 
50  per  cent.  The  demand  for  domestic  servants  exceeds  the 
supply,  and  there  is  no  economical  reason  why  a  woman  should 
degrade  herself  for  money.  There  is  no  evidence  that  woman 
suffrage  has  abolished  these  evils  ;  indeed,  it  would  appear  that 
the  increased  occupation  of  women  in  commercial  pursuits 
has  led  to  a  wider  spread  of  the  disease  in  a  less  virulent  form. 


i4o  SCIENCE  PROGRESS 

It  is  common  to  speak  of  an  immoral  person  as  a  brute,  but 
it  is  not  true.  If  all  women  had  the  healthy  sexual  and  maternal 
instincts  of  animals,  these  evils  would  not  exist. 

The  demand  for  equality  in  the  matter  of  divorce  is  not  well 
based,  for  it  pays  no  attention  to  the  physiological  differences 
in  the  two  sexes,  and,  if  it  should  be  granted,  would  probably 
decrease  the  stability  of  family  life,  which  is  the  fundamental 
basis  of  every  nation. 

These  subjects  have  been  mentioned  here  because  they  figure 
so  largely  in  the  discussions  on  the  supposed  inequality  of 
women.  Women  can  rightly  claim,  and  generally  receive,  pre- 
ferential treatment,  but  they  cannot  obtain  equal  treatment, 
except  to  their  own  detriment,  for  it  has  no  firm  basis  in 
biological  conditions.  The  natural  protector  of  womankind  is 
man,  not  woman.  Motherhood  is  the  true  ideal  for  women  ;  a 
voluntary  celibacy  is  not  virtue,  but  at  best  the  expression  of  a 
neurosis. 


II.— By   O.   A.   CRAGGS,    D.Sc. 

When— more  than  a  year  ago — a  number  of  women  knelt  in 
prayer  for  votes  before  the  Rhadamanthuses  of  Westminster 
and  hoped  that  they  were  at  the  very  point  of  melting  those 
stony  hearts  and  brains,  in  ran  a  wild  person  flourishing  a 
torch.  This  flambeau,  he  cried,  was  the  Torch  of  Science ; 
which  had  lighted  him  to  see  into  the  very  depths  of  feminine 
nature ;  in  which  he  had  descried  nothing  but  physical  and 
mental  weakness,  vanity,  silliness,  hysteria,  emotion,  partiality, 
dogmatism,  excitability,  unreasonableness,  and  utter  ignorance. 
Woman's  place  in  nature  was  (he  said)  merely  that  of  a  semi- 
human  matrix  of  humanity  (which  is  really  man)  ;  and  she  was 
fit  only  to  scrub  doorsteps,  to  cook,  and  to  bear  children.  At 
this,  not  only  did  the  assembled  idols  harden  their  hearts  and 
refuse  the  women's  petition,  but,  as  Carlyle  says,  innumerable 
Rushlights  and  Sulphur-matches  were  kindled  at  the  torch  and 
waved  up  and  down  the  world  by  other  wild  persons  ;  and  the 
women  went  away  and  redoubled  their  violences,  and  even 
rooted  up  Golf-greens. 

I  protest  that  the  torch  was  not  that  of  Science  at  all,  but  a 
miserable  counterfeit  lighted  by  politicians  to  dazzle  the  eyes  of 
their  own  likes.     For  votes  for  women  I  care  not  a  jot,  either 


WOMAN'S  PLACE  IN   NATURE  141 

for  or  against ;  because  the  whole  quackery  of  politics — votes, 
representation,  parties,  caucuses,  divisions — has  now  been  dis- 
covered by  the  intelligent  part  of  mankind.  But  the  name  of 
Science  should  not  be  dragged  into  this  welter  of  fraud ;  and  I 
have  enough  good  northern  blood  in  me  to  resent  rudeness  to 
women  under  any  plea.  It  may  or  may  not  be  wise  to  give 
them  votes  ;  there  may  be  other  reasons  against  it ;  but  those 
urged  by  these  farthing-dip  bearers  in  the  name  of  Science  are 
not  hers.  Her  light  is  shed  equally  on  all  sides  of  a  question — 
not  only  on  one.  Come  then,  let  us  see  how  the  same  argument 
will  apply  to  the  other  half  of  the  race,  the  males. 

Woman's  only  duty  is  motherhood,  they  say.  But  surely 
we  might  as  credibly  affirm  that  man's  only  duty  is  fatherhood. 
If  the  franchise  be  excluded  on  these  grounds,  none  but 
bachelors  and  spinsters  should  have  it.  But  sociologists  main- 
tain that  these  are  the  least  worthy  of  it  because  they  have  not 
performed  the  duty  of  parentage  to  the  State.  If,  then,  only 
parents  should  have  it,  why  not  mothers  as  well  as  fathers  ? 
And  the  mother's  share  of  the  burden  is  far  more  onerous  than 
the  father's,  involving  often  the  health  of  a  lifetime,  and,  indeed, 
life  itself.  Moreover,  nearly  the  whole  care  and  teaching  of 
young  children  is  in  the  mother's  hands — in  addition  to  many 
other  duties.  True  the  father  provides  the  livelihood ;  but, 
hour  for  hour,  is  his  work  harder,  or  more  difficult,  or  more 
painful  than  the  mother's?  Scarcely;  and  on  this  count,  if 
either  must  be  excluded  from  the  franchise,  it  should  be  the 
father.  As  regards  spinster  and  bachelor,  it  is  the  latter  who 
neglects  the  duty,  because  it  is  only  he  who  is  always,  or  gener- 
ally, able  to  marry  if  he  chooses.  So  here  again  the  woman's 
case  wins. 

But  if  the  performance  of  natural  duties  to  the  State  gives 
the  first  claim  to  a  vote,  what  shall  be  said  of  the  men  who 
neglect  to  train  themselves  for  war  ?  If  it  is  the  duty  of  woman 
to  be  a  mother,  it  is  that  of  the  man  to  defend  her  and  his 
country.  The  woman  performs  her  part  of  the  obligation — with 
travail  and  at  the  risk  of  her  life ;  but  how  many  of  the  young 
cubs  of  the  day  who  deride  her  claims  to  the  franchise  perform 
theirs  ?  What  of  the  idle,  unhealthy,  and  dirty  crowds  who  boo 
the  women  at  their  meetings,  but  who,  likely  as  not,  would  run 
like  rabbits  at  the  first  shot  of  war  if  ever  they  had  strength  to 
reach  the  front?    This  is  the  just  answer  to  their  contemptible 


i42  SCIENCE  PROGRESS 

contempt.  Nor  can  their  claim  be  allowed  that  they  pay  taxes 
to  hire  substitutes  in  a  voluntary  army.  For  sacred  duties  there 
can  be  no  substitutes  ;  and,  besides,  our  best  soldiers  tell  us 
with  unanswerable  reason  that  the  time  has  come  when  the 
country  needs  all  the  men  it  has.  In  the  light  of  this  logic,  then, 
every  woman  who  has  borne  a  child  should  have  the  franchise; 
but  not  a  single  man  who  has  not  done  his  turn  of  military 
service.  And  moreover  such  men  should  by  rights  be  forced  to 
pay  the  taxes  for  the  whole  army  and  navy.  But  in  our  brainless 
nation,  the  mother  has  no  vote ;  the  father  of  a  large  family  pays 
nearly  as  much  as  the  gay  and  careless  bachelor ;  and  the 
soldier  and  dutiful  volunteer  as  much  as  one  who  serves  the 
State  not  at  all ! 

But,  say  the  pretended  scientists,  the  women  do  not  possess 
the  knowledge  and  judgment  of  the  men.  Good  gracious,  how 
many  men  possess  either  ?  As  for  knowledge,  most  of  them 
know  a  few  tricks,  learnt  from  others,  which  they  call  a  trade  or 
a  profession,  and  which  as  a  rule  they  perform  indifferently. 
Not  one  in  a  thousand  ever  reads  a  worthy  book,  ancient  or 
modern,  or,  after  his  schooldays,  ever  troubles  himself  again  to 
study  anything.  Their  knowledge,  like  that  of  most  women, 
comes  from  newspapers,  poor  novels  and  plays,  picture  shows 
and  current  talk — good  enough  perhaps  for  the  mass  of 
humanity.  Women  have  their  own  knowledge,  of  the  same 
level.  Is  the  man  who  knows  only  how  to  rivet  boilers  or  how 
to  sell  cheese  a  better  judge  of  national  policies  than  a  woman 
who  knows  how  to  cook  or  how  to  keep  a  happy  home  ? 

In  the  end,  what  proof  have  we  that  the  knowledge  and 
intelligence  of  women  are  inferior  to  those  of  men  ?  To  measure 
either  with  close  enough  accuracy  for  comparison  is  almost 
impossible.  The  assertion  that  such  measurements  have  been 
made  by  "  Science,"  with  this  or  that  result,  is  a  pretence  and  a 
falsity.  The  only  possible  justification  might  be  that  women 
have  not  taken  the  first  place  in  most  of  the  highest  lines  of 
intellectual  work,  science,  art,  and  invention.  But  such  work  is 
the  rare,  the  very  rare,  efflorescence  of  mind  ;  and  we  must  not 
judge  the  average  degree  of  knowledge  and  intelligence  by  such 
exceptional  phenomena;  while  other  causes  than  that  of  mere 
inability  may  be  at  work. 

A  man  of  any  experience  of  the  world,  looking  broadly  at 
the  human  race  of  the  present,  will  not  easily  accept  the  im- 


WOMAN'S  PLACE  IN  NATURE  143 

mense  superiority  of  the  male.     It  is  a  common  thing  to  hear  of 

the  tallness,  healthiness,  and  strength  of  the  young  women  of 

the  day ;  and  also  of  the  weediness,  laziness,  and  unhealthiness 

of  the  young  men.     We  can   compare   them   in   any   train   or 

omnibus — not  at  all  to  the  advantage  of  the  latter.     Every  day, 

at   an  early  hour  in  the  morning  we  see  hundreds  of  young 

women  hurrying  happily  and  healthily  to  their  shops  and  offices 

for  a  hard  day's  work ;  and  also,  somewhat  later,  hundreds  of 

men  smoking  cigarettes  with  bored  expressions  and  evidently 

vacant  brains.     As  for  the  older  men,  how  dull  and  stale  they 

often  are — with  not  a  grain  of  enthusiasm  for  anything  in  the 

world,  yet  sniffing  in  a  superior  manner  about  the  efforts  of 

those  who  attempt  any  reform  whatever.     No ;  I  for  one  think 

that  the  woman  is  on  the  whole  the  better  of  the  two,  except 

only  in  the  matter  of  muscular  strength. 

And  what,  I  should  like  to  know,  have  the  greatly  superior 
political  aptitudes  of  the  men  done  for  humanity  all  these  cen- 
turies.    The  great  progress  of  the  world  in  health,  prosperity, 
and  general  happiness  has  been  due  almost  entirely  to  a  very 
few  men   of  genius — mostly   men   of  science,  writers,  and  in- 
ventors ;  and  not  at  all  to  the  politicians.     Measure  up  candidly 
what   these  people  have  actually   given   to   the  human  race — 
perhaps  a  few  good  factory  laws  ;  to  which,   by  the  by,  they 
have  almost  always  been  driven  by  public  opinion,  that  is,  by 
the  writers.   After  endless  heat,  immense  discussions,  portentous 
debates,    the   formation   of  endless  parties,   the   interaction    of 
innumerable  intrigues,  this  political  mountain  has  brought  forth 
only  this  one  little  mouse.     On  the  other  hand,  they  with  their 
false   notions  of  party,  their  trained   and  organised  party  pre- 
varication, and  the  false  ideals  which  they  ever  hold  before  the 
public,  are  mainly  responsible  for  the  international  and  the  inter- 
social  strifes  of  the  day  which  impede  further  progress.     What 
do  they  do  for  science,  art,   invention,  or  morality? — nothing 
whatever.      Their    very    laws    are   so   badly   framed   that   the 
lawyers  who  profit  most  by  that  bad  framing  condemn  them. 
Amateurs  at  their  own  art,  they  do  little  but  confuse  the  issues 
which  poor  humanity  is  called  upon  to  face. 

But  I  have  nothing  to  do  with  the  political  question  of  the 
franchise  for  women.  The  answer  for  that  depends,  does  it 
not  ?  on  what  is  the  use  of  the  franchise  at  all — a  very  difficult 
problem.     But   every  scientific  man,  however  humble,  is  con- 


144  SCIENCE  PROGRESS 

cerned  with  the  honour  of  Science.  It  is  false  to  say  that 
Science  has  discovered  the  inaptitude  of  women  for  votes. 
Science  has  not  even  discussed  the  subject ;  and  cannot  dis- 
cuss it  until  she  possesses  much  more  data  than  she  has  at 
present. 

It  would  be  easy  to  spin  a  dozen  similar  biological  explana- 
tions of  the  present  revolt  of  the  women.  For  instance  (it  may 
be  argued)  their  increasing  physical  and  mental  excellence  is 
some  subtle  compensation  of  nature  for  the  increasing  deteriora- 
tion of  the  men  in  this  country,  due  to  centuries  of  peace,  to  the 
neglect  of  true  warlike  exercises  and  physical  emulation,  to 
indulgence  in  mean  pleasures  and  indifference  to  all  high  effort ; 
that  the  women  are  conscious  of  this  relative  change,  and  are 
no  longer  content  to  be  ruled  by  masters  whom  they  no  longer 
trust  as  much  as  they  did.  That  is  as  good  a  theory  as  the 
other.     Neither  can  dare  claim  the  sanction  of  Science. 


THE   SEATS   OF  THE  SOUL  IN   HISTORY 

By   DAVID   FRASER   HARRIS,   M.D.,   B.Sc.   (Lond.) 

It  is  well  known  to  the  historian  of  biology  that  even  the 
plants  have  been  supposed  to  possess  souls. 

The  famous  naturalist,  Andrea  Caesalpinus  (15 19-1603),  of 
Arezzo,  who  is  even  now  regarded  in  Italy  as  the  dicoverer  of 
the  circulation  of  the  blood,  enters  into  a  long  discussion  on  the 
nature  and  seat  of  the  plant-soul  in  his  book,  De  Plantis  Librixvi. 
(Florence,  1583).  He  writes  :  "  Whether  any  one  part  in  plants 
can  be  assigned  as  the  seat  of  the  soul,  such  as  the  heart  in 
animals,  is  a  matter  for  consideration — for  since  the  soul  is  the 
active  principle  ('  actus ')  of  the  organic  body,  it  can  neither  be 
'  tota  in  toto'  nor  'tota  in  singulis  partibus,'  but  entirely  in 
some  one  and  chief  part  from  which  life  is  distributed  to  the 
other  dependent  parts.  If  the  function  of  the  root  is  to  draw 
food  from  the  earth,  and  of  the  stem  to  bear  the  seeds,  and  the 
two  cannot  exchange  functions  .  .  .  there  must  either  be  two 
souls,  different  in  kind  and  separate  in  place,  the  one  residing 
in  the  root,  the  other  in  the  shoot,  or  there  must  be  only  one, 
which  supplies  both  with  their  peculiar  capabilities.  But  that 
there  are  not  two  souls  of  different  kinds  and  in  a  different  part 
in  each  plant  may  be  argued  thus :  we  often  see  a  root  cut  off 
from  a  plant  send  forth  a  shoot,  and  in  like  manner  a  branch 
cut  off  send  a  root  into  the  ground,  as  though  there  were  a 
soul  indivisible  in  its  kind  present  in  both  parts.  But  this 
would  seem  to  show  that  the  whole  soul  is  present  in  both 
parts,  and  that  it  is  wholly  in  the  whole  plant,  if  there  were 
not  this  objection  that,  as  we  find  in  many  cases,  the  capabilities 
are  distributed  between  the  two  parts  in  such  a  way  that  the 
shoot,  though  buried  in  the  ground,  never  sends  out  roots — 
for  example,  in  Pinus  and  Abris,  in  which  plants  also  the  roots 
that  are  cut  off  perish." 

We  need  not  follow  the  subtle  Csesalpinus  through  all  the 
details  of  his  arguments  as  to  where  the  soul  of  the  plant  must 
reside,  but  he  finally  places  it  at  the  junction  between  the  root 
10  145 


i46  SCIENCE  PROGRESS 

and  the  stem.  This  region,  later  known  as  the  "collet"  or 
neck,  was,  even  after  the  time  of  Linnaeus,  regarded  with  a 
superstitious  respect,  as  though  here  had  been  established  some 
special  focus  of  vitality. 

Caesalpinus  is,  however,  later  on  in  this  dissertation,  quite 
inconsistent  with  the  notion  of  the  localisation  of  the  plant-soul, 
for,  although  he  has  assigned  it  to  the  union  of  the  root  and 
the  stem,  he  is  afterwards  forced  to  admit  that  the  vegetable 
soul  must  be  diffused  through  all  the  parts,  even  to  the 
extremities  of  the  leaves,  which,  of  course,  are  very  much  alive. 

Csesalpinus  had  only  followed  Aristotle  in  believing  in  a 
plant-soul :  his  conception  of  plant-life  is  quite  Aristotelian, 
thus  :  "  As  the  nature  of  plants  possesses  only  that  kind  of  soul 
by  which  they  are  nourished,  grow  and  produce  their  like,  and 
they  are  therefore  without  sensation  and  motion,  in  which  the 
nature  of  animals  consists,  plants  have  accordingly  need  of  a 
much  smaller  apparatus  of  organs  than  animals." 

The  well-known  man  of  science,  the  Burgundian  Mariotte 
(died  1684),  in  his  Sur  le  Sujet  des  P/antes,  declares  that,  as  we 
know  nothing  about  the  vegetable  soul,  the  assumption  of  it 
is  not  helpful  in  plant  physiology. 

If  we  go  far  enough  back  in  the  history  of  thought  about 
the  relations  of  the  soul  to  a  material  substratum,  we  find  that 
the  seat  of  the  mental  processes  was  not  originally  supposed 
to  be  within  the  nervous  system  at  all.  The  ancient  Egyptians 
regarded  the  soul  as  seated  in  the  heart,  as  also  did  Aristotle 
(b.c.  384-322),  an  idea  by  no  means  fantastic  when  we  reflect 
on  the  ease  and  certainty  with  which  emotional  states  influence 
the  force  and  rate  of  the  action  of  that  organ.  As  late  as  the 
time  of  the  Neapolitan  philosopher  Vico  (1678-1774)  tms  idea 
was  revived,  Vico  insisting,  contrary  to  Descartes,  that  the  mind 
was  in  the  heart  and  not  in  the  head. 

Aristotle,  in  particular,  referred  to  the  brain  as  "cold  and 
bloodness,"  and  imagined  its  function  to  be  that  of  cooling 
vapours  from  the  heart. 

Another  old  Greek  idea  was  that  the  mind  or  soul  resided 
in  the  diaphragm,  a  reference  to  which  still  lingers  in  our  own 
word  phrensy  (frenzy),  which  is  derived  from  phren,  the  Greek 
word  for  the  diaphragm.  "  Phreno-pathia"  is  a  now  little-used 
term  for  mental  disease,  and  "  phrenetic  "  means  mentally  ex- 
citable, while  "  phrenitis  "  has  actually  become  a  synonym  for 


THE  SEATS  OF  THE  SOUL  IN   HISTORY       147 

inflammation  of  the  brain.  Hence  the  word  "  phrenology,"  a 
term  for  that  pseudo-science  which  purports  to  be  a  discourse 
on  the  localisation  of  things  mental,  is  actually  derived  from 
a  word  which  refers  to  the  diaphragm,  and  neither  to  the  brain 
nor  the  head  at  all.  It  is  not  difficult  to  see  how  the  notion 
arose  that  the  soul  was  resident  in  the  diaphragm,  since  strong 
emotions — affections  of  the  soul — strongly  affect  that  great 
muscle  so  important  in  breathing.  Emotions  made  the  chest 
to  heave  visibly,  therefore  emotions  arose  or  existed  locally  in 
the  chest  and  in  its  chief  muscle,  the  diaphragm,  so  the  ancients 
argued. 

That  viscera  are  related  to  mental  and  emotional  states  is 
a  very  old  observation,  as  for  instance  in  the  Bible  when  we 
read  in  the  Psalms,  "  My  reins  instruct  me  in  the  night  seasons." 

From  time  immemorial  has  not  the  spleen  been  thought  to 
be  the  seat  of  anger  and  envy?  We  even  yet  talk  of  a 
"  splenetic"  man  and  of  a  "  fit  of  spleen  "  as  meaning  an  angry 
man  and  a  fit  of  anger.  While  Shakespeare  undoubtedly 
accepted  these  notions  on  the  visceral  distribution  of  the 
emotions,  placing  love,  for  instance,  in  the  liver,  he  had  at 
the  same  time  undoubtedly  heard  of  the  soul  as  seated  in  the 
brain,  for  he  wrote  in  King  John  (Act  V.  Sc.  7) : 

It  is  too  late  :   the  life  of  all  his  blood 
Is  touched  corruptibly,  and  his  pure  brain 
(Which  some  suppose  the  soul's  frail  dwelling-place) 
Doth,  by  the  idle  comments  that  it  makes, 
Foretell  the  ending  of  mortality. 

The  early  Belgian  chemist  van  Helmont  (1 577-1644)  was 
probably  one  of  the  last  men  of  science  to  regard  the  soul 
as  existing  outside  of  the  head  :  he  placed  it  in  the  pylorus 
of  the  stomach.  His  reasons  for  this  are  very  quaint  reading : 
"  Though  it  carries  out  sensations  and  movements  by  means 
of  the  brain  and  nerves,  its  actual  throne  is  in  the  pylorus ; 
it  resides  in  the  orifice  of  the  stomach."  In  proof  of  this  van 
Helmont  says  that  a  great  emotion  is  always  felt  at  the  "  pit 
of  the  stomach,"  and  that  "  a  man  may  have  his  head  blown  off 
by  a  cannon-ball  and  his  heart  continue  to  beat  for  some  time, 
whereas  a  severe  blow  over  the  pit  of  the  stomach  will  stop 
his  heart  and  take  away  his  consciousness  simultaneously." 
But  he  qualifies  this  in  the  following  subtle  manner  :  "Though 


148  SCIENCE  PROGRESS 

it  is  placed  in  a  locality  it  is  nevertheless  not  there  in  a  local 
manner ;  it  is  present  in  the  stomach  in  some  such  way  as 
light  is  present  in  a  burning  wick." 

Concurrently  with  these  ideas  regarding  the  extra-cranial 
seats  of  the  soul,  there  had  been  schools  of  thought  from  the 
earliest  times  which  regarded  the  central  nervous  system  as 
that  to  which  the  mind  was  related.  As  long  ago  as  about 
300  B.C.  Herophilus  of  Alexandria  had  imagined  the  soul  to 
be  inside  the  fluid  of  the  cerebral  ventricles — these  innermost 
recesses  of  the  entire  body,  the  mental  Holy  of  Holies. 
Herophilus  regarded  the  fourth  ventricle  as  particularly  mental : 
this  is  very  interesting  to  us,  seeing  that  below  that  cavity 
some  of  the  most  important  vital  centres  in  the  nervous  system 
are  undoubtedly  situated.  Claudius  Galen  (died  200  a.d.),  to 
do  him  justice,  taught  that  the  brain  was  the  place  where  the 
soul  and  intellect  had  their  home. 

We  may  pass  over  all  the  centuries  intervening  between 
Galen's  death  and  the  date  of  the  publication  of  Vesalius' 
great  work,  the  De  Corporis  Humani  Fabrica,  1543,  because 
they  contributed  nothing  towards  clear  thinking  about  the 
localisation  of  mental  attributes.  The  father  of  Anatomy 
(15 14-1564),  to  whom  physiological  problems  were  by  no 
means  uninteresting,  has  the  following  prescient  remarks  on 
the  mind  as  related  to  the  brain :  "  But  how  the  brain  performs 
its  functions  in  imagination,  in  reasoning,  in  thinking,  or  in 
memory  (or  in  whatever  way,  following  the  dogmas  of  this 
or  that  man,  you  prefer  to  classify  or  name  the  several  locations 
of  the  chief  soul)  I  can  form  no  opinion  whatever.  Nor  do 
I  think  that  anything  more  will  be  found  out  by  anatomy  or 
by  the  methods  of  those  theologians  who  deny  to  brute  animals 
all  power  of  reasoning  and  indeed  all  the  faculties  belonging 
to  what  we  call  the  chief  soul.  For  as  regards  the  structure 
of  the  brain  the  monkey,  dog,  horse,  cat,  and  all  quadrupeds 
which  I  have  hitherto  examined,  and  indeed  all  birds  and  many 
kinds  of  fish,  resemble  man  in  almost  'every  particular.  Nor 
do  we  by  dissection  come  upon  any  difference  which  would 
indicate  that  the  functions  of  those  animals  should  be  treated 
otherwise  than  those  of  man.  In  proportion  to  the  size  of 
the  body,  first  the  ape  and  then  the  dog  exhibit  a  large  brain, 
suggesting  that  animals  excel  in  the  size  of  their  brains  in 
proportion  as  they  seem  to  be  endowed  with  the  faculties  of 


THE  SEATS  OF  THE  SOUL  IN   HISTORY      149 

the  chief  soul.  I  wonder  at  what  I  read  in  the  scholastic 
theologians  and  the  lay  philosophers  concerning  the  three 
ventricles  with  which  they  say  the  brain  is  supplied." 

The  particular  views  Vesalius  could  not  accept  were  that 
the  most  anterior  cavity  in  the  brain  was  for  sensations,  the 
middle  one  for  imagination  and  the  posterior  for  memory ; 
notions  that  had  originated  with  the  Arabian  doctors  and  had 
been  adopted  by  such  scholars  as  Duns  Scotus  and  Thomas 
Aquinas. 

The  next  attempt  to  localise  the  soul  and  one  that  attained 
to  a  notoriety  commensurate  with  its  ingenuity  was  that  by 
the  Frenchman  Rene  Descartes.  The  great  philosopher  of 
Touraine  placed  the  soul  in  the  pineal  gland.  There  was  a 
show  of  reason  for  his  choice  of  this  local  habitation;  the  soul, 
according  to  all  current  conception,  had  to  be  one  and  indi- 
visible and  not  extended  in  space.  No  region  of  the  body 
seemed  so  suitable  for  the  seat  of  such  an  essence  as  the 
single,  simple,  not  bilaterally  developed  pineal  gland — the 
nearest  approach  to  a  single  point  which  could  be  discovered 
in  the  central  nervous  system.  Here,  after  the  manner  of  a 
general  governor  or  overseer,  sat  the  soul,  said  Descartes  , 
thither  came  information  from  all  the  senses  to  it,  thence  it 
issued  its  commands  to  all  parts. 

There  was  a  dark  side  to  Descartes'  speculations,  for  his 
followers,  denying  the  existence  of  a  rational  soul  in  the  lower 
animals,  taught  that  the  members  of  the  brute  creation  were 
unconscious  automata.  The  practical  outcome  of  this  philo- 
sophical absurdity  was  that  certain  Cartesians  treated  the 
lower  animals  with  positive  cruelty.  Very  unfortunately  for 
Descartes,  when  the  pineal  body  came  to  be  examined  under 
the  microscope,  it  was  found  to  consist  only  of  some  atrophied 
cells  and  a  few  crystals  of  carbonate  of  lime  and  other  earthly 
matter — a  most  unlikely  dwelling-place  for  the  soul,  for  "  dust 
thou  art,  to  dust  returnest,"  was  not  spoken  of  the  soul. 
Philosophy  had  to  try  again.  We  must  next  notice  the  views 
on  this  subject  of  a  great  Englishman— Thomas  Willis,  M.D., 
in  his  early  life  a  pupil  of  Harvey.  Though  Willis  wrote 
extensively  on  the  nervous  system,  his  views  are  not  nearly 
so  well  known  to  the  general  reader  as  those  of  Descartes. 
Whereas  according  to  Descartes  the  soul  was  as  nearly  as 
possible   an   indivisible   point  which  could   exist    only  in    an 


150  SCIENCE  PROGRESS 

organ  that  was  not  even  bilateral,  for  Willis  there  were  two 
souls,  each  widely  diffused,  the  one  in  the  blood,  the  other  in 
the  nervous  system.  Willis  asserted  that  the  soul  in  the  blood 
was  of  the  nature  of  a  flame,  that  in  the  nervous  system  of 
the  nature  of  light.  Willis's  explanation  of  the  way  the  soul 
(through  its  derived  spirits)  was  related  to  the  brain  was  some- 
what as  follows :  "  The  lighter  and  more  spirituous  parts  of 
the  blood  ascend  by  the  arteries  to  the  brain,  where  a  distilla- 
tion takes  place,  and  animal  spirits  are  the  result.  These 
spirits  flow  over  the  surface  of  the  cerebrum  and  cerebellum, 
whence  they  descend  all  over  the  nervous  system.  Only  the 
spirits  in  the  cerebrum  are  destined  for  voluntary  movement 
and  sensation,  those  in  the  cerebellum  are  for  involuntary 
movement."  This  last  idea  is  interesting  in  the  light  of 
modern  work,  for  although  we  cannot  admit  that,  as  stated, 
it  represents  the  truth,  still  it  is  a  fact  that  the  activities  of 
the  cerebellum  are  carried  on  entirely  outside  the  sphere  of 
consciousness.  Undoubtedly  Willis  had  glimmerings  that 
sensations  and  their  memories — mental  images — were  on  their 
physical  aspect  modifications  of  the  substance  of  the  brain. 
He  talks  of  "  the  pictures  or  images  of  all  sensible  things 
admitted  into  these  secret  places."  One  of  Willis's  books  is 
actually  named  De  Anima  Brutorum  (concerning  the  soul  of 
animals).  The  soul,  then,  was  by  Willis  allowed  to  reside  in 
the  cerebral  hemispheres,  where  it  has  ever  since  been  permitted 
to  rest  in  peace,  at  any  rate  on  the  part  of  those  who  believe 
that  it  needs  a  circumscribed  dwelling  within  the  bodily  frame. 

When  we  come  to  the  brilliant  young  man  of  science,  the 
Dane  Nicholas  Stensen  (1638-1686),  we  come  to  the  first  attempt 
to  express  the  modern  notion  of  localisation  of  function  within 
the  brain,  a  truth  parodied  by  the  phrenologists,  believed  in  by 
the  physiologists.  This  was  how  Stensen  put  it  when  writing 
of  the  fibres  in  the  white  core  of  nervous  matter  :  "  If,  indeed, 
the  white  substance  be  wholly  fibrous  in  nature,  we  must  neces- 
sarily admit  that  the  arrangement  of  its  fibres  is  made  according 
to  some  definite  pattern,  on  which  doubtless  depends  the 
diversity  of  sensations  and  movements.  It  is  my  opinion  that 
the  true  method  of  dissection  would  be  to  trace  the  nervous 
filaments  to  the  substance  of  the  brain  to  see  which  way  they 
pass  and  where  they  end  ;  but  this  method  is  accompanied  with 
so  many  difficulties  that  I  know  not  whether  we  may  hope  ever 


THE  SEATS  OF  THE  SOUL  IN   HISTORY       151 

to  see  it  executed  without  a  special  method  of  preparing"  (1662). 
We  had  to  wait  about  200  years  for  that  special  method. 

The  notions  of  a  central  soul  and  peripherally  acting  spirits 
in  the  nerves  of  the  senses  and  in  the  motor  nerves  lingered  for 
a  long  time  in  the  minds  of  the  learned.  The  closing  lines  of 
the  Principia  (1687)  show  that  they  were  the  working  hypothesis 
of  such  an  intellectual  giant  as  Sir  Isaac  Newton. 

A  return  to  the  idea  of  the  soul  as  permeating  the  entire  body 
was  made  by  the  famous  German  thinker,  Georg  Ernst  Stahl 
(1660-1734),  the  originator  of  the  unfortunate  conception  of 
phlogiston.  Stahl  spoke  of  an  "  anima  sensitiva  "  which  pene- 
trated into  and  possessed  every  organ  and  tissue  of  the  body. 
No  tissue  really  living  was  outside  the  sphere  of  its  imma- 
nence. The  views  of  Stahl  are  alluded  to  as  those  of 
"Animism." 

The  modern  statement  of  the  problem  has  come  to  be — Is 
consciousness  restricted  to  an  association  with  cerebral  activity, 
or  does  it  also  accompany  activity  of  lower  centres,  including 
those  of  the  spinal  cord  ?  Few  biologists  can  now  be  found 
who  uphold  the  doctrine  that  consciousness  is  awakened  by 
activity  of  the  spinal  cord  alone  :  all  inferences  from  experi- 
mental work  on  the  nervous  system  forbid  such  a  conclusion. 
We  cannot  imagine  that  the  decapitated  snake  with  only  its  cord 
intact  which  coils  itself  round  the  red-hot  poker  is  a  conscious 
organism.  On  the  contrary,  it  allows  itself  reflexly  to  be 
burnt  up  just  because  the  seat  of  its  consciousness,  its  brain, 
has  been  removed  from  the  intelligent  direction  of  its  body. 

As  regards  emotional  and  intellectual  localisation,  the 
phrenologists  have  neither  advanced  nor  retarded  the  scientific 
study  of  the  material  relationships  of  consciousness.  John 
Joseph  Gall  (1758-1828),  usually  thought  to  be  the  founder  of 
phrenology,  originated  neither  the  term  itself  nor  the  body  of 
beliefs  known  by  that  name.  The  term  was  given  by  one 
Forster  in  181 5.  Gall  was  imbued  with  the  notion,  correct, 
but  in  advance  of  his  time,  that  certain  mental  attributes  were 
localised  in  the  cerebrum.  He  rightly  supposed  centres  to  exist 
for  intelligent  speech  and  for  word-memories.  Gall  lectured  on 
the  functions  of  the  cerebrum  before  various  universities  in 
Germany.  His  colleague,  Spurtzheim,  much  less  of  a  man  of 
science  and  more  of  a  popular  lecturer,  developed  phrenology 
as  we  know  it  to-day.     Its  dogmas  and  absurdities  are  too  well 


152  SCIENCE  PROGRESS 

known  and  have  been  too  long  refuted  to  detain  us  now.  But 
possibly  some  of  us  have  little  idea  of  the  furore  that  phrenology 
caused  in  the  early  years  of  last  century.  The  Phrenological 
Society  of  Edinburgh  had  630  members,  that  of  London  300,  and 
a  Chair  of  Phrenology  was  actually  established  at  the  Ander- 
sonian  College  in  Glasgow. 

The  modern  problem  is  not  where  the  soul  is  seated,  but 
what  precise  modification  of  cerebral  tissue  constitutes  the 
physical  concomitant  of  a  mental  process— that  the  two  pro- 
cesses are  intimately  correlated  no  one  doubts.  Until  lately, 
physiologists  had  been  content  to  refer  states  of  consciousness 
to  states  of  activity  of  the  bodies  of  the  nerve-cells  found  inside 
the  grey  matter  of  the  cortex  of  the  cerebral  hemispheres.  But 
the  physiological  psychologist,  Dr.  MacDougal,  of  Oxford,  has 
brought  forward  some  evidence  which  points  to  certain  delicate 
junctions  between  the  processes  of  the  one  nerve-cell  and  those 
of  another  as  being  the  actual  seats  of  consciousness.  The 
problem  is  one  of  interest  entirely  to  the  specialist,  and  one  only 
to  be  solved  by  the  specialist ;  but  the  broad  fact  remains  that 
natural  science  knows  of  no  mind  as  apart  from  matter,  and  only 
a  very  specialised  kind  of  matter,  as  directly  related  to  the 
existence  and  development  of  what  we  understand  by  mind. 


THE  OUTLOOK  FOR  HUMAN  HEALTH 

By  BERNARD  HOUGHTON,  B.A. 

Indian  Civil  Service 

Mankind,  or  at  least  the  educated  portion  thereof,  have  within 
the  past  half-century  entered  into  a  new  and  very  beautiful 
world.  In  almost  every  branch  of  science,  whether  astronomy, 
biology,  geology,  chemistry,  physics  or  anthropology,  the 
atmosphere  teems  with  the  busy  toil  of  workers  and  is  electric 
with  the  actual  or  expectant  discovery  of  new  and  important 
facts.  Brilliant  and  fascinating  as  is  this  fairyland  of  science,  all 
may  not  fall  within  its  glamour  or  perceive  the  true  significance 
of  the  gifts  it  ceaselessly  tenders  for  the  benefit  of  humanity. 
But  there  is  one  branch  of  knowledge  which,  whether  we  will 
or  not,  intrudes  itself  on  our  attention  and  insists,  under  penalty 
of  death  or  torture,  on  a  punctilious  regard  to  its  teachings. 
Such  is  the  science  of  medicine  or  rather  hygiene,  viewed  in  its 
broadest  and  most  comprehensive  aspect.  The  goal  of  this 
science  is,  or  should  be,  to  maintain  human  beings  throughout 
their  lives  in  perfect  physical  health.  And  when  we  reflect  how 
profound  an  influence  health  or  its  absence  exerts  not  only  on 
our  happiness,  prosperity  and  material  welfare  but  also  on  our 
intellectual  achievements  and  outlook  on  life,  it  will  be  admitted 
that  the  progress  of  medical  science  possesses  for  all  of  us  a 
quite  exceptional  interest.  Has  it  shared  fully  and  completely 
in  the  grand  forward  march  of  knowledge,  or  is  there  reason 
for  supposing  that  in  some  respects  at  least  it  lingers  behind, 
a  loiterer  with  the  rearguard  ? 

To  understand  the  position  it  is  necessary  to  remember 
that,  at  least  from  the  standpoint  of  the  general  public,  medical 
science  is  separated  naturally  into  two  capital  divisions,  the 
prophylaxis  or  prevention  and  the  therapeutics  or  the  cure  of 
disease.  There  exist  various  other  important  sections,  such  as 
anatomy,  diagnosis,  histology,  pathology  and  so  forth  but,  so  far 
as  the  general  public  is  concerned,  prophylaxis  and  therapeutics 
constitute    the    really  vital    and    essential    ones.      And    since 

i53 


154  SCIENCE  PROGRESS 

diseases  generally  must  be  classified  as  parasitic  or  those  of 
microbic  origin,  such  as  tuberculosis,  cholera  and  plague,  and 
non-parasitic  or  those  arising  from  disorders  of  metabolism — as, 
for  instance,  gout,  heart-disease,  tumour,  etc.,  it  will  be  con- 
venient similarly  to  proceed  in  our  discussion  of  them,  that  is, 
we  will  first  consider  the  progress  of  medical  science  in  relation 
to  parasitic  diseases,  and  subsequently  its  position  in  relation  to 
the  remainder. 

Just  as  modern  biology  is  based  on  the  Origin  of  Species,  so 
the  foundation  of  our  knowledge  of  the  parasitic  or  microbic 
diseases,  so  far  as  it  is  scientific  and  not  mere  empiricism,  was 
laid  deep  and  true,  a  veritable  Yggdrasil  for  strength,  by  the 
investigations  of  M.  Pasteur.  Prior  to  his  revolutionary  dis- 
coveries, the  vague  theories  current  ascribed  their  etiology  to 
morbid  poisons — note  the  tautology— in  the  air,  to  decaying 
vegetable  matter,  to  ferments  floating  about  promiscuously,  and 
so  forth.  The  supporters  of  the  germ  theory  of  disease,  before 
the  increasing  body  of  facts  proved  too  strong  for  their  op- 
ponents, encountered  a  strenuous  opposition  from  the  more 
"  conservative  "  element  of  the  medical  profession;  they  had  in 
fact  to  fight  a  kind  of  Quatre  Bras  against  the  doctors  before 
aligning  themselves  for  their  Waterloo  against  the  microbes. 
All  such  controversies,  however  bitter  and  envenomed  at  the 
time,  are  fortunately  now  a  thing  of  the  past  and  possess  merely 
that  historic  interest  which  still  enchains  our  attention  when 
reading  of  the  discoveries  of  a  Galileo,  the  enunciation  of 
Newton's  laws,  or  the  gradual  acceptance  of  the  atomic 
theory. 

In  the  brief  period — scarce  a  third  of  a  century — since 
M.  Pasteur's  discoveries  marvellous  progress  has  been  made. 
Though  we  stand  as  yet  only  as  it  were  in  the  early  morning 
of  discoveries  touching  the  etiology  of  the  parasitic  diseases, 
their  prophylaxis  and  cure,  the  sun  of  science  shines  brightly 
above  the  horizon  and  all  the  air  is  radiant  with  hope.  In  spite 
of  the  opposition  of  such  fanatics  as  anti-vaccinationists — soon, 
let  us  hope,  to  be  as  extinct  as  the  Fifth  Monarchy  men — and  in 
spite  of  official  discouragement  and  of  a  lamentable  exiguity  of 
funds,  very  noteworthy  results  have  already  been  achieved.  In 
malaria,  perhaps,  estimated  both  in  its  annual  death-roll — some 
1,300,000  in  India  alone — and  in  the  chronic  ill-health  it  inflicts 
on   the  involuntary   hosts  of  Plasmodium    malarice,   the   most 


THE  OUTLOOK  FOR   HUMAN   HEALTH         155 

disastrous  scourge  the  human  race  has  known,  the  discoveries 
of  Laveran  and   Ross  have  clearly  demonstrated  the  etiology 
of  the   disease   and  have   pointed  the   way   to  its   extirpation. 
True   it    is   that,    owing   to    the  existence   in    many  places    of 
extensive    swamps    or    of    rice    cultivation,    the    cost    of    the 
necessary    measures    for    the    elimination    of    the    Anopheles 
mosquito  seems  at  present  prohibitive ;   but  the  improvements 
and    inventions    in    the    campaign   against   this   malign    insect 
which    will    surely   come   in   time  will   render   practicable  the 
latter's    disappearance    in    at    least    the    most   populous    areas. 
Final  success  may  come  slowly;    it  is  unreasonable  to  expect 
its   advent  swift  as  the  lightning  flash  from  a  summer  cloud. 
By  way  of  contrast  to  the  complexity  of  this  problem  stands 
the    case  of  Malta  fever.     Here,  once  it  had  been  ascertained 
that  goat's  milk  formed   the   medium  of  entry  of  the  bacillus 
into  its  human  host,  the  prophylaxis  was  ridiculously  easy;   it 
sufficed  simply  to  abstain  from  goat's  milk  in  order  to  eradicate 
the  disease.    Sleeping  sickness,  that  most  gruesome  and  fantastic 
of  human  ills,  after  decimating  the  population  of  Central  Africa, 
is   in   a   fair   way   to   be   abolished.     The   trypanosome   which 
causes  it  takes,  so  it  has  been  ascertained,  as  its  secondary  host 
a  tsetse  fly  which  fortunately  never  wanders  far  from  lakes  or 
rivers.     Hence  by  moving  the  population  to  a  specified  distance 
from  such  collections  of  water  there  is  every  hope  that  ere  long 
both  human  beings  (and  tsetse  flies)  will  emancipate  their  bodies 
from  this  parasite.     Turning  to  temperate  climes,  all  recognise 
the  enormous  gain  to  human  health  and  happiness  wrought  in 
such  cities  as  London  or  Glasgow,  for  instance,  by  measures  of 
sanitation — that  is  to  say,  by  measures  having  for  their  object 
the  prophylaxis  of  parasitic  diseases.     In  the  fall  of  the  death- 
rate,  in  the  absence  nowadays  of  serious  epidemics  and  in  the 
sinking  into  oblivion  of  diseases  whose  very  names  once  struck 
terror  in  the  heart  of  the  householder,  we  may  discern  the  gleam 
of  the  triumphant  standards  of  science  as  they  advance  against 
the  hosts  of  disease.     Even  with  diseases  such  as  phthisis,  which 
are  as  yet  far  from  being  under  control,  science  points   out 
certain  simple  precautions  which,  for  those  capable  of  following 
them,  render  this  dreaded  disease  as  remote  a  peril  as  small-pox 
to  the  properly  vaccinated.     No  deeper  chasm  indeed  divides 
modern  freedom  of  thought  and  independence  of  opinion  from 
the  superstition   of  the  middle  ages  than  the  immunity  from 


156  SCIENCE  PROGRESS 

parasitic  disease  enjoyed  by  the  modern  citizen  from  the  pest- 
ridden  existence  of  his  predecessors. 

So  promising  is  the  outlook  in  this  domain  that  the  final 
triumph  of  mankind  over  parasitic  diseases  would  seem  to  be 
trammelled  and  delayed  by  two  things  only.  Firstly,  there  is 
the  cloud  of  ignorance  which  still  conceals  the  real  etiology  of 
parasitic  disease  from  the  great  mass  of  the  public,  especially 
in  the  tropics.  The  once  universal  belief  in  the  supernatural 
origin  of  epidemic  diseases,  their  ascription  to  demons,  gods  and 
evil  spirits,  lingers  on  tenaciously  among  uneducated  people, 
who,  holding  this  belief,  naturally  regard  with  hostile  or  con- 
temptuous eyes  the  best  designed  efforts  of  sanitary  officials.  It 
is  this  ignorance  which  lies  at  the  root  of  the  appalling  death- 
roll  from  parasitic  diseases  in  India  and  until  it  is  removed  by 
appropriate  instruction  in  the  schools  and  elsewhere  no  real  and 
permanent  progress  in  their  prophylaxis  in  that  country  would 
appear  feasible.  The  second  obstacle  to  ultimate  victory  lies  in 
the  dearth  of  funds  for  original  research.  In  spite  of  some 
recent  donations  in  England,  America  and  Germany,  no  one 
who  takes  the  trouble  to  realise  clearly  in  his  own  mind  the 
awful  carnage  inflicted  on  humanity  by  parasitic  diseases  and 
the  brilliant  results  already  achieved  by  modern  scientific 
research  but  must  be  lost  in  amazement  that,  whilst  avalanches 
of  money  are  readily  forthcoming  for  objects  that  gratify  the 
vanity  or  subserve  the  complacence  of  the  wealthy,  so  little 
finds  its  way  to  furnish  the  very  moderate  assistance  required 
by  scientific  workers.  The  agonies  inflicted  by  many  of  these 
diseases  recall  the  hells  of  theological  imagination  ;  the  heca- 
tombs of  lives  sacrificed  to  them  in  the  past,  aye  even  to-day, 
utterly  dwarf  the  puny  efforts  at  wholesale  slaughter  of  an 
Attila,  a  Timour  or  a  Napoleon.  Yet  the  rivers  of  monetary  aid 
that  well  so  bounteously  nowadays  from  the  founts  of  benevo- 
lence and  kindness  for  the  most  part  lose  themselves  in  sterile 
and  unprofitable  deserts,  only  the  merest  trickle  reaching  the 
fertile  soil  of  scientific  research.  All  the  more  honour  then  to 
the  hardy  pioneers  of  science  who,  with  scanty  encouragement 
and  in  the  face  of  great  difficulties,  have  already  achieved  for 
humanity  such  great  and  permanent  alleviation  of  its  torments. 

But  in  the  domain  of  therapeutics  the  advance  made  of  recent 
years,  whilst  not  inconsiderable,  differs,  whether  in  respect  to 
method  or  the  results  achieved,  from  that  in  the  prophylaxis  of 


THE  OUTLOOK  FOR  HUMAN   HEALTH         157 

parasitic  disease  as  "Puffing  Billy"  from  a  modern  express 
locomotive.  The  technique  in  vogue  still  depends  largely  on 
the  empirical  use  of  drugs  and  relies  for  improvement  on  the 
primitive  method  of  progress  by  trial  and  failure.  Thus  the 
therapeutics  of  plague  consists  mainly  in  the  treatment  of  the 
symptoms  as  they  occur,  in  contrast  with  the  more  scientific 
methods  of  prophylaxis  by  the  elimination  of  the  rat  flea  or 
through  the  injection  of  Haffkine's  serum.  But  there  already 
exist  some  commencements  at  least  of  treatment  on  scientific 
lines  that  promise  important  results  ;  witness  the  discovery  of 
the  opsonic  index,  the  new  vaccine  therapy,  or  the  treatment  of 
phthisis  by  formalin  inhalations.  And  even  on  the  purely 
empirical  administration  of  drugs  some  light  has  been  thrown 
by  recent  developments  of  bacteriology.  For  instance,  whilst  it 
was  previously  known  by  experience  that  the  proper  time  to 
exhibit  quinine  in  an  attack  of  ague  was  during  the  sweating 
stage,  we  now  know  that  at  this  time  new  crops  of  malarial 
bacilli  are  born  and  that  the  occasion  is  therefore  appropriate 
for  a  massacre  of  these  innocents. 

If  the  therapeutics  of  parasitic  disease  still  leaves  so  much  to 
be  desired,  what  shall  we  say  of  the  next  division  of  our  subject, 
the  prophylaxis  of  metabolic  disease  ?  Progress,  if  any  there 
be,  resembles  closely  that  strategic  movement  to  the  rear  so 
dear  to  unsuccessful  military  commanders.  Anaemia,  rheumatism, 
gout,  dyspepsia,  diseases  of  the  heart  and  kidneys,  neurasthenia 
and  the  whole  Mas  malorum  due  to  faults  of  metabolism  still 
flourish  amongst  us  with  the  vigour  of  the  proverbial  bay- 
tree.  According  to  recent  statistics,  the  incidence  of  some  of 
them  at  least,  such  as  the  circulatory  diseases,  so  far  from 
exhibiting  any  sign  of  check,  seems  on  the  whole  to  show  a 
distinct  upward  tendency.  Others,  like  appendicitis,  threaten 
to  be  numbered  amongst  the  accomplishments  essential  in  polite 
society.  People  are  patched  up  more  effectually  and,  let  us  add, 
more  often  than  seemed  the  case  formerly — else  why  the  large 
increase  in  the  number  of  their  medical  advisers — but  as  for 
winning  free  or  partly  free  from  this  large  group  of  diseases, 
that,  it  would  seem,  is  a  consummation  so  hardly  obtainable  as 
to  be  a  mere  crying  for  the  moon.  With  the  exception  of  the 
prophylaxis  by  Bulgarian  bacilli,  the  discovery,  be  it  noted,  not 
of  a  doctor  but  of  a  Professor  of  Bacteriology,  no  real  attempt 
appears  to  have  been  made  by  the  orthodox  to  avert  those  ills 


158  SCIENCE  PROGRESS 

by  the  treatment  of  which  they  make  their  livelihood.     A  gross 
fatalism,  chill  and  hopeless  as  the  inscription  at  the  portals  of 
Dante's  Inferno,  would  in  this  respect  seem  to  brood  over  and 
benumb   the   minds   of  both   the   medical   profession    and   the 
general  public.     In  a  recent  work  on  that  somewhat  depressing- 
locality,  the  East  End  of  London,  the  writer  thus  describes  the 
mental   attitude   of   its   denizens   towards    their   unwholesome 
physical   environment  :    "  The   factory   chimney   belches    forth 
obstruction.      But  no  murmur  escapes  the  East-Ender.     Smoke 
in  his  view  is  inevitable,  part  of  the  ordinary  course  of  nature ; 
and  he  would  as  soon  think  of  opposing  it   as   he   would   of 
opposing  the  thunderstorm."     That,  with  all  deference,  appears 
to  be  the  present  standpoint  from  which  the  majority  of  doctors 
envisage   the   majority   of  this  large   class    of    diseases ;    they 
prescribe  for  the  symptoms  from  an  overgrown  yet  continually 
increasing    armamentum    of    drugs ;    they   will    recommend   a 
change  of  climate,  a  holiday  and  so  forth  ;    on  occasion   they 
even  suggest  some  half-hearted  alteration  in  the  diet  customary 
in  the  patient's  particular  class  ;  but  that  the  affliction  pressing 
upon  him  was  preventible,  that  through  any  acts  or  abstentions 
the  public  generally  may  attain  freedom  from  such  disease  or 
class  of  diseases,  these  are  ideas  wholly  foreign  as  yet  to  the 
psychosis  of  the  medical  profession.     Like  simple  Orientals  at 
the  shrine  of  Mariamma,  the  goddess  of  small-pox,  the  orthodox 
medical  practitioners  and  the  laity  in  their  train  abase  them- 
selves with  quite  pathetic  humility  before  the  spectre  of  metabolic 
disease. 

Perhaps  the  key  to  this  attitude  of  sterile  pessimism  may 
lie  in  the  very  word  "  laity,"  so  commonly  used  in  the  course 
of  medical  discussions.  Is  there  not  more  than  a  tinge  of 
sacerdotalism  in  the  mental  attitude  affected  by  the  great 
majority  of  the  profession ;  "  the  air  of  the  priest  with  the 
feeling  of  personal  importance,  the  thin  unction  and  private 
leanings  to  the  cord  and  the  stake  "  ?  Do  not  too  many  doctors 
still  regard  any  discussion  of  medical  matters  with  members  of 
the  public  as  unprofessional,  and  do  they  not  too  often  assail 
novel  ideas  as  to  the  etiology  of  disease  with  all  the  acrimony 
of  a  mediaeval  priest?  The  welcome  accorded  to  Jenner's  and 
Harding's  discoveries,  to  John  Brown  and  to  Ignatius  Sammel- 
weiss,  has  many  an  analogy  in  modern  times.  In  no  other 
profession  are  the  public  styled   the   laity;    no   other  men   of 


THE  OUTLOOK  FOR  HUMAN   HEALTH         159 

science  guard  so  jealously  from  the  profane  the  secrets  of 
their  art,  for  all  the  world  as  though  they  were  veritable 
mysteries  of  Isis  and  they  the  priests  of  her  temple.  As  an 
instance  of  this  attitude  let  us  take  the  famous — is  that  quite 
the  word  ? — manifesto  on  the  use  of  alcohol  issued  less  than 
four  years  ago  in  the  Lancet.  Previously  various  investigators, 
taking  different  lines  of  research,  with  much  accuracy,  diligence 
and  endeavour  to  eliminate  adventitious  factors,  had  arrived  at 
the  conclusion  that  alcohol,  except  as  a  drug,  affected  injuri- 
ously the  human  organism.  Did  the  signatories  to  this  manifesto 
refer  to  or  refute  the  reasoning  of  these  investigators?  Not 
at  all.  After  a  reference  to  the  use  of  alcohol  in  medicine — 
which  need  not  here  concern  us— they  announced  with  due 
decorum  and  solemnity  that  in  their  opinion  "  the  universal 
belief  of  civilised  mankind  as  to  the  beneficial  results  of  a  moderate 
use  of  alcoholic  beverages  is  amply  justified."  Now  that  kind 
of  thing  may  be  good  theology,  but  it  is  uncommonly  bad 
science.  Never,  indeed,  did  Council  of  Trent  thunder  forth 
dogmas  with  greater  unction  or  a  more  invincible  authority 
than  that  assumed  by  these  hierarchs  of  the  medical  world. 
(The  clerics  had,  however,  this  advantage,  that  whereas  their 
doctrines  were  enunciated  under  the  solemn  arches  of  cathe- 
drals, this  latter-day  creed  of  the  medical  profession  has  filtered 
down  to  the  laity  chiefly  through  the  agency  of  delighted 
publicans.)  In  the  discussion  that  followed  it  seems  quite 
natural  and  fitting  that  one  physician,  naively  abandoning  all 
reference  to  modern  science,  should  endeavour  to  bolster  up  the 
case  for  alcohol  with  the  aid  of  a  text  from  the  Book  of  Judges. 
By  what  abysmal  depths  is  not  this  fulmination  divided  from 
the  patient  collection  of  facts,  the  admission  of  possible  causes 
of  error,  the  frank  and  full  examination  of  arguments  that 
distinguish  a  Darwin  or  a  Pasteur?  Can  we  any  longer  feel 
surprise  at  the  halting  progress  of  medical  science  when  such 
convincing  expressions  of  opinion,  such  illuminating  arguments 
are  tendered  in  all  seriousness  in  a  scientific  journal  on  a  matter 
of  science  pure  and  simple  ?  Surely  it  is  not  through  methods 
such  as  these  that  knowledge  advances  and  the  spirit  of  human 
thought  makes  wide  her  boundaries. 

In  the  therapeutics  of  non-parasitic  disease,  as  distinguished 
from  their  prophylaxis,  some  progress  has  indubitably  been 
effected.    Thanks  to  a  notable  advance  in  diagnosis,  errors  of 


160  SCIENCE    PROGRESS 

treatment  occur  much  less  frequently  than  of  yore  ;  increased 
knowledge,  mostly,  however,  of  empirical  nature,  obtains  of  the 
uses  and  dangers  of  various  drugs  ;  whilst  owing  to  a  mar- 
vellous and  brilliant  advance  in  the  surgical  art  numerous 
diseases  formerly  regarded  as  desperate  or  hopeless  are  now 
cured  with  ease  and  certainty.  Indeed,  the  glittering  successes 
of  surgery  serve  in  no  small  measure  as  a  veil  to  conceal  from 
the  public  the  failures  of  the  medical  profession  viewed  as  the 
custodian  of  the  public  health.  Were  it  not  for  the  wonderful 
advance  in  the  use  of  the  knife  rendered  possible  by  the  dis- 
covery of  chloroform  and  of  aseptic  methods,  diseases  of 
metabolism  would  claim  a  tale  of  mortality  and  suffering  so 
shocking  as  long  since  to  have  called  forth  an  imperative 
demand  for  an  effective  prophylaxis.  As  it  is,  a  certain  portion 
of  the  public,  both  in  this  country  and  in  America,  are  beginning 
to  look  askance  at  a  profession  which  in  an  age  of  exceptional 
scientific  progress  has  failed  so  conspicuously  in  the  prophy- 
laxis of  a  large  class  of  diseases,  and  to  seek  for  themselves 
some  causeway  out  of  the  dismal  morass  of  ill-health  in  which 
the  orthodox  view  would  condemn  mankind  for  ever  to  wander. 
They  regard  with  more  than  suspicion  the  constantly  reiterated 
explanation  of  the  increase  of  diseases  of  the  heart,  of  appendi- 
citis, cancer,  lunacy  and  so  forth,  as  merely  due  to  more  accurate 
diagnosis.  The  treatment  of  symptoms  by  drugs  no  longer 
satisfies  their  aspirations ;  they  wish  to  know  whether  by  some 
radical  alteration  in  the  conduct  of  our  lives  it  may  not  be 
possible  to  avoid  absolutely  or  nearly  so  all  risk  of  diseases 
of  metabolism. 

Not  for  the  first  time,  indeed,  have  these  by  no  means 
unreasonable  aspirations  cheered  and  encouraged  the  minds  of 
men.  The  fact  is  that  after  an  interval  of  many  centuries  the 
civilised  world  is  once  again  beginning  to  realise  the  cardinal 
importance  of  good  health,  not  only  in  their  happiness,  but  in 
their  morals  and  their  intellectual  outlook,  to  realise  that  a 
healthy  body  forms  a  more  satisfactory  basis  for  a  healthy 
outlook  on  life  than  many  tomes  of  ethics  and  of  erudite  dogma. 
Amongst  the  ancient  Greeks  and  Romans,  especially  the  former, 
the  care  of  the  body  assumed  the  importance  of  a  religious  cult* 
so  much  so  that  regular  worship  was  accorded  to  the  goddesses 
of  health,  Hygeia  and  Salus.  Medical  science  had  reached  no 
standard  of  excellence  ;  bathing,  massage,  dieting,  in  addition  to 


THE  OUTLOOK   FOR   HUMAN    HEALTH         161 

the  more   primitive  use  of  drugs,   did  much   to  counteract  the 
evils  inevitable  in  a  voluptuous  and  self-indulgent   age.      But 
with  the  advent  of  Christianity  a  change  passed  over  the  scene  ; 
the  storm-cloud  of  the  new  theology  swept  over  the  country 
and  left  it  bare  not  only  of  the  old  superstitions  but  also,  alas! 
of    hygienic    knowledge.      Salus    and    Hygeia   passed   away — 
enjoyed  fairyland,  as  the  Burmese  quaintly  say — the  practice  of 
bathing  was  neglected,  and  the  baths  fell  into  disrepair;  since 
the  body  formed  ex  hypothesi  the  source  of  evil,  all  care  of  it  was 
naturally  contemned  as  sinful ;  the  rising  sciences  of  medicine 
and   of  hygiene   crumbled   into  ruins  and  almost   disappeared 
beneath  a  weedy  outcrop   of  superstitious   charms   and   magic 
observances.     When  people  trusted  in  all  seriousness  for  the 
cure  of  disease  to  pilgrimages  or  a  visit  to  a  shrine,  they  would 
scarcely,  it  will  be  admitted,  regard  seriously  their  treatment  or 
prophylaxis  on  scientific  principles.    But  against  these  untoward 
results  we  must  in  justice  set  the  gifts   brought  by   the   new 
religion,  namely  the  institution  of  hospitals,  a  tenderer  regard 
for  the  poor  and  the  increased  sanctity  of  human  life      Nowa- 
days, influenced  no  doubt  by  the  altered  mental  atmosphere  due 
to   modern   science — call   it   materialistic  or  not  as  you  will — 
men,  as  already  remarked,  once  more  begin  to  regard  bodily 
hygiene  of  at  least  equal  importance  with  say  the  "subtleties  of 
the  eastward  position,"  and  to  take  thought  how  to  avoid  the 
physical    evils    that    so    insistently    menace    them    and    their 
families.     And  with  this  increased  attention  there  necessarily 
follows  a  bitter  dissatisfaction  at  the  failure  hitherto  of  medical 
science  to  attack  resolutely  the  Hydra  of  metabolic  disease  and 
a  resolve,  joined  in  many  with  a  high  hope  of  success,  to  win 
clear  from  its  poisons  and  miseries. 

It  is  claimed  by  the  pioneers  of  this  new  movement  that, 
with  a  properly  conditioned  physical  environment,  disease 
should  be  practically  unknown  ("death  from  disease  is  an  abomi- 
nation," say  some  of  them)  and  dissolution  due  to  old  age  after 
3.  span  of  life  much  beyond  that  now  accepted  as  natural 
the  normal  bourne  of  human  beings.  And  in  a  consideration 
of  the  circumstances  affecting  the  human  body  they  not  un- 
naturally attach  a  special  importance  to  the  question  of  dietary 
— that  is  to  say,  the  kinds  and  quantity  of  food  necessary  to 
keep  the  human  body  well  nourished  and  in  perfect  health. 
(A  person  occasionally  subject  to  twinges  of  gout  or  rheumatism, 
ii 


162  SCIENCE  PROGRESS 

or  whose  blood  pressure  is  excessive,  or  who  harbours  an 
undue  amount  of  anaerobic  microbes  in  his  intestines  can 
hardly  lay  claim  to  the  latter  designation.)  The  importance 
of  this  branch  of  science  few  who  have  studied  the  biological 
significance  of  food  amongst  animals  in  a  state  of  nature  or 
the  variations  in  health  amongst  domestic  animals  resulting 
from  altered  dietaries  would  be  concerned  to  deny.  Yet  the 
attitude  of  orthodox  medical  men  on  this  crucial  matter  re- 
mains far  from  satisfactory.  In  the  first  place  the  physio- 
logical allowance  of  food  for  men  in  health — recently,  be  it 
noted,  seriously  impugned  by  actual  experiments  in  America 
— rests  on  that  customary  amongst  inhabitants  of  the  British 
Isles  at  the  present  day.  Now  the  consumption  of  meat  per 
head  in  these  islands  has  within  the  last  fifty  years  more  than 
doubled  itself.  Apart  then  from  the  questionable  propriety  of 
taking  as  standards  the  dietaries  in  use  amongst  a  people  like 
ourselves  riddled  with  diseases  of  metabolism,  either  the  present 
allowances  of  meat  are  excessive  or  those  customary  in  the 
good  old  days— before  physical  deterioration  commissions — 
were  very  deficient.  Again,  according  to  accepted  views  on 
human  physiology  and  nutrition,  what  is  more  clearly  demon- 
strated than  the  impossibility  of  maintaining  health  and  strength 
on  a  diet  of  rice  alone  ?  Nevertheless  there  is  reliable  evidence 
that  labourers  in  China,  living  on  such  a  diet,  carry  to  great 
distances  loads  that  an  Englishman  could  not  even  lift. 

The  fact  is  that  in  a  consideration  of  the  standards  of  health 
and  of  the  causation  of  disease — when  indeed  their  scrutiny 
extends  so  far — the  medical  profession  are  much  too  prone 
to  limit  their  inquiries  to  the  peculiar  and  special  circumstances 
of  humanity  as  found  in  their  present  day  of  grace  in  England, 
America,  France,  Germany  and  a  few  other  countries.  The 
diseases — where  not  microbic — diet,  drink,  clothing  and  mode 
of  life  generally  of  modern  civilised  man  they  regard  in  the 
light  of  established  norms  as  the  matrix  in  which  humanity, 
or  at  least  civilised  humanity,  must  inevitably  crystallise. 
Thus,  when  an  English  authority  defines  health  as  "that  con- 
dition of  structure  and  function  which,  on  an  examination  of 
a  sufficient  number  of  examples,  we  find  to  be  the  commonest," 
we  may  be  quite  certain  that  the  examples  in  question  will  be 
drawn  from  England  and  consequently  that  an  unduly  high 
number  of  anaerobic   microbes   in   the  colon  or  an   excessive 


THE  OUTLOOK   FOR   HUMAN    HEALTH         163 

blood  pressure  will  be  regarded  as  compatible  with  perfect 
health.  The  great  mass  of  humanity  which  lives,  thrives  and 
maintains  a  high  standard  of  physical  health  under  totally 
different  conditions  exists,  it  is  true,  but  to  their  myopic  vision 
the  outlines  of  the  physiology  of  these  peoples  appear  blurred 
and  indistinct,  to  them  as  little  worthy  of  study  as  would  be 
the  course  of  Halley's  comet  to  a  fish.  Like  the  ancient  Romans 
and  Greeks  or  the  Chinese  until  recently,  they  contemn  where 
they  do  not  ignore  the  habit  of  life  of  the  outer  barbarian  tribes. 
The  absence  of  any  particular  nexus  between  high  civilisation 
and  a  condition  of  rude  health  seems  to  have  wholly  escaped 
their  attention ;  on  the  contrary  not  a  few  seriously  connect 
the  present  custom  of  heavy  meat-eating  with  modern  in- 
tellectual development,  one  hardy  authority  even  ascribing 
the  lack  of  enterprise  amongst  South  Italians  to  the  absence 
of  this  substance  in  their  dietary.  Shades  of  Plato,  of  Pytha- 
goras, of  the  Caliph  Omar  and  hosts  of  other  vegetarian 
worthies  down,  we  had  almost  written,  to  Bernard  Shaw  ! 

Setting  aside  such   bizarre  suggestions   as   unworthy  of  a 
profession  which  at  least  claims   to   think  scientifically,  surely 
to  those  who   decline   to   accept   the  commoner  non-microbic 
diseases,  like   the   winter  sleet   and  the  summer   rain,  as  un- 
avoidable incidents  in  human  life,  the  existence  of  large  popu- 
lations   living   under   the   most   varied    conditions   of    climate, 
geographical    surroundings,    dietary,    clothing    and    dwellings 
affords    an    admirable   field   for   the   investigation   of  the   real 
etiology   of  these   diseases.     If  various   populations   in  which 
a  specified  disease  is   rife   have  only  one   outstanding  circum- 
stance in  common,  whilst  others  in  which  it  either  does  not 
occur   or   occurs   only  very  infrequently  have  nothing   else  in 
common  except   the  absence   of  that  circumstance,  why,  then, 
one  may  reasonably  link  the  causation  of  the  disease  with  the 
circumstance    in    question.      What    in   fact    is    required   is   an 
application   to   pathology   of  the   method  which    Dr.   Archdall 
Reid    has    used  with    such    brilliant   effect   in   respect   to   the 
mentality  of  races.     Thus,  as  he  has  pointed  out,  the  followers 
of  the  orthodox  religions  are  usually  inferior  to  the  heretics 
in  intelligence,  energy,  and  initiative,  tend  in  fact,  under  equal 
circumstances,  to   become   "  hewers   of  wood  and   drawers  of 
water  "  to  the  latter.     This  difference  is  not  due  to  any  question 
of  race,  for  portions  of  the  same  race  differ  in   mentality  ac- 


164  SCIENCE  PROGRESS 

cording  to  their  religious  belief,  and,  as  a  matter  of  history, 
sudden  changes  in  religious  belief  have  resulted  in  almost 
equally  sudden  variations  in  intellectual  outlook.  Similar  argu- 
ments preclude  or  minimise  the  connection  between  mental 
capacity  or  incapacity  and  climate,  geography,  soil,  situation, 
etc.  Into  the  reasons  connecting  religion  and  a  national 
psychosis  we  need  not  here  enter.  The  point  is  that  this 
method,  which  is  a  perfectly  logical  one,  lends  itself  readily 
to  the  investigation  of  the  etiology  of  disease,  since,  by  taking 
account  only  of  large  masses  of  men,  it  avoids  pitfalls  due  to 
local  peculiarities,  and  at  the  same  time  its  inductions,  based 
like  those  of  anthropology  on  data  supplied  by  the  whole 
world,  are  not  liable  to  refutation  by  facts  drawn  from  distant 
countries,  as,  for  example,  the  English  physiological  standards 
by  experience  amongst  the  Chinese.  A  few  authors  have,  it 
is  true,  done  some  excellent  pioneer  work  in  the  field  of  geo- 
graphical pathology ;  but  their  investigations,  which  relate 
chiefly  to  zymotic  diseases,  lack  much  in  exactness  and  in 
necessary  elaboration  of  detail,  nor  do  the  data  collected  permit 
of  discrimination  between  the  dietary,  clothing,  houses  and 
manner  of  life  of  the  races  concerned. 

As  a  concrete  instance  of  the  suggested  method  let  us  take 
the  case  of  appendicitis.  Certain  medical  men  point  out  that 
this  disease,  relatively  common  in  countries  such  as  England 
and  the  United  States,  with  a  high  consumption  of  meat  per 
capita,  is  rare,  if  not  quite  unknown,  amongst  wheat-  and 
rice-eating  populations,  such  as  the  Hindoos  and  the  Chinese, 
or  those,  such  as  the  inhabitants  of  the  Balkan  States  and 
Brittany,  where  a  minimum  of  meat  is  eaten.  From  this  and 
other  facts  they  argue  that  a  carnivorous  diet  or  at  least  one 
rich  in  purins  is  an  indispensable  concomitant  of  appendicitis. 
We  are  not  here  concerned  with  the  truth  or  falsehood  of 
this  theory,  which  at  any  rate,  so  far  as  it  based  on  an 
induction  from  racial  dietaries,  is  still  quite  incomplete.  But 
the  inquiry  proceeds  on  right  lines  and,  if  pushed,  should 
permit  of  a  definite  and  trustworthy  conclusion. 

After  all  the  goal  of  medical  science  is  the  maintenance  of 
a  high  standard  of  health,  not  merely  in  youth  but  in  later 
years ;  the  prolongation  of  human  life,  active  and  vigorous, 
into  years  now  abandoned  to  senility  and  ineptitude.  It  is 
idle  to  apply  the  epithet   of  healthy  to  people   who,  however 


THE   OUTLOOK   FOR   HUMAN    HEALTH         165 

vigorous  their  youth,  suffer  later  on  from  such  complaints  as 
gout,  rheumatism,  Bright's  disease,  or  arterio-sclerosis.  Nor 
will  the  man  in  the  street  greatly  laud  a  learned  discussion 
on  the  enzymes  of  the  stomach  when  such  discussion  wholly 
fails  to  point  the  way  whereby  he  may  assuage  the  pangs  of 
dyspepsia ;  he  does  not  yearn  so  much  after  a  knowledge  of 
the  histological  changes  of  the  kidney  in  Bright's  disease  as 
a  method  by  which  this  disease  may  be  safely  avoided.  To 
many  sufferers  such  discussions  must  appear  as  futile  as  the 
historic  controversy  of  Homoous  and  Homoious,  and  as  empty 
of  benefit  to  tortured  humanity.  What  kind  of  opinion  should 
we  entertain  of  gardeners  who  wiled  away  their  time  in 
acrimonious  discussions  on  the  diseases  of  their  plants,  and 
whose  utmost  endeavour  extended  only  to  the  temporary  cure 
of  their  distempers  or  to  the  alleviation  of  their  sufferings  ? 
Surely  we  would  say  :  "  Study  the  environment — using  the 
word  in  the  broadest  sense — of  your  plants  and  so  regulate 
it  that  these  diseases  become  at  least  as  rare  as  theft  and 
dishonesty  in  a  well-ordered  community.  In  neighbouring 
gardens  we  discern  whole  masses  of  plants  free  from  those 
disorders  which  plague  the  specimens  under  your  care ;  go 
and  examine  wherein  consist  the  conditions  through  which 
these  plants  enjoy  robust  health  whilst  yours  are  diseased. 
These  conditions  undoubtedly  exist;  it  is  for  you  by  patient 
inquiry  and  logical  induction  to  particularise  them." 

And  should  such  a  transfiguration  of  the  medical  profession 
dawn  on  an  expectant  public,  perhaps  not  the  least  of  its 
concomitant  advantages  may  be  the  disappearance  of  that  dark 
horde  of  quack  medicines  which  in  season  and  out  of  season 
intrude  themselves  on  our  unwilling  attention.  To  the  cynic 
few  subjects  tend  more  to  the  gaiet}'  of  nations  than  the 
execrations  and  anathemas  which  the  orthodox  doctor  never 
wearies  of  hurling  at  his  heretic  brother,  the  vendor  of  secret 
remedies.  After  the  profession  has  practised  the  treatment  of 
disease  for  many  centuries  by  the  empirical  use  ol  drugs,  and 
thoroughly  inoculated  the  public  with  the  belief  that  therein 
lay  at  once  their  certain,  facile  and  sole  hope  of  physical 
salvation,  what  wonder  that  others,  doubtless  ignorant  and 
mercenary — cela  va  sans  dire — should  trade  on  the  habit  of 
mind  thus  engendered,  and  "jump  the  claim  "  of  the  orthodox 
practitioners  ?      With    just  as  much    logic   did   the   mediaeval 


1 66  SCIENCE   PROGRESS 

ecclesiastics,  after  inculcating  as  a  pious  duty  the  murder, 
torture  and  maltreatment  of  heretics  and  witches,  hold  up 
their  hands  in  horror  at  the  brutalities  practised  by  nobles 
and  kings  on  those  who  differed  from  their  convictions  on 
details  of  fiscal  and  social  economy.  Quis  tulerit  Gracchos  de 
seditione  querentes  ? 

Perhaps  also  in  the  not  distant  future  we  may  see  the 
medical  profession  finally  discard  that  subtly  hierarchic  attitude 
— as  though  "angels  listen  when  they  speak" — which,  whilst 
it  impresses  so  profoundly  the  female  portion  of  their  clientele, 
accords  ill  with  their  position  as  men  of  science.  The  advisa- 
bility of  some  such  change  of  attitude  is  the  more  urgent 
since  Herbert  Spencer  had  the  temerity  to  allege  a  common 
cradle  in  primitive  times  for  physicians  and  priests.  Indeed, 
did  not  the  clergy  in  comparatively  recent  times  monopolise 
with  octopus  grip  the  art  of  medicine?  and  did  not  the 
Archbishop  of  Canterbury  confer  the  degree  of  M.D.  so  late 
as  1858?  Unless  care  be  taken,  evil-disposed  anthropologists 
may  trace  back  sacerdotal  leanings  amongst  modern  doctors 
to  the  thaumaturgics  of  the  primitive  medicine-men.  After 
the  doffing  of  the  priestly  biretta,  and  the  adoption  of  a 
mental  attitude  more  in  accordance  with  the  motto  Niillius  in 
verba,  we  may  perhaps  no  longer  find  medical  men,  when 
writing  to  support  a  new  theory  of  eye-strain,  not  daring  to 
publish  their  names ;  nor  one  well-known  man  of  science 
describing  "the  attitude  of  doctors  to  everything  new  as 
pitiful,  not  to  say  disgraceful " ;  and  another  affirming  them 
to  be  in  matters  of  science  "just  as '  non-receptive  to  fresh 
evidence  as  the  average  solicitor  or  merchant." 

Indeed  with  this  altered  outlook  the  very  title  of  doctor 
may  give  way  to  some  such  designation  as  officer  of  health. 
We  have  already  officers  of  health  in  municipalities ;  why  not 
private  officers  of  health  for  individuals?  Just  as  the  former 
(concerned  primarily  with  microbic  disease)  feel  as  a  stigma 
a  high  rate  of  mortality  amongst  the  citizens  under  their 
charge,  so  will  it  be  considered  disgraceful  in  the  latter  to 
possess  a  clientele  distinguished  by  a  low  state  of  vitality  or 
prone  to  metabolic  disease.  Nor  is  this  all.  The  public  no 
longer  cringing  before  the  least  utterance  of  the  priest- 
physician,  but  accustomed  in  matters  hygienic  to  think  and 
act  for  themselves  under  the  guidance  of  mere  men,  but  men 


THE  OUTLOOK   FOR   HUMAN    HEALTH         167 

of  science,  will,  we   may   hope,   constitute  a  body  of   opinion 
intelligent,  watchful  and  keenly  critical  of  results.      They  will 
come  to  regard  the  science  of  hygiene  not  as  something  vague 
and  remote  like  the  ethics  of  a  Spinosa  or  the  philosophy  of 
a  Hegel,  but  as  a  body  of  exact   knowledge  the   elements  of 
which  closely   concern   every  intelligent   being — form,   indeed, 
the    very   woof    and  weft    of    the    fabric    of    our    happiness. 
Under  the  influence  of    the   higher   standard   of  thought   and 
intelligence  thus  inculcated,  there  may  quite  probably  arise  a 
public  opinion  or  "herd  suggestion"  which  will  regard  every 
grave   infraction  of  the  rules  of  health,  every  serious  disease 
in    the    light    in    which    until   recently    people    contemplated 
theological    sin.      In    this   hygienic   Utopia  the   sufferer  from 
chronic  ill-health   will    incur   much    the   same   opprobrium   as 
for  instance   the   "  open   and   notorious    loose    livers "   of  our 
forefathers,  whilst  to  be   compelled   to   undergo — save   for  an 
accident — a  surgical   operation,    that   will   rank  as   a  criminal 
offence  stamping  the  patient  with  all  the  stigma  of  a  convicted 
felon.    And  since  the  mind  reacts  in  an  amazingly  close  degree 
to    the  health  or    sickness   of   the   body,  we  may   justly   look 
forward  in  this  Utopia— if  indeed  such  a  one  be  possible — to 
a  higher  and  brighter   spirit   in   civilised  man,   with  less   sel- 
fishness   and    cruelty    and    a    largely    increased    measure    of 
altruism,  public    spirit  and  all    that    makes    for  a  healthy  and 
prosperous  community 


REVIEWS 

The  Theory  of  Light.  By  the  late  Thomas  Preston.  Fourth  edition.  Edited 
by  W.  E.  Thrift,  M.A.  [Pp.  xxiii  +  618.]  (London:  Macmillan,  1912. 
Price  1 5-y.  net.) 

In  this  fourth  edition  of  Preston's  Theory  of  Light  the  unique  character  of  the 
original  work  has  been  jealously  preserved.  The  additions  made  to  the  text 
include  a  fuller  treatment  of  dispersion,  an  account  of  radiation  phenomena  in  a 
magnetic  field  and  a  more  complete  presentation  of  the  electromagnetic  theory. 
The  additions  made  to  the  text  in  these  respects  and  by  the  description  of  modern 
experimental  work  amount  to  some  thirty  pages  but  the  additions  have  been 
enclosed  in  brackets  in  order  that  they  may  be  distinguished  readily  from  the 
original  text.  The  brevity  of  the  description  given  of  recent  experiments  would 
be  regrettable  but  for  the  fact  that  they  are  described  in  detail  in  Prof.  Wood's 
Physical  Optics,  published  in  the  same  series  of  volumes.  Under  these  conditions 
there  is  every  justification  for  retaining  the  historical  and  mathematical  form  of 
Prof.  Preston's  work,  the  value  and  vigour  of  which  are  undiminished  after  twenty- 
two  years  of  active  service. 

T.  M.  L. 

The  Age  of  the  Earth.     By  Arthur  Holmes,  B.Sc,  A.R.C.S.     [Pp.   189, 
illustrated.]     (Harper's  Library  of  Living  Thought.     Price  2s.  6d.) 

Two  years  ago,  Mr.  Holmes  published  a  research  on  the  association  of  lead  with 
uranium  minerals  and  its  application  to  geologic  time.1  On  the  assumption  (not 
yet  directly  proved)  that  lead  is  the  final  product  of  the  uranium  series,  and  on 
several  other  assumptions,  the  quantity  of  lead  contained  in  a  mineral  affords 
some  clue  to  the  date  when  it  was  laid  down.  Mr.  Holmes's  results  were 
unusually  concordant,  and,  emboldened  by  his  success,  he  has  essayed  to  treat  the 
whole  subject  of  geologic  time. 

Needless  to  say,  the  chapters  (in  all  comprising  nearly  half  the  book)  dealing 
with  radioactivity  and  cognate  subjects  are  the  most  valuable.  A  somewhat  fuller 
account  of  experiments  such  as  those  he  has  himself  carried  out  would  have  been 
welcome,  but  this  part  of  his  work  is  clear  and  carefully  written.  Nor  is  he  unduly 
dogmatic  concerning  the  validity  of  his  own  method  compared  with  those  of  other 
workers.  There  is  a  danger  of  our  repeating  the  error  of  the  last  generation  and 
laying  too  much  stress  on  the  validity  of  physical  methods  of  investigation.  In 
place  of  the  dogmatism  of  Lord  Kelvin  and  Prof.  Tait,  we  are  liable  to  substitute 
that  of  modern  exponents  of  radioactivity.  But  such  an  attitude,  if  it  occurs, 
will  not  be  favoured  either  by  Prof.  Strutt  or  by  his  pupil  Mr.  Holmes. 

Nevertheless,  Mr.  Holmes,  having  reached  the  conclusion  that  many  minerals 
were  laid  down  1,500  million  years  ago,  is  bound  to  try  to  correlate  other  lines  of 
evidence,  and  to  attempt  to  show  that,  if  rightly  understood,  they  support  his 
view.  He  has  against  him  the  fact  that  the  greatest  modern  authorities,  arguing 
from  many  diverse  lines  of  thought,  have  repeatedly  stated  that  100  millions  of 

1  Proceedings  of  the  Royal  Society,  Series  A,  April  11,  191 1. 

16S  " 


REVIEWS  169 

years  is  ample  to  account  for  geologic  phenomena.  Prof.  Sollas  was  satisfied  with 
26  millions  of  years,  and,  though  his  recent  work  shows  some  sign  of  a  modifica- 
tion of  that  opinion,  the  discrepancy  between  the  results  is  great  and  glaring. 

On  this  side,  Mr.  Holmes's  work  must  be  described  as  weak.  He  neither 
proves  his  case  nor,  in  attempting  to  do  so,  does  he  make  the  best  use  of  the 
materials  at  his  disposal.  A  considerable  portion  of  the  book  may  be  dismissed 
as  padding.  Pictures  and  descriptions  of  spiral  nebulas,  and  of  the  polar  caps  of 
Mars,  look  very  pretty  in  a  semi-popular  work,  but  they  have  the  remotest  bearing 
on  the  matter  in  hand.  Mr.  Holmes  is  an  advocate  of  Prof.  Chamberlin's 
planetesmoid  hypothesis.  He  thinks  that,  after  the  first  sediments  were  formed 
(p.  31),  the  Earth  was  still  growing  by  reason  of  the  capture  of  planetesmals.  The 
speculation  seems  exceedingly  improbable,  and,  indeed,  we  are  entitled  to  ask 
why  we  find  no  traces  of  the  occurrence  in  the  earliest  sedimentaries,  but  this  and 
others  matters  we  may  pass  by  as  side  issues  and  irrelevant. 

To  come  to  the  sections  that  really  matter,  the  problem  of  the  duration  of  solar 
heat  presents  the  greatest  difficulty.  Mr.  Holmes  could  not  be  expected  to  make 
much  of  this.  At  the  time  his  book  was  written,  no  adequate  theory  of  the  subject 
was  published,  though  there  have  been  vague  anticipations  in  articles  by  the 
Messrs.  Jessup1  and  others.  Mr.  Holmes  accepts  Prof.  Arrhenius's  idea  of  the 
existence  in  the  Sun  of  compounds  which  contain  vast  stores  of  energy  due  to 
exceptional  conditions  of  great  heat  and  pressure  (p.  119).  There  is  no  space  to 
criticise  this  view.  It  will  be  sufficient  to  point  out  that  it  is  entirely  inconsistent 
with  the  planetesmal  hypothesis,  because  the  planetesmals,  ex  hypothesi,  are  not 
subject  to  great  heat  and  pressure.  Chamberlin's  planetesmals  and  Arrhenius's 
internal  heat  certainly  form  a  curious  eclectic  mixture. 

The  other  points  that  call  for  attention  are  Prof.  Joly's  researches  on  the 
saltness  of  the  sea,  and  Prof.  Sollas's  on  the  thickness  of  the  sedimentary  rocks. 
With  regard  to  neither  of  these  does  Mr.  Holmes  appear  to  be  aware  of  recent 
literature.  As  a  chemist,  Mr.  Holmes  ought  to  know  something  of  the  special 
liability  to  error  of  the  average  sodium  analysis  of  river  water,  especially  when  (as 
is  usually  the  case)  no  particular  trouble  is  taken  to  assess  it  with  the  necessary 
accuracy.  There  is  a  continual  tendency  towards  unduly  high  results.  The  fact 
has  been  pointed  out  repeatedly  by  Mr.  Acroyd,  Prof.  Dubois,  and  myself.2  Nor 
does  Mr.  Holmes  appear  to  realise  the  cumulative  effect  of  the  errors.  Mr. 
Holmes's  conclusion  that  the  quantitative  deductions  are  purely  provisional  is 
correct,  but  his  reasons  are  very  inadequate. 

Nor,  in  his  discussion  of  Prof.  Sollas's  theories  of  sedimentation,  is  he  much 

happier.     Prof.  Sollas  is  a  geologist  of  the  highest  rank,  and  certainly  deserves 

the  compliment  of  detailed  refutation.     On  this  matter,  Mr.  Holmes's  view,  which 

he  supports  by  a  private  communication  from  Prof.   Chamberlin,  is   that   land 

radients  to-day  are  much  higher  than  the  average,  and  that,  consequently,  the 

1  Philosophical  Magazine,  January  1908. 

3  Particularly  in  the  following  papers  :  1.  Proceedings  Geological  Society 
Yorkshire,  1902  (on  Cyclic  Salt);  2.  Chemical  News,  1901  (Discussion  between 
Mr.  Acroyd  and  Prof.  Joly)  ;  3.  Proceedings  Amsterdam  Academy,  1902  (On  the 
Ratio  between  the  Sodium  and  the  Chlorine  in  the  Salts  carried  by  the  Rivers 
into  the  Sea)  ;  4.  Chemical  News,  May  30,  1909  (On  the  Sodium  and  the  Chlorine 
in  River  and  Rain  Waters)  ;  5.  Journal  of  Geology,  1910  (The  Age  of  the  Earth 
and  the  Saltness  of  the  Sea)  ;  6.  Contemporary  Review,  February  191 1  (Modern 
Theories  of  Geologic  Time).  The  latter  paper  also  contains  a  criticism  of  Prof. 
Sollas. 


i;o  SCIENCE  PROGRESS 

sediments  now  brought  to  the  sea  are  from  nine  to  fourteen  times  as  great  as  those 
of  other  geologic  epochs.  Past  experience  in  matters  geological  teaches  us  to 
regard  with  great  suspicion  theories  that  require  a  departure  from  the  hypothesis 
of  practically  uniform  conditions.  What  Prof.  Chamberlin's  opinion  may  be  is 
known  only  to  himself,  but,  in  a  recently  published  paper  on  the  subject,  he 
assesses  the  lower  Cambrian  as,  roughly,  75,000,000  years  ago.1  In  any  case,  it 
will  be  sufficient  to  point  out  that  this  argument  is  not  available  against  Prof. 
Sollas.  Prof.  Sollas's  results  refer  to  the  maximum  thickness  of  sedimentary 
rock,  and  it  is  absurd  to  suppose  that  the  fastest  accumulation  of  sediment, 
presumably  representing  the  steepest  land  gradients,  has,  on  that  account,  pro- 
ceeded nine  to  fourteen  times  more  slowly  than  under  current  conditions.  The 
average  relief  of  the  land  has  no  bearing  on  the  subject.  Prof.  Sollas's  arguments 
are  valid  as  against  any  that  Mr.  Holmes  has  brought  forward.  As  a  matter  of 
fact,  an  attempt  at  a  detailed  refutation  has  been  published,  but  Mr.  Holmes 
does  not  appear  to  be  aware  of  it. 

With  all  the  faults,  however,  there  is  some  value  in  the  publication  of  a  book 
on  the  subject  by  one  specially  competent  to  speak  from  the  standpoint  of  radio- 
activity, and  we  can  echo  his  wish  that  the  work  will  stimulate  an  interest  in  the 
time  problem,  and  provide  material  for  further  discussion.  H.  S.  Shelton. 

Problems  of  Life  and  Reproduction.  By  Marcus  Hartog,  M.A,  D.Sc, 
F.L.S.,  F.R.H.S.,  Professor  of  Zoology  in  University  College,  Cork. 
[Pp.  xviii  +  362.]     (London  :  John  Murray,  1913.     Price  7s.  6d.  net.) 

Dr.  Hartog's  book  is,  actually,  a  collection  of  essays  published,  from  time  to  time, 
in  the  leading  scientific  and  popular  journals.  It  is  intelligible  to  those  having  no 
special  knowledge  of  the  subject  matter,  admirably  discursive,  and  yet  possesses  a 
unity  of  its  own.  In  such  a  work  it  is  not  easy  to  emphasise  the  salient  points  of 
interest  to  the  general  reader.  It  may  be  regarded  as  the  epitome  of  the  biological 
writings  of  a  lifetime.  The  three  features  that  stand  out  most  prominently  are, 
perhaps,  the  pronounced  neo-Lamarckian  tendency,  the  Spencerian  attitude 
towards  biological  problems,  and  the  appreciation  of  the  biological  writings  of  the 
late  Samuel  Butler.  All  of  these  are  of  interest  and  value.  Each  one,  separately, 
would  tend  to  give  the  writer  a  special  position  among  English  biologists,  and  all 
three  combined  make  his  position  distinctive  and  unique.  Fashions  in  biological 
theories  change  continually,  and  in  every  instance  Dr.  Hartog  has  the  distinction 
of  maintaining  the  point  of  view  that  is  not,  at  the  present  time,  fashionable,  and  he 
does  so  with  a  wealth  of  knowledge  and  a  clearness  of  exposition  that  ensure  him 
a  hearing  both  from  biological  specialists  and  from  the  general  intelligent  public. 

The  first  two  features  are,  perhaps,  but  aspects  of  the  same.  No  clearer  or 
more  consistent  statement  of  the  so-called  neo-Lamarckian  view  than  Spencer's  is 
to  be  found  in  modern  literature  ;  indeed,  in  its  modern  development,  it  might 
more  correctly  be  described  as  neo-Spencerian.  Dr.  Hartog  is  a  worthy  successor. 
The  uncritical  and  unphilosophical  dogmatism  of  present-day  neo-Darwinian 
biologists,  though  masked,  for  the  time  being,  by  the  rise  of  Mendelism,  requires 
a  corrective,  and  Dr.  Hartog  admirably  supplies  the  need.  It  is  difficult,  in  a 
brief  review,  to  summarise  or  to  criticise  Dr.  Hartog's  arguments  or  to  make 
any  original  contribution  to  the  discussion.  The  following  extracts  will  illustrate 
his  point  of  view  ; 

"We  must  consider  what  is   the  a  priori  ground  that  has   led  naturalists, 

1  Nature,  vol.  liii.  p.  80. 


REVIEWS  i;i 

themselves  not  wholly  devoid  of  that  merit  and  reasoning  power  which  they  deny 
to  their  opponents,  to  assert  the  impossibility  of  such  transfer.  The  reproductive 
bodies  are  not  formed  of  a  secretion  in  which  the  whole  organism  takes  a  part  : 
in  complex  animals  they  are  cells  set  apart  at  a  very  early  stage  in  the  develop- 
ment of  the  individual,  and  take  no  direct  share  in  the  life  of  the  parent,  which 
may  almost  be  said  to  play  the  nurse  to  them  in  the  way  of  feeding  them  ;  to  push 
the  view  to  an  extreme,  the  reproductive  or  germ-cells  are  in  the  body  but  not  of 
it.  .  .  .  Now  these  reproductive  cells  may  be  fed  and  grow  and  multiply  at  the 
expense  of  the  nourishment  brought  to  them  by  the  organism  in  which  they  lie  ; 
but,  so  far  as  we  know,  there  is  no  nervous  apparatus  connecting  them  with  the 
body,  to  influence  them  ;  and  without  nerves  we  know  of  no  transmission  of 
impulse  in  animals.  Therefore,  for  the  majority  of  adaptations,  there  is  no 
ascertained  mechanis)n  of  transfer  from  the  soma  to  the  stirp,  and  as  a  consequence 
there  can  be  no  transmission.  This  assumes  the  canon  :  '  No  mechanism  can 
exist  that  escapes  the  modicum  of  knowledge  that  we  have  gained  during  the 
century  and  a  half  or  so  that  we  have  had  to  learn  physiology'"  (pp.  180-1). 

This  is  one  of  the  reasons  which  have  led  so  many  to  deny  the  possibility  of  the 
inheritance  of  acquired  characters.  Dr.  Hartog  certainly  does  not  overstate  his 
case.  Indeed,  it  is  easy  to  go  a  step  further  and  to  ask  whether,  in  normal  instances, 
the  reproductive  cells  do  separate  from  the  body  soon  enough  to  justify  the 
fundamental  Weismannian  distinction  between  stirp  and  soma.  In  most  of  the 
cases  when  such  a  phenomenon  has  been  noted  {e.g.  the  aphides)  there  are  special 
biological  reasons  why  it  should  be  so.  Nor  is  dogmatism  based  on  our  ignorance 
of  physiology  the  only  factor  to  which  the  bias  is  due.  The  neo-Darwinian  theory 
is  specially  useful  to  those  who  advocate  a  very  narrow  and  mechanistic  view  of 
evolution.  Also,  as  Dr.  Hartog  has  briefly  noted  (p.  178),  the  view  that  Natural 
Selection  is  the  sole  and  only  cause  of  evolution  has  become  the  stock-in-trade  of 
a  certain  class  of  political  theorists,  of  whom  Mr.  Benjamin  Kidd  is  the  chief 
spokesman.  Because  Natural  Selection  amongst  individual  human  beings  has, 
by  modern  civilisation,  been  reduced  to  a  minimum,  therefore  it  must  be  trans- 
ferred to  groupings,  therefore  the  group  is  all-important,  therefore  the  individual 
must  be  subordinated  in  every  possible  way,  therefore  follows  socialism  or  cheap 
imperialism  according  to  the  bias  of  the  individual.  It  is  absurd  to  suppose  that 
considerations  of  this  kind  have  been  wholly  without  influence  in  biological  circles, 
especially  among  the  more  popular  writers  who  have  no  claim  to  rank  high  in  the 
biological  world. 

To  bring  the  question  back  again  to  the  basis  of  fact  and  pure  science  is 
exceedingly  difficult.  What  is  an  acquired  character  ?  Whatever  observations 
may  be  made,  whatever  experiments  may  be  performed,  there  is  always  a  loophole 
for  the  surmise  that  a  character  which  has  all  the  appearance  of  being  a  true  case 
of  the  transmission  of  the  effects  of  use  and  disuse  is  either  not  inherited  or  not 
acquired.  Moreover,  on  any  hypothesis,  there  are  cogent  reasons  for  such  trans- 
mission being  slow  and  gradual.  The  difficulty  of  proof  thereby  becomes  greatly 
enhanced.  But  the  neo-Darwinian  school,  which,  it  is  as  well  to  emphasise  once 
more,  did  not  include  Darwin,  is  not  entitled  to  claim  the  involved  character  of  the 
facts  and  the  extreme  difficulty  of  correct  interpretation  as  a  proof  of  their  view. 
The  searching  criticisms  of  a  competent  biologist  such  as  Dr.  Hartog  are  very 
valuable  to  enable  us  to  realise  that  much  of  this  current  so-called  science  is,  at 
the  best,  rash  theorising,  at  the  worst  palpable  pseudo-science. 

The  Spencerian  leanings  of  the  book  are  not  confined  to  the  neo-Lamarckian 
controversy.  In  many  other  ways  Dr.  Hartog  shows  an  appreciation  of  the  wider 
philosophical  view  of  biology  of  which  Spencer  has  been  the  greatest  representa- 


i72  SCIENCE   PROGRESS 

tive.     The  theories  of  physiological  units,  of  the  limitation  of  the  size  of  land 
animals,  and  others  of  less  general  interest  receive  careful  attention  and  criticism. 

The  exposition  of  the  biological  writings  of  the  late  Samuel  Butler  has  a 
peculiar  interest  of  its  own.  It  is  a  strange  fact,  with  all  our  professorships  and 
other  direct  or  indirect  forms  of  endowment  of  research,  that  so  much  of  the 
advancement  of  knowledge,  in  the  things  that  really  matter,  is  due  to  outsiders 
whom  the  scientific  world  is  careful  to  ignore.  Afterwards  they  are  dragged  into 
the  light  in  a  way  which  they  would  probably  not  appreciate.  The  case  of 
Mendel  is,  perhaps,  not  surprising.  A  modest  unassuming  monk,  who  loved  his 
experiments,  and  neither  sought  for  nor  desired  recognition,  had  nothing  to  gain 
by  self-advertisement.1  But  Samuel  Butler  was  by  no  means  disposed  to  hide  his 
light  under  a  bushel.  And  now  we  find  a  first-rate  biologist  telling  us  that 
Eretuhon  was  not  his  only  achievement,  but  that  his  biological  writings  were  really 
scientifically  valuable.  Dr.  Hartog  traces  his  influence  in  Romanes  and  others, 
and  is  unable  to  explain  why  Life  and  Habit  missed  its  mark.  Bergson  is  not 
mentioned.  The  Bergsonian  boom  had  not  started  when  most  of  these  essays 
were  written.  But  it  is  interesting  to  note  that  the  only  part  of  Bergson's  evolution- 
ary theories  which  have  any  particular  scientific  interest  or  value — Mattel'  and 
Memory— is  strangely  reminiscent  of  Samuel  Butler's  work  on  unconscious  memory. 

There  is  much  else  of  interest  in  this  collection  of  essays.  The  article  on 
nature  study  should  be  valuable  to  teachers.  Here,  as  in  other  instances,  Dr. 
Hartog  is  a  pronounced  opponent  of  fads.  Avoid  pseudo-science,  is  the  burden  of 
his  remarks.  Do  not  call  carbon  dioxide  chalk  stuff  gas,  and  do  not  teach  more 
than  you  can  help  which  will  have  to  be  unlearned  afterwards.  The  articles 
reprinted  from  the  Quarterly  Journal  of  Microscopic  Science  should  interest  the 
technical  biologist.  But  the  admirable  discursiveness,  though  interesting  to  the 
reader,  is  embarrassing  to  the  reviewer.  The  book  is  a  distinct  addition  to  the 
series,  and  the  essays  are  well  worth  reprinting  in  permanent  form. 

H.  S.  Shelton. 

Reduction  of  Domestic  Flies.   By  Edward  Halford  Ross,  M.R.C.S.,  L.R.C.P. 
[Pp.  98,  18  illustrations.]     (London  :  John  Murray.     Price  $s.  net.) 

This  work  emanates  from  the  researches  so  generously  organised  by  Mr.  John 
Howard  McFadden  and  is  written  by  Mr.  E.  H.  Ross,  who  was  formerly  Health 
Officer  of  Port  Said  and  is  now  connected  with  the  researches  referred  to.  The 
book  deals  with  the  whole  subject  of  Domestic  Flies  chiefly  from  the  sanitary 
point  of  view.  The  author  (my  brother)  is  one  of  the  few  Englishmen  who  have 
conducted  large-scale  work  against  insect  pests.  While  at  Port  Said  he  com- 
menced and  carried  through  a  campaign  of  extermination  against  the  mosquitoes 
which  used  to  abound  there  in  very  large  numbers — chiefly  Stegomyia  and  Culex. 
The  work  was  of  great  difficulty  because  the  town  contained  a  large  mixed 
population  of  many  nationalities  and  possessed  neither  sanitary  laws  nor  traditions  ; 
and  the  result  was  a  very  complete  and  brilliant  success— in  fact,  I  think  the 
greatest  success  which  has  been  obtained  in  British  possessions.  Mr.  Ross  s 
therefore  peculiarly  well  qualified  to  speak  on  the  practical  reduction  of  flies,  and 
his  book  deals  with  the  subject,  not  only  from  an  entomological  point  of  view,  but, 
what  is  very  different,  from  the  Health  Officer's  standpoint. 

The  method  of  breeding  house  flies  and  proposals  for  their  reduction  have 

1  Reference  to  the  Catholic  Encyclopedia  elucidates  the  fact  that  even  Mendel  was 
somewhat  bitter  at  the  manner  in  which  the  scientific  world  ignored  his  discoveries. 


REVIEWS  173 

really  been  before  the  public  for  about  fifty  years,  and  many  books  have  been 
written  on  the  subject.  These  are  usually,  however,  more  academical  than 
practical  ;  and  the  present  book  will  therefore  be  particularly  useful  in  the 
latter  direction.  Air.  Ross  is  very  gentle  with  the  authorities  in  that  he 
attributes  the  absence  of  practical  measures  mostly  to  ignorance.  Stupidity  is 
generally  the  appropriate  word.  People  who  are  pestered  by  flies  in  any  part  of 
the  world  ought  to  retort  by  pestering  the  local  Sanitary  Magnates  in  return. 
As  the  author  explains,  this  is  the  only  way  of  having  attention  paid  to  abuses. 

R.  ROSS. 


BOOKS   RECEIVED 

{Publishers  are  requested  to  notify  pi'ices) 

Man's  Place  in  the  Universe.  A  Study  of  the  Results  of  Scientific  Research  in 
Relation  to  the  Unity  or  Plurality  of  Worlds.  By  Alfred  R.  Wallace,  O.M., 
LL.D.,  D.C.L.,  F.R.S.,  etc.  New  and  Cheaper  Edition.  London: 
Chapman  &  Hall,  Ltd.,  191 2.     (Pp.  283.) 

A  Text-Book  of  Experimental  Metallurgy  and  Assaying.  By  Alfred  Roland 
Gower,  F.C.S.,  Lecturer  in  Chemistry  and  Metallurgy  to  the  Educational 
Authority,  Barrow-in-Furness.  London  :  Chapman  &  Hall,  Ltd.,  1913. 
(Pp.  xiv,  163.)     3-r.  6d.  net. 

Continuous  Beams  in  Reinforced  Concrete.  By  Burnard  Geen,  A.M.I.C.E., 
M.S.E.,  M.C.I  ,  Consulting  Engineer.  London  :  Chapman  &  Hall,  Ltd., 
11,  Henrietta  Street,  W.C.,  191 3.  (Pp.  210.)  4to,  many  tables  and 
diagrams,     gs.  net. 

Experimental  Domestic  Science.  By  R.  Henry  Jones,  M.Sc,  F.C.S.,  Head  of  the 
Chemical  Department,  Harris  Institute,  Preston  ;  Lecturer  in  Science,  School 
of  Domestic  Science,  Preston  ;  Dalton  Chemical  Scholar,  Manchester 
University  ;  Assistant  Examiner  in  Elementary  Science  and  Chemistry  to  the 
Central  Welsh  Board.  London:  William  Heinemann,  1912.  (Pp.  ix,  235.) 
2s.  6d. 
A  very  interesting  and  useful  little  book. 

Penal  Philosophy.  By  Gabriel  Tarde,  Late  Magistrate,  and  Professor  in  the 
College  of  France.  Translated  by  Rapelje  Howell,  of  the  New  York  Bar. 
With  an  Editorial  Preface  by  Edward  Lindsey,  of  the  Warren,  Pa.,  Bar,  and 
an  Introduction  by  Robert  H  Gault,  Assistant  Professor  of  Psychology  in 
North-Western  University  and  Managing  Editor  of  the  Journal  of  Criminal 
Law  and  Criminology.  London  :  William  Heinemann,  1912.  (Pp.  xxii,  581.) 
2o.f.  net. 

Wireless  Telegraphy.  By  C.  L.  Fortescue,  M.A.,  Professor  of  Physics,  Royal 
Naval  College,  Greenwich.  Cambridge  :  at  the  University  Press,  19 13. 
(Pp.  vi,  143.)     is.  net. 

For  "  the  reader  who,  possessing  a  general  scientific  knowledge,  is  anxious 
to  know  something,  not  only  of  the  accomplishments  of  wireless,  but  also  of 
the  means  by  which  they  are  attained." 

The  Wanderings  of  Animals.  By  Hans  Gadow,  F.R.S.,  Lecturer  in  Advanced 
Morphology  in  the  University  of  Cambridge.  Cambridge  :  at  the  University 
Press,  191 3.     (Pp.  vi,  150.)     is.  net. 


i74  SCIENCE  PROGRESS 

The   Religion  of  the  Open   Mind.     By  Adam  Gowans  Whyte,  B.Sc,  Author  of 
"A   Comedy  of  Ambition,"    "The  Templeton    Tradition,"    "  Yellowsands," 
With  Foreword  by  Eden  Phillpotts.     London:  Watts  &  Co.,   17,  Johnson's 
Court,  Fleet  Street,  E.C.,  191 3.     (Pp.  xi,  191.)     2s.  6d.  net. 
An  excellent  essay  upon  the  scientific  attitude. 

The  Science  of  the  Sciences.  Constituting  a  New  System  of  the  Universe  which 
Solves  Great  Ultimate  Problems.  By  H.  Jamyn  Brooks,  Author  of  "  The 
Elements  of  Mind."  London:  David  Nutt,  17,  Grape  Street,  New  Oxford 
Street,  W.C.     (Pp.  ix,  312.)     3^.  6d.  net. 

The  Britannica  Year-Book,  1913.  A  survey  of  the  World's  Progress  since 
the  Completion  in  1910  of  the  Encyclopaedia  Britannica,  Eleventh  Edition. 
Comprising  A  Register  and  Review  of  Current  Events  and  Additions  to  Know- 
ledge in  Politics,  Economics,  Engineering,  Industry,  Sport,  Law,  Science,  Art, 
Literature,  National  and  International,  up  to  the  end  of  1912.  Edited  by 
Hugh  Chisholm,  M.A.,  Oxon.,  Editor  of  the  "  Encyclopaedia  Britannica."  The 
Encyclopaedia  Britannica  Company,  London  ;  The  Encyclopaedia  Britannica 
Company,  New  York,  1913.  (Pp.  xliii,  1226.)  Price  \os.  upwards  according 
to  binding. 

Begins  with  diaries  of  important  events  during  191 1  and  191 2,  and  contains 
a  series  of  articles  on  important  developments  during  1912  in  politics,  science, 
art,  archaeology,  philosophy,  engineering,  and  information  on  and  statistics 
of  the  principal  countries. 

Researches  on  Irritability  of  Plants.  By  Jagadis  Chunder  Bose,  M.A.,  D.Sc, 
C.S.I.,  Professor,  Presidency  College,  Calcutta.  With  Illustration.  Longmans, 
Green  &  Co.,  39,  Paternoster  Row,  London,  New  York,  Bombay,  and 
Calcutta,  1913.     (Pp.  xxiv,  375.)     7s.  6d.  net. 

A  Beginner's  Star-book.  An  Easy  Guide  to  the  Stars  and  to  the  Astronomical 
Uses  of  the  Opera-Glass,  the  Field-Glass  and  the  Telescope.  By  Kelvin 
McKready.  With  Charts  of  the  Moon,  Tables  of  the  Planets,  and  Star  Maps 
on  a  new  plan.  Including  70  Illustrations.  G.  P.  Putnam's  Sons,  New 
York  and  London.     The  Knickerbocker  Press,  1912.     (Pp.  148.) 

Annual  Magazine  Subject- Index,  1912.  A  Subject-Index  to  a  Selected  List  of 
American  and  English  Periodicals  and  Society  Publications  not  Elsewhere 
Indexed.  Edited  by  Frederick  Winthrop  Faxon,  A.B.  (Harv.).  Compiled 
with  the  co-operation  of  Librarians.  Boston  :  The  Boston  Book  Company, 
1913.     (Pp.  299.) 

Fortschritte  der  Naturwissenschaftlichen  Forschung.  Edited  by  Prof.  Dr.  Emil 
Abderhalden,  Direktor  des  Physiologischen  Institutes  der  Universitat  Halle 
a.S.  Achter  Band.  Mit  217  Textabbildungen  und  1  Tafel.  Urban  & 
Schwarzenberg,  Berlin  N.,  Friedrichstrasse  105b  ;  Wien,  I.,  Maximilian- 
strasse4.  1913.  Contents.  The  Present  Position  of  Research  in  Metallurgy, 
by  Doz.  Dr.  W.  Guertler,  Berlin-Grunewald.  Our  Knowledge  about  the 
Oldest  Tetrapods,  by  Prof.  Dr.  F.  Broili,  Munich.  The  Scientific  and  Economic 
Importance  of  Pond  Management,  by  Doz  Dr.  Walter  Cronheim,  Berlin. 
About  the  Galls  in  Plants  (New  Results  and  Discussions  of  General 
Cecidology),  by  Prof.  Dr.  Ernst  Kuster,  Bonn  a.  Rh.  Propagation,  Mating, 
and  Spawning  of  Fresh-Water  Insects,  by  Dr.  C.  Wesenberg-Lund,  Hillerod 
(Denmark).  Architecture  and  Earthquakes,  by  Prof.  Dr.  F.  Freeh,  Breslau. 
(Pp.  308.) 


NOTES 

Professor  Nathaniel  Henry  Alcock,  M.D.,  D.Sc. 

Almost  at  the  moment  of  going  to  press,  news  reaches  us 
of  the  death,  in  Montreal,  at  the  early  age  of  forty-two,  of  Dr. 
Nathaniel  Henry  Alcock,  Professor  of  Physiology  at  McGill 
University,  who  was,  with  Mr.  W.  G.  Freeman,  one  of  the 
Editors  of  Science  Progress  (New  Series)  at  its  start.  His 
work  for  science  was  considerable  and  valuable;  but  of  that 
it  is  impossible  to  speak  adequately  in  this  passing  note. 
Of  his  personal  qualities  and  his  eagerness  for  the  success  of 
this  periodical  we  can  testify  with  cordial  appreciation  and 
gratitude.  He  proved  himself  in  those  difficult  pioneer  years 
keen  and  painstaking,  genial  and  charming ;  his  death  will  be 
regretted  by  all  who  have  known  him. 

The  University  of  Bristol 

The  affairs  of  this  young  University  continue  to  receive 
some  attention  in  Parliament  and  in  the  press.  Prima  facte, 
there  would  appear  to  be  some  division  of  opinion  between  the 
business  and  academical  elements  of  the  University  as  to  which 
shall  have  the  predominant  voice  in  its  administration.  At  an 
early  stage,  the  services  of  one  of  the  professors  who  was 
most  active  in  the  foundation  of  the  University  were,  it  is 
alleged,  dispensed  with  by  some  indirect  procedure  ;  and,  later, 
the  Council  bestowed  a  number  of  honorary  degrees,  of  which 
a  considerable  proportion  fell  to  the  share  of  members  of  their 
own  body.  Lastly,  the  services  of  another  member  of  the  staff 
who  objected  to  these  and  other  proceedings  have  also,  it  is  said, 
been  dispensed  with.  A  memorial  concerning  the  case  of  the 
professor  referred  to,  signed  by  a  large  number  of  men  of 
eminence,  was  forwarded  to  the  Chancellor  of  the  University, 
but  was,  we  understand,  referred  by  him  to  the  Visitor,  who, 
we  also  understand,  has  referred  it  again  to  the  existing  con- 
stitutional machinery  for  dealing  with  such  complaints  ;  but 
it  is  doubted  by  some  whether  this  machinery  is  competent  to 
conduct  an  independent  and  impartial  inquiry.  The  case, 
especially  as  regards  the  very  generous  distribution  of  honorary 
degrees,  appears  to  be  a  serious  one  ;  and  the  progress  of  it 
should  receive  close  attention  from  all  scientific  workers. 
Academic  life  is  by  no  means  too  prosperous  in  this  country; 
and  it  will  become  even  less  so  if  it  is  not  carefully  protected 
against  such  proceedings  as  those  which  are  alleged  to  have 
occurred  in  this  University. 

175 


NOTICE 
THE   EMOLUMENTS  OF   SCIENTIFIC   WORKERS 

It  is  proposed  to  undertake  an  inquiry  regarding  the  pay,  posi- 
tion, tenure  of  appointments,  and  pensions  of  scientific  workers 
and  teachers  in  this  country  and  the  Colonies.  The  Editor  will 
therefore  be  much  obliged  if  all  workers  and  teachers  who  hold 
such  appointments,  temporary  or  permanent,  paid  or  unpaid, 
will  give  him  the  necessary  information  suggested  below. 
The  figures  will  be  published  only  in  a  collective  form  and 
without  reference  to  the  names  of  correspondents,  unless  they 
expressly  wish  their  names  to  be  published.  The  Editor 
reserves  the  right  to  publish  or  not  to  publish  any  facts  com- 
municated to  him.  Workers  who  are  conducting  unpaid  private 
investigations  must  not  be  included.  The  required  informa- 
tion should  be  sent  as  soon  as  possible  and  should  be  placed 
under  the  following  headings  : 

(i)  Full  name 

(2)  Date  of  birth.     Whether  married.     Number  of  family 

living 

(3)  Qualifications,  diplomas,  and  degrees 

(4)  Titles  and  honorary  degrees 

(5)  Appointments  held  in  the  past 

(6)  Appointments  now  held,  with  actual  salary,  allowances, 

fees,  and  expected  rises,   if  any.     Whether  work  is 
whole-time  or  not 

(7)  Body  under  which  each  appointment  is  held 

(8)  Conditions  and  length  of  tenure 

(9)  Pension,  if  any,  with  conditions 

(10)  Insurance  against  injury,  if  any,  paid  by  employers 

(11)  Family  pensions,  if  any 

(12)  Remarks 

176 


SCIENCE  PROGRESS 

IN  THE  TWENTIETH   CENTURY 
[    A  QUARTERLY  JOURNAL  OF 
|  SCIENTIFIC    WORK 

&    THOUGHT 


VOL.  VIII 
NO.   30.     OCTOBER    1913 


EDITOR 


SIR    RONALD    ROSS,    K.C.B.,    F.R.S.,    N.L.: 
D.Sc,    LL.D.,    M.D.,   F.R.C.S. 


LONDON 
JOHN    MURRAY,   ALBEMARLE    STREET,    W. 

*9*3 


NOTICE 

Articles  and  reviews  offered  for  publication  should  be  addressed 
postage-paid  to  The  Editor  of  Science  Progress,  18,  Cavendish 
Square,  London,  IV.  They  must  be  accompanied  by  the  full  name, 
address,  and  scientific  and  academical  qualifications  and  appoint- 
ments of  the  writer — for  publication,  unless  otherwise  desired. 
All  possible  care  will  be  taken  of  scripts;  but  responsibility 
cannot  be  incurred  for  accidental  damage  or  loss.  It  must  be 
understood  that  papers  accepted  for  Science  Progress  shall 
not  be  published  elsewhere  without  the  Editor's  permission. 

Publications  sent  for  mention  or  review  should  also  be 
forwarded  postage-paid  to  the  Editor ;  but  such  mention  or 
review  cannot  be  promised.     Prices  should  always  be  notified. 

The  Editor  will  be  glad  to  receive  notice  of  scientific 
meetings  and  lectures  ;  of  public  appeals  for  scientific  purposes ; 
and  of  all  matters  concerned  with  the  interests  of  science  and 
of  scientific  workers. 

Correspondence  concerning  sales,  exchanges,  and  advertise- 
ments should  be  addressed  to  the  Publisher  of  Science  Progress, 
50A,  Albemarle  Street,  London,  W, 


CONTENTS 


cac.h 


i.     THE   BUSINESS   AFFAIRS   OF  SCIENCE    .         .         .        .177 

2.  THE   SANITARY  AWAKENING  OF   INDIA        .        .         .181 

Surgeon-General  Sir  Charles  Pardey  Lukis,  K.H.S., 
K.C.S.I.,  M.D.,F.R.C.S.,  Director-General,  Indian 
Medical  Service. 

3.  ATOMIC  THEORY   AND   RADIOACTIVITY        .         .         .197 

Sir   Oliver    Lodge,    F.R.S.,   D.Sc,   LL.D. 

4.  NOVEL     EXPERIMENTS    AND     FACTS     CONCERNING 

CORROSION 202 

J.  Newton  Friend,  D.Sc,  Ph.D.,  Carnegie  Gold 
Medallist. 

{Illustrated) 

5.  THE   DISTURBED   MOTION   OF  AN   AEROPLANE  .     209 

W.  Beverley,  M.Sc. 

6.  STEREOISOMERISM     AND     OPTICAL     ACTIVITY;     A 

Critical  Study,  With  a  New  Suggestion  .         .        .227 

G.  S.  Agashe,  M.Sc,  M.A. 
{Illustrated) 

7.  SOME   ASPECTS  OF   GEOLOGIC  TIME 250 

H.  S.  S HELTON,  B.Sc,  Lond. 

8.  THE  SIGNIFICANCE  OF  THE  PILTDOWN   DISCOVERY     275 

A.  G.  Thacker,  A.R.C.Sc,  Curator  of  the  Public 
Museum,  Gloucester. 

{Illustrated) 

9.  I.  NATURE  AND  NURTURE  IN  MENTAL  DEVELOPMENT     291 
II.  THE  INBORN  POTENTIALITY  OF  THE  CHILD  .     307 

F.  W.  Mott,  M.D.,  F.R.S.,  Pathologist  to  the  London 
County  Asylums. 

{Illustrated) 

iii 


iv  CONTENTS 


PAGE 


10.  THE  INTERPRETATION  OF  FACT  IN  THE  STUDY  OF 

HEREDITY 324 

Charles  Walker,  D.Sc. 

11.  THE    METHOD    OF   DARK-GROUND   ILLUMINATION 

IN   BOTANICAL  RESEARCH 343 

S.    Reginald    Price,    B.A.,   Late   University   Frank 
Smart,  Student  in  Botany,  Cambridge. 

12.  SCIENTIFIC   SPELLING 355 

I.     Sir  Harry  Johnston,  G.C.M.G.,  K.C.B.,  D.Sc. 
II.     Sir  Ronald*  Ross,  K.C.B.,  F.R.S.,  D.Sc 

13.  REVIEWS,   BOOKS   RECEIVED,   AND   NOTES. 

George   Paulin,    "  No    Struggle   for    Existence :    No   Natural 

Selection."     (T.  &  T.  Clark) 373 

Kelvin  McKready,  "  A  Beginner's  Star-Book."    (G.  P.  Putnam's 

Sons) 374 

J.    W.    Shepherd,    "Qualitative    Determination    of    Organic 

Compounds."  (University  Tutorial  Press)  .  .  .  .374 
Philip  A.  Morley  Parker,  "The  Control  of  Water."     (George 

Routledge  &  Sons,  Ltd.) 375 

C.  L.  Fortescue,  "Wireless  Telegraphy."   (Cambridge  University 

Press) 375 

Burnard  Geen,  "  Continuous  Beams  in  Reinforced  Concrete." 

(Chapman  &  Hall,  Ltd.) 376 

H.  v.  Buttel-Reepen,  Translation,  "  Man  and  His  Forerunners." 

(Longmans,  Green  &  Co.)    .......     376 

Norman    Robert    Campbell,    "  Modern    Electrical    Theory." 

(Cambridge  University  Press)      .         .         .         .         .         .378 

C.  W.  C.  Barlow,  "Mathematical  Physics:  Vol.  I.,  Electricity 

and  Magnetism."     (University  Tutorial  Press)       .         .         .     379 

Books  Received 380 

Notes.      The   International   Distribution    of    the    Nobel    Prizes 

during  Twelve  Years     .         .         .         .         .         -382 

The  University  of  Bristol      ......     384 

Mr.  Balfour  at  the  National  Physical  Laboratory   .         .     385 
The  International  Congress  of  Medicine         .         .         .     386 

NOTICE.     The  Emoluments  of  Scientific  Workers. 


THE   BUSINESS  AFFAIRS   OF   SCIENCE 

That  the  time  has  come  for  a  serious  stock-taking  in  the 
business  affairs  of  science  is  recognised  by  all  scientific  men — 
that  it  is  a  task  long  overdue  is  apparent  to  many.  During  the 
last  century  the  whole  position  of  scientific  work  in  relation  to 
other  forms  of  human  effort  has  changed.  Science  is  no  longer 
merely  a  gentle  preoccupation  for  the  leisured  and  intelligent 
few — for  the  philosophers  of  the  Cephissus,  the  rural  school- 
master, the  university  recluse,  the  physician,  or  the  well-to-do 
amateur.  It  was,  indeed,  these  who  made  the  beginnings  of 
science,  and  their  work  was  great ;  but  on  the  foundations  laid 
by  them  an  edifice  has  grown  up  which  it  is  beyond  their 
unaided  powers  to  carry  further  towards  completion  with  the 
rapidity  required  to-day.  Science  has  now  become  an  industry. 
It  has  indeed  become  the  premier  industry  of  all.  It  has 
grown  to  affect  every  other  industry  and  occupation  of  men. 
Mathematics  leavens  not  only  navigation  and  engineering,  but 
all  the  other  sciences,  and  is  coming  in  these  days  to  take 
possession  of  physics  and  chemistry,  and  even  of  epidemiology. 
In  their  turn,  chemistry  and  physics  enter  into  the  very  being 
of  almost  all  manufactures,  and  of  physiology  and  medicine. 
Physiology,  zoology,  and  chemistry  form  the  basis  of  the  daily 
work  of  the  physician  and  surgeon.  Chemistry  and  botany 
revolutionise  agriculture,  and  geology  and  mineralogy  illuminate 
mining.  Nothing  new  can  be  done  without  a  call  upon  some 
branch  of  science— often  upon  some  quite  unexpected  branch  of 
it.  The  wonders  of  modern  invention — steam-engines,  artificial 
lighting,  photography,  the  phonograph,  the  telephone  and 
telegraph,  X-rays,  wireless  telegraphy,  motor-cars,  aeroplanes, 
new  fire-arms,  aseptic  surgery,  scientific  medicine,  hygiene,  and 
agriculture — have  produced  a  greater  revolution  in  the  world 
than  has  ever  occurred  before  as  the  result  of  the  widest  tribal 
movements,  the  most  decisive  battles,  and  the  most  elaborate 
politics — the  change  made  during  recent  centuries  is  greater 
than  that  made  during  all  previous  known  periods  of  the  past 

12  177 


i78  SCIENCE  PROGRESS 

put  together.  After  all,  the  common  life  of  two  centuries  ago 
differed  little  from  that  of  previous  civilised  periods,  such  as  the 
great  ages  of  Greece  and  Rome.  Since  then  we  have  suddenly 
become  endowed  with  a  hundred  new  powers  which  were 
unthought  of  before — and  with  new  outlooks  upon  the  past,  the 
present,  and  the  future. 

The  complaint  has  been  made  that  science  furnishes  us  only 
with  petty  utilities,  and  adds  nothing  to  happiness,  character,  or 
greatness  of  mind.     But  this  is  the  opinion  of  those  who  have 
never  climbed  the  heights  of  science  to  see  the  view  disclosed 
from   that  summit.     The   mere  utilities  themselves  affect  both 
happiness  and  character.     The  humble  bicycle  possessed  by  the 
modern  workman  enables  him  to  see  something  of  the  world 
which  was  never  seen  by  his  pedestrian  ancestor.     Mechanical 
transit  is  probably  a  better  educator  than  some  schoolmasters, 
and  the  happiness  and  self-confidence  of  every  civilised   man 
are  vastly  increased  by  the  consciousness  of  scientific  knowledge. 
If  we   have  no   access   of  magnanimity,  it   is   not  the  fault  of 
science,  but  rather  of  defects  which  science  may  hope  to  remove. 
Some  one  once  said  that  a  knowledge  of  the  stars  is  of  no  con- 
sequence to  any  of  us,  and  that  the  Greeks  were  happy  without 
possessing  it ;   but  what  would  not  the   ancient  Greeks   have 
given  to  have  seen  what  we  can  see  in  the  heavens  to-day? 
Science  not  only  makes  us  "  lords  of  little  things,"  but  lifts  us 
into    higher     spheres     of    truth.      It    is    constantly    recalling 
philosophy  to  fact ;  and  gives,  or  ought  to  give,  more  concrete- 
ness  to   art.     It  has   revolutionised   the   military  arts ;   and   it 
should  revolutionise  politics.      It  brings  the  ends  of  the  earth 
together,  and  mingles  humanity  in   a  manner  which  was  un- 
dreamed of  a  century  ago. 

The  gifts  of  science,  unlike  those  of  war  and  politics,  are  not 
given  to  a  single  tribe  and  to  a  single  generation,  but  to  the 
whole  civilised  world  and  to  all  time,  until  "  the  future  dares 
forget  the  past."  But  they  also  affect  each  nation  separately. 
It  is  scarcely  too  much  to  say  that  the  overwhelming  superiority 
in  power  and  influence  of  a  few  nations  of  to-day  is  due,  not 
perhaps  to  their  physical  or  moral  superiority,  nor  even  to  the 
intellectual  superiority  of  their  individual  citizens,  but  to  the 
greater  scientific  knowledge  which  these  nations  possess.  It 
is  to  be  doubted,  for  instance,  whether  we  could  excel  in  arms 
and  conquer  savage  tribes  merely  by  our  personal  bravery  or 


THE   BUSINESS  AFFAIRS  OF  SCIENCE         179 

physical  strength.  It  has  seldom  been  the  general  or  the 
soldiers  who  have  won  the  victory  so  much  as  the  men  who 
invented  their  rifles  and  cannons.  Thus  science  possesses  a 
distinct  political  potentiality — it  gives  hegemony  to  the  nations 
which  possess  it  and  leaves  nations,  like  individuals,  which 
do  not  possess  it  in  a  backwater  of  failure  and  poverty. 
Efficiency  in  science  is  not  merely  an  academical  asset,  but  a 
practical  and  national  one.  In  the  great  international  com- 
petitions of  to-day,  whether  in  armaments,  policies,  industries, 
or  even  sport,  the  possession  of  scientific  knowledge  and 
especially  of  scientific  modes  of  thought  furnishes  the  deciding 
factor.  And  this  international  struggle  is  a  part  of  the  evolu- 
tionary scheme  of  nature.  Nations  no  more  than  individuals 
can  be  allowed  to  remain  ignorant,  sluggish,  and  unscientific. 
Like  individuals,  they  must  train  all  their  faculties,  or  else  they 
will  suffer  in  the  future  as  indolent  nations  have  invariably 
suffered  in  the  past.  Their  rivals  of  to-day  are  apt  to  become 
their  enemies  of  to-morrow,  and  possibly  their  conquerors  of 
the  day  after.  There  are  those  who  shudder  at  all  ideas  of  con- 
tention, and  who  would  have  the  world  be  a  pleasant  garden 
for  non-competitive  angels ;  but  the  world  must  be  taken  as  it 
is;  and, 'so  far  as  we  can  ascertain,  rivalry  is  the  only  instru- 
ment which  nature  possesses  to  maintain  racial  efficiency. 

At  two  points  science  goes  outside  direct  utilitarian  effort. 
The  study  of  disease  and  of  its  prevention  and  cure  has  become 
a  sacred  obligation  for  all  the  nations;  and,  secondly,  science 
trains  the  mind  to  better  ways  of  thinking.  Science  is  not 
merely  common  sense.  Her  judgments  are  not  merely  like 
those  of  the  law  courts,  which  consider  only  the  evidence 
placed  before  them,  and  which  are  prone  to  "  rule  out "  this 
or  that  fact  as  being  irrelevant  to  the  issue.  She  must  collect 
her  own  evidence  ;  with  her  scarcely  any  fact  can  be  altogether 
irrelevant  to  the  issue;  and  often  with  her  the  trial  is  always 
proceeding  and  the  final  judgment  never  given.  She  has  learnt, 
and  she  teaches,  humility  in  decision.  The  happy  jingoism  of 
dogma  should  not  be  hers.  She  has  learnt,  and  she  teaches, 
the  necessity  for  the  infinite  preparation  of  evidence  and  the 
infinite  distrust  of  personal  opinion.  Her  methods,  unlike  those 
of  the  dogmatist,  have  been  justified  by  her  wonderful  successes; 
and  it  will  be  good  if  these  methods  were  more  employed  in 
every  line  of  human  thought. 


180  SCIENCE   PROGRESS 

The  early  founders  of  science,  the  great  amateurs,  were 
sublime  figures  ;  but,  though  we  may  still  hope  for  such 
powerful  assistance  as  they  gave,  the  fact  is  that  science  now 
needs  professional  service  in  every  branch.  If  science  has 
become  the  first  industry,  then  for  rapid  progress  it  should  be 
treated  as  such.  Our  policy  should  direct  itself  towards  per- 
fecting the  organisation  which  makes  most  for  science — the 
scientific  education  of  the  individual  and  the  national  encourage- 
ment of  scientific  work.  We  must  ask,  what  is  the  world  doing 
to  render  more  smooth  the  machinery  of  scientific  thought  and 
investigation,  and  what  part  does  our  nation  play  in  this  great 
world-work  ?  Men  of  science  are  apt  to  think  that  their  duties 
extend  to  no  more  than  investigation.  But,  if  they  are  wise, 
they  will  attend  also  to  the  means  by  which  great  investigation 
is  to-day  rendered  possible.  They  will  unite  to  insist  that 
proper  attention  be  paid  to  science,  that  disabilities  be  removed, 
and  that  enough  means  be  provided.  The  first  duty  of 
individuals  and  of  nations  is  to  see  to  their  own  efficiency,  and 
the  first  duty  of  science  is  to  see  to  hers. 


THE   SANITARY  AWAKENING    OF    INDIA 

By  SURGEON-GENERAL  SIR   CHARLES  PARDEY   LUKIS,    K.H.S., 

K.C.S.I.,  M.D.,  F.R.C.S. 

Director-General,  Indian  Medical  Service 

In  the  admirable  address  with  which  the  Hon.  Mr.  S.  H.  Butler 
opened  the  proceedings  of  the  First  All-India  Sanitary  Con- 
ference, held  at  Bombay  on  November  13  and  14,  191 1,  he  said  : 
"  The  basis  of  all  sanitary  achievement  in  India  must  be  a 
knowledge  of  the  people  and  the  conditions  under  which  they 
live,  their  prejudices,  their  ways  of  life,  their  social  customs, 
their  habits,  surroundings  and  financial  means." 

This  was  emphasised  by  me  in  a  memorandum  which  I  laid 
upon  the  table  at  the  meeting  of  the  Imperial  Legislative 
Council,  held  at  Simla  on  September  15,  191 1.  In  this 
memorandum,  which  dealt  with  the  measures  taken  for  the 
suppression  of  plague  and  malaria  in  India,  I  pointed  out  that 
although  the  important  discoveries  and  the  vigorous  pro- 
phylactic efforts  that  had  been  made  in  India  had  resulted  in 
a  very  accurate  knowledge  of  the  measures  necessary  for  the 
control  of  the  above-mentioned  diseases,  even  a  modicum  of 
success  in  effective  prevention  could  not  be  hoped  for  unless 
the  people  themselves  were  willing  to  co-operate  whole- 
heartedly in  the  campaign.  I  stated  moreover  that,  in  my 
opinion,  this  active  co-operation  will  not  be  secured  until  the 
people  have  learned  to  understand  and  to  have  faith  in  the 
principles  on  which  these  preventive  measures  are  based,  and 
that  their  education  on  these  matters  is  a  primary  and  essential 
condition  of  success. 

No  one  unacquainted  with  the  conditions  of  life  in  tropical 
or  subtropical  countries  can  have  any  idea  of  the  difficulties  that 
beset  the  path  of  the  sanitary  reformer  in  a  continent  of  such 
vast  size  as  India.  The  illiteracy  of  the  vast  majority  of  the 
population,  their  prejudices,  their  conservatism  and  suspicion 
of  innovation  or  change,  their  fatalism,  and  their  ignorance  and 

disregard  of  the  most  elementary  rules  of  domestic  and  personal 

181 


i82  SCIENCE  PROGRESS 

hygiene,  all  combine  to  form  an  insurmountable  obstacle  to 
rapid  progress  in  sanitary  matters. 

The  life  of  the  Indian  peasant  is  one  long  struggle  with  his 
environment.  The  extremes  of  heat  and  cold  to  which  he  is 
subjected  have  led  to  the  adoption  of  a  type  of  dwelling  which 
from  the  sanitary  standpoint  leaves  everything  to  be  desired. 
The  question  of  ventilation  is  never  considered.  In  both  towns 
and  villages  the  houses,  originally  crowded  together  for  purposes 
of  defence,  still  remain  in  the  same  undesirable  juxtaposition 
even  though  the  necessity  for  crowding  no  longer  exists.  Cattle 
and  other  domestic  animals  live  in  close  contact  with  human 
beings,  and  water  is  used  indiscriminately  for  drinking,  washing, 
and  bathing.  Lastly  it  must  be  remembered  that  more  than 
75  per  cent,  of  the  population  live  "  on  the  land,"  leading  a  hand- 
to-mouth  existence,  and  being  absolutely  dependent  on  climatic 
conditions,  especially  rainfall,  for  their  very  existence.  Is  it 
surprising,  therefore,  that  their  resistance  to  disease  is  lower 
than  that  of  the  European,  or  that,  when  an  epidemic  breaks 
out  amongst  a  community  living  under  such  conditions,  it 
spreads  with  lightning  rapidity,  and  is  difficult  to  control  ? 

What  I  have  written  above  will  enable  the  reader  to 
appreciate  the  enormity  of  the  problems  before  us.  Sanitary 
measures  possible  and  effective  in  the  West  are  not  necessarily 
possible  and  effective  in  India.  We  must  work  out  our  own 
sanitary  salvation.  The  difficulties  before  us  are  many.  The 
ignorance  and  even  hostility  of  the  masses  are  still  fundamental 
obstacles.  But  a  thousand  difficulties  need  not  dismay  us.  On 
all  sides  there  is  evidence  that  the  more  enlightened  minds  in 
India  have  awakened  to  the  importance  of  sanitation,  and  the 
movement  in  its  favour  is  steadily  gaining  ground.  Both  in 
the  Council  Chamber  and  in  the  columns  of  the  Indian  Press 
constant  demands  are  made  for  the  three  great  essentials — pure 
water,  pure  food,  and  pure  air,  and,  as  the  Hon.  Mr.  Sivasawmy 
Iyer  said  in  a  recent  speech,  a  very  hopeful  feature  in  the 
situation  is  that  the  sanitary  consciousness  of  the  people  them- 
selves has  been  aroused. 

This  sanitary  awakening  of  India  I  regard  as  one  of  the  most 
important  developments  of  recent  years,  and  one  which  is 
fraught  with  infinite  possibilities  for  the  future.  Once  we  have 
the  people  with  us,  instead  of  against  us,  the  work  of  sanitary 
reform  will  advance  by  leaps  and  bounds,  especially  as  regards 


THE  SANITARY  AWAKENING  OF   INDIA        183 

the  avoidance,  prevention,  and  suppression  of  those  four  great 
scourges — plague,  malaria,  cholera,  and  dysentery — in   dealing 
with    which    we     are     hopelessly     handicapped     without    the 
assistance  and  co-operation  of  the  Indian  public.     Herein  lies 
the   importance   of  education   of  the   masses.     I  shall   devote, 
therefore,    a   few   lines   to   a   short   account   of    certain   recent 
developments  in  the  educational  policy  of  the  Government  of 
India,  to  which   allusion   was  made  by  Mr.  Montague   in  his 
Indian  Budget  speech  on  August  7  last.      In  a  resolution  dated 
February  21,  191 3,  the  Government  of  India  drew  attention  to 
three  matters  in  which  education  in  the  past  has  been  imperfect. 
One   of  these  was   the   teaching  of  hygiene    in    schools    and 
colleges,  and  attention  to  the  personal  hygiene  of  the  students. 
With   a   view    to    remedying    obvious    defects    and    ensuring 
practical  instruction,  the  Education  Department  has  commended 
to  local  Governments  a  thorough  inquiry,  by  a  small  committee 
of  experts,  into  school  and  college  hygiene ;  the  scope  of  the 
inquiry  to   comprehend   not    merely   medical    inspection,    but 
likewise   the   inclusion   of  practical   instruction.      For   various 
reasons  it  is   considered   desirable   to   make   these   courses   of 
instruction  voluntary,  at  any  rate  in  collegiate  institutions,  and 
it  is  felt  that  if  such  courses  are  voluntary  it  would  be  as  well  to 
introduce  the  influence  of  some  external  agency,  which  by  its 
reputation  and  its  rewards  will  be  able  to  encourage  private 
endeavour.      Such  an   agency  already   exists  in   the   St.  John 
Ambulance  Association,  which  might  well  provide  the  initial 
stimulus,  appealing  strongly,  as  it  does,  to  both  teachers  and 
taught.     Domestic  hygiene  is  now  a  recognised  branch  of  the 
Association's  work,   and  on  this  subject  useful  literature   and 
instruction  could  be  supplied   to  the   schools.     Instruction   in 
"  first-aid "   might   also   be   given,   and   active   workers   in    the 
provincial  branches  of  the  Association  would  be  encouraged  to 
afford   assistance   in   the   inspection   of  pupils   and    of    school 
premises,    and    in   giving   practical   instruction   in   all   matters 
connected  with  personal   hygiene.     It   is   also   suggested    that 
special  training  in  hygiene  should  form  part  of  the  curriculum 
for  teachers. 

The  practical  details  of  the  scheme  will  be  worked  out  when 
reports  have  been  received  from  the  Committees  of  Inquiry 
which  may  be  appointed  by  local  Governments  :  meanwhile  the 
Government  of  India  have  approached  the  Executive  Committee 


1 84  SCIENCE  PROGRESS 

of  the  Indian  Council  of  the  St.  John  Ambulance  Association, 
saying  that  they  would  be  glad  to  receive  their  views  on  the 
points  raised,  and  asking  whether  the  Executive  Committee  are 
willing  that  the  Association  should  be  enlisted  in  a  work  which 
it  is  believed  may  ultimately  prove  one  of  far-reaching  importance 
in  India. 

As  a  member  of  the  Executive  Committee  of  the  Indian 
Council,  I  know  that  this  matter  has  already  engaged  their 
serious  attention.  I  have  also  had  an  opportunity  of  discussing 
the  case  informally  with  the  authorities  at  St.  John's  Gate,  so 
that  I  have  no  doubt  as  to  the  favourable  nature  of  the  reply 
which  will  be  sent  to  the  Government  of  India,  and  I  am  con- 
fident that,  in  the  near  future,  we  shall  be  able  to  work  out  a 
scheme  which  will  have  a  lasting  effect  upon  the  welfare  of 
future  generations  of  our  Indian  fellow-subjects,  not  only  by  in- 
creasing their  knowledge  of  preventive  measures,  but  also  by 
improving  their  general  standard  of  health  and  raising  their 
powers  of  resistance  against  disease. 

Meanwhile  the  Government  of  India  is  actively  engaged  not 
only  in  remedying  sanitary  defects,  but  in  studying  the  condi- 
tions and  circumstances  which  affect  mortality  and  the  increase 
and  decrease  of  populations,  as  well  as  the  relative  effects  of 
personal  environment  and  of  the  social  and  economic  conditions 
in  the  different  parts  of  the  Indian  Empire.  Want  of  space 
prevents  me  from  discussing  the  various  recurring  and  non- 
recurring grants  made  under  the  head  of  Sanitation  or  from 
enumerating  the  numerous  important  sanitary  schemes  which 
have  been  carried  out  during  the  past  few  years.  It  will  suffice 
if  I  state  that  during  this  year  and  last  year  recurring  grants  of 
£261,000  and  non-recurring  grants  of  nearly  £1,500,000  have  been 
made,  the  bulk  of  which  are  intended  for  schemes  of  urban 
sanitation  ;  also  that  the  Budget  estimate  of  expenditure  under 
this  head  for  the  current  year  comes  to  nearly  £2,000,000,  show- 
ing an  increase  of  112  per  cent,  over  the  expenditure  of  three 
years  ago.  Nor  have  the  claims  of  rural  areas  been  overlooked. 
Assignments  have  been  made  to  local  Governments  to  enable 
them  to  forgo  the  amounts  which  at  present  are  appropriated 
for  provincial  use  from  the  cess  on  land.  This  will  increase  the 
resources  at  the  disposal  of  local  bodies,  and  it  is  hoped  that  it 
will  lead  to  a  great  improvement  in  village  sanitation  and  especi- 
ally to  the  provision  of  a  pure  water  supply  and  its  adequate 


THE  SANITARY  AWAKENING  OF   INDIA       185 

protection  from  pollution.  For  further  details  I  must  refer  the 
reader  to  the  Annual  Reports  of  the  Sanitary  Commissioner 
with  the  Government  of  India  and  to  the  various  Blue  Books 
presented  to  the  House  of  Commons,  and  I  shall  devote  the 
remainder  of  this  article  to  a  description  of  the  work  done  by 
the  General  Malarial  Committee  and  the  Indian  Research  Fund, 
and  to  an  account  of  the  inauguration  of  the  All-India  Sanitary 
Conferences  and  the  reorganisation  of  the  sanitary  services. 

The  General  Malarial  Committee  owes  its  origin  to  the  Im- 
perial Malarial  Conference  held  at  Simla  in  October  1909.  Its 
duties  are  the  direction  and  co-ordination  of  investigations  and 
the  selection,  at  the  request  of  local  Governments,  of  officers 
qualified  for  carrying  out  such  investigations.  A  similar 
organisation,  working  in  consultation  with  this  Central  Com- 
mittee, is  constituted  in  each  province,  and  a  conference  consist- 
ing of  the  members  of  the  Central  Committee  and  a  delegate  or 
delegates  from  each  local  organisation  is  held  annually  at  such 
place  as  may  be  convenient  for  the  purpose  of  reviewing  the 
work  done  and  preparing  a  programme  of  future  work.  Up  to 
the  present  three  conferences  have  been  held,  namely  at  Simla 
in  1909,  at  Bombay  in  191 1  and  at  Madras  in  1912,  and  the  fourth 
conference  will  be  held  at  Lucknow  in  January  1914.  The  value 
of  these  conferences  has  been  proved  by  the  interesting  nature 
of  the  discussions  that  have  taken  place,  by  the  opportunities 
afforded  to  delegates  of  studying  malaria  under  varying  condi- 
tions, by  the  stimulus  given  to  original  work,  and  by  the  valuable 
resolutions  that  have  been  passed  and  brought  to  the  notice  of 
Government.  It  is  not  necessary  to  give  all  these  resolutions 
in  detail,  but  the  following  summary  of  the  conclusions  arrived 
at  may  be  of  interest : 

(1)  Careful  malarial  surveys  such  as  those  made  by  Robert- 
son and  Graham  in  Saharanpur,  Kosi  and  Nagina,  and  researches 
in  the  field  such  as  those  carried  out  by  Bentley  in  Bombay  and 
Christophers  in  the  Andamans,  prove  the  value  of  preliminary 
scientific  investigation,  and  point  to  the  probability  that  anti- 
mosquito  measures  may  not  prove  so  costly  as  was  at  one  time 
feared.  Moreover,  although  further  research  and  expert  in- 
vestigation is  still  necessary,  enough  is  known  of  the  breeding 
habits  of  mosquitos,  etc.,  to  make  it  frequently  possible  for 
trained  workers  to  deal  with  malaria  in  an  efficient  manner. 

(2)  Quinine  prophylaxis,   applied   to   a  free  population,    is 


1 86  SCIENCE  PROGRESS 

difficult  to  carry  out  in  the  thorough  way  necessary  for  success, 
but  notwithstanding  these  difficulties  it  cannot  be  too  strongly 
emphasised  that  arrangements  for  the  treatment  by  quinine  of 
those  sick  from  malaria  is  a  matter  of  primary  importance  from 
the  point  of  view  of  saving  life,  of  preventing  suffering,  and  of 
destroying  a  potent  source  of  infection.  On  the  other  hand  ex- 
perience in  the  United  Provinces  and  elsewhere  has  shown  that 
the  regular  administration  of  quinine  to  school-children  during 
the  malarial  season  is  a  practical  measure  of  proved  utility  and 
easy  application. 

(3)  In  view  of  the  correlation  which  certain  observers  have 
found  to  exist  between  density  of  jungle  in  and  around  villages 
on  the  one  hand  and  intensity  of  malaria  on  the  other  it  is 
desirable  that  this  question  should  receive  the  careful  attention 
of  all  those  working  at  malaria  in  India. 

(4)  In  view  of  the  fact  that  investigation  has  shown  that  the 
cultivation  of  rice  and  other  crops,  for  which  an  abundance  of 
water  is  necessary  during  growth,  need  not  lead  to  the  forma- 
tion of  dangerous  breeding  grounds  for  mosquitos,  it  is  desirable 
in  the  interests  of  the  Indian  agriculturist  to  ascertain  definitely 
the  precise  conditions  under  which  such  cultivation  is  or  is  not 
likely  to  be  harmful. 

(5)  Further  research  is  necessary  with  a  view  to  ascertaining 
the  most  effective  larvaecides  and  natural  enemies  of  the  mos- 
quito, and  which  of  them  are  best  suited  for  use  in  particular 
localities  and  under  different  conditions  of  environment.  It  is 
desirable,  moreover,  to  consider  the  advisability  of  constructing 
ponds  in  centres  where  permanent  water  can  be  obtained  for 
the  breeding  on  a  large  scale  and  the  distribution  of  the  more 
important  of  the  natural  enemies  of  mosquito  larvae. 

Other  resolutions  deal  with  such  subjects  as  educational 
propaganda,  borrow-pits,  water-tidiness,  and  the  provision  of  a 
pure  and  protected  water  supply.  But  it  must  not  be  imagined 
that  the  functions  of  the  General  Malarial  Committee  begin  and 
end  in  the  passing  of  pious  resolutions  at  conferences.  On 
the  contrary  it  is  doing  much  practical  work,  and  its  organisa- 
tion has  been  materially  strengthened  by  the  appointment  of 
special  malarial  officers  in  Madras,  Bengal,  the  United  Provinces, 
the  Central  Provinces,  the  Punjab  and  Burmah.  A  Central 
Malarial  Bureau,  consisting  of  a  museum,  a  laboratory,  and  a 
reference  library,  under  the  charge  of  Major  Christophers,  has 


THE  SANITARY   AWAKENING  OF   INDIA        187 

been  started  at  the  Central  Research  Institute,  Kasauli,  where 
a  very  fine  collection  of  mosquitos  and  their  natural  enemies 
has  now  been  arranged  and  is  available  for  study.     We  have 
also   organised    classes    of    instruction    in   malarial   technique. 
These  classes  meet  twice  a  year,  and  the  course  lasts  for  two 
months.     During  the  last  two  years  the  system  of  these  classes 
has  been  modified  so  as  to  make  them  more  practical  and  to 
render  it  possible  for  any  medical  officer  or  subordinate,  who  is 
seriously  desirous  of  studying  malaria,  to  gain  admission  to  one 
of  the  classes,  and  it  is  hoped  that  ere  long  this  will  result  in  a 
large  number  of  competent  and  keenly  active  workers  being 
spread  over  the  country — a  result  which  cannot  fail  to  bring  about 
a  great  increase  in  our  knowledge,  not  only  of  malaria,  but  of 
other  closely  allied   diseases,  especially  those   of  the  "  Leish- 
mania"  group.     In  191 1  only  18  officers  were  trained  at  these 
classes,   all  from    the    civil    side.     During   19 12,   however,  we 
trained    57   candidates,   of  whom   27   were   in   civil   and    30   in 
military   employ;    whilst   in    1913  we   admitted  64  candidates, 
32  military  and  32  civil.     In  conformity  too  with  the  practical 
aspect  of  our  policy  we  arranged  that  the  last  two  classes,  instead 
of  meeting  at  Amritsar,  should  be  held  at  Delhi,  where  Captain 
Hodgson,  who  was  officiating  for  Major  Christophers,  was  con- 
ducting a  detailed  malarial  survey  of  the   Imperial  enclave — a 
survey  which,  by  the  way,  proved  of  the  greatest  value  to  the 
authorities  when  they  had  to  decide  upon  the  site  for  the  new 
Imperial  Delhi.     Thus  Captain  Hodgson's  pupils  have  actually 
participated    in  a  malarial   survey,  and   are!  fully  equipped  for 
carrying  on  similar  work  in  their  own  districts. 

There  are  at  the  present  moment  eight  officers  on  special 
duty  in  different  parts  of  India,  studying  the  local  conditions 
which  underlie  and  are  causing  the  malaria  and  devising  schemes 
for  its  reduction  or  abolition.  The  Government  of  India  has  set 
aside  a  sum  of  five  lakhs  for  anti-malarial  purposes,  and,  from 
this,  special  grants  have  been  made  for  such  investigations,  and 
as  schemes  have  been  prepared,  further  grants  have  been  given 
either  to  cover  their  full  cost  or  to  assist  in  bringing  them 
into  effect,  the  guiding  principle  being  as  far  as  possible  to 
recommend  expenditure  only  upon  schemes  which  preliminary 
investigations  have  shown  to  be  likely  to  accomplish  definite 
results.  Thus  to  Madras  Rs.  28,000  has  been  given  for  a 
malarial  survey  in  Ennore,  and  to  Bombay  Rs.  50,000  to  assist 


188  SCIENCE  PROGRESS 

in  carrying  out  Bentley's  recommendations  for  the  prevention  of 
malaria  in  Bombay  City.  Two  other  investigations — one  in 
Sind  and  the  other  in  the  Canara  district — are  also  in  progress 
in  the  Bombay  Presidency,  and  for  these  a  grant  of  Rs.  21,380 
has  been  made. 

In  the  United  Provinces  malarial  surveys  have  been  under- 
taken in  the  towns  of  Saharunpur,  Nagina,  Kosi,  Kairana,  and 
Meerut,  and  recommendations  have  been  made  for  each  place. 
In  Saharunpur,  Nagina,  and  Kosi  an  active  anti-mosquito 
campaign  is  now  being  carried  out  with  the  aid  of  a  grant  of 
Rs.  1,80,000  from  the  Government  of  India,  but  the  schemes  for 
Meerut  and  Kairana  were  still  under  consideration  when  I  left 
India  in  April  last. 

In  the  Punjab  Rs.  35,000  has  been  allotted  for  anti-malarial 
measures  at  Palwal,  which   lies  in  a  specially  malarious  tract. 
The  list  of  work  in  progress  is  a  fairly  satisfactory  one,  but  it  is 
the  intention  of  Government  to  extend  their  operations  to  other 
places  as  soon  as  funds  and  men  are  available.     In  Bengal  the 
conditions  are  very  different  from  those  in  other  parts  of  India, 
and   Stewart  and  Proctor  have  shown  that  in   Lower  Bengal 
there  is  a  close  connection  between  over-vegetation  and  intensity 
of  malaria — in  which  respect  they  are  in  close  agreement  with 
the  findings  of  Watson  in  Malaya.     At  the  suggestion  of  the 
Government  of  India,  the  Government  of  Bengal  has  taken  the 
matter  up,  and  a  grant  of  Rs.  50,000  has  been  allotted  to  them 
for  carrying  out  an  extensive  experiment  of  jungle-clearing  in 
the  vicinity  of  inhabited  areas.     Should  this  experiment  prove 
successful  we  shall  have  at  our  disposal  one  method,  at  least,  of 
improving  the  conditions  obtaining  in  small  villages,  specially 
those  in  the  deltaic  area.     Indeed,  I  am  of  opinion  that  if  with 
systematic  clearing  of  jungle  we  combine  the  provision  of  a  pure 
water   supply,    water -tidiness,    the   preservation    of  mosquito 
destroyers,  and  the  distribution  of  quinine,  it  may  be  possible  to 
achieve  wonderful  results  in  rural  areas  where  financial   con- 
siderations and  the  physical  conditions  render  elaborate  drainage 
schemes  practically  impossible.     For  this  reason  I  have  noted 
with  much  pleasure  the  formation  at  Jessore  of  a  Coronation 
Anti-malarial  Society  which  intends  to  work  in  villages  on  lines 
very  similar  to  those  indicated  above,  and  I  congratulate  Rai 
Jadunath  Mazumdar  Bahadur  on  its  inception.     It  is  yet  another 
sign  of  that  sanitary  awakening  to  which  I  have  alluded  above, 


THE   SANITARY  AWAKENING  OF   INDIA        189 

and  I  trust  that  it  marks  the  beginning  of  that  co-operation  of 
the  public,  upon  the  necessity  for  which  I  have  insisted  so 
frequently,  and  without  which  we  can  never  hope  to  achieve  a 
victory  in  our  campaign  against  malaria. 

But,  although  jungle-clearing  may  prove  useful  in  flat 
country,  it  is  doubtful  whether  it  will  avail  in  hilly  tracts 
intersected  by  ravines.  Watson  has  found  it  useless  in  Malaya, 
and  Major  Perry,  as  the  result  of  his  investigations  in  the 
Jeypore  Hill  Tracts,  confirms  these  conclusions.  In  a  paper 
which  he  read  before  the  last  Malarial  Conference  he  showed 
that,  whereas  on  the  3,000  ft.  plateau,  jungle-clearing  produces 
little  obvious  effect,  on  the  2,000  ft.  plateau  the  conditions  are 
different,  and  he  believes  that  in  this  situation  the  proper 
clearing  of  jungle  gives  hope  of  the  practical  eradication  of 
malaria. 

Much  important  work  has  been  done  in  India  in  connection 
with  the  stocking  of  pools  and  tanks  with  mosquito  destroyers, 
and  the  observations  of  Sewell  and  Chaudhri  in  Calcutta,  of 
Glen  Liston  in  Bombay,  and  of  Wilson  in  Madras  have  shown 
that  this  need  not  be  an  expensive  or  troublesome  task.  It  is 
not  necessary  thatiwe  should  import  the  much-vaunted  "millions" 
from  Barbadoes ;  we  have  in  India  numerous  fish  of  proved 
utility  as  mosquito  destroyers,  especially  species  belonging  to 
the  four  genera  Haplochilus,  Ambassis,  Trichogaster,  and 
Nuria. 

The  credit  for  the  inception  o{  the  Indian  Research  Fund  Asso- 
ciation, which  was  established  in  191 1,  is  due  to  the  late  Lieut- 
Col.  Leslie,  Sanitary  Commissioner  with  the  Government  of 
India,  whose  untimely  death  has  deprived  of  a  valued  colleague 
all  those  interested  in  the  cause  of  sanitation  in  the  East.  The 
objects  of  the  Association  are  the  prosecution  and  assistance  of 
research,  the  propagation  of  knowledge,  and  experimental 
measures  generally,  in  connection  with  the  causation,  mode  of 
spread,  and  prevention  of  communicable  diseases.  The  nucleus 
of  the  fund  was  a  grant  of  five  lakhs  from  the  Government  of 
India,  to  which  a  similar  amount  has  since  been  added,  and  the 
control  and  management  of  the  Association  are  vested  in  a 
governing  body  the  president  of  which  is  the  Honourable 
Member  in  charge  of  the  Education  Department.  The  Governing 
Body  is  assisted  by  a  "  Scientific  Advisory  Board,"  of  whom  not 
less  than  three  are  members  of  the  governing  body.  They  examine 


190  SCIENCE  PROGRESS 

all  proposals  in  connection  with  the  scientific  objects  of  the 
Association  and  report  as  to  their  feasibility.  The  members  of 
this  board  are  appointed  for  one  year,  but  are  eligible  for 
re-election,  and  they  have  power  to  add  to  their  number.  The 
present  members  are  the  Director-General  Indian  Medical 
Service,  the  Sanitary  Commissioner  with  the  Government  of 
India,  the  Director  of  the  Central  Research  Institute  at  Kasauli, 
the  officer  in  charge  of  the  Central  Malarial  Bureau,  and  the 
Assistant  Director-General  Indian  Medical  Service  (Sanitary), 
and  Sir  Ronald  Ross  has  been  elected  an  honorary  consulting 
member  of  the  board. 

The  scientific  objects  of  the  Association  are  carried  out  with 
the  aid  of  "Working  Committees,"  appointed  by  and  acting 
under  the  direction  of  the  Scientific  Advisory  Board — an 
arrangement  which  ensures  proper  correlation  of  research  and 
prevents  overlapping. 

Under  the  auspices  of  this  Fund,  exhaustive  inquiries  into 
various  problems  connected  with  Kala  Azar,  Yellow  Fever, 
Plague,  Relapsing  Fever,  Cholera,  and  Dysentery  have  been  con- 
ducted by  specially  selected  officers,  and  several  interesting  and 
important  discoveries  have  been  made. 

Kala  Azar. — The  researches  into  this  disease  have  been 
carried  out  under  the  direction  of  a  Working  Committee  con- 
sisting of  Surgeon-Gen.  Bannerman,  Lieut.-Col.  Donovan, 
Major  Christophers,  and  Dr.  Bentley,  the  chief  points  under 
consideration  being  the  possible  antagonism  between  Oriental 
Sore  and  Kala  Azar,  and  the  question  of  the  carrier  and 
reservoir  of  the  parasite  of  that  disease.  The  actual  investiga- 
tions have  been  entrusted  to  Captains  Patton  and  Mackie  and 
Dr.  Korke,  the  division  of  labour  being  as  follows :  Captain 
Mackie  has  conducted  an  epidemiological  inquiry  into  the 
distribution  and  prevalence  of  Kala  Azar  in  Assam,  where  the 
conditions  for  the  spread  of  the  disease  appear  to  be  peculiarly 
favourable.  Captain  Patton  and  Dr.  Korke  have  worked  in 
Madras,  the  former  devoting  himself  chiefly  to  laboratory 
experiments,  whilst  Dr.  Korke  undertook  the  investigation  of 
the  disease  in  the  endemic  area  at  Royapuram.  Patton's  results 
are  well  known.  He  has  undoubtedly  proved  that  under  certain 
definite  conditions  the  parasite  of  Kala  Azar  undergoes  its  full 
cycle  of  development  in  the  body  of  the  bug :  he  has  not,  how- 
ever, succeeded  in  transmitting  the  disease  from  one  animal  to 


THE  SANITARY  AWAKENING  OF   INDIA        191 

another.  The  difficulty,  of  course,  is  to  obtain  a  susceptible 
animal  for  the  transmission  experiments,  but  we  hope  that  this 
difficulty  will  soon  be  surmounted.  As  the  result  of  his 
investigations  in  Royapuram,  Dr.  Korke  has  discovered  the 
interesting  fact  that  the  disease  is  not  strictly  speaking  a  house- 
infection,  but  that  it  tends  to  cling  to  communities  having  close 
social  relations  with  one  another.  Another  valuable  experiment 
is  that  made  by  Colonel  Donovan,  in  which  he  succeeded  in 
infecting  an  Indian  dog  with  the  disease,  the  post-mortem 
examination  showing  extensive  infection  of  the  bone-marrow, 
whilst  the  liver  and  spleen  were  apparently  healthy.  This 
renders  it  necessary  that  we  should  reconsider  our  position  as 
regards  Indian  dogs,  and  I  am  of  opinion  that  a  further  series  of 
observations,  with  examination  of  the  bone-marrow,  will  be 
necessary  before  we  can  say  with  confidence  that  the  Indian  dog 
is  immune  to  "  Leishmania  Donovani,"  and  these  observations 
are  all  the  more  necessary  in  view  of  the  opinion  expressed  by 
Laveran  and  Nicolle,  in  their  recent  paper  read  before  the 
International  Medical  Congress,  as  to  the  probable  identity  of 
the  Mediterranean  and  Indian  forms  of  the  disease.  It  has  been 
decided,  therefore,  to  continue  the  inquiry  for  another  year,  both 
by  laboratory  experiments  and  investigations  in  the  field. 

Yellow  Fever. — In  view  of  the  opening  of  the  Panama  Canal, 
it  was  considered  to  be  of  importance  that  prior  to  the  actual 
opening  the  Government  of  India  should  obtain  definite  first- 
hand information  regarding  the  conditions  in  Central  America, 
where  Yellow  Fever  is  endemic,  and  in  the  principal  ports 
between  Central  America  and  India,  to  admit  of  adequate 
measures  being  devised  to  prevent  the  introduction  of  the 
disease  into  India.  Accordingly,  in  October  191 1  Major  S.  P. 
James,  I. M.S.,  was  deputed,  at  the  cost  of  the  Research  Fund,  to 
proceed  to  the  endemic  area  by  the  route  that  will  be  followed 
by  ships  coming  to  India  when  the  Canal  is  opened.  Major 
James  returned  to  India  last  November  and  submitted  a  most 
interesting  and  valuable  report,  which  is  now  under  con- 
sideration. After  a  careful  study  of  the  trade  routes,  he  is  of 
opinion  that  the  immediate  danger  to  India  on  the  opening  of 
the  Panama  Canal  is  not  as  great  as  was  anticipated  originally. 
His  chief  reasons  for  his  view  are  (1)  that  the  very  thorough 
precautions  taken  at  Honolulu,  which  is  the  first  port  of  call  for 
the  Transpacific  voyage  to  the  East,  affords  a  strong  protection 


192  SCIENCE  PROGRESS 

against  the  infection  of  Asia  and  the  East  Indies,  and  (2)  that,  on 
the  usual  route  to  Hong  Kong,  ships  after  leaving  Honolulu 
pass  northwards  into  latitudes  not  as  a  rule  favourable  to  the 
life  of  the  mosquito,  so  that  there  is  little  likelihood  at  present  of 
the  introduction  of  infected  mosquitos  into  our  ports.  This, 
however,  does  not  justify  the  conclusion  that  no  action  is  neces- 
sary at  this  stage.  Major  James  has  made  many  important 
recommendations  which  are  now  under  consideration.  Mean- 
while, an  active  "  Stegomyia"  survey  has  been  made  of  our  chief 
Indian  ports  by  specially  selected  officers  who  had  undergone  a 
preliminary  training  by  Mr.  Howlett  at  Pusa,  the  object  of  the 
survey  being  to  prove  whether  or  no  the  extermination  of  this 
mosquito  or  its  reduction  to  non-dangerous  numbers  in  our  sea- 
ports is  really  practicable.  So  far  the  preliminary  reports  are 
very  encouraging.  They  show  that  Stegomyia  fasciata  is 
essentially  a  domestic  mosquito,  breeding  in  small  collections  of 
stagnant  water  within  house  limits,  so  that  its  extermination  is 
largely  a  question  of  home  sanitation,  and  not  one  involving 
extensive  drainage  operations.  But  from  the  observations  made 
it  is  clear  that  the  problem  is  not  quite  so  simple  as  it  appears. 
We  can  easily  deal  with  discarded  tins,  bottles,  etc.,  but  if  we  are 
to  attain  success,  it  is  necessary  that  arrangements  should  be 
made  for  a  continuous  water  supply  to  the  houses  in  the  poorest 
localities,  thus  obviating  the  necessity  for  water-storage  in 
houses,  for  it  is  the  receptacles  for  such  storage  which  con- 
stitute the  most  important  breeding  grounds  of  this  mosquito. 
This  point  is  now  under  consideration.  I  may  also  mention 
that,  at  the  suggestion  of  the  Government  of  India,  the  Govern- 
ment of  Ceylon  has  arranged  to  conduct  a  similar  survey  of  the 
principal  ports  in  the  island,  and  that  for  this  purpose  the 
services  of  Major  S.  P.  James,  on  his  return  from  Panama,  have 
been  lent  temporarily  to  the  Colonial  Government. 

Plague. — Space  will  not  permit  of  a  discussion  of  the  many 
problems  associated  with  this  disease.  There  is,  however,  one 
point  on  which  I  wish  to  lay  stress,  and  that  is  the  large  part 
played  in  the  spread  of  plague  by  grain  stores  and  grain 
markets.  Captain  White,  I. M.S.,  in  a  paper  read  before  the  last 
All-India  Sanitary  Conference,  showed  clearly  that  there  is  a 
close  correlation  between  the  import  of  grain  into  each  trade 
block  and  the  amount  of  plague  from  which  such  areas  have 
suffered  in  the  past.     Experiments  have  therefore  been  made  at 


THE  SANITARY  AWAKENING  OF   INDIA        193 

the  Bacteriological  Laboratory,  Parel,  with  a  view  to  solving 
the  problem  of  the  disinfection  of  grain  in  bulk.  There  experi- 
ments have  proved  encouraging  under  laboratory  conditions, 
but  the  Scientific  Advisory  Board  consider  it  necessary  to  carry 
out  a  practical  experiment  of  disinfection  of  grain  on  a  larger 
scale,  and  for  this  purpose  a  sum  of  Rs.  1,000  has  been  sanc- 
tioned from  the  Research  Fund.  The  experiment  is  being 
carried  out  by  Major  Glen  Liston,  and  we  await  his  report. 

Relapsing  Fever. — Most  people  are  under  the  impression  that 
this  disease  has  practically  died  out  in  India,  but  Government 
has  known  for  some  time  that  small  outbreaks  occur  frequently 
in  certain  districts  in  the  United  Provinces.  They  are  not 
serious,  and  there  are  reasons  for  believing  that  the  disease  is 
endemic  in  the  villages  of  the  Jumna  Kadir,  where  it  is  usually 
unrecognised  and  treated  as  malaria.  In  the  spring  of  last  year 
the  death-rate  was  noticed  to  be  rising  in  the  Meerut  district, 
and  it  was  presumed  at  first  to  be  due  to  plague.  The  compara- 
tively low  mortality,  however,  aroused  suspicion,  and  the 
examination  of  blood  films  revealed  typical  Spirochaetse,  whilst 
subsequent  investigation  showed  that  some  seventy  villages 
were  infected  with  relapsing  fever.  At  the  request  of  the  local 
Government,  the  governing  body  of  the  Research  Fund  have 
deputed  Captain  Brown  from  the  Central  Research  Institute, 
Kasauli,  to  proceed  to  the  United  Provinces  to  investigate  the 
causes  of  the  recent  outbreak.  He  will  also  endeavour  to  con- 
firm the  recent  observations  of  Nicolle  as  to  the  exact  mechanism 
of  transmission  by  the  body-louse,  which,  as  Captain  Mackie 
was  the  first  to  demonstrate,  is  known  to  be  the  carrier  of  the 
disease. 

Cholera. — Major  Greig,  I. M.S.,  working  at  Calcutta  and  Puri, 
has  during  the  year  carried  out  a  most  important  series  of 
observations.  He  has  shown  that  we  can  no  longer  regard 
cholera  merely  as  a  water-borne  disease.  The  cholera  vibrio 
will  live  for  a  long  time  in  the  gall  bladder,  and  it  is  certain  that 
not  only  cholera  convalescents  but  also  healthy  persons  who 
have  been  in  contact  with  cholera  cases  can  act  as  "  carriers." 
Major  Greig  also  incriminates  flies.  His  researches  will  be 
continued  for  another  year,  and  we  trust  that  his  discoveries 
will  prove  of  much  value  to  the  committee  which,  under 
the  presidentship  of  the  Sanitary  Commissioner  with  the 
Government  of  India,  is  now  inquiring  into  the  possibility 
13 


t94  SCIENCE  PROGRESS 

of  improving  the  sanitary  arrangements  at  the  different  pilgrim 
centres. 

It  is  also  proposed  to  depute  a  second  officer  to  study  various 
problems  in  connection  with  the  life-history  of  the  cholera  vibrio 
outside  the  human  body. 

Dysentery. — As  regards  this  disease,  which  is  the  cause  of  so 
much  sickness  and  mortality  throughout  India  generally,  and 
specially  in  Eastern  Bengal  and  the  Andamans,  much  un- 
certainty and  doubt  still  exist  as  to  the  causation  of  its  different 
varieties,  especially  the  bacillary  forms.  It  has  been  decided 
therefore  that  the  whole  subject  shall  be  carefully  and  thoroughly 
investigated  by  Captain  Cunningham,  Assistant  Director,  Central 
Research  Institute,  who  has  been  placed  on  special  deputation 
for  that  purpose. 

Water  Analysis. — It  is  obvious  that  in  dealing  with  water- 
borne  diseases  we  must  be  in  a  position  to  say  definitely  whether 
or  no  a  given  sample  of  water  is  fit  for  human  consumption. 
This  is  a  point  on  which  there  is  much  difference  of  opinion.  It 
is  recognised  that  the  bacteriological  standards  fixed  for  England 
are  not  always  reliable  in  India.  Moreover,  samples  of  water 
sent  to  distant  laboratories,  especially  during  the  hot  months, 
are  liable  to  undergo  decomposition  en  route,  and  thus  the  analysis 
may  be  of  little  or  no  value.  It  has  been  decided,  therefore,  to 
hold  an  exhaustive  inquiry  into  the  whole  subject  with  a  view  to 
settling  (a)  what  are  the  most  suitable  methods  of  water 
analysis,  (b)  is  it  possible  to  fix  definite  bacteriological  standards 
for  India,  and  (c)  what  are  the  best  methods  of  conveying 
samples  of  water  to  distant  laboratories. 

The  Journal  of  Indian  Medical  Research. — Under  the  above 
title,  a  quarterly  journal  will  be  published,  the  first  number  of 
which  is  now  in  the  press.  It  will  be  edited  by  the  Director- 
General  Indian  Medical  Service  and  the  Sanitary  Commissioner 
with  the  Government  of  India,  and  it  will  contain  full  accounts 
and  reports  of  all  work  done  under  the  auspices  of  the  Indian 
Research  Fund.  There  will  be  special  sections  for  malaria, 
medical  entomology,  protozoology,  etc.,  and  all  original  com- 
munications will  be  welcomed.  Such  a  journal  will,  we  think, 
serve  a  useful  purpose — it  will  take  the  place  of  "  Paludism,"  and 
in  it  will  be  included  many  of  the  shorter  papers  by  officers  of 
the  Indian  Medical  Service  which  are  not  of  sufficient  length  to 
justify  publication  as  separate  "Scientific  Memoirs." 


THE  SANITARY  AWAKENING  OF   INDIA        195 

I  can  only  deal  very  briefly  with  the  subject  of  the  All-India 
Sanitary  Conferences.  The  first  of  these  was  held  in  Bombay 
in  November  191 1,  and  the  second  in  Madras  in  November  1912, 
whilst  the  third  will  meet  in  Lucknow  in  January  1914.  Their 
popularity  may  be  judged  from  the  fact  that  whereas  at  the  first 
conference  twenty-nine  delegates  attended  and  the  proceedings 
lasted  for  only  two  days,  at  the  second  conference  seventy-three 
delegates  were  present  and  the  proceedings  extended  over  a 
week,  with  both  morning  and  afternoon  sittings.  For  further 
information  as  to  the  subjects  discussed  and  the  important 
resolutions  passed,  I  must  refer  the  reader  to  the  published  Pro- 
ceedings. All  I  wish  to  say  here  is  that  the  value  of  these 
conferences  lies  not  so  much  in  the  conclusions  reached  as  in  the 
opportunity  which  they  afford  of  informing  and  interesting  the 
public,  and  of  interchange  of  views  between  men  working  under 
varying  conditions  in  isolated  parts  of  India.  I  have  already 
pointed  out  that  sanitary  measures  possible  and  effective  in  the 
West  may  not  be  suited  to  Indian  conditions.  Similarly  it  must 
be  clearly  understood  that  there  cannot  be  one  sanitary  pro- 
gramme for  all  India.  Sanitation  is  rightly  decentralised,  and  it 
is  only  by  the  examination  of  results  obtained  under  differing 
conditions  that  we  can  arrive  at  definite  conclusions  as  to  what 
is  suitable  for  a  particular  locality.  That  is  why  the  conference 
is  held  each  year  in  a  different  place.  The  last  two  meetings 
have  been  in  large  presidency  cities  ;  the  next  will  be  in  an 
up-country  town,  where  I  need  hardly  remark  the  conditions  are 
very  different  from  those  existing  in  Madras  and  Bombay. 

In  conclusion  I  must  say  a  few  words  about  the  reorganisation 
of  the  sanitary  services  in  India.  In  191 2  the  Government  of 
India  decided  to  create  eight  additional  appointments  of  Deputy 
Sanitary  Commissioner.  As  these  posts  did  not  fully  meet  the 
needs  of  the  provinces,  the  Secretary  of  State  for  India  has 
recently  approved  of  the  addition  of  four  appointments  to  this 
class. 

The  twelve  appointments  will  be  allotted  as  follows  :  three 
to  Bengal,  two  each  to  Madras,  the  United  Provinces  and  Behar 
and  Orissa,  and  one  each  to  the  Punjab,  the  North-West 
Frontier  Province,  and  Burmah. 

For  the  present  three  of  the  twelve  appointments  will  be  held 
by  officers  of  the  Indian  Medical  Service  and  the  remaining  nine 
are  open  to  officers  recruited  in  India.     Six  Indians  have  already 


ig6  SCIENCE   PROGRESS 

been  appointed  as  Deputy  Sanitary  Commissioners.  The 
remaining  three  appointments  have  not  yet  been  filled  up. 

In  addition  thirty-nine  first-class  and  104  second-class  health 
officers  are  to  be  appointed  to  the  municipalities,  and  in  order  to 
assist  local  Governments  in  organising  the  service  a  recurring 
grant  of  2*66  lakhs  of  rupees  has  been  sanctioned  from  Imperial 
revenues,  in  addition  to  an  expenditure  of  Rs.  25,560  per  annum 
in  the  North-West  Frontier  Province  which  will  be  met  by  the 
Imperial  Government. 

The  Government  of  India  are  meeting  the  cost  of  the  new 
appointments  of  Deputy  Sanitary  Commissioners  on  the  scale 
sanctioned  for  Indians  and  are  giving  a  subvention  amounting 
to  half  of  the  pay  of  first  and  second-class  health  officers. 

This  to  some  sanitary  enthusiasts  may  not  seem  sufficient 
provision,  but  I  would  point  out  that  one  must  cut  one's  coat 
according  to  the  cloth,  and  it  is  not  sound  policy  to  tax  the  clothes 
off  people's  backs  in  order  to  provide  them  with  the  benefits  of 
sanitation.  As  one  of  the  Indian  delegates  said  at  a  recent 
conference,  "  You  must  feed  us  before  you  educate  us,"  and  the 
same  remark  applies  here.  Moreover,  when  funds  are  limited  it 
is  unwise  to  spend  on  personnel  money  which  would  be  better 
applied  in  remedying  obvious  sanitary  defects.  An  expensive 
supervisory  staff  is  hopelessly  handicapped  if  there  be  no  money 
for  carrying  out  the  recommendations  submitted.  I  think  that 
what  I  have  written  suffices  to  justify  the  title  of  this  article,  and 
proves  that  the  Government  of  India,  the  medical  services,  and 
the  public  are  all  alive  to  the  value  of  preventive  measures,  and 
that  we  fully  realise  the  important  part  which  will  be  played  by 
sanitation  in  the  medicine  of  the  future. 


ATOMIC  THEORY  AND   RADIOACTIVITY 

By   SIR   OLIVER   LODGE,   F.R.S.,    D.Sc,  LL.D. 

In  the  April  number  of  Science  Progress  is  an  article  on 
11  The  Mystery  of  Radioactivity,"  signed  by  the  easily  recog- 
nisable initials  H.  E.  A. ;  and  in  spite  of  the  eminent  services 
of  the  author  of  that  article  to  Chemistry,  I  feel  that  some 
notice  ought  to  be  taken  of  it  because,  as  it  stands,  its  tendency 
is  obstructive  to  progress.  With  "  conservatism  "  I  confess  to 
a  good  deal  of  sympathy,  up  to  a  limit,  but  the  limit  is  trans- 
gressed when  facts  are  ignored  and  hypotheses  wildly 
manufactured  in  order  to  retain  some  old  and  superseded 
exclusive  and  negative  generalisation. 

That  radium  has  proved  itself  an  element,  to  be  classed  with 
the  other  elements  in  respect  of  such  things  as  a  recognised 
place  in  Mendelejeffs  series,  a  definite  spectrum,  regular 
chemical  compounds,  and  such  like,  is  surely  a  fact ;  and  to 
controvert  it  needs  something  more  than  an  etymological 
discussion  about  the  meaning  of  the  word  element.  The  term 
would  be  equally  applicable  or  inapplicable  if,  as  has  often  been 
surmised,  all  the  known  elements  turn  out  to  be  groupings 
of  some  one  fundamental  substance.  What  is  certain  is  that 
the  so-called  elements  form  a  definite  and  recognised  group 
of  substances  of  which  radium  is  a  member. 

Moreover,  it  must  be  permissible  to  speak  of  an   atom  of 

radium,  when  dealing  with  its  physical  and  atomic  properties, 

in  spite  of  the  fact  that  it  is  an  atom   liable  to   spontaneous 

explosion   or   fission.     To  hesitate  about  this — to  be  afraid  to 

use  the  convenient  and  brief  term  "  atom  "  because  of  historical 

derivation — would  involve  a  loss  of  this  useful  word  altogether. 

It  is  well   known   in  philology  that  significance  changes,  and 

that  the  meaning  associated  with  original  derivation  is  liable 

to  be  gradually  departed  from.      Besides,  even  pedantically,  we 

must  admit  that   the   idea  of  "  cutting "    suggests    something 

artificial,  and  that  the  artificial  stimulation  of  atomic  break-up 

has  yet  to  be  discovered. 

197 


i98  SCIENCE    PROGRESS 

This  is  a  minor  matter,  it  is  true,  but  it  leads  Prof.  Arm- 
strong to  liken  a  radium  atom  to  a  molecule  of  nitrogen 
chloride,  a  compound  which  explosively  resolves  itself  into 
what  are  called  its  "  constituent  "  atoms  ;  although  in  what  form 
the  nitrogen  and  the  chlorine  exist  in  the  compound,  is  a  matter 
on  which  I  would  gladly  learn  from  Prof.  Armstrong  rather  than 
attempt  to  instruct  him. 

But  it  is  misleading  to  liken  the  progressive  disintegration- 
process  responsible  for  radioactivity  to  the  ordinary  decom- 
position of  chemical  compounds.  Prof.  Armstrong  admits  that 
the  rupture  of  a  radium  atom  involves  the  formation  of  two 
neutral  substances,  the  Emanation  and  Helium ;  but  he  goes  on 
to  say  that  "  it  cannot  be  a  compound  of  such  substances,  and 
yet  they  are  obtained  from  it  "  ;  so  he  supposes  that  "  either  or 
both  must  be  present  in  it  in  some  active  form." 

This  guess  is  made  merely  because  he  is  unwilling  to 
recognise  any  mode  of  grouping  other  than  a  chemical  one — i.e. 
other  than  a  grouping  of  atoms  under  chemical  affinity.  Radium 
is  truly  not  a  chemical  compound,  but  its  atoms  appear  to 
embody  a  physical  grouping  such  that  definite  substances 
result  when  it  subdivides.  This  might  be  speculation,  were  it 
not  that  the  emission  of  observed  substances  from  radium 
actually  occurs.  In  no  chemical  decomposition  are  atoms 
shot  out  with  one-tenth  of  the  velocity  of  light.  The  energy' 
displayed  is  of  a  different  order  from  chemical  energy. 

In  the  effort  which  he  makes  to  liken  this  kind  of  volcanic 
disruption  to  chemical  decomposition,  on  the  analogy  of 
nitrogen  chloride,  Prof.  Armstrong  is  forced  into  hypotheses 
for  which  there  is  no  basis  whatever  beyond  his  own  speculative 
instinct.     This  is  what  he  says  : 

"  It  is  only  necessary  to  suppose  that  the  molecule  of  Helium 
as  we  know  it,  like  the  molecule  of  nitrogen  as  we  know  it,  is 
composed  of  several  '  atoms '  of — let  us  call  it  protohelium,  and 
that  the  atoms  of  protohelium  have  intense  affinity  for  one 
another— an  affinity  so  intense  that  it  is  far  beyond  anything  we 
have  experienced  in  the  case  of  any  other  element. 

"  When  argon  was  first  described  in  1895  by  Rayleigh  and 
Ramsay,  I  ventured  to  assert  such  a  view  in  explanation  of  its 
apparently  complete  inactivity.  What  is  true  of  argon  is  true 
doubtless  of  all  its  companions  in  air — helium,  neon,  and 
krypton.  .  .  .  Protohelium  apparently  is  the  wondrous  material 
at  the  root  of  radioactivity." 


ATOMIC  THEORY  AND  RADIOACTIVITY        199 

Now  speculative  instinct  is  extremely  valuable  as  a  guide 
among  new  facts,  but  it  is  not  powerful  enough  to  be  able  to 
withstand  them.  Prof.  Armstrong  feels  the  difficulty,  and 
presently  invents  a  supplementary  explanation,  devising  for 
the  purpose  not  only  the  as  yet  unknown  substance  "pro- 
tohelium,"  but  also  another  hypothetical  element  which  he 
names  "something  else";  and  by  then  postulating  strong 
chemical  affinity  between  his  two  imaginary  materials,  he 
manages  to  get  along.  Here  are  his  words,  beginning  with  a 
pertinent  question  : 

"  Why,  as  radium  decomposes  so  slowly,  does  it  decompose 
at  all ;  why  does  it  not  all  blow  up  suddenly,  like  an  ordinary 
explosive  ?  There  is  but  one  explanation — that,  like  the  other 
mere  chemical  compounds  Prof.  Soddy  speaks  of  so  slightingly, 
it  is  always  being  decomposed  reversibly — into  protohelium 
and  something  else,  the  which  products  reunite  more  frequently 
than  they  part  company  and  escape,  the  protohelium  after  it  has 
united  with  itself;  the  radium  does  not  blow  up,  because  of 
the  intense  affinity  of  protohelium  for  its  companion  product 
of  change." 

This  is  surely  an  extraordinary  statement  for  a  scientific 
man ;  and  we  are  constrained  to  ask,  why  does  Prof.  Armstrong 
strain  himself  into  this  singular  attitude  of  gratuitous  hypothesis, 
instead  of  yielding  gracefully  to  the  logic  of  facts  ?  He  gives 
the  answer  himself;  though  he  is  applying  the  criticism  to  other 
workers  who  have,  as  he  says,  "  so  long  overlooked  the 
potentialities  of  protohelium  " ;  it  is,  he  says, 

"  human  nature  to  have  chief  affection  for  one's  own  children ; 
to  be  blind  to  their  faults  and  disinclined  to  seek  virtues  in  those 
of  others." 

And  in  a  paragraph  already  quoted  he  specifies  the  "child" 
he  himself  is  fond  of: 

11  When  argon  was  first  described  in  1895  by  Rayleigh  and 
Ramsay,  I  ventured  to  assert  such  a  view  in  explanation  of  its 
apparently  complete  inactivity." 

And  so  he  goes  on  to  suggest  that 

"  it  were  time  to  discard  the  fiction  that  the  gases  of  the 
argon  family  are  monatomic  molecules  which  has  so  long 
retarded  progress." 

Here  we  come  to  the  root  of  the  matter ;  and  we  here  discern 
the  fundamental  cause  of  his   quixotic    tilting  at  ascertained 


200  SCIENCE  PROGRESS 

physical  facts,  the  bearing  of  which  he  fails  to  understand.  Let 
me  therefore  explain. 

The  monatomic  character  of  certain  gases  is  physically 
proved  by  arguments  deduced  from  an  experimental  deter- 
mination of  the  velocity  of  sound  through  them.  It  is  done  by 
a  curiously  simple,  and  apparently  to  Prof.  Armstrong 
despicable,  experiment  of  stroking  a  glass  tube  containing  the 
gas  and  a  powder.  Physicists  thus  ascertain  the  appropriate 
velocity  of  sound.  This  velocity,  combined  with  a  knowledge  of 
pressure  and  density,  gives  the  ratio  of  the  two  elasticities — the 
adiabatic  to  the  isothermal  ;  which  ratio  is  well  known  to  be  the 
same  as  the  ratio  of  the  two  specific  heats.  The  value  of  the 
elasticity-ratio  shows  how  the  heat  generated  by  sudden  com- 
pression is  disposed  of,  and  therefore  exhibits  the  number  of 
effective  degrees  of  freedom  of  the  molecules.  For  all  the 
translatory  motions  go  to  increase  the  velocity  of  sound,  while 
none  of  the  rotatory  motions  have  any  effect  upon  it. 

(This  is  one  of  the  few  cases  where  vulgar  fractions,  i.e.  com- 
mensurable numbers,  enter  into  physics  :  all  such  cases  are 
necessarily  important.)  Assuming  a  perfect  gas  :  if  the  ratio  of 
its  elasticities  is  7/5,  the  significance  of  that  number  is  that  each 
molecule  possesses  5  degrees  of  freedom  altogether,  2  of  rotatory 
and  3  of  translatory  freedom ;  so  the  molecule  must  be  diatomic, 
having  some  analogy  with  a  rigid  dumb-bell. 

If  the  ratio  were  4/3,  there  would  be  3  degrees  of  rotatory 
freedom,  and  the  molecule  must  be  tri-  or  polyatomic. 

But  if  the  ratio  is  5/3,  then  all  the  heat  goes  to  increase  the 
translatory  molecular  motions,  no  rotation  at  all  being  excited 
by  the  collisions.  For  that  to  be  possible  the  molecules  must  be 
monatomic,  and  must  act  on  each  other  during  collision  to  all 
intents  and  purposes  like  smooth  spheres. 

More  can  be  said  about  complications  introduced  by  incipient 
cohesion  among  the  molecules— the  so-called  "  imperfection  "  of  a 
gas;  but  this  is  sufficient.  The  argument  is  clear  and  only 
assailable  either  by  suspecting  the  law  of  partition  of  energy  or 
by  insisting  that  ordinary  molecular  collisions  must  excite 
atomic  vibrations.  Some  physicists  feel  a  difficulty  on  this 
latter  head  in  the  case  of  di-  and  tri-atomic  molecules,  though  I 
think  it  rather  a  needless  difficulty,  but  I  never  heard  one  raised 
about  the  monatomic  case. 

Now  for  the  application.      On  determining  the  velocity  of 


ATOMIC  THEORY  AND   RADIOACTIVITY        201 

sound,  the  ratio  of  the  elasticities  is  found  experimentally  to  be 
5/3  for  argon,  helium,  and  other  inert  gases  ;  therefore  they  are 
monatomic. 

If  the  argument  does  not  appeal  to  Prof.  Armstrong, 
physicists  are  not  to  blame ;  but  the  circumstance  that  it  does 
not  so  appeal  is  evidently  largely  responsible  for  the  attitude 
which  he  has  consistently  taken  up  in  connection  with  those 
unwelcome,  or  let  us  rather  say  indigestible,  chemical  dis- 
coveries which  have  been  made  by  purely  physical  processes. 

THE    ARGUMENT 

It  may  possibly  be  helpful  to  indicate  here  the  whole  argument,  so  far  as  it  can 
be  done  with  great  brevity  : 

Fundamental  kinetic-theory-of-gas  considerations,  as  old  as  Waterston,  give  for 
the  molecular  velocity,  u,  of  a  perfect  gas,  at  absolute  temperature  T,  and  with 
absolute  specific  heats  c1  and  c, 

u2  =  3P  =  3RT  =  3(c"  -  c)T (1) 

Equipartition  of  energy  among  the  degrees  of  freedom  available  in  molecular 
encounters,  combined  with  the  fact  that  3  of  these  degrees  of  freedom  are  necessarily 
translational,  causes  3/nths  of  the  total  heat  imparted  by  any  operation  to  go 
towards  increase  of  translational  velocity  ;  where  n  is  the  whole  number  of 
effective  degrees  of  freedom  possessed  by  each  molecule.  To  express  this 
sufficiently  well  we  may  write  : 

^(mcT)  =  -mu2  .         .  (2) 

rr        '      2 

From  these  two  equations  we  immediately  deduce  : 

Therefore      -  =  1  +  - (3) 

c  n 

which  justifies  the  statements  in  the  text ;  for  a  rigid  body  under  the  circumstances 
of  molecular  collisions  has  6  effective  degrees  of  freedom  or  modes  of  motion, 
unless  it  is  like  a  rod,  when  it  has  5,  or  like  a  sphere,  when  it  has  only  3. 

The  only  additional  equation  needed  is  the  one  required  to  interpret  the 
acoustic  experiment,  viz.  the  Laplacean  expression  for  the  velocity  of  sound, 

Tj2  =  e1     P  =  c_>  RT  =  i_  d_u2 (j 

e      p       c  3  c 


NOVEL   EXPERIMENTS   AND   FACTS 
CONCERNING   CORROSION 

By  J.  NEWTON  FRIEND,  D.Sc,  Ph.D. 

Carnegie  Gold  Medallist 

During  the  last  half-century  the  production  of  iron  by  the 
civilised  world  has  increased  at  a  phenomenal  rate  ;  so  much  so 
that  at  the  present  time  some  seventy  million  tons  of  pig  iron 
are  being  annually  placed  upon  the  market.  Such  being  the 
case  it  is  evident  that  all  problems  connected  with  the  decay  and 
preservation  of  iron  assume  increasing  importance  as  the  years 
roll  by.  The  object  of  this  article  is  to  draw  attention  to  some 
facts  concerning  corrosion  that  are  not  generally  known,  and  to 
describe  a  few  simple  experiments  capable  of  adaptation  for  class 
demonstrational  purposes. 

Inasmuch  as  the  usual  commercial  forms  of  iron  contain  a 
relatively  high  percentage  of  impurity,  it  will  be  assumed  in 
these  experiments  that  Kahlbaum's  pure  iron  foil  is  used  ;  other- 
wise the  results  are  liable  to  be  irregular  and  uncertain.  If  the 
foil  is  well  rubbed  with  finest  emery  and  not  touched  with  the 
fingers  the  reader  should  have  no  difficulty  in  obtaining  fairly 
regular  and  certain  results.  At  the  same  time  one  word  of 
warning  is  necessary.  The  corrosion  of  iron  is  affected  by  so 
many  apparently  trivial  factors  that  it  occasionally  happens  that 
two  experiments  may  be  conducted  under  what  appear  to  be 
identical  conditions,  and  yet  fail  to  give  the  same  results.  In 
many  cases  this  is  due  to  a  variation  in  the  metal  itself.  This  is 
particularly  the  case  with  the  ordinary  forms  of  commercial  iron, 
which  usually  lack  the  necessary  homogeneity  both  in  their 
chemical  composition  and  their  physical  condition.  Again,  the 
same  piece  of  iron  should  never  be  used  twice  for  experimental 
purposes,  otherwise  abnormal  results  are  very  liable  to  accrue 
despite  the  most  careful  superficial  cleaning.  This  is  probably 
due  to  the  fact  that  the  metal  is  slightly  porous,  so  that  minute 
particles  of  foreign  bodies,  particularly  solutions,  penetrate  to  a 
small  depth  below  the  metallic  surface  and  cause  a  disturbing 

203 


EXPERIMENTS  CONCERNING  CORROSION       203 

effect  in  later  experiments.  It  must  be  remembered,  too,  that 
fluctuations  in  the  intensity  of  the  light  and  temperature,  the 
composition  of  the  air  and  the  nature  of  the  containing  vessel  all 
play  an  important  part  in  determining  the  final  results. 

If  these  points  are  carefully  borne  in  mind  the  reader  will  be 
saved  from  many  disappointments  and  failures  in  carrying  out 
the  experiments  detailed  below. 

1.    Different  Types  of  Iron  Rust 

Let  us  place  a  rectangular  piece  of  iron  foil  in  a  beaker  in 
such  a  manner  that  its  four  corners  rest  in  contact  with  the  sides 
and  bottom  of  the  glass,  as  indicated  diagrammatically  in  fig.  1. 
Now  cover  with  distilled  water  to  such  a  depth  that  the  level  of 
the  liquid  A  shall  not  fall  by  evaporation  as  low  as  the  top  of 
the  metal  B,  otherwise  disturbing  effects  will  ensue. 

What  do  we  observe  ?     In  the  course  of  eight  or  nine  minutes 


Fig.  i. 

a  faint  yellow  skin  begins  to  make  its  appearance  on  the  surface 
of  the  metal  and  after  a  short  time  the  iron  becomes  covered 
with  a  thin  film  of  brown  rust.  In  the  course  of  two  or  three 
days  the  rust  thickens  but  remains  fairly  evenly  distributed  over 
the  surface  of  the  metal.  The  colour  likewise  remains  fairly 
constant  and  practically  no  green  rust  appears. 

If  we  remove  the  iron  and  gently  rub  it,  the  rust  will  easily 
wipe  off  and  a  localised  thin  green  stain  may  or  may  not  be  left 
behind  on  the  metal,  according  to  circumstances.  There  should 
be  no  pitting. 

This  is  the  simplest  or  "  normal "  form  of  rusting,  the  brown 
layers  consisting  of  a  very  pure  hydrated  ferric  oxide,  which  will 
be  referred  to  in  the  sequel  as  brown  rust. 

The  experiment  may  be  varied  by  laying  the  foil  flat  on  the 
bottom  of  the  beaker,  and  covering  with  water  as  before.  After 
a  few  hours  the  surface  of  the  iron  becomes  covered  with  an  even 
layer  of  brown  rust,  but  upon  lifting  up  the  foil  the  under-side, 


204 


SCIENCE  PROGRESS 


which  has  been  in  contact  with  the  glass,  is  seen  to  be  mainly 
green.  This,  however,  now  rapidly  oxidises  to  brown  rust  on 
exposure  to  air,  and  therefore  consists  of  iron  essentially  in  the 
ferrous  condition.  Although  the  corroded  under-side  of  the 
metal  may  be  unequally  attacked,  there  is  no  pitting  observable. 
A  very  similar  green  appearance  may  be  obtained  by  immers- 
ing iron  foil  in  a  saturated  solution  of  a  nitrate,  such  as  sodium 
or  potassium  nitrate.  In  this  case  the  iron  may  be  entirely  free 
from  the  containing  vessel,  save  of  course  at  the  four  corners  of 
support  as  in  the  first  experiment;  also  AB  (fig.  i)  should  not 
be  less  than  about  half  an  inch.  If,  after  a  few  days,  the  iron  is 
removed  and  gently  washed  with  distilled  water  the  green  rust 
steadily  oxidises  to  a  brown  colour.  There  is  no  pitting.  This 
reaction  is  interesting  as  being  fairly  characteristic  of  nitrates, 
for  in  most  other  aqueous  solutions,  such  as  those  of  the  chlorides 


NaNO, 


Fig.  2. 

and  sulphates  of  the  alkali  metals,  the  colour  of  the  rust  produced 
varies  from  a  ruddy  brown  to  a  much  darker  shade  with  varying 
amounts  of  green,  according  to  circumstances.  A  pretty  experi- 
ment is  as  follows :  Prepare  two  saturated  solutions  at  the 
temperature  of  the  room,  one  of  sodium  nitrate  and  one  of 
potassium  chloride.  Pour  the  former  into  a  gas  jar  and  then 
add  the  other  very  carefully,  either  pouring  on  to  a  piece  of  cork 
floating  on  the  nitrate,  or  else  allowing  it  to  flow  gently  down 
the  side  of  the  jar  held  in  an  inclined  position.  The  chloride 
solution  being  the  less  dense  floats  on  the  nitrate  solution.  Now 
insert  a  polished  strip  of  iron  as  in  fig.  2.  In  the  course  of  a  few 
hours  a  coating  of  green  rust  is  formed  on  B  C,  whilst  C  D  remains 
perfectly  bright.  This  is  well  illustrated  by  the  photograph 
(fig.  3),  where  the  dark  portion  represents  the  corroded  metal, 
and  the  light  the  uncorroded.  This  is  particularly  interesting 
because  we  might  have  expected  broivn  rust  from  B  to  C,  and 


I 


Fig.  4. 


Fig.  5. 


Fig.  6. 


Fig.  3. 


Fig.   11. 


204] 


EXPERIMENTS  CONCERNING  CORROSION        205 

green  from  C  to  D.  If  the  surface,  A,  of  the  chloride  solution  is 
very  near  to  the  top  B  of  the  iron,  a  little  of  the  green  rust 
oxidises  and  the  metal  presents  a  very  pretty  appearance — 
brown,  green,  and  polished  respectively. 

2.  The  Influence  of  Partial  Immersion 

Quite  a  different  type  of  oxidation  takes  place  when  iron  is 
only  partially  immersed  in  water.  The  portion  of  the  metal  not 
touched  by  the  liquid  may  remain  quite  bright,  whilst  the 
submerged  portion  becomes  covered  with  brown  rust.  But  at 
the  surface  of  the  water,  where  the  air  can  dissolve  most  rapidly, 
the  corrosion  is  most  vigorous,  a  thick  mass  of  green  and  brown 
rust  being  quickly  formed.  Fig.  4  shows  this  extremely  well, 
the  metal  there  figured  having  been  removed  after  about  forty- 
eight  hours  of  suspension  in  distilled  water,  and  gently  rubbed. 
The  upper  portion  retains  its  polish,  whilst  the  lower  is  some- 
what tarnished.  At  the  water  line  the  metal  is  seen  to  be 
heavily  attacked. 

3.   Pitting 

By  the  term  "  pitting "  we  understand  the  localisation  of 
severe  corrosion  at  definite  points  on  the  surface  of  the  metal, 
whereby  little  hollows  or  pits  are  eaten  out  of  the  iron.  This  is 
undoubtedly  the  most  serious  form  of  corrosion,  and  a  simple 
example  will  make  this  clear.  Suppose  we  have  a  tank  of  water 
built  of  steel  plates.  In  all  probability  these  plates  might  safely 
lose  a  few  ounces  in  weight  through  uniform  corrosion  without 
seriously  affecting  the  strength  of  the  tank.  But  a  quarter  of  an 
ounce  lost  through  the  formation  of  a  single  pit  might  be 
sufficient  to  perforate  a  plate  and  make  the  tank  leak. 

In  the  experiments  already  described  there  is,  or  should  be, 
no  pitting  with  Kahlbaum's  foil,  although  pieces  of  the  usual 
commercial  metal  treated  in  the  above  ways  will  sometimes  pit 
and  sometimes  not. 

Some  very  beautiful  pitting  effects  may  be  obtained,  however, 
with  pure  iron  foil  in  solutions  of  mineral  salts  rendered  weakly 
alkaline.  Fig.  5  shows  the  result  of  immersing  a  piece  of  foil  for 
several  days  in  a  beaker  (as  in  fig.  1)  containing  a  dilute  solution 
of  potassium  chloride  in  about  one-twentieth  normal  potassium 
hydroxide  solution.  Here  the  pitting  is  very  pronounced,  and 
usually  follows  some  scratch  or  irregularity  in  the  metal,  the 


206  SCIENCE  PROGRESS 

effect  of  which,  however,  is  so  slight  that  in  neutral  solutions  no 
pitting  is  observed. 

The  masses  of  rust  are  mostly  of  the  green  variety,  and 
rapidly  oxidise  on  removal  and  exposure  to  air.  The  metal 
really  looks  much  prettier  than  the  photograph  indicates  owing 
to  the  colours  ranging  from  light  moss-green  through  dark  green 
to  dark  brown,  the  edges  being  relieved  with  the  ruddy  tinge  of 
ordinary  brown  rust. 

By  increasing  the  quantity  of  alkali  to  about  twice  normal, 
that  is,  112  grams  of  caustic  potash  per  litre,  no  corrosion  of 
any  kind  will  take  place,  whatever  the  concentration  of  the 
chloride. 

Particularly  pretty  results  are  obtainable  by  suspending 
pieces  of  iron  foil  in  weakly  alkaline  solutions  of  potassium 
chloride  by  means  of  glass  hooks.  The  rust  accumulates  in  the 
form  of  threads  and  hangs  down  from  the  metal  like  skeins  of 
brown  silk.  This  is  illustrated  by  fig.  6,  where  A  B  is  the 
corroded  metal,  the  lower  portion  being  rust. 


OXYGtN 


OXYC.EN 


Partial  immersion  of  iron  in  weakly  alkaline  salt  solutions 
also  yields  interesting  results,  the  corrosion  occurring  locally,  but 
being  particularly  severe  at  the  surface  of  the  liquid  where  thick 
masses  of  green  and  brown  rust  accumulate. 

4.   The  Corrosion  Zone 

If  a  sphere  of  iron  is  suspended  in  a  tank  of  still  water  it 
tends  to  combine  with  the  dissolved  oxygen  in  its  immediate 
vicinity.  Fresh  supplies  of  oxygen  gradually  diffuse  towards 
the  iron  from  surrounding  layers  of  water  until  equilibrium  sets 
in.  When  this  has  been  attained  a  more  or  less  spherical  shell 
might  be  sketched  out  in  the  water  as  represented  in  section  by 
the  circle  ABC  in  fig.  7  through  which  oxygen  is  constantly 


EXPERIMENTS  CONCERNING  CORROSION      207 

diffusing,  and  outside  of  which,  as  at  C,  C,'  C,"  the  concentration 
of  dissolved  oxygen  is  constant.  Inside  this  sphere  the  amount 
of  oxygen  will  gradually  fall  towards  the  surface  of  the  iron, 
at  which  place  it  will  be  lowest.  The  same  argument  applies 
whatever  shape  the  iron  may  possess,  but  the  configuration  of 
the  shell  will,  of  course,  vary  accordingly.  Such  a  shell  is 
known  as  the  "  Corrosion  Zone." 

Now  what  will  happen  if  we  bring  a  second  ball  of  iron  into 
the  same  tank  of  water?  If  the  distance  between  the  two 
spheres  is  greater  than  twice  the  radius  of  the  corrosion  zone, 
the  metals  will  not  affect  each  other,  and  they  will  each  corrode 
at  their  maximum  rate.  But  if,  as  in  fig.  8,  the  corrosion  zones 
intersect,  the  amount  of  oxygen  that  can  diffuse  towards  each 
metal  ball  is  reduced,  and  corrosion  is  proportionately  retarded. 
If  three  such  balls  are  brought  together  in  line,  clearly  the  two 


Fig.  8. 

outer  ones  stand  the  best  chance  of  corroding,  for  oxygen  can 
diffuse  towards  the  middle  one  in  two  directions  only,  namely 
from  above  and  below. 

This  illustrates  the  importance  of  using  tanks  of  sufficiently 
large  capacity,  and  of  having  the  metals  a  sufficient  distance 
apart  when  an  attempt  is  made  to  determine  the  relative  rates 
of  corrosion  of  a  series  of  samples. 

The  same  argument  applies  to  the  employment  of  series  of 
small  containing  vessels  in  cases  where  only  one  piece  of  metal 
is  suspended  in  each.  Air  can  only  penetrate  to  the  sides  and 
bottom  of  the  vessel  from  the  surface ;  hence,  if  the  vessel  is  not 
larger  than  the  corrosion  zone  (as  in  fig.  9),  the  air  at  the  surface 
will  pass  into  the  corrosion  zone  and  be  absorbed  by  the  metal, 
and  there  is  none  left  to  replenish  that  at  A  and  B,  which  is 
likewise  diffusing  into  the  corrosion  zone.  In  a  short  time, 
therefore,  we  shall  have  equilibrium  after  the  manner  of  fig.  10, 
and  the  rate  of  oxidation  of  the  metal  now  becomes  a  function 
of  the  surface  area  of  the  liquid.     It  is  difficult  to  arrange  a 


208 


SCIENCE  PROGRESS 


lecture  experiment  to  show  this  because  water  containing 
dissolved  oxygen  has  the  same  colour  and  appearance  as 
absolutely  air-free  water.  But  the  principle  may  be  made  clear 
by  a  striking  experiment  with  copper. 

Some  cuprous  chloride  is  dissolved  in   strong  hydrochloric 
acid  and  allowed  to  turn  black  by  absorption  of  oxygen  from 


AIR 

1 

J 

I 

5SSSS 

M^ 

^^ 

cc 

• 

Iron 
ZONfc 

V 

Fig.  9. 


Fig.  10. 


the  air.  The  solution  is  transferred  to  a  narrow  rectangular 
glass  tank  and  a  piece  of  copper  suspended  in  it  by  a  glass  rod. 
The  top  of  the  tank  may  be  loosely  covered  with  glass  plates. 
In  the  course  of  a  few  hours  or  days,  depending  upon  the 
strength  of  the  acid,  the  liquid  becomes  clear  around  the  copper, 
indicating  that  the  oxygen  has  been  removed.  This  clear 
portion  corresponds  exactly  to  the  corrosion  zone  in  the  case 
of  iron,  and  the  effect  is  decidedly  pretty.  Some  idea  of  it  may 
be  obtained  from  the  photograph  (fig.  11),  which  shows  a  con- 
dition of  equilibrium  closely  corresponding  to  that  indicated  in 
fig.  10. 

The  ideal  condition  for  testing  the  rate  of  corrosion  of  a 


AIR 

OXYGEN 

• 

Iron 

OXYGEN 

OXYGEN 

OXYGEN 

Fig.  12. 


piece  of  metal  is  shown  in  fig.  12,  and  the  probability  is  that 
if  /  is  the  length  of  the  iron  plate  or  the  diameter  of  the  iron 
sphere  employed,  the  distance  of  the  metal  from  the  side  of  the 
containing  vessel  ought  not  to  be  less  than  about  2  /. 


THE   DISTURBED   MOTION   OF  AN 

AEROPLANE 

By  W.    BEVERLEY,   M.Sc. 

In  the  following  pages  I  have  attempted  a  mathematical  account 
of  the  forces  at  work  in  restoring  equilibrium  to  an  aeroplane 
possessing  dynamical  stability  and  disturbed  from  steady  motion 
by  periodic  gusts  of  wind.  Damping  effects  have  also  been 
found. 

We  take  the  centre  of  mass  as  origin  and  three  mutually 
perpendicular  directions  through  it  as  axes  fixed  relative  to  the 
aeroplane. 

Let  W  =  mass  of  machine  in  lbs.  (also  weight  in  lbs.-wt.). 

A,  B,  C,  D,  E,  F  =  moments  and  products  of  inertia. 

u,  v,  w ;  and  p,  q,  r  =  components  of  translational  and  angular 
velocities  respectively. 

We   have  F  =  —  lbs.-wt.   as   a  standard   equation,   where 

m  =  mass  in  lbs.  and  a  =  acceleration  in  ft./sec.2  X,  /x,  v  are  the 
components  of  angular  momentum. 


X  =  Ap  -  Fq  -  Er  =  Ap  -  Fq, 
fx  =  Bq  -  Dr  -  Fp  =  Bq  -  Fp 
v  =  Cr  -  Ep  -  Dq  =  Cr, 


,'  I  if  D  =  O 


In  steady  horizontal  flight  the  axis  of  x  is  that  of  flight,  the 
axis  of  y  being  vertically  downwards,  and  the  axis  of  z  to  the 
left  for  a  right-handed  system.  For  all  cases  of  flight  we  take 
the  direction  of  flight  as  the  "  x "  axis  and  the  others  fixed 
relatively  to  it  as  above.  In  most  aeroplanes  z  =  o  is  a  plane 
of  symmetry  and  D  =  O  =  E.1 

When  the  aeroplane  is  tilted  downwards  through  an  angle 

1  N.B. — We  assume  that  the  aeroplane  has  two  propellers  rotating  in  opposite 
directions,  so  that  gyrostatic  effects  annul  each  other. 
14  209 


210  SCIENCE  PROGRESS 

0  and  canted  through  <£  (see  Stability  in  Aviation,  pp.  20-27)  we 
have  by  the  theory  of  moving  axes  : 

—  f-Tj-  +  qw  -  rv )  =  accelerating  force  along  Gx  =  Wsintf  +  H  -  X 

W/dv  \ 

"gAdT  +  ru  ""  pwJ  =  "  "  "      Gy  =  Wcosecos(i>  ~  Y 

Yldf  +  pv  ~  qu)  =  "  "  "      Gz  =  "  Wcos0sin(£  -  Z 

A.  ^P  _  Z_  ^9.  .   c  -  B  ESL    .   F  EI  =  (  accelerating  moment  of  \  Gx  _  _  L 
g    dt  "  g  dt  '        g  g     "I  forces  about  / 

g   dt  gdt  T  g  g 

gdt  T  g  g 

where  X,  Y,  Z,  L,  M,  N  are  the  components  of  air  resistance, 
H  the  propeller  thrust  acting  in  general  parallel  to  the  axis  Gx 
at  a  perpendicular  distance  h  below.  For  simplicity  F  may  be 
taken  to  be  zero,  in  which  case  the  axes  are  the  principal  axes. 
To  X,  etc.,  may  be  added  terms  Xu  etc.,  due  to  gusts  of  wind. 
We  start  with  the  assumption  that  X1(  etc.,  are  zero — i.e.  that  the 
air  is  still. 

Assuming  that  the  plane  is  descending  uniformly  at  an  angle 
60  with  the  horizon  so  that  </>  =  o,  i.e.  it  is  upright,  u  =  v  =  p  = 
q  =  r  =  w  =  o  initially.  On  disturbance  they  represent  small 
increments.     U  is  the  steady  velocity  forward. 

Let  X0,  Y0,  etc.,  represent  the  initial  resistances. 


.-.  O  =  Wsin0o  +  H0  -  X0  =  Wcos0o  -  Y0  =  ZQ 
=  -  L0  =  -  MQ  =  -  H0h  -  N0 

these  being  the  equations  of  equilibrium  in  steady  motion. 
Where  H  is  inclined  at  an  angle  i)  with  the  direction  of  flight, 
the  first  two  equations  reduce  to 

O  =  Wsin0o  +  H0cos>7  -  X0 
O  =  Wcos0o  +  H0sin»7  -  Y0. 

Now  let  the  aeroplane  be  disturbed  and  the  above  increments 
enter.  The  resistances  are  functions  of  the  velocities,  and  we 
have — neglecting  squares  of  small  quantities — 

X  =  X0  +  Xuu  +  Xvv  +  Xrr  +  Xww  +  Xpp  +  Xqq 

with  similar  expressions  for  Y,  Z,  L,  M,  and  N. 


THE  DISTURBED  MOTION  OF  AN  AEROPLANE   211 

It  may  be  shown  that  X,  Y,  N  are  independent  of  p,  q,  w ; 
and  Z,  L,  M  of  u,  v,  and  r. 

In  a  small  change  the  angle  of  the  tilt  becomes  0  =  0O  +  £ . 
(S  small)  and  cos#  =  cos#0  —  £  sin#0,  sin0  =  sin0o  +  £  cos0o.  <f>  is 
small  and  is  equal  to  sin</>. 

Then  -77 =  3-.      Substituting  from   the    equations   of 

equilibrium  we  have : 

Wdu 

~g  d7  =  Wsmd  +  H  -  X  (since  X,  =  o)  1. 

=  Wcos0o  £  +  8H  -  uXu  -  vXv  -  rXr 
Y\dT  +  r  U)  =  "  Wsin^0  £  -  uYu  -  vYv  -  rYr 
~g{  dl   -  qU/  =  -  W<£cos0o  -  wZw  -  pZp  -  qZq  (Z0  =  o)  3 

A  |rt  ~  F  Ju  =  -  wLw  -  plp  -  qLq  (Lo  =  °)  4 

B   £dt  ~  F  &t  =  "  WM«  -  PMP  -  <lMq  <Mo  =  °)  5 

C  dr 

-yt    =-8Hh-uNu  -  vNv-rNr  6, 

Equations  1,  2,  and  6  form  a  symmetrical  group  involving 
(XYN)uvr,  and  3,  4,  5  form  an  asymmetrical  group  of  oscillations 
— representing  translations  and  rotations  to  the  left  or  right  of 
the  plane  of  symmetry,  z  =  o — involving  (ZLM)P 


/pqw 


Symmetrical  Oscillations 

In  disturbed  steady  horizontal  flight  we  have 

d£       d<9 

^  =  0jfl  =  ^0+e)_  =  —  ==r(=x£) 

assuming  u,  v,  r  £  proportional  to  eKt  (\  to  be  found).  For  sim- 
plicity we  may  take  8H  =  o — i.e.  the  thrust  H  is  independent  of 
changes  in  the  velocity.  Substitute  in  the  equations  of  motion 
above. 

•'•  (\V^  +  Xu)u  +  Xvv  +  (Xr  -  y cos0o)r  =  8H  =  O 
Yuu  +  (w|  +  Yv)v  +  (^sin0o  +  Ym.  +  yr)r  =  O 
fuu+Nvv  +  (c|  +  Nr)r  =  0 


N, 


212 


SCIENCE   PROGRESS 


X  is  therefore  given  by 


Wj+Xa 


X. 


w 

xr  -  x  cos^> 


wx     „    „      wu     w  .  . 

~^  +  Yv    Yr+  —  +Tsintffl 


N. 


CX 


+  Nr 


=  O. 


Multiplying  the  last  column  by  \  we  have  on   expanding  an 
equation  of  the  fourth  degree  in  X. 

Asymmetrical  Oscillations l 

<£cos0o  =  pcos#    —  qsin0o 
but 

<£=  -^  =  \<p  (assumed) 
.'.    \<f>cosd0  =  pcos#0  -  qsin0o. 

The  equations  3,  4,  and  5  on  p.       become 

wu     w  .  a \       n 

in0oJq  =  O 


Gj  +  Zw)w  +  (^  cos*0  +  Zp)  p  +  (Zc 


su 


g 


Lww  +  (A^+Lp)p  +  (-F^  +  Lq)q  =  0 
Mww+(Mp-F^)p  +  (B^  +  Mq)q  =  0. 

Again  we  have  an  equation  of  the  fourth  degree  to  find  \  by 
expanding  the  following : 


WX     _       _    ,  w      a      „       WU     W  .  a 
—  +  ZW,    Zp  +  Tcos^0,    Zq--j^-Tsm6a 


M 


w 


AX  T 

g  P 

-  F-  +  M 


g 


P> 


g         q 

B-  +  Mq 
g  q 


=  O. 


In  both  types  of  oscillations  we  have  u,  v,  w,  etc.,  of  the  form 
a^'1  +  a2eA-*1  +  aseA»l  +  a4e^  or  2(ase*st). 

For  stability  then  Xs  must  be  such  that  the  real  part  is  negative 
or  zero.     If  the  real  part  is  positive  there  is  instability. 

For  stability  \  =  -  as  ±  i&  {as  =  or  >  o}.  If  &  is  zero 
there  is  subsidence,  and  if  &  is  not  zero  there  is  oscilla- 
tion  and   subsidence,   two   of  the   terms   2(aseAst)  reducing   to 

e~°st(acos/3st  +  bsin£st)  where  a  and  b  are  arbitrary  constants. 


1  See  Stability  in  Aviation,  p.  31. 


THE  DISTURBED  MOTION  OF  AN  AEROPLANE    213 

u  :  v  :  w  can  be  found  from  the  above  determinant ;  the  ratios 
being  equal  to  certain  first  minors  and  similarly  for  p,  q,  w.  The 
equations  to  find  \(on  reducing  the  respective  determinants)  are: 

Symmetrical  oscillations  :   AQX4  +  B0X3  +  C0X2  +  D0X  +  E0  =  O 
Asymmetrical  oscillations :  A'0\*  +  B'0X3  +  C'0X2  +  D'0X  +  E'0  =  O. 

For  stability l  A0,  B0,  C0,  D0,  and  E0  must  all  be  positive  and 
B0C0D0  —  E0B02  —  A0D02  >  O,  and  similarly  for  the  values  A'0  etc. 

Forced  Oscillations 

Those  forces,  —  X„  —  Ylf  —  Zlt  —  L*,  —  M„  —  Nx  representing 
gusts  of  wind  are  periodic  when  they  set  up  indefinitely 
increasing  oscillations  in  the  aeroplane.  As  such  they  may  be 
represented  as  follows,  assuming  also  that  they  are  continuous  : 

3  Any  force  =  f(t)  =  Pe  "kt  cos(Xt  +  a)  +  P'e  -k'1  cos(X't  +  a) 

=  lPse-kstcos(Xst  +  as),' 

where  each  term  in  the  summation  is  called  a  disturbing  force — 
permanent  or  evanescent  according  as  K  is  or  is  not  zero 
respectively. 

Symmetrical  Oscillations 

The  equations  of  motion  on  substituting  values  for  Xlf  etc., 
are  now : 

(w|  +  Xu)u  +  Xvv  +  (Xr  -  ™  cos0o)r  =  -  IX^e'Vcos  (p^t  +  g^) 

Yuu  +  (Yv  +  ^)  v  +  (Yr  +  ^U  +  W  s.n^  r  =  _  ?y ^  -  »  Vcos^t  +  ^ 

Nuu  +  Nvv  +  ((£  +  Nr)r  =  -  f  N^e'"  "•tcos(p*.$t  +  £"Bg). 

Since  B  may  be  computed  and  operated  on  as  any  ordinary 
algebraic  symbol  may,  we  have  : 

u  =  -Vm^e""''cos(p"1 + ^ + ^>fY=.e~nVc°s(pv + £y + 

^?N,e-"".'cos(^t  +By] 

1  Routh's  Stability  in  Motion. 

*  See    Routh's  Advanced   Rigid  Dynamics,    vol.   ii.,  chapter    on    "Forced 
Oscillations*" 


214 


SCIENCE  PROGRESS 


-  -[T I ?>?'"' '""<*•  f  +  "%> +  W)  I V"°*' Ws.  +  *y  + 


;)pse-vcos(p»Sit  +  sv] 


A(S)  s 


-  -Clf  ?Iv"Vcos(iv + ^> + w^V^W,. + ev + 


^pS0e-°'Vcos(pV+£.3i)] 


where 


A(8) 


™  +  xt 
g 


N. 


X, 


y„  + 


N, 


g 


w 

Xr  -  -ycos0o 
Wsinfl0      WU 


g 


Nr  + 


g 


and  UtCS),  U2(8),  U3(S) ;  V.(8),  V2(S),  V3(S) ;  and  R^S),  R2(8)  and 
R3(6")  are  the  cofactors  of  the  constituents  of  the  first  column, 
second  column,  and  third  column  respectively. 

Let 

U,(8) 


F,(«) 


and  consider  the  solution  of 


A(d) 


-n<,t 


F(8)XS  e      '  cos(ps  t  +  £s  ) 


as  a  type.     We  have 
Let 


F(S) .  Pemt  =  F(m) .  Pemt. 
ms  =  -  ns   +  ips    and  Ps  =  Qs  4-  iRs  5 


-nBt 


ms,1 


and  Xs  e      '  cos(ps  t  +  Ss )  =  real  part  of  Ps  e    ' 


e     S|  (Qs  cos  p3 1  -  Rs  sin  ps  t) ; 


whence  we  have 


i         i 


Qs.  =  Xs  cosS:s.>  Rs.  =  Xs   sin£s 


i£5 


Xs  (cos£s  +  i  sin£s  )  =  Xs  e     '. 


Similarly  under  the  same  conditions  of  solution 


P'  =  Yce   S2andP"    =  N,e 


.-.  u  =  -  real  part  of  [~2F  (fi)Ps  eV  +  2FS(8)P'S 


nv_  t  n"    t-i 

^3(8)P"S3e    S'J 


e    s'-'  +  2F3 


s. 


+  free  vibrations 


Ui(m,  ) 


=  -  the  real  part  of  [s  1     !V  Ps  em«(  l 


A(ms) 


t     ,    ,.  U,(m's  )  TJ,      m'a,t 

s„ 


3  A(m'   ) 


+  fjW*2v»  sem'V] 


THE  DISTURBED  MOTION  OF  AN  AEROPLANE    215 

+  the  real  part  of  2{(asexst).  U,(XS)} 

r     V,(ms)         m  t         V2(m'  )         m,  t 

v  =  -  the  real  part  of    2  —, V  P,  e     *  +  a2  A/    ,  \  P'  e     2 

*  Ls,  A(ms)      si  s3  A(m'Sj)      s2 

V3(m\)  m"s  t-1 

+   s   A(m"r)  P"s3e      3  J 

s  .1 

+  the  real  part  of  2{(aseXst)V,(Xs)} 


R-(ms.)         m.  t  R2(m's ) 


e    s2' 


r  =  -  the  real  part  of  [  «  ^  P.,  e    .  +  S  ^-y  P's  < 

+  the  real  part  of  ^{(ase^).  R,(XS)} 

where  the  "  Vs  "  under  the  summation  refer  to  the  free  vibra- 
tions of  which  values  there  cannot  be  more  than  four — see  the 
free  vibrational  equation — with  the  respective  four  arbitrary- 
constant  values  as. 

Where  Xs  is  complex  we  have  the  free  vibrations  given  by 

\  =  —  a*  ±  i&. 

These  are 

(as  cos/3st  +  bs  sin/3st). 

The  ratios  u  :  v :  r  will  possess  certain  definable  determinantal 
values  easily  found.  The  ratios  p :  q :  r  possess  the  same 
qualities  as  u  :  v  :  r. 

1  Where  Xs  is  real  we  see  that  the  free  vibrations  are  propor- 
tional to 

U,(XS) :  V^)  :  R^)  or  U  (Xs) :  V  (Xg)  :  R2(XS)  or  U  (Xs) :  V  (Xs) :  R/X,). 

If  ms  be  a  root  of  A(m)  =  o,  the  denominators  of  the  forced 
vibrations  become  indefinitely  small.  This  gives,  however,  a 
value  of  ms  equal  to  that  of  a  free  vibration.  We  infer,  there- 
fore, that,  if  any  one  disturbing  force  has  a  period  and  a  real 
exponential  nearly  equal  to  those  of  any  one  free  vibration,  a 
very  large  forced  oscillation  will  be  produced  in  the  co-ordinates 
possessing  that  free  vibration. 

Usually  the  disturbing  gusts  of  wind  are  of  the  permanent 
type  Pcos(pt  +  E).  Since  resistances — surface  friction  and  head 
resistances — to  motion  enter  the  roots  of  A(A-)  =  o  giving  the 
free  vibrations  will  all  be  complex.  A  real  exponential  is  intro- 
duced into  the  values  of  X,  none  of  which,  therefore,  can  equal 

1  See  Routh's  Advanced  Rigid  Dynamics,  vol.  ii. 


216  SCIENCE  PROGRESS 

the  value  of  the  "m's"(=ip)  of  the  gusts.  Stability  is  here 
retained.  Again,  in  this  case,  the  forced  oscillations  on  the 
co-ordinate  acted  upon  will  be  permanent,  and  will  supersede 
the  free  vibrations,  which  in  the  case  of  stability  contain  a  real 
negative  exponential  and  are  therefore  evanescent,  vanishing 
ultimately.  The  free  vibrations,  of  course,  decrease  among 
themselves  at  varying  rates  depending  upon  the  indices  —  aa  of 
the  exponential.  as,  a  positive  quantity,  is  the  co-efficient  of 
decay  or  subsidence. 

The  Limits  of  the  Forced  Vibrations 

If  ms  =  \s  so  that  U^m^for  Ui(Xs)  =  o}  then  \  represents  a 
free  vibration  asU^XjeV  which  therefore  vanishes.     The  forced 

vibration  containing  the  fraction  -ttj — y  is  finite,  however,  if  there 

are  an  equal  number  of  roots  (ms)  in  Ui(m)  =  o  and  A(m)  =  o. 
Therefore  if  any  free  vibration  is  absent  from  a  co-ordinate — u, 
say — though  present  in  the  other  co-ordinates,  then  a  disturbing 
force  of  the  same  period  and  real  exponential  will  produce  a 
finite  forced  vibration  only.  We  may  then  conclude  that  a  dis- 
turbing force  can  produce  a  large  vibration  in  any  co-ordinate 
only  if  there  be  present  in  that  co-ordinate  a  free  vibration  of 
nearly  the  same  period  and  real  exponential. 

Again,  if  the  period  of  a  forced  vibration  is  very  small  "  p  " 
in  the  complex  value  "m"  is  very  great.  There  are  higher 
powers  of  m  and  therefore  of  p  in  A(m)  than  in  U^m),  etc. 

Al    J,  etc.,  become  insignificant.    The  forced  oscillations  are  now 

of  no  serious  account. 

The  forced  oscillation  on  a  co-ordinate  vanishes  when  the 
disturbing  force  on  that  co-ordinate — u,  say — is  of  the  type 

U1(S){|Xse-nstcos(pst+Es)>  =0. 

1  U^SyV  =  O  is,  however,  the  determinantal  equation  which 
gives  a  free  vibration  constraining  "  u "  to  zero.  Therefore 
when  the  type  of  the  disturbing  force  which  acts  directly  on 
any  co-ordinate  is  the  same  as  that  of  any  mode  of  free  vibration 
which  constrains  that  co-ordinate  to  zero  the  forced  vibration 
will  vanish. 

1  See  lko\i\.}\,s\Advanced  Rigid  Dynamics,  vol.  ii.,  chapter  on  "  Forced  Oscillations." 


THE  DISTURBED  MOTION  OF  AN  AEROPLANE    217 

Complete  Solutions 

In  the  general  case  we  consider  A(m)  {or  A(S)}  has  a  roots 
equal  to  m0  {  =  —  n0  -f-  ip0}  and  Ui(8) — taking  a  type — has  /?  roots 
equal  to  m0.     a  and  /3  cannot  be  greater  than  4. 
[N.B. — Do  not  confuse  a  and  ft  with  as  and  /3S  in  Xs  =  —  as 

±  iA.] 

Let  m  =  m0  +  h,  where  h  is  ultimately  zero.     Expanding  we 
have : 

VjP#r*  +  £  {U,(m0)e"»'! .  h  +  . . .  g£,  JD^J  .  e™«'}  j* 

— j^  gmt.  =  - '-= 

M)  A(m0)  +  A'(m0)  + A»(m0)  £ 

.,      .       &aA(m0) 
where  A°(m0)  =  -^J-^. 

Since  there  are  a  roots  equal  to  m0  in  A(m0)  =  o,  then  A(m0)  =  o 
=  A'(m0)  =  A"(m0)  = Aa_I(m0).     Similarly, 

U>      (m°)  =  °-^rn7rr~ 
and  U^-'Cm,,)  =  U^-3(m0)  =  . . . .  U',(m0)  =  U/mJ  =  o. 

.  .  A(8)  e       -  (a0  +  a,  t  +  . . . .  a a_^_xt         )e       +  ^        A<x(mo) 

on  putting  h  equal  to  zero. 

We  also  see  that  the  coefficient  of  emot  is  infinite,  containing 

powers   of  [j-j-     It  may,  however,  be  absorbed  into  the  free 

vibrations — A(x)  =  o,  where  X  =  m0 — which  are 

(a0  +  a1t  +  ...aa_^It*-e-I)emot? 

the  coefficients  being  arbitrary  constants. 

The  forced  oscillation  on  the  co-ordinate  u  is  obtained  by 
expanding  the  last  term,  the  coefficients  being  similar  to  those  of 
a  binomial  expansion.     It  is 

-  real  par,  offsg  {u.tmJ+.U,- W+ . . . .  •("£^"»  U, W} 

The  free  vibrations  are  given  by  single  roots  of  A(X)  =  o  and 
s'  equal  roots  X0  and  roots  m0  as  above.  The  terms  containing 
X0  are  similar  to  those  containing  m0  and  may  be  included  in 
them.  /3  may  or  may  not  be  equal  to  o  and  a  =  s'.  The  sign  2 
denotes  terms  obtained  from  values  similar  to  m0  and  X0,  or  X8> 
or  ms.  The  roots  for  the  forced  vibrations  are  ms  such  that 
A(ms)  £  o  and  m0  as  above. 


218  SCIENCE  PROGRESS 

u  -  real  part  of  [2  {ase^  .  U  (Xs)}  +  2(a0"+  a"t+ . . . .  a"a_^_1tn-^I)eniot . tj  (m0)] 
-real  part  of  2^^[u;(m0)  + aU;"1^).  t  +  Si^i)  u;-2(m0) .  t3  +  . . ..+ 

+..^-^^-)U>o),;^] 

r      U,(ms)        m  t         U:(m's)         m-  t        U3(m"s)  m»   t.-. 

-  real  part  of    2  ■  '  Ps e  s'  +2  ,  ■  P'  e    s»  +2    A,    „\  P"s e      3      . 

r  L  si  A(ms )     si  s2  A(m's  )      s»  s3  A(m  s )      s3  J 


as,  a0",  a"i,  etc.,  are  arbitrary,  giving  the  free  vibrations.  Of 
course  there  may  be  free  vibrations  of  the  type  given  by  X  =  m0 
when  there  are  no  forced  vibrations  of  that  type  (m  =  m0) ;  but 
if  there  are  forced  vibrations  of  the  type  (m  =  m0)  there  are  also 
free  vibrations,  into  which  they  may  be  absorbed,  of  the  same  type. 

There  can  be  two  double  conjugate  roots  only  of  A,  since 
there  are  only  four  values  of  X.  Similarly,  there  are  not  more 
than  two  such  roots  of  the  type  m0.  The  signs  ',  ", '",  etc.,  are 
merely  symbols  when  used  with  "  a's "  and  "  /3's "  and  not 
symbols  of  operation.  V^m,,),  Ri(m0)  are  taken  as  possessing 
/3'  and  /3"  roots  respectively.     Hence 

v  =  the  real  part  of  [S{aseV  .  V,(XS)}  +  S(a*0+a'l'|t 
+  ...a"a_^-1ta^'-I)emot.Vl(m0).] 

p„emot  r 

-  the  real  part  of  2  ^__  [^(m,)  +  aV.-'K)! 

4- ^""gl/  +l)V/(mp)t^] 

-  the  real  part  of  [2  ^  Ps  .V+1  ^  P;  e»V 

L  s,  A(ms  )     si  s2  A(m's  )      sj 


V3(m"s  )  m.  t-. 

+  2  — ^-  P"   e      3 


r  =  the  real  part  of  [Ka^s1 .  R(AS)}  +  2(a"0  +  a",t 
+ a"a_^_1ta-^"-I)emot .  R,(m0)] 


-  the  real  part  of  2  ^— }  |_R  »(m0)  +  aRx°-  \m0)t 

+  ...g(a-^J^0+l)R^(mo)t^"] 

tRi(ms )        m.  t         R^Cm'g  )         m<   t 
5  -D rP  e     '  +2    A,    ,  x  P'e     2 
si  A(msl)      .  s2  A(m  a )      s2 


sg  A(m  s3)       s3 


'} 


THE  DISTURBED  MOTION  OF  AN  AEROPLANE   219 

The  free  and  forced  vibrations  contain  the  term  ta~^,  being 
magnified  to  the  (a  —  /3)th  degree,  thus  confirming  the  conclusion 
previously  inferred  as  to  the  indefinite  increase — A(ms)  =  o— of 
the  forced  vibrations. 

The  solution  for  the  symmetrical  vibrations  is  now  complete. 
U^m),  U2(m),  U3(m) ;  V^m),  V2(m),  V3(m) ;  and  R^m),  R2(m), 
R3(m)  are  known,  and  their  derivations  with  respect  to  m0  can 
be  found. 

The  reader  will  do  well  to  refer  to  the  remarks  made  on 
page  213  with  respect  to  the  minors  in  the  free  vibrations,  and 
to  read  Routh's  Advanced  Rigid  Dynamics — "  Forced  and  Free 
Oscillations." 

Asymmetrical  Vibrations 

The  equations  of  motion  are  now  : 

/wtf     „  *\       /w     .    ,  7  \       /7       wu     w     a  \ 
\Y  +  zwJw  +  (tcos^  +  zpJp  +  lzq  ~  ~Y~  ~  T  *m6oh 

-  S  Zs  e"D"'tcos(ps  t  +  B  ) 


si 


Lww  +  (a|  +  Lp)p  +  (  -  Fg  +  Lq)q  -  -  S  LS2e~nVCos(p'S2t  +  S^) 
Mww  +  (Mp  -  F|)p  +  (f£  +  M  )q  =  -  i  Ms  e"n"s4os(p"s  t  +  &  ). 

N.B.— The  values  n  ,  n's ,  n"s  ;  ps ,  p's ,  p"     and  e     e'3  ,  s"s 

1  2  3  *  2  3  '23 

are   not  necessarily  the  same   as  those   corresponding  to   the 
symmetrical  disturbing  forces. 
Consider 


PSl    =Zse     ' 

»E's 
P's    =Lse    s* 

P"s  =  Ms  e'£  s* 
3  3 


and  ms  =  -ns  +  ips  ;  m'    =  -  n's  +  ip's  ;  and  m"s  =  -  n"s  -f 

1112  22  «»  3 

ip"s  then 

,     W,KJ  mst  W,(m's)  m'st 

w=-therealpartof{s-?-rTPSie    '  +l-X7rCTIV     2  + 


%  A(mSi)     s.  T  s2  A(m'S2) 

W,(m"s)         m,st 
,  A(m'  s  )      s3 


+  the  real  part  of  S{(asev)W,(X,)}, 


220 


SCIENCE  PROGRESS 


Xs  being  a  root  as  on  page  212,  and  the  last  term  containing  four 
terms  which  are  the  free  vibrations. 


A«tx 


p  =the  real  part  of  2(ase  s  )P  (Xs). 


the  real  part  of  {2 -^Pe  s' +2  — - ^P'e    W^-^P'e    9*  } 


A(ms) 


1 


s2  A(m's  )      s2 


s3  A(m"s  )       s3 


q  =the  real  part  of  S^eV).    Q/Xg)}. 


the  real  part  of  {  2  SjS^P  ,***<+  2  |^P'SieraV  +  2  %^P''S3emV}. 
*   s,A(mSi)    s>  s„A(m'S2)     s'  s3A(m'S3)      s»  '■ 


Instead  of  the  free  vibrations  being  proportional  to  W^X), 
Pi(^-)i  Qi(^)»  they  could  have  been  taken  proportional  to  W2(A<), 
PA),  QM  or  Ws(\),  Ps(\),  Q3(V). 

Note  that 


A(m)  = 


Wm 
g    +     w 


M 


w 


W 
ZP  +  mC0S^o 

g         p 

-  F™  +  Mp 
g  p 


7      wu     w  . 


g 


m 


-  F-4-L 
g  q 


and  that  W,(m),  W2(m),  W3(m);  P^m),  P2(m),  P3(m) ;  and 
Qi(m),  Q2(m),  Q3(m)  are  the  cofactors  of  the  constituents  re- 
spectively of  the  first,  second  and  third  columns.  To  prevent 
confusion  I  might  mention  that  there  is  no  connection  between 
the  coefficient  "  P "  of  the  disturbing  forces  and  the  cofactors 
"  P  "  of  the  determinant. 

The  conclusions  re  —  large  forced  oscillations,  etc.,  when 
A(m)  =  0;  re  —  the  failure  of  A(m)  to  be  zero  if  the  gusts  are 
of  the  permanent  periodic  type ;  re  —  the  vanishing  or  limiting 
of  the  forced  oscillations,  i.e.  a  forced  oscillation  can  be  large, 
only  if  there  be  present,  in  the  co-ordinate  directly  acted  on,  a 
free  vibration  of  the  same  period  and  real  exponential  as  those 
of  the  disturbing  force ;  and  also  re  —  the  vanishing  of  the  forced 
oscillations  by  means  of  two  other  conditions  are  the  same 
as  on  the  pages  referring  to  the  symmetrical  oscillations. 

Complete  Solution 

In  the  general  case  A(m)  =  o  may  have  a  roots  equal  to 
m0(=  —  n0  +  ip0)  and  W^S),  say,  may  have  fi  roots  also  equal 


THE  DISTURBED  MOTION  OF  AN  AEROPLANE    221 

to  m0.    a  and  /3  cannot  be  greater  than  4.    They  may  differ  from 
the  similar  symbols  of  the  symmetrical  solution  (see  pp.  217-219). 

.'.  w  =  the  real  part  of  [2s(aseAsl) .  W,(Xs)  +  2(a"0  +  a/'t  + 
...a'*a_^_Ita-e-I)emot.w,(m0)] 

Poemotr 

-  the  real  part  of  2^^j[ W,«(m0)  +  oW^-^m^t .  + 

-  the  real  part  of  {2       A'"»i'P  ems,t  ,   2      »v    yp,  em'S2t 


s3  A(m"S3) 


2      *v      ^p",emVt 


Again'  /?  may  be  zero. 

p  =  the  real  part  of  [2{(aseAst) .  P/X,).  }  +  2(a0"  +  a/'t 
+  ...a"a_^_Ita-^-I)emotpi(mo)] 

P  emot  ( 

-  the  real  part  of  2^^-)|Pla(m0)  +  aP*-1^)! 

+ a(a"I/);:/,+I)-p,^o)ta-^} 

-  the  real  part  of  [_  2  ^-g-  PSie  .,  .  +   \%  ^q  •  P  s,e    « 

+  2S3A(m"S3)^^      3  J 
q  =  the  real  part  of[2s{(asexsl).  Q/Xg)}  +  2(a"0  +  a/'t 

+  . . .  a"a_/r-ita-'5"-1)  •  emol .  Q,(m0) .] 

Poe^r 

-  the  real  part  of  2  £=7^-)\Q,a(mo)  +  aQ.a   Vo)1  • 

+  •••  /a-/3"  ^>    ^mo)t         J 

-therea,Par,of[7|^P«,e-,.+  ^?gp^V 

Again  the  coefficients  P"s  (not  cofactors),  the  m's,  m0,  \0,  the  a's, 
as,  and  /3's  are  not  necessarily  those  of  the  symmetrical 
vibrations. 

The  cofactors  of  the  determinant  are  known  from  page  220. 
Here,  again,  we  see  that  the  forced  oscillations  can  be  magnified. 


222  SCIENCE  PROGRESS 

General  Conclusions 

We  shall  see  later  that  X„,  etc.,  can  be  found  and  therefore 
Ps,  P's,  P"8,  for  approximately  ideal  and  at  the  same  time  prac- 
tical cases,  in  terms  of  a — the  angle  of  incidence  of  the  air  on 
the  planes — and  the  forward  velocity  U  of  the  aeroplane. 

If  for  certain  ranges  of  U  and  a  the  aeroplane  is  so  con- 
structed that  there  are  no  multiple  roots  of  A(X)  =  o,  and  also 
because  the  values  of  X  will  be  of  the  type  —  as  ±  i/3s  or 
—  ns  ±  ips,  there  being  resistances,  the  forced  oscillations  will 
not  in  general  become  large,  since  the  disturbing  forces  are  in 
general  permanent,  and  the  terms  which  stand  for  them  will 
have  no  real  exponential. 

In  a  few  cases  we  see  that,  the  disturbing  forces  being 
evanescent,  there  is  danger  of  an  indefinitely  large  increase  of 
the  forced  oscillations  whether  the  roots  are  multiple  or  not. 
Again,  where  for  certain  ranges  of  the  velocity  U  and  the  angle 
of  incidence  a  there  are  multiple  roots  of  A(X)  =  o,  the  free 
vibrations  once  set  up  by  an  impulsive  gust  are  magnified. 
Such  a  machine  would  be  unstable  for  those  ranges  of  U  and  a. 

In  the  case  of  indefinitely  increasing  disturbed  motion  much 
depends  on  the  aviator's  skill.  The  vibration  increases  inde- 
finitely about  some  axis,  and  excessive  pitching  and  canting  will 
occur.  The  moments  of  inertia,  entering  into  the  equations  of 
motion,  will  affect  this  oscillation.  The  aviator  then  elevates 
or  depresses,  and  turns  his  steering  planes  until  stability  is 
restored.  Instinctively  he  has  caused  the  aeroplane  to  strike 
the  air  so  that  the  oscillation  now  takes  place  about  a  new  axis 
relative  to  the  machine.  The  moments  of  inertia,  etc.,  about 
this  axis  not  being  the  same  as  those  about  the  old  will  alter 
the  equations  of  stability  and  give  new  values  for  \  in  the  free 
vibrations.  These  values  of  X  may  not  then  be  multiple,  nor  be 
equal  to  the  "  m  "  of  the  disturbing  force.  The  increasing  dis- 
turbances are  thus  damped  by  a  skilled  aviator  who  possesses 
developed  instinctive  steering  capabilities. 

The   Resistance   Derivatives 

The  following  is  a  brief  summary  of  and  reference  to  certain 
chapters  in  Prof.  Bryan's  Stability  in  Aviation  1 : 

1  See  pp.  38-56. 


THE  DISTURBED  MOTION  OF  AN  AEROPLANE   223 


Symmetrical  Derivatives 

C  is  an  arbitrary  point  (xy).     P  is  the  centre  of  pressure,  so 
that  CP  =  a<f)(a)  (a  being  small)  and  R  is  the  normal  thrust. 


>x 


direction  of 

flight   —>* 


The  aeroplane  receives  increments  u,  v,  w,  p,  q,  r,  so  that 

v  +xr 


8a 


U 


R  =  KS(U  +  d\i)H(a  +  8a)  =  KSU2f(a)  +  ^  Su  +  ~  6a 

=  KSU2f(a)  +  2KSUf(a)(u  -  yr)  +  KSUf(a)(v  +  xr) 

v  -4-  xr 
£  =  xcosa  -  ysina  +  a<£  (a)  +  a$'(a)  .  — =-= — . 

Prof.  Bryan  also  finds  that  due  to  the  rotation  "r"  of  the 
plane  about  C,  f(a),  <£(a)  are  functions  of — .    He  calls 

frW(=^.u)and*rW(=^)u 
the  rotary  derivatives. 

X  =  Rsina,  Y  =  Rcosa,  N  =  R£. 

We  then  find  that 


XQ  =  KSU2f(a)sina, 
Xu  =  2KSUf(a)sina, 
X,;  =  KSUf'(a)sina, 


Y0  =  KSU»f(a)cosa, 
Yu  =  2KSUf(a)cosa, 
Yv  =  KSUf'(a)C0Sa, 


Xr  =  KSU{xf'(a)  +  fr(a)  -  2yf(a)}sina,    Yr  =  KSU{fr(a)  +  xf'(a)  -  2yf(a)}cosa. 
N0  =  KSU>f(«)£,     Nv  =  KSU  {f'(a)£  +  af(a)(/)'(a)}, 
Nu  =  2KSUf(a)£,     Nr  =  KSU{f'(a)x  -  2yf(a)  +  fr(a)j£,  + 

KSUf(a)  .  {xa(£'(a)  +  a«/)r(a)j. 

See  Prof.  Bryan's  work  (p.  41). 


224  SCIENCE  PROGRESS 

fr(a),  <j)r(a)  can  be  found  experimentally.     For  more  than  one 
plane  we  add  the  separate  effects. 

Theory  to  Find  f(a) 

Fix  CP  =  a<£(a)  =  o,  i.e.  take  the  centre  of  pressure  as  the 
arbitrary  point.     Duchmein  gives 

R=2R9°'7+1sin'a  =  2lVsina  (approximately). 

Prof.  Bryan  then  obtains  f(a)  <x  R,  f(a)  =  sina. 

H  =  X0  =  SKSlPsin'a,         -  Hh  =  NQ  -  U22KS£'sina, 
W  =  Y0  =  SKSU2cosasina, 

where  l-  =  xcosa  —  ysina,  f"  =  xcosa  —  2ysina  for  brevity. 

The  sign  5"  refers  to  more  than  one  plane. 

If  the  planes  are  narrow — as  assumed  above — fr(a),  a<£r(a),  and 
a(f>'(a)  are  negligible. 


X 

2KSsin2a, 

xu 
u 

=  22KSsin2a, 

xv 
u 

=  SKSsinacosa, 

^J=  SKS^'sina, 

Y0 
U»~ 

SKSsinacosa, 

Y„ 
U 

=  22KSsinacosa, 

Yv 
U 

=  SKScos2a, 

^j  =  SKSrcosa, 

N0 
IP  " 

SKSrsina, 

Nu 
U 

=  2SKSsinar, 

Nv 
U 

=  SKSS'cosa, 

^  =  ZKSfr. 

Allowances  as  to  the  above  values  must  be  made  for  the 
inclination  (77)  of  the  thrust  H  with  the  axis  Gx,  for  head  resist- 
ances, for  propeller  effects,  and  for  the  effect  of  the  direction  of 
flight  relative  to  the  horizon  on  the  derivatives.  See  Prof. 
Bryan's  work  (pp.  75-122). 

Development  of  the  Asymmetrical  Derivatives 

See  Prof.  Bryan's  work  (pp.  123-164). 

The  law  used  is  that  of  Newton.  Resultant  pressure  on 
element  dSoc  resultant  velocity  x  normal  velocity  of  air  relative 
to  the  machine. 

An  element  dS  is  taken  at  (xyz)  so  that  the  direction  cosines 
of  the  normal  to  it  are  1,  m,  and  n.  The  velocity  of  the  plane  is 
U  when  increments  u,  v,  w,  p,  q,  and  r  are  added. 

X  =/Kl2U2dS  +  2Uu/Kl2dS  +  Uv/lmKdS  +  Ur/l(mx  -  2ly)KdS 

Y  =  IP/KmldS  +  2Uu/KlmdS  +  Uv/m2KdS  +  Ur/m(mx  -  2ly)KdS 

Z  =  Uw/n2KdS  +  Up/Kn(ny  -  mz)dS  +  Uq/n(2lz  -  nx)KdS 

L  =  U\v/Kn(ny  -  mz)dS  +  Up/(ny  -  mz)2KdS  +  Uq/(ny  -  mz)(2lz  -  nx)KdS 

M  =  Uw/Kn(lz  -  nx)dS  +  Up/K(ny  -  mz)(lz  -  nx)dS 

+  Uq/K(2lz  -  nx)(lz  -  nx)ds 
N  =  U VKl(mx  -  ly)dS  +  2Uu/Kl(mx  -  ly)dS  +  Uv/m(mx  -  ly)KdS 

Ur/(mx  -  ly)(mx  -  2ly)KdS. 


THE  DISTURBED  MOTION  OF  AN  AEROPLANE   225 

Here  we  see  that  (XYN)uvr  are  the  symmetrical  group  and 
(ZLM)wpq  are  the  asymmetrical  group,  when  the  plane  is  sym- 
metrical to  z  =  o,  and  when  D  =  O  =  E,  odd  powers  of  z  and  n 
being  neglected  in  the  above. 

For  planes  bent  up  at  an  angle  ft  the  direction  cosines  of  the 
normal  are  sina,  cosacos/3,  cosasin/3.  Where  ft  =  o — i.e.  the 
planes  are  normal  to  the  plane  z  =  o — these  reduce  to  sina, 
cosa,  o,  and  we  see  that  Xu,  Yu,  etc.,  reduce  to  the  values  already 
found  (p.  224). 

Asymmetrical  Derivatives  (ft  =  o) 

Let  I  =  the  moment  of  inertia  of  the  plane  with  respect  to  xy 
similarly  (density  =  1),  then  I  =/z2dS. 

Lp  =  KUIcos2a,  L    =  -  2KUIcosa  sina, 

Mp=  -KU I  sina  cosa,  Mq  -  2KUIsin2a. 

Prof.  Bryan  concludes  that  fins  are  needed  for  stability  in 
this  case. 

A  Single  Fin 

Let  its  area  =  T;  K'  its  coefficient  of  resistance  ;  Xi,  yl(  zx  the 
co-ordinates  of  its  centre  of  pressure  (1  =  o,  m  =  o,  n  =  1 — i.e. 
it  is  parallel  to  the  plane  z  =  o). 

Then  substituting  in  the  expressions  on  page  224, 

Zw  =  -  K'TU,  Zp  =  K'TUy,,  Zq  =  -  K'TUx, 

Lt  =      K'U /moment  of  inertia  of  fin  relative  to  the  plane  y  =  o] 

Lq  =  -  K'U  {product  of  inertia  with  respect  to  x  =  o,  y  =  o} 

MP  =  -  K'U  {product  of  inertia} 

Mq  =      K'U /moment  of  inertia  with  respect  to  x  =  o] 

Lw  =      K'TUy,  ;  Mw  =  -  K'TUXl. 

A  Number  oj  Small  Fins.    (General  Case) 

T  =  STi  =  sum  of  the  separate  areas  =  Total  area,  x,  y,  z  are 
the  co-ordinates  of  the  centre  of  pressure  of  all  the  fins. 

Mlf  M2,  and  P  are  the  moments  and  product  of  inertia 
respectively  with  respect  to  planes  through  x,  y,  z,  parallel  to 
y  =  o,  x  =  o  respectively.     Then 

Lp=      K'U{Ty2+M1},  Mp=  -  K'U{Txy  +  P} 
Lq  =  -  K'U{Txy+P},    Mq  =  K'U{T5c2  +  M3} 

and  ZW|  ZP,  Zq,  Lw,  and  Mw  hold  good  as  in  the  last  paragraph. 
15 


226  SCIENCE  PROGRESS 

Asymmetrical  Derivatives  for  Two  Transverse  Planes 

Let  alf  a2  be  the  angles  of  attack,  and  lu  I2  the  moments  of 
inertia  of  the  planes  respectively. 

Let  (I,  2a)  be  the  vector  sum  of  (I„  2ax)  and  (I2,  2a2). 

Then  Zw  =  Zy  =  Zq  =  Lw  =  Mw  =  o  for  the  planes  with 
values  as  above  added  for  fins. 

Take  K  the  same  for  both  planes.  We  find  for  such  planes 
and  fins  as  above  that 

Lp  -      KUIcos'a  +  KU{Ty»  +  M,  +  \{h  +  L  -  I)} 

Lq  =-  2KUIcosasina  -KU{Txy+P} 

Mp  =  - KUIcosasina  -KU{Txy  +  P} 

Mq=      2KUIsin3a  +  KU{Tx2  +  M2  +  A(h  +  U-  0} 

[Note  that,  from  page  225, 
Lw  =  KTUy,    Mw  =  -  KTUx,   Zw  =  --  KTU,    Zp  =  +  KTUy,   Zq  =  -  KTUx 

are  due  to  the  fins.] 

Ii  +  I2  —  I  may  be  proved  to  be  positive.  Prof.  Bryan  points 
out  that  M2  increases  stability,  and  therefore  the  additions — 
|(Ii  +  I2  —  I) — to  it  will  also  do  so.  Two  transverse  planes  with 
fins  will  give  stability  in  steady  motion.  Frictional  resistances, 
etc.,  will  again  effect  the  above  values.  The  wash  from  the 
front  plane  to  the  back  may  be  overcome  by  placing  the  back 
planes  on  a  slightly  higher  level. 

See  pp.  150-164,  Stability  in  Aviation,  for  /3  =}=  °-  From  these 
pages  we  may  conclude  that  bent-up  planes  are  equivalent  to 
the  planes  /3  =  o  with  fins,  and  therefore  give  stability. 


STEREOISOMERISM   AND   OPTICAL 

ACTIVITY 

A  CRITICAL  STUDY,  WITH  A  NEW  SUGGESTION 

Bv  G.  S.  AGASHE,  M.Sc.  (Manchester),  M.A.  (Bombay) 

PART  I.— INTRODUCTORY 

In  the  year  1808  Malus  discovered  the  phenomenon  of  the 
polarisation  of  light.  His  pupil  Arago  discovered  that  quartz 
crystals  possessed  the  power  of  rotating  the  plane  of  polarisation 
of  polarised  light,  i.e.  they  were  optically  active.  He  further 
noticed  that  there  were  two  modifications  of  crystalline  quartz, 
which  rotated  the  plane  of  polarisation  in  opposite  directions. 

Some  years  before,  Abbe  Hauy  had  noticed  that  there  were 
two  kinds  of  quartz  crystals,  possessing  hemihedral  facets  on 
opposite  sides  of  the  crystal,  thus  constituting  what  are  called 
enantiomorphous  forms. 

These  two  independent  observations  of  Arago  and  Hauy 
were  brought  together  by  Sir  John  Herschel,  who,  in  1820, 
suggested  a  possible  connection  between  the  two  phenomena 
of  opposite  rotation  and  the  reversed  position  of  facets  on  the 
crystals. 

In  the  meanwhile  (181 5)  Biot  had  discovered  that  many 
natural  organic  substances  like  sugar,  oil  of  turpentine,  and 
tartaric  acid  were  optically  active  in  the  liquid  or  dissolved  state. 
He  also  pointed  out  the  difference  between  these  substances  and 
quartz,  which  loses  optical  activity,  when  the  crystalline  form  is 
destroyed.  But  the  suggestion  of  Herschel,  just  mentioned,  was 
first  applied  to  such  substances  by  Pasteur,1  who,  in  1848, 
succeeded  in  preparing  from  sodium  ammonium  racemate 
(optically  inactive)  a  mixture  of  sodium  ammonium  dextro-  and 
laevo-tartrates,  showing  oppositely  situated  hemihedral  facets, 
the  crystals  of  the  dextro-salt  having  them  on  the  right,  and 
those  of  the  laevo-salt  on  the  left. 

1  Chemical  Society  Pasteur  Memorial  Lecture,  1897. 

227 


228  SCIENCE   PROGRESS 

Having  thus  established  the  truth  of  the  idea  that  asymmetry 
and  enantiomorphism  mark  the  property  of  optical  activity,  he 
went  a  step  further,  and  pointed  out  that  the  asymmetry  was 
due  to  the  arrangement  of  molecules  (or  groups  of  molecules)  in 
the  crystal  in  the  case  of  quartz,  sodium  chlorate,  etc.,  which 
lost  their  activity  with  the  crystalline  structure,  and  to  the 
arrangement  of  atoms  in  the  molecule,  in  the  case  of  tartaric 
acid,  etc.,  which  were  active  in  the  liquid  or  dissolved  state. 

The  asymmetry  of  the  crystal  could  be  easily  understood  as 
a  direct  result  of  the  presence  of  the  facets,  without  any 
hypothesis  as  to  the  particular  arrangement  of  the  molecules  in 
the  crystal.  But  to  explain  molecular  asymmetry  some  hypo- 
thesis as  regards  the  arrangement  of  atoms  seemed  to  be 
necessary. 

"Are  the  atoms  of  right-handed  tartaric  acid,"  asks  Pasteur, 
"  arranged  along  the  spiral  of  a  right-handed  screw,  or  are  they 
situated  at  the  corners  of  an  irregular  tetrahedron,  or  have  they 
some  other  asymmetric  grouping?  "  He  is  very  diffident  about 
the  true  answer,  and  remarks,  "  We  cannot  answer  these 
questions.  But  of  this  there  is  no  doubt,  the  atoms  possess  an 
asymmetric  arrangement,  having  a  non-superposable  image." 1 

The  step,  which  Pasteur  hesitated  to  take,  Van't  Hoflf  took 
soon  after,  and  explained  molecular  asymmetry  or  enantiomor- 
phism, and  consequently  also  optical  activity  in  the  liquid  or 
dissolved  state,  by  assuming  the  tetrahedral  grouping,  which  is 
almost  universally  accepted  at  the  present  time. 

Thus  the  idea,  that  enantiomorphism  or  asymmetry  in  a 
molecule  is  necessarily  present  when  a  substance  is  active  in 
the  dissolved  condition,  was  thoroughly  established,  and  has 
been  abundantly  confirmed  by  later  research. 

Chemists,  however,  have  gone  further.  They  have  assumed 
first  that  enantiomorphism  is  the  cause  of  optical  activity,  and 
secondly,  as  a  corollary  of  this,  that  when  a  molecular  con- 
figuration is  asymmetric  and  enantiomorphous,  the  substance 
represented  by  that  configuration  must  be  necessarily  optically 
active  (or  capable  of  being  resolved  into  optically  active 
isomers). 

These  assumptions  seem  to  the  writer  to  be  quite  un- 
justifiable. 

In  the  first  place,  the  evidence  of  crystallography,  from  which 
1  Alembic  Club  Reprints,  No.  14. 


STEREOISOMERISM   AND   OPTICAL  ACTIVITY  229 

all  these  ideas  were  brought  into  chemistry,  is  against  them. 
Crystallographists  recognise  230  possible  point-systems,  grouped 
in  32  classes,  of  which  1 1  classes  give  enantiomorphous  crystal- 
forms.  So,  all  optically  active  crystals,  like  quartz  or  sodium 
chlorate,  belong  to  one  of  these  1 1  classes ;  but  the  converse  ot 
this  is  not  true,  and  there  are  cases  known  where  the  crystals 
are  enantiomorphous  but  optically  inactive,  e.g.  barium  nitrate. 1 
This  clearly  shows  that  enantiomorphism  is  not  always  accom- 
panied by,  and  cannot  therefore  be  the  cause  of,  optical 
activity. 

This  must  hold  good  even  in  stereo-chemistry  ;  and  thus  we 
may  get  cases  where  the  configuration  of  the  molecule  is  enan- 
tiomorphous and  still  the  substance  is  inactive. 

Secondly,  even  if  enantiomorphism  were  always  accompanied 
by  optical  activity,  it  can  hardly  be  regarded  as  the  efficient 
cause  of  it.  The  nature  of  the  phenomenon  rather  suggests 
something  analogous  to  a  twisted  or  screw-spiral  structure  in 
the  substance.  Not  only  the  rotation  produced  by  a  naturally 
active  substance  can  be  removed  by  retraversing  it,  but  also  an 
optically  active  body  can  be,  and  has  been,  artificially  prepared 
by  piling  together  a  number  of  mica  plates  in  such  a  manner 
that  the  optical  axis  of  each  is  turned  through  a  definite  angle 
with  respect  to  that  of  the  preceding  plate.  This  makes  it  very 
probable  that  the  cause  of  optical  activity  is  screw-spiral 
structure  of  some  sort,  enantiomorphism  being  another  simul- 
taneous effect  of  the  same  cause. 

This  fact  seems  to  have  been  well  recognised  in  crystal- 
lography. It  is  by  resorting  to  this  that  Sohncke2  has  tried  to 
explain  why  barium  nitrate  crystals  are  optically  inactive,  while 
sodium  chlorate  crystals,  belonging  to  the  same  crystal  class,  are 
active.  According  to  him,  barium  nitrate  possesses  a  point- 
system,  in  which  there  is  no  screw-spiral  structure,  while  such  a 
structure  is  present  in  the  point-system  belonging  to  sodium 
chlorate. 

In  stereo-chemistry,  however,  this  fact  has  been  entirely 
ignored,  and  we  still  find  enantiomorphism  described  as  the 
cause  of  optical  activity.  Logically  speaking,  if  screw-spiral 
structure  is  the  cause  of  optical  activity,  it  must  be  assumed  to 
be  present  in  the  configurations  of  optically  active  compounds. 

1  Tutton's  Crystallography  and  Practical  Crystal  Measurement,  p.  139. 

2  Tutton's  Crystals,  p.  151. 


23o  SCIENCE   PROGRESS 

In  the  case  of  crystals,  the  arrangement  taken  into  consideration 
was  that  of  the  molecules  or  groups  of  molecules  in  the  crystal 
structure ;  here,  of  course,  the  arrangement  of  atoms  or  groups 
of  atoms  in  the  molecule  itself  will  have  to  be  considered. 

So  the  problem  is  to  suggest  an  hypothesis  as  regards  the 
arrangement  of  atoms  in  the  molecule,  which  will  satisfy  the  two 
conditions  of  showing  the  screw-spiral  structure  to  be  present 
in  the  configuration  of  all  optically  active  compounds,  and  show- 
ing it  to  be  absent  in  that  of  all  the  inactive  compounds.  The 
following  is  an  attempt  to  solve  this  problem  with  reference  to 
compounds  of  carbon  and  nitrogen. 

PART  II.— COMPOUNDS  OF  CARBON 

It  has  been  mentioned  already,  that  Van't  Hoff  assumed  the 
tetrahedral  grouping  for  the  four  radicals  joined  to  a  carbon 
atom,  the  carbon  itself  being  at  the  centre  of  the  tetrahedron. 
He  did  not  commit  himself  as  to  the  nature  of  the  tetrahedron, 
because  it  was  unnecessary  for  his  purpose ;  the  structure 
becomes  asymmetric  and  enantiomorphous,  when  all  the  four 
radicals  are  different,  whatever  the  nature  of  the  tetrahedron, 
and  enantiomorphism  by  itself  apparently  seemed  to  him  quite 
sufficient  to  account  for  optical  activity.  But  if  it  is  not  enough, 
and  if  some  sort  of  screw-spiral  arrangement  of  the  radicals  has 
to  be  postulated,  we  shall  be  obliged  to  make  some  further 
assumptions  about  the  tetrahedron.  The  assumptions  suggested 
below  seem  to  the  writer  very  plausible  and  dynamically  sound. 

The  linkages  of  the  carbon  may  be  pictured  as  the  horns  of 
a  snail ;  they  can  be  pushed  out  or  pulled  in,  and  can  also  be 
twirled  round,  their  orientation  being  determined  by  the  four 
radicals  attached  to  them.  The  configuration  of  a  substance 
like  methane  or  carbon  tetrachloride  may  be  represented  by  a 
regular  tetrahedron.  The  structure  will  possess  its  full  number 
of  planes  of  symmetry,  viz.  six ;  the  distance  of  each  radical  from 
the  central  carbon  will  be  the  same ;  the  angle  between  any  pair 
of  linkages  will  be  equal  to  that  between  any  other  pair;  and 
so  on. 

This  high  degree  of  symmetry  will  gradually  diminish  as 
more  and  more  different  groups  appear.  Thus,  for  example,  in 
a  compound  of  the  type  C,a3,b,  the  distance  of  all  the  a's  from 
the  central  carbon  will  be  the  same,  but  will  be  different  from 


STEREOISOMERISM   AND   OPTICAL  ACTIVITY   231 

the  distance  of  b  from  the  central  carbon ;  any  pair  of  a's  will 
contain  the  same  angle,  but  this  angle  will  be  different  from 
the  angle  contained  by  b  and  any  of  the  a's ;  the  structure  will 
possess  only  three  planes  of  symmetry  ;  and  so  on. 

Finally,  when  the  groups  are  different,  the  structure  becomes 
perfectly  irregular,  devoid  of  any  plane  of  symmetry,  having  all 
distances  different,  all  angles  different. 

When  a  molecule  of  such  a  perfectly  irregular  configuration 
lies  in  the  path  of  a  ray  of  plane-polarised  light,  let  us  suppose 
the  direction  of  the  ray  to  lie  along  one  of  the  carbon-bonds. 
Then  it  is  easy  to  see  that  the  other  three  bonds  will  not  lie 
symmetrically  round  the  ray,  but  will  be  found  to  be  twisted  out 
of  shape  in  such  a  manner  that  the  line  joining  the  centres  of 
inertia  of  the  three  groups  attached  to  them  will  describe  a  spiral 
round  the  ray,  as  shown  diagrammatically  in  the  figure : 


And  it  does  not  seem  unreasonable  to  suppose  that  this  twisting 
of  the  bonds  will  produce  the  effect  of  rotating  the  plane  of 
polarisation,  and  also  that  the  amount  of  rotation  will  be  directly 
proportional  to  the  degree  of  this  twist  in  the  orientation  of  the 
bonds  round  the  ray. 

This  twist  will  be  present  along  whichever  of  the  four  bonds 
we  imagine  the  path  of  the  ray  to  lie.  Whether  the  twisting  of 
the  bonds  in  each  case  will  be  the  same  or  not,  the  writer  cannot 
say  for  certain.  Most  probably  it  will  be  equal ;  but  even  if  it 
is  not,  the  principle  of  "least  resistance"  will  come  into  opera- 
tion, and  as  the  molecules  are  perfectly  mobile  they  will  take 
such  a  position  with  reference  to  the  path  of  the  ray  as  will 
produce  minimum  rotation. 

Further,  even  if  the  path  of  the  ray  lies  along  none  of  the  four 
bonds,  the  screw-spiral  twisting  will  still  be  there ;  and  whether 
the  molecule  will  take  any  such  position  or  not  will  depend  on 
whether  the  twisting  is  the  least  or  not  in  that  position.     But 


232  SCIENCE   PROGRESS 

this  seems  highly  improbable.  Most  probably  the  position 
involving  least  rotation  will  be  such  as  to  have  the  path  of  the 
ray  along  one  of  the  bonds. 

It  is  obvious  that  the  twisting  will  be  equal  but  in  the  oppo- 
site direction  in  the  other  enantiomorph. 

The  orientation  of  the  radicals,  and  consequently  also  the 
degree  of  twisting  of  the  bonds,  is,  as  has  been  indicated  already, 
most  probably  determined  by  two  factors:  (i)  The  affinity  of 
the  central  carbon  to  each  of  the  four  radicals,  and  (2)  their 
action  upon  each  other.  Both  of  these  may  indeed  be  grouped 
together  under  the  one  heading  of  the  chemical  nature  of  the 
groups.  This  being  the  case,  it  seems  almost  impossible  to  find 
a  quantitative  relation  between  the  degree  of  rotation  produced 
and  the  nature  of  the  groups — at  least,  in  the  present  state  of 
our  knowledge ;  and  it  is  no  wonder  that  all  attempts  at  such  a 
co-ordination,  based  upon  only  one  property  of  the  groups,  viz. 
their  mass  (which  alone  lends  itself  to  a  quantitative  treatment, 
but  which  is  nevertheless  probably  the  least  influential  in  the 
matter  under  consideration),  have  entirely  failed. 

With  the  help  of  this  idea,  it  further  becomes  easier  to  under- 
stand why  the  amount  of  rotation  of  one  and  the  same  substance 
changes  with  the  external  conditions  like  temperature  and 
solvent.  The  amount  of  rotation  changes  for  the  simple  reason 
that  the  chemical  nature  of  a  group  changes  with  the  external 
conditions. 

Now  we  shall  consider  the  cases  (1)  Ca3b,  (2)  Ca2b2,  and 
(3)  Ca2bc. 

If  we  take  the  first  case,  for  example,  we  find  that  it  is  indeed 
possible  to  imagine  a  direction  for  the  path  of  the  ray  through 
such  a  molecule,  which  will  have  the  groups  arranged  in  a 
spiral  round  itself ;  but  that  matters  little.  What  we  have  to 
decide  is  whether  there  is  a  direction  possible  for  the  ray,  which 
can  avoid  this  twisting,  and  the  consequent  rotation  of  the  plane 
of  polarisation.  Because,  if  there  is  such  a  direction,  then  the 
molecule  being  mobile  will  assume  the  corresponding  position, 
in  accordance  with  the  principle  of  "  least  resistance."  And  it  is 
not  difficult  to  see  that  there  is  such  a  direction  in  each  of  the 
three  types  under  consideration. 

In  the  first  case,  such  a  direction  is  that  of  the  bond  between 
the  central  carbon  and  b. 

In  the  second   case,  it  is  the  direction  joining  the  central 


STEREOISOMERISM   AND   OPTICAL  ACTIVITY  233 

carbon  to  the  middle  points  of  the  straight  lines  joining  a — a  or 
b— b. 

In  the  third  case,  it  is  the  line  joining  the  central  carbon  to 
the  middle  point  of  the  straight  line  joining  a — a.  When  the 
ray  passes  along  that  direction,  the  two  other  groups  b  and  c 
can  in  no  sense  be  said  to  describe  a  spiral  round  it. 

Thus  it  is  clear,  that  substances  of  these  types  will  not  be 
optically  active  according  to  this  new  hypothesis;  and  none 
such  are  known. 

The  same  considerations  apply  in  cases  where  there  are  more 
than  one  asymmetric  carbons. 

Of  these,  we  need  only  consider  the  apparently  anomalous 
case  of  trihydroxy-glutaric  acid. 

COOH  .  CHOH  .  CHOH  .  CHOH  .  COOH 

When  in  this  formula  the  two  side  carbons  are  of  opposite  sign, 
they  neutralise  each  other's  optical  effect,  but  make  the  central 
carbon  asymmetric  ;  but  the  difference  in  the  nature  of  the  two 
groups  is  not  of  a  kind  calculated  to  have  any  effect  on  the 
twisting  of  the  bonds  ;  as  far  as  that  is  concerned,  the  substance 
is  of  the  type  Ca2,  b,  c  ;  the  structure  as  a  whole  does  possess  a 
plane  of  symmetry,  and  thus  shows  no  optical  activity.  But  the 
isomerism  manifests  itself  in  different  chemical  and  physical 
properties;  it  thus  suggests  an  analogy  with  the  cis-trans- 
isomerism  in  the  alicyclic  compounds. 

A  carbon,  like  the  central  carbon  here,  which  is  united  with 
four  radicals,  which  are  not  all  different  structurally,  but  only  so 
configurationally,  is  called  a  "  pseudo-asymmetric  "  carbon. 

Le  Bel's  Views 

The  view  of  the  spatial  distribution  of  the  four  valencies  of 
carbon,  put  forth  above,  comes  very  near  to  that  of  Le  Bel.  Le 
Bel's  ideas  appear  to  the  writer  to  be  more  sound ;  but  they 
were  not  further  developed  because  they  were  more  complicated 
than  the  rigid  ideas  of  Van't  Hoff.  Although  Van't  Hoff 
originally  made  no  definite  statement  as  to  the  nature  of  his 
tetrahedron,  all  the  further  developments  of  the  tetrahedron 
hypothesis  have  been  based  on  the  tacit  assumption  that  it  is 
regular.     All  this  is  very  clearly  shown  in  the  case  of 


234  SCIENCE  PROGRESS 

The  Ethylenic  Linkage 
Let  us  consider  a  substance  of  the  following  configuration  : 

a\       ',/VN        /C 

>c ;    \  c< 

In  such  a  configuration,  according  to  the  Van't  Hoff  hypothesis, 
a,  b,  c,  and  d  all  lie  in  one  plane,  which  is  at  right  angles  to  the 
plane  containing  the  linkages  joining  the  two  carbons.  So,  the 
structure  does  have  a  plane  of  symmetry,  and  it  is  identical  with 
its  mirror-image ;  and  so  no  optical  activity  is  to  be  expected. 

On  the  other  hand,  according  to  Le  Bel's  ideas  (and  also 
according  to  the  ideas  set  forth  above),  the  four  groups  a,  b,  c, 
and  d  may  not,  and  very  probably  will  not,  lie  in  the  same  plane. 
The  structure  thus  may  become  asymmetric  and  enantiomor- 
phous  ;  and  the  possibility  of  optical  activity  arises. 

In  fact  it  was  at  one  time  expected  to  get  optically  active 
substances  of  such  a  configuration  ;  and  Le  Bel x  himself  carried 
out  a  number  of  experiments  with  the  hope  of  isolating  them. 
Similar  researches  were  made  by  Anschiitz  and  Walden  ;  but  all 
of  them  were  unsuccessful ;  and  now  it  is  generally  agreed  that 
there  is  no  possibility  of  optical  activity  in  such  compounds. 

It  appears  that  this  was  considered  as  a  great  difficulty  in  the 
way  of  accepting  Le  Bel's  views.  Now  please  notice  the  tacit 
assumption  made  here,  that  asymmetry  and  the  consequent 
enantiomorphism  necessarily  imply  optical  activity,  which 
assumption  appears  to  the  writer  to  be  unjustifiable.  According 
to  the  ideas  set  forth  above,  there  must  be  something  else 
present  besides  enantiomorphism,  viz.  the  unsymmetrical  spatial 
distribution  of  the  linkages,  and  the  screw-spiral  arrangement  of 
the  radicals  round  the  carbon.  This  is  obviously  not  the  case 
here  ;  for  the  two  linkages  of  each  carbon,  by  which  it  is  joined 
to  the  other  carbon,  may  be  regarded  as  acting  along  practically 
the  same  line.  And  so  there  is  no  real  difficulty  in  reconciling 
the  absence  of  optical  activity,  which  is  an  experimental  fact, 
and  the  presence  of  enantiomorphism,  demanded  by  Le  Bel's 
hypothesis. 

The  case  of  the  acetylenic  linkage  is  simpler  still,  and  need 
not  be  further  considered. 

1  For  references  to  the  original  papers,  see  Stewart's  Stereochemistry,  p.  158. 


STEREOISOMERISM   AND   OPTICAL  ACTIVITY   235 

The  Difference  between  Saturated  Open-Chain-  and 

Ring-Compounds 

So  far  the  two  terms  "  asymmetry"  and  "enantiomorphism  " 
have  been  used  as  being  coextensive  in  their  denotation.  This 
is  quite  true,  if  we  define  an  asymmetric  carbon  as  one  that  is 
united  to  four  structurally  different  radicals,  and  call  it  "  pseudo- 
asymmetric"  if  any  of  the  radicals  are  structurally  similar,  but 
differ  only  in  configuration,  but  it  is  true  only  in  the  case  of  open- 
chain  compounds. 

In  open-chain-compounds  of  all  types  (except  one,  for  which 
see  p.  241)  the  following  three  relations  hold  good  : 

(1)  The  presence  of  an  asymmetric  carbon  makes  the  whole 
structure  both  asymmetric  and  enantiomorphous ;  and  con- 
versely all  asymmetric  and  enantiomorphous  structures  contain 
at  least  one  asymmetric  carbon. 

(2)  The  presence  of  a  pseudo-asymmetric  carbon  does  not 
make  the  structure  asymmetric  or  enantiomorphous  :  e.g.  the 
inactive  indivisible  tri-hydroxyglutaric  acids. 

(3)  And  further,  a  meso-pair  of  asymmetric  carbons  makes  the 
whole  structure  symmetric  and  also,  of  course,  identical  with 
its  mirror-image :  e.g.  meso-tartaric  acid,  mucic  and  allo-mucic 
acids. 

But  these  relations  do  not  always  hold  good  in  alicyclic  or 
saturated 

Ring-  Compo  u  nds 

In  these,  the  presence  of  an  asymmetric  carbon  does  indeed 
make  it  asymmetric  and  enantiomorphous  ;  but  the  converse  is 
not  always  true,  asymmetry  and  enantiomorphism  being  often 
effected  by  one  or  more  pseudo-asymmetric  carbons. 

Let  us,  for  example,  consider  the  case  of 

Inosites 

These  have  the  constitutional  formula  C6H6(OH)6.  A 
constitutional  formula  of  this  type  admits  in  all  of  nine  con- 
figurations, shown  below.  Three  isomers  only  are  known  so 
far ;  one  is  of  the  inactive  indivisible  type,  the  other  two  being 
optical  antipodes. 


236 


SCIENCE  PROGRESS 


a) 


(2) 


(3) 


(4) 


(5) 


(8) 


[N.B. — The  numbering  of  the  carbons  is  the  same  in  all  cases.] 
It  is  easy  to  see  that  in  this  case  there  is  no  truly  asymmetric 
carbon  at  all ;  but  in  each  of  the  configurations  all  the  carbons 
are  pseudo-asymmetric.  In  some  cases,  we  find  one  carbon 
neutralising  the  pseudo-asymmetry  of  another,  e.g.  carbons  3 
and  5  in  configuration  No.  3. 

In  configuration  No.  1  all  the  carbons  are  pseudo-asymmetric 
in  the  same  sense,  there  being  no  meso-pair  at  all.  The  molecule 
as  a  whole  is  symmetric  and  identical  with  its  mirror-image.  In 
Nos.  2-7,  also,  we  find  the  structures  symmetric. 


STEREOISOMERISM  AND  OPTICAL  ACTIVITY  237 

But  when  we  come  to  No.  8,  we  see  at  once  that  here  the 
molecule  is  not  only  asymmetric,  but  also  non-superposable  on 
its  mirror-image,  which  is  No.  9.  Evidently  these  two  con- 
figurations represent  the  two  optical  isomers. 

Here  we  have  asymmetry,  enantiomorphism,  and  optical 
activity,  without  the  presence  of  an  asymmetric  carbon. 

Let  us  consider  another  important  case  among  the  alicyclic 
compounds,  viz.  that  of  molecules  having  the  so-called 

Indirect  Plane  of  Symmetry 

Ladenburg1  was  the  first  to  draw  attention  to  what  he 
thought  to  be  the  exceptional  character  of  a  configuration  like 
this  : 

a    /  x yx     b 

C 


It  contains  two  truly  asymmetric  carbons  forming  a  meso-pair; 
but  the  structure  as  a  whole  possesses  no  plane  of  symmetry, 
although  it  is  identical  with  its  mirror-image.  Here  again  the 
behaviour  of  a  meso-pair  is  different  from  what  it  is  in  open- 
chain-compounds. 

Several  examples  of  this  type  are  known  :  e.g.  the  keto-form 
of  trans-succinylo-succinic  acid,  and  trans-3,  6-dimethyl-i,4- 
cyclo-hexadiene-i,4-dicarboxylic  acid  ;  and  they  are  all  inactive. 

There  are  some  substances  of  this  class  known  which  contain 
two  meso-pairs  :  e.g.  1,  3-dimethyl-cyclobutane-2,4-dicarboxylic 
acid. 

COOH 


Here  again  the  structure  is  asymmetric. 

These  examples  clearly  show   the  difference   in   behaviour 
between  open-chain-  and  ring-  compounds.    The  cause  of  this 

1  Ber.  28,  1995,  3104  (1895). 


238  SCIENCE  PROGRESS 

difference  is  not  far  to  seek.  It  is  the  same  which  gives  rise  to 
other  differences  between  saturated  open-chain  and  ring-com- 
pounds, like  cis-trans-isomerism  ;  viz.  that  ring- formation 
deprives  the  two  end-carbons  of  a  chain  of  their  free  rotation. 
The  writer  has  nowhere  seen  this  difference  put  in  the  form 
which  is  here  given  to  it.  It  usually  appears  in  another  form, 
viz.  in  the  distinction  that  is  drawn  between  ordinary  asym- 
metry, where  it  can  be  referred  as  being  due  to  a  particular 
asymmetric  carbon,  and 

The  so-called  Molecular  Asymmetry 

where  it  is  not  so  referable,  as  for  example,  in  the  case  of 
inosites.  This  distinction  is  considered  by  many  chemists  to  be 
unnecessary  and  even  illogical ;  and  so  it  appears,  when  stated 
in  such  a  form ;  because  all  optically  active  molecules  are  asym- 
metric, whether  they  contain  an  asymmetric  carbon  or  not. 
Further,  it  is  to  be  noted  that  all  substances  whose  activity  is 
alleged  to  be  due  to  the  asymmetry  of  the  molecule  as  a  whole, 
are  ring-compounds  (the  only  open-chain  grouping,  which,  if 
realised,  will  fall  in  this  category,  is  the  allene  grouping, 
which  will  be  fully  discussed  presently).  For  these  reasons,  it 
appears  to  the  writer  both  logical  and  convenient  to  state  this 
difference  as  a  difference  between  saturated  open-chain-  and  ring- 
compounds. 

This  can  be  further  illustrated  by  taking  a  concrete  example, 
which  has  been  a  subject  of  great  controversy  recently.  In  1909, 
Perkin,  Pope,  and  Wallach  l  synthesised 

i-Methyl-cyclohexylidene-4-Acetic  Acid 

CHj-,        /CH2 CH2\  /H 

\q/  '  )C:::::::;;(/ 

H  /  '\cH, CH,/  >N\COOH 

(1)  (4)  (7) 

which   they   subsequently   succeeded   in   resolving  into  optical 
isomers. 

[In  the  configuration,  all  the  linkages  represented  by  whole 
lines  lie  in  one  plane,  while  the  linkages  represented  by  the 
dotted  lines  lie  in  a  plane  at  right  angles  to  the  first,  according 
to  the  Van't  Hoff  view,  and  in  any  other  plane  or  planes,  accord- 
ing to  the  writer's  view.] 

1  Trans.  Chetn.  Soc.  1909,  1789. 


STEREOISOMERISM   AND  OPTICAL  ACTIVITY   239 

The  structure  as  a  whole  is  devoid  of  any  plane  or  symmetry, 
and  is  not  identical  with  its  mirror-image  ;  but  here,  as  in  the 
case  of  the  inosites,  there  is  no  truly  asymmetric  carbon,  although 
there  is  a  pseudo-asymmetric  one,  viz.  C  (1). 

The  authors  maintain  that  this  is  a  case  where  the  optical 
activity  is  due  to  the  asymmetry  of  the  molecule  as  a  whole  ; 
while  Everest1  and  others  maintain  that  C  (1)  can  be  regarded 
as  asymmetric,  by  a  suitable  modification  of  the  definition.  Now 
this  latter  view  is  only  a  round-about  and  clumsy  way  of  putting 
the  distinction  between  open-chain-  and  ring-compounds,  which 
has  been  alluded  to  above.  The  former  view  emphasises  this 
distinction  more  strongly  (although  in  a  different  form)  than  the 
latter,  and  so  far  it  is  better.  But  what  is  meant  by  saying  that 
the  activity  is  due  to  the  asymmetry  of  the  whole  molecule? 
We  have  seen  that  this  has  no  meaning,  that  the  optical  activity 
cannot  be  regarded  as  being  produced  by  asymmetry,  but  must 
be  regarded  as  an  effect  of  a  screw-spiral  structure  of  some  sort. 
Such  an  arrangement,  as  far  as  the  writer  can  see,  can  only  be 
regarded  round  one  particular  carbon,  and  not  round  the  whole 
ring;  and  that  particular  carbon  in  this  case  must  be  C  (1). 
And  this  is  where  Everest's  view  is  more  suggestive  than  the 
other  view. 

To  recapitulate :  we  started  with  the  fact  that  enantio- 
morphism  does  not  necessarily  involve  optical  activity  in 
crystals ;  further  it  was  pointed  out,  that  even  if  it  were  the 
case,  enantiomorphism  can  hardly  be  considered  as  the  efficient 
cause  of  optical  activity,  but  that  the  nature  of  the  phenomenon 
suggests  something  of  the  nature  of  a  screw-spiral  arrangement 
of  particles  as  its  probable  cause.  And  then  an  attempt  was 
made  to  apply  this  idea  to  the  various  types  of  carbon  com- 
pounds, which  are  optically  active  in  the  liquid  or  dissolved 
state,  and  in  which,  therefore,  the  activity  is  due  to  the  arrange- 
ment of  atoms  in  the  molecule. 

So  far,  the  new  hypothesis  has  given  us  nothing  essentially 
new.  It  has  only  satisfied  what  seems  to  the  writer  to  be  a 
logical  necessity.  This  logical  necessity  may  not  perhaps  obtain 
general  admittance  for  the  hypothesis,  unless  it  has  been  put  to 
a  more  concrete  test.  This  test  is  fortunately  supplied  by  the 
following  important  case. 

'  Chem.  News,  1909,  100,  295. 


24o  SCIENCE  PROGRESS 

Van't  Hoff1  has  predicted  that  a  molecule  of  the  allene 
type 

xv  /x     (a) 

>C  :  C : C< 

y/  \y     (d) 

will  be  optically  active,  inasmuch  as  it  is  asymmetric  and 
enantiomorphous.  Substances  of  this  type  are  very  unstable  and 
very  difficult  of  preparation.  In  1910  Lapvvorth  and  Wechsler  2 
prepared  a  substance  which  they  thought  to  be 

C,H5s.  /CfiH5 

>C  :  C  :  C;' 
C10H7/  *  -  COOH 

diphenyl-naphthyl-aller.e-carboxylic  acid. 

They  tried  to  resolve  it  into  two  optical  isomerides  by  the  usual 
methods,  but  were  unsuccessful.  But  on  account  of  the  great 
difficulty  of  handling  such  substances,  their  experiments  cannot 
be  regarded  as  decisive.  The  question  is  still  an  open  one,  and 
there  is  room  for  prediction. 

According  to  the  ideas  put  forth  in  the  preceding  pages, 
substances  of  such  a  configuration  should  not  be  optically  active, 
in  spite  of  enantiomorphism,  for  want  of  the  necessary  screw- 
spiral  structure.  The  deductions  drawn  from  the  two  hypotheses 
are  at  variance  with  each  other  in  this  case,  which  will  therefore 
serve  as  an  excellent  test-case. 

It  is  usually  argued  that  a  structure  like  this 


XHC/^'V^SCHX 

\(CH,)/     X(CH2)/ 


simulates  the  allene  structure,  for  all  practical  purposes,  so  far 
as  optical  activity  is  concerned.  The  writer  ventures  to  doubt 
this.  He  submits  that  there  is  a  world  of  difference  between 
the  two.  In  the  allene  type  the  presence  of  the  double  bonds 
makes  a  screw-spiral  structure  impossible;  but  such  is  not  the 
case  in  the  other  type,  where  the  spatial  distribution  of  the 
linkages  is  similar  to  that  in  the  case  of  an  ordinary  carbon,  thus 
making  a  screw-spiral  structure  possible. 

1  La  Chimie  dans  Pespace  (1875). 
'  Trans.  Chem.  Soc,  19 10,  38. 


STEREOISOMERISM  AND  OPTICAL  ACTIVITY  241 

[Supplementary  Note 

On  p.  235  it  has  been  stated  that  certain  relations  hold  good 
in  open-chain-compounds  of  all  types,  except  one.  The  exception 
is  of  such  an  extraordinary  character  that  it  deserves  some 
attention  in  this  place.  It  may  be  represented  by  the  following 
general  formula : l 

Rd\c/R1 

Rl/   ^Rd 

where  Rd  and  Rl  represent  two  enantiomorphous  radicals.  If  a 
model  of  such  a  formula  be  constructed,  it  will  be  found  that 
the  structure  as  a  whole  is  devoid  of  any  plane  of  symmetry,  if 
the  symmetry  of  the  radicals  also  is  taken  into  consideration. 
This  is  shown  in  the  following  figure  : 


If  P  is  a  plane  that  passes  through  the  central  carbon  so  as  to 
make  3  and  4  lie  symmetrically  on  either  side,  it  does  cut  1  and  2 
asymmetrically,  as  in  each  case  the  black  ball  is  opposed  by  the 
dotted  ball,  the  white  being  supposed  to  lie  in  the  plane  itself; 
and  the  same  will  be  found  to  be  the  case  with  every  plane. 

But  this  configuration  is  identical  with  its  mirror-image. 

If  the  two  pairs  of  radicals  are,  however,  joined  up  to  form 
two  rings,  so  that  the  central  carbon  is  a  member  of  both  the 
rings,  we  get  a  structure  like  this  : 


XHC 


/(CHsK       /(CH2)nx 
NCH,)/    X(CH2)n< 


which  is  enantiomorphous.     This  again  brings  out  the  distinction 
between  open-chain-  and  ring-compounds.] 


16 


1  Mohr,/.  Pr.  Chem.  [2]  68,  369  (1903). 


242  SCIENCE  PROGRESS 

PART   III.-COMPOUNDS  OF  NITROGEN 

Tervalent  Nitrogen 

When  we  consider  a  compound,  in  which  a  nitrogen  atom  is 
linked  to  three  univalent  atoms  or  groups,  two  configurational 
formulae  at  once  suggest  themselves  to  us.  The  first  is  the  plane 
formula,  in  which  all  the  valencies  lie  in  the  same  plane.  The 
second  is  the  tetrahedral  formula,  in  which  the  nitrogen  occupies 
one  corner  of  the  tetrahedron,  and  the  three  atoms  or  groups  the 
remaining  corners,  the  valencies  being  directed  along  the  edges. 
Facts  must  decide  which  of  these  two  is  the  more  probable  one. 

According  to  the  usual  idea,  the  tetrahedral  formula  necessi- 
tates the  existence  of  optical  isomers,  when  all  the  three  groups 
attached  to  the  nitrogen  are  different.  But  all  attempts  made 
up  till  now  to  resolve  substances  of  that  kind  into  optical 
isomers  have  invariably  failed.  Neither  are  there  any  facts  that 
give  any  hope  of  success  in  the  matter.  So  the  general  tendency 
now  is  towards  giving  up  the  tetrahedral  formula,  and  accepting 
the  plane  one. 

On  the  other  hand,  there  are  many  facts  that  tell  against  the 
plane  configuration.  The  most  important  of  these  is  the  existence 
of  two  isomers  in  case  of  substances  like  aldoximes,  ketoximes, 
hydrazones,  etc.,  and  the  diazo-compounds.  It  has  been  con- 
clusively proved  that  the  isomers  in  each  of  these  cases  are 
structurally  identical,  and  must  therefore  be  stereo-isomers,  and 
the  hypothesis  of  Hantzsch  and  Werner1  is  generally  accepted 
as  the  true  explanation  of  the  isomerism.  Hantzsch  and  Werner 
assign  the  following  configurations  to  the  isomers  in  the  different 
cases : 


Syn-form. 

Anti-form. 

Aldoximes     . 

R— C— H 

R— C— H 

II 
N— OH 

II 
HO— N 

Ketoximes     .        . 

R— C— R' 

R— C— R' 

II 

N— OH 

II 
HO— N 

Diazo-compounds  . 

Ar— N 

II 
X— N 

Ar— N 

II 
N-X 

1 

Ber.  23,  ii  (1890). 

STEREOISOMERISM   AND  OPTICAL  ACTIVITY  243 

Here  the  two  nitrogen-bonds  that  join  it  to  the  carbon  or  the 
other  nitrogen  are  supposed  to  be  in  one  plane,  while  the  third 
bond  lies  in  a  different  plane.  This  creates  a  strong  presumption 
in  favour  of  the  tetrahedral  formula. 

The  hypothesis  of  Hantzsch  and  Werner,  although  it  explained 
the  numerous  phenomena  in  question  in  a  beautifully  simple 
manner,  did  not  make  its  way  unopposed.  Even  now  it  is 
accepted  by  chemists  with  considerable  reserve.  The  reason  is, 
that  it  seems  impossible  to  understand  by  what  mysterious  forces 
the  nitrogen-bonds  are  deviated  from  their  normal  arrangement 
in  one  plane. 

Evidence  of  an  interesting  kind  has  been  recently  brought 
forward  by  Mills  and  Bain,1  in  support  of  the  Hantzsch-Werner 
hypothesis.  These  workers  prepared  the  oxime  of  cyclo-hexa- 
none-4-carboxylic  acid  : 

Hx       /CH, CH2X 

>C<  >C:-_- ------- -.1 N  .  OH 

COOH/       \CH, CH/ 

(4)  *     (1) 

and  found  that  this  acid  forms  both  dextro-  and  laevo-rotatory 
salts  of  the  alkali  metals.  Now  in  this  configuration,  whether 
we  consider  the  optical  activity  as  due  to  the  asymmetric  C  (4), 
or  we  consider  it  as  due  to  the  asymmetry  of  the  whole  molecule, 
its  mere  presence  demands  that  the  single  bond  joining  OH  to  N 
lies  in  a  plane  different  from  that  of  the  other  two  bonds.  This 
fact  obviously  gives  considerable  support  to  the  Hantzsch- 
Werner  hypothesis. 

So  here  there  seems  to  be  a  dead-lock.  One  set  of  facts 
requires  one  configuration  for  tervalent  nitrogen,  another  set 
requires  another.  Now  let  us  see  if  the  new  hypothesis  helps 
us  out  of  the  difficulty. 

As  has  been  mentioned  above,  it  has  been  tacitly  assumed 
that  a  tetrahedral  formula  for  tervalent  nitrogen  will  require  the 
existence  of  optical  isomers,  when  all  the  three  groups  attached 
to  it  are  different,  because  it  will  give  two  enantiomorphous 
configurations.  But  we  have  seen  already  that  this  assumption 
is  not  valid.  Besides  enantiomorphism,  some  sort  of  screw- 
spiral  structure  must  be  present  in  the  configuration,  if  it  is  to 
show  optical  activity. 

1   Trans.  Chan.  Soc.  1910,  1866. 


244  SCIENCE   PROGRESS 

So  let  us  see  whether  a  compound  N,  a,  b,  c  has  such  a 
structure,  when  we  represent  it  by  the  tetrahedral  formula.  In 
order  to  find  out  whether  a  given  configuration  will  be  optically 
active  or  not,  we  have  simply  to  ask  the  question  (as  we  have 
done  before  in  the  case  of  carbon-compounds),  whether  it  is 
possible  for  the  plane-polarised  ray  to  find  a  direction  through 
the  molecule,  such  that  there  will  be  no  forces  round  it,  that  will 
tend  to  twist  the  plane  of  polarisation.  If  there  is  no  such 
direction,  then  the  molecule  will  lie  in  such  a  position  as  will 
produce  minimum  rotation.  But  if  there  is  such  a  direction, 
then  the  molecule,  being  mobile,  will  take  the  corresponding 
position,  in  accordance  with  the  principle  of  "  least  resistance." 

Now,  clearly  there  is  such  a  direction  possible  in  the  con- 
figuration under  consideration.  Suppose  the  ray  passes  along 
one  of  the  three  bonds;  then  it  is  clear  that  the  remaining  two 
groups  can  in  no  sense  be  described  as  lying  on  a  spiral  round 
the  ray,  and  hence  there  will  be  no  rotation. 

Then  there  arises  the  further  question,  whether  the  isomerism 
of  the  two  enantiomorphous  configurations  : 


a*-- 


will  at  all  be  made  manifest  in  any  of  the  other  physical  or 
chemical  properties.  By  analogy  of  carbon-compounds,  it  seems 
probable  that  the  two  configurations  will  be  identical  in  physical 
and  chemical  properties.  The  evidence  of  facts  has  so  far  been 
of  a  very  indecisive  character;  and  it  is  too  early  yet  to  form 
any  conclusion  in  the  matter.  But  if  we  look  at  all  the  cases  ! 
of  alleged  differences  in  properties  of  such  isomers,  one  fact  at 
once  strikes  our  notice,  viz.  that  in  all  the  cases  the  groups 
attached  to  the  nitrogen  are  of  a  very  complex  character. 

1  For  examples  see  Stewart's  Stereochemistry,  p.  264. 


STEREOISOMERISM  AND  OPTICAL  ACTIVITY  245 

Pentavalent  Nitrogen 

If  one  has  to  suggest  a  possible  configuration  for  a  compound 
containing  pentavalent  nitrogen,  one  must  bear  in  mind  all  the 
facts  which  are  known  at  present,  and  which  it  must  satis- 
factorily explain.  One  has  to  take  the  following  facts  into 
consideration,  viz.  (1)  existence  or  non-existence  of  optical 
isomers  in  the  different  types,  (2)  existence  or  non-existence  of 
ordinary  stereo-isomers,  and  finally  (3)  derivation  from  tervalent 
nitrogen. 

Various  configurations  have  been  suggested ;  but  we  need 
not  discuss  all  of  them  here.  The  one  that  explains  the  facts 
most  satisfactorily,  and  is  therefore  most  in  vogue,  is  the 
pyramidal  formula  of  Bischoff. 


a^ vd 


Let  us  see  how  it  works  out  in  the  different  cases. 

For  convenience,  let  us  consider  the  type  N,  a,  b,  c,  d,  x,  first. 
Optically  active  substances  of  this  type  have  now  been  con- 
clusively proved  to  exist,  and  Bischoffs  formula,  as  can  be 
easily  seen,  accounts  for  the  optical  activity ;  but  the  formula 
demands  two  stereo-isomers  (each  being  divisible  into  d-  and  1- 
enantiomorphs)  that  are  not  yet  known  to  exist. 

X  X 


ri 


H- 


N 


a. 


d 


Further,  there  is  the  difficulty  of  deriving  it  from  the  generally 
accepted  plane  configuration  of  tervalent  nitrogen. 

H.  O.  Jones1  has  attempted  to  explain  the  absence  of  the  two 


1  Trans.  Chem.  Soc.  1903,  1403;  1905,  1721. 


246 


SCIENCE  PROGRESS 


stereoisomers.  He  points  out  that  all  the  substances  of  this  type 
thus  far  prepared  have  been  prepared  from  tervalent  compounds 
of  the  type  N,  a,  b,  c ;  and  when  we  add  a  substance  like  d  x  to 
it,  the  new  group  d  chooses  that  position  with  respect  to  the 
already  existing  radicals  which  produces  the  most  stable  con- 
figuration. He  starts  with  the  plane  formula  of  tervalent 
nitrogen,  and  ends  with  the  pyramidal  formula  for  the  penta- 
valent  nitrogen.     He  represents  the  changes  thus  : 


-> 


><J 


P^ 


The  last  two  configurations  are  enantiomorphous  and  represent 
the  d-  and  1-  modifications  of  the  one  stable  isomer. 

Jones's  theory  gives  an  ingenious  explanation  of  the  absence 
of  stereo-isomers ;  but  the  weak  point  in  his  theory  is  that  it 
does  not  give  an  adequate  explanation  of  the  deviation  of  the 
nitrogen-bonds  from  their  original  arrangement  in  one  plane 
into  two  different  directions  as  represented  above.  In  fact,  his 
hypothesis  is  open  to  the  same  objection  as  the  Hantzsch- 
Werner  hypothesis. 

It  has  been  shown  above,  while  discussing  the  formula  of 
tervalent  nitrogen,  that  we  may  assign  a  tetrahedral  configuration 
to  it,  if  any  facts  demand  it,  in  spite  of  the  fact  that  no  tervalent 
nitrogen  compounds  show  optical  activity ;  and  so  there  is  no 
difficulty  about  the  whole  question  at  all. 

If  we  assume  with  Jones  that  the  most  stable  configuration 
results  by  the  addition  of  d  x  to  N,  a,  b,  c,  the  change  from 
tervalent  to  pentavalent  nitrogen,  with  only  one  pair  of 
enantiomorphs  being  formed,  can  be  very  simply  represented 
as  follows  : 


STEREOISOMERISM  AND  OPTICAL  ACTIVITY  247 
N  N 


V 

X 


N 


The  two  resulting  substances  are  enantiomorphs,  as  are  also 
their  originals.  But  now  the  molecule  has  become  more 
complex,  so  that  it  is  no  longer  possible  for  the  plane-polarised 
ray  to  find  a  direction  through  the  molecule,  so  as  to  avoid 
having  the  atoms  or  groups  arranged  in  a  spiral  round  itself, 
because  the  pyramid  is  irregular,1  the  four  groups  a,  b,  c,  and 
d  being  all  different.  Hence  the  configurations  will  be  optically 
active,  one  being  dextro-  and  the  other  laevo-rotatory. 

Now  passing  on  to  the  other  types,  we  find  that  in  the  type 
Na3bx  no  stereo-isomers  are  possible,  and  none  are  known. 
The  case  of  trimethyl-ethyl-ammonium-iodide,  which  was  at  first 
thought  to  be  a  case  of  stereo-isomerism,  is  now  shown  to  be 
only  one  of  dimorphism. 

As  regards  optical  activity,  that  also  is  not  possible,  as  the 
molecule  certainly  gives  a  smooth  path  to  the  ray  in  at  least 
two  directions.  Suppose,  for  instance,  the  ray  lies  along  x — N, 
then  the  line  joining  the  four  radicals  a,  a,  a,  and  b  will  not  be 


1  The  conception  of  the  nature  of  the  linkages  is  the  same  here  as  in  the  case 
of  carbon.  In  the  case  of  carbon,  however  irregular  the  spatial  distribution  of  the 
linkages  and  the  radicals,  the  resulting  figure  could  always  be  accurately  described 
as  a  tetrahedron.  But  here  the  distribution  of  the  linkages  and  the  radicals  will 
often  make  the  formation  of  a  pyramid  impossible.  Still,  in  the  sequel,  the  word 
"pyramid"  has  been  used  loosely  to  describe  the  resulting  polyhedron  in  all 
cases. 


248  SCIENCE  PROGRESS 

a  spiral  because  three  of  them  are  identical,  and  so  there  will  be 
a  break.     The  same  is  also  true  of  the  direction  b — N. 

In  the  type  Na2bcx,  stereo-isomerism  is  possible,  as  the  two 
identical  radicals  a,  a  may  lie  opposite  or  contiguous  to  each 
other  at  the  base  of  the  pyramid.  The  evidence  of  facts  is 
inconclusive.  Schryver  and  Collie1  first  succeeded  in  pre- 
paring two  crystalline  modifications  of  dimethyl-ethyl-ammonium 
chloro-platinate;  but  there  is  no  evidence  to  prove  that  the 
phenomenon  is  not  due  to  dimorphism,  which  was  shown  to  be 
present  in  the  last  case.  Other  attempts  in  this  direction  have 
been  equally  unsuccessful. 

In  both  the  possible  isomers  a  smooth  path  is  possible  for 
the  polarised  ray  along  N — x,  because,  in  that  case,  the  line 
joining  the  other  four  groups  a,  a,  b,  c  will  not  be  a  continuous 
spiral,  as  two  of  the  groups  are  identical,  and  so  there  will  be  a 
break.  So  substances  of  this  type  will  not  show  optical  activity, 
and  none  has  been  observed  so  far. 

In  all  the  three  cases  we  have  so  far  considered,  the  theory 
is  quite  open  so  far  as  stereo-isomers  (other  than  optical  isomers) 
are  concerned.  The  absence  of  such  in  each  case  can  be  ex- 
plained by  Jones's  hypothesis,  referred  to  above,  viz.  that  the 
most  stable  configuration  is  produced ;  but  if  in  future  facts  are 
discovered  proving  conclusively  the  existence  of  such  isomers, 
we  have  simply  to  drop  this  assumption,  without  making  any 
other  changes  in  the  general  conception. 

An  interesting  case,  apparently  similar  to  but  really  quite 

different  from  the  last  one  above  considered,  is  that  of  amino- 

oxides : 

a\  a\        /OH 

b-)N  =  O      or      b-)N< 
c/  c/     \OH 

In  1908  Meisenheimer2  showed  that  methyl-ethyl-aniline 
oxide  could  be  resolved  into  two  active  components.  But  at 
that  time  it  could  not  be  decided  whether  the  free  active  bases 
were  true  amino-oxides  or  the  corresponding  di-hydroxy-com- 
pounds,  the  general  tendency  of  chemists  being  in  favour  of 
the  di-hydroxy  constitution.  But  recently  Meisenheimer3  has 
proved  that  these  substances  are  optically  active  When  dissolved 

1  Proc.  Chem.  Soc.  1891,  39. 

2  Ber.  41,  3966  (1908). 

3  Annalen,  385,  117  (191 1). 


STEREOISOMERISM   AND   OPTICAL  ACTIVITY   249 

in  anhydrous  benzene,  in  which  solvent  they  can  only  be  present 
as  true  oxides. 

The  optical  activity  in  this  case  is  easily  explained.  The 
oxygen  is  linked  up  to  two  nitrogen-bonds  ;  these  were  originally 
at  an  angle,  but  may  now  be  supposed  to  be  practically  parallel 
and  very  close  to  each  other — in  fact,  equivalent  to  one  bond 
as  far  as  the  spatial  arrangement  of  groups  or  radicals  is  con- 
cerned. The  whole  structure  thus  becomes  tetrahedral,  exactly 
like  the  carbon  structure ;  and  as  the  four  radicals  are  different, 
optical  activity  is  to  be  expected. 

Conclusion 

In  the  foregoing  pages  the  writer  has  tried  to  show  that  the 
idea  that  optical  activity  is  not  a  result  of  enantiomorphism,  but 
that  both  of  them  (where  they  coexist)  are  results  of  another 
structural   cause,   viz.   the   screw-spiral  arrangement,  although 
recognised  by  crystallographists,  has  been  ignored  entirely  by 
chemists,  in  spite  of  the  fact  that  what  holds  good  in  crystallo- 
graphy,  as   regards   optical   activity,  must   also   hold   good   in 
chemistry,  with  this  difference,  that  while  the  crystallographist 
deals  with  the  arrangement  of  molecules  (or  some  other  higher 
units)   in   the   crystal    structure,    the    chemist    deals   with   the 
arrangement  of  atoms  within  the  molecule  itself.     He  has  further 
tried  to  show  that  the  same  idea  can  be  successfully  applied  in 
chemistry,  giving  illustrations  from  the  various  types  of  com- 
pounds of  carbon  and  nitrogen.     For  this  purpose  he  has  made 
certain  assumptions,  drawn  certain  deductions  from  them,  and 
has  even  ventured  on  a  prediction.     If  that  prediction  is  not 
fulfilled,  or  if  those  assumptions  are  found  to  be  untenable  on 
other  grounds,  they  will  have  to  be  abandoned  ;  and  with  them 
the  particular  way,  here   suggested,  of  conceiving  the  screw- 
spiral  structure  must  also  go.     But  some  other  way  must  be 
found,  or  some  cause  of  optical  activity  other  than  screw-spiral 
arrangement  must  be  postulated ;  because  we  can  hardly  regard 
enantiomorphism  as  the  cause  of  optical  activity,  in  the  face  of 
the  enantiomorphous  but  optically  inactive  crystals  of  barium 
nitrate. 


SOME   ASPECTS   OF   GEOLOGIC   TIME 

By  H.  S.  SHELTON,  B.Sc.  Lond. 

PART  I.— GEOLOGIC  PROCESSES  AND  GEOLOGIC 

TIME 

It  is  a  fact  of  common  knowledge  that  the  opinion  of  men  of 
science  on  the  much-vexed  question  of  geologic  time  is  in  a 
state  of  flux.  Recent  criticism  and  discovery  have  completely 
shattered  the  theories  of  Lord  Kelvin.  The  collateral  methods 
of  Prof.  Joly  (on  sea  salt)  and  of  Prof.  Sollas  (on  the  thickness 
of  sedimentaries)  have  been  subjected  to  trenchant  criticism.1 
A  new  method  has  arisen  in  the  estimates  of  the  amount  of 
helium  accumulated  in  radioactive  deposits.2  A  few  words  of 
introduction  are,  therefore,  desirable,  to  set  forward  my  own 
point  of  view.  I  would,  therefore,  say  that,  in  my  opinion,  no 
single  one  of  the  methods,  which,  until  a  few  years  ago,  were 
regarded  by  men  of  science  as  valid,  and,  within  reasonable 
limits,  final,  is  of  any  value  whatever.3  My  own  opinion  is  that 
geologic  time  is  vastly  greater  than  the  geologist,  since  the  days 
of  Lord  Kelvin,  has  thought  probable.  But  the  opinion  does 
not  greatly  matter  for  the  purposes  of  this  essay.  Here  we  are 
suggesting  various  methods  of  attacking  our  problem.  If  the 
suggested  methods,  or  other  new  methods,  confirm  the  con- 
clusion of  the  present-day  geologist,  the  labour  will  not  be 
wasted.  If,  after  careful  study,  they  establish  an  entirely 
different  order  of  time,  their  necessity  will  be  all  the  more 
certain.  For,  even  if  present-day  views  and  methods  are 
mistaken,   it  does   not  follow   that   the   problem   is   insoluble. 

1  See  my  article  in  the  Contemporary  Review,  February  igu. 

2  See  particularly  papers  by  Prof,  the  Hon.  R.  J.  Strutt  in  the  Proceedings  of 
the  Royal  Society. 

3  I  have  dealt  with  them  individually  in  the  following  papers,  in  addition  to  the 
one  already  mentioned  :  "  On  the  Tidal  Retardation  of  the  Earth  "  {New  Quarterly, 
November  1909)  ;  "  The  Age  of  the  Earth  and  the  Saltness  of  the  Sea  "  {Journal 
of  Geology,  February — March  1910);  "Secular  Cooling  as  an  Illustration  of  the 
Methods  of  Applied  Mathematics"  {Journal  of  Philosophy,  September  1,  1910) ; 
"  The  Age  of  the  Sun's  Heat"  {Contemporary,  June  1913). 

250 


SOME  ASPECTS   OF  GEOLOGIC  TIME  251 

The  structure  of  the  crust  of  the  earth  contains  within  itself 
so  many  signs  of  the  manner  of  its  formation,  that  it  is  surely 
possible  to  disentangle  valid  methods,  if  only  the  geologist  will 
diligently  search  them  out.  If  he  will  cease  from  following 
false  clues,  it  is  not  impossible  that  he  may,  even  now,  be  on 
the  way  to  clearer  and  more  certain  knowledge. 

Towards  the  accomplishment  of  this  end,  it  is,  as  yet, 
impossible  for  any  single  worker  to  do  more  than  to  make  a 
few  tentative  suggestions.  As  the  question  is  seriously  attacked, 
and  as  it  is  made  the  subject  of  careful  and  detailed  research, 
new  paths  will  open,  and  new  methods  will  be  discovered. 
Meanwhile,  it  will  be  of  interest  to  note  a  number  of  possibilities, 
the  full  bearing  of  which  the  geologist  of  to-day  is  liable  to 
overlook. 

Let  us  first  consider  the  use  that  can  be  made  of  the  data  we 
are  supposed  to  possess  concerning  the  rate  of  erosion.  The 
discharge  of  sediment  at  the  mouths  of  a  number  of  rivers  has 
been  measured,  and,  by  these  measurements,  geologists  have 
attempted  to  estimate  the  rate  at  which  the  continents  are  being 
carried  to  the  ocean.  But  difficulties  arise  when  we  attempt  to 
obtain  from  our  data  a  general  average  rate  of  denudation, 
especially  such  as  it  is  possible  to  apply  to  previous  geologic 
epochs.  The  rate  of  erosion  must  vary  enormously.  In  a 
rainless  district,  such  as  the  canons  of  the  Colorado,  it  is  very 
slow.  In  a  country  of  torrential  rainfall,  such  as  the  Ganges 
basin,  it  is  very  great.  The  question,  therefore,  must  be  faced 
which  conditions  can  be  regarded  as  typical.  The  rivers  men- 
tioned by  Geikie,  concerning  which  reliable  measurements 
exist,  are  the  Mississippi,  the  Ganges,  the  Hoang-Ho,  the  Rhone, 
the  Danube,  and  the  Po.  To  these  Chamberlin  adds  the 
Potomac,  the  Rio  Grande,  the  Uraguay,  the  Nile,  and  the 
Irrawady.1  The  majority  of  the  data  measure  the  transport  of 
alluvium  from  irrigated  and  cultivated  soils.  Small  particles 
of  alluvium  are  carried  a  short  distance,  and  are  either  deposited 
elsewhere  in  the  basin  or  in  the  region  of  the  slowly  forming 
delta.  To  interpret  correctly  what  this  transportation  means 
requires  careful  thought  and  analysis.  The  discharge  may 
represent  the  normal  and  average  lowering  of  the  level  of  the 
river  basin.     But  there  is  another  possibility  which  must  not  be 

1  See  Geikie,  Geology ■,  p.  589  ;  Chamberlin  and  Salisbury,  Geology ',  etc.,  vol.  i. 
p.  101. 


252  SCIENCE   PROGRESS 

overlooked.  Alluvial  land,  irrigated  and  manured,  is,  clearly  and 
obviously,  subject  to  rapid  denudation.  The  ground  is  porous. 
The  roots  of  trees  and  crops  are  continually  loosening  new  rock. 
The  ground  is  soaked  by  the  percolation  of  water.  Passage 
is  made  in  winter  for  the  water  to  enter  the  rock  below,  to 
freeze  and  break  it  up.  The  humus  acids  formed  by  the  rotting 
of  manure  are  not  without  their  effect.  It  is,  indeed,  not 
unlikely  that  much  of  the  observed  erosion  is  due  to  human- 
kind. We  must  not  forget  the  influence  of  man  as  a  geologic 
agent. 

The  data  at  our  disposal  are  too  scattered  for  us  to  form 
definite  conclusions,  but  it  is  an  interesting  fact  that  all  rivers 
with  a  high,  or  an  abnormal,  discharge  of  sediment  are  situated 
in  densely  populated  and  highly  cultivated  districts.  Those 
with  a  calculated  rate  of  erosion  greater  than  a  foot  in  2,000 
years  are  the  Ganges,  the  Irrawady,  the  Hoang-Ho,  the  Po, 
the  Rhone,  the  basins  of  all  of  which  have  been  highly  cultivated 
for  generations.  Those  with  a  moderate  rate  of  erosion  (more 
than  a  foot  in  7,000  years)  are  the  Potomac,  the  Mississippi,  the 
Danube,  all  of  which  drain  districts  of  considerable  cultivation. 
The  rivers  with  an  abnormally  low  rate  of  discharge  of  sediment 
are  the  Uraguay,  the  Rio  Grande,  the  Nile.  The  Nile  is  ex- 
ceptional owing  to  the  absence  of  rainfall  in  the  lower  part  of 
its  basin  and  to  the  fact  that  a  proportion  of  the  sediment  from 
the  upper  reaches  is  deposited  in  the  rainless  district  during 
the  annual  river  overflow.  The  Uraguay  and  the  Rio  Grande 
are  situated  in  districts  of  comparatively  sparse  cultivation. 
These  facts  are  striking.  The  conclusion  may  or  may  not  be 
that  here  suggested,  namely  that  the  discharge  of  sediment 
does  not  represent  true  geologic  erosion,  but  merely  the  effect 
of  cultivation,  but,  at  least,  the  coincidence  shows  that  the 
problem  of  the  rate  of  erosion  under  diverse  conditions  requires 
further  investigation. 

Wider  data  are  needed  to  avoid  possible  sources  of  error. 
We  should  endeavour  to  find  river  basins  under  conditions 
similar  to  those  which  existed  before  the  earth  was  trodden  by 
the  foot  of  man.  If  we  could  obtain,  for  example,  reliable 
experimental  data  for  the  Amazon  (a  tropical  and  sparsely 
populated  district),  the  Colorado,  and  Murray  (districts  of 
scanty  rainfall),  the  Mackenzie  (a  district  under  glacial  condi- 
tions),  and   one   or    two   miscellaneous    results   (such    as    the 


SOME  ASPECTS   OF  GEOLOGIC  TIME  253 

Zambesi)  for  other  districts  where  the  population  was  sparse, 
we  should  throw  some  light  on  our  problem.  Measurements 
for  the  upper  reaches  of  rivers  would  be  helpful.  Also  we  must 
note  that,  though  the  rate  of  discharge  of  sediment  is,  as  yet, 
our  best  guide  to  the  rate  of  erosion,  it  is  not  impossible  that 
others  may  be  discovered.  For  the  present,  however,  we  must 
clearly  realise  that  such  information  as  we  do  possess  is  scanty 
and  uncertain.  There  is  one  other  point  of  importance.  It  is 
highly  probable  that,  in  all  normal  cases,  there  must  be  some 
relation  between  true  geologic  erosion  and  the  soluble  content 
of  the  river.  The  relation  would  not  be  strictly  proportionate 
because  of  the  solubility  of  carbonate  of  lime,  but  there  would, 
as  a  rule,  be  some  relation.  Now  it  is  a  suggestive  fact  that  so 
many  rivers  which  pass  through  districts  of  sparse  population 
have  a  comparatively  small  soluble  content.  If  we  mark  out 
those  like  the  Colorado  and  the  Kansas,  draining  "  bad  lands," 
impregnated  with  large  quantities  of  saline  deposits,  the  soluble 
content  is  unusually  small.  The  Amazon,  for  example,  has  a 
soluble  content  of  less  than  50  parts  per  million.  The  rivers 
of  Northern  Sweden  are  remarkably  pure.  Other  instances 
can  be  given.  Though  rough  and  inaccurate,  the  suggestion 
is  one  on  which  I  lay  some  stress.  It  has  been  shown  that 
the  process  of  weathering  is,  largely,  a  chemical  change,  in 
which  a  portion  of  the  substance  is  carried  away  in  solution, 
and,  by  that  change,  the  remainder  is  loosened  and  comes  away 
in  the  form  of  sediment.  Erosion  and  solvent  denudation  must 
always  be  interrelated. 

Other  circumstances  that  point  to  the  conclusion  that  the 
rate  of  erosion  has  probably  been  overestimated  are  the  long 
periods,  in  all  climates  (except  the  neighbourhood  of  large 
manufacturing  towns),  during  which  inscriptions  will  remain 
legible.  Some,  not  deeply  cut,  will  last  for  many  thousands 
of  years.  Once  again,  it  is  well  known  that  we  can  still  see, 
on  the  rocks  in  mountainous  regions,  striae  which  date  back 
to  the  last  glacial  epoch.  If  this  occurred  (say)  30,000  years 
ago,  several  feet  of  strata  must,  according  to  current  theories, 
have  been  removed  in  the  meantime.  How  anything  of  the 
kind  could  happen  and  leave  the  striae  as  we  now  find  them 
requires  some  explanation.  It  thus  seems  probable  that  the 
rapidity  of  land  erosion  may  be  smaller  than  our  data  would 
tend  to  show.     This  suggestion   I  put  forward   for  what  it  is 


254  SCIENCE   PROGRESS 

worth.     In  any  case,  we  require  more  experiments,  and  more 


carefully  chosen  experiments,  before  we  can  lay  any  stress  on 
the  results  that  have  been  obtained. 


... 

The  principal  point  it  is  necessary  to  emphasise  is  that  the 
rate  of  erosion,  when  we  have  got  it,  is  a  very  useful  guide  to 
the  rapidity  of  geologic  process.  Unfortunately  it  is  the  case 
that  the  enormous  variations  that  are  known  to  exist  are  not 
yet  correlated  with  the  configuration  of  the  country  or  with 
any  other  known  cause.  Thus  we  cannot,  with  any  confidence, 
apply  our  averages  to  particular  cases.  But,  taking  our  present 
information  for  what  it  is  worth,  it  is  surprising  that  geologists 
do  not  apply  it  directly,  instead  of  indirectly.  The  formation 
of  sedimentary  rock  is  a  variable  and  uncertain  process.  It  is 
liable,  not  only  to  extreme  variations,  but  to  actual  reversal, 
without  always  leaving  obvious  indications.  The  rate  of 
erosion  is,  comparatively,  a  constant  quantity.  Let  the  geolo- 
gists, therefore,  endeavour  to  ascertain  the  amount  of  erosion 
which  has  occurred  at  particular  places  and  in  particular 
geologic  epochs.  Instead  of  measuring  deposition,  let  us 
measure  erosion.  We  shall  not  then  be  encumbered  by  in- 
soluble conundrums  concerning  the  ratios  of  the  areas  of 
denudation  and  deposition. 

Some  facts  are  now  available  which  bear  directly  on  this 
particular  problem.  One  very  interesting  research  dates  back 
to  1845.  In  the  course  of  a  thorough  survey  of  a  district  in 
South  Wales,  the  late  Sir  Andrew  Ramsay  discovered  evidence 
of  extensive  denudation.  His  arguments  are  somewhat  difficult 
to  follow,  and  the  conclusions  concerning  erosion  are  not  clearly 
classified  and  tabulated,  but  a  chance  example  will  show  how 
extreme  erosion  has  been.  It  is  stated  that  unconformable  beds 
of  New  Red  marl  overlie  strata  which  show  a  denudation  of  at 
least  5,000  feet  between  that  time  and  the  laying  down  of  the 
Carboniferous  limestone.  It  is  stated  as  probable  that  some 
thousands  of  feet  of  coal  measures  may  also  have  been  eroded. 
This  has  taken  place  in  only  a  part  of  two  adjacent  geologic 
epochs.  This  is,  unfortunately,  local,  as  distinguished  from 
general  or  average  erosion,  but  if  we  allow  more  than  double 
the  very  highest  estimate  of  general  erosion,  and  assume  that  it 
took  place  at  the  rate  of  a  foot  in  a  thousand  years,  we  have  a 
minimum  of  5,000,000  years  for  less  than  a  single  recognised 
geologic  epoch. 


SOME  ASPECTS   OF  GEOLOGIC   TIME  255 

Other  evidence  of  long-continued  erosion  is  found  in  the 
existence  of  "  faults."  In  times  of  terrestrial  upheaval,  the  crust 
of  the  earth  has  been  twisted  in  all  directions.  Strata,  laid  down 
horizontally  in  the  bed  of  the  ocean,  are  upheaved  into  gigantic 
folds.  Locally,  the  series  will  break.  Younger  strata,  in  the 
course  of  time,  will  be  thrust  upwards  over  older  formations, 
and  the  consequent  "  faults  "  often  imply  a  vertical  displacement 
of  many  thousands  of  feet.  Where,  as  is  usually  the  case,  the 
fault  has  been  subject  to  subsequent  erosion,  so  that  there  is 
no  trace  of  it  in  the  conformation  of  the  country,  and  its  presence 
is  only  indicated  by  the  juxtaposition  of  strata  of  different  ages, 
we  have  definite  evidence  of  prolonged  denudation.  The  depth 
of  the  fault  is  shown  by  comparing  the  structure  of  the  strata  on 
opposite  sides,  and  we  are  able  to  infer  that  the  total  erosion 
has  been  much  greater  than  the  thickness  of  the  fault.  The 
ground  on  the  lower  side  must  also  have  been  eroded,  and  the 
depth  of  the  fault  merely  shows  the  excess  of  the  erosion  of  the 
upper  over  the  lower  levels. 

One  striking  example  we  owe  to  the  researches  of  Prof.  Judd. 
He  has  shown  that,  at  Movern  in  Scotland,  since  the  Miocene 
epoch,  a  fault  of  no  less  than  2,000  feet  has  been  formed,  and  the 
upper  side  has  been  denuded  so  that  Miocene  basalts  lie  against 
Silurian  gneiss.  Assuming  the  erosion  on  the  upper  side  of  the 
fault  to  be  twice  as  rapid  as  on  the  lower  side,  4,000  feet  will 
have  been  removed.  At  Prof.  Sollas'  rate  of  denudation,  this 
would  take  more  than  10,000,000  years.  Allowing  every  possible 
weight  to  the  advocates  of  a  minimum  of  geologic  time,  we  could 
indicate  a  minimum  of  5,000,000  years  for  Pleistocene,  Pliocene, 
and  a  small  fraction  of  the  Miocene. 

Many  other  instances  have  been  brought  forward  by  the  late 
James  Croll.  Near  Dunbar,  there  is  a  fault  of  no  less  than 
15,000  feet,  eroded  between  the  Silurian  and  the  Carboniferous. 
In  the  Appalachians,  a  region  has  been  eroded  to  the  extent  of 
no  less  than  35,000  feet.  Nearly  10,000  feet  of  strata  have 
been  removed  between  the  Millstone  Grit  and  the  Permian. 

Present  knowledge,  as  yet,  does  not  allow  us,  from  such  data 
as  these,  to  make  definite  numerical  conclusions,  but  here  is  a 
method  of  research  which  should  be  developed  by  geologists. 
If  they  can  first  find  the  rate  of  erosion  under  a  great  variety  of 
conditions,  and  then  discover  the  extent  of  erosion  and  the  con- 
ditions under  which  it  took  place  in  particular  instances,  during 


256  SCIENCE   PROGRESS 

this  or  that  geologic  epoch,  the  addition  of  the  various  results 
should  give  some  clue  to  geologic  time. 

Further  information  could  be  obtained  if  we  possessed  fuller 
information  concerning  the  extent  of  particular  local  formations. 
The  structure  of  coal  beds  will  illustrate  my  meaning  very  well. 
If  and  when  it  is  possible  to  map  out  the  extent  and  structure  of 
particular  beds,  and  of  the  intervening  strata,  it  might  be  possible 
to  put  together  a  connected  history  of  that  particular  tract  of 
land.  For  this  we  require  detailed  information.  We  require  to 
know  where  and  how  a  particular  bed  commences,  its  extent,  its 
manner  of  grading  into  other  strata,  and  many  other  details. 
We  require  to  be  able  to  make  a  model  of  the  ground  so  as  to 
show  the  configuration  of  its  strata  in  as  much  detail  as  possible. 
We  want  a  geologic  map  of  some  special  tract  of  country  which 
will  show,  not  only  epochs,  but  small  individual  formations. 
The  detailed  sections  of  various  parts  of  a  district  require  com- 
parison and  co-ordination.  Then  its  history  can  be  written. 
Then  we  can  compare  the  processes  of  the  past  with  those  now 
going  on,  and  form  some  idea  of  how,  and  in  what  space  of  time, 
they  occurred.  The  estimate  of  time  would  be  rough,  but,  at 
least,  so  far  as  it  went,  it  would  be  by  the  reconstruction  of 
actual  events. 

The  idea  will  be  made  clearer  if  I  utilise  an  example  which 
I  have  mentioned  before.1  I  refer  to  coal  beds.  The  view  has 
now  received  general  acceptance  that  a  considerable  proportion 
of  these  have  been  formed  in  situ.  There  are,  no  doubt,  such 
things  as  drift  beds,  but  many  of  the  coal  beds,  especially  the 
seams  that  are  large  and  workable,  undoubtedly  represent  the 
actual  sites  of  the  old  Carboniferous  swamps  which  flourished  so 
largely  and  were  so  widespread.  Some  of  these  seams  are  of 
enormous  extent.  There  is,  for  example,  the  "  Pittsburg,"  in 
Pennsylvania,  at  least  12,000  miles  in  area.  Why  should  it  not  be 
possible  to  map  out  a  coal-field  in  detail,  to  show  roughly  where 
each  particular  seam  begins  and  ends,  where  each  divides,  to 
indicate  the  extent  of  each  intervening  layer  of  sandstone,  shale, 
or  limestone,  if  and  when  the  latter  occurs  ? 

Each  successive  coal  bed  indicates  an  advance  and  a  recession 

of  the  sea.     If  and  when  this  has  taken  place  over  large  areas, 

events   have   occurred   to   which    a   minimum   of  time   can   be 

assessed,  or,  at  any  rate,  some  idea  of  the  necessary  time  can  be 

1  See  article  in  Contemporary,  Feb.  191 1. 


SOME  ASPECTS  OF  GEOLOGIC  TIME  25/ 

put  forward.  We  have  several  historical  instances  of  advance 
and  recession  of  the  sea.  Winchelsea  was  a  port  in  Norman 
times.  Hudson  Bay  is  disappearing  at  a  measurable  rate. 
Estimates  of  geologic  periods,  on  lines  like  this,  are,  at  any  rate, 
based  on  events  that  actually  occurred.  They  may  vary,  but 
they  can  only  do  so  within  reasonable  limits.  When  we  have 
no  idea,  or  a  false  idea,  and  can  only  be  guided  by  the  maximum 
thickness  of  sediment,  estimates  may  vary  to  any  degree. 

I  mention  coal  beds  for  two  reasons.  In  the  first  place  they 
represent  the  most  important  of  the  few  strata,  which  are,  for 
commercial  purposes,  actually  bored.  Borings  for  purely 
scientific  investigation  are  far  too  costly  to  be  undertaken  on 
a  large  scale.  Consequently,  in  the  mapping  of  most  strata,  the 
geologist  must  confine  himself  to  the  outcrops.  Such  a  method 
does  quite  well  for  the  tracing  of  the  strata  of  the  larger  epochs, 
but  it  is  very  doubtful  how  far  it  would  suffice  for  mapping  out 
small  beds.  The  borings  in  the  coal  fields  are  already  made, 
and  a  suggestion  such  as  this  will  not  present  insuperable  diffi- 
culties. The  second  reason  is  to  put  a  doubtful  or  disputed 
point,  in  one  specific  instance,  beyond  the  range  of  controversy. 
If  we  have  two  successive  coal  beds  of  known  large  area,  with  a 
layer  of  shale  in  between,  there  can  be  no  possible  doubt,  grant- 
ing that  the  beds  were  formed  in  situ,  of  an  advance  and  a 
recession  of  the  sea.  That  such  events  have  continually  taken 
place  in  the  ordinary  strata,  I  thoroughly  believe.  That  even 
the  maximum  thicknesses  were  formed  intermittently  with  con- 
siderable intervals  of  emergence  from  the  sea  masking  the  great 
epochal  submergence,  is  a  fixed  opinion  of  my  own.  But  proof, 
as  a  general  rule,  is  not  easy.  Fortunately,  the  structure  and 
arrangement  of  coal  beds  make  the  speculation,  for  certain  times 
and  conditions,  a  certainty. 

As  the  science  of  geology  progresses,  and  as  more  and  more 
detailed  facts  are  discovered,  new  methods  will  come  to  light, 
and  such  suggestions  as  these  will  be  trite  and  obvious.  There 
is,  in  the  study  of  the  rocks,  a  wealth  of  material  which  requires 
only  careful  and  intelligent  study  to  solve  many  problems  now 
obscure.  But  such  careful  study  will  not  be  the  work  of 
a  day. 

Until  the  science  of  geology  attains  greater  clearness  and 
exactness,  some  other  lines  of  investigation  may  assist  in  giving 
a  clue  to  the  order  of  the  result.     One  of  these  is  found  in  the 

17 


258  SCIENCE  PROGRESS 

chemical  structure  of  the  Earth's  crust.  Of  the  geochemical 
methods,  the  best  so  far  discovered  is  probably  that  based  on 
calculations  concerning  the  amount  of  limestone  in  the  rocks  of 
the  Earth.  As  is  well  known,  limestone  rock  is  not,  and  cannot 
be,  a  part  of  the  Earth's  original  crust.  It  has  been  slowly  dis- 
solved out  of  the  primitive  and  the  newer  igneous  rocks,  carried 
to  the  sea  in  solution,  and  there  used  by  the  various  marine 
organisms  for  the  formation  of  their  shells.  These  minute  shells 
have  either  formed  comparatively  rapid  local  concretions  of  coral 
reef,  or  have  gathered,  at  a  rate  inconceivably  slow,  in  the 
abysses  of  the  ocean.  Geologic  time  must  have  been  great 
enough  to  admit  of  the  removal  of  all  this  substance  from  its 
place  of  origin  and  its  deposition  in  the  conditions  where  we 
now  find  it. 

The  geologist  whose  name  is  most  intimately  associated  with 
the  question  of  the  evolution  of  carbonate  of  lime  is  the  late 
Mr.  Mellard  Reade.1  Mr.  Reade  did  not  attempt  to  fix  any 
actual  figures.  He  did  not  think  the  subject  was  ripe  for  such 
exactitude  ;  but  he  maintained  strongly  that  these  data  proved 
that  the  Earth  had  existed  for  a  much  longer  period  than  the 
mathematical  physicist  of  his  time  had  thought  to  be  possible. 
The  results  of  the  Challenger  expedition  have  enabled  us, 
within  a  reasonable  degree  of  accuracy,  to  map  out  the  character 
of  the  ocean  floor.  In  the  neighbourhood  of  land,  the  sediments 
are,  in  the  main,  composed  of  detritus  from  the  rivers.  In  the 
greatest  depths,  the  carbonate  redissolves  and  the  floor  is 
composed  of  "  red  clay."  Between  these  two  limits,  the  main 
covering  of  the  ocean  floor  is  carbonate  of  lime. 

Mr.  Mellard  Reade  made  deductions  from  the  calculated 
amount  of  carbonate  of  lime,  and  the  time  that  it  would  take  for 
this  to  be  evolved  from  igneous  rock.  From  that  amount,  he 
inferred  that  the  process  must  have  been  going  on  for  at  least 
600,000,000  years.  This  calculation  I  believe  to  be  substantially 
sound,  though  the  details  will  require  revision  in  the  light  of 
more  recent  knowledge.  It  is,  I  believe,  possible  to  assert  a 
probable  minimum  of  the  order  of  500,000,000  of  years.  The 
number  is  a  minimum  for  two  reasons.  In  the  first  place, 
igneous  action,  whether  at  the  surface  or  deep-seated,  is  con- 

1  See  various  papers  in  the  Geological  Magazine,  also  papers  read  to  the 
Geological  Society.  A  most  important  pamphlet  is  republished  under  the  title  of 
Chemical  Denudation . 


SOME  ASPECTS  OF  GEOLOGIC  TIME  259 

tinually  re-absorbing  carbonates,  with  the  probable  evolution  of 
volcanic  carbon  dioxide.1  In  the  second  place,  Mr.  Reade 
made  a  very  modest  estimate  of  the  limestone  buried  under 
the  ocean. 

Another  aspect  of  the  same  subject  is  found  in  the  masses 
of  marine  limestone  found  in  the  sedimentaries  of  particular 
geologic  epochs.  According  to  the  data  of  Sir  John  Murray, 
there  is  brought  down  to  the  sea  each  year  roughly  2,000 
million  tons  of  calcium  carbonate.  This,  if  evenly  deposited 
over  the  ocean  floor  (say  150  millions  of  square  miles),  would 
raise  its  level  to  the  extent  of  only  a  foot  in  90,000  years.  Sir 
John  Murray  has  calculated  that  carbonate  deposition  is  actually 
taking  place  over  only  a  third  of  that  area.  It  therefore  follows 
that,  at  the  present  time,  under  the  sea-floor,  vast  areas  of  lime- 
stone are  being  laid  down  at  the  rate  of  about  a  foot  in  30,000 
years.  We  must  note  that  we  have  here  merely  the  order  of  the 
result.  The  very  deepest  sediments  are  formed  more  slowly, 
because,  in  the  vaster  abysses,  the  pressure  of  the  water  causes 
the  re-solution  of  the  more  delicate  of  the  shells  of  the  forameni- 
ferse  which  make  the  bulk  of  the  oceanic  lime  deposits.  On 
the  other  hand,  local  deposits,  and  particularly  coral,  are  often 
formed  much  more  rapidly.  We  must  notice,  however,  that 
excess  in  particular  places  implies  that  the  rate  of  formation  in 
the  ordinary  deep  sea  deposits  must  be  slower  by  a  correspond- 
ing amount. 

There  remains  the  question  whether  the  vast  masses  of 
mountain  limestone  found  in  the  strata  of  so  many  different 
ages  are  marine  in  this  sense  of  the  word.  Let  us,  as  an 
example,  take  the  Cretaceous  and  the  Carboniferous  deposits. 
There  has  been  some  dispute  as  to  whether  these  are  oceanic, 
or  were  formed  in  shallow  water.  From  the  point  of  view 
of  rapidity  of  formation,  however,  it  does  not  greatly  matter. 
What  is  important  for  our  purpose  is  whether  or  no  strictly 
contemporaneous  limestone  deposits  are  widespread.  Let  us, 
therefore,  consider  the  Carboniferous  in  greater  detail.  Early 
Carboniferous  limestone,  attaining  sometimes  to  several 
thousands  of  feet  in  thickness,  underlies  newer  rock  in  nearly 
all  the  area  of  Great  Britain.  It  outcrops  in  several  places,  and 
constitutes  the  greater  part  of  the  bulk  of  the  Mendips.     Sir 

1  It  has  been  stated  that  Mr.  Reade  overestimated  the  proportion  of  limestone. 
If  so,  his  estimate  is  liable  to  a  reduction  on  that  account. 


26o  SCIENCE   PROGRESS 

Archibald  Geikie  states  that  a  continuous  formation  can  be 
traced  over  750  English  miles  from  the  Western  headlands 
of  Ireland  into  the  heart  of  Europe.  How  far  it  extends,  or 
once  extended,  under  what  is  now  the  Atlantic,  and  its  extreme 
limits  north  and  south  do  not  appear  to  have  been  determined. 
Contemporaneous  limestone  (though  interstratified  with  coal 
beds)  is  stated  to  be  found  in  Scotland,  Silesia,  Central  and 
Southern  Europe,  Spain,  and  the  Urals.  Limestone  of  the  same 
era  is  found  in  China,  in  the  Central  Himalayas,  in  Morocco, 
Algeria,  and  other  parts  of  Africa,  and  also  in  Australia.  In 
America,  early  Carboniferous  (Mississippian)  limestone  (in  some 
places  mixed  with  sedimentary)  underlies  a  large  portion  of  the 
United  States.  It  is  5,000  feet  thick  in  the  Canadian  Rockies, 
and  is  extensively  developed  in  Alaska.  The  known  area  of  the 
formation  must  be  reckoned  in  millions  of  square  miles.  If  we 
add  to  this  an  estimate  for  countries  as  yet  geologically  un- 
explored, for  that  which  is  now  under  the  ocean,  for  that  which 
has  been  eroded  in  the  vast  period  which  has  elapsed  since  early 
Carboniferous  times,  there  can  be  no  doubt  that  it  was  deposited 
under  oceanic  conditions.  For  the  essential  point  is  the  area 
and  thickness  of  the  formation.  If  we  can  reckon  the  area  of 
contemporaneous  limestone  at  many  millions  of  square  miles, 
the  current  controversy  whether  it  was  deposited  under  deep  or 
under  shallow  water  conditions  becomes  of  small  importance  for 
the  purposes  of  our  argument.  Under  no  circumstances  is  it 
possible  for  the  ocean,  which  contains  an  infinitesimal  pro- 
portion of  carbonate  of  lime,  to  deposit,  for  any  prolonged 
period,  more  than  is  brought  down  by  the  rivers  to  the  sea. 
Let  us,  therefore,  assume  ordinary  marine  conditions,  and  assess 
the  probable  average  thickness  of  early  Carboniferous  limestone 
at  the  very  low  estimate  of  1,000  feet,  and  let  us  allow  as  the 
probable  rapidity  of  formation  three  times  the  present  average, 
a  foot  in  ten  thousand  years,  we  thereby  obtain  a  minimum  of 
ten  million  years  for  only  a  portion  of  a  recognised  geologic 
epoch.  Such  figures  as  it  is  possible  to  give  are,  of  course,  very 
crude  guess-work,  and  no  stress  is  laid  on  them,  but  they  will 
serve  to  point  out  a  useful  line  of  research. 

The  only  important  query  which  is  likely  to  be  raised,  and 
which,  indeed,  has  been  raised,  is  whether,  in  past  times,  the 
proportion  of  carbon  dioxide  in  the  atmosphere  might  not  have 
been  excessive,  and  so  the  amount  of  carbonate  carried  to  the 


SOME  ASPECTS  OF  GEOLOGIC   TIME  261 

sea  might  have  been  larger  than  it  now  is.  This  suggestion, 
at  first  sight,  seems  probable.  The  erosion  of  the  chalk  hills 
and  their  conveyance  to  the  sea  in  solution  by  the  rivers  is 
certainly  occasioned  mainly  by  the  carbon  dioxide  which  falls  to 
the  ground  in  the  rain.  The  same  cause  is  an  important  factor 
in  all  erosion.  For  that  reason  the  factor  must  be  briefly 
considered.  Here  it  is  hardly  possible  to  dogmatise  either  way. 
Nothing  is  easier  than  to  make  rash  and  unfounded  theories.  It 
is  certainly  difficult  to  imagine  causes  which  would  enormously 
increase  the  carbon  dioxide  in  the  air  for  a  particular  geologic 
period.  Where  it  would  come  from,  and  why  it  should  vanish, 
are,  at  least,  problems  which  require  careful  consideration.  It 
will  suffice,  however,  to  make  two  comments. 

In  the  first  place  we  must  note  that  we  have,  in  the  sea, 
an  enormous  reservoir  which  acts  as  a  giant  fly-wheel  on  the 
composition  of  the  atmosphere.  Those  who  accept  this  theory 
must  account,  not  only  for  the  production  of  the  carbon  dioxide 
to  fill  the  atmosphere,  but  also  for  that  enormously  greater 
amount  which  would  dissolve  in  the  ocean.  The  amount  of 
carbon  dioxide  in  the  atmosphere  and  in  the  ocean  is  in  approxi- 
mate equilibrium,  and  the  amount  in  the  atmosphere  is  only 
a  small  fraction  of  that  contained  in  the  sea.  In  the  next  place, 
we  must  note  that  the  suggestion  only  affects  the  time  necessary 
to  evolve  the  limestone  from  igneous  rock  in  so  far  as  it  affects 
nearly  all  the  recognised  methods  of  estimating  geologic  time. 
It  is,  of  course,  true  that  a  more  acid  rain  would  more  rapidly 
dissolve  the  lime  from  the  igneous  rock,  and  so  increase  the  total 
mass  of  terrestrial  limestone,  but  the  same  factor  would  hasten 
all  the  processes  of  erosion  and  deposition.  Rock  would  more 
quickly  be  crumbled,  and  carried  away  in  sediment  by  the  rain. 
The  dissolved  sodium  would  more  quickly  reach  the  sea.  Thus, 
if  this  hypothesis  seek  to  harmonise  any  discrepancy  that  may 
be  supposed  to  exist  between  the  evidence  of  limestone  and  that 
supplied  by  other  methods  of  denudation,  the  suggestion  will 
utterly  fail.  It  cannot  too  strongly  be  emphasised,  in  all  geologic 
speculation,  that  it  is  necessary  to  try  to  disentangle  the  full 
bearing  of  many  correlated  factors. 

It  must  be  admitted,  however,  that,  for  a  special  period, 
which  would  not  greatly  affect  general  averages,  the  factor 
might  not  be  without  its  effect  on  the  rate  of  formation  of 
particular  deposits,  such  as  those  we  have  noted  at  some  length 


262  SCIENCE  PROGRESS 

in  the  Carboniferous.  Carbon  dioxide  has  a  special  solvent  effect 
on  limestone,  over  and  above  all  other  kinds  of  rock,  and  so  far 
as  this  was  exposed  on  hill-tops  and  in  cliffs  facing  the  sea,  the 
solvent  effect  might  be  much  greater.  Some  small  allowance 
would  probably  be  required  for  greater  erosion  in  underground 
caverns.  But,  to  all  this,  there  is  a  very  definite  limit.  The 
erosion  could  not,  except  under  special  conditions,  affect  the 
limestone  so  as  to  take  it  below  the  level  of  the  surrounding 
country.  If  this  happened,  lakes  would  form,  and  the  remaining 
limestone  would  be  covered  with  a  protecting  layer  of  shale. 
The  dependence  of  special  erosion  on  general  erosion  is  shown 
by  the  fact  that  salt  beds  are  so  extensive  and  so  numerous. 
No  possible  conditions  could  make  the  solubility  of  limestone 
approach  that  of  salt  in  water.  Yet  salt  beds  are  very  slowly 
removed  to  the  sea,  and  it  seldom,  if  ever,  happens  that  we  can 
detect  their  presence  by  the  greater  salt  content  of  river  water. 
With  these  remarks,  the  objection  must  be  left.  Like  so  much 
other  geological  controversy,  it  appears  to  have  been  made 
because  of  the  supposed  necessity  to  "  hurry  up "  geologic 
phenomena,  so  as  to  make  them  fit  the  dogmas  of  the  physicist. 
But  the  assumption  of  comparative  uniformity  is  the  soundest 
that  can  be  made. 

Without,  however,  dogmatising  concerning  details  such  as 
these,  we  must  note  how  important,  in  its  relation  to  geologic 
time,  is  the  question  of  the  evolution  of  carbonate  of  lime,  both 
in  general  and  in  special  geological  epochs.  It  is  a  consideration 
on  which  considerable  stress  should  be  laid. 

Very  brief  mention  must  suffice  for  the  one  other  method  that 
is  now  attracting  attention.  I  refer  to  the  estimation  of  the 
amount  of  helium  and  of  lead  in  minerals  containing  appreciable 
quantities  of  uranium.  The  elements  uranium  and  thorium,  as 
the  modern  chemist  has  abundantly  shown,  are  slowly  disinte- 
grating and  giving  rise  to  other  elemental  forms.  Assuming 
that  the  helium  found  in  these  minerals  is  obtained  from  the 
radioactive  elements  contained  in  them,  an  estimate  of  the  time 
that  has  elapsed  since  they  were  formed  can  be  made.  The 
work  of  Mr.  R.  J.  Strutt l  has  placed  beyond  doubt  that,  on  that 
assumption,  the  time  that  has  elapsed  since  geologic  epochs,  not 
the  most  ancient,  must  be  measured  in  hundreds  of  millions  of 
years.  But  accurate  and  entirely  self-consistent  results  have  not 
1  See  various  papers  in  the  Proceedings  pf  the  Royal  Society. 


SOME  ASPECTS   OF  GEOLOGIC   TIME  263 

yet  been  obtained.  On  a  very  few  assumptions,  the  actual 
measured  results  must  be  regarded  as  minima.  But  there  is 
much  research  yet  to  be  accomplished  before  we  can  be  quite 
sure  what  value  to  place  upon  them.  So  far  as  they  go,  however, 
they  support  the  main  contention  of  this  paper.  The  radioactive 
method  must  be  accepted  as  another  valuable  line  of  research.1 

PART   II.— ORGANIC   EVOLUTION   AND 
GEOLOGIC   TIME 

A.    Biologic  Theory  and  Geologic  Time 

In  the  whole  history  of  human  thought,  it  would  be  difficult 
to  find  two  topics  so  intimately  connected  as  evolution  and 
geologic  time.  In  the  days  of  catastrophic  cosmogony,  no  theory 
of  evolution  was  possible.  The  discoveries  of  the  early  geologist 
paved  the  way  for  the  superstructure  of  the  evolutionist.  When 
we  discovered  that  the  earth  dated  back  to  a  remote  antiquity, 
and  that,  during  this  lapse  of  time,  the  forms  of  life  were 
continually  changing,  the  naturalist  was  then  able  to  investigate 
the  causes  of  the  change. 

Thus  the  evolutionary  ideas  of  Darwin  were  founded  on  the 
uniformitarian  geology  of  Hutton  and  Lyell,  which  postulated 
an  indefinite  lapse  of  time,  a  postulate  of  which  Darwinian  theory 
took  full  advantage.  A  number  of  philosophers,  Lamarck  and 
Herbert  Spencer  in  particular,  had  anticipated  Darwin  in  the 
advocacy  of  evolution,  but  had  differed  in  their  opinion  of  its 
causes.  By  a  strange  coincidence,  the  theory  of  Darwin 
demanded  a  vaster  extent  of  time  than  had  the  ideas  of  any 
previous  worker.  By  laying  such  great  stress  on  natural 
selection,  by  postulating  that,  in  the  main,  the  changes  in  the 
forms  of  animal  and  vegetable  life  were  due  to  the  selection  of 
minute  and  imperceptible  variations  which  happened  to  be  of 
advantage  in  the  struggle  for  existence,  he  required  the  assump- 
tion that  the  time  must  be  of  the  order  that  commended  itself  to 
the  geologists  of  his  day.     So  much  was  this  the  case  that,  when 

1  In  view  of  the  possibility  that  too  much  stress  may  be  laid  on  this,  as  dis- 
tinguished from  other  lines  of  research,  I  think  it  well  to  say  that,  in  my  opinion, 
though  detailed  criticism  is  outside  the  scope  of  this  article,  attempts  to  assess 
exact  times  from  consideration  of  bad  ratios,  are,  to  say  the  least,  premature. 
There  are  so  many  causes  of  uncertainty.  The  most  that  we  can  now  infer  is  a 
moderate  minimum  of  time,  a  result  that  is  given  equally  well  by  other  data  if 
properly  handled. 


264  SCIENCE   PROGRESS 

the  late  Lord  Kelvin  dogmatically  asserted  that  geologic  time 
must  be  compressed  within  ioo  millions  of  years,  Darwin  was 
seriously  perturbed,  not  so  much  on  account  of  the  truth  of  the 
crucial  fact  of  evolution,  as  of  his  own  particular  theory  of 
natural  selection.  The  cause  for  alarm  has  now  been  removed, 
but  it  still  remains  true  that  the  subjects  of  geologic  time  and  of 
methods  of  evolution  are  closely  interrelated. 

If  we  consider  the  interrelation  from  the  biological  standpoint, 
and  endeavour  to  ascertain  what  light  can  be  thrown  on  our 
subject  with  the  aid  of  the  bare  facts  of  that  science,  we  discover 
that  very  little  information  is  available.  We  soon  find  ourselves 
arguing  in  a  vicious  circle.  We  know  (for  example)  that  man 
has  developed  from  a  pithecanthropoid  form  since  the  Pliocene, 
and  that  the  horse  has  evolved  from  a  beast  with  five  small  hoofs 
on  each  spray  foot  since  the  early  Eocene.  But  if  we  desire  to 
state  the  time  in  figures,  we  can  only  say  that  the  Pleistocene  is 
the  period  that  has  been  required  to  develop  man,  and  that  man 
has  developed  during  the  Pleistocene.  The  biologist  has  no 
independent  standard  of  time.  Vague  as  are  the  data  of  the 
geologist,  those  of  the  biologist  are  still  more  uncertain. 

It  is,  of  course,  possible  to  utilise  the  fact  that  no  considerable 
natural  change  has  been  observed,  during  the  historical  period, 
in  any  organic  form,  and  from  this  fact  to  posit  a  minor  limit. 
Here,  however,  the  Mendelian  theorist,  who  has  been  so 
prominent  of  late  years,  will  assert  that  evolution  proceeds  by 
jerks,  and  that  the  observed  forms  of  life  are  in  the  resting 
phase.  Improbable  as  such  speculations  may  seem,  there  are  no 
plain  and  obvious  facts  by  which  they  can  be  refuted,  so,  here 
again,  the  biologist  is  referred  to  geological  data.  As  in  the 
time  of  Kelvin  and  Huxley,  so  to-day,  it  still  remains  for  those 
who  deal  in  physical  and  geological  data  to  find  the  measure  of 
time  to  which  the  biologist  must  fit  his  theories.  There  is  so 
much  theory  in  modern  biology. 

A  number  of  biologists,  of  whom  Prof.  Poulton  is  the  most 
prominent,  admit  this  statement,  so  far  as  it  deals  with  known 
fossiliferous  rocks,  but  express  the  opinion  that  biologists  can 
confidently  assert  that  these  represent  but  the  last  phase  of  an 
evolution  which  represents  a  vaster  vista  of  time,  an  evolution 
of  which  all  record  has  been  lost.1  As  Prof.  Poulton  has  shown, 
all  the  known  phyla  of  the  animal  kingdom  are  found  in  the 

1  Essays  on  Evolution,  pp.  1-45. 


SOME  ASPECTS  OF  GEOLOGIC  TIME  265 

early  Paleozoic  deposits,  and,  of  these,  a  considerable  number  of 
genera  and  orders  are  of  a  remote  antiquity.  Thus,  four  out  of 
nine  orders  of  insects  have  been  found  in  the  Carboniferous, 
Crustacea  in  the  Cambrian  and  pre-Cambrian,  arachnida  in  the 
Silurian.  From  these  facts  he  infers  that  pre-Cambrian  evolution 
must  have  occupied  a  time  vastly  greater  than  that  of  which  we 
have  a  record. 

Though  I  am  of  opinion  that  this  line  of  argument  contains  a 
great  amount  of  truth,  I  am  bound  to  demur  that  all  that  can 
definitely  be  asserted  is  an  antecedent  probability.  If  we  assume, 
as  appears  to  be  the  case,  that  these  invertebrate  forms,  at  the 
commencement  of  the  period  of  the  known  fossiliferous  strata, 
had  attained  to  correspondence  with  conditions  that  have 
remained  approximately  constant  during  geologic  time,  we  have 
insufficient  data  on  which  to  make  definite  assertions  concerning 
the  time  that  preceded  it.  Let  us  put  the  matter  more  concretely. 
It  is  very  probable  that  all  vertebrate  life  has  developed  from  a 
single  type  since  the  lower  Cambrian.  No  phylum  approaches 
the  vertebrates  in  the  complexity  of  its  ramifications.  What 
reason  have  we  to  assert  that,  when  in  process  of  active  evolution, 
each  phylum  found  in  the  lower  Cambrian  could  not  have  been 
formed  in  an  equal  time  ?  And  what  reason  have  we  to  assert 
that  all  these  other  phyla  were  not  developed  contemporaneously? 
If  we  give  to  the  argument  its  utmost  value,  we  are  unable  to 
assert  that  pre-Cambrian  time  has  been  greater  than  post- 
Cambrian.  The  assertion  that  it  is  of  equivalent  length,  which 
is  all  the  argument  is  worth,  will  help  us  very  little.  Such  an 
assertion  is  highly  probable  on  other  grounds.1  A  maximum 
thickness  of  more  than  100,000  feet  of  strata  can  definitely  be 
assigned  to  pre-Cambrian  times,  and  the  primitive  Archaean 
undoubtedly  contains  a  large  amount  of  metamorphosed  sediment. 
Such  a  conclusion  is  all  we  can  obtain  from  this  broad  aspect  of 
biologic  fact.  Whatever  time  may  be  proved  to  have  been 
required  to  form  Cambrian  and  post-Cambrian  strata,  to  it  must, 
probably,  be  added  at  least  an  equal  time  for  pre-Cambrian 
strata.  Whatever  we  may  think  concerning  probabilities,  it 
would  be  rash  dogmatism  to  assert  more. 

The  futility  of  dogmatism  is  also  shown  by  the  scarcity  of 

1  Recent  researches  are  showing  the  probability  that  pre-Cambrian  time  is, 
probably,  considerably  greater  than  post-Cambrian.  See  address  by  Prof.  A.  P, 
Coleman,  British  Association  Report,  Sheffield,  igio. 


266  SCIENCE    PROGRESS 

fossil  forms  in  the  pre-Cambrian.  Although  a  very  considerable 
bulk  of  pre-Cambrian  rock  has  been  examined,  the  remains  of 
life  are  few  and  far  between.  In  the  Torridon  sandstone,  laid 
down  under  the  calm  and  peaceful  conditions  so  graphically 
described  by  Sir  Archibald  Geikie,1  no  fossils  have  been  found. 
Crustacea  have  been  found  in  the  Proterozoic.  There  is  a  lime- 
stone deposit,  which  may  or  may  not  be  organic,  at  the  base  of 
the  Huronian,  but  the  comparative  scarcity  of  life  is  a  striking 
and  interesting  fact.  There  is  no  evidence  of  metamorphism, 
and  there  is  no  apparent  reason  why  fossils  should  not  have 
been  found.  Though  reasoning  from  the  absence  of  such  remains 
is  a  very  risky  proceeding,  the  contrast  between  this  scarcity 
and  the  relative  abundance  in  later  strata  at  any  rate  suggests 
the  probability  that  the  known  forms  of  life  were  then  local  and 
in  process  of  establishment  as  world-wide  types.  If  this  were 
so,  it  is  easy  to  point  out  that  the  relatively  rapid  change  of  con- 
ditions connoted  by  our  hypothesis  is  a  strong  presumption  in 
favour  of  a  rapid  process  of  evolution. 

There  are  one  or  two  other  speculations  to  account  for  this 
interesting  fact.  One  is  that  the  early  seas  were  acid,  and  that 
the  organisms  were  therefore  unable  to  form  protective  coatings 
by  the  secretion  of  carbonate  of  lime.  The  very  early  date  of 
some  limestone  deposits  will  require  explanation  on  this  hypo- 
thesis. If  the  speculation  were  accurate,  lime  deposition  could 
only  take  place  locally  in  lakes  when  the  process  of  deposition 
had  gone  far  enough  to  neutralise  the  prevailing  acid,  or,  when 
such  lakes  had  not  been  part  of  the  sea,  in  places  where  the 
influx  of  the  rivers  would  not  be  neutralised  by  the  acid  of  the 
sea.  The  speculation  is  somewhat  wild,  but  some  light  would 
be  thrown  on  it  if  and  when  we  have  discovered  whether  or  no 
the  earliest  limestone  deposits  are  invariably  lacustrine. 

Whether  this  or  some  other  reason  be  the  explanation,  it  is 
interesting  to  note  that  a  very  considerable  proportion  of  such 
pre-Cambrian  fossils  as  have  been  discovered  are  chitinous 
rather  than  calcareous  ;  and  whether  this  fact  be  due  to  deficiency 
in  carbonate  of  lime,  or  whether  it  be  due  to  the  fact  that  the 
species  at  that  time  had  not  acquired  what  has  been  described 
as  the  lime  habit,  the  facts  point  to  the  probability  of  a  com- 
paratively rapid  pre-Cambrian  evolution.  Whether  or  no  the 
reasons  that  have  been  given  are  sufficient,  it  will  be  generally 
1  See  address  to  British  Association,  1899. 


SOME  ASPECTS   OF  GEOLOGIC   TIME  267 

admitted  that  the  formation  of  exterior  protective  lime  coatings 
is  likely  to  render  further  developments  both  difficult  and 
unnecessary.  The  one  notable  instance  of  the  higher  develop- 
ment of  such  invertebrate  forms,  the  cephalopods,  has  only 
taken  place  as  and  when  the  protective  coating  has  obsolesced. 
Thus  we  have  further  evidence  in  favour  of  our  conclusion 
that  this  aspect  of  the  relation  between  organic  evolution  and 
geologic  time  is  not  likely  to  give  us  tangible  and  certain  con- 
clusions. The  probability  we  have  already  noted,  that  pre- 
Cambrian  time  is  at  least  of  the  same  order  as  post-Cambrian, 
is,  however,  a  valuable  result  to  glean  from  a  first  cursory  glance 
at  main  principles. 

B.   Geologic  Time  and  Biologic  Theory 

Our  results,  so  far,  are  interesting  but  scanty.  The  biologist 
can  give  us  much  useful  information,  but  his  conclusions  must 
not  be  pressed  too  far.  It  will  now  be  interesting  to  consider 
the  converse,  i.e.  the  effect  of  our  knowledge  of  geologic  time  on 
biologic  theory.  Much  has  been  written  of  late  years  concern- 
ing theories  of  evolution,  and  recent  speculations  on  geologic 
time  have  been  used  as  a  controversial  weapon.  The  arguments 
of  a  class  of  biologist  runs  somewhat  on  the  following  lines : 
Natural  selection,  as  postulated  by  Darwin,  requires  a  great 
vista  of  time  in  which  to  work.  Use-inheritance,  which  was 
accepted,  not  only  by  the  early  evolutionists  and  by  Herbert 
Spencer,  but  by  Darwin  himself,  has  been  thought  to  have  been 
disproved  by  Weismann  and  his  followers.  Therefore  the 
theorist,  to  escape  from  the  dilemma,  has  made  the  inference 
that  evolution  has  proceeded  discontinuously  by  a  succession 
of  "sports"  which  have  happened  to  be  of  advantage  in  the 
struggle  for  existence.  The  inference  receives  some  support 
from  the  discoveries  of  Mendel,  which  have  recently  been 
brought  into  such  prominence  by  Prof.  Bateson  and  others. 

We  cannot  here  discuss  the  evidence  for  and  against  use- 
inheritance.  In  case  the  reader  should  suspect  bias  on  grounds 
not  stated  here,  it  may  be  as  well  to  state  that  I  should  classify 
myself  as  neo-Lamarckian,  and  that  I  do  not  attach  great  im- 
portance to  Mendel's  discoveries — at  any  rate,  in  their  relation 
to  the  problem  now  before  us.  While  there  can  be  no  doubt 
concerning  Mendel's  facts,  and  the  interesting  light  they  throw 
on  some  problems  of  heredity,  the  evolutionary  and  theoretical 


268  SCIENCE   PROGRESS 

superstructure  erected  on  them  by  some  theorists  appears  to  me 
to  be  unsound.  Here,  however,  it  is  only  possible  to  note  the 
inference  that  has  been  made  from  modern  ideas  of  geologic 
time.  That  inference  falls  entirely  to  the  ground.  There  is 
now  no  recognised  maximum  limit  to  geologic  time.  There  are 
no  valid  arguments  which  enable  us  to  limit  the  time  for  organic 
evolution  to  less  than  a  thousand  million  of  years.  And  that 
period  would  suffice  for  any  known  theory  of  evolution.  Conse- 
quently, whatever  may  be  said  for  or  against  the  neo-Mendelian 
theory  of  sports,  this  particular  argument  is  invalid.  It  is 
desirable  also  to  state  that  the  argument  from  geologic  time  is 
not  available  for  the  neo-Lamarckian  as  against  the  neo-Dar- 
winian.  I  am  not  aware  that  any  recognised  neo-Lamarckian 
controversialist  has  made  use  of  it,  but  if  he  has,  it  is  invalid. 
Our  knowledge  of  geologic  time  is  equally  consistent  with  any 
and  every  theory  of  evolution.  The  conclusion  of  this  aspect  of 
our  subject  is  purely  negative.  Biologists  and  others  who  have 
made  use  of  the  geologic  argument  must  abandon  it,  and  must 
reconsider  their  theories,  in  view  of  the  fact  that  recent  and 
current  speculations  on  geologic  time  have  broken  down. 

C. .  A  Suggestion  concerning  Physiological  Infertility 

Although  the  first  crude  and  obvious  arguments  that  arise 
from  attempts  to  correlate  the  sciences  of  geology  and  biology 
are  of  little  value,  it  does  not  therefore  follow  that  the  use  of 
biological  data  is  impossible.  But  the  data  must  be  used  more 
fully  and  more  carefully  than  has  yet  been  done.  Many  ways 
of  combining  our  data  are,  no  doubt,  theoretically  possible.  For 
our  present  purpose,  however,  it  will  suffice  if  we  call  attention 
to  one  aspect  of  evolution — on  which  Darwin,  in  his  Origin  of 
Species,  and  Spencer,  in  the  Principles  of  Biology,  laid  consider- 
able stress,  yet  which  has  been  overlooked  in  recent  biological 
speculation.  We  have  already  noted  the  problem  of  the  time 
required  for  the  making  of  new  species.  As  we  have  already 
seen,  nothing  of  the  kind  has  been  observed.  Nor  is  this  state- 
ment an  example  of  reasoning  in  a  circle.  It  might  be  contended 
that  changes  which  we  have  produced  by  breeding  and  cultiva- 
tion are  not  called  species  changes,  for  the  simple  reason  that 
we  have  observed  them.  With  regard  to  some  forms  of  life 
there  is  substance  in  the  argument.  Darwin,  in  his  famous 
investigations  on  cirripedes,  found  great   difficulty  in  deciding 


SOME  ASPECTS  OF  GEOLOGIC  TIME  269 

what  exactly  were  species  and  what  were  merely  varieties. 
Other  naturalists  have  been  involved  in  the  same  difficulty. 
But  with  regard  to  the  higher  forms  of  animal  life  we  have  an 
independent  criterion.  It  is  generally  recognised  that  the  mutual 
infertility  of  nearly  allied  animals  is  a  test  of  species  difference. 
In  the  rare  exceptional  cases,  such  as  the  horse  and  the  donkey, 
when  hybrids  can  be  formed,  the  hybrids  are  infertile. 

We  shall,  therefore,  do  well  to  leave  the  morphological  side 
and  to  pay  more  attention  to  the  aspect  of  physiological  fertility. 
It  is  hopeless  to  attempt  to  decide  what  degree  of  morphological 
change  does  or  does  not  constitute  species  difference.  The 
difference  in  shape  between  the  horse  and  the  donkey  is 
comparatively  small,  yet  a  fertile  cross  cannot  be  obtained.  On 
the  other  hand,  notwithstanding  the  enormous  differences 
between  the  varieties  of  domestic  dogs,  differences  of  size,  shape, 
proportion,  colour,  character  of  coat,  these  varieties  are  mutually 
fertile.1  The  variegated  types  of  domestic  pigeons,  notwith- 
standing enormous  differences,  are  not  only  mutually  fertile,  but,  if 
left  to  themselves,  revert  to  the  ordinary  rock  pigeon  from  which 
they  are  descended.  Yet  the  differences,  were  they  found  in  fossil 
forms,  would  probably  be  classed  as  greater  than  species  difference. 

Such  facts  as  these  throw  some  light  on  the  course  of  organic 
evolution.  Physiological  infertility  is  evidently  not  correlated 
with  accidental  differences  in  shape,  colour,  or  form,  but  connotes 
an  essential,  deep-seated  organic  change.  It  seems  probable, 
therefore,  that  this  may  not  be  obtainable  by  artificial  breeding, 
but  that  it  may  be  a  natural  process,  which,  for  its  accomplish- 
ment, requires  a  prolonged  time.  It  has  certainly  not  been 
found  among  the  multitudinous  races  of  human-kind.  If  this 
theory  were  actually  proved  (as  yet  it  is  only  a  speculation),  it 
might  give  us  a  minor  limit  for  the  time  required  for  the  pro- 
duction of  species. 

It  is  interesting  to  note  that  the  discoveries  of  Mendel  can, 
without  undue  straining,  be  made  to  fit  into  the  same  hypothesis. 
It  has  not  yet  been  proved  that  all  inheritance  can  be  described 
in  Mendelian  terms.  Mendelism  may  account  for  inheritance  in 
mixed  races,  such  as  the  Caucasian  and  Negro  half-breeds,  but 
even  this  is  doubtful.     Certainly,  in  ordinary  human  inheritance, 

1  For  obvious  reasons,  it  would  hardly  be  possible  to  obtain  a  first  cross  when 
there  was  more  than  a  certain  difference  in  size,  but  this  is  not  true  physiological 
infertility. 


270  SCIENCE   PROGRESS 

we  see  all  degrees  of  blending,  and  there  seems  no  possibility  of 
expressing  it  as  a  sorting  out  of  minor  characters. 

Let  us,  therefore,  look  at  the  matter  from  another  standpoint. 
Let  us  look  at  Mendelian  inheritance,  not  as  the  normal  form  of 
inheritance,  but  as  a  modified  form  of  mutual  infertility.  Men- 
delian inheritance  is  the  characteristic  of  stocks  that  do  not  truly 
blend.  The  various  varieties  emerge  from  the  process  of  inter- 
crossing practically  unchanged.  This  clearly  tends  to  fix  the 
types  of  the  crossing  varieties.  It  accomplishes,  in  a  different 
way,  the  same  purpose  as  the  mutual  infertility  of  allied  species. 
Does  it  not,  therefore,  seem  a  plausible  suggestion  that  this  is 
merely  a  step  on  the  road  towards  species  formation,  that  the 
practically  complete  blending  of  ordinary  inheritance,  the 
emergence  of  unaltered  types  from  the  process  of  Mendelian 
crossing,  the  partial  infertility  of  the  equidse,  the  entire  mutual 
infertility  of  other  allied  species,  may  be  but  parts  of  a  continuous 
process,  the  formation  of  distinct  physiological  species? 

This  is,  of  course,  merely  a  speculation,  and  will  require 
considerable  confirmation  before  it  is  possible  to  make  use  of  it, 
but  I  put  it  forward  as  an  illustration  of  the  necessity  of  avoiding 
undue  dogmatism  concerning  the  possible  methods  of  deter- 
mining geologic  time.  Because  biological  data  have,  as  yet, 
thrown  no  light  on  this  subject,  we  must  not  be  too  ready  to 
assume  that  such  may  not  be  available  in  the  future.  It  is 
therefore,  of  interest  once  more  to  raise  the  question  :  has  a 
truly  infertile  physiological  species  ever  been  formed  within  the 
time  of  human  observation,  or  has,  indeed,  any  series  of  varieties 
been  formed  which  will  intercross  in  a  definitely  determinable 
Mendelian  manner?  Changes  of  form  are  produced  quickly, 
whether  by  selective  breeding  or  by*  change  of  conditions.  But 
the  problem  of  physiological  species  is  still  unsolved  and  it  may 
be  that  a  great  lapse  of  time  is  required  to  form  them. 

D.   Fossils  as  an  Index  of  Geologic  Time 

Suggestions  such  as  those  referred  to  in  the  last  section  are 
problems  for  future  research.  For  the  present,  pure  biological 
methods,  particular  as  well  as  general,  have  yet  to  be  found. 
We  shall,  therefore,  now  glance  at  the  more  obvious  line  of 
advance  found  in  the  co-ordination  and  correlation  of  biologic 
and  geologic  data.     In  its  broad  outlines,  the  method  has  been 


SOME  ASPECTS   OF  GEOLOGIC   TIME  271 

carried  out  since  the  dawn  of  geology.  Geologists,  in  deter- 
mining the  age  of  strata,  are  almost  entirely  dependent  on  the 
biologist.  But  for  the  discovery  of  characteristic  fossils,  they 
would,  in  many  cases,  be  without  the  slightest  clue  to  the  age  of 
particular  formations.  And,  by  this  method,  it  has  been  possible 
to  divide  geologic  time,  not  only  into  the  broad  recognised 
epochs,  but  into  a  varying  number  of  zones.  This  line  of 
investigation  appears  to  be  open  to  further  development. 

A  useful  and  striking  example,  which  has  recently  been  very 
ably  popularised  by  Prof.  Sollas,1  is  found  in  the  famous  Oppel 
zones  of  the  Jurassic.  No  less  than  thirty-three  distinct  zones 
have  beenidentifiedbyobservingthe  structure  of  fossil  ammonites. 
Each  species  is  found  in  a  particular  zone,  and  nowhere  else.  It 
has  been  proved  that  the  sub-divisions  are  world  wide.  Every- 
where, in  Europe,  India,  America,  Australia,  theyfollow  each  other 
in  the  same  succession.  Types  like  this  do  not  arise  in  a  day. 
They  are  not  distributed  over  the  whole  world  in  a  short  time. 
Previous  types  are  not  displaced  all  at  once.  In  particular 
regions,  species  may  be  exterminated  rapidly,  but  surely  not  all 
over  the  world.  It  will  be  noted  that  these  ammonites  are 
definite  and  distinctive  types.  The  manner  of  their  evolution 
does  not  appear  to  have  been  determined.  The  minute  grades 
by  means  of  which  they  must  have  been  evolved  from  preceding 
creatures  have  not  been  found.  Such  have  probably  been 
formed  locally,  in  some  specialised  and  confined  area,  and,  when 
the  barriers  have  been  removed,  the  species  would  gradually 
penetrate  all  over  the  world.  We  know  little  as  yet  of  the  rate 
of  the  evolution  of  life,  but  the  suggestiveness  of  these  facts  in 
connection  with  our  subject  does  not  require  to  be  pointed  out. 
Such  facts  as  these  have  a  very  cogent  bearing  on  our  subject. 
In  the  first  place,  the  very  existence  of  this  continual  succession 
of  organic  forms  is  itself  striking.  Prof.  Sollas,  who  is  committed 
to  an  unusually  small  estimate  of  geologic  time,  thinks  that 
these  forms  have  succeeded  each  other  with  unusual  rapidity. 
His  suggestion  cannot  be  rejected  on  a  priori  grounds.  So 
small  is  our  knowledge  of  the  possible  rapidity  of  organic 
evolution,  that  we  are  unable  to  say  that  species  may  not,  as  he 
surmises,  have  succeeded  each  other  at  intervals  of  25,000  years.1 
The  study  of  recent  strata  does  not  appear  to  have  disclosed  any 
similar   case   of  rapid  evolution,  but  the  hypothesis  cannot  be 

1  Age  of  the  Earth,  pp.  273  seq. 


272  SCIENCE   PROGRESS 

called  absolutely  impossible.     It  does,  however,  show  an  ante- 
cedent probability  in  favour  of  a  much  vaster  vista  of  time. 

I  think,  however,  if  the  data  be  examined  more  closely  and 
are  duly  correlated,  they  might  throw  some  light  on  our  basal 
problem,  and  the  methods  by  which  our  knowledge  can  be 
advanced  are  but  a  continuation  of  those  which  Prof.  Sollas 
himself  has  so  graphically  described.  Prof.  Sollas  is  of  opinion 
that  the  fossil  ammonites  were  not,  as  a  rule,  deposited  where 
we  now  find  them  by  ocean  currents,  but  that  their  occurrence 
in  any  strata,  in  any  considerable  quantity,  implies  that  they 
actually  lived  in  that  region.  One  point,  therefore,  needs 
emphasis.  The  difficulties  with  regard  to  the  origin  and 
development  of  species  are,  by  these  discoveries,  greatly  magni- 
fied. All  over  the  world,  in  a  small  zone  of  the  Jurassic,  roughly 
one  thirty-third  of  the  whole  period,  a  species  appears,  lives, 
disappears.  How  was  it  evolved,  and  what  are  the  stages  in  its 
evolution  ?  We  must  note  the  strong  probability  that  the 
species  was  evolved  since  the  end  of  the  period  indicated  by  the 
last  zone,  but  how  and  where  ?  Where  are  the  intermediate 
stages  by  which  it  was  developed  from  pre-existing  types  ? 

This  aspect  deserves  special  consideration.  The  sudden 
appearance  and  disappearance  of  world-wide  species  is  striking, 
and  gives  rise  to  considerable  speculation.  The  fact  that  such  a 
succession  of  commonly  found  species  is  continually  found 
without  intermediate  stages  might,  at  first  sight,  tempt  us  to 
deny  the  hypothesis  of  evolution  and  to  say  that  intermediate 
forms  do  not  exist.  Fortunately,  however,  it  does  sometimes 
happen,  particularly  in  the  fossil  forameniferae,  which  make  up 
the  main  substance  of  the  chalk  cliffs,  that  the  change  of  organic 
forms  is  so  gradual  that  division  into  distinct  species  is  difficult. 
We  must  assume  that  the  missing  intermediate  forms  existed. 
But  where  are  they?  Here  is  an  ocean  species,  as  Prof.  Sollas 
so  pertinently  remarks,  like  our  contemporary  spirula,  the  shell 
of  which  is  one  of  the  commonest  objects  on  the  seashore.  It  is 
found  fairly  plentifully  in  a  particular  zone  of  the  Jurassic.  Yet, 
apparently,  it  arises  from  nowhere,  and  disappears  suddenly. 
Such  a  problem  calls  for  investigation.  The  sudden  disappearance 
may,  perhaps,  be  due  to  the  advance  of  some  predatory  enemy. 
But  what  about  the  appearance  ?  And  would  they  suddenly 
disappear  all  over  the  globe  ?  Assuming  the  facts  to  be  as 
stated,  we  have  an  admirable  guide  to  help  us  to  piece  together 


SOME  ASPECTS  OF  GEOLOGIC  TIME  273 

the  changes  in  the  earth  structures  of  early  times.  The  point  I 
am  specially  concerned  to  urge  is  this  :  If,  in  any  group  of  strata, 
one  species  suddenly  vanishes,  and  another  allied  species 
suddenly  takes  its  place,  which  is  exactly  what  does  appear  to 
occur,  there  is  prima  facie  evidence  for  a  considerable  gap  in  the 
succession  of  the  rocks, 

The  remarkable  succession  of  "  Oppel's  zones  "  gives  rise  to 
many  interesting  questions.  The  more  detailed  information  we 
can  get  the  better.  We  require,  from  the  researches  of  specialist 
geologists,  a  clear  answer  to  a  series  of  questions  such  as  the 
following : 

(a)  Is  the  species  marking  what  we  will  call  a  zone  identical 
at  its  base  and  at  its  summit  ? 

(b)  Is  the  species  identical  at  the  base  in  India  and  at  the  base 
in  Europe,  at  the  base  in  India  and  the  summit  in  Europe  ?  If 
not,  what,  so  far  as  can  be  discovered,  is  the  extent  of  the  varia- 
tion for  time  and  space  ? 

(c)  In  each  district  containing  a  fairly  complete  series  of 
Jurassic  beds,  what  zones  are  present  and  what  are  absent  ? 

And  so  on. 

Facts  such  as  these  are  probably  known.  The  zonal  classi- 
fication probably  merely  implies  that  certain  dominant  forms 
occur  in  a  definite  order.  When  such  a  classification  is  made 
the  essential  point  occurs  in  locating  a  gap.  The  fact  that 
certain  zones  are  missing  in  certain  groups  of  strata  in  certain 
districts  has  a  clear  and  definite  meaning.  But  the  point  of 
greatest  interest  is  found  in  the  gaps,  and  particularly  in  gaps 
that  appear  to  be  world-wide.  Here  we  come  somewhere  near 
bedrock  in  our  co-ordination  of  organic  evolution  and  geologic 
time.  If  in  certain  strata  we  find  a  sudden  disappearance  of 
form  (a),  and  a  sudden  replacement  for  it  of  form  (£),  and 
we  find  no  strata  in  which  form  (a)  and  form  (b)  are  found 
together,  the  natural  inference  is  that  a  considerable  interval 
of  time  has  elapsed  between  the  two  depositions.  If  any- 
where in  strata  roughly  contemporaneous  we  can  discover  a 
filling  of  the  evolutionary  gap,  either  the  two  forms  occurring 
together  or  the  existence  of  forms  intermediate  between  the 
two,  the  problem  of  the  intermission  is  partially  solved.  If 
nowhere  in  any  strata  are  intermediate  forms  to  be  found,  and 
if,  as  appears  to  be  the  case,  fossils  (a)  and  (b)  are  plentiful  in 
their  respective  zones,  are  never  found  together,  and  inter- 
18 


274  SCIENCE   PROGRESS 

mediate  forms  have  yet  to  be  discovered,  the  probable  conclusion 
is  that,  in  all  districts  of  the  world  where  seemingly  from  a 
cursory  reading  of  the  signs  sedimentation  may  have  proceeded 
continuously,  there  is  a  gap  implying  a   large   lapse  of  time. 
The  conclusion  that  emerges  is  that  between  the  deposition  of 
the  two  sets  of  strata  there  have  been  considerable  and  world- 
wide changes  in  the  configuration  of  land  and  sea.     And  if  that 
be  so,  it  does  not  seem  absurd  to  suggest  that  there  may,  after 
all,  be  a  very  close  relation  between  the  amount  of  change  in 
any  dominant  form  and  the  time  that  has  elapsed,  respectively, 
in  the  formation  of  sediments  and  in  the  unknown  era  repre- 
sented by  the  intervening  gaps.     The  elucidation  of  the  precise 
relation  demands   careful   research   of  some   particular  period, 
and  that  the  numerous  facts  known  concerning  graptolites  and 
ammonites  (to   mention   the  groups  principally  used  in  zonal 
classification)  should  be  correlated  in  a  more  intelligent  manner. 
The  few  suggestions  contained  in  this  essay  are  tentative 
and  illustrative.     They  are  but  anticipations  and  indications  of 
the  manner  in  which  the  twin  subjects  of  organic  evolution  and 
geologic  time  can  be  more  intimately  connected.     To  do  more 
would  be  difficult  in  the  present  state  of  scientific  knowledge 
and   opinion.     For   fuller    information    the    great   necessity  is 
careful,  detailed,  and  independent  research.     It  is  necessary  that 
the  fundamental  problem  of  geology  should  be  deemed  more 
worthy  of  time  and  attention  than  the  minor  questions  which 
everywhere  receive  such  detailed  treatment  and  which  result  in 
so  many  carefully  written  and  voluminous  monographs.     The 
subject   is   as   yet    hardly    touched,   and    a    clearer   and   more 
wonderful  science  of  geology  can  be  built  up  by  those  who  apply 
to  it  true  methods  of  scientific  investigation. 

What  we  are  entitled  to  say  on  the  evidence  before  us, 
biological,  geological,  and  physical,  is  this :  It  would  be  absurd 
to  attempt,  on  very  insufficient  data,  to  give  an  estimate  of  the 
probable  lapse  of  geologic  time.  But  there  is,  at  the  present 
day,  no  reason  whatever  why  it  should  not  be  a  thousand  million 
of  years  or  a  time  even  greater.  The  hundred-million  maximum  of 
the  old  physicist  and  geologist  is  now  exploded.  To  make  any 
estimate  in  the  place  of  that  which  has  been  shown  to  be  invalid 
will  only  be  possible  after  long  and  careful  research.  It  is  hoped 
that  the  criticisms  and  suggestions  contained  in  this  paper  may  do 
something  to  show  on  what  lines  such  research  should  proceed. 


THE     SIGNIFICANCE     OF    THE 
PILTDOWN     DISCOVERY 

By  A.  G.    TRACKER,  A.R.C.Sc. 
Curator  of  the  Public  Museum,   Gloucester 

It  is  often  the  fate  of  technical  words  to  serve  their  purpose  and 
become  obsolete.  It  was  so  with  the  word  "  Invertebrata."  The 
earlier  naturalists  saw  that  there  was  a  great  group  of  animals 
clearly  related  to  one  another  by  the  possession  of  a  vertebral 
column.  And  it  appeared  to  these  earlier  scholars  that  the 
lower  organisms  which  lacked  this  characteristic  might  be 
regarded  as  akin  to  one  another  and  thrown  together  into  a 
single  sub-kingdom  called  the  "  Invertebrata."  But  with  the 
progress  of  zoology  it  came  to  be  realised  that  the  various 
divisions  of  the  invertebrates  differed  from  one  another  quite  as 
much  as,  and  in  some  cases  more  than,  each  differed  from  the 
Vertebrata  ;  and  hence  the  term  "  Invertebrata  "  was  altogether 
discarded  by  zoologists. 

The  recent  advances  in  prehistoric  anthropology  have  been 
so  remarkable  that  it  seems  probable  that  a  like  fate  will  over- 
take the  word  "Paleolithic."  When  in  the  year  1865  the  late 
Lord  Avebury  (then  Sir  John  Lubbock)  proposed  that  the  Stone 
Age  should  be  divided  into  two  periods,  his  suggestion  very 
aptly  expressed  the  facts  of  prehistory  as  they  were  then  known, 
at  least  so  far  as  Europe  is  concerned.  The  people  of  the  later 
or  Neolithic  division  lived  in  our  own  geological  period  ;  they 
were  certainly  our  own  direct  ancestors ;  and  they  were  semi- 
civilised,  building  huts,  understanding  agriculture,  and  possess- 
ing divers  domestic  animals.  Behind  these  Neolithic  peoples, 
separated  from  them  in  many  places  by  a  great  interval  of  time 
—the  so-called  "  hiatus  "—and  living  under  very  different 
geographical  circumstances,  various  entirely  savage  races  were 
known  to  have  existed.  These  flourished  during  the  Pleistocene 
or  Glacial  Period,  being  consequently  surrounded  by  extinct 
animals  such  as  the  mammoth,  the  cave-bear,  the  cave-hyena, 
Rhinoceros    antiquitatis    and     others ;     they    dwelt    mainly    in 

275 


276  SCIENCE   PROGRESS 

caves;  they  were  entirely  ignorant  of  husbandry;  they  knew 
nothing  of  domestic  animals  ;  and  unlike  their  Neolithic  suc- 
cessors they  never  polished,  but  only  chipped  their  stone 
implements.  It  will  be  seen,  however,  that  these  Paleo- 
lithic savages  were,  like  the  invertebrates,  grouped  together 
merely  on  negative  grounds.  They  all  lacked  the  cultural 
characteristics  of  the  Neolithic  Iberians  and  Aryans. 

This  classification  was  for  the  time  being  a  satisfactory 
arrangement,  but  the  Paleolithic  Period  as  so  defined  was,  of 
course,  of  very  indefinite  extent.  Indeed,  theoretically  it  com- 
prised all  the  vast  and  little-known  ages  of  time  which  elapsed 
from  the  moment  when  our  ancestors  first  deserved  to  be  called 
human  down  to  the  time  when  the  Neolithic  immigrants  made 
their  way  into  Europe.  And  it  has  always  been  evident  that  so 
soon  as  any  considerable  knowledge  was  gained  of  the  pre- 
Neolithic  epochs,  some  other  classification  would  have  to  be 
adopted.  For  on  the  Darwinian  theory  of  continuous  or  gradual 
evolution,  it  is  abundantly  clear  that  the  first  men  must  have 
differed  from  the  late  Paleolithic  hunters,  anatomically,  mentally, 
and  socially,  far  more  than  these  same  Paleolithic  hunters 
differed  from  ourselves. 

As  a  makeshift  arrangement  the  Early  Stone  Age  has  been 
recently  broken  up  into  "  Early  Paleolithic  "  and  "  Late  Paleo- 
lithic "  divisions,  but  even  this  modification  inadequately 
expresses  the  newly  discovered  facts,  and  in  the  opinion  of  the 
present  writer  the  term  "  Paleolithic  "  will  have  to  be  carefully 
redefined  or  perhaps  entirely  abandoned. 

Let  us  briefly  recapitulate  what  is  now  known  of  the  pre- 
Neolithic  men.  The  Paleolithic  Period,  as  already  stated,  lies 
within  the  Pleistocene  or  Glacial  Period  of  the  geologists,  the 
period  of  the  earth's  history  immediately  preceding  that  in  which 
we  live,  or,  in  other  words,  the  penultimate  of  the  sixteen 
periods  into  which  it  is  customary  to  divide  the  story  of  life  on 
the  globe.  It  is  now  known  that  in  Central  and  Western 
Europe  the  Pleistocene  was  not  a  period  of  continuous  glaciation, 
although  in  Scandinavia  the  conditions  were  in  all  probability 
perpetually  arctic.  In  Britain,  France,  and  Germany  there  were 
several,  probably  at  least  four,  glacial  cycles ;  that  is  to  say, 
there  were  four  ice-ages  or  "glacial  episodes,"  with  consequently 
three  warm  interglacial  periods  between  them.  Although  a 
number    of   subdivisions   of   the   Paleolithic   Period    are    now 


SIGNIFICANCE  OF  THE  PILTDOWN  DISCOVERY   277 

generally  accepted,  the  exact  relationship  of  these  to  the  phases 
of  the  Pleistocene  is  still  in  dispute.  The  names  of  these 
Paleolithic  epochs  are  as  follows  :  (10)  Azilian,  (9)  Magdalenian, 
(8)  Solutrean,  (7)  Aurignacian,  (6)  Mousterian,  (5)  Acheulean, 
(4)  Chellean,  (3)  Strepyan,  (2)  Mesvinian,  (1)  Icenian,  reading 
from  above  downwards,  that  is,  from  the  latest  to  the  oldest  age. 

Of  the  ten  divisions,  the  Azilian  certainly  extends  into  Post- 
glacial times,  and  in  many  places  this  epoch  bridges  to  some 
extent  the  hiatus  between  the  Paleolithic  and  Neolithic  Periods, 
which  has  already  been  mentioned.  The  first  two  divisions 
have  still  a  somewhat  uncertain  status.  The  epochs  are  defined, 
of  course,  in  accordance  with  the  character  of  the  stone 
(or  bone)  implements  which  are  discovered  at  the  several 
levels,  the  implements  being  preserved  as  a  rule  either  in 
river-gravels  or  in  cave-deposits.  The  Mesvinian  implements 
have  often  been  described  as  "  eoliths,"  that  is,  as  alleged  stone 
implements  which  antedate  the  paleoliths,  and  whose  authenticity 
is  still  questioned  by  some  authorities.  The  Mesvinian  imple- 
ments are,  however,  on  a  somewhat  different  footing  from  other 
eoliths,  since  they  are  more  widely  accepted.1  The  Icenian'imple- 
ments  are  also  in  a  rather  dubious  position,  especially  as  some 
of  them  are  stated  by  Reid  Moir,  Ray  Lankester,  and  others  to 
be  Pre-glacial,  but  some  at  least  of  these  appear  to  be  genuine 
(particularly  the  later  or  Pleistocene  specimens)  and  they  will 
probably  be  accepted  eventually.  The  implements  of  the  third, 
fourth,  and  fifth  ages  have  been  found  chiefly  in  drift  left  by  rivers, 
those  of  the  subsequent  epochs  chiefly  in  caves ;  hence  the  now 
discarded  expressions  "  river-drift  man  "  and  "  cave-man." 

As  already  stated,  the  Paleolithic  epochs  and  the  Pleistocene 
phases  have  not  been  finally  correlated  with  one  another,  but  it  is 
probable  that  the  Aurignacian  Age  lies  wholly  within  the  last 
Interglacial  phase,  that  the  Magdalenian  extends  on  to  the  very 
end  of  the  Pleistocene,  that  the  Mousterian  begins  in  the  second 
or  middle  Interglacial  episode  and  overlaps  the  Aurignacian,  and 
that  the  Strepyan,  Chellean,  and  Acheulean  cultures  flourished 
during  the  Middle  Interglacial. 

Now  the  greatest  break  in  the  story  of  man  in  Europe  occurs 

not    between    the    Stone   Ages   and   the  Metal   Ages,  and  not 

between   the  Paleolithic  and    Neolithic  Ages,  but  between  the 

Mousterian    and     Aurignacian     divisions     of    the     Paleolithic. 

1  Notably  by  Prof,  Sollas,  who  is  a  keen  critic  of  eoliths. 


278  SCIENCE  PROGRESS 

During  the  last  four  Paleolithic  Ages  several  distinct  races 
inhabited  Europe,  which  may  or  may  not  have  left  survivors 
into  Neolithic  times,  and  which  may  or  may  not,  therefore, 
have  been  our  own  direct  forefathers.  But  whether  or  not  these 
peoples  were  exterminated  by  the  incoming  Neolithic  tribes, 
they  differed  in  minor  characters  only  from  ourselves,  and 
differed  from  one  another  less  than  the  divergent  races  still 
living  in  different  parts  of  the  world.  In  a  word,  they  belonged 
to  our  own  species,  Homo  sapiens.  In  their  anatomy  they  were 
entirely  human,  and  in  their  culture  they  were  less  rude  than 
some  savages  of  the  Nineteenth  Century. 

When,  however,  we  pass  back  from  the  Aurignacian  into  the 
Mousterian  Age  the  scene  entirely  changes.  We  find  ourselves 
on  utterly  unfamiliar  ground,  and  in  surroundings  where  the 
analogy  with  the  lowest  living  races  no  longer  affords  a  very 
safe  guide.  Europe  was  inhabited  during  Acheulean  and  Mous- 
terian times,  and  possibly  earlier  also,  by  the  famous  Neandertal 
race,  who,  it  is  now  realised,  constituted  a  distinct  species,  named 
Homo  neandertalensis  or  Homo  primigenius.  This  extinct  species 
is  now  familiar  to  us  from  a  number  of  discoveries,  of  which  the 
most  important  are  those  at  Neandertal  itself,  Gibraltar,  Spy  in 
Belgium,  Krapina  in  Hungary,  and  La  Chapelle-aux-Saints,  Le 
Moustier,  and  La  Ferrassie  in  the  south  of  France.  As  is  well 
known,  the  Neandertaler  differed  from  Homo  sapiens  in  having 
an  extremely  receding  forehead,  with  enormously  developed 
brow-ridges,  and  in  having  his  cranial  axis  disposed  at  a  somewhat 
different  angle.  Moreover  he  exhibited  a  heavier  and  stouter 
development  of  bone  in  all  parts  of  his  body,  and  his  brain, 
although  as  large  as  that  of  the  living  species,  was  distinctly 
more  simian  in  structure. 

These  Neandertalers  were  contemporary  for  a  short  time,  but 
probably  only  for  a  short  time,  with  the  very  different  Aurigna- 
cian races.  It  is  natural  to  suppose  that  the  brutish  Mousterians 
were  exterminated  by  the  higher  type,  and  so  different  are  the 
two  species  that  it  is  more  than  doubtful  whether  it  was  physically 
possible  for  any  miscegenation  to  have  occurred.  The  displace- 
ment of  Homo  neandertalensis  by  Homo  sapiens  was  probably  not 
a  very  long  process.  It  is  true  that  from  time  to  time  various 
11  discoveries  "  have  been  announced  in  which  skeletons  of  the 
modern  type  of  man  have  been  found  in  strata  older,  sometimes 
much  older,  than  the  Aurignacian.     As  a  rule  these  skeletons 


SIGNIFICANCE  OF  THE  PILTDOWN   DISCOVERY   279 

have  been  remarkably  well  preserved,  and  under  these  circum- 
stances it  is  not  surprising  that  they  have  been  received  with  a 
great  deal  of  scepticism,  and  that  it  has  been  suggested  that 
they  are  probably  interments.  One  of  the  most  recent  of  these 
finds  is  the  so-called  Ipswich  skeleton,  which  was  unearthed  by 
Reid  Moir,  and  has  found  a  powerful  advocate  in  Prof.  Keith. 
This  discovery  has,  however,  recently  been  subjected  to  most 
severe  criticism  by  W.  H.  Sutcliffe  *  and  others ;  and  it  may  be 
taken  as  certain  that  all  the  supposed  discoveries  of  pre-Aurigna- 
cian  sapiens  will  not  bear  close  examination.  And,  indeed,  it 
appears  very  unlikely  that  true  man  can  have  inhabited  Europe 
for  long  before  the  Aurignacian  epoch,  because  we  know  that 
the  Neandertalers  lived  here,  probably  in  considerable  numbers, 
before  that  age,  and  it  is  improbable  that  the  higher  and  better 
armed  type,  if  it  had  then  been  living  in  this  part  of  the  world, 
would  have  tolerated  the  presence  of  its  bestial  relative. 

Thus  it  will  be  seen  that  the  Paleolithic  Period  includes 
within  itself  very  dissimilar  elements.  The  gap  which  separates 
the  Mousterian  from  the  Aurignacian  is  more  profound  than 
any  break  which  occurs  in  all  the  succeeding  ages  from  the 
Aurignacian  to  the  Twentieth  Century.  The  Aurignacian  and 
all  that  comes  after  it  constitute  the  era  of  Homo  sapiens,  of 
true  man  ;  before  the  Aurignacian  we  are  back  among  kindred 
but  unfamiliar  creatures.  It  is  clearly  an  irrational  arrange- 
ment to  group  the  earliest  true  men  together  with  the  various 
extinct  species  under  the  title  "  Paleolithic "  ;  and  even  if  it 
be  argued  that  the  prehistoric  periods  are  founded  upon  cultural 
not  upon  racial  considerations,  the  break  between  the  Neander- 
talers and  the  artistic  and  much  more  skilful  Aurignacians 
is  very  great — and,  in  any  case,  an  event  of  such  importance 
as  the  appearance  of  true  man  should  be  expressed  in 
classification.2 

Passing  farther  back  behind  the  Aurignacians,  our  knowledge 
of  the  extinct  members  of  the  Hominidae  has  been  greatly 
extended  by  the  epoch-making  discovery  at  Piltdown,  Sussex, 
which  we  owe  to  the  enterprise  and  patient  research  of  Mr. 
Charles  Dawson  and  Dr.  Smith  Woodward.  This  discovery 
has  given  us  a  fifth  species  of  the  Hominidae.     The  Neander- 

1  Proceedings  of  the  Manchester  Literary  and  Philosophical  Society,  191 3. 

2  I  make  the  suggestion  that  the  Aurignacian  and  three  subsequent  ages  should 
be  classed  together  as  Deutolithic,  and  the  previous  epochs  grouped  as  Protolithic . 


28o  SCIENCE  PROGRESS 

talers  are  not  certainly  known  to  extend  back  farther  than  the 
Acheulean  Age,  but  behind  them  we  are  acquainted  with  the 
existence  of  three  still  more  ancient  species.  Unfortunately 
each  of  these  is  only  known  from  a  single  discovery,  as  follows : 
the  Ape-man  of  Java,  Pithecanthropus  eredus  (Dubois);  the 
Heidelberg  man,  Homo  heidelbergensis  (Schcetensack) ;  and  the 
Piltdown   Race,  Eoanthropus  dawsoni. 

The  Javan  specimen  is  very  distinct  from  Eoanthropus,  from 
the  Neandertalers,  and  still  more,  of  course,  from  man — so 
distinct  indeed  that  the  creature  may  even  be  nearer  to  the 
Simiidce  than  to  the  Hominidce.  As  for  H.  heidelbergensis,  only 
one  lower  jaw  of  the  species  has  been  discovered,  so  that 
it  is  impossible  to  speak  with  any  confidence!  of  the  characters 
of  this  type.  The  jaw  has  indeed  been  variously  described 
as  akin  to  Pithecanthropus  (by  Duckworth),  and  as  the  first  and 
most  primitive  of  the  Neandertalers  (by  Keith).  Only  a  small 
fragment1  of  the  Javan  animal's  jaw  was  found,  but  so  far  as 
it  is  possible  to  judge  it  seems  probable  that  heidelbergensis 
claimed  closer  affinity  with  the  Neandertalers  than  with  Pithecan- 
thropus. The  Heidelberg  mandible  is  not  very  unlike  the  various 
jaws  of  neandertalensis  that  have  been  unearthed,  but  it  would, 
of  course,  be  unsafe  to  assume  from  this  that  the  complete 
skeletons  of  the  two  types  were  also  similar,  and  it  is  not 
even  possible  to  be  absolutely  certain  that  this  most  ancient 
mandible  was  associated  with  the  very  receding  forehead  which 
is  so  characteristic  alike  of  the  Neandertalers  and  of  Pithecan- 
thropus. 

It  is,  however,  when  we  compare  the  well-preserved  Heidel- 
berg jaw  with  the  right  half  of  a  mandible  that  was  found  with 
the  skull  at  Piltdown  that  we  find  ourselves  face  to  face  with 
certain  most  remarkable  facts.  These  two  jaws  are  utterly 
unlike  one  another.  And  in  various  respects  each  diverges 
more  from  the  other  than  either  differs  from  a  human  jaw. 
At  first  sight  this  is  perhaps  not  very  surprising,  since  it  might 
have  been  foreseen  that  in  the  last  stages  of  the  upward  evolution 
of  the  Primates  towards  humanity,  as  in  the  earlier  stages, 
side  branches  would  have  been  thrown  off.  When,  however, 
the  differences  between  the  extinct  species  are  examined  in 
close  detail,  the  problem  becomes  puzzling  in  the  extreme. 
The  inter-relationships  of  the  several  kinds  in  the  family  tree 
1  The  fragment  has  not  yet  been  described. 


SIGNIFICANCE  OF  THE  PILTDOWN  DISCOVERY   281 

are  very  difficult  to  discern.  No  doubt  this  is  due  to  the  very 
meagre  amount  of  evidence  available.  But  as  this  evidence 
is  likely  to  remain  scanty  for  many  years  to  come,  it  is  worth 
while  following  up  the  suggestions  that  Dr.  Woodward  has 
thrown  out  in  regard  to  the  genealogy  of  the  Hominidse. 

The  Piltdown  skull  has  now  been  fully  described  by  Wood- 
ward,1 and  the  brain  case  proves  to  be  thoroughly  human, 
differing  from  man  only  in  the  extreme  thickness  of  the  bones 
and  a  few  minor  features.  The  cranial  capacity  is  very  low 
(about  1,070  ccm.),  but  not  below  that  of  the  lowest  modern 
savages,  the  Tasmanians.  The  forehead  is  fairly  steep  and 
there  are  only  small  brow-ridges,  so  that  in  this  respect 
Eoanthropus  resembles  H.  sapiens,  not  H.  neandertalensis.  The 
facial  parts  were  not  found,  and  their  form  can  therefore  only 
be  inferred  from  the  mandible.  It  is,  however,  mainly  in  the  man- 
dible that  the  new  genus  differs  from  man.  As  in  other  ancient 
jaws,  the  ascending  ramus  is  wide  and  the  sigmoid  notch  (the 
concavity  in  the  dorsal  border  of  the  ascending  ramus)  is  rela- 
tively shallow.  The  chief  peculiarity  occurs,  however,  in  the 
region  of  the  symphysis,  where  the  jaw  is  strengthened  by  a 
horizontal  plate,  or  flange,  which  constitutes,  in  fact,  a  very  short 
bony  floor  to  the  jaw  (see  fig.  1).  This  flange  is  completely 
absent  in  man,  and  is,  indeed,  an  entirely  simian  structure,  the 
chimpanzee  possessing  an  identical  piece  of  bone.  From  the 
presence  of  this  flange  it  is  evident  that  the  genio-hyo-glossal 
and  genio-hyoid  muscles  took  their  origin  in  a  deep  pit,  and 
were  therefore  presumably  weakly  developed  ;  and  it  is  a 
legitimate  inference  from  this,  and  from  the  related  fact 
that  the  mylo-hyoid  and  internal  pterygoid  were  also  weakly 
developed  (as  proved  by  the  markings  on  the  inner  face  of  the 
ramus),  that  the  Piltdown  race  was  almost  or  quite  speechless. 
The  upper  part  of  the  front  of  the  jaw  was  broken  away,  so  that 
the  anterior  teeth  can  only  be  filled  in  by  intelligent  guesswork. 
It  is  clear,  however,  that  whether  or  not  the  teeth  were  quite 
as  large  as  Woodward  makes  them,  they  must  have  been  con- 
siderably bigger2  than  those  of  any  other  known  member  of 
the  Hominidae,  with  the  possible  exception  of  Pithecanthropus. 

1  Quarterly  Journal  of  the  Geological  Society,  March  1913. 

3  Note  added  to  press  :  This  statement  is  confirmed  by  the  discovery  at  Pilt- 
down on  August  30  of  a  canine  tooth,  which  is  only  slightly  smaller  in  size  than 
*he  hypothetical  canines  in  fig.  1. 


282 


SCIENCE  PROGRESS 


Woodward  founds  his  new  genus  mainly  upon  the  form  of 
the  mandibular  symphysis,  which  he  contrasts  with  that  of  the 
three  species  of  Homo.  The  contrast  in  this  respect  between 
Eoanthropus  and  heidelbergensis  is,  however,  less  striking  than 
Woodward  seems  to  imply,  for  there  is  a  clear  vestige  of  the 
flange  in  the  Heidelberg  jaw,  and  in  the  latter,  as  in  the 
Piltdown  mandible,  the  genio-hyo-glossal  and  genio-hyoid 
originate  in  a  pit.  In  fact,  as  Prof.  Sollas  has  well  remarked, 
in  the  structure  of  its  symphysis  the  Heidelberg  jaw  "stands 


~.-/ 


Fig.   i. — The  Piltdown  jaw,  as  reconstructed  by  Smith  Woodward.     S  =  the 

horizontal  flange.     The  parts  shaded  are  those  actually  known. 
(Reproduced  by  kind  permission  from  the  Quarterly  Journal  of  the  Geological  Society.) 

midway  between  man  and  the  anthropoid  apes,"  and  therefore 
midway  between  sapiens  and  E.  dawsoni.  As  regards  date, 
there  is  little  reason  to  doubt  that  Dawson  is  right  in  believing 
that  the  Piltdown  skull  is  contemporaneous  with  the  Paleolithic 
implements  which  were  found  near  it.  These  implements  are 
late  Chellean  or  early  Acheulean.  It  is  certainly  remarkable 
that  a  creature  with  such  a  simian  jaw  should  have  been  living 
in  Chellean  times,  but  it  is  probable,  as  Woodward  suggests, 
that  the  representatives  of  the  Piltdown  race  living  in  what  is 
now  Britain  were  a  surviving  remnant  of  a  very  ancient  stock. 


SIGNIFICANCE  OF  THE  PILTDOWN   DISCOVERY   283 

They  were  no  doubt  exterminated  eventually  either  by  heidel- 
bergensis  or  neandertalensis.  The  Heidelberg  jaw  is  certainly 
not  later  than  the  Mesvinian  Age  (which  must  be  placed  in  the 
first  Interglacial  phase),  and  it  may  be  earlier ;  it  is  thus  at  least 
one  glacial  cycle  older  than  the  Piltdown  specimen. 

The  characters  of  the  five  species  may  therefore  be  tabulated 
as  below  : 


Pithecan- 
thropus. 

EoanthropHS. 

H.  heidelberg- 
ensis. 

H.  neander- 
talensis. 

H.  sapiens. 

Cranial  capacity  . 

850  ccm. 

1,150  ccm.1 



1,400  ccm. 

1,500  ccm.2 

Forehead     . 

Receding 

High 

— 

Receding 

High 

Brow-ridges 

Large 

Small 

— 

Large 

Small 

Teeth . 

Large  (?) 

Large 

Small 

Small 

Small 

Ascending  ramus 

of  mandible 

— 

Intermediate 

Very  wide 

Intermediate 

Narrow 

Sigmoid  notch     . 

— 

Intermediate 

Very  shallow 

Intermediate 

Deep 

Symphysis  . 

— 

Simian 

Intermediate 

Almost  human 

Human 

Date  . 

Pliocene 

Middle 

Early 

Middle 

Late  Pleistocene 

Pleistocene 

Pleistocene 

Pleistocene 

and  Recent 

Now,  it  used  to  be  generally  believed  that  neandertalensis 
was  directly  ancestral  to  sapiens,  a  belief  that  was  in  no  way 
inconsistent  with  the  sudden  appearance  of  sapiens  in  Europe, 
for  the  evolution  from  one  type  to  the  other  might  well  have 
taken  place  in  another  continent,  whilst  the  Neandertalers  in 
Europe  were  in  a  stagnant  condition.  This  theory  has  been 
recently  losing  ground,  however,  and  it  is  now  more  commonly 
held  that  the  Neandertalers  represent  a  side  branch,  showing 
some  signs  of  what  is  loosely  called  degeneracy,  and  leading 
nowhere.  Woodward  adopts  this  latter  hypothesis,  and  de- 
velops it  further.  He  believes  that  the  discovery  of  Eoanthropus 
proves  that  the  high  forehead  is  a  primitive  character  of  the 
Hominidae,  and  that  the  low  forehead  and  great  brow-ridges 
of  neandertalensis  are  therefore  a  secondary  acquirement,  and 
he  proceeds  to  expound  the  view  that  because  the  young  ol 
all  the  anthropoid  apes  have  likewise  a  relatively  high  forehead, 
therefore  (on  the  recapitulation  theory)  the  apes  too  are  to  be 
regarded   as   descended   from   animals  with   a  steep,   manlike, 


1  The  specimen  found  is  that  of  a  female,  and  therefore  below  the  average  for 
the  race.  (Prof.  Keith's  estimate,  recently  given  at  the  International  Medical 
Congress,  is  higher.) 

3  Europeans. 


284  SCIENCE   PROGRESS 

cranial  arc.  Thus  Dr.  Woodward  inclines  towards  Prof. 
Klaatsch's  famous  heresy  that  the  apes  are  descended  from 
creatures  who  were  in  many  respects  almost  human,  although 
of  course  he  does  not  countenance  the  more  extravagant  part 
of  Klaatsch's  hypothesis,  in  which  that  authority  associates 
particular  apes  with  particular  races  of  men — the  gorilla  with 
the  negro,  and  the  orang  with  white  men. 

Due  weight  should  certainly  be  attached  to  the  fact  that  in 
the  case  of  Eoanthropus  a  high  forehead  is  associated  with  such 
a  primitive  jaw.  And  the  manlike  skull  of  the  young  ape  is 
certainly  a  curious  feature,  although  a  tendency  towards  the 
same  rounded  form  may  be  seen  in  the  foetus  of  many  other 
mammals  besides  apes,  which  robs  this  fact  of  much  of  its 
importance.  It  must  be  remembered,  however,  that  a  low 
receding  forehead  is  universal  among  the  lower  Primates, 
and  hence  was  indubitably  present  in  the  more  distant  ancestors 
of  both  Hominidce  and  Simiidce.  Thus  convincing  proof  is 
necessary  before  we  are  justified  in  interpreting  the  low 
forehead  of  the  apes,  of  Pithecanthropus,  and  of  neandertalensis 
as  a  secondary  acquirement ;  for  there  is  of  course  the  alter- 
native explanation  that  all  these  animals  possess  a  low  forehead 
merely  because  their  ancestors  never  had  anything  else. 
This  is  at  first  sight  the  simpler  theory,  and  the  importance 
of  the  mandibular  symphysis,  as  a  sign  of  kinship,  is  not 
strengthened  by  an  examination  of  the  Heidelberg  jaw.  The 
Piltdown  and  Heidelberg  mandibles  are  compared  in  fig.  2. 
It  will  be  seen  at  once  that  the  "ascending"  (or  vertical) 
part  of  the  ramus  is  much  wider  in  the  German  specimen,  and 
that  the  whole  conformation  of  the  two  bones  is  entirely  dis- 
similar. The  first  and  second  molar  teeth  are  the  same  size  in 
the  two  jaws,  but  the  Sussex  specimen  is  much  the  larger 
anteriorly,  hence  the  larger  front  teeth.  Now,  Woodward 
derives  both  sapiens  and  neandertalensis  directly  from  Eoanthropus, 
It  is  not  quite  clear  where  he  would  place  heidelbergcnsis,  but 
since  he  is  content  to  leave  the  latter  species  in  the  genus  Homo, 
he  presumably  regards  it  as  a  twig  of  the  branch  which  gave  rise 
to  the  other  two  species.  Now,  it  may  be  possible  to  derive 
the  relatively  narrow  jaw  of  a  Neandertaler  from  the  type  of 
mandible  exhibited  by  Eoanthropus,  but  it  is  difficult  to  see  how 
heidelbergensis  could  have  been  evolved  from  the  same  source. 
It  has  long  been  known  that  a  shallow  sigmoid  notch  and  a 


SIGNIFICANCE  OF  THE  PILTDOWN  DISCOVERY  2S5 

powerful  wide  ascending  ramus  are  characteristic  of  all  the 
lower  human  jaws.  And  now  we  are  faced  with  the  curious 
paradox  that  the  Heidelberg  mandible  possesses  a  somewhat 
shallower  sigmoid  notch  and  a  much  wider  ascending  ramus 
than  the  Piltdown  jaw.  If,  therefore,  heidelbergensis  be  descended 
from  the  Piltdown  race,  the  ordinary  course  of  evolution  was 
reversed,  and  the  wide  ascending  ramus  of  heidelbergensis  must 
be  regarded  as  a  secondary  acquirement.  It  would  be  rash  to 
say  that  this  is  an  impossibility,  but  it  is  certainly  a  curious 
conclusion.  The  family  tree  constituted  on  this  hypothesis  is 
represented  in  fig.  3.     H.  heidelbergensis  is  here  conceived  to  be 


Fig.  2. — Mandibular  ramus  from  Piltdown  superposed  on  that  of  Homo 
heidelbergensis.     Two- thirds  of  the  natural  size. 

(Reproduced  by  kind  permission  from  the  Quarterly  Journal  of  the  Geological  Society.) 

a  "  degenerating  "  branch,  given  off  from  the  main  stem  at  a 
point  where  the  symphysis  had  become  half-human. 

The  only  further  comment  that  it  is  necessary  to  make  on 
this  theory  is  that  it  is  fatal  to  the  conception  that  heidelbergensis 
is  directly  ancestral  to  neandcrtalensis ;  it  would  be  too  much  to 
believe  that  the  immensely  wide  ascending  ramus  was  acquired 
and  then  lost  again. 

If,  however,  we  abandon  the  hypothesis  that  Eoanthropus 
is  directly  ancestral  to  Homo,  another  explanation  of  the 
characters  becomes  possible.  Why,  it  may  be  asked,  should 
not  heidelbergensis  and  Eoanthropus  be  descended  from  a  not 
distant  ancestor  which  combined  the  primitive  features  of  each, 


286 


SCIENCE  PROGRESS 


that  is,  combined  the  massive  ramus  of  the  one  with  the  large 
teeth  and  simian  mandibular  symphysis  of  the  other?  The 
genealogy  of  the  four  species  concerned  would  then  be  as 
shown  in  fig.  4.  This  second  hypothesis  obviates  the  neces- 
sity of  assuming  a  reversed  evolution  in  the  case  of  the 
Heidelberg  jaw,  and  the  low  forehead  of  the  Neandertalers 
may  be  once  more  explained  as  degeneracy,  it  being  assumed 
that  "  X,"  like  Eoanthropus  and  sapiens,  had  a  high  forehead. 
But  the  theory  encounters  formidable  difficulties.     It  is  clear, 


H. sapiens. 


H.neandertalensis. 


H.heidelbergensis. 


Eoanthropus. 

Fig.  3. 


for  instance,  that  if  it  be  true,  the  narrower  ascending  ramus  and 
the  deeper  sigmoid  notch  were  acquired  independently  by 
Eoanthropus  and  sapiens — that  is,  that  these  similarities  are  no 
sign  of  kinship,  but  are  due  to  parallelism  in  development.  In 
this  connection  it  is  interesting  to  notice  that  if  the  outline  of  the 
jaw  of  a  European  be  superimposed  upon  that  of  heidelbergensis, 
the  chin  region  of  the  European's  jaw  projects  beyond  the  front 
of  the  ancient  jaw,  just  as  that  of  Eoanthropus  projects  in  Fig.  2, 
only  rather  less  so.  Since,  however,  modern  jaws  have  a  chin 
prominence,  which  Eoanthropus  certainly  had  not,  the  front 
curve  of  the  jaw  passes  backwards  again  as  it  passes  upwards, 


SIGNIFICANCE  OF  THE  PILTDOWN  DISCOVERY  287 

the  teeth  of  sapiens  being  as  small  as,  or  smaller  than,  those  of 
heidelbergensis.  The  chin  prominence  of  modern  man  is  usually 
explained  by  the  rapid  contraction  of  the  alveolar  surface  in 
accordance  with  the  reduction  of  the  size  of  the  teeth  during 
the  latest  stages  in  human  evolution,  and  the  chin  is  therefore  a 
hint,  though  only  a  hint,  that  true  man  has  a  very  recent 
ancestor  with  teeth  larger  than  those  of  heidelbergensis.  Or, 
in  other  words,  it  is  easier  to  derive  the  human  jaw  from  one 
that  was  large  anteriorly  and  small  posteriorly,  than  to  derive  it 


H. sapiens. 


toanthropus 


H.neandertalensls. 


H.  heidelbergensis. 


Fig.  4. 


from  a  mandible  of  the  Heidelberg  type,  and  Woodward's 
Piltdown  jaw  has  just  the  form  required  by  theory.  Amidst  the 
maze  of  uncertainties,  it  appears  that  Woodward  is  wholly 
right  in  claiming  a  close  relationship  between  the  Piltdown 
Race  and  true  man. 

Thus  both  these  theories,  though  not  impossible,  are  difficult 
to  reconcile  with  the  extraordinary  differences  between  the  two 
most  ancient  jaws.  But  the  facts  are  susceptible  to  another 
interpretation  of  a  totally  different  kind.  Is  Dr.  Woodward 
right  in  the  importance  he  attaches  to  the  mandibular  symphysis 
as  a  sign  of  relationship  ?     May  not  the  absence  of  a  flange, 


288  SCIENCE  PROGRESS 

and   the  greater  development    of   the  tongue-muscles   therein 
implied,  have  been  developed  independently  in  more  than  one 
branch   of  the  evolving   Primates  ?     The  phenomenon  of  con- 
vergence, or  parallelism  in  evolution,  is  one  that  has  long  been 
familiar   to    naturalists.      There    is    the    famous    case    of    the 
cephalopod  eye,  which  simulates  so  closely  in  its  structure  the 
eye  of  a  vertebrate.     In  two  widely  separated  branches  of  the 
animal   kingdom   the   same   need   was   met   in   the   same  way. 
Again,  there  is  in  Australia  a  little  animal  called  the  pouched 
mole.     This  creature  is  a  marsupial  and  is  consequently  allied 
to  the  kangaroos.     But  it  lives  underground,  and  in  its  appear- 
ance,  and    in    the    adaptation    of    its    limbs    and    form    to    a 
subterranean  mode  of  life,  the  little  beast  exactly  resembles  the 
real  moles  of  Europe.     In  this  case,  too,  the  same  need  has  been 
met  in  the  same  way.     With   our   present   knowledge   of  the 
early  Hominidse  it  is  of  course  impossible  to  speak  with  con- 
fidence of  the  factors  at  work  in  the  evolution  of  those  creatures, 
but  it  is  quite  likely  that  this  principle  of  convergence  played 
some   part   in   that   process.     Our   second   hypothesis,    indeed, 
necessitated  it  in  certain  minor  respects.     But  when  we  recall 
in  imagination  the  conditions  under  which  the  divers  sorts  of 
half-men  lived,  we  can  see  that  convergence  may  have  been  a 
most  conspicuous  phenomenon  in  their  progress.     They  were 
highly  gregarious  animals,  whose  very  survival  must  constantly 
have  depended  upon  the  power  of  the  individuals  efficiently  to 
combine.     And  to  combine  effectively  it  was  before  all  things 
necessary  that  they  should   be  able  to  communicate  with  one 
another.      The   power   of    speech   was   a   crying   need   of    the 
advancing   Primates — a   want   no   less    urgent    than    muscular 
fossorial  limbs   to   the   marsupial  of  mole-like  habits.     It  was 
language   that   transformed   the    horde    into    the    tribe.      The 
creatures    were    probably    widely    dispersed    over    the    earth 
whilst  they  were  yet  speechless.     And  rudimentary  powers  of 
speech  may  thus  have  been  acquired  independently   by  more 
than  one  species  ;  and  this,  not  blood-relationship,  may  be  the 
explanation  of  the  man-like  symphysis  of  the  Heidelberg  jaw. 
And  those  who  are  impressed  with  the  neandertaloid  features  of 
that  specimen  might  go  farther  and  re-establish  the  connection 
between  heidelbergensis  and  neandertalensis.    The  descent  would 
then  work  out  as  shown  in  fig.  5. 

On  this  last  hypothesis  the  common  ancestor,  "  X,"  is  con- 


SIGNIFICANCE  OF  THE  PILTDOWN  DISCOVERY  289 

ceived  as  possessing  a  simian  mandibular  symphysis,  a  massive 
jaw,  large  teeth,  and  probably  a  low  forehead.  Pithecanthropus 
may  possibly  have  exhibited  all  these  primitive  characters.  If 
this  interpretation  of  the  phenomena  were  established,  it  would 
of  course  become  necessary  to  remove  heidelbergensis  (and 
possibly  neandertalensis  also)  from  the  genus  Homo.1 

The  suggestions  thrown  out  in  this  paper  suffice  only  to 
show  how  little  is  certainly  known  of  the  inter-relationships  of 
the  fossil   Hominidae.     It  would   be  altogether  premature  to 

H  sapiens. 


Eoanthropus. 


Fig.  5. 

attempt  to  dogmatise  upon  the  rival  possibilities  ;  none  is  free 
from  difficulties.  I  am,  however,  strongly  inclined  to  think 
that  both  the  apes  and  Pithecanthropus  have  a  low  forehead  not 
because  they  are  degenerate,  but  because  they  are  immediately 
descended  from  monkeys.  And  even  in  its  more  plausible 
application  to  Neandertal  man,  I  view  the  degeneracy  theory 
with  considerable  suspicion. 

1  Whilst  the  present  article  was  in  the  press,  Mr.  W.  H.  Sutcliffe  kindly  sent 
me  a  copy  of  his  above-mentioned  paper,  of  which  I  had  only  seen  a  preliminary 
report.  His  main  theme  is  a  convincing  criticism  of  pre-Aurignacian  sapiens  and 
of  eoliths,  but  I  find  that  incidentally  he  adopts  what  I  have  called  Hypothesis  3, 
although  without  giving  any  reasons  for  his  belief. 

19 


29o  SCIENCE   PROGRESS 

New  light  may  be  thrown  upon  man's  origin  from  an  entirely 
different  direction.  One  school  of  naturalists,  including  the 
most  erudite  of  experimental  biologists,  now  deny  that  there  is 
any  evidence  that  evolution  has  ever  taken  place  gradually,  in 
the  manner  Darwin  supposed.  They  believe  that  living  organ- 
isms have  progressed  not  by  imperceptible  stages,  but  by  sudden 
mutations  or  transformations.  Certainly  students  of  human 
paleontology  are  not  in  a  position  to  refute  such  a  statement. 
As  far  back  as  the  Aurignacian  everything  is  only  too  familiar ; 
behind  the  Aurignacian  all  is  mystery. 


LECTURE  I1 

NATURE   AND    NURTURE    IN    MENTAL 

DEVELOPMENT 

By  F.  W.  MOTT,  M.D.,  F.R.S. 

Pathologist  to  the  London  Coioity  Asylums 

The  problem  of  nature  and  nurture  in  mental  development  is 
one  that  has  recently  acquired  importance  for  various  reasons, 
such  as  the  increase  of  certified  insanity  and  the  enormous  sums 
of  money  spent  on  asylums  for  housing  lunatics;  and  the  recog- 
nition by  the  public  that  insanity,  epilepsy,  and  feeble-mindedness 
are  in  great  measure  due  to  inheritance  has  lead  to  a  widespread 
feeling  that  some  check  should  be  placed  upon  propagation  of 
the  mentally  unfit.  This  is  becoming  daily  more  manifest  from 
two  causes :  The  migration  and  emigration  of  the  mentally 
and  physically  fit  from  the  rural  districts  and  the  sedimentation 
of  the  unfit  in  the  slums  of  our  large  cities  where  degraded 
pauperism  exists  to  so  great  an  extent. 

The  rapid  growth  of  population  in  this  country  commenced 
with  the  growth  of  industrialism  and  the  rise  of  towns  and  cities 
with  inhabitants  engaged  in  factories  and  manual  occupations, 
where  individualism  necessarily  became  subject  to  collectivism. 
Just  as  in  the  human  body  there  is  differentiation  of  structure 
and  function,  so  there  is  in  the  modern  complex  social  organism  ; 
and  just  as  in  the  human  body  the  failure  of  function  of  one 
organ  may  disturb  the  harmony  of  function  of  the  whole  body 
and  mind,  so  in  the  social  organism  a  strike,  even  by  a  humble 
section  of  it,  may  lead  to  disorganisation  of  the  whole. 

The  collection  of  large  numbers  of  people  in  towns  and  cities 
who  were  previously  accustomed  to  individualism  in  matters  of 
sanitation  led  to  a  most  deplorable  state  of  affairs,  and  Sir  Edwin 
Chadwick,  a  pioneer  in  sanitary  science,  in  whose  honour  these 
lectures  were  given,  was  the  first  to  call  attention  to  the  necessity 
of  legislation  to  remedy  the  growing  evil. 

In  1842  a  report  was  published  by  him  on  "The  Sanitary 
Condition  of  the  Labouring  Population  of  Great  Britain."     In 

1  The  Chadwick  Public  Lectures,  1913. 
291 


292  SCIENCE  PROGRESS 

this  he  called  attention  to  the  filthy  conditions  under  which  the 
English  labouring  classes  lived.  To  remedy  this,  collective 
responsibility  undertook  the  first  stage  of  social  reform  by 
cleansing,  lighting,  and  policing  of  the  streets,  and  by  establish- 
ing systems  of  water-supply  and  drainage  in  our  cities  and  large 
towns. 

The  second  stage  of  social  reform  was  factory  legislation,  for 
regulating  the  conditions  of  work  in  factories,  for  protecting  those 
employed  in  unhealthy  occupations  and  industries,  and  for 
restricting  the  work  of  women  and  restraining  the  work  of 
children.  Like  many  other  essential  social  reforms,  it  met  with 
much  opposition. 

The  third  stage  was  the  nationalisation  of  education  in  1870 
and  the  extension  of  the  meaning  of  education  has  so  far  pro- 
gressed that  it  now  includes  not  only  mental  but  also  physical 
development,  the  exercising  and  even  feeding  of  children  where 
necessary,  the  care  of  the  feeble-minded  by  the  formation  of 
special  schools,  medical  inspection  and  notification  of  infectious 
diseases,  treatment  of  children's  ailments,  and  attention  to  the 
eyes,  ears,  and  teeth  at  the  school-age. 

Last  to  occur,  the  effort  to  guard  the  child  before  the  school- 
age,  even  as  soon  as  it  is  born,  even  before  birth  through 
attention  to  the  future  mother.  There  is  yet  one  other  educa- 
tional method  of  far-reaching  importance  to  the  masses,  and  that 
is  the  scout  movement  and  officers'  training  corps,  by  which 
boys  and  youths  are  trained  to  become  self-reliant  yet  unselfish, 
and  submissive  to  discipline  without  losing  individuality.  That 
spirit  of  esprit  de  corps  which  is  the  striking  feature  of  our  public 
schools  and  universities  is  by  this  movement  extended  to  the 
boys  and  youths  of  all  classes,  and  it  cannot  fail  to  have  an 
important  influence  upon  development  of  character.  Each  of 
these  stages  has  supplemented  and  reinforced  the  other ;  yet  we 
hear  on  all  sides  the  pessimistic  cry  of  the  degeneration  of  the 
race  set  up  by  a  few  unthinking  people  who  advocate  a  "  laissez- 
faire  "  or  the  so-called  "  better  dead  "  theory  of  all  those  who  are 
unable,  through  inborn  lack  of  vitality,  to  resist  racial  diseases. 
Are  we  to  listen  to  these  pessimists  ?  No !  Rather  should  we 
look  with  pride  to  what  has  been  done  in  the  last  fifty  years  to 
better  the  condition  of  the  people. 

In  respect  to  tuberculosis  I  will  quote  the  words  of  a  great 
French  scientist  uttered  at  the  International  Congress  of  Tuber- 


MENTAL  DEVELOPMENT  293 

culosis  held  in  London  in  1901.  Professor  Brouardel,  of  Paris, 
said  in  his  address  :  "  You  have  diminished  the  mortality  in 
England  from  tuberculosis  by  40  per  cent.,"  and  he  attributed 
this  decline  to  the  numerous  Acts  of  Parliament  and  measures 
promoted  by  private  individuals  to  render  more  salubrious  the 
dwellings  of  the  poor  and  the  conditions  under  which  they  live 
and  carry  on  their  occupation  in  factories,  mines,  and  workshops 
throughout  the  kingdom.  We  can  from  this  realise  what  a  great 
work  Sir  Edwin  Chadwick  did  in  combating  this  racial  disease 
by  his  pioneer  work  in  sanitary  science. 

The  housing  of  the  poor  is  now  the  bed-rock  of  physical  and 
mental  hygiene  and  still  calls  for  all  the  efforts  which  Parliament 
and  private  enterprise  can  exert.  By  energetic  amelioration  of 
the  present  conditions,  especially  those  of  the  casual  workers  in 
cities,  and  of  the  rural  population,  more  can  be  done  than  by 
any  other  means  to  "  diminish  "  the  death-rate  from  tuberculosis, 
the  contamination  of  the  morals  of  the  poor  and  the  infant 
mortality.  The  social  reformer  justly  recognises  that  much 
good  raw  material  may  be  spoilt  by  a  bad  environment;  he 
recognises  also  the  fact  that  a  healthy  mind  can  only  exist  in  a 
healthy  body  and  that  an  inborn  virtue  may  by  evil  surround- 
ings and  imitation  be  the  source  of  contracted  vices.  The  ardent 
and  enthusiastic  social  reformer  should  recognise  the  fact  that 
you  do  not  gather  grapes  from  thorns  nor  figs  from  thistles  ; 
that  the  children  of  feeble-minded  parents  will,  in  spite  of  good 
nutrition  and  favourable  surroundings,  tend  to  be  more  or  less 
feeble-minded  ;  that  the  most  dangerous  form  of  feeble-minded- 
ness,  now  that  Nature  is  no  longer  left  to  itself  to  select  by 
survival  of  the  fittest,  is  the  higher-grade  imbecile,  who  is  fertile 
and  able  under  the  easier  conditions  of  survival  brought  about 
by  social  reform  to  multiply  and  infect  good  stocks.  Seeing  that 
we  cannot  prevent  this  occurring,  the  only  hope  is  that  the 
Mental  Deficiency  Bill  which  has  now  passed  a  second  reading 
may  become  law;  its  object  being  to  segregate  early  mentally 
defective  children  in  their  own  interests  and  in  the  interests  of 
the  community.  Inasmuch  as  feeble-mindedness  occurs  in  all 
classes,  I  should  advocate  notification  of  all  mental  defectives ; 
and  where  parental  responsibility  has  failed,  then  in  the  interests 
of  the  child  the  Government  should  take  up  the  responsibility  of 
guardianship  as  a  protective  measure — due  precautions  being 
taken    and  every  opportunity  given    of   restoration   to   social 


294  SCIENCE   PROGRESS 

privileges,  should  it  be  found  desirable  by  the  properly  con- 
stituted authorities.  Some  of  these  practical  problems  concern- 
ing mental  hygiene  will,  I  trust,  be  better  understood  by  the 
public,  if  they  will  consider  the  subject  from  the  physiological 
and  medical  points  of  view,  as  well  as  from  the  economic  and 
political. 

Mental  Hygiene  from  a  Physiological  Standpoint 

Structure  and  Development  of  the  Brain. — The  most  striking 
anatomical  distinction  of  man  from  the  anthropoid  apes  is  the 
enormous  increase  in  the  development  of  the  great  brain — the 
cerebrum — and  this  increase  in  size  is  due  almost  entirely  to  an 
enlargement  of  that  part  of  the  great  brain  which  occupies  the 
cranial  vault  and  gives  to  man  a  dome-like  shape  to  the  skull. 

Gall,  the  phrenologist,  more  than  one  hundred  years  ago, 
was  the  first  to  point  out  that  that  part  of  the  brain  with  which 
the  higher  mental  activities  are  connected  must  be  the  cerebral 
hemispheres.  He  said  :  "  If  we  compare  man  with  animals  we 
find  that  the  sensory  functions  of  animals  are  much  finer  and 
more  highly  developed  than  in  man  ;  in  man,  on  the  other  hand, 
we  find  intelligence  much  more  highly  developed  than  in  animals. 
Upon  comparing  the  corresponding  anatomical  conditions  we 
see,"  he  said,  "  that  in  animals  the  deeper  situated  parts  of  the 
brain  are  relatively  more  developed  and  the  hemispheres  less 
developed  than  in  man  ;  in  man  the  hemispheres  so  surpass  in 
development  those  of  animals  that  we  can  find  no  analogy."  Gall 
moreover  studied  the  brains  of  imbeciles  and  demented  persons, 
and  was  the  first  to  point  out  that  the  disorder  and  deficiency  of 
mind  of  one,  and  the  disorder  and  loss  of  mind  of  the  other, 
should  be  correlated  with  the  deficient  development  of  the  hemi- 
spheres in  the  feeble-minded  imbecile  and  the  destruction  of  the 
hemispheres  in  the  demented  lunatic. 

Unfortunately  Gall's  imagination  outstripped  his  judgment 
and  he  wrecked  his  fame  as  a  scientist  by  associating  mental 
traits  of  character  with  conditions  of  the  skull ;  then,  encouraged 
by  a  wide-spread  wave  of  popular  sympathy  in  the  endeavour 
to  materialise  and  localise  the  functions  of  mind,  he  launched  into 
speculative  hypothesis  unsupported  by  facts.  His  doctrine  of 
phrenology  was  shown  to  be  absolutely  illogical ;  but  the 
importance  of  his  work  in  showing  that  the  brain  was  the  organ 
of  mind  has  since  been  recognised. 


MENTAL  DEVELOPMENT  295 

"  Body  and  Mind." — Although  the  brain  is  the  organ  which 
stores  the  recollection  of  past  experiences  and  the  bonds  that 
unite  them,  thereby  enabling  the  individual  to  adapt  himself 
to  environment,  yet  strictly  speaking  the  mind  is  directly  de- 
pendent upon  the  vital  activities  and  harmonious  interactions 
of  all  the  organs  and  tissues  of  the  body ;  for  of  what  use 
would  the  brain  be  without  the  peripheral  sense  organs  and 
the  nerves  which  connect  them  with  the  spinal  cord  and 
brain  ?  These  are  the  avenues  of  intelligence,  as  was  clearly 
recognised  by  Aristotle  in  his  famous  dictum :  "  Nihil  in 
intellectu  quod  non  fuerit  prius  in  sensu."  But  another  funda- 
mental function  of  the  brain  besides  perception  of  the  external 
world  and  its  surroundings  is  the  consciousness  of  the  in- 
dividual's own  personality,  his  appetites  and  desires,  which 
are  due  in  great  part  to  the  organic  sensibility  of  the  nerves 
of  the  body  and  internal  organs,  which  without  cessation  are 
continually  carrying  messages  to  the  brain,  making  us  aware 
of  our  existence  and  our  needs.  The  quality  of  the  blood  and 
the  presence  in  it  of  subtle  bio-chemical  substances  produced  by 
secreting  glands  and  the  viscera  have  a  profound  influence 
upon  states  of  consciousness  and  mental  activity.  It  is  the 
consciousness  of  feelings  connected  with  the  preservation  of 
the  individual  and  the  preservation  of  the  species  which  con- 
stitutes the  fundamental  biological  source  of  all  vital  activity, 
and  is  thus  poetically  expressed  by  Schiller  in  the  following 
lines  : 

Durch  Hunger  und  durch  Liebe, 
Erhalt  sich  die  Weltgetriebe. 

The  mental  states  concerned  with  the  consciousness  of  appetites 
and  desires  and  the  control  of  the  instincts  and  habits  asso- 
ciated with  their  gratification,  the  avoidance  of  pain  and  the 
obtaining  of  pleasure  essential  for  the  preservation  of  the  life 
of  the  individual  and  reproduction  are  the  mainspring  of 
human  activities,  passions,  and  emotions. 

Plan  of  a  Simple  Nervous  System. — Let  us  now  consider  for 
a  few  moments  the  general  plan  of  a  nervous  system. 

The  nervous  system  of  all  animals  with  a  nervous  system  is 
constructed  on  the  same  plan.  As  we  rise  in  the  zoological 
scale  it  consists  of  more  and  more  complex  systems  and  groups 
of  neurones.  A  neurone  is  a  nervous  unit  which  consists  of 
a  nerve-cell  with   branching   processes ;  one  process   becomes 


296 


SCIENCE  PROGRESS 


the  axial  core  of  a  nerve  fibre :  this  is  termed  the  axon,  the 
others  are  termed  dendrons.  All  nervous  action  is  reflex,  and 
the  simplest  reflex  act  is  the  first  term  of  a  series,  of  which 
the  most  complex  volition  is  the  last.  Therefore  before  pro- 
ceeding to  discuss  the  brain,  the  most  complex  organ  in  nature 
both  as  regards  structure  and  function,  let  me  call  your  atten- 
tion to  the  simplest  form  of  nervous  system  illustrated  in  this 
diagram.     You  observe  S  (fig.   1)  is  a  sensory  nerve-cell  with 


Fig.  1. 


branching  processes;  one  branch  ends  in  the  skin,  the  other 
branch  proceeds  centrally,  and  this  you  see  breaks  up  into  a 
number  of  fine  terminals  which  are  brought  into  relation  with 
the  branching  processes  of  M1,  a  motor  cell ;  proceeding  away 
from  this  cell  is  a  process,  the  motor  nerve,  which  terminates  in 
a  muscle  connected  with  the  sensitive  skin.  Stimulation  of  the 
sensory  nerve  in  the  skin,  it  matters  not  whether  it  is  chemical 
or  physical,  produces  what  is  known  as  an  afferent  nervous 
stimulus,  which  travels  in  the  direction  shown  by  the  arrow  to 


PLATE    I 


Fig.  i. — The  three  systems  of  afferent,  efferent,  and  association  neurones.     Spinal,  cerebellar, 
and  cerebral  necessary  for  perfect  conscious  voluntary  movement. 

It  will  be  observed  that  when  a  muscle  contracts  under  the  influence  of  voluntary  stimuli  from  the  brain, 
alterations  in  tension  of  the  skin,  muscle  tendon  and  structures  of  joints  cause  afferent  impulses  (kin- 
aesthetic)  to  pass  up  to  the  brain.  Every  movement  is  associated  with  ingoing  and  outgoing  currents. 
The  cerebellar  system  which  is  indicated  by  afferent  and  efferent  systems  is  especially  concerned  with 
reinforcement  of  muscular  action. 


296] 


MENTAL   DEVELOPMENT  297 

the  terminals  of  the  sensory  neurone  S,  where  it  excites  the 
terminals  of  the  motor  neurone  M,  giving  rise  to  an  outgoing 
efferent  current  which  stimulates  the  muscles  and  causes  its 
contraction. 

Let  us  suppose  the  stimulus  to  be  a  painful  and  therefore 
a  harmful  one,  the  effect  of  the  neuro-muscular  mechanism  will 
be  a  protective  reflex  action,  the  contracting  muscle  with- 
drawing the  skin  surface  from  the  cause  of  the  pain.  You 
will  observe  that  the  diagram  shows  that  the  sensory  neurone 
consists  of  a  cell  with  a  process  which  divides  into  two  branches  ; 
one  proceeding  to  the  skin — this  is  the  sensory  nerve — the  other 
branch  dendron  proceeding  centrally  to  end  in  a  terminal 
arborisation.  The  current  of  nervous  action  resulting  from  the 
stimulus  always  proceeds  towards  the  centre ;  it  is  afferent ;  the 
fine  terminals  of  the  central  projection  of  the  nerve  cell  are  in 
physiological  (that  is  functional)  but  not  anatomical  connection 
with  the  branching  processes,  dendrites  of  M,  the  motor  cell- 
This  alterable  functional  connection  is  spoken  of  as  the  synapse  ; 
the  motor  cell,  M1,  gives  off  one  process  which  becomes  the 
essential  conducting  axial  core  of  a  motor  nerve  fibre  which  ends 
in  the  muscle ;  and  the  current  of  nervous  action  along  this  is 
always  outgoing  or  efferent.  We  have  thus  two  systems  of 
neurones  :  (a)  afferent  sensory,  {b)  motor  efferent.  There  is  yet 
another  neurone,  A,  which  you  observe  associates  the  synapse 
of  S  and  M1  with  a  second  motor  neurone  element  M2,  which 
innervates  another  muscle  that  is  antagonistic  in  its  action  to 
that  supplied  by  M1.  Stimulation  of  the  sensory  nerve  in  the 
skin  may  give  rise  not  only  to  reflex  contraction  of  the  muscle 
supplied  by  M1,  but  also  through  the  association  neurone  A,  to 
relaxation  by  inhibition  of  contraction  of  the  muscle  supplied 
by  M2. 

The  special  function  of  the  brain  is  inhibition  or  control  of 
instinctive  reflex  action,  and  this  is  done  by  its  associative 
memory  of  past  experiences. 

The  neurones,  I  have  said,  are  independent  nervous  units ; 
they  are  in  anatomical  contiguity  but  not  in  continuity.  The 
cerebro-spinal  and  sympathetic  nervous  systems  are  made 
up  of  neurones  which  we  may  regard  as  complex  highly 
differentiated  cells  obeying,  however,  the  same  laws  of  nutrition, 
repair,  and  waste  as  other  cells  of  the  body. 

The  neurones  are  the  essential  nervous  elements,  and  they, 


298  SCIENCE   PROGRESS 

together  with  the  supporting  connective  tissue  elements,  neu- 
roglia cells,  blood  vessels,  and  lymphatics,  form  the  central 
nervous  system.  Functionally  speaking  there  are  three  systems 
of  neurones  in  the  brain  and  spinal  cord  :  (i)  afferent  pro- 
jection system ;  (2)  efferent  projection  system  ;  (3)  association 
system  (Plate  I,  fig.  1). 

The  Convolntional  Pattern  of  the  Brain. — If  we  look  at  a 
human  brain  we  see  that  the  surface  of  the  hemispheres 
exhibits  a  number  of  folds  and  fissures  giving  rise  to  a  pattern 
which  I  will  speak  of  as  the  convolutional  pattern  (Plate  II, 
fig.  1).  A  section  through  any  of  these  folds  or  fissures  shows 
that  the  external  surface  or  cortex,  as  it  is  called,  is  of  a 
pinkish  grey  appearance  contrasting  with  the  dead  white  of 
the  subjacent  part  of  the  brain.  Now  a  microscopic  examina- 
tion of  the  grey  matter  and  the  white  matter  explains  why 
there  should  be  this  difference  in  colour.  When  highly  magnified 
a  thin  section  appropriately  stained  by  dyes  shows  the  grey 
matter  to  consist  of  innumerable  ganglion  cells  to  and  from 
which  conducting  fibres  proceed.  The  microscopic  architecture 
of  the  grey  cortex  exhibits  a  cell  and  fibre  structure  of  extra- 
ordinary complexity.  The  diagram  (Plate  III,  fig.  2)  of  a  section  of 
an  adult  brain  is  to  illustrate  this  cell  and  fibre  architecture.  You 
observe  that  the  cells  are  arranged  in  six  layers,  and  there  are 
also  layers  of  fibres,  some  of  which  run  horizontally  and  some 
have  a  radial  direction.  The  horizontal  conduct  association 
impulses.  Although  there  is  a  general  similarity  in  the  cell 
and  fibre  structure  of  the  cortex  of  the  brain,  yet  the  whole 
surface  of  the  brain  can  be  mapped  out  into  territories  of 
different  cell  and  fibre  architecture  (Plate  II,  fig.  2) ;  and  physio- 
logy and  medical  science  teach  that  there  is  a  corresponding 
difference  in  function. 

I  have  remarked  that  the  grey  cortex  has  a  pinkish  colour 
because  (relatively  to  the  white  matter)  the  blood  supply  is  very 
abundant.  Now  the  subcortical  matter  is  white  because  the 
nervous  processes  of  the  cells  of  the  grey  matter  are  sur- 
rounded with  a  sheath  of  myelin  or  phosphoretted  fatty 
substance.  The  bio-chemical  processes  incidental  to  all  nervous 
action,  therefore  to  the  mental  activity  of  the  brain,  take  place 
in  the  cell  structure  of  the  neurone.  The  cortex  is  the  seat  of_ 
consciousness  and  mental  activity,  and  the  functions  of  the 
cortex  require  a  continuous  supply  of  oxygenated  blood.     Un- 


PLATE    II 


Fig.  I. — External  surface  of  the  left  hemisphere  of  brain  of  an  intellectual  man  shewing 

a  complex  convolutional  pattern. 


Foot  &  Toes 
Knee 

HiP-    JZ 

Shoulder  * 

Elbow- 
Written  Speech- 
Hand 
Index- 
Thumb- - 

Upper 

Face 

Lower 

Face 

Motor  _  . 
Speech 
Tongue"  - 
Larynx- 


Movements  of 

Eye  (probable)  Taste 

and 
Smell 


Great  Toe 


Tactile  &  Muscular  sensation 


Visual  word, 
Memory 


Hearing, 
Auditory  word 
Memory 


Half  Vision  centre 


Fig.  2  —  The  same  hemisphere  as  fig.  I,   to  show  the  various  areas  of  ascertained  definite 

physiological  function. 

The  coarse  black  dots  in  the  precential  region  indicate  points  which  when  electrically  excited  give  rise  to 
definite  movements.  Behind  the  central  fissure  the  cross  shading  indicates  the  region  of  tactile 
muscular  sense.  A  large  part  of  the  auditory  centre  cannot  be  seen  as  it  forms  the  floor  of  the  posterior 
part  of  the  sylvian  fissure.  The  greater  portion  of  the  half  vision  centre  lies  on  the  mesial  surface  and 
cannot  be  seen.  The  sensory  speech  centres  are  indicated  by  oblique  shading  ;  the  motor  speech 
centre  of  Broca  is  indicated  by  fine  dots,  and  above  it  the  centre  for  writing.  Destruction  of  these 
centres  causes  motor  aphasia  and  agraphia. 


MENTAL   DEVELOPMENT  299 

consciousness  occurs  if  the  blood  supply  fails  for  a  few  seconds, 
hence  we  understand  why  the  superficial  cortex  of  the  brain  is 
pinkish  and  receives  so  abundant  a  supply  of  blood. 

Now  if  we  look  at  a  child's  brain  before  birth  at  an  early 
period,  the  surface  is  quite  smooth  and  there  is  no  internal  white 
matter.  As  the  embryo  grows,  primitive  folds  and  fissures 
appear,  and  a  month  or  so  before  birth  we  have  a  brain 
characteristic  of  the  species ;  at  birth  we  have  the  brain  of 
the  individual ;  the  convolutional  pattern  formed  by  the  folds 
and  fissures  (as  with  the  physiognomy)  may  bear  a  resem- 
blance to  other  individuals,  but  will  exhibit  features  which 
differ  from  other  individuals  (Plate  IV,  figs.  I,  2).  No  two 
patterns  are  identically  similar  any  more  than  two  faces  are 
identical ;  but  just  as  the  faces  of  relatives  are  likely  to  be 
similar,  so  Karplus  showed  that  the  pattern  of  the  brains  of 
infants  who  were  related  exhibited  similarities;  and  Dr.  Edgar 
Schuster,  at  my  suggestion  and  from  material  with  which  I 
provided  him,  has  carefully  investigated  and  recorded  the 
similarities  in  the  brains  of  adult  relatives. 

Now  we  may  ask  :  Why  should  the  brain  exhibit  these  folds 
and  fissures  ?  The  blood  vessels  which  supply  the  brain  lie  in 
the  fissures  and  are  thereby  protected  from  pressure  ;  but  probably 
economy  of  space  determines  the  balance  between  the  dynamic 
forces  which  determine  the  growth  of  the  skull  and  the  growth 
of  the  brain,  and  by  throwing  into  folds  the  grey  matter,  its 
area  is  increased  enormously  without  increasing  the  size  of  the 
head.  A  very  small  head  means  a  small  brain  and  mental 
deficiency,  but  the  simpler  the  convolutional  pattern  (that  is,  the 
fewer  the  folds  and  fissures)  the  less  will  be  the  extent  of  the 
grey  matter  and  consequently  the  fewer  the  number  of  neurones. 
It  is  not  surprising,  therefore,  to  find  that  not  only  are  the  brains 
of  idiots  and  imbeciles  deficient  in  the  relative  proportion  by 
weight  of  the  cerebral  hemispheres  to  the  rest  of  the  brain,  but 
the  convolutional  pattern  is  simple,  consequently  the  superficial 
area  of  cortex  is  diminished  (vide  Plate  IV,  figs.  3,  4).  The  degree 
of  amentia  or  congenital  absence  of  mind  is  proportional  to  the 
failure  of  superficial  extent  of  the  grey  matter  of  the  cortex — 
the  anatomical  basis  of  mind.  Savage  man  has  a  superficial 
area  three  times  that  of  the  gorilla,  but  a  microcephalic  idiot's 
brain  weighed  onlyeight  ounces  (Plate  IV,  fig.  3).  Not  infrequently 
an  idiot  or  imbecile  has  a  large  head  caused  by  distension  of  the 


3oo  SCIENCE  PROGRESS 

cavities  of  the  brain  with  fluid — hydrocephalus,  popularly 
known  as  "  water  on  the  brain"  — or  there  may  be  overgrowth 
of  the  connective  tissue  causing  arrest  of  development  of  the 
nerve  cells  and  fibres — the  essential  structures  of  mind. 

Microscopic  Examination  oj  the  Brain  oj  the  Child  before  Birth 
and  after  Birth,  and  What  it  Teaches. — There  is  no  white  matter 
in  the  cerebral  hemispheres  before  birth  because  the  myelin 
sheath  of  the  nerve  fibres  has  not  been  deposited  around  the 
axial  processes  of  the  afferent,  efferent,  and  association  fibres 
proceeding  to  and  from  the  cortical  grey  matter.  Appropriate 
staining  of  thin  sections  of  the  brain  shows  no  evidence  of 
myelin  sheath  formation.  Now  when  the  myelin  sheath  is 
formed  an  indication  is  afforded  that  a  particular  system  of 
nerve  fibres  is  capable  of  functioning  by  conducting  nervous 
impulses.  We  shall  see  that  this  important  fact  has  been  made 
use  of  by  Flechsig  for  showing  certain  fundamental  principles 
connected  with  the  development  and  correlation  of  structure  and 
function  in  the  growing  infant's  brain  after  birth.  But  before 
proceeding  to  discuss  this  I  will  consider  the  structure  of  the 
grey  matter — the  cortex — of  the  child's  brain  before  birth. 
Examined  microscopically,  we  see  that  it  consists  of  six  layers 
of  cells,  as  the  diagram  of  the  adult  brain  shows,  with  indi- 
vidual differences  in  different  parts  ;  but  these  differences  are  not 
so  marked  as  in  the  adult  brain.  In  fact,  Brodmann  has  shown 
from  his  studies  of  foetal  brains  that  the  six-layer  type  is  the 
characteristic  type. 

We  also  observe  that  the  cells  are  very  simple  in  their  form 
and  that  they  are  closely  packed  together,  forming  columns  and 
layers.  They  increase  in  size  and  they  grow  and  develop  by 
pushing  out  processes  which  extend  like  the  branches  of  a  tree 
(fig.  2).  There  are  two  types  of  neurone  :  the  first  type,  the  larger, 
in  which  a  process  of  the  cell  called  the  axon  leaves  the  grey 
matter;  it  becomes  covered  with  myelin  and  forms  a  nerve 
fibre.  In  the  other,  the  second  type,  the  axon  never  leaves  the 
grey  matter.  It  is  probable  that  these  two  different  types  of 
neurones  have  fundamental  differences  in  function.  The  small 
second  type  is  especially  numerous,  forming  a  dense  layer  in 
the  sensory  regions  of  the  cortex  of  the  brain.  The  sensory 
projection  system  of  fibres  conveying  nerve  currents  from  the 
muscles  and  special  sense  organs  to  the  brain  terminate  in  the 
layer  of  small  neurones. 


PLATE    III 


Fig.   I. — The   left    hemisphere  of  the   brain  of  a  chronic  lunatic  who  has  become  grossly 

demented. 

Observe  the  broad  deep  fissures  caused  by  the  wasting  of  the  grey  matter  of  the  cortex,  particularly  of  the 
frontal  lobes.  The  convolutions  are  shrivelled,  and  a  microscopic  examination  of  them  would  show 
chiefly  a  destruction  of  the  cells  and  fibres  constituting  their  microscopic  architecture. 


Fig    2.— Diagrammatic   illustration  after  Brodmann   of  the    cell   and  fibre  architecture  of 

the  cerebral  cortex. 

There  are  six  layers  of  cells  and  six  layers  of  fibres.  To  the  left  are  exhibited  the  different  types  of  cells 
in  the  successive  layers  stained  by  the  silver  method,  which  only  picks  out  a  few  cells.  In  the  next 
column  all  the  cells  are  stained  by  the  Nisol  method.  Number  IV  layer  consists  of  small  granules,  and 
above  this  are  three  layers  of  pyramids.  Below  the  granules  are  larger  pyramids  in  the  layer  V. 
Beneath  this  in  the  sixth  layer  are  multiform  cells.  In  the  next  column  is  represented  the  fibre 
structure;  the  vertical  fibres  are  projection' fibres  carrying  impulses  afferent  and  efferent  to  and  from 
the  brain  cortex.  The  layer  of  pyramids  above  the  granules  is  especially  connected  with  the  function 
of  associative  memory.      The  horizontal  systems  of  fibres  are  association  systems. 

300] 


MENTAL  DEVELOPMENT 


301 


The  new-born  male  brain  weighs  321  grams;  the  female 
361  grams.  In  the  course  of  the  first  nine  months  the  weight  of 
the  brain  is  doubled,  and  microscopic  examination  shows  why 
this  is.  The  myelin  insulating  material  has  been  deposited 
around  a  large  bulk  of  the  axon  processes  of  the  neurones  and 
the  white  matter  has  in  consequence  greatly  increased.  The 
neurones  have  not  increased  in  numbers,  they  have  increased  in 


m;WAsw 


Fig.  2. — Diagram  after  Ramon  y  Cajal  to  show  the  phylogenetic  and  ontogenetic  develop- 
ment of  a  psycho-motor  neurone. 

A,  frog  ;  B,  newt  ;  C,  mouse  ;  D,  man.  It  will  be  noticed  that  in  ascending  the  zoological  scale  there  is 
an  increase  in  complexity  of  the  neurone  and  in  the  multitude  of  points  of  contact  produced  especially 
by  an  increase  in  the  dendrons  and  dendrites,  also  but  to  a  less  degree  by  the  collaterals  of  the  axon. 
a,  b,  c,  d,  e,  show  the  development  of  a  psycho-motor  cell  in  the  human  embyro  as  it  grows. 
Neurones  may  be  arrested  in  their  growth,  and  in  the  brains  of  idiots  an  arrest  takes  place. 

complexity  and  preparedness  for  function.  The  weight  of  the 
brain  still  continues  to  increase  for  the  same  reason,  and  in  the 
course  of  the  first  three  years  the  weight  is  treble  that  at  birth. 
After  this  the  addition  to  the  brain  weight  gradually  diminishes 
in  amount  and  only  slowly  continues  to  increase  in  the  male  sex 
up   to   nineteen   or   twenty ;    in   the   female    up   to   sixteen  to 


3o2  SCIENCE  PROGRESS 

eighteen.     After  sixteen  the  increase  in   brain  weight  is  very 
slight.     In  old  age  the  brain  tends  to  lose  weight. 

Myelination  and  Preparedness  for  Function. — Now  let  me  call 
your  attention  to  these  diagrams  after  Flechsig  (Plate  IV,  fig.  5) ; 
see,  the  dots  on  these  two  diagrams  are  situated  around  the  primary 
fissures  which  physiological  experiments  and  observations  on 
the  brains  of  human  beings  suffering  from  disease  show  to  be 
the  arrival  and  departure  platforms  of  the  sensory  and  motor 
impulses.  The  portion  of  the  brain  where  voluntary  motor 
impulses  are  generated  for  the  control  of  movements  of  the 
opposite  side  of  the  body  lies  in  front  of  the  central  fissure ; 
behind  the  central  fissure  is  the  central  station  for  the  reception 
of  impulses  from  the  skin,  muscles,  joints,  and  tendons  and 
the  general  organic  sensibility  of  the  body.  The  half-vision 
centre  occupies  the  posterior  part  of  the  brain ;  only  a  small 
portion  of  this  cortex  is  here  seen  because  the  greater  portion 
is  deeply  situated  in  the  floor  and  walls  of  the  calcarine  fissure 
on  the  mesial  surface.  The  centre  of  hearing  sounds  received, 
especially  in  the  opposite  ear,  is  also  in  great  part  hidden  from 
view,  occupying  the  posterior  part  of  the  floor  of  the  Sylvian 
fissure  ;  likewise  the  cortex  having  for  its  function  the  sense  of 
smell  is  almost  completely  hidden;  the  sense  is  shown  as 
occupying  a  region  at  the  tip  of  the  temporal  lobe. 

The  Association  Centres. —The  portions  of  the  cortex  indi- 
cated by  dots  situated  around  the  primary  fissures  are,  according 
to  Flechsig,  the  arrival  and  departure  stations  for  afferent  and 
efferent  stimuli.  He  terms  them  Projection  Centres.  But  it 
will  be  observed  that  the  greater  part  of  the  surface  grey  matter 
of  the  brain  in  Plate  IV,  fig.  5  shows  no  dots  indicative  of 
projection  systems ;  these  areas  Flechsig  terms  the  association 
centres ;  and  although  in  man  the  afferent  sensory  and  motor 
efferent  projection  centres  occupy  a  larger  surface  area  than 
in  the  highest  anthropoid  apes,  it  is  especially  the  great 
development  of  the  association  centres  which  accounts  for  the 
fact  that  the  cerebral  cortex  of  a  savage,  even,  is  three  times 
as  extensive  as  that  of  the  gorilla.  Now  how  do  we  know  by 
a  study  of  the  brain  of  the  new-born  child  compared  with 
the  brain  at  later  periods  of  growth  that  the  projection  systems 
are  localised  in  the  regions  indicated  ?  I  have  already  told  you 
that  by  appropriate  staining  the  myelin  sheaths  of  nerve  fibres 
can  be  detected  in  microscopic  sections  of  the  brain.     I  have 


MENTAL  DEVELOPMENT  303 

said  that  the  cerebral  hemispheres  at  birth  only  show  staining 
indicating  preparedness  for  function  in  the  base  and  stem  of  the 
great   brain.     The   structures    which    are   stained   in    Plate   V, 
fig.   1   are  the  systems  of  neurones  essential  for  the  perform- 
ance of  the  complex,  automatic,  co-ordinate  movements  of  the 
new-born    child,  viz.   breathing,  crying,   sucking,    swallowing. 
Occasionally  anencephalous  monsters  are  born  in  which  this  is 
the  only  portion  of  the  brain  present,  the  cerebral  hemispheres 
being  absent.     Such  monsters  are  capable  of  breathing,  crying, 
sucking,  and  swallowing  by  the  preorganised  nervous  mechanism 
in  the  stem  of  the  great  brain  which  is  present  in  these  creatures. 
The  first  appearance   of  myelin   staining  after  birth  is  in  the 
regions  about  the  primary  fissures — the  sensory  afferent  pro- 
jection  systems,  the  avenues   of  experience   and  intelligence; 
later  the  motor  efferent  projection  system  is  myelinated.     You 
observe    that    these    several    sensory    perceptual    centres    of 
vision,  hearing,  smell,  taste,  and   tactile-motor  perception   are 
independent.    At  this  stage  of  development  the  child  is  capable 
of  experiencing  a  simple  elemental  sensation,  but  later  as  the 
association  neurones  take  on  function  as  indicated  by  myelination 
of  their  fibres,  the  independent  perceptor  centres  are  physio- 
logically connected  and  functionally  associated.     That  being  the 
case  the  child  is  no  longer  capable  of  a  simple  sensation.     You 
have   only   to   watch   an   infant   follow  with  its  eyes  a  bright 
object ;   it    makes  very  clumsy  efforts    at    first,    it    does    not 
recognise  what  the  object  is ;  but  after  a  time  and  numbers  of 
experiments  it  learns  to  stretch  out  its  hand  to  get  it,  and  if  it 
succeeds  it  will  take  it  to  its  mouth ;  nutrition  is  its  object.     If 
the   spoon  contains   sugar   the   infant,  having  experienced  the 
pleasure  of  sweet  taste,   at  the   sight  of   the    spoon   exhibits 
satisfaction  and  attempts  to  grasp  it ;  this  means  that  the  visual 
centre    has    been   associated  with   the   motor  centre   and    the 
successive  movements  it  makes  successfully  to  grasp  the  spoon 
cause  sensory  impulses  from  skin,  muscles,  tendons,  and  joints  to 
be  registered  in  the  sensory  tactile-motor  sphere,  so  that  after 
numerous  experiences  association  for    the    eye    and   hand    is 
effected.     Suppose  the  infant  is  subsequently  given  a  powder 
in   the   spoonful   of  sugar,    the   sense   of  taste   and   smell    is 
excited  and  disgust  produced,  with  signs  of  nausea,  spitting  out, 
and  crying.    A  new  experience  has  been  made  and  the  sight  of 
the  spoon,  instead  of  awakening  pleasurable  feelings,  will  arouse 


304  SCIENCE   PROGRESS 

disgust  and  aversion  by  associative  memory.  As  Gallon  in  his 
inquiries  into  the  human  faculties  truly  remarks  :  "  The  furniture 
of  a  man's  mind  chiefly  consists  of  his  recollections  and  the 
bonds  that  unite  them.  As  all  this  is  the  fruit  of  experience  it 
must  differ  greatly  in  different  minds  according  to  their  indi- 
vidual experiences." 

A  glance  at  this  diagram  of  a  section  of  the  brain  of  a  three 
months'  child  shows  you  that  the  whole  of  the  white  matter  now 
contains  myelinated  fibres  and  all  the  primary  projection  centres 
are  associated  one  with  another  (Plate  V,  fig.  2). 

The  Anatomical  Substratum  of  Mind. — The  proportional 
weight  of  the  stem  of  the  brain  and  cerebellum  to  the  whole 
brain  should  be  as  1  to  8.  In  the  case  of  the  idiot,  the 
imbecile,  and  the  dement  the  proportion  is  much  lower,  viz.  1 
to  6  or  even  less.  In  the  idiot  and  imbecile  the  superficial  area 
of  grey  matter  is  greatly  diminished;  in  the  dement  the  grey 
matter  is  wasted  and  destroyed.  Not  only  do  we  see  these 
obvious  defects,  but  if  we  compare  the  microscopic  appearances 
of  a  section  of  the  normal  brain,  stained  so  as  to  show  the  cell 
and  fibre  architecture,  with  a  section  of  the  brain  of  a  congenital 
feeble-minded  person  and  the  sections  of  the  brain  of  a  lunatic 
who  is  demented  or  has  lost  his  mind,  we  shall  find  in  the  case  of 
the  ament  born  with  deficient  mind  a  deficiency  of  cells  and 
fibres  in  his  cortex ;  the  superficial  pyramidal  cells  which  give 
rise  especially  to  the  association  fibres  are  poorly  developed  and 
deficient  in  numbers  ;  the  cells  have  but  few  branching  processes 
and  are  incomplete  in  their  development,  and  there  is  not  only, 
as  I  have  said  before,  a  parallelism  between  the  diminished 
superficial  extent  of  the  cortical  grey  matter,  but  there  is  also  a 
parallelism  between  the  depth  of  the  mental  deficiency  and  the 
failure  in  numbers  and  development  of  the  nerve  cells  and  fibres. 
Correspondingly,  in  the  loss  of  mind  of  a  chronic  lunatic  there 
is  a  parallelism  between  the  decay  and  atrophy  of  the  cortical 
grey  matter  and  the  degree  of  dementia ;  the  deeper  the 
dementia  (loss  of  mind),  the  greater  are  the  number  of  nerve 
cells  and  fibres  destroyed  or  undergoing  decay  and  destruction 
(fig.  3).  I  think  then  I  have  shown  you  sufficient  evidence 
to  prove  that  the  cortex  cerebri  is  the  material  basis  of  mind. 

Causes  of  Mental  Failure. — We  must  recognise  the  two  great 
groups  of  causes  of  mental  deficiency  or  failure  of  the  brain 
to  develop  :  (1)  Germinal  or  gametic,  an  inborn  failure  of  the 


PLATE    IV 


Fig.    i.— Left  hemisphere  of  seven  months'      FlGl  4-— Left  hemisphere  of  a  low-grade  imbecile  ;  there 
foetus,  showing  the  primary  fissures.  is  a  §reat   failure  of  development   of  the   parietal 

lobe  and  the  convolutional  pattern  is  very  simple. 


A 

%1 

K 
HE 

«    r    /  j 

1?&>%1 

k         Jrafll  t* 

«^^  *»• 

^       '\^.;?*«efV* 

^    IJ»(»«i^~- 

Fig.    2. — Left  hemisphere   of  new-born  child, 
full  term. 


Fig.  3. — Brain  of  microcephalic  idiot.  Notice 
that  the  cerebellum  is  almost  entirely  un- 
covered. 


.     1  "\  Assauw 


Gr»l  fast? 

ife8JlC?fltfl 


Cu«fi3 


Mi3d!f  Assofulion  Cptfr? 
U»*  »f  lh(  Insula 

'■Auditory  Onfre 


Gifaf  Froebl- 
AsmcbHoi 


S)WS  h.  -.  1 
Olfactory  Nerre 


^Cnitre  (I  S**ll 


CVf''<"  Occpito  Temp"*  *** 
FLECHSIG'S    ASSOCIATION    CENTRES 

Fig.  5  is  a  diagram  showing  the  projection  and 
association  centres  of  Flechsig  as  seen  on  the 
external  and  internal  surfaces  of  the  right 
hemisphere. 


304I 


MENTAL  DEVELOPMENT 


305 


germinal  determinants  of  the  cortical  neurones,  whereby  the 
neuroblasts  or  primordial  cells  from  which  the  neurones  develop 
may,  in  consequence  of  an  inherited  defect,  be  deficient  in 
numbers  or  deficient  in  specific  energy,  consequently  they  do 
not  grow  and  develop.  "  Like  tends  to  beget  like,"  and  the 
cause  arises  in  most  cases  from  defective  progenitors.     If  one 


Fig.  3 — Diagram  to  illustrate  the  comparative  architecture  of  the  cortex,  of  the  healthy 
normal  brain,  of  the  brain  of  the  feeble-minded  (inborn  amentia),  and  of  the  brain  of 
the  dement  who  has  lost  his  mind. 

Observe  that  the  cells  have  lost  their  processes  and  are  shrunken  and  irregular  in  form,  also  note  the 
comparative  poverty  of  fibres  especially  of  the  horizontal  association  fibres  in  Amentia  and  Dementia. 


parent  be  feeble-minded,  only  some  of  the  offspring  will  be 
mental  defectives.  If  both  are  feeble-minded,  the  chances  are 
the  whole  of  the  offspring  may  be  more  or  less  feeble-minded. 
It  was  calculated  by  the  late  Dr.  Ashby,  a  very  experienced 
children's  physician,  that  75  per  cent,  of  the  mental  defectives 
20 


306  SCIENCE  PROGRESS 

owe  their  mental  deficiency  to  inborn  germinal  defect.  Mentally 
defective  children  of  this  type  may  be  born  to  normal  parents, 
but  the  chances  of  such  occurring  are  extraordinarily  less  than 
if  a  parent  is  feeble-minded,  epileptic,  or  insane,  or  exhibits 
other  signs  of  the  neuropathic  inheritance.  (2)  Mental  deficiency 
from  other  causes  occurs  in  25  per  cent,  of  the  cases,  and  this 
includes  pre-natal,  natal,  and  early  post-natal  conditions.  The 
pre-natal  conditions  are  those  associated  with  disease  of  the 
mother  especially  from  such  poisons  as  syphilis  (giving  rise  to 
congenital  syphilis),  lead  and  alcohol,  injuries,  falls  and  de- 
pressing conditions  by  which  the  developing  offspring  is 
imperfectly  nourished,  and  absence  of  the  thyroid  gland,  which 
gives  rise  to  myxoedematous  cretinism.  Natal  or  post-natal 
causes  are  difficult  labour,  fevers  and  poisoning  in  early  infancy, 
which  cause  arrest  of  the  development  of  the  brain  cortex ;  its 
damage  may  also  be  occasioned  by  rupture  of  blood  vessels  and 
tumours.  It  is  extraordinary  how  well  the  brain  is  protected 
from  injury  and  failing  nutrition  of  the  body.  In  starvation  all 
the  tissues  of  the  body  waste  away,  yet  the  brain  loses  hardly 
any  weight  at  all.  Donaldson  at  the  Wistar  Institute  has  clearly 
shown  by  a  large  number  of  experiments  on  white  rats  that  the 
growth  of  the  brain  is  hardly  at  all  impaired  by  insufficient  food. 
He  took  litters  of  white  rats  and  divided  them  into  two  groups; 
one  group  he  fed  well,  the  other  insufficiently.  Although  there  was 
a  great  difference  in  the  weight  of  the  bodies  of  the  two  groups, 
the  brains  showed  hardly  any  appreciable  difference  ;  proving 
that  all  the  tissues  of  the  body  may  suffer  in  order  that  the  brain 
may  grow.  This  shows  that  the  neurones  have  normally  a  great 
inborn  specific  energy,  as  they  should  have,  for  they  are  perpetual 
cellsof  thegreatestimportance  forthe  preservation  of  the  common- 
weal of  the  social  organism  of  the  body.  All  the  neurones  are 
present  at  birth  with  all  their  latent  potentialities;  some  are  fully 
developed  ;  the  majority,  especially  the  neurones  of  the  grey 
matter  of  the  surface  of  the  brain,  are  in  their  infancy  ;  those 
which  in  the  process  of  evolution  have  been  the  latest  to  appear 
— the  association  neurones — will  be  the  latest  to  complete  their 
growth  by  extension  of  their  processes.  I  have  said  these  cells 
are  perpetual  cells  ;  by  this  I  mean  that  in  a  healthy  brain  they 
are  endowed  with  a  durability  to  function  during  the  life  of  the 
individual.  Unlike  the  cells  of  the  body  generally,  neurones 
destroyed    cannot    be    replaced.      They    are    the    master-cell- 


THE   INBORN    POTENTIALITY  OF  THE  CHILD     307 

elements  for  the  preservation  of  the  individual,  as  the  repro- 
ductive cells  are  the  master  cells  in  the  preservation  of  the 
species,  and  they  are  functionally  interdependent. 


LECTURE   II 


THE    INBORN    POTENTIALITY   OF  THE 

CHILD 

By  the  inborn  potentiality  of  the  child  I  do  not  mean  altogether 
what  the  child  is  born  with,  for  it  might  be  born  with  a  disease 
or  defect  which  was  really  not  inherited  but  due  to  injury  or 
disease  acquired  by  the  developing  embryo  before  birth.  Now 
in  order  to  make  the  distinction  between  hereditary  conditions 
and  congenital  conditions  of  the  child  quite  clear  to  you,  it  is 
necessary  for  me  to  explain  some  essential  facts  concerning 
heredity. 

All  the  broad  facts  concerning  heredity  were  known  to  the 
ancients,  as  is  clearly  shown  by  the  poet  and  philosopher 
Lucretius,  who  in  De  Rerum  Naturce  says :  "  Sometimes,  too, 
the  children  may  spring  up  like  the  grandfathers,  and  often 
resemble  the  forms  of  their  grandfathers'  fathers,  because  the 
parents  often  keep  concealed  in  their  bodies  many  first  be- 
ginnings mixed  in  many  ways,  which,  first  proceeding  from 
the  original  stock,  one  father  hands  down  to  the  next  father ; 
and  then  proceeding  from  these,  Venus  produces  forms  after 
a  manifold  chance,  and  repeats  not  only  the  features,  but  the 
voice  and  hair  of  the  forefathers ;  and  the  female  sex  equally 
springs  from  the  father's,  and  males  go  forth  equally  from  the 
mother's  body,  since  these  distinctions  no  more  proceed  from 
the  fixed  seed  of  one  or  other  parent  than  our  face  and  bodies 
and  limbs.  Again,  we  perceive  that  the  mind  is  begotten 
along  with  the  body  and  grows  up  together  with  it  and  grows 
old  along  with  it."  It  was  the  custom,  you  remember,  of 
noble  Romans  to  carry  in  their  triumphant  processions  the 
masks  of  their  ancestors ;  consequently  many  of  these  facts 
became  apparent  to  them. 

Of  the  broad  principles  of  human  heredity  we  know  very 
little  more  than  this  ancient  philosopher.  Science,  aided  by 
the  microscope,  has   taught   us    much  concerning  the  material 


308 


SCIENCE  PROGRESS 


basis  of  inheritance ;  it  has  shown  that  plants  and  animals  are 
reproduced  on  the  same  common  plan  of  a  dual  inheritance 
from  the  male  and  female  germs.  Let  us  briefly  consider  the 
union  of  the  male  and  female  germs  of  fertilisation  in  the 
higher  animals,  for  it  will  help  you  to  understand  some  of  the 
problems  of  inheritance. 

The  male  germs  are  formed  in  countless  millions  in  the  male 
reproductive  organs.  The  female  germ-cells,  ova  or  egg-shells, 
are  contained  in  the  ovaries  ;  they  are  about  40,000  in  number 
at  birth,  and  the  germ  which  constitutes  the  material  basis  of 


p&.i 


Fig.  4. 

1)  Diagram  of  egg-cell  before  ripening.  (2)  Maturation  or  ripening  of  the  ovum  casting  out  of  half  of  the 
nucleus  to  form  the  first  polar  body.  (3)  Formation  of  second  polar  body  and  entry  of  spermatozoon  (S) 
into  egg.  (4)  Approximation  of  (M)  male  and  (F)  female  germs.  (5)  Enlarged  diagram  of  the  two 
germs  (F  and  M)  before  the  first  cleavage  of  the  egg.  (6)  Enlarged  diagram  of  egg  after  first  cleavage. 
P.  Bi,  first  polar  body  ;  P.  B2,  second  polar  body;  S.  sperm;  Ni  and  N2,  nuclei  of  first  two  cells 
of  the  organism  containing  representative  particles  (germinal  determinants)  of  (F)  the  female  germ  and 
(M)  the  male  germ. 

inheritance  is  a  minute  round  body  in  the  cell  (fig.  4,  F).  When 
the  ovum  ripens  (2,  3),  which  occurs  periodically,  one  half  of 
this  germ  is  cast  out  of  the  cell.  Why  is  this  ?  It  is  to  make 
way  for  a  union  with  the  incoming  male  germ,  the  bearer  of  the 
potential  inheritance  from  the  male,  as  the  female  germ  is  from 
the  female.  These  two  germs  constitute  the  woof  and  the  warp 
of  the  material  basis  of  inheritance  ;  while  the  male  germ  brings 
in  a  body  called  the  centrosome,  which  acts  as  the  shuttle  which 
weaves  the  woof  into  the  warp.     The  main  substance  of  the 


PLATE    V 

C.f' 


V 


) 


FAG 


■*" 


Fig.    I. — Diagram  of  vertical  section  through  the  brain  of  a  new-born  child  stained   by  the 
Weigut-Hsematoxylon  method  to  show  myelination  of  the  fibres. 

All  the  parts  which  are  dark  contain  myelinated  fibres.  Attention  is  particularly  directed  to  the  staining 
about  C.F.,  the  central  fissure  which  corresponds  to  the  tactile-motor  area.  It  will  be  observed  that 
the  remainder  of  the  cortex  is  unstained.  M.O.  medulla  oblongata;  P.V.  pons  varolii;  O.M.N. 
oculo-motor  nerve;  O.C.  optic  commissure;  F.A.C.  frontal  association  centre;  C.C.  corpus 
callor.um  ;  C.F.  central  fissure;  P.  A.C.  posterior  association  centre;  Y.S.  visual  sphere;  C. 
cerebellum  ;   S.C.  spinal  cord. 

C  F 


F.A.C" 


Fig.   2.  —  Diagram  of  vertical  section  of  the  brain  of  a  child  of  five  months. 

The  greater  part  of  the  brain  now  shows,  by  the  staining,  myelination  of  the  white  matter,  thus  indicating 
functional  activity  of  the  association  centres.  F.A.C.  frontal  association  centre  ;  C.F.  central  fissure  ; 
P. A.C.  posterior  association  centre  ;  V.S.  visual  sphere  ;  C.  cerebellum.  It  will  also  be  noted  the 
corona  radiata  and  internal  capsule  which  were  not  myelinated  in  fig.  i  ate  now  myelinated,  as 
shown  by  the  staining  in  the  basal  ganglia 

3°S] 


THE   INBORN   POTENTIALITY  OF  THE  CHILD    309 

egg-cell  surrounding  the  germinal  substance  or  nucleus  provides 
the  material  out  of  which  fresh  nuclear  material  is  built  until 
division  of  the  nucleus  occurs  (6);  the  cell  then  divides, 
and  the  process  is  continually  repeated.  In  the  case  of  other 
eggS—e.g.  that  of  the  chicken,  there  is  sufficient  material  to 
build  up  the  young  chick  ;  in  animals,  however,  the  fertilised 
egg-cell  receives  its  nutrition  after  a  short  time  from  the  blood 
of  the  mother. 

The  reason  why  I  have  endeavoured,  in  simple  language,  to 
explain  these  facts  to  you  is  in  order  to  make  you  better  under- 
stand the  essential  biological  fact  of  reproduction  and  how  it  is 
necessary  to  the  perpetuation  of  the  species ;  also  to  explain  the 
differences  between  congenital  disease  and  true  hereditary 
disease.  As  soon  as  the  fertilised  ovum,  which  is  to  form  first 
the  embryo  and  then  the  child,  is  nourished  by  the  blood  of  the 
mother,  it  is  liable  to  be  affected  by  poisoned  states  of  her  blood. 
The  best  example  I  can  offer  of  this  is  syphilis  affecting  the 
maternal  blood,  whereby  the  embryo  is  killed  or  the  child  is 
born  with  congenital  syphilis.  But  you  may  ask  :  Can  the  male 
germs  be  in  no  way  affected  by  the  fact  that  the  man  had  had 
syphilis,  or  that  he  had  been  a  chronic  drunkard,  or  suffered 
with  chronic  lead  poisoning?  This  is  a  crucial  point  in  the  study 
of  heredity.  "  The  neo-Lamarckian  doctrine  of  the  inheritance 
of  acquired  characters  is  a  question  of  great  social  importance. 
It  does  not  assert  that  a  change  produced  in  an  individual  by 
functional  activity  or  external  conditions  is  inherited  at  once 
and  completely  by  that  individual's  offspring ;  but  what  the 
neo-Lamarckians  mean  is  that  when  a  certain  functional  activity 
produces  a  certain  change  in  one  generation,  it  will  produce  it 
more  readily  in  the  next  and  so  on — until  ultimately  structural 
modifications  will  appear  in  the  young  even  before  the  function 
which  has  produced  them  has  commenced,  and  the  process  may 
go  on  indefinitely  until  the  structural  character  in  question  will 
be  inherited  for  many  generations  after  the  exercise  of  such  a 
function  has  altogether  ceased."    (Cunningham.) 

The  majority  of  biologists  deny  the  possibility  of  the  trans- 
mission of  an  acquired  character,  and  I  would  agree  up  to  a 
certain  point  that  there  is  no  evidence  or  proof  that  an  acquired 
character  can  be  transmitted.  That  a  father  who  drinks  heavily 
and  sees  his  wife  and  family  starving  transmits  the  desire  to 
drink  in  his  offspring  is  illogical  and   unproven;   but  he  may 


3io  SCIENCE  PROGRESS 

transmit  that  inborn  character  which  will  lead  to  his  offspring 
drinking,  viz.  lack  of  moral  sense  and  feeble  will.  You  naturally 
ask  :  Are  the  Scriptures  wrong  in  saying  that  "  the  sins  of  the 
fathers  are  visited  upon  the  children  even  to  the  third  and  fourth 
generation "  ?  and  when  I  come  to  deal  with  the  question  of 
Insanity  and  how  I  believe  Nature  is  continually  striving  to  end 
or  mend  degenerate  stocks  you  may  ask  :  What  then  is  the 
reservoir  which  is  continually  supplying  degeneracy  ?  Is  it  a 
continuous  fresh  generation  of  poor  types  consequent  upon  the 
pathological  factors  of  modern  social  conditions,  or  is  it  that 
natural  selection  and  survival  of  the  fittest  are  less  effectual  in 
weeding  out  poor  types  ?  How  far  is  medical  science,  legislation, 
and  collective  responsibility  replacing  family  responsibility, 
thereby  interfering  with  natural  selection  and  survival  of  the 
fittest  ?  Let  us  view  the  question  from  a  physiological  stand- 
point. I  will  take  the  male  germs  which  are  continually  being 
produced  in  countless  millions  for  the  greater  part  of  a  man's 
life.  Each  germ  is  the  bearer  of  an  extraordinary  specific 
potential  energy  ;  and  it  produces  effects  far  more  complex  and 
wonderful  than  the  emanations  of  a  similar  sized  speck  of 
radium.  The  reproductive  organs  that  produce  these  germs  are 
contained  in  the  body  and  nourished  by  the  same  blood  and 
lymph.  Although  physiology  proves  that  Nature  in  a  marvellous 
way  has  protected  the  brain,  which  is  essential  for  the  preser- 
vation of  the  individual,  and  the  reproductive  organs,  which  are 
essential  for  the  preservation  of  the  species,  and  has  established, 
by  subtle  bio-chemical  influences  in  the  blood,  a  correlation 
of  functions  of  the  two,  yet  it  is  a  fact  that  in  prolonged  con- 
ditions of  poisoning  of  the  blood  the  brain  suffers  permanently 
in  the  production  of  specific  energy,  as  shown  by  failure  of 
its  higher  functions,  and  the  male  germ  cells,  which  are  con- 
tinually building  up  the  male-germs  out  of  constituents  taken 
from  the  blood,  may  by  analogy  suffer  in  their  specific  energy 
and  vitality.  If  this  devitalising  agency  caused  by  a  poisoned 
condition  of  the  blood  is  carried  on  in  several  successive 
generations,  and  especially  if  reinforced  by  a  similar  loss  of 
specific  energy  in  the  female  germs  from  similar  and  other 
causes,  weakly  types  of  offspring  will  be  produced,  and  these 
weakly  types,  being  more  susceptible  to  infective  diseases, 
will  be  cut  off  early  by  invading  microbes,  especially  by 
tuberculosis.     But    is    the    transmitted    lack    of   vital    energy 


THE   INBORN   POTENTIALITY  OF  THE   CHILD    311 

generally  enough  to  account  for  mental  degeneracy  ?  Mental 
energy  is  mainly  used  up  in  the  exercise  of  will-power  and 
attention  in  acquiring  knowledge  and  making  new  adaptations 
to  environment  and  controlling  and  regulating  the  instincts 
and  desires  to  the  best  advantage  of  the  individual  in  the 
struggle  for  existence  in  the  social  life.  Now  a  healthy  mind 
can  only  exist  in  a  healthy  body,  and  the  proper  storage  of 
mind-energy  and  its  liberation,  as  well  as  recuperation  neces- 
sary for  a  well-balanced  mind,  are  largely  dependent  upon  an 
inherited  good  and  virile  constitution :  whereas  the  higher 
functions  of  the  mind  on  the  side  of  feeling,  viz.  imagination 
and  the  affective  nature,  are  specifically  inherited,  and  more 
dependent  upon  inborn  variation  from  the  normal  average 
mind. 

I  have  not  time  to  discuss  Galton's  Law  of  Ancestral  In- 
heritance nor  Mendel's  Law ;  I  will  only  say  in  respect  to 
Galton's  Law  that  it  only  applies  to  the  average  inheritance  of 
masses  of  people  and  not  to  the  individual,  and  this  was  clearly 
recognised  by  Galton  himself,  for  he  says  :  "  Though  one  half 
of  every  child  may  be  said  to  be  derived  from  either  parent,  yet 
he  may  receive  a  heritage  from  a  distant  progenitor  that  neither 
of  his  parents  possessed  as  personal  characteristics."  Again, 
speaking  of  particulate  inheritance  he  remarks :  "  All  living 
beings  are  individuals  in  one  aspect,  composite  in  another.  We 
seem  to  inherit,  bit  by  bit,  this  element  from  one  progenitor,  that 
from  another;  in  the  process  of  transmission  by  inheritance, 
elements  derived  from  the  same  ancestor  are  apt  to  appear  in 
large  groups,  just  as  if  they  had  clung  together  in  the  pre- 
embryonic  stage,  as  perhaps  they  did."  They  form  what  is  well 
expressed  by  the  word  "  traits  " — traits  of  feature  and  character. 
The  offspring  of  parents  possess  a  mosaic  of  inheritance 
bearing  usually  a  more  or  less  similarity,  yet  the  mosaics  of 
characters,  whether  bodily  or  mental,  are  not  in  any  way 
identical  except  in  the  case  of  identical  twins.  Probably  nothing 
has  shown  more  conclusively  the  dominant  influence  of  heredity 
on  character  than  Galton's  inquiries  on  the  history  of  twins. 
He  found  that  similar  twins  living  in  a  different  environment 
nevertheless  remained  similar  in  temperament  and  character, 
while  dissimilar  twins  brought  up  and  living  in  the  same 
environment  remained  dissimilar.  These  dissimilar  twins, 
however,    were    the    product    of   two  separate    ova,    whereas 


3i2  SCIENCE  PROGRESS 

identical  or  similar  twins  were  the  result  of  fertilisation  of  one 
ovum  containing  two  germs  of  identical  substance  ;  which  proves 
conclusively  how  untrue  is  the  theory  that  all  persons  are  born 
with  equal  mental  capacities,  the  differences  of  development 
being  due  to  education. 

The  Mendelian  doctrine  of  heredity  is  proved  as  regards 
segregation  of  unit  characters  in  the  human  subject ;  but  even 
Bateson  (the  champion  of  Mendelism)  does  not  claim  that 
Mendelian  proportions  have  been  proved  as  regards  human 
characters  except  in  the  case  of  eye-colour  and  certain  abnor- 
malities and  defects.  He  himself  admits  that  as  regards  mental 
characters  the  factorial  analysis  is  so  complex  that  proof  is  still 
wanting. 

Primitive  Emotions  and  Instincts  independent  of  Education  and 
Environment. — In  considering  the  inborn  potentiality  of  the 
child's  mind,  it  is  necessary  to  recognise  that  there  is  a  pre- 
organised  nervous  mechanism  in  the  brain  and  spinal  cord  which 
acts  independently  of  education  and  social  environment.  This 
pre-organised  nervous  mechanism  presides  over  the  instincts 
and  emotions  essential  for  the  preservation  of  the  individual  and 
of  the  species.  The  instincts  are  of  the  same  nature  in  man  as 
in  animals,  and  the  primitive  emotions  are  similar  in  character 
but  are  of  a  lower  order  and  incapable  of  developing  into 
passions  or  sentiments  ;  they  differ  in  their  mode  of  expression 
owing  to  the  more  refined  nature  of  the  human  body  and 
complexity  of  its  movements.  The  desires,  the  associated 
instincts,  the  primitive  emotions  and  passions  are  common  to  all 
human  beings  whether  primitive  savages  or  cultured  races. 
They  are  best  observed  in  children,  savages,  and  feeble-minded 
adults  in  whom  the  highest  control  is  either  undeveloped  or 
imperfectly  developed.  Whereas  the  individual  experience 
of  every  other  animal  is  almost  entirely  lost  when  it  dies,  man, 
by  virtue  of  his  acquirement  of  speech  and  the  creative  use  of 
the  hand  in  perpetuating  his  thoughts,  feelings,  and  ideals,  has 
slowly  built  up  a  great  social  heritage.  The  brain  of  the 
individual  is  the  receptor  of  this  social  mind  which  printed 
language  (especially)  and  other  creations  of  man's  hand  have 
placed  at  the  disposal  of  all  mankind. 

The  Social  Mind. — What  would  happen  to  the  child  if  it  were 
deprived  of  this  social  inheritance?  It  is  said  that  one  of  the 
Pharaohs  made  the  experiment  of  causing  a  child  to  be  brought 


THE  INBORN   POTENTIALITY  OF  THE  CHILD    313 

up  without  its  hearing  any  spoken  language,  in  order  to  see 
what  language  it  would  speak.  Hearing  no  language  it  spoke 
no  language.  Again,  in  1840  a  wild  man  was  found  in  the 
forests  in  Germany ;  he  spoke  no  language,  but  when  brought  to 
a  town  he  learnt  German. 

Let  us  imagine  for  the  sake  then  of  explaining  the  important 
part  played  by  this  social  heritage  on  the  individual  mind,  what 
would  happen  if  man  were  suddenly  deprived  of  this  heritage, 
which  as  Huxley  says,  has  "  placed  him  as  upon  a  mountain 
top,  far  above  the  level  of  his  humble  fellows  and  transported 
his  grosser  nature  by  reflecting  here  and  there  a  ray  from  the 
infinite  source  of  truth."  Supposing  another  flood  came,  and 
instead  of  Noah  and  his  family  having  been  preserved  with  the 
animals,  only  two  infants  (male  and  female)  survived  by  some 
such  agency  as  the  mythical  she-wolf  that  suckled  Romulus  and 
Remus,  the  founders  of  ancient  Rome :  and  let  us  imagine  that 
they  grew  up  and  became  the  progenitors  of  a  new  race. 
Deprived  of  a  social  heritage,  they  would  have  had  to  start 
building  it  up  anew,  but  probably  this  would  have  taken 
countless  ages,  for  there  is  no  proof  that  the  innate  potential 
brain  power  of  these  two  children  of  modern  civilised  man  to 
create  a  social  heritage  would  be  immeasurably  superior  or 
even  much  superior  to  the  reindeer  men  who  lived  in  Europe 
and  left  their  handwork  in  caves  ages  ago.  According  to  Ray 
Lankester,  these  men  had  as  largely  developed  brains  as  modern 
men.  The  man  who  made  those  drawings  of  deer  with  his  rude 
instruments  was  a  great  artist,  and  the  man  who  first  discovered 
how  to  forge  metal  into  an  instrument  for  the  use  of  the  hand 
instead  of  a  chipped  flint  was  potentially  as  great  a  genius  as 
Galileo  or  Newton. 

The  life  of  two  such  human  beings  without  a  social  environ- 
ment would  at  first  depend  almost  entirely  upon  the  fixed, 
stable,  and  preorganised  characters  of  the  species  and  sex, 
which  would  determine  by  an  untaught  aptitude  the  instinctive 
actions  and  behaviour  necessary  for  the  preservation  of  the 
individual  and  the  species,  with  primitive  emotional  states  of 
feeling  and  their  special  characteristic  manifestations.  Hence 
might  be  displayed  fear  and  anger,  joy  and  sorrow,  wonder 
and  surprise,  play  and  self-display,  curiosity,  taste,  and  disgust. 

In  common  with  all  human  beings,  including  savages,  our 
imagined  pair  would  exhibit  not   only  the  primitive  emotions, 


3i4  SCIENCE   PROGRESS 

but  sentiments  and  passions  in  their  elemental  form,  such  as 
love  and  hatred,  pride  and  contempt,  suspicion,  vengeance, 
grief,  and  despair,  displayed  by  attitude,  gesture,  and  facial 
expression,  accompanied  by  the  utterance  of  inarticulate  vocal 
sounds,  by  crying  and  laughing,  and  signs  of  pain  and  pleasure. 
Such  expressions  of  the  feelings  constitute  a  universal  language 
understood  b}'  all  human  beings,  because  common  to  all  human 
beings. 

At  the  proper  season,  an  attraction  of  the  two  sexes  neces- 
sary for  the  preservation  of  the  species  would  occur,  for  this 
sexual  attraction  which  we  term  love  possesses  a  universal 
language.  In  the  normal  conditions  of  life  it  is  both  a  physio- 
logical and  psychological  process ;  it  is  the  fountain  head  of  the 
emotions  and  passions,  stronger  even  than  the  fear  of  death. 
Love,  though  mute,  speaks  more  eloquently  by  signs  than  any 
spoken  language. 

Next,  the  maternal  instinct.  What  is  stronger  and  appeals 
more  forcibly  to  our  highest  ideals  than  the  tender  emotion  of 
the  mother  for  her  child  and  the  devoted  sacrifices  she  will 
make  for  its  preservation?  Yet  do  we  not  find  this  common 
to  ,all  the  higher  animals?  Indeed,  we  can  see  that  the 
moral  sense,  consisting  in  the  highest  altruistic  feelings  and 
sentiments,  has  its  roots  in  these  two  physiological  instincts ; 
for  when  pure  and  undefiled  there  is  nothing  more  noble 
and  ennobling  than  love  and  parentage.  We  must  therefore 
regard  the  sentiments  as  having  an  evolutional  biological  basis 
founded  on  the  preservation  of  the  individual  and  the  species. 

The  inborn  raw  material  of  character  is  a  complex  dependent 
upon  species,  sex,  racial  and  family  ancestors ;  it  is  therefore 
apparent  that  the  inborn  physiological  characters  of  the  species 
and  sex  are  fixed  and  stable ;  they  are  the  stem  of  the  tree  of 
life,  on  which  has  been  grafted  the  characters  of  race  and  family 
progenitors,  these  being  of  later  evolution,  and  more  capable  of 
variation  and  mutation. 

The  future  of  the  race,  born  of  these  two  hypothetical 
children,  would  depend  upon  whether  they  were  well-born — 
and  by  well-born  I  do  not  necessarily  mean  of  wealthy  or 
aristocratic  parents,  but  of  parents  possessed  of  healthy  minds 
in  healthy  bodies,  coming  from  good  stocks  of  broad-chested 
sires  and  deep-bosomed  mothers ;  endowed  with  courage, 
honesty,   and  common-sense,  which   is   the  inborn  aptitude  of 


THE   INBORN   POTENTIALITY   OF  THE  CHILD    315 

profiting  by  experience  to  do  the  right  thing  at  the  right 
moment.  With  such  a  heritage  these  two  human  beings,  with 
the  instincts  for  the  preservation  of  the  individual  and  the 
species,  would  possess  as  inborn  qualities  tendencies  which 
would  be  productive  of  a  virile  stock  endowed  with  superior 
energy,  sagacity,  and  racial  temperament,  thus  enabling  their 
descendants  to  have  a  great  advantage  over  primitive  races 
possessed  of  a  language  and  a  limited  social  heritage.  There 
might  be  an  inborn  tendency  to  artistic  feeling  and  expression, 
derived  from  progenitors,  which  under  favourable  conditions 
would  find  expression.  There  might  be  an  inborn  tendency 
to  the  instinct  of  curiosity  which  would  lead  them  to  observe 
and  reason  on  natural  phenomena,  and  thereby  learn  to  obtain 
fire  and  to  make  rude  weapons.  If  their  parents  were  right- 
handed,  as  in  all  probability  they  were,  they  would  use  the 
right  hand  in  preference ;  that  is  to  say,  the  left  half  of  the  brain 
would  be  the  active  partner,  and  predominate  in  voluntary 
movements  of  the  hand  as  an  instrument  of  the  mind. 

It  would  be  safe  to  assume  that  prior  to  the  acquisition  of 
articulate  speech  and  language  this  new  race  of  beings  would 
at  first  only  be  able  to  communicate  with  one  another  by  gesture 
language ;  then  some  creative  mind  would  employ  articulate 
sounds  to  supplement  the  primitive  gesture  language  as  a 
means  of  communicating  ideas,  and  correspondingly  would 
arise  the  dawn  of  intellectual  development  and  abstract  thought 
and  reasoning,  because  thought  in  all  the  higher  mental  pro- 
cesses cannot  be  carried  on  without  the  aid  of  language.  Then, 
as  language  by  graphic  signs  and  articulate  speech  progressed 
together,  simultaneously  supporting  each  other  in  the  develop- 
ment of  the  higher  mental  faculties  that  differentiate  the  brute 
from  the  savage  and  the  savage  from  the  civilised  human  being, 
so  the  social  heritage — the  Universal  Mind— would  expand  and 
increase.  Man,  instead  of  thinking  by  associating  concrete 
images,  would  now  carry  on  the  processes  of  thought  and 
memory  by  means  of  words  heard  and  seen  (symbols),  in  the 
form  of  spoken,  written,  and  printed  language. 

How  great  a  part  language  has  played  in  the  development 
of  the  mind  can  be  gathered  by  a  little  consideration  of  the  fact 
that  individual  human  experience  would  be  almost  entirely  lost 
by  the  cessation  of  every  individual  life,  without  language. 
Moreover,  completely  developed  languages,  when  studied  from 


3i6  SCIENCE  PROGRESS 

the  point  of  view  of  their  evolution,  show  that  they  are  stamped 
with  the  print  of  unconscious  labour  that  has  been  fashioning 
them  in  the  long  'procession  of  ages.  Reflection  upon  new 
words  coined  in  our  own  time  proves  that  the  evolution  of 
language  exhibits  an  abstract  and  brief  chronicle  of  the  history 
and  progress  of  the  race,  and  it  constitutes  the  Social  Mind, 
embodying  the  record  of  past  experience  which  each  later 
individual  of  the  race  can  utilise  through  his  senses  and  his 
brain.  We  know  that  the  offspring  from  a  savage  tribe  in 
Africa,  brought  up  among  cultured  people,  can,  by  imitation, 
through  his  senses  utilise  this  social  heritage;  he  fails,  however, 
individually  and  collectively,  to  initiate  new  ideas  and  to  add 
to  the  social  inheritance  of  mankind.  The  millions  of  negroes 
in  America  have  added  little  or  nothing  to  the  sum  of  human 
knowledge  since  their  emancipation  from  slavery. 

The  Brain  a  Transformer  and  Accumulator  of  Neural  Energy 
from  Cosmic  Energy. — You  may  ask  :  Will  not  the  brain  be 
affected  in  its  growth  by  deprivation  of  the  stimulus  of  the  social 
heritage  ?  There  are  certain  facts  which  point  to  its  not  being 
affected  in  its  growth  and  structural  development.  First  of  all 
we  must  look  upon  the  whole  nervous  system,  and  particularly 
the  brain  which  forms  the  greater  part  of  its  bulk,  as  possessing 
the  function  of  transforming  cosmic  energy  into  neural  energy 
and  storing  it  up  as  nerve  potential.  This  function  would  not 
suffer  in  the  least  by  the  deprivation  of  the  social  heritage  built 
up  by  language.  Moreover,  the  fact  that  the  wild  man  found  in 
the  forest  in  Germany  was  able  to  learn  German  shows  that  the 
latent  capacity  was  there  in  spite  of  the  fact  that  he  had  never 
since  childhood  heard  spoken  language.  When  I  speak  of  the 
transformation  of  cosmic  into  neural  energy  I  mean  that  a  nerve 
current  is  a  specific  molecular  vibration  travelling  along  the 
nerve  at  the  rate  of  about  30  yards  a  second  ;  it  is  not  therefore 
an  electrical  current  although  it  produces  an  electrical  disturbance 
in  the  tissue  involved.  The  effect  on  the  mind  produced  by  an 
external  stimulus  we  say  is  due  to  the  nature  of  the  stimulus ; 
that  is  true,  but  it  is  also  due  to  the  specific  function  of  the 
neural  systems  of  peripheral  receptor,  transmitter,  and  central 
perceptor  in  the  brain.  For  the  same  stimulus  will  give  rise  to 
different  sensations  according  to  the  different  special  sense 
organs  stimulated.  Thus  if  an  interrupted  electrical  current  be 
applied  to   the  tongue  so  as  to  stimulate  the  gustatory  nerve, 


THE   INBORN   POTENTIALITY  OF  THE  CHILD    317 

taste  is  experienced ;  if  the  eye  or  optic  nerve,  a  bright  light ; 
and  the  auditory  nerve  excited  gives  rise  to  the  sensation  of 
sound ;  and  the  skin,  a  sensation  of  painful  vibration.  Each 
neural  system  then  has  a  specific  energy  of  its  own  to  transform 
this  electrical  energy  into  specific  neural  energy  and  to  store  up 
memories  of  the  same  in  the  brain. 

The  Temperament — A  Complex  of  Characters  derived  from 
Species,  Sex,  Race,  and  Progenitors. — It  is  obvious  that  the  fixed 
characters  of  species  and  sex  form  an  important  basis  of  the 
inborn  potentialities  of  the  mind  of  the  child  ;  they  are  dependent 
upon  preorganised  nervous  mechanisms  ;  in  addition  to  these 
which  are  similar  in  all  human  beings,  we  have  other  potentialities 
due  to  race.  I  need  not  tell  you  that  just  as  there  are  inborn 
structural  characters  of  the  body,  including  the  brain  peculiar  to 
different  races,  so  there  are  temperamental  characteristics,  and 
these  inborn  racial  temperamental  qualities  play  an  important 
part  in  the  formation  of  the  raw  material  of  character,  which  is  a 
complex  derived  from  species,  sex,  race,  and  progenitors.  We 
are  all  familiar  with  the  quick  perceptive  emotional  temperament 
of  the  Celts,  and  both  history  and  biography  teach  us  the  success 
that  has  attended  the  blending  of  the  Irish,  Celtic,  and  Anglo- 
Saxon  temperaments  in  the  production  of  great  generals  and 
statesmen. 

As  Pathologist  to  the  London  County  Asylums  I  have  been 
for  a  long  time  engaged  in  studying  the  effects  of  family  inheri- 
tance in  relation  to  disorders  and  diseases  of  the  organ  of  mind, 
and  with  this  part  of  the  subject  I  will  next  deal. 

Ancestral  Inheritance  in  relation  to  the  Inborn  Potentialities  of 
the  Child's  Brain. — I  pointed  out  to  you  in  my  last  lecture  that 
the  convolutional  pattern  of  the  brain — the  organ  of  mind — is  no 
haphazard  affair,  but  is  dependent  upon  the  inheritance  of  similar 
folds  and  fissures  from  progenitors  ;  just  as  we  know  that  in 
every  face  are  the  features  of  ancestors,  so  in  every  character  may 
be  the  character  of  ancestors.  Galton's  statistical  inquiry  into 
the  inheritance  of  good  and  bad  tempers  showed  that  one  set  of 
influences  tends  to  mix  good  and  bad  tempers  in  a  family  at 
haphazard  ;  another  tends  to  assimilate  them,  or  that  they  should 
all  be  good  or  all  be  bad  ;  a  third  set  tends  to  divide  families  into 
contracted  portions.  This  pedigree  (fig.  5)  shows  in  the  third 
generation  a  sorting  out  or  segregation  of  good  and  bad  tempers 
according    as   the   children   resembled   the   father   and   mother 


3i8 


SCIENCE  PROGRESS 


respectively.  No  child  is  born  insane,  but  it  may  be  born  with 
an  insane  or  neuropathic  tendency  ;  certainly  it  may  be  born 
mentally  deficient  owing  to  failure  of  development  or  arrest  of 
growth  of  the  grey  matter  of  the  brain.  Such  mental  defectives 
are  low-grade  imbeciles  and  idiots,  in  whom  in  my  last  lecture  I 
demonstrated  a  correlation  of  deficiency  of  mind  and  the  material 


<? 


C* 


9  *©  4<J) 


cT- 


12 


14 


Fig.  s 


No. 


The  above  pedigree  shows  the  transmission  of  insanity,  immorality,  and  violent 

temper, 
i,  the  grandmother,  was  immoral.  Of  her  children,  No.  2,  an  engine-driver,  was  "a  man  of  violent 
temper  who  smashed  things  on  a  wholesale  scale  at  home.  He  died  with  the  delusion  that  he  was 
going  to  heaven  on  the  footplate  of  an  engine."  No.  3  was  also  a  man  with  a  violent  temper,  dangerous 
to  himself  and  others,  who  eventually  died  from  general  paralysis.  The  daughter,  No.  4,  was  criminally 
immoral  ;  she  had  an  illegitimate  child,  but  no  children  by  her  marriage.  The  children  of  No.  3 
are  as  follows:  Nos.  5  and  6,  both  men  with  violent  tempers,  drunken  and  immoral;  No.  7,  a 
daughter,  criminally  immoral,  who  eventually  was  detained  in  Bethlem  for  a  period.  No.  8  is  a 
woman  with  a  very  violent  temper,  smashes  things,  and  has  attacked  her  husband  with  a  poker, 
etc.  ;  has  tried  to  commit  suicide  by  poison  and  once  by  hanging  ;  gushes  to  every  man,  but  repels 
her  husband.  The  husband  asks,  "Is  she  mad,  or  bad,  or  both?"  The  husband  is  a  healthy, 
robust  man,  who  comes  from  a  good  healthy  stock.  The  children  were  five  in  number  ;  two  survive 
(Nos.  11  and  14),  and  these  fortunately  resemble  the  father  ;  they  are  healthy,  robust  and  energetic. 
The  first-born,  No.  10,  was  a  boy  resembling  his  mother  ;  he  was  nervous,  reserved,  lacked  mental 
energy,  and  was  prone  to  somnambulism  and  night-terrors,  which  existed  in  his  mother's  family  ; 
he  died  under  an  operation  at  the  age  of  12.  No.  12  was  the  image  of  his  father,  but  died  from 
measles  when  10  months  old.  No.  13  was  nervous  and  resembled  his  mother;  at  19  months  he  died 
from  whooping-cough. 

basis  of  mind — the  grey  matter  of  the  brain.  But  the  higher- 
grade  imbecile,  the  epileptic,  and  the  insane  adolescent  do  not 
usually  show  sufficient  obvious  defects  of  structure  (even  by  the 
aid  of  the  microscope)  to  satisfactorily  account  for  the  mental 
disorder,  but  this  may   well  be  because  methods  have  not  yet 


THE   INBORN   POTENTIALITY   OF  THE  CHILD    319 

been  devised  to  exhibit  the  bio-physical  and  bio-chemical  con- 
ditions underlying  normal  physiological  processes  in  the  organ 
of  mind;  and  until  we  have  some  conception  of  this  we  cannot 
explain  such  abnormal  temperamental  and  disordered  mental 
conditions  due  to  functional  derangement  of  the  complex 
mechanism   of  mind. 

We  know,  however,  that  "  like  tends  to  beget  like,"  and 
everybody  recognises  the  potential  value  to  the  individual  of 
coming  from  a  mentally  sound  and  good  stock. 

The  inborn  mental  potentiality  of  the  child  may  be  sound, 
partially   sound,   or   unstable   or   totally   unsound.      A   careful 
inquiry  into  the  family  histories  of  the   progenitors   and   the 
collateral   members   of  the   ancestral   stocks  will  in  the  great 
majority  of  cases  show  that  a  child  born  sound  in  mind  and  body 
is  begotten   by  parents  sound  in  mind  and  body  themselves, 
whose  stocks  are  free  from  any  neuropathic  or  physical  taint. 
Such  a  child  with  a  good  inheritance  is  very  unlikely  to  suffer  in 
later  life  with  feeble-mindedness,  epilepsy,  insanity,  or  functional 
nervous  disease.     Occasionally,  however,  from  some  inexplicable 
cause  parents  of  sound  stocks  may  beget  an  idiot  or  imbecile 
child,  or  a  child  who  in  later  life  becomes  insane  or  epileptic. 
But  every   effect   owns   a  cause ;  although  we   may  not   have 
discovered  it,  and  it  is  unscientific  to  speak  of  it  as  a  sport.     It 
may  occur  as  a  result  of  a  latent  morbid  tendency  in  the  germ 
plasm  of  the  two   stocks,   as  we  know  frequently  happens  in 
consanguineous   marriages,   when    both    stocks    are    apparently 
healthy,  yet  one  or  more  of  the  offspring  are  mentally  or  physic- 
ally unsound.     A   partially   sound   or   unstable   inborn   mental 
constitution  is  usually  inherited,  and  careful  inquiry  generally 
shows  one  of  the  parents  or  some  other  member  of  the  parental 
stocks  to  have  been  mentally  unsound  or  unstable.     The  child 
may  give  evidence  of  mental  defect  by  being  dull  and  backward 
in  learning,  or  it  may  exhibit  fits  of  uncontrollable  temper  with- 
out cause,  or  other  signs  of  nervous  irritability  such  as  convulsive 
attacks  which  may  be  precursors  of  true  epilepsy.     If  the  child 
escapes  any  distinct   morbid    manifestation   during  childhood, 
there   is  a  danger  of  its  showing  vicious  tendencies  later,   or 
developing  insanity  or  epilepsy  at   the  period  of  adolescence 
when  the  sexual  instinct  is  aroused  and  new  desires  and  passions 
stimulate  the  brain  to  a  new  activity.     It  seems  that  a  mental 
breakdown    is   also   liable   to   occur   in   such   individuals   from 


320  SCIENCE  PROGRESS 

repression  of  the  sexual  passions  and  emotions  producing 
mental  pain  and  stress  causing  exhaustion  of  neural  energy. 
The  more  evidence  of  degeneracy  there  is  in  the  progenitors  and 
their  stocks,  the  greater  will  be  the  number  of  children  born 
suffering  with  feeble-mindedness,  epilepsy,  criminality, or  insanity. 
If  both  parents  are  feeble-minded,  or  one  feeble-minded  and  the 
other  epileptic,  the  chances  are  that  all  the  offspring  will  be 
feeble-minded  or  epileptic.  No  good  can  come  from  a  stock  in 
which  there  is  mental  deficiency;  it  is  otherwise  in  the  case  of 
mental  instability,  for  that  very  instability  which  leads  to  a 
mutation  from  the  "  honourable  ordinary "  may  lead  to  the 
genesis  of  constructive  imagination  and  a  temper  which,  disre- 
garding moral  traditions  and  social  usages,  is  often  found 
associated  with  genius.  History  and  biography  proclaim  that 
the  genius  of  imagination  of  the  poet,  of  the  prophet,  of  the 
artist,  of  the  philosopher,  and  the  lust  for  action  of  the  world's 
great  leaders  of  men  have  been  so  frequently  associated  directly 
or  indirectly  with  epilepsy,  insanity,  or  a  neuropathic  tendency 
that  Dryden's  lines  have  become  a  recognised  truism  : 

"  Great  wit  to  madness  sure  is  near  allied, 
And  thin  partitions  do  their  walls  divide." 

Still,  if  a  nation  (in  order  to  progress)  must  have  an  admixture 
of  mental  instability  in  the  form  of  genius  and  insanity,  a 
streak  of  it  is  sufficient ;  for  that  nation  will  be  the  most 
virile  which  can  breed  from  the  greatest  number  of  the 
"  honourable  ordinaries  "  endowed  with  the  attributes  of  civic 
worth,  courage,  honesty,  and  common  sense.  Moreover,  it  is  a 
great  mistake  to  suppose  that  a  stock  that  does  not  show 
pathological  mental  instability  in  the  form  of  epilepsy  or 
madness  cannot  therefore  produce  genius.  One  of  the  striking 
instances  of  hereditary  genius  is  the  Bach  family.  In  his 
work  on  hereditary  genius  Galton  did  not  refer  to  his  own 
remarkable  family,  but  I  will  throw  on  the  screen  the  abridged 
pedigree  of  the  Darwin-Galton-Wedgwood  family,  and  it  is  of 
interest  here  to  remark  that  Erasmus  Darwin  anticipated 
many  of  the  theories  of  evolution  and  heredity  subsequently 
elaborated  and  demonstrated  by  his  illustrious  grandsons 
Charles  Darwin  and  Francis  Galton.  Genius  often  springs  up 
in  a  stock  we  know  not  how  or  why,  and  with  meteor-like 
flash  it  disappears.  How  far  the  epoch  makes  a  man  of  genius, 
or  the  man  of  genius   makes    the    epoch,  it  is  difficult  to  say. 


THE  INBORN   POTENTIALITY  OF  THE  CHILD    321 

Dr.  Maudsley  has  remarked  that  many  a  Napoleon  has  died  an 
inglorious  death  upon  the  scaffold.  Genius  belongs  to  no  social 
order  or  class,  nor  can  we  explain  in  the  majority  of  cases 
whence  it  comes.  The  part  that  chance  plays  by  a  happy  and 
harmonious  combination  of  germs  in  the  production  of  genius 
is  shown  by  the  fact  that  the  most  outstanding  figure  of  the 
Renaissance  period — Leonardo  da  Vinci  (1452-1516) — sculptor, 
painter,  architect,  engineer,  musician,  philosopher,  and  universal 
genius,  was  the  illegitimate  son  of  a  Florentine  lawyer  by  a 
peasant  woman.  There  was  nothing  in  the  history  of  the  Da 
Vinci  family  to  suggest  constructive  imagination ;  several 
generations  of  lawyers  of  no  remarkable  note  was  the  only  family 
history  pointing  to  intellectual  ability.  Moreover,  the  father 
of  Leonardo  had  a  large  family  born  to  him  in  wedlock ;  he  was 
married  to  four  women,  the  last  two  gave  birth  to  nine  sons  and 
two  daughters.  He  had  but  one  illegitimate  child  by  the  peasant 
woman,  who  subsequently  married  and  had  a  family,  none  of 
whom  attained  any  fame.  The  wonderful  child,  as  remarkable 
for  its  beauty  and  strength  as  in  its  early  manifestations  of 
supreme  mental  endowments,  was  fortunately  for  posterity 
cherished  by  its  father,  who  spared  no  opportunity  which 
nurture  and  education  could  provide  to  develop  this  marvellous 
product  of  Nature.  Would  Leonardo  have  been  what  he  was, 
had  he  not  been  born  in  the  Renaissance  period  and  had  his 
wonderful  talents  developed  by  education  ?  I  could  cite 
numbers  of  other  illustrious  men  whose  forbears  had  given 
no  evidence  of  especial  genius  or  talent,  and  who  attained  an 
everlasting  place  on  the  scroll  of  fame.  Isaac  Newton  was  the 
son  of  a  small  farmer  proprietor  of  Cleethorpes ;  Michael 
Faraday  the  son  of  a  blacksmith  ;  Dalton,  the  son  of  a  weaver  ; 
Turner  the  painter  the  son  of  a  barber  whose  mother  became 
insane,  and  from  whom  he  probably  inherited  his  eccentricity 
and  imaginative  genius.  It  is  a  probable  fact  that  great  men 
owe  their  genius  in  a  great  number  of  instances  to  their  mother 
in  whom  it  is  latent.  Abraham  Lincoln  himself  said,  "  All 
I  have  and  all  I  hope  for  I  owe  to  my  angel  mother,"  and 
Goethe  poetically  described  his  dual  inheritance  of  body  and 
mind  in  the  following  lines  : 

Vom  Vater  hab  ich  die  Statur, 
Des  Ernstes  Lebens  fiihren, 
Vom  Miitterchen  die  Frohnatur, 
Und  Lust  zu  fabulieren, 
21 


322 


SCIENCE  PROGRESS 


which  freely  translated  means  he  resembled  his  father  in  stature 
and  energy  and  his  mother  in  his  poetic  imagination  ;  yet  his 
son  had  none  of  his  father's  genius  and  is  spoken  of  as  the  son 
of  the  maid-servant.  The  greatest  and  best  of  all  the  Roman 
Emperors,  Marcus  Aurelius,  says,  "To  the  gods  I  am  indebted 
for  having  good  grandparents,  good  parents,  a  good  sister,  good 
teachers,  good  associates,  good  kinsmen  and  friends ;  nearly 
everything  good."  Yet  this  man  who  practised  the  noble 
precepts  he  taught  begot  the  infamous  Commodus,  one  of  the 


Charles  the  Bold. 
MAKr    BuRCUNBt 


5  I  '    3fAlf» 


Fig.  6. 


worst  of  the  Roman  Emperors.  That  Commodus  was  the  son 
of  Marcus  Aurelius  is  shown  by  their  physical  resemblance, 
and  not  the  son  of  a  gladiator,  as  some  have  asserted,  by  the 
licentious  Faustina  the  Empress.  As  it  is  stated  that  in  spite 
of  careful  bringing  up  he  early  evinced  depraved  tastes,  it  is 
probable  that  he  inherited  his  temperament  from  his  mother,  as 
he  certainly  did  his  bodily  form  from  his  father. 

Perhaps  one  of  the  most  striking  facts  of  heredity  in  history 
is  the  Spanish  Succession,  of  which  I  will  show  an  illustrative 
pedigree  on  the  screen  (fig.  6).    It  shows  an  hereditary  neuropathic 


THE  INBORN   POTENTIALITY  OF  THE  CHILD    323 

taint  following  a  family  for  350  years,  and  as  Ireland  in  his  work 
A  Blot  on  the  Brain  says  :  "Sometimes  passing  over  a  generation 
and  appearing  in  various  forms  and  intensities  as  epilepsy, 
hypochondria,  melancholia,  mania,  and  imbecility  till  at  length 
it  extinguished  the  direct  royal  line  of  Spain."  The  tendency 
in  the  blood  was,  as  you  see,  reinforced  by  close  intermarriages 
with  families  of  the  same  stock,  and  it  is  worthy  of  notice  that 
the  house  of  Austria,  with  which  the  Spanish  line  was  so  often 
connected  by  marriage,  had  few  members  insane,  and  in  the  end 
threw  off  the  hereditary  curse.  "  Such  vigour  as  was  in  the  first 
Spanish  kings  appeared  in  their  illegitimate  descendants, 
whereas  those  born  in  wedlock  inherited  the  disease  in  spite  of 
the  known  ancestral  taint.  A  match  with  Spain  was  much 
coveted  by  the  royal  families  of  Europe ;  as  an  example  we  may 
recall  the  silly  eagerness  shown  by  James  I.  of  England  to  marry 
his  son  Charles  with  the  Infanta  Maria.  Whoever  attends 
closely  to  history  must  know  that  there  is  a  great  deal  in  birth, 
but  not  birth  fixed  by  laws  and  traced  by  heralds.  A  man  who 
is  well-made,  strong,  mentally  gifted,  and  able  to  do  much  work 
and  stand  much  strain  must  be  well  born,  and  a  race  sodden 
with  epilepsy  and  insanity  and  scrofula,  whatever  its  fictitious 
rank,  is  necessarily  low  born  and  in  reality  not  worth  pre- 
serving." I  have  already  given  you  many  facts  which  certainly 
show  that  the  raw  material  of  character  which  may  be  good,  bad, 
or  indifferent  is  inherited  ;  just  as  some  children  are  born  weak 
and  others  strong,  some  energetic  and  others  inherently  lazy. 
It  is  an  undoubted  fact  that  the  foundations  of  moral  characters 
are  inborn,  but  the  influence  of  education,  example,  environment, 
and  nutrition  is  more  potent  for  good  or  evil  than  is  the  case  in 
morphological  characters. 

Finally,  remember  the  words  of  Sir  Thomas  Browne  :  "  Bless 
not  thyself  that  thou  wert  born  in  Athens  but  among  thy 
multiplied  acknowledgments ;  lift  up  one  hand  to  heaven  that 
thou  wert  born  of  honest  parents,  that  modesty,  veracity,  and 
humility  lay  in  the  same  egg,  and  came  into  the  world  with 
thee." 

In  the  next  number  the  third  lecture  will  be  given,  which  will 
deal  with  "The  Influence  of  Nutrition  and  the  Influence  of 
Education  in  Mental  Development." 


THE   INTERPRETATION   OF   FACT   IN 
THE   STUDY   OF   HEREDITY 

By  CHARLES  WALKER,  D.Sc. 

Heredity  in  Relation  to  Eugenics,  by  Charles  Benedict  Davenport.  (London  : 
Williams  &  Norgate,  1912.) — Problems  of  Life  and  Reproduction,  by  Marcus 
Hartog.  (London:  John  Murray,  1913.) — Heredity,  by  J.  Arthur  Thomson. 
2nd  edition.  (London  :  John  Murray,  1912.) — "The  Logic  of  Darwinism,"  by 
Archer  Wilde.    (Science  Progress,  April,  191 3.) 

There  is,  I  should  imagine,  no  branch  of  knowledge  in  which 
the  intelligent  reader  is  more  likely  to  be  misled  than  that  which 
we  know  as  "  heredity."  In  no  other  subject  are  there  greater 
divergences  of  opinion  upon  fundamental  points  among  recog- 
nised exponents,  nor  have  differences  of  opinion  in  any  case 
been  expressed  with  greater  fanaticism  and  disregard  or  mis- 
representation of  the  arguments  and  facts  advanced  by  opponents. 
I  do  not  mean  to  imply  that  all  exponents  of  views  upon  heredity 
are  guilty,  but  that  such  offences  are  very  common. 

The  study  of  heredity  involves  so  many  branches  of  knowledge 
that  it  is  not  surprising  that  students  in  one  branch  often  fail  to 
understand  what  those  in  another  mean,  owing  to  the  very 
different  character  and  bearing  of  the  facts  dealt  with.  The 
violent  controversy  between  the  Mendelians  and  Biometricians 
is  a  case  in  point.  To  put  it  broadly,  the  Mendelians  are  dealing 
with  the  individual,  while  the  Biometricians  are  dealing  with  the 
race.  The  Mendelians  record  facts  connected  with  the  trans- 
mission of  particular  and  chosen  characters  which  are  easily 
observed,  from  individual  to  individual ;  they  show  how  these 
particular  characters  behave  in  the  offspring  when  individuals 
differing  with  regard  to  them  are  crossed.  The  Biometricians, 
on  the  other  hand,  deal  with  the  behaviour  of  chosen  characters 
in  a  large  number  of  individuals  in  successive  generations. 
They  show  to  what  extent,  on  the  average,  the  characters  of  the 
parents  are  inherited  by  the  offspring  and  how  the  average 
standard  of  a  character  may  vary  in  a  race.  I  do  not  see  the 
slightest  reason   to   question  the  facts   put  forward   by  either 

324 


THE  STUDY  OF   HEREDITY  325 

party,  nor  do  I  see  that  the  facts  contradict  each  other  in  any 
way.  The  mode  of  transmission  of  characters  from  individual  to 
individual  is  quite  a  different  matter  from  that  of  recording  the 
average  standard  of  any  given  character  in  successive  generations 
of  a  large  number  of  individuals. 

Where  the  real  difficulty  to  the  outsider  interested  in  heredity 
comes  in  is  that  the  Mendelians  treat  all  characters  as  unit 
characters  which  do  not  blend  at  all  in  the  offspring.  A  father 
with  a  certain  definite  character  has  offspring  by  a  mother  who 
has  the  opposite  (the  allelomorph)  of  this  character,  including  in 
opposite  the  presence  or  absence  of  a  character.  The  immediate 
offspring  will  show  one  or  the  other  of  this  pair  of  characters  ; 
in  the  next  generation  individuals  will  appear  in  which  one  or 
the  other  character  will  be  produced  to  the  exclusion  of  the 
opposite,  and  in  these  the  characters  extracted  from  the  cross 
will  behave  more  or  less  as  pure  characters  and  breed  true. 
This  is  Mendelian  or  alternative  inheritance.  Prof.  Davenport 
in  his  very  valuable  book  practically  ignores  any  other  kind  of 
inheritance,  the  result  being  that  the  uninformed  reader  must 
believe  that  all  characters  are  inherited  in  this  alternative 
manner.  This  is  strange,  as  he  wrote  in  1906  :  "  Very  frequently 
if  not  always  the  character  that  has  once  been  crossed  has  been 
affected  by  its  opposite  with  which  it  was  mated  and  whose 
place  it  has  taken  in  the  hybrid.  It  may  be  extracted  therefrom 
to  use  in  a  new  combination,  but  it  will  be  found  altered.  This 
we  have  seen  to  be  true  for  almost  every  character  sufficiently 
studied.  .  .  .  Everywhere  unit  characters  are  changed  by 
hybridism."1  There  is,  of  course,  not  the  slightest  doubt  that 
many  characters  present  in  the  parent  appear  in  succeeding 
generations  of  offspring  in  an  alternative  manner,  but  is  this  true 
of  all  characters  ?  And  if  it  be  not,  is  there  anything  which 
suggests  which  characters  are  transmitted  in  this  way  ?  Prof. 
J.  A.  Thomson  gives  but  little  help  in  this  direction.  In  an 
admirable  account  of  the  Mendelian  theory  and  experiments,  he 
appears  to  agree  with  its  most  bigoted  supporters.  He  gives 
also  an  admirable  account  of  the  theories  and  observations 
which  are  supposed  by  some  to  contradict  the  Mendelians,  and 
he  appears  to  agree  with  those  who  uphold  them. 

Now  it  is  quite  obvious  that  the  bulk  of  the  characters  in  any 
individual  are  not  inherited  in  an  alternative  manner.     Whether 

1  Inheritance  in  Poultry ',  p.  80. 


326  SCIENCE  PROGRESS 

they  originated  in  the  remote  past  from  characters  that  were 
Mendelian  is  beside  the  question  ;  they  certainly  are  not  so  now. 
In  following  the  behaviour  of  what  are  really  small,  more  or  less 
individual  differences,  the  Mendelian  school  have  apparently  so 
lost  sight  of  the  bulk  of  the  characters  in  the  organisms  they 
have  studied,  that  these  comparatively  slight  differences  are 
treated  by  them  as  though  they  were  the  only  characters  that 
exist.  A  very  little  consideration  will  show  what  a  mistake  this 
is.  Take  the  whole  of  the  characters  of  man.  I  will  not  trouble 
to  deal  even  briefly  with  those  which  he  possesses  in  common 
with  other  animals  lower  in  the  scale  than  mammals,  though 
they  are  numerous  enough  to  fill  volumes.  Among  the  characters 
possessed  by  man  in  common  with  all  other  mammals  but  not 
by  other  vertebrates  are  the  special  modification  which  provides 
for  the  feeding  of  the  young  after  birth  ;  hairs  upon  the  skin  ; 
sweat  and  sebaceous  glands ;  a  peculiar  formation  of  the  skull, 
skeleton  generally,  and  brain  ;  a  particular  form  of  red  blood 
corpuscle  ;  and  the  separation  of  the  body  cavity  into  two  large 
compartments  by  the  diaphragm  which  provides  an  addition  to 
the  breathing  mechanism  not  found  in  other  animals.  I  must 
pass  on  to  the  nearest  relations  of  man,  the  existing  higher  apes. 
When  we  consider  the  characters  common  to  man  and  the 
chimpanzee  or  gorilla,  we  find  that  the  resemblances  extend  to 
the  bulk  of  even  minute  details.  Compared  with  the  points  of 
resemblance  the  points  of  difference  are  small  and  very  few. 
The  differences  between  the  different  races  of  men  are  smaller 
and  fewer.  To  me,  therefore,  it  appears  perfectly  clear  that  the 
overwhelming  bulk  of  the  characters  inherited  by  each  individual 
is  derived  from  very  remote  and  prehuman  ancestors.  The 
differences  which  constitute  the  characters  studied  by  the 
Mendelians  are  almost  as  nothing  when  considered  in  relation  to 
the  characters  which  are  common  to  all  the  members  of  the  race. 
But  these  characters  common  to  all  individuals  obviously  cannot 
be  transmitted  alternatively.  They  are  always  present.  It  is 
therefore  evident  that  the  characters  that  are  inherited  in  the 
Mendelian  manner  are  really  slight  additions  to  or  subtractions 
from  characters  already  present.  If  we  choose  even  the  largest 
of  such  differences,  albinism  for  instance,  it  is  clear  that  this  is 
comparatively  a  small  difference.  Pigment  is  not  entirely  absent 
from  the  organism,  it  is  absent  only  from  certain  parts  and  in 
most  cases  is  not  quite  absent  even  from  them. 


THE   STUDY  OF   HEREDITY  327 

To  realise  what  is  happening,  it  is  necessary  to  appreciate 
a  certain  property  of  living  matter,  a  property  which  is  abso- 
lutely universal  throughout  the  animal  and  vegetable  kingdom 
from  amoeba  to  man,  from  algae  and  the  like  to  the  most  highly 
differentiated  plants.  This  is  the  property  of  variation.  No 
two  organisms  or  parts  of  organisms  are  ever  exactly  alike. 
Living  organisms  consist  of  single  cells  or  of  groups  of  cells 
living  together.  No  two  cells  are  ever  exactly  alike.  When 
I  realise  that  every  biologist  believes  in  evolution  of  some 
kind  through  some  process  of  selection — and  they  all  appear 
to  realise  that  variations  in  the  offspring  are  necessary  to  evo- 
lution— I  marvel  at  the  fact  that  so  many  theories  exist  to 
account  for  the  production  of  these  variations  during  the  later 
stages  of  evolution.  The  variations  must  have  been  present 
from  the  very  first  stage,  otherwise  evolution  would  obviously 
have  been  impossible.  A  loss  of  the  property  of  varying  by 
the  cells  forming  any  organism  would  of  necessity  have  meant 
that  evolution  and  the  appearance  of  new,  and  the  increase  or 
diminution  and  disappearance  of  existing,  characters  would 
have  ceased.  But  actual  observation  shows  that  in  no  type  of 
cell  has  variation  ceased.  Examine  the  cells  forming  the  most 
highly  differentiated  tissues  of  the  most  highly  differentiated 
organism  and  you  will  never  find  two  cells  exactly  alike. 
This  being  the  case,  it  must  be  perfectly  obvious  that  the 
organisms  built  up  from  these  cells  can  never  be  exactly  alike. 
Offspring  must  always  vary  from  their  parents  and  offspring 
of  the  same  parents  from  each  other.  Sometimes  the  differences 
are  considerable,  sometimes  small.  Obviously  when  minute 
organisms  with  which  the  observer  is  not  very  familiar  are 
examined,  these  small  differences  will  escape  his  notice. 
Familiarity  is  a  great  factor.  To  the  white  man  all  negroes 
appear  alike,  but  when  he  has  lived  among  them  for  some  years 
he  sees  as  much  difference  between  them  as  between  his 
fellow  white  men.  In  the  case  of  microscopic  animals  and 
plants,  small  differences  are  even  more  likely  to  escape  notice, 
but  a  careful  examination  by  a  skilled  observer  shows  that 
they  are  always  there.1  Naturally  if  the  environment  of  an 
organism  remain  unchanged  for  a  long  period  of  time,  any 
variations    which    tend    to   interfere   with     adaptation   will   be 

1  I  have  dealt  with  many  cases  in  which  variation  has  been  claimed  as  absent 
in  Hereditary  Characters  (Arnold,  London,  19 10). 


328  SCIENCE   PROGRESS 

eliminated.  Thus  we  may  find  some  cases  in  which  the  char- 
acters of  organisms  have  not  changed  materially  during 
geological  epochs  of  time.  Any  considerable  variation  would 
have  been  disadvantageous  and  so  must  have  been  eliminated. 
Such  cases  are,  however,  as  would  be  expected,  comparatively 
rare  and  occur  chiefly  among  stationary  or  slowly  moving 
organisms.  For  the  origin  of  this  property  of  varying  we 
must  therefore  look  back  to  the  origin  of  life  itself,  and  it 
seems  a  work  of  supererogation  to  invent  theories  as  to  the 
causes  of  variations  during  the  later  stages  of  evolution  and 
to  treat  them  as  though  they  had  not  been  there  all  along. 

But  there  is  one  point  about  the  variability  of  living 
organisms  which  I  do  not  think  has  received  much  attention, 
and  that  is  that  it  must  obviously  be  the  object  of  selection 
just  as  much  as  any  other  character.  Selection  must  increase 
the  variability  among  the  individuals  of  a  race  just  as  it  must 
affect  the  length  of  a  tail  or  the  shape  of  a  head.  I  shall  have 
more  to  say  of  this  later. 

Prof.  Thomson  gives  a  number  of  theories  as  to  the 
causes  of  variation  during  the  advanced  stages  of  evolution,  but 
he  assumes  that  in  many  cases  variability  does  not  already 
exist.  In  explanation  of  this  he  says :  "  The  cell  which  in  the 
embryo  begins  the  germ-cell  lineage  may  be  identical  with  the 
fertilised  ovum,  and  the  complete  heritage  may  be  continued 
intact  through  successive  cell  divisions  until  the  next  genera- 
tion is  started  and  the  process  begins  anew.  The  completeness 
of  hereditary  resemblances  depends,  in  Bateson's  phrase,  on 
1  that  qualitative  symmetry  characteristic  of  all  non-differen- 
tiating cell  divisions.' "  To  me  this  appears  to  be  a  most 
unwarrantable  assumption.  I  have  examined  hundreds  of  thou- 
sands of  germ-cells  destined  to  produce  ova  or  sperms  and  I 
have  never  seen  two  exactly  alike  even  from  the  same  indi- 
vidual ;  no  one  among  the  hundreds  who  have  made  similar 
observations  has  ever  done  so  either.  Profs.  Thomson  and 
Bateson  must  realise  this  themselves  after  due  consideration. 
Furthermore,  the  fertilised  ovum  cannot  possibly  be  identical 
with  each  of  the  germ  cells  which  goes  to  form  it.  "  That 
qualitative  symmetry  characteristic  of  all  non-differentiating 
cell  divisions  "  means  no  more  in  relation  to  Prof.  Thomson's 
"completeness  of  hereditary  resemblance  {i.e.  the  absence  of 
variation)"  than    that    cells    tend   to  produce  cells   more   like 


THE  STUDY   OF   HEREDITY  329 

themselves  and  like  each  other,  than  like  any  other  kind  of  cell. 
It  can  easily  be  demonstrated  that  there  is  no  such  thing  as 
absence  of  variation  in  any  living  organisms  ;  therefore,  why 
trouble  to  evolve  hypotheses  which  are  quite  unnecessary  ? 

I  turn  to  Prof.  Hartog  and  find  that  he  attributes  the  origin 
of  variation  to  the  inheritance  of  acquired  characters.  But  I 
find  also  that  he  has  realised  that  the  inheritance  of  mutilations 
cannot  occur,  for  "  any  tendency  to  transmit  such  deficiencies 
would  in  course  of  time  result  in  a  generation  of  formless 
imperfections  that  must  needs  be  eliminated  by  natural  selec- 
tion." It  is  therefore  evident  that  he  believes  that,  if  the  tendency 
to  inherit  particular  acquirements  made  through  the  action  of  the 
environment  be  injurious,  the  tendency  will  disappear.  But  a 
very  large  proportion  of  the  effects  of  every  environment  is 
injurious  to  the  organism.  Certainly  we  find  that  the  organism 
has,  as  a  rule,  the  power  of  reacting  to  these  injurious  factors 
and  surviving  in  spite  of  them  ;  but  they  must  always  do  some 
harm  to  the  individual,  as  in  the  case  of  the  children  described 
by  Galton,1  who  invariably  showed  an  arrest  of  growth  during 
even  slight  illnesses.  We  have  ample  material  in  the  innate 
variability  of  living  matter  without  assuming  the  transmission 
of  the  effect  of  the  environment  from  parent  to  offspring;  the 
advantages  of  germ  cells  which  do  not  transmit  such  acquire- 
ments are  obviously  so  great  that  they  must  have  come  under 
the  action  of  selection  and  any  tendency  to  transmit  acquirements 
been  eliminated.  Prof.  Hartog  frequently  expresses  his  dis- 
approval of  unnecessary  assumptions,  theories,  and  hypotheses. 
I  entirely  agree  with  him,  and  as  the  fact  that  cells  never 
produce  other  cells  exactly  like  themselves  or  like  each  other 
seems  ample  to  account  for  every  diverse  organism  that  exists 
or  has  existed,  I  think  his  theory  "  falls  under  the  ever  trenchant 
blade  of  Occam's  razor." 

Of  the  whole  stock  of  characters  present  in  an  individual 
then,  the  great  bulk  have  been  derived  from  remote  ancestors. 
This  stock  is  constantly  being  varied  by  what  are  comparatively 
small  additions  and  subtractions.  Some  of  these  are  variations 
of  the  individual  organisms :  its  private  property,  so  to  speak. 
They  may  be  transmitted  with  increases  or  diminutions  to  the 
offspring.  Thus  it  becomes  evident  that  a  number  of  these 
minor  characters   are   inherited  from  near  ancestors.     Besides 

1  Inquiries  into  Human  Faculty. 


330  SCIENCE   PROGRESS 

the  number  of  great  characters  common  to  all  the  individuals  of 
*he  race,  each  individual  therefore  shows  a  number  of  differences 
in  these  characters  which  are  common  to  a  section  of  the  race 
but  not  to  the  whole  race  ;  a  smaller  number  of  smaller  differ- 
ences which  are  common  to  a  smaller  number  of  individuals ; 
and  so  on  to  those  differences  which  are  peculiar  to  himself 
alone. 

As  these  considerations  lead  me  to  believe  that  but  com- 
paratively few  characters  are  transmitted  from  pprent  to 
offspring  in  the  Mendelian  manner,  so  I  am  convinced  that 
Galton's  law  of  Ancestral  Inheritance  can  only  be  applied,  even 
in  its  broadest  and  most  "averaging"  sense,  to  precisely  the 
same  group  of  characters.  The  overwhelming  bulk  of  our 
characters  come  equally  through,  not  from,  both  parents.  Half 
of  them  certainly  do  not  come  from  each.  On  the  other  hand, 
it  does  not  seem  improbable  that,  on  the  average  in  a  large 
number  of  individuals,  small  differences  may  be  inherited 
approximately  half  from  each  parent,  a  quarter  from  each 
grandparent  and  so  on.  It  cannot  quite  work  out  at  this  rate, 
however,  for  each  individual  in  the  ancestry  makes  some 
addition  to  or  subtraction  from  what  he  or  she  inherited  from 
the  parents.  The  individual  contributes  his  own  variations. 
The  "half"  contributed  by  each  parent  is  made  up  of  two 
"  quarters  "  contributed  by  each  grandparent,  plus  the  variations 
of  the  parents.  Without  this,  evolution  would  have  been  im- 
possible. 

I  have  elsewhere  put  forward  the  view  that  the  characters 
that  are  transmitted  in  the  Mendelian  or  alternative  manner  are 
those  which  have  comparatively  recently  arisen  as  variations  in 
individuals.1  Those  that  have  become  so  established  as  to  be 
common  to  all  the  individuals  of  a  race  do  not  behave  as 
Mendelian  characters  when  crossed.  To  make  my  meaning 
clear  it  is  here  necessary  to  deal  with  some  features  of  the 
Mendelian  experiments.  One  of  the  most  important  of  these  is, 
that  the  overwhelming  majority  of  them  have  been  made  with 
domesticated  races.  Here  I  must  refer  to  that  very  able 
exposition,  "  The  Logic  of  Darwinism,"  by  Mr.  Archer  Wilde. 
I  imagine  that  almost  every  one  who  gives  the  matter  serious 
consideration  must  agree  with  him  that  it  is  quite  unreasonable 

1  Essentials  of  Cytology  (Constable,  London,   1907)  ;  Hereditary   Characters, 
1910. 


THE  STUDY   OF   HEREDITY  331 

to  hold  that  there  is  really  any  fundamental  difference  between 
what  are  commonly  called  "  natural  "  and  "  artificial  "  selection. 
What  we  know  as  artificial  selection  is  merely  the  experimental 
proof  of  the  effect  of  selection  upon  variations  ;  it  does  not 
matter  in  the  least  whether  the  selection  be  applied  by  man  or 
by  other  factors  in  the  environment  of  the  organism.  The  only 
difference  is  that  the  one  is  under  the  control,  conscious  or 
unconscious,  of  an  experimenter,  whilst  the  other  is  not.  But 
he  entirely  missed  the  point  I  wish  to  emphasise  here,  and  that 
is,  that  domesticated  races  possess  a  character  in  common  or 
rather  an  exaggeration  of  a  character  which  is  not  present  in 
wild  races.  This  is  a  tendency  to  produce  comparatively  large 
variations.  Take  even  the  most  inbred  stocks  which  are  said 
to  breed  quite  true  and  to  impress  their  peculiar  characters 
upon  the  offspring  when  crossed  with  another  breed.  Look  at 
the  pedigrees.  The  same  individuals  appear  constantly  as 
ancestors  in  the  pedigrees  of  each  descendant.  This  means 
that  only  those  individuals  have  been  used  for  breeding 
purposes  who  exhibited  the  desired  variations  ;  what  is  more 
important,  that  there  were  but  few  such  individuals.  Then,  if 
in  such  a  pedigree  we  look  at  characters  which  were  not  the 
objects  of  selection,  as  colour  in  racehorses,  we  find  such 
variations  common  as  are  rarely  or  never  found  in  wild  animals. 
Domesticated  races  are,  in  fact,  far  more  variable  than  are  wild 
races.  Why  ?  Man  is  generally  unable  to  detect  small 
differences.  "  He  has  always  selected  animals  or  plants  which 
vary  from  the  mean  of  the  race  more  than  did  their  fellows. 
Whatever  else  he  has  selected  then,  he  has  always  selected 
variability,  which  is  just  as  much  a  character  as  anything  else."  ! 
Those  characters  which  in  the  domesticated  races  behave  in  the 
Mendelian  manner  may  therefore  reasonably  be  regarded  as 
recent  variations  in  individuals  which  have  been  rapidly 
exaggerated  in  the  offspring  by  the  mode  of  selection.  Man, 
in  his  process  of  selection,  has  substituted  his  desires  for  many 
other  factors  in  the  environment  and  has  allowed  characters  in 
which  he  was  not  interested  to  run  riot  in  a  manner  that  would 
certainly  have  entailed  the  destruction  of  the  organism  if  it  had 
not  been  protected  by  him.  I  would  suggest  that  these 
characters  which  are  apparently  recent  and  which  are  trans- 
mitted alternatively  should  be  called  "individual"  or  "personal" 

1  Hereditary  Characters,  p.  71. 


332  SCIENCE   PROGRESS 

characters,  whilst  those  which  are  common  to  all  the  individuals 
of  a  race  should  be  called  "  racial." 

Do  we  know  anything  of  the  behaviour  of  racial  characters 
when  crossed  ?  There  are  a  great  many  illustrations  from 
which  I  will  select  only  a  few.  The  cross  between  negro  and 
Caucasian  is  a  good  example,  and  I  take  it  the  more  willingly 
because  Prof.  Davenport,  who  as  I  have  already  pointed  out 
apparently  believes  that  all  characters  are  transmitted  alterna- 
tively, has  used  it.  I  am  enabled  to  go  further  than  this  and 
use  his  statement  of  the  case  because  of  the  very  frank  and  fair 
manner  in  which  he  has  dealt  with  the  facts.  He  shows  that  the 
individuals  forming  consecutive  generations  may  vary  from  as 
light  as  Caucasians  to  46  per  cent,  of  black  in  the  skin.  He  goes 
on  to  say:  "Just  as  perfect  white  skin  colour  can  be  extracted 
from  the  hybrid,  so  may  other  Caucasian  physical  and  mental 
qualities  be  extracted  and  a  typical  Caucasian  arise  out  of  the 
mixture.  However,  this  result  will  occur  only  in  the  third  or 
later  hybrid  generation,  and  the  event  will  not  be  very  common." 
I  suppose  that  we  may  presume  that  fresh  white  blood  is  being 
brought  in  at  each  generation  and  that  even  when-  several 
individuals  who  appear  to  be  pure  white  have  been  produced, 
negro  characters  will  be  liable  to  appear  in  their  offspring.  The 
final  production  of  a  pure  white  race  could  therefore  be  more 
easily  explained  by  a  process  of  swamping  than  by  alternative 
inheritance. 

A  better  example,  because  it  affords  a  direct  comparison  of 
the  behaviour  after  crossing  between  similar  characters,  one  of 
which  is  racial  and  the  other  individual,  is  afforded  by  the 
breeding  experiments  of  Messrs.  Prout  and  Bacot.1  They  found 
that  the  moth  Acidalia  virgularia  in  the  neighbourhood  of 
London  was  dark.  The  same  moth  found  at  Hyeres  in  the 
South  of  France  was  white.  They  crossed  individuals  from  the 
two  races  and  bred  ten  generations  which  provided  between  five 
and  six  thousand  specimens.  There  was  no  segregation  into 
dark  and  white  groups,  but  such  delicate  intergrading  between 
the  two  parent  forms  that  grouping  was  impracticable.  In  the 
case  of  local  variants  of  other  Lepidoptera,  e.g.  Tryphoena  comes 
and   its   dark   aberration,   Xanthorhoe  ferrugata    and   its   black 

1  "  On  the  Cross-breeding  of  the  Moth  Acidalia  virgularia?  Proc.  Roy.  Soc. 
B,  vol.  lxxxi.  1909. 


THE  STUDY   OF   HEREDITY  333 

aberration,1  the  same  authors  obtained  Mendelian  results.  They 
came  to  the  conclusion  that,  in  order  to  obtain  Mendelian 
segregation,  variations  occurring  in  a  race  occupying  the  same 
geographical  area  must  be  crossed  ;  but  that  if  characters  in 
geographically  separated  races  are  crossed,  they  blend.  My 
belief  is  that  this  happens  simply  because  the  variations  in  the 
same  locality  are  individual  characters  of  recent  origin,  whilst 
differences  between  two  geographically  separated  races,  which 
are  common  to  all  the  individuals  of  each  race,  are  racial 
characters  and  are  comparatively  ancient. 

Crosses  between  individuals  belonging  to  different  species 
and  even  to  different  genera  of  fish,  among  the  Salmonidae  parti- 
cularly, are  common,  and  practically  perfect  blending  of  the 
characters  is  almost  invariable. 

The  alternative  transmission  of  personal  or  individual  varia- 
tions must  be  of  enormous  advantage  in  the  process  of  evolution. 
As  even  every  cell  is  different  from  every  other  cell,  the  number  of 
variations  round  the  mean  of  any  character  in  the  multicellular 
organism  must  be  incalculable.  It  is  also  obvious  that  most  of 
these  variations  must  be  useless  and  some  actually  injurious. 
The  rapid  elimination  of  useless  variations  is  of  great  importance, 
and  this  rapidity  is  provided  for  by  the  alternative  inheritance 
of  recent  variations.  Only  25  per  cent,  of  the  second  generation 
from  the  introduction  of  the  variation  can  possess  gametes  which 
all  carry  the  character.  Of  the  rest,  25  per  cent,  will  not  possess 
the  character  at  all  and  in  50  per  cent,  it  will  be  present  in  only 
half  the  gametes.  If  the  variation  be  advantageous,  it  will  thus 
be  more  easily  preserved  ;  if  it  be  useless  or  injurious,  it  will  be 
more  readily  and  rapidly  eliminated. 

We  have  in  certain  constituents  of  the  cell — the  chromosomes 
— and  the  mode  in  which  they  are  alternatively  distributed  to  the 
gametes  upon  fertilisation,  an  exact  parallel  to  the  distribution 
of  the  characters  in  Mendelian  inheritance.  I  have  elsewhere 
suggested  the  probability  of  the  intimate  connection  between 
these  phenomena.2 

Sex  is  claimed  as  a  Mendelian  character,  and  with  some 
modifications  I  feel  that  this  claim  is  justified.  Leaving  aside 
the  highly  technical  points  in  relation  to  chromosomes  as  deter- 

1  Entomologist's  Record,  xv.  and  xvi.  ;  Trans.  Entomol.  Soc.  London,  1906,  and 
Proc.  1907. 

2  Hereditary  Characters. 


334  SCIENCE   PROGRESS 

minants  of  sex,  described  by  both  Profs.  Davenport  and 
Thomson,  I  think  that  the  conclusion  may  be  arrived  at  on 
more  general  lines.  Such  differences  as  constitute  sex,  funda- 
mentally the  difference  between  the  production  of  cells  that 
actively  fertilise  and  those  that  are  passively  fertilised,  must, 
like  other  characters,  have  arisen  from  variations  that  were 
transmitted  in  an  alternative  manner.  In  the  case  of  variations 
generally  which  are  of  sufficient  advantage  to  the  race  to  be  pre- 
served by  selection,  the  alternative  inheritance  disappears  in 
time  and  the  character  becomes  racial.  But  the  advantages  of 
the  differentiation  of  individuals  into  two  sexes  is  dependent 
upon  the  alternative  occurrence  of  particular  characters,  so 
selection  would  necessarily  have  eliminated  the  tendency  to 
blend  to  a  great  extent.  That  it  has  not  done  so  beyond  the 
necessary  point  is  evident  from  the  potentiality  of  producing 
the  secondary  characters  of  the  opposite  sex  under  certain  con- 
ditions, a  potentiality  which  varies  in  different  individuals  just 
as  do  all  other  characters.  Thus  we  see  that,  as  Prof.  Daven- 
port says,  opposite  characters  when  crossed  always  leave  their 
marks  upon  each  other  when  extracted  ;  and  also  we  see  that 
the  variation  towards  blending  is  always  appearing,  which  fact 
Prof.  Davenport  has  missed. 

I  must  confess  that  I  am  unable  to  follow  the  argument  of 
Prof.  Thomson,  who  says  that  "  the  difference  between  an  ovum 
producer  and  a  sperm  producer  is  fundamentally  a  difference  in 
the  balance  of  chemical  changes,  i.e.  in  the  ratio  of  anabolic  and 
katabolic  processes."  Why  should  not  the  difference  in  the 
"  ratio  of  anabolic  and  katabolic  processes  "  be  the  result,  not 
the  cause,  of  sexual  differences  ? 

A  comparatively  recent  and  serious  cause  of  contention  has 
arisen  out  of  de  Vries'  mutation  hypothesis.  In  de  Vries'  own 
words,  quoted  by  Prof.  Thomson,  this  may  be  briefly  described 
as  follows  :  "  The  current  belief  assumes  that  species  are  slowly 
changed  into  new  types.  In  contradiction  to  this  conception 
the  theory  of  mutation  assumes  that  the  new  species  and 
varieties  are  produced  from  existing  forms  by  sudden  leaps. 
The  parent  type  itself  remains  unchanged  throughout  this  pro- 
cess and  may  repeatedly  give  rise  to  new  forms."  Prof.  Thom- 
son has  such  a  high  opinion  of  this  hypothesis  that  he  constantly 
treats  it  as  though  it  were  generally  accepted  by  biologists  all 
over  the  world.     It  certainly  accords  well  with  the  tendency  he 


THE  STUDY  OF  HEREDITY  335 

frequently  shows  in  his  book  towards  a  belief  in  some  kind  of 
supernatural  directive  power  which  regulates  evolution,  and  on 
these  lines  is  a  most  desirable  asset  to  his  arguments  ;  but  it  is 
not  the   case  that   the   hypothesis   has   been   accepted  by  the 
majority  of   biologists,   indeed   many  repudiate   it   altogether. 
Prof.  Thomson  is  certainly  more  reasonable  in  one  respect  than 
Prof.    Bateson,    the  apostle   in   this  country   of  the   mutation 
hypothesis.      The    latter    and    his    school    assume    that    "  all 
organised  nature  is  arranged  in  disconnected  series  of  groups, 
differing  from  each  other  by  differences  which  are  specific."  1     I 
think  that  those  biologists  who  have  been  largely  occupied  in 
the  study  of  species  and  varieties  are  unanimously  of  opinion 
that  so-called  species  very  frequently,  if  not  generally,  merge 
into  each  other  by  almost  insensible  gradations.     When  these 
links  are  not  found,  their  absence  may  reasonably  be  accounted 
for  by  the  fact   that   enormous   numbers   of  forms   have  dis- 
appeared in  the  past,  without  leaving  any  traces.   Prof.  Thomson 
realises    that    "  species   are   often    connected    by   intermediate 
links,"  but  suggests  that  these  links  "  may  have  been  formed 
after  the  species  from  which  they  are  theoretically  supposed  to 
give  rise."    To  me  this  explanation  appears  inconceivable.    The 
intermediate    links    are    admittedly     there.      Therefore     the 
organisms  are  obviously  capable  of  producing  these  links  be- 
tween  the  two  extremes.     If  they  are  produced  gradually  in 
response  to  slight  changes  in  the  environment,  they  will  not 
throw  the  individual  out  of  harmony  with  it,  which  any  sudden 
large  change  must  very   frequently,  if  not  always,  do.     Prof. 
Thomson  lays  great  stress  upon  the  criticism  that  the  theory 
that  evolution  has  been  due  to  the  selection  of  small  variations 
"  places  such  a  heavy  burden  on  the  shoulders  of  natural  selec- 
tion that  the  idea  of  a  leaping  instead  of  a  creeping  Proteus  has 
always  been  welcome."      But   to   me   the   burden   appears   to 
remain  the  same,  whether  the  intermediate  links  were  produced 
in  the  process  of  species  making  or  afterwards,  for  they  have 
been  produced  in  either  case. 

Whilst  then  the  gradual  small  change  in  characters  appears 
to  offer  so  many  advantages,  the  utility  of  sudden  and  large 
changes  seems  so  highly  problematical  and  this  hypothesis 
seems  so  much  in  the  nature  of  an  intellectual  "  mutation  "  on 
insufficient  grounds  that  I  am  not  inclined  to  accept  it. 

1  Materials  for  the  Study  of  Variation,  p.  17  (London,  1894). 


336  SCIENCE   PROGRESS 

Prof.  Thomson  gives  a  full  and  excellent  account  of  the  facts 
that  led  to  the  formulation  of  the  mutation  hypothesis,  and  here 
we  find  the  explanation  of  its  origin.  I  cannot  find  an  instance 
of  an  established  "  mutation "  except  in  domesticated  races. 
De  Vries'  original  case  of  a  "  mutating  form  "  was  the  evening 
primrose.  It  was  introduced  into  Europe  from  America  prob- 
ably during  the  eighteenth  century,  so  there  is  no  doubt  as  to 
its  having  been  subjected  to  selection  by  man.  All  the  other 
instances  are  similar,  and  when  large  variations  in  wild  species 
are  taken  and  bred  from  by  man  precisely  the  same  criticism 
applies.  No  one  denies  that  large  variations  do  sometimes 
occur  in  races  which  have  not  been  selected  by  man,  though  de 
Vries  was  not  able  to  find  any  among  the  hundreds  of  wild 
plants  he  investigated.  These  large  variations  must  throw  the 
organism  in  which  they  occur  so  much  out  of  adaptation  to  its 
environment  that  they  must  as  a  rule  end  in  elimination,  though 
it  is  conceivable  that  there  might  be  some  sudden  change  in  the 
environment  occasionally  which  would  favour  the  preservation 
of  a  large  variation  in  a  particular  direction  should  it  occur. 
Changes  in  the  environment  are,  however,  almost  invariably 
very  gradual.  But  as  I  have  already  pointed  out,  man  has 
always  selected  variability  in  the  animals  and  plants  he  has 
domesticated.  He  has  done  more  than  this.  He  has  selected 
the  character  of  producing  large  variations,  as  large  variations 
have  been  most  easily  selected  by  him,  and  as  he  has  substituted 
himself  for  many  other  factors  in  the  environment,  he  has 
removed  that  check  upon  the  constant  production  of  large  varia- 
tions which  must  usually  be  present  under  natural  conditions. 
It  is  thus  not  surprising  that  de  Vries  found  large  variations  in 
the  first  domesticated  plant  with  which  he  experimented.  But 
the  selection  of  large  variations  by  man  will  not  be  constant. 
When  he  has  reached  a  certain  standard  he  will  in  certain  cases 
do  no  more  than  try  to  keep  up  this  standard,  and  he  will  then 
reject  large  variations  to  some  extent.  Thus  a  particular 
organism  will  exhibit  a  tendency  to  produce  large  or  small 
variations  according  to  whether  it  has  been  recently  selected  for 
one  or  the  other  character.  This  may  very  possibly  account  for 
the  origin  of  de  Vries'  hypothesis  that  "  mutations  "  appear  in 
considerable  numbers  in  a  given  race  at  intervals  but  that  be- 
tween these  "  mutating"  periods  the  race  remains  stationary. 

The  application  of  all  these  facts  and  theories  about  heredity 


THE   STUDY  OF   HEREDITY  337 

is  of  the  greatest  importance  in  relation  to  eugenics.     I  think 
that   almost   every    one    who    has    studied    the    matter  at   all 
thoroughly   will    agree   in    the    main    with    Prof.    Davenport's 
general   conclusions.     His   opinion   that   all   characters  are  in- 
herited in  an  alternative  manner  does  not  matter  so  very  much, 
whether  he  be  right  or,  as  I  think,  wrong ;  for  the  overwhelm- 
ing proportion  of  the  characters  which  would  be  selected  by 
the  eugenic  methods  would  be  recent  variations — individual  or 
personal  characters,  in  fact — which  are,  according  to  the  evidence 
available,  inherited  alternatively.     I  cannot,  however,  see  eye  to 
eye  with  him  with  regard  to  the  crossing  of  black  and  white 
races  or  indeed  any  races,  for  the  process  of  swamping  unde- 
sirable racial  characters  would  be  a  very  lengthy  and  uncertain 
one;   as  1    have   already   said,   it   does   not   appear  that  racial 
characters  can  be  segregated  by  breeding.     I  cannot  agree  with 
him  either  that  mental  traits,  such  as  imbecility  and  criminalistic 
tendencies,  have  come  down  directly  through  an  unbroken  suc- 
cession of  generations  of  individuals  from  our  animal  ancestors. 
The  very  factors  in  the  environment  which  have  produced  an 
intellect  incomparably  superior  to  that  of  our  ape-like  progenitors, 
and  a  high  standard  of  morality  in  the  majority  of  individuals, 
must  have  continually  eliminated  variations  in  other  directions. 
It  seems  to  me  more  reasonable  to  account  for  these  characters 
through  the  constant  occurrence  of  variations  in  all  directions. 
The  latter  view  is  surely  also  a  much  more  hopeful  one.     There 
is  some  danger  in  Prof.  Davenport's  suggestion  that  individuals 
who,  according  to  the  results  of  the  Mendelian  experiments  and 
observations,   are   capable   of  producing   offspring  with   unde- 
sirable   characters    only    when    mated    with    others    who   are 
similarly  capable,  should  be  allowed  to  marry  individuals  that 
possess  a  clean  pedigree.     This  means  preserving  the  potenti- 
ality of  producing  the  undesirable  characters  indefinitely.     In 
his   conclusions   he   appears   also    to    have   forgotten   his   own 
statement,  that  crossed  characters  always  bear  traces  of  their 
opposite.     In   spite    of    being    apparently    at   times   too   much 
influenced  by  sentimental  reasons  in  his  suggestions,  there  is 
no  doubt  that  if  the  measures  Prof.  Davenport  advocates  in  his 
valuable  book  were  adopted,  an  enormous  benefit  to  mankind 
would   result.     His    reasons    are    stated    clearly,    and    though 
apparently  his  softer  feelings   prevent   him   in   all   cases   from 
arriving  at  the  complete  logical  conclusions  which  must  result 
22 


338  SCIENCE   PROGRESS 

from  them,  there  is  never  any  appeal  to  the  metaphysical,  nor 
does  he  allow  sentiment  to  gloss  over  facts. 

In  the  case  of  Prof.  Thomson's  book  these  matters  are  dealt 
with  in  a  very  different  way.  He  appears  to  me  to  belittle  facts 
and  to  enlarge  sentimentality ;  he  shows  frequently  that  he 
places  reliance  in  what,  as  far  as  I  can  make  out,  is  a  meta- 
physical directive  power  in  evolution ;  though  he  has  not 
formulated  this  definitely,  as  Bergson  does,  he  has  very  decided 
leanings  in  that  direction.  A  not  inconsiderable  number  of 
biologists,  most  unfortunately,  are  inclined  to  somewhat  similar 
opinions.  Prof.  Thomson  lays  great  stress  upon  the  danger  of 
adopting  legislative  measures  of  limiting  the  breeding  of  the 
unfit,  because  many  variations  are  "  unknown  quantities";  be- 
cause "the  unpromising  bud  may  burst  into  a  fair  flower"; 
because  evil  traits  may  work  themselves  out ;  because  many  bad 
traits  may  be  due  to  modifications  produced  in  the  individual 
by  the  environment  (he  quotes  the  Jukes  as  a  possible  example 
of  the  modificational  effect  of  "  social  ostracism  ") ;  and  because 
"  preoccupation  with  the  biological  outlook — the  breeder's  point 
of  view — will  undoubtedly  lead  to  fallacy  upon  fallacy,  the 
1  materialisms '  to  which  we  have  already  referred." 

If  we  take  facts  as  they  are,  there  can  be  no  doubt  that  there 
is  a  constant  interchange  between  the  various  grades  of  indi- 
viduals in  the  civilised  state.  Variations  towards  mental  and 
physical  inferiority  tend  to  cause  a  fall,  and  vice  versa.  The 
mortality  in  the  lowest  class  is  higher  than  in  any  other,  and 
thus  provides  a  process  of  elimination  acting  most  forcibly  upon 
the  most  undesirable  part  of  the  population.  But  modern 
sentimental  legislation  is  altering  all  this.  The  mortality  per 
thousand  has  fallen  greatly  all  over  the  country,  in  the  town 
population  particularly.  Dr.  Chalmers  recently  gave  an  analysis 
of  the  mortality  in  the  population  of  Glasgow.  This  shows  that 
the  mortality  has  fallen  19/4  per  cent,  during  the  past  ten  years, 
but  that  the  greater  part  of  this  fall  has  been  in  families  living 
in  one  or  two  rooms.  The  mortality  of  that  part  of  the  popula- 
tion consisting  of  families  living  in  four  rooms  or  more  has 
remained  practically  unchanged.  This  gives  one  seriously  to 
think,  for  it  means  that  a  most  necessary  form  of  selection  is 
ceasing  and  nothing  is  taking  its  place. 

It  is  quite  certain  that  any  form  of  selection  may  occasion- 
ally destroy  desirable  individuals,  but  this  cannot  be  the  usual 


THE  STUDY  OF   HEREDITY  339 

course  of  events.  Besides,  it  does  not  seem  to  me  worth  while 
to  preserve  and  breed  from  thousands  of  undesirables  in  order 
to  avoid  the  possible  loss  of  one  desirable  individual.  Prof. 
Davenport's  book  shows  that  the  production  of  the  efficient  by 
inefficient  parents  is  very  rare,  whilst  efficient  parents  commonly 
produce  efficient  children. 

The  question  as  to  what  proportion  of  undesirable  traits  may 
be  modificational  is  a  very  important  one,  and  one  upon  which  it 
is  very  easy  to  fall  into  serious  errors.  It  involves  the  question 
of  the  inheritance  of  acquired  characters  to  some  extent.  The 
question  to  deal  with  is — which  of  the  characters  of  the  adult 
organism  are  acquired  and  which  inborn  ?  We  speak  of  them 
as  those  due  to  "  nurture  "  and  "  nature"  respectively;  as  being 
in  fact  divided  into  two  distinct  and  easily  separated  groups. 
As  Dr.  Archdall  Reid  has  pointed  out,  they  are  not  to  be  thus 
easily  distinguished.  Every  multicellular  organism  begins  its 
existence  as  a  single  cell,  the  fertilised  ovum ;  it  is  quite 
evident  that  the  characters  of  the  adult  organism  cannot  be 
present  as  such  in  a  single  cell.  What  then  represent  the 
characters  of  the  adult  organism  in  the  ovum  ?  The  capacity  to 
develop  along  certain  lines  within  certain  comparatively  narrow 
limits  under  certain  conditions.  We  may  regard  the  ovum  as  a 
portion  of  very  complex  matter  of  such  a  nature  and  so  shaped 
that  additions  can  only  be  made  to  it  in  certain  very  definite 
directions  and  in  certain  very  definite  ways,  with  the  result 
that  it  is  capable  of  growing  only  into  a  particular  form  with 
particular  characters.  It  is  then  these  capacities  for  develop- 
ment along  particular  lines,  these  potentialities,  which  are 
inborn.  The  resulting  development  of  these  capacities  must 
obviously  be  modified  from  the  very  first  by  the  environment. 
The  amount  of  possible  modification  by  the  environment  varies 
enormously  in  different  organisms.  In  the  butterfly  it  is  extra- 
ordinarily small ;  in  man  it  is  extraordinarily  great.  This  great 
dependence  of  man  upon  modifications  by  the  environment  has 
led  many  people  to  attach  too  great  importance  to  it  and  not 
enough  to  the  inborn  capacities.  Take  any  class  of  school-boys. 
No  two  boys  will  show  the  same  capacity  for  obtaining  know- 
ledge and  skill  in  any  given  subject ;  the  boy  who  is  above  the 
average  capacity  in  one  may  be  below  it  in  another,  though  most 
will  be  able  to  reach  an  average  standard  in  all.  Now  it  is  quite 
evident  that  in  such  cases  the  difference  in  the  environment  is 


340  SCIENCE   PROGRESS 

not  sufficient  to  account  for  the  difference  in  facility  with  which 
the  different  individuals  acquire  knowledge  and  skill ;  indeed  it 
would  be  easy  to  find  innumerable  examples  where  individuals 
with  greater  facilities  had  not  done  as  well  as  individuals  with 
less.  The  difference  lies  in  the  capacity  of  making  acquirements 
in  particular  directions.  It  certainly  may  happen  that  the  en- 
vironment of  an  individual  with  a  small  capacity  may  result  in 
his  acquirements  in  a  particular  line  being  as  great  as  those  of 
an  individual  in  a  different  environment  who  possesses  a  greater 
capacity,  but  the  difference  in  the  environments  must  be  greater 
than  the  difference  in  the  capacities  to  produce  this  result ; 
which  in  many  cases  is  unattainable  under  any  circumstances. 

Take  the  case  of  the  Jukes  quoted  by  Prof.  Thomson.  The 
"  criminal  taint "  which  he  regards  as  being  among  the  sugges- 
tions "  quaint  in  their  unpracticality  "  was  in  no  ways  due  to  the 
effect  of  "  social  ostracism,"  to  the  environment,  in  fact,  for 
several  members  of  the  family  were  taken  away  in  babyhood 
and  brought  up  under  circumstances  most  favourable  to  the 
development  of  any  moral  and  other  desirable  mental  capacities 
they  might  happen  to  possess.  Unfortunately  for  Prof.  Thomson's 
views,  they  all  turned  out  as  criminally  inclined  as  their  ancestors. 
Their  performances  appear  to  have  been  limited  mainly  by  their 
opportunities. 

We  know  quite  well  that  mental  capacities,  that  is,  capacities 
for  making  particular  mental  acquirements,  are  subject  to 
selection  just  as  much  as  capacities  for  making  physical 
acquirements.  Breeds  of  sporting  dogs  are  examples  of  this 
point.  Therefore  I  do  not  see  any  valid  reason  for  saying  that 
the  biological  point  of  view  is  likely  to  lead  to  fallacies.  Cer- 
tainly it  is  less  liable  to  lead  us  astray  than  a  combination  of 
sentimentality  and  metaphysical  speculation. 

With  regard  to  the  transmission  of  acquired  characters  the 
real  question  is,  therefore,  whether  these  inborn  differences  in 
capacities  for  making  acquirements  can  be  reproduced  in  the 
germ  cells  by  the  action  of  the  environment  upon  the  organisms 
producing  the  germ  cells  ;  whether  in  fact  the  effects  of  the 
environment  upon  the  parent  can  be  metamorphosed  into  a 
capacity  for  acquiring  characters  in  the  offspring.  To  me  it 
appears  rather  like  saying  that  the  effect  produces  the  cause. 
However,  as  there  are  apparently  many  who  do  believe  that 
acquirements    are    transmuted    into    capacities    in    successive 


THE   STUDY   OF   HEREDITY  341 

generations,  a  consideration  of  the  nature  of  the  evidence  is 
necessary.  Prof.  Thomson  gives  a  full  account  of  the  evidence 
on  both  sides  which  occupies  eighty-five  pages  of  his  book.  He 
is  able  to  arrive  only  at  the  following  conclusion,  however, 
which  he  obviously  considers  to  be  of  the  utmost  importance,  as 
he  prints  it  in  italics  : 

"  If  there  is  little  or  no  scientific  warrant  for  our  being  other  than 
extremely  sceptical  at  present  as  to  the  inheritance  of  acquired 
characters — or  better,  the  transmission  of  modifications — this  scepticism 
lends  greater  importance  than  ever  on  the  one  hand  to  a  good 
'  nature,1  to  secure  which  is  the  business  of  careful  mating ;  and, 
on  the  other  hand,  to  a  good  '  nurture1  to  secure  which  for  our 
children  is  one  of  our  most  obvious  and  binding  duties ;  the  hope- 
fulness of  the  task  resting  especially  upon  the  fact  that,  unlike  the  beasts 
that  perish,  man  has  a  lasting  external  heritage,  capable  of  endless 
modifications  for  the  better,  a  heritage  of  ideas  and  ideals,  embodied 
in  prose  and  verse,  in  statue  and  painting,  in  cathedral  and  university, 
in  tradition  and  convention,  and  above  all  in  society  itself." 

This  does  not  seem  to  help  very  much.  Prof.  Hartog's 
evidence  is  all  one-sided.  Beyond  what  I  have  already  said  as 
to  the  improbability  of  the  transmission  of  acquirements,  we  find 
that,  in  fact,  a  very  favourable  environment  when  applied  to  all 
the  individuals  of  a  race  tends  to  result  in  the  disappearance  of 
characters.  Characters  are  preserved  only  when  necessary  or 
beneficial  to  the  individual.  But  necessary  and  beneficial 
characters,  or  rather  the  potentiality  of  producing  them,  must 
generally  be  of  such  a  nature  as  to  enable  their  possessors  to 
resist  or  overcome  unfavourable  factors  in  the  environment.  But 
unfavourable  factors  in  the  environment  must  always  be  injurious 
to  the  individual,  and  if  the  inheritance  of  the  response  to  the  en- 
vironment be  accepted  it  involves  the  belief  in  the  evolution  of  a 
potentiality,  which  must  be  present  in  every  individual,  of  selecting 
which  kind  of  acquirement  is  to  be  inherited  and  which  is  not — 
just  as  big  a  result  in  itself  as  all  the  rest  of  evolution  without 
it.  Without  something  of  this  kind  an  unfavourable  environ- 
ment must  necessarily  cause  a  race  to  grow  weaker,  while  a 
very  favourable  environment  would  cause  it  to  grow  stronger. 
We  know  that  this  is  not  what  happens.  On  the  other  hand, 
that  the  capacities  for  development  along  certain  lines  should 
be  produced  by  the  selection  of  favourable  variations  occurring 
in  individuals  seems  easy  to  understand. 


342  SCIENCE   PROGRESS 

Perhaps  the  most  important  point  as  regards  eugenics  is  how 
far  the  Mendelian  phenomena  apply  to  the  human  race.  Any 
means  which  are  to  act  in  a  selective  manner  in  improving  or 
preventing  the  degeneration  of  the  race  must  be  applied  to 
characters  appearing  in  individuals.  Particular  characters  in 
individuals,  as  individuals,  must  be  dealt  with.  It  seems 
probable  that  most  of  these  will  prove  to  be  comparatively 
ecent  variations  and  so  will  be  transmitted  alternatively. 

It  is  in  fact  the  selection  of  variations  occurring  in  individuals 
which  offers  the  only  chance  of  improving  the  characters,  mental 
and  physical,  of  a  race.  Nothing  in  the  way  of  forcing  acquire- 
ments upon  individuals  with  inferior  capacities  can  raise  the 
standard  of  capacity  in  the  race  any  more  than  teaching  bull- 
dogs to  point  would  produce  a  capacity  of  learning  to  point. 
Selection  of  variations  in  the  capacity  for  acquiring  the 
necessary  characters  involved  in  pointing,  if  extended  over 
many  generations,  would  no  doubt  produce  a  race  of  bull-dogs 
that  were  comparatively  easy  to  train  to  point,  but  it  would 
hardly  be  a  practical  proposition,  as  we  already  have  a  breed 
of  dogs  which  has  been  subjected  to  selection  with  regard  to 
these  capacities  for  hundreds  of  generations.  In  the  same  way 
it  does  not  seem  to  be  a  practical  proposition  to  attempt  to  breed 
men  with  desirable  and  without  undesirable  qualities  from  the 
failures  by  selecting  the  favourable  variations  they  may  produce. 
They  would  reproduce  thousands  of  unfavourable  variations  to 
one  favourable  one,  and  that  one  would  vary  from  a  lower 
mean  than  the  average  ;  and  worse  than  all,  the  undesirable 
offspring  cannot  be  drowned  as  puppies  are  by  the  breeder,  but 
must  be  kept  alive  to  produce  more  undesirables. 

Such  characters  as  lunacy  and  idiocy,  deaf-mutism  and 
criminal  tendencies,  were,  until  recently,  subjected  to  such 
stringent  selection  that  they  must  have  been  eliminated  very 
soon  after  the  unfavourable  variations  appeared.  So  far 
Prof.  Davenport's  views  are,  I  think,  unassailable.  But  when 
it  comes  to  crossing  racial  characters,  mental  or  physical, 
the  problem  is  a  more  serious  one  and  involves  far  greater 
dangers  ;  as,  if  my  views  are  correct,  even  a  slight  blend  of 
undesirable  racial  characters  may  be  almost  impossible  to 
eliminate. 


THE   METHOD   OF   DARK-GROUND 

ILLUMINATION    IN    BOTANICAL 

RESEARCH 

By  S.  REGINALD   PRICE,   B.A. 

Late  University  Frank  Smart  Student  in  Botany,  Cambridge 

To  the  microscopist  the  method  of  dark-ground  illumination, 
and  its  recent  extended  applications,  are  so  well  known  as  to 
need  no  general  description,  but  to  many  of  those  who  use  the 
microscope  as  an  instrument  of  research  the  method  is  more  or 
less  strange.  Hence  a  short  description  of  the  general  principles 
may  not  be  out  of  place,  as  an  introduction  to  a  brief  review  of 
botanical  work  which  has  been  done  of  late  by  its  use. 

It  is  a  well-known  fact  that  small  particles  when  illuminated 
strongly  from  the  side  appear  to  the  observer  as  though  they 
were  self-luminous — diffraction  images  are  produced  and  ob- 
served by  the  eye.  By  means  of  these  diffraction  images, 
particles  which  are  too  small  for  observation  with  the  unaided 
eye  may  be  made  visible,  much  in  the  same  way  as  the  stars, 
although  point  sources  of  light,  are  visible  by  their  diffraction 
images. 

Every  one  must  have  observed  in  an  early  morning  walk  in 
the  woods,  how  fine  spiders'  webs,  illuminated  by  lateral  shafts 
of  sunlight  through  the  trees,  appear  as  incandescent  silver  lines, 
even  when  so  far  from  the  eye  as  to  be  quite  invisible  under 
ordinary  conditions. 

Prof.  Buller  1  has  also  shown  that  spores  of  certain  fungi, 
measuring  only  10  /x  or  even  less,  can  be  rendered  apparent  to 
the  unaided  eye  by  means  of  an  intense  beam  of  light  projected 
through  a  spore  cloud,  in  a  direction  perpendicular  to  the 
observer's  line  of  vision.  It  is  obvious  that  both  the  spider's 
web  at  a  considerable  distance  from  the  eye,  and  the  fungus 
spore  in  any  case,  are  outside  the  possibility  of  unaided  vision, 

1  Buller,  Prof.  A.  H.  R.,  Researches  o?t  Fungi,  vii.  p.  94.     (Longmans  &  Co., 
1909.) 

343 


344  SCIENCE  PROGRESS 

and  are  only  rendered  visible  by  the  scattering  of  light  which 
they  bring  about. 

This  general  method  of  illumination,  which  is  aptly  called 
dark-ground  illumination,  has  been  applied  to  observation  with 
the  microscope.  For  use  with  low  powers  of  the  microscope 
only,  the  method  has  long  been  known,  but  it  is  since  the 
beginning  of  the  present  century  that  the  great  development  of 
the  method  for  high-power  work  has  taken  place. 

In  1903,  by  the  employment  of  the  ultramicroscope,  Siedentopf 
and  Zsigmondy  showed  the  possibility  of  demonstrating  the 
presence  of  particles  which  were  below  the  limits  of  microscopic 
vision.  For  a  short  general  discussion  of  the  principles  and 
methods  of  ultramicroscopy  reference  may  be  made  to  the  article 
by  H.  Thirkill  in  this  journal  for  1909.1 

As  there  is  a  growing  confusion  with  regard  to  terminology, 
a  few  words  on  the  subject  may  not  be  out  of  place.  The  term 
"  ultramicroscope  "  is  best  confined  to  the  form  of  apparatus  with 
unilateral  illumination  as  originally  devised  by  Siedentopf, 
although  on  the  continent  there  is  a  great  tendency  to  extend 
the  term.  Sub-stage  condensers  especially  designed  to  give  dark- 
ground  illumination  should  be  called  dark-ground  illuminators, 
although  in  many  cases  it  is  possible  by  their  means  to  observe 
particles  which  are  below  the  limits  of  observation  with  the 
microscope  with  direct  illumination.  The  apparatus  of  Sieden- 
topf and  Zsigmondy  is  thus  a  special  means  of  producing  dark- 
ground  illumination  applicable  for  ultramicroscopic  observation  ; 
but  dark-ground  illumination  does  not  necessarily  imply  ultra- 
microscopic  vision. 

So  also  the  newer  illuminators,  the  Cardioid  condenser  of 
Zeiss  2  and  the  Ultracondenser  of  Leitz  3  are  best  regarded  as 
dark-ground  illuminators,  although  their  light-concentrating 
power  is  greater  than  that  of  the  ultramicroscope. 

Attention  will  now  be  turned  to  the  special  subject  under 
discussion,  and  an  indication  will  first  be  given  of  how  the 
method  is  best  applied  in  the  observation  of  suitable  plant 
structures. 

For  microscopic  observation,  botanical  objects  have  generally 

1  Thirkill,   H.,   "  Ultramicroscopy  and  Ultramicroscopic  Particles,"  Science 
Progress,  1909,  p.  55. 

2  v.  Zeiss  pamphlets  :  "  Mikro  306,"  "  Cardioid  Ultramicroscope." 

3  v.  Leitz  pamphlet* 


DARK-GROUND   ILLUMINATION  345 

to  be  mounted  between  an  object  slide  and  a  cover  slip,  so  that 
the  ultramicroscope  of  Siedentopf  is  quite  unsuitable  for  ordin- 
ary work ;  moreover,  the  method  gives  apparently  no  better 
results  for  this  class  of  work,  and  is  considerably  more  difficult 
to  use,  than  various  types  of  dark-ground  illuminators.  Most  of 
the  sub-stage  immersion  condensers  give  good  results  for  such 
work  as  the  study  of  small  transparent  structures,  or  for  the 
observation  of  the  intimate  arrangement  of  the  living  cell. 
Gaidukov  1  also  used,  with  considerable  advantage  in  the  case  of 
thick  objects,  Siedentopf 's2  method  of  stopping  out  the  central 
portion  of  the  front  lens  of  the  objective ;  but  observation  is 
rather  difficult  with  this  apparatus. 

Dry  objectives  give  on  the  whole  the  best  results,  but  the 
apochromatic  series  is  greatly  superior  to  ordinary  objectives. 
If  homogeneous  immersion  is  used,  a  suitable  stop  must  be 
introduced,  when  very  good  results  are  obtained.  A.  E.  Conrady 
has  recently  shown  3  that  the  maximum  resolving  power  with 
dark-ground  illumination  is  obtained  when  the  condenser  has 
not  less  than  three  times  the  N.A.  of  the  objective. 

The  centring  of  the  sub-stage  condenser  is  very  important. 
As  a  source  of  light  a  good  Nernst  lamp  is  sufficient  for  some 
work  on  ciliation  and  the  study  of  bacteria,  but  for  the  colloid 
structure  of  the  cell  a  small  arc  lamp  is  much  more  suitable  and 
shows  particles  which  are  missed  with  a  weaker  light.  As  a 
condenser  a  spherical  flask  of  water  is  very  useful,  and  prevents 
a  large  heating  effect  on  the  stage  of  the  microscope.  The 
object  slides — of  selected  thickness — and  cover  glasses  should 
be  of  good  quality,  specially  cleaned,  kept  in  alcohol,  and  rapidly 
dried  just  before  use. 

Work  of  a  botanical  nature  which  has  been  done  by  the 
application  of  this  method  falls  generally  into  two  main 
categories,  which  will  be  considered  separately.  The  method 
has  greatly  facilitated  the  observation  of  small,  transparent 
structures  such  as  cilia,  and  of  minute  bacteria  in  the  living  state, 
and  as  a  development  of  its  application  to  the  study  of  colloids 
it  has  been  applied  to  the  optical  analysis  of  the  living  plant  cell 
and  the  protoplast. 

1  Gaidukov,  v.  infra. 

2  Siedentopf,  v.  Zeiss  pamphlet  No.  228. 

3  Conrady,  A.  E.,/our.  Quekett  Micro.  Club,  xi.  1912,  pp.  475-80  ;  v,  abstract, 
Jour.  Roy.  Micro.  Soc,  April  1913,  p.  210. 


346  SCIENCE  PROGRESS 

I.  Study  of  Minute  Organisms  and  Ciliation 

In  1904  Rahlmann1  showed  that  the  method  of  Siedentopf 
and  Zsigmondy  could  be  used  with  advantage  for  the  study 
of  bacteria  in  the  unstained  condition.  Even  when  of  com- 
paratively large  dimensions  these  are  difficult  to  observe  in 
direct  illumination,  but  by  the  dark-ground  method  diffraction 
images  of  even  the  very  minute  ones  appear  as  bright  patches 
of  light  against  a  dark  background. 

Cotton  and  Mouton2  showed  that  observation  of  bacteria  was 
also  possible  with  their  special  total  reflection  apparatus,  and  it 
has  since  been  shown  that  the  sub-stage  dark-ground  illuminator 
is  in  general  very  suitable  for  observations  upon  living  bacteria. 

It  is  obvious  from  the  theory  of  the  method  that  true  images 
of  the  organisms  are  never  obtained,  but  that  generally  a  very 
good  idea  of  the  actual  form  is  given,  since  the  diffraction  images 
are  produced  by  objects  whose  dimensions  are  within  the  limits 
of  microscopic  vision. 

A  considerable  number  of  observations  have  been  made  on 
the  flagella  of  living  bacteria.  As  the  observations  are  mostly 
of  interest  to  the  specialist  they  will  not  be  discussed  further 
here.  For  a  list  of  some  of  the  more  important  papers  which 
have  appeared  among  a  large  literature,  reference  may  be  made 
to  the  work  of  Dr.  Gaidukov.3 

The  method  also  provided  a  means  for  study  of  the  moving 
cilia  of  motile  algae,  of  zoospores,  and  so  on.  These  extremely 
fine  and  transparent  structures  when  illuminated  by  this  method 
appear  as  bright  moving  lines  against  a  dark  background.  As 
is  well  known,  it  is  much  easier  to  see  a  bright  line  on  a  dark 
ground  than  a  dark  line  of  the  same  width  on  a  bright  ground, 
so  that  if  this  were  the  only  effect  the  visibility  of  these  cilia 
would  be  greatly  increased.  As  they  are  by  no  means  black 
lines  when  viewed  in  direct  illumination,  the  contrast  obtained 
by  the  two  methods  of  illumination  is  even  more  pronounced. 
V.  Ulelah4  has  recently  published  a  series  of  researches  on  the 
movements  of  cilia  of  various  organisms,  the  observations  being 
performed  by  the  aid  of  a  Zeiss  paraboloid.     The  following  list 

1  Rahlmann,  E.,  Munch.  Med.  Wochenschr.  Nr.  2,  7S.  1904. 

*  Cotton  and  Mouton,  Les  Ultramicroscopes,  etc.     Masson,  Paris,  1906. 
3   V.  infra. 

*  Ulelah,  V.,  Biol.  Centralblatl.,  191 1. 


DARK-GROUND   ILLUMINATION  347 

of  some  of  the  organisms  which  he  studied  will  give  an  idea  of 
the  general  utility  of  the  method  for  this  class  of  work  : 

Flagellata : 

Monas,  Bodo,  Euglena. 
Bacteria. 
Chlorophycece : 

Chlamydomonas,     Pandorina,     zoospores     of    Ulothrix, 

Coleochaete. 
Phazophyccce  : 

Scytosiphon. 
Bryophyta  : 

Spermatozoids  of  Marchantia. 

The  actual  results  obtained  are  hardly  of  general  interest, 
but  from  the  point  of  view  of  this  discussion  the  interest  attaches 
rather  to  the  method  employed. 

II.  Study  of  the  Plant  Cell  and  the  Protoplast 

The  great  utility  of  the  method  in  studying  the  structure  of 
colloids  had  been  demonstrated  by  Zsigmondy,  and  as  it  was 
generally  becoming  realised  that  protoplasm  was  colloidal  in 
nature,  a  study  of  the  plant  cell  by  this  method  was  likely  to 
throw  further  light  on  the  actual  state  involved. 

Observations  in  this  direction  were  first  made  by  Dr. 
N.  Gaidukov,  the  appearances  of  certain  objects  being  de- 
scribed in  the  Berichte  der  deutschen  botanischen  Gesellschaft  for 
1906.1  Most  of  the  published  work  on  the  subject  is  due  to 
Gaidukov,  and  a  full  account  of  his  researches  will  be  found  in 
his  work,  Dunkelfeldbeleuchtung  und  Ultramikroskopie  in  der 
Biologie  und  in  der  Medizin? 

In  the  practical  application  of  the  method  the  observer  is 
confronted  at  the  outset  with  numerous  experimental  difficulties, 
chiefly  perhaps  in  the  task  of  finding  suitable  material  for  in- 
vestigation. For  observation  with  a  sub-stage  condenser  the 
material  must  be  mounted  in  water  in  the  usual  way,  and  for 
good  results  must  be  only  one  cell  in  thickness,  otherwise  the 

1  Gaidukov,  N.,  Berichte  d.  d.  bot.  Ges.,  1906  ;  Unters.  mit  Hilfe  des  Ultra- 
mikroskopes,  p.  107;  Weitere  Unters.,  etc.,  p.  155;  Uber  tilt.  Eigenschaften  der 
Protoplasten,  p.  192  ;   Ult.  Unters.  der  Stdrkekomer,  etc.,  p.  581. 

2  Gaidukov,  N.,  Dunkelfeldbeleuchtung  und  Ultramikroskopie  in  der  Biologie 
und  in  der  Medizin.     (Gustav  Fischer,  1910,  8  marks.) 


348  SCIENCE   PROGRESS 

greater  portion  of  the  light  is  scattered  by  the  lower  cell  layer. 
This  at  once  limits  the  field  of  choice ;  sections  with  torn 
cell  walls  and  escaping  contents  are  generally  useless,  the 
scattering  effect  of  these  preventing  any  good  observation  of  the 
contents  of  unbroken  cells.  Unicellular  organisms,  filamentous 
Algae,  leaves  of  some  water-plants,  leaves  of  some  Bryophytes, 
fungal  hyphae,  and  plant  hairs  give  most  of  the  categories 
from  which  selection  can  be  made.  There  are  still  other 
desiderata  for  good  observations  to  be  possible.  The  diameter 
of  the  cell  or  the  filament  must  not  be  very  small,  as  if  this  is 
the  case  the  diffraction  effects  produced  by  the  walls  greatly 
interfere  with  observation  of  the  cell  contents.  The  walls 
should  be  free  from  markings  and  generally  optically  homo- 
geneous, the  slightest  heterogeneity  again  preventing  satisfactory 
study  of  the  cell  contents.  If  possible  also  chromatophores 
should  not  be  too  conspicuous  as  the}''  also  tend  to  scatter  light, 
though  not  very  strongly  in  most  cases,  but  their  images  mask 
those  of  some  of  the  smaller  particles. 

The  scarcity  of  good  material  is  undoubtedly  the  greatest 
barrier  to  the  comprehensive  use  of  the  method.  Some  of  the 
best  objects  so  far  examined  are  :  Spirogyra,  Mougeotia,  Desmids, 
staminal  hairs  of  Trade scantia,  Myxomycetes,1  the  leaf-edge  cells 
of  Elodea  canadensis,  root  hairs,  hairs  of  certain  flowering 
plants,2  and  the  hyphae  of  Saprolegnia  and  other  fungi. 

Only  one  or  two  filaments  of  the  Algae,  a  single  leaf  of 
Elodea  as  clean  as  possible,  and  so  on,  should  be  used  to  get  the 
maximum  light  effect.  There  is  no  need  to  use  specially  prepared 
"  ultra  water  "  for  this  kind  of  work,  ordinary  distilled  water 
being  free  enough  from  particles,  and  in  any  case  it  is  almost 
impossible  to  prevent  such  from  escaping  from  broken  cells  into 
the  mounting  liquid. 

In  many  cases  the  appearance  of  a  living  cell  when  first 
viewed  by  this  method  is  undoubtedly  surprising,  especially  if 
no  previous  study  of  colloids  by  the  method  has  been  made. 
Perhaps  it  may  be  said  that  a  little  study  of  the  cell  in  this  way 
serves  to  emphasise  more  strongly  than  ever  the  fact  that  the 
single  cell  is  a  system  of  great  activity.  This  is  the  case  for 
some  cells  only,  as  will  be  seen  below,  and  obviously  we  cannot 

1  Gaidukov,  I.e. 

2  Price,  S.  R.,  "Observations  with  Dark-ground  Illumination  on  Plant  Cells," 
Proc.  Camb,  PHI.  Soe.,  vol.  xvi.  p.  481. 


DARK-GROUND   ILLUMINATION  349 

postulate  a  similar  organisation  and  structure  for  cells  of  all 
types. 

Spirogyra  is  undoubtedly  one  of  the  best  and  most  easily 
obtained  objects,  and  this  part  of  the  subject  can  hardly  be 
introduced  better  than  by  a  short  description  of  the  general 
appearances  presented  by  the  cells  under  this  type  of  illumina- 
tion. A  species  of  rather  large  diameter  with  a  fairly  loose 
spiral  chloroplast  is  most  suitable,  but  any  species  of  not  too 
small  diameter  will  suffice. 

As  is  well  known,  the  protoplast  forms  a  layer  lining  the 
wall  of  the  cell ;  in  this  layer  is  the  chloroplast,  while  the  nucleus 
is  suspended  in  the  central  vacuole  by  cytoplasmic  threads.  Under 
dark-ground  illumination  the  protoplasmic  layer  is  seen  to 
contain  large  numbers  of  small  particles,  manifested  of  course  as 
bright  points  of  light,  and  in  the  living  cell  exhibiting  a  constant 
oscillating  motion,  generally  about  a  small  orbit.  As  is  well 
known,  the  protoplast  in  direct  illumination  appears  as  practic- 
ally homogeneous.  These  particles  (which  are  probably  to  be 
classed  as  sub-microns  x)  can  be  brought  into  focus  above,  that 
is  outside  the  chloroplast,  so  that  without  doubt  they  are  actually 
in  the  protoplasm.  So  also  these  particles  can  be  seen  in  the 
cytoplasmic  threads  which  suspend  the  nucleus,  where  they  also 
show  this  oscillatory  movement.2  More  careful  study,  and  the 
examination  of  plasmolysed  cells,3  reveal  the  presence  of  smaller 
particles  in  the  protoplasm,  which  are  undoubtedly  completely 
ultramicroscopic. 

On  focussing  below  the  upper  part  of  the  chloroplast,  that 
is  to  say  in  the  vacuole,  particles  of  much  larger  size  can  usually 
be  observed  also  in  oscillation.  These  particles  can  often  be  seen 
on  careful  examination  of  the  cell  in  transmitted  light,  and  they 
are  obviously  of  quite  another  order  of  magnitude.  Gaidukov 
thinks  that  they  are  particles  of  some  colloid  nature  in  the  cell 
sap.  Such  particles  seem  to  occur  quite  frequently  in  the  sap 
vacuoles  of  plant  cells,  and  on  account  of  this  they  may  be 
referred  to  as  "  sap  particles  "  or  "  sap  inclusions." 

The  chloroplast  shows  little  detailed  structure,  giving  rather 

1  The  terms  are  generally  thus  applied  :  Microns  are  small  particles  visible 
with  direct  illumination  in  the  microscope.  Sub-microns  are  ultramicroscopic,  but 
may  be  made  visible  by  methods  of  dark-ground  illumination.  Amicrons  are 
below  the  limits  of  observation. 

2  Price,  loc.  cit. 

3  Price,  from  unpublished  work. 


350  SCIENCE   PROGRESS 

a  dull  reflection  image,  while  the  pyrenoids  appear  as  bright 
spots.     The  cell  wall  itself  is  optically  homogeneous. 

The  oscillating  movement  of  the  particles  both  in  the  proto- 
plasm and  cell  sap,  already  referred  to,  is  undoubtedly  of  the 
nature  of  a  Brownian  movement.  Since  the  great  impetus  given 
to  the  study  of  colloids  by  Siedentopf  and  Zsigmondy's  work, 
this  phenomenon  has  been  brought  into  fresh  prominence. 
Discovered  by  a  botanist,  Dr.  Brown,  in  1827  (after  whom  it  is 
called),  it  was  shown  to  extend  to  particles  of  extremely  minute 
and  ultimately  of  ultramicroscopic  size,  though  here  the  move- 
ment is  very  much  more  rapid.  It  has  been  shown  that  the 
rapidity  of  motion  varies  inversely  with  the  size  of  the  particles, 
and,  as  a  result  chiefly  of  Perrin's  beautiful  researches,  it  has 
been  shown  almost  without  doubt  that  the  movement  is  a  direct 
expression  of  the  actual  molecular  movement  in  the  surrounding 
fluid.  Zsigmondy  observed  that  the  minute  particles  present  in 
liquid  colloid  solutions— of  the  nature  of  "  sols  " — showed  such  a 
Brownian  movement  in  a  very  striking  manner. 

Spirogyra  is  quite  good  for  the  stud3'  of  this  Brownian  move- 
ment, for  the  larger  sap  particles  can  be  seen  to  oscillate  much 
more  slowly  than  the  minute  particles  of  the  protoplasm, 
illustrating  the  variation  of  the  rate  of  movement  with  variation 
in  size  of  the  particles. 

Very  similar  appearances  are  given  by  other  cells  examined. 
Mongeotia,  for  example,  shows  a  similar  structure,  with  well- 
marked  Brownian  movement,  but  on  account  of  the  character  of 
the  chloroplast  is  not  quite  so  suitable  for  observation. 

The  staminal  hairs  of  Tradescantia ,  used  by  Gaidukov,  have 
a  cell  wall  which  is  optically  heterogeneous,  and  this  interferes 
with  the  clear  observation  of  the  cell  contents.  Cells  in  four 
different  states  of  vitality  were  examined. 

1.  Young  cells  without  sap  vacuoles. — Particles  with  strong 
Brownian  movement  were  present  in  the  protoplasm. 

2.  Older  cells  with  vacuoles  and  streaming  protoplasm. — In 
spite  of  which  the  Brownian  movement  was  clearly  seen. 

3.  Dying  cells. — A  moderately  active  movement  could  be  seen. 

4.  Dead  cells. — The  protoplast  had  coagulated  and  the  con- 
stituent particles  were  motionless. 

In  the  young  cells  the  Brownian  movement  is  more  difficult 
to  see,  on  account  of  the  closer  aggregation  of  the  particles  in 
the  complex. 


DARK-GROUND   ILLUMINATION  351 

Myxomycetes  in  the  "  amoeba  condition  "  were  also  examined, 
and  generally  showed  the  protoplasm  filled  with  moving 
particles. 

In  Vaucheria,  Cladophora,  (Edogonium,  and  Stigeoclonium,  the 
chloroplasts  generally  prevent  the  clear  observation  of  the 
cytoplasm,  so  that  these  are  not  good  objects  for  study. 

The  leaf  edge  of  Elodea  canadensis 1  makes  quite  an  instruc- 
tive object.  The  leaf  edge  is  only  one  cell  thick,  and  the  cell 
walls  are  very  clear.  The  protoplast  usually  lines  the  cell  wall, 
while  the  chloroplasts  of  these  edge  cells  are  comparatively  few 
in  number  and  relatively  inconspicuous  under  this  illumination. 
"  Sap  particles  "  are  nearly  always  present  in  the  cell  sap.  The 
protoplasm  is  seen  to  contain  very  numerous  small  particles, 
which  exhibit  the  usual  Brownian  movement.  After  a  time, 
circulation  of  the  protoplasm  usually  occurs,  and  the  particles 
can  be  clearly  seen,  as  they  are  carried  on  by  the  stream,  still 
executing  their  Brownian  oscillations.  The  sap  particles  are 
usually  unaffected  by  this  circulation. 

Gaidukov2  states  that  towards  the  cell  wall  and  the  vacuole 
the  hydrosol  is  covered  by  a  layer  of  gel — "  hydrogelschict  " — 
which  is  produced  by  the  contact  of  the  hydrosol  with  the 
electrolytes  of  the  cell  sap.  These  electrolytes  coagulate  the 
hydrosol  and  protect  the  inner  portion  of  the  complex  from 
further  reaction  with  the  solution — the  reversible  portion  from 
forming  a  colloid  solution  with  the  water,  and  the  irreversible 
portion  from  coagulation.  There  is,  of  course,  considerable 
reason  for  identifying  this  layer  with  the  plasmahaut ;  but  there 
is  here  room  for  a  great  deal  of  work. 

In  other  cases  of  cells  examined  the  protoplasm  presents 
another  appearance.  No  discrete  particles  can  be  made  out  in 
the  protoplasm  and  no  motion  can  be  detected.  In  some  cases 
the  protoplasm  has  a  somewhat  mottled  appearance,  recalling 
perhaps  the  network-like  structure  as  postulated  by  Butschli 
and  other  observers. 

On  the  death  of  a  cell  which  shows  a  structure  with  moving 
particles,  a  complete  cessation  of  the  movement  in  the  proto- 
plasm is  brought  about.  This  is  also  naturally  the  case  when 
fixing  agents  are  allowed  to  act  on  the  living  cell.  The  proto- 
plasm then  appears  as  a  mass  of  overlapping  diffraction  images — 

1  S.  R.  Price,  I.e. 

2  Gaidukov,  Beriehte,  I.e.  p.  587;  Dunkelfeld.,  etc.,  p.  62. 


352  SCIENCE   PROGRESS 

an  appearance,  of  course,  indicating  a  heterogeneous  structure 
for  the  fixed  plasma. 

The  living  material  of  the  plant  cell  in  many  cases  thus 
exhibits  a  structure  which  we  have  been  led  to  attribute  to  that 
type  of  colloid  solution,  the  hydrosol.  This  was  perhaps  the 
most  important  fact  established  by  Gaidukov's  researches.  As 
has  been  mentioned  above,  with  the  gradual  development  of 
the  study  of  the  physics  and  chemistry  of  colloids  it  became 
increasingly  evident  that  the  protoplasm  was  to  be  regarded  as 
a  complex  of  this  type.  Thus  the  activity  of  the  cell  depends  in 
a  certain  measure  on  the  activity  of  the  colloid  hydrosol,  and 
the  death  of  the  cell  and  coagulation  of  the  colloid  complex  are 
probably  closely  inter-related ;  in  fact,  we  may  say  that  the 
coagulation  of  the  hydrosol  causes  the  cessation  of  living  pro- 
cesses in  the  protoplasm,  and  the  irreversible  change  hydrosol 
— hydrogel,  is  synonymous  with  death.  This,  at  least,  appears 
to  be  Gaidukov's  view. 

There  are,  however,  those  cases  of  cells  which  do  not  appear 
to  show  the  hydrosol  structure,  to  be  considered ;  for  here  also, 
in  most  cases,  the  protoplasm  must  certainly  be  regarded  as  in 
an  actively  living  state.  It  may  be  said  that  most  cells  which 
permitted  of  favourable  observation  did  show  Brownian  move- 
ment, and  Gaidukov  considers  that  the  cases  referred  to  may 
possibly  be  explained  as  follows  :  the  particles  in  a  young  cell 
are  much  more  difficult  to  make  out,  and  the  Brownian  move- 
ment is  more  difficult  to  observe,  chiefly,  it  would  seem,  through 
the  close  proximity  of  the  particles  of  the  disperse  phase  in 
the  continuous  phase.  The  same  reasoning,  he  thinks,  may 
apply  to  these  other  cells,  the  particles  being  too  close  and 
too  small  to  manifest  their  motion  by  this  method.  What- 
ever the  explanation  may  be,  however,  there  is  no  doubt 
that  the  protoplasm  is  not  to  be  regarded  as  a  single  type 
of  complex,  but  a  series  of  different  colloids  with  differing 
properties  in  different  cases — "  the  protoplasm  is  very  poly- 
morphic."1 

A  short  summary  of  the  main  conclusions  reached  by 
Gaidukov  may  be  useful,  although  involving  some  repetition  of 
what  has  already  been  described.2 

1  Gaidukov,  I.e.  p.  61. 

2  Gaidukov,  v.   Bechold,  Die  Koll.  in  Biol,  und  Med.,  p.  256.     (Steinkopff, 
Dresden,  1912.) 


DARK-GROUND   ILLUMINATION  353 

i.  The  small  particles  with  Brownian  movement  generally 
seen  in  favourable  cases  showed  the  protoplasmic  colloid  to  be 
of  the  nature  of  a  hydrosol. 

2.  These  particles  can  unite  with  one  another,  forming  aggre- 
gates ;  or  break  up,  thus  decreasing  or  increasing  in  number. 
(This  may  be  related  to  variations  in  the  general  vitality  or 
nutritive  condition  of  the  cell.1) 

3.  In  other  cases,  cells  which  were  undoubtedly  living,  and 
generally  speaking  well  nourished,  failed  to  show  any  such 
movement,  but  the  motion  may  have  been  masked  by  the  small- 
ness  and  close  proximity  of  the  particles. 

4.  The  spontaneous  change  from  the  sol  state  to  the  gel  or 
vice  versa  was  not  observed  in  the  living  cell.  On  the  death  of 
a  cell,  however,  complete  coagulation  of  the  sol  takes  place,  with 
cessation  of  the  Brownian  movement,  while  the  gel  thus  formed 
gives  an  appearance  of  crowded  diffraction  images  under  dark- 
ground  illumination. 

5.  The  colloid  complex  of  the  protoplasm  consists  of  a 
reversible  and  an  irreversible  portion.2  This  is  deduced  from 
the  behaviour  of  broken  living  and  dead  cells  in  water.  Some 
particles  produce  a  colloid  solution  with  the  water — the  rever- 
sible portion — while  others  aggregate  and  remain  together — the 
irreversible  portion. 

6.  Since  the  protoplasm  contains  an  irreversible  colloid,  the 
taking  up  of  an  electrolyte  by  the  cell  should  result  in  its 
coagulation.  Some  evidence  is  brought  forward  to  show  this, 
but  the  matter  requires  further  investigation. 

It  may  perhaps  be  said  that  the  method  has  not  realised  to 
the  full,  the  expectations  of  those  who  hoped  it  would  clear  up 
definitely  certain  vexed  questions  of  cell  structure.  The  idea  of 
the  method  generally  suggests  the  possibility  of  its  application 
to  the  cytological  study  of  the  nucleus  and  the  behaviour  of  the 
chromosomes  in  the  living  nucleus.  In  this  direction  but  little 
help  has  been  derived  from  the  method  up  to  the  present,  and 
only  in  a  few  cases  has  nuclear  structure  been  observed.  The 
difficulty  of  choosing  suitable  material  is  even  greater  than  ever, 
and  generally  only  resting  nuclei  have  been  observed.  Where 
this  has  been  done,  the  nucleus  seems  to  show  little  except  the 

1  v.  Bechold,  I.e.  p.  256. 

2  See  any  work  on  colloids,  e.g.   Introduction  to  Physics  and  Chemistry  of 
Colloids,  Emil  Hatschek.     (T.  &  A.  Churchill,  1913,  2s.  6d.) 

23 


354  SCIENCE   PROGRESS 

ordinary  colloid  structure.1  It  may  be  that  further  careful  use 
of  the  method  will  add  to  our  knowledge  of  the  behaviour  of  the 
nucleus  in  the  living  state,  but  on  account  of  its  limitations 
the  method  can  never  become  a  general  one  for  the  study  of 
nuclear  cytology. 

These  limitations  are  also  an  obstacle  in  the  way  of  progress 
by  the  method,  in  the  extended  study  of  the  intimate  physics 
and  constitution  of  the  plant  cell.  As  has  been  indicated,  the 
protoplasm  is  by  no  means  constant  in  characters  in  the  cases 
which  have  been  examined,  so  that  for  a  logical  study  of  cell 
physiology  in  relation  to  the  plant  the  component  cells  in  ques- 
tion must  be  examined.  There  is  no  doubt,  however,  that  the 
method  has  given  us  a  further  insight  into  the  actual  structure 
of  the  living  cell,  and  considering  its  comparatively  recent 
development  these  results  are  sufficient  to  establish  it  as  an  im- 
portant method  of  research.  Certain  attributes  of  cell  structure 
must  be  of  more  or  less  general  application,  and  along  these  lines 
the  results  should  be  of  great  use. 

No  attempt  has  been  made  in  the  present  brief  account  to 
discuss  the  problems  which  arise  from  considerations  of  the 
results  obtained.  It  has  been  rather  desired  to  give  in  outline 
the  methods  of  practical  application  of  the  principle  to  botanical 
work,  and  to  state  without  any  full  discussion  the  main  results 
which  have  so  far  been  achieved.  In  the  study  of  colloids  the 
method  is  now  an  indispensable  one,  and  undoubtedly  it  must 
become  so  in  researches  into  the  behaviour  of  the  colloid  proto- 
plast. 

1  v.  Gaidukov ;  also  from  unpublished  work  of  the  Author. 


SCIENTIFIC    SPELLING 

I.— By  SIR  HARRY  JOHNSTON,  G.C.M.G.,  K.C.B.,  D.Sc. 

The  Editor  of  this  review  has  asked  me,  who  have  just  published 
a  work  on  Phonetic  Spelling  through  the  Cambridge  University 
Press,  to  write  on  the  subject  of  '  Scientific  Spelling '  in  the 
pages  of  this  quarterly. 

In  some  ways  I  prefer  the  Editor's  suggested  title  to  that 
which  covers  my  book,  for  any  change  of  a  radical  nature  which 
we  may  attempt  to  make  in  the  orthography  of  English  or  any 
other  well-established  tongue  should  be  scientific  as  well  as 
what  may  be  called  phonetic ;  that  is  to  say,  that  as  nearly 
as  possible  we  should  interpret  the  utterances  of  the  human 
voice  with  scientific  exactitude,  classifying  the  sounds — vowel 
and  consonant — in  relation  to  the  parts  of  the  mouth  and  throat 
which  utter  them. 

Phonetic  or  scientific  spelling  must  be  logical.  All  sounds 
which  we  describe  as  single  because  it  is  exceedingly  difficult, 
if  not  impossible,  to  split  them  up  into  component  utterances, 
must  be  represented  by  distinct  single  letters,  and  compound 
sounds  be  expressed  by  the  letter  symbols  of  their  component 
parts,  only  a  very  few  exceptions  being  made  in  cases  where 
the  compound  sounds  are  so  nearly  fused  that  division  becomes 
an  act  of  preciosity,  or  where  the  construction  is  so  common 
and  so  frequently  uttered  that  it  should  be  given  one  simple  and 
easily  formed  symbol.  A  case  in  point  is  the  sound  of  o  in 
'bone'  and  'mow.'  This  in  most  reasonable  phonetic  systems 
is  represented  by  the  Greek  letter  &>,  whether  or  not  this  was 
the  value  of  the  omega.  In  reality  it  is  a  fusion  of  the  separate 
vowel  sounds  of  6  and  it.  Similarly,  in  the  scientific  alphabet 
I  propose,  and  in  the  majority  of  those  already  adopted  by 
scientific  men  abroad,  the  letter  c  stands  for  the  English  ch  in 
'church'  or  the  Italian  c  in  'cielo'  or  '  cera,'  and  j  likewise  has 
its  English  value,  instead  of  being  used  as  the  consonantal  i  (y). 
Logically,  it  would  be  more  correct  to  express  c  by  tsh  (if  one 
used  the  orthography  of  the  India  Office  or  Royal  Geographical 

355 


356  SCIENCE   PROGRESS 

Society),  and  j  by  dzh.  Personally,  I  object  to  adopting  what 
may  be  called  the  India  Office  alphabet  as  the  final  scientific 
orthography  for  the  rendering  of  all  tongues  all  over  the  world  ; 
for  the  reason  that  it  is  not  strictly  logical,  and  does  not  take 
into  account  the  need  for  expressing  a  variety  of  sounds  and 
combinations  of  sounds  which  occur  not  only  in  English  but  in 
many  other  important  languages.  Take,  for  example,  the  matter 
of  aspirated  letters.  In  English,  and  very  much  so  in  Arabic 
and  the  languages  of  India  and  of  East  Africa,  we  have  aspirated 
consonants — th,  ph,  dh,  sh,  kh,  ch,  and  zh,  which  require  the  h  to 
express  the  aspiration  that  follows.  This  need  precludes  the 
use  of  th  and  dh  to  express  the  English  th  in  '  this '  and  '  think,' 
and  zh  for  the  French  j  or  the  z  in  '  azure,'  or  ph  in  '  physic ' 
(which  last  we  pronounce  literally  as  p  h  in  '  Clapham '  and 
*  haphazard  ').  The  Arab  name  of  the  Muhammadan  university 
at  Cairo— Al-Azhar — is  pronounced  '  Az-har,'  and  not  as  if  it 
were  written  in  French,  '  Ajar.'  A  large  proportion  of  the  klis> 
that  we  meet  with  in  Indian  words  are  not  pronounced  like  the 
ch  in  the  Scotch  '  loch,'  but  like  the  aspirated  k  in  '  bloc£/zead.' 

Consequently,  we  need  in  our  scientific  alphabet  single 
symbols  for  the  German  and  Scottish  ch  (or  the  kh  so  con- 
stantly used  in  transcribing  Arabic,  etc.),  for  the  modern  Greek 
X,  for  the  quite  different  ch  in  the  English,  Spanish,  and  Indian 
languages,  for  the  gh  represented  by  the  Arabic  p,  for  th  in 
'  theory '  and  th  in  '  that,'  for  the  sh  and  zh.  We  require  to 
discriminate  between  the  ordinary  s  represented  by  s  in  '  sea ' 
and  55  in  '  fussy,'  and  the  alveolar  Arabic  5  (,j*),  between  the 
German  ch  in  '  machen '  and  that  in  '  ich  '  and  '  dicht.'  (This 
last,  represented  in  the  standard  alphabet  of  Lepsius  by  %,  is 
practically  the  pronunciation  of  the  Polish  £,  and  the  sound  is 
alleged  to  occur  in  certain  forms  of  East  African  speech.  It  is 
a  transition  between  the  English  sh  and  the  German  ch — 5  and  %.) 
Then,  again,  we  must  provide  a  symbol  for  the  Arabic  d  (^>), 
V(A»),  and  z  (Jo),  most  of  which  are  alveolar,  almost  palatal  pro- 
nunciations of  the  ordinary  d,  t,  and  z.  The  nasal  consonant — 
expressed  clumsily  by  ng  in  most  modern  European  tongues, 
and  still  more  clumsily  by  the  apposition  of  two  gutturals  in 
Greek — must  have  a  symbol  all  to  itself,  and  this  is  most  con- 
veniently supplied  by  the  n.  It  is  true  that  n  is  associated  in 
Spanish  with  the  palatalised  n,  but  this  is  really  nothing  but 
ny%  two  separate  sounds  combined.     We  are,  however,  used  to 


SCIENTIFIC   SPELLING  357 

the  tilde  (~)  in  Portuguese  and  in  a  good  many  conventional 
alphabets  as  a  sign  of  nasalisation.  To  employ  the  ng  for  this 
suggests  the  carrying  on  of  the  g  sound.  This  no  doubt  was 
the  original  pronunciation  of  ng  in  English  as  well  as  in  the 
Teutonic  languages  of  the  Continent,  but  in  modern  German 
and  Dutch,  for  example,  ng  has  become  identified  exclusively 
with  n  ;  and  if  one  wishes  (say,  in  transcribing  words  in  the 
Malay  Archipelago)  to  give  it  the  value  of  the  English  ng  in 
'  linger,'  '  finger,'  one  has  to  write  it  ngg.  If  it  is  required  to 
express  the  value  of  fik  in  '  think '  or  '  blinker,'  it  must  be  written 
ngk.  Ng  in  English  writing  is  a  most  puzzling  combination  to 
the  foreigner.  When  it  terminates  a  word  it  is  pronounced  like 
n,  as  also  when  it  occurs  in  the  middle  of  words  like  '  singing,' 
1  clinging.'  Where  it  is  derived  anciently  from  the  French  it  is 
pronounced  like  nj,  as  '  ranging,'  '  manger,'  '  danger.'  And  it 
is  given  its  logical  pronunciation  as  fig  in  '  finger,'  '  anger,' 
1  Rangoon,'  etc. 

The  value  of  the  modern  Greek  gamma  (7),  of  the  Arabic 
ghain,  and  of  the  velar  r  in  modern  German  and  French  pro- 
nunciation is  best  represented  by  the  Greek  7  ;  though  in  the  case 
of  the  velar  r,  which  exists — unacknowledged — in  the  modern 
pronunciation  of  French,  German,  Danish,  and  Northumbrian 
English,  this  ugly  variation,  if  it  is  to  be  encouraged  and 
recognised  at  all,  is  most  conveniently  expressed  by  r. 

In  the  scientific  alphabet  I  propose,  the  four  distinct  clicks 
of  Hottentot  and  Zulu  (and  four  out  of  the  numerous  Bushman 
clicks)  are  represented  by  clearly  differing  modifications  of  the 
letter  c,  as  these  prove  to  be  easy  to  write  and  constitute  a  com- 
promise between  the  inconvenient  types  of  Lepsius  and  the 
inadmissible  rendering  of  these  clicks  in  the  South  African 
alphabet  by  the  letters  c,  q,  x,  and  qc.  The  other  and  more 
obscure  clicks  in  Bushman  can  be  distinguished  by  the  symbols 
proposed  by  Bleek  and  other  writers  on  the  Bushman  language. 
It  is  impossible  to  follow  official  South  Africa  in  the  allocation 
of  c,  q,  x,  and  qc  for  the  four  click  sounds  in  Zulu  and  Hottentot 
(one  of  which  is  sometimes  employed  in  Sesuto),  because  c  is 
already  required  for  tsh,  q  is  the  natural  equivalent  of  the  Arabic 
j  (which  also  occurs  in  Hebrew,  Phoenician,  and  most  of  the 
Semitic  tongues,  besides  in  certain  Hamitic,  Asiatic,  Oceanic, 
and  African  languages),  and  x  must  be  taken  from  the  Greek 
(as  x  or  x)  to  represent  the  guttural  of  widespread  use  heard 


358  SCIENCE   PROGRESS 

in  the  Scottish  ch  and  inadequately  represented  hitherto 
by  kh. 

When  we  add  the  Polish  /  (/)  and  the  strong  Arabic  h  (//), 
s  and  z  for  the  palatalised  5  and  z  (English  sh  and  zh),  d  for  the 
th  in  '  this,'  and  ^  for  the  th  in  '  think '  to  the  already  familiar 
m,  b,  w,  v,  p,  f,  s,  z,  d,  t,  n,  /,  rty,  n,  k,  g,  q,  and  h,  we  have  all  the 
consonantal  symbols  which  can — in  reason — be  possibly  required 
for  writing  and  printing  all  the  known  languages  of  the  world. 

As  regards  vowel  sounds,  we  have  first  of  all  to  recognise 
the  curious  fact  that  some  which  would  appear  to  be  primordial 
and  simple  vowel  sounds  (amongst  those  first  uttered  in  human 
speech)  have,  in  the  alphabets  of  the  Mediterranean  which  laid 
the  foundation  of  our  own  Greek,  Latin,  Cyrillic,  German,  and 
Irish  letters,  received  no  single,  individual  equivalent  in  a  sign 
without  a  special  accent  or  a  diacritic  mark.  Such  primordial 
vowels  of  world-wide  use  are  0  as  in  '  store,'  or  as  represented 
by  the  diphthong  aw  or  au  in  English  ;  6  like  the  English  u  in 
1  hurt,'  ea  in  '  heard,'  or  ir  in  '  bird  '  (the  German  0,  the  French 
ceu,  the  Scandinavian  <j>) ;  n  as  in  '  hut ' ;  a  as  in  '  hat ' ;  the 
Welsh  y  and  the  Slavic  y  or  hi.  The  Greek  u  (upsilon),  heard 
in  modern  French  and  in  Dutch  and  met  with  in  many  modern 
forms  of  civilised  and  savage  speech,  secured  for  itself  the 
ordinary  u  symbol  in  Greek,  leaving  its  original  sound  to  be 
represented  by  two  letters — on  ;  but  in  Latin  the  Greek  u  (i'l) 
came  to  be  represented  by  y,  and  this  value  of  y  is  still  con- 
tinued under  some  conditions  in  Germany,  and  much  more  so  in 
Scandinavia.  In  Western  Europe  the  Latin  symbol  y  faded 
into  a  light  i  sound  as  a  vowel,  or  became  the  equivalent  of  the 
consonantal  i  which  in  other  directions  was  taking  the  form  of/ 
It  has  been  frequently  suggested  by  German  phonologists  that 
we  should  represent  the  French  u  or  the  German  u  by  the  Latin 
y  and  recur  to  /  for  the  consonantal  i.  But  on  the  whole,  for 
reasons  which  I  have  given  at  length  in  my  book  on  Phonetic 
Spelling,  I  think  it  is  wiser  to  continue  the  use  of/  for  the 
palatal  combination  dz,  and  retain  y  for  expressing  the  con- 
sonantal it  a  sound  between  vowel  and  consonant  which  links 
guttural  and  palatal  consonants  together,  yis  as  necessary  as 
a  separate  symbol  (instead  of  using  the  short  /)  as  w  is  to  repre- 
sent a  consonantal  it,  for  w,  though  nearly  equivalent  to  the 
short  u,  is  also  a  semi-consonant  and  is  closely  connected  in 
speech  development  with  b,  v,  and  p ;  and,  strange  to  say,  with 


SCIENTIFIC   SPELLING  359 

g  and  7.  In  common  with  others  writing  on  phonetics,  I  adopt 
in  slightly  modified  form  the  Greek  omega  as  an  equivalent  for 
the  diphthongal  sound  of  o  in  '  bone.'  I  adopt  the  italic  a  as  the 
equivalent  of  the  sound  of  u  in  '  but,'  or  of  the  short  a  met  with 
in  Arabic  and  so  many  Indian  tongues,  also  in  parts  of  West 
Africa.  This  vowel  (a)  is  of  course  extremely  common  in 
modern  English  and  represents  the  perversion  of  the  short  u 
which  began  in  Elizabethan  times.  This  perversion  had  its 
analogue  on  the  Continent,  where  we  find,  earlier  than  the 
period  mentioned,  the  diphthonging  of  an  original  Teutonic  u 
into  au  ('  hus  '  into  '  haus  ').  At  the  same  time  in  England,  and 
very  slightly  in  Holland  and  Flanders,  the  short  11  was  pro- 
nounced like  a,  which  is  really  an  extremely  abbreviated 
pronunciation  of  the  diphthong  au.  We  see  this  in  the  rela- 
tions of  'out'  and  'utter,'  'bout'  and  'but'  (the  surname 
Butterfield  is  really  derived  from  one  of  the  many  Flemish 
names  in  Eastern  England,  and  was  originally  Bouterfeld,  or 
the  '  outer  field,'  as  contrasted  with  Binnenfeld  or  Binfield). 
In  transcribing  English,  as  well  as  various  Oriental  tongues, 
it  is  highly  necessary  to  distinguish  between  the  short  a  sound 
and  the  long ;  the  short  being  represented  by  the  unaccented 
alt/  or  fatha  in  so  many  Arabic,  Indian,  or  Persian  words,  as 
contrasted  with  the  long  alt/  This  short  a  is  sufficiently  near 
to  the  English  sound  of  u  in  '  but '  as  to  be  represented  by  the 
same  symbol, «,  while  the  long  sound  is  best  indicated  uniformly 
by  the  original  type — a.  If  we  make  this  distinction — that  is  to 
say,  use  our  existing  italic  a  (made  erect  for  Roman  type  and 
supplied  with  an  enlarged  form  as  a  capital),  and  reserve  a  in 
its  Roman  form  with  an  equivalent  italic  for  the  sound  of  a  in 
'  father,'  '  hard,'  etc.  (the  Continental  a) — we  shall  make  phonetic 
transcription  much  simpler.  Similarly,  a  convenient  symbol 
for  the  sound  of  a  in  '  hat ' — a  very  prominent  sound  in  English 
and  in  North  African  Arabic — is  a.  This  was  probably  its 
equivalent,  more  or  less,  in  Anglo-Saxon  pronunciation.  The  a 
in  '  hat'  is  really  a  very  short  pronunciation  of  the  diphthong  ea 
or  eo.  Ea  in  Anglo-Saxon  was  probably  pronounced  exactly  as 
we  pronounce  it  in  '  pear '  (or  like  a  in  '  stare ').  In  modern 
English  this,  however,  is  perhaps  most  logically  rendered  by  eb\ 
and  the  fused  letters  se  are  best  reserved  for  the  short  sound  in 
1  hat '  or  '  mad.' 

One  cannot  consider  the  question  of  the  phonetic  writing  of 


360  SCIENCE   PROGRESS 

English  without  dealing  with  that  of  French.  I  would  propose 
for  the  peculiar  French  sounds  represented  by  the  diphthong 
eu  and  the  nasalised  e  and  i  in  many  words,  the  symbol  ft  which 
when  nasalised  has  only  to  be  surmounted  by  a  ^  ;  thus  'peu' 
would  be  spelt pf,  and  'pin'  would  be  written  pt,  'bien,'  bis,  and 
1  rien,'  rit.  For  the  French  unaccented  e  as  heard  in  '  le,'  '  de,' 
'  menu,'  I  would  supply  a  new  symbol,  a  reversed  e  (9).  For  the 
Welsh  accented  y  as  heard  in  words  like  ty  —  '  house,'  and 
similarly  for  the  Slavic  y  and  bj,  I  would  propose  a  new  symbol 
(y)  which  by  its  form  suggests  something  like  a  union  of  u  and 
i.  For  this  peculiar,  almost  guttural,  vowel,  which  is  derived 
from  the  Central  Asian  languages  and  extends  in  its  modern 
range  almost  from  China  to  Poland  (its  reappearance  in  modern 
Welsh  is  probably  an  accidental  coincidence),  is  like  a  mingling 
of  ii  and  i  (as  in  '  hit ')  ;  pronounced,  however,  in  a  very  guttural 
fashion.  The  vocalised  r  and  z  met  with  in  so  many  Slavic 
tongues,  and  in  some  of  the  Indian  languages  descended  from 
Sanskrit  (similar  sounds  occur  occasionally  in  dialectal  English), 
are  best  represented  by  r  and  z.  The  little  mark  on  the  top  of 
this  r  and  z  is  my  equivalent  for  the  simple  vocalisation  of  a 
consonant  and  is  nothing  but  a  miniature  form  of  the  reversed  e 
which  I  propose  for  the  French  unaccented  c.  Very  often  in 
writing  Bantu  languages  or  in  writing  English,  it  is  not  necessary 
to  insert  this  little  symbol  above  the  consonant  which  is  to  be 
vocalised,  for  common  sense  in  reading  the  words  suggests  this 
vocalisation.  But  it  will  be  necessary  to  use  this  symbol  above 
the  line  in  transcribing  many  French  words  exactly  as  they  are 
pronounced  in  ordinary  speech.  For  instance,  while  we  must 
write  '  le '  and  '  sera,'  h  and  sara,  we  must  often  transcribe 
'lettre,'  Ufa*. 

In  my  proposed  alphabet  I  discriminate  between  the  e  in 
'met'  and  the  e  in  'fete'  by  the  placing  of  a  stress  mark  over 
the  strongly  pronounced  e,  and  similarly  between  i  in  '  hit '  and  i 
in  '  ravine.'  Likewise  between  the  u  in  '  put '  and  the  u  in 
'rule,'  between  o  in  'store'  or  'gone,'  and  the  o  in  'not'  and 
'  gong.'  Some  have  suggested  that  instead  of  writing  a  stress 
mark,  which,  when  carelessly  made,  may  be  confused  with  the 
nasal  sign,  or  perhaps  with  an  accent,  it  is  better  to  double  the 
vowel  which  is  to  be  broadly  pronounced.  But  as  the  result  of 
much  practice,  I  consider  that  both  in  printing  and  in  writing  it 
is  more  convenient  to  indicate  the  strongly  pronounced  vowel 


SCIENTIFIC  SPELLING  361 

by  a  stress  mark,  since  the  double  vowel  must  be  reserved  often 
for  a  double  or  repeated  pronunciation,  which  it  is  inconvenient 
to  indicate  by  a  diaeresis. 

It  would  be  seen  therefore  that  amongst  the  vowel  symbols 
I  propose  there  are  not  many  that  are  completely  new  to  our 
types.  0  is  familiar  to  us  through  German,  but  as  a  matter  of 
fact  I  think  it  is  most  conveniently  represented  in  printing,  if 
not  in  writing,  by  •©-.  The  two  forms,  however,  might  be  allowed 
to  co-exist,  both  of  them  equivalent  to  the  sound  of  u  in  '  hurt.' 
B ,  which  I  have  proposed  for  the  French  eu,  is  familiar  to 
many  of  us  through  the  systems  published  by  the  International 
Phonetic  Association. 

3  (9)  is  best  represented  in  the  majuscule  (not  often  required) 
by  3.     The  minuscule — already  described — is  9  (a  reversed  e). 

CI  is  familiar  to  us  in  its  italic  form  of  a.  This  must  be 
enlarged  for  the   majuscule,  and  made  erect  for  Roman  print. 

0  for  the  French  u  is  made  familiar  to  us  by  German,  and  i/r 
for  the  peculiar  Slavic  and  Welsh  sound  already  described  is 
so  far  outside  the  transcription  of  other  European  languages 
that  its  consideration  need  not  detain  us  here,  especially  as  it  is 
not  required  in  transcribing  English  phonetically  and  need 
scarcely  be  used  in  Welsh,  except  perhaps  in  place  of  the 
accented  y.  The  ordinary  equivalent  of  the  Welsh  unaccented 
y  is  «,  1,  or  9. 

In  addition  to  these  consonants  and  vowels  there  is  a  long 
list  of  what  I  call  half-letters ;  that  is  to  say,  signs,  accents, 
tone  and  stress  marks,  aspirates,  gasps,  clicks,  nasalisation,  etc. 
'  is  the  ordinary  apostrophe  or  an  indication  of  an  elided  vowel, 
the  equivalent  of  the  Greek  '  and  of  the  Hebrew  ^  ;  ;  =  the 
hiatus  or  gasp,  the  Arabic  hamza,  or  the  French  h  in   '  haut,' 

1  Sahara.'  f  =  the  light  aspirate,  the  English  h  or  the  Greek  '. 
It  is  not  a  symbol  that  need  be  much  employed  in  phonetic 
writing,  as  its  place  is  best  taken  by  the  ordinary  letter  h. 
P  =  the  Arabic  c  (Bin),  a  faucal  or  velar  contraction  of  the  voice 
very  marked  in  the  Semitic  languages  and  imparting  to  the 
vowel  that  follows  an  almost  snarling  sound.  It  is,  however, 
only  a  '  half-consonant,'  and  is  best  placed  above  the  vowel  that 
it  influences,  instead  of — as  it  were— breaking  up  a  word  by 
appearing  in  the  form  of  a  consonant.  ~  =  nasalisation.  Thus 
n  is  sounded  like  the  English  ng.  in  'singing,'  and  not  like  the  n 
in  '  vanguard,'     Nasalised  vowels — 1>,  a,  $  ,  ^ — are  sounded  as  if 


362  SCIENCE   PROGRESS 

written  in  French,  on}  otn,  in,  tin.  Also  o}  a,  e,  I  would  be  pro- 
nounced like  the  Portuguese  o,  a,  e,  i ;  or  om,  a,m,  em,  im.  The 
difference  between  the  French  and  English  pronunciations  of 
'  long  '  are  that  the  French  should  be  written  Id  and  the  English 
Ion.  '  would  indicate  palatalisation,  a  faint  y  sound,  frequently 
met  with  in  the  Slavic  tongues  of  Europe  and  the  Hamitic 
languages  of  East  Africa.  I  have  already  alluded  to  the  9  as  the 
symbol  for  the  indeterminate  vowel  sounds,  £,  /,  s,  z,  m,  t,  etc., 
in  so  many  Aryan  tongues,  in  Chinese,  in  Bantu,  Sanskrit, 
Slavic,  etc.  It  is  often  heard  in  English  words  in  the  unaccented 
vowels,  and  in  the  terminal  le.  But  I  propose  to  leave  it  out  of 
English  use  as  an  unnecessary  complication,  either  to  write  the 
consonant  without  any  vowel  asfibl  for  'feeble,'  or  to  represent 
it  by  the  vowel  it  most  nearly  resembles,  e,  a,  or  &. 

Almost  the  only  accent  required  in  transcribing  English, 
French,  and  most  European  languages  would  be  the  acute 
accent — ',  which  indicates  the  ordinary  pitch  of  an  accented 
syllable,  the  rising  tone  of  voice.  The  assumption  in  writing 
all  tongues  will  be  that  the  customary  pronunciation  is  to  accent 
the  penultimate  syllable  in  all  words  of  more  than  one  syllable. 
It  is  only  where  these  rules  are  departed  from  in  accentuating 
the  first  or  last  syllable  that  this  accent  would  be  required. 
The  other  accents,  of  which  I  supply  a  good  many  forms  in  my 
book,  are  for  the  most  part  only  required  in  transcribing  certain 
West  and  Central  African  languages,  Chinese,  Burmese,  and  the 
languages  of  Indo-China.  The  symbols  of  stressed  and  marked 
unstressed  vowels  are  the  familiar  -  and  v.  I  have  already 
referred  to  the  equivalents  of  the  clicks,  and  thus  in  this  sketch 
I  have  more  or  less  covered  the  whole  range  of  recognised 
phonetics.  It  might,  however,  be  convenient  for  the  reader  to 
set  out  succinctly  the  full  range  of  the  phonetic  alphabet  I 
propose,  with  its  equivalents  as  nearly  as  possible  in  old- 
fashioned  English  spelling. 
Half-consonants  : — 

'    =  apostrophe  for  an  elided  letter  or  indication  of  initial 
utterance  of  vowel,  like  Arabic  '. 

i    =  the  hiatus  or  gasp  between  two  letters,  and  French 
'  aspirated '  h. 

e    =  the  light  aspirate  (Greek  '). 

?  =  the  Arabic  p. 

■"  ~  nasalisation, 


SCIENTIFIC   SPELLING  363 

'     =  palatalisation. 
"     =  indeterminate  vowel. 

'   =  the  acute,  v  the  grave,  and  A  the  '  intense '  accents. 
-   =  stress  on  a  vowel,  and  «  unstress  or  special  tenuity  of 
.  sound. 

C  =  the  dental  click  (in  Zulu,  etc.  ;  3,  the  alveolar;  CJ,  the 
palatal ;  and  C  the  lateral. 

Consonants  : — 

m,  b,  w,  v,  p,f,  s,  z,j,  d,  t,  n,  I,  r,y,  k,  g,  and  h  as  in  English ; 
p  like  English  sh  ;  3  like  French/  or  z  in  '  azure  ' ;  c  like 
English  ch ;  d  for  the  th  in  '  that '  and  t>  for  the  th  in 
'theory';  5,  z,  It,  \i  like  peculiar  Arabic  sibilants  and 
dentals  (^  lb,  le,  ^j,) ;  %  or  a;  for  the  Scottish  and  German 
ch ;  ^  for  the  Polish  s  and  the  German  ch  in  '  ich ' ;  r 
for  the  velar  r  (the  Northumbrian  '  burr ') ;  r  for  the 
vocalised  r  (the  '  Midland'  r) ;  7  for  the  Arabic  ghain 
(?)  often  expressed  in  English  ^/j  ;  q  for  the  Arabic  j  ; 
«  for  the  »^  in  '  singing ' ;  i  for  the  Polish  /;  and  li  for 
the  strong  Arabic  //  (Z). 

Vowels  : — 

0,0;   e  ,  (f>,  or  0 ;  9,9;  &> ;  ^,  a  ;  « ;  e,  e ;  /,  ? ;  -»|r ;  w ;  u,  u. 

So  much  for  the  system  of  scientific  spelling  which — bor- 
rowing from  many  sources  and  adding  a  few  original  suggestions 
of  my  own — I  have  published  in  my  book.  I  believe  that 
this  will  be  found  in  every  way  the  most  convenient  alphabet  for 
transcribing  all  African,  Asiatic,  and  Amerindian  languages 
which  are  now  being  put  into  print.  It  will,  perhaps,  have  been 
already  noticed  by  one  or  two  critics  that  my  alphabet  looks  a 
good  deal  simpler  than  that  which  is  in  use  by  certain  German 
philologists  for  transcribing  African  languages  —  philologists 
who  attempt  to  discriminate  between  three  or  four  different 
ways  of  pronouncing  the  letters  /,  d,  z,  n,  r,  I,  etc.,  in  Bantu  or 
Sudanese  Africa.  I  have  given,  perhaps,  equal  time  and  attention 
to  the  consideration  of  this  problem,  and  I  have  decided  that  to 
mar  one's  print  and  tire  one's  readers'  eyes  with  an  infinitude 
of  diacritical  marks  above  or  below  a  consonant  is  a  useless 
preciosity.  It  must  be  taken  for  granted  that  Africans,  as  well 
as  Asiatics  and  Europeans,  do  not  always  clearly  enunciate 
their  words  ;  also,  that  there  is  great  individual  variation  (within 
a  certain  degree  of  range)  in  the  pronunciation  of  consonants. 


364  SCIENCE   PROGRESS 

We  have  the  same  in  our  own  country.  Look,  for  example,  at 
the  widely  different  pronunciations  of  the  letter  r  throughout 
Great  Britain  and  Ireland.  The  r  in  the  speech  of  cultivated 
people,  especially  in  London  and  Oxford,  at  the  great  English 
centres  of  education,  and  in  Southern  England  generally,  is  com- 
pletely elided  in  many  words,  and  its  elision  has  been  carried 
to  such  an  extent  in  past  decades  that,  in  transcribing  the 
fashionable  utterances  of  the  'sixties  and  'seventies,  it  was  often 
represented  by  a  w.  We  still  meet  with  people  in  what  is  called 
conventionally  '  good  society,'  who  say  '  vewy  '  or  '  vey '  instead 
of  'very,'  and  '  bwait'  instead  of  '  bright.'  In  the  Midlands  the 
r  is  pronounced  wherever  written,  but  often  with  a  peculiar 
cerebral  or  palatal  growl,  unmistakable  to  those  who  have 
heard  it,  easy  to  imitate,  and  equivalent  to  the  vocalised  r  of 
Indian  and  Slavic  speech.  The  r  of  Northumbria  is  burred  or 
pronounced  with  the  velar  palate,  like  French  r  in  grasseye. 
The  r  of  Scotland  and  Ireland  is  more  or  less  strongly  trilled. 
Then  again,  the  t,  which  varies  so  much  in  Bantu  Africa,  varies 
a  good  deal  in  Great  Britain  (in  dialect),  being  sometimes  pro- 
nounced like  d,  sometimes  as  an  actual  hiatus,  and  even  as  an  r. 
Well :  similarly,  in  Bantu  and  Sudanese  Africa  it  is  occasionally 
difficult  for  a  listener  to  determine  whether  the  speaker  is  utter- 
ing an  r,  a  d,  or  a  t.  The  /  is  sometimes  strongly  aspirated. 
But  I  hold  that  as  long  as  one  writes  it  t  when  it  is  most  like  a  t, 
d  when  it  is  most  like  a  d,  and  r  when  it  most  like  an  r,  it  will  be 
quite  sufficiently  discriminated,  and  I  take  the  same  line  in 
regard  to  other  consonants  ;  a  reasonable  line,  in  view  of  the 
mutability  of  human  speech  and  the  unreasonableness  of  expect- 
ing any  student  of  a  foreign  language  to  be  able  to  speak  that 
language  so  as  to  give  his  hearers  the  impression  that  it  is  his 
native  tongue.  Of  course  there  are  cases  where  a  man  or 
woman  has  lived  a  long  time  in  a  foreign  country  and  caught 
up,  like  a  child,  the  exact  local  pronunciation  of  the  local  speech. 
But  it  is  well-nigh  impossible  to  teach  any  one  such  perfection 
of  imitation  by  book  study ;  and  the  multiplication  of  symbols 
to  indicate  every  conceivable  grade  of  utterance  will  only 
embarrass  students  and  deter  them  from  studies  which  appear 
too  difficult.  The  discrimination,  as  it  is,  between  the  dental 
and  the  alveolar  5  and  z,  d  and  /,  between  the  ordinary  and  the 
Polish  or  Welsh  /'s,  the  %  and  the  %,  the  r  and  the  r  and  r,  has 
been  carried  quite  far  enough.     We  wish  to  aim  at  an  alphabet 


SCIENTIFIC   SPELLING  365 

sufficiently  copious  to  reproduce  human  speech— standardised 
human  speech — by  a  series  of  easily  written  and  printed  symbols 
of  unchanging  application  ;  but  it  is  not  necessary  to  carry  our 
accuracy  to  a  ridiculous  extreme  by  supplying  tedious  equivalents 
for  every  slurred  or  hesitating  utterance.  It  is  this  preciosity 
which  has  done  so  much  to  prejudice  busy  people  against 
phonetic  spelling,  or  which  is  driving  them  into  the  opposite 
camp  of  the  Indian  Government  or  Royal  Geographical  method, 
one  which  makes  no  pretence  at  being  either  logical  or  exact. 

Now  comes  in  the  question  whether  or  not  we  should  change 
the  official  spelling  of  our  own  tongue — English — and  adopt 
some  such  scientific  orthography  as  that  set  forth  in  this  article. 
The  reasons  against  doing  so  do  not  seem  to  me  very  adequate. 
They  are  usually  three  in  number. 

(1)  That  the  phonetic  spelling  of  English  must  first  of  all 
depend  on  what  is  to  be  regarded  as  the  standard  pronunciation. 
If  we  render  it  phonetically  and  logically  as  it  is  spoken  by 
educated  people  in  London  and  Oxford,  such  a  pronunciation  is 
at  once  out  of  keeping  with  that  which  is  in  vogue  even  amongst 
educated  people  in  Scotland,  Ireland,  or  America,  to  say  nothing 
of  the  wide  difference  between  the  pronunciation  of  academic 
English  and  dialectal  English. 

(2)  That  in  spelling  English  phonetically  we  may  lose  count 
of  the  extremely  interesting  historical  etymology  of  words. 

(3)  That  the  revolution  would  be  so  great,  so  tiresome,  so 
productive  of  printers'  strikes,  that  it  would  altogether  outweigh 
the  gain  in  simplicity  and  the  saving  of  trouble  to  children  and 
foreigners. 

As  regards  the  first  objection,  I  admit  that  a  standard  pro- 
nunciation must  be  determined  by  some  committee  or  educational 
body  whose  decision  would  secure  acceptance,  at  any  rate 
amongst  the  majority  in  the  United  Kingdom,  in  the  United 
States,  and  in  the  great  dominions  under  the  British  Crown. 
But  once  having  fixed  this  standard  pronunciation,  the  whole 
mass  of  English-speaking  peoples  of  the  world  would  in  course 
of  time  adhere  to  it  more  or  less,  especially  as  it  became  adopted 
in  their  schools.  Supposing,  however,  that  the  United  States, 
out  of  national  pride,  refused  to  accept  the  standard  of  this 
British  committee  and  set  up  a  standard  of  its  own.  American 
pronunciation,  nevertheless,  at  the  present  day  does  not  differ 
more  from  the  pronunciation  of  the  conventional,  correct  English 


366  SCIENCE   PROGRESS 

of  London  than  the  latter  differs  from  Scottish,  Midland,  or 
Irish  English.  Even  if  some  English  words  were  differently 
written  to  agree  with  local  pronunciation  in  the  United  States, 
their  meaning  would  be  rapidly  grasped  by  any  one  who  read 
them  phonetically.  The  probability  is,  however  (in  view  of  the 
importance  of  the  subject  and  of  the  language)  that,  especially  if 
the  United  States  was  well  represented  on  this  commission 
(together  with  the  Dominions)  there  would  be  universal  accept- 
ance of  the  standard. 

The  argument  as  to  the  loss  of  historical  etymology,  etc.,  is 
mostly  rubbish.  The  spelling  of  English  in  the  early  18th 
century  is  appreciably  different  from  the  spelling  of  English  at 
the  commencement  of  the  20th  century,  and  that  again  differs 
from  the  conventional  spelling  in  the  time  of  Shakespeare,  or  in 
the  reign  of  Henry  VII.  Still  more  marked  is  the  divergence  in 
orthography  between  the  period  of  Chaucer  and  the  present  day, 
the  fact  being  that  the  spelling  of  English  has  insensibly,  but 
continuously,  altered  as  century  succeeded  century.  There  is 
far  more  hope  of  its  stability  if  a  standard  of  pronunciation  was 
fixed  and  the  spelling  was  made  to  conform  logically  with  that 
standard. 

I  admit  the  trouble  that  will  be  caused  by  the  change,  but  in 
my  book  I  have  attempted  to  explain  how  in  many  ways  that 
might  be  avoided  or  lessened. 

On  the  other  hand,  the  gain  would  be  great.  The  logical 
spelling  of  English  is  the  one  obstacle  which  stands  in  the  way  of 
our  tongue  becoming  a  universal  world-speech  and  knocking  the 
stuffing  out  of  inventions  like  Esperanto,  inventions  which  seem 
almost  as  horrible  to  me  as  would  be  some  artificially  manu- 
factured human  being,  something  more  wonderful  and  self-acting 
than  the  manikins  put  before  us  by  Maskelyne  and  Devant. 
Much  time  and  many  tears  would  be  saved  the  childhood  of  the 
coming  and  of  future  generations  by  a  simplification  of  spelling. 
I  have  shown  in  my  book  that  the  new  spelling  is  practically  as 
easy  to  write  as  the  old  ;  it  is  far  easier  to  print,  and  still  more 
easy  to  read.  To  convince  the  reader  on  all  these  points,  I 
would  venture  to  refer  him  to  my  book  on  Phonetic  Spelling. 


SCIENTIFIC  SPELLING  367 

II.— By  Sir  RONALD   ROSS,  K.C.B.,  F.R.S.,  D.Sc. 

The  subject  of  spelling  reform  does  not  directly  concern  science, 
but  is  of  some  indirect  importance  to  it,  as  to  other  forms  of 
intellectual  effort,  on  account  of  mischief  caused  by  our  present 
irrational  '  orthography  ' — which  distracts  our  children,  im- 
pedes the  learning  of  English  by  foreigners,  wastes  about  one- 
tenth  of  the  money  spent  on  printing  and  writing,  and  assists 
the  disintegration  of  our  pronunciation.  Unavailing  efforts  at 
reform  have  been  made  during  some  centuries.  Years  ago 
Pitman  and  Ellis  poured  out  large  sums  on  the  cause,  and  scores 
of  reformers  have  invented  scores  of  systems  which  they 
advocated  as  substitutes  for  the  one  in  use — all  quite  fruitlessly. 
More  recently,  however,  the  creation  of  the  science  of  phonetics 
and  the  teaching  of  it  in  some  schools  and  universities,  the 
establishment  of  the  International  Phonetic  Association,  and  of 
Mr.  Carnegie's  spelling  reform  committees  in  Britain  and  the 
States,  and  especially  the  official  adoption  of  some  small 
changes  by  Mr.  Roosevelt  in  America,  have  suggested  hopes  of 
better  fortune  in  the  future.  Still  more  recently,  books  touching 
the  subject  have  been  published  by  two  distinguished  men.  Sir 
Harry  Johnston,  whose  article  is  printed  above,  has  also  given 
us  an  interesting  book  on  Phonetic  Spelling  (University  Press, 
Cambridge),  in  which  he  suggests  a  good  scheme  of  international 
spelling  applicable  to  all  languages,  including  the  African 
tongues  which  he  has  studied  so  well ;  and  the  Poet  Laureate 
has  written  a  witty  and  pregnant  tract  on  the  Present  State  of 
English  Pronunciation  (Clarendon  Press,  Oxford),  in  which  he 
calls  attention  to  some  of  the  vulgar  degradations  of  our  speech 
and  suggests  another  phonetic  scheme  (applicable  to  English 
alone). 

My  own  excuse  for  adding  a  note  is  that  I  wish  to  make  yet 
another  suggestion,  which,  I  believe,  has  never  been  made 
before  in  spite  of  the  immense  amount  of  matter  written  on  the 
theme — and  I  think  that  during  many  years'  attention  to  this 
curious  side-branch  of  human  endeavour,  I  have  studied  every 
important  proposal  which  has  been  advocated.  I  should  say 
first  that  the  failure  of  these  proposals  has  been  due,  in  my 
opinion,  to  two  causes.  The  first  is  that  the  Anglo-Saxon  mind, 
whatever  its  merits  may  be,  is  extremely  illogical — so  that  its 
illogical  spelling  is  really  an  accurate  expression  of  itself.     This 


368  SCIENCE   PROGRESS 

quality  springs  from  mental  indolence,  which  is  unwilling  to 
face  new  thoughts,  and  leads  to  mental  subservience,  which  for 
ever  finds  rest  in  dogmas.  Our  spelling  has  therefore  become 
a  dogma,  which,  like  other  dogmas  of  ours,  the  national  intellect 
does  not  possess  enough  energy  to  break  through,  however 
exigent  and  obvious  may  be  the  reasons  for  doing  so.  The 
second  cause  for  the  failure  of  spelling  reform  is  that  such  a 
large  number  of  almost  equally  good  new  schemes  may  be 
suggested  that  there  is  great  difficulty  in  selecting  the  best  one 
— much  more  so  in  obtaining  unanimity  of  choice  ;  and  it  is 
absurd  to  suppose  that  the  public  will  make  any  change  until 
this  point  is  decided.  Thus  the  old  spelling  easily  holds  its 
ground  in  spite  of  all  attacks. 

I  classify  all  the  previously  suggested  schemes  as  follows  : 
(i)  The  Deletory  Scheme,  which  merely  consists  in  dropping 
useless  letters,  as  in  such  spellings  as  ar,  hav,  wit,  hed,  peple, 
beuty,  etc. ;  without  making  any  other  change. 

(2)  The  Emendatory  Scheme,  which  consists  in  substituting 
good  for  bad  letters,  without  attempting  any  complete  revo- 
lution— as  in  such  spellings  as  haz,  woz,  duz,  luv,  whot,  etc.  This 
is  generally  proposed  in  addition  to  the  previous  scheme. 

(3)  Old-Letter  Homographies,  which  aim  at  rendering  each 
sound  in  one  way,  without  the  introduction  of  new  letters.  This 
class  is  divided  into  two  groups,  (a)  digraphic  schemes,  in  which 
most  of  the  longer  vowels  are  uniformly  expressed  by  digraphs, 
as  in  bait,  beet,  biet,  boet,  boot,  etc.,  whether  the  digraphs  are 
based  on  English  or  continental  values  of  vowels ;  and  (b) 
diacritical  schemes,  which  use  marked  or  accented  letters  for 
some  of  the  vowels,  such  letters  being  supposed  to  be  already 
available  for  printing. 

(4)  Neiv-Letter  Homograph ies,  which  effect  the  same  purpose 
by  using,  in  the  place  of  digraphs  or  marked  letters,  new  letters 
in  addition  to  those  contained  in  our  present  alphabet.  These 
schemes  may  be  either  meant  for  English  use  only,  such  as 
Dr.  Bridges'  system  ;  or  may  be  international,  such  as  Sir  Harry 
Johnston's  one. 

The  two  first  schemes  could  be  employed  at  once — almost 
without  discussion,  because  the  reasonableness  of  the  proposed 
changes  in  detail  is  unquestionable.  They  would  produce  a 
very  great  amelioration  of  our  spelling ;  would  entail  no  extra 
cost  for  new  letters,  and  would  indeed  save  a  vast  sum  of  money 


SCIENTIFIC   SPELLING  369 

every  year  in  the  nation's  printing  bill.  They  are  not  employed 
only  because  of  public  inertia  and  because  of  the  opposition  of 
a  few  people  who  imagine  that  they  may  change  the  spirit  of 
the  language.  With  regard  to  the  third  class  of  schemes, 
adoption  is  much  more  difficult  owing  to  the  necessity  of 
selection.  Literally  a  score  of  good  schemes  may  be  devised 
under  this  heading,  each  possessing  something  to  commend  it. 
The  system  of  the  Simplified  Speling  Soesiety  belongs  to 
the  digraphic  group,  but,  like  other  systems  of  this  group,  has 
the  defect  of  using  many  letters  and  of  failing  to  indicate  the 
syllabic  stress — which  is  just  as  important  as  the  length  of  the 
vowels,  and  which  can  be  easily  given  by  well-arranged  dia- 
critical systems.  The  latter  group  also  saves  money  in  printing, 
but  requires  the  insertion  of  marks  in  writing  and  typing.  The 
new-letter  systems  are,  of  course,  ideally  the  best,  but  are 
usually  so  expensive  and  troublesome  to  print  that  they  cannot 
be  used  at  once.  They  also  require  selection ;  and,  moreover, 
such  excellent  diacritical  systems  may  be  devised  that  the 
necessity  for  costly  new  letters  is  not  always  apparent.  Few  of 
the  proposed  schemes  (apart  from  strictly  phonetic  ones)  ever 
attempt  to  indicate  the  syllabic  stresses. 

The  scheme  now  suggested  by  me  belongs  to  none  of  these 
classes.  In  its  simplest  form  it  consists  merely  in  the  intro- 
duction of  a  diacritic  to  mark  the  syllabic  stress  on  certain 
vowels,  without  making  any  actual  change  at  all  in  the  accepted 
spelling.  The  rule  under  which  this  is  done  serves,  not  only 
to  indicate  the  accent  in  many  words,  but  also  to  give  the 
quality  of  the  vowels  in  others,  or,  at  least,  to  show  where 
irregularity  occurs.  The  scheme  does  not  of  course  perfect 
our  spelling,  but  it  improves  it  greatly  without  altering  it.  If 
anything,  it  adds  elegance  to  it,  especially  in  verse ;  and  can 
be  employed  at  once  in  printing  with  little  additional  cost.  The 
scheme  can  be  extended  by  the  employment,  if  we  please,  of 
more  than  one  diacritic,  and  will  thus  serve  as  an  introduction 
to  more  ambitious  schemes.  Combined  with  the  first  two 
schemes  mentioned  above,  it  will  give  us  what  is  almost  an 
homography  in  place  of  our  present  jumble. 

Let  us  begin,  however,  with  the  simplest  form,  and  suppose 
that  only  one  diacritic  is  allowed.     The  best  mark — the  easiest 
one  to  write  and  the  most  elegant  in  print — is  the  acute  accent.1 
1  Except  on  z,  where  it  may  be  replaced  by  the  dieresis. 

24 


37o  SCIENCE   PROGRESS 

I  propose  then  that  we  should  first  lay  down  a  general,  but 
somewhat  arbitrary,  rule  regarding  English  vowels,  and  then 
mark  only  those  vowels  which  do  not  conform  to  it. 

The  vowel  symbols  a,  e,  i,  o,  u  may  have  in  English  when 
stressed  no  less  than  five  different  groups  of  values,  which  I 
classify  as  follows : 

(i)  Long  idiomatic  values,  as  in  mate,  mete,  mite,  mote,  mute. 

(2)  Short  idiomatic  values,  as  in  bat,  bet,  bit,  bot,  but. 

(3)  Orthoepic  values,  as  in  far,  father;  great,  vein,  bear,  fete ; 
priest,  field,  police  ;  bought,  broad,  born  ;  full,  push  ;  rude,  truth. 

(4)  Degraded  values,  which  are  numerous  and  irregular. 
The  commonest  occur,  especially  after  w  and  qu,  when  orthoepic 
a  degenerates  into  some  value  of  o,  as  in  was,  what, yacht,  want, 
wander,  war,  all,  dzvl,  caught;  when  o  degenerates  into  some 
value  of  u,  as  in  mother,  one,  flood,  dost,  word,  who,  to,  woman, 
tomb,  good,  food ;  and  when  er,  ir,  ur  take  nearly  the  same  value, 
as  in  her,  fir,  fur. 

(5)  Silent  values,  as  in  head,  made,  receive,  people,  guard. 
Now  let  us  assume  the  following  general  Rule  : 

Stressed  vowels  should  have  long. idiomatic  values  when  final, 
before  other  vowels,  and  in  the  last  sounded  syllable  of  words 
ending  in  e  mute  and  their  derivatives  1 :  otherwise  they  should 
have  short  idiomatic  values. 

If  this  Rule  is  obeyed,  the  accent  is  not  marked :  if  it  is 
infringed,  the  accent  is  marked  on  the  offending  letter. 

Thus  the  accent  should  be  marked  on  all  orthoepic  and 
degraded  values ;  on  short  idiomatic  values  before  vowels,  or 
in  the  penultimate  of  words  ending  in  e  mute  and  their  de- 
rivatives ;  and  on  long  idiomatic  values  placed  otherwise — that 
is,  in  the  exceptions  to  the  Rule. 

This  serves  to  indicate  both  stress  and  length  of  vowel  in 
a  vast  number  of  words,  such  as  nature,  natural,  nation,  national, 
future,  futurity,  study,  studious ;  dunce,  flange,  revenge,  askance, 
sconce;  mild,  mind, gold,  most,  etc.,  especially  if  subsidiary  rules 
are  adopted  regarding  the  effect  of  suffixes  (which  I  have  no 
space  to  deal  with  here). 

It  also  fixes  the  pronunciation  of  most  of  the  numerous 
irregular  vowel-digraphs  which  at  present  cause  such  confusion 

1  It  may  be  better  to  lay  down  that  vowels  shall  be  long  before  a  single 
consonant  followed  by  any  vowel.  This  will  serve  to  indicate  the  accentuation 
on  a  greater  number  of  words. 


SCIENTIFIC   SPELLING  37i 

in  our  spelling — for,  if  such  digraphs  are  stressed,  the  accent 
should  be  marked  upon  their  first  vowel  if  this  is  short  or 
irregular,  but  not  if  it  is  long.  We  thus  have  ail,  aisle,  aye 
(ever),  dye,  say,  said,  grease,  great,  breathe,  breath,  read,  read 
(p.p.),  ear,  earth,  tear,  tear  (verb),  steer,  stead,  steak,  receive,  believe, 
ceil,  yield,  pierce,  vein,  their,  obey,  people,  leopard,  jeopardy,  pie,  piece, 
denied,  niece;  know,  now,  bozv,  bozv  (obeisance),  bough,  roe,  row, 
row  (noise)  soul,  sought,  thou,  boat,  board,  broad,  though,  through, 
youth,  young,  could,  route,  flood,  door,  beauty,  adieu  (where  a 
whole  polygraph  is  irregular  the  accent  should  be  marked  on 
the  last  letter  concerned). 

It  also  indicates  the  presence  of  orthoepic  or  degraded  values. 
The  accepted  spelling  generally  expresses  the  long  idiomatic 
values  either  by  digraphs  or  by  e  mute,  at  least  in  monosyllables 
and  their  derivatives,  except  in  a  few  words  such  as  mild,  mind, 
pint,  sign,  most,  old,  wont.  Except  in  these,  therefore,  the  accent 
in  monosyllables  will  denote  orthoepic  or  degraded  values. 
Before  s,  n,  and  often  /,  marked  a  generally  indicates  the  long 
orthoepic  value  (at  least  in  Standard  English),  as  in  pass,  cast, 
answer,  dance,  calm,  half,  enchantment;  otherwise  it  indicates 
degraded  values,  because  there  is  no  digraph  or  e  mute  to 
suggest  long  idiomatic  values.  The  short  o  is  also  often 
lengthened,  especially  before  s,  as  in  loss,  lost,  off;  but  as  this 
pronunciation  is  very  variable,  I  do  not  mark  it. 

Before  single  r,  followed  by  a  consonant,  or  final,  a  and  o 
generally  have  orthoepic  values,  and  e,  i,  u  degenerate  to  the 
ur  sound.  I  mark  therefore  only  the  exceptions  as  commonly 
pronounced,  such  as  starry,  glory,  story.  Ore,  and  oar  and  their 
rhymes  are  so  variously  pronounced  that  they  also  need  not 
be  marked. 

We  may  also  excuse  the  mark  where  the  quality  of  the 
vowels  is  fixed ;  that  is,  on  au  and  aw ;  oi  and  oy ;  oo,  long  and 
short ;  *  before  gh ;  a,  e,  o,  u  before  final  -Hon  and  -sion ;  and  in 
the  twelve  common  constructive  words  to,  you,  your,  who,  whom, 
whose,  our,  they,  their,  are,  we're,  have — especially  the  first,  as  in 
this  article.  The  object  of  such  omissions  is  to  save  trouble 
in  writing  and  the  excessive  use  of  the  marks  in  print ;  and 
if  all  the  omissions  just  suggested  are  allowed  there  would  be 
many  fewer  accents  than  have  been  employed  here,  where, 
of  course,  they  are  required  for  an  exemplar.  A  still  greater 
simplification  would  consist  in  using  the  marks   only  for  the 


372  SCIENCE   PROGRESS 

idiomatic  vowels,  where  needed,  and  letting  the  others  look 
after  themselves.  The  degraded  vowels  of  course  disappear 
if  we  use  the  emendatory  scheme  as  well. 

Accents  may  also  be  neglected  on  capitals ;  and  the  mark 
of  dieresis  may  be  used  on  i,  instead  of  the  acute  accent,  which 
does  not  look  well  on  that  letter. 

It  may  be  thought  that  much  confusion  will  still  be  caused 
by  the  employment  of  the  same  mark  for  so  many  values ;  but 
the  confusion  is  not  so  great  as  might  be  expected,  because  the 
different  groups  of  values  tend  to  occur  in  different  classes  of 
words.  Thus  the  marks  on  idiomatic  values  are  required 
principally  in  polysyllables,  and  those  on  the  other  groups, 
chiefly  in  monosyllables. 

Of  course  we  can  be  much  more  exact  if  we  are  allowed  more 
than  one  diacritic.  A  good  plan  is  to  use  the  dieresis,  where 
required,  for  the  long  idiomatic  values  (somewhat  as  in  German), 
and  the  acute  accent  for  the  other  values  only ;  and  this  gives 
much  greater  accuracy  without  much  change.  The  grave  accent 
may  also  be  used  for  irregular  unstressed  values  and  for  silent 
letters.  But  the  difficulty  is  that  the  employment  of  many 
diverse  marks  makes  the  printing  unsightly — as  will  be  observed 
on  comparing  a  page  of  French  with  one  of  Spanish,  with  its 
almost  exclusive  and  elegant  use  of  the  acute  accent. 

But  I  cannot  discuss  all  the  details  here.  My  main  point  is 
to  suggest  that  English  spelling  could  be  greatly  improved  by 
the  introduction  of  one  or  even  more  diacritics,  without  making 
the  alterations  which  offend  so  many  people.  At  all  events,  the 
marks  would  serve  to  call  attention  to  existing  defects,  and 
therefore  to  encourage  efforts  to  remedy  them. 


REVIEWS 

No  Struggle  for  Existence:  No  Natural  Selection.    A  critical  examination  of 
the  fundamental  principles  of  the  Darwinian  theory.     By  GEORGE  Paulin. 
[Pp.  xx  +  261.]     (Edinburgh  :  T.  &  T.  Clark,  1908.     Price  $s.) 

We  can  infer  from  the  mere  title  of  this  book  that  the  author  has  not  only 
undertaken  a  critical  examination  of  the  Darwinian  theory,  but  has  established 
its  inaccuracy  ;  and  from  the  paper  wrapper  of  the  book  we  learn  that  he  "proves 
that  Nature  has  made  special  provision  for  eliminating  all  excess  of  reproduction 
so  as  to  avert  a  Darwinian  struggle,  and  that  individual  qualities  or  variations 
play  no  part  in  her  elimination.     His  second  chapter  is  devoted  to  a  demonstration 
that  Nature  does  not  make  use  of  individual  variations  to  originate  new  forms. 
The  second  book,  dealing  with  the  Law  of  Population,  shows  that  neither  Mal- 
thusian  nor  Darwinian  principles  affect,  in  any  wise,  the  movements  of  population." 
The   italics  are   ours,  and  the  italicised  words  "prove"  only  the  author's  self- 
confidence.     On   looking  through  the  twenty  pages  of  preface  we  find  nothing 
but  repetitions  of  the  same  statements.     He  states  that  he  has  been  a  lifelong 
evolutionist,  but  that  he  has  now  altered  his  previous  convictions  ;  that  he  believes 
in  a  moral  basis  to  the  universe,  and  is  therefore  convinced  that  "  Darwin's  con- 
ception of  the  cruelty  of  Nature  to  her  sentient  offspring  is  wholly  mistaken." 
Darwin's  theory,  he  says,  is  "  an  extraordinary  concatenation  of  weird  concepts 
of  sins  against  logic  and  common  sense,  of  criminal  violations  of  Nature's  known 
laws,  and  of  audacious  and  indefensible  assertions.     My  investigation  proved  it  to 
be  so — a  rotten  tenement  tottering  in  its  every  joint,  a  ship  tumbling  helplessly  on 
the  brine,  leaking  at  every  plank."     He  says  that  he  wishes  to  "  counteract,  in 
short,  that  gross  and  degrading  materialism  which  Darwin  has  gone  far  to  make 
the  recognised  stamp  of  present-day  scientific  thought."     But  even  after  twenty 
pages  of  preface,  and  twenty  more  pages  of  the  first  chapter  of  the  book,  we  still 
fail  to  ascertain  the  nature  of  this  remarkable  "  proof."     We  then  learn  that  there 
is  no  struggle  for  existence  amongst  animals,  because  of  the  destruction  of  their 
young  offspring  by  the  ravenous  males  !     When  the  population  becomes  crowded, 
the  females  cannot  hide  their  young  sufficiently  easily  from  their  unnatural  mates  ; 
when,  however,  the  population  becomes  thinner,  they  succeed  in  doing  so.     Thus 
the  numbers  of  animals  are  maintained  by  Nature  always  at  about  the  same  level. 
Thus  also  there  is  no  struggle  for  existence,  and  consequently  no  natural  selection 
on  the  principles  enunciated  by  Darwin.     The  author  does  not,  apparently  and 
fortunately,    extend   this   explanation    to   the   cases    where   a  human   population 
remains  fixed  ;  but  here  he  introduces  another  hypothesis,  to  the  effect  that  the 
birth-rate  declines  when  the  food  supply  does  so.     The  evidence  which  he  adduces 
for  both  these  arguments  is  of  the  slenderest  nature  ;  but  worse  than  that,  he 
seems  to  have  failed  to  understand  Darwin's  meaning.     He  takes  Darwin's  meta- 
phorical expression    "struggle  for  existence"  in  a  literal   sense,  and   seems  to 
imagine  that  animals  do  nothing  but  fight  each  other  for  their  food.     Cases  such 
as  those  of  innumerable  insects,  of  which  the  population  remains  limited  though 

373 


374  SCIENCE   PROGRESS 

they  have  unlimited  food  and  though  they  cannot  possibly  destroy  their  offspring, 
do  not  concern  him  ;  and  he  reaches  his  proofs  and  demonstrations  with  the 
security  of  those  who  start  with  preconceived  ideas.  If  the  man  of  science  should 
be  defined  as  one  who  is  engaged  on  the  laborious  task  of  fitting  theories  to  many 
facts,  his  opposite,  the  dogmatist,  may  be  defined  as  one  who  is  engaged  upon  the 
easy  one  of  fitting  facts  to  many  theories.  Surely  his  theory  of  the  destruction  of 
the  young  by  the  males  is,  if  anything,  more  revolting  than  the  most  horrible 
struggle  for  existence  suggested  by  Darwin  ;  and  the  attempt  to  fix  a  charge  of 
immorality  upon  scientific  theorems  with  which  we  do  not  agree  is  itself  of  doubtful 
morality. 

O.  A.  Craggs. 

A  Beginner's  Star-Book.    By  Kelvin  McKready.    [Pp.  148 ;  70  illustrations, 
including  charts,  etc.]     (London  :  Knickerbocker  Press,  1912.) 

This  book  is  written  for  the  use  of  beginners  whose  instrumental  equipment 
ranges  from  an  opera-glass  to  a  3-in.  telescope.  It  contains  a  series  of  night- 
charts  of  the  sky  at  intervals  throughout  the  year,  which,  together,  practically 
serve  as  a  planisphere.  For  any  given  date  there  are  two  charts,  depicting  the 
sky  as  seen  by  an  observer  looking  north  and  south  respectively,  each  accom- 
panied by  a  concise  general  description  of  the  constellations  and  stars  in  it. 
Opposite  each  chart  is  a  corresponding  key-map,  with  notes  of  the  objects  of  more 
especial  interest  to  observers  with  a  field-glass,  a  2-in.  or  a  3-in.  telescope.  For 
more  detailed  information  cross-references  are  given  to  a  compact  but  very  useful 
Observer's  Catalogue.  It  is  hoped  that  by  this  method  the  beginner  will  be  able 
more  easily  to  identify  the  various  objects  which  he  sees  than  when  he  has  only 
the  usual  form  of  printed  map,  covered  with  lines  and  symbols,  with  which  to 
compare  the  sky  before  him. 

Subsequent  chapters  describe  simply  and  briefly  the  chief  points  of  interest  for 
the  observer  in  the  sun,  moon,  and  brighter  planets  ;  and  tables  are  given  of  the 
position  in  the  sky  of  Venus,  Mars,  Jupiter,  and  Saturn  month  by  month  until 
the  year  1930.  Practical  hints  are  also  given  as  to  the  choice  of  a  field-glass  or 
telescope. 

The  paper  and  printing  are  both  good,  while  the  many  beautiful  reproductions 

of  recent  astronomical  photographs  cannot  be  too  highly  praised.     Those  of  the 

moon  may  be  specially  mentioned.     It  is  to  be  hoped  that  this  interesting  and 

practical  book  will  achieve  the  author's  purpose  in  stimulating  the  interest  of  the 

beginner  sufficiently  for  him  to  pursue  the  study  of  the  subject  further,  and  to  seek 

fuller  information  elsewhere. 

H.  S.  J. 

Qualitative  Determination  of  Organic  Compounds.     By  J.  W.  Shepherd, 
B.Sc,  A.R.C.S.   [Pp.  xvi  +  347.]  (London  :  W.  B.  Clive,  1913.  Price  6j.  6d.) 

The  volume  is  one  of  the  numerous  examination  text-books  issued  by  the 
University  Tutorial  Press,  and  is  intended  for  the  advanced  science  student.  It 
is  divided  into  two  parts,  dealing  respectively  with  the  tests  for  the  various  groups 
of  organic  compounds  and  the  various  types  of  organic  reactions.  The  scheme  of 
identification  (Chapter  XX.)  is  the  result  of  many  years'  experience  in  this  class  of 
work,  and,  with  the  scale  of  melting  and  boiling  points,  will  probably  be  found  to 
be  the  most  practically  useful. 

It  seems  a  pity,  however,  as  the  qualitative  tests  for  organic  compounds  are 
given  so  fully,  that  a  short  resume  of  the  methods  of  quantitative  determination  was 


REVIEWS  375 

not  included  in  place  of  the  second  part  of  the  work.  The  subject  is  so  closely 
allied  to  the  separation  of  mixtures.  There  are  one  or  two  books  dealing  with 
quantitative  determination,  but  there  is  room  for  a  complete  work  on  the  elementary 
methods  of  organic  analysis.  In  its  present  form,  however,  it  should  be  of  service 
to  the  examination  student.  H.   S.  S. 

The  Control  of  Water  as  applied  to  Irrigation,  Power,  and  Town  Water 

Supply  Purposes.     By  Philip  A.  Morley  Parker.    [Pp.  vi  +  1055,  with 

full  diagrammatic  illustrations.]     (London  :  George  Routledge  &  Sons,  Ltd., 

1913.     Price  21s.  net.) 

Although  the  title  of  this  book  is  -almost  alarming  in  its  comprehensiveness,  it 

is  only  fair  to  say  that  in  this  closely  printed  volume  of  more  than  one  thousand 

pages,   a  fairly  successful  attempt  is  made  to  produce  a  manual  covering  all  the 

ground  which  is  generally  necessary  for  engineers  in  practical  work  ;  and  the 

author    certainly   displays    both    judgment  and   industry   in    the   collection   and 

arrangement  of  his  material. 

The  book  presupposes  the  usual  training  that  any  educated  engineer  receives 
at  the  present  time  in  the  subject  of  hydraulics  at  a  technical  school  or  college  ;  and 
there  is  a  good  deal  to  be  said  for  the  view  of  the  writer,  that  results  from  well- 
conducted  observations  are  more  accurate  than  the  assumptions  made  in  most 
modern  mathematical  treatments  of  hydraulics  :  indeed  the  author  might  have 
gone  farther  and  said  that  there  is  no  really  accurate  and  scientific  basis  of 
practical  hydraulics  since  there  is  practically  no  such  thing  as  steady  motion  in  a 
large  number  of  the  most  important  cases  with  which  the  hydraulic  engineer  has 
to  deal. 

The  subjects  of  critical  velocities,  capillary  elevation,  and  velocity  of  percolation 
dealt  with  in  the  second  chapter  are  well  treated.  In  the  third  chapter  the 
gauging  of  streams  and  rivers  shows  that  the  author  himself  has  practical 
acquaintance  with  the  subject,  although  he  does  not  deal  with  one  or  two  of  the 
best  modern  meters. 

Pressure  tubes  are  clearly  treated  :  and  the  modern  methods  of  chemical 
gauging  are  more  fully  dealt  with  than  anywhere  else,  although  it  is  doubtful  if  such 
methods  would  be  allowed  in  many  waters. 

The  theory  of  Venturi  meter  and  results  with  it  are  also  well  treated.  It  is  of 
course  impossible  in  the  space  available  to  comment  at  length  on  the  various 
chapters  which  deal  with  the  questions  of  Gauging  by  Weirs,  Discharge  of 
Orifices,  Dams  and  Reservoirs,  Pipes,  Open  Channels,  Filtration  and  Purification 
of  Water,  Problems  connected  with  Town  Water  Supply,  Irrigation,  Movable  Dams, 
Hydraulic  Machinery  other  than  Turbines,  Turbines  and  Centrifugal  Pumps  : 
concluding  with  the  chapter  on  Concrete,  Ironwork,  and  Allied  Hydraulic 
Construction  ;  but  it  may  be  said  that  the  treatise  is  worthy  to  take  its  place  as  a 
standard  one  among  the  literature  of  water  supply. 

Wireless  Telegraphy.    By  C.  L.  Fortescue,  M.A.  [Pp.  vi+143.]  (Cambridge: 

at  the  University  Press,  1913.     Price  is.) 
This  little  book   is  written  for  readers  possessing  general  scientific  knowledge 
who  may  be  anxious  to  know  something  about  both  the  accomplishments  of  wireless 
telegraphy  and  the  means  by  which  results  have  been  obtained. 

The  first  four  chapters  are  devoted  to  explanations  of  the  electrical  phenomena 
concerned,  and  the  last  seven  to  a  general  survey  of  the  applications  of  wireless 
telegraphy. 


376  SCIENCE   PROGRESS 

The  fifth  and  sixth  chapters  are  devoted  respectively  to  the  transmitting  and 
receiving  instruments  employed.  It  may  be  said  at  once  that  the  matter  is  dealt 
with  throughout  in  an  elementary  and  instructive  manner,  and  entirely  fulfils  the 
object  of  the  writer.  One  excellent  feature  is  the  clear  way  in  which  the  processes 
of  wireless  telegraphy  are  made  more  simple  by  analogy  with  hydraulics,  though 
in  a  future  edition  the  picture  of  the  hydraulic  model  of  a  condenser  should  be 
re-drawn  with  a  little  more  care  in  order  to  make  clear  which  are  the  pipe 
arrangements  and  which  are  the  cylinders. 

Continuous  Beams  in  Reinforced  Concrete.  By  Burnard  Geen,  A.M.I.C.E., 
M.S.E.,  M.C.I.  [Pp.  210,  illustrated.]  (London  :  Chapman  &  Hall,  Ltd., 
1913.     Price  gs.  net.). 

The  subject-matter  of  this  volume  is  rather  more  limited  in  its  scope  than  the 
title  would  lead  one  to  expect,  consisting  as  it  does  chiefly  in  a  series  of  diagrams 
and  tables  dealing  with  the  theoretical  Bending  Moments,  Shears  and  Reactions 
in  continuous  beams  of  reinforced  concrete,  and  their  supports,  though  the  results 
are  in  general  equally  applicable  to  any  other  form  of  continuous  girder. 

The  aim  of  the  author  is  to  place  in  the  hands  of  the  designer  of  such  structures 
as  warehouses  and  other  buildings  in  which  a  great  many  of  such  reinforced 
concrete  beams  are  employed  a  set  of  tables  from  which  he  can  deduce  by  a 
simple  operation  the  Bending  Moments,  Shearing  Forces  and  Reactions  for  any 
system  and  any  intensity  of  dead  and  live  loads,  thus  avoiding  the  laborious 
calculations  entailed  on  the  application  of  the  Theorem  of  Three  Moments  to  each 
individual  case.  This  end  is  accomplished  fairly  comprehensively  by  reducing  to 
standard  spans  and  intensities  of  loads. 

All  results  are  calculated  from  a  consideration  of  the  General  Theorem  of 
Three  Moments,  which  is  enunciated  and  proved  in  a  clear  manner  in  Chapter  II. 

There  is  a  wealth  of  diagrams  covering  almost  every  possible  case  of  loading 
over  2,  3,  and  5  spans,  and  on  a  scale  sufficiently  large  to  be  of  use  ;  but  it  would 
be  of  advantage  if  a  few  words  of  explanation  were  appended  to  some  of  them,  as 
it  is  now  necessary  to  count  the  number  of  spans  in  diagrams  1  to  39  in  order  to 
ascertain  which  case  is  being  treated. 

There  are  short  chapters  dealing  with  the  utility  of  haunches  in  coping  with  the 

excessive  negative  Bending  Moments  at  supports,  the  effects  of  support  subsidence 

on  the  stresses  in  the  beams,  etc.,  and  interesting  paragraphs  on  the  insufficiency 

wL"*  .  . 

of  the  usual  formula  recommended  by  the   Institution  of  British  Architects 

12 

for  the  Bending  Moments  at  centres  of  spans  and  supports  in  the  case  of  rigid 

beams  on  rigid  supports,  and  on  the  extent  to  which  the  columns  may  be  assumed 

to  withstand  bending.     Examples  of  the  method  of  application  of  the  tables  are 

given,  from  which  it  appears  that  the  necessary  calculations  are  very  simply  made  ; 

and  no  doubt  this  work  will  find  its  place  in  the  drawing  offices  of  those  who  are 

engaged  in  the  design  of  this  increasingly  important  class  of  structure. 

Man  and  His  Forerunners.    By  Prof.  H.  von  Buttel-Reepen  ;  authorised 

translation   by   A.    G.    Thacker.     [Pp.   x  +  96,  8vo,  with   a  frontispiece, 

70  figures  in  the  text,  and  3  tables.]     (London  :  Longmans,  Green  &  Co., 

I9I3-) 

The    last    few    years    have    witnessed  a  tremendous    growth  of  interest  in  the 

earliest  remains  of  mankind.     This  no  doubt  has  been  due  partly  to  the  normal 


REVIEWS  377 

growth  of  scientific  knowledge,  which  is  ever  adding  new  significance  to  old 
material,  and  transmuting  the  dry  technicalities  of  anatomy  and  geology  into  a 
more  or  less  intelligible  story  of  Man  in  the  making,  or  Nature's  attempts  at  man- 
making,  that  naturally  appeals  to  all  mankind.  But  fresh  fuel,  often  of  a  highly 
inflammable  kind,  has  been  repeatedly  added  to  this  flame  of  popular  interest 
within  recent  years  as,  one  after  another,  surprising  fragments  of  ancient  types  of 
man  and  his  handiwork  have  come  to  light. 

Naturally  enough,  with  this  rapid  growth  of  knowledge  and  constant  conflict  on 
the  part  of  the  pundits  as  to  the  meaning  of  each  new  fact  that  is  brought  to  light, 
there  is  a  constant  demand  on  the  part  of  the  intelligent  public  for  information 
concerning  the  progress  made  and  for  some  light  on  the  significance  of  the  new 
knowledge  of  our  earliest  human  forbears  and  their  relations.  A  host  of  small 
books  of  a  more  or  less  expository  nature  have  been  issued  to  meet  this  demand 
within  the  last  few  years.  There  have  been  new  editions  of  such  standard 
treatises  as  those  of  Ranke  and  Haeckel,  and  smaller  new  books  dealing 
specifically  with  this  problem  of  man's  origin,  such  as  those  written  by  Leche, 
Branca  and  this  work  of  v.  Buttel-Reepen's  ("  Aus  dem  Werdegang  der  Mens- 
chenheit  ")  on  the  Continent,  and  the  books  by  Sollas,  Keith,  Duckworth,  McCabe 
and  others  in  this  country. 

The  English  version  of  v.  Buttel-Reepen's  work  has  been  brought  right  up  to 
date  by  giving  a  full  summary  of  Dr.  Smith  Woodward's  and  Mr.  Charles 
Dawson's  account  of  the  Piltdown  skull,  perhaps  the  most  surprising  type  of  very 
early  man  yet  discovered. 

Every  one  who  has  read  anything  whatever  of  the  recent  literature  relating  to 
early  man  must  be  aware  that  at  the  present  time  there  are  very  considerable 
discrepancies  between  the  views  of  different  scholars  as  to  the  relative  values  and 
precise  significance  of  the  various  remains  of  fossil  men. 

Since  characteristically  human  remains  such  as  the  Heidelberg  and  Piltdown 
specimens  must  be  referred  back  to  the  commencement  of  the  Pleistocene  period, 
it  seems  quite  certain  that  man  must  have  lived  in  the  Pliocene  period.  So  much, 
I  think,  will  be  granted  by  most  scientific  men  who  have  given  any  thought  to  this 
problem  ;  but  what  most  of  these  authorities  are  not  yet  convinced  of  is  whether 
such  traces  of  man  and  his  works,  the  existence  of  which  they  do  not  doubt,  have 
actually  been  found,  as  Rutot,  Verworn,  Ray  Lankester,  and  Keith,  among  others, 
believe,  each  in  his  own  way. 

In  the  little  book  before  us,  which  is  written  in  a  delightfully  clear  and  simple 
style,  the  writers  (there  is  no  indication  whether  Prof.  v.  Buttel-Reepen  is 
wholly  responsible  or  Mr.  Thacker  shares  also  in  this  result)  display  the  utmost 
catholicity  in  their  acceptance,  partially  or  wholly,  of  the  views  of  those  whom 
other  writers  regard,  collectively  or  individually,  as  extremists.  They  accept 
Verworn's  evidence  of  Upper  Miocene  man  ;  go  the  whole  way  with  Rutot  ;  and 
set  forth  Klaatsch's  extraordinary  speculations  concerning  the  kinship  of  different 
human  races  with  the  various  species  of  anthropoid  apes  as  quite  serious  contribu- 
tions to  the  discussion,  although  they  add  at  the  end  that  "  it  would  be  well  to  take 
the  theory  cum  grano  salts." 

The  whole  book,  in  fact,  may  be  regarded  as  a  pleasantly  written,  wholly 
uncritical,  and  very  credulous  summary  of  recent  literature  dealing  with  early 
types  of  mankind  ;  and  the  reader  who  enjoys  this  delightfully  unfettered  romance 
should  remember  that  he  ought  also,  as  a  corrective,  to  refer  to  the  original  sources 
of  information  which  appear  in  the  bibliography  at  the  end  of  the  volume. 

The   book  bears   the   obvious    impress   of  its    origin.     There   is   hardly   any 


378  SCIENCE   PROGRESS 

reference  to  the  important  Gibraltar  skull,  and  the  translator  makes  certain 
passages  unintelligible  to  any  except  the  expert  by  his  ignorance  of  anatomical 
terms.  The  worst  instance  of  this  is  the  use  of  the  expression  "third  lobe  of  the 
brain  "  (p.  49)  for  the  third  frontal  gyrus. 

G.  Elliot  Smith. 

Modern  Electrical  Theory.    By  Norman  Robert  Campbell.    [Pp.  xii  +  400.] 
Second  edition.     (Cambridge  University  Press.     Price  gs.  net.) 

A  CAREFUL  comparison  of  this  second  edition  with  the  first  edition  (1907)  fully 
confirms  the  author's  statement  in  the  preface  that  this  is  really  a  new  book  ;  even 
in  the  places  where  the  work  of  the  last  six  years  has  not  added  to  or  much  affected 
our  knowledge,  the  book  has  been  rewritten  and  recast.  A  mention  of  some  of 
the  remarkable  experiments  and  revolutionary  theory  of  the  last  six  years  which  are 
discussed  will  make  it  clear  how  completely  a  recent  book  on  electrical  theory 
must  necessarily  differ  from  one  six  years  old  ;  reference  need  only  be  made  to 
Planck  and  Einstein's  theory  of  light  quanta,  Nernst's  work  on  specific  heats,  the 
experiments  of  Barkla,  Bragg,  and  Lane  and  his  collaborators  on  X-rays,  and  the 
principle  of  relativity.  This  work  is  all  too  recent  to  have  found  its  way  into  the 
text-books,  and  the  papers  and  pamphlets  on  it  are  enormous  in  number,  scattered, 
and  not  always  particularly  clearly  written.  Whether  they  are  to  stand  or  fall, 
these  modern  theories  of  light  and  electro-dynamics  in  general  are  far  too 
important  for  any  physicist  to  be  able  to  ignore  them,  and  a  book  where  he  can 
get  a  general  yet  correct  presentation  of  them,  and  find  them  compared  with  the 
older  theories,  is  badly  needed,  although  it  may  be,  probably  will  be,  out  of  date  in 
another  five  years.  We  can  congratulate  the  author  both  on  his  courage  in 
attempting  such  a  book,  and  on  the  successful  result  ;  for,  on  the  whole,  the  book 
gives  a  presentation  of  just  the  nature  required  by  the  working  physicist,  neither 
too  "popular"  nor  too  mathematical.  If  he  shows  a  disposition  to  try  to  bully 
the  reader  into  an  acceptance  of  every  view  which  has  won  his  own  belief,  it  must 
be  remembered  that  a  certain  amount  of  personal  opinion  and  partisanship  is 
probably  necessary  to  give  unity  to  the  book,  and  to  make  it  the  connected 
presentation  it  is  rather  than  a  mere  collection  of  independent  theories  and 
observations. 

The  book  is  now  divided  into  three  parts — the  electron  theory,  radiation,  and 
■electricity  and  matter.  In  the  first  part,  besides  a  good  account  of  the  Faraday- 
Maxwell  theory  and  the  electromagnetic  theory  of  dispersion,  there  is  an  account 
of  many  important  matters  not  treated  at  all  in  the  standard  English  books  ; 
especially  needed  is  the  chapter  on  the  electronic  theory  of  magnetisation,  giving 
an  account  of  the  work  of  Langevin  and  Weiss.  Elsewhere,  in  the  treatment  of 
conduction,  we  think  the  author  might  point  out  the  difficulty  of  supposing  electrons 
to  be  gas-kinetically  reflected  from  atoms  and  molecules,  considering  that  experi- 
ment points  rather  to  their  being  absorbed  and  subsequently  liberated  by  the 
molecules,  a  very  different  mechanism  which,  we  think,  may  possibly  form  the 
basis  of  a  more  complete  theory. 

Two  chapters  in  the  second  part  of  the  book  contain  an  interesting  and  able 
discussion  of  the  relative  merits  of  the  wave  theory  and  Einstein's  corpuscular 
theory  of  light,  and  of  the  nature  of  X-rays,  in  which  it  is  made  clear  that  while 
modern  experiment  seems  to  have  conclusively  established  that  X-rays  are 
essentially  similar  to  light,  the  nature  of  both  light  and  X-rays  is  very  doubtful. 
It  may  be  mentioned  that  Lane's  and  Bragg's  X-ray  photographs  of  191 2  receive 


REVIEWS  379 

adequate  reference.  The  electrical  mechanism  by  which  light  is  emitted  from  the 
atom  or  molecule  is,  however,  not  so  adequately  treated.  While  Stark's  theory 
that  positively  charged  atoms  emit  the  line  spectra  can  be  reconciled  with  Wien's 
observations  on  canal  rays,  there  is  no  good  confirmation  of  it,  and  in  a  paper  not 
mentioned  by  the  author  Baerwald  (Annalen  der  Physik,  34,  p.  883,  191 1)  from 
modified  experiments  on  the  Doppler  effect  in  canal  rays  comes  to  the  conclusion 
that  the  carriers  of  the  series  cannot  be  positively  charged,  but  are  in  all  probability 
neutral  atoms  which  emit  light  at  the  moment  of  neutralisation  by  an  electron,  in 
accordance  with  the  theory  developed  by  Lenard  in  his  work  on  phosphorescence 
and  elsewhere,  and  adopted  by  Wien  for  canal  rays.  There  also  seems  little  doubt 
that  line  spectra  are  to  be  attributed  to  atoms,  band  spectra  to  molecules,  which 
hypothesis  will  account  for  the  emission  sometimes  of  lines,  sometimes  of  bands  by 
the  same  element  according  to  conditions,  a  fact  which  the  author  describes  as 
unexplained. 

In  the  third  part  of  the  book  a  chapter  is  devoted  to  the  structure  of  the  atom, 
in  which,  we  think,  an  unnecessary  amount  of  attention  is  given  to  Stark's  theory, 
which  has  not  proved  particularly  valuable,  and  which  for  those  interested  is 
easily  accessible  elsewhere  (in  Stark's  Atomdynamik)  :  there  is  no  mention  of 
Nicholson's  work.  The  last  chapter  is  on  the  principle  of  relativity.  The  author 
begins  by  giving  the  Einstein  transformations,  and  does  not  state  the  physical 
reasons  which  led  up  to  them,  or  the  physical  assumptions  underlying  them,  until 
he  has  deduced  their  chief  results  ;  this  seems  rather  unsatisfactory  for  those 
approaching  the  subject  for  the  first  time.  Again,  we  do  not  think  he  gives  quite 
a  fair  account  of  the  obstacles  in  the  way  of  acceptation  of  the  principle  in  its 
present  form,  at  any  rate  ;  no  mention  is  made  of  the  difficulties  presented  by  the 
dynamics  of  rigid  body  rotation.  But  the  most  important  applications  to  electro- 
dynamics are  fully  and  clearly  presented  :  we  only  trust  that  Dr.  Campbell's 
evident  contempt  for  the  yet  unconverted  will  not  offend  intending  converts. 

The  book  is  full  of  matter  of  extraordinary  interest,  the  treatment  is  always 
vigorous,  and  such  small  faults  as  we  have  found  are  quite  insufficient  to  warrant 
us  treating  it  as  anything  but  a  very  successful  attempt  to  deal  with  the  difficult 
task  of  giving  an  account  of  electrical  theory  as  it  stood  at  the  beginning  of  this 
year.  The  specialist  may  find  small  omissions  in  his  particular  branch,  but  he  will 
not  find  any  very  serious  fault ;  in  general  he  will  find  the  book  stimulating, 
informative,  and  an  excellent  preliminary  when  he  wishes  to  read  up  any  other 
branch.  To  the  student  and  scientist  engaged  in  other  departments  of  science 
who  have  not  time  for  much  reference  to  original  papers,  the  book  will  be 
invaluable. 

E.  N.  DA  C.  A. 

Mathematical  Physics.    Vol.  I.  Electricity  and  Magnetism.    By  C.  W.  C.  Bar- 
low.    [Pp.  vi  +  312.]     (University  Tutorial  Press.) 

As  the  book  does  not,  as  far  as  we  can  see,  pretend  to  be  more  than  a 
cram-book  for  examinations,  it  is  not  necessary  to  point  out  that  it  is  not  always 
particularly  clear  on  the  fundamental  conceptions  which  underlie  the  mathe- 
matical theory  of  electricity.  It  has  many  examples,  with  answers,  and  will,  we 
think,  answer  its  purpose. 

E.  N.  DA  C.  A. 


38o  SCIENCE  PROGRESS 

BOOKS   RECEIVED 

{Publishers  are  requested  to  notify  p?-ices) 

The  Petrology  of  the  Sedimentary  Rocks.  A  Description  of  the  Sediments  and 
their  Metamorphic  Derivatives.  By  F.  H.  Hatch,  Ph.D.,  Mem.  Inst.  Civil 
Engineers,  Vice-President  of  the  Inst,  of  Mining  and  Metallurgy,  and 
Past  President  of  the  Geol.  Soc.  of  South  Africa,  and  R.  H.  Rastall,  M.A., 
Demonstrator  of  Geology  in  the  University  of  Cambridge.  With  an 
Appendix  on  the  Systematic  Examination  of  Loose  Detrital  Sediments  by 
T.  Crook,  A.R.Sc.  (Dublin).  London  :  George  Allen  &  Co.,  Ltd.,  44  and  45, 
Rathbone  Place,  191 3.     (Pp.  xii,  425.)     Crown  8vo.     ys.  6d.  net. 

G.  W.  Bacon  &  Co.'s  New  Contour  Globe.  Fifteen  inch  diameter,  with  compass. 
Three  heights  of  land  and  four  depths  of  sea  are  shown  in  different  colours. 
Total  weight  only  a\  lbs.  Price  25^.  net. — Also  Bacon's  Wall  Maps.  United 
States.  4  by  5  ft.  Scale,  1  :  3,200,000.  Drawn  on  a  secant  conical  projection 
with  errorless  parallels,  340  and  44°  North  latitude.  Price,  on  cloth,  rollers  and 
varnished,  or  on  cloth,  cut  to  fold,  16s. — Also  a  New  Contour  Map  of  England 
mounted  to  fold.  Price  ys.  6d.~ Also  a  New  Contour  Map  of  Wales  in 
Welsh,  edited  by  Prof.  Timothy  Lewis,  M.A.  Price  ys.  6d. — Also  Excelsior 
Map  of  Mediterranean  Lands.  Also  New  Contour  Map  of  the  Near  and 
Middle  East  (the  Land  of  the  Five  Seas).  Size,  40  by  30  inches.  Price,  to 
hang  on  the  wall,  cut  to  fold  and  eyeletted,  or  on  rollers  and  varnished,  with 
or  without  names,  ys-  6d.     Bacon  &  Co.,  127,  Strand,  London. 

Panama,  the  Creation,  Destruction,  and  Resurrection.  By  Philippe  Bunau-Varilla. 
•London  :  Constable  &  Co.,  Ltd.,  1913.     (Pp.  xx,  565.)     12s.  6d.  net. 

Text-Book  of  Zoology.  By  H.  G.  Wells,  B.Sc,  F.Z.S.,  F.C.P.,  and  A.  M.  Davies, 
D.Sc.  Seventh  impression  (sixth  edition).  Revised  by  J.  T.  Cunningham, 
M.A.,  Oxon.  London  :  W.  B.  Clive,  University  Tutorial  Press,  Ltd.,  High 
Street,  New  Oxford  Street,  W.C,  1913.     (Pp.  vii,  487.)     6s.  6d.  net. 

Beitrage  zur  Rassenkunde,  Heft  12.  Die  "  Natiirlichen "  Grundstamme  der 
Menscheit,  von  Maurus  Horst.  Hildburghausen,  1913:  Thuringische  Verlags- 
Anstalt.     (Pp.  35.)     Price  75  Pfg. 

The  British  Journal  of  Tuberculosis.  Edited  by  T.  N.  Kelynack,  M.D.  London  : 
Bailliere,  Tindall  &  Co.,  8,  Henrietta  Street,  Covent  Garden.  Publishers  in 
the  United  States  :  G.  E.  Stechert  &  Co.,  151-155,  West  25th  Street,  New 
York.     (Pp.  xxx,  216.)     is.  6d.  net. 

Irritability.  A  Physiological  Analysis  of  the  General  Effect  of  Stimuli  in  Living 
Substance.  By  Max  Verworn,  M.D.,  Ph.D.,  Professor  at  Bonn  Physiological 
Institute.  With  Diagrams  and  Illustrations.  New  Haven  :  Yale  University 
Press.  London:  Henry  Frowde.  Oxford:  University  Press,  1913.  (Pp.  xii, 
264.)     i$s.  net. 

Guide  to  Photo-Micrography.  Primarily  prepared  for  Users  of  Apparatus  made 
by  E.  Leitz.     (Pp.  38.) 

The  Microscope,  and  Some  Hints  on  How  to  Use  it.     By  E.  Leitz.     (Pp.  42.) 

Organic  Chemistry  for  Advanced  Students.  Vol.  II.  By  Julius  B.  Cohen,  Ph.D., 
B.Sc,  F.R.S.,  Professor  of  Organic  Chemistry  in  the  University  of  Leeds, 
and  Associate  of  Owens  College,  Manchester.  London  :  Edward  Arnold, 
41  and  43,  Maddox  Street,  Bond  Street,  W.,  191 3.     (Pp.  vii,  427.)     16s.  net. 


BOOKS   RECEIVED  381 

Evolution  by  Co-operation,  a  Study  in  Bio-Economics.  By  Hermann  Reinheimer. 
Author  of  "Nutrition  and  Evolution"  and  "Survival  and  Reproduction." 
London  :  Kegan  Paul,  Trench,  Triibner&  Co.,  Ltd.,  Broadway  House,  68-74, 
Carter  Lane,  E.C.,  1913.     (Pp.  xiii,  199.) 

A  Systematic  Course  of  Practical  Science.  For  Secondary  and  other  Schools. 
Book  I.  Introductory  Physical  Measurements.  (Pp.  vi,  126.)  is.  6d.  net. 
Book  II.  Experimental  Heat.  (Pp.  vi,  162.)  2s.  6d.  net.  By  Arthur 
W.  Mason,  B.Sc,  B.A.  (Lond.),  Senior  Science  Master,  Municipal  High 
School,  Tynemouth.  Rivingtons,  14,  King  Street,  Covent  Garden,  London, 
1912. 

Life,  Light,  and  Cleanliness.  A  Health  Primer  for  Schools.  Published  under  the 
Direction  of  the  Director  of  Public  Instruction,  Punjab.  Lahore  :  Rai  Sahib 
M.  Gulab  Singh  &  Sons,  1912.     (Pp.  128.)     Price  8  annas. 

Australian  Institute  of  Tropical  Medicine.  Report  for  the  year  191 1.  By  Anton 
Breinl,  M.D.,  Director  of  the  Institute,  in  Collaboration  with  Frank  H.Taylor, 
F.E.S.,  and  T.  Harvey  Johnston,  M.A.,  D.Sc,  F.L.S.,  Lecturer  in  Biology, 
University,  Brisbane.  Printed  by  W.  A.  Pepperday  &  Co.,  119a,  Pitt  Street, 
Sydney.  Published  by  Angus  &  Robertson,  Ltd.,  publishers  to  the  University 
of  Sydney";  the  Oxford  University  Press,  Amen  Corner,  London,  E.C.,  and 
29  West  32nd  Street,  New  York.     (Pp.  iii,  96.)    With  eleven  plates. 

LITERARY  NOTE. 

Messrs.  Constable  will  publish  almost  immediately  the  "  Life  and  Letters  of 
Alexander  Agassiz  "  edited  by  his  son. 


NOTES 

The  International  Distribution  of  the  Nobel  Prizes  during  Twelve  Years 

It  will  be  of  interest  to  examine  how  the  literary  and 
scientific  Nobel  Prizes  have  been  distributed  among  the  nations 
since  the  inauguration  of  the  prizes  in  1901.  The  prizes  were 
rendered  possible  by  the  will  of  Alfred  Nobel,  who  left  a  vast 
sum  of  money,  the  interest  of  which  provides  the  necessary 
funds.  The  Peace  Prize  is  given  in  Stockholm,  and  we  do  not 
consider  it  here  because  it  refers  to  a  species  of  human  effort 
which  is  outside  our  immediate  province.  The  literary  and 
scientific  prizes  are  allotted  and  distributed  by  Sweden. 
Workers  are  not  allowed  to  ask  for  prizes  ;  but  every  year  the 
Nobel  Committee  issues  an  invitation  to  leading  men  asking  for 
nominations.  These  are  then  collected  and  carefully  considered 
during  a  whole  year  by  the  committees,  on  the  report  of 
assessors  who,  we  understand,  make  the  most  exhaustive  study 
of  the  literature  connected  with  the  nominations.  Four  prizes 
are  given  every  year  by  Sweden,  each  one  consisting  of  a 
medal,  an  illuminated  album,  and  a  cheque  for  between  seven 
and  eight  thousand  pounds.  Sometimes,  however,  one  prize  is 
divided  between  two  recipients.  The  presentation  is  usually 
made  by  His  Majesty  the  King  of  Sweden  himself  (on 
December  10)  in  a  very  distinguished  ceremony;  and  the 
recipients  are  required  to  give  lectures  on  their  work,  which 
are  published  annually  by  the  Nobel  Committee.  The  four 
prizes  distributed  by  Sweden  are  for  Literature,  Physics, 
Chemistry,  and  Medicine.  It  is  obvious  that  the  exceptional 
and  international  nature  of  the  prizes  attaches  very  great 
honour  to  them ;  while  the  pecuniary  addition  constitutes  the 
first  attempt  ever  made  by  mankind  to  give  some  suitable 
recompense  to  their  benefactors  in  great  branches  of  work 
which  often  receive  no  other  reward.  On  the  whole,  therefore, 
the  title  of  Nobel  Laureate,  which  is  assumed  by  the  recipients, 
is  perhaps  the  greatest  of  honours.  The  conditions  of  the 
awards  are  such  that  there  can  be  no  possibility  of  the  interplay 

382 


NOTES 


383 


of  personal  influence  or  of  prize-hunting  ;  and  probably  as  much 
impartiality  and  care  is  bestowed  upon  the  allotments  as  is 
possible  in  this  world. 

During  the  twelve  years  from  1 901- 12  inclusive,  fifty-six 
prizes  have  been  allotted  to  citizens  of  fourteen  different 
countries.  So  far  as  we  can  ascertain  the  nationalities  are 
correctly  placed  in  the  following  table.  In  this  we  have  entered 
the  numbers  of  recipients  of  each  country  which  have  received 
each  class  of  prize  ;  and  have  compared  the  total  prizes  received 
by  each  country  with  the  population  of  that  country — the  com- 
parison being  expressed  in  a  common  rate  per  100,000,000  of 
people.  The  populations  are  taken  from  the  Census  figures  in 
1910  or  191 1,  given  in  the  Britannica  Year  Book  for  1913 — 
except  in  those  countries  where  there  has  been  no  census,  and 
where  the  population  is  "estimated."  The  countries  are 
arranged  in  the  order  of  their  success  in  obtaining  prizes. 

Comparative  Table  of  the  Scientific  and  Literary  Nobel  Prizes 

AWARDED   DURING   TWELVE   YEARS,    igol    TO    I912 


Country. 

Popula- 
tion in 

million  ^ 

Prizes  awarded  for 

Rate  per 
100  millions 

of  popula- 

1111 llluilOi 

Physics. 

Chemistry. 

Medicine. 

Literature. 

Total. 

tion. 

I.  Sweden 

5'6 

I 

I 

I 

I 

4 

71-9 

2.  Holland 

5 '9 

3 

O 

O 

O 

50-5 

3.  Norway 

2-4 

0 

O 

O 

I 

1 

41-8 

4.  Denmark    . 

27 

0 

O 

I 

O 

1 

36-4 

5.  France 

39'6 

4 

4 

n 

2 

13 

32-8 

6.  Germany    . 

64 '9 

4 

6 

4 

4 

18 

277 

7.  Switzerland 

37 

0 

0 

1 

0 

1 

267 

8.  Belgium 

7'A 

0 

0 

0 

1 

I3"5 

9.  Britain 

45'4 

2 

2 

1 

6 

i3'3 

10.  Spain. 

I9"6 

0 

0 

1 

2 

IO'2 

11.   Italy  . 

347 

1 

0 

1 

8-6 

12.  Poland  (Russian) 

I2'5 

0 

0 

0 

1 

8-o 

13.  United  States     . 

92*0 

1 

0 

0 

0 

1 

ri 

14.  Russia 

I20-6 

0 

0 

1 

0 

1 

08 

It  is  obvious  from  statistical  considerations  that  the  Rate 
Column  cannot  be  considered  very  exact  for  the  smaller 
countries,  especially  when  they  have  received  only  one  prize ; 
and  there  may  be  some  subconscious  desire  to  give  a  prize  to 
nations,  especially  the  smaller  ones,  which  have  not  yet  received 
one.  There  has  also  been  some  outcry  in  Sweden  upon  this  subject. 
In  these  cases,  a  single  prize  will  obviously  affect  very  greatly 


384  SCIENCE   PROGRESS 

the  position  of  one  of  these  nations  on  the  list ;  but  for  the 
larger  nations  the  numbers  are  more  decisive.  It  will  be 
observed  that  Holland,  France,  and  Germany  have  been  by  far 
the  most  successful  among  these  ;  that  Belgium,  Britain,  Spain, 
and  Italy  come  in  a  second  class ;  and  that  the  United  States 
and  Russia  are  in  the  third  class. 

Neither  Britain  nor  the  United  States  can  be  congratulated 
on  the  result.  The  table  probably  gives  a  good  rough  measure 
of  intellectual  development  in  the  respective  nations,  and  one 
which  would  be  likely  to  be  confirmed  in  other  lines  such  as 
mathematics,  zoology,  and  botany,  art,  music,  and  even  inven- 
tion during  the  present  century.  The  failure  of  Britain  and  the 
United  States  is  probably  due  to  their  attitude  towards 
intellectual  effort,  to  their  preoccupation  with  politics  and 
game-playing,  and  possibly  to  the  unreality  of  their  education. 
It  is  probably  due,  however,  still  more  to  the  poor  payment 
made  for  scientific  work  in  comparison  with  other  lines  of 
effort  or  of  no-effort.  How  little  interest  is  taken  in  this 
country  in  the  higher  intellectual  work  may  be  gauged  from  the 
very  small  references  to  the  Nobel  Prizes  which  appear  in  the 
British  press,  compared  with  the  endless  talk  about  such  matters 
as  the  so-called  Olympic  Games.  But  the  country  of  Shakespeare 
and  Newton  can  scarcely  be  second  to  any  in  fertility  of  genius- 
production,  and  there  are  probably  secondary  factors  at  work 
to-day  which  are  suppressing  that  invaluable  asset. 

The  University  of  Bristol 

In  the  July  Number  we  inserted  a  brief  note  on  the  affairs 
of  the  University  of  Bristol,  mentioning  some  of  the  criticisms 
which  had  previously  been  published  upon  the  management  of 
this  institution.  Since  then  we  have  been  asked  to  make  a 
thorough  examination  of  the  questions  at  issue.  We  have 
consequently  studied  all  the  documents  on  the  subject  which 
have  already  been  published,  including  papers  on  both  sides  of 
the  controversy. 

We  have  no  bias  at  all  in  the  matter ;  and  it  is  one  which 
concerns  science  only  in  regard  to  the  general  influence  of 
university  management  upon  scientific  work  and  teaching.  To 
us,  as  to  all,  it  is  unpleasant  to  have  to  criticise  any  public 
institution;   but  it   must   be   confessed   that   the   study   of  the 


NOTES  385 

documents  which  we  have  made  is  very  convincing  as  to  the 
soundness  of  the  allegations  against  the  conduct  of  this 
University. 

On  the  other  hand,  the  explanations  which  have  been  put  for- 
ward do  not  appear  to  be  at  all  satisfactory  ;  and  we  are  strongly 
of  opinion  that  the  matter  is  one  which  certainly  calls  for  public 
inquiry,  either  by  the  authority  constitutionally  appointed  for 
that  purpose,  namely  the  Visitor,  or  by  the  Board  of  Education. 
The  case  has  aroused  and  is  arousing  very  serious  criticism  ;  it 
touches  the  whole  question  of  academical  life  and  prosperity  in 
this  country ;  and,  if  it  is  not  one  for  intervention,  we  cannot 
understand  how  there  can  often  be  any  case  which  will  call  for  such. 
The  careful  scrutiny  of  the  facts  which  we  have  made  justify  us 
in  stating  our  opinion  ;  and  we  add  no  more  at  present,  only 
because  we  still  hope  that  a  public  inquiry  will  be  made. 

Mr.  Balfour  at  the  National  Physical  Laboratory 

On  June  26  the  Right  Hon.  A.  J.  Balfour,  M.P.,  opened  the 
new  buildings  of  the  National  Physical  Laboratory,  Sir  Archi- 
bald Geikie,  P.R.S.,  being  in  the  chair.  The  scheme  for 
additional  laboratories  and  offices,  planned  in  1909,  was  estimated 
to  cost  more  than  £35,000,  towards  which  the  Treasury  has 
promised  £15,000  provided  that  there  is  no  further  application 
to  the  Government.  Dr.  Glazebrook  remarked  that  the  build- 
ings had  been  erected  in  no  small  degree  by  faith — faith  in  the 
importance  of  the  work  and  faith  in  the  liberality  of  friends. 
Lord  Rayleigh  emphasised  the  fact  that  funds  were  still  needed 
for  the  equipment  of  the  laboratory,  and  wished  that  pure 
science  might  have  figured  a  little  more  there.  He  trusted  that 
in  future  funds  would  be  devoted  to  pure  science  as  well  as  to 
the  immediate  advantage  of  industry.  Mr.  Balfour  fully  ad- 
mitted the  great  importance  of  science  to-day.  "  Everybody,  1 
think,"  he  said  inter  alia,  "  would  be  ready  to  admit  that  one  of 
the  great  conditions  of  human  progress  is  our  growing  com- 
mand over  nature ;  that  this  growing  command  over  nature  is 
the  sphere  of  our  activities  in  which  it  is  most  plainly  and 
obviously  certain  that  immense  advance  has  been  made  in  the 
last  one  hundred  and  fifty  years — an  advance  which,  instead  of 
diminishing  in  its  rate  of  progress,  seems  to  me  to  be  increasing. 
You  may  argue  as  to  whether  we  have  improved  in  this  or  in 
that  respect ;  you  may  debate  whether  great  social  or  political 
25 


386  SCIENCE   PROGRESS 

influences  are  or  are  not  for  the  general  advantage  of  society ; 
but  the  one  thing  you  cannot  argue  about  is  the  command  which 
science  has  given  us— which  science  is  teaching  to  those  who 
are  engaged  in  the  technical  work  of  industry.  Nobody  can 
dispute  that  that,  at  all  events,  has  covered  an  immense  range 
of  progress,  and  that  we  are  still  moving  rapidly  in  the  right 
direction.  .  .  .  Lord  Rayleigh  incidentally  dropped  a  criticism — 
I  hardly  like  to  call  it  a  criticism — to  express  faint  regret  that 
in  the  history  of  this  institution  a  larger  fraction  of  the  labour 
had  been  devoted  to  matter  immediately  connected  with  industry 
than  to  the  abstract  or  purely  scientific  investigations,  on  the 
successes  of  which  ultimately,  and  as  years  go  on,  the  future  of 
industry  depends.  Now  I  think  all  of  us  must  share  that  regret. 
I  have  not  sufficient  acquaintance  with  the  work  of  the  institu- 
tion to  know  how  much  of  the  time  and  labour  of  the  staff  have 
been  devoted  to  pure  research,  but  believing  as  I  do — it  is, 
indeed,  one  of  my  foremost  articles  of  social  faith — that  it  is  to 
the  labours  of  the  man  of  science,  working  for  purely  scientific 
ends  and  without  any  thought  of  the  application  of  his  dis- 
coveries to  the  practical  needs  of  mankind,  that  mankind  will  be 
most  indebted  as  time  goes  on ;  holding,  as  I  say,  that  faith,  I 
should  desire  that  as  much  advance  should  be  made  in  pure 
science  in  these  buildings  as  money  and  space  allow." 

The  Seventeenth  International  Congress  of  Medicine  (Philip  Hamill, 
M.A.,  M.D.,  D.Sc,  M.R.C.P.) 

At  the  seventeenth  International  Congress  held  in  London  this  year  remarkable 
progress  in  the  knowledge  and  treatment  of  disease  was  recorded.  The  com- 
munications dealing  with  the  notable  advances  which  have  recently  been  made 
in  the  more  purely  scientific  domain  of  medicine  are  of  especial  interest  and 
significance  in  their  bearing  upon  the  future  of  practical  medicine.  It  may  be 
useful,  therefore,  briefly  to  review  some  of  the  ..more  important  discoveries  which 
were  considered  and  discussed  at  the  Congress/ 

Chemiotherapy. — The  address  delivered  by  Prof.  Ehrlich  summarised  in 
masterly  fashion  the  advances  which  have  been  made  in  this  subject.  Specific 
chemiotherapy  is  a  recent  development  of  medicine,  and  rests  upon  a  foundation 
of  extensive  researches  on  parasitology. 

It  has  been  found  that  if  an  animal  be  infected  by  a  parasite  the  injection  into 
the  circulation  of  certain  substances  which  can  be  prepared  synthetically  will  bring 
about  the  death  of  the  parasite  whilst  leaving  the  host  unharmed — i.e.  the  drug  is 
"  parasitotropic  "  rather  than  "organotropic."  But  the  mode  of  action  of  such  a 
drug  is  more  complicated  than  can  be  accounted  for  on  the  assumption  that  it  acts 
merely  as  a  differential  poison.  If  a  particular  parasite  be  exposed  to  the  action 
of  the  drug  in  vitro,  it  may  escape  death ;  and  if  it  be  a  motile  organism,  such  as 


NOTES  387 

a  spirochete,  its  activity  may  remain  undiminished.  If,  however,  the  parasite, 
after  treatment  with  the  drug,  be  injected  into  a  living  animal,  it  is  immediately 
killed  by  the  blood  of  the  host.  The  same  result  is  obtained  if  the  drug  be 
injected  into  the  circulation  of  an  infected  animal.  To  this  method  of  treatment 
Ehrlich  has  applied  the  term  Therapia  sterilans  magna,  and  by  such  means  it  is 
possible  to  sterilise  the  host  as  far  as  a  particular  parasite  in  question  is  concerned. 
The  problem  of  chemiotherapy  therefore  resolves  itself  into  the  discovery  of  a 
substance  which  can  be  administered  in  a  dose  large  enough  to  secure  death  of 
the  parasite  as  a  result  of  the  combined  action  of  the  drug  and  the  tissues  of  the 
host,  without  producing  toxic  effects  upon  the  host.  Amongst  the  substances 
which  appear  to  be  particularly  effective  in  this  respect  are  certain  organic  com- 
pounds of  arsenic,  notably  those  in  which  the  arsenic  is  linked  to  a  benzene 
nucleus  bearing  an  amino  group.     Up  till  quite  recently,  atoxyl 

NH/       >AsO 
X—/  \ONa 

was  much  used,  and  was  of  considerable  service  ;  but  unfortunately  it  is  somewhat 
too  markedly  "  organotropic,"  and  several  cases  of  optic  atrophy  resulting  in  total 
blindness  have  been  recorded  as  a  result  of  its  use.  After  extensive  researches, 
in  which  605  synthetic  organic  compounds  containing  arsenic  were  tested,  ex- 
cellent results  were  obtained  with  the  606th  compound,  dihydroxy-diamino- 
arsenobenzene, 

As    As 


NH,ly^yNH2 
OH  OH 

now  universally  known  as  "  Salvarsan "  or  "  606."  More  recently  a  derivative 
of  salvarsan,  neo-salvarsan,  has  come  into  use,  and  although  it  is  rather  more 
unstable  than  salvarsan,  it  can  be  administered  with  greater  ease. 

Several  interesting  phenomena  have  been  observed  during  researches  on  this 
subject  ;  from  the  practical  standpoint  one  of  the  most  important  is  the  acquisition 
by  the  parasite  of  tolerance  to  the  drug.  If  small  doses,  insufficient  to  sterilise  the 
host,  are  given,  the  parasites  may  become  increasingly  difficult  to  destroy  by 
subsequent  injections  ;  hence  it  is  important,  from  a  therapeutical  point  of  view, 
to  give  the  largest  doses  which  can  be  tolerated  in  order  to  ensure  immediate 
sterilisation.  For  this  reason  it  is  clearly  desirable  to  use  a  drug  having  as  low 
an  "organotropic"  tendency  as  possible.  Such  an  acquisition  of  tolerance  is 
shown  by  many  parasites.  The  tolerance  so  acquired  is  specific  for  the  drug 
employed. 

The  great  practical  value  of  the  new  therapy  has  been  most  clearly  demon- 
strated in  connection  with  syphilis  and  certain  tropical  diseases  such  as  yaws 
(frambcesia),  caused  by  a  spirochete  allied  to  that  of  syphilis.  The  success  which 
has  attended  the  new  treatment  of  these  diseases  is  remarkable.  In  the  case  of 
soldiers  treated  for  syphilis  at  the  military  hospital  in  Rochester  Row,  the  recovery 
has  been  such  as  to  result  in  the  annual  saving  to  the  army  of  a  number  of  days 
of  sickness  which  is  equivalent  to  the  services  of  a  battalion  for  nearly  three 
months.  Even  more  remarkable  results  have  been  obtained  in  the  case  of  yaws, 
which  can  be  cured  with  a  single  dose  of  salvarsan.     As  a  result  of  this  treatmen 


388  SCIENCE   PROGRESS 

a  hospital  which  contained  on  an  average  300  patients  suffering  from  this  disease 
was  no  longer  required. 

Up  to  the  present  the  most  brilliant  successes  have  resulted  from  the  treatment 
of  diseases  due  to  animal  parasites  ;  but  evidence  is  not  wanting  that  similar 
successes  will  soon  be  forthcoming  in  the  case  of  diseases  of  bacterial  origin.  In 
this  connection  organic  compounds  of  copper  and  other  metals  are  being  in- 
vestigated, and  there  is  ground  for  hope  that  valuable  remedies  for  tuberculous 
infections  may  before  long  be  found. 

Dietetics. — Recently  the  significance  of  hitherto  unsuspected  constituents  of 

food  has  come  to  be  recognised,  and  it  is  now  realised  that  dietary  factors  which 

until  lately  have  not  received  consideration  are  of  cardinal  importance   in   the 

maintenance  of  normal  metabolism.     It  is  now  clear  that  in  addition  to  what  are 

known  as  the  proximate  principles — proteins,  carbohydrates,  fats,  and  salts — there 

are  in  a  mixed  diet  minute  amounts  of  certain    substances   which  seem  to   be 

essential  for  the  normal  nutrition  of  the  body.    If,  for  any  reason,  these  substances 

are  absent  or  deficient,  various  disorders  of  metabolism,  resulting  in  the  production 

of  characteristic  symptoms,  make  their  appearance.     Beri-beri  appears  to  be  a 

disorder  of  this  nature.     It  has  been  found  associated  with  a  diet  of  rice  from 

which  the  pericarp  has  been  removed  by  milling  (polished  rice).     In  the  rice 

grain  the  essential  substances  above  mentioned,  for  which  the  name  "  trophones  " 

has    been   suggested,   are   located   mainly   in   the   pericarp.      Beri-beri   can    be 

prevented  by  using  rice  from  which  the  pericarp  has  not  been  removed,  or  by 

including  in  the  diet  foods  which  are  rich  in  trophones.     Polyneuritis,  simulating 

many  of  the  symptoms  of  beri-beri,  has  been  produced  in  animals  as  a  result 

of  feeding  them  on  a  diet  poor  in   trophones.       Young   animals   fed  on   diets 

consisting  of  purified  proteins,  fats,  and  carbohydrates,  even  with  the  addition  of 

salts  and  phosphatides,  soon  cease  growing  ;  but  the  addition  of  minute  amounts 

of  fresh  foods  or  tissue  extracts  is  sufficient  to  ensure  normal  growth. 

The  nature  of  these  essential  substances  (trophones)  is  not  yet  precisely 
known.  There  appear  to  be  several  substances  concerned,  of  which  the  vitamine 
of  Kunk  is  probably  one.  They  do  not  seem  to  exist  free,  but  are  probably 
portions  of  more  complicated  molecules.  Many  of  them  are  cyclic  compounds, 
purin  and  pyrimidin  bases,  which  the  animal  seems  incapable  of  synthesising,  and 
which,  as  sources  of  energy,  are  negligible.  The  trophones  are  unstable  bodies, 
and  are  injuriously  affected  by  prolonged  storage,  by  cooling,  and  by  a  variety  of 
other  agencies. 

The  nature  of  the  salts  in  the  food  also  appears  to  be  of  importance.  There 
is  evidence  to  show  that  the  ash  of  mixed  foods  is  much  more  valuable  than 
an  artificial  mixture  of  salts  corresponding  in  every  chemical  detail  with  the  ash. 
Possibly  a  minute  trace  of  fluorine  and  manganese  may  be  essential  to  proper 
nutrition. 

Cardiac  Pathology  and  Therapeutics. — In  almost  every  branch  of  medical 
science  the  application  of  exact  methods  of  observation  has  been  followed  by  the 
discovery  of  important  results.  This  is  strikingly  exemplified  by  the  advances 
which  have  been  made  in  recent  years  in  the  physiology,  pathology,  and 
therapeutics  of  the  cardio- vascular  system.  In  this  field  English  workers  have 
been  prominent.  When  the  Congress  was  last  held  in  London  in  1881,  much 
mystery  surrounded  the  mechanism  of  the  heart's  rhythm.  Shortly  before  that 
time  Gaskell  had  begun  his  classical  researches  on  the  heart  of  the  tortoise, 
and  had  promulgated  his  theory  of  muscular  conduction  from  chamber  to 
chamber  without  the  intervention  of  nervous  mechanism.    This  was  followed  by 


NOTES  389 

the  discovery  by  Kent  and  by  His  of  the  specialised  conducting  bundle  gener- 
ally associated  with  the  name  of  the  latter  observer.  In  recent  years  the 
"pacemaker"  of  the  heart,  or  the  point  of  origin  of  the  cardiac  rhythm,  has 
been  definitely  localised  as  a  result  of  the  work  of  Keith,  Flack,  and  Lewis. 
The  pioneer  work  of  Mackenzie  on  disorders  of  cardiac  rhythm  has  been 
greatly  extended  by  the  use  of  Einthoven's  storing  galvanometer,  which,  in  the 
hands  of  Lewis  and  other  workers,  has  yielded  results  of  great  scientific  interest 
and  clinical  value.  The  exact  nature  of  disorders  of  cardiac  rhythm  has  been 
determined,  and  complete  irregularity  of  the  pulse  has  been  shown  to  be  due  to 
fibrillary  contraction  of  the  auricles.  Clinically,  these  results  are  of  great 
importance,  inasmuch  as  they  help  to  differentiate  serious  from  trivial  conditions, 
previously  often  confused,  and  furnish  a  rational  basis  for  the  administration 
of  cardiac  remedies. 

In  contrast  to  the  advances  made  in  the  study  of  the  disorders  of  rhythm  and 
conduction  is  the  unsatisfactory  state  of  present  knowledge  in  regard  to  the 
functional  competence  of  the  heart.  Prognosis  in  cardiac  failure  is  a  matter  of 
extreme  difficulty,  for  as  yet  there  is  no  method  of  ascertaining  the  reserve  power 
of  the  heart  muscle.  If  a  method  could  be  devised  which  could  be  applied 
clinically,  it  would  be  possible  to  substitute  facts  for  conjecture,  and  thus  enable 
prognosis  to  be  placed  upon  a  more  reliable  basis. 

Radiology. — Radium  is  now  being  widely  used  in  the  treatment  of  malignant 
growths.  It  is,  however,  not  yet  possible  definitely  to  appraise  its  value  in 
this  respect ;  it  cannot  yet  be  said  to  what  extent  radium  treatment  is  likely 
to  supplant  operative  interference,  although  it  is  generally  accepted  that  radium 
treatment  is  useful  as  an  aid  to  eradicating  traces  of  growth  left  behind  after 
operation.  There  appears,  however,  to  be  general  agreement  on  the  following 
points  :  (1)  Unfiltered  rays  have  a  high  power  of  tissue  destruction  ;  (2)  certain 
rays,  notably  the  (3-rays,  have  the  power  of  stimulating  growth,  and  they  may 
therefore  act  harmfully  by  inducing  increased  multiplication  of  cancer  cells  ; 
(3)  the  7-rays  are  the  most  useful  therapeutically,  since  young  actively  growing 
cells  are  most  susceptible  to  their  influence  ;  (4)  malignant  growths  of  mesoblastic 
origin  (sarcomata)  are  more  amenable  to  treatment  than  carcinomata  ; 
(5)  filters  of  aluminium  or  lead  or  even  air  are  useful  in  removing  the  undesirable 
radiations. 

At  present,  although  radium  is  of  value  in  treating  superficial  growths,  its 
penetrating  power  is  limited,  so  that  for  deep-seated  growths,  such  as  cancer 
of  the  breast,  it  is  unjustifiable  to  rely  on  this  treatment  to  the  exclusion  of 
operative  measures.  There  is  evidence  to  show  that  the  application  of  X-rays  and 
radium  to  the  field  of  operation  tends  to  lower  the  liability  to  recurrence.  All 
cancerous  growths  are  not  equally  amenable  to  treatment ;  those  of  the  mouth  and 
tongue  are  less  favourably  affected  than  those  of  the  breast,  whilst  carcinoma 
of  the  uterus  affords  a  hopeful  field  for  radiotherapy. 

Successes  which  have  attended  other  applications  of  science  to  the  practice 
of  medicine,  such,  for  instance,  as  inoculation  against  typhoid  fever,  were 
reported  to  the  Congress,  but  space  does  not  permit  of  their  mention  here.  It 
should  be  noted  that  the  advances  in  scientific  medicine  which  have  been 
communicated  to  the  Congress  could  not  have  been  made  without  experiments 
on  animals.  This  was  fully  recognised  by  the  Congress,  which  was  unanimously 
of  opinion  that  no  restrictions  which  might  in  any  way  impede  the  progress 
of  medicine  should  be  placed  upon  such  experiments. 

The  future  is  full  of  hope  ;  increasing  interest  is  being  taken  by  the  people  in 


39o  SCIENCE  PROGRESS 

the  advances  of  medicine  ;  all  the  great  departments  of  State  directly  concerned 
with  the  well-being  of  the  community  are  realising  the  importance  of  scientific 
inquiry,  and  it  may  confidently  be  predicted  that  when  the  Congress  next  meets 
in  London  many  of  the  diseases  which  have  vexed  the  present  assembly  will  have 
lost  their  terrors  for  humanity. 


PrinUd  by  Hazell,  Watson  &  Viney,  Ld.,  London  and  Aylesbury. 


SCIENCE  PROGRESS 

IN  THE  TWENTIETH   CENTURY 
I    A  QUARTERLY  JOURNAL  OF 
\  SCIENTIFIC    WORK 

I  &    THOUGHT 


VOL.  VIII 
NO.   31.     JANUARY    1914 


EDITOR 


SIR    RONALD    ROSS,    K.C.B.,    F.R.S.,    N.L., 
D.Sc,    LL.D.,    M.D.,   F.R.C.S. 


LONDON 
JOHN    MURRAY,   ALI3EMARLE    STREET,    W. 

1914 


NOTICE 

Articles  and  reviews  offered  for  publication  should  be  addressed 
postage-paid  to  The  Editor  of  Science  Progress,  18,  Cavendish 
Square,  London,  W.  They  must  be  accompanied  by  the  full  name, 
address,  and  scientific  and  academical  qualifications  and  appoint- 
ments of  the  writer — for  publication,  unless  otherwise  desired. 
All  possible  care  will  be  taken  of  scripts ;  but  responsibility 
cannot  be  incurred  for  accidental  damage  or  loss.  It  must  be 
understood  that  papers  accepted  for  Science  Progress  shall 
not  be  published  elsewhere  without  the  Editor's  permission. 

Publications  sent  for  mention  or  review  should  also  be 
forwarded  postage-paid  to  the  Editor ;  but  such  mention  or 
review  cannot  be  promised.     Prices  should  always  be  notified. 

The  Editor  will  be  glad  to  receive  notice  of  scientific 
meetings  and  lectures  ;  of  public  appeals  for  scientific  purposes ; 
and  of  all  matters  concerned  with  the  interests  of  science  and 
of  scientific  workers. 

Correspondence  concerning  sales,  exchanges,  and  advertise- 
ments should  be  addressed  to  the  Publisher  of  Science  Progress, 
50A,  Albemarle  Street,  London,  IV. 


CONTENTS 


i.     THE   GENIUS   OF  SCIENCE 

2.  SIR   OLIVER   LODGE'S   ADDRESS      .... 

I.   The  Logic  of  Science.     F.  C.  S.  Schiller,  D.Sc 
II.  The  Philosophy  of  Science.    H.  S.  Shelton,  B.Sc 

3.  SOME  VIEWS  ON  LORD   KELVIN'S   WORK    . 

George  Green,  D.Sc,  University  of  Glasgow. 

4.  THE  DISPLACEMENT  OF  SPECTRAL  LINES  BY  PRES- 

SURE     

H.  Spencer  Jones,  B.A.,  B.Sc,  Chief  Assistant,  Royal 
Observatory,  Greenwich. 

5.  A     SUGGESTION     CONCERNING     THE     ORIGIN      OF 

RADIOACTIVE    MATTER 

H.  S.  Shelton,  B.Sc. 

6.  THE    INFLUENCE    OF    NUTRITION     AND    THE    IN- 

FLUENCE OF  EDUCATION  IN   MENTAL  DEVELOP- 
MENT.     III.    (continued     from    "Science     Progress," 

October  1913)       

F.  W.  Mott,  M.D.,  F.R.S.,  Pathologist  to  the  London 
County  Asylums. 
{Illustrated) 

7.  ENZYMES   AS    SYNTHETIC    AGENTS  (continued    from 

"Science  Progress,"  July  1913) 

II.   In  Protein  Metabolism.     Prof.  Priestley,  B.Sc, 
University,  Leeds. 

S.     THE  PHYSICAL  ASPECT  OF  THE   OPSONIC   EXPERI- 
MENT   

Major  A.  G.  McKendrick,  M.B.,  Ch.B.,  I.M.S. 
9.     THE  HISTORY  OF  THE  VIEWS  OF  NERVOUS  ACTIVITY 
Prof.    D.   Fraser    Harris,   M.D.,    D.Sc,    Dalhousie 
University,  Nova  Scotia. 

jo.     DIFFERENCES   IN   ANIMAL  AND   PLANT   LIFE   . 
F.  Carrel. 

11.  THE  RELATIONS  OF  SPEECH  TO  HUMAN  PROGRESS 

Louis  Robinson,  M.D. 

12.  RECENT     ADVANCES     IN     OUR     KNOWLEDGE     OF 

SYPHILIS 

Edward  Halford  Ross,  M.R.C.S.,  L.R.C.P. 

(Coloured  Illustrations) 

iii 


PAGE 

391 

39S 


419 


433 


45^ 


460 


482 

497 
S°5 

519 

535 


iv  CONTENTS 

PAGE 

13.  WHY  ARE  PEOPLE  SO  CONFINED,  WHEN  FREEDOM 

CAN  BE  ENJOYED? 547 

T.  Brownbridge,  North  Shields. 

14.  THE  PROTECTION   OF  SCIENCE   BY   PATENT     .        .551 

An  Authority  on  Patent  Law. 

15.  REVIEWS   AND   BOOKS   RECEIVED. 

F.  C.  S.  Schiller,  "  Formal  Logic :  A  Scientific  Social  Problem." 

(Macmillan)  .........     559 

A.  W.   Mason,  "  A   Systematic  Course  of  Poetical  Science : 

Book  I.,   Introductory  Physical  Measurements ;   Book   II., 

Experimental  Heat."     (Rivingtons)      .  562 

H.  J.  Brooks,  "  The  Science  of  the  Sciences."  (David  Nutt)  .  562 
L.  Silberstein,  "  Vectorial  Mechanics."  (Macmillan)  .  .  564 
P.  Zeeman,  "  Researches  in  Magneto-Optics."  (Macmillan)  .  565 
J.  P.  C.  Southall,    "Principles   and  Methods  of  Geometrical 

Optics."     (Macmillan) 566 

W.  W.  Campbell,  "  Stellar  Motions."  (Oxford  University  Press)  567 
A.  C.  Cumming,  "  Quantitative  Chemical  Analysis."     (Gurney 

&  Jackson) ..........     569 

J.  B.  Cohen,    "  Organic  Chemistry  for   Advanced  Students." 

(Arnold) 570 

M.    Nierenstein,    "Organische   Arsenverbindungen   und   ihre 

chemotherapeutische  Bedeutung "  .  .  .  .  .572 
L.  W.  Lyde,  "The  Continent  of  Europe."  (Macmillan)  .  .572 
J.  W.  Gregory,  "The  Nature  and  Origin  of  Fiords."  (Murray)  574 
J.    Chunder   Bose,    "Researches    on    Irritability   of    Plants." 

(Longmans,  Green  &  Co.) .         .         .         .         .         .         -576 

H.  G.  Wells  and   A.    M.    Davies,    "Text-book   of  Zoology." 

(University  Tutorial  Press,  London)  .  .  .  .  -577 
Hans  Gadow,   "  The  Wanderings   of  Animals."     (Cambridge 

University  Press) 578 

Gabriel  Tarde,  "  Penal  Philosophy."     (Heinemann)  .         .     578 

H.  A.   Fleming,   "  The    Wonders    of    Wireless   Telegraphy." 

(Society  for  Promoting  Christian  Knowledge)  .  .  .581 
J.  S.  Haldane,  "Mechanism,  Life,  and  Personality."  (Murray)  582 
H.  R.  Mill,  "The  Realm  of  Nature."  (Murray)  .  .  .583 
Sir  John  Murray,  "The  Ocean."  (Williams  &  Norgate)  .  .  5S3 
S.  C.  Schmucker,  "The  Meaning  of  Evolution."     (Macmillan).     584 

"  Life,  Light,  and  Cleanliness  " 584 

P.  Bunau-Varilla,    "  Panama :  The  Creation,  Destruction,  and 

Resurrection."     (Constable)  ......     584 

R.  H.  Jones,  "Experimental  Domestic  Science."  (Heinemann)  585 
Books  Received 586 

16.  CORRESPONDENCE  :  A.  G.  Thacker,  Prof.  Elliot  Smith,  H.  S. 

Shelton 588 

17.  NOTES.     The  Finances  of  Tropical  Medicine     ....     589 

Eugenics  and  War       .         .         .         .         .         .         .     591 

Bristol  University         .         .         .         .         .         .         •     593 

Science  and  the  Lay  Press  ......     594 

The  Nobel  Prizes  for  19 13  .         .         .         .         .         .     597 

NOTICE.     The  Emoluments  of  Scientific  Workers     .         .         .598 


THE  GENIUS  OF  SCIENCE 

When  we  examine  the  little  animals  in  a  droplet  of  water,  the 
first  thing  which  strikes  us  is  their  movement.  But  is  the 
movement  merely  a  chance  transference  hither  and  thither  into 
new  places  where  perhaps  the  food  elements  have  not  already 
been  exhausted  ;  or  is  it  a  purposeful  search  ?  The  latter  im- 
plies, even  in  these  minute  creatures,  the  first  element  of  mind — 
the  mind  of  amoebae  and  of  infusoria.  The  aimless  transference 
requires  no  consciousness  of  direction  ;  but  the  first  property 
of  mind  should  be  that  its  possessor  can  remember  directions 
which  prove  on  trial  to  be  rich  or  deficient  in  nutritive  elements ; 
can  store  its  past  impressions ;  and  can  select  the  directions 
which  give  good  results.  Even  among  these  little  bodies  there 
is  often  some  evidence  of  purposeful  movement — the  creature 
stops,  turns  or  accelerates  its  speed,  or,  when  it  is  interrupted 
by  some  great  mass  of  vegetable  fibre  or  other  detritus,  still 
attempts  to  persist  in  its  former  course.  It  seems  to  be  con- 
sciously searching  its  food — to  be  rejecting  profitless  directions 
and  following  profitable  ones.  Higher  in  the  animal  scale,  we 
find  the  ants  and  bees  travelling  abroad  in  the  most  obviously 
conscious  seekings  for  food ;  and  indeed,  animals  in  general 
seem  to  exist  upon  the  principle  given  by  the  proverbial  injunc- 
tion "  If  at  first  you  don't  succeed,  try,  try,  try  again." 

On  watching  their  movements,  however,  we  are  impressed  by 
the  fact  that  the  intelligence  seems  to  be  very  elementary. 
Thus,  as  the  American  humorist  remarks,  the  busy  ant,  instead 
of  having  the  wisdom  to  walk  round  a  stalk  of  grass,  will  take 
the  trouble  of  ascending  it  to  its  top  and  running  down  the 
other  side.  Similarly  the  wasp,  led  by  the  scent  of  sugar,  will 
enter  a  window,  but  does  not  possess  the  good  sense  to  find  its 
way  out  again  at  the  same  opening.  The  neglected  subject  of 
comparative  psychology  gives  us  many  other  instances.  To 
attach  a  dog  to  a  post,  it  is  sufficient  to  tie  the  rope  with  any 
knot — and  the  animal  never  has  the  wit  to  undo  the  knot  with 
his  teeth.  So  also  with  horses,  and  even  with  monkeys  and 
26  391 


392  SCIENCE  PROGRESS 

baboons ;  but   it   is  another  story  with   the  anthropoid   apes, 
which   will  quickly   loosen  the  knot.     All  the  faculties  of  the 
lower  animals  are  devoted  merely  to  the  search  for  immediate 
necessities,  and  they  are  satisfied  when  the  object  is  attained. 
It  does  not  occur  to  them  that  they  might  facilitate  the  search  by 
a  previous   investigation   of  phenomena.      Similarly   when  we 
rise  in  the  scale  of  mankind,  we  find  that  most   of  them   are 
merely  searching  for  their  food ;  they  try  here  and  there  ;  they 
remember  the  directions  in  which  they  do  or  do  not  succeed, 
and   are  thus   able  to  follow   the  most  promising   course — the 
agriculturist  in  a  search  for  the  best  crops,  the  shopkeeper  in 
the  choice  of  goods  for  sale,  the  financier  in  his  selection  of 
securities,  the   politician   in   search   of  policies,   and   even   the 
mathematician  in  the  solution  of  numerical  equations.     That  is, 
they  seek  by  the  method  of  trial  and  failure  for  a  solution  of  the 
immediate  problem  before  them — which  is  generally  concerned 
with  their  livelihood.     It  does  not  occur  to  them  to  investigate 
the  phenomena  under  consideration,  to  generalise,  and  to  make 
one  solution  suffice  for  many.     When  we  rise  to  this  point  we 
become  men  of  science  and  inventors.     In  the  great  dumb  ages 
which  elapsed  before  men  became  conscious  of  science  many  of 
them  must  have  observed  the  different  shapes  of  stones,  and 
have  even  selected  certain  shapes  for  their  houses.     Then  some 
genius    thought   of   investigating  shapes   in   general,   and   the 
science  of  geometry  was  created,  and  the  Pyramids  and  Parthe- 
non rose  from  the  ground.     Every  one  was  acquainted  with  fire, 
but  it  was  not  until   we  commenced  to  investigate  burning  in 
general  that  chemistry  was  born  ;  and  men  were  almost  helpless 
before  infectious  disease  until  a  few  students  began  to  investi- 
gate its  cause. 

The  dog  does  not  untie  the  knot  because  it  never  occurs  to 
him  to  attempt  to  do  so,  though  he  would  be  easily  able  to  do  so 
with  his  teeth  if  it  had  occurred  to  him.  All  those  who  observed 
the  different  shapes  of  stones  did  not  found  geometry,  not  per- 
haps because  they  would  have  been  unable  to  do  so,  but  because 
the  conception  of  generalisation  and  the  wish  for  it  never 
entered  their  mind.  How  many  millions  of  dogs  or  of  men  may 
have  performed  these  feats  if  only  they  had  thought  of  them  ? 
The  new  idea  is  always  the  rarest  idea.  How  many  millions  or 
billions  of  men  and  how  many  thousands  of  sages  must  have 
watched  the  heavenly  bodies  rising  and  setting  and  evidently 


THE  GENIUS  OF  SCIENCE  393 

circulating  round  the  world,  without  ever  having  thought  for  a 
moment  that  this  evident  movement  was  not  real,  and  was  only 
an  apparent  movement  due  to  the  rotation  of  the  seemingly 
steadfast  mass  upon  which  they  were  standing ;  and  what  an 
extraordinary  flash  of  genius  it  was  which  gave  Copernicus  that 
new  idea.  After  him,  none  of  the  great  astronomers  until 
Newton  ever  dreamed  that  these  heavenly  bodies  are  chained 
to  each  other  by  the  same  law  as  that  which  attaches  loose 
stones  to  the  surface  of  the  earth.  Why  did  not  the  innumer- 
able arithmeticians  of  old  days  conceive  the  possibility  of 
generalising  the  arithmetical  laws  and  creating  algebra ;  and 
why  again  was  it  left  to  the  supreme  genius  of  Newton  to 
analyse  movement  by  its  fluxion  and,  on  the  converse,  to  sum 
fluxion  into  movement  ?  Why  is  it  that  so  few  of  us  think  of 
these  things  ?  Indeed,  the  masses  of  men  tend  to  ridicule  the 
very  flashes  of  genius  which  are  of  such  supreme  benefit  to 
them — as  witness  the  case  of  Columbus  and  of  many  others. 
But  their  obtuseness  punishes  themselves. 

In  science  therefore  the  first  requirement  is  that  flash  of 
intelligence,  imagination,  or  inspiration — call  it  what  you  will — 
which  awakens  the  idea  ;  but  this  of  itself  is  not  sufficient.  The 
person  to  whom  the  idea  has  occurred  must  have  the  sagacity 
to  become  convinced  of  its  usefulness ;  and  this  requires  a  mind 
which  can  attain  to  a  high  purview  of  things  in  general.  The 
mass  of  men  would  attach  no  importance  whatever  to  any  of 
the  ideas  just  mentioned,  even  if  they  had  thought  of  them. 
They  are  not  interested  in  generalisations,  which  give  them 
neither  bread,  nor  fortune,  nor  such  fame  as  they  may  desire ; 
their  efforts  are  directed  to  the  benefit  only  of  their  self  or 
perhaps  their  family  or  their  country.  Even  if  they  possess 
very  great  natural  ability,  they  concentrate  it  upon  such  objects, 
and  become  prosperous  citizens,  millionaires,  generals,  and 
politicians — men  of  merit  perhaps,  but  who  bestow  small 
benefits,  or  even  disasters,  upon  mankind  in  general.  This 
leads  us  to  ask,  what  is  greatness?  It  is  in  the  first  place 
knowledge  of  what  is  really  great.  The  able  man  can  do 
things ;  but  the  great  man  can  first  select  what  is  best  to  be 
done.  The  first  may  be  great  in  small  things,  but  the  second 
is  great  in  great  things.  The  youth  in  search  of  the  work  for 
his  lifetime  will  select  it  according  to  the  degree  of  his  mental 
ability.     If  this  is  very  low  he  will  seek  only  pleasure;  if  it  is 


394  SCIENCE   PROGRESS 

higher,  he  will  seek  for  wealth  or  fame  or  both,  and  chiefly 
for  himself;  if  it  is  still  higher,  he  will  work  for  his  country; 
if  it  is  very  high,  he  will  seek  to  confer  great  benefits  on  man- 
kind in  general,  regardless  of  himself.  We  often  hear  it  dis- 
cussed as  to  who  were  the  greatest  men.  So  far  as  simple 
personal  ability  is  concerned,  it  would  be  difficult  to  choose 
between  a  Newton,  a  Shakespeare,  and  a  Bonaparte.  But  the 
last  worked  really  only  for  himself,  with  some  secondary 
thoughts  for  his  adopted  country.  When  good  fortune  took 
him  by  the  hand,  he  asked  her  only  for  enormous  fame ;  he 
saw  himself  become  a  thunderbolt  among  men  and  the  wonder 
of  all ;  but  since  he  died,  what  has  been  left  of  him  and  his 
work  except  a  story  and  a  name  which  are  scarcely  greater  than 
the  stories  and  names  created  out  of  Shakespeare's  brain — 
to-day  he  is  nothing  more  to  us  than  Hamlet  and  Othello. 
But  we  can  imagine  that  Shakespeare  said  to  himself  "  I  will 
hold  the  mirror  up  to  men  and  teach  them  their  own  nature." 
He  therefore  gave  us  a  boon  incomparably  greater  than  that 
given  by  Napoleon.  In  this  supreme  line  of  effort  the  great 
poet  and  the  great  man  of  science  are  one ;  for  indeed  the  two 
muses  are  twin  sisters.  Newton  did  not  demonstrate  men  to 
man,  but  he  demonstrated  to  him  the  heavens  and  the  science 
of  numbers.  Scarcely  less  are  the  travellers  and  soldiers  who 
confer  civilisation  upon  barbaric  tracts  ;  and  the  inventors  who 
confer  innumerable  utilities  upon  the  whole  race.  In  all  of 
such,  not  only  must  there  have  been  the  flash  of  the  original 
idea;  but  also  the  appreciation  of  its  value  to  the  world  in 
general.  Where,  compared  with  these,  are  the  numerous  men 
of  talent  who  are  great  only  for  themselves  ? 

But  even  these  two  supreme  qualities  are  not  alone  sufficient, 
and  the  scientific  man  must  possess  the  determination  and 
the  vigour  to  overcome  many  difficulties  before  the  original 
idea  can  be  materialised.  That  which  when  discovered  be- 
comes an  easy  commonplace  is  when  undiscovered  an  almost 
unattainable  summit.  He  sees  that  summit  only  at  moments 
through  the  drifting  clouds  of  doubt ;  he  commences  the 
ascent  weighted  by  endless  troubles  and  perplexities,  and  new 
difficulties  confront  him  at  each  footstep.  How  often  does  he 
fail  and  turn  back  to  the  pleasant  vales  of  ordinary  life !  It 
is  a  commonplace  to  think  that  Shakespeare  dashed  off  his 
dramas  without  thought ;  but  each  one  shows  by  the  evidence 


THE   GENIUS  OF   SCIENCE  395 

of  its  structure  that  it  was  created  only  by  ceaseless  labour.  What 
must  have  been  the  toil  necessary  to  found  geometry,  algebra, 
the  calculus,  the  atomic  theory,  the  theories  of  gravitation, 
electricity,  and  evolution  ? — not  less  than  the  toils  which  gave  the 
New  World  to  the  Old  World  and  the  map  of  Africa  to  Europe. 

But  in  addition  to  all  these  qualities  which  the  man  of  science 
must  possess — the  genius  to  conceive,  the  sagacity  to  perceive, 
the  determination  to  succeed,  and  the  strength  to  work — he 
must  also  be  fortunate  enough  to  find  an  opportunity.  There 
may  have  been,  and  probably  were,  many  potential  Newtons 
and  Shakespeares,  as  well  as  Napoleons  in  the  old,  old  history 
of  mankind ;  but  the  opportunities,  that  is  the  powers  given 
by  previous  workers,  were  not  there.  But  to  say  this  is  not 
to  depreciate  the  value  of  the  personal  qualities  required.  We 
often  hear  it  said  scornfully  of  some  discoverer  that  if  he  had 
not  lived  some  one  else  would  have  taken  his  place;  but  this 
is  generally  true  only  of  small  workers.  There  have  been 
revolutions  without  Napoleons,  and  many  opportunities  with- 
out discoveries.  Here  again  the  personal  qualities  enable  the 
man  to  seize  the  opportunity.  In  fact  opportunities  are  common 
but  genius  is  rare ;  and  to  a  great  extent  genius  makes  its  own 
opportunities. 

The  conjunction  of  circumstances  leading  to  the  production 
of  scientific  genius  must  therefore  be  very  rare.  It  is  rare, 
and  its  rarity  explains  the  slowness  of  human  advance.  There 
is  much  evidence  to  show  that  nations  produce  genius  of  all 
kinds  only  at  certain  epochs — that  a  nation  may  exist  for  ages 
without  new  science,  new  art,  or  indeed  advance  in  any  par- 
ticular. Suddenly,  however,  there  comes  a  blossoming-forth. 
Indeed  a  biological  law  may  be  suspected  here — that  genius 
is  like  the  flowers  on  the  tree,  and  that  the  mass  of  mankind 
are  but  the  leaves.  The  latter  serve  the  ordinary  purposes 
of  the  plant;  the  former  serve  the  extraordinary  purpose  of 
a  greater  growth  and  a  more  glorious  future.  The  first  asset 
which  a  nation  possesses  is  its  capacity  for  producing  genius — 
greater  than  the  possession  of  a  fertile  soil,  or  of  mineral  wealth, 
or  of  opportunity  for  commerce ;  as  great  as  the  assets  of 
industry  and  honesty  in  its  people.  The  history  of  nations 
is  mostly  the  history  of  their  men  of  genius  great  and  small ; 
and  there  are  nations  which,  possessing  no  men  of  genius,  have 
taken  no  part  in  the  history  of  the  world  for  ages. 


396  SCIENCE   PROGRESS 

Science,  however,  needs  not  only  men  of  supreme  genius, 
but  men  of  another  class  who  are  scarcely  less  meritorious 
though  fortunately  much  more  common — the  class  of  men  who 
are  engaged  upon  the  record  and  classification  of  observations, 
without  attempting  wide  generalisations.  And  this  branch  of 
science  requires  qualities,  not  so  rare  and  brilliant  perhaps,  but 
also  great — the  desire  to  do  important  work,  the  determination 
to  attempt  it,  and  the  patience  to  accomplish  it — and  that, 
generally  without  hope  of  any  adequate  recompense.  Such 
work  often  leads  by  chance  to  very  important  discoveries,  and 
has  now  become  an  actual  necessity  for  advance.  We  may 
distinguish  the  two  classes  of  mind.  The  first  is  essentially  the 
solver  of  problems  ;  the  second  the  observer  of  facts.  To  some 
extent  every  man  of  science  must  be  composed  of  both  ;  but  in  a 
few  the  former  essence  predominates,  and  in  most,  the  latter 
one.  Science  may  be  almost  said  to  require  nine  parts  of 
thought  to  one  of  observation — but  there  must  always  be  some- 
thing of  both  in  it. 

Lombroso  attempted  to  prove  by  statistics  the  kinship  of 
genius  and  madness ;  but  it  is  more  probable  that  the  latter 
grows  from  the  former  and  not  the  former  from  the  latter. 
Genius  is  the  most  terrible  of  all  tyrants ;  it  exacts  endless 
service  and  it  spares  not  either  its  victim,  nor  his  fortune,  nor 
even  his  children.  It  is  in  that  way  that  the  madness  lies.  The 
fire  which  impels  also  consumes.  Now  it  burns  low  with 
despondency,  now  it  frets  at  each  obstacle,  now  it  overwhelms 
with  success  ;  and  it  must  be  fed  eternally  with  all  the  man's 
possessions.  Even  his  cup  of  triumph  is  mingled  with  myrrh — 
the  scepticism  of  friends,  the  puerilities  of  critics,  the  spite  of 
ools,  the  jealousy  of  rivals,  the  intrigues  of  the  schemers  who 
profit  by  every  new  discovery  at  the  expense  of  the  discoverer, 
and  the  large  indifference  of  the  dull  public.  Is  not  all  this 
written  in  the  book  of  the  history  of  science — the  poison  for 
Socrates,  the  flame  for  Bruno,  the  prison  for  Galileo  and 
Columbus,  opposition  for  Jenner,  and  poverty,  obloquy,  or 
neglect  for  scores  of  the  world's  greatest  benefactors  ?  Nor  has 
it  ceased  to-day*  The  noblest  of  histories  and  religions  is 
based  upon  this  theme.  The  greatest  man  of  science,  who 
obtained  from  his  study  of  human  morality  a  divine  medicine 
for  many  of  the  world's  evils,  suffered  for  his  work  in  a  manner 
which  we  hear  of  in  every  church  to-day ;  yet  those  who  hear  it 


THE   GENIUS  OF  SCIENCE  397 

go  about  to  do  precisely  the  thing  which  was  done  to  him — to 
punish  their  benefactors.  But  then,  they  say  that  these  bene- 
factors are  mad ;  or  that  their  work  was  really  done  by  others, 
or  that  it  was  useless,  or  injurious,  or  contrary  to  religion,  or 
even  to  science  !  And  cases  of  this  kind  have  occurred  recently 
and  will  continue  to  occur.  The  kink  is  really  in  the  mind,  not 
of  the  man  of  genius,  but  of  the  public. 

Of  course  these  are  also  some  of  the  troubles  of  all  good 
workers,  not  only  of  those  of  genius  ;  but  men  of  science  are 
perhaps  the  greatest  sufferers,  because  science  brings  no  material 
reward  to  them.  Science  is  not  protected  by  copyright  or 
patent ;  and  their  labours  are  therefore  not  counterbalanced  by 
any  hope  of  payment  except  the  consciousness  of  their  own  good 
works.  They  are  exploited  by  all  and  paid  by  no  one ;  and  few 
are  found  to  face  the  prospect. 

Hitherto  the  world  has  done  nothing  for  the  most  wonderful 
of  its  products,  the  higher  genius.  It  has  regarded  only  the 
leaves  of  the  tree  of  life— not  the  flowers  and  the  fruit ;  and, 
with  a  strange  obtuseness,  has  indeed  often  cut  the  flowers  or 
pulled  the  fruit  before  it  was  ripe.  It  has  left  all  to  nature,  and 
nature  has  often  responded  according  to  her  wont — by  barren- 
ness. Where  this  has  occurred — where  the  higher  genius  has 
died  out — the  whole  intellectual  life  of  the  people  has  tended  to 
fall  to  the  lower  and  sordid  level  at  which  it  stands  among  some 
nations  to-day ;  and  it  is  the  duty  and  interest  of  mankind  to 
work  for  the  prevention  of  this  calamity  in  the  future. 


SIR  OLIVER   LODGE'S   ADDRESS1 
I.-THE  LOGIC  OF  SCIENCE 

BY   F.   C.    S.   SCHILLER,  M.A.  D.Sc. 
Corpus  Ckriiti  College,  Oxford 

The  Presidential  Address  at  the  British  Association  is  the  great 
manifesto  which  annually  announces  urbi  et  orbi  what  advances 
in  scientific  knowledge  seem  to  its  distinguished  author  to  be 
worthy  of  the  attention  of  the  English-speaking  world,  and 
usually  excites  keen  interest  and  debate.  It  is  therefore  highly 
flattering  to  a  philosopher  who  is  not  callous  to  the  progress  of 
knowledge  to  be  invited  to  take  part  in  this  debate  and  to  have 
an  opportunity  of  expressing  his  characteristic  comment  before 
a  scientific  audience.  But  to  avoid  misunderstandings,  he  should 
make  clear  at  the  outset  how  very  restricted  is  the  philosopher's 
competence  in  such  a  case.  His  primary  attitude  ought  to  be 
that  of  a  learner  who  welcomes  gratefully  the  improvements  in 
human  knowledge  which  the  sciences  have  achieved.  It  is  only 
secondarily  that  he  should  claim  the  right  to  comment  critically 
on  those  aspects  of  scientific  controversy  which  are  ultimately 
logical,  and,  skirmishing  ahead  as  an  unauthorised  raider,  to 
"speculate"  about  those  subjects  which  cannot  yet  be  culti- 
vated by  the  approved  methods  of  scientific  experiment 

In  the  latter  case  his  ingenuity  may  enable  him  to  guess  at 
analogies  that  may  hereafter  lead  to  a  successful  cultivation  of 
the  field  ;  in  the  former,  he  may  sometimes  protect  the  scientist 
against  the  deceptive  glamour  of  words  and  help  him  to  have 
the  courage  of  his  convictions  and  his  methods,  in  spite  of  the 
arrogant  pretensions  and  misleading  suggestions  of  philosophic 
"  logic."  For  the  philosopher  should  never  forget  that  the 
scientist  is  doing  the  actual  work  of  human  knowing,  of  which 
logic  professes  to  expound  the  theory.  But  unfortunately 
science  and  logic  at  present  conduct  their  operations  almost 
completely  out  of  each  other's  sight,  and  only  so  avoid  a  conflict 
which,  if  they  met,  would  be  fatal  to  one  or  the  other.     Modern 

1  Recently  republished  with  notes  (J.  M.  Dent  &  Sons). 

398 


THE  LOGIC  OF  SCIENCE  399 

science  flourishes  because  it  rests  on  a  salutary  ignorance  of 
logic  and  a  healthy  contempt  for  the  traditional  philosophies ; 
modern  logic  survives,  together  with  the  ancient  philosophies  it 
springs  from,  because  it  has  entrenched  itself  in  a  culpable 
ignorance  of  science.  It  is  in  consequence  of  this  specialism 
that  philosophers  have  been  so  slow  to  recognise  the  logical 
value  of  the  actual  procedure  of  the  sciences,  while  scientists 
have  hardly  troubled  as  yet  to  appreciate  the  scientific  import- 
ance of  the  radical  conversion  of  philosophers  to  empiricism 
and  Darwinism  which  goes  under  the  name  of  Pragmatism. 

But  to  a  pragmatist  philosopher  the  scientific  situation  of  the 
present  day  is  full  of  interest  and  stimulus,  and  beautifully  con- 
firms his  generalisations  about  the  real  nature  of  scientific 
method.  Dogmas  are  no  longer  received  on  mere  authority, 
and  are  everywhere  quoted  at  a  discount.  Experiment  has 
everywhere  established  its  right  to  test  assertions  and  to  ques- 
tion prejudices.  Principles  are  no  longer  conceived  as  self- 
evident  and  self-proving  "intuitions"  or  immutable  "necessities 
of  thought,"  but  are  everywhere  treated  as  convenient  postulates 
or  methodological  assumptions,  whose  effective  truth  depends  on 
confirmation  by  experience  rather  than  on  a  man's  psycho- 
logical willingness  to  accept  them  at  a  first  hearing,  so  that  their 
real  proof  comes  from  their  scientific  services  and  their  success 
in  handling  the  "  facts  "  of  the  sciences  that  were  boldly  built 
upon  them.  Hence  the  man  of  science  has  won  great  freedom 
for  himself  in  his  attitude  towards  his  "  principles."  It  has 
everywhere  become  permissible  to  discuss  principles,  to  con- 
sider what  formulations  of  what  principles  are  most  useful,  and 
to  suggest  alternatives  and  improvements  on  those  in  use.  As  a 
matter  of  fact  the  principles  of  most  sciences  have  been  greatly 
modified,  with  the  happiest  effects.  Those  of  biology  have  been 
revolutionised  by  evolutionism,  those  of  geometry  by  meta- 
geometry,  those  of  physics  by  radioactivity,  those  of  mechanics 
and  chemistry  by  the  electric  theory  of  matter,  etc.,  and  even 
such  fundamental  assumptions  as  the  conservation  of  energy 
and  the  indestructibility  of  matter  have  to  submit  to  the  indignity 
of  experimental  verification. 

Nowhere  can  one  see  a  set  of  principles,  even  in  the  sciences 
which  have  not  experienced  such  convulsions,  that  do  not  seem 
to  be  essentially  open  to  discussion  and  that  merely  force  them- 
selves upon  the  mind  through  our  sheer  inability  to  think  of 


4oo  SCIENCE   PROGRESS 

alternatives  to  them  which  are  more  convenient  and  more  fertile 
scientifically.  In  arithmetic  alone  old-fashioned  philosophers 
still  fancy  that  they  are  confronted  by  this  brute  and  uninstruc- 
tive  sort  of  "  a  priori  necessity  of  thought  "  ;  but  only  because 
arithmetic  is  the  oldest,  and  has  become  the  least  progressive, 
of  the  sciences,  and  no  one  has  taken  the  trouble  to  devise  a 
calculus  which  would  systematically  vary  the  initial  postulates 
of  common  arithmetic. 

Now  what  is  the  meaning  of  all  this  unsettling  of  traditions 
and  upsetting  of  scientific  "  foundations  "  ?  According  to  philo- 
sophic <(  logic"  it  reveals  how  incurable  are  the  defects  of  scientific 
method,  how  uncertain  are  all  the  principles  of  the  sciences, 
how  incapable  they  are  of  conducting  to  real  proof  and  stable 
conclusions.  It  is  held  that  "  demonstration  "  is  the  sine  qua  non 
of  reasoning,  and  that  demonstration  is  impossible  unless  the 
principles  on  which  it  rests  are  certain.  Now  inferences  from 
hypothetical  assumptions  are  infected  with  the  defects  of  the 
premisses  from  which  they  are  deduced.  Empirical  verification 
also  is  useless,  because  it  can  never  lead  to  a  "  valid  "  conclusion. 
It  must  always  commit  the  "fallacy"  of  "affirming  the  con- 
sequent," because  it  tries  to  argue  from  the  success  of  the 
consequences  to  the  truth  of  the  initial  premisses.  Once  this 
paralysing  criticism  is  grasped,  the  greater  the  activity  of  thought 
the  greater  the  danger  seems.  The  freedom  to  think  and  the 
licence  to  speculate  can  conduce  only  to  anarchy  and  augment 
the  chances  of  going  wrong.  The  situation  therefore  ought  to 
mean  chaos  in  the  scientific  world,  and  the  discrediting  of 
science. 

But  this  is  not  the  way  either  the  scientists  or  the  public 
take  it.  We  all  imagine  ourselves  to  be  living  in  an  era  of 
unexampled  scientific  progress,  of  enormous  scientific  activity, 
of  infinite  scientific  ingenuity  and  resource.  Moreover,  the 
differences  of  scientific  opinion,  the  struggle  for  existence  of 
ideas,  appears  to  do  no  harm;  the  keener  it  is,  the  more  rapidly 
and  certainly  the  sciences  progress. 

Evidently,  therefore,  something  has  gone  wrong  with  the 
traditional  valuation  of  scientific  method.  The  facts  do  not  bear 
out  the  belief  that  science  flourishes  best  when  it  conceives  itself  to 
be  under  obligation  to  start  from  certainties  and  to  play  for  safety, 
to  anchor  itself  to  unquestionable  dogmas,  or  when  it  dreads 
freedom   of   thought  and   of   debate    and   resents    doubt   and 


THE  LOGIC  OF  SCIENCE  401 

criticism.  On  the  contrary  it  seems  to  grow  all  the  faster  for 
cutting  itself  loose  from  what  has  always  been  believed,  plung- 
ing into  an  agitated  sea  of  wild  hypotheses  and  hazardous  experi- 
ments, and  hailing  as  "true"  whatever  belief  most  successfully 
emerges  from  the  rough  and  tumble  of  the  conflict  of  opinions. 

What  then  is  the  solution  of  the  paradox  that  the  prosperity 
of  science  seems  to  depend  on  its  ignoring  all  the  rules  laid 
down  for  its  guidance  in  the  traditional  logic?  Simply  this, 
that  the  traditional  logic  is  wrong  in  all  its  regulations,  that 
scientific  practice  is  right,  and  that  logical  theory  should  be  based 
on  scientific  practice.  The  pragmatist  is  the  philosopher  who 
has  grasped  all  this  and  has  therefore  discarded  the  meaning- 
less ideals  of  an  impracticable  "  logic."  He  has  recognised 
instead  that  certainty  is  not  the  "  presupposition  "  of  scientific 
inquiry  but  its  (distant)  aim,  and  that  no  matter  how  much 
confirmation  a  scientific  theory  acquires,  it  can  never  become 
absolutely  certain.  He  willingly  admits  the  "formal  fallacy" 
involved  in  "  verification,"  but  does  not  draw  the  formal 
logician's  inference  therefrom.  Instead  of  inferring  that  there- 
fore empirical  evidence  can  never  be  conclusive,  that  experi- 
ence can  never  "  prove  "  anything,  he  infers  that  since  science 
nevertheless  accumulates  such  stores  of  valuable  truth,  it  must 
be  possible  to  dispense  with  evidence  coming  up  to  the  logician's 
specifications  and  with  the  logical  ideal  of  "  proof."  An  ever- 
growing probability,  sufficient  for  the  purposes  of  the  science, 
must  be  what  "  certainty  "  really  means  in  the  concrete,  and  the 
existence  of  alternative  explanations  and  rival  probabilities 
must  be  recognised  in  theory,  as  in  fact. 

Logic,  in  other  words,  must  assimilate  the  great  dictum  of 
Sir  J.  J.  Thomson  that  "  a  scientific  theory  is  a  policy  and  not  a 
creed,"  and  modify  itself  accordingly.  If  truth  (like  honesty)  is 
the  best  policy,  our  keenness  to  attain  it  will  be  enhanced ;  but 
so  will  the  (apparent)  difficulties  of  ensuring  that  we  are  pursuing 
the  best  policy  and  picking  it  out  from  among  the  alterna- 
tives that  present  themselves.  For  we  clearly  run  the  risk  that 
by  adopting  one  policy  we  blind  ourselves  to  the  good  that  is  in 
the  others  and  to  the  facts  that  they  could  bring  to  light.  T6 
minimise  this  risk,  it  is  evident  that  science  must  systematically 
cultivate  open-mindedness  and  practise  toleration.  Alternative 
theories  must  always  be  borne  in  mind,  even  when  the  known 
facts  are  on  the  whole  against  them,  and  no  working  theory 


402  SCIENCE   PROGRESS 

should  be  utterly  condemned.  Nor  can  it  be  wrong  to  experi- 
ment with  a  variety  of  working  theories,  even  though  it  is 
recognised  that  they  are  not,  as  they  stand,  compatible  with  each 
other.  Only  so  shall  we  secure  a  willingness  to  try  experiments 
in  every  direction  and  have  our  attention  directed  upon  the 
facts  that  may  lurk  in  every  quarter.  In  short,  for  the  narrow- 
minded  intolerance  of  a  logic  that  speaks  only  in  terms  of 
"necessity,"  "cogency,"  and  "proof,"  and  leaves  us  wrecked  on 
the  rocks  of  scepticism  when  it  turns  out  that  absolute  truth  and 
certainty  are  nowhere  attainable  by  man,  we  must  substitute  a 
logic  that  will  allow  us  to  take  risks  and  is  familiar  with  the 
notions  of  freedom,  toleration,  and  success,  and  knows  how  to 
justify  its  selections  and  preferences  by  their  superiority  in 
scientific  value. 

It  may  be  thought  that  these  general  considerations  are 
somewhat  remote  from  the  special  topics  of  Sir  Oliver  Lodge's 
Address  ;  but  in  fact  they  conduce  directly  to  its  proper  apprecia- 
tion and  supply  the  principles  which  are  properly  applicable  to 
the  controversial  issues  which  it  raises.  Not  only  do  they 
render  rational  and  intelligible  that  profusion  of  speculation 
of  which  Sir  Oliver  Lodge  gives  so  lucid  and  fascinating  a 
description,  but  they  justify  also  such  of  his  speculations  as  are 
still  somewhat  repugnant  to  the  prejudices  of  those  who  have 
been  brought  up  to  believe  that  at  every  temporary  halting-place 
of  knowledge  they  had  attained  absolute  and  final  truth. 

I  will  not  presume,  however,  to  discuss  what  I  take  to  be  the 
primary  subjects  of  scientific  interest  in  Sir  Oliver  Lodge's 
Address.  These  appear  to  lie  in  the  region  of  physics,  and 
concern  the  scientific  status  of  the  ether  and  the  atom.  I  will 
not  venture  to  comment  on  Sir  Oliver's  championship  of  the 
reality  of  the  ether,  beyond  remarking  that  he  still  seems  to  me 
to  leave  all  the  properties  of  the  ether  functional  and  the  belief 
in  it  a  methodological  assumption,  i.e.  one  of  those  pragmatic 
postulates  which  pave  the  way  for  the  advance  of  science.  But 
this  is  not  of  course  to  deny  that  our  notion  may  not  some 
day  be  found  to  be  something  more  than  a  convenience  of 
thought.  The  strange  romance  of  the  atom,  which  began  as  a 
bit  of  metaphysical  dogmatism,  which  had  a  long  career  as 
a  methodological  assumption,  and  seemed  just  about  to  be  reduced 
to  a  methodological  fiction  when  it  was  shown  to  be  a  real  fact  in 
nature,   should    serve   as   a   signal    warning   against   the   rash 


THE  LOGIC   OF  SCIENCE  403 

presumption  that  what  is  assumed  because  it  is  convenient 
cannot  be  really  true.  But  it  should  be  remembered  also  that 
even  as  the  atom  was  proved  to  exist  only  by  being  exploded 
and  became  good  science  only  by  becoming  a  logical  contradiction 
and  ceasing  to  be  as  indivisible  as  an  "atom"  is  verbally  bound 
to  be,  so  the  ether  may  be  promoted  out  of  the  methodological 
status  it  bears  at  present  only  by  being  so  transformed  in  the 
advance  of  physics  that  its  best  friends,  like  Sir  Oliver  Lodge,  will 
hesitate  to  recognise  it. 

I  will  refrain  also  from  contesting  minor  points,  e.g.  from 
cavilling  at  the  variety  of  his  definitions  of  Time,  which  declare 
in  one  passage  that  time  is  "  essentially  unchangeable,"  even 
for  mathematicians,  and  in  another  that  it  is  an  "  abstraction  " 
of  the  element  of"  progressiveness,"  and  so  presumably  of  our 
own  construction,  together  with  its  "  uniformity,"  which  is 
postulated,  but  assuredly  could  not  be  established  experimen- 
tally. I  will  pass  rather  to  those  points  of  Sir  Oliver  Lodge's 
which  are  likely  to  be  unpopular  with  scientists,  and  show 
that  they  contain  nothing  that  is  contrary  to  the  true  spirit  and 
methods  of  science. 

To  discuss  first  the  legitimacy  of  "  Vitalism."  We  are  here 
confronted  with  a  dispute  which  has  grown  intricate  because  it 
was  not  observed  that  no  conceptions  which  are  capable  of 
being  scientifically  tested  are  either  scientific  or  unscientific 
perse.  It  is  not  scientific  to  believe  in  matter,  anymore  than 
in  spirit,  as  an  unreasoning  act  of  faith,  nor  unscientific  to 
believe  in  devils,  any  more  than  in  ether,  as  a  definite  hypothesis 
from  which  verifiable  consequences  are  deducible.  What  is 
unscientific  is  to  believe  in  devils  without  good  and  sufficient 
evidence,  and  to  disbelieve  in  them  merely  because  they  are 
such  an  uncomfortable  hypothesis.  Even  the  conception  of 
"  law "  may  be  conceived  in  a  thoroughly  anti-scientific  way 
and  used  as  a  method  of  burking  scientific  inquiry.  E.g.  socio- 
logists are  prone,  so  soon  as  they  have  detected  any  uniformity 
in  human  affairs,  to  dub  it  a  "law,"  and  to  think  that  this  ends 
the  matter,  instead  of  investigating  what  combinations  of  forces, 
often  very  various,  have  produced  the  apparently  uniform  result, 
such  as  e.g.  the  fall  of  the  birth-rate  in  all  civilised  societies. 
Or  again,  it  is  very  common  to  hear  the  law  of  evolution  talked 
about  as  if  it  were  an  adequate  explanation  and  assured 
guarantee  of  the  changes  which  we  value  as  "  progress."      In 


404  SCIENCE   PROGRESS 

both  cases  the  notion  of  law  is  used  to  procure  a  facile  satisfac- 
tion and  to  bar  the  way  to  further  inquiry. 

Hence  I  would  venture  with  all  deference  to  suggest  to  the 
disputants  here  that  the  case  is  similar,  and  that  both  vitalism 
and   mechanism    are   scientifically   legitimate    or    the    reverse, 
according   to   the   spirit    in   which   they   are   held.     They   are 
legitimate  if,  and  in  so  far  as,  they  are  meant  to  further  scientific 
inquiry  ;   they  cease  to  be  so  if,  and  so  soon  as,  they  are   in- 
tended to   block  and   to   preclude   any   inquiry   that   promises 
scientific  gain.     Both  also  are  capable  of  being  used  and  mis- 
used.    If  belief  in  the  "mechanical"  nature  of  the  world  means 
the  intention  to  employ  to  the  utmost  a  bold  working  assump- 
tion which,  after  many  crudities,  blunders,  and  false  starts,  from 
Thales  to  Descartes,  we  have  at  last  got  to   apply  to   a  large 
proportion  of  happenings,  it  is  a  good  thing  and  legitimate  ;  if 
it  means  a  dogmatic  refusal  to  let  any  other  methods  of  inter- 
preting nature  be  tried,  a  wilful  blindness  to  the   differences 
between  the  different  sorts  of  happenings,  and  a  stupid  ostracism 
of  the  inevitable  question  as  to  how  the  mind  is  to  be  placed  in 
relation  to  the  mechanical  theory  it  has   itself  devised,  it  is  a 
bad  thing,  because  it  allies   itself  with   ignorance   against  the 
spirit  of  inquiry.     Similarly,  if  vitalism    means   that  vital   pro- 
cesses are  not  to   be   investigated   by  "mechanical"  methods, 
that  their  apparent  differences  are  to  be  accepted  as  ultimate, 
that  the  vital  is  simply  incalculable  and  "  not  mechanical,"  and 
eludes  the  methods  of  physics  and  chemistry  ;   or   again,  that 
pseudo-explanations  are  to  be  given  in  terms  of  a  "  vital  force  " 
which  we  are  forbidden  to  inquire   into  further,  or   even  that 
the  convenient  distinction  between  "life"  and  "matter"  must 
be  taken  as  absolute  and  may  not  be  questioned,  then  vitalism 
is  essentially  negative  and  merely  obstructive,  bad  in  method, 
and   scientifically   noxious.      But   if  it   merely  pleads  for  per- 
mission to   devise   appropriate   methods   for   dealing  with   the 
peculiar  subject-matter  of  each  science,  and   asserts   the  right 
of  biology  to  pay  regard  to  the  peculiarities  of"  living"  matter 
and  to  become  as  "  independent "  as  its  work  requires,  or  that 
in  the  presence  of  "  living"  matter  effects  are  observed  which  do 
not   occur   when  matter  is  "  dead,"  there  can  be  no  scientific 
objection  to  "  vitalism." 

A   complication   is,   however,   introduced   by   the   fact    that 
truly   disputable   extensions   of    vitalism    exist.     For   example, 


THE  LOGIC  OF  SCIENCE  40S 

shall  we  hold  that  biology  is  entitled  by  the  nature  of  its 
problems  to  operate  with  the  conception  of  a  real  efficacy  of 
mind,  in  spite  of  the  fact  that  the  (methodological)  principle 
of  the  conservation  of  energy  is  usually  so  stated  as  to  rule  out 
the  possibility  that  what  is  classified  as  "  psychical"  can  initiate 
"physical"  changes?  If  we  grant  to  a  science  this  licence  to 
go  on  its  own  way  without  regard  to  the  way  it  contradicts 
principles  which  are  useful  in  another  science,  we  must 
evidently  appeal  to  the  doctrine  that  conflicting  hypotheses 
may  be  provisionally  used.  This  will  seem  more  reasonable 
when  we  recollect  that  originally  all  hypotheses  were  devised 
by  us  for  our  use.  Or  again,  how  much  emphasis  is  it  legiti- 
mate to  put  on  the  corollary  that  if  vital  phenomena  are  more 
than  "mechanical,"  they  are  mechanically  incalculable  and 
"free"?  Clearly  if  this  is  over-emphasised,  it  will  conflict  with 
the  tacit  scientific  postulate  that  whatever  it  is  desired  to 
investigate  must  be  assumed  to  be  knowable.  Hence  it  may 
be  well  to  remind  ourselves  that  what  is  not  mechanically 
calculable  need  not  be,  on  that  account,  incalculable  altogether, 
and  that  actions  and  events  may  be  foreseen  also  by  an  appeal 
to  psychological  principles.  In  both  cases  the  more  tolerant 
attitude  towards  these  corollaries  of  vitalism  will  probably  be  to 
the  greater  advantage  of  science,  and,  if  we  adopt  it,  I  can  see 
nothing  in  Sir  Oliver  Lodge's  pronouncements  that  would 
justify  the  rejection  of  his  vitalism  as  anti-scientific. 

But  its  vitalism  is  not  the  greatest  stumbling-block  of  Sir 
Oliver  Lodge's  Address.  His  plea  for  "Psychical  Research"  is 
undoubtedly  still  more  of  a  shock  to  the  susceptibilities  of  many. 
Here  again,  however,  I  hold  that  the  logic  of  science  substantially 
justifies  his  attitude,  even  though  those  who  see  this  may  not 
all  agree  that  the  evidence  accumulated  up  to  date  by  Psychical 
Research  is  such  as  to  generate  in  themselves  a  positive  and 
assured  belief  that  immortality  has  been  proved. 

An  impartial  logician,  i.e.  one  who  is  aware  of  his  personal 
bias  and  endeavours  to  counteract  it,  would  I  think  at  present 
feel  unable  to  attribute  such  high  value  to  the  evidence  in 
question.  Not  because  he  personally  disbelieves  it  or  fails  to 
recognise  that  it  is  a  considerable  improvement  on  the  evidence 
that  was  in  existence  when  the  Society  for  Psychical  Research 
began  its  operations  and  for  the  first  time  in  the  world's  history 
attempted  to  investigate  the  most  momentous  of  all  questions  in 


4o6  SCIENCE   PROGRESS 

a  scientific  spirit  and  by  scientific  methods,  but  because  he  sees 
that  the  scientific  conquest  of  this  dim  region  of  experience  is 
only  just  beginning.  The  science  of  psychology  is  not  yet 
sufficiently  advanced  to  gauge  with  any  confidence  the  limits  of 
insanity,  hallucination,  error,  self-deception,  and  fraud.  Even 
where  the  good  faith  of  the  experience  is  not  to  be  questioned,  it 
is  impossible  to  exclude  a  great  variety  of  interpretations.  The 
evidence  is  not  yet  recorded  much  better  than  that  which  we 
have  for  the  ordinary  occurrences  of  life,  though  its  quality  is 
appreciably  rising.  Its  quantity  also  has  increased,  though  it  is 
still  miserably  insufficient  for  scientific  requirements.  But  the 
most  fatal  defect  in  it  is  that  it  has  not  yet  been  really  subjected 
to  experimental  control.  It  is  still  mainly  observational  in  its 
nature,  and  so  the  conditions  of  the  phenomena  under  investiga- 
tion cannot  be  explored. 

The  result  is  that  it  has  little  or  no  logical  "cogency"  as 
against  those  whose  bias  impels  them  to  disbelieve  it,  even 
though  it  has  become  dangerously  attractive  to  many  who 
merely  wish  to  believe,  and  not  to  know.  Disputes  about 
"  what  Psychical  Research  has  proved  "  must  at  present  end  in 
a  drawn  battle.  For  each  disputant,  by  looking  at  what  favours 
his  own  interpretation  and  viewing  the  evidence  in  the  light  of 
his  bias,  can  justify  his  belief  in  his  own  eyes,  though  he  usually 
fails  to  do  so  in  those  of  his  opponent.  Neither  party  can, 
strictly,  "  prove  "  its  case,  and  the  great  mass  of  mankind,  which 
only  wants  to  "  believe,"  i.e.  not  to  think,  is  indifferent,  and  does 
little  to  help  either. 

This  being  so,  what,  the  logician  may  ask,  are  the  conditions 
of  proof  in  such  a  matter  ?  It  is  in  the  answers  given  to  this 
question  that  the  mischiefs  of  false  logic  become  most  apparent. 
If  we  assume  that  no  man  has  a  right  to  believe  in  what  is  not 
fully  proved,  and  that  it  is  our  duty  to  demand  absolutely  con- 
clusive evidence  before  we  lift  a  hand  or  stir  a  foot,  and  if  it  is 
good  scientific  method  to  employ  every  art  of  pettifogging 
prosecution  and  every  resource  of  scientific  ingenuity  to  crush 
every  bit  of  evidence  as  it  arises,  it  is  clear  that  no  proof  will 
ever  be  forthcoming.  We  shall  never  get  to  the  end  we  profess 
to  aim  at,  because  we  shall  never  be  allowed  to  take  the  first 
step  towards  it,  and  whatever  facts  may  exist  to  be  discovered 
we  shall  never  find  them,  because  we  shall  not  permit  ourselves 
to  look  for  them.     But  if  we  lay  claim  to  a  right  to  experiment 


THE  LOGIC  OF  SCIENCE  407 

and  to  risk  beliefs,  if  we  allow  our  logic  to  observe  that  absolute 
proof  does  not  exist  and  that  scientific  proof  is  in  its  nature 
cumulative,  that  the  objects  of  scientific  research  are  always 
objects  of  scientific  interest  and  desire,  that  facts  which  are  not 
looked  for  are  in  general  not  seen,  that  nature  everywhere 
insists  that  to  find  we  must  seek  and  usually  contrives  to  hide 
away  her  most  important  treasures  in  the  oddest  corners,  it  will 
not  seem  credible  that  the  procedure  hitherto  recommended  and 
pursued  deserves  to  be  described  as  a  search  for  knowledge  at 
all.  It  will  look  rather  like  a  clumsy  and  unfair  attempt  to  burk 
inquiry,  and  it  will  have  to  be  pointed  out  that  if  we  wish  to 
prove  anything  we  must  allow  the  evidence  to  accumulate  and 
permit  the  theory  to  grow  gradually  more  probable,  until  it  is 
no  longer  worth  a  reasonable  man's  while  to  dispute  its  truth. 

With  such  a  reformed  notion  of  proof  the  researches  to  which 
the  psychical  researchers  addict  themselves  appear  in  a  new 
light.  They  are  no  longer  impossible,  unreasonable,  or  anti- 
scientific.  True,  they  are  still  risky,  and  demand  the  courage 
that  braves  the  terrors  of  the  unknown  in  a  higher  degree  than 
most ;  for  they  may  fail  altogether  and  lead  to  nothing,  or  to 
nothing  that  was  desired  or  expected.  But  this  risk  is  taken  by 
every  one  who  undertakes  to  extend  the  borders  of  science. 
They  may  also  be  difficult  and  protracted,  and  a  weariness  to 
the  flesh.  This  again  is  not  uncommon  in  scientific  research. 
But  both  interscientific  comity  and  the  true  interests  of  science 
demand  that  those  who  are  here  sinking  a  shaft  into  the 
unknown  should  not  be  thwarted  and  persecuted,  but  rather 
assisted,  by  all  who  are  interested  in  the  fullest  exploration  of 
the  universe.  Sir  Oliver  Lodge's  eloquent  appeal  for  toleration — 
"  Allow  us  anyhow  to  make  the  attempt.  Give  us  a  fair  field. 
Let  those  who  prefer  the  materialistic  hypothesis  by  all  means 
try  to  develop  their  thesis  as  far  as  they  can ;  but  let  us  try  what 
we  can  do  in  the  psychical  region  and  see  which  wins  " — is  not 
only  the  voice  of  the  good  sportsman  and  the  fair  and  open- 
minded  man,  it  is  also  good  empiricism  and  good  logic,  and, 
above  all,  an  expression  of  the  truly  scientific  spirit. 


27 


SIR   OLIVER   LODGE'S   ADDRESS 

II.— THE   PHILOSOPHY    OF  SCIENCE 

By  H.  S.  SHELTON,  B.Sc 

Comment  on  Sir  Oliver  Lodge's  broad  philosophical  survey  of 
the  field  of  science,  as  might,  perhaps,  have  been  expected,  has 
been  concentrated  on  one  point.  Incidentally,  in  one  short 
paragraph,  this  year's  "  boss  scientist "  (as  Lord  Rayleigh  so 
fittingly  put  it)  stated  that  the  study  of  psychical  research  had 
convinced  him  that  human  personality  survives  bodily  death. 
There  is,  needless  to  say,  nothing  new  in  the  belief,  nor  in 
psychical  research,  and  every  one  acquainted  with  Sir  Oliver 
Lodge  was  well  aware  beforehand  that  such  was  his  personal 
opinion.  There  is,  in  the  address,  no  discussion  of  the  evidence. 
The  opinion  is  stated  in  very  few  words.  It  might,  indeed, 
well  be  ignored  as  a  minor  feature  were  it  not  that  the  journalistic 
instinct  of  many  critics  has  magnified  it  so  as  to  make  it  appear 
the  main  topic  of  the  address.  Thus  the  campaign  of  journalistic 
headlines  compels  the  writer,  much  against  his  inclination,  to 
devote  some  space  to  the  well-worn  theme. 

In  so  doing,  it  is  as  well,  even  though  superfluous,  to  preface 
such  remarks  by  saying  that  the  subject  is  one  on  which  the 
writer  is  much  less  competent  to  speak  than  Sir  Oliver  Lodge. 
Sir  Oliver  Lodge,  in  spite  of  his  many  scientific  achievements, 
really  has,  during  more  than  thirty  years,  found  the  leisure  to 
study  the  details  of  the  evidence  investigated  by  the  Society  for 
Psychical  Research.  Of  such  matters  the  writer  knows  little 
and  cares  less.  His  only  qualifications  for  making  any  comment 
whatever  are  some  knowledge  of  psychology,  a  careful  study 
(several  years  ago,  which  has  not  recently  been  renewed)  of  that 
monumental  volume  by  the  late  F.  W.  H.  Myers,  Human 
Personality  and  its  Survival  of  Bodily  Death,  and  such  common 
sense  as  nature  has  endowed  him  with  and  circumstances 
allowed  him  to  retain.  For  what  such  qualifications  are  worth, 
he  will  now  say,  as  briefly  as  may  be,  how  the  statement 
appears  to  him. 

408 


THE   PHILOSOPHY  OF  SCIENCE  409 

Sir  Oliver  Lodge,  and  other  men  of  science  who  hold  similar 
views,  appear  to  fall  between  two  stools.  On  the  evidential 
side,  the  writer  has  found  nothing,  either  in  Myers'  book  or  else- 
where, which  could  carry  conviction  to,  or  even  merit  serious 
consideration  by,  any  one  not  naturally  predisposed  to  form  the 
"  spiritualist "  conclusions.  On  the  other  hand,  if  the  evidence 
proves  anything  at  all,  it  proves  far  too  much,  and  it  is  more 
logical  to  go  to  those  who,  for  nineteen  centuries,  have  stated 
dogmatically,  as  a  matter  of  faith,  that  human  personality  does 
survive  bodily  death,  and,  moreover,  told  us  more  about  it,  than 
to  attempt,  in  an  amateur  way,  to  build  up  a  little  heresy  of 
one's  own.  These  statements  will,  perhaps,  bear  some  ampli- 
fication. 

On  the  evidential  side,  all  serious  investigators  proceed  on 
the  well-known  philosophic  maxim  :  "  Entia  non  sunt  multipli- 
canda  praeter  necessitatem."  In  all  attempts  to  establish,  by 
observation  or  experiment,  the  existence  of  survival  after  death, 
the  would-be  investigator  has  to  consider  at  least  the  following 
four  explanations  of  any  phenomena  he  may  observe :  (1) 
trickery,  conscious  or  unconscious  ;  (2)  that  striking  series  of 
facts  which  psychologists  are  slowly  gathering  together  con- 
cerning hypnosis  and  dual  and  multiple  personalities ;  (3) 
telepathy ;  (4)  ghosts.  He  will  not  invoke  (3)  until  he  has 
exhausted  (1)  and  (2)  and  all  other  known  explanations.  He 
will  not  invoke  (4)  until  he  has  exhausted  (3). 

Taking  these  in  order,  with  regard  to  the  first,  few  will  need 
reminding  that  a  well-known  conjuror  has  never  yet  failed  to 
reproduce  every  phenomenon  credited  to  "  spirits "  that  has 
been  brought  before  him.  Moreover,  he  is  also  known  to  have 
remarked  that,  for  the  detection  of  trickery  of  this  kind,  he 
would  place  more  reliance  on  the  acumen  of  two  smart  school- 
boys than  in  the  whole  Council  of  the  Royal  Society. 

The  second  is,  scientifically,  a  problem  of  surpassing  interest. 
The  curious  series  of  facts  constituting  multiple  personalities, 
and  other  allied  phenomena,  are  adding  an  important  province 
to  the  realm  of  psychology,  and  are,  indeed,  doing  something  to 
redeem  that  science  from  the  charge  of  verbalism  and  futility. 
But  why  invoke  the  "  spirits  "  ?  Are  not  all  these  phenomena  as 
readily  explained  in  a  perfectly  natural  manner  as  sleep  uncon- 
sciousness and  dreams  ?  Their  evidential  value  is  nil.  And, 
moreover,  the  very  fact  of  their  existence  supplies  an  alternative 


4io  SCIENCE   PROGRESS 

explanation  for  many  phenomena  that  might  otherwise  be  taken 
as  supplying  evidence  of"  possession." 

The  writer  is  not  prepared  to  admit  that  there  is  sufficient 
evidence  for  asserting  the  existence  of  telepathy.  Even  this 
must  be  regarded  as  not  proven.  But  even  if  we  grant,  for  the 
sake  of  argument,  that  such  a  thing  does  exist,  none  knows 
better  than  Sir  Oliver  Lodge  that  the  "  spiritualistic"  hypothesis 
is  not  advanced  one  iota.  All  the  materialist  would  thereby 
admit  as  proved  would  be  that,  as  the  larynx  can  emit  and  the 
ear  receive  the  atmospheric  waves  of  sound,  as  the  eye  can 
receive  the  aetherial  waves  of  light,  so  the  undifferentiated 
nervous  matter  of  the  brain  has  some  residual  power  of  emitting 
and  receiving  vibrations  of  a  wave-length  previously  unsuspected. 

If  we  admit  such  an  idea,  which  in  the  present  state  of 
scientific  knowledge  it  would  be  rash  folly  to  admit,  all  that 
follows  is  that  the  possible  explanations  of  any  unexplained 
residuum  of  "  spiritualistic"  phenomena  are  so  increased  that  the 
residuum  ceases  to  be  worth  investigating. 

The  above  line  of  argument,  it  should  be  noted,  is  one 
which  both  Catholic  and  Freethinker  (and  everyone  else)  can 
accept  without  detriment  to  any  views  they  may  hold  on  matters 
of  religion.  To  the  sceptic  it  will  naturally  appeal.  And  the 
Catholic,  though  he  believes  on  faith  that  there  is  a  life 
beyond  the  grave,  is  not  thereby  committed  to  the  opinion 
that  Sir  Oliver  Lodge  and  the  Society  for  Psychical  Research 
have  a  shred  of  evidence  worthy  of  serious  consideration. 

It  is  with  great  reluctance  that  the  writer  passes  to  the  other 
horn  of  the  dilemma  on  which,  both  in  this  and  cognate 
matters,  Sir  Oliver  Lodge  has  impaled  himself.  But  he  is  open 
to  a  criticism  from  another  quarter  quite  as  deadly  as  any  the 
materialist  can  bring  against  him.  The  Catholic,  also,  is  capable 
of  speaking  to  him  in  tones  of  sound  common  sense. 

"  So  you  are  convinced  that  human  personality  survives 
bodily  death,"  we  can  imagine  him  saying,  "  are  you  ?  That 
is  very  interesting.  Perhaps  you  have  evidence.  Perhaps  you 
have  not.  Personally,  I  should  not  like  to  base  my  belief  on 
your  evidence.  But  let  us  suppose  you  have,  what  then  ?  You 
think  you  are  in  communication  with  disembodied  spirits. 
There  is  nothing  impossible  in  that.  But  my  religion  teaches 
me  that  investigations  of  your  kind  are  better  not  attempted. 
If  you  will  not  accept  our  faith,  at  least  accept  the  fact  that  we 


THE   PHILOSOPHY   OF  SCIENCE  411 

have  not  dealt  with  matters  such  as  these  for  nineteen  centuries 
without  learning  something.  Take  our  advice  and  leave  it 
alone." l 

And  really,  as  a  matter  of  common  sense,  granted 
that  there  is  anything  in  Sir  Oliver  Lodge's  views,  the 
subject  is  one  on  which  the  Catholic  Church  should  be  heard. 
To  put  it  mildly,  they  are  not  novices.  And  the  subject 
really  is  in  their  line.  It  may,  perhaps,  not  have  occurred 
to  him  that  (in  his  own  words)  to  believe  everything  or  to 
believe  nothing  are  the  two  most  logical  attitudes  on  the  matter 
in  question.2 

The  Catholic,  also,  will  be  interested  in  Sir  Oliver  Lodge's 
final  assertion  of  the  existence  of  a  transcendent  God.  He  will 
congratulate  Sir  Oliver  on  his  power  of  reasoning,  It  happens 
to  be  one  of  the  latest  defined  dogmas  of  the  Catholic  Church 
that  the  existence  of  God  can  be  inferred  by  man's  natural 
reason.  That  Sir  Oliver  has  come  to  the  same  conclusion  is  a 
matter  for  congratulation.  Many  (like  the  writer),  whose 
intellect  fails  to  follow  the  course  of  reasoning  in  such  high 
matters,  will  envy  him  his  perspicacity  and  intellectual  power. 
But,  if  he  is  convinced  so  far,  why  does  he  not  drop  all  these 
attempts  at  amateur  theology  and  see  what  Rome  has  to  teach 
him  ?  It  is  really  the  most  logical  course.  One  of  our  most 
prominent  journalists  once  said  : 

11  It  may  be,  Heaven  forgive  me,  that  I  did  try  to  be  original, 
but  I  only  succeeded  in  inventing  all  by  myself  an  inferior  copy 
of  the  existing  traditions  of  civilised  religion.  The  man  from 
the  yacht  thought  he  was  the  first  to  discover  England  ;  I 
thought  I  was  the  first  to  find  Europe.  I  did  try  to  found  a 
heresy  of  my  own ;  and  when  I  had  put  the  last  touches  to  it,  I 
discovered  that  it  was  orthodoxy."  3 

1  In  fairness  to  the  Catholics,  it  should  be  said  that  I  have  never  heard  of  any 
objection  from  that  quarter  to  psychological  research. 

2  Not  having  the  position  or  the  world-wide  repute  of  Sir  Oliver  Lodge,  I  think 
it  desirable  to  state  explicitly  what  should  be  obvious  from  the  whole  discussion, 
that  I  am  not,  in  this  article,  compromising  any  reputation  I  may  possess  as  a 
writer  on  philosophy  and  matters  scientific  by  expressing  positive  opinions  on 
matters  of  religion.  I  am  merely  putting  forward  points  of  view.  The  "  religion 
of  all  sensible  men  "  is  certainly  the  standpoint  of  this  article.  But  if  the  "  boss 
scientist  "  will  introduce  matters  like  this  into  his  address,  what  can  the  critic  do 
but  write  journalese  ? 

3  Orthodoxy,  by  G.  K.  Chesterton,  p.  17. 


412  SCIENCE   PROGRESS 

Very  natural,  no  doubt,  but  why  try  to  found  a  new  heresy  ? 
We  are  reminded  of  the  "  religion  of  all  sensible  men  " — "  that's 
what  sensible  men  never  tell,"  certainly  not  in  presidential 
addresses  to  the  British  Association  for  the  Advancement  of 
Science. 

It  is  with  a  feeling  of  relief  that  we  pass  to  other  ground,  and 
proceed  to  discuss  topics  with  which  Sir  Oliver  Lodge,  and  the 
writer,  are  more  competent  to  deal.  No  greater  injustice  could 
be  done  to  that  able  and  scholarly  address  than  the  injustice 
which  has  continually  been  done,  to  concentrate  criticism  on 
its  weakest  point.  To  some  extent  Sir  Oliver  has  himself  to 
thank.  He  should  have  remembered  that  he  was  not  alone  in 
feeling  the  fascination  of  creating  a  sensation,  and  of  discussing 
matters  with  which  he  is  scarcely  competent  to  deal.  Neverthe- 
less, it  is  as  well  to  remind  readers  of  this  journal  that  Sir 
Oliver  Lodge  is  a  man  of  science,  that  his  address  was  given  to 
the  British  Association  for  the  Advancement  of  Science,  and, 
moreover,  that,  in  dealing  with  matters  of  science,  he  showed 
not  only  specialist  knowledge,  but  that  broad,  clear-sighted, 
philosophic  insight  into  fundamentals  which,  even  among  men 
of  science,  is  rarely  found.  It  is  to  this  side  of  the  address  that 
attention  should  be  directed,  and,  on  this  side,  it  is  worthy  of 
the  highest  praise. 

It  has,  for  several  years,  been  a  favourite  theme  with  the 
present  writer  that  the  abstractions  of  men  of  science  are  often 
and  again  mistaken  for  realities.  In  mathematical  processes, 
the  chain  of  reasoning  is  long  and  involved.  In  all  such 
reasoning,  in  whatever  sense  the  conclusions  may  be  true,  may 
be  absolutely  valid,  that  sense  is  not  the  sense  of  material 
concrete  reality.  Hence  all  such  reasonings,  if  definite  and 
actual  deductions  are  made  from  them,  must  be  submitted  once 
more  to  the  concrete  process  of  observation  and  experiment. 

Simple  and  obvious  as  these  statements  may  appear,  they 
have  important  consequences  in  all  applications  of  scientific 
reasoning  to  philosophy,  to  cosmology,  to  the  affairs  of  every- 
day life.  Numerous  practical  proposals,  advocated  by  men  of 
science  and  others  (especially  others)  on  scientific  grounds,  if 
these  considerations  are  fully  worked  out,  appear  speculative 
and  unpractical.  That  all  men  of  science  should  realise,  as  the 
broad-minded  and  eminent  ones  do,  the  real  meaning  of  their 
results  and  the  limitations  of  their  methods,  is  one  great  object 


THE   PHILOSOPHY   OF   SCIENCE  413 

contemplated  by  those  of  us  who  are  desirous  of  founding  an 
efficient  and  valid  methodology. 

The  support  of  so  eminent  a  man  of  science,  given  in  so 
official  a  capacity  and  in  so  public  a  manner,  is  of  the  highest 
value.  Many  of  the  assertions  contained  in  the  address,  the 
main  trend  and  aspect  of  it,  need  only  to  be  mentioned. 
"  Science  should  not  deal  in  negations,  it  is  strong  in  affirma- 
tions, but  nothing  based  on  abstractions  should  presume  to 
deny  outside  its  own  region" — an  admirable  and  valid  saying, 
to  which  should  be  added  the  corollary  that,  as  all  affirmation 
is,  of  necessity,  denial  of  the  contradictory,  science  should  not 
presume  to  make  dogmatic  and  confident  assertions  outside 
its  own  region.  In  short,  the  limits  of  the  applicability  of 
scientific  truths  require  careful  philosophical  delimitation. 

"  All  intellectual  processes  are  based  on  abstractions.  Science 
makes  a  diagram  of  reality,  displaying  the  works  like  a  skeleton 
clock.  .  .  .  The  laws  of  nature  are  a  diagrammatic  framework  ana- 
lysed and  abstracted  out  of  the  full  comprehensiveness  of  reality." 
Let  us  disregard,  for  the  moment,  the  particular  applications 
and  regard  the  principles.  The  statements  are  true,  valuable, 
practical.  They  are  of  the  greatest  service  to  the  right  under- 
standing of  scientific  truths,  to  common  sense  in  common  life, 
to  sanity  in  politics,  to  the  advancement  of  the  wider  aspects 
of  human  knowledge.  It  is  the  main  object  of  this  essay  to 
ensure  that  they  shall  not  be  ignored,  that  they  should  not  be 
buried  out  of  sight  by  the  concentration  of  attention  and 
criticism  on  the  detail  with  which  we  have  already  dealt,  and 
which,  in  view  of  the  importance  of  the  main  current  of  the 
address,  would  much  better  have  been  omitted.  Before  pro- 
ceeding to  some  of  the  special  applications,  on  which  there  are 
controversy  and  difference  of  opinion,  it  will  be  well  to  indicate 
the  significance  of  these  few  assertions,  to  emphasise  them,  and 
to  express  appreciation  of  Sir  Oliver  Lodge's  sound  judgment 
and  philosophic  insight. 

Concerning  particular  applications,  space  will  only  allow  us 
briefly  to  consider  one  or  two.  One  of  these  concerns  the 
present-day  developments  known  as  non-Newtonian  mechanics 
and  the  Principle  of  Relativity.  The  statements  in  the  address 
are  an  admirable  support  to  those  who  are  pressing  upon  men 
ol  science  the  essential  truth  and  importance  of  fixity  in  funda- 
mentals.    By  mathematical  analysis  and  experimental  investi- 


4i4  SCIENCE   PROGRESS 

gation,  we  are  continually  increasing  the  detail  of  scientific 
knowledge.  Such  detail  often  leads  to  valuable  results  in  the 
practical  affairs  of  everyday  life.  But  there  is  continually  the 
danger  that  the  mathematician  and  the  physicist  should  (more 
or  less  unknowingly)  turn  themselves  into  metaphysicians  and 
give  explanations  of  their  results  which,  to  every  common-sense 
mind,  are  intrinsically  and  obviously  absurd.  Any  one  can  do 
this  if  they  concentrate  attention  on  one  small  point  and  ignore 
the  comprehensiveness  of  reality.  When  the  offender  has  this 
concentration  combined  with  a  certain  degree  of  positive  ignor- 
ance, we  call  him  a  crank.  When  his  facts  are  newly  discovered 
and  such  that  a  high  degree  of  skill  is  required  to  note  and 
classify  them,  he  is  a  not  uncommon  type  of  scientific  investi- 
gator, an  exponent  of  ultra-modern  physics. 

Let  us  consider  this  very  question  of  variable  masses.  The 
great  axiom  is — mass  is  indestructible,  it  is  impossible  for  some- 
thing to  become  nothing.  But  an  ignorant  man  could  well 
devise  many  experiments  on  seaweed,  catgut,  wood,  any  mois- 
ture-absorbent substance,  and  demonstrate  conclusively  that 
mass  varies  with  the  weather  or  the  season  of  the  year.  "  I 
have  more  catgut  in  winter,  weigh  it  and  see,"  you  can  imagine 
him  saying.  "  The  fundamental  laws  of  chemistry  are  wrong." 
Now  while  it  is  perfectly  possible  to  prove  that  he  has  not 
more  catgut,  but  only  more  or  less  moisture  obtained  from  the 
atmosphere,  to  do  so  conclusively  would  be  a  long  and  trouble- 
some analytical  process,  which  the  crank  would  not  understand, 
and  to  which  he  could  readily  make  a  number  of  objections. 

The  indestructibility  of  mass,  of  substance,  is  simply  un- 
provable. It  is  an  axiom  to  which  we  fit  our  observations. 
All  that  chemistry  can  do  is  to  show  that  certain  apparent 
changes  of  mass  are  only  apparent.  It  traces  in  detail  the 
distribution  of  certain  masses  under  certain  conditions. 

The  point  of  these  observations  lies  here.  Without  ex- 
amining in  detail  the  experiments  on  the  velocities  of  a  and 
fi  rays,  we  are  entitled  to  say  that  the  experimentalist  who 
mforms  us  that  mass  is  a  function  of  velocity  is  giving  us 
information  every  whit  as  absurd  as  the  crank  who  informs  us 
that  mass  is  a  function  of  the  season  of  the  year,  and  more  so 
than  the  crank  who  thinks  he  has  discovered  a  perpetual  motion 
machine.  The  experiments,  no  doubt,  are  valid,  but  they  have 
been   misinterpreted.      Sir   Oliver   Lodge    says    that    there    is 


THE   PHILOSOPHY  OF   SCIENCE  415 

actually  an  accretion  of  mass  with  velocity.  There  are  a 
number  of  interpretations  possible.  It  may  be  that  that  of 
Sir  Oliver  Lodge  is  the  correct  one.  But  certainly  that  of  the 
exponent  of  non-Newtonian  mechanics  is  wrong.  On  this 
point,  no  words  can  be  clearer  than  those  of  Sir  Oliver  Lodge  !  : 

"  That  mass  is  constant  is  only  an  approximation.  That 
mass  equal  to  ratio  of  force  and  acceleration  is  a  definition  and 
can  be  absolutely  accurate.  It  holds  perfectly  even  for  an 
electron  with  a  speed  near  that  of  light.  ...  I  urge  that  we 
remain  with  or  go  back  to  Newton.  I  see  no  reason  against 
retaining  all  Newton's  laws,  discarding  nothing,  but  supple- 
menting them  in  the  light  of  further  knowledge." 

On  the  question  of  metageometry,  the  address  is  not  so 
clear,  but,  here  again,  we  can  apply  still  further  the  underlying 
principles.  In  Riemann's  space,  a  line  returns  on  itself.  In 
the  space  of  Lobatschewsky,  "  parallel"  lines  bend  apart.  Does 
either  of  these  or  Euclidean  space  represent  actual  space  ?  To 
this  question  there  is  only  one  possible  answer.  The  line 
returning  on  itself  is  not  straight,  and  the  bending  parallel 
straight  lines  are  neither  straight  nor  parallel.  No  possible 
experiments  can  alter  or  modify  this  fundamental.  It  may 
be  that  non-Euclidean  geometry  is  applicable  to  real  existent 
conditions.  It  may  be  that  the  parallaxes  of  very  distant  stars 
are   negative,   and    there   may  be    means    of  proving   that   the 

1  There  is,  however,  one  point  on  which  Sir  Oliver  Lodge  is  not  quite 
clear.  He  speaks  of  variable  masses,  and  compares  electrons  to  raindrops  or  a 
locomotive.  Elsewhere,  he  says  :  "  The  dependence  of  inertia  and  shape  on 
speed  is  a  genuine  discovery  and,  I  believe,  a  physical  fact."  The  writer  is  pre- 
pared to  admit  this  only  on  the  same  assumption  that  is  applied  to  raindrops  — 
that  the  additional  mass  comes  from  somewhere.  It  is  not  clear  whether  or  no 
this  is  Sir  Oliver  Lodge's  meaning.  If  not,  I  would  add  it  as  a  corollary.  I 
regard  the  indestructibility  of  mass  as  as  fundamental  an  axiom  as  the  unchange- 
ability  of  space  and  time,  and  I  am  not  aware  of  any  more  fundamental  measure 
of  mass  than  inertia. 

The  idea  has  occurred  to  me  that  electrons,  when  their  velocity  exceeds  a 
certain  amount,  may  meet  with  some  resistance  from  the  cether,  and  that  the  very 
experiments  which  have  occasioned  a  doubt  as  to  its  existence  may  be  an 
additional  means  of  proving  it.  As  I  have  not  had  an  opportunity  of  witnessing 
the  actual  experiments,  I  merely  put  this  forward  as  a  suggestion  and  with  all 
reserve.  I  am  informed  that  there  is  some  objection  on  the  ground  of  the  path 
of  the  /3  rays,  but  that  the  experiments  have  not  been  performed  with  sufficient 
care  to  enable  us  to  speak  definitely,  hence  the  reserve.  But,  personally,  on 
present  knowledge,  I  am  inclined  to  think  variable  resistance  more  probable  than 
variable  mass- 


4i6  SCIENCE   PROGRESS 

stars  which,  by  astronomical  measurement,  are  found  to  be 
nearer,  should  ultimately  be  discovered  to  be  farther.  On  such 
a  question  it  is  possible  to  admit  evidence.1  A  non-Euclidean 
aether  is  as  metaphysically  possible  as  a  centaur  or  a  hippogriff. 
A  non-Euclidean  space  is  as  contradictory  as  a  round  square. 
Our  material  lines  may  bend  ;  our  rays  of  light  may  bend  ;  but 
our  straight  lines  are  not  straight  unless  they  are  straight.  It 
may  be  that  we  always  see  crooked,  but  that  is  no  reason  why 
we  should  not  think  straight.  The  writer  would  urge  not  only 
that  we  go  back  with  or  remain  with  Newton,  but  that  we  go 
back  to  or  remain  with  Euclid.  Non-Euclidean  geometry,  non- 
Newtonian  mechanics,  and  the  Principle  of  Relativity  are  admir- 
able examples  of  the  coherence  of  thought  whatever  may  be  the 
material  supplied  to  it  as  foundation,  but  they  must  not  be  mis- 
taken for  reality. 

Some  physicists  would  try  to  inform  us  that  there  is  no 
velocity  greater  than  that  of  light.  It  may  be  that  it  is  so.  It 
may  be  that  the  aether  of  space,  which,  in  spite  of  the  re- 
lativists, we  must  emphatically  assert  is  an  assumption  almost 
essential  to  the  explanation  of  the  world  as  we  see  and  know  it, 
imposes  an  impenetrable  barrier  upon  more  rapid  motion.  Even 
here,  however,  there  is  no  sufficient  evidence.  But  the  physicist 
who  says  that  there  is  anything  in  velocity  that  prevents  a 
greater  speed  than  that  of  light  is  talking  absurdly.  Velocity 
and  limit  are  contradictory  concepts.  It  is  a  round  square  and  a 
crooked  straight  line  over  again.  Nor  should  it  be  admitted  too 
hastily  that  no  actual  velocity  can  exceed  that  of  light.  Even 
here  the  physicist  is  extrapolating  unduly.  All  experiments  on 
high  velocities  necessarily  have  reference  to  minute  electrified 
particles,  and  it  may  be  that  electrified  and  non-electrified  bodies 
differ  in  properties  such  as  these.  Moreover,  once  again,  all  he 
can  say  is  that  his  equations  apply  only  to  velocities  smaller 
than  that  of  light.  Once  again,  as  so  often  before  in  the  realm 
of  practical  science,  we  are  bound  to  demur  that  it  is  not  allow- 
able to  extrapolate  an  empirical  rule  one  iota  beyond  the  point 
where  it  is  experimentally  proved.  Prof.  Dewar  discovered  the 
importance  of  this  principle  when  he  wrongly  estimated  the 
temperature  of  liquid  hydrogen.     And  the  rationale  of  relativism 

1  It  is  as  well  to  be  explicit  and  say  that  I  have  never  heard  it  suggested  that 
there  is  any  evidence  of  the  kind.  The  matter  here  briefly  touched  I  have  treated 
more  fully  in  two  articles  in  Mind,  No.  73  and  No.  88. 


THE   PHILOSOPHY   OF  SCIENCE  417 

is  just  what  the  methodologist  is  anxious  to  discuss  with  the 
relativist.  The  point,  however,  will  readily  illustrate  the  differ- 
ence between  matters  on  which  evidence  is  admissible  and 
those  on  which  evidence  is  impossible.  It  is  possible  (but  im- 
probable) that  no  actual  velocity  can  exceed  that  of  light.  By  all 
means  let  us  investigate  the  evidence  and  gather  more  when  we 
can.  It  is  impossible  and  inconceivable  that  the  limit  to  velocity 
can  be  the  velocity  of  light. 

So  rarely  does  it  happen  that  men  of  science  are  also  philo- 
sophers that  we  must  express  our  gratitude  to  Sir  Oliver  Lodge 
for  placing  considerations  like  these  in  a  clear  light  and  for 
showing  that  there  are  explanations  to  all  physical  facts  not  at 
variance  with  the  laws  of  thought.  The  laws  of  thought,  as  the 
greatest  philosophers  of  all  eras  have  pointed  out  in  one  way  or 
another,  are  the  conceptual  framework  which  we  throw  over  the 
material  of  perceptual  reality.  Why  there  should  be  laws  of 
thought  and  why  these  should  possess  validity  over  and  above 
the  empirical  rules  we  call  the  laws  of  science  is  a  problem  we 
cannot  discuss  here.  It  will  suffice  to  point  out  that  it  is  so, 
and  that  those  of  philosophic  training  have  always  recognised 
the  fact.  The  mathematician  and  the  physicist  on  this  point  are 
continually  blundering.  One  generation,  that  of  Kelvin  and 
Tait,  will  use  the  laws  of  thought  as  mathematical  reasoning, 
and  will  mistake  them  for  the  laws  of  things.  We  thereby  get 
grotesque  estimates  of  geologic  time,  and  the  Dissipation  of 
Energy.  The  next  generation  will  make  the  inverse  mistake. 
They  will  discover  the  peculiar  behaviour  of  certain  things  and 
will  mistake  the  laws  of  things  for  the  laws  of  thought.  All  we 
are  entitled  to  say  is  that  electrons,  under  certain  conditions, 
behave  in  a  certain  manner.  The  certainty  and  security  of 
fundamentals  continually  needs  to  be  emphasised  by  those  who 
deal  with  the  wider  aspects  of  physical  science.  Space  is  space, 
and  there  is  no  such  thing  as  crooked  space.  Velocity  is  a  con- 
cept which  does  not  admit  a  finite  limit.  The  ultimate  entities 
of  the  Universe  are  constant  in  quantity.  Something  cannot 
become  nothing.  Action  at  a  distance  is  inconceivable.  Truths 
like  these  can  be  misapplied,  but  they  are  more  fundamental 
than  any  derived  from  experiment. 

To  the  writer,  the  above  is  the  most  important  aspect  of  the 
address.  To  him,  to  speak  candidly,  the  "  spiritualism  "  is  a 
hasty  and  unwarranted  assertion.   The  discussion  of  the  dogmas 


4i8  SCIENCE   PROGRESS 

of  religion  seems  entirely  out  of  place,  and,  moreover,  the 
reasoning  is  of  such  a  character  that  the  writer  is  unable  to 
follow.  The  remarks  concerning  the  origin  of  life  and  the  con- 
trast between  the  views  of  Sir  Oliver  Lodge  and  those  of  his 
predecessor,  Prof.  Schafer,  there  is  no  space  to  discuss.  The 
main  value  consists  in  the  assertion  of  the  fixity  of  scientific 
fundamentals.  And  for  support  on  this  point  the  methodo- 
logist,  and  the  philosopher  who  really  possesses  knowledge  of 
matters  scientific,  will  be  grateful.  The  details  of  scientific  ex- 
periment and  of  mathematical  calculation  are  problems  which 
lie  within  the  sphere  of  science.  Their  interpretation,  their 
interrelation,  their  co-ordination,  are  problems  which  properly 
belong  to  philosophy.  On  this  point  Sir  Oliver  Lodge  is  truly 
philosophic,  and  his  remarks  deserve  the  most  careful  attention 
of  the  scientific  specialist,  who  is  naturally  more  ready  to  listen 
to  one  eminent  in  his  own  sphere  than  to  those  whose  know- 
ledge of  matters  scientific  is  less  specialised.  The  address  is  a 
valuable  asset  to  those  who  maintain,  against  opposition  from 
both  sides,  that  the  co-ordination  of  the  facts  and  theories  of 
science  lies  within  the  sphere  of  philosophy,  and,  moreover,  that 
the  co-ordination  should  not  be  a  shadow  or  a  figment  but  a 
solid  reality. 


SOME  VIEWS  ON  LORD  KELVIN'S  WORK 

By  GEORGE  GREEN,  D.Sc. 
Lecturer  on  Natural  Philosophy,  University  of  Glasgow 

The  work  of  Lord  Kelvin  is  so  fundamental  and  his  fields  of 
activity  so  diverse  that  it  is  practically  impossible  to  estimate  the 
benefits  conferred  by  it  in  his  own  time  and  still  less  possible  to 
estimate  those  yet  to  come  from  his  moulding  and  directing 
influence  in  the  movements  of  his  time.  Broadly  speaking,  his 
gift  has  been  to  teach  us  how  to  discover  the  processes  of 
Nature  and  how  to  bring  them  into  common  use.  His  pioneer 
work  in  the  training  of  his  students  in  experimental  physics  was 
the  foundation  of  the  modern  laboratory.  His  numerous  inven- 
tions and  his  constant  occupation  with  practical  industrial  affairs 
as  the  daily  duty  of  his  life  have  wrought  improvements  of  the 
ordinary  conditions  of  life  that  are  enormous,  have  helped  to 
revolutionise  our  industrial  system,  and  have  pointed  the  line 
of  further  progress  by  establishing  research  as  an  essential  part 
of  industrial  enterprise.  His  collected  patents  are  almost  as 
bulky  as  the  volumes  of  his  collected  scientific  papers,  and  the 
subjects  to  which  they  refer  are  as  valuable  in  their  potency  for 
the  extension  of  knowledge  as  for  good  and  useful  daily 
service. 

In  the  field  of  pure  science  we  find  the  same  feature  of  his 
work.  He  not  only  adds  to  our  knowledge  ;  he  is  the  interpreter 
and  dispenser  to  mankind  of  the  great  works  of  others.  When 
not  engaged  in  independent  search  he  is  shaping  and  transform- 
ing the  ideas  of  others  for  the  daily  use  of  his  contemporaries, 
and  making  their  ideas  more  fit  instruments  for  future  work. 
He  brought  to  light  the  work  of  George  Green  of  Nottingham 
and  revealed  its  value.  What  he  received  from  Carnot  and  from 
Joule  he  expounded  in  applications  to  the  whole  domain  of 
Physics,  and  defined  the  limitations  to  our  use  of  energy  by 
discovering  the  great  principle  of  Dissipation  of  Energy  and 
the  Second  Law  of  Thermodynamics.  He  took  the  discoveries 
of  Faraday    and    the   investigations   of  Helmholtz    on   Vortex 

419 


420  SCIENCE   PROGRESS 

motion,  and  derived  from  them  a  theory  of  matter  which  has 
illumined  the  whole  region  of  molecular  physics. 

To  write  a  full  account  of  Lord  Kelvin's  work  in  science  is 
practically  to  write  the  history  of  modern  science  and  to  indicate 
the  bearing  of  modern  lines  of  investigation.  In  almost  every 
branch  of  science  his  work  is  fundamental.  His  labours  have 
been  extended  by  later  workers  and  each  field  developed  in 
detail  so  that  each  worker  realises  the  greatness  of  Lord 
Kelvin's  pioneering  achievements  only  in  his  own  domain. 
In  the  presence  of  so  extensive  a  volume  of  material  no  explana- 
tion is  required  regarding  the  subjects  dealt  with  in  the  following 
pages  other  than  that  they  constitute  the  present  writer's  main 
line  of  interest  in  the  work  of  Lord  Kelvin  and  fall  in  best  with 
his  experience.  The  intention  is  to  sketch  roughly  his  own 
personal  work  with  a  view  to  arriving  at  the  foundation  of  his 
attitude  to  modern  views  on  molecular  physics,  and  to  indicate 
the  bearing  of  his  later  work,  with  the  developments  which  it 
has  received  since  his  death  in  1907,  on  modern  speculations 
regarding  the  mechanism  of  radiation. 

Some  guiding  principle  is  necessary  to  explain  the  appar- 
ently miscellaneous  and  diverse  nature  of  his  earlier  papers. 
The  ideas  promulgated  by  Faraday,  and  his  success  in  establish- 
ing a  relation  between  Magnetism  and  Light  on  the  experimental 
side,  the  scope  of  the  work  of  Green,  and  the  development  by 
Stokes  of  the  analogy  between  equilibrium  conditions  of  elastic 
solids  and  viscous  fluid  motion,  accompanied  by  Lord  Kelvin's 
own  success  in  connecting  Flow  of  Heat  with  Electrostatics  and 
Attraction,  seem  to  have  firmly  rooted  in  his  mind  the  conception 
of  the  underlying  unity  of  physical  processes  and,  thus  early  in 
his  career,  made  the  achievement  of  uniting  the  known  laws  of 
Nature  within  a  single  scheme  a  dominating  ambition  of  his 
life.  Evidence  of  this  appears  throughout  his  works.  One  of 
the  most  prominent  features  of  his  writings  is  his  fondness  for 
mathematical  analogies.  Almost  from  the  beginning  of  his 
writings  we  can  trace  the  conscious  extension  of  his  range 
along  this  line  towards  that  "  comprehensive  dynamics  of  ether, 
electricity,  and  ponderable  matter,  which  shall  include  electro- 
static force,  magnetostatic  force,  electromagnetism,  electro- 
chemistry, and  the  wave  theory  of  light  "  (Baltimore  Lectures, 
Preface). 

One  of  his  earliest  contributions  to   the    Cambridge  Math. 


SOME  VIEWS  ON   LORD   KELVIN'S  WORK     421 

Journal  points  out  the  analogy  between  the  steady  motion  of 
heat  and  the  chief  theorems  on  Attraction,  thus  uniting  flow  of 
heat  with  flow  of  force  in  electrostatics  and  paving  the  way 
towards  the  banishment  of  action  at  a  distance  ideas  in  the  latter 
subject.  The  support  which  such  an  analogy  lent  to  the  views 
then  being  put  forward  by  Faraday  is  clearly  indicated  at  the 
end  of  Thomson's  paper  "  On  the  Elementary  Laws  of  Statical 
Electricity,"  of  date  1845  ;  and  there  is  little  doubt  that  this  dis- 
covery deepened  his  interest  in  Faraday's  researches  and  gave  his 
thoughts  an  added  stimulus  in  the  direction  of  physical  theories. 
From  the  importance  of  his  mathematical  work  his  interests 
grew  and  extended  to  the  region  of  practical  physics  under  the 
influence  first  of  Faraday  and  afterwards  of  Joule.  Being  also 
closely  in  touch  with  the  work  of  Stokes  "  On  the  Friction  of 
Fluids  in  Motion,  and  the  Equilibrium  and  Motion  of  Elastic 
Solids,"  which  virtually  brought  two  new  regions  within  the 
scope  of  his  mathematical  analogies,  he  was  naturally  inspired 
by  Faraday's  discovery,  in  1845,  of  rotation  of  the  plane  of 
polarised  light  in  transparent  bodies  by  a  magnetic  field,  to 
attempt  and  to  achieve  the  elastic  solid  illustration  of  Electro- 
magnetic actions.  His  paper  "  On  a  Mechanical  Representation 
of  Electric,  Magnetic,  and  Galvanic  Forces,"  which  appeared  in 
1847,  marks  the  consolidation  of  his  views  with  respect  to  the 
medium  of  electromagnetic  action.  Lord  Kelvin  in  later  life  never 
hesitated  to  employ  action  at  a  distance  principles  in  his  later 
speculations  as  to  the  constitution  of  atoms  and  their  interactions, 
whenever  insufficiency  of  knowledge  made  such  tentative  methods 
expedient,  but  Faraday's  discovery  of  1845  seems  to  have  con- 
vinced him  of  the  necessity  for  some  elastic  solid  explanation  of 
the  actions  manifested  in  the  ether  as  Electrostatic,  Magnetic,  or 
Electromagnetic  forces.  This  same  paper,  which  marks  his 
decision  in  this  matter,  practically  adhered  to  throughout  his 
life,  assisted  largely  in  the  development  of  Maxwell's  views 
towards  the  electromagnetic  theory  of  light  which  he  reached 
in  1864. 

In  this  connection,  as  in  other  important  decisions  regarding 
the  larger  questions  in  Physics,  it  is  evident  that  the  mathe- 
matical bent  of  Lord  Kelvin's  mind  largely  determined  his 
attitude  towards  physical  theories.  A  quotation  which  he  makes 
from  Green's  writings,  regarding  general  matter-of-fact  explana- 
tions of  physical  processes,  reveals  clearly  his  own  attitude  of 


422  SCIENCE  PROGRESS 

mind  :  "  I  have  no  faith  in  speculations  of  this  kind  unless  they 
can  be  reduced  to  regular  analysis."  Overcaution  and  entire 
avoidance  of  speculation  not  warranted  by  the  analysis  delayed 
his  full  acceptance  of  the  teaching  of  Joule.  The  absence  of  a 
definite  physical  basis  for  the  formulas  brought  forward  by 
Maxwell  was  an  impassable  barrier  to  Lord  Kelvin's  acceptance 
of  them  as  substantial  theory,  in  spite  of  their  power  to  meet  the 
facts.  Wherever  an  element  of  uncertainty  remained,  as  in 
the  application  of  the  Boltzmann  Maxwell  Law,  or  with  regard 
to  pressure  of  radiation  and  the  manner  in  which  thermodynamics 
was  employed  in  the  theory  of  that  subject,  his  attitude  was  one 
of  entire  distrust. 

The  explanations,  inspired  by  Faraday's  discovery  of  1845,  °f 
Electrostatic,  Magnetic,  and  Electromagnetic  forces  by  various 
types  of  Strain  in  an  elastic  solid,  and  the  Dynamical  illustration 
which  he  provided  in  1856  for  the  action  of  Magnetism  on  Light 
and  for  the  rotary  action  of  transparent  bodies  on  polarised 
light,  are  typical  examples  of  his  requirements  in  the  way  of 
satisfactory  explanation.  The  latter  paper  led  ultimately  to  the 
analogy  for  ether  of  a  fluid  constituted  of  imbedded  gyrostats ; 
but  being,  in  the  years  immediately  preceding  1856,  engrossed 
with  the  difficulties  of  reconciling  Carnot  and  Joule  and,  later, 
with  the  application  of  the  principles  of  thermodynamics  to 
gases,  to  electrolysis,  to  thermoelectricity,  to  magnetism  and  other 
subjects,  and  with  the  development  of  the  doctrine  of  available 
energy,  he  naturally  did  not  regard  the  realising  of  his  "  grand 
object  "  as  an  object  for  immediate  pursuit.  His  constant  appeal 
to  analogy,  however,  in  his  writings  of  this  period  bears 
testimony  to  his  constant  review  of  the  range  of  mathematical 
analysis  to  discover  the  most  promising  line  of  advance  towards 
his  object.  And  when  the  tide  of  his  thermodynamic  researches 
had  spent  its  first  rush  in  the  full  stream  of  investigation 
emanating  from  the  two  great  energy  principles,  and  when  other 
interests  could  reassert  their  claims,  the  appearance  of  Helm- 
holtz  memoir  on  the  dynamical  theory  of  Vortex  Motion  in  1858 
inspired  him  to  fresh  efforts  to  accomplish  his  original  aim. 
The  promise  of  success  which  the  vortex  atom  theory  of  matter 
for  a  time  held  out  spurred  him  to  eager  mathematical  investiga- 
tions. The  memoir  on  Vortex  Motion,  read  first  in  April  1867,  was 
undertaken,  according  to  his  own  statement,  "  to  illustrate  the 
hypothesis   that  space  is  continuously  occupied  by  an  incom- 


SOME  VIEWS  ON   LORD   KELVIN'S  WORK      423 

pressible  frictionless  liquid  acted  on  by  no  forces,  and  that 
material  phenomena  of  every  kind  depend  solely  on  motions 
created  in  this  liquid."  As  the  investigation  proceeded,  it 
branched  off  into  a  long  series  of  additions  to  General  Hydro- 
dynamics, including  Motion  of  Solids  through  a  Liquid,  Motion  of 
a  Viscous  Fluid,  Turbulent  Motion  of  an  Inviscid  Fluid,  and 
followed  later  by  Wave  Motion  in  Dispersive  Media  and  Waves 
on  Water. 

The  memoir  on  Vortex  Motion,  with  the  underlying  idea 
of  all  material  properties  being  ultimately  due  to  motion,  taken 
with  the  series  of  investigations  in  Molecular  Theory  to  which 
it  gave  rise,  virtually  introduces  us  to  modern  molecular  theory 
and  carries  us  almost  as  far  forward  in  forming  a  mental  picture 
of  the  world  of  atomic  actions  as  it  is  possible  to  go  without 
the  knowledge  of  the  electron.  Its  immediate  effect  was  to  lead 
Lord  Kelvin  on  to  a  vigorous  attack  on  a  host  of  hydrodynamical 
problems  connected  with  vortex  filaments  and  their  stability, 
and  with  the  motion  of  free  solids  through  a  liquid.  Associated 
with  this  work  came  the  completion  and  publication  in  1871  of 
the  memoir,  partly  written  in  1849,  on  the  Mathematical  Theory 
of  Magnetism — now  much  enriched  by  the  hydrokinetic  ana- 
logies arising  from  his  hydrodynamical  investigations.  The 
questions  of  stability  of  various  configurations  of  vortices 
have  reappeared  again  in  connection  with  the  modern  electron 
theory,  and  have  led  to  important  results.  Difficulties  of  the 
vortex  atom  theory  arose,  however,  in  connection  with  the 
velocity  of  sound  in  gases,  and  with  the  relation  of  inertia  to 
temperature,  and  in  the  explanation  of  chemical  combinations 
and  atomic  weights.  The  advance  of  the  atomic  theory  of 
electricity,  and  the  impossibility,  in  Lord  Kelvin's  view,  of 
accounting,  by  the  aid  of  the  vortex  theory  alone,  for  the  infinite 
variety  of  chemical  substances,  crystalline  configurations,  or  elec- 
trical or  chemical  or  gravitational  forces,  led  to  his  abandoning 
it ;  but  not  before  the  investigation  had  opened  up  possibilities 
of  accounting  for  the  properties  required  in  a  medium  capable 
of  producing  electromagnetic  actions  by  some  complex  foun- 
dation of  vortex  motion  in  a  liquid.  In  this  connection  it  led 
to  extended  efforts  "  to  construct,  by  giving  vortex  motions  to 
an  incompressible  inviscid  liquid,  a  medium  which  shall  transmit 
waves  of  laminar  motion  as  the  luminiferous  ether  transmits 
waves  of  light,"  an  idea  advocated  for  many  years  by  Fitzgerald. 
28 


424  SCIENCE   PROGRESS 

After  examination  of  the  matter  in  his  paper  of  1887,  "  On  the 
Propagation  of  Laminar  Motion  through  a  Turbulently  Moving 
Inviscid  Liquid,"  in  which  he  derived  equations  similar  to 
Maxwell's,  the  turbulent  ether  full  of  vortical  motion  did  not 
satisfy  Lord  Kelvin,  owing  to  the  uncertainty  that  irregularity 
would  not  arise  in  the  properties  of  the  medium  within  the 
period  of  a  wave  or  vibration,  due  to  possible  rearrangement 
of  the  turbulent  state  of  motion  within  it  destroying  its  average 
homogeneousness. 

The  two  lines  of  investigation  arising  from  considerations 
of  vortex  motion  had  a  permanent  influence  in  determining 
Lord  Kelvin's  later  views.  The  abandonment  of  the  idea  that 
ether  is  a  fluid,  presenting  appearances  of  elasticity  due  to 
motion,  turned  him  once  more  to  seek  for  some  form  of  elastic 
solid  ether,  as  this  seemed  to  him  to  present  the  simplest 
and  the  only  certain  foundation  of  any  theory  fulfilling  the 
requirements  of  the  wave  theory  of  light.  The  failure  of  the 
explanation  of  atomic  properties  by  motion  turned  him  towards 
the   statical  foundations  of  atomic  structure  dealt  with  in  the 

• 

Baltimore  Lectures  and  later  papers,  and  made  him  regard  it 
as  "  extremely  improbable  that  differences  of  arrangement  of 
atoms  all  equal  and  similar  could  suffice  to  explain  all  the 
different  chemical  and  other  properties  of  the  great  number 
of  substances  now  commonly  called  chemical  elements." 
Practically  the  whole  of  his  later  work,  emanating  directly 
from  his  philosophic  views — comprising  the  last  six  papers  of 
vol.  iii  of  his  Collected  Papers  which  relate  chiefly  to  the  proposed 
gyrostatic  structure  for  ether,  with  the  whole  of  the  Baltimore 
Lectures,  and  the  papers  in  vols,  iv,  v,  and  vi  on  Molecular  and 
Crystalline  Theory,  on  Voltaic  Theory,  Radioactivity,  Electrons, 
and  on  Waves  on  Water — constitute  a  pursuance  of  his  original 
aim  of  reconciling  Optical  and  Electromagnetic  Theory  on  some 
elastic  solid  theory,  and  of  finding  a  relation  between  matter 
and  ether  consistent  with  this  view. 

Amongst  the  later  papers,  the  subjects  which  received  most 
of  Lord  Kelvin's  attention  were  those  relating  to  Atoms  and 
Electrons  and  Waves  on  Water.  Of  these,  perhaps  the  most 
interesting,  and  that  bearing  most  strongly  on  modern  views 
on  the  electrical  theory  of  matter,  is  the  first-mentioned,  which 
he  refers  to  as  Atomic  Electrostatics.  Here,  as  always  in  the 
matter  of  foundations,  Lord  Kelvin  is  conservative,  preferring 


SOME  VIEWS  ON   LORD   KELVIN'S  WORK     425 

the  definite  groundwork  presented   for  the  ether  in   his   own 
compressible  elastic  solid  theory  of  1888,  and  for  matter  simply 
a  substance  acting  on  the  ether  with  a  force  depending  on  the 
distance.      The    introduction    of    eighteenth-century   views   of 
atoms  as  mere  centres  of  force  is  of  course  merely  tentative, 
as  explained  in  Appendix  A  to  the  Baltimore  Lectures,  where 
the  necessary  relations  of  atoms  and  ether  depending  on  their 
relative  motion  is  discussed.     As  a  simplest  case,  for  the  atom 
of  matter,  Lord  Kelvin  assumes  a  spherical  nucleus  occupying 
a   portion   of  space   without   excluding   the   ether.     The   atom 
produces  by  its  action  on  the  ether  condensation  and  rarefaction 
at  different  distances  from  its  centre,  the  total  quantity  of  ether 
within  its  boundary  being  the  same  as  in  an  equal  volume  of 
space  free  of  matter,  so  that  the  outside  ether  is  undisturbed. 
In  such  an  atom,  the  conditions  of  free  mobility  through  space 
are  fulfilled  for  velocities  less  than  the  velocity  of  light.    Beyond 
this  the  essential  quality  of  the  atom  is  its  positive  electrification, 
and  the  law  of  force  experienced  by  an  electron  placed  anywhere 
within  it.     The  latter  is  taken  the  same  as  the  law  of  force  due 
to   a  uniform   distribution    of   positive    electricity   within    the 
boundary  of  the  atom.     That  the  material  nucleus  may  have 
additional  qualities  of  its  own  is  a  condition  derived  no  doubt 
from   the  failure  of  the   vortex  atom   theory.      Differences   in 
quality  between   atoms   may   be   due   in   part   at   least   to   the 
quantum  numbers  of  the  electrons  required  to  neutralise  each 
atom.     Lord  Kelvin,  however,  expressly  disclaims  the  idea  that 
any  theory  of  matter  can  be  founded  merely  on  the  interaction 
of  positive  nuclei  with  electrons.     "  We  might   be  tempted   to 
assume  that  all  chemical  action  is  electric,  and  that  all  varieties 
of  chemical  substance  are  to  be  explained  by  the  numbers  of 
the  electrons  required  to  neutralise  an  atom  or  set  of  atoms ; 
but  we  can  feel  no  satisfaction  in  this  idea  when  we  consider 
the  great  and  wild  variety  of  quality  and  affinities  manifested 
by   the   different   chemical   elements.      It   is   possible  that  the 
differences   of  quality  are   to   be   wholly  explained  in   merely 
Boscovichian  fashion  by  differences  in  the  laws  of  force  between 
the  atoms,  and  may  not  imply  any  differences  in  the  numbers 
of  electrons  constituting  their  quantums."     As  to  the  influence 
of  radiation,   the   atom   is   assumed   to   be   unmoved   by  ether 
waves,   which,   however,    set   electrons    vibrating    about    their 
positions  of  stable  equilibrium  within  the  atom. 


426  SCIENCE  PROGRESS 

With  these  fundamental  assumptions  for  electron  theory  it 
is  interesting  to  find  how  great  a  range  of  physical  actions  are 
illustrated  by  simple  combinations  of  electrons  and  atoms  in 
his  article  "Aepinus  Atomised,"  Baltimore  Lectures,  Appendix 
E,  1901,  and  later  papers.  Electrification  by  contact  between 
different  substances  and  electrification  by  friction  appear  as 
actions  in  which  a  smaller  atom  robs  a  larger  of  its  electron. 
The  difference  of  potential  energy  of  a  system  of  two  dissimilar 
atoms  in  their  initial  and  final  configurations  represents  the 
energy  radiated  in  the  impulses  occurring  in  the  process  of 
separation  and  in  the  oscillations  preceding  the  final  settlement 
in  the  new  equilibrium  position.  It  is  thus  a  constant  for  each 
encounter  of  atoms.  The  positions  of  equilibrium  and  con- 
ditions of  stability  of  equilibrium  for  various  numbers  of 
electrons  within  an  atom  are  discussed  for  systems  involving 
as  many  as  twenty-one  electrons.  The  possibility  of  more  than 
one  position  of  equilibrium  for  a  given  number  of  electrons, 
and  the  definite  amount  of  potential  energy  radiated  in  a  change 
to  the  more  stable  configuration,  are  points  of  interest  in  relation 
to  the  requirements  of  recent  theory.  Similar  questions  of 
stability  appear  earlier  in  Lord  Kelvin's  work  in  connection 
with  crystalline  configurations  and  with  respect  to  the  equi- 
librium of  groups  of  columnar  vortices  revolving  round  their 
common  centre  of  gravity  illustrated  by  Mayer's  well-known 
experiment  with  floating  magnets  of  1878.  These  questions 
have  been  dealt  with  mathematically  by  Prof.  J.  J.  Thomson 
in  his  "Motion  of  Vortex  Rings"  of  1883,  and  in  more  recent 
papers  (in  the  Phil.  Mag.,  1904  and  later),  where  valuable  illus- 
trations of  possible  mechanics  of  radiation  and  radioactivity 
are  given,  involving  suggestions  as  to  emission  of  energy 
occurring  in  the  passage  of  a  system  from  one  stable  con- 
figuration of  motion  to  another  involving  less  kinetic  energy. 
Quite  recently,  too,  the  structure  of  an  atom  has  been  given 
in  which  emission  of  energy  takes  place  in  discrete  quanta  in 
accordance  with  Planck's  theory  of  radiation.  The  investi- 
gations of  the  same  author  on  the  corpuscular  theory  of  matter 
prove  that  the  capacity  of  the  electron  theory  to  account  for  atomic 
weights  is  probably  much  greater  than  Lord  Kelvin  supposed. 
Taking  only  the  positions  of  equilibrium  of  electrons  in  one 
plane,  and  assuming  that  atomic  weight  is  proportional  to  the 
number  of  corpuscles  in  the  atom,  it  is  possible  to  obtain  a 


SOME  VIEWS   ON   LORD   KELVIN'S   WORK      427 

scheme   representing   the   chemical   elements    as    arranged    in 
Mendelejeff's  table  {Physical  Review,  April  191 2). 

The  "Aepinus  Atomised"  article  of  1901  illustrates  a  host 
of  electrical  actions  and  electrical  properties  of  solids,  liquids, 
and  gases,  such  as  electrolysis,  chemical  affinity,  heat  of  com- 
bination, electric  conductivity  of  solids  and  its  changes  with 
temperature,  specific  inductive  capacity,  very  much  as  on  other 
electron  theories.  Combinations  of  atoms  in  various  configu- 
rations are  obtained  to  account  for  crystalline  formations  and 
for  the  electrical  properties  of  crystals.  The  results  of  experi- 
mental investigations  on  Radioactivity,  which  Lord  Kelvin 
followed  with  the  keenest  interest,  prompted  him  to  visualise 
the  actions  within  radioactive  bodies  by  constructing  model 
atoms  having  the  properties  of  radium  and  polonium,  and  to 
extend  his  system  of  atoms  and  electrons  to  account  for  the 
various  types  of  rays  which  experiment  revealed.  A  typical 
paper  of  Lord  Kelvin's  belonging  to  this  group  is  the  one 
entitled  "Electric  Insulation  in  'Vacuum,'"  in  which  he  com- 
pares the  force  required  to  pluck  an  electron  from  its  atom 
with  the  breaking  weight  of  the  strongest  steel.  The  bearing 
of  this  work  of  atom  construction  on  the  explanation  of 
spectroscopic  series,  and  of  the  general  mechanism  of  radia- 
tion, is  discussed  fully  in  Lord  Kelvin's  latest  completed  paper 
"  On  the  Motions  of  Ether  produced  by  Collisions  of  Atoms  or 
Molecules  containing  or  not  containing  Electrons"  {Phil.  Mag., 
September  1907).  A  clear  statement  given  in  this  paper  of  Lord 
Kelvin's  views  regarding  radiation  is  of  importance  in  relation  to 
the  extensions  referred  to  in  the  following  pages  :  "  The  pulses 
described  in  §§  11,  12,  as  due  merely  to  mutual  collisions  between 
ponderable  atoms  (without  consideration  of  electrons  whether 
present  or  not),  constitute  a  kind  of  motion  in  the  ether,  which, 
if  intense  enough  to  produce  visible  light,  would,  when  analysed 
by  the  spectroscope,  show  a  continuous  spectrum  without  the 
bright  lines,  which,  when  seen,  prove  the  existence  of  long-con- 
tinued trains  of  sinusoidal  vibrations  of  particles  of  ether  in  the 
eye  perceiving  them,  and  therefore  also  in  the  source,  and  in 
all  the  ether  between  the  source  and  the  eye.  On  the  other 
hand,  the  vibrations  of  electrons  referred  to  in  §  13  would,  if 
intense  enough,  produce  bright  lines  in  the  spectrum."  The 
main  difference  between  Lord  Kelvin's  views  and  current  ideas 
regarding  atomic   structure   lies   in   his   choice   of   static  con- 


428  SCIENCE   PROGRESS 

ditions  for  atoms  and  electrons,  when  undisturbed  by  collisions. 
The  difference  was  not  wholly  due  to  the  fact  that  static  con- 
ditions lend  themselves  to  a  simpler  discussion.  It  is  natural, 
however,  that  experimentalists  should  prefer  a  stable  configura- 
tion of  motion,  as  no  doubt  the  aspect  of  motion  is  the  one 
most  prominently  before  them.  All  speculations  in  this  direc- 
tion are  at  present  merely  tentative  suggestions  awaiting 
confirmation.  It  is  interesting  to  find,  however,  Lord  Kelvin's 
latest  description  of  the  atom,  given  at  the  British  Association 
Meeting  at  Leicester  1907,  as  a  gun  loaded  with  an  explosive 
shell,   recurring  in    another    connection   {Phil.  Mag.,   October 

I9i3»  P-  579). 

Turning   now  to  the  other   section  of  Lord   Kelvin's  work 

referred  to  above,  which  occupied  his  attention  from  1886  onwards, 
but  more  especially  in  his  later  years,  we  shall  find  that  it  is 
complementary  to  the  papers  just  discussed.  The  section  of  his 
work  included  under  the  title  Waves  on  Water,  containing  as  it 
does  some  of  his  most  beautiful  applications  of  the  Fourier 
analysis  which  attracted  him  so  much  in  his  student  days,  recalls 
his  early  intimacy  with  the  writings  of  the  French  mathematical 
school,  especially  those  of  Cauchy  and  Poisson.  For  the  begin- 
nings of  this  series  of  investigations  in  his  own  writings,  we 
have  to  go  back  to  the  early  papers  on  Hydrodynamics  contri- 
buted in  conjunction  with  Stokes  to  the  Cambridge  Mathe- 
matical Journal  before  1849.  Hydrodynamical  analogies  are 
continually  appearing  in  his  work  on  Magnetism  and  Elasticity 
and  Electric  Currents,  and,  as  we  have  seen  above,  in  his  philoso- 
phic speculations  on  matter.  A  group  dealing  with  diffusion 
forms  the  subject  of  a  separate  paper  in  vol.  iii.  The  influence 
of  Stokes'  Hydrodynamical  Papers— on  the  application  of  the 
Method  of  Images,  on  waves  and  on  the  work  against  viscosity 
of  water  required  to  maintain  a  wave — no  doubt  accounts  largely 
for  his  special  interest  in  purely  hydrodynamical  waves  pro- 
blems. The  experiments  of  Froude  on  resistance  experienced 
by  models  towed  through  water,  and  Lord  Kelvin's  own  acquaint- 
ance with  the  sea  in  cable  and  yachting  expeditions,  brought  him 
directly  in  contact  with  the  problems  of  ship  waves  and  the  action 
of  wind  in  generating  waves  at  sea. 

The  earlier  papers  of  the  group  all  belong  to  the  purely 
hydrodynamical  aspect  of  the  subject.  In  1871  he  gave  the 
theoretical  explanation  of  the  influence  of  wind  and  of  surface 


SOME  VIEWS  ON   LORD  KELVIN'S  WORK     429 

tension  on  Water  Waves  illustrated  by  experiments  carried  out 
with  the  assistance  of  Prof.  Helmholtz  and  Prof.  James  Thom- 
son on  one  of  his  yachting  expeditions,  when  becalmed  in  the 
Sound  of  Mull.  The  series  of  "  Stationary  Waves  in  Flowing 
Water  "  is  evidently  undertaken  with  the  view  of  leading  up  to 
the  problems  of  Ship  Waves  and  Waves  due  to  Wind.  The  solu- 
tion of  the  Ship  Waves  problem  was  obtained  long  before  it  was 
published  (in  1906).  In  a  manner  the  investigation  of  water 
waves  was  more  or  less  a  recreation  study  to  Lord  Kelvin,  being 
a  natural  interest  aside  from  his  more  pressing  practical  affairs 
and  from  the  deeper  problems  of  matter  and  ether,  and  yet 
bearing  on  both  and  providing  scope  for  the  applications  of 
his  skill  in  Fourier  mathematics,  of  which  these  papers  contain 
many  examples. 

But  from  1884  onwards  the  main  purpose  of  the  continued 
series  of  papers  on  Water  Waves  ceased  to  be  merely  the 
hydrodynamical  value  of  the  solutions  of  the  several  problems 
with  which  they  are  concerned,  though  these  are  interesting 
enough  in  themselves,  and  though  Lord  Kelvin  preferred  to 
confine  himself  in  the  main  to  their  strictly  hydrodynamical 
bearing  as  continuations  of  the  Stationary  Waves  Group.  The 
main  interest  of  the  later  hydrodynamical  papers  is  to  be  found 
in  their  bearing  upon  Optical  questions  requiring  elucidation,  as 
is  clearly  indicated  in  Lectures  V  to  X  of  the  Baltimore  Lectures. 
"Take  any  conceivable  supposition  as  to  the  origin  of  light,  in  a 
flame,  or  a  wire  made  incandescent  by  an  electric  current,  or  any 
other  source  of  light.  One  molecule,  of  enormous  mass  in 
comparison  with  the  luminiferous  ether  that  it  displaces,  gets  a 
shock,  and  it  performs  a  set  of  vibrations  until  it  comes  to  rest, 
or  gets  a  shock  in  some  other  direction.  .  .  .  We  thus  see  that 
light  is  essentially  composed  of  groups  of  waves ;  and  if  the 
velocity  of  the  front  or  rear  of  a  group  of  waves,  or  of  the  centre 
of  gravity  of  a  group,  differs  from  the  wave  velocity  of  absolutely 
continuous  sequences  of  waves,  in  water  or  glass,  or  other 
dispersively  refracting  mediums,  we  have  some  of  the  ground 
cut  from  under  us  in  respect  to  the  velocity  of  waves  of  light  in 
all  such  mediums.  I  mean  to  say,  that  all  light  consists  of  groups 
following  one  another  irregularly,  and  that  there  is  a  difficulty  to 
see  what  to  make  of  the  beginning  and  end  of  the  vibrations  of  a 
group."  In  Lecture  VIII  we  find  later:  "A  question  is  now 
forced  upon  us, — What  is  the  velocity  of  a  group  of  waves  in  the 


430  SCIENCE   PROGRESS 

luminiferous  ether  disturbed  by  ordinary  matter  ?  With  a 
constant  velocity  of  propagation,  as  in  pure  ether,  each  group 
remains  unchanged.  But  how  about  the  propagation  of  light 
sequences  in  a  transparent  medium  like  glass  ? "  References 
are  also  made  to  difficulties  that  might  arise  in  connection  with 
refraction  or  interference  phenomena  if  these  were  dealt  with  by 
consideration  of  groups  of  waves.  Then  again,  taking  the 
production  of  light  from  a  molecule  as  a  sudden  beginning  of  a 
long  regular  group  of  waves  followed  by  a  gradual  falling  off,  we 
are  confronted  with  the  question,  how  would  irregularity  invade 
the  regular  group  in  its  passage  through  a  dispersive  medium  ? 

With  the  single  exception  of  the  papers  dealing  with  Ship 
Waves,  in  which  Lord  Kelvin  had  a  special  interest  arising  from 
his  earlier  hydrodynamical  work,  the  problems  solved  in  the 
later  Waves  Papers  are  the  water  wave  analogues  of  the  Optical 
problems  referred  to  in  the  above  quotations.  We  have  "  On  the 
Front  and  Rear  of  a  Free  Procession  of  Waves  in  Deep  Water" 
appearing  in  1887  and  later  in  1904.  In  his  last  paper  we  have 
the  graphical  solutions  for  the  motions  of  a  finite  group  of 
waves,  and  the  effect  of  a  sudden  beginning  of  regular  vibra- 
tions is  represented  in  the  problem  of  determining  the  effect 
of  a  suddenly  applied  periodically  varying  pressure  acting  at 
a  certain  region  of  the  water  surface.  In  this  connection  it 
may  be  of  interest  to  note  that  the  optical  analogue  of  the 
Ship  Waves  problem  is  the  problem  of  the  passage  of  a  plane 
light  pulse  from  air  into  glass  or  other  dispersive  medium, 
and  that  the  Ship  Waves  solutions  have  since  been  used 
to  illustrate  the  modus-operandi  of  the  prism.  It  is  clear 
that  the  intention  of  these  papers  is  to  provide  illustrations 
of  wave  motion  which  might  provide  definite  information  as 
to  the  process  of  dispersion,  and  which  might  be  useful  in 
helping  to  clear  up  some  of  the  difficulties  .which  still  re- 
mained in  connection  with  the  theory  of  group-velocity  and 
the  propagation  of  waves  in  dispersive  media.  They  were, 
so  to  speak,  models  illustrating  the  Optical  problems  referred 
to  in  the  Baltimore  Lectures  and  in  his  papers  on  Atoms  and 
Electrons. 

From  this  point  of  view  the  most  important  paper  of  the 
section  is  that  entitled  "  On  the  Waves  produced  by  a  Single 
Impulse  in  Water  of  any  Depth,  or  in  a  Dispersive  Medium  " 
{Phil.   Mag.,    1887).      In    this    paper    the    displacement    pro- 


SOME  VIEWS   ON    LORD   KELVIN'S   WORK     431 

duced  by  an  Impulse  delivered  at  the  origin  is  given  for  place 
X  and  time  t  by  £  where 

S=i/*°°dkcos[k{x-tV}]    ....    (1) 

o 

where  V  =  f  (k),  V  being  the  velocity  of  the  Fourier  train  of 
wave-length  \,  and  k  =  2irJ\.  When  t  is  large,  the  effect  at  any 
point  is  due  to  the  trains  whose  phases  agree  or  nearly  agree  at 
the  point  chosen  for  observation.  The  remaining  trains  being 
infinite  in  number  and  differing  in  phase  can  be  assumed  to 
produce  zero  effect.  Thus  the  predominant  trains  at  point  x 
are  determined  by 

8  [k  {x-t  V}]  -  0,  or  x  =  t  (f(k)  +  kf  (k)}  -  t  U 

where  U  is  called  the  group-velocity  of  the  trains  which  produce 
the  maximum  effect  at  place  %  and  time  t.  In  this  the  idea  of 
group-velocity  is  restricted  simply  to  mean  the  principle  of 
stationary-phase  as  employed  by  Prof.  Lamb  in  his  investigation 
of  Ship  Waves  (Hydrodynamics,  §  253),  but  applied  to  the  Fourier 
trains  which  constitute  any  wave  disturbance.  When  this  view 
is  accepted,  the  difficulties  referred  to  by  Lord  Kelvin  in  the 
passage  quoted  above  are  removed ;  and  the  results  to  which  it 
leads  are  consistent  with  the  dynamical  theory  of  group-velocity 
given  by  Osborne  Reynolds  and  Lord  Rayleigh. 

Strangely  enough,  this  is  the  meaning  attached  to  group- 
velocity  in  Lord  Kelvin's  paper  of  1887,  and  the  ke}'  to  the 
explanation  of  the  problems  regarding  groups  of  light  waves  in 
glass,  and  indeed  of  any  problem  involving  dispersion,  lay 
unnoticed  in  his  earlier  work.  The  development  of  the  funda- 
mental process  of  dispersion  along  the  lines  laid  down  in  Lord 
Kelvin's  original  paper  was  completed  by  Dr.  T.  H.  Havelock 
in  1908,  in  his  paper  on  "  The  Propagation  of  Groups  of  Waves 
in  Dispersive  Media,"  Proc.  R.S.,  vol.  lxxxi,  and  by  G.  Green  in 
Proc.  R.S.E.,  1909.  Lord  Rayleigh,  however,  has  pointed  out 
that  the  principle  of  stationary  phase  applied  to  the  fundamental 
Fourier  trains,  as  indicated  above,  does  not  account  for  an 
instantaneous  propagation  of  any  disturbance  which  occurs  in  any- 
dispersive  medium,  thus  calling  attention  to  a  gap  between 
initial  actions  and  those  determined  by  group-velocity  theory, 
which  would  call  for  some  new  method  of  determining  the 
value  of  the  above  integral. 


432  SCIENCE   PROGRESS 

It  is  unnecessary  to  do  more  than  indicate  here  the  wide 
field  of  applications  of  the  principle  of  group-velocity  by  stating 
one  or  two  recent  investigations  depending  on  it.  It  has  been 
applied  in  the  difficult  problem  of  Ship  Resistance  to  determine 
the  part  of  the  total  resistance  arising  from  wave-production  in 
experiments  with  models.  The  theory  has  been  extended  by 
Lord  Rayleigh  to  deal  with  the  case  of  media  in  which  there 
is  minimum  wave-velocity  such  as  water,  when  the  influence  of 
gravity  and  surface  tension  combined  is  to  be  considered  ;  and 
the  same  writer  has  discussed  its  application  in  the  case  of 
Aberration  in  a  Dispersive  Medium. 

The  questions  which  formed  the  basis  of  Lord  Kelvin's 
investigations  on  Water  Waves,  as  to  the  cause  of  the  formation 
of  the  front  and  rear  of  groups  of  waves  travelling  in  a  dis- 
persive medium,  and  as  to  the  manner  in  which  irregularity 
invades  a  group  of  waves  originally  regular,  from  the  mere 
kinematical  point  of  view,  have  been  satisfactorily  answered. 
In  view  of  the  smallness  of  light  waves,  the  applications  of 
principles  primarily  derived  for  the  case  of  infinitely  extended 
media  to  groups  of  waves  in  lenses  and  prisms  is  fairly  direct ; 
nevertheless,  a  consistent  development  of  many  parts  of  Optical 
Theory  from  the  point  of  view  of  Group-velocity  would  still  be 
a  useful  undertaking. 

The  questions  raised  by  Lord  Kelvin,  however,  have  a 
physical  as  well  as  a  geometrical  aspect.  The  problem  regarding 
the  falling  off  from  regularity  of  a  group  is  simply,  How  is  the 
distribution  of  energy  to  be  determined  when  a  regular  group 
of  waves  enters  a  dispersive  medium  ?  The  kinematical  investi- 
gations in  Lord  Kelvin's  work  and  its  extensions  are  thus 
intimately  connected  with  and  are  the  necessary  preliminaries 
to  the  study  of  the  passage  of  energy  by  means  of  wave  motion 
through  a  dispersive  medium,  and  have  thus  a  very  important 
bearing  on  the  modern  Theory  of  Radiation.  Some  rather 
important  results  in  this  connection  can  be  very  simply  derived 
from  the  solution  given  by  Lord  Kelvin  in  1887  for  the  case  of 
the  waves  produced  by  a  single  impulse  in  a  dispersive 
medium.  His  evaluation  of  the  integral  in  equation  (1)  is  as 
follows  : 

cos[k  {x  -  tf(k)}  +  ?] 
^  =  V  +  27rt{2f  (k)  +  kf"(k)j 


SOME  VIEWS   ON   LORD   KELVIN'S   WORK     433 

where  k  determines  the  wave-length,  X,  of  the  particular  group 
of  Fourier  wave-trains  which  predominate  at  point  %  at  time  t. 
The  ambiguous  sign  in  the  denominator  is  to  be  chosen  so  as 
to  make  the  expression  positive.  By  the  principle  of  stationary 
phase,  the  relation  between  k  and  %  is 

x-t{f(k)  +  kf'(k)}-tU 
where  U  is  the  group-velocity  corresponding  to  wave-length  A,. 
Consider  now  the  wave  energy  contained  in  the  medium,  at 
time  t,  from  the  place  where  wave-length  X  predominates  to  the 
place  where  wave-length  X  +  SX  predominates,  that  is,  the  energy 
corresponding   to  wave-length   X.     The  extent   of  the   medium 

concerned,  at  time  t,  is 

Sx  =  t  {2f'(k)  +  kf"(k)}  5k 

and,  as  the  energy  per  unit  length  of  the  medium  is  proportional 

to  the  square  of  the  amplitude,   the  total  wave  energy  in  the 

medium  associated  with  wave-length  X  is  as  follows  : 

E8X  =  (Amplitude)3  x  AS^  where  A  is  a  constant 
=  constant  X  8k  =  constant  x  SX/X2 

Thus  we  arrive  at  the  result  that  the  energy  corresponding  to 
wave-length  X,  and  carried  along  through  the  medium,  is 
independent  of  the  time  elapsed  from  the  beginning  of  motion, 
and  of  the  place  in  the  medium  where  the  Fourier  trains  of 
wave-length  A,  predominate,  and  of  the  dispersive  quality  of  the 
medium  itself.  This  means  that  the  energy  associated  with  each 
wave-length  remains  unchanged  during  its  distribution  through- 
out the  medium,  and  is  therefore  the  same  at  all  times  as  the 
energy,  belonging  to  the  wave-length  considered,  in  the  initial 
pulse,  before  its  resolution  and  transformation  by  the  medium  into 
energy  of  wave-motion.  The  same  is  of  course  true  for  any  form 
of  initial  pulse,  and  the  theorem  is  an  illustration  of  the  fact  that 
the  group-velocity  U  is  the  velocity  at  which  a  certain  quantity 
of  energy,  that  belonging  to  Fourier  trains  of  wave-length  X, 
as  given  by  Fourier's  theorem,  moves  through  the  medium — a 
theorem  proved  originally  by  Lord  Rayleigh  for  the  case  of  a 
regular  group  of  waves  (Sound,  vol.  i.  Appendix).  One  case  of 
the  theorem  is  that  with  any  form  of  initial  pulse  the  maximum 
energy  per  wave-length  is  always  associated  with  the  same  wave- 
length, and  depends  only  on  the  form  of  the  initial  pulse  itself. 
The  importance  of  the  result  in  connection  with  radiation  lies  in 
the  fact  that  radiant  energy,  emitted  at  a  fixed  temperature,  has 
always  the  same  distribution  of  the  energy  among  the  various 


434  SCIENCE   PROGRESS 

wave-lengths,  and  that  the  law  of  radiation  given  by  Planck  may 
be  a  statement  of  the  distribution  of  energy  per  wave-length  in  a 
series  of  similar  pulses  which  constitute  the  radiation,  that  is, 
without  actual  wave  motion. 

To  test  this  idea,  let^us  take  the  case  of  two  pulses  follow- 
ing each  other  in  close  succession,  and  let  us  assume,  as  is 
generally  done  in  connection  with  light  pulses,  that  the  com- 
ponent pulses  are  equal  and  opposite.  If  we  consider  the  effect 
of  the  combined  pulses  at  a  point  very  distant  from  the  source, 
the  predominant  wave-lengths  at  the  point  belonging  to  the 
positive  and  negative  parts  of  the  original  disturbance  will  be 
very  nearly  equal.  Thus  for  the  case  of  the  long  waves,  the  theory 
of  group-velocity  indicates  that  the  wave-length  X,,  and  therefore 

k,  varies  very  slowly  with  %  and  therefore  3-    is  nearly  zero. 

Accordingly  we  may  take  as  the  expression  representing  the 
displacement  due  to  the  combined  pulse 

^      -  k  sin  [k  {x  -  tf(k)}  ±  zr] 
U  =  d^=  V  +  2irt{2f'(k)   +  kf"(k)} 

The  energy  corresponding  to  the  region  of  wave-lengths  from 
X  to  X  +  S\,  estimated  exactly  as  in  the  case  of  a  single  pulse, 
is  now 

E8X  =  constant  x  k2Sk  :  or,  E8X  =  constant  x  -n 

'  A4 

This  is  of  course  the  law  of  radiation  arrived  at  by  Lord 
Rayleigh  by  an  application  of  the  Boltzmann-Maxwell  theorem 
of  partition  of  energy  to  the  ether  in  a  closed  rectangular  space 
containing  radiant  energy.  Again  the  result  is  true  for  any 
form  of  pulse  consisting  of  equal  and  opposite  parts,  as  has  been 
proved  by  E.  T.  Whittaker  in  Monthly  Notices,  Astr.  Soc,  1906. 
The  same  note  explains  how,  by  an  application  of  thermo- 
dynamics, we  can  deduce  from  the  above  that  the  radiation  of  a 
body  at  temperature  T  absolute  is  proportional  to  TX_4S\. 
Thus,  so  far,  the  pulse  form  of  radiant  energy  satisfies  the 
requirements.  It  is  impossible  to  proceed  further  without 
introducing  some  speculation  as  to  the  mechanism  of  radiation. 

A  prominent  feature  of  modern  doctrine  with  respect  to  the 
mechanism  of  radiation  is  the  idea  that  the  emission  of  energy 
takes  place,  not  gradually,  but  in  a  statistically  regular  sequence 
of  finite  and  perhaps  nearly  equal  quantities,  or  quanta  ;  and  it 
is  suggested  by  some  that  the   absorption  of  energy  likewise 


SOME  VIEWS  ON    LORD   KELVIN'S   WORK      435 

takes  place  by  finite  steps.  If  we  consider  the  radiation  from  a 
system  of  atoms  and  electrons,  such  as  is  presented  by  the 
kinetic  theory  of  gases,  enclosed  in  a  perfectly  reflecting  en- 
closure at  a  fixed  temperature,  the  view  expressed  by  Lord 
Kelvin  in  the  passage  quoted  earlier  is  that  the  emitted  energy 
may  consist  largely  of  pulses  due  to  collisions.  This  view  may 
still  be  regarded  as  in  harmony  with  modern  requirements  of 
Planck's  theory,  as  it  would  naturally  involve  the  emission  of 
energy  in  discrete  quanta  from  a  molecule,  when  an  electron  was 
expelled  from  it  or  detached  by  the  influence  of  other  molecules. 
The  sudden  expulsion  would  in  this  way  constitute  a  pulse,  of 
some  definite  form  depending  on  the  constitution  of  the  atom, 
which  would  carry  with  it  a  definite  quantit}'  of  energy  into  the 
enclosure.  As  is  pointed  out  above,  there  is  no  need  to  suppose 
that  this  energy  takes  the  form  of  actual  wave  motion.  The  energy 
per  wave-length  is  the  same  in  the  unresolved  form  of  the  pulse, 
as  when  resolved  mathematically  by  Fourier's  theorem  or  experi- 
mentally by  any  form  of  resolving  apparatus  ;  and  would  restore 
the  radiated  energy  to  the  system  equally  effectively  in  this  form 
in  the  process  of  absorption  as  in  the  form  of  regular  wave-trains. 
These  suggestions  are  similar  to  those  put  forward  by  Prof. 
Sir  J.  J.  Thomson — namely,  that  the  quanta  of  energy  which 
have  been  proved  to  exist,  do  not  indicate  a  molecular  structure 
for  radiant  energy,  but  merely  that  emission  occurs  when  some 
system  within  the  atom  is  ruptured  and  that  the  change  involves 
a  definite  quantity  of  energy.  It  is  clear  that  if  we  adopt  the 
idea  that  the  quanta  of  energy  introduced  by  Planck  are  to  be 
identified  with  pulses  all  of  some  definite  form,  considering  the 
agreement  of  Planck's  formula  with  experimental  facts,  we  must 
regard  these  pulses  as  constituting  practically  the  whole  of  the 
energy  emitted  by  the  radiating  body.  In  this  line  of  specula- 
tion the  steadiness  of  the  emission  of  such  a  sequence  of  pulses 
at  any  given  temperature  is  to  be  accounted  for  by  the  existence 
of  some  instability  or  weak  connection  in  the  atomic  constitu- 
tion, leading  readily  to  expulsion  of  an  electron  or  rearrange- 
ment of  the  atomic  system  in  some  new  equilibrium  configuration; 
and  in  the  statistical  steadiness  of  the  conditions  within  the 
enclosure  this  instability  may  belong  to  all  or,  though  less  likely, 
only  to  one  large  group  of  the  colliding  molecules,  all  of  this 
group  being  in  a  similar  state  of  motion  or  atomic  constitution 
which  is  subject  to  variation  with  increase  of  temperature.     Some 


436  SCIENCE   PROGRESS 

such  explanation  would  be  necessary  to  account  for  the  variation 
in  frequency  and  intensity  of  the  sequence  of  pulses  with  tem- 
perature, which  is  required  to  secure  their  agreement  with  the 
law  of  radiation  given  by  Planck.  At  any  rate,  the  form  of 
Planck's  law  of  radiation,  with  the  distribution  of  energy  per 
wave-length  constant  for  any  particular  temperature,  combined 
with  the  emission  of  energy  by  discrete  quanta,  which  has  been 
satisfactorily  confirmed,  strongly  suggests  some  kind  of  pulse  as 
the  fundamental  constituent  in  radiation. 

It  would  therefore  be  extremely  desirable  to  determine  from 
Planck's  law  the  form  of  pulse  which  would  be  in  agreement 
with  the  law  at  any  temperature,  as  this  might  lead  to  important 
information  as  to  the  actions  going  on  within  an  atom  to  which 
radiant  energy  is  due.  The  difficulty  of  such  a  problem  is 
obvious,  as  the  consideration  of  pulses  all  in  one  plane  does  not 
seem  to  comply  with  the  actual  conditions  of  the  mechanism  of 
radiation  we  have  assumed.  For  the  case  of  two  dimensional 
motion,  however,  the  form  of  pulse  required  for  agreement  with 
Wien's  Law  has  been  recently  discovered  by  Dr.  R.  A.  Hous- 
toun,  being  published  in  Proc.  Roy.  Soc.  He  finds  that  the  initial 
form  of  displacement 

cos  \  e 


b      (h2  +  x)\ 
where  0  =  tan-1^,  leads  to  the  expression  for  the  energy  per 

wave-length, 

E  =  constant  x  X  e      a,  with  c  =  constant 

From  the  point  of  view  taken  in  this  article,  it  is  important  to 
remark  that  the  above  initial  form  is  one  of  a  series  of  initial 
forms  given  by  Lord  Kelvin  for  "  Initiation  of  Deep  Sea 
Waves"  {Proc' R.S.E.   1906). 

An  important  aspect  of  the  pulse  hypothesis  with  regard  to 
the  genesis  of  radiation  referred  to  above  is  that  the  form  of  the 
pulse  is  understood  to  be  definite  at  any  given  temperature,  and 
accordingly  the  various  characteristics  of  the  pulse,  or  sequence 
of  pulses,  which  vary  with  the  temperature  may  be  used  as  a 
measure  of  it.  In  the  above,  the  variation  of  the  constant  h 
allows  for  the  representation  of  pulses  belonging  to  different 
temperatures,  h  being  in  fact  inversely  proportional  to  the  abso- 
lute temperature.     We  also  have  h|  inversely  proportional  to 


SOME  VIEWS  ON   LORD   KELVIN'S   WORK     437 

the  maximum  ordinate  in  the  initial  pulse.  In  this  we  are  virtu- 
ally connecting  temperature  with  some  definite  characteristic  of 
the  group  of  molecules  concerned  in  the  emission  of  the  sequence 
of  pulses.  Certainly  the  artificial  procedure  of  referring  to  tem- 
perature as  something  belonging  to  a  space  full  of  radiant  energy 
of  a  definite  constitution  per  wave-length  does  not  arise  in  con- 
nection with  the  pulse  view  of  radiation.  The  applications  of 
thermodynamics  to  an  enclosure  full  of  radiant  energy  are  of 
course  in  reality  applications  to  the  matter  within  the  enclosure. 
They  of  necessity  depend  on  the  existence  of  a  pressure  on  the 
enclosure  and  on  the  radiating  body  applied  by  the  radiation, 
and  this  has  been  fully  established  by  experiment. 

The  above  pages  give  in  outline  the  developments  in  the  direct 
line  of  Lord  Kelvin's  later  work  in  both  its  aspects.  His  attitude 
with  regard  to  other  lines  of  investigation  on  the  law  of  Radia- 
tion may  be  understood  from  his  opinions  regarding  the  Boltz- 
mann-Maxwell  Law  of  partition  of  energy  and  regarding  the 
pressure  due  to  radiation.  With  regard  to  the  former,  he  says, 
in  Appendix  B  of  the  Baltimore  Lectures  :  "  I  have  never  seen 
validity  in  the  demonstration  on  which  Maxwell  founds  this 
statement,  and  it  has  always  seemed  to  me  exceedingly  im- 
probable that  it  can  be  true."  With  regard  to  the  latter,  in  a 
letter  to  Prof.  Larmor  of  date  May  8,  1907,  already  published  in 
Proc.  Roy.  Soc.  1908,  Obituary  Notice,  we  have  the  statement : 
"  There  are  certainly  very  wonderful  '  push  and  pull '  forces  in 
the  action  of  light  on  movable  bodies  in  high  vacuum  (and  also 
in  not  very  high  vacuum,  as  shown  in  Varley's  communication 
to  Royal  Society  'Proceedings'  of  about  1871,  demonstrating 
cathode  torrent  of  '  negatively '  electrified  particles).  I  do  not, 
however,  think  that  there  is  any  foundation  for  push  and  pull  in 
Maxwell's  (a,  /3,  7)  formulas,  or  in  the  (a,  /3,  7),  (P,  Q,  R)  of  your 
leaves."  This  latter  subject  has  been  cleared  of  uncertainties  in 
the  interval  since  Lord  Kelvin's  death.  The  difficulties  of  the 
former  still  remain.  Lord  Kelvin  preferred  the  direct  line  of 
attack  on  the  difficulties  of  the  subject  of  Radiation  on  the 
ground  clear  of  fundamental  uncertainties  presented  by  problems 
of  Wave  Motion.  The  developments  outlined  in  the  preceding 
pages,  mixed  with  some  speculation  on  the  role  of  the  pulse  in 
the  genesis  of  radiation,  serve  to  show  how  directly  the  main 
sections  of  his  later  work  bear  on  the  foundations  of  the  modern 
theory  of  radiation. 


THE  DISPLACEMENT  OF  SPECTRAL 
LINES  BY  PRESSURE 

By  H.  SPENCER  JONES,  B.A.,  B.Sc. 

Late  Isaac  Newton  Student  in  the  University  of  Cambridge  ;  Chief  Assistant,  Royal 

Observatory,  Greenwich 

Up  to  the  year  1896,  the  Fraunhofer  lines  in  the  solar  spectrum 
had  been  regarded  as  fixed  marks  of  reference,  subject  to  no 
possible  change  in  position.  In  that  year,  L.  E.  Jewell,1  when 
engaged  in  carrying  out  some  measurements  of  their  positions 
for  Rowland's  "  New  Table  of  Standard  Wave  Lengths,"  dis- 
covered certain  systematic  differences  between  the  wave  lengths 
of  the  metallic  lines  in  the  solar  spectrum  and  of  the  correspond- 
ing lines  in  the  arc  and  spark  spectra  obtained  experimentally  : 
the  differences  of  wave  length  were  found  to  vary  from  line  to 
line,  proving  that  the  displacements  were  not  due  to  the  Doppler 
effect,  arising  from  a  motion  in  the  line  of  sight.  He  suggested, 
as  a  possible  explanation,  that  the  wave  length  of  a  line  might 
depend  upon  the  physical  conditions  under  which  it  was  pro- 
duced, or,  in  other  words,  that  the  vibration  period  of  an  atom 
might  depend  to  some  extent  upon  its  environment,  and  that 
presumably  an  increase  of  density  or  of  pressure  would  produce 
a  damping  effect  upon  the  vibrating  and  radiating  systems. 

Following  upon  this  suggestion,  Humphreys  and  Mohler2 
investigated  experimentally  the  effect  of  pressure  upon  the 
positions  of  the  lines  in  metallic  spectra,  by  placing  the  arc  in 
a  vessel  containing  air,  with  an  arrangement  by  which  the 
pressure  could  be  varied  by  known  amounts.  This  proved  but 
the  commencing  point  of  a  long  series  of  experiments  by 
Humphreys,3  Hale  and  Kent,4  Anderson,5  Duffield,6  Rossi,7  Gale 

1  Astroph.  Journ.  3,  p.  92,  1896. 
*  Ibid.  3,  p.  114,  1896. 

3  Ibid.  4,  p.  249,  1896;  6,  p.  169,  1897  ;  22,  p.  217,  1905  ;  26,  p.  18,  1907. 

4  Ibid.  17,  p.  154,  1903. 
4  Ibid..  24,  p.  221,  1906. 

6  Ibid.  26,  p.  375,  1907  ;  Phil.  Trans.  A.  208,  p.  in,  1908. 

7  Proc.  P.S.,  A.  83,  p.  414,  1910;  Phil.  Mag.^  21,  p.  499,  191 1. 

43S 


SPECTRAL  LINES  439 

and  Adams,1  and  others,  who  have  shown  that  the  phenomenon 
is  a  very  complicated  one.  There  are,  in  reality,  two  separate 
effects  involved  :  as  the  density  of  the  substance  in  the  arc  is 
increased  the  spectral  lines  are  broadened,  in  some  cases 
symmetrically,  in  others  very  unsymmetrically  towards  the  red  ; 
and  superposed  upon  this  broadening  is  a  progressive  displace- 
ment of  the  lines  towards  the  region  of  longer  wave  lengths. 
Gale  and  Adams 2  divide  the  various  spectral  lines  into  five 
main  classes  according  to  their  behaviour  under  pressure  : 

i.  Lines  which  are  symmetrically  reversed.  These  lines  are 
the  ones  which  are  most  readily  and  most  accurately  measur- 
able, and  in  general  are  amongst  the  strongest  lines  in  the 
spectrum. 

2.  Lines  which  are  unsymmetrically  reversed.  These  lines 
are  not  so  numerous  as  those  belonging  to  the  first  class,  and 
the  reversals  are  as  a  rule  fainter.  Most  of  the  enhanced  lines 3 
belong  to  this  class. 

3.  Lines  which  remain  bright  and  fairly  narrow  under 
pressure. 

4.  Lines  which  remain  bright  and  symmetrical,  but  become 
wide  and  diffuse  under  pressure.  Most  of  the  lines  in  the 
metallic  spectra  belong  to  these  two  classes,  whose  distinction  is 
more  or  less  arbitrary. 

5.  Lines  which  remain  bright  and  are  widened  very  un- 
symmetrically towards  the  red.  These  lines  are  almost  all  in 
the  yellow-red  portion  of  the  spectrum  and  are  all  enormously 
displaced,  but  owing  to  the  lack  of  symmetry  and  the  extent  of 
the  widening,  it  is  difficult  to  measure  the  displacement  with 
any  great  degree  of  accuracy. 

They  also  found  that  most  of  the  characteristics  of  the  lines 
in  the  arc  spectra  under  pressure  were  retained  in  the  spark 
spectra,  but  that  in  the  latter  case  the  lines  were  much  more 
diffuse,  and  the  accuracy  of  measurement  was  accordingly 
correspondingly  reduced. 

Experiment  has  shown  that  the  amount  of  the  displacement 
is  practically  independent  of  whether  the   line    is   or  is   not 

1  Astroph.  Journ.  35,  p.  10,  1912. 

'  Gale  and  Adams,  ibid.  p.  15. 

3  The   enhanced  lines  are  lines  which  appear  in  the  spectrum  when  strong 
spark  discharges  are  used.     Their  presence  indicates  the  characteristic  difference 
between  the  spark  and  the  arc. 
29 


440  SCIENCE  PROGRESS 

reversed ;  that  is  to  say,  other  things  being  equal,  emission  and 
absorption  lines  are  similarly  and  equally  affected.  The  dis- 
placement has  also  been  found  to  be  independent  of  the  nature 
of  the  gas  surrounding  the  arc.  This  indicates  that  the  pheno- 
menon is  primarily  due  to  a  change  of  density  of  the  metallic 
vapour  rather  than  to  a  change  of  pressure.  The  two  terms 
have  been  used  rather  loosely  and  indiscriminately,  but  the 
distinction  is  of  some  importance  from  the  theoretical  point  of 
view.  All  the  facts  point  to  the  displacement  as  arising  from 
the  closeness  of  the  packing  of  the  radiating  molecules.  It  is 
certain  that  with  increase  of  pressure  of  the  surrounding  gas 
the  density  of  the  metallic  vapours  in  the  arc  increases,  because 
the  electrodes  are  found  to  burn  away  faster,  reversals  become 
more  frequent,  and  there  is  an  increase  in  the  brilliancy  of  the 
arc.  Moreover,  as  Larmor  has  observed,  "  mechanical  pressure 
arises  merely  from  the  translatory  motions  of  the  molecules, 
and  these  are  so  slow  as  hardly  to  count  in  connection  with 
radiation  periods." 

All  the  experiments  agree  in  proving  that  the  displacement 
is  proportional  to  the  increase  in  pressure,  at  least  for  pressures 
up  to  a  limit  of  ioo  atmospheres ;  and  also  that  it  increases  with 
the  wave  length  for  lines  of  the  same  series.  There  has  been 
some  diversity  of  opinion  as  to  the  actual  law  of  its  dependence 
upon  wave  length,  and  a  knowledge  of  the  law  is  of  great  import- 
ance as  a  means  of  testing  the  theory.  Humphreys's  experiments 
seemed  to  indicate  a  linear  relation,  and  indeed  Sanford,1  in 
discussing  this  subject,  has  used  the  fact  that  certain  theories  do 
not  give  a  linear  relation  as  an  argument  against  them.  More 
recent  investigations  have,  however,  negatived  this  result. 
Duffield  a  found  that  a  linear  law  would  not  hold  in  the  case  of 
the  spectra  of  iron,  gold  or  silver,  and  that  the  displacement 
varied  with  a  higher  power  of  the  wave  length  than  the  first. 
Rossi3  showed  that,  in  the  case  of  vanadium,  "  the  displacement 
seems  to  be  roughly  proportional  to  the  square  or  a  higher 
power  of  the  wave  length."  The  more  complete  investigation 
of  the  iron  spectrum  by  Gale  and  Adams4  has  shown  that,  in  this 
case,  the  displacement  varies  as  the  cube  of  the  wave  length. 
By  plotting  their  results  upon  a  large  scale,  with  wave  lengths 
as  abscissae  and  displacements  as  ordinates,  they  found  that  the 

1  Astroph.  Journ.  35,  p.  3,  1912.  3  Astroph.  Journ.  34,  p.  21,  191 1. 

2  I^oc.  tit.  ante.  K  Loc.  tit.  ante. 


SPECTRAL  LINES  441 

lines  in  the  spectrum  could  be  separated  into  four  well-defined 
groups  :  the  displacements  of  the  components  of  each  group 
varied  as  the  cube  of  the  wave  length,  whilst  the  displacements 
in  the  four  groups  are  in  the  ratio  1  :  1*5  :  3*4  : 6'6.  For  titanium, 
on  the  contrary,  the  experiments  indicate  a  dependence  upon  the 
square,  and  not  upon  the  cube  of  the  wave  length. 

The  same  experimenters  obtained  some  interesting  results  in 
connection  with  the  enhanced  lines  of  titanium.  In  general  it 
was  found  that  there  was  but  little  difference  between  the  dis- 
placements of  corresponding  arc  and  spark  lines  at  the  same 
pressure  :  the  enhanced  lines  provided  the  exception,  for  with 
them  the  displacements  of  the  spark  lines  are  much  larger  than 
the  displacements  of  the  arc  lines.  In  general  also,  the  dis- 
placements of  the  spectral  lines  are  practically  identical,  whether 
the  arc  is  surrounded  by  hydrogen  or  carbon  dioxide,  but  with 
the  enhanced  lines,  which  are  known  to  be  strengthened  in  a 
hydrogen  atmosphere,  there  was  an  increase  in  the  displace- 
ment amounting  to  about  25  per  cent,  at  a  pressure  of  4 
atmospheres. 

These  results  are  of  importance  in  the  study  of  solar  pheno- 
mena, and  as  Gale  and  Adams  remark :  "  The  fact  that  the 
enhanced  lines  show  materially  larger  displacements  both  at 
the  sun's  limb  and  also  under  pressure  than  do  the  other  lines, 
strengthens  greatly  the  view  that  pressure  is  the  effective  agent 
in  producing  the  solar  displacements."  In  the  sun,  of  course, 
there  are  necessarily  a  number  of  complicating  factors,  such  as 
scattering  and  absorption  and  varying  displacements  due  to 
different  levels ;  but  a  more  complete  study  of  the  whole 
phenomenon  in  all  its  aspects  should  be  of  considerable  value 
in  any  discussion  of  the  relative  merits  of  the  various  solar 
theories.  In  determinations  also  of  the  radial  motions  of  stars, 
based  upon  the  measurements  of  the  displacements  of  spectral 
lines  due  to  the  Doppler  effect,  the  possibility  of  there  being  a  dis- 
placement due  to  pressure  must  be  considered :  if  the  reversing 
layer  of  a  star  is  under  heavy  pressure,  the  displacements 
resulting  from  this  cause  will  be  quite  appreciable. 

To  explain  these  phenomena  several  theories  have  been 
advanced.  The  first  attempted  explanation  was  based  upon 
Lommel's  l  theory  of  absorption  and  fluorescence,  and  attributed 
the  phenomena  to  the  damping  of  the  vibrations  to  which  the 

1   IVied.  Ann.  3,  p.  251,  1878. 


442  SCIENCE  PROGRESS 

emission  of  light  is  due.  The  theory  was  in  agreement  with 
observation  in  so  far  as  it  required  a  displacement  of  the  bright 
emission  lines  towards  the  region  of  longer  wave  length  to 
follow  the  increased  damping  consequent  upon  the  closer 
packing  of  the  molecules ;  but  for  the  absorption  lines,  it 
required  a  widening  unaccompanied  by  any  displacement, 
whereas  experiment  shows  that  both  emission  and  absorption 
lines  suffer  the  same  displacement.  A  modification  of  the 
theory  was  attempted  by  Wilsing,1  but  was  unsatisfactory,  and 
we  must  look  to  the  electric  rather  than  to  the  mechanical 
properties  of  the  medium  to  find  an  explanation. 

Such  an  explanation  was  offered  by  Fitzgerald,2  who  sup- 
posed  that  when   the   pressure  was    increased    the    luminous 
vibrations  were  slowed  down  owing  to  the  increased  specific 
inductive  capacity  of  the  medium  in  which  the  vibrations  take 
place.     In  fact,  if  we  imagine  the  vibrating  systems   as   small 
Hertzian  oscillators,  vibrating  in  a  medium  of  specific  inductive 
capacity  K,  the  frequency,  N,  of  the  vibrations  emitted  is  such 
that  N~2  varies  as  K.     Thus  when  K  is  large  N  is  small.     Now 
an  increase  of  pressure  causes  an  increase  in  the  specific  induc- 
tive capacity  of  a  gas,  and  so  it  follows  that  there  is  a  vera  causa 
for  some  shift  towards  the  longer  wave  lengths  of  the  emitted 
vibrations.     The  same  argument  has  been  in   a  more  general 
form  expressed  by  Sir  Joseph  Larmor 3  thus  :  "  Each  molecule 
individually,  through  the  agency  of  its  plastic  field  of  force  or 
aether  strain,  provides  a  yielding  region  in  the  aether  in  which 
the  effective  stiffness  is  diminished.     The  elastic  energy  which 
maintains  the  free  vibrations  of  the  radiator  is  located   in  the 
field  of  force  in  the  adjacent  aether;  and,  by  dynamical  principles, 
any  loosening  of  the  constraints  in  that  field  such  as  an  adjacent 
molecule  would  produce,  which  would  itself  be  somewhat  inten- 
sified  by  equality  of   period,   must   in  general   tend   towards 
increasing  the  free  period,  involving  displacement  of  the  radia- 
tion towards  longer  wave  length." 

Humphreys,4  using  this  theory,  obtained  a  pressure  shift 
about  three  hundred  times  larger  than  the  observed  value.  The 
calculation  was,  however,  implicitly  based  upon  the  assumption 
that  the  surrounding  medium  was  continuous  right  up  to  the 
vibrator  in  question.    This   is   not  permissible ;    since  we  are 

1  Astroph.  Journ.  7,  p.  317,  1898.  *  Ibid.  25,  p.  120,  1907. 

'  Ibid.  5,  p.  210,  1,897.  4  Ibid.  26,  p.  30,  1907. 


SPECTRAL  LINES  443 

not  dealing  with  statistical  or  averaged  effects,  but  considering 
a  single  vibrator,  some  hypothesis  must  be  made  as  to  the 
molecular  constitution  of  the  medium.  This  was  done  by  Sir 
Joseph  Larmor,1  who  considered  a  spherical  vibrator  of  radius 
a,  which  acts  as  a  simple  Hertzian  oscillator,  and  replaced  the 
surrounding  gas  by  a  medium  of  specific  inductive  capacity  K, 
assumed  continuous,  but  extending  only  up  to  a  distance  ka 
from  the  centre  of  the  vibrator.  Since  the  electric  field  of  such 
a  vibrator  varies,  as  regards  distance,  according  to  the  inverse 
cube  law,  the  static  energy  in  the  field  outside  and  up  to  a 
distance  r  from  the  centre  of  the  oscillator,  supposed  alone  in 
free  aether,  is  proportional  to 


/: 


r~6 .  47rr*dr  or  —  rex"* 


and  so,  in  the  case  considered,  since  where  the  specific  inductive 
capacity  is  K,  the  electrical  energy  is  altered  as  compared  with 
a  vacuum  in  the  ratio  K~l,  it  is  evident  that  the  total  static  energy 
is  altered  in  the  ratio 

a-3  -  (ka)~3(i  -  K-1)  to  a"3 

and  since  the  frequency  is  increased  as  the  square  root  of  this 
ratio,  it  follows  that 

d\       1       K  -  1 


X   ~  2k3  '       K 

The  value  of  K  which  occurs  in  this  equation  is  not  the 
specific  inductive  capacity  as  determined  by  ordinary  static  ex- 
periments, but  the  value  appropriate  to  light  waves  of  a  frequency 
corresponding  to  the  wave  length  X,  and  by  the  electromagnetic 
theory  of  light  is  defined  by  means  of  the  relation  K  =  /t2,  in 
which  [J,,  a  function  of  the  wave  length,  is  the  refractive  index 
of  the  gas  for  the  wave  length  X.  Thus  Larmor's  theory  gives 
a  displacement  of  amount  dX  where 

dx        1        u?  -  1 


X        2k»  *       /i* 

Using  the  value  of  fi  for  air  at  normal  temperature  and 
pressure,  and  the  observed  values  of  dX/X,  Larmor  obtained  k=8, 
and  concluded  that  the  dielectric  influence  of  the  surrounding 
medium  is  a  vera  causa  of  the  right  order  of  magnitude.  It 
seems  more  reasonable,  however,  to  use  the  value  of  /x  corre- 

1  Astroph.  Journ.  26,  p.  120,  1907. 


444  SCIENCE   PROGRESS 

sponding  to  the  arc  temperature  (say  27300  abs.).  The  value  of 
(/i2—  1)  is  then  reduced  to  one-tenth  of  its  previous  value,  and, 
with  this  modification,  the  theory  gives  k  =  3,  i.e.  the  sur- 
rounding medium  must  be  regarded  as  extending  to  within  a 
distance  of  three  times  the  molecular  radius  from  the  vibrating 
molecule;  but  at  this  temperature  the  average  distance  apart 
of  the  molecules  is  about  sixty  times  the  molecular  radius.  It 
seems,  then,  as  though  the  above  estimate  of  k  is  much  too 
small,  and  if  a  larger  value  be  substituted  in  the  formula  for  d\ 
the  displacement  obtained  is  much  smaller  than  the  observed 
value. 

Moreover,  if  this  theory  were  true,  the  displacement  should 
vary  with  the  nature  of  the  gas  surrounding  the  arc.  In  fact, 
for  a  gas  //.  is  nearly  unity,  and  (fi—  1)  varies  as  the  density 
(Gladstone  and  Dale's  Law),  so  that  the  displacement  obtained 
should  be  proportional  to  the  density  of  the  surrounding  gas. 
For  example,  in  the  case  of  arcs  in  atmospheres  of  air  and 
carbon  dioxide  at  the  same  pressure,  the  displacements  should 
be  respectively  in  the  ratio  of  2:3,  whereas  Rossi  was  unable 
to  obtain  any  differences  in  the  displacements  in  the  two  cases 
beyond  the  limits  of  experimental  error.  Gale  and  Adams  did 
indeed  find  an  effect  in  the  case  of  the  enhanced  lines  of  titanium, 
but  it  was  in  a  direction  opposite  to  that  given  by  the  above 
formula.  Another  objection  to  the  theory  is  that  experiment 
-shows  that  the  displacement  varies  accurately  as  the  pressure. 
Now,  for  a  gas  (/x2—  1)  is  proportional  to  the  density  or  pressure, 
and  k3  may  be  expected  to  vary  approximately  inversely  as  the 
pressure,  so  that  this  theory  requires  a  displacement  varying 
as  the  square  of  the  pressure.  Further,  other  things  being 
equal,  dx.  is  proportional  to  \  and  this  has  been  disproved  by 
experiment. 

It  must  be  concluded  that  although  the  effect  of  the  surround- 
ing medium  pictured  by  Larmor  and  Fitzgerald  must  exist,  the 
resulting  displacement  is  many  times  smaller  than  that  experi- 
mentally observed,  and  that  an  explanation  of  the  facts  must  be 
sought  in  another  direction. 

A  different  theory  which  was  advanced  by  Humphreys 1 
attempted  to  explain  the  effect  by  means  of  the  mutual  inter- 
action of  atomic  magnetic  fields,  in  a  manner  analogous  to  the 
Zeeman  effect.     It  is  well  known  that  the  periods  of  the  radia- 

1  Astroph.  Journ.  23,  p.  233,  1906. 


SPECTRAL  LINES  445 

tions  emitted  by  a  source  of  light  are  changed  under  the  action 
of  a  magnetic  field.  Humphreys  argued  that  this  being  so,  the 
luminous  particles  must  have  a  magnetic  field  of  their  own,  and 
consequently,  since  they  can  be  acted  upon  by  an  external 
magnetic  field,  they  must  of  necessity  be  acted  upon  by  the 
fields  of  the  neighbouring  particles.  He  took  for  his  model 
of  the  atom  that  pictured  by  Sir  J.  J.  Thomson,  in  which  a 
number  of  coaxial  rings  of  electrons  rotate  inside  a  sphere  of 
positive  electricity  uniformly  distributed  ;  and  with  certain 
assumptions  as  to  the  radius  of  the  sphere  and  the  number  of 
electrons  contained  in  the  atom  he  was  able  to  calculate  the 
strength  of  the  atomic  magnetic  field.  In  the  case  of  the  iron 
atom,  by  assuming  it  to  contain  5,000  electrons  the  strength  of 
the  magnetic  field  at  the  centre  of  the  atom  was  found  to  be 
57rT0r  C.G.S.  units.  Humphreys  l  also  found  that  the  observed 
displacement  could  be  accounted  for  by  means  of  a  strength  of 
field  of  45' io7  units.  This  is  a  field  ten  thousand  times  as 
strong  as  the  field  of  the  strongest  electromagnet  used  in  pro- 
ducing the  Zeeman  effect,  and  it  seems  a  priori  improbable  that 
the  atoms  of  all  metals  could  have  such  enormously  strong 
magnetic  fields  without  their  existence  being  revealed  in  other 
ways.  Humphreys  admitted  that  the  result  was,  at  first  sight, 
somewhat  startling,  but  argued  that  the  magnetic  properties  of 
atoms  when  luminous  might  be  vastly  different  from  the 
magnetic  properties  of  cold  masses  of  the  pure  elements.  The 
Zeeman  effect,  however,  seems  to  disprove  the  existence  of 
atomic  fields  of  such  magnitude.  In  the  elementary  theory  of 
this  effect,  the  assumption  is  made  that  the  atomic  magnetic 
fields  are  small  compared  with  the  externally  applied  field,  and 
the  agreement  between  the  calculated  separation  of  the  com- 
ponents into  which  the  original  line  is  resolved  and  the  observed 
separation  is  sufficient  justification  of  the  assumption.  The 
error  in  Humphreys'  calculations  appears  to  lie  in  the  assump- 
tion as  to  the  number  of  electrons  which  are  contained  in 
an  atom. 

Modern  researches  in  connection  with  radioactivity  indicate 
that  this  number  is  roughly  equal  to  half  the  atomic  weight. 
This  may  be,  and  probably  is,  an  under-estimate.  A  model  of 
the  hydrogen  atom  which  contains  only  one  electron  appears  to 
be  too  simple  and  too  unstable  to  be  the  true  one  :  yet  it  should 

1  Astroph.  Journ.  27,  p.  194,  1908. 


446  SCIENCE  PROGRESS 

be  noted  that  Dr.  Bohr1  has  recently,  using  this  model  and 
basing  his  work  upon  Planck's  theory  of  the  discontinuity  of 
emission  of  energy,  obtained  an  explanation  of  Balmer's  formula 
for  the  positions  of  the  lines  in  the  hydrogen  series,  although 
the  discussion  was  not  completed  by  finding  whether  the  lines 
have  their  proper  intensities.  But  even  if  this  estimate  of  the 
number  of  electrons  in  an  atom  is  not  accurately  true,  it  is  cer- 
tainly very  much  nearer  the  truth  than  is  the  number  assumed 
by  Humphreys.  If  then  instead  of  supposing  the  iron  atom  to 
contain  five  thousand  electrons  we  suppose  it  contains  only 
thirty,  the  atomic  strength  of  field  is  only  the  one-four  hundred 
and  fiftieth  part  of  that  necessary  to  account  for  the  observed 
separation.  The  conclusion  is  inevitable  that  the  atomic  mag- 
netic fields  are  such  that  their  mutual  influence  is  entirely 
negligible,  and  incapable  of  accounting  for  the  observed  pressure 
shift.  There  are  other  considerations  which  justify  this  con- 
clusion. As  Humphreys  himself  states,  if  this  theory  were  true 
the  lines  which  give  large  Zeeman  effects  should  also  show 
large  pressure  displacements,  whilst  those  with  small  Zeeman 
effects  should  be  shifted  but  little.  The  connection  between 
these  two  phenomena  has  been  investigated  by  King,2  who  com- 
pared the  Zeeman  separation  of  a  large  number  of  lines  with 
their  pressure  shifts  as  determined  by  Humphreys,  and  found  a 
complete  lack  of  connection  :  for  example,  in  the  case  of  iron, 
the  ratio  of  the  Zeeman  displacement  to  the  pressure  shift 
varied  from  078  to  1 5*5,  and  in  the  case  of  several  lines  showing 
large  pressure  displacements,  no  Zeeman  effect  could  be  observed 
even  with  the  most  intense  magnetic  fields. 

Prof.  O.  W.  Richardson  3  formulated  another  theory  which 
sought  to  explain  the  displacement  by  means  of  sympathetic 
vibrations  occurring  in  the  surrounding  atoms.  To  quote  his 
own  words  :  "  The  fact  that  an  atom  A  is  emitting  light  shows 
that  it  is  surrounded  by  an  alternating  field  of  electric  force. 
This  alternating  electric  field  will  produce  forced  vibrations  of 
equal  period  and,  under  certain  conditions,  of  like  phase  in 
neighbouring  atoms.  The  electric  field  due  to  the  forced  vibra- 
tions will  react  upon  the  emitting  electron  in  the  atom  A  and  in 
such  a  way — as  will  be  shown — as  to  increase  the  period  of  the 

1  Phil.  Mag.  July  and  September  191 3. 

*  Astroph.  Journ.  31,  p.  433,  1910  ;  33,  p.  250,  1911. 

3  Phil.  Mag.  14,  p.  557,  1907. 


SPECTRAL  LINES  447 

latter.  It  will  be  necessary  then  to  calculate  the  reaction  at  A 
due  to  the  forced  vibrations  set  up  in  the  atom  at  B  by  a  given 
vibration  at  A,  to  sum  this  up  for  all  the  atoms  B  which 
occur,  and  to  find  the  effect  of  the  resultant  reaction  on  the 
period  of  A." 

Working  on  these  lines,  by  a  straightforward  but  rather 
tedious  piece  of  analysis  Richardson  arrived  at  a  displacement 
dX  of  the  wave  length  X  given  by 

dX       e'AV  -  i) 
X   '       67r2mc1!a3 

where  fi  is  the  refractive  index  of  the  surrounding  gas,  c  is  the 
velocity  of  radiation  in  free  aether,  e  and  m  denote  the  electronic 
charge  and  mass,  and  a  is  the  radius  of  a  sphere  within  which  it 
is  impossible  for  the  centre  of  an  atom  of  class  B  to  lie  and  is 
supposed  to  be  between  a  and  2a,  where  a  is  the  atomic  radius. 

Supposing  that  the  surrounding  gas  is  air  at  the  arc  tempera- 
ture (27300  abs.),  so  that  ji2—  1  =  5-9.  io-5,  and  taking  for  a  a  mean 
value  of  r5.io~8  cms.,  Richardson  calculated  that  for  a  wave 
length  X  =  4.  io-5  cms.,  dX/X  =  9. io-6,  which  is  about  one  hundred 
times  as  large  as  the  average  value  obtained  experimentally 
for  the  wave  length  used.  The  cause  of  this  discrepancy  is 
easily  found.  Richardson  first  calculated  the  effect  of  one  atom 
of  class  B  on  the  atom  A,  and  then  obtains  the  effect  for  the 
whole  of  the  surrounding  gas  by  multiplying  this  by  the  number 
of  atoms  per  unit  volume  and  integrating  throughout  the  whole 
volume  external  to  the  atom  A.  Thus  the  surrounding  medium 
was  implicitly  treated  as  continuous  right  up  to  the  vibrating 
molecule  A,  which,  as  has  been  remarked  above,  is  not  per- 
missible. If,  as  in  Larmor's  theory,  the  surrounding  medium  be 
treated  as  continuous  outside  a  sphere  of  radius  ka  concentric 
with  the  atom,  and  if  k  be  calculated  from  the  above  formula 
using  the  observed  mean  value  of  dX/X,  it  is  found  that  k  is 
approximately  5,  which  is  too  small  since  the  atoms  of  the  gas 
are,  on  the  average,  under  these  conditions  at  a  distance  apart 
which  is  equal  to  fifty  or  sixty  times  the  atomic  radius.  If,  on 
the  other  hand,  a  larger  and  more  probable  value  of  k  be  used, 
dX/X  is  again  much  smaller  than  the  observed  value  and  the 
theory  cannot  be  regarded  as  affording  an  adequate  explanation 
of  the  pressure  shift.  Even  apart  from  the  numerical  disagree- 
ment there  are  the  additional  objections  that,  as  with  the  theory 
of  Larmor,  it  gives  a  shift  proportional  to  the  square   of  the 


448  SCIENCE   PROGRESS 

pressure  and  also  to  (/a2— i),  both  of  which  relations  are  con- 
tradicted by  experiment. 

There  remains  only  one  other  theory  which  need  be 
seriously  considered  and  which  has  been  advanced  indepen- 
dently by  Livens1  and  Havelock.2  This  theory  will  be 
discussed  in  somewhat  greater  detail  as,  in  the  author's  opinion, 
it  is  probably  the  correct  one.  It  has  been  mentioned  above 
that  it  is  certain  that,  under  the  conditions  of  the  experiments, 
an  actual  increase  in  the  density  of  the  metallic  vapour  in  the 
arc  takes  place  simultaneously  with  an  increase  in  the  pressure 
of  the  surrounding  gas.  It  is  to  this  density  change  in  the 
incandescent  vapour  that  the  present  theory  attributes  the 
observed  displacement.  The  theories  of  Larmor  and  of 
Richardson  both  attempted  to  explain  it  by  means  of  some 
influence  exerted  by  the  surrounding  gas,  and  in  both  cases 
they  were  found  incapable  of  accounting  for  a  displacement 
of  the  observed  magnitude.  No  account  was  taken  by  them 
of  the  neighbouring  metallic  atoms  of  the  same  free  period. 
Richardson3  indeed  expressly  ruled  these  out ^of  consideration 
by  asserting  that  their  effect  is  to  cause  only  a  broadening  of 
the  lines,  unaccompanied  by  any  displacement,  but  no  reasons 
were  given  to  justify  the  statement. 

Thus  the  present  theory  is  concerned  with  the  vibrations 
emitted,  not  by  a  single  vibrator,  but  by  an  aggregate  of  similar 
vibrators  with  the  same  free  period.  The  method  of  procedure 
consists  in  forming  the  equation  of  motion  of  a  typical  electron 
and  then  making  a  summation  with  respect  to  all  the  electrons 
in  a  unit  of  volume.  The  essential  point  of  the  theory  consists 
in  the  introduction  into  that  equation  of  a  force  acting  upon  the 
electron  and  arising  from  the  electric  polarisation  of  the  sur- 
rounding medium.  It  is  assumed  in  order  to  satisfy  theoretical 
requirements  that  each  electron  may  be  surrounded  by  a  sphere 
of  a  radius  sufficiently  large  for  it  to  contain  a  great  number  of 
electrons,  but  yet,  at  the  same  time,  small  when  compared  with 
the  wave  length  :  the  matter  inside  this  sphere  is  imagined 
removed.  Then  if  a  single  electron  is  placed  at  its  centre  O, 
the  force  on  this  electron  when  an  electric  field  of  strength  E  is 
acting  is  not  simply  eE,  as  it  would  be  if  the  electron  were 

1  Phil.  Mag.  p.  268,  August  191 2. 

2  Astroph.  Journ.  35,  p.  304,  191 2. 
5  ]Loc.  cit.  ante,  p.  563. 


SPECTRAL  LINES  449 

completely  isolated :  there  is  an  additional  term  arising  from 
the  polarisation  of  the  surrounding  matter,  and  since  only  the 
matter  in  the  immediate  neighbourhood  of  the  electron  produces 
any  appreciable  effect  on  it,  this  polarisation  (which  is,  of 
course,  a  vector  quantity)  may  be  assumed  constant  and  equal 
to  its  value  at  O  ;  and  just  as,  in  the  theory  of  magnetism,  any 
distribution  of  magnetism  may  be  averaged  out  into  a  volume 
and  surface  distribution  of  "imaginary  magnetic  matter"  so,  in 
the  present  case,  the  effect  of  the  polarisation  of  the  medium  is 
equivalent  to  that  of  a  surface  distribution  of  electricity  on 
the  wall  of  the  spherical  cavity,  of  density  Pcos#  at  any 
point,  where  P  denotes  the  magnitude  of  the  polarisation  and 
0  is  the  angle  between  its  direction  and  the  line  from  the  point  to 
the  centre  of  the  sphere,  and  so  the  force  on  the  electron  is  at 
once  obtained  as  -f  7reP  in  the  direction  of  P.  If  now  the  matter 
which  was  removed  from  the  sphere  be  replaced  there  will,  due 
to  it,  be  an  additional  force,  esP,  which,  as  Lorentz1  has  shown, 
vanishes  if  the  molecules  have  a  regular  cubic  arrangement. 
In  general  for  a  gas,  S  will  be  small,  and  the  complete  expression 
for  the  force  of  the  typical  electron  due  to  the  electric  intensity 
may  be  written  in  the  form  e  (E  +  47raP),  where  a  is  approxi- 
mately equal  to  one-third  in  the  case  under  discussion,  but  for 
solids  and  liquids  it  may  depart  widely  from  its  value.  The 
polarisation  is  analogous  to  the  magnetic  vector  called  the 
"  intensity  of  magnetisation  "  and  defined  as  the  magnetic  moment 
per  unit  volume.  It  is  equal  to  2er,  where  r  denotes  the  dis- 
placement of  any  electron  from  its  position  of  equilibrium  and 
the  summation  is  with  regard  to  all  the  electrons  per  unit 
of  volume. 

The  equation  of  motion  of  the  typical  electron  when  vibrating 
under  the  action  of  an  external  periodic  electric  intensity  E  may 
accordingly  be  writen  in  the  form 

m'r  +  hf  +  mn-r  =  e(E  +  47raP) 

The  term  hf  represents  a  frictional  or  resistance  term.  Its 
presence  is  found  to  be  necessary  to  account  for  the  phenomena 
of  absorption  and  of  selective  dispersion,  although  its  exact 
physical  significance  is  obscure.  Lorentz  sought  to  explain  it  as 
arising  from  the  disturbance  of  the  motions  of  the  electrons 
consequent  upon  molecular   collisions,  but  although  his  hypo- 

Theory  of  Electrons  (B.  G.  Teubner,  Leipzig),  p.  306, 


1    7- 


450  SCIENCE  PROGRESS 

thesis  gave  a  term  of  the  above  type,  its  magnitude  was  too  small 
to  account  for  the  observed  facts  of  absorption.  The  term 
mn*  r  is  a  force  of  elastic  type,  tending  to  draw  the  electron  back 
to  its  mean  position.  The  electron,  if  isolated,  and  under  the 
action  of  this  force,  would  emit  radiation  of  frequency  n0,  which 
may  accordingly  be  called  the  "  natural  free  period "  of  the 
electron. 

The  root  of  the  present  theory  is  contained  in  the  fact  that 
the  electron,  when  in  the  presence  of  other  electrons,  will  emit 
radiation  of  a  frequency  differing  from  n0.  It  has  been  shown  by 
Larmor  (vide  ALther  and  Matter)  that  a  system  of  electrons 
will  emit  no  radiation  if,  and  only  if,  a  certain  condition  holds, 
viz.  that 

Se'f  =  o  or  P  =  o 

If  then  a  gas  is  in  such  a  condition  that  it  is  emitting  radiation, 
P  must  be  different  from  zero,  and  it  must  be  concluded  that  it 
is  electrically  polarised.  The  gas  on  the  whole  will  not  neces- 
sarily exhibit  any  signs  of  polarisation,  because  the  polarisation 
will  change  rapidly  from  point  to  point  in  both  magnitude  and 
direction,  but  in  the  neighbourhood  of  each  point  it  must  be 
assumed  that  there  exists  a  polarisation  P  definite  as  regards 
magnitude  and  direction,  so  that  the  equation  of  motion  of  an 
electron  in  it  is  given  by 

mr  +  mn'r  =  47raeP 

The  frictional  term  has  been  dropped  from  this  equation  because 
it  only  becomes  important  when  the  electron  is  acted  upon  by  a 
periodic  force  whose  period  is  nearly  equal  to  its  own  natural 
free  period.  That  this  is  permissible  is  also  evidenced  by  the 
fact  that  light  from  a  flame  or  arc  may  be  made  to  interfere  with 
a  path  difference  of  millions  of  wave  lengths,  showing  that  the 
electrons  maintain  their  vibrations  undamped  through  an 
enormous  number  of  periods. 

Consider,  therefore,  the  ideal  case  of  a  system  consisting 
simply  of  N  similar  electrons  per  unit  of  volume.  Then  P  =  Ner, 
and  may  be  eliminated  from  the  equation  of  motion  giving 

mr  +  (mil*  -  47rNae2)r  =  o 

and  so  radiation  is  emitted  of  a  frequency  n  given  by  the  equation 

n2  =  n0  -  47rNae!/m 
or,  since  the  second  term  is  found  to  be  small,  n  is  given  by 

n  =  n0  -  2jrNae2/mn0 


SPECTRAL  LINES  451 

Thus  the  frequency  of  the  emitted  radiation  differs  from  the 
natural  frequency  by  an  amount 

dn  =  —  27rNae2/mno 

and  the  corresponding  change  of  wave  length  is  given  by 

$X  dn  _  Nae*\* 

X  n   —  27rmca 

since  X  =  27rc/n. 

Now  the  number  of  electrons  per  unit  volume  may  be 
assumed  proportional  to  the  density  and  therefore  to  the 
pressure ;  and  so  when  the  pressure  is  increased  there  is  an 
increase  in  the  wave  length  of  the  emitted  light  which  is  pro- 
portional to  the  increase  in  pressure  and  also  to  the  cube  of  the 
wave  length.  The  increase  is  moreover  independent  of  the 
nature  of  the  gas  surrounding  the  arc.  These  results  are  all  in 
accordance  with  experiment. 

In  the  more  general  case  in  which  the  gas  emits  a  number  of 
spectral  lines,  corresponding  to  electrons  with  different  free 
periods,  P  is  given  by  2Ner,  the  summation  being  with  regard 
to  the  different  free  periods.  If  light  of  frequency  n  is  emitted, 
the  equation  of  motion  of  an  electron  becomes 

m(n*  -  n2)r  =  4?raeP 

and  using  the  relation  P  =  2Ner  to  eliminate  P,  the  frequencies 
of  the  emitted  light  are  given  by  the  equation 

4?rNae* 
2m(n;-n*)=I 

For  the  value  of  n  near  n0  only  the  term  in  the  summation 
which  contains  (n2— n*)  in  the  denominator  need  be  retained  as 
a  first  approximation,  and  this  value  of  n  is  thus  the  same  as 
that  first  obtained.  It  should  be  noted  that  now  N  will  probably 
vary  from  line  to  line,  and  one  cannot  expect  to  deduce  any 
general  law  of  variation  of  displacement  with  wave  length,  but 
other  things  being  equal,  the  result  points  to  a  variation  pro- 
portional to  the  cube  of  the  wave  length.  This  law  may  be 
expected  to  hold  for  lines  which  have  a  common  origin. 

The  effect  of  a  change  of  density  upon  the  positions  of  the 
absorption  lines  may  be  treated  in  a  somewhat  similar  manner. 
If  the  electrons  are  set  into  vibration  by  the  periodic  electric 
force  E  of  frequency  n  (varying  as  eint),  in  an  advancing  light 
wave,  the  typical  equation  of  motion  becomes,  in  the  usual  way, 

m(n*  -  n'  +  ihn)r  =  e(E  +  47raP) 


452  SCIENCE  PROGRESS 

and  by  the  electromagnetic  theory  of  light 

4ttP  =  47r2Ner  =  (jx3  -  i)E 

/i  being  the  refractive  index  of  the  medium  for  the  frequency  n. 
Putting  a  ==  J  for  simplicity,  which  is  very  nearly  true  for  a  gas, 
we  obtain,  by  eliminating  E  and  P  from  the  above  equations, 
the  relation 

— —  =—<■   ttS  (K  -  n   +  ihn)-1 

fiJ  +  2        3  m 

For  values  of  n  near  the  free  period  n0  we  may  for  a  gas 
neglect  the  effect  produced  by  all  the  electrons  other  than  those 
with  this  free  period :  since  n*  —  n2  in  the  denominator  of  this 
term  is  then  small,  the  imaginary  part,  ihn,  now  becomes 
important,  signifying  absorption.  Therefore,  near  an  absorption 
band,  it  follows  that 

/x3  -  i  =  47rNe2{m(nf  -  n3)  +  ihn}-1 

where  n^  is  defined  by  means  of 

nf  =  n*  -  47rNe2/3m 

If  s  is  the  real  refractive  index  of  the  gas  and  k  its  absorp- 
tion coefficient,  then  yx=s  — ik,  and  there  results 

sk  =  27rNe2hn{ms(X3  -  n2)2  +  h2n2}-x 

The  centre  of  the  absorption  band,  defined  as  the  position  of 
maximum  absorption,  is  evidently  give  by 

n  =  n'0  =  n0  -  2rrNe2/3mnJ 

(approximately),  and  so,  due  to  a  given  change  of  pressure,  the 
position  of  the  absorption  band  is  shifted  by  exactly  the  same 
amount  as  the  corresponding  emission  line,  in  agreement  with 
experimental  results. 

Moreover,  if  the  width  of  the  absorption  band  be  defined 
as  the  distance  between  the  two  places  where  the  absorption 
has  a  value  which  is  some  definite  fraction  of  the  maximum 
absorption,  the  width  is  found  to  be  proportional  to  h,  and 
since  the  resistance  coefficient  will  increase  with  the  pressure, 
a  symmetrical  broadening  of  the  absorption  band  is  to  be 
expected  on  this  account.  That  the  broadening  observed  is  not 
always  s^ymmetrical  is  due  to  other  and  obscure  causes  which 
need  not  be  discussed  here. 

This  theory  is  thus  seen  to  give  a  very  satisfactory  and 
complete   explanation   of  the  main   experimental  results,  with 


SPECTRAL  LINES  453 

perhaps  one  exception.  The  shift  has  been  shown  to  be  pro- 
portional to  N,  which  was  assumed  to  be  proportional  to  the 
density  of  the  vapour  in  the  arc.  Experiment  shows  it  to  be 
proportional  to  the  pressure  of  the  surrounding  gas.  Can  these 
two  be  assumed  proportional  to  one  another?  No  experiments 
seem  to  have  been  conducted  which  could  decisively  settle  this 
point,  and  in  the  absence  of  further  evidence  it  seems  legitimate 
to  assume  that  the  proportionality  holds  until  it  should  be  dis- 
proved. 

It  remains  now  to  examine  whether  the  quantitative  agree- 
ment between  theory  and  experiment  is  as  good  as  the  qualita- 
tive. Unfortunately,  the  comparison  is  made  somewhat  un- 
certain by  a  lack  of  definite  knowledge  of  N,  the  number  of 
electrons  per  unit  volume  in  the  arc,  emitting  vibrations  of  a 
given  period.  Humphreys'  experiments  gave,  as  a  result  of 
measurements  of  a  large  number  of  iron  lines  ranging  round 
A.  =  4.10-"5  cms.  values  of  d\/\  per  atmosphere  varying  between 
2.10-6  and  4.10 ~~7.     Using  the  formula 

dX       NeaXa 
X  "~  67rmce 

an  approximate  value  of  N  can  be  calculated. 

Taking  e/mc  =  1 77.  io7,  e  =  47.  io~ 10,  which  are  the  mean  values 
of  the  best  recent  determinations,  values  of  N  are  obtained 
which  range  between  17.1016  and  8*5. io16. 

This  is  the  approximate  number  of  electrons  per  unit  volume 
which  are  concerned  in  the  production  of  a  given  spectral  line 
for  iron.  For  the  other  metals  tried  by  Humphreys  N  is  found 
to  have  about  the  same  value.  Now  if  the  arc  were  an  ideal 
gas  at  27300  absolute  temperature  and  a  pressure  of  one  atmo- 
sphere, the  number  of  molecules  per  cubic  centimetre  would  be 
4.1018.  The  conditions  in  the  arc  are  too  uncertain  to  permit  of 
the  estimate  of  the  vapour  density,  but  at  first  sight  it  does  not 
appear  that  the  two  results  are  discordant  inter  se.  The  ques- 
tion is  really,  however,  whether  the  above  estimate  of  N  is  a 
reasonable  one.  To  determine  this  it  is  interesting  to  compare 
this  value  with  the  value  determined  by  other  methods.  Hallo1 
deduced  N  for  the  case  of  sodium  vapour  in  a  flame  from 
measurements  of  the  breadth  of  an  absorption  line  and  of  the 
magnitude  of  the  magnetic  rotation  of  the  plane  of  polarisation, 
and  obtained  for  the  constant  p  =  47rNe2/m  of  the   dispersion 

1  Diss.  Amsterdam,  1902,  Arch.  N/er/.  (2),  10,  p.  148,  1905. 


4S4  SCIENCE  PROGRESS 

formula  the  value  p  =  y6$.io2Z.  The  value  of  the  e/mc  was 
deduced  from  the  same  experiments  to  be  2*04.  io7,  and  the 
tolerable  agreement  with  the  values  found  by  more  direct 
methods  serves  as  a  measure  of  the  degree  of  accuracy  attained. 
This  value  of  p  gives  N  =  3.1014  as  the  number  of  electrons  per 
unit  volume  in  a  flame  coloured  by  sodium  vapour. 

Another  mode  of  experiment,  devised  by  Macaluso  and 
Corbino,  was  used  by  Geiger,1  depending  upon  the  displacements 
of  interference  bands,  and  values  of  p  were  obtained  varying 
with  the  wave  length  between  the  limits  for 

Sodium r63.io2S  to  4'83.io33 

Potassium          ....     0.82.10"  to  2 ro.io93 
Lithium 5*2. 10" 

values  which  are  of  the  same  order  of  magnitude  as  the  one 
above.  Now  Hallo  (Dissert  p.  92)  estimated  the  number  of 
molecules  present  per  unit  volume  in  his  experiments,  and 
concluded  that  only  a  small  fraction  of  these  molecules  are,  at 
any  instant,  concerned  in  the  emission  or  absorption  of  light, 
and  that  accordingly  the  mere  presence  of  a  sodium  molecule  in 
the  flame  is  not  a  sufficient  condition  for  its  taking  part  in 
radiation  or  absorption  :  to  do  so,  it  must  necessarily  be  in  some 
special  state.  The  exact  nature  of  that  state  is  unknown,  but 
only  a  small  fraction  of  the  molecules  are  in  it  at  any  given 
instant. 

If  now  this  result  be  accepted  it  would  appear  as  though 
the  values  of  N  required  to  account  for  the  observed  pressure 
displacement  are  possibly  rather  large ;  if,  on  the  other  hand, 
these  are  decreased  the  calculated  value  of  dX/A,  will  become 
smaller  than  the  experimental.  There  is  the  further  difficulty 
that  if  this  conclusion  is  true  there  is  no  reason  why  the  number 
of  electrons  emitting  radiation  of  any  given  wave  length  should 
increase  proportionately  to  the  density,  as  it  has  above  been 
assumed  to  do.  Too  much  stress  must  not,  however,  be  laid  on 
these  objections.  Hallo's  result  is  by  no  means  conclusive,  and 
the  conditions  existing  in  the  arc  are  so  different  from  those  in 
a  flame  coloured  with  sodium  vapour,  and  so  little  is  known 
about  the  exact  nature  of  these  conditions,  that  it  cannot  be  said 
with  certainty  whether  the  numerical  agreement  between  theory 
and  experiment  is  good  or  otherwise,  and  to  draw  premature 

1  Ann.  der  Phys.  23,  p.  758,  1907  ;  24.  p.  597,  1907. 


SPECTRAL   LINES  455 

conclusions  would  be  very  rash.  It  should  be  remembered  also 
that  too  good  an  agreement  cannot  be  expected  when  one 
recollects  that  some  of  the  assumptions  which  underlie  the 
theory  are  somewhat  ideal,  and  are  certainly  departed  from  in 
nature.  The  atom  has  been  pictured  above  as  a  collection  of 
electrons  each  vibrating  about  a  position  of  equilibrium,  and 
each,  by  its  vibrations,  emitting  radiation  of  a  definite  frequency 
and  so  giving  rise  to  a  single  spectral  line.  The  limitations  of 
mathematical  analysis  and  our  lack  of  knowledge  of  the  definite 
arrangement  of  the  electrons  inside  an  atom  compel  some  such 
simple  assumption,  which  indeed  is  in  a  sense  justified  by  the 
success  with  which  it  has  explained  many  of  the  phenomena  of 
absorption  and  dispersion.  Yet  it  is  much  more  probable  that 
one  has  really  to  deal  with  the  vibrations  of  groups  of  electrons, 
which  are  jointly  responsible  by  their  radiation  for  the  produc- 
tion of  a  number  of  spectral  lines ;  the  existence  of  spectral 
series  supports  this  view.  The  limitations  of  the  above  theory 
are  shown  in  a  marked  manner  by  one  of  the  results  obtained  ; 
it  was  proved  that  with  increase  of  density  there  is,  apart  from 
the  displacement,  a  symmetrical  broadening  of  the  absorption 
lines.  In  many  cases  such  actually  occurs,  but  in  many  others 
there  is  a  marked  dissymmetry  in  the  broadening,  generally  to- 
wards the  direction  of  longer  wave  length.  The  case  of  mercury 
vapour,  investigated  by  R.  W.  Wood,1  is  a  very  striking  example. 
Of  such  abnormal  effects,  as  they  may  be  called,  the  theory  in 
its  present  form  can  give  no  explanation.  Neither  can  it  account 
for  the  anomalous  behaviour  of.  the  enhanced  lines.  The  chief 
experimental  results  have,  however,  been — qualitatively,  at  least 
— explained  by  it  in  a  remarkable  manner,  and  therein  lies  the 
justification  for  the  belief  that  its  fundamental  assumptions  con- 
tain the  germ  of  truth.  For  the  present  this  must  suffice;  and 
just  as  in  the  development  of  other  branches  of  physics  such 
ideal  conceptions  as,  for  instance,  those  of  a  perfect  fluid  or  of  a 
perfectly  rigid  body  have  been  found  most  fruitful,  so  also  the 
present  theory  may  be  regarded  as  throwing  some  light  upon  a 
complicated  series  of  phenomena.  A  more  definite  discussion 
must  wait  until  experimental  physicists  have  obtained  a  com- 
pleter knowledge  of  the  structure  of  the  atom. 

1  Phil.  Mag.  August  1909. 


30 


A  SUGGESTION   CONCERNING  THE 
ORIGIN    OF    RADIOACTIVE   MATTER 

By   H.   S.   SHELTON,   B.Sc. 

The  suggestion  here  put  forward  was  written  by  me  several 
years  ago,  in  1908,  but,  finding  that  it  had  been  anticipated,  I 
made  no  attempt  to  publish  it.  Recent  correspondence  in 
scientific  journals  indicates  the  probability  that  others  may  take 
it  up  and  expand  it.  I  therefore  take  this  opportunity  of  stating 
it  explicitly. 

The  suggestion  is,  briefly,  that  radioactive  substances,  par- 
ticularly uranium  compounds,  are  synthesised  from  other 
elements  as  a  result  of  the  conditions  of  great  temperature  and 
pressure  found  in  the  Earth's  interior. 

The  anticipation  will  be  found  in  Prof.  Rutherford's  Radio- 
active Transformations  (p.  194),  where  the  suggestion  is  credited 
to  Dr.  Barrell.  It  is  mentioned  there  only  in  a  sentence  with 
no  indication  whatever  of  the  possible  implications  of  the  idea. 
So  far  as  I  am  aware,  this  is  the  first  suggestion  of  the  kind  that 
has  been  made. 

The  manner  in  which  it  arose  in  my  own  mind  will  best 
be  indicated  by  quoting  verbatim  from  my  MS.  written  in  1908  : 

"The  result  of  Prof.  Joly's  investigations  discloses  a  great 
disparity  between  the  known  radioactive  content  of  the  crust 
of  the  Earth  (36 x  10 ~12  parts  of  radium  per  unit  mass)  and  the 
calculated  radioactive  content  of  the  interior  (4'6x  io~14  parts  of 
radium  per  unit  mass  less  the  necessary  allowance  for  the 
radioactive  content  of  the  crust).  In  consequence,  on  the  usual 
supposition  concerning  the  interior  of  the  Earth,  we  need  to 
assume  either  an  almost  entire  absence  of  radioactive  matter  in 
the  interior,  or  an  interior,  with  an  absence  of  convective  action, 
heating  gradually  to  some  colossal  temperature.  May  not  the 
following  suggestion  provide  a  possible  solution  of  the 
difficulty  ? 

"  Is  it  not  possible  that  extreme  physical  conditions,  par- 
ticularly  of  temperature  and  pressure,  may  affect  the  rate  of, 

456 


RADIOACTIVE  MATTER  457 

stop  or  reverse  the  process  of  radioactive  decay  ?  So  far  as  our 
present  knowledge  goes,  no  change  of  conditions  has  any 
appreciable  effect  on  radioactive  decay,  but  we  are  inclined  to 
forget  the  infinitesimal  nature  of  such  changes  in  proportion  to 
the  colossal  energy  equivalent  involved  in  intra-atomic  change. 

"  The  great  majority  of  ordinary  chemical  actions,  especially 
those  which  occur  in  nature,  are  not  appreciably  affected,  and 
are  certainly  not  reversed,  by  a  few  degrees  of  temperature  or 
by  a  small  change  of  pressure.  The  energy  equivalent  of 
radioactive  decay  is,  mass  for  mass,  many  thousand  times 
greater  than  that  of  the  most  violent  chemical  action,  conse- 
quently we  are  not  entitled  to  infer  the  irreversibility  of  this 
change  until  we  are  able  to  control  changes  of  physical  con- 
ditions proportionately  greater  than  those  we  commonly  apply 
to  chemical  reactions. 

"  But,  in  the  interior  of  the  Earth,  these  plutonic  conditions 
actually  exist.  Mr.  Clarence  King  has  calculated  that  the 
pressure  would  probably  be  measured  in  millions  of  atmo- 
spheres, and  Sir  George  Darwin  has  shown  that  theories  of 
tidal  action  necessitate  the  assumption  that  there  is  continual 
addition  to  the  heat  stored  in  the  interior.  .  .  .  The  difficulties 
are  removed  if  we  combine  this  idea  of  Dr.  Barrell  concerning 
the  origin  of  radioactive  matter  with  the  assumption  of  a  very 
slow  convective  action  in  the  Earth's  interior.  It  is  not  then 
necessary  to  assume  that  radioactive  substances  are  confined 
to  the  Earth's  surface,  or  that  the  interior  of  the  Earth  possesses 
any  colossal  temperature.  According  to  this  hypothesis,  when 
conditions  of  temperature  and  pressure  exceed  a  certain  critical 
amount,  the  energy  will  be  stored  metachemically,  in  the  form 
of  radioactive  compounds.  As  these  find  their  way  very  slowly 
to  the  surface,  energy  will  be  given  off  again  in  their  slow 
disintegration."  ! 

After  the  lapse  of  several  years,  what  is  there  to  add  to  the 
passage  I  have  quoted  ?  There  is  very  little  of  any  moment. 
The  problem  remains  now  very  much  as  it  did  then.  Quite 
recently  there  had  been  a  discussion  in  the  columns  of  Nature, 
in  which  Mr.  Arthur  Holmes  and  Dr.  Schiller  took  part,  but 

1  Sir  George  Darwin's  paper  is  published  in  the  Philosophical  Transactions, 
Series  A,  1879;  the  passage  in  question  is  found  on  p.  592.  For  Prof.  Joly's 
statement  see  his  Address  to  Section  C  of  the  British  Association,  1908.  Mr. 
Clarence  King's  paper  was  published  in  the  American  Journal  of  Science,  Jan.  1903. 


458  SCIENCE  PROGRESS 

neither  of  them  seemed  to  have  gripped  the  problem.  Mr. 
Holmes  tried  to  give  reasons  for  thinking  that  uranium,  one  of 
the  heaviest  known  substances,  would  not  be  found  in  the  interior 
of  the  Earth,  but  would  be  concentrated  in  the  outer  layer.  His 
argument  was  based  on  its  distribution  in  the  acid  and  basic 
rocks  of  the  Earth's  crust.  He  put  forward  as  speculative  the 
idea  that  radioactive  decay  might  be  inhibited  by  great  heat  and 
pressure.  I  think  there  can  be  no  doubt  that  the  first  idea  is 
the  more  speculative  of  the  two.  By  what  conceivable  means 
could  radioactive  matter  be  concentrated  in  the  crust  to  the 
degree  required  by  theory  ?  On  the  other  hand,  if  we  admit 
that  external  conditions  can  inhibit  radiochemical  action,  why 
should  it  not  be  reversed  ?  Ordinary  chemical  actions  are  re- 
versible, given  the  necessary  change  of  conditions.  I  do  not 
mean  to  suggest  that  uranium  would  be  built  up  from  radium 
and  emanation,  merely  that  it  would  be  synthesised  from  other 
elements  given  the  necessary  conditions. 

On  the  question  of  the  speculative  nature  of  the  suggestion, 
it  must  be  admitted  that,  in  a  sense,  speculative  it  is.  We  have 
never  been  able,  by  artificial  means,  to  vary  the  rate  of  radio- 
active decay.  But,  so  far  as  reasoning  can  be  applied  to  such 
matters,  what  inference  is  simpler  ?  Uranium  compounds  are 
continually  and  slowly  decaying  at  a  constant  rate.  It  is, 
therefore,  a  temporary  element.  And  a  temporary  element  must 
have  had  a  beginning.  The  argument  is  as  sound  for  uranium 
as  for  radium.  The  time  scale  only  is  altered.  On  the  sup- 
position that  the  rate  of  decay  is  a  constant  quantity,  an 
origin  of  uranium  is  a  necessary  inference.  If  this  is  not  the 
origin,  what  is? 

Scientific  men  are  often  slow  to  appreciate  the  simple  and 
natural  inferences  from  their  discoveries.  Is  not  the  fact  that 
uranium  and  radium  are  elements  in  every  sense  but  one  a 
clear  indication  that  other  elements  are  not  elements  in  the  old- 
fashioned  sense,  but  that  they  could  be  more  correctly  described, 
as  some  one  has  suggested,  as  chemical  primaries? 

The  necessity  for  some  such  idea  can  be  found  in  other 
departments  of  science.     As  I  have  indicated  elsewhere,1  it  is 

1  See  Contemporary  Review,  June  1913,  "On  the  Age  of  the  Sun's  Heat"; 
Knowledge,  Jan.  1910,  "  A  Theory  of  the  Structure  of  the  Solar  Photosphere."  An 
article  by  the  Messrs.  Jessup,  in  the  Philosophical  Magazine,  January  1908, 
though  not  directly  dealing  with  the  problem,  is  of  interest  in  the  same  connection. 


RADIOACTIVE  MATTER  459 

impossible,  without  some  such  hypothesis,  to  correlate  geologic 
time  with  the  duration  of  solar  heat.  Other  lines  of  thought 
lead  to  the  same  idea.  But  it  is  impossible  to  deal  with  remote 
implications  in  a  brief  note.  In  view  of  current  scientific  views, 
I  think  it  desirable  to  publish  the  idea  for  what  it  is  worth,  and 
to  indicate  the  origin  of  the  first  suggestion  of  the  kind  I  have 
been  able  to  discover. 


THE   INFLUENCE   OF   NUTRITION   AND 
THE   INFLUENCE  OF   EDUCATION    IN 
MENTAL   DEVELOPMENT1 

By  F.   W.   MOTT,    M.D.,    F.R.S. 

In  the  last  lecture  I  pointed  out  to  you  that  the  brain  consists  of 
innumerable  nervous  units  or  neurones  and  that  these  nervous 
units  or  neurones  are  collected  into  groups,  systems,  and  com- 
munities having  different  functions,  but  that  broadly  speaking 
they  form  three  great  groups  or  classes,  viz.  (i)  efferent  sensory 
chains  of  neurones ;  (2)  efferent  motor  chains  ;  and  (3)  associa- 
tion chains  of  neurones  (fig.  1).  A  neurone  consists  of  a  nerve 
cell  and  all  its  branches  ;  one  branch  forms  a  nerve  fibre  which 
is  called  the  axon  because  it  forms  the  central  axial  core  of  the 
nerve,  the  other  branches,  like  those  of  a  tree,  are  called  den- 
drons.  The  grey  matter  of  the  cortex  covering  the  surface  of 
the  brain  which  is  the  seat  of  consciousness  consists  of  countless 
millions  of  nerve  cells  and  processes  and  thus  gives  it  its  grey 
appearance. 

Innate  Potentiality  of  the  Neurones,  and  Brain 

Development 

In  the  child's  brain  before  birth  these  cells  are  packed  closely 
together,  and  at  one  period  they  have  no  processes ;  as  the 
brain  develops  and  grows  these  cells,  which  are  termed  neuro- 
blasts (neurone-formers),  send  out  processes  which,  extending 
and  branching  like  a  tree,  lead  to  an  increased  complexity  of 
structure.  This  capacity  to  grow  and  develop  is  inherent  in  all 
the  neuroblasts  of  the  brain,  but  in  order  to  grow  and  develop 
they  must  be  fed  by  the  blood  with  suitable  food.  Just  as  some 
individuals  with  abundance  of  food-supply  do  not  develop  and 
grow  because  they  are  unable  to  take  it,  or  if  they  do  to 
assimilate  it,  so  it  is  with  the  neurones;  if  there  is  an  inborn 
failure  to  take  up  from  the  blood  and  assimilate  the  food  sup- 
plied, they  will  not  develop  and  grow. 

1  Third  Chadwick  Trust  Lecture,  continued  from  Science  PROGRESS,  October 

1913. 

460 


MENTAL  DEVELOPMENT  461 

The    neurone    is    a    complex    cell  behaving    like    a  living 
organism  ;  it  nourishes  itself  and  is  not  nourished.     Now  the 
neurones  forming  the  grey  matter  of  the  cortex  are  the  most 
complex  and  latest  developed  ontogenetically  and  phylogeneti- 
cally,  consequently  the  germinal  determinants  of  these  cells  are 
less  fixed  and  stable,  therefore  more  likely  to  undergo  patho- 
logical mutations  than  other  cells  of  the  body  under  the  influence 
of  chronic   poisoned   conditions   of  the   blood   of  the   parents. 
Whether  this  be  so  or  not,  it  is  certain  that  these  cells  are  the 
latest  to  mature  and  become  capable  of  active  employment,  thus 
they  are  more  susceptible  to  arrest  of  growth,  and  development 
by  prenatal   and   postnatal  nutritional  failure,  or  by  poisoned 
conditions  of  the  blood.     Various  forms  of  failure  of  develop- 
ment of  the  brain  occur  owing  to  the  lack  of  innate  capacity  or 
specific  energy  of  the  neurones  to  grow,  and  since  the  brain 
does  not  grow  the  skull-bones  also  fail  to  grow,  and  we  have 
what  is   termed    a    microcephalic    idiot.     It  was   at  one   time 
thought   that  the  brain  was  prevented   from  growing   by   the 
closure   of  the  bones  of  the  skull,  and  surgeons  attempted  to 
remedy  this  by  removing  pieces  of  the  skull  so  as  to  allow  the 
brain  space  to  grow ;  but  experience  proved  that  the  operation 
did  not  cause  the  brain  to  grow  and  the  operative  treatment  of 
microcephalic  idiocy  was  given  up.     A  little  reflection  and  ob- 
servation would  have  shown  that  the  brain  is  the  master  tissue 
and  determines  the  growth  of  the  skull,  and  the  reason  why  the 
skull  closed  early  was  the  natural  response  to  the  cessation 
of  the  dynamic  force  of  growth  of  the  nervous  structures  of  the 
brain.     I  have  already  alluded  to  the  fact  that  all  the  tissues  of 
the  body  will  suffer  in  order  that  the  brain  may  grow ;  in  starva- 
tion the  brain  hardly  loses  any  weight.    The  brain  weight  of 
infants  dying  of  exhausting  diseases  does  not  seem  to  suffer, 
and    the    experiments    of  Donaldson   at  the   Wistar   Institute 
(already  alluded  to  in  the  previous  lecture)  show  that  imperfect 
nutrition  does  not  lead  to  arrest  of  growth  and  development  of 
the  brain.    An  inborn  germinal  lack  of  capacity  of  the  neurones 
forming  the  anatomical  basis  of  mind  to  develop  and  function 
properly  cannot  be  remedied  by  improved  nutrition  of  the  body, 
and  this  is  shown  by  the  fact  that  mental  deficiency  is  found  in 
children  of  all  grades  of  society ;  in  fact,  the  majority  of  cases  of 
feeble-minded  children  are   ineducable   because  of  an  inborn 
physiological  deficiency. 


462  SCIENCE  PROGRESS 


The  Blood  Supply  and  its  Quality,  in  Relation  to  Growth 

and  Function  of  the  Brain 

Have  nutrition  and  education  then  no  influence  in  mental 
development  ?  Let  us  first  consider  the  subject  of  nutrition 
from  a  physiological  standpoint.  The  brain  in  order  to  grow 
and  function  requires  a  proper  supply  of  oxygenated  blood  con- 
taining the  necessary  materials  out  of  which  the  nervous  matter 
can  be  assimilated  and  built  up.  We  know  that  if  the  secre- 
tion of  the  thyroid  gland  is  lacking  owing  to  congenital  absence 
of  the  gland,  the  brain  is  arrested  in  its  development,  and  the 
child  is  a  cretinous  idiot.  Medical  science  has  shown  that  if  the 
child  receives  daily  a  small  quantity  of  thyroid  gland  (obtained 
from  sheep),  it  stimulates  the  brain  cells  to  grow  and  probably 
supplies  the  blood  not  only  with  an  excitant  to  growth  but  some 
essential  substance  for  the  growth  of  the  brain  tissue.  The 
reason  why  there  is  such  a  large  blood  supply  to  the  grey 
matter  of  the  brain  is  that  important  bio-chemical  processes 
occur  there,  constituting  the  physiological  basis  of  mental 
activity.  In  all  mental  operations  nervous  energy  is  used  up; 
the  neurones  are  the  agents  for  the  storage  and  liberation  of 
nervous  energy ;  and  its  liberation  is  the  physiological  basis  of 
mental  activity,  whether  it  be  in  simple  or  complex  processes. 
The  neurones  automatically  store  energy  when  they  liberate  it, 
but  there  is  a  reserve  store  for  emergencies.  Now  liberation  of 
nervous  energy,  that  is,  conversion  of  latent  neuro-potential  into 
active  neuro-potential  involves  oxidation ;  consequently  oxygen 
is  essential  for  the  process.  This  is  shown  by  the  fact  that  un- 
consciousness results  if  the  cortex  of  the  brain  is  deprived  of 
arterial  blood  for  a  few  seconds. 

We  are  conscious  of  the  external  world  and  our  own 
personality  and  existence  by  continuous  stimuli  arising  from 
the  external  world  and  from  our  own  body.  If  those  stimuli 
were  cut  off,  we  should  lose  consciousness,  notwithstanding 
that  the  blood  supply  to  the  cortex  of  the  brain  continues. 
The  neurones  of  the  cortex  of  the  brain,  besides  innate 
potentiality  to  function,  require  also  the  stimulus  from  the 
external  world  together  with  a  proper  supply  of  oxygenated 
blood ;  and  this  implies  a  sufficient  number  of  red  blood 
corpuscles    provided    with    an    adequate   quantity  of  the   red 


MENTAL  DEVELOPMENT  463 

colouring  matter — haemoglobin.  Not  only  may  an  impoverished 
blood  deficient  in  red  blood  corpuscles  and  other  essential 
constituents  be  the  cause  of  a  mental  functional  deficiency 
by  depriving  the  nervous  elements  of  their  capacity  to  grow, 
develop,  store,  and  liberate  energy,  but  a  poisoned  condition 
of  the  blood  is  a  far  more  frequent  cause  of  acquired  failure 
of  mental  energy  in  infants  and  children  as  well  as  in  adults. 
Such  impoverished  and  poisoned  conditions  of  the  blood  in 
infancy  arise  in  a  large  majority  of  cases  from  gastro-intestinal 
disturbances  owing  to  improper  feeding,  and  may,  if  con- 
tinuous, interfere  with  bodily  nutrition  and  brain  development. 
The  intelligent  mother  accepts  such  warnings  as  fits  of 
screaming,  restless  sleep,  crying  without  obvious  cause,  refusal 
of  food,  and  convulsions  ;  she  does  not  think  the  infant  exhibits 
these  symptoms  from  temper,  but  as  an  evidence  of  suffering 
requiring  maternal  sympathy  and  protection,  and  she  seeks  the 
cause  in  order  to  remove  it.  Now,  imperfect  nutrition  and 
poisoned  conditions  of  the  blood  brought  about  by  fermentation 
and  putrefaction  in  the  gastro-intestinal  canal  from  improper 
feeding,  and  from  acquired  or  inherited  disease,  may  not 
actually  arrest  the  growth  of  the  neurones  of  the  brain  any 
more  than  they  very  materially  interfere  with  the  growth  of 
the  child,  and  cause  arrest  of  development ;  but  such  unfavour- 
able conditions  of  nutrition  at  the  time  when  the  brain  is 
undergoing  its  most  active  development  cannot  but  be  harmful. 
I  told  you  in  my  first  lecture  that  during  the  first  three  years 
after  birth  the  greatest  increase  in  the  weight  of  the  brain 
occurred,  and  that  at  three  years  old  it  had  trebled  its  weight 
at  birth.  Even  if  with  an  unfavourable  bodily  nutrition  of  the 
infant  the  brain  grows  and  develops  to  nearly  treble  its  weight 
at  the  end  of  three  years,  we  cannot  therefore  assume  that  it 
has  in  no  way  suffered  from  mal-nutrition,  any  more  than  we 
can  assume  that  because  a  child  has  grown  in  stature  a  few 
inches  less  than  a  well-nourished  child,  it  has  not  seriously 
suffered.  You  naturally  ask  :  How  then  has  the  brain  suffered  ? 
It  has  suffered  constitutionally,  as  the  child  has  suffered  con- 
stitutionally ;  it  is  less  able  to  resist  the  effects  of  stress  from 
any  cause ;  it  is  more  liable  to  exhibit  signs  of  nervous 
irritability,  convulsions  of  teething,  and  if  the  child  is  infected 
by  the  micro-organisms  of  pneumonia,  tubercle,  whooping- 
cough,   measles,   or  scarlet  fever,  the  brain  as  well   as   other 


464  SCIENCE  PROGRESS 

parts  of  the   body  has  less  vital   resistance    to    the    poisons 
produced  by  the  organisms. 

Infant  Feeding 

Children  often  suffer  from  over-feeding  and  from  being 
given  unsuitable  food  that  sets  up  gastro-intestinal  irritation, 
vomiting,  and  diarrhoea  with  various  manifestations  of  nervous 
irritability  due  to  absorption  of  bacterial  poisons  by  the  blood. 
The  greatest  preventable  cause  of  infant  mortality  and  con- 
stitutional weakness  of  the  child  after  birth  is  improper  and 
insufficient  feeding.  Other  preventable  causes  of  infantile 
mortality  are  congenital  syphilis  and  tubercular  meningitis. 
Collective  responsibility  should  not  be  undertaken  to  replace 
parental  responsibility,  but  to  educate  and  assist  it ;  and 
this  is  the  method  adopted  by  health  visitors.  This  system 
of  educating  the  mothers  is  beginning  in  a  right  way  by 
giving  every  infant  a  better  chance  for  growth  of  body  and 
mind.  Collectivism  and  individualism  should  work  together 
by  improving  the  mother's  health  and  instructing  her  how 
to  nourish  her  offspring.  Now,  there  can  be  no  doubt  that 
the  natural  food  for  the  infant  up  to  the  time  that  it  has 
teeth  is  the  mother's  milk,  which  is  the  only  perfect  food 
for  the  baby  during  the  first  nine  months  of  its  life,  and 
only  under  exceptional  circumstances  is  it  justifiable  to  employ 
artificial  feeding,  in  the  interests  not  only  of  the  infant  but  of 
the  mother  also.  For  not  only  has  nature  provided  the  milk 
glands,  but  also  an  internal  secretion  by  the  cells  which  occupy 
the  position  in  the  ovary  whence  the  ovum  that  developed  into 
the  child  came,  and  this  internal  secretion  has  the  special 
function  of  stimulating  the  secretion  of  milk.  Prof.  Karl 
Pearson  in  his  second  Chadwick  Lecture  showed  the  fallacy 
of  statistics  in  regard  to  infant  mortality  and  various  modes  of 
feeding  in  town  populations.  His  argument  was  that  the 
statistics  showed  that  infant  mortality  only  corresponded  with 
the  health  and  habits  of  the  parents  ;  it  did  not  seem  to  matter 
whether  the  child  was  breast  fed  or  artificially  fed,  nor  did  it 
seem  to  point  to  one  form  of  artificial  feeding  being  superior  to 
another.  Are  we  therefore  to  conclude  that  it  does  not  really 
matter  whether  a  child  receives  the  nourishment  nature  itself 
provides  or  not  ?  No !  The  reason  why  artificial  feeding  of 
infants  appeared  in  statistics  to  be  good,  or  better  than  breast- 


MENTAL  DEVELOPMENT  465 

feeding,  is  that  poor  and  destitute  women  unable  to  purchase 
milk  are  very  numerous.  They  themselves  have  large  families 
which,  owing  to  their  own  nutritional  failure,  they  are  not  able 
to  rear. 

Stimulus  in  Relation  to  Development  of  the  Brain 

There  are  two  other  factors  to  consider  beside  innate 
potentiality  of  the  neurones  and  their  supply  of  the  necessary 
materials  for  growth  by  a  pure  and  adequate  blood  supply. 
They  are  the  stimulus  to  growth  by  the  physical  and  chemical 
excitation  of  the  nerve  endings  in  the  sense  organs  and  bodily 
structures.  Let  us  consider  this  a  little  more  fully.  The 
infant  learns  to  know  its  own  existence  and  the  desires 
necessary  for  its  life  by  its  organic  sensibility ;  the  nerve 
endings  in  the  skin,  muscle,  tendons,  and  joints  carry  messages 
continually  to  its  brain,  inciting  the  desire  to  breathe,  to  take 
nourishment,  and  to  perform  the  calls  of  nature.  The  special 
sense  organs  associated  with  the  muscle  sense — which  con- 
tributes to  every  other  sense — are  especially  represented  in  the 
grey  matter  covering  the  brain ;  they  are  the  avenues  of 
intelligence  and  by  motor  reaction  and  adaptation  the  source 
of  information  concerning  the  external  world.  As  I  pointed 
out  in  my  first  lecture,  preparedness  for  function  by  myelination 
is  first  shown  in  the  structures  of  the  cortex  which  serve  as 
the  arrival  platform  of  sensations  of  organic  and  bodily  sensi- 
bility, of  smell  and  of  taste  ;  then  of  vision,  and  lastly  of  hearing  ; 
these,  combined  with  the  kinaesthetic  sense,  constitute  the 
primary  perceptive  centres.  A  simple  experiment  shows  that 
the  chains  of  neurones  which  constitute  the  peripheral  receptor 
(sense  organ),  the  transmitter,  and  the  central  perceptor  have 
the  power  of  transforming  cosmic  energy  into  neural  energy. 
The  experiment  is  this  :  if  you  take  a  pair  of  fine  electrodes  con- 
nected with  an  electrical  apparatus  discharging  an  interrupted 
electrical  current,  and  place  them  on  the  tongue,  a  sensation  of 
taste  is  produced  ;  if  on  the  skin  a  vibratile  sensation  is  felt ; 
if  the  eyeball  is  excited  a  bright  light  is  seen ;  and  if  the  nerve 
of  hearing  is  stimulated  a  noise  is  heard.  Since  the  stimulus 
does  not  vary  in  any  one  of  these  experiments  it  necessarily 
follows  that  each  sensory  nervous  mechanism  has  the  power  of 
transforming  the  stimulus  and  producing  a  specific  effect  on 
consciousness.    The  neurones  then  not  only  act  as  receptors, 


/ 


466  SCIENCE  PROGRESS 

but  transformers  of  energy,  and  they  use  up  ox}^gen  in  the 
vital  functions  associated  with  this  specific  transformation. 
Moreover,  traces  of  the  specific  effects  are  left  in  the  perceptor 
cortical  neurones  constituting  memory.  Now  what  will  be 
the  effect  on  the  growth  of  the  neurones  forming  the  central 
perceptor  for  vision,  if  the  child  is  born  blind,  and  all  light 
stimulus  is  thereby  cut  off  from  the  brain  ?  Experiment  has 
answered  this  question.  A  microscopic  examination  of  the 
visual  area  of  the  brain  of  a  puppy  whose  eyes  were  removed 
at  birth  was  compared  with  a  normal  puppy,  and  the  accom- 
panying figures  show  that  the  cells  of  the  grey  matter  of  the 
blind  dog  were  small  and  shrunken  as  compared  with  the  cells 
of  the  grey  matter  of  the  normal  dog.  Stimulus,  therefore, 
is  necessary  for  development  and  growth  of  the  neurone. 

Helen  Keller  and  Laura  Bridgeman  in  Relation  to  the 

Tactile-Motor  Sense 

You  may  ask  how  it  was  that  Laura  Bridgeman  and  Helen 
Keller,  both  blind  and  deaf  in  early  life,  were  able  to  develop 
such  a  high  degree  of  intelligence  when  the  two  principal 
avenues  of  intelligence  were  cut  off  in  early  life.  My  answer  is 
this  :  Look  at  this  diagram  of  the  child's  brain  at  three  months 
and  you  see  every  part  of  the  grey  matter  of  the  cortex  is 
connected  by  fibres  capable  of  functioning;  all  the  elementary 
perceptor  centres  of  the  special  senses  are  connected  by  associa- 
tion fibres  with  the  kinaesthetic  sense  area  and  the  motor  efferent 
area.  The  child  at  three  months  is  no  longer  capable  of  an 
elemental  sensation ;  the  visual  and  tactile-motor  senses  have 
become  associated  ;  the  child  has  learnt  to  handle  things  seen 
and  to  memorise  the  meaning  of  things  seen,  as  regards  other 
qualities  than  form  and  colour.  Now  both  Laura  Bridgeman 
and  Helen  Keller  were  not  affected  with  blindness  and  deafness 
till  such  a  time  after  birth  had  elapsed  for  a  very  complete 
development  of  the  association  systems.  Sensory  stimuli  had 
poured  in  through  all  the  sensory  avenues  for  twenty-six  months 
in  the  case  of  Laura  Bridgeman  and  for  nineteen  months  in  the 
case  of  Helen  Keller ;  consequently  we  should  not  expect  those 
regions  of  the  brain  which  had  served  for  seeing  and  hearing 
— which  had  been  shut  off  by  damage  to  the  transmitter — to 
undergo  atrophy  and  arrest  of  development  the  same,  as  if  no 
stimulus  of  light  or  sound  had  ever  affected  them.     It  may  be 


MENTAL  DEVELOPMENT  467 

asked,  How  could  these  areas  of  the  brain  be  utilised  when  cut 
off  from  the  external  world  by  interruption  to  the  transmitter  ? 
The  kinaesthetic  sense  (or  sense  of  movement)  is  the  sense 
which  contributes  to  every  other  sense ;  it  is  especially 
associated  with  vision  and  touch,  but  also  with  hearing  in  the 
movements  of  the  lips  and  tongue  in  the  production  of  articulate 
sounds.  Now  this  kinaesthetic  sense  and  the  tactile  sense  were 
not  interrupted  in  the  cases  of  Laura  Bridgeman  and  Helen 
Keller.  The  innate  potentialities  of  the  brains  of  these  two 
remarkable  beings  must  have  been  of  the  best,  and  the  greatest 
credit  is  due  to  that  pioneer  Dr.  Gridley  Howe  for  finding  his 
way  to  Laura  Bridgeman's  intelligence  through  her  finger  tips. 
His  plan  was  to  teach  her  by  raised  types  and  then  by  the 
manual  alphabet. 

One  of  the  most  interesting  psychological  studies  that  I  know 
of  is  The  Story  of  My  Life,  by  Helen  Keller.  She  was  evidently 
a  precocious  child,  for  at  six  months  she  could  utter  articulate 
sounds  ;  even  three  months  after  the  illness  which  made  her 
blind  and  deaf  she  uttered  the  word  "  water."  She  walked  at 
one  year,  and  as  she  says,  "  During  the  first  nineteen  months  of 
my  life  I  had  caught  glimpses  of  broad  green  fields  which  the 
darkness  that  followed  could  not  utterly  blot  out."  In  the  first 
months  after  her  illness  she  says :  "  My  hands  felt  every  object 
and  observed  every  motion  and  in  this  way  I  learned  to  know 
many  things,"  and  she  indicated  her  wants  by  gesture  language 
encouraged  by  her  mother.  She  lived  a  normal  life  on  a  farm 
sans  sight  and  hearing,  but  was  wonderfully  intelligent  and 
exercised  reason  in  her  actions.  She  was  always  happy  when 
she  could  keep  her  mind  and  fingers  busy.  Systematic  teaching 
by  Ann  Mansfield  Sullivan  was  commenced  when  she  was 
seven,  the  system  being  the  association  of  tactile-motor  verbal 
symbols  made  with  the  finger  in  the  palm  of  the  hand  with  the 
tactile-motor  impression  of  objects.  Everything  had  a  name 
and  each  name  gave  birth  to  a  new  thought.  She  remarks  :  "  At 
the  first  I  was  only  a  little  mass  of  possibilities ;  it  was  my 
teacher  who  unfolded  and  developed  them."  At  the  age  of  ten 
she  learned  to  speak.  She  was  taught  by  a  Miss  Fuller,  and  the 
method,  in  Helen  Keller's  own  words,  was  this  :  "  She  passed 
my  hand  lightly  over  her  face  and  let  me  feel  the  position  of  the 
tongue  and  lips  when  she  made  a  sound."  In  reading  her 
teacher's  speech  she  was  dependent  on  her  fingers,  she  placed 


468  SCIENCE  PROGRESS 

her  hand  on  her  teacher's  throat,  mouth,  and  face,  and  read  the 
vibrations  and  movements  of  the  mouth  and  expressions  of  the 
face ;  the  same  movements  she  learned  to  reproduce  and  thus 
learned  articulate  speech.  The  sense  of  movement  combined 
with  touch  and  smell  were  in  her  case  the  sole  avenues  of 
stimulus  to  the  brain  from  the  external  world,  but  inasmuch  as 
all  the  primary  sensory  areas  including  hearing  and  vision  are 
connected  with  these  areas  by  association  channels,  the  whole 
brain  responded  to  the  stimulus  and  developed  to  the  full  its 
innate  educable  possibilities. 

Sleep  and  Mental  Development 

We  now  come  to  the  last  factor  requisite  for  proper  develop- 
ment of  the  brain  and  especially  its  efficient  function — sleep — 
that  sweet  unconscious  quiet  of  the  mind  which  permits  all  the 
vital  bodily  functions  to  continue  (although  less  actively)  while 
the  cortex  of  the  brain  rests  and  the  whole  organ  stores  energy 
and  recuperates.  Sleeplessness  is  a  sign  of  nervous  irritability 
and  is  cause  as  well  as  effect  of  mental  fatigue  and  nervous 
exhaustion.  Darkness,  stillness  of  the  body,  and  silence  favour 
sleep  by  removing  the  principal  causes  of  wakefulness  and 
activity  of  the  mind.  Habit  fortunately  permits  of  sleep  under 
the  most  unfavourable  conditions ;  still,  the  sleep  of  young 
children  must  necessarily  be  a  broken  one  in  the  single-room 
tenement  dwellings  of  the  poor  of  our  large  cities.  This  is  an 
important  unhygienic  condition  relating  to  mental  development; 
for  insufficiency  of  rest  to  the  brain  tends  to  failure  of  mental 
energy.  The  growing  infant  requires  plenty  of  sleep  ;  so  also 
does  the  growing  child,  and  especially  is  it  so  when  the  child  is 
suffering  from  bodily  ill-health  or  nervous  irritability.  When 
I  was  in  Chicago  recently  I  observed  that  all  the  children  in  the 
Special  School  for  Tuberculosis  were  made  to  lie  in  bed  for  an 
hour  in  the  afternoon. 

The  question  of  nutrition  in  relation  to  mental  development, 
ability,  and  efficiency  is  one  that  until  quite  recently  was  not 
properly  considered  by  the  authorities ;  for  until  the  mother's 
health  and  her  mode  of  feeding  her  offspring  became  a  part  of 
social  reform,  the  most  important  step  in  relation  to  nutrition 
and  mental  development  was  left  out.  Statistics  of  Willesden 
and  Chester  (which  I  throw  on  the  screen)  show  that  not  many 
children  in  these  localities  were  suffering  from  imperfect  nutri- 


MENTAL  DEVELOPMENT  469 

tion  when  medically  inspected.  The  minor  ailments  were  the 
chief  cause  of  trouble,  viz.  defective  teeth,  adenoids,  large  tonsils, 
defective  vision,  and  especially  parasitic  head  affections.  Eye 
strain  from  errors  of  refraction  may  lead  to  nervous  affections 
in  children  with  a  neurotic  or  neuropathic  temperament; 
adenoids  and  large  tonsils  are  a  very  frequent  cause  of  deafness 
and  consequent  mental  dullness. 

The  extension  of  the  meaning  of  education  by  collective 
responsibility  to  the  bodily  welfare  of  the  child  from  birth 
onwards  is  one  of  the  greatest  steps  made  towards  increasing 
the  educability  of  the  child  when  it  arrives  in  the  school.  We 
have  seen  that  the  factors  underlying  educability  are  first  and 
foremost  the  germinal  inborn  potentialities  derived  from  pro- 
genitors (Nature)  ;  secondly,  those  conditions  of  nurture  which 
are  favourable  to  the  morphological  development  of  inborn 
potentialities,  viz.  bodily  nutrition,  sleep,  and  stimulus. 

The  Influence  of  Education  on  the  Development  of 

the  Mind 

The  teacher  is  powerless  to  develop  intelligence  where  there 
is  an  absence  of  the  material  basis  of  mind,  or  an  inherent  low 
functional  value  and  ready  fatiguability ;  so  that  sustained 
attention,  necessary  for  the  acquirement  of  knowledge,  fails. 
The  former  condition  is  quite  hopeless,  the  latter  may  not  be 
due  to  inborn  defects,  but  to  bad  nurture ;  therefore  preventable 
and,  in  a  measure,  curable. 

The  object  of  education  should  be  to  establish  physical, 
intellectual,  and  moral  efficiency  in  the  child  by  drawing  out  and 
developing  the  good  inborn  qualities,  by  installing  and  fixing 
good  habits,  and  by  repressing,  controlling,  and  preventing  as 
far  as  possible  the  acquirement  of  bad  habits.  In  the  acquire- 
ment of  good  or  bad  habits  early  in  life  when  the  mind  is  most 
susceptible,  imitation  and  suggestion  play  a  most  important 
part ;  thus  an  inborn  virtue  such  as  an  amiable  and  confiding 
disposition  may  under  the  influence  of  bad  companionship  lead 
to  the  ready  acquirement  of  vicious  habits.  The  teacher  has 
only  a  partial  influence  in  forming  character  and  education  for 
efficiency.  Home  influence,  good  as  well  as  bad,  companions  in 
school  and  out  of  school,  chance  and  opportunity,  all  play  their 
part  in  the  general  making  of  success  or  failure  in  the  final 
product  of  education.     Home  influence  is  the  most  important 


4;o  SCIENCE  PROGRESS 

factor  in  efficiency,  especially  in  the  formation  of  character  ;  the 
individual  efforts  of  good  parents,  especially  of  good  mothers, 
cannot  be  replaced  by  the  collective  efforts  of  society  in  schools 
and  institutions.  Yet  much  may  be  done  by  health  visitors  and 
domiciliary  visits  of  school  nurses  in  improving  the  home 
conditions  of  the  child,  and  thus  helping  the  teachers  in  their 
work  of  education.  When  the  home  conditions  are  impossible 
for  the  child,  the  relief  of  the  parents  of  responsibility  for  its 
care  has  been  attended  with  marked  success  ;  so  also  the  poor 
material  furnished  by  waifs,  strays,  and  orphans  formerly 
dragged  up  in  the  workhouse  has  been  made  into  more  or  less 
efficient  material  in  the  industrial  schools  and  Barnardo's  homes. 
Social  reform  has  thus  made  great  progress  in  the  interest  of  the 
child  by  the  extension  of  the  meaning  of  education.  I  have  been 
much  impressed  by  the  growing  interest  teachers  take  in  their 
pupils  ;  especially  have  I  had  the  opportunity  of  observing  this 
in  the  teachers  at  special  schools.  They  know  of  the  home  life 
of  their  pupils,  and  show  interest  in  understanding  the  cause  of 
the  physical  and  mental  defect  from  which  the  child  suffers.  It 
seemed  to  me  almost  pathetic  that  teachers  with  such  intelligence, 
human  sympathy,  and  untiring  energy  in  their  work  should  be 
entrusted  with  the  almost  hopeless  task  of  trying  to  draw  out 
from  mental  defectives  initiation  or  efficiency.  It  is  otherwise  in 
the  special  schools  for  tuberculosis,  deaf  and  dumb,  and  blind 
children  ;  here  there  is  educable  material  which  will  in  future 
make  for  efficient  service.  The  open-air  schools  for  the  treat- 
ment of  tuberculosis  which  I  visited  at  Birmingham  made  me 
exclaim  :  "  Why,  these  children  look  healthier  than  the  normal ! 
Why  not  have  all  the  children  taught  in  open-air  schools?  " 

The  special  schools  for  the  deaf  and  the  blind  yield  gratifying 
results  to  the  teachers,  because  in  the  majority  of  cases  the 
children  are  not  mind-blind  or  mind-deaf;  they  are  educable 
because  the  material  basis  of  mind  in  the  brain  is  there,  and  the 
teacher  finds  her  way  to  the  mind  of  the  blind  through  the  finger- 
tips and  to  the  mind  of  the  deaf  through  sense  of  sight.  The 
deaf  child,  by  watching  the  movements  of  the  lips,  is  able  to 
speak  by  imitating  the  movements.  Do  not  these  facts  show 
the  great  importance  of  training  the  tactile-motor  sense  and  the 
sense  of  movement  (kinesthetic  sense)  in  our  normal  schools  ? 

The  kinesthetic  sense  is  one  of  the  most  important  which 
can  be  cultivated ;  it  is  the  essence  of  the  joie  de  vivre  in  play, 


j  CorJ>.  S trial ^7) 


Neuron  <■•/'.  '    *  Ti 
Ant.  Horn    0*.*"' 

4 


Fig.  i. — Diagram  to  illustrate  afferent  kinesthetic  system  conveying  impulses  from  tactile 
corpuscles,  from  muscle  and  tendon  by  way  of  the  sensory  nerves  to  the  spinal  cord,  and 
thence  to  the  cerebrum  and  cerebellum. 

The  efferent  motor  projection  systems  from  the  cortex  cerebri  and  the  cerebellum  are  shown  terminating  at 
the  spinal  motor  efferent  neurones,  which  transmit  impulses  by  the  motor  nerves  to  the  muscles.  The 
numerous  pyramidal  cells  of  the  cortex  represent  the  association  system  of  neurones  which  link  up  all 
the  perceptor  centres  with  the  sensori-motor  region. 


47°] 


MENTAL   DEVELOPMENT  471 

which  is  instinctive  in  children  and  animals;  and  not  only  do 
the  feelings  aroused  in  connection  with  it  give  pleasure,  but  they 
are  stimulating  to  growth  of  body  and  mind.  Every  movement 
of  the  limbs  leads  to  ingoing  currents  of  nervous  energy  {vide 
fig.  1).  Bodily  fatigue  from  exercise  arises  more  from  accumu- 
lation of  fatigue  products  (that  is,  chemical  substances)  in  the 
muscles  than  from  exhaustion  of  the  nervous  structures ;  indeed, 
the  nerves  as  conductors  do  not  get  fatigued. 

The  Evolution  of  Association  of  the  Eye  and  the  Hand 

A  study  of  the  association  of  the  eye  and  the  hand  is  of  great 
interest  in  showing  the  reciprocal  simultaneity  in  the  develop- 
ment of  the  visual  directive  and  the  tactile-motor  executive 
faculties.  In  the  animal  series  it  is  not  till  we  reach  the 
primates  (apes,  anthropoid  apes,  and  man)  that  we  find  dissocia- 
tion of  the  fore  limbs  from  progression  ;  the  nose  is  lifted  from 
the  ground  and  the  sense  of  smell  and  capture  of  food  by  the 
mouth  gives  place  to  capture  of  food  by  the  hand  guided  by 
vision.  The  primates  are  microsmatic,  that  is  to  say  the 
olfactory  nerves  and  the  structures  of  the  brain  subserving  the 
sense  of  smell  are  relatively  poorly  developed,  but  the  structures 
of  the  brain  which  serve  the  function  of  vision,  hearing,  and  touch 
are  largely  developed.  It  is  not  till  we  reach  the  primates  in  the  r 
animal  series  that  the  eyes  are  set  with  their  visual  axes  parallel 
and  that  therefore  these  axes  are  capable  of  convergence ;  con- 
sequently by  accommodation  the  image  is  always  made  to  fall  on 
the  yellow  spot.  Moreover,  it  is  not  till  we  reach  the  primates 
that  a  yellow  spot  is  found  to  exist.  The  panoramic  vision  of 
the  macrosmatic  quadrupeds  is  replaced  in  the  primates  by 
binocular  stereoscopic  vision.  But  with  the  development  of 
binocular  stereoscopic  vision,  there  has  simultaneously  developed 
the  sterognostic  sense,  or  the  sense  arising  by  the  association  of 
the  experiences  of  the  visual  directive  and  tactile-motor  executive 
faculties,  by  which  the  mind  can  recall  the  visual  image  of  an 
object  handled  or  touched.  Every  object  seen  is  associated  with 
the  experiences  of  touching  and  handling  it,  and  makes  us  con- 
scious of  its  realities  of  form,  of  smoothness,  of  roughness,  of 
hardness.  A  little  reflection  will  show  how  great  a  part  this 
association  of  the  eye  and  the  hand  has  played  in  the  pro- 
gressive evolution  of  the  brain  as  an  organ  of  mind.  Now  some 
people  have  the  power  of  visualising,  that  is,  summoning  to  the 
3i 


4;2  SCIENCE   PROGRESS 

mind's  eye  images  to  a  remarkable  degree,  and  all  possess  it  to 
some  degree.  Yet  as  Galton  truly  remarks  :  "  Our  bookish  and 
wordy  education  tends  to  repress  this  valuable  gift  of  nature.  A 
faculty  that  is  of  importance  in  all  technical  and  artistic  occupa- 
tions, that  gives  accuracy  to  our  perceptions  and  justness  to  our 
generalisations,  is  starved  by  lazy  disuse,  instead  of  being 
cultivated  judiciously  in  such  a  way  as  will  on  the  whole 
produce  the  best  return.  I  believe  that  the  serious  study  of  the 
best  method  of  developing  and  utilising  the  faculty  without 
prejudice  to  the  practice  of  abstract  thought  in  symbols  is  one  of 
the  many  pressing  desiderata  in  the  yet  unformed  science  ol 
education."  This  appeal  of  Galton  emphasises  the  importance 
of  educating  the  association  of  the  eye  and  the  hand. 

The  child  has  imagination,  and  it  loves  to  picture  in  its 
mind's  eye  visions  of  the  beautiful.  What  greater  proof  can  we 
have  of  this  than  the  universal  popularity  of  Hans  Andersen's 
fairy  tales,  Alice  in  Wonderland,  and  Peter  Pan.  The  child 
is  naturally  idealistic  and  romantic,  and  its  character  can  be 
studied  best  in  its  ideals  and  play,  because  there  is  no  repression. 
Now  it  is  well  to  train  a  child  to  give  expression  to  its  ideas  and 
ideals,  not  only  by  words,  but  by  acts,  especially  by  the  hand, 
the  instrument  of  the  mind,  and  yet  the  mind's  instructor. 

In  this  country  Mr.  Cooke  has  been  a  pioneer  in  teaching 
free-hand  drawing  by  children  on  proper  lines  ;  and  those  who 
are  interested  in  this  important  branch  of  education  should  read 
New  Methods  in  Education,  by  J.  Liberty  Tadd  of  the  Adirondack 
Schools. 

The  Order  of  Development  of  the  Physiological  Functions 
of  the  Brain  in  Relation  to  Education 

It  will  be  observed  from  what  I  have  said  in  my  two  previous 
lectures — in  which  I  dealt  with  the  morphology  of  the  brain  and 
its  development — that  the  earliest  parts  of  the  cerebral  cortex  to 
exhibit  functional  capacity  are  those  areas  which  serve  as  the 
receptors  of  the  organic  and  general  body  sensibility  and  the 
special  senses.  A  very  little  time  after  birth  the  motor  area  is 
myelinated,  and  therefore  prepared  to  react  in  response  to 
sensory  stimuli,  whether  coming  from  the  body  itself  in  the 
form  of  organic  needs  or  from  without  in  response  to  stimuli 
from  the  external  world.  The  former  are  fundamental  to  the 
preservation  of  the  individual,  for  upon  the  organic  needs  are 


MENTAL   DEVELOPMENT  473 

based  the  desires  which  excite  the  brain,  through  the  senses,  to 
explore  the  external  world  in  order  to  gratify  them.     This  is 
well  exemplified  by  observing  that   an  infant  at  first  conveys 
all  objects,   that  it  sees   and   grasps,  to   its  mouth.     A  simple 
elemental  sensation  soon  after  birth  becomes   impossible  ;  for 
every  simple  sensation  tends  to  reflex  activation,  and  each  phase 
in  that  motor  reaction  which  occurs  is  immediately  followed  by 
incoming  sensory  stimuli  registering  in  the  mind  the  successive 
movements  brought  about  {vide  fig.  i).     At  the  same  time  each 
experience  perfects  the   association  of  the  sense  of  movement 
with  the  mental  image  of  the  sensation  ;  thus  the  memory  of  the 
visual  image  is  associated  with  the  memory  of  the  movements  of 
the  eyes  necessary  for  it  to  be  clearly  seen ;  likewise  the  memory 
of  the  visual  image  of  an  object  is  associated  with  the  memory 
of  the  movements  of  the  arm  and  hand  by  which  it  was  grasped. 
Thus  it  may  be  truly  said  that  the  muscular  sense  contributes 
to  every  other  sense,  and  all  the  sensory  areas  of  vision,  hearing, 
smell,  taste,  and  touch  become  linked  up  by  the  bonds  of  asso- 
ciative memory  with  the  muscular  sense.     Now  the  muscular 
sense   is  combined  with  the  active  sense  of  touch;   but  it  is 
better  to  speak  of  it  as  the  kinaesthetic  sense,  for  this  includes 
the  sensation  arising  from  the  stretching  of  tendons,  the  move- 
ments of  joints,  as  well  as  of  movements  of  the  muscles.     All 
the  sensory  receptor  spheres  of  the  brain  are  associated  with 
the  voluntary  efferent   motor   sphere  (vide   fig.  3),    and   every 
sensation   in   the    infant    tends   to    activation,    that    is    motor 
expression;    for  it    is    by    handling  and   touching  parts  of  its 
own  body  that  it  becomes   aware  of  its  own  personality,  and 
by   motor  reaction   to  sensory  stimulus   it   learns   the   reality 
of  things  in  the  world  external  to  it ;    consequently  with  the 
progressive  evolution   of   the  child's    mind  there   is  constant 
sensori-motor   association.      Not   only  is   there  association  of 
each  sensory  sphere  with  the  motor  and  kinaesthetic  spheres, 
but  there  is  also   an  association   of  all  the  sensory  spheres 
with  one  another;    so  that  a  simple    sensory  stimulus   from 
within   or  without    the    body  revives   in  the   memory  a  com- 
plexus    of   previous   sensory    experiences   which    are    termed 
"  percepts."    The  perceptive  faculty  of  associative   memory  of 
concrete  images  of  previous  experiences  with  elemental  time 
and  space  relations  and  the  acquisition  of  appropriate  motor 
reactions  under  the  influence  of  the  will,  is  also  possessed  by 


474  SCIENCE  PROGRESS 

all  the  higher  animals ;  and  while  the  infant  is  crawling  on  all 
fours  like  an  animal,  it  possesses  only  these  animal  faculties  of 
mind.  As  the  child  obtains  the  erect  posture  and  the  fore 
limbs  are  dissociated  from  progression,  it  begins  to  acquire  the 
human  faculties  of  forming  concepts  and  of  giving  expression 
to  them  by  speech,  the  primary  incitation  of  which  is  hearing; 
and  later  writing,  reading,  and  measurements  of  time  and  space, 
in  which  vision  plays  a  dominant  part,  are  acquired.  As  these 
human  faculties  are  evolved,  so  the  processes  of  abstract 
thought  and  reasoning  by  associative  memory  of  symbols — par- 
ticularly in  a  cultured  and  civilised  environment — gradually 
tend  to  replace  in  the  child  associative  memory  of  concrete 
images.  I  have  already  alluded  to  the  importance  of  freedom 
from  restraint  to  the  child's  natural  instincts  of  curiosity  and 
play,  and  Mr.  Edmond  Holmes,  in  What  Is  and  What  Might  Be ; 
A  Study  of  Education  in  General,  and  Elementary  Education  in 
Particular,  says  :  "  There  is  nothing  that  a  healthy  child  hates 
so  much  as  to  have  the  use  of  his  natural  faculties  and  the  play 
of  his  natural  energies  unduly  restricted  by  pedagogic  and 
parental  control."  We  should  indeed  recognise  that  one  of  the 
child's  greatest  assets  is  its  childishness.  It  should  be  interested 
in  its  lessons  because  it  enjoys  them,  and  not  to  win  prizes  and 
rewards,  which  in  a  number  of  instances  only  indicates  an 
ability  to  receive,  retain,  and  retail  information.  Knowledge  in 
later  life  will  be  its  own  reward,  ignorance  its  own  punishment. 

Holmes  asks  :  "  Does  elementary  education,  as  at  present 
conducted  in  this  country,  tend  to  foster  the  growth  of  the 
child's  faculties?"  According  to  Holmes  the  answer  is  an 
emphatic  No!  "  For  in  the  school,  as  I  have  sketched  it,  the 
one  aim  and  end  of  the  teacher  is  to  prevent  the  child  doing 
anything  whatever  for  himself,  and  where  independence  is 
prohibited  the  growth  of  every  faculty  must  needs  be  arrested, 
the  growth  of  every  faculty  as  of  every  limb  and  organ  being 
duly  and  suitably  exercised  by  its  owner." 

From  what  I  have  previously  said  it  will  be  observed  that 
perception  and  expression  are  interdependent,  and  an  educa- 
tional policy  or  system  which  does  not  make  self-expression,  in 
other  words  sincere  expression,  its  aim,  is  necessarily  fatal  to  the 
normal  psycho-physiological  development  of  the  mental  faculties. 

The  kindergarten  system  introduced  by  Froebel,  and  lately 
modified  and  developed  by  Dr.  Marie  Montessori,  is  based  upon 


&4 

— 

*.  * 

"Q 

$ 


A'  \ 


& 


Fig.  2. — Two  groups  of  Cells,  one  from  the  occipital  cortex  of  a  normal  dug,  the  other,  pale 
undeveloped  cells,  from  the  dug  with  the  eyes  removed  at  birth      (  After  Berger.) 


Foot  &  Toe?  Great  Toe 
Knee     ^>< — -y-Tt 
Hip. 
Shoulder 
Elbow- 
Written  Speech- 
Hand 
Index 

Thumb — 
Upper_  _ 
Face 

Lower 

Face 

Motor 

Speech 
Tongue- - 
Larynx- 


Movements  of 

Eye  (probable)  Taste    ,  -  <£>: 

and 
Smell ' 


Tactile*  Muscular  sensation 


Visual  word, 
, Memory 


Hearing, 
Auditory  word 
Memory 


Half  Vision  centre 


Fig.  3- — A  lateral  view  of  the  left  hemisphere,  showing  the  localisation  of  the  various 
motor  and  sensory  spheres  and  speech  centres. 

The  greater  part  of  the  visual  centre  is  on  the  mesial  surface  of  the  hemisphere  and  is  not  shown  ;  likewise 
the  greater  part  of  the  auditory  centre  lies  in  the  floor  of  the  S\  Ivian  fissure,  and  is  covered  up  and 
concealed. 


474 


MENTAL  DEVELOPMENT  475 

sound  psycho-physiological  principles,  such  as  I  have  outlined 
in  the  development  of  the  structure  and  function  of  the  brain. 
The  Board  of  Education  in  England,  recognising  the  importance 
of  this  work,  issued,  in  October  191 2,  a  special  report  on  the 
subject  by  Mr.  Holmes ;  it  is  probable  that  the  study  by  Mr. 
Holmes  of  this  system,  the  fundamental  object  of  which  is 
self-education  by  the  pupils  themselves,  a  system  in  which 
there  is  neither  reward  nor  punishment  of  the  ordinary  kind, 
and  in  which  there  are  no  time  tables,  no  set  lessons,  and  no 
classes,  led  Mr.  Holmes  to  write  the  book  above  mentioned — 
What  Is  and  What  Might  Be. 

The  first  stage  in  the  Montessori  system,  as  would  be  expected 
from  what  I  have  just  said,  is  the  development  of  the  senses, 
mainly  touch,  then  sight  and  hearing ;  this  is  accomplished  by 
various  sorts  of  games  and  by  drawing  the  attention  of  the  child  to 
the  association  of  things,  names,  and  ideas.  Such  operations  are 
preliminary  to  writing  and  reading,  but  naturally  lead  up  to  both. 

As  Mr.  Holmes  says,  the  first  impulse  of  the  ordinary  teacher 
is  to  tell  a  child  how  to  do  a  thing  which  it  has  never  attempted 
before ;  the  second  is  to  rush  to  the  child's  aid,  who  having  been 
allowed  to  try  his  hand  at  something  new,  is  confronted  by  a 
difficulty  and  is  in  doubt  as  to  his  next  step  ;  the  third  is  to 
correct  his  mistakes  for  him,  instead  of  leaving  him  to  correct 
them  himself.  Dr.  Montessori  in  Mr.  Holmes's  words  has 
"  rediscovered  "  Froebel's  master  principle  of  "auto-education"; 
the  teacher  is  the  director  of  the  spontaneous  work  of  the  child, 
"  she  is  a  passive  force,  a  silent  presence."  Dr.  Montessori 
employs  an  extensive  variety  of  apparatus  suitable  for  educational 
games  by  which  the  children  are  interested  and  stimulated  to 
acquire  knowledge,  and  her  educational  system  is  an  original 
and  practical  expression  of  sound  psychological  principles  ;  these 
principles  are  based  upon  the  anatomical  and  physiological  order 
of  development  of  structure  and  of  function  of  the  organ  of  mind. 

Little  has  previously  been  said  in  respect  to  the  sense  ot 
smell  and  taste,  but  the  cultivation  of  these  senses  is  of  more  use 
than  many  people  imagine  ;  for  they  are  a  daily  source  of  keen 
gratification  ;  they  frequently  serve  to  revive  pleasant  associa- 
tions and  they  are  the  best  natural  protector  against  unsound 
food,  unwholesome  drink,  and  vitiated  air.  It  is  a  remarkable 
fact  that  most  mineral  and  vegetable  substances  that  are  poison- 
ous are  acrid,  unpleasant,  pungent,  or  bitter,  and  readily  excite 


476  SCIENCE   PROGRESS 

nausea,  disgust,  and  rejection  from  the  mouth  when  tasted,  like- 
wise all  foul  and  many  poisonous  odours  excite  nausea,  disgust, 
and  aversion  ;  whereas  pleasant  tasting  and  smelling  substances 
found  in  nature  are  usually  wholesome  and  nutritious. 

Pain  and  Pleasure  in  Relation  to  Mental  Development 

The  associative  memory  of  painful  and  pleasurable  feelings 
plays  an  important  part  in  mental  development.  The  sense  of 
well-being  and  pleasurable  feeling  is  a  vague  state  of  conscious- 
ness clothed  and  enriched  by  perceptual  and  intellectual  associ- 
ated memories  which  we  desire  to  experience  again,  and  they  form 
an  accompaniment  of  the  healthy  activity  of  the  functions  of  body 
and  mind  when  not  exceeding  the  ordinary  normal  powers  of 
reparation  that  the  organism  possesses.  The  preservation  of 
the  individual  and  the  species  depends  not  only  upon  the  gratifi- 
cation of  the  desires,  but  also  upon  the  protection  of  the  body 
from  physical  and  chemical  injury  by  pain  ;  moreover,  the  senses 
of  smell  and  taste  are  sentinels  to  the  alimentary  and  respiratory 
systems,  protecting  them  from  injury,  by  exciting  nausea  and 
disgust  or  reflex  acts  such  as  coughing,  sneezing,  and  vomiting. 
These  are  states  of  consciousness  which  there  is  no  desire  to 
experience  again,  and  when  associated  with  perceptual  and 
intellectual  memories  their  causes  can  be  avoided. 

There  is  evidence  to  show  that  if  pain  is  felt  in  the  optic 
thalamus  the  perceptual  concomitants  with  which  it  is  asso- 
ciated are  registered  in  the  cortex  cerebri ;  for  the  optic 
thalamus  is  connected  with  every  part  of  the  cerebral  cortex, 
the  seat  of  associative  memory  and  recollection.  The  cortex 
is  not  the  perceiver  of  pain  but  the  perceiver  of  the  causes 
which  produced  it  and  by  which  it  may  be  avoided.  The  cortex 
can  be  cut  and  stimulated  without  producing  pain ;  not  so  the 
optic  thalamus.  If  by  associative  memory  of  the  conditions  and 
instrument  which  cause  pain,  revival  of  pain  occurred,  what 
would  our  state  of  mind  be  normally  ?  Pain  is  the  great  pro- 
tector of  the  body  from  injury.  One  of  the  trite  sayings  of 
Oliver  Wendell  Holmes  was  "That  clergymen  and  persons 
without  wisdom  consider  pain  a  mystery  ;  it  is  a  revelation ! " 
We  can  understand  therefore  the  great  biological  significance  of 
pain  in  evolution.  Richet  indeed  is  right  in  asserting  that 
instead  of  considering  pain  as  an  evil  we  ought  to  consider  it 
fundamental  to  human  progress,  for  as  instinct  is  blind,  intelli- 


MENTAL  DEVELOPMENT  477 

gence  is  necessary  to  avoid  pain  which  by  associative  memory  it 
foresees  and  prevents  in  innumerable  ways,  whether  arising 
from  direct  bodily  injury  or  a  craving  due  to  the  non-gratification 
of  the  organic  needs  of  the  body,  e.g.  hunger,  thirst,  the  desire 
for  fresh  air,  for  sleep,  for  exercise,  for  recuperation  and  repose 
after  muscular  or  mental  fatigue  and  for  the  satisfaction  of  the 
sexual  appetite.  It  is  not  too  much  to  say  that  the  affective 
life  or  subjective  feeling  of  the  child  as  well  as  of  the  adult 
depends  largely  upon  the  organic  sensibility  (caenaesthesia),  the 
source  and  foundation  of  all  stable  perceptual  associations  and 
of  the  vast  majority  of  habitual  actions.  It  is  necessary  to 
remark  that  the  subjective  attitude  of  the  individual  determines 
the  severity  of  pain  felt,  as  much  as  the  intensity  of  the  stimulus. 
We  know  how  an  irritable  state  of  the  nervous  system  enhances 
pain,  whether  it  be  due  to  inflammatory  conditions  of  the  peri- 
pheral nervous  structures,  of  the  chains  of  neurones  forming  the 
transmitter  to  the  seat  of  consciousness,  or  of  the  central  receptor 
which  in  certain  abnormal  mental  states  {e.g.  neurasthenia  and 
hysteria)  may  evince  hyperesthesia  or  anaesthesia. 

The  Control  of  the  Emotions  and  Inculcation  of 

Good  Habits 

In  the  formation  of  character  no  problem  in  education  is 
more  important  than  the  acquirement  of  self-esteem,  self- 
reliance,  and  self-control ;  but  this  education  of  self,  to  be 
effective  in  the  struggle  for  existence  in  our  social  organism, 
must  be  tempered  by  sympathy  and  unselfishness  to  others 
for  the  essence  of  social  evolution  and  progress  is  altruistic 
egoism.  It  is  never  too  early  to  begin  to  inculcate  in  a  child 
the  habit  of  self-control ;  thus  it  should  be  taught  to  acquire 
the  habit  of  control  of  the  primitive  emotions  of  anger,  of  fear, 
and  of  disgust  in  infancy,  and  to  limit  or  repress  their  motor 
reactions ;  but  their  repression  or  suppression  should  in  great 
measure  be  determined  by  the  nature  and  intensity  of  the 
cause  of  the  emotional  disturbance.  Crying  and  screaming  of 
an  infant  is  a  protective  appeal  to  the  mother  for  relief  of  pain 
or  the  satisfaction  of  a  natural  desire  or  organic  need,  but 
this  natural  expression  of  a  physiological  necessity  may  become 
the  expression  of  a  bad  temper;  thus  a  child,  who  learns  that 
it  can  get  its  own  way  in  obtaining  something  it  desires  against 
its  parents'  wishes,  very  soon  contracts  the  bad  habit  of  falling 


478  SCIENCE   PROGRESS 

into  a  passion  whenever  it  is  thwarted.  The  indulgent  mother 
to  stop  the  fits  of  crying,  screaming,  and  outbursts  of  angry 
temper  too  often  yields  to  the  child's  will,  and  gradually  but 
surely  a  weakening  in  the  development  of  self-control  occurs, 
which  has  a  profound  influence  upon  the  development  of 
character;  especially  is  this  the  case  in  a  child  with  an  inborn 
unstable  temperament.  The  influence  of  education  on  self- 
control  is  well  illustrated  in  the  lines  of  Childe  Harold  where 
Byron  doubtless  refers  to  his  own  bringing  up  : 

I  have  thought 
Too  long  and  darkly  till  my  brain  became, 
In  its  own  eddy  boiling,  and  o'er- wrought, 
A  whirling  gulf  of  fantasy  and  flame. 
And  thus  untaught  in  youth  to  tame, 
My  springs  of  life  were  poisoned. 

The  emotion  of  fear  is  protective ;  the  instinctive  reaction 
is  either  flight  or  concealment ;  naturally  therefore  darkness  is 
associated  with  this  emotion,  and  it  is  not  surprising  that 
children  and  savages  should  have  an  inborn  tendency  to  fear 
the  dark.  Seeing  that  there  is  this  natural  tendency  of  children 
to  fear  darkness,  some  discretion  is  required  in  overcoming  the 
dread  of  a  naturally  timid  child  to  sleep  inthe  dark,  and  harm 
may  be  done  by  too  rigidly  applying  the  principle  of  forcing 
it  to  go  to  sleep  without  a  light,  especially  if  it  has  become 
accustomed  to  one  in  its  infancy.  The  habit  should  be  gradually 
broken,  if  it  has  been  contracted.  Much  injury  is  done  to 
young  children  by  ignorant  nurses  and  servants  by  frightening 
them  with  stories  of  ghosts  and  bogeys.  Indeed,  the  tempers 
and  morals  of  many  children  have  been  ruined  by  mothers  leav- 
ing the  care  of  their  children  to  ignorant  and  vicious  nursemaids. 

Another  bad  habit  which  may  be  contracted  by  the  child 
in  early  life  is  an  unnatural  desire  for  sympathy ;  too  often  an 
only  child  of  indulgent  parents,  sometimes  under  the  cloak  of 
the  possession  of  a  fondly  supposed  aesthetic  or  artistic  tempera- 
ment is  allowed  to  contract  the  habit  of  unreasonably  soliciting 
sympathy  whenever  opportunity  offers ;  and  the  penalty  in 
later  life  is  paid  by  the  unnatural  development  of  the  self- 
regarding  sentiment,  a  precursor  so  frequently  of  functional, 
nervous,  and  mental  disorders. 

While  it  is  highly  desirable  to  train  children  to  exercise 
control  over  the  primitive  emotions,   it   is  essential  that   they 


MENTAL   DEVELOPMENT  479 

should  not  be  so  suppressed  as  to  injure  the  natural  spontaneous- 
ness  of  the  child.  The  natural  expression  of  the  emotions  is 
motor  reaction,  and  when  emotions  or  passions  are  pent  up  by 
voluntary  restraint  they  are  apt  to  lead  to  exhaustion  of  mind 
and  body. 

The  suppression  of  the  manifestation  of  tears  and  anger 
from  fear  of  punishment,  especially  if  the  punishment  does  not 
fit  the  crime,  may  produce  a  sulky  habit  in  the  child  ;  and  this 
pent-up  anger  and  fear  may  in  later  life  tend  to  the  formation 
of  a  character  in  which  hatred  and  revenge  find  a  suitable  soil 
for  development.  By  suppressing  the  manifestation  of  an 
emotion  or  passion  it  becomes  continuous  and  contemplative. 
For  as  Shakespeare  says  : 

Give  sorrow  words  :  the  grief  that  does  not  speak 
Whispers  the  o'er-fraught  heart  and  bids  it  break. 

A  child  in  earliest  infancy  manifests  by  characteristic  ex- 
pression the  emotion  of  disgust ;  this  emotion  and  its  instinctive 
rejection  of  bitter,  acrid,  and  nauseous  substances  by  spitting 
out  and  vomiting  is  protective  in  the  highest  degree ;  thus  it  is 
natural  for  a  child  to  show  signs  of  disgust  and  anger  when 
nasty  medicines  or  unpalatable  food  are  given  to  it.  But 
a  child  may  acquire  a  habit  of  screaming  and  rejecting  with 
tears  and  signs  of  anger  wholesome  food  when  it  sees  other  food 
intended  for  adults.  Here  the  child  owing  to  the  initiation  of 
a  bad  habit  is  behaving  contrary  to  the  instinct  of  preservation, 
and  the  only  course  to  adopt  is  to  give  it  no  food  until  its 
natural  food  is  accepted.  Too  often,  however,  an  indulgent  or 
ignorant  parent  yields  to  the  child,  and  very  soon  a  bad  habit  is 
firmly  installed,  which  may  later  be  a  determining  cause  of 
bodily  ailments  and  weakened  self-control. 

Children  are,  like  many  animals,  naturally  curious,  and  this 
instinct  of  curiosity  is  closely  associated  with  the  emotions  of 
surprise  and  wonder.  Curiosity  in  children  manifests  itself  by 
inquisitiveness  regarding  the  natural  phenomena  they  observe 
and  their  causation ;  too  often  this  instinct  in  which  science  has 
its  roots  is  repressed  by  "  don't  ask  questions,"  or  some  foolish 
commonplace  answer  is  given  to  their  inquiry,  which  upon 
reflection  the  child  knows  to  be  untrue.  Every  child  is  a 
natural  philosopher,  and  all  natural  phenomena,  the  result  of 
perception,  that  the  child  is  fit  and  capable  of  understanding, 


48o  SCIENCE   PROGRESS 

should  be  explained,  or  the  child  should  be  told  truthfully,  "  I 
can't  explain  the  fact."  It  is,  however,  in  my  opinion  a  mistake 
to  lead  the  young  child  too  far  into  experiences  which  an  adult 
alone  can  understand  and  appreciate  in  their  full  biological 
significance. 

Sex  and  Education 

With  the  dawn  of  the  sexual  passion  at  puberty,  a  new  and 
intense  emotional  phase  of  existence  occurs,  which  even  when  it 
is  mature  and  developed,  may  not  be  shown  in  daily  conversa- 
tion, yet  as  a  deep  and  silent  undercurrent  of  consciousness  and 
silent  thought  is  continually  influencing  character  and  be- 
haviour. Now  and  again,  it  reveals  itself  by  springing  to  the 
surface  and  bursting  its  bonds  in  a  flood  of  passion  ;  still  there 
are  many  people  who  can  and  do  go  through  life  without  mani- 
festing to  the  external  world  the  profound  influence  which  the 
sexual  passion  has  on  their  behaviour. 

But  "  still  waters  run  deep,"  and  in  the  majority  of  people  this 
silent  undercurrent  of  emotion,  although  not  manifested  to  the 
external  world,  nevertheless  occupies  a  large  place  in  the  con- 
scious and  subconscious  self;  it  suffuses  silent  thought  and 
consciousness  with  an  emotional  tone,  which  may  find  outward 
expression  in  aesthetic  and  religious  forms  and  observances.  It 
is  a  more  important  factor  than  any  other  in  the  formation  of 
character,  for  it  must  be  conceded  that  human  motives  and  con- 
duct originate  in  great  measure  from  the  depths  of  the  passion 
engendered  by  the  natural  attraction  of  the  sexes  ;  but  inasmuch 
as  the  bodily  characters  that  distinguish  the  sexes  are  different, 
so  are  the  mental  characters.  Although  each  sex  is  represented 
in  all  the  cells  of  the  body,  the  sexual  organs  peculiar  to  each 
sex  make  dominant  by  their  internal  secretion  the  male  or  female 
secondary  sexual  bodily  and  mental  characters.  Observation 
and  experiment  show  that  the  opposite  sexual  character  is 
present  in  the  somatic  cells,  but  it  is  latent  or  recessive. 

It  is  an  important  fact  to  bear  in  mind  in  the  education  of  the 
two  sexes,  that  there  is  as  radical  a  biological  difference  in  the 
mind  of  the  woman  to  that  of  the  man  as  there  is  bodily  differ- 
ence, and  this  different  mental  attitude  peculiar  to  sex  shows 
itself  especially  in  the  contrast  of  emotional  feelings  and  their 
manifestations  ;  moreover  a  woman  is  different  intellectually ; 
she  has  quicker  perception  and  association  of  ideas,  she  deliber- 


MENTAL  DEVELOPMENT  481 

ates  less  and  arrives  intuitively  at  a  judgment  quicker  than  a 
man.  She  has,  however,  less  mental  energy  and  power  of  will 
than  a  man.  Being  constitutionally  different  from  a  man,  a 
woman's  physical  and  mental  education,  in  order  to  bring  out 
her  noblest  and  best  qualities,  should  not  be  identical  with  that 
of  a  man.  I  may  here  remark  that  co-education  of  the  two  sexes 
in  adult  life  has  not  proved  a  great  success.  Just  as  a  woman 
prefers  a  manly  man  and  despises  an  effeminate  man,  so  a  man 
is  attracted  to  a  womanly  woman  and  is  repelled  by  a  mannish 
woman;  this  is  the  natural  consequence  of  sexual  attraction  and 
should  be  duly  borne  in  mind  in  the  education  of  girls;  the 
feminine  charms  and  graces  should  not  be  sacrificed  lightly  by 
copying  slavishly  man's  physical  and  mental  development. 
Still  it  is  an  acknowledged  fact  that  social  conditions  prevent  a 
very  large  proportion  of  marriageable  women  from  fulfilling  the 
natural  functions  of  motherhood,  and  they  have  therefore  only 
to  consider  their  own  individual  life  and  its  preservation.  Educa- 
tion and  intellectual  development  of  women  to  enable  them  to 
earn  their  own  living  and  thus  become  efficient  social  units,  will 
not  make  them  any  less  capable  of  becoming  good  mothers,  pro- 
vided there  is  in  their  training  ample  scope  for  natural  physio- 
logical development,  and  the  normality  of  the  reproductive 
organs  is  not  interfered  with  by  too  strenuous  mental  or 
physical  exercise.  It  is  necessary  to  give  a  word  of  warning 
against  girls  being  pressed  at  schools  by  night  work  and  com- 
petitive examinations,  just  at  the  time  when  the  reproductive 
organs  are  commencing  to  function  and  exercise  a  profound 
influence  on  the  mind.  Nor  do  I  regard  it  as  wise  to  overdo 
sports  and  games  at  a  period  of  life  when  important  physio- 
logical processes  connected  with  the  storage  of  energy  and 
nutrition  are  called  for  by  Nature  in  the  preparation  of  its 
supreme  effort  of  reproduction.  Over-pressure  at  schools  and 
competitive  examinations  at  puberty  and  early  adolescence  is 
often  due  to  the  ambition  of  parents,  but  it  not  infrequently 
leads  to  a  nervous  or  mental  breakdown,  especially  if  the  child 
has  an  inborn  neuropathic  tendency. 

We  have  now  seen  that  a  healthy  mind  can  only  exist  in  a 
healthy  body ;  and  it  is  becoming  widely  recognised  that  the 
essential  feature  of  education  should  be  to  develop  the  inborn 
physical  and  mental  qualities  that  make  for  efficiency  and  thus  to 
prolong  the  period  of  individual  productiveness  and  civic  worth. 


ENZYMES  AS    SYNTHETIC   AGENTS 
II.    IN    PROTEIN   METABOLISM1 

By  J.   H.    PRIESTLEY,   B.Sc,   F.L.S. 

Professor  of  Botany,   University  of  Leeds 

Much  of  the  work  upon  the  synthesis  of  carbohydrates  has  been 
done  with  a  view  to  solving  the  questions  of  constructive  meta- 
bolism in  the  plant,  but  in  the  study  of  protein  metabolism 
attention  has  been  chiefly  directed  to  the  problems  presented  in 
the  animal  organism. 

In  the  present  paper,  which  is  a  survey  of  recent  work, 
the  point  of  view  taken  will  be  the  bearing  that  some  of  this 
work  upon  proteins  may  possibly  have  upon  constructive 
metabolism  in  the  plant.  Considered  from  this  standpoint,  the 
facts,  so  far  as  they  are  known  to  the  present  writer,  may  per- 
haps be  summarised  without  presenting  too  familiar  an  aspect. 

The  problem  of  presentation  is  simplified  in  some  respects 
by  the  fact  that,  at  the  present  time,  questions  of  molecular 
symmetry  need  scarcely  be  considered.  They  will  emerge  when 
our  knowledge  of  the  various  phases  leading  to  the  natural 
proteins  becomes  much  more  detailed. 

In  considering  the  possible  significance  of  enzymes  in  the 
construction  of  these  complex  bodies,  it  will  be  possible  to  draw 
attention  to  only  a  few  groups  of  problems  out  of  a  very  wide 
range.  In  plant  physiology  at  the  present  time,  the  following- 
questions  seem  to  the  writer  worthy  of  attention  in  that  they 
may  suggest  opportunities  for  experimental  attack  through  a 
study  of  enzyme  activity. 

i.  The  manner  in  which  nitrogen  is  first  included  in  the 
simpler  substances  from  which  the  protein  is  subsequently 
formed. 

2.  The  possible  relation  of  carbohydrate  metabolism  to  the 
synthesis  of  proteins. 

3.  The  role  played  by  enzymes  in  the  hydrolysis  of  storage 
forms  of  proteins. 

4.  The  significance  of  recent  attempts  to  produce  a  re- 
versible reaction  in  definite  cases  of  the  hydrolysis  of  proteins 
by  enzymes. 

1  For  Part  I.  see  Science  Progress,  July  191 3. 

482 


ENZYMES  AS  SYNTHETIC  AGENTS  483 

For  the  sake  of  clearness  these  four  questions  will  be  con- 
sidered separately,  though  obviously  they  are  all  sub-divisions 
of  the  one  general  problem  of  constructive  nitrogen  metabolism 
in  the  organism. 

1.  The  First  Inclusion  of  Nitrogen 

There  is  now  a  very  general  consensus  of  opinion  that  the 
nitrogen  absorbed  by  a  green  plant  through  its  roots  may  have 
been  presented  to  it  in  various  forms,  the  most  suitable  being 
nitrates,  though  ammonium  compounds  may  readily  be  utilised.1 

The  greater  value  of  nitrates  to  the  plant  may  be  due  to  the 
fact  that  in  the  reduction  of  these  compounds  energy  may  be 
liberated  that  can  be  utilised  in  synthetic  processes.  Thus  the 
agricultural  chemist  is  familiar  with  the  fact  that  the  employ- 
ment of  nitrate  as  a  manure  is  followed  by  accelerated  vegetative 
growth ;  and  there  is  considerable  evidence  that  energy  supplied 
in  the  form  of  nitrate  may  be  in  part  utilised  in  the  series  of 
katabolic  changes  connected  with  respiration  and  growth. 

The  nitrate  supplied  to  the  plant  has  to  be  reduced,  as  in 
the  protein  molecule  it  occurs  in  association  with  hydrogen. 
The  distribution  of  nitrates  within  the  plant  indicates  that  this 
reduction  usually  occurs  in  the  tissues  of  the  leaf,  as  it  is  here 
that  the  nitrates  are  found  to  disappear.  If  then  enzymes  are 
employed  in  this  reduction,  they  should  be  present  in  the  leaf. 
Enzymes  with  this  power  of  reducing  nitrate  have  been  obtained 
from  plant  tissues  by  some  investigators,  but  they  do  not 
represent  the  only  possible  agency  for  the  reduction  of  nitrates. 

Bach  has  suggested  that  formaldehyde,  so  often  reported  as 
present  in  leaves,  might  reduce  the  nitrate  to  hydroxylamine, 
this  subsequently  giving  rise  to  formaldoxime  and  ultimately  to 
formamide : 

H  H 

I  I 

CHO  +  NH..OH  ^C:N.OH+H20 


and 


H 

H 

I  H 

C:  N.  OH  -»    I 

I  CO.NH, 
H 

Formaldoxime.  Formamide. 


1  Hutchinson  and  Miller,  "The  Assimilation  of  Nitrogen  by  Higher  Plants," 
Journal  of  Agricultural  Science >  vol.  iv.  p.  282,  191 2. 


434  SCIENCE  PROGRESS 

Recently  Baudisch l  has  shown  that  daylight  alone  may 
reduce  nitrates  in  solution  to  nitrites,  and  that  both  nitrates 
and  nitrites  are  readily  reduced  by  aldehydes  in  presence  of  light 
with  the  ultimate  production  of  ammonia  and  amino-compounds. 

In  view  of  these  possibilities,  the  aid  of  reducing  enzymes  or 
reductases  may  not  be  necessary;  on  the  other  hand  their  pres- 
ence may  enable  protein  synthesis  to  continue  in  the  dark.  In  any 
case,  the  evidence  is  increasing  that  enzymes  of  specific  or  general 
reducing  activity  are  present  in  both  plant  and  animal  tissues.2 

There  are  indications  that  reductases  would  be  more  fre- 
quently met  with  in  plant  extracts  if  it  were  not  for  the  presence, 
in  the  same  juice,  of  oxidising  enzymes  or  oxidases.  These  two 
types  of  enzymes  may  exist  side  by  side  in  the  same  cell,  and 
both  exert  their  full  activity  without  interference,  because  their 
respective  spheres  of  action  may  be  limited  by  living  semi- 
permeable membranes.  In  crushing  the  tissues  to  extract  the 
enzymes,  these  controlling  membranes  are  destroyed,  the  two 
enzymes  come  in  contact,  and  the  reductase  may  be  destroyed  or 
its  activity  neutralised. 

The  immediate  result  of  the  reduction  of  a  nitrate  in  the 
living  cell  must  be  the  production  of  the  very  poisonous  nitrite. 
This  body  must  be  again  transformed  immediately  or  the  death  of 
the  cell  will  follow.  It  may  therefore  be  very  difficult  to  detect 
the  transitory  appearance  within  the  organism  of  the  nitrite,  and 
thus  establish  the  existence  of  a  reducing  action.  On  the  other 
hand,  as  we  have  seen,  in  experimenting  "  in  vitro,"  there  is  the 
difficulty  of  extracting  the  reductase  in  an  active  condition. 

Irving  and  Hankinson  obtained  evidence  of  the  presence  of  a 
nitrate-reducing  enzyme  in  the  plant  by  placing  chloroformed 
leaf  tissue  in  a  solution  of  asparagin  and  potassium  nitrate. 

The  sap  of  the  plant  was  acid,  and  in  an  acid  medium,  if 
nitrites  are  formed  in  the  presence  of  asparagin,  gaseous  nitrogen 
must  be  liberated.    Thus — 

2HNO, +  CH.NH2-  COOH        CH.OH-COOH 

I  ->    I  +  2N2  +  2H20 

CH2  -  CONH2  CH2  -  COOH 

(Asparagin.)  (Malic  acid.) 

1  Baudisch,  Ber.deut.  Chem.  Ges.  44,  p.  1009,  191 1. 

3  On  animal  reductases,  see  D.  F.  Harris  and  H.  J.  M.  Creighton,  Proc. 
Roy.  Soc.  85  B.  p.  486,  and  Bioch.  Journ.  vi.  p.  429.  On  plant  reductases,  see 
Kastle  and  Elvove,  Amer.  Chem.  Journ.  31,  p.  606,  1904,  and  Irving  and 
Hankinson,  Bioch.  Journ,,  vol.  vii.  p.  87. 


ENZYMES  AS  SYNTHETIC  AGENTS  485 

Considerable  quantities  of  nitrogen  were  given  off  by  these 
chloroformed  plants  in  the  presence  of  asparagin,  and  there 
seems  little  doubt  that  this  was  evolved  as  the  result  of  reduction 
of  nitrate  by  the  reductase  present  in  the  tissue. 

There  is  no  reason  at  present  to  anticipate  that  enzymes  play 
a  part  in  the  stages  that  follow  upon  the  formation  of  nitrites 
until  at  length  the  "amino"  linkage,  NH2,  is  reached.  The 
intervening  compounds  are  likely  to  be  so  highly  reactive  that 
the  successive  changes  are  probably  instantaneous  and  there 
seems  no  necessity  to  assume  the  intervention  of  a  catalyst. 

The  suggestions  of  Bach  and  Baudisch  previously  mentioned 
raise  the  question  whether  the  synthesis  of  proteins  can  be 
considered  independently  of  carbohydrate  metabolism.  Alde- 
hydes play  a  part  in  the  suggested  reactions,  and  it  is  during 
photosynthesis  that  such  bodies  are  likely  to  be  formed  in  the 
plant.  Moreover,  recent  work  in  another  direction  has  drawn 
attention  to  the  possibility  of  the  intervention  of  enzymes  in  the 
passage  from  the  carbohydrate  to  the  amino-acid.  This  work 
will  be  considered  in  the  succeeding  section. 

2.  Relation  of  Carbohydrate  Metabolism  to  Protein 

Synthesis 

In  the  preceding  section  reference  was  made  to  a  possible 
inter-relation  between  the  metabolism  of  carbohydrates  and 
protein  synthesis. 

The  result  of  the  brilliant  synthesis  of  proteins  from  amino- 
acids  carried  out  in  the  chemical  laboratory  by  Emil  Fischer  and 
others  l  has  been  to  focus  attention  upon  the  amino-acids  as  the 
primary  bodies  from  which  must  start  the  synthesis  of  proteins 
within  the  organism.  In  the  plant  these  amino-acids  have  to  be 
constructed. 

We  have  seen  that  the  nitrogen,  however  supplied,  is 
probably  brought  gradually  to  the  NH2  grouping,  but  we  have 
still  to  ascertain  whence  the  organic  acid  or  aldehyde  is 
obtained,  with  which  this  NH2  grouping  may  be  linked.  In  this 
connection  the  recent  work  of  Dakin  and  Dudley  upon  the 
activities  of  an  enzyme  they  have  termed  glyoxalase,  may  have 
great  significance  for  students  of  plant  metabolism. 

1  See  R.  H.  Plimmer,  "Chemical  Constitution  of  the  Proteins,"  I.  and  II. 
Biochem.  Monographs,  pub.  Longmans,  Green  &  Co.,  for  a  valuable  summary  of 
recent  work. 


486  SCIENCE  PROGRESS 

Dakin  and  Dudley  1  have  obtained  this  enzyme  from  various 
animal  tissues,  such  as  the  muscle  and  liver  of  exsanguinated 
dogs  or  rabbits.  It  possesses  the  power  of  accelerating  very 
markedly,  even  under  "in  vitro"  conditions,  the  reversible 
reactions  by  which  methyl  and  phenyl  glyoxal  are  converted 
into  lactic  and  mandelic  acid  respectively. 

CH,  -  CO  -  CHO  +  H.,0       "7*     CH3.CHOH  -  COOH 

Methyl  glyoxal.  Lactic  acid. 

C6H5  -  CO  -  CHO  +  H,0     "*     C6HS  -  CHOH  -  COOH 

Phenyl  glyoxal.  Mandelic  acid. 

The  enzyme  is  readily  obtained  in  aqueous  extract,  and  the 
extract  loses  its  activity  on  being  heated  to  6o°  C.  Dakin  and 
Dudley  failed  to  precipitate  and  separate  the  enzyme  by  the 
addition  of  alcohol,  but  they  succeeded  in  obtaining  an  active 
preparation  by  precipitating  it  with  solid  ammonium  sulphate 
and  then  dialysing  the  suspension  in  water. 

The  wide  distribution  of  this  enzyme  may  be  of  considerable 
significance  in  reference  to  the  inter-relation  of  carbohydrate  and 
protein  metabolism. 

Methyl  glyoxal  or  a  closely  allied  substance  is  obtained  from 
the  action  of  sodium  phosphate  on  glucose.  It  is  therefore 
possible  to  obtain  from  glucose  both  organic  acids  and  alde- 
hydes, and  these  are  bodies  from  which  amino-acids  may  readily 
be  derived.  Thus  it  may  be  anticipated  that  within  the  living 
cell  alanine  may  be  derived  from  methyl  glyoxal,  in  much  the 
same  manner  in  which  glycine  has  been  obtained  from  glyoxal. 
The  relation  of  glucose  to  amino-acids  and  to  organic  acids 
might  then  be  expressed  in  the  following  manner  : 2 

Glucose. 

CsH,j,06 
4     t 

Lactic  acid.  Methyl  glyoxal.  Alanine. 

CHs.CH.OH.COOH  *~  CH3.  CO  .  CHO   ~*  CH3 .  CH  .  NH, .  COOH 

The  distribution  of  this  enzyme  is  clearly  of  importance  to 
the  animal  physiologist  and  may  account  for  the  production  of 
glucose  in  the  glycosuric  organism,  but  its  distribution  in  the 
plant  must  be  known  before  its  significance  in  plant  metabolism 

1  Dakin  and  Dudley,  Joum.  Biological  Chem.  xiv.  p.  155,  and  xiv.  p.  423. 
3  Ibid.  xv.  p.  127,  191 3.     Alanine  has  not  yet  been  synthesised  directly  from 
methyl  glyoxal. 


ENZYMES  AS  SYNTHETIC  AGENTS  487 

can  be  estimated.  Dakin  and  Dudley  have  found  glyoxalase  in 
yeast,  an  organism  which  is  capable  of  solving  its  synthetic 
problems  upon  a  diet  containing  glucose  and  ammonium  com- 
pounds as  the  sources  of  its  carbon  and  nitrogen  respectively. 
If  subsequent  work  should  show  the  enzyme  to  be  widely 
distributed  in  the  plant  kingdom,  it  will  have  to  be  seriously 
considered  as  a  possible  aid  in  the  production  of  amino-acids, 
and  as  one  link  in  the  chain  relating  carbohydrate  metabolism 
to  protein  synthesis. 

3.  The  Hydrolysis  of  Protein  Reserves 

Logically  the  next  step  would  seem  to  be  to  consider  the 
part  played  by  enzymes  in  the  subsequent  construction  of  pro- 
teins from  the  primary  amino-acids.  Unfortunately  this  field  is 
almost  untouched,  and  it  is  impossible  to  attack  it  directly.  In 
this  section  the  present  position  of  our  knowledge  of  the  hydro- 
lysis of  the  storage  proteins  of  the  plant  will  be  first  discussed. 
This  will  be'followed  in  the  subsequent  section  by  a  considera- 
tion of  the  attempts  that  have  been  made  to  produce  reversible 
catalysis  in  the  hydrolyses  of  proteins  by  altering  concentration 
conditions. 

At  the  present  time,  when  the  decomposition  products  of  the 
hydrolysis  of  proteins  are  still  incompletely  known,  and  when 
the  series  of  hydrolytic  changes  accompanying  that  hydrolysis 
cannot  be  pictured,  it  is  natural  that  there  should  be  con- 
siderable confusion  in  the  definition  of  the  proteinases,  the 
enzymes  or  groups  of  enzymes  which  are  responsible  for  the 
hydrolysis. 

In  the  animal  kingdom  the  simplest  classification  is  based 
upon  the  distribution  of  the  enzymes  within  the  body,  and  by 
this  means  it  is  possible  to  distinguish  three  groups  of  pro- 
teinases, viz.  the  peptase  (pepsin)  of  the  gastric  secretion,  the 
tryptase  (trypsin)  of  the  pancreas,  and  the  ereptase  (erepsin)  of 
the  intestinal  mucus.1 

In  addition  to  this  difference  in  origin,  the  peptases  are 
usually  credited  with  an  activity,  restricted  to  slightly  acid 
solutions,  which  does  not  produce  complete  hydrolysis  of  the 
protein  digested,  the  products  formed  being  albumose  and 
peptones. 

1  For  a  general  account,  see  Euler,  General  Chemistry  of  Enzymes^  translated 
by  Pope,  pp.  33  et  seq, 

32 


488  SCIENCE  PROGRESS 

Tryptase  on  the  other  hand  is  regarded  as  being  capable 
both  of  acting  in  neutral,  slightly  acid,  or  alkaline  solutions,  and 
of  carrying  the  digestive  hydrolysis  as  far  as  the  production  of 
polypeptides  and  amino-acids.  Recent  work  suggests  that  this 
difference  in  the  extent  to  which  hydrolysis  is  carried  is  not 
really  significant,  but  that,  if  sufficient  time  be  allowed,  amino- 
acids  will  be  found  among  the  products  of  peptic  digestion.1 

Ereptase  activates  hydrolysis  from  the  point  at  which  peptase 
is  usually  regarded  as  ceasing  to  act.  Acting  upon  albumoses 
and  peptones,  it  converts  them,  apparently  completely,  into 
polypeptides  and  amino-acids. 

In  plants  these  three  groups  of  enzymes  cannot  be  separated 
by  any  reference  to  their  distribution.  The  peptic  type  of 
enzyme  seems  to  be  chiefly  represented  in  the  secretions  of 
insectivorous  plants,  such  as  Nepenthes.  These  enzymes  Vines 
terms  ecto-peptases  to  distinguish  them  from  the  internally  held 
and  controlled  enzymes  of  similar  catalytic  activity  in  protein 
hydrolysis,  such  as  the  endo-peptase  present  in  yeast. 

The  enzymes  which  are  usually  regarded  as  active  in  re- 
converting the  deposits  of  aleurone  grains  within  the  seed  into 
amino-acids  were  first  described  as  tryptic,  because  their  activity 
resulted  in  the  formation  of  amino-acids  from  the  proteins 
hydrolysed.  Vines  in  a  series  of  papers2  has  built  up  a  strong 
case  for  interpreting  all  cases  of  so-called  "  tryptic  "  digestion  in 
plants  as  due  in  reality  to  two  enzymes,  acting  on  two  different 
stages.  The  first  stage  from  protein  to  peptone  is  regarded  as 
due  to  the  catalytic  action  of  a  peptase — an  ecto-peptase  in  the 
excretion  of  Nepenthes  capable  of  acting  in  the  presence  of 
hydrochloric  acid  or  organic  acids,  but  inactive  in  neutral  or 
alkaline  solutions,  and  an  endo-peptase  in  the  tissues  of  the 
seedling  and  elsewhere,  incapable  of  action  in  the  presence  of 
hydrochloric  acid.  The  second  stage  from  peptone  to  amino- 
acid  is  regarded  as  due  to  the  catalytic  activity  of  a  widely 
distributed  ereptase  capable  of  acting  in  either  acid,  neutral  or 
alkaline  solution. 

Vines  was  led  to  suspect  the  existence  of  these  two  stages  by 
noticing  the  different  effect  exerted  upon  the  rate  of  the  two 

1  Lawrow,  Zeit.filr  Physiol.  Chem.  26,  p.  513. 

3  Vines,  Annals  of  Botany,  xi.  p.  563,  xii.  p.  545,  xv.  p.  563,  xvi.  p.  I,  xvii. 
p.  237,  xviii.  p.  289,  xix.  pp.  149  and  171,  xx.  p.  113,  xxii.  p.  103,  xxiii.  p.  I,  xxiv. 
p.  215. 


ENZYMES  AS  SYNTHETIC  AGENTS  489 

stages  of  the  hydrolysis,  by  various  antiseptics  used  in  the 
course  of  his  investigation.  If  the  same  enzyme  was  responsible 
for  both  stages  of  the  hydrolysis,  then  the  change  in  velocity 
in  the  two  stages  produced  by  the  addition  of  the  reagent 
should  be  proportionately  the  same,  but  it  was  very  far  from 
being  so.  Guided  by  this  clue  he  subsequently  succeeded  in 
isolating  from  hemp  seed  and  from  other  sources  extracts  of 
the  two  enzymes  which  were  each  strictly  limited  in  their 
activity  to  one  stage  of  the  hydrolysis.  This  separation  had 
proved  to  be  possible  owing  to  the  fact  that  while  ereptase  is 
readily  soluble  in  water,  the  endo-peptase  present  with  it  is 
practically  insoluble  in  distilled  water  but  readily  soluble  in 
solutions  of  sodium  chloride. 

The  importance  of  these  investigations  from  our  present 
point  of  view  is  obvious ;  everything  points  to  the  complex 
series  of  changes  which  ultimately  effect  the  conversion  of  a 
protein  into  an  amino-acid,  occurring  under  the  action  of  a 
series  of  enzymes  or  groups  of  enzymes.  In  view  of  the  fact 
that  of  the  animal  enzymes,  peptase  acts  with  the  greater 
celerity  on  complex  proteins,  it  should  perhaps  be  regarded  as 
the  first  group  of  enzymes  in  the  series,  and  the  protein  in  its 
decomposition  would  then  come  under  the  action  of  three 
groups  of  enzymes  successively  : ! 

"Pepsin"  "Trypsin"  Erepiase 

or  Ecto-peptase  group.         or  Endo-peptase  group.  group. 

Protein  — $►  Albumoses.  —>  Peptones.  ->  Amino-acids. 

Clearly  then,  when  an  attempt  is  made  to  follow  this  series 
of  reactions  with  enzyme  catalysts  in  the  direction  of  synthesis, 
it  would  seem  advisable  to  attempt  to  follow  these  steps  in 
the  reverse  order.  But  the  significance  of  ereptase  has  been 
recognised  only  in  comparatively  recent  times,  and  as  the  work 
we  shall  have  to  consider  in  the  succeeding  section  has  been 
carried  out  with  the  other  enzymes  of  the  series,  the  starting 
point  for  the  synthesis  has  been  a  vaguely  defined  admixture 
of  bodies  instead  of  amino-acids  of  definitely  known  com- 
position. 

In  the  case  of  the  plant,  the  question  is  at  present  com- 
plicated by  the  incompleteness  of  our  knowledge  of  the  amino- 

1  See  Bayliss,  Nature  of  Enzyme  Action,  2nd  ed.  p.  115.  It  is  as  yet 
impossible,  however,  to  correlate  with  any  certainty  this  series  of  three  enzyme 
groups  with  the  phenomena  of  proteoclastic  digestion  in  the  plant. 


490  SCIENCE  PROGRESS 

acids  formed  upon  the  digestion  of  the  protein  food  reserves. 
Very  little  is  known  beyond  the  fact  that  asparagin  seems 
usually  to  be  the  chief  amino-acid  formed,  accompanied  by 
certain  quantities  of  leucin  and  tryrosin.  These  amino-acids 
pass  up  the  stem  of  the  germinating  seedling  and  seem  to 
disappear  in  the  leaf  contemporaneously  with  the  beginning 
of  photosynthetic  activity.  But  our  knowledge  of  these 
phenomena  is  still  far  too  nebulous  to  make  speculation 
profitable  regarding  the  part  played  by  enzymes  in  this  subse- 
quent synthesis  in  the  leaf. 

The  succeeding  section  of  this  paper  will  therefore  consist 
simply  of  a  critical  review  of  certain  supposed  syntheses  of 
proteins  with  the  aid  of  enzymes,  under  "  in  vitro  "  conditions. 
The  earlier  and  more  significant  stage  in  synthesis,  the  first 
linkages  of  the  amino-acids,  unfortunately  cannot  be  discussed 
at  all  from  the  standpoint  of  enzyme  catalysis,1  owing  to  the 
fact  that  no  reversible  syntheses  with  the  ereptase  group  of 
enzymes  have  been  described. 

4.  Protein  Synthesis  by  Reversible  Catalysis,  from  the 
Products  of  Protein  Hydrolysis 

The  probability  is  that  the  experiments  now  to  be  described 
provide  sufficient  evidence  to  establish  the  fact  that  the  catalysis 
of  protein  hydrolysis  can  proceed  in  the  reverse  direction,  that 
of  synthesis,  under  the  action  of  the  same  enzyme ;  but  owing 
to  the  difficulty  of  identifying  with  chemical  exactitude  either 
initial  or  end  products,  very  little  definite  information  has  yet 
been  obtained  of  the  course  of  such  a  synthetic  reaction. 

The  so-called  "  plastein  "3  formation  obtained  by  Danilewski 
and  his  co-workers  is  a  typical  example  of  this  class  of  experi- 
ment. This  investigator  found  that  by  leaving  concentrated 
solutions  of  Witte's  peptone  in  contact  with  rennet,  precipitates 
were  obtained  which  gave  characteristic  protein  reactions. 

Preparations  of  peptase  introduced  into  peptones  produced 
the  same  result.  This  work  has  since  been  confirmed  and 
extended,  other  enzymes  being  employed,  and  in  some  cases 
similar  precipitates  have  been  obtained  from  solutions  initially 
containing  amino-acids  and  polypeptides. 

1  Lawrow,     Hoppe-Seyler's  Zeit.  f.  Physiol.  Chem.  51,  p.  I. 

*  See  Euler,  Trans.  Pope,  he.  cit.  p.  265,  for  summary  of  this  work. 


ENZYMES  AS  SYNTHETIC  AGENTS  491 

In  respect  to  the  difficulties  of  interpretation,  this  work  is 
typical  of  this  class  of  investigation.  In  the  first  place  there 
is  no  certain  evidence  that  the  precipitates  obtained  are  com- 
posed of  proteins  ;  according  to  some  statements  they  contain 
too  little  nitrogen  to  be  classed  as  protein  although  they  give 
the  reactions  of  bodies  of  this  class.  There  is  certainly  no 
evidence  that  they  represent  the  protein  bodies  from  which  the 
peptones  were  derived  by  previous  hydrolysis,  consequently  the 
relation  of  the  reaction  to  the  catalysis  of  a  reversible  hydrolysis 
is  not  clear. 

This  brings  us  to  the  second  outstanding  difficulty,  namely 
that  it  is  not  at  all  clear  that  the  production  of  these  bodies  is  to 
be  associated  in  any  way  with  a  catalysis  of  a  chemical  reaction. 
Under  the  existing  conditions  nothing  would  seem  more  pro- 
bable than  a  precipitation  due  to  the  withdrawal  of  water  from 
some  of  the  more  complex  colloids  present.  The  precipitation 
would  in  that  case  be  equivalent  to  the  phenomenon  of  "  salting 
out,"  and  if  there  were  any  protein-like  bodies  present  which 
did  not  form  part  of  the  original  precipitate,  they  would  almost 
certainly  be  carried  out  of  solution  by  the  precipitate  as  the 
result  of  adsorption. 

In  a  less  degree  the  same  criticism  applies  to  the  experiments 
of  Taylor,1  who  in  the  first  place  subjected  400  grams  of  pro- 
tamin  to  complete  tryptic  digestion,  and  then,  converting  the 
products  of  hydrolysis  into  carbonates,  subjected  them  to  the 
action  of  a  considerable  quantity  of  tryptase.  At  the  end  of  five 
months,  about  2  grams  of  protamin,  weighed  as  sulphate,  were 
recovered  from  the  solution. 

If  these  experiments  are  regarded  as  synthesis  under  the 
concentration  conditions  existing,  a  certain  amount  of  support  is 
afforded  to  this  point  of  view  by  other  phenomena. 

In  the  first  place,  this  is  the  simplest  explanation  to  give 
of  the  retardation  of  protein  hydrolysis  produced  by  the 
accumulation  of  the  products  of  hydrolysis.  The  equilibrium 
point  in  a  reversible  reaction  is  being  approached,  and  if  the 
products  of  hydrolysis  are  present  in  sufficient  quantity  a  re- 
versal of  the  reaction  in  a  synthetic  direction  may  be  expected. 
Secondly,  such  a  reversal  of  the  reaction  is  the  simplest  ex- 
planation of  the  changes  in   conductivity  of  a  tryptic  digest 

1  A.  E.  Taylor,   Univ.  of  California  Publ.  Pathol,  i.  p.  343  ;  and  Journ.  of 
Biol.  Chem.  iii.  p.  87. 


492  SCIENCE  PROGRESS 

upon  concentration.  Bayliss  *  found  that  as  the  hydrolysis  of 
caseinogen  by  tryptase  proceeded,  the  conductivity  of  the 
solution  increased,  but  that  after  concentration  of  the  solution, 
in  the  presence  of  the  enzyme,  the  conductivity  diminished. 
This  certainly  seems  to  point  to  a  reversal  of  reaction  in  the 
direction  of  synthesis. 

More  recently  Brailsford  Robertson2  has  made  a  very  full 
study  of  one  reaction  of  this  type.  His  investigations  deserve 
fuller  description  because  of  the  attempt  he  has  made  to  meet 
the  theoretical  difficulties  created  by  the  concentration  condi- 
tions which  are  found  necessary  to  bring  about  these  reactions. 

In  Robertson's  initial  experiments  400  c.c  of  N/50  potassium 
hydroxide  saturated  with  casein  were,  after  complete  digestion, 
concentrated  to  70  c.c.  To  this  solution  were  added  30  c.c.  of  a 
10  per  cent,  solution  of  Grubler's  pepsin.  Within  two  hours  a 
precipitate  had  formed  which  was  shown  to  be  one  of  the  con- 
stituents— paranuclein  A — of  the  mixture  of  proteins  which  had 
been  previously  hydrolysed. 

At  first  sight  this  was  again  to  be  interpreted  as  simply  a 
case  of  a  reversible  reaction  undergoing  catalysis,  under  the 
concentration  conditions  existing,  in  the  direction  of  synthesis ; 
but  further  experiments  rendered  this  simpler  explanation 
impossible.  In  the  first  place,  if  this  were  purely  a  catalytic 
action,  then  the  enzyme  catalyst  could  produce  no  change  in  the 
point  of  equilibrium  of  the  reaction.  But  as  a  matter  of  fact 
Robertson  found  that  by  adding  the  pepsin  in  sufficiently  con- 
centrated form,  synthesis  could  be  brought  about  in  a  solution 
containing  the  products  of  hydrolysis  without  any  previous 
concentration  whatever  of  this  solution. 

Further,  it  was  found  possible  to  obtain  the  reversible  syn- 
thesis in  lower  concentration  of  enzyme  and  substrate  by  simply 
raising  the  temperature,  and  in  the  end  ready  reversal  of  the 
hydrolytic  action  was  obtained  at  a  temperature  of  650  C,  a 
temperature  ten  to  fifteen  degrees  higher  than  that  at  which  the 
normal  hydrolytic  activity  of  pepsin  is  known  to  occur. 

Now  obviously  these  facts  cannot  be  explained  upon  the 
usual  assumption  that  the  enzyme  present  is  behaving  as  a 
normal  organic  catalyst,  in  fact  the  last  experiments  referred  to 
clearly  point  to  a  synthetic  action,  if  catalytic,  as  resulting  from 

1  Bayliss.  Nature  of  Enzyme  Action,  2nd  ed.  p.  53. 

2  T.  B.  Robertson,  Journ.  Biol.  Chcm.  iii.  p.  95  and  v.  p.  493. 


ENZYMES  AS  SYNTHETIC  AGENTS  493 

the  activity  of  a  catalyst  of  a  different  nature  from  the  original 
pepsin  employed. 

Before  proceeding  to  consider  Robertson's  theory  as  to 
how  these  phenomena  may  best  be  correlated  with  theories 
of  enzyme  catalysts,  it  will  be  well  to  consider  critically  the 
validity  of  the  evidence  upon  which  the  theory  of  enzyme 
catalysis  is  to  be  extended  to  cover  new  phenomena. 

It  is  obvious  that  the  statement  that  we  are  dealing  in  these 
experiments  with  a  reversible  catalysis  induced  by  enzymes 
implies  that  we  are  satisfied  with  the  evidence  in  reference  to 
two  points.  These  are  (i)  that  the  body  produced  after  con- 
centration and  addition  of  the  enzyme  is  really  "  paranuclein  A," 
and  identical  with  one  of  the  original  bodies  hydrolysed ;  (2) 
that  this  body  is  actually  produced  in  the  solution  as  the  result 
of  chemical  action  of  a  synthetic  nature. 

On  both  these  points  it  is  necessary  at  present  to  withhold  a 
definite  opinion. 

With  regard  to  the  first  point,  the  paranucleins  are  a  group 
of  bodies  which  are  indefinitely  characterized  and  separated  to 
a  large  extent  upon  the  evidence  of  the  phosphorus  content. 
The  percentage  of  phosphorus  in  the  bodies  produced  in  these 
experiments  was  by  no  means  always  constant  or  identical  with 
that  usually  associated  with  "  paranuclein  A."  At  the  same 
time  it  was  well  within  the  limits  usually  associated  with  this 
class  of  bodies  and  it  would  be  natural  that  the  results  of  syn- 
thesis, like  the  starting  point  of  hydrolysis,  should  be  an 
admixture  of  bodies. 

In  view  of  the  difficulty  of  characterising  "  paranuclein," 
considerable  importance  attaches  to  the  comparison  by  Gay  and 
Robertson1  of  the  immunity  reactions  produced  by  paranuclein, 
and  by  this  body  synthetically  produced  from  the  products  of 
hydrolysis. 

These  two  bodies  apparently  possess,  as  tested  by  sub- 
cutaneous injections  into  guinea  pigs,  identical  and  specific 
antigenic  properties  which  are  not  present  in  the  original 
products  of  peptic  digestion.  It  has,  however,  to  be  remem- 
bered that  the  products  of  peptic  hydrolysis  would  contain 
this  "  synthetic  paranuclein,"  if  present,  in  considerable  dilution, 
and  the  effects  produced  by  injections  might  therefore  be  much 
less  marked. 

1  Gay  and  Robertson,  Journ.  of  Biol.  Client,  xii.  p.  233. 


494  SCIENCE  PROGRESS 

At  the  present  time  it  is  perhaps  advisable  to  regard  the 
identity  of  the  "synthetic  paranuclein"  as  an  open  question, 
especially  in  view  of  the  recent  experiments  of  Bayliss.1 

The  latter  investigator  has  thrown  considerable  doubt  on 
the  second  point  at  issue  in  relation  to  this  reaction,  viz.  its 
chemical  nature.  His  experiments  point  definitely  to  a  colloidal 
precipitation  between  the  enzyme  and  a  colloid  present  in  the 
peptic  digest  owing  to  the  method  of  its  preparation.  If  this 
other  colloid  is  first  removed  from  the  digest,  for  instance  by 
addition  of  hydrochloric  acid  up  to  a  concentration  of  0*5  per 
cent,  then  upon  subsequent  filtration  and  neutralisation  it  is 
impossible  to  get  this  precipitate  formed  upon  the  addition  of 
the  enzyme.  On  the  other  hand  the  precipitate  given  by  the 
acid,  upon  redissolving  in  the  smallest  possible  quantity  of 
alkali,  is  readily  reprecipitated  by  the  addition  of  pepsin. 

This  suggests  that  the  appearance  of  this  precipitate  is  due 
to  the  precipitation  of  oppositely  charged  colloids,  a  view  which 
is  supported  by  the  comparative  rapidity  with  which  it  is 
brought  about.  Bayliss  strengthens  the  evidence  for  this  hypo- 
thesis by  showing  that  a  similar  precipitation  may  be  produced 
in  the  products  of  the  peptic  hydrolysis  by  the  additions  of  other 
substances  than  pepsin,  that  is  to  say,  by  other  colloids  which 
are  not  enzymes. 

It  is  therefore  unnecessary  at  the  present  time  to  do  more 
than  glance  at  the  interesting  hypothesis  of  reciprocal  catalysis 
put  forward  by  Robertson  2  to  reconcile  in  the  simplest  manner 
these  apparently  new  types  of  enzyme  catalysis  with  the  Van  't 
Hoff  view  that  enzymes,  behaving  as  normal  catalysts,  must, 
given  proper  concentration  conditions,  accelerate  synthetic 
actions.  Robertson  suggests  that  at  high  concentration  the 
enzyme  may  be  present  in  a  dehydrated  form  and  that  this 
form,  which  is  stable  at  higher  temperature  than  the  normal 
enzyme,  may  be  responsible  for  the  catalysis  of  the  synthetic 
reaction. 

If  further  investigation  should  show  the  necessity  for  it,  this 
ingenious  hypothesis  will  certainly  deserve  serious  consideration. 
But  it  cannot  be  too  strongly  emphasised  that  advance  in  a 
complex  series  of  problems  such  as  these  will  probably  be 
facilitated    by    a     rigid    adherence    to    the    simplest    possible 

1  Journ.  of  Physiology,  xlvi.  p.  236. 

2  Journ.  of  Biol.  C&em.,  v.  p.  510. 


ENZYMES  AS  SYNTHETIC  AGENTS  495 

explanation  of  observed  phenomena  until  investigation  shall 
establish  beyond  a  doubt  that  the  simple  explanation,  such  as 
that  an  enzyme  as  a  catalyst  obeys  the  physico-chemical  laws 
governing  the  definition  of  a  catalyst,  will  no  longer  cover  the 
whole  of  the  ascertained  phenomena. 

It  is  therefore  considered  premature  for  the  same  reason  to 
discuss  Euler's  l  suggestions  as  to  anti-enzymes  being  active  in 
synthesis.  It  is  not  yet  clear  that  simpler  explanations  will  not 
suffice. 

Euler  points  out  that  various  investigators  have  found  that 
the  result  of  subcutaneous  injection  of  enzymes  into  the  animal 
organism  is  the  production  of  specific  anti-bodies.  These 
bodies,  termed  in  some  cases  anti-enzymes,  have  been  reported 
to  exhibit  catalytic  activity,  and  it  is  suggested  that  they  act  in 
the  direction  of  synthesis  and  not  of  hydrolysis. 

It  is  quite  possible  that  this  hypothesis  may  ultimately  prove 
of  value,  but  it  is  at  present  unnecessary  for  the  explanation  of 
the  observed  reversal  of  enzyme  action.  It  is  also  perhaps 
worth  pointing  out  that  the  terminology  adopted  is  a  little 
unfortunate,  because  the  term  anti-enzyme  has  often  been  used 
in  reference  to  specific  cases,  and  the  implication  has  been  that 
the  anti-enzyme  concerned  produced  its  inhibiting  effect  directly 
upon  another  enzyme,2  and  not  necessarily  by  accelerating  a 
reaction  against  its  normal  equilibrium  conditions.  Further- 
more, such  bodies  as  Euler  refers  to  should  surely  have  no  claim 
at  all  to  the  name  of  enzyme.  An  enzyme  has  been  generally 
regarded  as  an  organic  catalyst,  and  these  bodies  cannot  be 
regarded  as,  in  any  sense  of  the  word,  chemical  catalysts.  They 
seem  to  act  in  defiance  of  the  laws  of  mass  action. 

Finally,  in  considering  the  various  aspects  of  the  subject 
reviewed  in  this  paper,  the  writer  would  emphasise  the  fact 
that  there  is  no  pretence  of  giving  more  than  partial  glimpses 
of  a  very  extensive  problem.  Both  in  relation  to  carbohydrate 
and  protein  metabolism,  the  physiologist  anxious  for  guidance 
in  his  attempt  to  outline  experimentally  the  highways  of 
metabolic  activity  in  the  organism  is  bewildered  by  the  variety 
of  hypothesis  permitted  him    by    the    fruitful    discoveries    of 

1  Euler,  loc.  cit.  p.  267  (Eng.  ed.). 

s  See,  for  instance,  Czapek  upon  anti-oxidase,  Ann.  of  Botany,  or  the  use  of 
the  term  anti-glyoxalose  by  Dakin  and  Dudley,  Journ.  of  Biol.  Chem.  xiv.  p.  463. 


496  SCIENCE  PROGRESS 

organic  chemistry.  If  a  student  of  the  problem  is  ever  to  pass 
from  the  contemplation  of  the  work  of  his  colleagues  to  experi- 
ment, then  he  must  resolutely  close  his  eyes  to  many  of  these 
alluring  possibilities  and,  concentrating  his  attention  upon  one 
feature  of  the  problem,  learn  by  experience  what  facilities 
physical  and  chemical  methods  provide  him  for  its  experimental 
solution. 

In  these  pages  an  attempt  has  been  made  to  consider  the 
enzyme  as  a  possible  agent  of  synthesis  with  a  view  to  sub- 
mitting the  problem  to  subsequent  investigation  in  the 
laboratory.  No  one  is  more  conscious  than  the  writer  of  his 
inability  to  treat  this  side  of  a  general  problem  with  adequate 
freedom  and  confidence,  and  he  would  greatly  appreciate  the 
criticisms  and  suggestions  of  others  who  are  more  conversant 
with  the  questions  discussed  or  who  are  approaching  them  from 
different  points  of  view. 


THE   PHYSICAL  ASPECT   OF  THE 
OPSONIC   EXPERIMENT 

By  MAJOR  A.   G.    McKENDRICK,   M.B.,   Ch.B.,  F.R.S.E. 

Indian  Medical  Service 

The  recognition  of  the  principle  that  prevention  is  better  than 
cure,  obvious  though  it  may  seem,  has  of  late  years  exercised 
a  considerable  influence  on  medical  research.  Side  by  side  with 
the  development  of  preventive  sanitation  has  advanced  the 
investigation  into  the  reasons  why  infection  is  escaped  by 
certain  individuals.  The  importance  of  leucocyte  and  serum  as 
protective  agents  has  been  fully  established,  and  the  reinforce- 
ment of  their  potency  by  vaccine  therapy,  general  hygiene,  and 
the  like,  has  led  to  the  foundation  of  a  new  school  of  medical 
practice.  That  the  serum  alone  may  overcome  the  intruding 
microbe  of  disease  is  an  accepted  fact,  and  the  discovery  by  Sir 
Almroth  Wright  of  its  important  role  in  the  vital  phenomenon 
of  phagocytosis  has  still  further  focussed  attention  on  it.  As 
the  serum  is  a  fluid,  and  as  a  fluid  can  hardly  be  credited  with 
vital  activity,  the  part  which  it  plays  in  the  process  of  immunity 
is  capable  of  investigation  by  the  methods  of  physics  and 
chemistry.  On  account,  however,  of  the  complex  nature  of  the 
substances  involved,  little  advance  has  been  made  by  purely 
chemical  methods.  In  place  of  these,  the  mathematical  methods 
of  physical  chemistry  which  deal  with  velocities  of  reaction,  and 
equilibrium  states,  have  been  applied,  and  in  this  direction  con- 
siderable progress  has  been  made  by  Arrhenius  and  others. 
Thus  in  this  case  at  least  the  application  of  mathematics  has 
been  of  service  to  medicine.  But  immunity  does  not  depend  on 
the  serum  alone.  The  leucocyte  is,  as  I  have  said,  a  factor  in 
the  destruction  of  the  intruding  microbe,  and  it  is  with  this 
aspect  of  the  question  that  I  propose  to  deal. 

The  phenomenon   of  phagocytosis  as  it  applies  to  disease 

497 


498  SCIENCE    PROGRESS 

may  be  described  as  the  ingestion  of  micro-organisms  by 
leucocytes.  Wright  has  shown  that  this  ingestion  is  more 
rapid  when  it  takes  place  in  serum  from  an  immune  animal,  than 
in  that  from  a  non-immune.  This  fact  can  be  quantitatively 
determined  by  the  method  of  measuring  the  degree  of 
phagocytosis  devised  by  Leishman.  The  experiment  as  per- 
formed in  the  laboratory  is  as  follows  :  An  intimate  mixture  of 
leucocytes  and  micro-organisms  is  placed  in  an  appropriate 
vessel  and  kept  at  blood  heat.  After  about  fifteen  minutes,  a 
sample  drop  of  the  mixture  is  taken  out,  placed  on  a  microscope 
slide,  and  spread  out  into  a  thin  film.  The  film  is  fixed  and 
stained  by  a  method  which  causes  leucocytes  and  organisms  to 
assume  different  colours.  The  number  of  micro-organisms  in- 
gested by  (say)  ioo  leucocytes  is  counted — and  this  divided  by 
ioo  gives  the  average  content.  If  two  experiments  are  performed 
in  this  manner,  one  with  an  unknown  serum  and  the  other  with 
a  serum  which  is  known  to  be  normal,  and  if  the  average 
content  with  unknown  serum  is  divided  by  the  average  content 
with  the  normal  serum,  a  value  is  obtained  which  is  called  the 
opsonic  index. 

The  phenomenon  which  has  taken  place  between  the  two 
types  of  cell,  leucocyte  and  micro-organism,  is  a  complex  one. 
Leaving  the  mode  of  action  of  the  immune  serum  out  of  account, 
each  ingestion  may  be  considered  as  having  taken  place  in  two 
stages :  firstly,  collision  between  a  leucocyte  and  an  organism  ; 
and  secondly,  the  inclusion  of  that  organism  in  the  protoplasm 
of  the  leucocyte. 

The  stage  of  collision,  and  the  conditions  which  lead  up  to 
it,  are  obviously  capable  of  statistical  treatment — just  as  the 
kinetic  theory  of  gases  can  be  treated  from  a  statistical  point  of 
view.  It  may  be  argued,  however,  that  no  comparison  can  be 
drawn  between  the  conduct  of  a  molecule  of  a  gas  and  that 
of  a  living  cell ;  that  whilst,  where  there  is  no  life,  particles 
may  follow  random  paths,  such  will  not  be  the  case  with  living 
cells  which  are  apparently  capable  of  voluntary  movement  and 
effort.  (Such  movements  are  no  doubt  chemio-tactic  and  only 
simulate  voluntary  movements.)  But  on  the  other  hand  it  must 
be  remembered  that  the  leucocyte  is  in  an  environment  of 
particles  of  food  of  an  equally  tempting  nature  which  are 
scattered  at  random  in  its  vicinity.  It  need  only  browse  at 
random  as  a  cow  browses  over  a  fat  pasture. 


THE  OPSONIC  EXPERIMENT  499 

Let  us,  for  convenience,  divide  the  leucocytes  which  have 
been  counted  into  groups,  according  to  the  number  of  organisms 
they  contain  ;  and  let  the  number  of  leucocytes  in  any  particular 
group  m  be  ym.  Thus  y0  denotes  the  number  of  empty  leuco- 
cytes counted,  and  yx  denotes  the  number  of  leucocytes  which 
contain  one  micro-organism.  Now  if  we  compare  two  records  of 
counts  which  give  the  same  average,  and  if  collisions  occur  at 
random,  the  distribution  of  leucocytes  amongst  the  various 
groups  should  be  the  same  in  the  two  records,  apart  from  errors 
of  experiment ;  and  such  is  found  to  be  the  case.  Certain 
workers  have  adopted  the  proportion  of  empty  cells,  in  place  of 
the  mean  content,  as  a  basis  of  comparison  for  obtaining  the 
opsonic  index.  That  there  is  a  relation  between  the  proportion 
of  empty  cells  and  the  mean  is  true  ;  but  to  estimate  the  activity 
of  a  community  on  the  basis  of  the  proportion  of  individuals 
who  have  failed  to  obtain  work,  is  hardly  as  fair  as  to  compare 
average  work  performed.  If,  however,  such  a  relation  exists — 
that  is,  if  the  average  content  can  be  calculated  from  the  pro- 
portion of  empty  cells — we  shall  have  a  method  by  which  an 
estimation  may  be  made  in  a  few  minutes  with  very  little 
trouble. 

The  mathematical  treatment  is  as  follows  :  When  a  leuco- 
cyte which  contains,  say,  5  organisms  collides  with  a  free 
organism,  it  becomes  a  member  of  the  group  which  contains 
6;  and  the  rate  at  which  such  collisions  occur  is  proportional 
to  the  number  in  the  group  5.  Similarly,  an  individual  in 
group  6  passes  into  group  7  on  collision,  and  the  rate  at  which 
such  collisions  occur  is  proportional  to  the  number  in  group  6. 
Thus  the  population  of  group  6  is  increased  at  a  rate  pro- 
portional to  the  number  in  group  5,  and  depleted  at  a  rate 
proportional  to  the  number  in  its  own  group  (6);  or,  for 
group  m : 

(1)  ^5  =  (y.n-I-y  )*(t) 

where  </>(t)  is  a  complex  factor  denoting  the  probability  of  an 
ingestion  occurring. 

(1)  It  depends  on  the  number  of  micro-organisms  which  are 
free  at  the  moment,  but  this  is  being  gradually  diminished  as  the 
time  goes  on. 

(2)  It  depends  on  the  concentration  of  certain  factors  in  the 
serum,  and  this  also  decreases  as  the  time  passes. 


5oo  SCIENCE  PROGRESS 

(3)  It  depends  on  the  temperature,  which  may  be  constant, 
or  may  be  allowed  to  vary. 

Thus  (f>(t)  is  a  function  oi  the  time  which,  in  the  present  state 
of  our  knowledge,  we  cannot  define.  Under  the  conditions  of 
experiment  all  the  leucocytes  were  originally  empty,  hence 
for  (m  =  o), 

the  existence  of  groups  containing  a  minus  number  being  im- 
possible. 

From  these  two  equations  we  can  eliminate  the  time,  and 
consequently  all  the  unknown  factors ;  and  we  have  : 

dy 

—  =  y»  - ,  -  ym 
uz 

where  z  =  \oge  — 

a0  being  the  initial  number  of  empty  leucocytes. 
From  this  equation  we  have  : 


yi  =  y0z 
ya=y0~, 


z2 


nua 

ym=yoi_ 

m! 


Now  the  average  content  is 


oy0  +  'yi  +  2y,,  + mym  +  .  .  . 

y0  +  yi  +  y*  +  y»  +  —  y*  + . . . 


z2  z3 

_  yo(z  +  2  jr  +  3  jr  +  • 

y0(i  +  z  +  ^-+  — 
=  z 
=  log.  - 


This  is,  then,  the  relation  between  the  average  content  and 
the  proportion  of  empty  cells,  and  gives  a  practical  method  of 
estimating  the  average  which  is  of  considerable  value  when  the 
proportion  of  empty  cells  is  not  too  low. 


THE  OPSONIC  EXPERIMENT  501 

The  opsonic  index  is  thus  : 

(log  an  -  log  yn)  unknown 
(log  ao  -  log  y0)  normal 

In  this  calculation  ordinary  logarithms  to  base  10  may  be  used. 

In  Table  I.  a  close  agreement  between  observed  and  calcu- 
lated figures  is  shown.  The  first  column  gives  the  group 
number — /.^.containing  o,  1,  . . .,  etc.  Observed  and  calculated 
figures  of  numbers  of  cells  in  each  group  are  tabulated  side  by 
side  in  the  other  columns.  The  first  three  experiments  are 
from  Fleming  (quoted  by  Greenwood,  Biometrica) ;  the  latter 
two  are  by  Harvey  {Biometrica,  vii.  p.  64). 

Table  I. 


Obs. 

Calc. 

Obs. 

Calc. 

Obs. 

Calc. 

Obs. 

Calc. 

Obs. 

Calc. 

Cells    con- 

tain 

ing  0 

19 

(19) 

99 

(99) 

41 

(41) 

620 

(620) 

632 

(632) 

,       I 

59 

5789 

227 

2068 

126 

II91 

282 

296-3 

282 

290 

»       2 

98 

88-2 

208 

2161 

154 

I73'i 

79 

708 

65 

66-5 

»      3 

88 

897 

134 

150-5 

164 

167-7 

16 

11-29 

16 

IOI 

»       4 

65 

68-24 

78 

78-63 

121 

1218 

2 

1-349 

4 

II 

>      5 

37 

4I-S8 

34 

32-85 

62 

708 

1 

0-131 

1 

01 

,       6 

17 

2112 

9 

11-44 

36 

34'3 

— 

— 

— 

— 

,       7 

8 

9-192 

7 

3415 

35 

14-2 

— 

— 

— 

— 

,       8 

5 

3-501 

3 

08921 

5 

5-i7 

— 

— 

— 

— 

,      9 

2 

1-185 

0 

— 

2 

167 

— 

— 

— 

— 

,     10 

1 

0-361 

0 

— 

3 

0-48 

— 

— 

— 

— 

,     11 

0 

— 

0 

— 

1 

— 

— 

— 

— 

— 

1     12 

1 

— 

1 

Mean  .     . 

3-005 

3  047 

2-0825 

2-0832 

3-040 

2-9065 

0-50 

0-478 

0-48 

045887 

In  the  foregoing  argument  two  factors  have  been  neglected 
which  may  operate  during  an  experiment.  In  the  first  place,  it 
is  very  probable  that  the  faculty  of  ingestion  will  diminish  as 
the  leucocyte  fills  up ;  and  in  the  second,  if  under  the  con- 
ditions of  experiment  sedimentation  be  permitted,  and  if  there  be 
a  difference  in  the  specific  gravities  of  micro-organism  and 
leucocyte,  then  the  engorged  leucocyte  may  move  into  a  thicker 
swarm.  These  two  factors  will  operate  in  contrary  directions, 
the  former  causing  a  decreased  appetite  and  the  latter  an 
apparent  increase  of  appetite.  I  have  seen  no  indication  of 
decreased  appetite  in  the  figures  which  I  have  examined,  but 
comparison  between  the  column  with  heading  "  Mean  ob- 
served"  and   the   column  "z"  (mean  calculated)  in  Table  II., 


502 


SCIENCE  PROGRESS 


Table  II. 


Description. 

Observed. 

-g-  from  SD  s 

ao- 

y<>- 

Mean. 

SD. 

z. 

c 
-J-  2 

=  e  D       x  mean. 

Fleming,  Norm.  S.B.  . 

400 

19 

3-005 

1*8207 

3-04702 

0*032 

„        Norm.  S.A.  . 

750 

41 

3-040 

1*8927 

2*9065 

OO56 

„         No.  2.   . 

800 

99 

2*0825 

1*5397 

2*0832 

0-059 

„        T.  Ch.  . 

I,000 

152 

2-145 

1*6401 

1*88388 

0"I20 

„         10  Norm. 

I,OIO 

in 

2-571 

1-8448 

2*20818 

0"I2I 

T.  A.     . 

I,IOO 

58 

3-7291 

2-3820 

2*94263 

0*142 

Greenwood   . 

20,000 

1,428 

3'6797 

2*6031 

2-63946 

0*196 

Strangeways  I.      . 

I,000 

219 

1-927 

1*7370 

1*51869 

0'292 

II.  S.C.      . 

1,000 

279 

1-521 

1*4885 

1*27655 

0*294 

„          II.C.&S.  . 

I,000 

198 

1-888 

1*7209 

1*61949 

0-277 

IV.  S.C.      . 

I,000 

243 

1-706 

i*6o86 

1*41470 

0*294 

„        III.      .        . 

I,000 

188 

2*014 

17239 

1*67132 

0*293 

V.      .        . 

I,000 

192 

2-119 

1*8207 

1*65026 

0*271 

„         VI.     .         . 

1,000 

207 

1-901 

1*6091 

I '57504 

C246 

„       VII.     .        . 

I,000 

240 

1-851 

1-6730 

1*42712 

0*289 

IV.      .        . 

2,000 

495 

1-689 

1-5825 

1*39635 

0'282 

shows  that  an  apparent  increase  may  occur.  It  must,  however, 
be  clearly  borne  in  mind  that  this  apparent  increase,  though 
true  for  the  particular  experiment,  is  not  a  true  measure  of 
Immunity  as  it  affects  the  host,  from  which  the  serum  is  drawn, 
for  in  the  swirl  of  the  blood-stream  such  sedimentation  cannot 
occur.  It  is,  in  short,  an  experimental  error  which  should  be 
eliminated  if  a  correct  estimate  of  Immunity  is  sought  for.  The 
point  may  be  investigated  as  follows :  If  there  be  an  alteration 
of  appetite  with  ingestion,  equation  (1)  takes  the  form  : 


fei  =  (f       V 


fm  y.u)  <}> 


As  the  variation  of  appetite  is  a  very  slight  one,  we  may  use 
the  approximations : 


fm  =  b  4-  cm  or  fm  =  b  -  cm 


And  we  find 


for  fm  =  b  4-  cm 


yn.=  y0 


b  /b 


tT+-I)-'"(T+m-0 


(i-e 


zjm 


m! 


Mean  =  —  (  e  b     -  1  J 


(Standard  deviation) a  =  e  x  mean. 


THE  OPSONIC  EXPERIMENT 


503 


For  fra  =  b  -  cm 

c 

b  /  b  \  /b  \(eT 

y-  =  yoT(- 1 -)••••  (T-m  +  Ij — 

Mean  =  *T"  (1  -  e  ~  ^~  *  J 

c   r 

(Standard deviation)3  =  e      b     x  mean. 


i)' 


m! 


The  figures  in  Table  III.  show  the  result  of  a   calculation 

Table  III. 


Strangeways  No.  1. 

Obs. 

Calc. 

0 
I 

2 

3 

4 

5 
6 

7 
8 

9 
10 

11 

Mean 

S.D 

219 
267 
219 
129 
70 

50 
26 

13 

5 
2 

0 

0 
1-927 
17370 

(219) 
267-4 
211-78 

I37-45 
79'38 
42-437 

21-473 
10-427 

4'9°35 

2-2475 

1-0087 

0-44484 

1-9168 

1-7347 

on  the  basis  of  increased  appetite.  Table  II.  gives  in  the 
columns  headed  "Mean"  and  "z"  a  comparison  between  ob- 
served means  and  z,  and  in  the  last  column  I  have  added  values 

of -r  calculated  roughly  from  the  equation  : 

(Standard  deviation) 8  «*  e  b      x  mean. 

An  exceedingly  interesting  result  is  obtained. 

It  will  be  observed  that  in  the  case  of  one  worker,  Dr.  Flem- 
ing, the  first  three  values  lie  between  003  and  0*06,  and  that  the 
last  three  vary  between  0*12  and  0-145.  In  Dr.  Greenwood's 
experiment  the  figure  rises  to  0-196,  in  spite  of  the  magnitude 
of  the  experiment ;  whilst  Dr.  Strangeways'  experiments  show 
values  varying  from  0-247  to  0*295  (i.e.  twice  as  great  as  Fleming's 
latter  figures,  and  six  times  as  great  as  his  first  three).  The 
consistency  of  the   figures  obtained  by  the   different  workers 

33 


504  SCIENCE   PROGRESS 

points  to  differences  of  method,  and  is  in  itself  an  indication 
that  the  apparent  increase  of  appetite  is  due  to  the  artificial 
conditions  of  the  experiment. 

From  the  above  analysis  we  see  : 

(i)  That  the  phenomenon  of  phagocytosis  can  be  satis- 
factorily treated  from  the  physical  point  of  view  as  a  random 
interfusion  between  two  perfectly  intermixed  systems  of  particles, 
each  of  which  is  evenly  distributed,  in  which  ingestion  takes 
place  when  individuals  of  opposite  type  have  collided. 

(2)  That  the  average  content  can  be  calculated  from  the 
proportion  of  leucocytes  which  remain  empty  at  the  conclusion 
of  the  experiment,  the  actual  observation  involving  a  minimum 
of  labour.  And  that  this  method  eliminates,  to  a  large  extent, 
the  personal  factor  of  the  particular  investigator. 

(3)  The  frequency  distribution  obtained,  and  the  consequent 
relation  between  the  average  content  and  the  proportion  of  cells, 
is  independent  of  <£(t).  For  example,  the  same  relations  will 
hold  good  in  an  experiment  conducted  at  constant  temperature 
and  in  one  in  which  the  temperature  has  been  allowed  to  vary 
in  any  way  whatsoever.  In  other  words,  the  frequency  dis- 
tribution, or  the  relation  between  the  populations  in  the  various 
groups,  is  obtained  after  the  elimination  of  an  unknown 
chemical  law  which  governs  the  velocity  of  reaction,  and  is 
thus  independent  of  it. 


HISTORY  OF   THE   VIEWS   OF    NERVOUS 

ACTIVITY 

By  D.  FRASER  HARRIS,  M.D.,  D.Sc,  B.Sc.  (Lond.),  F.R.S.E. 

Professor  of  Histology  and  Physiology,  Dalhousie  University,  Halifax,  Nova  Scotia 

It  is  always  instructive  to  trace  the  growth  of  an  idea,  to  be 
able  to  watch  the  notion  of  something,  even  of  so  elusive  a  thing 
as  the  nerve-impulse,  grow  gradually  in  clearness  and  in  definite- 
ness  as  the  centuries  roll  on. 

The  term  "nerve-impulse"  is  of  course  wholly  modern.  It 
would  not  be  profitable  to  go  farther  back  than  the  time  when 
the  Greek  philosophers  imagined  that  the  nerves  were  hollow 
and  conveyed  "  spirits "  through  the  pores  (poroi)  of  their 
substance. 

The  Alexandrine  School  of  Greek  Anatomy,  founded  as  far 
back  as  300  b.c.  by  Ptolemy  I.,  recognised  the  functional  differ- 
ence between  sensory  and  motor  nerves.  The  two  best  known 
teachers  in  it — Herophilus  and  Erasistratus — devoted  much 
attention  to  the  nervous  system ;  they  dissected  the  nerves  to 
their  origins  in  the  brain  and  spinal  cord,  they  displayed  the 
veins  of  the  brain  and  investigated  its  cavities  or  ventricles, 
believing  that  in  the  Fourth  of  these,  in  the  Medulla  Oblongata, 
the  soul  was  situated.  The  meeting  place  of  the  venous  sinuses 
of  the  coverings  of  the  brain  is  still  known  as  the  Torcular 
Herophili.  The  physiology  taught  by  Claudius  Galen  of  Rome 
(131-200  a.d.)  was  an  outgrowth  of  the  Alexandrian.  Galen  had 
the  clearest  conception  of  the  nerve-trunks  as  merely  conductors 
of  something — he  called  it  spirits — to  or  from  the  brain  and 
spinal  cord.  The  doctrine  of  spirits  in  general  he  elaborates  so 
as  to  recognise  three  kinds  of  spirits — natural,  vital,  and  animal. 
We  can  hardly  understand  the  nerve  physiology  of  the  Middle 
Ages  without  some  notion  of  these  three  kinds  of  spirit.  Briefly 
it  was  this  :  the  food  in  the  intestine  is  absorbed  into  the  portal 
vein  and  goes  to  the  liver,  where  it  is  worked  up  into  blood 
which  is  endowed  with  natural  spirits,  or,  in  modern  language, 

S05 


5o6  SCIENCE  PROGRESS 

with  the  powers  of  nourishing  the  tissues  of  the  body.  The 
crude  blood  was  then  supposed  to  pass  from  the  liver  to  the 
right  side  of  the  heart  whence  most  of  it  percolated  through  the 
septum  to  the  left  ventricle.  This  process  to  some  extent  refined 
the  blood.  In  the  left  auricle  in  diastole,  air  was  sucked  into  the 
heart ;  which  brought  about  two  results,  the  cooling  of  the 
innate  heat  of  the  heart  and  the  generating  of  vital  spirits. 
The  vital  spirits  were  carried  by  the  blood  in  the  arteries  to  all 
tissues  and  organs  to  enable  them  to  perform  vital  functions. 
The  blood  with  its  vital  spirits  that  went  to  the  brain  was 
supposed  to  undergo  a  sort  of  distillation  or  refining  for  the  last 
time,  with  the  result  that  the  animal  spirits  were  separated 
from  it  and  carried  to  the  body  by  the  nerve-trunks.  The 
animal  spirits  in  motor  nerves  made  muscular  movements 
possible,  those  in  sensory  nerves  were  productive  of  sensations. 

We  still  speak  of  animal  spirits,  of  "  a  man  of  spirit  "  and  so 
forth  ;  and  the  expression  "  the  vapours  of  alcohol "  or  "  fumes  of 
drugs  ascending  to  the  brain  "  are  based  on  the  analogous  ascent 
of  vital  spirits  from  the  heart  to  the  brain.  As  recently  as  the 
time  of  Queen  Anne  (1708)  the  Daily  Conrant  advertised  a  per- 
fume as  efficacious  because  "  it  increases  all  the  spirits,  natural, 
vital,  and  animal."     This  is  exactly  in  the  Galenical  order. 

The  point  of  interest  for  us  in  all  this  about  spirits  is  that 
thus  early  we  have  glimmerings  of  the  notion  of  innervation, 
the  agent  of  which  is  spirits  ;  for  the  animal  spirits  of  Galen  are 
the  nerve-impulses  of  to-day.  It  will  be  noticed,  however,  that 
there  is  in  this  ancient  doctrine  of  spirits  some  sort  of  latent 
distinction  between  powers  of  absorbing  nourishment,  of 
expressing  vitality,  and  of  conferring  movements.  The  modern 
advance  on  this  is  that  not  even  the  absorption  of  nourishment 
is  outside  of  innervation.  The  growth  of  the  ideas  of  innervation 
centred,  as  might  have  been  expected,  round  the  power  to 
arouse  movements  in  muscles,  in  fact  around  motor  innervation 
only. 

The  problem  which  so  agitated  the  physiologists  of  the 
eighteenth  century  had  not  arisen  in  Galen's  time,  namely 
whether  muscles  contracted  of  themselves,  for  instance  after  all 
their  nerves  were  cut  (doctrine  of  Inherent  Irritability),  or 
whether  all  their  irritability  was  conferred  on  them  through 
their  nerves,  that  is  from  outside,  the  so-called  doctrine  of  the 
Neurologists. 


NERVOUS  ACTIVITY  507 

For  the  sake  of  clearness  it  may  be  well  to  say  at  once  that 
muscles  have  irritability  of  their  own,  after  all  their  nerves  are 
cut,  but  that  unless  nerve-impulses  (tonic)  are  constantly 
pouring  down  upon  them,  and  unless  stimuli  to  action  are 
frequently  being  received  by  them,  they  will  waste  away  because 
there  is  nothing  to  call  forth  the  power  of  contraction  which 
they  do  possess. 

As  regards  views  on  the  working  of  the  nerves,  we  find 
nothing  of  any  consequence  from  the  death  of  Galen  (200  a.d.) 
to  the  time  of  Vesalius  (1543),  for  the  interval  of  more  than 
a  thousand  years  was  occupied  by  the  Dark  Ages  when  there 
was  hardly  any  investigation  of  living  nature,  and  very  little 
curiosity  about  the  mysteries  of  life. 

Vesalius  wrote  of  muscle  that  it  "  also  receives  branches  of 
arteries,  veins,  and  nerves,  and  by  reason  of  the  presence  of  the 
nerve  is  never  destitute  of  animal  spirits  so  long  as  the 
animal  is  sound  and  well ....  Nor  do  I  with  Plato  and 
Aristotle  (who  do  not  at  all  understand  the  nature  of 
muscle)  attribute  to  the  flesh  so  slight  a  duty  as  to  serve 
the  purpose  of  lessening  the  effects  of  heat  in  summer  and 
of  cold  in  winter.  On  the  contrary,  I  am  persuaded  that  the 
flesh  of  muscles,  which  is  different  from  everything  else  in  the 
whole  body,  is  the  chief  agent  by  the  aid  of  which  (the  nerves, 
the  messengers  of  the  animal  spirits,  not  being  wanting)  the 
muscle  becomes  thicker,  shortens  and  gathers  itself  together." 
Thus  writes  Vesalius,  who  does  not  attempt  any  explanation  : 
he  does  not  know  what  spirits  are,  or  how  they  affect  the 
muscle,  or  why  it  shortens  when  they  do  affect  it ;  he  only  knows 
that  something  in  nerves  does  influence  muscle. 

G.  A.  Borelli  of  the  University  of  Pisa  (1608-1679)  the 
mathematician  and  author  of  the  De  motu  animalium,  en- 
deavoured to  be  more  exact  in  his  conception  of  how  this 
activity  of  muscle  came  about  under  the  influence  of  nerve- 
impulses. 

Borelli  at  the  outset  fell  into  the  error  that  a  muscle 
increases  in  volume  when  it  goes  into  activity.  He  then 
attempted  to  get  some  idea  of  what  these  animal  spirits  were 
which  apparently  could  inflate  muscle,  and  he  thought  they 
must  resemble  air.  But  when  he  cut  an  active  muscle  across 
under  water  no  bubbles  of  air  or  gas  come  out  of  it ;  therefore, 
he   concluded,   the   spirits   were    not    gaseous.      Nevertheless, 


5o8  SCIENCE   PROGRESS 

something  real  descends  the  nerves  to  influence  the  muscles, 
and  so  Borelli  finally  called  this  something  the  "  succus 
nerveus  "  or  nerve-juice.  The  analogy  he  had  in  his  mind  was 
that  of  an  incompressible  fluid  in  a  flexible  tube  which  can  con- 
duct rapidly  from  one  end  to  the  other  of  it  the  disturbance 
produced  by  a  tap  or  concussion. 

The  position  of  the  acute  and  critical  Dane,  Stensen  or  Steno 
(1638-1686),  was  wholly  agnostic  :  he  wrote,  "As  the  substance 
of  this  fluid  (nerve-juice)  is  unknown  to  us,  so  is  its  movement 
undetermined."  Although  Steno  left  the  problem  of  the  nature 
of  nerve-impulses  unsolved,  yet  he  clearly  distinguished  between 
neural  activity  and  muscular  irritability. 

The  Englishman  Thomas  Willis  (1621-1675)  reverted  to 
Borelli's  position,  believing  that  spirits  leapt  from  the  nerves 
into  the  muscle-fibres  and  so  dilated  them. 

Francis  Glisson  (1 579-1677),  who  formally  introduced  the 
conception  of  irritability  into  physiology  in  1662,  contributed 
something  to  this  subject  by  showing  experimentally  that  a 
muscle  did  not  alter  in  volume  when  it  went  into  a  state  of 
activity  or  contraction.  By  muscular  "  contraction,"  therefore, 
we  do  not  mean  shrinking  in  volume  ;  the  volume  and  the 
density  of  a  muscle  remain  constant  whether  in  rest  or  in 
action. 

The  great  investigator  Stephen  Hales  (1677-1761)  made  an 
interesting  remark  about  the  nerve-impulse,  asking  "whether 
it  is  confined  in  channels  within  the  nerves  or  acts  along  their 
surfaces  like  electrical  powers."  This  is  probably  the  earliest 
suggestion  that  the  nerve-impulse  and  electricity  have  any- 
thing in  common. 

By  many  subsequent  writers,  nerve-impulses  were  considered 
identical  with  electricity.  The  discoveries  of  Galvani  seemed  to 
make  such  a  thing  probable.  Those  experiments  of  his  known 
as  "contractions  without  metals"  seemed  to  prove  that  muscles 
would  contract  when  stimulated  by  electricity  of  purely  animal 
origin.  What,  then,  more  probable  than  that  nerve-impulses 
and  animal  electricity  were  the  same  thing?  Popular  writers 
forthwith  assumed  this  to  be  the  case,  although  it  was  not 
warranted  by  any  of  Galvani's  experiments.  Galvani's  experi- 
ments really  proved  that  the  feeble  differences  of  electrical 
potential  developed  by  injuring  nerves  or,  for  instance,  by  the 
activity  of  the  heart,  were  sufficient  to  make  a  muscle  (of  the 


NERVOUS  ACTIVITY  509 

frog)  contract.  Galvani  was  right  that  there  was  such  a  thing 
as  animal  electricity,  but  he  was  wrong  in  attributing  muscular 
contraction  to  it  in  such  cases  as  those  where  there  were  contacts 
of  dissimilar  metals  ;  Volta  was  wrong  in  denying  the  existence 
of  electricity  of  animal  origin,  but  right  in  claiming  that  some 
electricity  was  of  metallic  origin  and  was  the  true  stimulus 
in  several  cases  in  which  Galvani  thought  it  to  be  of  animal 
origin. 

It  is  only  comparatively  recently  that  the  non-electrical  nature 
of  nerve-impulses  has  been  established. 

Albrecht  Haller  (1708-1777)  brought  the  subject  into  the 
domain  of  modern  thought  by  distinguishing  three  things : 
the  inherent  irritability  of  muscle  (the  vis  insita),  the  nerve- 
impulse  (vis  nervosa),  and  the  stimulus  to  the  muscle  which 
might  or  might  not  be  the  vis  nervosa.  Writing  of  the  vis 
nervosa  he  said :  "  It  comes  from  without,  and  is  carried  to  the 
muscles  from  the  brain  by  the  nerves  ;  it  is  the  power  by  which 
the  muscles  are  called  into  action."  The  vis  nervosa,  taking  the 
place  of  the  succus  nervens,  remained  in  nerve  physiology  until 
about  the  middle  of  the  nineteenth  century. 

Robert  Whytt,  of  the  University  of  Edinburgh  (1714-1766), 
though  he  furthered  the  study  of  reflex  action,  did  not  under- 
stand nerve-impulses  as  clearly  as  did  Haller  with  whom  he 
had  a  long  controversy.  Whytt  denied  to  muscles  inherent 
irritability,  and  thought  it  was  conferred  on  them  by  the  nerves ; 
he  held  that  the  stimulus  could  convey  energy — a  view  now 
rightly  regarded  as  a  neurological  heresy.  The  controversy 
lingered  on  until  John  Reid  (1809-1849)  demonstrated  that 
muscles  severed  from  their  nerves  could,  under  suitable  con- 
ditions, retain  their  contractility  for  months. 

The  suitable  conditions  were,  (a)  blood-supply  for  the  muscles 
and  (b)  their  being  constantly  "  exercised  by  Galvanism."  Reid 
in  this  way  prevented  the  muscles  showing  atrophy  from  disuse. 
He  kept  them  in  good  condition  by  artificial,  electrical  instead 
of  by  normal,  neural  stimulation ;  but  the  irritability  must  have 
been  inherent  in  them  in  order  that  the  stimuli  should  act  on 
them  at  all.  The  artificial  stimuli  could  not  have  conferred 
irritability  on  the  muscles,  neither,  then,  did  the  normal,  neural 
stimuli.  The  reception  of  nerve-impulses  (neural  stimuli)  was 
only  the  occasion  of  the  muscles  exhibiting  the  contractility 
which  they  possessed  independently. 


5io  SCIENCE  PROGRESS 

This  incomplete  historical  survey  affords  us  one  more 
instance  of  what  is  so  interesting  in  the  progress  of  science — 
the  tendency  towards  concreteness  in  conception.  We  begin 
in  Antiquity  with  "spirits"  in  the  nerves;  the  science  of  the 
Renaissance  converts  these  into  succus  nerveus,  an  incom- 
pressible fluid  such  as  was  being  investigated  by  the  physicists 
of  that  time ;  the  eighteenth  century  gives  us  the  vis  nervosa, 
which  later  is  identified  with  the  electric  current  then  being 
studied  both  in  Italy  and  in  England.  In  the  nineteenth 
century  we  have  nerve-impulses  not  only  measured  as  to  the 
velocity  of  their  travelling,  but  actually  rendered  visible  through 
their  concomitant  electrical  effects.  Nerve-impulses  are  not 
electricity,  but  they  produce  it  and  can  be  manifested  by  it. 
Thus  each  generation  must  think  and  express  itself  in  the 
language  of  its  own  time. 


DIFFERENCES   IN   ANIMAL  AND 
PLANT  LIFE. 

By   F.    CARREL. 

In  biology  no  essential  difference  is  considered  to  exist  between 
animal  and  vegetal  life.  Resemblances  of  reproduction,  cell- 
construction  and  development,  nutrition,  digestion,  and 
metabolism  are  observable  in  the  two  states.  Some  organisms 
partake  of  the  nature  of  both  kingdoms.  Some  spores  and 
leaves  of  plants  are  motile,  and  a  few  animals  possess 
characteristics  which  are  common  in  plant  life. 

For  these  reasons  the  life-principle  is  held  to  be  identical 
throughout  living  nature. 

But  when  the  word  principle  is  used  in  this  connection,  it 
is  necessary  to  be  clear  as  to  its  meaning.  What  is  termed  the 
principle  of  life  is  evidently  that  series  of  circumstances 
whereby  organised  matter  is  enabled  to  stand  for  a  space  of 
time  in  accretional  and  assimilatory  relationship  with  the 
environment.  The  circumstances  are  common  to  both  plants 
and  animals,  but  there  are  differences  in  the  way  in  which  the 
relationships  occur,  and  these  differences  are  great  enough  to 
divide  the  manifestations  of  the  principle  into  two  parts  which 
may  be  called  the  major  and  the  minor  according  as  they  are 
produced  in  animal  or  vegetal  form. 

In  the  vegetal  form,  as  is  well  known,  the  non-parasitic 
organism  derives  its  nutriment  from  the  soil l  and  air,  and  not 
directly  from  the  flora  or  the  fauna  (except  partly  in  the  case  of 
insectivorous  plants)  which  surround  it.  ? It  is  thus  dependent 
upon  the  gases  which  it  obtains  from  the  air,  and  the  salts  which 
it  derives  from  the  soil  as  well  as  upon  water.  It  possesses  no 
real  nervous  system,  no  blood  to  act  as  a  distributor  of  nutri- 
ment, but  is  indebted  to  the  influence  of  chlorophyll  and  sunlight 

1  Although  the  bacteria  in  the  soil  which  convert  nitrogen  compounds  into 
a  mmonia  are  the  means  of  supplying  ammonia  to  plants,  they  are,  of  course,  not 
themselves  plant-food.  Neither  are  the  symbiotic  fungi  of  the  roots  of  forest  trees 
directly  alimentary. 

5" 


512  SCIENCE  PROGRESS 

for  the  assimilation  of  its  principal  food,  and  although  a  few 
animals  possess  chlorophyll  the  vast  majority  do  not :  con- 
sequently chlorophyll,  is  a  distinct  feature  of  vegetal  existence. 

Again,  the  plant  is  surrounded  by  an  almost  impervious 
envelope  of  cellulose,  and  although  a  few  animals  are  said  to 
possess  this  substance,  the  great  majority  are  destitute  of  it : 
therefore  it  constitutes  a  special  vegetal  characteristic.  No 
plant  has  visual  organs,  and  though  what  are  known  as  eye- 
spots  have  been  observed  in  plants,  these  probably  serve  as 
means  whereby  greater  response  to  light  is  obtained.  It  is 
needless  to  say  that  no  plant  possesses  the  semblance  of  a 
heart. 

Luminosity  is  a  characteristic  of  plants  as  well  as  of 
animals,  but  while  in  the  former  the  effect  is  mainly  produced 
in  swarms  of  minute  organisms,  in  the  latter  it  appears  in 
higher  forms — in  worms  and  fishes. 

Electrical  conditions  differ  in  intensity  in  the  two  kingdoms. 
In  plants,  so  far  as  our  present  knowledge  goes,  the  currents 
set  up  by  metabolic  changes  or  the  movements  of  water  are 
very  faint.  No  plant  yet  discovered  exhibits  the  same 
phenomenon  as  the  electric  fishes  which  are  capable  of  impart- 
ing shocks.  Dioncea  muscipula,  which  among  the  plants  pro- 
duces the  strongest  currents,  is  precisely  one  that  partly  feeds 
on  insects.  In  animals  not  only  do  appreciable  currents  occur, 
but  in  man  there  are  rare  but  well-authenticated  cases  where 
the  whole  or  part  of  the  body  gives  rise  to  what  appear  to 
be  magnetic  forces. 

It  is  hardly  necessary  to  say  that  it  is  impossible  to  speak 
of  intelligence  in  plants  in  the  same  terms  as  of  intelligence  in 
animals.  All  that  corresponds  to  an  animal  intelligence  in 
plants  is  the  well-known  sensitiveness  to  light  which  causes 
the  plant  to  turn  its  leaves  to  the  luminous  source — undoubtedly 
a  chemical  effect— and  the  "movement"  of  petiole  and  leaves 
produced  in  certain  plants  of  which  Mimosa  pudica  is  the  best 
example  in  response  to  stimulus.  But  this  movement  is  not 
conscious  movement,  and  it  is  now  known  that  it  is  caused  by 
a  difference  of  turgidity  in  the  protoplasm  of  the  cells  brought 
about  either  under  the  influence  of  darkness  or  by  shock. 

In  the  matter  of  longevity,  the  passivity  of  plant  life  appears 
to  be  in  its  favour,  since  none  of  the  higher  animals  have  the 
longevity  of  many  trees.     Few  animals  hibernate.     The  forces 


DIFFERENCES   IN  ANIMAL  AND  PLANT  LIFE    513 

of  the  great  majority  are  expended  during  the  whole  of  their 
adult  life.  The  greater  part  of  the  higher  vegetal  life  in 
temperate  climates  can  be  said  to  rest  for  half  the  year,  and  it 
may  well  be  that  this  annual  period  of  quiescence,  during  which 
the  tree  merely  absorbs  sufficient  nutriment  to  preserve  its 
vitality,  is  one  of  the  causes  of  its  long  life. 

All  land  plants  are  anchored  to  the  soil  or  rock  on  which 
they  grow  and  have  no  free  conscious  movement.  It  is  true 
that  many  vegetal  spores  are  motile.  Those  of  Vaucheria 
rotate  with  a  screw-like  motion  on  their  longer  axis,  but  this 
movement  of  plant  spores  is  different  from  the  swimming  of 
animals  in  the  water,  and  it  may  possibly  be  accounted  for  by 
an  absence  of  symmetry  in  the  molecular  arrangement  of  the 
protoplasm  of  which  they  are  composed.  Plant  spores,  for  the 
rest,  are  only  temporarily  motile,  and  are  in  transition  to 
the  plant  state  to  which  they  essentially  belong.  If  the 
spermatozoids  of  certain  plants  resemble  those  of  animals,  the 
resemblance  is  no  cause  for  concluding  that  they  are  much 
nearer  to  animal  life  than  their  development  shows  them  to  be, 
and  if  insectivorous  plants  have  not  their  internal  cavity  fully 
developed,  they  are  none  the  less  rooted  to  the  soil,  and  derive 
a  portion  of  their  nutrition  from  it.  They  have  been  known 
to  exist  for  as  long  as  two  years  without  animal  food. 

Mobility  affords  irrefragable  proof  of  life,  but  whereas  in 
animals  it  is  almost  always  perceptible  or  easily  excitable, 
in  plants  (excepting  in  the  spore  phases  above  alluded  to)  it 
may  be  said  to  be  absent — the  leafing  of  trees  and  the  extension 
of  roots  being  in  reality  phenomena  of  growth.  If  an  animal, 
like  a  plant,  were  chained  to  one  spot  without  the  power  of 
movement  it  would  slowly  perish  although  supplied  with  food 
and  going  through  physiological  exchanges  with  the  outer 
world.  The  adult  plant,  on  the  contrar}',  thrives  in  immobility. 
On  the  part  of  plants  there  is  no  conscious  search  for  food  unless 
it  be  in  the  faintest  manner  by  the  roots.  The  plant  accepts  the 
nutriment  which  the  soil  offers  in  which  it  is  able  to  grow  as 
well  as  the  moisture  which  the  rains  provide.  If  moisture  is 
withdrawn  from  the  site  on  which  it  stands,  then  death  ensues, 
since  the  plant,  unlike  the  animal,  cannot  remove  to  more  favour- 
able pastures,  and  must  share  the  fortunes  of  its  environment. 

In  the  matter  of  nutrition  there  is  a  considerable  difference 
of  process.     In  plants  all  food  is  taken  in  a  soluble  form,  for  the 


5i4  SCIENCE  PROGRESS 

plant  has  the  power  of  forming  complex  substances  from  simple 
ones.  In  animals  the  food  has  to  be  reduced  from  the  solid  and 
complex  to  the  soluble  condition  before  it  can  be  assimilated. 
On  the  whole,  however,  the  substances  absorbed  by  the  entire 
plant  kingdom  are  the  same  as  those  absorbed  by  animals  con- 
sidered as  a  whole.  Like  the  animal,  also,  a  plant  feeds  partly 
on  nitrogenous  substances  and  constructs  proteids.  If,  how- 
ever, plants  absorb  the  same  elementary  substances  as  animals 
they  absorb  them  in  different  forms  and  combinations.  Plants 
are  fed  largely  by  means  of  the  carbon  dioxide  existing  in  the 
atmosphere,  which  they  accumulate  and  which,  though  given 
off  by  animals,  cannot  be  breathed  by  animals,  except  in  minute 
quantities,  without  producing  suffocation  owing  to  the  effect  it 
has  of  diluting  down  and  excluding  the  necessary  oxygen.  For 
although  animals  can  take  this  gas  into  their  stomachs,  they 
do  not  feed  upon  it  directly.  Notwithstanding  the  fact  that  plants 
do,  like  animals,  absorb  and  return  oxygen,  and  exhale  carbon 
dioxide  (probably  what  is  not  needed  for  the  formation  of  starch 
and  other  substances)  it  is  known  that  the  inhalation  of  an  excess 
of  C02  does  not  kill  them. 

These  differences  of  functions  in  this  important  particular 
constitute  a  gap  between  the  two  kingdoms.  What  is  rejected 
in  the  process  of  expiration  by  the  one  is  received  as  an 
alimentary  necessity  by  the  other  in  the  form  in  which  it  is 
rejected,  and  although  in  animals  carbon  is  also  an  alimentary 
necessity  it  is  received  in  the  food  of  animals  in  combination 
with  other  substances  and  is  not  directly  assimilated.  Further, 
although  plants  take  in  both  carbon  and  water  and  reject  what 
they  do  not  want  of  these  substances,  they  absorb  the  carbon  in 
the  form  of  gas  and  eject  the  surplus  water  in  the  form  of 
vapour.  Animals,  on  the  other  hand,  take  in  carbon  in  their 
food  and  reject  what  they  do  not  need  chiefly  in  the  form  of  gas, 
eliminating  surplus  water  mostly  in  a  liquid  state  and  nitrogen 
in  combination.  Neither  the  plant  nor  the  animal,  however,  can 
live  for  any  length  of  time  without  oxygen.  Both  need  this 
substance  for  the  purpose  of  combustion  and  both  eject  it.  It  is, 
as  we  know,  by  reason  of  the  differences  in  the  manner  of  nutri- 
tion that  the  balance  is  maintained  whereby  life  is  possible  on 
earth,  and  they  are  of  the  highest  significance  in  a  comparison  of 
animal  and  plant  life. 

The  methods  of  reproduction  are  not  all  similar  in  the  two 


DIFFERENCES  IN  ANIMAL  AND  PLANT  LIFE    515 

reigns.  Self-fertilisation  is  largely  to  be  found  in  plant  life,  but 
is  only  to  be  met  with  among  animals  in  some  of  the  lower 
forms.  No  doubt  the  reproductive  process  is  very  much  the 
same  in  plants  and  animals  once  fertilisation  has  taken  place. 
The  agency  of  chance,  however,  plays  a  greater  part  in  the  one 
than  in  the  other.  Since  plants  require  the  help  of  the  wind 
and  of  insects  to  convey  the  fertilising  element  and  animals  have 
no  such  need,  this  fact  constitutes  a  difference,  and  the  difference 
is  accentuated  when  the  selective  characteristic  in  animals  is 
taken  into  account.  The  seeds  of  plants  and  animals  are  not 
interchangeable.  The  pollen  of  a  plant,  it  is  needless  to  say,  will 
not  develop  in  the  ovary  of  an  animal,  and  crosses  between 
distinct  representatives  of  the  two  kingdoms  are  not  obtained, 
although  no  doubt  it  is  not  impossible  to  suppose  that  zoophytes 
originally  resulted  from  some  accidental  cellular  fusion  between 
algae  and  marine  animals.  It  is  true  that  in  the  manner  of  cell- 
division  there  is  not  a  great  apparent  difference  between  plants 
and  animals.  The  attractive  and  repulsive  forces  at  work  in  the 
cell-field  whereby  the  transformations  are  effected  which  result 
in  the  splitting  of  the  chromosomes  are  practically  the  same,  as 
far  as  staining  reveals  their  working ;  but  the  material  on  which 
they  work  must  necessarily  be  different.  If  it  were  not  so  it 
seems  evident  there  would  not  be  dissimilarity  of  growth ;  there 
would  only  be  one  category  of  living  things. 

The  tissues  differ  in  the  two  kingdoms.  If  a  section  be  cut 
from  the  stem  of  a  higher  plant  and  another  from  a  typical 
organ  of  the  body  of  a  higher  animal  and  both  be  examined 
under  the  microscope,  it  will  be  seen  at  once  that  a  considerable 
difference  of  structure  exists.  The  cells  in  the  former  are 
regular  and  separated  by  clearly  defined  cell-walls  of  definite 
thickness,  whereas  in  the  latter  they  are  irregular  and  almost 
continuous.  As  Claus  and  other  observers  have  shown,  while 
the  plant  cells  retain  their  original  and  independent  form, 
sharply  defined,  those  of  animal  tissue  suffer  numerous  changes 
at  the  cost  of  their  independence  and  are  often  scarcely  dis- 
tinguishable in  the  mass  of  protoplasmic  material,  the  reason  for 
this  being  that  the  plant  cell  is  surrounded  by  a  non-nitrogenous, 
while  the  animal  possesses  a  strongly  nitrogenous  boundary 
wall  of  a  far  less  definite  character.  The  resemblance  between 
the  two  tissues  is  greatest  in  the  lower  forms  of  life.  It  becomes 
gradually  fainter  as  organic  complexity  increases. 


516  SCIENCE  PROGRESS 

There  are  thus  dissimilarities  between  plants  and  animals 
which  taken  as  a  whole  appear  sufficient  to  constitute  an  essential 
difference  between  the  two  phases  of  existence,  a  difference  that 
must  necessarily  extend  to  the  primal  substance  of  which  they  are 
composed.  If  we  cannot  know  whether  or  not  there  was  unity 
in  the  origin  of  the  substance  we  need  not  for  that  reason  be 
deterred  from  concluding  that  there  is  duality  in  the  develop- 
ment, that  is  to  say  in  the  protoplasm  at  present  extant  in  the 
world.  The  fact  that  there  are  minute  unicellular  organisms 
which  appear  composed  of  the  same  material  and  yet  to  be  on 
the  border-line  between  the  two  categories  of  life,  need  not 
embarrass  us.  These  organisms  stop  short  at  the  rudimentary 
condition.  They  are  rough  sketches  which  are  not  elaborated 
and  are  no  obstacles  to  the  view  that  the  principle  of  life  has 
a  dual  manifestation.  Throughout  nature,  in  addition  to  well- 
defined  activities,  there  are  to  be  found  tendencies,  overlappings, 
rough  models  and  abortive  schemes  which  need  not  disturb  the 
judgment  in  the  consideration  of  the  finished  work.  It  is  the 
indeterminate  protista  that  have  mainly  given  rise  to  the  theory 
of  the  unity  of  protoplasm,  but  these  protista  go  no  farther 
than  protista  and  should  not  give  the  rule  for  the  well-defined 
divisions  that  come  after  them.  Even  at  the  origin  of  life  it 
seems  probable  that  the  two  phases  must  have  been  separate 
unless  we  are  to  suppose  that  the  one  developed  from  the  other 
at  some  later  period.  But  this  is  not  a  view  to  which  it 
seems  possible  to  attach  much  weight.  The  motile  spores  of 
algae  can  scarcely  have  passed  out  of  the  plant  phase  and  become 
the  ancestors  of  animal  existence.  The  amoeba  which  incorporate 
their  food  and  move  by  alternate  contraction  and  extension  of 
their  edges,  together  with  all  motile  feeding  micro-organisms 
not  undergoing  transformation,  might  conveniently  be  considered 
as  animal  and  the  few  thousand  temporary  motile  spores  as 
vegetal. 

Certain  authors  like  Verworn  frequently  insist  on  the  identity 
of  plant  and  animal  life.  It  does  not  seem  possible  that  there 
should  be  identity  when  there  are  so  many  differences  of  habit 
and  of  function.  There  is  some  reason  to  believe  that  the  views 
of  the  older  investigators  who  saw  an  absolute  division  between 
the  two  life  states  will  be  ultimately  found  to  be  less  erroneous 
than  they  have  been  held  to  be. 

It  is  not  easy  to  find  an  exact  parallel  for  the  dualism  which 


DIFFERENCES   IN  ANIMAL  AND  PLANT  LIFE    517 

evidently  exists  in  life,  though  of  course  dualism  is  plainly 
evident  in  nature.  The  force  of  electricity  which  divides  itself 
perceptibly  into  static  and  dynamic,  presents  a  somewhat  close 
analogy.  The  inter-relations  of  the  two  manifestations  might 
not  inconceivably  be  represented  thus  : 


•.*•.-. 


the  dotted  lines  merely  indicating  the  necessary  chemical 
connection. 

It  is  indeed  hard  to  know  why  there  should  be  so  much 
straining  after  unity  on  the  part  of  modern  inquirers.  Since 
we  are  not  even  sure  that  the  living  protoplasm  of  a  horse 
is  absolutely  the  same  as  that  of  a  snail  or  whether  there  may 
not  be  differences  in  this  respect  in  individuals  of  the  same 
species,  how  are  we  to  assume  that  the  protoplasm  of  plants 
and  animals  is  one  and  the  same  substance  ? 

It  is  the  modern  habit  of  not  discriminating  between  the 
primal  substances  of  the  two  kingdoms  that  has  been  the 
cause  of  errors  of  interpretation  in  the  application  of  Mendelian 
principles.  What  is  true  of  certain  plants  in  this  connection 
is  largely  false  of  many  animals.  In  the  absence  of  any 
means  of  analysing  living  protoplasm,  it  is  difficult  to  under- 
stand how  the  identity  of  the  primal  material  of  plants  and 
animals  can  be  positively  asserted.  If  protist  life  in  which  the 
two  principles  tend  to  merge  could  be  seen  to  develop  into 
higher  forms,  there  might  be  some  foundation  for  the  unitarian 
belief;  but  on  the  contrary  we  see,  as  before  observed,  that  it 
does  not  emerge  from  its  lowly  state,  and  what  it  did  at  its 
origin  is  a  subject  of  conjecture.  It  is  not  easy  to  concede  that 
the  plasmic  constitution  of  a  tree  whose  ancestors  since  the 
origin   of  higher   plants  have   led  a  vegetal    existence   is   the 


5i8  SCIENCE  PROGRESS 

counterpart  of  that  of  a  being  whose  ancestors  since  the  origin 
of  higher  animals  have  led  the  animal  existence.  We  can  hardly 
admit  that  without  ignoring  the  importance  of  agreement  and 
difference,  the  recognition  of  which,  according  to  logicians,  is 
the  essential  part  of  knowledge. 

There  are  now  in  nature  two  definite  phases  of  the  life 
principle,  and  at  the  side  of  these  an  elementary  indeterminate 
condition  in  which  they  merge.  In  the  latter  condition 
organisms  are  for  the  most  part  microscopic,  difficult  of  analysis, 
and  with  few  direct  connecting  links  with  higher  life. 

Evolution,  if  it  has  been  operative  in  the  world,  has  turned 
away  from  them.  The  fact  that  they  resemble  the  cellular  units 
of  which  the  higher  animals  and,  in  a  lesser  degree,  the  higher 
plants  consist,  is  no  reason  for  offering  them  as  proofs  of  unity, 
especially  as  they  themselves  are  composite  in  character. 

Although  biology  is  concerned  with  both  animal  and  vegetal 
life,  there  can  be  little  doubt  that  its  chief  interest  is  with  the 
former,  which  represents  the  human  phase.  At  all  events  there 
are  grounds  for  thinking  that  in  the  pursuit  of  this  science  the 
practice  of  attaching  equal  evidential  value  to  examples  drawn 
from  both  kingdoms  is  not  likely  to  lead  to  accurate  results. 

Undoubtedly  the  same  elementary  substances  are  operative 
in  both  divisions  to  maintain  life ;  but  the  manner  and  the  form 
in  which  they  are  employed  are  different,  and  this  difference  is 
sufficient  to  render  it  inexpedient  to  regard  the  primal  sub- 
stance of  which  plants  and  animals  consist  as  one  and  the 
same  thing. 


THE   RELATIONS   OF   SPEECH   TO 
HUMAN    PROGRESS 

By  LOUIS   ROBINSON,   M.D. 

While  we  are  of  course  quite  sure  that  human  speech  once 
had  a  beginning  it  is  very  difficult  to  guess  what  that  beginning 
was.  We  often  get  some  indication  of  evolutionary  history  by 
observing  the  development  of  the  embryo ;  but  when  we  study 
the  processes  of  vocal  expression  in  human  beings  this  method 
is  of  very  little  use,  because  the  imitative  faculty  seems  to 
account  for  most  such  manifestations  of  mental  working  in 
young  children. 

Did  speech  originally  begin  as  a  mere  development  of  those 
stereotyped  noises  which  practically  take  its  place  amongst  most 
of  the  lower  animals  ?  Or  did  our  ancestors  have  the  capacity 
which  we  observe  in  so  many  birds,  and  in  the  young  of  our 
own  species,  of  mimicking  other  sounds  by  the  voice?  In  this 
direction  we  appear  to  get  no  aid  from  the  study  of  our  nearest 
relatives  in  the  animal  world.  In  a  state  of  semi-domestication 
they  appear  ready  to  imitate  our  actions  in  some  particulars, 
but  as  far  as  I  have  been  able  to  learn  this  does  not  extend 
to  vocal  efforts  at  all.  Indeed  the  anthropoids  best  known  to 
us  appear  to  be  curiously  silent  beings  whose  vocal  activity 
is  very  much  less  than  that  of  many  creatures  far  behind  them 
in  intelligence.  One  would  think  that  creatures  with  such  large 
and  versatile  brains  as  the  chimpanzee  and  the  other  great 
apes,  must  have,  in  their  natural  state,  some  habitual  method 
of  intercommunication  corresponding  in  some  degree  to  their 
mental  development.  If  this  be  so  naturalists  have  altogether 
failed  to  discover  it. 

This  inarticulateness  certainly  is  an  argument,  when  we 
consider  what  a  vociferous  being  is  man,  against  our  near 
kinship  with  the  great  anthropoids.  It  is  said,  however,  that 
among  those  humbler  manlike  apes,  the  gibbons,  which  in  many 
ways  seem  so  far  removed  from  us,  there  is  a  far  greater  use 
34  Si9 


52o  SCIENCE  PROGRESS 

of  varied  vocal  sounds  in  the  wild  state  than  is  observable  in 
the  gorillas,  chimpanzees,  and  orangs.  Hence  possibly  the 
suggestions  which  have  been  made  by  comparative  anatomists 
that  we  must  seek  our  forefathers  rather  in  the  direction  of  the 
gibbons  than  among,  or  near,  the  greater  apes,  receive  some 
support  from  the  study  of  the  beginnings  of  articulate  speech. 

A  very  little  imagination  will  show  what  an  enormous 
advance  was  made  as  soon  as  artificial  verbal  counters  or 
tokens  were  invented  which  enabled  men  to  traffic  in  ideas 
by  means  of  the  mouth  and  the  ear.  Among  many  non- 
speaking  creatures  there  is  a  system  of  vocal  signalling  which 
meets  most  of  their  needs.  Like  ourselves  many  of  them  also 
seem  to  have  a  good  flow  of  small-talk,  which  advertises  their 
presence  and  serves  certain  social  purposes,  but  conveys  very 
little  meaning.  Animal  cries  are  for  the  most  part  mere 
stereotyped  signals  for  awaking  the  attention  of  the  senses. 
They  are  incapable  of  expansion  or  adaptation  to  give  an 
elaborate  message.  That  they  are  effective  is  almost  always 
due  to  the  exceedingly  keen  perceptions  of  most  creatures 
whose  lives  are  constantly  in  peril,  and  not  to  any  explanation 
which  they  may  convey  of  the  exact  state  of  affairs.  The  senses 
of  most  lower  animals  are  so  much  more  acute  than  ours, 
especially  as  regards  scent,  sight,  and  hearing,  that  on  receiving 
ever  so  small  a  hint  they  will  get  detailed  information  of  the 
approach  of  an  enemy  when  it  seems  to  the  human  watcher 
that  the  only  possible  way  in  which  such  information  could  be 
obtained  must  be  through  some  detailed  communication  from 
one  of  their  fellows. 

All  animals  and  birds  which  are  either  gregarious  or  are  in 
the  habit  of  associating  habitually  with  other  creatures  have 
a  very  alert  sense  of  the  behaviour  of  their  comrades  round 
about  them.  Let  one  beast  arrive  in  the  herd  panting  and 
frightened  from  near  a  neighbouring  thicket  where  an  enemy 
might  lurk,  and  all  the  rest  do  not  need  to  ask  a  single  question 
before  seeking  safety.  There  can  be  no  doubt  that  the  con- 
spicuous marking  of  many  gregarious  animals,  such  as  for 
instance  the  white  tail  in  the  deer  and  the  rabbit,  are  specially 
adapted  for  aid  in  this  method  of  self-preservation. 

Often  a  good  deal  of  system  and  intelligence  is  shown  in 
giving  and  receiving  warnings  of  this  sort.  Mr.  Stewart  White 
has  given  a  most   amusing  account  of  the   behaviour  of  the 


RELATIONS  OF  SPEECH  TO  HUMAN  PROGRESS    521 

kongoni  antelopes  on  the  East  African  plains.  These  creatures 
seem,  from  a  kind  of  natural  officiousness,  to  have  assumed 
the  position  of  guardians  over  the  zebras,  gnus,  and  other 
antelopes  which  habitually  graze  with  them.  Not  only  does  the 
kongoni  mount  himself  upon  an  anthill  to  watch  for  danger — 
this  is  common  enough — but  evidently  he  is  determined  that, 
if  any  warning  is  given  of  the  approach  of  a  beast  of  prey,  it 
should  not  be  ignored  by  the  other  beasts  which  he  has  set 
himself  to  serve.  He  will  attract  their  attention  by  various 
antics  when  he  has  a  warning  to  give,  and  will  even  start  to 
round  them  up  almost  like  a  sheep-dog  if  they  should  persist 
in  ignoring  his  advice. 

Obviously  among  forest-dwelling  animals  sight  and  scent 
must  play  a  much  less  important  part  than  in  those  who  live 
out  on  the  plains ;  hence  we  find  that  here  vocal  methods  of 
intercommunication  take  precedence  over  such  safeguards  as 
those  employed  by  the  antelopes  and  their  allies.  One  common 
habit  resorted  to  among  gregarious  creatures,  who  are  perforce 
concealed  from  one  another  while  seeking  food  among  the 
herbage,  is  that  of  making  a  continual  subdued  noise  so  that 
their  kindred  who  are  not  far  off  can  keep  in  touch  with  them. 
This  is  doubtless  the  explanation  of  the  continuous  automatic 
grunting  of  the  pig,  and  the  "small-talk"  of  many  other  birds 
and  animals.  It  is  certainly  an  interesting  fact  that  the  same 
widely  distributed  habit  reaches  to  the  lemurs — who  are  con- 
tinually grunting;  but  whether  it  goes  beyond  them  among 
the  Primates  proper  I  have  not  been  able  to  ascertain. 

Now  useful  as  this  instinctive  or  mechanical  method  shows 
itself  to  be,  it  is  easy  to  see  what  an  enormous  stride  would 
at  once  be  made  if,  when  the  alarmed  animal  warned  its  fellows, 
it  could  so  adapt  its  vocal  message  to  a  special  case  as  to  tell 
the  exact  nature  of  the  danger,  and  the  direction  from  which 
it  might  be  expected.  For  instance,  let  the  approaching  enemy 
be  either  a  tiger  or  a  leopard.  If  the  giver  of  the  warning — 
who  we  will  suppose  to  be  a  very  primitive  man  approaching 
a  band  of  his  fellows — could  clearly  indicate  that  it  was  a  tiger, 
obviously  the  climbing  of  any  stout  tree  would  suffice  to  procure 
safety  for  every  one.  But  if  the  warning  said  "  leopard  "  only 
an  immediate  flight  to  certain  selected  places  of  safety  in  the 
very  tree-tops  would  give  security. 

As  soon  as  the  ground  became  the  new  theatre   of  man's 


522  SCIENCE  PROGRESS 

operations,  and  hunting  by  co-operative  measures  took  the 
place  of  a  solitary  search  for  such  vegetable  nutriment  as 
the  forest  afforded,  it  is  plain  that  a  power  to  express  plainly 
what  part  each  hunter  was  to  play  would  be  most  essential.  It 
should  be  remembered  that  man  must  have  been  for  a  long  time 
an  amateur,  a  mere  blundering  novice,  rather  than  a  finished 
professional,  as  are  all  the  true  beasts  of  prey.  A  pack  of  dogs 
or  wolves  manage  to  co-operate  and  follow  the  hints  of  the 
leaders  with  extraordinary  success ;  but  then  they  have  been 
bred  to  the  trade  for  innumerable  generations,  and  their  instincts 
sharpened  in  this  particular  to  an  extraordinary  degree.  Early 
man  had  to  find  some  short  cut  in  attaining  the  results  which 
the  carnivora  attained  as  a  result  of  an  apprenticeship  through 
whole  epochs  of  time.  His  brain  was  amply  sufficient,  in  all 
probability,  for  the  task,  but  it  was  needful  to  find  a  method 
by  which  schemes  and  artifices  springing  from  that  already 
active  brain  could  be  communicated  with  accuracy  to  his 
partners  in  the  enterprise.  Here  I  do  not  think  that  any 
elaboration  of  those  natural  animal  noises,  which  came  to  him, 
like  his  physical  attributes,  ready-made  from  a  more  brutish 
generation,  would  have  gone  far.  But  if  he  possessed  a  very 
little  of  the  mimicking  faculty  and  a  fair  vocal  range,  the 
beginnings  of  human  speech  become  possible.  As  a  matter 
of  fact  all  languages  give  proof  of  the  large  use  made  of  sounds 
which  were  originally  the  mimicking  of  the  voices  of  nature. 

The  question  as  to  the  possible  remnants  still  existing  in 
our  elaborate  methods  of  speech  of  the  original  sounds  and 
cries  belonging  to  a  pre-human  existence  is  an  intensely 
interesting  one.  That  they  still  persist  in  some  degree  is  fairly 
obvious  in  the  form  of  certain  semi-articulate  exclamations 
common  to  practically  all  the  peoples  of  the  earth.  What 
used  to  be  known  in  our  grammar  books  as  Interjections  are 
probably  their  fossil  remnants,  more  or  less  modified  by  the 
pressure  of  superincumbent  ages.  The  wrriter  paid  a  good  deal 
of  attention  to  this  subject  some  years  ago  when  investigating 
the  ancestral  traits  in  very  young  children.  Of  course  the 
"  crowing "  and  scolding  cries  in  young  infants  are  of  this 
character,  as  also  are  many  of  the  "o"  sounds  of  later  life 
indicating  distress,  wonder,  or  surprise. 

A  complete  catalogue  of  such  vestigial  pre-human  parts  of 
speech  cannot  be   attempted    here,    but  the  subject   is   a  very 


RELATIONS  OF  SPEECH  TO  HUMAN  PROGRESS    523 

fascinating  one,  and  any  anthropologist  who  could  travel  the 
world  over  and  study  vocal  exclamations  among  various  back- 
ward peoples,  and  the  early  sounds  uttered  by  very  young 
children  before  imitative  speech  was  acquired,  might,  I  think, 
make  a  good  deal  of  it. 

It  is  evident  that  tone  has  a  great  deal  to  do  with  the  matter, 
and  it  seems  probable  that  we  have  here  a  much  more  persistent 
relic  of  the  pre-human  stage  of  vocal  communication  than  is 
found  among  actual  words.  Tone  indicating  emotion  appeals 
to  our  feelings — which  are  primeval — far  more  than  any  mere 
words,  and  is  at  once  understood,  even  by  the  lower  animals. 
Indeed  it  is  largely  made  use  of  throughout  nature.  By  it  such 
animals  as  dogs  will  give  a  greatly  increased  range  of  expres- 
sion to  a  very  limited  collection  of  vocal  sounds.  Possibly  the 
agglutinative  languages  such  as  Chinese,  where  tone  plays  such 
a  large  part,  and  the  same  identical  word  may  mean  a  dozen 
different  things  in  accordance  with  the  tone  in  which  it  is 
uttered,  bear  more  traces  of  the  original  pre-human  "  speech  " 
than  the  languages  of  the  western  world. 

One  very  obvious  advantage  of  the  beginning  of  true  speech 
is  the  power  it  immediately  gave  of  sharing  and  storing  up 
experiences.  Let  us  imagine  our  ancient  and  almost  inarticulate 
forefather  arriving  at  the  common  lair  after  an  encounter  with 
some  wild  beast  from  which  he  had  escaped  with  difficulty. 
His  scared  look  and  blood-stained  skin  provoke  cries  of  distress 
and  wonder,  and  he  is  led — probably  through  the  sympathetic 
curiosity  of  the  "  women  " — to  give  some  sort  of  a  narrative  of 
what  has  occurred.  His  words  are  very  few.  A  growl,  roar, 
or  grunt,  with  a  few  characteristic  movements,  represent  the 
specific  beast  that  attacked  him.  Probably  imitated  sounds 
mostly  stood  for  nouns  in  his  "  composition,"  and  gestures  took 
the  place  of  verbs,  while  adjectives  giving  the  degree  of  his 
pain  and  terror  would  be  conveyed  by  a  mimicry  of  his  own 
animal  cries  of  distress  uttered  at  the  time.  The  total  result, 
however,  would  be  that  the  young  pre-human  things  sitting 
on  their  heels  open-mouthed  round  about  him,  could  not  fail  to 
learn,  even  from  such  a  halting  account  of  an  adventure,  a 
great  deal  that  would  be  of  service  to  them  if  they  ever  found 
themselves  in  a  kindred  plight. 

From  what  we  know  of  all  the  lower  savages  such  narratives 
of  the  day's  adventures  are  an  almost  invariable  custom  around 


524  SCIENCE  PROGRESS 

the  camp-fire,  and  are  not  unfrequently  repeated  in  the  form 
of  a  chant  or  song.  Such  was  probably  the  first  beginning  of 
every  subsequent  educational  institution  from  the  dame  school 
to  the  Post-Graduate  Course.  The  very  fact  that  the  deeds 
of  the  day  are  still  often  chanted  in  a  kind  of  rhythm  by  the 
lower  savages  shows  the  purpose  served  by  such  narrations. 
Probably  we  may  trace  the  beginning  of  all  rhythmic  utterance 
to  a  mnemonic  system  which  prevailed  through  untold  ages 
before  the  crudest  writing  was  invented.  This  was  the  one 
way  then  possible  of  fixing  and  preserving  experience  for 
general  future  use.  For  such  a  purpose  a  fairly  good  voca- 
bulary was  needful,  though  doubtless  at  first  such  didactic 
recitations  necessitated  a  good  deal  of  acting  or  gesture.  Even 
to  this  day  there  are  said  to  be  some  low  tribes  in  South 
America  whose  spoken  language  is  so  imperfect  that  they 
cannot  converse  in  the  dark. 

If  we  learn  anything  from  the  relics  of  the  stone  ages  it  is 
that  man  dwelt  in  small  separate  communities  and  lived  by 
hunting  alone  for  a  period  a  hundred  times  as  long  as  that  of 
which  we  have  any  historical  record.  At  the  end  of  this  period, 
wonderful  to  relate,  he  appears  to  emerge  from  primeval  dark- 
ness practically  such  a  being  as  ourselves,  with  a  truly  human 
body  and  a  great  brain  capable,  if  opportunity  offered,  of 
practically  all  the  intellectual  pursuits  with  which  we  busy 
ourselves  at  the  present  day !  If  there  is  anything  in  the 
evolutionary  doctrine,  this  was  all  a  product  of  the  normal 
forces  of  his  savage  forest  life. 

Without  a  doubt  throughout  the  whole  of  this  period  com- 
petition was  keen  between  tribe  and  tribe  and  between  individual 
and  individual — and  in  every  case  it  was  a  duel  to  the  death. 
Many  a  race  like  the  Neandermen  proved  unfit,  and  went  under 
in  the  struggle.  Where  small  communities  exist  by  hunting  and 
fishing  alone  there  is  bound  to  be  eternal  friction  leading  to 
warfare  about  boundaries  and  game  rights ;  so  that  even  without 
any  desire  for  scalps  or  heads,  or  tribal  glory,  or  other  provoca- 
tives of  blood-lust  only  too  evident  to-day,  we  may  assume  that 
throughout  the  whole  enormous  period  which  preceded  history 
the  fateful  struggle  for  existence  between  man  and  man  and 
between  tribe  and  tribe  never  failed  or  relaxed. 

It  is  very  easy  to  discern  the  enormous  power  which  speech 
must  have   exercised   in   this   struggle.     Probably  through  no 


RELATIONS  OF  SPEECH  TO  HUMAN  PROGRESS    525 

other  way  were  the  brain  capacities,  already  existing,  made 
available  to  determine  which  tribe  or  individual  should  survive. 
The  first  man  able  to  persuade  others  to  act  with  him  would  at 
once  be  victor  over  a  more  brutish  rival  who  lacked  the  vocal 
wherewithal ;  while  a  tribe  which  could  take  counsel  together 
and  form  well-understood  plans  of  action  would  easily  overcome 
and  exterminate  its  competitors  whose  powers  of  speech  did  not 
suffice  for  such  an  end. 

There  can  be  no  doubt  that  throughout  the  whole  course  of 
the  development  of  human  speech  the  brain  processes  continually 
outran  all  powers  of  organic  expression.  Even  to-day,  however 
great  be  our  knowledge  of  the  contents  of  our  dictionaries,  and 
however  cunning  we  may  have  become  in  arranging  such 
material  to  the  very  best  advantage,  we  are  aware  whenever  we 
speak  or  write  that  we  are  translating  our  thoughts  into  a  very 
imperfect  medium.  Although  in  our  minds  the  conception  may 
stand  out  with  the  utmost  clearness  we  are  often  able  to  do  no 
more  than  the  artist  who  with  a  few  suggestive  lines  leads  the 
imagination  to  see  the  thing  which  he  wishes  to  bring  before  us 
and  does  not  attempt  the  task  of  representing  it  in  all  its  photo- 
graphic detail. 

How  the  brain  reached  this  wonderful  power  of  clear  internal 
expression  long  before  there  could  have  arisen  any  verbal  traffic 
in  ideas  is  at  present  a  mystery  wholly  beyond  us.  It  would 
seem  as  if  there  is  spoken  within  each  one  of  us  an  unknown 
tongue  (yet  for  self-communings  known  far  better  than  any 
spoken  language)  which  defies  full  translation  into  any  artificial 
assemblage  of  words.  The  same  thing  seems  true  of  mathe- 
matical processes  which  man  has  laboriously  endeavoured  to 
translate  into  arbitrary  symbols  based  originally,  it  would  seem, 
upon  the  number  of  his  fingers.  It  is  a  curious  thought  that  if 
the  first  pen-dactylic  thing  of  the  carboniferous  epoch  had  been 
differently  constructed,  if,  for  instance,  his  limbs  terminated  in 
a  few  more,  or  less,  developments  of  the  fin  rays  of  his  fishy 
forefathers,  our  whole  world  of  mathematics  would  have  been 
an  utterly  different  one. 

A  little  thought  will  show  that  in  every  movement  of  an 
animal,  such  for  instance  as  a  goat  leaping  from  rock  to  rock, 
certain  mathematical  and  physical  problems  are  continually 
presenting  themselves  and  being  solved  by  the  nervous  and 
muscular  mechanism.     The  exact  force  required  by  the  muscles, 


526  SCIENCE  PROGRESS 

to  enable  the  beast  to  reach  a  certain  pinnacle  is  estimated 
beforehand,  and  the  proper  orders  given  to  the  various  muscles 
which  come  into  play.  Any  mistake  or  miscalculation  as  to  the 
weight  to  be  moved,  the  direction  of  the  movement,  or  the 
momentum  to  be  reckoned  with  would  often  mean  instant  death. 
Now  we  cannot  conceive  any  such  mathematical  process  without 
certain  standard  units  of  value,  but  how  our  nervous  systems 
work  it  out  no  one  can  say.  Plainly  such  sums  are  continually 
in  progress  whenever  we  move,  and  must  be,  even  in  their 
simpler  forms,  infinitely  more  complex  than  anything  attempted 
by  our  astronomers  in  reckoning  and  foretelling  the  movements 
of  the  heavenly  bodies.  The  whole  thing,  whilst  obvious  as 
our  own  existence,  is  so  bewildering  and  mysterious  that  the 
theological  mazes  in  which  the  old  School-men  loved  to  lose 
themselves  are  mere  child's  play  in  comparison. 

Our  words  at  the  best  are  a  mere  scratch  pack  of  artificial 
noises  gathered  by  hook  and  by  crook  from  all  sorts  of  sources 
during  our  progress  from  brute  to  man.  The  inward  expres- 
sions that  they  lamely  stand  for  we  know  within  ourselves 
perfectly  well,  but  can  explain  to  others  only  a  little  better  than 
the  dumb  things  about  us.  Whether  any  other  method  will  be 
ever  found  of  tapping  the  wondrous  mental  reservoir  by  conduits 
less  continually  choked  by  our  imperfections  of  expression  one 
can  only  guess.  Thought  transference  seems  to  offer  the  most 
promise,  if  it  ever  can  be  better  understood  and  got  under  control. 
Should,  however,  such  a  consummation  ever  be  reached  it  seems 
certain  that  we  should  be  put  en  rapport  with  those  fellow- 
creatures  which  we  at  present  call  dumb  to  an  extent  which  it  is 
difficult  to  conceive.  For  the  "  unknown  tongue  "  is  probably 
one  and  the  same  throughout  nature.  Here  is  a  philosophic 
possibility  which  writers  of  stories  such  as  The  Jungle  Book 
have  often  imagined,  where  the  hero,  generally  a  child,  learns 
the  language  of  the  beasts  and  the  birds  and  is  able  to  foregather 
with  them  as  one  of  themselves. 

So  much  for  a  speculation  which  at  present  I  fear  is  as 
profitless  as  it  is  fascinating — let  us  turn  again  to  things  more 
material  and  within  our  reach. 

Human  speech,  whatever  it  was  originally  based  upon,  re- 
quires certain  bodily  machinery  to  give  it  utterance,  and  there 
are  not  wanting  many  perfectly  clear  and  tangible  evidences 
which,  from  the  writer's  point  of  view,  show  how  the  develop- 


RELATIONS  OF  SPEECH  TO  HUMAN  PROGRESS    527 

ment  of  speech  has  marched  pari  passu  with  human  progress. 
Of  the  brain  machinery  involved  in  articulate  speech  we  can 
never  know  much.  We  have  learned  that  there  is  a  kind  of 
speech  centre  (or  more  probably  a  kind  of  nervous  clearing 
house  in  the  to-and-fro  traffic  of  reflex  action)  in  the  third 
anterior  frontal  convolution  at  the  left  side  of  the  average 
brain.  The  skull  interiors  of  primitive  men  and  apes  have  been 
diligently  examined  to  see  how  they  differ  in  this  region,  and 
guesses  have  been  based  on  what  has  been  found  as  to  whether 
in  this  or  that  being  articulate  speech  was  possible.  Personally 
I  do  not  think  this  line  of  investigation  is  likely  to  lead  us  very 
far  unless  we  get  a  much  more  accurate  knowledge  of  how  the 
brain  works  and  where  are  the  actual  centres  for  the  bewildering 
multitude  of  reflexes  and  other  media  of  co-ordination  which  are 
brought  into  play  when  we  talk. 

Moreover,  it  must  be  remembered  that  speech  is  almost 
purely  artificial,  and  is  an  exceedingly  modern  invention  from 
an  evolutionary  point  of  view,  and  that  it  is  working  perforce 
through  certain  primeval  mechanical  media  which  existed  before 
it  began. 

We  are  on  much  more  solid  ground  when  we  come  to  deal 
with  man's  outward  organs  of  speech,  such  as  the  larynx  and 
the  tongue.  As  regards  the  larynx  I  do  not  think  that  any  very 
great  changes  can  be  pointed  out  in  the  way  of  structural 
elaborations  which  are  due  to  our  human  needs.  With  the  lips 
and  tongue,  however,  it  is  very  different,  especially  as  regards 
the  muscular  attachments  of  the  latter.  The  writer,  after  study- 
ing the  subject  for  a  good  many  years,  has  become  firmly 
convinced  that  a  muscle  which  appears  to  have  been  almost 
totally  ignored  by  the  anatomists,  except  as  a  mere  protruderer 
and  withdrawer  of  the  tongue,  is  one  of  the  most  important 
factors  in  articulate  speech.  This  is  the  genio-glossus,  which 
takes  its  origin  by  a  little  tendon  from  a  point  inside  our  lower 
jawbone  about  half-way  between  the  roots  of  the  incisor  teeth 
and  the  point  of  the  chin. 

This  tendon  almost  immediately  divides  into  a  number  of 
muscular  fibres  or  bundles,  which  spread  out  like  a  fan  from 
before  backwards,  and  run  up  through  the  fleshy  part  of  the 
tongue,  from  its  root  to  its  tip,  until  they  terminate  quite  near 
the  upper  surface.  Certain  of  the  lower  fibres  go  almost 
straight  back  from  the  lower  jawbone  to  the  hyoid  bone  which 


528  SCIENCE  PROGRESS 

lies  between  the  tongue  and  the  larynx,  and  for  this  reason  the 
muscle  is  called  by  many  anatomists  the  genio-hyo-glossus. 
When  the  tongue  is  at  rest  the  front  fibres  of  this  muscle  follow 
the  outline  of  its  under-part  as  seen  from  the  front,  and  hence  are 
concave  forwards.  The  central  and  posterior  fasciculi  of  this 
fan-like  muscle  are  usually  almost  straight.  The  very  fact  of 
its  spreading  from  its  point  of  origin  like  an  open  fan  shows 
that  there  is  a  widening  interval  between  the  composing  bundles 
of  muscular  tissue  as  they  pass  to  their  place  of  insertion,  which 
interval  is  filled  up  by  loose  connective  tissue  comparable  to 
that  which  lies  between  contiguous  muscles  elsewhere,  in  order 
to  allow  free  movement  between  the  neighbouring  parts.  There 
are  two  of  these  muscles  lying  side  by  side  separated  by  that 
gristly  septum  which  divides  our  tongue  into  two  almost  distinct 
halves.  One  marked  peculiarity  of  the  muscle  in  man  it  may 
be  as  well  to  describe  here.  It  gets  its  nerve  supply  from  the 
ninth  pair  of  cerebral  nerves  (the  hypo-glossal)  and  each  fasciculus 
receives  a  distinct  branch,  just  as  if  it  were  a  separate  muscle. 

Now  it  is  plain  that  whatever  the  functions  of  the  genio- 
glossus  may  be  (and  that  they  are  very  important  is  shown  by 
its  greatly  increased  size  in  man  as  compared  with  other  animals) 
it  requires  considerable  room  beneath  the  tongue  in  which  to 
exercise  those  functions.  If  we  examine  it  in  most  of  the  lower 
animals  we  find  it  is  merely  a  feeble  slip  of  flesh  lying  in  a 
position  too  cramped  to  be  of  any  great  service,  since  in  dogs, 
cats,  pigs,  and  most  other  quadrupeds  the  tongue  lies  in  almost 
immediate  contact  with  the  inner  surface  of  the  jaw. 

Now  we  come  to  some  exceedingly  curious  and  suggestive 
facts.  In  the  apes  this  muscle  begins  to  show  signs  of  having 
important  functions.  These  functions  probably  are  to  enable 
the  tongue  to  move  freely  about  the  mouth  for  the  purpose  of 
sorting  the  food  which  is  already  there  and  rejecting  such  things 
as  nutshells  which  are  of  no  use  to  the  animal.  If  we  examine 
the  lower  jawbone  of  any  ape  we  find  that  there  is  on  its  inner 
side  a  deep  pit  or  hole  specially  to  accommodate  the genio-glossus 
muscle.  Outwardly  many  of  the  apes,  and  especially  the  baboons, 
bear  a  considerable  resemblance  to  dogs,  but  no  one  could  possibly 
mistake  the  lower  jawbone  of  a  baboon  for  that  of  a  dog. 

Here  we  have  a  very  remarkable  difference  of  structure 
between  ourselves  and  all  our  nearest  relations  in  the  animal 
world.     In  man  the  genio-glossus  muscle  springs  from  the  top 


RELATIONS  OF  SPEECH  TO  HUMAN  PROGRESS    529 

of  a  bony  prominence ;  in  all  the  lower  Primates  it  comes  out  of 
a  pit.  Moreover,  in  the  apes  it  is  found  not  only  to  be  much 
smaller  than  in  man — which  is  a  sure  sign  that  it  meets  certain 
specific  human  needs — but  it  lis  also  obviously  much  less  versa- 
tile,-in  that  the  separate  fasciculi  of  the  muscle  are  bound  closely 
together.  In  several  of  the  lower  monkeys  dissected  by  the 
writer  no  trace  could  be  found  of  that  curious  splitting  of  the 
hypo-glossal  nerve  before  it  enters  the  muscle  found  in  the 
human  subject.  Further  information  on  this  detail  of  compara- 
tive anatomy  is  very  desirable. 

Why  should  the  genio-gloss us  muscle  appear  so  much  larger 
in  man  than  in  his  nearest  congeners  the  great  apes?  As  far 
as  the  other,  and  especially  the  intrinsic,  muscles  of  the  tongue 
are  concerned,  I  have  not  been  able  to  discern  very  much 
difference  between  our  tongues  and  those  of  gorillas  and  chim- 
panzees. It  cannot  be  because  we  want  to  sort  our  food  with 
our  tongue  to  a  greater  degree  than  do  the  monkeys.  We  have 
no  cheek  pouches,  which  among  many  of  the  Old  World  apes 
form  a  kind  of  banking  account,  of  which  the  tongue  plays  the 
part  of  the  cashier.  Man's  intelligence,  inventiveness,  and 
versatile  hands  free  the  tongue  from  many  of  the  discriminating 
duties  it  has  to  exercise  lower  down  the  scale. 

It  is  only  I  think  when  we  consider  the  functions  of  the 
genio-glossus  muscle  as  an  important  aid  in  articulate  speech 
that  we  are  able  to  account  for  new  facts.  The  mechanism 
of  speech  is  exceedingly  complex,  and  here  it  must  suffice  to 
discuss  the  part  of  it  which  refers  more  particularly  to  the 
question  before  us.  When  we  speak  at  the  rate  of  (let  us 
say)  150  words  a  minute  the  number  of  separate  tongue 
movements  involved  must  come  to  nearly  500.  These  move- 
ments are  following  one  another  in  ever-varying  order,  and 
most  of  them  are  composite,  i.e.  several  groups  of  muscles 
are  brought  into  action  at  practically  the  same  time  and  must 
act  in  harmony  with  one  another.  Moreover,  absolute  preci- 
sion in  all  these  movements  is  necessary,  and  any  failure  re- 
sults in  a  breakdown  of  clear  articulation.  Stammering  is 
undoubtedly  due  to  such  failures  of  co-ordination,  for  any  hitch 
in  the  exact  timing  of  the  muscle  contractions  (at  the  rate  of 
nearly  ten  per  second)  causes  a  clashing  of  the  forces  brought 
into  play  comparable  to  the  result  of  commutator  troubles  in 
internal  combustion  engines. 


530  SCIENCE  PROGRESS 

Now  it  is  obvious  that  to  achieve  such  feats  the  speech 
mechanism  of  the  tongue  must  be  simple  and  unhampered 
from  an  engineering  standpoint.  Let  us  examine  briefly  how 
the  genio-glossus  muscle  acts  when  we  articulate  certain  sounds. 
When  we  pronounce  the  letter  T  the  tip  of  the  tongue  is 
placed  against  the  front  part  of  the  palate  by  the  contraction 
of  the  upper  intrinsic  fibres  of  the  lingualis  superior.  In  this 
position  the  front  fasciculi  of  the  fan-like  genio-glossus  are 
drawn  taut,  so  that  a  simple  shortening  will  instantaneously 
draw  the  tip  of  the  tongue  down.  In  pronouncing  the  hard 
G  and  K  exactly  the  same  thing  takes  place  with  the  central 
bundles,  while  in  the  uttering  of  all  vowel  sounds  and  of 
others  where  the  exact  placing  of  the  upper  surface  of  the 
tongue  against  or  near  the  palate  is  required,  some  or  other 
of  the  bundles  of  fibres  of  the  genio-glossus  would  be  in  a 
position  to  exercise  exact  control  with  the  greatest  possible 
mechanical  advantage. 

Now  all  anatomists  are  agreed  that  the  different  parts  of 
the  human  genio-glossus  muscle  must  act  independently  of  one 
another,  because  the  posterior  fibres  appear  to  thrust  the 
tongue  out  while  the  anterior  ones  draw  it  in.  The  total 
action  is  described  in  some  books  of  anatomy  as  that  of 
lowering  the  central  part  of  the  tongue  in  the  mouth  as  in 
the  action  of  sucking,  and  it  has  been  suggested  that  this  is 
one  of  the  important  duties  performed  by  the  genio-glossus. 
The  writer,  by  a  series  of  dissections  of  the  muscles  in  young 
animals  and  infants,  soon  became  convinced  that  this  view 
could  not  be  supported,  since  in  early  life  the  genio-glossus  is 
smaller  in  proportion  to  the  rest  of  the  tongue  than  it  is 
later.  Moreover,  the  act  of  sucking  is  common  to  all  the 
mammalia,  and  certainly  man  is  not  commonly  credited  with 
any  unique  gifts  in  this  direction. 

When  the  genio-glossus  muscle  came  out  of  a  deep  pit,  as  in 
the  monkeys,  and  was  "  cabined,  cribbed,  confined  "  between  the 
lower  jaw  of  the  under-surface  of  the  tongue,  it  was  impossible 
for  the  separate  fasciculi  to  exercise  the  free  movements 
requisite  for  articulate  speech.  Hence  as  soon  as  this  new 
function  was  demanded  we  find  that  nature  discarded  the  pit 
and  designed  another  method  of  obtaining  engine-room  beneath 
the  tongue. 

This  was  effected  by  a  tilting  forwards  of  the  lower  surface 


RELATIONS  OF  SPEECH  TO  HUMAN  PROGRESS    531 

of  the  under-jaw,  and  hence  the  characteristic  chin  which  so 
distinguishes  the  human  countenance. 

By  this  radical  change  of  structure  (for  it  involved  a  complete 
departure  from  the  fixed  type  of  mandible  common  among  all 
vertebrates)  the  muscle  was  at  once  set  free  and  the  separate 
fasciculi  were  enabled  to  act  upon  the  under-surface  of  the 
tongue  without  being  hampered  by  overcrowding.  Even  now 
mechanical  perfection  was  not  quite  reached,  for  it  is  obvious 
that  if  the  fan-like  muscle  sprang  from  a  prominence  the  requisite 
independence  of  its  component  parts  would  be  facilitated  still 
more.  This  would  necessitate  still  further  room  in  what  was 
originally  the  cramped  space  between  the  tongue  and  the  inferior 
maxilla,  which  could  only  be  obtained  by  a  still  further  tilting 
forward  of  the  lower  margin  of  the  bone. 

Now  when  we  come  to  examine  by  comparative  methods  the 
jawbones  of  apes,  prehistoric  men,  primitive  savages  with  im- 
perfect articulate  speech,  and  finally  the  more  highly  developed 
and  civilised  races  the  world  over,  we  find  indubitable  evidence 
of  such  changes  having  taken  place.  The  writer  for  many  years 
has  been  collecting  specimens  or  making  plaster  casts  of  this 
part  of  the  jawbone,  and  a  mere  glance  at  the  complete  series 
demonstrates  the  facts  with  scarcely  any  further  explanation. 
First  there  is  the  usual  type  of  monkey's  jaw  with  its  deep  pit, 
sometimes  almost  penetrating  through  to  the  anterior  surface. 
Then  among  certain  anthropoids  where  a  decided  tilted  move- 
ment has  begun,  such  as  the  chimpanzee  and  certain  of  the 
gibbons,  the  pit  becomes  shallower  because  it  was  no  longer 
so  much  needed.  In  certain  prehistoric  jaws  such  as  the 
Heidelberg  and  Naulette  specimens  the  pit  is  still  there,  but 
has  become  shallower  still.  Among  practically  all  the  Bush- 
men, and  many  of  the  Central  African  Pygmies,  Andamanese 
and  Veddahs,  there  are  still  signs  of  the  pit,  but  on  the  whole 
the  surface  is  a  flat  one  with  only  slight  roughnesses  upon  it. 
In  several  interesting  specimens  of  Hottentot  jaws  the  genio- 
glossus  tubercles  are  seen  as  tiny  prominences  coming  up  from 
the  lower  side  of  the  cavity,  while  in  practically  all  the  peoples 
of  the  earth  who  have  adapted  an  elaborate  form  of  articulate 
speech  the  whole  inner  surface  of  the  jaw  from  above  down- 
wards is  slightly  convex,  and  in  the  centre  of  it  are  the  genial 
prominences  that  are  described  in  all  current  works  on  anatomy. 

An  examination  of  the  development  of  this  part  in  the  young 


532  SCIENCE   PROGRESS 

shows  that  children  possess  no  tubercles  at  all.  At  about 
fourteen  years  old  the  European  jaw  almost  exactly  resembles 
that  of  the  primitive  races,  while  between  fifteen  and  seventeen 
years  of  age  the  prominences  assume  their  fully  developed 
form. 

A  very  interesting  piece  of  evidence  comes  from  the 
examination  of  deaf  mutes.  The  writer  has  had  great  difficulties 
in  obtaining  trustworthy  information  in  this  direction.  The 
one  specimen  in  his  possession  of  a  French  deaf  mute  of  adult 
age  seems  to  show  that  when  speech  is  absent  the  tubercles 
do  not  develop  at  all,  even  in  civilised  races.  It  is  interesting, 
by  the  way,  to  note  that  the  evidence  seems  to  show  that  in 
French  and  Italian  jaws,  and  also  in  Irish,  there  is  a  fuller  and 
more  uniform  development  in  the  genial  tubercles  than  in  the 
average  specimens  found  in  our  English  museums.  Possibly 
this  may  be  because  these  peoples  speak  their  language  with  a 
more  painstaking  articulation  than  is  habitual  in  England.  The 
evidence  tends  to  show  that  the  tubercles  are  really  not  an 
inevitable  part  of  us,  but  that  they  are  in  each  case  a  sign  of 
the  activity  of  the  muscle  comparable  to  those  rough  ridges  and 
lines  found  on  the  bones  in  all  muscular  subjects.  Such  ridges 
and  roughenings  have  already  been  used  as  pieces  of  historical 
evidence,  for  Rutimeyer  in  his  researches  among  the  remains 
of  prehistoric  lake  dwellings  of  Central  Europe  professed  to  be 
able,  by  examining  the  bones,  to  differentiate  between  those  of 
wild  animals  which  had  led  an  active  existence  and  those  of 
domestic  animals  which  had  lived  a  comparatively  lazy  life  under 
man's  protection. 

Hence  we  possibly  have  in  our  genial  tubercles  an  historic 
record  of  the  extent  of  which  we  have  made  use  of  articulate 
speech.  Moreover  it  seems  to  the  writer  quite  possible  that  a 
close  and  systematic  examination  of  the  arrangement  of  the 
varying  tubercles  (for  they  do  vary  in  a  very  strange  manner) 
in  different  races  might  give  certain  information  as  to  the 
characters  of  the  languages  spoken.  We  know  how  exceedingly 
different  are  the  muscular  requirements  for  different  languages, 
since  it  is  impossible,  in  many  instances,  for  adults  to  so  work 
their  tongues  as  to  articulate  an  acquired  language  with  anything 
like  correctness. 

The  ethnological  part  of  the  writer's  collection  of  casts  of 
jaws,  although  it  contains  specimens  of  nearly  all  families  of  the 


RELATIONS  OF  SPEECH  TO  HUMAN  PROGRESS    533 

human  race,  is  nothing  like  complete  enough  for  an  inquiry  of 
this  kind  ;  but  it  should  be  easy,  considering  the  vast  amount  of 
material  now  available  in  our  museums,  for  any  one  who  has  the 
time  at  his  disposal  to  make  a  fairly  complete  comparative  collec- 
tion of  such  plaster  casts.  The  process  is  very  simple.  The 
writer's  practice  has  been  to  carry  about  him  some  pieces  of 
wax,  preferably  the  paraffin  wax  of  which  ordinary  candles  are 
made,  which  can  be  softened  at  a  comparatively  low  temperature. 
A  piece  no  bigger  than  a  walnut  suffices  for  the  purpose  of 
taking  an  impression  of  the  part  of  the  lower  jaw  involved.  The 
whole  proceeding  takes  but  a  few  moments,  and  a  permanent 
record  is  obtained  which  can  be  stored  away  and  easily  trans- 
formed into  a  plaster  cast  at  any  convenient  time. 

Incomplete  as  my  material  is  it  already  demonstrates  some 
interesting  facts  bearing  upon  the  relations  of  articulate  speech 
to  human  progress.  There  can  be  little  doubt  that  the  almost 
universal  absence  of  the  tubercles  in  the  Bushman,  and  their 
exceedingly  imperfect  development  among  other  primitive  races 
which  we  know  to  speak  languages  which,  from  our  European 
point  of  view,  are  very  imperfect,  tend  to  show  that  those  pre- 
historic peoples  which  present  a  like  peculiarity  must  have  been 
far  behind  modern  men  in  this  respect. 

There  is  a  peculiarity  about  the  Heidelberg  and  certain  other 
prehistoric  jaws  which  I  have  examined  which  it  may  be  as  well 
to  draw[attention  to  here,  as  it  has  already  given  rise  to  misunder- 
standings as  to  the  value  of  the  evidence  from  the  genial  tubercles. 
Beneath  the  prominence  for  the  attachment  for  the  genio-glossus 
muscle,  and  nearer  the  lower  rim  of  the  bone,  are  two  smaller 
prominences  which  often  take  the  form  of  slight  rough  ridges 
more  or  less  united.     These  are  found  not  only  in  man  but  in 
the  apes  and  certain  of  the  lower  animals.     They  are  the  points 
of  attachment  for  a  muscular  strip  which  has  nothing  to  do  with 
the  tongue,  called  the  genio-hyoideus,  because  it  connects  the  chin 
with  the  hyoid  bone.     In  the  Heidelberg  jaw  there  is  a  pro- 
minence representing  this  tubercle,  but  if  the  part  above  it  is 
examined   carefully   the   region   occupied  in   our  jaws   by   the 
prominent  genial  tubercles  is  represented  by  a  decided  depres- 
sion.     Most  jaws   of  the   Neanderthal   or  Spy   type   seem  to 
indicate  a  state  of  development  comparable  to  the  Bushmen  and 
Hottentots.     The  Piltdown  jaw  unfortunately  is  broken  off  at 
some  distance  from  the  symphisis,  and  hence  this  most  interest- 


534  SCIENCE  PROGRESS 

ing  relic  is  not  able  to  offer  evidence  bearing  upon  our  present 
inquiry. 

The  question  as  to  whether  the  Piltdown  "  woman  "  and  other 
very  early  men  could  talk,  which  has  been  discussed  a  good  deal 
in  the  papers,  seems  to  the  writer  of  very  little  profit.  We  have 
only  to  go  among  some  of  the  more  backward  races  of  the  earth 
to  find  that  methods  of  vocal  communication  sufficient  for  their 
needs  are  obtained  by  guttural  noises,  hisses,  grunts,  and  clicks 
which  involve  very  little  use  of  the  machinery  for  clear  articula- 
tion employed  among  ourselves.  An  examination  of  the  writer's 
collection  shows,  however,  that  wherever  one  has  a  race  which 
has  risen  far  enough  for  those  complex  social  institutions  to 
come  into  play  which  are  the  foundation  of  all  civilised  life  and 
which  involve  storytelling  and  oratory,  a  prominent  chin  has 
become  developed  and  the  genial  tubercles  are  well  shown.  It 
seems  more  than  probable  that  such  developments  from  a  state 
of  almost  inarticulate  savagery  have  gone  on  independently  in 
various  parts  of  the  world. 

It  is  scarcely  necessary  to  dwell  upon  the  influence  of 
articulate  speech  on  human  progress  after  civilised  methods  of 
life  had  once  been  adopted.  Among  all  the  peoples  of  the  world 
the  capable  speaker  has  won  prominence  and  prosperity  beyond 
his  fellows,  and  hence  would  be  one  of  the  winners  in  the  con- 
tinual struggle  which  eliminated  the  unfit.  Parliamentary 
institutions — using  the  term  in  its  broadest  sense — have  left  their 
mark  upon  the  human  countenance;  for  there  seems  good  reason 
for  supposing  that  not  only  the  lower  jaw,  but  also  the  nose  and 
the  cheek-bones  (the  hollow  chambers  of  which  have  a  great 
deal  to  do  with  the  resonance  and  quality  of  the  voice),  have 
been  shaped  amid  such  evolutionary  forces. 

A  good  deal  of  the  matter  discussed  in  the  present  article 
seems  to  be  practically  virgin  soil  to  the  anthropologist,  and  the 
present  writer  is  quite  prepared  to  find  that  many  of  his  pioneer 
efforts  to  get  at  the  truth  may  be  corrected  when  more  capable 
investigators  give  earnest  attention  to  the  subject.  It  appears 
to  him,  however,  a  line  of  research  of  great  promise,  which  may 
enable  us  to  glean  knowledge  obtainable  in  no  other  way  con- 
cerning the  dark  places  of  early  human  history. 


PLATE   I. 


8 


Cell-inclusions  found  in  Scarlet  Fever 


[535 


RECENT  ADVANCES    IN   OUR   KNOW- 
LEDGE  OF  SYPHILIS 

By  EDWARD  HALFORD  ROSS,  M.R.C.S.,  L.R.C.P. 

Of  The  John  Howard  McFadden  Researches  at  the  Lister  Institute  of  Preventive  Medicine 

The  origin  of  the  name  of  the  disease  called  syphilis  is  still  a 
matter  of  dispute,  and  the  genesis  of  the  affection  is  unknown. 
I  am  informed  by  Mr.  E.  Bennet,  Fellow  of  Hertford  College, 
Oxford,  that  there  is  no  definite  mention  of  the  disease  in  the 
classics :   and  this  is  the  reason,  probably,  for  the  belief  that 
syphilis  did  not  begin  until  the  Christian  era  had  well  advanced. 
Hippocrates,  the  Father  of  Medicine,  does  not  mention  it — even 
the  Aphorisms  contain  no  admonitions  which  certainly  apply  to 
venereal  diseases  ;  the  heroes  of  the  Iliad  and  ALneid  were  either 
blameless   or  fortunate ;   and   neither  Xenophon,  Tacitus,   nor 
even   Caesar  himself  give   it   a  definite    place   in    history.     In 
Priapeia  et  in  Diversorum  Lusus,  which  contains  the  lewd  stories 
of  the  Greek  and  Latin  authors,  including  those  of  Ovid,  syphilis 
is  not  described.     But  it  has  been  suggested  that  the  Biblical 
prophecy  "The  sins  of  the  fathers  shall  be  visited  upon  the  children 
unto  the  third  and  fourth  generation  "  refers  to  the  disease  ;  yet,  if 
this  is  the  case,  the  statement  is  inaccurate,  for,  as  is  well  known, 
syphilis  is  transmitted  from  parents  to  children  for  one  genera- 
tion  only.     The   religion  of  the   ancient   dynasties    of  Egypt 
seemed  to  centre  round  the  worship  of  generation,  as  many  of 
the  monuments  on  the  banks  of  the  Nile  show ;  yet  venereal 
disease  is  not  mentioned  in  the  papyri  nor  in  the  inscriptions 
at    Karnac,   Thebes,    Memphis,    or   Philae.      But    Dr.   Armand 
Ruffer,  C.M.G.,  and  Prof.  Elliot  Smith  have  recently  examined  a 
number    of  well-preserved   mummies   from    the   tombs   of  the 
kings,  and  the  former  has  informed  me  that  in  some  instances 
the  bones  showed  changes  which  resemble  those  that  are  known 
to  us  now  as  being  due  to  syphilis.     It  is  commonly  believed, 
however,  that  this  affection,  which  is  the  source  of  an  enormous 
premature  mortality,  produces  great  and  lasting  disability,  is  the 
frequent  cause  of  idiocy,  imbecility,  and  insanity,  a  predisposing 
35  535 


536  SCIENCE   PROGRESS 

cause  of  cancer,  and  the  fount  of  great  expense  to  the  State,  did 
not  exist  until  the  fifteenth  century.  And,  until  recently,  it  has 
been  generally  accepted  that  it  is  confined  to  human  beings  and 
that  it  originated  among  the  soldiers  engaged  in  the  later 
crusades  or  among  those  who  accompanied  Columbus  and 
Cortez  in  the  conquest  of  America.  Yet,  probably,  the  reason 
why  it  is  not  mentioned  in  the  classics  is  the  same  reason  why 
it  is  not  mentioned  in  our  public  literature  to-day ;  syphilis  is 
not  described  in  our  public  print  even  now  in  the  twentieth 
century,  and  as  recently  as  July  1913  many  of  the  London  news- 
papers declined  to  publish  a  calmly  and  carefully  worded  appeal 
from  the  medical  profession  for  an  inquiry  into  the  ravages  of 
the  affection  owing,  apparently,  to  an  inborn  dread  of  the  public 
use  of  the  word  "  syphilis." 

The  discovery  by  Pasteur  of  the  capabilities  of  bacteria  to 
cause  disease  and  that  of  Ray  Lankester  of  the  powers  of  the 
parasitic  blood  protozoa  in  producting  distinct  maladies,  induced 
a  young  research  scholar  named  Klebs  in  1897  (Archiv.  /. 
exper.  Path.)  to  suggest  that  syphilis  was  due  to  a  micro- 
organism which  he  supposed  is  transmitted  from  one  person  to 
another  and  from  parents  to  children.  But  very  little  fruitful 
work  was  done  on  the  subject  for  twenty  years,  owing  to  the 
insufficient  methods  of  microscopy  then  in  vogue,  the  results  of 
research  being  ineffectual.  In  the  meantime,  Koch  had  dis- 
covered the  bacillus  of  tuberculosis,  Eberth  and  Gaffky  that  of 
typhoid  fever,  Kitasato  that  of  plague  and  Hansen  that  of 
leprosy;  and  Laveran  had  found  the  protozoal  blood-parasite 
of  malaria,  Lewis  that  of  trypanosomiasis — discoveries  which 
have  led  to  the  most  important  of  practical  results,  namely,  the 
prevention  of  disease.  But,  until  the  last  decade,  nothing  certain 
or  definite  was  known  of  the  actual  causative  agent  of  syphilis ; 
for,  although  much  work  was  done  and  there  were  many 
conjectures  and  theories,  nothing  was  proven  and  no  hypothesis 
would  bear  critical  examination.  The  methods  of  microscope 
examination  were  inefficient  and  faulty. 

Early  in  the  nineties,  Louis  Jenner  invented  his  method  of 
staining  dead  cells  by  a  compound  stain,  and  eight  years  later 
this  method  was  improved  upon  by  Romanowsky,  whose 
method  was  again  modified  by  Nocht,  Leishman,  and  finally 
Giemsa.  Then,  in  the  years  1900-1,  Losdorfer  (Wien  Klin.  Woch. 
1900)  and  Stassano  (Acad,  des  Sciences,  1901)  described  peculiar 


SYPHILIS  537 

microscopic  bodies  in  the  humours  of  persons  suffering  from 
secondary  syphilis.  The  objects  they  described  were  very 
indefinite,  and  their  observations  were  not  regarded  very 
seriously.  It  is  very  difficult,  even  in  the  light  of  our  present 
knowledge,  to  be  certain  that  the  objects  they  pictured  are 
connected  with  those  which  we  now  know  to  be  the  cause  of 
the  disease. 

It  was  not  until  the  year  1905,  when  Giemsa's  stain  was  better 
handled,  that  something  definite  appeared.  A  young  German 
doctor  named  Siegel  had  begun  work  on  the  subject.  He  seems 
to  have  realised  that  there  is  some  resemblance  between  syphilis 
and  the  affections  known  as  the  zymotic  diseases — small-pox, 
vaccinia,  scarlet  fever,  measles,  etc. — inasmuch  as  they  are  all 
accompanied  by  skin-rashes,  though  they  differ  widely  in  many 
other  respects.  He  remembered  that  Guanieri  had,  in  1892, 
described  peculiar  bodies  in  the  cells  taken  from  the  vesicles  in 
cases  of  small-pox  and  in  pustules  caused  by  vaccination— cell- 
inclusions,  Guanieri  called  them,  or  cytoryctes.  Siegel  examined 
syphilitics  and  found  cell-inclusions  somewhat  resembling  those 
described  by  Guanieri  in  small-pox  and  in  vaccine  lymph  ;  they 
were  found  in  cells  taken  from  syphilitic  ulcers.  Siegel  called 
these  bodies  Cytoryctes  lues,  to  distinguish  them  from  Cytoryctes 


f 


Some  phases  of  Cytoryctes  lues  (Siegel). 

variolm  and  vaccinias  of  Guanieri.  Yet  his  method  consisted 
largely  of  staining  dead  cells,  and  he  had  no  means  of  improving 
his  observations  or  of  proving  his  interpretations.  But,  among 
the  others,  he  described  a  form  of  his  Cytoryctes,  a  many-tailed, 
free  body  which  we  know  now  as  an  appearance  often  taken  by 
the  parasite  of  syphilis,  though  he  was  unable  to  bring  forward 
any  evidence  that  the  objects  he  saw  were  parasites  at  all. 

Siegel's  statements  (Abhandl.  d.  h.  preuss.  Akad.  Wiss.  1905) 
gave  rise  to  considerable  discussion  at  the  time.  Most  scientists 
were  opposed.  Many  said  that  the  Cytoryctes  were  artefacts 
made  by  faulty  technique,  and  that  they  were  due  to  degenera- 


S38  SCIENCE  PROGRESS 

tion  of  the  cells  which  contained  them — a  time-honoured  criticism 
against  many  cell-observations  and  often  as  unreasonable  as  the 
observations  themselves.  A  few  thought  that  "  there  might  be 
something  in  it,"  while  the  majority  awaited  further  develop- 
ments. 

Then  the  German  Government  sent  a  rising  Berlin  University 
Professor  named  Schaudinn  to  report  on  Siegel's  work,  which 
probably  was  but  an  elaboration  of  that  done  by  Losdorfer  and 
Stassano  some  years  before  and  obviously  based  on  the  teaching 
of  Guanieri.  Schaudinn  discredited  Siegel's  claim.  But  a  few 
weeks  later  he  published  the  existence,  as  a  new  factor,  of 
minute,  tailed,  snake-like  bodies  found  in  syphilis  ;  and  these  he 
claimed  as  his  own  discovery  and  stated  were  the  cause  of 
syphilis  (Arb.  aus  d.  kaiser.  Gesund,  1905  and  Deut.  med.  IVoch. 
1905).  These  objects,  which,  owing  to  their  stained  appearance 
and  their  capabilities   of  motion,  he  named  Spirochceta  pallida, 


Spirochceta  pallida  as  seen  sometimes  by  dark-ground  illumination. 

very  closely  resembled  part  of  those  which  Siegel  had  alread}' 
described.  But  Schaudinn  ignored  Siegel's  protests  and 
explained  the  spirochete  as  his  own  observation  to  Metchnikoff 
and  Roux — the  co-directors  of  the  Pasteur  Institute  at  Paris — 
who  inoculated  syphilis  into  apes  and  found  the  same  snake-like 
bodies  in  the  disease  produced.  Thus  it  was  Metchnikoff  and 
Roux  who  brought  forward  proof,  and  the  world  accepted 
Schaudinn's  Spirochceta  pallida  as  the  causative  agent  of  syphilis; 
Siegel  was  forgotten. 

For  four  years,  the  scientific  and  medical  profession  examined 
the  Spirochceta  pallida  in  all  its  aspects.  Its  length  was  described, 
its  breadth,  its  curls,  its  twists,  the  way  in  which  it  multiplies 
was  pictured  ;  and  when  facts  were  not  forthcoming  the  imagina- 
tion was  drawn  upon.  Writers  wrote  about  long  forms,  short 
forms,  fat  forms,  thin  forms,  round  forms,  oblong  forms,  oval 
forms,  dividing  forms,  double  forms.  It  was  described  vividly 
how  the  spirochsete,  with  venomous  malice  aforethought,  pricks 
cells  with  its  tail  and  destroys  them,  how  a  single  spirochaete 
could  enter  the  human  brain,  remain  quiescent  there  for  twenty 


LYMPHOCYTOZOON  COBAYsE 
DESCRIPTION   OF   PLATE    II. 

Fig.  i. — A  small  extracellular  amoeboid  form  of  the  parasite  as  it  occurs  in  the 
peritoneal  fluid  of  guinea-pigs.  Fig.  io  shows  these  to  be  amoeboid  as  seen  in  the  blood 
on  the  jelly  :  in  fig.  1 1  one  is  stained  by  Giemsa's  method. 

Figs.  2,  3. — The  early  included  parasite  found  in  the  lymphocytes  of  the  blood  of 
guinea-pigs — the  dot  stage. 

Development  of  the  Female  and  Asexual  Elements 

Fig.  4. — Two  parasites  included  within  a  lymphocyte  of  the  peritoneal  fluid  of  a 
guinea-pig— the  chromatin  dots  have  multiplied  ;  one  shows  the  next  phase  to  fig.  3  in  the 
formation  of  the  female  element,  the  other  is  an  example  of  the  rod  formation  (male 
element). 

Figs.  5,  6,  7,  8.  —Other  examples  of  the  intracellular  development  of  the  asexual  and 
female  elements.     The  parasites  grow  and  their  chromatin  dots  increase  in  numbers. 

Fig.  9.  — The  newly  freed  parasite  as  it  sometimes  appears  in  the  peritoneal  fluid  of 
guinea-pigs ;  occasionally  it  breaks  away  from  its  host-cell  before  its  development  is 
complete. 

Figs.  10,  11. — The  completely  developed  female  and  asexual  elements.  One  is  shown 
with  a  pseudopodium  protruded,  as  frequently  seen  by  the  jelly  method.  The  only 
apparent  means  of  distinguishing  between  the  female  and  asexual  elements  is  to  observe  the 
acts  of  conjugation. 

Development  of  the  Male  Element 

Fig.  12. —The  chromatin  dot  in  fig.  3  becomes  elongated  into  a  dumb-bell,  which 
splits  longitudinally  into  two  rods. 

Figs.  13,  14.  15. — -The  chromatin  rods  multiply  by. simple  fission  within  the  parasite 
inclusion  in  the  lymphocytes  of  the  blood  of  guinea-pigs. 

Fig.  16. — Each  rod  develops  a  flagellum  at  each  end.  This  figure  shows  one  rod  as 
seen  within  the  cell-inclusion  highly  magnified 

Fig.  17. — -A  parasite  in  a  lymphocyte  of  the  blood  of  guinea-pigs.  It  contains  many 
rods  and  many  fligella  as  seen  stained  by  the  jelly  method. 

Fig.  18. —  From  a  central  point  in  each  rod  longitudinal  splitting  takes  place  both 
ways  along  the  length  of  the  rod  anil  each  flagellum,  until  there  is  a  maze  of  threads 
radiating  from  the  central  point  wound  up  within  the  cell-inclusion. 

Fig.  19.— A  parasitic  inclusion  prematurely  burst  on  the  jelly.  The  chromatin  of  the 
microgametes  (spirochetes)  is  stained  ;  the  central  chromatin  hub  and  the  spokes  are 
developed  from  the  rod. 

Fig.  20. — The  completely  develope  I  gametes  as  seen  just  bef>re  the  cell-inclusion 
(the  microgametocyte)  bursts  ;  the  nucleus  of  the  lymphocyte  is  squeezed  into  a  corner  of 
the  cell.      From  the  blood  of  a  guinea-pig. 

Fig.  21. — A  maze  of  gametes  just  born  from  a  burst  parasite,  but  caught  in  a  clot  and 
stained  by  the  jelly  method. 

Fig.  22. — The  male  elemsnts,  the  microgametes  (spirochetes  \ 

Development  of  the  Conjugated  Forms 

Fig.  23. — Conjugation  between  male  and  female  elements. 

Fig.  24. — The  chromatin  of  the  conjugated  form  divides  and  subdivides,  and  the 
parasite  becomes  included  within  a  lymphocyte  of  the  blood,  peritoneal  flaid,  etc.,  of  the 
guinea-pig. 

Figs.  25,  26,  27,  28. — The  growth  of  the  conjugated  parasite  in  the  cytoplasm  of  the 
lymphocyte;  this  phase  consists  of  a  sphere  containing  a  great  number  of  small  chromatin 
masses. 

Figs.  29,  30,  31,  32. — Budding.  Each  conjugated  parasite  gives  off  buds.  Each  bud 
contains  chromatin,  and  on  the  jelly  the  process  of  their  separation  can  be  watched. 
Sometimes,  as  in  fig.  32,  the  conjugated  form  buds  within  the  host-cell  and  the  buds  can  then 
be  seen  embedded  in  the  cytoplasm.  Each  bud  resembles  the  free  amoeboid  forms  as 
shown  in  fig.  1.  Thus  the  cycles  of  schizogony  and  sporogony  are  complete.  All  figures 
are  as  seen  on  the  jellies  except  fig.  11,  which  is  stained  by  Giemsa's  method.  The  pictures 
are  by  Miss  E.  Barry,  E.   A.  Ross,  and  J.  W.  Cropper. 

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Parasites  in  Guinea-pig  Syphilis 


53SJ 


SYPHILIS  539 

years,  and  then  suddenly  wake  up  from  its  long  lethargy  and 
cause  general  paralysis  of  the  insane  or  locomotor  ataxy ;  and 
the  way  mercury  affected  it  and  the  way  mercury  did  not  affect 
it  was  pictured  in  consummate  detail.  There  were  discussions 
as  to  its  true  nature,  and  authorities  became  heated  over  the 
question  of  its  bacterial  or  protozoal  origin,  forgetting  that  these 
adjectives  are  of  human  manufacture  only.  Then  there  were 
described  with  varying  elaboration  curious  developmental, 
involution,  or  degeneration  phases  of  the  spirochete  ;  but  there 
was  not  a  tittle  of  proof  brought  forward  in  support  of  the 
statements  made.  Too  often  these  writers  seemed  to  forget  that 
it  is  insufficient  to  describe  "  bodies"  in  the  lesions  of  a  disease 
in  any  one  species  of  animal  for  them  to  be  accepted  as  the 
causative  agent  of  that  disease.  More  evidence  is  required  than 
the  mere  finding  of  "  bodies."  It  is  indeed  doubtful  whether 
Schaudinn's  discovery  would  have  been  accepted  had  not 
Metchnikoff  and  Roux  reproduced  the  disease  in  chimpanzees  by 
inoculation  and  again  found  the  same  spirochaetes  in  the  lesions 
produced.  Moreover,  it  is  not  sufficient  to  see  different  shaped 
bodies  in  a  disease  in  any  one  species  of  animal  and  to  weave 
them  into  a  life-cycle.  Inoculation  experiments  are  always 
required.     In  other  words,  proof  is  necessary. 

Since  1905,  however,  medical  men  have  regarded  Spirochcsta 
(or  Treponema)  pallida  as  the  causative  agent  of  syphilis.  When 
this  organism  is  found  in  sores  the  disease  is  at  once  labelled 
syphilis  ;  and  Schaudinn  has  the  credit,  at  present,  of  having 
discovered  the  nature  of  the  disease.  Yet,  lately,  there  have 
been  some  authorities  in  science  who  have  considered  that  the 
spirochaete  is  not  in  itself  sufficient  to  account  for  the  manifold 
manifestations  of  this  malady.  They  remember  that  syphilis 
may  remain  latent  in  the  human  body  for  long  periods  and  may 
then  reappear  in  some  part,  which  before  was  apparently  un- 
affected, years  after  the  disease  is  seemingly  cured.  Such 
thinkers — a  small  minority — have  found  it  difficult  to  accept  that 
this  organism  unchanged  can  alone  cause  the  varied  sores  of 
syphilis,  the  multiform  rashes  which  "  imitate  all  and  originate 
none  "  ;  can  remain  quiet  in  the  body  and  can  then  cause  the 
conditions  known  as  the  parasyphilitic  affections — general 
paralysis  and  locomotor  ataxy — years  after  the  disease  first 
appeared  ;  and  they  find  it  hard  to  believe  that  the  Spirochata 
pallida   can   by   itself  cause   primary,   secondary,   and   tertiary 


540  SCIENCE   PROGRESS 

syphilis,  idiocy,  insanity,  and  hereditary  locomotor  ataxy.  But, 
except  for  a  few  malcontents,  the  world  has  accepted  that  the 
nature  of  the  disease  is  known  in  its  entirety. 

In  the  meanwhile,  the  means  of  diagnosis  and  the  methods 
of  treatment  of  the  disease  have  greatly  improved.  The  Wasser- 
man  reaction  has  proved  to  be  a  means  whereby  the  existence 
of  the  disease  can  be  recognised  even  after  all  symptoms  have 
disappeared,  and  when  an  immunity  has  been  established.  But 
it  is  not  operative  until  the  disease  has  progressed,  though  its 
value  in  later  diagnosis  and  in  controlling  treatment  is  vast. 
The  treatment  of  the  disease,  too,  has  made  a  great  advance  in 
Ehrlich's  discovery  of  salvarsan,  or  "  606."  It  is  the  outcome  of 
an  evolution  of  knowledge.  The  history  of  the  treatment  of 
syphilis  would  fill  the  pages  of  a  profoundly  interesting  book. 
It  is  not  known  who  first  noted  the  curative  powers  of  mercury, 
arsenic,  antimony,  and  their  compounds  in  this  disease  ;  nor  is 
it  known  when  the  discovery  was  made.  It  ranks  with  that  of 
the  effects  of  quinine  and  arsenic  on  the  parasite  of  malaria. 
Both  discoveries  were  blind  shots  in  the  dark  which  hit  the 
mark.  For  more  than  a  century,  compounds  of  mercury  have 
been  administered  in  syphilis  and  the  disease  cured  by  them. 
In  the  Early  Victorian  age  it  became  fashionable  to  give  it  com- 
monly to  children  as  a  cure  for  all  trivial  ailments,  and  mercurial 
stomatitis  and  teeth  disorders  were  frequent.  But  until  the  last 
few  years  the  slow  method  of  treating  syphilis  by  mercury,  a 
treatment  extending  over  a  period  of  two  years  or  more  in 
every  case,  followed  by  a  year's  dosing  with  iodide  of  potassium, 
was  the  rule.  Then  the  known  effects  of  arsenic  on  the  pro- 
tozoal parasite  of  sleeping  sickness  led  to  pharmacological 
research  and  the  production  of  a  complex  compound  of  that 
metal  was  the  result ;  it  was  named  Atoxyl,  and  was  tried  on 
animals  infected  with  trypanosomes  (the  cause  of  sleeping  sick- 
ness) ;  for  it  was  realised  that  a  drug  more  rapid  in  its  action 
was  required  for  those  affections  which  kill  more  rapidly  than 
syphilis.  Step  by  step  these  compounds  were  improved  upon 
until  at  last  Ehrlich  found  his  salvarsan.  Perhaps  its  effects 
are  not  all  that  were  claimed  at  first,  but  it  signals  the  beginning 
of  a  great  advance  in  the  treatment  of  syphilis,  for  it  rapidly 
curtails  the  more  obvious  symptoms  of  the  disease,  and,  when 
combined  with  mercury,  leads  to  a  quicker  cure  than  was 
formerly  possible. 


SYPHILIS  541 

But  prevention  is  better  than  cure.  So  far  as  medicine  is 
concerned,  the  opening  of  the  twentieth  century  will  be  recorded 
in  history  probably  as  the  beginning  of  the  era  of  disease-pre- 
vention. It  was  Edward  Jenner  who  pointed  out  the  path  a 
hundred  years  ago.  He  found  that  the  inoculation  of  cow-pox 
into  human  beings  modified  and  prevented  small-pox ;  and  to- 
day small-pox  does  not  exist  in  civilised  communities.  This  is 
advance  indeed,  and  the  beginning  of  the  present  century  has 
given  us  the  application  of  his  teaching — malaria,  yellow  fever, 
tuberculosis,  Malta  fever,  dengue,  are  being  prevented  wholesale, 
and  prevention  is  replacing  the  old  retail  method  of  individual 
cures.  We  are  learning  to  regard  disease  as  an  armed  enemy 
standing  on  the  threshold  of  an  unarmed  homestead ;  we  must 
find  a  means  of  shutting  the  door  in  his  face  rather  than  try  to 
attack  him  when  inside.  It  was  with  this  object  in  view  that  in 
July  191 1  Mr.  McFadden  instituted  researches  at  the  Lister 
Institute  of  Preventive  Medicine  into  the  causation  and  preven- 
tion of  certain  of  the  zymotic  diseases ;  he  suggested  those 
which  produce  the  greatest  death-rate — measles  and  scarlet 
fever.  His  object  was  to  find  out  a  means  of  preventing  them. 
These  researches  have  resulted  in  advancing  our  knowledge, 
not  only  of  scarlet  fever  and  measles,  but  also  of  syphilis. 

A  start  was  made  with  the  examination  of  the  blood  of  cases 
of  acute  scarlet  fever  and  measles.  For  this  the  newly  invented 
"jelly  method"  of  staining  living  cells  was  employed.  The 
jelly  method  is  a  considerable  improvement  on  the  older  tech- 
niques by  which  dead  cells  distorted  by  alcohol  and  other 
fixatives  were  examined  ;  it  is  better  than  the  dark-ground 
illumination,  which  only  shows  the  shadows  of  living  things.  It 
consists  in  placing  living  cells  on  a  soft  jelly  where  they  can  be 
watched  under  the  microscope  ;  they  are  spread  out  gently, 
remain  alive  for  hours,  and  their  component  parts  are  made  to 
stain  slowly.  Thus  their  action  can  be  observed  and  the  pre- 
sence of  parasites  detected  better  than  by  any  other  known 
method.  The  jelly  method  showed  peculiar  inclusions  within 
the  large  mononuclear  cells  of  the  blood  in  all  cases  of  scarlet 
fever  and  measles  during  the  acute  febrile  stages  of  those 
diseases. 

But,  as  it  was  found  difficult  to  ascertain  the  exact  nature  of 
these  intracellular  bodies  (the  same  difficulty  which  Siegel  had 
to  face)  which  stain  in  a  peculiar  manner  by  the  jelly  method,  a 


542  SCIENCE  PROGRESS 

halt  was  made  until  some  similar  but  simpler  cell-inclusions  had 
been  examined,  and  observations  were  made  on  the  blood  of  the 
lower  animals;  for  the  finding  of  bodies  is  not  sufficient  in  itself 
to  label  them  as  the  parasitic  causes  of  disease,  even  when  their 
appearance  is  constant. 

The  discovery  of  somewhat  similar  cell-inclusions  in  the 
mononuclear  cells  of  the  blood  of  guinea-pigs,  and  which  are 
known  as  Kurloff-Demel  bodies,  led  to  the  establishment  of  a 
new  genus  of  parasite  called  the  Lymphocytozoa,  because  these 
bodies  were  found  (by  the  jelly  method)  to  develop  into 
spirochaetes.  These  intracellular  parasites  stain  in  a  very  re- 
markable manner  on  the  jellies,  and  the  development  of  their 
nuclear  material,  even  while  within  the  substance  of  the  cells, 
can  be  observed  very  accurately.  It  was  found  that  they  pass 
through  a  certain,  constant,  definite  development  into  spiro- 
chaetes while  within  the  cells.  It  was  also  found  that  the 
affected  guinea-pigs  frequently  show  signs  of  disease  which  are 
similar  to  those  seen  in  syphilis  ;  and  the  spirochaetes  were  dis- 
covered free  in  the  blood  of  these  animals.  The  parasitic  nature 
of  the  cell-inclusions  therefore  was  evident. 

Then  J.  W.  Cropper  of  the  McFadden  Researches  discovered 
similar  cell-inclusions  in  the  male  generative  organs  of  earth- 
worms ;  these  also  were  shown  by  him  to  develop  into  spiro- 
chaetes and  to  pass  through  the  same  phases  of  development  as 
the  guinea-pig  parasite.  This  train  of  information  was  so 
suggestive  that  a  thorough  examination  of  cases  of  human 
syphilis  was  undertaken  to  see  if  similar  intracellular  parasites 
were  present  in  that  disease  also,  which  resulted  in  the  finding 
of  them  in  every  one  of  five  hundred  cases  of  syphilis  examined. 
They  have  been  seen  in  all  the  lesions  of  the  disease — those  of 
the  primary,  secondary,  and  tertiary  stages ;  and  they  have  been 
demonstrated  by  the  jelly  method  to  develop  into  spirochaetes 
which  resemble  the  Spirochceta  pallida.  But  it  was  noted  also 
that  there  were  other  forms  of  the  parasite,  namely,  free  amoeboid 
bodies,  and  various  other  phases  were  recognised  in  the  circu- 
lating blood  of  syphilitics  ;  this  led  to  the  suggestion  that  the 
spirochaetes  really  represented  gametes,  or  male  elements  of  a 
large  and  complex  parasite.  Phases  which  may  well  be  the 
female  elements  have  been  seen  in  both  guinea-pigs  and  in 
human  beings,  and  conjugation  has  been  observed  in  the 
former ;  but  this  aspect  of  the  question  remains  for  the  present 


L  YMPHOC  YTOZO ON  PA  LLID  UM 
DESCRIPTION   OF    PLATE    III. 

Fig.     i. — Free   amoeboid    forms    found   by   the    jelly    method    of   chancres,    glands, 
condylomata,  and  sores  of  syphilitics.      Each  contains  chromatin. 

Fig.  2.  -A  small  amceba  included  within  the  cytoplasm  of  a  lymphocyte. 

Fig.  3. — The  chromatin  of  the  ced-inclusion  becomes  surrounded  by  a  definite  cell- 
wall,  and  divides  into  three  circular  masses,  each  containing  a  ceniral  dot. 

FlG.  4.— Two  parasites  included  in  a  lymphocyte.  One  possesses  three  deeply 
staining  dots,  the  other  a  dot  and  a  rod  ;  the  former  is  an  early  stage  of  the  development 
of  the  female  and  asexual  form,  the  latter  is  an  early  phase  of  the  development  of  the 
male  form. 

Development  of  the  Female  and  Asexual  Elements 

Fig.  5. — This  cell,  from  a  chancre,  contains  two  female  and  asexual  parasites.  In 
one  the  chromatin  is  in  the  act  of  division  ;  in  the  other  it  has  already  divided. 

Fig.  6. — A  parasite  found  in  a  lymphocyte  of  the  blood  squeezed  from  a  syphilitic 
papule.  Within  the  parasite  there  are  eleven  separate  chromatin  masses,  one  of  which  is  in 
the  act  of  dividing.  Each  chromatin  mass  contains  a  de  ply  staining  dot — a  feature  of 
these  parasites. 

Figs.  7,  8,  9,  10 — Free  amoeboid  forms  derived  from  the  bursting  of  forms  like 
fig.  6.  On  the  jelly  they  are  highly  amoeboid.  Each  contains  a  nucleus  and  granules, 
some  contain  vacuoles,  and  all  hive  a  central  intranuclear  dot.  These  represent,  according 
to  their  close  analogy  to  Lymphocytozoon  cobayut,  the  female  and  asexual  forms. 

Development  of  the  Male  Elements 

Fig.  11. — The  chromatin  rod  and  dot  in  fig.  4.  have  multiplied  within  the  cell- 
inclusion  into  three  rods.     The  cell  is  irom  a  chancre. 

Fig.  12. — A  mononuclear  cell  from  a  chancre  containing  three  parasites.  Two  show 
the  formation  of  the  microgametes  within  the  microgametocyte  ;  the  third  is  an  early  phase. 
The  pink-coloured  sausage-shaped  body  is  probably  a  diffusi-in  vacuole;  it  contains  no 
structure. 

FlG.  13. — An  epithelial  cell  from  a  syphilitic  gland.  It  contains  a  large  parasite  in 
which  there  is  a  bunch  of  microgametes.  These  are  radiating  from  a  common  centre  or 
hub  like  the  spokes  of  a  wheel.  Some  of  these  gametes  have  the  same  optical  appearance 
as  Spirochata  pallida,  but  only  the  chromatin  of  the  spirochetes  is  stained.  From  the 
analogy  of  Lymphocytozoon  cobayce  the  hub  is  formed  from  the  rod  pictured  in  fig.  11. 

Fig.  14. — A  large  mononuclear  cell  found  in  the  finger-blood  of  a  case  of  secondary 
(macular)  syphilis.  It  shows  the  mode  of  the  formation  of  the  microgametes  within  the 
microgametocyte.  The  lymphocyte  was  alive  on  the  jelly,  as  is  demonstrated  by  its 
pseudopodia,  and  the  parasitic  inclusion  burst  while  under  examination  ;  the  spirochetes 
were  ejected  into  the  plasma.     Note  how  the  nucleus  of  the  host  cell  is  squeezed. 

Development  of  the  Conjugatkd  Forms 

Figs.  15,  16,  17,  18. — Copper-coloured  holies  found  in  the  chancres,  glands,  sores,  and 
peripheral  blood  of  syphilitics.  They  contain  numbers  of  deeply  staining  granules.  By 
analogy  with  Lymphocylozoon  cobayie  ihese  represent  the  conjugated  fwrms,  but  they  are 
generally  found  free  and  not  included  within  the  cells. 

Fig.  19.  —  A  cell-inclusion,  stained  by  Leishman's  stain,  from  a  syphilitic  gland 
found  by  Colonel  Jennings.  The  chromatin  granules  are  very  similar  to  those  of  the 
conjugated  forms  of  Lymphocytozoon  cohayec.  If,  as  is  the  case  of  the  guinea-pig  parasite, 
these  give  rise  to  buds  containing  the  granules,  the  cycles  of  schizogony  and  sporogony 
of  this  parasite  are  complete.  With  the  exception  of  fig.  19,  all  the  drawings  are  as  seen  on 
the  jellies.     They  are  by  E.  H.  Ross. 

The  parasites  seen  in  rabbit  syphilis  {Lymphocytozoon  lepofis)  are  smaller  than  the 
above,  otherwise  they  are  identical. 

542] 


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The  Parasites  in  Human  and  Rabbit  Syphilis 


S42l 


SYPHILIS  543 

unsettled,  though  the  evidence  in  favour  of  the  theory  is  very 
strong. 

Yet,  although  the  spirochaetes  seen  developing  within  the 
cells  of  syphilitics  very  closely  resembled  the  Spirochceta  pallida 
in  appearance,  and  although  there  was  the  evidence  of  the 
disease  in  guinea-pigs,  and  the  corollary  of  the  similar  intra- 
cellular parasite  developing  into  spirochaetes  in  these  animals 
also,  proof  by  inoculation  was  wanting ;  for  it  is  impossible  to 
experiment  with  syphilis  in  human  beings,  and  the  manifesta- 
tions of  the  guinea-pig  disease  are  inconveniently  confined  to 
the  blood-cells  and  internal  organs.  Nevertheless,  these  inocu- 
lation experiments  soon  became  possible,  and  in  a  very  curious 
way.  I  was  told  by  Lord  Kimberley  that  the  wild  rabbits  and 
hares  in  the  county  of  Norfolk  were  suffering  from  a  disease 
named  by  gamekeepers  "  rabbit-pox."  Very  soon  afterwards, 
a  paragraph  appeared  in  Country  Life  (October  6,  191 2)  in  which 
it  was  stated  that  the  wild  rabbits  on  the  east  coast  of  Scotland 
were  infected  with  a  peculiar  disease.  Some  of  these  infected 
animals  were  obtained  and  the  disease  examined  at  the  Lister 
Institute.  It  was  soon  found  by  me  that  these  rabbits  had  a 
naturally  contracted  affection  similar  to  human  syphilis,  though 
probably  not  identical  with  it.  And  examination  showed  the 
presence  of  similar  but  smaller  intracellular  parasites  like  those 
which  had  been  already  seen  in  cases  of  human  syphilis,  in  the 
guinea-pig  disease,  and  in  earthworms.  These  animals  were 
watched,  and  the  progress  of  this  affection  observed.  It  coin- 
cided with  the  progress  of  syphilis  in  human  beings,  except  that 
it  is  more  severe  under  the  natural  conditions  of  rabbit-life,  and 
the  animals  frequently  die  when  uncared  for.  Some  were  treated 
with  salvarsan  and  mercury,  and  improvement  began  at  once ; 
several  infected  animals  have  now  been  apparently  cured. 

But,  as  stated  before,  it  was  necessary  to  prove  the  deduction 
that  these  intracellular  parasites  are  the  real  causative  agents  of 
these  diseases.  Therefore,  a  young  healthy  rabbit  was  inocu- 
lated from  a  diseased  rabbit.  The  inoculation  was  accomplished 
by  scratching  with  the  point  of  a  contaminated  sewing-needle, 
as  a  calf-lymph  vaccination  is  performed.  In  twenty-five  days 
a  small  sore  appeared  at  the  seat  of  inoculation,  and  the  disease 
began.  In  this  sore  the  same  intracellular  parasites  were 
found,  and,  finally,  free  swimming  spirochaetes,  which  appear 
to  be  exactly  similar  to  the  Spirochccta  pallida,  were  seen  by 


544  SCIENCE  PROGRESS 

Bayon,  Noguchi,  Martin,  the  writer,  and  others  (see  the  British 
Medical  Journal,  November  I,  191 3,  p.  1 1 59)- 

Therefore,  the  train  of  evidence  that  these  intracellular 
parasites  which  develop  into  spirochetes  are  the  causative 
agents  of  syphilis  is  complete,  because  similar  parasites  which 
develop  into  spirochsetes  have  been  found  in  several  species  of 
animals,  accompanied  by  diseases  in  those  animals  which  re- 
semble syphilis ;  and  inoculation  experiments  based  on  this 
belief  have  been  successful,  for  the  disease  and  the  same 
parasites  have  been  reproduced  artificially ;  spirochsetes  are 
found  always  accompanying  the  intracellular  parasites  in  all 
the  lesions  in  all  the  animals.  But  this  belief  has  received  still 
further  proof.  Noguchi  has  succeeded  in  cultivating  several  of 
the  spirochetes,  including  Spirochceta  pallida,  in  test-tubes.  But 
he  has  found  that  the  latter  will  only  grow  in  the  presence  of 
living  tissue  cells.  Some  of  these  cultures  were  obtained  (they 
were  subcultures  taken  from  those  sent  from  the  Rockefeller 
Institute,  New  York),  and  in  the  living  cells  the  intracellular 
parasites  were  found.  Noguchi  himself  noticed  some  peculiar 
bodies  which  are  very  similar  to  those  seen  by  the  jelly  method 
in  human,  guinea-pig,  and  rabbit  syphilis.  These  he  described 
at  a  recent  meeting  of  the  Royal  Society  of  Medicine. 

The  discovery  of  syphilis — or  a  disease  closely  allied  to  it — 
in  the  lower  animals  heralds  a  most  important  advance  in  our 
knowledge  of„the  disease.  It  throws  a  new  light  on  its  origin. 
For,  although  the  parasites  of  human,  rabbit,  and  guinea-pig 
syphilis  differ  slightly  from  each  other,  the  difference  is  no 
greater  than  the  difference  between  the  animals  which  contain 
them.  From  their  appearance  one  is  struck  by  the  probability 
that  they  were  derived  from  the  same  original  source.  The 
old  idea  which  placed  the  origin  of  syphilis  in  Divine  wrath  is 
no  longer  tenable,  for  surely  rabbits  have  incurred  no  such 
displeasure  ;  nor  did  rabbits  or  guinea-pigs  play  any  part  in 
the  Crusades,  nor  in  the  conquest  of  America.  It  seems  more 
likely  that  syphilis  has  existed  in  the  human  race  as  long  as 
that  race  has  existed,  and  even  longer ;  and  that  perhaps  it  has 
taken  its  place  in  the  evolution  of  the  animal  kingdom,  and  with 
the  evolution  of  the  species  has  come  the  evolution  of  their 
parasites  and  their  diseases.  The  reason  why  the  ancients  did 
not  mention  syphilis  is  probably  the  reason  why  we  do  not 
mention  it  now — we  are  ashamed  of  it, 


SYPHILIS  545 

The  finding  of  syphilis  in  rabbits  has  opened  up  a  new  road 
for  research  which  should  lead  to  the  prevention  of  the  disease. 
It  may  be  possible  to  apply  Edward  Jenner's  discovery  of  the 
means  of  preventing  small-pox  to  syphilis.  He  inoculated 
human  beings  with  cow-pox,  and  this  modified  and  prevented 
small-pox.  The  parasites  of  small-pox,  cow-pox,  human  and 
animal  syphilis,  seem  to  belong  to  the  same  family ;  and  there- 
fore it  appears  reasonable  to  suppose  that  rabbit  syphilis,  if 
vaccinated  into  human  beings,  would  modify  or  prevent  the 
human  disease.  If  this  proves  to  be  the  case,  there  will  be  an 
enormous  saving  of  health  and  money.  In  our  naval  and 
military  forces  alone  an  immense  boon  would  be  gained,  and 
in  the  civil  population  idiocy  and  insanity,  with  the  expenses 
they  incur,  would  be  enormously  reduced.  There  will  be  diffi- 
culties to  encounter,  but  with  patience  and  careful  experiment 
these  should  be  overcome  in  time.  Experiments  to  this  end 
with  monkeys  are  being  instituted  forthwith. 

Such  a  method  of  preventing  syphilis  appears  to  hold  out 
the  best  hope  of  solving  the  problem.  Up  to  the  present  time 
other  methods  have  proved  most  unsatisfactory. 

Attempts  to  prevent  disease  by  treatment  are  not  generally 
efficacious  either.  There  is  the  example  of  the  old  attempts  to 
prevent  malaria  by  enforcing  the  administration  of  quinine. 
At  Ismailia,  in  the  old  days  before  mosquito  reduction,  the 
fever  continued  notwithstanding  the  quinine.  People  will  not 
do  it.  So  in  the  British  Navy  and  in  the  Army  attempts  to 
enforce  the  hospital  treatment  of  syphilitics  have  not  been 
entirely  successful.  I  can  remember  how  the  infected  sailors 
were  sent  to  hospital  and  treated  until  their  obvious  symptoms 
disappeared.  Then  they  returned  to  their  ships,  and,  although 
under  nominal  observation,  they  continued  to  spread  the  disease 
as  soon  as  they  were  given  general  leave,  for  syphilis  remains 
infective  for  two  years  or  more.  The  Army  during  the  South 
African  War  was  the  same. 

Without  doubt  some  form  of  protective  vaccine  such  as  I 
have  suggested  holds  out  the  best  hope  of  prevention.  But 
there  is  one  important  factor  which  must  be  grasped.  So  long 
as  the  name  of  syphilis  is  hidden  in  a  halo  of  hush,  so  long  as 
all  research  into  the  problem  is  fettered  by  the  shackles  of 
silence,  the  greater  will  the  difficulties  be.  If  only  the  public 
generally  could  be  taught  the  facts  of  the  disease,  if  old-world 


546  SCIENCE   PROGRESS 

prejudices  could  be  laid  on  one  side,  and  if  every  one  could 
realise  that  this  disease  is  curable  easily  if  taken  at  once,  an 
enormous  step  would  be  gained.  Let  us  preach  prevention, 
or,  failing  this,  cure.  All  important  health-work  requires 
publicity  for  its  accomplishment.  Freedom  of  publicity  and 
the  right  of  sincere  discussion  are  essential.  It  is  time  the 
public  grasped  the  true  nature  of  this  disease.  Silence  can  do 
no  good.  We  cannot  prevent  mosquitoes  and  abolish  malaria 
and  yellow  fever  by  remaining  silent.  So  it  is  with  syphilis. 
Surely  every  one  should  be  taught  the  dangers  of  life  ?  At 
present  each  man  tells  himself  that  it  will  not  be  his  lot  until 
he  is  stricken — then  he  is  dumb.  Let  us  bring  the  whole  matter 
to  light,  place  our  cards  upon  the  table  face  uppermost,  and 
examine  critically  our  position.  And,  finally,  let  us  remember 
the  last  words  of  Pasteur,  "  II  faut  travailler." 


WHY  ARE   PEOPLE   SO   CONFINED, 
WHEN    FREEDOM   CAN    BE   ENJOYED 

By   MR.  T.   BROWNBRIDGE 

North  Shields 

Why  are  people  so  confined  when  freedom  can  be  had  in  the 
open  where  the  air  is  pure.  The  lifes  of  men  women  and 
children  are  over  estimated  by  the  sulphur  and  smoke  that  sur- 
rounds them.  The  Universe  and  the  Natures  of  the  Universe 
desire  every  individual  life  to  attend  to  the  Natures  that  are  in 
want  of  Maturity  of  their  Natures,  as  every  life  is  deffecient  of 
that  purity  Nature  offers.  Every  life  of  the  human,  animal,  and 
vegetable  kind  is  suffering  for  for  the  want  of  purity  where 
sulphurs  and  smoke  are.  The  world  desires  purity  as  a  right  in 
all  its  spheres.  The  extensions  of  waves  of  sulphur  and  smoke 
are  wavering  the  Atmospheres  lifes  of  molecules,  bacteria,  and 
germs,  and  these  Atoms  are  our  lifes  and  to  injure  them  hinders 
our  own  progression.  To  fill  a  life  with  contaminated  atoms  is 
to  destroy  any  life  of  the  above  mentioned  spheres. 

Are  we  not  getting  further  further  away  from  purity  ? 
While  the  earth  is  raidiatively  acting  the  worlds  life  there  is 
shooting  out  volumes  of  poisonous  sulphurs  and  smoke  out  and 
up  into  the  Atmospheres  from  furnaces  and  chimneys  to  destroy 
lifes  of  the  invisible  to  the  naked  eye.     Also  visible  lifes. 

Mankind  is  truly  making  a  trap  for  himself  to  shorten  the 
worlds  life,  and  there  is  increasing  sulphur  and  smoke  as  lifes 
increase,  to  be  insulted  by  being  enforced  into  unnatural  works. 
And  more  increasing  of  Armaments  causes  more  lifes  to  suffer, 
who  work  at  the  Shot  and  Shell.  Also  the  manufacturing  of 
the  Guns,  and  Ships,  and  Armants. 

The  solidarity  of  these  plans  of  works,  of  all  sources,  as 
shell,  steel  shipping  causes  Vibrative  of  the  Atmospheres  to  be 
attracted  from  their  naturalism  as  forces  of  Units  acting  for  the 
good  of  lifes  of  our  World,  of  all  sources. 

1  We  make  no  apology  for  printing  this  utterance  of  a  voice  from  the  smoke, — 
Editor. 

547 


543  SCIENCE  PROGRESS 

The  lifes  of  these  Atomic  Units  are  despondent  through  the 
advantage  took  of  their  Natures,  and  are  rebellious  against 
the  different  lifes  in  which  they  represent  as  natural  forces  of 
Nature.  Although  invisible  they  must  be  allowed  to  act  their 
part  as  pure  as  the  Atmospheres  allows,  but  it  is  the  duty  of 
Mankind  to  protect  the  Atmospheres  in  every  environment. 

No  Sulphur,  and  no  Smoke  should  never  have  been  allowed 
to  contaminate  the  Atmospheres. 

But  1  think  I  hear  the  words  how  are  we  to  do  this.  The 
actions  are  now  done  and  cannot  be  undone. 

But  1  maintain  that  the  working  condittions  of  our  World 
can  and  must  be  altered  if  we  are  to  prolong  our  Worlds  life. 

The  vacant  earth  will  supply  our  needs,  the  beautiful  surface 
of  the  earth  so  neglected  whilst  we  are  poisoning  the  Atmo- 
sphers  and  shortening  our  lifes  of  the  World  we  live  by.  We 
are  suffering  by  our  units,  suffering  by  the  Sulphur,  and 
Smoke. 

And  our  attributes  as  Attorns  are  to  be  higher  up  in  the 
Altitudes  instead  of  being  nearer  to  us.  They  are  the  life  of 
our  being  and  are  our  existence  but  we  are  robbed  from  them 
doing  us  good. 

And  without  we  learn  how  to  exist  Naturally  in  pure  Atmo- 
pheres  we  shall  be  ignorant  and  defective,  and  deffecient  of 
pure  life. 

Time  is  arriving  when  man  will  suggest  but  will  not  fullfill 
or  even  try  to  help  to  prolong  his  World.  But  it  must  come  to 
pass  that  there  is  a  responsibility  rests  on  the  consciousness  of 
some-one.  But  do  we  not  hold  a  responseability  individually, 
since  the  Area  of  the  World  up  to  its  present  position  ? 

Our  World's  position  and  its  life  are  not  so  rife  with  stability 
and  endurance  as  of  yore.  The  connections  of  our  World  is 
weakening  through  our  weaknesses,  and  without  support  of 
every  individual  life  of  the  World,  the  weakining  must  increase 
as  the  supports  of  our  World,  because  of  the  weakening  Connec- 
tions of  the  Worlds  life.  And,  stratus,  that  is  in  communica- 
tion with  our  .Our  Atoms  and  all  lifes  between  the  Stratus  and 
the  Atoms  must  either  increase  purity  or  impurity,  but  impurity 
is  on  the  increase  through  the  Contamination  of  the  invisible 
agents  of  the  Atmosphere  and  Stratus. 

We  must  allow  our  agencies  to  be  pure,  as  it  is  of  the  great- 
est necessity  to  be  pure  ourselfs.     In  the  vicinities  of  Sulphur 


WHY  ARE  PEOPLE  SO  CONFINED  549 

and  Smoke  it  is  most  disstracting  to  these  lifes  of  minute  forces, 
of  our  lifes.  These  germs  are  most  welcome  in  their  Atomic 
state  but  they  must  be  encouraged  purity  by  keeping  the 
Atmospheres  pure. 

Although  we  have  to  take  them  as  they  come  through  diff- 
culties  of  weaknesses  through  the  poisonous  sulphur  and  smoke 
that  so  corrupts  the  pure  Atmospheres. 

We  are  to  live  with,  and  by  them,  as  we  inhale  them  into 
our  bodies,  they  are  our  lifes,  and  we  are  theirs  and  we  must 
encourage  them  to  purity,  if  not  something  is  wrong  with  us  as 
they  through  the  impurity  of  the  Atmospheres,  and  we  must  en- 
courage a  life  for  a  life,  as  the  lifes  of  the  invisible  forces  so 
encourages  us,  more  so  when  kept  in  a  pure  state. 

We  are  brought  to  great  difficulties  and  even  stagnation  of 
the  body  in  environments  where  impure  Atmospheres  exists, 
and  the  suffering  ones  in  lead  works  and  other  works  where- 
ever  ores  Stratus  are  extracted  from  their  beds  of  devolopment 
and  experiments  upon  and  manufactured  by  the  workers  in  the 
different  particular  spheres  of  life  where  the  different  units  of 
Atoms  are  put  asunder  through  the  ignorance  of  man. 

Then  the  Atoms  of  his  life  cannot  get  near  him,  and  his 
life  is  awaiting  his  attributes,  Atoms  are  waiting  to  be  near 
their  parent. 

These  Atoms  have  derived  their  existence  by  inalations  by 
breathing  in  from  pure  Atmospheres  and  passed  out  of  the 
'  being '  by  passages  after  they  have  passed  through  the  system, 
1  they  our  Atoms  '  Naturally  and  instinctively  claim  us  as  their 
parent  and  we  have  to  give  our  lifes  for  them,  as  we  increase 
them  as  long  as  we  breathe  either  by  impure  auras,  or  pure 
auras. 

Now  the  time  is  with  us  to  speak  out  and  express  our  selfs 
as  we  know  the  health  is  not  with  our  world  and  its  lifes.  The 
lifes  of  all  are  so  weakened  by  the  weakening  of  the  World,  by 
taking  away  the  stratus,  the  structures  and  relaxing  the  invisible 
powers  that  upholds  them.  These  invisible  forces  and  units  of 
the  stratus  are  in  conjunction  with  our  units.  '  Atoms '  and 
these  correspondencies  are  by  their  Natures,  Natural  Conscious 
lifes  of  their  own  spheres,  assisting  our  lifes  to  maturity. 

Now  how  are  we  to  act  to  Justify  these  minute  lifes,  of  our 
lifes,  to  be  constantly  with  us.  for  all  lifes,  for  all  time.  They 
must  have  pure  Atmospheres  to  give  us  the  pure  Quickening 


S5o  SCIENCE  PROGRESS 

help.  The  lifes  of  these  Conscious  minute  forces  are  wronged 
by  the  wronging  of  the  stratus  and  the  Atmospheres  and  to 
make  life  complete,  the  stratus  the  life  and  body,  of  the  bowels 
of  our  World  must  be  left  to  mature,  as  the  Worlds  individual 
lifes  and  and  their  Attributes. 

The  surface  of  the  earth  will  accept  all  life,  to  labour  and 
live,  to  mature  by  having  plenty  of  fruits  of  the  earth  and 
Natural  labour,  to  help  our  Attributes  to  help  us. 


THE   PROTECTION   OF  SCIENCE   BY 

PATENT 

By  An  Authority  on  Patent  Law 

In  The  Times  of  February  13,  191 3,  a  letter  from  Sir  Ronald 
Ross  appeared  concerning  the  Patents  Act  and  Medical 
Research.  In  the  course  of  the  letter  it  was  shown  how  the 
present  Patents  Act  excluded  certain  scientific  workers  from  the 
benefit  of  the  protection  which  is  given  to  other  inventors,  and 
the  opinion  was  expressed  that  the  time  had  arrived  for  reform 
in  the  British  method  of  dealing  with  science. 

The  subject  of  The  Times  letter  deserves  more  than  the 
passing  reference  to  which  the  columns  of  a  great  newspaper 
necessarily  confined  it,  while  its  importance  to  workers  in  the 
higher  branches  of  science  is  so  great  that  detailed  examination 
of  the  complaint  against  existing  conditions  is  desirable,  while 
a  discussion  of  the  means  which  may  be  proposed  for  removing 
the  disabilities  under  which  scientists  labour  may  assist  in  the 
removal  of  the  disabilities  in  question. 

There  is  scarcely  a  department  of  life  but  has  been  influenced 
by  the  researches  of  the  scientist,  researches  which  do  not 
necessarily  result  in  manufactures.  His  operations  touch  us  on 
every  hand,  while  his  labour  is  fraught  with  momentous  con- 
sequences. In  the  realm  of  electricity,  such  matters  as  telegraphy, 
telephony,  and  the  transmission  of  power  are  directly  referable 
to  his  discoveries,  while  in  the  chemical  industry,  the  develop- 
ment of  dyes,  the  production  of  alkali,  and  the  formation  of 
sulphuric  acid  are  immediately  attributable  to  his  foresight. 
And  what  is  to  be  said  concerning  discoveries  of  bacteria 
whereby  soil  may  be  enriched,  and  concerning  astronomical 
investigation,  which  enables  navigation  to  be  more  safely 
pursued  ?  What  of  the  discoveries  of  Pasteur  and  his  followers 
as  bearing  on  the  preservation  of  food  ?  And  what  of  medical 
investigations  which  resulted  in  vaccination  and  those  which, 
eliminating  yellow  fever  and  other  ailments,  have  secured  the 
cutting  of  the  Panama  Canal  ? 

Yet  however  highly  meritorious  or  beneficial  to  the  State  or 
36  55' 


552  SCIENCE  PROGRESS 

to  the  world  at  large  the  practical  applications  of  the  scientist's 
researches  may  be,  unless  a  manufacture  which  exhibits  inven- 
tive ingenuity  over  and  above  the  merit  of  his  discovery  is  the 
result,  no  patent  protection  is  obtainable  by  him.  On  the 
ground  of  fairness  alone  some  variation  of  the  existing  method 
of  distributing  recompense  is  urgently  called  for;  and  when  in 
addition  it  is  remembered  that  the  chief  justification  of  an 
elaborate  patent  system  is  the  stimulating  effect  of  the  hope 
of  the  reward  held  out  to  those  who  create  an  enterprise  bene- 
ficial to  the  community,  the  demand  for  extension  of  the  patent 
law  appears  irresistible. 

At  the  present  time,  if  an  invention  or  discovery  is  to  receive 
the  protection  of  a  patent,  it  must  result  in  what  is  styled  in  the 
Statute  of  Monopolies  of  the  time  of  James  I.  a  "new  manufac- 
ture." The  invention  must  be  new  and  it  must  also  be  a 
manufacture.  The  meaning  of  each  of  these  terms  has  many 
times  been  expounded  by  the  judiciary,  so  that  their  application 
is  clear,  and  as  The  Times  correspondent  has  pointed  out,  newness 
or  novelty  of  an  invention  has  been  interpreted  so  as  to 
preclude,  in  particular  instances,  highly  deserving  discoverers 
from  the  benefits  of  the  patent  law.  If  by  any  chance  an  inventor 
has  published  his  invention  before  the  date  upon  which  he  has 
applied  for  a  patent,  no  patent  which  could  withstand  the  ordeal 
of  the  Courts  is  obtainable.  Thus,  in  the  case  referred  to  in 
The  Times  letter,  Mr.  X.  had  for  years  been  engaged  on  certain 
research  work,  with  the  result  that  pernicious  samples  of  a 
natural  product  could  be  distinguished  from  those  which  were 
innocuous  and  the  illness  of  the  workman  engaged  in  converting 
the  natural  product  into  serviceable  form  consequently  mini- 
mised. Since,  however,  the  research  had  extended  over  so  long 
a  period,  Mr.  X.,  before  the  date  of  his  application  for  a  patent, 
had  published  his  discovery,  "  an  absolutely  necessary  procedure 
for  genuine  scientific  work."  Consequently,  on  the  ground  of 
want  of  newness  in  his  invention,  this  research-worker  was 
denied  the  reward  of  patent  protection.  The  details  of  his 
practical  method  of  eliminating  the  deleterious  element  of  the 
natural  product  might  have  been  patented,  provided  those 
details  were  new  and  exhibited  what  has  been  termed  inventive 
ingenuity ;  but  in  such  a  case,  as  Sir  Ronald  Ross  points  out,  a 
rule  of  medical  ethics  would  forbid.  As  a  result,  although 
workmen,  employers,  and   the   State  would    probably    derive 


THE  PROTECTION   OF  SCIENCE   BY   PATENT    553 

great  advantage,  the  originator  of  the  discovery  could  obtain  no 
such  benefit  as  he  might  hope  to  have  obtained  from  the  granting 
of  a  patent. 

Apart  from  the  particular  example,  there  is  a  further  reason 
why  a  discoverer,  however  meritorious  he  may  be,  cannot  become 
a  patentee.  The  Statute  of  Monopolies,  as  already  alluded  to, 
restricts  protection  to  a  "  manufacture,"  and  although  the  word 
manufacture  has  gradually  been  moulded  by  the  judges  so  as  to 
include  manufacturing  operations,  processes  and  articles,  it  has 
not  been  held  to  cover  the  very  highly  ingenious,  original,  and 
meritorious  operations  of  the  purely  scientific  man  which  do 
not  result  in  a  manufacture.  When  we  approach  the  matter 
more  closely  with  the  view  to  ascertaining  what  practical  steps 
ought  to  be  taken  to  remedy  the  grievances  in  question,  we  find 
two  distinct  issues  in  connection  with  the  present  system  of 
granting  patent  protection,  viz. : 

(1)  Whether  the  originator  of  a  scientific  discovery  by  com- 
municating the  results  of  his  research  to  a  learned  society  ought 
thereby  to  lose  the  right  to  apply  subsequently  for  a  patent ;  and 

(2)  WThether  the  protection  awarded  to  new  manufactures 
ought  not  to  be  extended  to  other  applications  of  scientific 
discoveries  which  may  be  of  utility  to  the  public. 

The  question  touched  upon  in  The  Times  whether  medical 
etiquette  should  so  far  be  relaxed  as  to  permit  a  practitioner  to 
obtain  a  patent  concerns  the  medical  profession  alone  and  falls 
outside  the  present  inquiry. 

(1)  Communications  to  Learned  Societies. — As  previously  stated, 
if  an  individual  before  the  date  of  applying  for  a  patent  com- 
municates his  invention  to  the  public  or  to  any  section  of  it,  the 
invention  is  henceforth  devoid  of  the  element  of  novelty  which 
the  law  demands  in  an  invention  which  is  to  be  protected.  It 
is  immaterial  whether  the  invention  is  published  piece-meal  or 
at  a  stroke.  Provided  a  divulgence  takes  place  in  any  way 
whatever,  the  invention  is  no  longer  new  in  the  eye  of  patent 
law  and,  with  one  or  two  exceptions  which  need  not  be  entered 
upon,  is  incapable  of  being  protected  by  a  patent  grant.  The 
scientific  investigator  who  reads  a  paper  or  series  of  papers 
before  a  learned  society,  for  instance,  and  gives  an  account  of 
his  discoveries  will  be  precluded  from  receiving  a  patent  which 
is  unexceptionable.  Not  only  is  this  the  case,  but  he  is  even 
denied  the  exclusive  enjoyment  of  obvious  novel  applications  of 


554  SCIENCE  PROGRESS 

his  discovery.  These  are  open  to  others  equally  with  himself, 
while  as  regards  those  applications  which  are  not  obvious,  an}'- 
one  who  can  exercise  inventive  ingenuity  may  obtain  protection 
for  the  exhibition  of  this  ingenuity  whether  he  is  or  is  not  the 
originator  of  the  basic  idea.  No  matter  what  may  be  the  amount 
of  invention  present,  whether  large  or  small,  which  may  be 
involved  in  furthering  the  original  discovery,  provided  invention 
can  be  proved,  the  originator  of  the  foundation  discovery  is 
refused  the  right  to  use  the  subsequent  invention  without 
permission  of  its  patentee,  and  this  although  the  originator 
could  easily  have  produced  the  invention  had  he  known  what 
was  required. 

Inroad  into  the  sacrosanct  requirement  of  novelty  in  a 
patented  invention  has  already  been  effected ;  for  the  Patents 
Act,  which  now  governs  the  grantings  of  patents,  stipulates  that 
a  patent  shall  not  be  rendered  invalid  by  a  prior  publication  which 
is  made  without  the  consent  of  the  inventor,  if  the  inventor 
applies  quickly  for  a  patent  after  learning  of  the  unauthorised 
publication. 

Here  then  nefarious  publication  is  not  prejudicial  to  the 
inventor;  but  what  is  to  be  said  of  commendable  publication  by 
the  inventor  himself  before  he  decides  to  exclude  the  public  from 
the  free  use  of  the  result  of  his  researches  ?  Surely,  the  right  to 
receive  protection  after  an  invention  has  been  published  by  one 
who  is  not  the  inventor  ought  to  be  conceded  to  him  who,  being 
the  inventor,  meritoriously  publishes  his  invention.  It  can  be 
no  great  step  to  accord  him  a  similar  measure  of  redress  when, 
say,  before  the  Royal  Society,  he  himself  has  promulgated  the 
result  of  his  researches  before  having  lodged  his  application  for 
a  patent.  But  the  principle  of  granting  protection  as  against 
publication  by  the  inventor,  as  opposed  to  the  publication  by  a 
stranger,  has  already  been  affirmed.  By  a  series  of  Patents  Acts 
spread  over  the  last  sixty  years,  the  publication  of  an  inven- 
tion at  selected  exhibitions  does  not  prejudice  the  inventor 
against  applying  for  and  receiving  a  grant  at  a  subsequent  date, 
a  grant  which  otherwise  would  be  invalid  on  the  score  of  want  of 
novelty.  In  this  instance,  the  publication  is  not  unauthorised  by 
the  inventor  as  in  the  other  case  where  the  legislature  has  pro- 
tected him,  but  is  the  direct  result  of  his  own  action  and  desire. 

We  see  then  two  exceptions  to  the  rule  that  the  publication 
of  an  invention  prior  to  the  date  of  the  application  for  a  patent 


THE  PROTECTION   OF  SCIENCE   BY  PATENT    55  5 

is  fatal  to  the  validity  of  the  patent  which  may  be  issued  as  a 
consequence  of  the  subsequent  application.  The  first  exception 
is  where  publication  is  unauthorised,  and  the  second  where  the 
publication  is  due  directly  to  the  inventor.  The  suggested 
reform,  which  would  permit  an  inventor  who  had  published  the 
result  of  his  investigations  before  a  learned  society  to  apply  at  a 
later  date  for  a  patent  and  receive  a  valid  grant,  would  not  only 
do  no  violence  to  the  law  as  it  now  stands,  but  would  be  the 
natural  complement  to  the  steps  which  have  already  been  taken. 
This  demand  for  alteration  of  the  law  is,  however,  no  new  thing. 
Prof.  Sylvanus  Thompson,  F.R.S.,  lent  his  powerful  advocacy, 
but  without  avail,  towards  securing  amendment  on  these  lines 
while  the  Patents  Bill  was  before  Parliament;  while  in  the 
United  States  the  patent  law  from  the  commencement  has 
allowed  an  inventor,  during  a  period  of  two  years  before 
making  a  formal  application  for  a  patent,  to  publish  his  inven- 
tion freely  without  detriment  to  himself. 

Doubtless  there  are  several  methods  by  which  this  improve- 
ment in  the  law  might  be  brought  about.  One  method  of  so 
doing  would  be  to  grant  the  inventor  in  the  case  under  dis- 
cussion what  in  the  Patents  Act  is  technically  termed  "  Pro- 
visional protection."  By  the  reading  of  a  paper  before  a  learned 
society  and  an  application  for  a  patent  being  made  within  a 
specified  time,  say  two  or  five  years,  together  with  the  simul- 
taneous deposit  of  a  "  complete  specification,"  provisional 
protection  might  be  conferred  and  antedated  to  the  date  of  the 
reading  of  the  paper.  Complementary  provisions  of  a  simple  and 
practical  nature  would  also  be  required,  so  as  to  restrict  the 
benefits  to  those  for  whom  they  were  intended.  By  the  con- 
ferring of  provisional  protection  upon  the  inventor  ipso  facto  by 
the  reading  of  his  paper,  the  patent  to  be  subsequently  received 
would  bear  the  date  of  the  reading  and  nominally  there  would 
be  no  publication  before  the  date  which  the  subsequently 
acquired  patent  bore.  The  inventor  would  hold  the  field  during 
the  period  of  two  or  five  years,  or  whatever  time  might  be 
provided,  against  everybody,  and  in  particular  against  the  mere 
snapper-up  of  a  good  idea  who  conceived  some  slight  improve- 
ment or  further  step  in  advance  and  patented  it,  an  advance 
which  after  all  might  be  but  little  removed  from  the  obvious 
and  which  was  naturally  within  the  ability  of  the  originator  of 
the  main  idea  to  produce. 


556  SCIENCE  PROGRESS 

(2)  Extension  of  the  Area  covered  by  Patent  Protection. — The 
originator  of  a  scientific  discovery  cannot  obtain  patent  pro- 
tection for  the  practical  applications  of  his  discovery,  whatever 
may  be  their  importance  to  the  welfare  of  the  community,  unless 
they  are  by  their  nature  "  manufactures  "  within  the  meaning  of 
the  statute  of  James  I.  This  statute  was  the  direct  outcome  of 
the  economic  conditions  which  prevailed  at  the  time  it  was 
enacted,  viz.  in  the  year  1624,  and  of  the  economic  theories 
which  then  obtained.  It  was  designed  to  incite  individuals  to 
provide  means  whereby  workless  men  might  be  put  to  profitable 
labour.  The  restrictions  of  the  various  trade  guilds,  particularly 
in  the  direction  of  what  virtually  amounted  to  limitation  of 
output,  and  of  their  inelasticity  as  regards  extension  of  the  scope 
of  the  energies  of  their  craftsmen,  had  been  seen  for  a  century  or 
more  to  be  affecting  detrimentally  the  conditions  of  the  labour 
market.  At  the  time  when  the  Statute  of  Monopolies  was 
drafted  what  more  likely  means  for  coping  with  the  prevailing 
distress  could  have  been  thought  of  than  the  bringing  into  this 
country  a  knowledge  of  new  manufacturing  operations  or 
incidentally  by  the  creation  of  manufactures  by  inventive 
ingenuity  ? 

The  more  the  subject  is  examined  the  more  certain  it  appears 
that  the  restriction  of  patent  protection  to  mere  "  manufactures  " 
was  an  historical  accident.  But  the  times  have  changed,  economic 
conditions  and  thought  have  advanced,  and  the  judiciary  has 
deemed  itself  capable  of  extending  the  meaning  of  the  word 
"manufacture"  but  little  beyond  that  which  it  originally  bore,  at 
any  rate  not  to  the  extent  which  modern  requirements  suggest. 
Within  the  rigid  boundaries  to  which  the  Courts  have  held 
themselves  to  be  confined,  the  judges  have  tried  to  deal  with  the 
matter  on  an  equitable  basis  and  to  differentiate  between  the 
pioneer  inventor  and  the  follower,  the  discoverer  of  a  master 
idea  and  the  mere  improver.  Where  they  have  found  that  a  new 
discovery,  purpose,  or  end  has  been  brought  to  light  and  some 
ingenious  means  have  been  patented  whereby  the  new  discovery 
might  profitably  be  employed,  the  judiciary  has  extended  the 
scope  of  the  protection  given  by  the  patent  beyond  that  invention 
which  the  words  of  the  patentee  as  they  occur  in  the  complete 
description  of  the  invention  might  at  first  sight  appear  to  describe. 
The  judiciary  has  not  been  niggardly  in  its  interpretation  of  the 
pioneer's  own  specification.     But  what  is  now  wanted  is  legisla- 


THE  PROTECTION   OF  SCIENCE   BY   PATENT    557 

tive  enlargement  of  the  scope  of  our  patent  law  infused  with 
a  similar  spirit  of  equity.  As  regards  Parliamentary  action, 
although  nearly  three  centuries  have  elapsed  since  the  Statute 
of  Monopolies  was  passed,  no  statute  has  been  brought  to  bear 
whereby  patent  protection  has  been  conferred  on  aught  but 
"  manufactures."  A  discovery  by  its  very  nature  is  not,  it  is 
true,  capable  of  protection.  Thought  is  free,  and  there  is  no 
monopoly  in  knowledge.  A  monopoly  could  be  granted  only 
for  improved  arts  or  practices  the  outcome  of  discovery. 

Subject  to  this  natural  limitation  the  question  may  now  well 
be  asked  whether  there  is  any  valid  reason  why  a  more  generous 
measure  of  protection  should  not  be  accorded  to  the  scientific 
worker.  Why,  for  instance,  should  not  an  individual  receive 
patent  protection  who  discovers  a  method  of  breeding  a  rot- 
proof  sheep,  who  originates  new  varieties  of  plants  and  cereals, 
or  who  invents  new  methods  of  fruit-culture,  matters  of  no  less 
moment  in  view  of  the  ever-increasing  demands  of  the  community 
than  are  the  more  orthodox  subjects  of  patents.  Is  not  the  man 
who  advances  public  health  by  the  application  of  some  scientific 
or  medical  discovery  as  much  entitled  to  a  monopoly  as,  let 
us  say,  one  who  improves  a  mustard-pot  ?  Surely  the  ques- 
tion only  requires  to  be  formulated.  Justice  and  expediency 
concur  in  requiring  extension  of  the  law  whereby  originators 
may  receive  a  reward  adequate  to  the  importance  of  their  dis- 
coveries, or,  at  any  rate,  proportioned  to  their  public  use.  If 
deserving  scientists  are  to  be  protected  as  regards  researches 
which  result  in  amelioration  of  the  conditions  of  living,  the 
11  new  manufacture  "  of  the  statute  of  James  I.  should  be  amplified 
and  protection  granted  to  any  other  new  practice  which  is 
originated  by  the  scientific  mind  and  is  of  utility  to  the  public. 
In  other  words,  letters  patent  ought  not  to  be  confined  to 
manufactures,  but  ought  to  be  granted  in  respect  of  every 
invention  of  any  new  and  useful  art  founded  upon  scientific 
discovery. 

(3)  Suggested  Provisions  for  Amending  the  Law.  —  The  fol- 
lowing provisions,  which  would  require  the  authority  of  an 
Act  of  Parliament,  appear  to  be  the  simplest  means  by  which 
the  existing  patent  system  could  be  modified  so  as  to  remove 
the  disabilities  which  are  dealt  with  in  the  preceding  pages. 
Their  effect  would  be  (1)  for  a  limited  period  to  attach  to  the 
reading  of  a   paper  before   a  learned    society  the   measure  of 


558  SCIENCE  PROGRESS 

protection  which  is  technically  known  as  "  provisional  pro- 
tection," with  its  beneficial  consequences,  and  (2)  to  extend  the 
scope  of  patent  protection  from  "  new  manufactures  "  to  every 
invention  of  any  new  and  useful  art  founded  upon  scientific 
discovery.  The  amendments,  moreover,  are  of  such  a  character 
that,  with  no  disturbance  of  current  practice,  all  the  elaborate 
machinery  which  has  been  erected  to  effectuate  the  patent 
system  would  be  applicable. 

New  provisions  to  be  read  with  the  Patents,  etc.,  Act,  1907  : 

I.  (1)  If  application  for  a  patent  in  respect  of  an  invention 
accompanied  by  a  complete  specification  is  made  by  the  reader 
of  a  paper  before  a  learned  society  within  a  period  of  two  (or 
five)  years  from  the  reading  of  the  paper,  the  reading  of  the 
paper  shall,  on  request  being  made  by  the  applicant  to  the 
Comptroller,  be  deemed  to  be  an  application  for  provisional 
protection  of  the  invention,  and  the  paper  so  read  shall  be 
deemed  to  be  the  provisional  specification  accompanying  such 
application  and  the  application  shall  bear  date  accordingly  : 

Provided  that — 

(a)  the   learned   society   shall,   for   the   purposes   of   this 

section,  have  been  certified  as  such  by  the  Board  of 
Trade ; 

(b)  the   paper  read   before  the  learned  society  has  been 

printed  and  published  within  a  year  from  the  reading 
of  such  paper  ;  and 

(c)  the  application,  which  is  accompanied  by  the  complete 

specification,  shall  also  be  accompanied  by  a  copy  of 
the  paper  or  papers  or  extracts  therefrom  as  read. 

(2)  The  application  shall  be  subject  to  examination  and 
investigation  in  like  manner  as  though  it  had  not  been  made 
under  the  provisions  of  this  section. 

(3)  The  times  within  which  all  proceedings  in  connection 
with  the  application  must  be  made  shall  be  extended  by  a 
period  equal  to  that  between  the  reading  of  the  paper  and  the 
lodging  of  the  application,  and,  save  as  aforesaid,  all  proceedings 
shall  be  taken  within  the  time  and  in  the  manner  prescribed 
by  the  Patents  and  Designs  Acts,  1907,  or  by  rules  made 
thereunder. 

II.  (1)  The  meaning  of  the  word  "invention,"  shall  include, 
in  addition  to  its  content  as  defined  in  Section  93,  any  new  and 
useful  art  founded  on  scientific  discovery. 

(2)  A  patent  granted  for  any  new  and  useful  art  founded  on 
scientific  discovery  shall  not  be  held  to  be  invalid  by  reason 
only  that  the  new  and  useful  art  is  not  a  manufacture  within 
the  meaning  of  Section  6  of  the  Statute  of  Monopolies. 


REVIEWS 

Formal  Logic:  a  Scientific  and  Social  Problem.  By  F.  C.  S.  Schiller, 
M.A.,  D.Sc,  Fellow  and  Senior  Tutor  of  Corpus  Christi  College,  Oxford. 
[Pp.  xviii  +  423.]    (London  :  Macmillan  &  Co.,  191 2.     Price  10s.  net.) 

The  ordinary  treatise  on  Formal  Logic  neither  claims,  nor  in  fact  has,  direct 
bearing  on  scientific  fact  or  special  interest  for  men  of  science.  Of  recent  years 
there  has  arisen  an  extension  known  as  methodology,  which  has,  unfortunately, 
consisted  of  verbal  and  abstract  discussion  and  has  had  small  bearing  on  scientific 
work.  Attempts  to  make  the  science  practical  and  to  criticise  the  methods  used 
by  scientific  men  are  refused  the  recognition  due  to  them  because  academic 
philosophers  do  not  understand  science,  and  men  of  science  know  little  of 
philosophy  and  have  made  no  careful  and  systematic  study  of  scientific  method. 
Therefore  the  blunders  of  one  generation  of  scientific  men,  when  some  uncomfort- 
able new  series  of  fact  reveals  them,  are  silently  glossed  over  and  their  successors 
proceed  to  repeat  them  in  accentuated  forms.  Nothing  is  more  needed  than  an 
extension  of  logic  having  some  relation  to  science.  We  therefore  turn  expectantly 
to  one  of  the  prominent  exponents  of  the  pragmatist  school  of  thought  ;  for  prag- 
matism, if  it  is  nothing  else,  is  at  least  an  attempt  to  bring  philosophy  closer  to 
practical  life. 

Regretfully  we  are  obliged  to  note  that  the  positive  contributions  to  a  logic  of 
science  are  meagre.  The  greater  part  of  the  volume  consists  of  an  attack  on 
formal  logic  as  commonly  accepted  and  taught.  The  author  describes  it  as  an 
attempt  to  put  the  logicians'  house  in  order  and  to  clear  the  ground  for  a  new 
logic  that  has  yet  to  be  written.  It  is,  however,  hopeless  to  attempt  to  deduce 
from  the  present  book  what  the  new  logic  would  be  if  the  author  had  time  to  write 
it.  But  such  contributions  to  the  advancement  of  the  study  of  scientific  method 
as  are  put  forward  it  will  be  well  to  note. 

In  a  vvay,  the  whole  book  may  be  regarded  as  a  defence  of  science  in  a  sense 
not  very  intelligible  to  any  one  unacquainted  with  the  Oxford  atmosphere.  The 
intellectualist  and  academic  school  are  disposed  to  depreciate  the  study  of  science, 
and  in  so  doing  they  will  not  omit  to  mention  the  obvious  fact  that  the  typical 
inductive  proof  of  scientific  principles  is  not  formally  valid.  The  burden  of 
Dr.  Schiller's  book  is  that  formal  validity  is  of  no  value  or  importance.  It  would 
perhaps  be  unwise  to  underrate  the  significance  of  the  Oxford  atmosphere,  and  the 
bearing  of  Dr.  Schiller's  attack  should  be  duly  noted. 

More  specific  points  will  be  found  in  the  treatment  of  induction.  Mill  put 
forward  five  classic  methods  of  inferring  from  effect  to  cause,  and  these  methods 
have  been  subjected  to  interminable  criticism  ever  since.  Dr.  Schiller  demurs 
that  the  essential  point  is  relevance.  "  Instead  of  talking  about  facts  at  large,  let 
us  say  relevant  facts  "  (p.  268).  But  Dr.  Schiller  does  not  think  that  the  validity 
of  the  methods  is  thus  saved.  He  thinks,  on  the  other  hand,  that  the  introduction 
of  the  idea  would  make  out  a  case  for  a  "  third  branch  of  logic,  underlying  both 
deduction  and  induction,  which  would  determine  the  relevance  of  fact  and  be  more 

559 


56o  SCIENCE  PROGRESS 

important  than  either"  (p.  270).  Dr.  Schiller's  view  is  that  relevance  consists  in 
what  is  selected 'by  a  knower  as  helpful  for  his  purpose,  and,  consequently,  purpose 
and  personal  psychology  are  introduced  into  the  very  foundation  of  scientific 
investigation.  By  this  road  an  opening  is  made  for  the  distinctive  catchwords  of 
the  pragmatist  philosophy.  All  this  would  have  been  made  so  much  clearer,  in 
the  way  Mill  so  admirably  expressed  himself,  by  a  few  well-chosen  examples.  It 
is  so  easy  to  infer  anything  you  please  so  long  as  you  confine  discussion  merely  to 
general  terms.  We  can  only  reply  in  general  terms  that  it  is  the  universal 
experience  of  men  of  science  that  valid  results  are  only  obtainable  in  so  far  as 
personal  psychology  and  special  conscious  purpose  are  eliminated  from  the  process 
of  inference.  It  is  probable  that  Mill  would  have  had  little  difficulty  in  disposing 
of  Dr.  Schiller's  criticisms.  There  are  also  a  number  of  points  in  the  chapter  on 
causation  which  it  is  not  possible  to  discuss  in  the  space  at  our  disposal. 

Needless  to  say,  there  is  much  cogent  criticism  in  Dr.  Schiller's  diatribes. 
The  currently  taught  methodology  is  certainly  somewhat  futile  from  the  standpoint 
of  scientific  investigation.  It  is,  as  the  author  points  out,  strangely  paradoxical 
that  the  theory  of  science  is  in  Oxford  (at  London  it  is  admitted  as  a  science 
subject)  taught  only  to  those  who  know  nothing  of  its  practice.  But  surely  not 
even  the  current  methodology  is  such  as  to  delay  the  progress  of  the  science 
student.  Certainly  it  is  far  from  adequate.  But  there  have  been  valuable  works 
on  the  logic  of  science.     Dr.  Schiller  has  forgotten  Jevons. 

To  turn  to  the  more  strictly  logical  part  of  the  book,  it  should  be  remarked  that 
the  term  logic  is  commonly  used  in  two  senses.  It  may  mean  purely  formal  logic 
(represented  by  Jevons  and  Keynes),  it  may  mean  metaphysical  logic  (represented 
by  Bradley  and  Bosanquet),  which  is  partly  logic,  partly  methodology,  partly  meta- 
physics, and  partly,  to  some  extent,  psychology.  We  shall  confine  ourselves 
almost  entirely  to  the  formal  side.  That  curious  medley,  metaphysical  logic,  will, 
no  doubt,  in  time,  sort  itself  out.  Dr.  Schiller  is  entirely  antagonistic  to  both,  and 
his  attempt  to  set  the  logicians'  house  in  order  greatly  resembles  the  Chinese 
method  of  burning  it  down.  It  will  be  advisable,  therefore,  to  devote  some  space 
to  the  consideration  of  one  or  two  fundamentals,  the  full  bearing  of  which  Dr. 
Schiller  seems  to  have  disregarded. 

The  first  concerns  axioms.  Reasoning  need  not  be  based  on  axioms,  but  it 
often  is,  and  a  careful  study  of  their  import  is  essential  to  any  attempt  to  clarify 
logic.  Dr.  Schiller  objects  to  the  use  of  the  term  a  priori.  There  are,  certainly, 
several  senses  in  which  it  can  be  used.  But  the  term,  whatever  its  demerits,  does, 
at  least,  show  the  fundamental  difference  between  such  truths  as  the  axiom  of  quantity 
and  the  everyday  facts  of  observation  and  experience.  On  this  matter,  Aristotle, 
Kant,  and  Spencer,  notwithstanding  differences,  all  agree.  Dr.  Schiller  disagrees,  or 
appears  to  do  so.  He  regards  postulation  as  the  source  of  universal  propositions, 
and  makes  no  clear  distinction  between  the  method  of  arriving  at  universal  truths, 
in  which,  no  doubt,  postulation  plays  a  part,  and  the  certainty  which  accrues  to 
such  truths  when  enunciated.  Dr.  Schiller's  views  on  this  matter  are  more  fully 
expressed  in  Axioms  as  Postulates}  These  views  I  have  already  criticised  at  some 
length,  and  do  not  care  now  to  repeat  the  criticisms.  In  the  volume  under  review, 
it  is  not  at  all  clear  whether  Dr.  Schiller  has  modified  the  views  he  previously 
expressed.      His    exposition    requires    clearer   and  fuller  statement  with  special 

1  The  essay  in  question  is  published  in  a  volume  entitled  Personal  Idealism, 
edited  by  Mr.  Henry  Sturt,  and  published  by  Macmillan.  My  criticisms  will  be 
found  in  an  article  entitled  "  Evolutionary  Empiricism  "  {Mind,  No.  73). 


REVIEWS  561 

reference  to  scientific  principles.  The  statement  (p.  244)  that  the  scientific 
status  of  the  indestructibility  of  matter  has  been  impaired  by  the  discovery  of 
radioactivity  is  highly  disputable.  It  depends  on  definition  and  point  of 
view.  The  sentence  on  the  conservation  and  the  dissipation  of  energy  is  liable  to 
give  the  impression  that  the  author  does  not  understand  the  meaning  of  the  latter 
principle.  Moreover,  any  one  speaking  of  "gravitation  "  as  axiomatic  is  using  the 
term  in  a  sense  very  different  from  that  commonly  understood.  The  importance 
of  the  treatment  of  axioms  in  all  discussions  on  the  foundations  of  logic  can 
hardly  be  over-estimated,  and  the  critic  approaching  Dr.  Schiller's  volume  with 
the  desire  to  find  a  clear  and  coherent  view  will  be  left  with  the  impression 
that  an  adequate  discussion  of  this  point  would  exhibit  inconsistencies  with  the 
main  trend  of  the  argument. 

The  second  fundamental  is  that  ancient  problem,  the  nature  of  formally  valid 
inference.  The  old  logical  query  whether  syllogistic  reasoning  ever  elucidates  new 
truth  is  a  particular  case  of  the  larger  general  question.  Those  who  maintained 
that  the  syllogism  was  a.petitio  principii  were  confronted  with  the  inference  that 
any  one  acquainted  with  the  axioms  and  postulates  of  Euclid,  therefore,  knew  and 
understood  every  truth  of  geometry.  It  was  evident,  in  this  case,  that  something 
new  was  elucidated.  Dr.  Schiller's  solution  is  interesting  and  plausible.  He  says 
that,  in  all  real  reasoning,  we  reason  with  regard  to  a  doubt.  Every  syllogism 
applied  to  a  particular  case  is  an  experiment  to  discover  whether  an  individual  who 
belongs  to  a  class  for  most  purposes  can  have  attributed  to  him  some  specific 
character  possessed  by  other  members  of  the  class.  This  is  true  enough  in  its 
way.  But  it  hardly  elucidates  the  relation  between  the  properties  of  a  parallelo- 
gram and  the  axioms  and  postulates  of  Euclid.  The  meaning  of  the  iron  rigidity 
of  logical  inference  is  a  problem  which  none  who  seeks  to  penetrate  to  the 
foundations  of  logic  can  ignore.  Dr.  Schiller,  unfortunately,  talks  round  the 
problem.  I  am,  no  doubt,  free  to  infer  that  the  angles  of  a  triangle  are  together 
equal  to  two  right  angles,  or  that  the  diagonals  of  a  rhombus  bisect  each  other 
at  right  angles,  or  neither.  But  this  does  not  explain  why  both  are  absolutely 
certain  formally  valid  truths  implicit  in  Euclidean  geometry.  What  is  the  meaning 
of  this  certainty?  Why  does  each  step  of  the  reasoning  follow  from  the  last? 
The  problem  is  very  similar  to  the  one  concerning  the  nature  of  axioms. 

Considerations  of  this  kind  will  show  a  sphere  for  formal  logic  much  greater 
than  Dr.  Schiller  is  willing  to  admit.  Dr.  Schiller  wishes  to  displace  logic  by 
some  as  yet  unformulated  science  of  "psychologic."  In  a  later  chapter  he,  semi- 
humorously,  commends  formal  logic  as  a  good  game.  The  passage  is  worth 
quoting  : 

"  Friends,  your  judgment  is  too  harsh.  You  must  not  judge  logic  by  your  own 
feelings  nor  condemn  it  because  you  have  no  use  for  it.  You  should  live  and  let 
logic  live.  Moreover,  it  really  has  a  use.  Its  use  is  to  keep  logicians  employed 
and  amused.  The  study  of  Formal  Logic  makes  a  highly  intellectual  game.  .  .  . 
You  think  it  a  silly  game  ;  well,  in  a  sense,  all  games  are  silly.  ..."  and  so  on 
(p.  388). 

This  is  interesting  and  amusing.  But  Dr.  Schiller  does  not  appear  to 
realise  that  every  time  we  make  any  inference  whatever,  practical  or  theoretical, 
a  part  of  the  process,  the  conceptual  part,  the  formation  of  the  conceptual  systems 
which  we  apply  to  reality,  whether  in  mathematics,  in  science,  or  elsewhere,  comes 
within  the  sphere  of  influence  of  this  game.  Granted  that  it  is  not  the  whole 
process.  It  is  sufficiently  important  if  it  is  only  a  part.  Also,  with  regard  to  the 
extension  of  logic  which  all  philosophers  contemplate,  it  is  very  doubtful  whether 


562  SCIENCE   PROGRESS 

"  psychologic  "  would  be  a  correct  description.      The  nearer  we  get  to  exact  know- 
ledge of  anything  the  more  the  "psychology"  disappears. 

The  dominant  note  of  this  brief  review  is  criticism.  It  is  bound  to  be  so  with 
Dr.  Schiller.  His  whole  volume  is  so  critical.  But  he  is  always  interesting.  His 
style  is  vigorous.  His  remarks  are  always  relevant  to  the  state  of  knowledge  of 
the  time.  His  criticisms  on  the  details  of  formal  logic  as  actually  taught  we  must 
leave  to  the  strictly  formal  logicians  to  answer.  They  are  very  cogent,  and 
require  an  answer.  The  book  will  be  of  considerable  interest  to  any  one  to  whom 
the  subject  appeals.  But  it  is  to  be  regretted,  in  so  large  and  bulky  a  volume,  that 
there  has  been  no  attempt  at  definite  and  positive  construction.  Is  there  anything 
constructive  in  pragmatist  philosophy  ?  Or  is  pragmatism  merely  a  revolt  from  the 
current  academic  intellectualism  ? 

H.  S.  Shelton. 

A  Systematic  Course  of  Practical  Science.  For  Secondary  and  Other  Schools. 
By  Arthur  W.  Mason,  B.Sc,  B.A.  (Lond.)  Book  I.— Introductory 
Physical  Measurements,  is.  6d.  net.  [Pp.  126.]  Book  II. — Experimental 
Heat.     2s.  6d.  net.     [Pp.  161.]     (London:  Rivingtons,  1912  and  1913.) 

The  two  volumes  contain  the  outlines  of  the  first  two  years  of  a  course  of  practical 
science.     The  directions  are  given  clearly,  as  are  also  the  methods  of  entering 
and  of  tabulating  the  results.     The  book  should  be  of  great  assistance  to  the 
teacher  in  charge  of  a  practical  class.     It  is  certainly  one  of  the  best  and  one  of 
the  most  thorough  of  the  many  class-books  at  present  on  the  market. 

It  should  be  said,  byway  of  criticism,  that  it  is  one  which  a  teacher  would  need 
to  use  with  considerable  discretion.  Some  of  the  experiments,  especially  in  the 
book  on  heat,  seem  much  more  suitable  for  the  lecture-table  than  for  the  laboratory. 
A  secondary  school  laboratory  would  need  to  be  exceedingly  well  equipped  in 
order  to  allow  some  of  the  experiments  to  be  performed  by  a  class  of  pupils.  The 
one  on  the  variation  of  boiling  points  with  pressure  (42)  and  the  use  of  Bunsen's 
ice  calorimeter  are  cases  in  point.  Some  of  them  point  to  the  probability  of  the 
smashing  of  apparatus  and  the  loss  of  mercury.  Nothing  is  said  of  the  age  of 
the  pupils  for  whom  the  experiments  are  intended. 

On  the  other  hand,  the  teacher  using  the  book  with  discretion  will  find  that 
most  of  the  ordinary  easy  experiments  illustrating  elementary  physics  are  included 
and  are  described  in  a  thoroughly  practical  manner.  He  is  in  no  way  bound 
to  follow  the  order  of  the  book  or  to  include  all  the  experiments  in  the  course. 
Indeed,  he  would  be  foolish  to  attempt  to  do  so.  So  used,  a  better  book  could 
hardly  be  obtained. 

It  is  a  small  point,  but  one  that  the  teacher  will  appreciate.  The  dimensions 
of  the  book  are  such  as  to  allow  it  readily  to  remain  open  at  any  page,  a  great 
convenience  for  laboratory  use. 

H.  S.  S. 

The  Science  of  the  Sciences.  Constituting  a  New  System  of  the  Universe  which 
Solves  Great  Ultimate  Problems.  By  H.  Jamyn  Brooks,  author  of  The 
Elements  of  Mind.     [Pp.   312.]     (London  :  David  Nutt.     Price  5  s.) 

As  indicated  by  the  title,  the  author's  System  claims  to  "  explain,  or  to  form  the 
nucleus  of  explaining  every  mystery  in  the  universe  excepting — (1)  The  Mystery 
of  Beginning  and  End  ;  (2)  The  Subjectivity  of  Substance." 


REVIEWS  563 

The  System  is  stated  in  outline  in  eleven  propositions,  of  which  the  first  three 
are  quoted  below  : 

"(1)  That  the  principal  basis  of  mind  is  a  quasi-chemical  substance  (to  which  the 
term  '  mental  ether '  is  given),  and  that  it  can  be  analysed  into  quasi-chemical 
elements. 

"  (2)  That  the  principal  basis  of  physical  force  is  also  a  quasi-chemical  substance 
(to  which  the  term  'physical  ether'  is  given),  and  that  it  can  be  analysed  into 
quasi-chemical  elements. 

"(3)  That  these  elements,  together  with  all  universal  elements,  are  funda- 
mentally the  same  as  the  chemical  elements." 

There  are  also  four  hypotheses  which  constitute  an  important  part  of  the 
System,  entitled  respectively — "The  Universal  and  Monistic  Hypothesis,  The 
Chemical  Hypothesis,  The  Physical  Hypothesis,  The  Mental  Hypothesis."  Once 
again,  perhaps,  it  will  be  well  to  allow  the  author  to  speak  for  himself.  The  first 
two  hypotheses  are  as  follows  : 

"1.  That  the  universe  is  a  compound  of  all  the  universal  elements,  and  that 
each  element  is  coextensive  with  space  and  can  have  no  independent  existence. 

"2.  That  all  matter  contains  the  whole  of  the  chemical  elements  and  that 
each  element  is  universally  diffused  throughout  the  whole  space  occupied  by  the 
elements." 

It  should  also  be  mentioned  that  the  author  has  received  congratulatory  letters 
from  such  men  as  the  late  Prof.  William  James  and  Prof.  James  Sully.  These 
refer  strictly  to  an  earlier  work,  but,  as  the  essential  ideas  are  the  same,  the 
recommendation  should  be  mentioned  for  what  it  is  worth.  The  present  volume 
has  been  critically  investigated  by  two  of  the  foremost  Fellows  of  the  Royal 
Society,  who  said  that  it  ought  to  be  published. 

No  doubt  it  ought,  and  the  author  is  to  be  congratulated  on  at  last  being  able 
to  place  his  views  before  the  public.  Any  one  who  is  interested  in  hypotheses 
of  this  kind,  and  in  the  study  of  systems  of  the  universe,  will  find  much  to  interest 
and  amuse.  It  is  to  be  hoped  that  the  work  will  have  a  sale  sufficient  to  encourage 
publishers  of  serious  works,  in  case  of  doubt,  to  take  the  risk. 

In  the  present  case  it  is  necessary  to  make  one  decisive  criticism.  The  author 
plainly  and  obviously  does  not  understand  the  elementary  facts  and  theories  of 
the  sciences  with  which  he  deals.  A  large  portion  of  the  book  would  have  to  be 
rewritten  if  he  had  troubled  to  acquire  the  most  elementary  knowledge  of  chemistry 
and  physics.  The  assistance  of  men  of  science  has  not  enabled  him  to  remedy 
the  defect.  As  an  example,  on  p.  49,  air  is  referred  to  as  a  compound,  and  it  is 
absolutely  impossible,  from  the  trend  of  the  argument,  to  decide  whether  the 
statement  is  a  slip  or  sheer  ignorance.  Because  atmospheric  nitrogen — which, 
by  the  way,  is  considerably  heavier  than  nitrogen  obtained  from  compounds — 
is  found  to  contain  considerable  quantities  of  other  elements  than  nitrogen, 
therefore  chemically  pure  nitrogen  contains  infinitesimal  traces  of  every  known 
and  unknown  element — so  runs  the  trend  of  the  argument.  There  is  absolutely 
no  connection  between  fact  and  inference.  Again,  in  the  chapter  on  the  tides, 
the  author  shows  plainly  that  he  does  not  understand  the  simplest  elements  of 
the  current  tidal  theory  that  he  is  attempting  to  displace.  He  apparently 
does  not  know  that  the  tide-raising  force  is,  approximately,  inversely  propor- 
tional to  the  cube  of  the  distance  between  the  attracting  bodies,  and  inquires 
(with  the  proviso  that  the  question  may  be  answerable)  why  dry  leaves  and  other 
loose  materials  are  not  sucked  up  by  the  attraction  of  the  Moon. 

The  author  says  somewhere  that  it  is  a  pity  that  his  system  did  not  originate 


564  SCIENCE  PROGRESS 

with  a  Huxley  or  a  Kelvin.  He  means,  I  suppose,  a  Hegel  or  a  Spencer,  for 
Kelvin  and  Huxley  were  essentially  specialists.  But  the  value  of  the  works  of 
philosophers  such  as  these  lies  not  so  much  in  their  systems  as  in  their  profound 
knowledge  and  insight,  in  their  grip  of  the  knowledge  of  their  time,  in  the  fact 
that  they  understood  the  principles  of  science  more  clearly  than  the  men  of 
science  themselves,  and  were  sufficiently  well  acquainted  with  the  details.  Kant 
was  a  physicist  before  he  became  a  philosopher.  Spencer  would  have  achieved 
eminence  on  biological  work  alone.  It  is  not  much  use  putting  forward  systems 
unless  one  knows  enough  to  know  when  one  is  not  talking  sense. 

Mr.  Jamyn  Brooks  has  written  a  work  on  psychology  which,  it  seems,  has 
been  well  received.  If  his  work  in  that  department  is  unsound,  he  is  covered  by 
the  fact  that  the  whole  science  is  a  little  vague  and  shadowy.  The  reviewer 
would  suggest  that  it  would  be  better  if  he  concentrated  on  the  psychological 
side  and  if  he  did  not  attempt  to  deal  with  problems  of  natural  science  until  he 
has  acquired  a  sound  elementary  knowledge  of  the  sciences  with  which  he  deals. 
Let  us  assume  that  the  author's  hypotheses  are  all  true  and  valuable  (to  the 
reviewer  they  scarcely  appear  so),  it  would  still  require  the  ability  and  the 
knowledge  of  a  Hegel  or  a  Spencer  to  set  them  forth  in  detail.  The  present 
volume  provides  no  evidence  that  Mr.  Brooks  possesses  either,  and,  if  he  does 
not,  the  very  existence  of  his  book  is  a  weapon  in  the  hands  of  the  "  stodgy  " 
man  of  science  who  is  impervious  to  new  ideas.  Who  was  it  called  van  't  HofPs 
chemistry  in  space  the  vapouring  of  an  unsound  mind  ?  The  type  always  exists, 
and  a  book  like  that  of  Mr.  Brooks  is  so  much  grist  to  his  mill.  Those  who  think 
they  are  the  originators  of  new  ideas  may  look  at  this  volume  and  decide  that, 
after  all,  it  is  safer  to  leave  it  alone. 

H.  S.  S. 

Vectorial  Mechanics.   By  L.  Silberstein.    [Pp.  vi  +  197.]    (Macmillan  <fcCo., 
19 1 3.     Price  7s.  bd.  net.) 

The  work  of  Heaviside,  which  has  demonstrated  so  clearly  the  power  and  relative 
simplicity  of  vector  methods  for  dealing  with  quantities  essentially  vectorial,  is 
bearing  good  fruit.  There  are  already  in  Germany  good  textbooks,  such  as  those 
of  Bucherer  and  Gans,  which  give  an  introduction  to  the  methods  of  vector 
analysis.  In  the  book  under  review  we  welcome  at  last  an  English  book  in  which 
a  systematic  account  is  given  of  the  vector  analysis  in  use  among  the  physicists  of 
the  present  day,  and  its  applications  to  mechanics.  Even  to  those  with  a  good 
knowledge  of  the  subject  it  will  prove  very  interesting,  as  there  is  a  distinct 
originality  of  treatment  and  a  unity  and  sequence  which  make  a  strong  appeal. 

The  work  is  divided  into  six  chapters.  We  have  first  a  general  introduction  to 
vector  analysis,  which  is  probably  the  best  in  any  English  textbook.  In  this  the 
vector  and  scalar  products,  the  curl,  divergence,  and  the  important  theorems  con- 
nected with  them  are  exposed.  There  follow  three  chapters,  under  the  headings 
of  General  Principles,  Special  Principles,  and  Rigid  Dynamic,  dealing  with  the 
application  of  the  analysis  to  dynamics,  those  parts,  such  as  the  motion  of  a  body 
under  no  forces,  which  best  lend  themselves  to  vector  methods  being  naturally 
treated  in  the  greatest  detail.  The  final  two  chapters  deal  with  the  theory  of 
elasticity  and  hydrodynamics.  There  is  a  useful  and  instructive  appendix,  giving 
the  most  important  equations  of  the  book,  together  with  their  Cartesian  equiva- 
lents. The  linear  vector  operator,  of  which,  outside  Heaviside's  work,  it  is  hard  to 
find  an  account,  is  introduced  in  connection  with  moments  of  inertia,  and  developed 


REVIEWS  565 

at  greater  length  in  the  treatment  of  the  fundamental  equations  of  strain  :  its 
properties  are  demonstrated  in  a  very  lucid  manner.  The  section  on  vortex  motion 
affords  an  excellent  example  of  the  advantages  of  vector  methods  in  dealing  with 
problems  of  this  kind. 

The  author  has  evidently  spared  himself  no  pains  to  make  the  book  clear  and 
consequent,  and  the  care  with  which  the  difficulties  likely  to  present  themselves  to 
the  student  have  been  foreseen  bears  witness  to  his  discrimination.  The  abstract 
dynamical  principles  are  illustrated  by  simple  and  direct  examples,  which  make 
their  scope  and  meaning  clearer  than  could  be  done  in  a  discussion  occupying 
many  times  their  space.  One  of  the  most  striking  features  of  the  book  is  the 
brevity  which  has  been  achieved  without  sacrifice  of  either  clearness  or 
accuracy. 

The  student  will  find    here    an    excellent    introduction  to  the  whole    field  of 

vector  mathematics,  and  especially,  although  electrical  problems  are  not  directly 

treated,  a  very  good  preliminary  to  the  study  of  modern  electrodynamics.     The 

collection  of  examples,  with  hints  for  the  solution  of  the  harder  ones,  is  likely  to 

prove  exceedingly  useful. 

E.  N.  da  C.  A. 

Researches  in  Magneto-Optics.    By  P.  Zeeman.    [Pp.  xi  -f  219.]    (Macmillan 
&  Co.,  191 3.     Price  6s.  net.) 

In  this  book,  which  forms  one  of  Messrs.  Macmillan's  excellent  series  of  Science 
Monographs,  the  famous  author  gives  an  account  of  the  researches  carried  out  on 
the  phenomenon  associated  with  his  name — the  modification  of  the  nature  of  the 
emitted  light  which  takes  place  when  the  source  of  light  is  placed  in  a  magnetic 
field — and  the  closely  allied  magnetic  rotation  and  magnetic  double  refraction  of 
light.  While  dealing  largely  with  the  author's  own  experiments,  as  is  necessarily 
and  desiredly  the  case,  the  book  gives  an  account  of  all  work  done  on  the  subject 
from  the  fundamental  discovery  in  1896  down  to  the  middle  of  the  year  1913. 
Starting  with  a  chapter  on  modern  spectroscopes — in  which  he  discusses  Ray- 
leigh's  theory  of  resolving  power  and  the  performances  of  the  Rowland  grating,  the 
echelon,  e'talon,  and  other  recent  devices  for  the  finer  analysis  of  light — the  author 
passes  on  to  the  fundamental  experiment,  the  magnetic  resolution  of  emission 
lines,  giving  his  original  paper  and  Lorentz's  simple  and  brilliant  theory  of  the 
effect.  It  is  interesting  to  note  that  this  supplied  the  first  proof  that  the  centres  of 
light  emission  are  negative  electrons,  and  that  the  value  ofe/m  deduced  was  one  of 
the  very  earliest  determinations.  In  other  chapters  he  treats  of  the  inverse  effect 
— i.e.  the  multiplication  of  the  absorption  line  when  the  absorbing  body,  such  as  a 
salted  flame,  is  placed  in  a  magnetic  field,  the  types  of  resolution  more  compli- 
cated than  that  indicated  by  Lorentz's  simple  theory  and  found  in  the  first  experi- 
ments, and  the  magnetic  rotation  of  the  plane  of  polarisation.  This  phenomenon 
follows  theoretically  from  the  unequal  velocities  of  propagation  of  the  right-handed 
and  left-handed  circularly  polarised  components,  demonstrated  by  Zeeman  to 
exist  for  rays  propagated  paralled  to  the  force  when  the  absorbing  body  is  placed 
in  a  magnetic  field.  The  importance  of  the  Zeeman  effect  for  astrophysics  is 
brought  out  in  the  chapter  on  Hale's  researches,  which  revealed  the  effect  in  the 
light  coming  from  the  sun  in  the  neighbourhood  of  spots.  This  is  in  striking 
accord  with  the  theory  that  the  sun-spots  are  solar  vortices,  for  the  electrons 
whirled  round  in  these  vortices  would  produce  the  magnetic  field  required  for  the 
phenomenon. 


566  SCIENCE  PROGRESS 

The  theoretical  work  which  has  been  done  on  the  subject  is  most  attractively 
exposed,  the  essential  assumptions  of  each  theory  and  its  main  consequences 
being  set  out  with  brevity  and  great  clearness.  In  the  last  chapter  the  origin  of 
the  spectral  series,  and  the  complicated  types  of  resolution  of  the  lines  in  the 
magnetic  field,  are  considered  from  the  theoretical  standpoint,  and  an  account 
given  of  Ritz's  theory  of  the  series,  and  Lorentz's  theories  of  the  coupling  of  the 
emission  centres  by  the  magnetic  field,  which,  with  Voigt's  modifications,  is  capable 
of  accounting  for  the  various  types  of  resolution.  The  necessary  assumptions, 
however,  appear  most  artificial,  and  it  cannot  be  said  that  the  present  state  of  the 
theory  is  altogether  satisfactory.  Ritz's  theory  of  the  Zeeman  effect  has  been 
shown  to  be  unworkable  by  Voigt.  Dr.  Bohr's  papers  on  the  constitution  of  the 
atom,  which  have  appeared  during  the  last  few  months,  seem  to  supply  a  more 
simple  and  inclusive  theory  of  the  spectral  series,  though  it  remains  to  be  seen  if 
his  atom  can  be  induced  to  give  the  experimental  Zeeman  resolutions. 

The  style  and  arrangement  of  the  book  are  throughout  admirable,  and  the 
author  has  contrived  to  give  a  very  clear  account  of  mathematical  theories  with  a 
minimum  of  symbolic  working.  The  many  personal  touches,  such  as  the  rather 
pathetic  account  of  the  postponement  of  the  work  on  the  types  of  resolution  of 
lines  of  the  same  series  for  lack  of  suitable  equipment,  give  an  added  attractive- 
ness. It  would  be  difficult  to  speak  too  highly  of  the  general  production  of  the 
book,  which  contains  a  large  number  of  the  most  beautiful  photographs  illustrating 
the  various  effects. 

E.  N.  DA  C.  A. 


Principles  and  Methods  of  Geometrical  Optics.  By  J.  P.  C.  Southall. 
[Pp.  xxiii  +  626.]  Second  Edition.  (Macmillan  &  Co.,  1913.  Price 
2  5 j.  net.) 

The  fact  that  Professor  SouthalPs  work  on  Geometrical  Optics,  first  published  in 
1910,  has  already  appeared  in  a  second  edition,  shows  that  it  has  speedily  won 
the  recognition  it  deserves  as  the  best  book  on  the  subject  in  English.  The 
changes  in  the  new  edition  are  small ;  the  arrangement  and  pagination  have  been 
left  exactly  as  in  the  first  edition,  two  appendices  to  the  chapters  on  Refraction 
of  a  Narrow  Bundle  of  Rays  through  a  System  and  on  the  Theory  of  Spherical 
Aberration  respectively  having  been  bodily  inserted  on  lettered,  not  numbered, 
pages.  These  appendices  are  in  the  nature  of  further  notes  to  the  chapters  ;  the 
second  contains  a  detailed  account  of  the  calculation  of  the  spherical  errors  of 
a  centred  system  by  means  of  the  Seidel  formulae. 

To  the  English  reader  who  wishes  a  full  and  clear  account  of  the  recent  work 
on  geometrical  optics,  especially  that  of  the  Germans — we  need  only  mention  the 
names  of  Abbe,  Petzval,  Seidel,  and  Czapski — to  whom  most  of  the  recent  advances 
are  due,  the  book  can  be  unreservedly  recommended.  It  covers  the  whole  field 
in  a  complete  and  satisfactory  way,  making  full  use  of  the  most  modern  methods, 
many  of  which  are  not  to  be  found  in  any  other  text-book  of  which  we  know. 
Especial  attention  is  throughout  devoted  to  the  applications  to  the  design  of 
modern  optical  instruments. 

It  is  to  be  hoped  and  expected  that  the  book  will  do  much  to  revive  the  study 
of  geometrical  optics  in  England,  which,  although  at  present  the  Germans  are  its 
undisputed  masters,  was  the  first  home  of  the  science. 

E.  N.  DA  C.  A. 


REVIEWS  567 

Stellar  Motions — with  special  reference  to  motions  determined  by  the  Spectro- 
graph. By  William  Wallace  Campbell,  Sc.D.,  LL.D.,  Director  of 
the  Lick  Observatory,  Univ.  of  California.  [328  pp.,  8vo,  14  figures  and 
34  tables  in  text.]  (Henry  Frowde,  University  Press,  Oxford,  1913. 
Price  17s.) 

Science,  in  all  its  branches,  has  during  the  last  century  advanced  with  enormous 
rapidity.  What  to  one  generation  seems  impossible  may,  to  the  succeeding 
generation,  be  merely  a  commonplace.  Thus  it  was  but  about  seventy-five  years 
ago  that  Auguste  Comte  wrote  that  "we  shall  never  be  able  to  study  the  chemical 
composition  of  the  celestial  bodies  ;  .  .  .  our  positive  knowledge  with  regard  to 
them  will  necessarily  be  limited  to  their  geometrical  and  mechanical  phenomena. 
It  will  be  impossible,  by  any  means,  to  include  investigations  of  their  physical, 
chemical  (and  other)  properties."  So  much  for  the  dogmatism  of  the  philosopher, 
for  within  twenty-five  years  from  the  time  of  writing  the  fundamental  principles 
of  spectroscopy  were  formulated  by  Kirchoff.  Sixty-five  years  ago  the  possibility 
of  determining  the  radial  motions  of  the  stars  was  undreamt  of;  but  with  the 
enunciation  by  Doppler  in  1842  of  the  effect  of  the  motion  of  the  source  upon 
the  wave-length  of  the  emitted  disturbance,  and  with  its  application  to  optical 
problems  by  Fizeau  in  1848,  the  way  was  paved  for  the  solution  of  the  problem. 
Little  progress  was  made,  however,  for  some  time.  Visual  methods  of  determi- 
nation are  difficult,  even  in  the  hands  of  skilled  observers,  and  liable  to  errors 
which  may  greatly  exceed  the  velocity  to  be  found  :  thus  the  star  "a  Cassiopeia?" 
which,  according  to  the  best  modern  determinations,  has  a  radial  velocity  towards 
the  sun  of  3'a.  ±  C15  km.  per  sec.  was  found  by  visual  observations  at  Greenwich 
in  1885  and  1887  to  have  velocities  of  90  km.  and  58  km.  per  sec.  respectively, 
away  from  the  sun.  Twenty-five  years  ago  the  radial  motion  of  not  a  single  star 
was  known,  even  approximately.  The  rapid  development  of  this  branch  of 
astronomy  during  recent  years  has  resulted  from  the  introduction  of  photographic 
methods.  Even  with  this  great  advance,  the  displacements  of  the  spectral  lines 
to  be  measured  are  so  small  and  systematic,  and  other  errors  may  so  easily  enter, 
that  great  precautions  have  to  be  taken  if  an  accurate  result  is  to  be  obtained  : 
in  1890  the  radial  velocity  of  the  star  cited  above  was  determined  photographically 
at  Potsdam  as  15*2  km.  per  sec.  towards  the  sun,  almost  four  times  as  large  as 
the  correct  value.  It  is  to  the  improvements  in  the  spectrograph  and  in  the 
methods  of  measurement  introduced  by  Dr.  Campbell,  that  the  present  degree 
of  accuracy  is  largely  due,  and  it  is  to  the  untiring  labours  of  him  and  his 
colleagues  at  the  Lick  Observatory,  and  at  its  southern  dependance  at  Cerro 
San  Cristobal,  Santiago,  Chile,  that  we  owe  almost  the  whole  of  our  knowledge 
of  the  radial  velocities  of  stars  ;  it  is,  therefore,  very  fitting  that  an  account  of  the 
theory  and  methods  used,  and  discussions  of  some  of  the  problems  which  have 
arisen  in  connection  with  the  results  obtained,  should  be  for  the  first  time  collected 
together  into  one  volume  by  Dr.  Campbell  himself. 

The  eight  chapters  of  this  volume  formed  the  Silliman  lectures  delivered  by 
the  author  in  Yale  University  in  1910.  To  bring  the  volume  up  to  date,  a  series 
of  footnotes  have  been  added  incorporating  the  chief  results  obtained  since  their 
delivery.  An  important  feature  of  the  book  is  the  valuable  series  of  tables, 
thirty-four  in  number,  which  illustrate  the  text,  and  contain  a  mine  of  information. 
Each  chapter  of  the  book  is  essentially  complete  in  itself,  and  more  or  less 
independent  of  the  others.  The  first  two  are  introductory,  and  include  a  brief 
account  of  the  development  of  the  subject,  and  a  description  of  the  D.  O.  Mills 

37 


568  SCIENCE  PROGRESS 

spectrograph,  and  of  the  precautions  which  are  taken  in  order  to  secure  accurate 
results.  There  follow  in  the  third  chapter  the  applications  of  these  principles 
to  various  problems  of  the  solar  system,  such  as  the  period  of  rotation  of  the  sun, 
and  of  Saturn's  rings,  and  also  to  individual  stars.  The  fourth  chapter  deals 
with  the  various  methods  of  determining  the  solar  motion  from  statistical 
considerations  of  the  proper  motions  of  stars,  whilst  in  the  following  chapter 
the  same  problem  is  discussed  from  the  radial  velocity  determinations.  This 
method  has  considerable  advantages  as  compared  with  the  older  one.  In  it 
the  actual  radial  velocities  are  used,  whereas  proper  motions  are  determined 
in  arc,  and  for  given  linear  motions  they  vary  inversely  as  the  (unknown)  stellar 
distances  :  moreover,  radial  velocities  can  be  measured  very  accurately  in  a  short 
period  of  time,  whereas  the  accurate  determination  of  a  proper  motion  requires 
a  series  of  observations  extending  over  a  long  interval.  The  one  disadvantage 
of  the  method  is  that,  at  present,  the  velocities  of  the  faint  stars  cannot  be  found, 
but  with  increase  in  the  power  of  the  instruments  used  this  difficulty  will  be 
largely  overcome.  It  is  probable  the  velocity  of  the  solar  system  in  space  as 
determined  by  Campbell  is  the  most  accurate  yet  made. 

The  sixth  chapter  contains  several  applications  of  the  results  obtained  to  the 
stellar  system.  By  eliminating  the  solar  motion  so  as  to  leave  the  peculiar 
motions  of  the  stars,  it  is  found  that  the  number  of  positive  velocities  is  con- 
siderably larger  than  the  number  of  negative,  whereas  the  numbers  should  be 
very  nearly  equal.  The  residual  average  velocity  belongs  almost  entirely  to 
the  stars  of  class  B,  and  can  be  explained  if  there  is  an  average  increase  in  the 
wave-lengths  of  all  lines  utilised  of  '07  A  :  such  an  increase  could  be  caused  by 
a  pressure  of  from  twenty  to  thirty  atmospheres  ;  and  this  may  be  the  correct 
explanation,  because  in  these  stars  the  absorption  bands  are  of  considerable 
breadth,  as  if  widened  by  pressure.  Such  a  pressure  effect  appearing  in  so 
unexpected  a  manner  is  of  peculiar  interest,  and  may  throw  some  light  on  our 
knowledge  of  class  B  stars.  In  this  chapter  also  is  a  conclusive  proof  that  stars 
of  early  spectral  types  are  travelling  slower  than  those  of  later  classes,  as  the 
following  table  vividly  shows  : 


Spectral  class. 

No 

.  of  stars. 

Av.  Rad.  veloc. 

OandB 

141 

8  "99  km. 

A 

133 

9  "94  km. 

F 

159 

13-90  km. 

GandK 

529 

15-15  km. 

M 

72 

16*55  km. 

On  the  other  hand,  stellar  velocities  are  not  functions  of  the  visual  magnitudes. 
There  is  no  indication  that  the  fainter  stars  are  travelling  more  rapidly  than  the 
brighter.  Another  important  result  is  drawn  by  the  author  from  statistical  con- 
siderations, and  by  comparison  with  results  previously  deduced  from  Proper  Motion 
data,  viz.  that  the  stars  of  various  magnitudes  are  more  thoroughly  mixed  in  space 
than  had  been  previously  supposed.  These  are  but  a  few  of  the  important 
problems  discussed  in  this  fascinating  chapter. 

The  last  two  chapters  are  concerned  respectively  with  visual  and  spectroscopic 
binary  stars,  and  with  variable  stars,  and  give  a  conspectus  of  our  present  know- 
ledge on  these  subjects,  which  the  study  of  radial  velocities  has  helped  to  increase 
in  no  small  measure. 

The  treatment  of  such  a  vast  subject  is  necessarily  incomplete ;  but  the  author 
has  well  succeeded  in  showing  how  rich  a  field  of  investigation  is  being  opened 
by  the  study  of  radial  velocities,  which,  taken  in  conjunction  with  proper  motion 


REVIEWS  569 

determinations,  promise,  in  time,  to  materially  assist  in  forwarding  the  solution 

of  the  fundamental  problem  of  astronomy — the  problem  of  the  evolution  of  the 

Universe. 

H.  S.  J. 

Quantitative  Chemical  Analysis.  By  A.  C.  Cumming,  D.Sc,  Lecturer  in 
Chemistry,  University  of  Edinburgh,  and  S.  A.  K.\Y,  D.Sc,  Assistant 
in  Chemistry,  University  of  Edinburgh.  [Pp.  xi -1- 382.]  (London: 
Gurney  &  Jackson,  191 3.     Price  7s.  6d.) 

The  average  student  who  attacks  for  the  first  time  a  particular  analytical 
determination  usually  finds  that,  although  he  may  follow  the  instructions  of  his 
text-book,  his  results  are  erroneous ;  and  unless  he  has  been  shown  the  process 
in  full  detail  by  the  teacher,  this  is  almost  bound  to  be  the  case.  There  has 
hitherto  been,  in  fact,  no  book  on  analytical  chemistry  which  properly  instructed 
the  student  in  the  complicated  technique  which  even  the  simpler  analytical 
processes  demand.  It  may  be  said  that  such  instruction  should  be  conveyed 
by  example  and  not  by  precept ;  but  whilst  this  is  undeniable  up  to  a  certain 
point,  it  remains  true  that  fully  one-third  of  the  time  given  by  laboratory  teachers 
in  demonstrating  all  the  small  but  essential  points  of  technique  to  each  separate 
student  could  be  saved  by  a  little  more  attention  to  detail  on  the  part  of  authors 
of  text-books  on  analysis.  Nor  can  it  be  said  that  these  remarks  smack  unduly 
of  "  spoon-feeding "  ;  for  in  these  days  no  student  has  time  to  re-discover  for 
himself  the  "tips'-'  which  are  our  heritage  from  generations  of  analysts,  let  alone 
the  broader  details  of  practice  ;  he  must  be  "spoon-fed"  to  some  extent,  and  the 
successful  relegation  of  any  part  of  this  process  to  the  pages  of  a  text-book  confers 
a  boon  upon  all  teachers  in  large  laboratories. 

By  this  standard,  as  well  as  by  others  possibly  higher,  the  work  now  under 
review  is  emphatically  a  success.  The  descriptions  of  procedure  are  so  carefully 
done,  and  the  gradation  of  the  difficulties  is  so  thoughtfully  carried  out,  that 
any  student  who  works  along  the  suggested  lines  could  hardly  fail  to  become 
thoroughly  competent.  It  would  have  been  beyond  the  scope  of  a  book  such 
as  this  to  have  dealt  with  the  theories  underlying  analysis,  and  the  authors  have 
wisely  confined  themselves  to  practice  pure  and  simple.  A  multiplicity  of  methods 
has  been  avoided,  with  the  result  of  freeing  the  student  from  the  feeling  of 
embarras  de  richesse  which  some  of  the  larger  works  in  vogue  tend  to  induce  ; 
at  the  same  time,  the  methods  given  are  numerous  enough  to  be  quite  repre- 
sentative, they  are  up-to-date,  and  in  frequent  instances  they  include  many  most 
useful  novelties  ;  and  all  bear  the  mark  of  having  been  proved  by  the  author's 
own  experience. 

After  the  first  general  chapter,  volumetric  analyses  are  first  dealt  with  ;  then 
follows  a  series  of  typical  gravimetric  determinations,  then  a  chapter  on  electrolytic 
methods.  This  and  the  succeeding  section  on  colorimetric  analysis  are  especially 
valuable.  (In  passing,  it  may  be  suggested  that  the  bismuthate  method,  now  so 
widely  used  for  determining  manganese,  might  be  included  in  later  editions.) 
Part  V.  contains  a  systematic  account  of  the  separation  and  determination  of 
each  of  the  common  radicles,  conveniently  arranged  alphabetically.  All  that 
is  in  this  section  is  good,  but  the  omission  of  cobalt  from  the  list  is  somewhat 
strange.  The  treatment  of  alloys  and  of  ores  is  dealt  with  in  Part  VI.  ;  then 
comes  gas-analysis,  followed  by  an  admirable  section  on  water-analysis.  Part  IX. 
treats  of  organic  analysis,  and  is  sure  to  be  found  valuable,  since  it  includes  an 


S7o  SCIENCE  PROGRESS 

account  of  the  method  of  combustion,  introduced  by  Walker  and  Blackadder, 
which  has  generally  replaced  the  older  methods  wherever  it  has  been  tried.  The 
last  section  is  a  clear  account  of  the  determination  of  molecular  weights.  The 
appendix  contains  data  and  useful  tables  concerning  reagents,  also  a  table  of 
logarithms.     Finally,  the  book  is  judiciously  illustrated  in  a  helpful  manner. 

Altogether,  the  authors  are  to  be  congratulated  on  having  produced  a  book 
which  cannot  be  too  highly  recommended  for  its  purpose,  and  whose  worth  has 
already  been  discovered  both  by  teachers  and  by  students  in  more  than  one 
laboratory.  j    jyj 

Organic  Chemistry  for  Advanced  Students.   Vol.  II.    By  Julius  B.  Cohen, 
F.R.S.,  etc.     [Pp.  vii  +  427.]    (London  :  Arnold,  1913.     Price  16^.  net.) 

To  write  a  book  dealing  generally  with  any  one  of  the  three  main  branches  of 
chemistry  is  a  task  which  becomes  yearly  more  difficult ;  and  this  is  particularly 
true  in  the  case  of  the  organic  branch.  Physical  chemistry  has  reached  the 
quantitative  stage,  and,  guided  by  mathematics,  it  keeps  on  a  fairly  straight 
path  ;  inorganic  chemistry  is  now  semi-quantitative  as  a  result  of  the  affiliation 
with  physical  chemistry  of  which  Abegg's  Handbuch  is  a  visible  sign.  In  the 
eyes  of  many  followers  of  these  two  branches,  their  organic  colleagues  are 
simply  wallowing  in  the  mire  of  qualitative  thought  ;  and  yet  it  was  from  the 
study  of  organic  compounds  that  some  of  the  fundamental  principles  of  general 
chemistry  arose,  and  the  inorganic  worker  is  often  apt  to  overlook  the  very 
important  contributions  which  his  own  branch  is  continually  receiving  from  the 
organic  side. 

Nevertheless,  organic  chemistry  is  certainly  in  a  less  advanced  state,  and  it 
is  deficient  as  yet  in  quantitative  laws.  Failing  these,  classification  of  the  vast 
masses  of  fact  must  be  resorted  to ;  and  after  classification  comes  theorising. 
The  regrettable  fact  is  that  frequently  theories  are  propounded  before  classification 
is  properly  begun  ;  and,  in  addition,  what  are  in  reality  tentative  schemes  of 
classification  are  often  mistaken  for  explanatory  theories. 

It  is  here  that  the  teacher  enters  the  field ;  and  the  chief  purposes  of  an 
advanced  course  of  organic  chemistry  should  be  to  direct  the  student's  steps  away 
from  these  two  pitfalls,  and  at  the  same  time  to  criticise,  both  destructively  and 
constructively,  actual  theories.  Viewed  from  this  standpoint,  Prof.  Cohen's 
second  volume  is  curiously  patchy.  Impartiality  in  a  teacher  is  a  very  necessary 
virtue,  but  it  can  be  practised  to  excess  ;  and  this  is  the  chief  fault  of  an  otherwise 
interesting  book. 

The  five  chapters  which  compose  the  volume  under  review  naturally  dovetail 
into  the  earlier  parts  of  the  first  volume,  which  has  been  widely  used  during 
the  last  five  years.  With  the  author,  we  may  hope  that  in  later  editions  a 
re-arrangement  may  be  effected  ;  but  in  the  meantime,  these  five  chapters  in 
themselves  form  on  the  whole  a  fairly  natural  sequence.  The  theme  around 
which  they  chiefly  centre  may  be  said  to  be  the  perturbations  of  atoms  and  of 
interatomic  forces  within  the  molecule  ;  in  other  words,  the  central  problems 
of  present-day  organic  chemistry.  It  follows  that  many  of  the  subjects  dealt 
with  are  of  a  physico-chemical  character,  and  thus  the  value  of  the  completed 
work  is  much  enhanced. 

The  first  two  chapters  ("The  Valency  of  Carbon"  and  "The  Nature  of 
Organic  Reactions  "),  which  occupy  some  200  pages,  are  undoubtedly  the  most 
interesting  of  the  five.     Theories  of  valency  may  be  said  to  deal  with  one  or 


REVIEWS  571 

more  of  the  topics  of  intermolecular  linkage,  interatomic  linkage,  and  the  intra- 
atomic  origins  of  these.  The  last  variety  is  best  left  to  the  physicist  to  elaborate  ; 
inorganic  chemists  are  striving  with  the  first,  but  it  is  from  organic  chemistry 
that  we  derive  most  light  both  on  this  and  on  interatomic  linkage. 

Most  of  the  first  chapters  of  the  book,  and  the  first  fifty  pages  of  the  second, 
deal  with  unsaturated  carbon.  The  student  who  can  think  for  himself  will  be 
both  stimulated  and  provoked  into  doing  so  as  he  reads  this  part  of  the  work  ; 
he  will  be  stimulated  by  several  very  lucid  accounts  such  as  that  of  Thiele's  views 
on  double  linking,  and  he  will  be  provoked  into  thinking  for  himself  by  the 
absence  of  more  than  a  slight  correlation  between  the  divers  theories.  This  is 
due  rather  to  the  present  condition  of  the  subject  itself  than  to  faults  of  treatment, 
and  although  one  could  wish  for  more  blending  of  the  theories  than  the  author 
has  shown,  the  fact  stands  out  that  the  day  of  the  all-embracing  theory  is 
not  yet. 

Broadly  speaking,  there  are  two  views  respecting  the  nature  of  unsaturated 
carbon  atoms,  of  which  one  is  that  the  atoms  are  in  a  "carbonous"  state  of 
di-  or  of  trivalency.  In  Chapter  I.  is  to  be  found  a  survey  of  the  work  of  Nef 
and  others  on  divalent  carbon,  which  is  clear  and  concise.  The  controversial 
topic  of  triphenylmethyl  is  impartially  reviewed  ;  but  it  is  not  clear  why  the 
existence  of  ions  of  triphenylmethyl  in  solution  should  imply  the  existence 
of  molecules  of  the  single  radicle,  nor  is  the  probability  of  union  with  the  solvent 
pointed  out.  In  passing,  attention  may  be  directed  to  a  misprinted  equation  on 
p.  7.  Hinrichsen's  and  Thorpe's  extensions  of  the  "  carbonous  "  idea  to  ethylenic 
compounds  are  well  treated.  In  the  first  portion  of  Chapter  II.  the  nature  of 
addition  and  substitution  processes  is  discussed  ;  and  here  we  meet  the  second 
kind  of  idea  of  unsaturation,  that  of  partial  valencies,  which  lies  at  the  root  of 
many  hypotheses  besides  Thiele's.  The  whole  section  is  an  interesting  one,  and 
the  author's  criticisms  are  valuable. 

Then  follows  a  section  devoted  to  "dry"  catalytic  actions  such  as  those  of 
Sabatier  and  Senderens.  This  is  perhaps  a  digression,  dealing,  as  it  does, 
for  the  most  part  with  practical  methods  and  results  ;  but  it  is  followed  by  the 
best  part  of  the  book,  namely,  that  on  chain  and  ring  formation.  This  is  really 
a  revision  and  amplification  of  the  chapter  on  Condensation  in  Vol.  I.,  and 
without  doubt  the  improvements  justify  its  inclusion  here.  The  simple  classi- 
fication of  condensations  which  the  author  introduces  on  pp.  109-10  will 
greatly  help  the  student  to  cope  with  this  huge  subject,  and  the  historical  mode 
of  treatment  adopted  at  the  same  time  is  of  much  educational  value.  The  only 
criticism  which  is  called  for  is  that,  in  discussing  "  Grignard "  reactions,  the 
author  might  have  taken  the  opportunity  to  abandon  the  usual  text-book  basis  of 
treatment,  which  regards  Grignard  reagents  merely  as  useful  aids  in  preparing 
otherwise  difficultly  obtainable  compounds.  All  applications  of  these  reagents 
fall  under  one  or  other  of  two  headings — double  decomposition,  or  addition 
followed  by  hydrolysis  or  other  suitable  double  decomposition  ;  and  some  such 
treatment  as  this,  perhaps  in  connection  with  Lapworth's  views,  would  have  been 
welcome. 

Coming  to  the  third  chapter  ("The  Dynamics  of  Organic  Reactions"),  written 
by  Dr.  H.  M.  Dawson,  the  reader  must  readjust  his  standpoint ;  in  fact,  excellent 
though  the  chapter  is,  it  is  not  quite  in  harmony  with  the  rest  of  the  book.  Here 
again,  however,  the  fault  lies  with  the  subject  and  less  with  the  author ;  for 
dynamical  studies  in  organic  chemistry  have  not  yet  fulfilled  their  early  promise, 
except  in  comparatively  few  cases  of  systematic  researches.     This  being  so,  the 


572  SCIENCE   PROGRESS 

subject  is  hardly  susceptible  to  arrangement  according  to  broad  results  and 
general  conclusions,  and  the  chapter  hence  takes  the  form  of  a  clearly  written 
summary  of  the  various  types  of  reactions — unimolecular,  bimolecular,  and  so 
on — with  well-chosen  illustrations  from  organic  chemistry. 

In  the  chapter  dealing  with  the  relationships  between  physical  properties  and 
structure,  Prof.  Cohen  has  given  a  particularly  lucid  account  of  the  development 
and  present  state  of  most  of  the  subject.  If  any  criticism  must  be  made,  it  is  that 
photographs  and  descriptions  of  apparatus  seem  to  be  superfluous  in  a  work  of 
this  kind,  which  is  already  sufficiently  bulky. 

One  cannot  help  thinking  that  the  author  has  been  less  happy  in  discussing 
colour  and  the  absorption  of  light.  The  section  on  absorption-spectra  is  relegated 
to  the  chapter  on  physical  properties,  which  is  inconsistent  with  the  identity  of 
visible  and  of  invisible  colour  to  which  the  author  himself  calls  attention.  The 
present  stage  of  our  knowledge  of  the  influences  of  structure  on  light-absorption 
is  one  of  classification  chiefly;  and  many  of  the  so-called  "theories"  of  colour 
are  hardly  more  than  summaries  of  the  compounds  which  possess  the  faculty  of 
absorbing  light  rays.  Greater  discrimination  in  this  direction  would  have  been 
acceptable,  and  the  sifting  and  blending  processes  before  referred  to  could  have 
been  utilised  in  this  chapter  to  great  advantage. 

The  volume  contains  few  noteworthy  misprints  ;  the  reproduction  of  the 
photographs  of  absorption-spectra,  however,  might  well  be  improved.  There 
are  full  indexes,  and  references  are  given  throughout  both  to  original  papers 
and  to  larger  monographs. 

On  the  whole,  then,  the  virtues  of  the  book,  which  are  many,  are  to  be  found 
in  the  clear  presentment  of  facts  and  of  separate  theories  ;  and  its  chief  fault  is 
one  of  omission,  consisting  of  insufficient  correlation  of  these  theories.  Never- 
theless, the  two  volumes  together  form  a  valuable  acquisition,  and  will  earn  a  wide 
circulation.  Irvine  Masson. 

Organisclie  Arsenverbindungen  und  ihre  chemotherapeutische  Bedeutung. 
By  Dr.  M.  Nierenstein.  (Stuttgart :  Sammlung  Chemischer  und 
Chemisch-technischer  Vortrage,  vol.  ix,  1912.) 

After  a  short  historical  sketch  of  the  employment  of  arsenic  and  its  compounds 
in  medicine  from  the  earliest  times,  the  author  gives  a  complete  list  of  the  arsenical 
compounds  prepared  by  Bunsen  in  his  investigation  of  the  Kakodyl  series,  and 
also  a  selection  of  the  more  important  substances  synthesised  by  Michaelis  ;  then 
follows  an  account  of  Ehrlich's  so-called  Reduction  Theory  of  the  mechanism  of 
the  action  of  the  azo-dyes  Trypan  Red  and  Trypan  Blue  and  of  Atoxyl  on 
trypanosomes,  a  theory  which  led  ultimately  to  the  discovery  of  Salvarsan.  Some 
space  is  next  devoted  to  the  discussion  of  two  alternative  theories  described  as 
the  Oxidation  Theory  of  Breinl  and  Nierenstein  and  the  Partial  Cell-function 
Theory  of  Uhlenhuth,  in  connection  with  which  the  pharmacological  action  of 
a  number  of  synthetic  arsenic  compounds  is  described.  The  monograph  may 
be  welcomed  as  a  useful  summary  of  a  somewhat  extensive  subject. 

The  Continent  of  Europe.  By  Lionel  W.  Lyde,  M.A.,  F.R.G.S.  [Pp.  xvi  + 
446.  With  12  coloured  maps,  and  numerous  smaller  maps  in  the  text.] 
(London  :  Macmillan  &  Co.,  1913.     Price  ys.  6d.) 

It  is  to  be  hoped  that  the  users  of  books  read  the  prefaces  that  are  prefixed  by 
conscientious  authors.     Mr.  Lyde's  preface  is  unusually  helpful,  and  is  an  intro- 


REVIEWS  573 

duction  to  a  series  of  books  on  the  continents  of  the  world.  Physical  features  are 
here  described  rather  than  explained ;  geography  is  thus  wisely  delimited  from 
geology.  Mr.  Lyde  regards  the  "  political  control "  as  providing  "the  dominant 
note  in  the  most  important  areas."  The  fact  that  the  three  parts  of  Poland 
contradict  his  first  page  in  every  essential  only  makes  the  position  of  Poland 
appear  more  melancholy  and  more  exceptional. 

In  the  next  page,  the  tetrahedral  theory  of  earth-structure  is  adopted,  as 
explaining  the  grouping  of  land-areas  in  fairly  high  northern  latitudes.  On  the 
third  page  we  have  a  discussion  on  technical  nomenclature,  in  which  it  is  wisely 
urged  that  it  is  better  to  introduce  a  specialised  term  for  a  special  thing,  rather 
than  an  existing  word  in  a  narrowed  sense.  Mr.  Lyde  justly  objects  to  "a  high" 
and  "alow"  in  meteorology;  but  he  introduces  us  to  "a  wyr,"  instead  of  "an 
anti-cyclone,"  which  is  only  replacing  a  well-established  technical  term  by  another 
that  we  tremble  to  pronounce.  How  did  Robert  Bruce's  military  engineers 
pronounce  "wyr"?  And  was  this  pronunciation  the  same  on  both  sides  of  the 
border  ?  Lies  there  yet  at  Lanercost  or  Douce  Coeur  a  craftsman  who  can  rise 
to  tell  us? 

Mr.  Lyde  has  a  love  of  the  picturesque  in  history,  and  this  prefatory  episode 
is  a  foretaste.  All  through  his  book  we  are  led  off  into  delightful  trains  of  thought ; 
to  complete  the  scene  that  he  conjures  up  we  must  go  from  one  of  our  bookshelves 
to  another,  from  Gibbon  to  Motley,  from  De  Comines  to  Miller  on  the  Balkans. 
He  holds  himself,  however,  in  great  restraint,  and  the  compression  of  some  of  his 
sentences  is  almost  too  severe.  "What  we  miscall  Macedonia  "  (p.  149)  is  just 
thrown  out  to  make  us  think  ;  but  the  connection  suggested  between  "  the  western 
end  of  this  old  folded  highland  "  and  the  formation  of  coal  and  salt  (pp.  4  and  5) 
remains,  we  must  confess,  entirely  obscure.  Mr.  Lyde's  facts  are,  as  a  rule,  well 
incorporated  in  paragraphs  that  reveal  their  interest  and  relationship.  We  are 
sure  that  it  revolts  him  to  put  in  a  footnote  that  "  onions  are  exported  to  the  value 
of  over  ,£530,000  per  annum." 

It  seems  ungrateful  to  question  certain  passages  ;  but  what  are  we  to  under- 
stand (p.  31)  by  "the  normal  activity  of  glaciers  intermediate  in  character  between 
the  dry  rigidity  of  the  tropics  and  the  constant  fluidity  of  the  Polar  regions"? 
Why  are  the  Polar  regions  fluid  ;  or  can  it  be  the  glaciers  or  their  activity  that 
show  this  character?  Surely  a  glacier  moves  from  other  causes  than  fluidity? 
And  are  glaciers  more  rigid  in  the  tropics  ?     We  still  wonder. 

What,  again,  are  the  "volcanic  upheavals"  (p.  225)  of  Scafell,  Helvellyn, 
Snowdon,  and  Cader  Idris,  which  have  had  an  effect  upon  the  scenery?  Surely 
it  is  the  hardness  of  the  igneous  rocks  that  has  given  us  their  peaks  and  precipices. 
The  sentence  that  follows  should  probably  not  be  laid  to  the  author's  score. 
Something  has  certainly  gone  wrong  with  it,  for  we  read  that  "the  volcanic  action, 
which  was  probably  due  to  the  amount  of  water  embedded  in  the  sedimentary 
'Silurian' rock,  seems  to  have  played  some  part  in  the  damming  of  the  glacial 
valleys,  as  in  the  case  of  Derwentwater  and  Windermere." 

In  a  book  so  full  of  condensed  but  always  suggestive  information,  it  may  be 
easy  to  find  small  points  that  one  would  question.  The  fact  that  Homo  heidelber- 
gensis  was  found  "in  the  Danube  valley"  (p.  45)  would  not  show,  as  the  author 
implies,  that  man  originated  in  valley-lands.  He  was  really  found,  however,  high 
up  at  Mauer  on  the  Rhine-wall,  where  he  doubtless  kept  himself  dry  out  of  the 
swampy  flats  below.  The  Tiber  valley,  again  (p.  85),  cannot  have  suggested  to 
the  Romans  that  good  roads  should  be  made  up  river-valleys.  Any  one  who  has 
followed  the  Via  Flaminia  from  Prima  Porta  knows  how  little  use  it  has  found 


574  SCIENCE   PROGRESS 

for  the  valley  of  the  Tiber,  and  how  the  deep  clefts  of  the  streams  are  a  hindrance 
to  it  at  Civita  Castellana  and  at  Narni.  It  is  a  different  matter  in  the  Gold  del 
Furlo,  where,  on  the  far  side  of  the  Apennines,  there  seems  only  one  possible 
descent.  Continuing  the  very  interesting  account  of  Italy,  we  fail  to  see  how 
"  decaying  vegetation  "  (p.  90)  affects  the  distribution  of  malaria;  and  Mr.  Lyde 
must  have  observed  that  the  frequency  of  umbrellas  (p.  91)  is  just  as  much  a  sign 
of  a  hot  climate  as  of  rain.  It  is  a  pleasure  to  go  through  this  volume  critically, 
because  one  learns  so  much  upon  the  way.  It  is  not  meant  as  a  compendium 
of  elementary  truisms,  but  as  an  encouragement  to  geographic  thought.  As 
a  sharp  contrast  in  physical  conditions,  Scandinavia  follows  upon  Italy.  Then, 
in  "  The  Balkan  Peninsula,"  we  have  a  crisp  little  sketch  of  Montenegro,  land 
and  people.  The  "dominant  note"  of  the  book  unfortunately  separates  it  by 
more  than  two  hundred  pages  from  an  equally  effective  sketch  of  Carniola  and 
Dalmatia. 

It  is  not  likely  that  any  one  person  has  seen  all  that  is  here  described. 
Mr.  Lyde  has  gathered  his  material  so  skilfully  that  it  is  impossible  to  say  how 
much  has  depended  on  personal  observation.  The  description  of  the  Portuguese 
on  p.  166  is  out  of  place  in  a  book  that  should  be  used  in  the  impressionable 
higher  forms  of  schools,  and  contact  with  other  iraces  than  our  own  usually 
smooths  away  a  host  of  prejudices.  The  book  as  a  whole,  however,  is  an 
incentive  to  intelligent  and  thoughtful  travel,  and  the  coloured  physical  maps 
at  once  suggest  attractive  fields. 

G.  A.  J.  C. 


The  Nature  and  Origin  of  Fiords.  By  J.  W.  Gregory,  F.R.S.,  D.Sc. 
[Pp.  xvi  +  542.  With  8  plates,  and  84  figures  in  the  text.]  (London  : 
John  Murray,  1913.     Price  16s.) 

The  title  and  dimensions  of  this  handsome  book  are  a  proof  of  the  considerable 
interest  aroused  in  recent  years  by  questions  of  physical  geography.  We  are 
still  a  long  way  from  the  time  when  the  author  of  a  first-class  work  of  travel 
will  be  required  to  show  some  knowledge  of  the  origins  of  topographic 
forms  ;  but  Prof.  Gregory's  own  writings,  and  a  general  acquaintance  with 
the  methods  of  Prof.  W.  M.  Davis,  must  surely  have  helped  many  in  this 
desirable  direction.  All  visitors  to  Norway  hear  something  about  fjords  or 
fiords,  and  they  will  now  be  able  to  realise  the  extent  and  interest  of  the 
literature  that  has  connected  these  long  sea-inlets  with  the  movements  of 
continental  margins. 

Prof.  Gregory  dismisses  at  an  early  stage  the  theory  that  glaciers  have  been 
responsible  for  fjords.  The  Shetland  Islands,  for  example,  record  a  direction  of 
ice-movement  at  right  angles  to  the  trend  of  the  sea-filled  valleys.  "  In  all  the 
fiord  districts,"  the  author  urges,  "  of  which  we  have  adequate  evidence,  the  fiord- 
valleys  were  excavated  during  the  Pliocene  period,  so  that  the  later  ice  of  the 
Pleistocene  period  used  the  fiords  and  did  not  originate  them"  (p.  15).  Even 
the  thresholds  where  shallow  water  occurs  in  the  mouths  of  so  many  fjords  are 
not  relied  on  as  an  essential  character,  although  it  is  admitted  that  they  are 
often  due  to  the  form  of  the  rock-floor.  Those  who  believe  more  strongly  than 
Prof.  Gregory  in  the  potency  of  glacial  erosion  have  of  course  found  an  important 
argument  in  the  existence  of  rock-thresholds  in  glaciated  ravines  below  the 
sea-level.      Such  features  have  been  compared  with  much  justice  to  the  rock- 


REVIEWS  575 

barriers  of  Alpine  valleys,  across  which,  the   post-glacial   rivers   have   now   cut 
their  way. 

We  find  that  we  have  to  deal  with  (i)  "fiords,"  which  are  long  and  fairly 
straight,  and  which  usually  have  parallel  sides  ;  (ii)  "  fiards"  (p.  67),  a  name  that 
affords  dangerous  possibilities  for  the  printer,  though  they  are  admirably  escaped 
by  Messrs.  Hazell,  Watson  &  Viney,  Ld.,  in  the  present  volume  ;  fiards  represent 
the  drowned  regions  of  low  coasts  that  are  formed  of  hard  rocks,  and  they  usually 
have  deep  interior  basins  and  rock-bars  ;  (iii)  "  fohrden,"  a  name  rather  like  the 
Swedish  fjarden^  the  word  that  has  been  translated  by  Prof.  Gregory  as  "fiards  "  ; 
the  "fohrden"  (p.  128)  find  their  type  in  the  inlets  of  Schleswig,  which  are  fiards 
originally  formed  by  river-erosion  on  a  low  country  of  soft  rocks,  and  which 
commonly  have  alluvial  bars  ;  and  (iv)  von  Richthofen's  "  rias "  (p.  69),  which 
are  "  submerged  valleys  found  between  the  ends  of  mountain-lines  which  run  out 
to  sea." 

Those  who  know  the  pleasant  wooded  inlets  of  Schleswig-Holstein  will  approve 
the  rather  hesitating  way  in  which  Prof.  Gregory  mentions  them  as  a  separate 
type.  The  conditions  of  the  Danish  peninsula,  during  its  recent  recovery  from 
ice-sheets  and  the  sea,  are  so  decidedly  specialised  that  we  need  hardly  extend 
fohrden  as  a  geographical  term.  The  distinction  between  fjords  and  rias  is  often 
difficult  enough,  unless  we  limit  the  former  term  to  grooves  resulting  from  the 
widening,  but  not  too  great  widening,  of  lines  of  fracture. 

This  is  practically  the  conclusion  of  Prof.  Gregory.  "  The  most  typical  fiord- 
valleys  occur  where  wide  areas  have  been  slowly  upheaved  into  a  flat  dome  or 
arch.  The  slow  uplift  has  rent  the  land  along  parallel  or  intersecting  cracks  " 
(p.  479).  He  ranges  over  the  coast-lines  of  the  world,  and  again  and  again 
describes  their  features  from  his  personal  observations.  Though  the  triangular 
facets  in  the  fine  photograph  of  the  Cattaro  Fjord  (Plate  VI.)  appear  to  be 
surfaces  of  dip  and  not  of  faulting,  he  usually  makes  a  strong  case  for  fracturing 
as  determining  fjord-trend.  An  interesting  problem,  extending  the  conception 
of  marginal  fractures  to  the  continents  as  a  whole,  is  stated  on  p.  468,  but  so 
briefly  as  not  to  be  generally  intelligible.  Do  we  not,  in  ordinary  usage,  say  that 
the  earth  rotates  from  west  to  east,  rather  than  "from  east  to  west"?  The  rest 
of  the  book  is  so  clear  that  we  should  like  to  hear  further  of  these  matters,  much 
in  the  manner  of  Mr.  Dickson's  treatment  of  the  atmosphere  in  a  recent  book 
about  the  weather. 

Geographers,  geologists,  and  lovers  of  scenery  will  alike  value  this  new  treatise. 
The  photographic  plates  are  very  fine,  and  should  set  even  the  indolent  turner 
of  pages  upon  paths  of  travel.  The  maps  in  the  text  are  sometimes  rather  robust 
in  execution,  and  we  cannot  see  anything  in  fig.  10  to  justify  its  introduction 
as  evidence  that  the  mountain- lines  in  Southern  Peru  are  not  parallel  with  the 
coast.  The  text  is  admirably  printed,  and  draws  the  reader  on  throughout  its 
five  hundred  pages.  The  author  is  responsible  for  "  Bohnsland  "  on  pp.  121  and 
122  ;  but  the  fief  or  Ian  of  Bohns  is  not  translatable  as  "  land."  "  Polje,"  on  p.  206, 
should  be  a  singular  and  not  a  plural ;  if  we  reject  the  Croatian  plural  polja, 
geographers  may  wisely  speak  of  "poljes."  Is  not  "  dolinas "  similarly  more 
correct  than  "  dolinje,"  for  the  hollows  so  aptly  recognised  as  vertical  valleys  by 
the  peasant  dwellers  of  the  karstland  ?  The  mention  of  these  names  shows  how 
wide  a  field  is  covered  by  a  book  on  fjords,  written  by  one  who,  in  regional 
surveys,  has  emulated  the  exploits  of  Camilla. 

G.  A.  T.  C. 


576  SCIENCE   PROGRESS 

Researches  on  Irritability  of  Plants.  By  Jagadis  Chunder  Bose,  M.A., 
D.Sc,  C.S.I.,  Professor,  Presidency  College,  Calcutta.  [Pp.  xxiv  +  376; 
190  figures.]     (London  :  Longmans,  Green  &  Co.,  191 3.     Price  js.  6d.  net) 

IT  is  with  mixed  feelings  that  one  takes  up  a  new  volume  by  Professor  Bose. 
One  expects  to  be  filled  with  appreciation  of  extremely  delicate  experimentation 
and  of  apparatus  most  ingeniously  devised.  On  the  other  hand,  one  is  sure  to 
be  repelled  by  the  curious  standpoint  from  which  the  author  views  living 
organisms,  a  position  quite  impossible  of  acceptance  by  physiologists  generally. 
In  the  several  volumes  which  the  author  has  already  published  we  always  find 
insistence  on  the  view  that  the  internal  energy  of  the  plant,  such  as  is  exhibited  in 
movements  in  response  to  stimuli,  is  derived  from  without  by  the  absorption 
of  "stimuli  "  received  from  the  environment  in  the  form  of  light,  heat,  and  even 
mechanical  energy.  The  author  never  explains  how  the  energy  obtained  from, 
say,  wind  and  heat  is  stored  up  in  the  plant,  nor,  on  the  other  hand,  does  he 
explain  why  he  rejects  the  ordinary  view  that  the  energy  exhibited  by  the  plant 
is  derived  from  the  oxidation  of  organic  material  elaborated  by  the  leaves. 
Prof.  Bose's  almost  bizarre  attitude  towards  living  organisms  is  perhaps  to  be 
explained  by  the  fact  that  he  entered  physiology  from  physics.  It  is,  however, 
particularly  unfortunate,  for  it  is,  no  doubt,  mainly  responsible  for  the  neglect 
of  his  work  by  biologists  generally. 

Fortunately,  in  the  present  work  theory  is  kept  in  the  background,  though 
the  author  speaks  in  one  place  of  a  portion  of  a  stimulus  bringing  about  an 
immediate  response,  while  another  portion  is  stored  up  and  causes  response  later, 
or  else  increases  the  tonic  condition  of  the  plant  !  Leaving  theory  on  one  side, 
we  find  a  large  amount  of  valuable  work.  As  was  to  be  expected,  he  describes 
some  very  ingenious  apparatus,  his  Resonant  Recorder  and  Oscillating  Recorder 
being  particularly  worthy  of  mention.  There  is  very  great  difficulty  in  obtaining 
in  the  ordinary  way  direct  records  of  the  movements  of  such  leaves  as  those  of 
Mimosa  and  Biophytum,  for  the  force  producing  the  movements  is  very  slight, 
so  that  the  mere  friction  of  the  style  on  a  smoked  plate  causes  distortion,  or 
even  complete  arrest  of  the  movement.  In  these  two  instruments  the  difficulty 
is  completely  surmounted  by  making  the  contact  between  the  smoked  plate  and 
writing  style  intermittent.  By  this  means  the  friction  is  greatly  reduced,  the 
record  appearing  as  a  number  of  dots,  and  as  contact  occurs  at  regular  intervals 
no  other  time-record  is  necessary.  By  means  of  the  first  of  these  instruments 
Prof.  Bose  has  been  able  to  show  that  the  "latent  period  in  Mimosa  is  o"i  sec, 
and  that  the  rate  of  transmission  of  the  stimulus  in  the  petiole  may  reach  30  mm. 
per  sec.  ;  but  is  markedly  retarded,  and  finally  abolished  by  lowering  the  tem- 
perature." These  results  are  quite  incompatible  with  the  commonly  received 
hydro-mechanical  theory  of  the  transmission  of  the  stimulus.  They  indicate 
that  the  transmission  is  a  protoplasmic  one  and  of  a  nature  similar  to  that  in 
animal  nerve.  In  fact,  very  strong  evidence  is  brought  forward  in  support 
of  a  close  similarity  between  Mimosa  and  a  nerve-muscle  preparation  ;  for  the 
pulverius  appears  to  behave  like  a  contracting  muscle  in  doing  more  work  as 
the  load  is  increased.  Besides  these  important  results  there  are  a  large  number 
of  valuable  observations  on  multiple  response  to  a  single  stimulus  (the  existence 
of  this  type  of  response  the  reviewer  can  confirm  from  his  own  observations), 
on  polar  effects  of  electrical  currents,  on  the  contrasted  effect  of  anode  and 
kathode,  and  on  many  other  phenomena  exhibited  by  motile  organs.  The  book 
is  certainly  one  that   cannot  be  neglected  by  workers   in   the   fields   of  either 


REVIEWS  577 

electrical  response  or  of  irritability  of  plants  in  general.  Of  course  many  of  the 
problems  investigated  lie  on  the  border-line  between  physics  and  biology,  and 
this  volume  shows  clearly  the  advantages  and  disadvantages  of  an  attack  on 
such  problems  by  one  who  is  mainly  a  physicist.  Cannot  Prof.  Bose,  with  his 
knowledge  of  physics,  his  great  ingenuity  in  devising  apparatus  and  experiments, 
and  his  interest  in  biological  problems,  find  some  sound  biologist  with  whom  he 
could  collaborate  in  what  should  be  an  almost  ideal  partnership  ? 

V.  H.  Black  man. 

Text-book  of  Zoology.  By  H.  G.  Wells  and  A.  M.  Davies.  Sixth  Edition. 
Revised  by  J.  T.  Cunningham.  [Pp.  viii  4-  487.]  (University  Tutorial 
Press,  London,  1913.     Price  6s.  6d.) 

In  theory,  the  proper  persons  to  conduct  university  examinations  are  the  teachers 
who  have  conducted  the  course,  who  already  know  something  of  the  capacities 
and  attainments  of  the  candidates,  and  who  can  set  the  papers  so  as  to  make 
them  an  adequate  test  of  the  fashion  in  which  the  students  have  taken  advantage 
of  the  range  of  teaching  offered  to  them.  Where  the  examiner  knows  precisely 
what  the  candidate  ought  to  know,  the  apparent  difficulty  of  the  paper  ought  to  be 
great,  and  the  standard  of  the  pass  mark  ought  to  be  high.  But  it  is  a  hard  world, 
and  there  is  competition  even  between  universities  and  amongst  the  schools  of 
a  university. 

Students  who  attend  a  teaching  university  expect  to  pass  its  examinations,  and 
attain  its  degrees,  and  it  simply  does  not  do  if  this  achievement  be  made  too 
hard  for  them.  In  theory  a  university  that  was  merely  or  chiefly  an  examining 
body,  that  knew  its  candidates  only  by  their  examination  papers  and  the 
examination  fees  they  had  to  tender,  was  a  poor  mechanical  thing.  In  practice 
the  University  of  London,  before  its  translation  to  South  Kensington  and  the 
emergence  of  its  internal  side  into  the  arena  of  competition,  certainly  secured  a 
very  high  standard  of  attainment  from  its  successful  candidates.  However  you 
chose  to  sneer  at  them  as  the  products  of  an  artificial  system,  you  could  not 
doubt  but  they  had  acquired  a  large  body  of  exact  knowledge  and  had  attained 
the  art  of  exhibiting  it  at  the  stimulus  of  examination  papers.  Many  of  the 
applicants  for  degrees  came  from  the  remote  provinces,  where  they  had  to  depend 
on  their  own  unaided  efforts  to  find  in  books  what  was  necessai-y  for  the  syllabus. 
For  such  persons  the  system  of  tuition  by  correspondence  was  devised,  and  the 
members  of  an  able  staff  learned  the  special  needs  and  difficulties  of  isolated 
students,  and  after  such  experience,  wrote  a  set  of  text-books  of  which  Mr.  Wells's 
"Zoology  "  is  an  excellent  example.  It  is  now  in  its  sixth  edition,  and  has  been 
revised  and  brought  up  to  date  successively  by  Mr.  A.  M.  Davies  and  Mr.  J.  T. 
Cunningham.  It  must  be  judged  entirely  from  its  genesis  and  purpose  ;  criticisms 
of  the  system  cannot  be  applied  fairly  to  a  book  adapted  to  the  system.  From 
this  standpoint  it  is  almost  miraculously  good.  It  is  self-explanatory,  well- 
arranged,  comprehensive,  and  precise.  Even  the  diagrams  are  such  as  could  be 
reproduced  in  an  examination.  Mr.  Cunningham,  perhaps,  ought  to  have 
explained  that  his  pemmican  chapter  on  evolution  was  a  summary  of  his  own 
views  rather  than  those  of  "the  ablest  biologists  from  the  time  of  Darwin  to  the 
present  day,"  but  a  fair  examiner  reading  an  answer  based  on  the  chapter  would 
only  laugh  and  give  the  necessary  marks.  It  would  be  more  serious,  however,  if 
an  unlucky  candidate  were  to  reproduce  the  word  "  Echmodermata"  for  "  Echino- 
derma." 


578  SCIENCE   PROGRESS 

The  Wanderings  of  Animals.  By  Hans  Gadow,  F.R.S.  Cambridge  Manuals 
of  Science  and  Literature.  [Pp.  vi  +  150.]  (Cambridge  :  University  Press, 
1913.     Price  is.  net.) 

Dr.  Gadow's  little  volume  of  150  pages  with  17  outline  maps  is  a  marvel  of 
comprehensive  lucidity,  and  in  many  respects  the  best  book  on  the  geographical 
distribution  of  animals  that  has  been  written.  He  begins  with  a  just  and  lively 
account  of  the  history  of  his  subject  from  Bufifon  to  the  latest  treatise,  and  from 
his  criticism  of  his  predecessors  leads  us  gently  to  his  own  point  of  view.  The 
attempt  to  divide  the  world  into  zoological  regions  of  general  application  is  doomed 
to  failure  ;  even  with  regard  to  single  groups  such  as  birds,  beasts,  or  fishes,  there 
is  the  trouble  that  the  regions  must  have  been  different  at  different  geological 
epochs.  Study  of  geographical  distribution  is  nothing  less  than  "  the  history  of 
life  in  time  and  space."  The  fossil  history  of  each  group  must  be  studied  and  an 
idea  obtained  as  to  the  geographical  configuration  of  land  and  water  at  the  time 
of  its  appearance,  and  throughout  its  subsequent  history.  Pan  passu  there  must 
be  an  investigation  of  animals  with  regard  to  their  environment,  because  the 
power  of  taking  advantage  of  land  connections  or  other  possible  avenues  of 
dispersal  is  limited  by  the  presence  of  suitable  conditions  for  the  radiating 
animals. 

In  his  second  chapter  Dr.  Gadow  discusses  the  effect  of  the  environment  in 
moulding  the  fauna  and  flora  of  any  locality,  selecting  forests,  deserts,  and 
high  mountains  as  extreme  examples.  He  states  briefly  the  characteristic  facies 
of  each  of  these  regions  and  comments  on  the  possibility  of  making  the  difficult 
discrimination  between  convergence  and  blood  relationship.  In  a  short  chapter 
on  "  Spreading"  he  points  out  that  the  many  forms  with  an  almost  world-wide, 
continuous  distribution  must  be  supposed  to  have  spread  from  a  common  centre, 
and  in  simple  language  he  enunciates  the  bearing  of  limited  food-supply  and 
progressive  increase  in  numbers  due  to  reproduction.  After  discussing  the 
density  of  the  existing  fauna,  he  proceeds  to  give  a  short  summary  of  what  he 
conceives  to  have  been  the  leading  features  of  terrestrial  geography  from  Permian 
to  recent  geological  ages,  and  illustrates  his  views  with  an  ingenious  set  of 
diagrams.  Obviously  he  is  on  controversial  ground  here,  but  although  every  one 
will  not  agree  with  all  the  details  he  suggests,  no  one  can  dispute  the  almost 
incredible  amount  of  information  that  he  has  contrived  to  pack  into  a  short 
chapter. 

The  second  half  of  his  volume  is  occupied  by  an  account  of  the  distribution  of 
various  selected  groups — Earthworms,  Fresh-water  Crabs  and  Crayfishes,  Fish, 
Amphibians,  Reptiles,  Birds,  and  Mammals.  His  object  appears  to  have  been  an 
explanation  of  the  principles  by  which  the  subject  must  be  elucidated  rather  than 
a  detailed  statement  of  the  facts. 

We  regard  the  book  as  quite  admirable  ;  experts  will  rejoice  in  the  freshness 
and  interest  of  the  exposition,  and  the  novice  will  acquire  from  it  much  knowledge 
and  a  wide  grasp  of  how  to  gain  more. 

Penal   Philosophy.    By  Gabriel  Tarde.    English  Translation  by  Rapelje 
Howell.    [Pp.  xxxii  +  581.]    (London  :  W.  Heinemann,  1912.     Price  20^.) 

THE  late  Prof.  Tarde's  well-known  work,  Philosophie  penale,  appeared  first  in 
1890,  and  had  reached  a  fourth  edition  in  1903.  The  version  now  before  us  was 
undertaken,  and  has  been  very  ably  made,  by  the  translator,  and  those  who  hav  e 


REVIEWS  579 

in  various  ways  shared  his  labours,  with  the  object  of  bringing  to  the  knowledge 
of  a  number  of  readers,  even  larger  than  he  had  himself  secured  in  his  life-time 
and  through  his  own  language,  the  researches  and  the  conclusions  of  a  remarkable 
man. 

Mr.  Edward  Lindsey,  who  contributes  an  editorial  preface— a  gracefully 
accomplished  task,  for  which  his  own  position  and  attainments  well  qualify  him — 
reminds  us  that  Tarde  was  an  original  thinker  in  three  separate  fields  of  know- 
ledge—psychology, sociology,  and  criminology— and  that  he  pursued  with  success 
the  careers  of  magistrate,  statistician,  and  professor  of  political  science.  It  is  not 
irrelevant  to  note  (though  in  the  most  summary  fashion)  the  chief  phases  or 
chapters  of  his  full  and  varied  life.  Born  at  Sarlat  in  Southern  France  in  1843, 
and  educated  at  the  Jesuit  College  in  that  place,  he  early  showed  an  inclination 
for  philosophical  inquiry.  After  studying  law  at  Toulouse  and  at  Paris,  he 
returned  to  his  native  town  to  practise  as  a  lawyer. 

In  1869  he  was  made  a  judge  of  the  Tribunal  of  First  Instance  at  Sarlat,  and 
in  1875  juge  diminution.  This  position  he  occupied  till  1894,  when  he  was 
appointed  chief  of  the  Bureau  of  Statistics  in  the  Department  of  Justice. 
Established  in  Paris,  Tarde  was  soon  appointed  to  a  chair  in  the  School  of 
Political  Sciences  ;  in  1900  he  became  Professor  in  the  College  of  France,  and 
was  elected  to  the  Institute  as  a  member  of  the  Academy  of  Moral  and  Political 
Sciences. 

Throughout  this  life,  which  ended  in  1904,  he  supplemented  and  enriched  his 
public  and  professional  work  by  numerous  writings.  In  1880  he  contributed  to 
the  Revue  philosophique  a  series  of  discussions  and  criticism  of  the  theories 
of  Lombroso.  He  was  associated  with  Professor  Lacassaque  in  the  establishment 
of  the  Archives  cT Anthropologic  Criminelle,  and  regularly  contributed  to  this 
journal  his  life  long.  His  books  followed  one  another  in  rapid  succession. 
La  Criminalite  comparfe,  the  earliest,  appeared  in  1886,  and  passed  through 
several  editions.  The  author  sets  out  the  view,  which  he  developed  and  illustrated 
afterwards  in  other  publications,  that  the  criminal  is  a  professional  type,  and  treats 
crime  as  a  social  phenomenon.  In  1890,  when  he  also  produced  the  book  now 
given  in  English  translation,  he  wrote  Les  Lois  limitation  ;  in  1895  came  La 
Logique  Sociale,  and  two  years  later  L'Opposition  Universelle.  fetudes  penales  et 
Sociales  (1891),  Les  Transformations  du  Droit  (1894),  Les  Transformations  die 
pouvoir  (1899),  L? Opinion  et  la  Foitle  ( 1 90 1 ),  and  Psychologie  iconomique  (1902), 
are  among  his  other  writings.  The  titles  illustrate  at  once  the  wide  range  of 
Tarde's  interests,  and  his  concentration  upon  a  single  problem  for  the  elucidation 
of  which  he  was  able  to  draw  not  only  upon  the  resources  of  his  varied  learning, 
but  upon  his  experience  as  a  man  of  affairs. 

The  present  volume  belongs  to  the  Modern  Criminal  Science  Series,  in  which 
it  is  intended  to  include  important  treaties  on  criminology  written  in  foreign 
languages,  but  presented  in  English  Versions.  It  is  issued  under  the  auspices 
of  the  American  Institute  of  Criminal  Law  and  Criminology,  which  was  organised 
in  1909  at  the  National  Conference  held  in  that  year  at  the  North-Western 
University  in  Chicago.  A  committee  was  entrusted  with  the  duty  of  selecting 
works  for  translation,  and  for  arranging  that  they  should  be  published.  The 
members  of  the  committee  have  prefixed  a  brief  introduction  to  the  book  novy  before 
us.  They  declare  their  opinion  that  "  for  the  community  at  large  it  is  important 
to  recognise  that  Criminal  Science  is  a  larger  thing  than  Criminal  Law.  The 
legal  profession,"  they  add,  "  in  particular,  has  a  duty  to  familiarise  itself  with 
the  principles  of  that  science  as  the  sole  means  for  intelligent  and  systematic 


58o  SCIENCE  PROGRESS 

improvement  of  the  Criminal  Law."  They  have  been  well  advised  in  selecting 
Tarde's  Treatise,  for  it  amply  justifies  their  thesis.  Tarde  was  at  the  same  time 
a  philosopher  and  a  practical  man  ;  his  philosophy,  based  upon  a  wide  observation, 
which  was  prompted  and  directed  by  a  mind  of  extraordinary  versatility  and,  what 
too  seldom  accompanies  versatility,  precision  ;  his  practice  was  guided  by  his 
philosophy,  which  again  was  based  upon  a  shrewd  and  instinctive  common-sense. 
As  M.  Bergson  pointed  out,  Tarde  was  not  one  of  those  philosophers  who  set 
out  with  a  theory,  and  devote  their  labours  to  establishing  it.  He  set  out  rather 
with  a  mind  alert,  individual,  sensitive,  and  in  itself  so  well  balanced  and  adjusted 
that  it  made  the  natural  and  the  right  response  to  facts,  seeing  them  justly,  feeling 
them  accurately,  and  interpreting  them  in  such  a  fashion  as  to  fuse  them  into 
a  theory,  which  shows  itself  to  be  no  subtle  invention  of  the  author,  but  rather 
his  discovery  by  a  law,  a  principle  of  unity  and  intelligibility  in  things 
themselves. 

It  may  be  expected,  and  it  is  certainly  much  to  be  hoped,  that  Penal  Philosophy ■, 
not  a  new  book,  as  we  have  seen,  and  already  well  known,  may  in  this  new  form 
make  its  way  among  many  readers  whom  it  has  not  hitherto  reached.  Produced 
now,  in  very  clear  and  vigorous  English,  for  which  the  translator  deserves  high 
praise,  it  is  intended  primarily  for  lawyers,  and  they  will  no  doubt  welcome  it ; 
but  it  will  receive  a  welcome,  we  are  confident,  not  only  from  them.  It  deserves 
and  should  receive  careful  attention  from  those  who  are  concerned  (and  who  are 
not  ?)  in  any  way  with  social  problems  and  sociological  investigations,  from  students 
of  history  and  anthropology  and  of  philosophy  generally.  It  lends  powerful 
support  to  the  belief,  constantly  repeated,  but  perhaps  rarely  entertained  with 
vivid  conviction,  in  the  reality  and  organic  development  of  Society. 

In  criticism  as  well  as  in  construction  it  is  a  great  achievement.  The  question 
of  freedom  is  dealt  with  in  a  vigorous  and  penetrating  discussion  ;  the  theoretical 
and  practical  defects,  both  of  philosophical  and  of  scientific  determinism,  are 
adroitly  and  convincingly  exhibited  ;  the  doctrine  that  responsibility  rests  upon 
freedom  of  the  will  is  examined  in  an  admirable  analysis  and  rejected,  respectfully 
but  definitely.  The  writer  recalls  Rameau's  distinction  drawn  between  the  "will 
of  all"  and  "the  general  will"  in  an  eloquent  passage  on  the  efficacy  of  punish- 
ments, and  the  reason  for  which  they  are  imposed.  While  refusing  to  admit 
"  utility  "  as  the  justification  and  ground  of  punishment,  he  strikes  the  "  utilitarians  " 
with  their  own  weapon,  and  yet  his  thrust  is  as  gentle  as  it  is  well  aimed,  for 
he  finds  in  them  a  certain  inconsistency — their  plea  is  "aesthetic"  after  all. 
Responsibility  rests,  we  learn,  upon  identity  of  the  self  and  upon  similarity  of 
environment  ;  and  to  substantiate  his  position  the  writer  traverses  the  territory 
of  the  alienist  and  the  religious  teacher ;  he  considers  the  phenomena  of  madness 
and  of  conversion  ;  and  considers  the  question  whether  a  new-comer  to  a  society, 
the  traditions  of  which  are  wholly  unlike  those  in  which  he  was  himself  brought 
up,  can  be  regarded  as  "  criminal  "  if  he  violates  its  rules  and  customs. 

It  is  not  necessary  to  agree  with  Tarde  in  order  to  admire  him  ;  it  is  impossible 
to  read  a  page  of  his  work  without  receiving  the  stimulus  which  is  to  be  derived 
from  witnessing  the  operations  of  an  intellect,  fearless  and  generous,  as  it  occupies 
itself  with  problems  which,  while  they  specially  attract  students  in  a  particular 
field  of  human  inquiry,  get  their  significance  for  such  students  because  they  touch 
human  experience  and  rouse  human  inquiry  beyond  the  borders  of  any  single 
profession. 

E.  T.  C. 


REVIEWS  581 

The  Wonders  of  Wireles3  Telegraphy.  By  H.  A.  Fleming,  M.A.,  D.Sc, 
F.R.S.  [Pp.  xi  +  279.]  (London  :  Society  for  Promoting  Christian  Know- 
ledge, 1913-     Price  y.  6d.) 

There  are  very  few  scientific  men  of  eminence  who  have  the  gift  of  making  the  most 
abstruse  subjects  clear  and  interesting  to  the  multitude.  Prof.  Fleming  is  happily 
one  of  these,  and  his  little  book  on  the  Wonders  of  Wireless  Telegraphy  is  not 
only  a  model  of  clear  exposition,  but  is  an  example  of  how  to  select  and  arrange 
just  the  features  of  interest  which  the  ordinary  reader  desires  to  hear  about.  If 
we  add  to  these  points  yet  one  more,  and  probably  the  most  important  of  all,  that 
there  is  from  cover  to  cover  of  the  little  book  neither  a  loose  statement  nor  an 
unfounded  assertion,  and  that  there  is  nothing  in  the  way  of  unsound  popular 
science,  it  is  clear  that  this  book  may  be  warmly  and  heartily  recommended 
to  readers  young  and  old. 

The  first  chapter,  dealing  with  the  aether,  electricity,  and  electrons,  commences 
with  a  brief  account  of  what  we  know  of  the  aether  itself,  treating  historically  the 
different  steps  in  the  discovery  of  the  velocity  of  light,  and  putting  clearly  and 
concisely  the  electrical  and  optical  phenomena  which  science  helps  us  to  under- 
stand, and  a  knowledge  of  which  is  the  first  step  in  a  study  of  the  nature  of  the 
aether  itself.  An  interesting  and  popular  account  is  given  of  the  researches  of 
Thomson,  Rutherford,  Soddy,  and  M.  and  Madame  Curie.  Having  given  an 
outline  of  the  constitution  and  structure  attributed  to  the  universal  space-filling 
aether,  and  the  way  in  which  the  electricity  atoms  are  now  supposed  to  be  built 
up  from  it,  the  next  step  is  naturally  to  discuss  electric  waves  and  oscillations, 
and  the  second  chapter  deals  with  these  oscillations,  making  use  of  the  hypothesis 
of  the  lines  of  strain  or  lines  of  force,  and  the  electrons  or  strain  forms  or  centres 
from  which  twists  or  waves  in  aether  start.  In  this  chapter  is  clearly  shown  the 
difference  between  damped  intermittent  oscillations  and  undamped  oscillations, 
and  the  way  in  which  lines  of  electric  force  surround  the  Hertzian  Oscillator. 

The  third  chapter  deals  with  actual  wireless  telegraph  instruments,  and  the 
sending  of  wireless  messages  ;  but  the  author  leads  up  to  this  important  subject 
by  a  description  of  signalling  both  in  the  Army  and  Navy,  and  continental  practice 
and  mode  generally,  in  which  intelligence  is  transmitted  at  a  distance  by  signals, 
particularly  the  Morse  Code,  giving  as  prelude  to  wireless  telegraphy  the  more 
simple  case  of  telegraphy  in  which  wires  are  used.  This  is  followed  by  a  descrip- 
tion of  various  types  of  antenna  or  aerial  used  with  wireless  telegraphy.  Also  a 
special  account  is  given  of  the  Marconi  discharges  and  arrangements  for  producing 
persistent  oscillations  by  the  electric  arc. 

The  next  chapter  deals  generally  with  the  subject  of  force  receivers  as  distin- 
guished from  transmitters,  showing  how  connections  are  made  with  the  receiving 
circuits.  It  is  explained  how  with  a  combination  of  a  telephone  in  series  with  an 
electrical  valve  a  telephone  can  make  audible  the  sparks  of  a  transmitter  hundreds 
of  miles  away. 

The  Marconi  magnetic  detector  and  coherer  is  described,  and  the  author's 
own  cymometer.  The  two  final  chapters  deal  with  wireless  telegraphy  over  land 
and  sea,  the  transmission  of  wireless  waves  around  the  world,  wireless  telegraphy 
and  telephony  in  practice,  and  the  utilisation  of  electromagnetic  waves. 

It  may  be  remarked— and  this  is  a  matter  of  no  small  importance — that  the 
illustrations  of  the  book  throughout  are  excellent ;  and  the  diagrammatic  figures, 
many  if  not  most  of  which  are  new,  tend  to  make  the  descriptions  of  the  text 
admirably  clear. 


582  SCIENCE  PROGRESS 

Mechanism,   Life,   and   Personality.     By  J.    S.    Haldane,    M.D.,   F.R.S. 
[Pp.  vi  +  139.]     (John  Murray.     Price  2.?.  6d.) 

This  small  volume  consists  of  four  lectures  delivered  to  senior  students  of  the 
London  University,  and  is  an  attempt  to  bring  the  great  biological  movement 
of  the  nineteenth  century  into  definite  relation  with  the  main  stream  of  human 
thought. 

Dr.  Haldane  has  proved  himself  well  fitted  for  the  task,  for  he,  unlike  many 
men  of  science,  never  loses  himself  in  "  the  snare  of  words  "  as  Locke  called  it, 
and  has  dealt  with  a  somewhat  abstruse  subject  in  an  admirably  simple  and 
lucid  manner.  The  arguments  are  so  clear,  that  even  those  wholly  unversed  in 
philosophy  will  have  no  difficulty  in  following  it  to  its  striking  conclusion. 

The  aim  of  the  first  two  lectures  is  to  examine  the  hypothesis  that  living 
organisms  may  be  regarded  as  conscious  or  unconscious  physical  and  chemical 
mechanisms,  and  can  be  satisfactorily  investigated  from  that  standpoint. 

The  author  first  states  the  case  of  those  who  hold  that  the  two  great  physical 
laws  of  the  conservation  of  matter  and  the  conservation  of  energy  can  be 
extended  with  apparently  rigorous  accuracy  to  all  living  mechanisms.  We  now 
know,  as  the  fruit  of  years  of  experiment  and  observation,  that  nowhere  does 
simple  protoplasm  exist,  not  even  among  the  lowest  and  most  primitive  saprophytic 
bacteria. 

The  Mechanistic  Theory  is  obliged  to  assume  that  a  living  organism,  such  as 
man,  is  a  complex  system  of  physico-chemical  mechanisms,  each  of  which  is 
controlled  by  the  rest  in  such  a  way  that  the  normal  structure  and  activity  of  the 
organism  is,  under  ordinary  conditions,  maintained.  Many  of  these  mechanisms 
have  been  proved  to  exist  by  exact  experiment,  and  hence  no  real  difficulty 
presents  itself  in  the  assumption.  The  fundamental  mistake  of  the  mechanistic 
physiologists  of  the  middle  of  the  last  century  was  that  they  completely  failed  to 
realise  that  living  structure  was  organised,  and  such  processes  as  secretion, 
absorption,  growth,  were  treated  as  if  each  were  an  isolated  physical  or  chemical 
process  instead  of  being  one  side  of  a  many-sided  metabolic  activity,  of  which  the 
different  sides  are  indissolubly  associated. 

Dr.  Haldane,  by  some  admirably  destructive  criticism,  disposes  of  the 
mechanistic  theory,  and  leaves  us  fully  convinced  of  the  inadequacy  of  that 
theory  to  explain  the  phenomena  of  Life. 

Scientific  materialism  superseded  the  scepticism  of  the  Victorian  era,  and  now 
we  are  told  on  many  sides  that  the  trend  of  modern  philosophic  thought  is  in  the 
direction  of  some  form  of  vitalism.  It  is  no  longer  widely  held  that  "a  generation 
which  speculates  upon  the  unknowable  sacrifices  progress  for  safety."  Dr.  Haldane, 
in  his  fourth  and  concluding  lecture,  comes  down  definitely  on  the  side  of  a 
fundamental  dualism.  It  is,  he  writes,  necessary  to  draw  a  sharp  and  clear 
distinction  between  biology  which  deals  simply  with  organic  life,  and  psychology 
which  deals  with  conscious  life  or  Personality.  He  holds  that  the  physiologist, 
who  treats  of  perception  and  volition,  is  going  outside  his  own  subject  endeavour- 
ing to  explain  psychological  phenomena  in  terms  which  cannot  be  applied  to 
them.  We  are  thus  led  on  gradually  until  we  find  ourselves  compelled  to  adopt 
the  spiritual  hypothesis,  an  attitude  of  mind  with  which  Henri  Bergson, 
Poincard,  and  others  of  the  modern  French  philosophic  school  have  made  us 
familiar. 

Dr.  Haldane  concludes  with  an  admirably  clear  summary  of  his  views  on  the 
whole  subject : 


REVIEWS  583 

"  The  relation  of  a  person,"  he  writes,  "  to  his  surrounding  world  with  which 
he  is  in  contact,  through  perception  and  volition  is  not  a  mere  external  relation, 
since  his  surrounding  world  is  ideologically  determined  in  relation  to  his  organic 
life.  It  is  a  mere  illogical  illusion  to  regard  the  world  we  perceive  as  independent 
of  its  relations  to  us  in  perception  and  volition.  The  visible  world  around  us  is 
a  world  moulded  by  our  own  personality,  and  there  is  no  other  world.  In  scientific 
work  we  can  abstract  from,  or  disregard,  the  psychological  aspect  of  things,  but  in 
so  far  as  we  do  so  we  are  dealing  with  abstractions.  The  relations  of  personality, 
mere  organism,  and  matter  are  relations  of  increasing  abstraction  from  reality. 

"Just  as  the  individual  organism  can  only  be  understood  as  participating  in  a 
wider  life,  so  the  individual  person  exists  only  in  participating  in  a  wider  personal 
existence.  He  can  only  realise  his  true  personality  in  losing  his  personality  as 
a  mere  individual.  Personality  is  the  great  central  fact  of  the  universe.  This 
world,  with'all  that  lies  within  it,  is  a  spiritual  world."  R.  F.  O. 

The  Realm  of  Nature:  An  Outline  of  Physiography.  By  Hugh  Robert  Mill, 
D.Sc,  LL.D.  [Pp.  xii,  404,  with  Illustrations.]  (London  :  John  Murray. 
2nd  Edition,  1913.  Price  5-r.  net.) 
This  is  a  second  and  revised  edition  of  a  well-known  book,  which  was  originally 
published  in  1891  and  which  has  been  previously  reprinted  six  times.  We  need 
not  be  surprised  at  its  popularity,  because  it  really  gives  concisely  a  very  excellent 
review  of  much  of  our  present  knowledge  of  Nature.  It  is  advisable  to  print  the 
following  complete  list  of  the  headings  of  the  chapters  in  order  to  indicate  the 
scope  of  the  work.  These  are  :  The  Study  of  Nature  ;  The  Substance  of  Nature  ; 
Energy,  the  Power  of  Nature  ;  The  Earth  a  Spinning  Ball ;  The  Earth  a  Planet  ; 
The  Solar  System  and  Universe  ;  The  Atmosphere  ;  Atmospheric  Phenomena  ; 
Climates  of  the  World  ;  Weather  and  Storms  ;  The  Hydrosphere  ;  The  Bed  of  the 
Oceans  ;  The  Crust  of  the  Earth  ;  Action  of  Water  on  the  Land  ;  The  Record  of 
the  Rocks  ;  The  Continental  Area  ;  Life  and  Living  Creatures  ;  Man  in  Nature. 
The  large  number  of  maps  and  illustrations  are  a  great  additional  attraction  ;  and 
the  whole  book,  cheap  as  it  is,  is  one  which  can  well  be  read,  not  only  by  young 
people,  but  by  scientific  men  who  wish  to  know  about  things  outside  the  small 
tracts  to  which  science  condemns  them  too  often  to  confine  their  labour.  An 
additional  chapter  upon  what  is  now  known  regarding  the  causation  of  the 
infectious  diseases  would  have  been  useful,  but  it  may  have  been  felt  that  this 
was  somewhat  outside  the  range  of  physiography.  The  whole  book  gives  us  what 
is  really  indeed  a  bird's-eye  view  of  natural  knowledge  ;  and  the  student  can 
afterwards  explore  what  regions  he  pleases  in  more  detail. 

The  Oceaa.    A  General  Account  of  the   Science  of  the   Sea.     By   Sir  John 

Murray,    K.C.B.,    F.R.S.,    LL.D.,    D.Sc,    Ph.D.      [Pp.    256    with    12 

Plates.]     (London  :  Williams  &  Norgate.     Price  is.  net.) 

The  British  public  ought  to  be  the  best  educated  people  in  the  world,  because 

they  can  obtain  information  from  the  most  highly  qualified  experts  on  almost  any 

subject  for  the  sum  of  one  shilling.     This  little  book  by  Sir  John  Murray  raises 

the  question  whether  higher  education  is  not  most  economically  given  by  works 

of  this  nature.     It  is  really  an  admirable  summary  of  the  subject.     Beginning 

with   some   historical   notes   and  a   brief  account   ot   the   various   methods  and 

instruments  used  for  deep-sea  research,  it  proceeds  to  consider  the  depth  of  the 

ocean,  its  waters,  salinity,  gases  and  temperature,  compressibility,  pressure,  colour, 

viscosity,  penetration  of  light,  tides,  waves  and  seiches.     The  oceanic  currents  are 

lucidly  described,  and  the  remainder  of  the  book  deals  with  life  in  the  ocean  and 

marine  deposits,  etc.    There  is  a  glossary,  a  bibliography,  and  an  excellent  index  ; 

and  also  some  useful  maps  and  figures.     The  book  is  very  carefully  written  and 

38 


584  SCIENCE   PROGRESS 

printed,  and  can  be  recommended  for  all  readers  from  boyhood  even  to  the  mature 
years  at  which  the  scientific  mind  is  supposed  to  reach  its  zenith  of  power.  The 
account  of  the  flora  and  fauna  of  the  ocean,  however,  would  have  been  somewhat 
clearer  if  the  various  groups  had  been  considered  in  some  better  biological  order. 

The  Meaning  of  Evolution.    By  Samuel    Christian    Schmucker,  Ph.D, 

[Pp.  298.]  (London  :  Macmillan  Co.,  1913.  Price  6s.  bd.  net.) 
A  very  clearly  written  popular  exposition  of  evolution.  The  book  begins  with 
a  history  of  the  development  of  our  ideas  on  the  subject  from  the  time  of  the 
Greek  philosophers  up  to  Cuvier  and  Lamarck,  and  then  gives  in  much  greater 
detail  the  life  and  work  of  Darwin.  Next  the  various  strands  of  thought  which 
make  up  the  total  conception  are  well  analysed  and  explained,  with  many  examples 
which  will  be  of  interest  to  all  readers.  The  work  also  contains  numerous 
references  to  interesting  special  discoveries,  and  has  an  excellent  chapter  on 
evolutionary  theories  since  Darwin.  This  would  have  been  much  better,  how- 
ever, if  there  had  been  some  account  of  Mendelianism.  The  book  concludes 
with  a  theistic  chapter.  It  is  a  very  sane  and  lucid  abstract  of  the  subject,  and 
will  be  useful  to  all  general  readers. 

Life,  Light,  and  Cleanliness.  A  Health  Primer  for  Schools.  Published  under 
the  Director  of  Public  Instruction,  Punjaub.  [Pp.  126.]  (Lahore  :  Rai 
Sahib  M.  Gulab  Singh  &  Sons,  191 2.  Price  8  annas.) 
This  little  book  is  perhaps  the  very  best  primer  ever  published  for  teaching 
sanitation  in  Indian  schools,  or  even  in  any  schools  in  the  tropics.  Although  it 
has  been  published  anonymously,  it  is  written  by  Major  E.  L.  Perry  of  the  Indian 
Medical  Service.  A  large  number  of  primers  of  this  kind  are  on  the  market  ;  but 
Major  Perry's  booklet  has  the  great  advantage  that  it  is  put  in  the  form  almost 
of  the  Arabian  Nights  Entertainments.  The  story  is  that  of  a  conversation 
between  a  Rajah  of  India,  "who  ruled  over  a  very  fine  country,"  and  various  indi- 
viduals, such  as  merchants  and  physicians.  In  consequence  of  these  conversations 
the  Rajah  sent  his  eldest  son  to  investigate  matters  of  health  in  a  neighbouring 
country,  where  the  people  "  were  a  fine  sturdy  race  because  from  childhood  up 
they  obey  the  rules  of  health."  The  details  of  this  journey  are  so  interesting 
that  children  will  read  them  with  pleasure,  and  will  learn  everything  about 
sanitary  matters  en  route — mosquitoes  and  malaria,  the  taking  of  quinine,  the 
causation  of  plague  by  rat-fleas,  and  the  mode  of  spread  of  cholera.  These 
become  fixed  in  the  mind  of  youth  in  a  manner  which,  we  fear,  is  not  done  by 
the  much  more  stately  but  less  effective  works  of  formal  sanitation  which  are 
usually  disseminated  amongst  the  public.  We  should  like  to  see  this  work 
translated  into  many  languages,  and  cast  broadside  throughout  the  schools  in 
the  tropics.  The  Director-General  of  the  Indian  Medical  Service  pointed  out 
in  Science  Progress  for  October,  191 3,  the  difficulties  with  which  sanitation 
in  India  is  confronted  in  consequence  of  the  ignorance  of  the  native  population — 
and  the  European  population  is  not  always  very  much  better.  This  little  book 
ought  to  do  much  to  remove  that  ignorance.  R.  ROSS. 

Panama:   The  Creation,   Destruction,    and   Resurrection.     By   Philippe 

Bunau-Varilla.     With  Portrait  of  Author  and  numerous  other  portraits, 

plates,  and    figures    referring    to  the    Panama    Canal.       [Pp.    xx  +  568.] 

(London:  Constable  &  Co.,  1913.     Price  12J.  6d.) 

We  have  space  only  to  refer  briefly  to  this  great  book — written  in  English  and  in 

French  by  the  author  himself,  who  was  one  of  the  principal  moving  spirits  in  the 


REVIEWS  585 

construction  of  the  Canal.  The  book  is  a  great  one  because  it  recalls  a  great 
work.  M.  Bunau-Varilla  went  to  Panama  at  the  age  of  twenty-five  in  the  year 
1884,  and,  owing  to  the  death  of  senior  officials,  soon  found  himself  Acting 
Director  of  the  works.  Owing  to  his  great  ability  and  energy  the  labour  pro- 
gressed rapidly  under  the  French  management,  in  spite  of  the  terrible  mortality 
from  yellow  fever.  The  book  records  in  the  admirable  French  style  all  the  difficulties 
which  were  contended  with,  and  the  part  played  by  him,  not  only  in  the  early 
developments,  but  in  the  later  negotiations  resulting  in  the  retention  of  the  Panama 
Canal  Zone  as  the  site  of  this  magnificent  enterprise.  I  may  venture  to  say  here 
that  when  I  was  in  Panama  in  1904,  the  Americans  were  loud  in  their  praises  of 
the  previous  works  of  the  French — with  which  the  author  was  so  gloriously 
connected.  The  book  contains  many  points  which  will  interest  all  scientific  men, 
especially  engineers,  and  those  medical  men  who  have  been  connected  with  the 
prevention  of  disease  in  the  tropics — though,  of  course,  the  author,  being  an 
engineer,  does  not  deal  very  specifically  with  this  part  of  the  subject,  beyond 
giving  us  an  idea  of  how  yellow  fever  impeded  the  work  in  the  early  days.  Such 
books,  being  records  of  great  work  done,  should  be  read  by  every  one. 

R.  Ross. 

Experimental  Domestic  Science.  By  R.  Henry  Jones,  M.Sc,  F.C.S., 
Chemical  Department,  Harris  Institute,  Preston.  [Pp.  ix  +  235.]  (London  : 
W.  Heinemann,  1912.     Price  2S.  6d.) 

THE  promotion  of  domestic  science  is  one  of  the  most  promising  of  recent 
developments  in  modern  education.  It  is  all-important  to  have  science,  and 
especially  that  of  hygiene,  applied  to  the  home  ;  but  the  chief  centre  of  science 
in  every  home  is  undoubtedly  the  kitchen,  and  this  well  deserves  to  be  elevated 
to  a  higher  position,  and  to  receive  more  attention  and  study  than  it  has  done  in 
the  past.  It  is  there  that  energy  is  developed  and  health  maintained,  and  without 
due  regard  to  proper  foods  and  their  careful  preparation  it  is  almost  impossible 
to  have  either  a  healthy  or  a  happy  and  contented  household. 

Any  work,  therefore,  which  contributes  tangibly  to  attain  this  end  is  worthy 
of  consideration,  and  that  which  has  just  been  issued  by  Mr.  R.  H.  Jones  is  a  very 
practical  and  useful  addition  to  the  limited  facilities  now  at  the  disposal  of  the 
student.  It  is  chiefly  devoted  to  explaining  the  character,  and  giving  the  con- 
stituents, of  the  different  foods  in  every-day  consumption  and  use,  while  also 
showing  the  chemical  changes  that  take  place  in  the  various  processes  of  cooking. 
This  is  very  valuable  and  much-required  information,  and  Mr.  Jones  gives  it  in 
a  simple,  concise,  and  explicit  form.  A  series  of  experiments  are  offered  through- 
out the  book,  which  can  be  tried  without  any  expert  knowledge  of  chemistry,  and 
these  should  add  considerable  interest  to  the  study  of  the  subject  while  impressing 
facts  and  results  upon  the  memory.  A  number  of  the  experiments  have  been 
tested  in  the  laboratory  of  the  Institute  of  Hygiene,  and  they  have  been  found 
to  be  invariably  accurate  and  quite  reliable.  There  is,  further,  a  series  of 
questions  at  the  end  of  each  chapter  which  should  prove  very  useful  when  the 
work  is  adopted  as  a  class-book  in  schools. 

It  is  not  claimed  that  "  Experimental  Domestic  Science  "  deals  with  such  a 
wide  subject  comprehensively — that  would  be  impossible  within  the  limitations 
of  a  comparatively  small  volume  ;  but,  as  far  as  it  goes,  it  is  well  done,  and  it  is 
a  praiseworthy  effort  to  bring  science  and  the  home  into  closer  touch.  It  repre- 
sents a  branch  of  study  yet  in  its  infancy,  and,  while  it  is  written  for  and  fully 


586  SCIENCE   PROGRESS 

meets  the  requirements  of  our  present  state  of  progress,  it  is  to  be  hoped,  and 
we^anticipate,  that  extension  on  the  same  lines  and  a  work  more  advanced  will 
be  a  pressing  need  of  the  future. 

J.  Grant  Ramsay 

(Incorporated  Institute  of  Hygiene). 


BOOKS   RECEIVED 

{Publishers  are  requested  to  notijy  prices) 

The  Hindustan  Review.  Vol.  xxviii.  No.  167.  Verbatim  reprints  of  the  Indian 
Law  Reports  (1876-1900)  in  the  Indian  Decisions  (new  series).  Published  by 
I.  A.  Venkasawmy  Row  and  T.   S.  Krishnasawmy  Row,    The  Law  Printing 

"«-»  House,  Mount  Road,  Madras.     (Pp.  540.)     Price  10  Annas. 

Problems  of  Genetics.  By  William  Bateson,  M.A.,  F.R.S.,  Director  of  the  John 
Innes  Horticultural  Institution,  Hon.  Fellow  of  St.  John's  College, 
Cambridge,  and  formerly  Professor  of  Biology  in  the  University.  With 
illustrations.  Humphrey  Milford,  Oxford  University  Press,  London,  E.C., 
and  at  Toronto,  Melbourne,  and  Bombay.     (Pp.  ix,  258.)     Price  17s.  net. 

Fortschritte  der  Naturwissenschaftlichen  Forschung.  Edited  by  Prof.  Dr.  Emil 
Abderhalden,  Direktor  des  Physiologischen  Institut  der  Universitat,  Halle 
a.S.  With  102  Illustrations  and  2  Plates.  Vol.  9.  Urban  &  Schwarzenberg, 
Berlin  and  Vienna,  1913.     (Pp.  280.)     Price  17  marks. 

Rubber  and  Rubber  Planting.  By  R.  H.  Lock,  Sc.D.,  Inspector  H.M.  Board 
of  Agriculture  and  Fisheries,  Sometime  Scholar  and  Fellow  of  Gonville  and 
Caius  College,  Cambridge,  and  Assistant  Director  of  Botanic  Gardens, 
Ceylon.  Cambridge  University  Press,  Fetter  Lane,  E.C.  Crown  8vo. 
(Pp.  xiv,  246.)     With  10  Plates  and  18  Text  Figures.     Price  5.9.  net. 

Hope  and  Health.  Golden  Advice  to  Overcome  the  Drink  Habit.  By  "  One  who 
Cured  Himself.''  London :  A.  M.  King  &  Co.,  Wine  Office  Court,  E.C. 
(Pp.  44.)     Price  is. 

Science  of  Nature-History.  A  Line  of  Study  for  Assigning  Places  to  all  Events 
in  Creation  in  Order  of  Time  showing  their  Genesis,  which  may  Define 
Themselves.  A  Guide  to  Systematise  Knowledge.  By  Nasarvanji  Jevanji 
Readymoney.  Bombay  :  The  Times  of  India  Office  ;  London  Agency,  121, 
Fleet  Street,  E.C,  1907.    (Pp.  103.) 

Metallography.  By  Cecil  H.  Desch,  D.Sc.  (Lond.),  Ph.D.  (Wiirzb.),  Graham 
Young,  Lecturer  in  Metallurgical  Chemistry  in  the  University  of  Glasgow. 
With  14  Plates  and  108  Diagrams  in  the  Text.  Second  Edition.  Longmans, 
Green  &  Co.,  39,  Paternoster  Row,  London,  New  York,  Bombay,  and  Calcutta, 
1913.     (Pp.  x,  431.)     Price  9.?.  net. 

Die  Physik  der  bewegten  Materie  und  die  Relativitatstheorie.  Von  Max  B. 
Weinstein.  Leipzig,  1913  :  Verlag  von  Johann  Ambrosius  Barth.  (Pp.  xii,  424.) 
Price  17  marks. 

A  Dictionary  of  Applied  Chemistry.  By  Sir  Edward  Thorpe,  C.B.,  LL.D., 
F.R.S.,  Emeritus  Professor  of  Chemistry,  Imperial  College  of  Science  and 
Technology,  South  Kensington,  London  ;  Late  Principal  of  the  Government 
Laboratory,  and  a  Past  President  of  the  Chemical  Society  and  of  the  Society 
of  Chemical  Industry.  Assisted  by  Eminent  Contributors.  Revised  and 
Enlarged  Edition.  In  5  Vols.  Vol.  v.  With  Illustrations.  Longmans, 
Green  &  Co.,  39,  Paternoster  Row,  London,  New  York,  Bombay,  and  Calcutta, 
1913.     (Pp.  830.)     Price  455-.  net. 

Scienta  (Rivista  di  Scienza),  Organo  Internazionale  di  sintesi  scientifica  (Inter- 
national Review  of  Scientific  Synthesis).  Editors,  G.  Bruni,  A.  Dionisi,  F. 
Enriques,  A.  Giardina,  E.  Rignano.  Vol.  xiv.,  Year  VII.  Bologna  :  Nicola 
Zanichelli.  London  :  Williams  &  Norgate.  French  Translations  of  Italian, 
German,  and  English  articles.     (Pp.  251.) 


BOOKS  RECEIVED  587 

Spencer's  Philosophy  of  Science.  The  Herbert  Spencer  Lecture,  delivered  at  the 
Museum,  November  7,  1913,  by  C.  Lloyd  Morgan,  F.R.S.  Oxford  :  At  the 
Clarendon  Press.     (Pp.  53.)     Price  2s.  net. 

American  Chemical  Journal.  Ira  Remsen,  Editor.  Charles  A.  Rouiller,  Assistant 
Editor.     November,  1913.     Vol.  1.     (Pp.  82.) 

Les  Zooce'cidies  des  Plantes  d'Europe  et  du  Bassin  de  la  Mediterranee.  Descrip- 
tion des  Galles.  Illustration.  Bibliographie  detaillee,  Repartition  geogra- 
phique.  Index  bibliographique.  1567  figures  dans  le  texte,  3  planches  hors 
texte,  8  portraits.  Tome  Troisieme.  Supplement,  1909-12.  Nos.  6240  a 
7556.  Librairie  Scientifique.  A.  Hermann  et  Fils,  6  Rue  de  la  Sorbonne, 
Paris  (V.),  1913.     (Pp.  310).     Price  10  francs. 

Text-Book  of  Paleontology.  Edited  by  Charles  R.  Eastman,  A.M.,  Ph.D. 
Professor  of  Paleontology  in  the  University  of  Pittsburgh  and  Curator  at  the 
Carnegie  Museum,  Pittsburgh.  Adapted  from  the  German  of  Karl  A.  von 
Zittel,  late  Professor  of  Geology  and  Paleontology  in  the  University  of 
Munich.  Second  Edition,  revised  and  enlarged  by  the  editor  in  collaboration 
with  the  following  named  specialists  :  R.  S.  Bassler,  W.  T.  Caiman,  A.  H. 
Clark,  H.  L.  Clark,  J.  M.  Clarke,  J.  A.  Cushman,  W.  H.  Dall,  A.  Handlirsch, 
R.  T.  Jackson,  A.  Petrunkevitch,  P.  E.  Raymond,  R.  Ruedemann,  C. 
Schuchert,  J.  P.  Smith,  F.  Springer,  T.  W.  Vaughan,  C.  D.  Walcott.  Vol.  I. 
with  about  1,600  Illustrations.  London  :  Macmillan  &  Co.,  Ltd.,  St.  Martin's 
Street.     (Pp.  xi,  839.)     Price  25^.  net. 

Cabinet  Timbers  of  Australia.  Technical  Education  Series,  No.  18.  Techno- 
logical Museum,  Sydney.  By  R.  T.  Baker,  F.L.S.,  Corr.  Memb.  Phar. 
Soc.  Great  Britain,  Curator  and  Economic  Botanist.  Published  by  the 
authority  of  the  Government  of  the  State  of  N.S.W.  Sydney:  W.  A. 
Gullick,  Printer,  1913.     (Pp.  186.) 

Modern  Astrology.  The  Astrologers'  Magazine,  Christmas  Number.  Edited  by 
Alan  Leo.  Modem  Astrology  Offices,  Imperial  Buildings,  Ludgate  Circus, E.C. 
(Pp.  xi,  49.)     Price  6d. 

Logic.  Vol.  i.  Encyclopaedia  of  the  Philosophical  Sciences.  By  Arnold  Ruge, 
Wilhelm  Windelband,  Josiah  Royce,  Louis  Couturat,  Benedetto  Croce, 
Federigo  Enriquez  and  Nicolaj  Losskij.  Translated  by  Ethel  Meyer. 
London  :  Macmillan  &  Co.,  Ltd.,  St.  Martin's  Street,  191 3.     (Pp.  vi,  268.) 

Philosophy  of  the  Practical,  Economic  and  Ethic.  Translated  from  the  Italian  of 
Benedetto  Croce  by  Douglas  Ainslie,  B.A.  (Oxon),  M.R.A.S.  London: 
Macmillan  &  Co.,  St.  Martin's  Street,  1913.  (Pp.  xxxvii,  590.)  Price 
\2S.  net. 

The  Diseases  of  Tropical  Plants.  By  Melville  Thurston  Cook,  Ph.D.,  Professor 
of  Plant  Pathology,  Rutgers  College,  formerly  Chief  of  the  Department  of 
Plant  Pathology  for  the  Republic  of  Cuba.  London  :  Macmillan  &  Co.,  Ltd., 
St.  Martin's  Street,  1913.     (Pp.  vi,  317)     Price  8s.  6d.  net. 

The  Progress  of  Scientific  Chemistry,  in  Our  Own  Times.  With  Biographical 
Notices.  By  Sir  William  A.  Tilden,  F.R.S.,  D.Sc.  Lond.,  Sc.D.  Dub.,  D.Sc. 
Vict.,  LL.D.  Birm.,  Fellow  of  the  University  of  London,  Corresponding 
Member  of  the  Imperial  Academy  of  Sciences,  St.  Petersburg,  formerly 
Professor  of  Chemistry  and  Dean  of  the  Royal  College  of  Science,  Professor- 
Emeritus  in  the  Imperial  College  of  Science  and  Technology,  London. 
Second  Edition.  Longmans,  Green  &  Co.,  39,  Paternoster  Row,  London, 
New  York,  Bombay,  and  Calcutta,  1913.     (Pp.  x,  366.)     Price  ys.  6d.  net. 

Handbuch  der  Hygiene.  Edited  by  Prof.  Dr.  M.  Rubner,  Geh.  Medizinalrat, 
Berlin  ;  Prof.  Dr.  M.  S.  Gruber,  Obermedizinalrat,  Miinchen  ;  and  Prof. 
Dr.  M.  Fischer,  Berlin.  Vol.  3,  Third  Part.  Die  Infektionskrank- 
heiten,  Pathogene  tierisch  Parasiten  (Protozoen,  Wiirmer,  Gliederfussler). 
With  192  figures  and  32  Coloured  Plates.  Leipzig:  Published  by  S.  H. 
Hirzel,  1913.     (Pp.  390.)     Price  24  marks. 


CORRESPONDENCE 

"MAN   AND   HIS   FORERUNNERS" 

To  the  Editor  of  "Science  Progress" 

Sir,— 

I  have  been  asked  by  Prof.  v.  Buttel-Reepen  to  correct  an  error  in  the 
review  of  his  book,  Man  and  His  Forerunners,  which  appears  in  the  October 
number  of  Science  Progress.  Your  reviewer  states  that  we  "go  the  whole 
way  with  Rutot."  It  is  not  clear  to  what  this  vague  statement  refers,  since 
Dr.  Rutot  necessarily  "  goes  "  in  different  directions  on  different  subjects,  but  if 
(as  appears  probable)  it  refers  to  that  scholar's  well-known  advocacy  of  Oligocene 
eoliths,  it  is  quite  erroneous.  The  question  of  Oligocene  eoliths  is  discussed  on 
p.  II,  and  the  author  rejects  their  claims,  stating  that  he  believes  the  Upper 
Miocene  to  be  the  oldest  stratum  in  which  worked  stones  have  been  found.  It 
is  true  that  the  "  some  experts  "  who  believe  in  the  genuineness  of  the  Oligocene 
specimens  are  not  mentioned  by  name,  but  of  course  we  cannot  suppose 
Prof.  Elliot  Smith  to  be  ignorant  of  the  fact  that  Rutot  is  one  of  the  chief 
upholders  of  this  doctrine.  So  far  from  going  the  whole  way  with  Rutot  on  this 
question,  Prof.  v.  Buttel  goes  no  more  than  half  the  way  with  that  authority. 

Several  of  Prof.  Smith's  other  comments  are  misleading,  and  I  may  add  that 
the  opinions  expressed  in  the  book  are  not  necessarily  in  all  cases  those  of  the 
translator. 

Yours  faithfully, 

A.  G.  Thacker. 
Gloucester,  November  15,  1913. 

To  the  Editor  of  "  Science  Progress  " 
Sir,— 

I  accept  Mr.  Thacker's  correction  that  "  Prof.  v.  Buttel-Reepen  goes  no 
more  than  half  way  with  Rutot " ;  but  at  the  same  time  I  do  not  think  such  an 
arithmetical  qualification  seriously  affects  the  real  meaning  of  my  criticism. 
Prof.  v.  Buttel-Reepen  leaves  the  solid  ground  of  fact  (i.e.  that  no  unquestionable 
human  remains  or  certain  evidence  of  human  workmanship  has  been  found  except  in 
the  Pleistocene,  so  that  even  to  postulate  the  existence  of  man  in  the  late  Pliocene 
is  straining  inference  to  its  uttermost)  and  when  he  takes  the  plunge  into  the 
waters  of  unrestrained  conjecture  it  does  not  matter  much  whether  he  floats  in 
the  Upper  Miocene  or  dives  into  Oligocene,  or  even  Eocene,  depths.  In  either 
case  he  is  in  the  water  with  Rutot. 

Yours  faithfully, 

G.  Elliot  Smith. 
The  University  of  Manchester,  November  17,  1913. 


To  the  Editor  of  "Science  Progress" 
Dear  Sir,— 

Will  you  allow  me  to  correct  a  misprint  in  your  last  issue.  In  the 
footnote  on  p.  263  occurs  the  term  bad  ratios  ;  it  should  be  lead  ratios.  The 
value  of  this  method  I  hope  to  deal  with  on  a  future  occasion. 

Youis  truly, 

H.  S.  Shelton. 
5S8 


NOTES 

The  Finances  of  Tropical  Medicine 

Whether  Britain  has  taken  as  leading  a  place  in  the  great 
world-movements  of  recent  years  as  she  did  in  those  of  last 
century  may  perhaps  be  doubted  ;  but  she  has  certainly  done  so 
in  the  line  of  tropical  medicine.  Summed  up,  the  recent  work  in 
this  branch  of  science  has  resulted  in  the  finding  of  the  cause  and 
mode  of  propagation  of  many  of  the  most  important  tropical 
diseases — a  discovery  which  is  obviously  of  fundamental  value 
as  regards  the  development  of  more  than  half  the  world.  It  will 
therefore  be  of  interest  to  all  scientific  men  to  learn  some  facts 
regarding  the  finances  of  the  movement. 

Putting  aside  the  large  work  done  by  the  public  medical 
services  and  by  foreigners,  we  shall  touch  only  the  work  of  the 
two  schools  of  Liverpool  and  London,  which  were  founded  in 
1899,  and  have  consequently  been  in  existence  for  fourteen  years. 
From  figures  which  are  probably  as  accurate  as  can  be  obtained, 
we  gather  that  the  Liverpool  School  has  collected  from  the 
beginning  a  sum  of  about  £130,000,  entirely  from  private  sources, 
including  bequests,  special  subscriptions,  annual  subscriptions, 
donations  for  the  founding  of  Chairs,  students'  fees,  etc.  In 
addition  to  this  it  has  received  over  £8,000  from  Government. 
The  London  School  appears  to  have  received  about  £133,000 
from  such  private  sources  as  those  mentioned  above,  and  also 
about  £22,000  from  various  Government  sources.  Thus  the 
contributions  by  Governments  amount  to  about  £30,000  during 
the  fourteen  years,  against  a  sum  of  about  £264,000  contributed 
from  private  sources  and  students'  fees ;  so  that  the  Government 
contribution  comes  to  a  little  over  10  per  cent,  of  the  total 
receipts  of  the  two  schools  (£294,000).  For  this,  our  tropical 
possessions  have  received  very  great  benefits,  including  the 
carrying  out  of  many  expeditions  and  of  innumerable  researches 
on  tropical  medicine,  the  permanent  establishment  of  two  Schools 
of  Tropical  Medicine  with  buildings  and  two  endowed  Chairs,  the 

5S9 


59o  SCIENCE   PROGRESS 

instruction  of  about  two  thousand  medical  men,  including  officers 
of  the  Services ;  the  maintenance  of  experts  to  advise  on  official 
committees  and  on  sanitary  matters,  the  establishment  of  special 
museums,  and  the  publication  of  scientific  journals.  In  most 
other  countries,  all  these  expenses  would  have  been  met  out  of 
Government  funds  ;  and  it  must  be  admitted  that  British  adminis- 
tration is  fortunate  in  that  it  can  persuade  private  persons  to 
help  it  in  such  matters  on  such  a  large  scale. 

The  total  sum  of  money  appears  to  be  large,  although  it  is 
less  than  the  fortune  of  hundreds  of  private  citizens  in  Britain. 
As  a  matter  of  fact,  the  work  could  not  have  been  done  so  cheaply 
but  for  the  circumstance  that  most  of  the  workers  have  been 
content  to  sacrifice  their  time  and  themselves  for  the  public 
benefit  by  accepting  extremely  small  payment.  The  highest 
salary  given  at  either  of  the  Schools  has  reached  only  to  ^800  a 
year,  and  that  was  continued  only  for  three  years.  The  most 
serious  aspect  of  the  business  is  that  no  attempt  has  yet  been 
made  to  lay  down  pensions  for  any  of  the  workers  except  small 
ones  in  connection  with  the  two  Chairs.  To  put  it  briefly,  this 
great  imperial  work  has  really  been  carried  out,  not  only  by  the 
genius  of  the  workers,  but  very  largely  at  their  own  pecuniary 
expense — a  thing  which  can  only  be  described  as  being  rather 
dishonourable  for  a  country  which  is  so  wealthy  as  Great 
Britain.  The  fact  is  that  this  country  has  come  to  believe 
that  it  will  receive  almost  all  its  "medical  benefit"  for  nothing. 
The  poor  have  become  accustomed  to  receiving  treatment  in 
hospitals  for  nothing ;  the  well-to-do  frequently  escape  paying 
their  doctors'  fees ;  and  it  is  scarcely  proper  that  the  great 
British  Empire  itself  should  be  under  the  impression  that  it 
may  adopt  the  same  attitude  towards  those  who  have  benefited 
it  in  the  line  of  tropical  medical  science. 

The  result  is  as  may  be  imagined — that  good  workers  are 
becoming  increasingly  difficult  to  obtain,  for  the  simple  reason 
that  the  work  does  not  pay.  Though  Britain  probably  has 
greater  opportunities  for  such  researches  than  all  the  other 
nations  put  together,  her  output  of  labour  in  this  line  is  falling 
below  such  a  standard.  Thus,  out  of  two  hundred  articles  con- 
sidered in  Numbers  9  and  10  of  the  Tropical  Diseases  Bulletin 
(October  and  November  191 3),  only  47  were  by  British  workers  ; 
and  what  work  is  done  is  too  often  of  the  nature  of  hasty  observa- 
tion or  immature  hypothesis.     Unless  a  remedy  can  be  found. 


NOTES  59* 

l 

the  movement  is  not  likely  to  continue  to  prosper  so  far  as  the 
British  Empire  is  concerned. 


Eugenics  and  War 

In  the  Times  of  October  15,  Prof.  Carl  Pearson  published 
an  important  letter  on  the  position  of  eugenics  as  a  science,  in 
which  he  criticised  the  present  tendency  to  publish  premature 
theorems  upon  this  subject.  He  admitted  that  Sir  Francis 
Galton  thought  that  progress  towards  increased  race  efficiency 
should  be  made  by  two  routes,  namely  (1)  by  the  scientific 
study  of  heredity  and  environment  as  they  bore  on  racial 
development,  and  (2)  by  a  popular  movement  emphasising  the 
importance  of  these  factors  in  national  welfare  and  urging  their 
proper  appreciation  by  legislators  and  social  reformers.  Prof. 
Pearson  now  thinks  that  the  latter  line  of  work  is  being  rather 
overdone.  Eugenics,  he  thinks,  "  has  become  a  subject  for 
buffoonery  on  the  stage  and  in  the  cheap  press,"  and  he  adds 
that  "  eugenics  is  rapidly  developing  into  a  topic  for  the  poseur,. 
the  Kongressbummler  and  paragraphist  "  ;  and  he  gives  instances 
of  fallacious  dogmas  which  are  being  put  about.  His  warning 
is  a  timely  one — especially  in  view  of  such  a  "  Criticism  of 
Eugenics  "  as  is  given  by  A.  M.  Carr-Saunders  in  the  October 
number  of  the  Eugenics  Review.  Indeed,  the  same  number  of 
the  Eugenics  Review  contains  an  address  on  the  Eugenics  of  War 
by  Chancellor  Dr.  David  Starr  Jordan  of  Stamford  Universit}',. 
U.S.A.,  to  which  Prof.  Carl  Pearson's  criticism  appears  to  be 
most  pertinently  applicable. 

Chancellor  Jordan's  position  is  that  "the  effect  of  war  on 
nations  is  to  spoil  the  breed,  by  the  very  simple  process  of  the 
reversion  of  selection  .  .  .  because  the  result  of  it  would  be  that 
the  nations  would  breed  from  inferior  stock,  that  the  strong  men 
would  be  destroyed,  or  kept  from  marriage,  and  those  at  home — 
those  that  war  could  not  use — would  be  the  parents  of  the  next 
generation " — an  opinion  which  he  attributes  to  Benjamin 
Franklin.  "  If,"  he  says,  "  a  nation  has  destroyed  its  bravest,  its 
most  courageous,  its  most  soldierly  men,  it  will  cease  to  breed 
that  kind  of  man.  If  a  nation  destroys  its  men  who  are  over  six 
feet  high,  in  time  it  will  not  have  many  men  who  will  reach  that 
stature."  Thus,  he  argues,  war  must  be  disastrous  to  a  nation 
which  indulges  in  that  business — which  many  of  the  philanthro- 


592  SCIENCE   PROGRESS 

pists  of  Britain  and  America  seem  to  look  upon  as  being  a  kind 
of  pernicious  pastime  easily  capable  of  suppression.  "  If  you  go 
over  the  history  of  nations,"  he  says,  "  you  will  find  that  the 
downfall  of  any  nation  arises  through  the  gradual  weakening  of 
its  people,  and  the  gradual  rise  of  the  dominance  of  the  ruling 
power.  That  has  gone  on  in  proportion  to  the  destruction  of 
the  strong  and  the  fit."  He  gives  some  attempts  at  historical 
proof  of  this  hypothesis  ;  but  on  examination  they  can  scarcely 
be  called  satisfactory  ;  and  indeed  other  instances  suggesting  the 
opposite  conclusion  can  easily  be  cited.  For  example,  one  of  the 
most  virile  periods  of  English  history  was  that  which  followed 
immediately  upon  the  dreadful  Wars  of  the  Roses.  The  greatest 
development  of  Prussia  followed  shortly  after  the  wars  of 
Frederick  the  Great.  Rome  reached  her  highest  stage  at  a  time 
when  her  individual  citizens  were  themselves  most  engaged  in 
fighting  and  began  to  decay  as  soon  as  they  conducted  their  wars 
more  by  the  help  of  mercenaries.  Perhaps,  however,  the  most 
remarkable  historical  instances  of  the  good  effect  of  war  upon 
national  physique  are  to  be  found  in  the  cases  of  the  Zulus  and 
Masai  of  Africa,  who  were  well  known  to  be  at  once  the  finest  and 
most  warlike  men.  The  Sikhs  of  India  were  originally  a  religious 
sect  simply  drawn  from  the  surrounding  population  but  obliged 
to  defend  themselves  by  incessant  fighting  from  the  attacks  of 
their  neighbours.  Nevertheless  they  became  and  are  the  finest 
men  in  India,  as  admitted  by  the  British  soldiers  who  recruit  and 
train  Indian  troops.  Another  example  is  the  case  of  the  moun- 
taineers on  the  north-west  frontier  of  India — men  who  look  upon 
fighting  as  a  pleasure,  and  have  been  engaged  upon  it  amongst 
themselves  from  time  immemorial,  and  yet  possess  a  magnificent 
physique  and  morale  far  superior  to  that  of  the  plain-dwellers. 
At  the  same  time  the  Japanese  and  the  Indian  Ghurkas,  who 
have  also  done  much  fighting,  are  small  people,  but  remarkably 
warlike  and  efficient  nevertheless.  On  the  other  hand,  some  of 
the  feeblest  races  are  those  which  never  fight  if  they  can  help  it, 
or  always  run  away  in  order  to  live  and  fight  another  day. 
According  to  Chancellor  Jordan,  these  should  be  the  big  and 
strong  men,  whereas  the  Zulus,  the  Sikhs,  and  the  Afridis  should 
be  small  and  feeble. 

Of  course  the  subject,  vastly  important  as  it  is  as  regards  the 
whole  theory  of  civilisation,  is  much  more  complex  than  he  seems 
to  imagine.     It  is  quite  possible  that  hand-to-hand  and  modern 


NOTES  593 

fighting  may  have  different  effects  upon  racial  development. 
The  former  was  indeed  likely  to  have  precisely  the  opposite 
effect  to  that  imagined  by  Dr.  Jordan,  because  the  weak  men 
would  be  killed  out  by  the  fighting,  especially  where  all  the 
males  are  forced  into  war.  It  may  be  more  plausibly  argued 
that  in  modern  war  the  big,  the  courageous,  and  the  dutiful  men 
are  more  likely  to  be  selected  as  soldiers,  and  are  therefore  more 
likely  to  be  killed  in  battle;  but  this  would  apply  chiefly  to 
nations  which  adopt  voluntary  service  and  not  to  those  which 
adopt  universal  service.  But  even  here  there  are  qualifying 
considerations.  In  modern  war  the  greatest  mortality  is  due» 
not  to  the  fighting,  but  to  diseases.  In  fact,  the  subject  is  much 
too  complex  for  such  treatment  as  the  Chancellor  of  Stamford 
University  seems  to  think.  Moreover,  universal  military  train- 
ing may  possibly  have  such  a  good  effect  as  will  swamp  the 
occasional  loss  of  good  men  in  the  comparatively  rare  moments 
of  war  ;  while,  lastly,  we  have  no  scientific  grounds  for  assuming 
the  general  eugenic  law  which  he  appears  to  accept.  The 
children  of  weak  men  are  not  always  strong  nor  the  children  of 
strong  men  weak.  It  is  possible  that  the  training,  the  exercise, 
the  stimulation  of  all  effort  caused  by  war  do  far  more  towards 
raising  the  physique  and  morale  of  a  nation  than  the  selective 
slaughter  of  some  of  the  better  individuals  does  towards 
depressing  them.  In  our  last  number  we  drew  attention  to 
the  fact  that  the  French  and  the  Germans  have  obtained  leading 
places  among  the  great  nations  as  regards  the  scientific  Nobel 
Prizes  ;  and  yet  these  nations  are  precisely  those  which  were 
engaged  most  in  the  numerous  wars  of  last  century.  In  fact 
a  general  survey  of  human  history  appears  to  lead  us  to  a 
conclusion  precisely  opposite  to  that  arrived  at  by  Dr.  Jordan. 
War  is  a  dreadful  thing  ;  but  nevertheless  it  may  quite  possibly 
be  utilised  by  nature  for  raising  racial  standards  ;  and  the  first 
concern  of  science  is  to  ascertain  truth. 

The  University  of  Bristol 

Owing  to  the  energetic  action  of  the  Athenaeum,  which  has 
devoted  weekly  articles  to  the  affairs  of  this  University,  a 
resolution  was  moved  at  the  Meeting  of  the  University  Court 
held  on  November  14,  begging  that  the  Council  of  the  Univer- 
sity be  asked  to  inform  the  Court  fully  of  the  circumstances 
connected  with  the  appointment  of  Prof.  Cowl.    The  resolu- 


594  SCIENCE   PROGRESS 

tion  was  rejected  by  a  large  majority,  and  another  motion, 
namely,  "  that  a  full  public  inquiry  take  place  into  the  serious 
charges  of  maladministration  in  the  University,"  was  ruled  out 
of  order  by  the  Chairman.  The  Athenceum  has  expressed 
itself  very  clearly  to  the  effect  (and  we  agree  with  it)  that  the 
action  of  the  University  Court  cannot  be  looked  upon  as  being 
satisfactory  or  final.  Moreover,  only  one  of  the  doubtful 
points  in  the  action  of  the  University  was  referred  to  at  the 
meeting.  It  will  be  remembered  that  the  allegations  are 
(i)  that  one  of  the  professors  was  dismissed  under  circum- 
stances which  suggest  incorrect  procedure  or  unfair  treatment, 
or  both  ;  and  (2)  that  the  Council  bestowed  honorary  degrees, 
not  previously  recommended  by  the  Senate,  largely  upon  its 
own  members.  It  is  unfortunate  for  the  interests  of  univer- 
sity life  in  general  that  no  proper  inquiry  upon  these 
allegations  can  be  obtained. 

Science  and  the  Lay  Press  (Gordon  D.  Knox,  Morning  Post). 

"Nations,"  in  the  words  of  the  last  number  of  Science 
Progress,  "  no  more  than  individuals  can  be  allowed  to  remain 
ignorant,  sluggish,  and  unscientific."  If  the  statement  is  to  be 
something  more  than  a  pious  opinion,  means  will  have  to  be 
devised  for  the  education  of  the  public  in  the  results  and  in  the 
methods  of  science.  The  complete  victory  of  the  Huxley  School 
of  Thought  over  the  older  School  of  Theology  has  had  the 
unfortunate  effect  that  the  missionaries  of  science  have  found 
themselves  without  an  objective.  Lacking  the  stimulus  of 
opposition  they  have  left  the  market-place  for  the  laboratory, 
and,  science  being  kept  only  spasmodically  before  the  public 
eyes  by  such  sectional  disputes  as  centre  in  the  question  of 
vivisection,  the  public  is  ignorant  of  its  aims  and  indifferent  as 
to  its  condition.  The  inadequacy  of  the  payment  of  scientific 
men,  the  lack  of  funds  for  research,  and  the  apathetic  attitude  of 
the  Government  to  the  needs  of  science  are  the  reflection  of  the 
public  indifference  ;  and  if  this  attitude  of  mind  is  to  be  changed 
it  will  have  to  be  done  largely  through  the  public  press. 

The  misunderstanding  between  the  press  and  men  of  science 
is  so  complete  that  it  may  be  well  to  put  forward  a  few  of  the 
principles  that  must  inevitably  govern  any  attempt  that  is  made 
through  the  cojumns  of  the  press  to  enlist  the  public  interest  and 


NOTES  595 

support.  Men  of  science  must  abandon  once  and  for  all  the  idea 
that  the  newspapers  can  be  induced  to  publish  articles  of  the 
type  that  could  be  derived  from  the  evidence  of  such  Blue  Books 
as  the  Report  of  the  Vivisection  Commission.  The  historical 
article  is  a  thing  of  the  past,  and  the  history  of  scientific  achieve- 
ment can  only  find  a  place  in  the  columns  of  a  paper  in  connec- 
tion with  Centenary  Celebrations  and  public  events  of  current 
interest.  To  give  an  illustration.  It  is  of  no  use  to  ask  the 
editor  of  a  daily  paper  to  publish  afresh  the  dramatic  story  of 
the  victory  over  yellow  fever.  It  is  true  that  nine-tenths  of  the 
public  are  entirely  ignorant  of  it,  but  the  experience  of  the 
journalist  shows  that  that  same  nine-tenths  will  not  read  it  if  it 
comes  before  them  in  the  form  of  an  independent  article.  When 
the  Panama  Canal,  however,  is  opened  to  traffic  the  public  will 
wish  to  read  of  how  that  engineering  feat  has  been  accomplished 
and  it  will  then  be  possible  for  the  daily  papers  to  deal  with  such 
a  subject  as  that  of  yellow  fever  in  a  way  that  the  public  will 
read.  With  the  way  cleared  by  the  ruling  out  of  the  article  of 
the  historic  type,  one  may  consider  in  what  way  newspaper 
co-operation  can  be  looked  for.  The  essential  thing  to  remember 
is  that  the  primary  function  of  the  newspaper  is  to  disseminate 
news,  and  that  if  the  work  of  science  is  to  be  reported  it  must  be 
done  in  the  guise  of  news. 

At  the  present  time  few  of  the  learned  societies  or  institu- 
tions attempt  to  co-operate  with  the  correspondents  of  news- 
papers. And  yet  from  time  to  time  each  of  these  societies  has 
before  it  papers  that  are  of  great  public  interest,  papers,  that  is 
to  say,  which  chronicle  an  advance  in  some  direction  and  that 
by  careful  handling  can  be  brought  into  relation  with  the  stock 
of  ideas  possessed  by  the  ordinary  reader.  It  is  within  the 
knowledge  of  the  secretaries  of  the  societies  when  such  papers 
are  to  be  read  ;  but  I  believe  there  is  not  a  single  case  where  the 
governing  body  of  a  society  or  an  institution  has  made  it  an 
instruction  to  its  secretary  to  look  out  for  the  reading  of  such 
papers  and  to  warn  the  press  that  there  will  be  news  for  them  if 
they  care  to  attend. 

While  the  majority  of  the  scientific  societies  are  self-support- 
ing organisations,  and  therefore  under  no  obligation  to  the  press, 
the  same  is  not  the  case  with  the  majority  of  the  great  scientific 
institutions.  These  are  supported  largely  by  public  funds,  the 
money  being  derived  from  the  Government,  from  local  authorities, 


596  SCIENCE   PROGRESS 

from  popular  subscriptions,  or  from  the  donation  of  some  wealthy- 
individual.  The  mere  fact  of  a  newspaper  existing  is  presump- 
tive evidence  that  it  represents  a  section  of  public  opinion,  and 
the  fact  of  a  newspaper  representative  being  sent  to  make  an 
inquiry  is  an  indication  of  there  being  a  popular  demand  which 
it  should  be  the  duty  of  the  institution  to  supply.  If  it  is 
desirable  that  the  public  should  be  interested  in  science,  the 
heads  of  the  large  institutions  should  be  expected  to  go  out  of 
their  way  to  supply  the  daily  papers  with  news,  being  no  less 
careful  to  give  suitable  material  to  the  halfpenny  press  to  be 
served  up  in  the  style  which  experience  has  shown  is  best  suited 
to  their  readers  than  to  those  newspapers  which  will  treat  of  the 
subject  more  or  less  from  the  standpoint  of  the  man  of  science. 
Such  service  will  have  to  be  unpaid,  unfair  as  this  may  seem  at 
first  sight.  If  the  matter  is  looked  at  as  a  whole,  it  has  to  be 
remembered  that  the  service  rendered  to  science  by  the  news- 
paper in  publishing  outweighs  that  rendered  by  the  individual 
organisation  in  contributing.  The  politician,  the  Government 
office,  and  the  various  bodies  that  wish  to  influence  public 
opinion  all  supply  their  information,  recognising  that  the  press 
gives  more  than  it  receives ;  and  the  great  laboratories  and 
institutions  should  regard  it  as  an  obligation  to  teach  the  public 
to  think  on  scientific  lines  and  to  take  an  interest  in  scientific 
progress.  Even  from  the  money  standpoint,  however,  the 
bargain  will  not  be  such  a  bad  one.  Once  let  it  be  recognised, 
as  it  already  is  in  some  newspapers,  that  scientific  news  must  be 
treated  as  seriously  as  political  news,  and  a  fresh  opening  will 
be  made  for  those  who  have  had  a  scientific  training. 

Lastly  as  regards  the  presentation  of  news.  The  man  of 
science  must  trust  the  instinct  of  the  journalist.  Few  papers 
can  afford  to  present  scientific  news  in  the  way  that  is  acceptable 
to  those  who  furnish  it,  for  if  it  is  to  be  read  by  the  public  at 
large  it  must  be  presented  in  a  form  that  the  public  will  appre- 
ciate. Even  a  distorted  representation  of  the  truth  is  of  value, 
because  it  will  stimulate  some  readers  to  inquire  further;  and  it 
must  be  remembered  that  as  scientific  knowledge  increases,  the 
demand  for  accurate  presentation  will  grow.  What  journalist 
to-day  would  dare  to  write  such  a  description  of  a  cricket  match 
as  Charles  Dickens  wrote  in  the  Pickwick  Papers  ?  Or,  again, 
what  paper  dares  to  publish  absurd  canards  as  to  motoring  or 
aviation  ? 


NOTES  597 

In  conclusion,  it  has  to  be  remembered  that  all  is  not  well  in 
science.  Politicians  are  indifferent  to  its  welfare ;  public 
authorities  are  adepts  at  sweating  the  Medical  Officers  of  Health 
and  there  is  nothing  said ;  the  Universities  are  unable  to  pay 
respectable  salaries  even  to  their  professors ;  manufacturers  are 
only  beginning  to  realise  the  part  that  science  can  play  in 
developing  their  business  ;  the  city  is  open  at  any  time  to  the 
bait  offered  by  the  charlatan  (I  have  myself  been  sent  out  by  a 
newspaper  to  investigate  the  case  of  a  man  who  was  kept  for 
two  years  in  the  city  on  his  bare  statement  that  he  could  synthe- 
sise  radium)  ;  many  of  the  most  promising  men  who  would 
gladly  undertake  research,  finding  that  it  offers  them  no  career, 
turn  their  attention  instead  to  money-making;  and  industries 
that  are  ours  by  right  are  being  driven  abroad.  These  national 
evils  will  continue  so  long  as  we  remain  unscientific  as  a  nation. 
The  salvation  of  the  situation  lies  in  the  hands  of  the  press  ;  but 
the  press  is  and  will  remain  powerless  to  help,  so  long  as  the 
men  of  science  only  give  it,  as  at  present,  their  grudging 
co-operation. 

The  Noble  Prizes  for  1913 

These  have  been  awarded  as  follows  : 

For  Physics,  to  Prof.  Kammerlingh-Onnes,  Leyden. 
For  Chemistry,  to  Prof.  Alfred  Weiner,  Zurich. 
For  Medicine,  to  Prof.  Charles  Richet,  Paris. 
For  Literature,  to  Rabindra  Nath  Tagore,  India. 


NOTICE 

THE   EMOLUMENTS  OF  SCIENTIFIC   WORKERS 

It  is  proposed  to  undertake  an  inquiry  regarding  the  pay,  posi- 
tion, tenure  of  appointments,  and  pensions  of  scientific  workers 
and  teachers  in  this  country  and  the  Colonies.  The  Editor  will 
therefore  be  much  obliged  if  all  workers  and  teachers  who  hold 
such  appointments,  temporary  or  permanent,  paid  or  unpaid, 
will  give  him  the  necessary  information  suggested  below. 
The  figures  will  be  published  only  in  a  collective  form  and 
without  reference  to  the  names  of  correspondents,  unless  they 
expressly  wish  their  names  to  be  published.  The  Editor 
reserves  the  right  not  to  publish  any  facts  communicated  to 
him.  Workers  who  are  conducting  unpaid  private  investigations 
must  not  be  included.  The  required  information  should  be 
sent  as  soon  as  possible  and  should  be  placed  under  the 
following  headings  : 

(i)  Full  name 

(2)  Date  of  birth.     Whether   married.     Number   of  family 

living 

(3)  Qualifications,  diplomas,  and  degrees 

(4)  Titles  and  honorary  degrees 

(5)  Appointments  held  in  the  past 

(6)  Appointments  now  held,  with  actual  salary,  allowances, 

fees,  and  expected   rises,  if  any.     Whether  work  is 
whole  time  or  not 

(7)  Body  under  which  appointment  is  held 

(8)  Conditions  and  length  of  tenure 

(9)  Pension,  if  any,  with  conditions 

(10)  Insurance  against  injury,  if  any,  paid  by  employers 

(11)  Family  pensions,  if  any 

(12)  Remarks 


Printed  by  Hazell,  Watson  &  Vmey,  Ld.,  London  and  Aylesbury. 


SCIENCE  PROGRESS 

IN  THE  TWENTIETH   CENTURY 

A  QUARTERLY  JOURNAL  OF 

SCIENTIFIC    WORK 

&    THOUGHT 


VOL.  VIII 
NO.   32.     APRIL    19 14 


EDITOR 


SIR    RONALD    ROSS,   K.C.B.,    F.R.S.,    N.L., 
D.Sc,    LL.D.,   M.D.,  F.R.C.S. 


LONDON 
JOHN    MURRAY,    ALBEMARLE    STREET,   W, 

1914 


NOTICE 

Articles  and  reviews  offered  for  publication  should  be  addressed 
postage-paid  to  The  Editor  of  Science  Progress,  18,  Cavendish 
Square,  London,  W.  They  must  be  accompanied  by  the  full  name, 
address,  and  scientific  and  academical  qualifications  and  appoint- 
ments of  the  writer — for  publication,  unless  otherwise  desired. 
All  possible  care  will  be  taken  of  scripts ;  but  responsibility 
cannot  be  incurred  for  accidental  damage  or  loss.  It  must  be 
understood  that  papers  accepted  for  Science  Progress  shall 
not  be  published  elsewhere  without  the  Editor's  permission. 

Publications  sent  for  mention  or  review  should  also  be 
forwarded  postage-paid  to  the  Editor ;  but  such  mention  or 
review  cannot  be  promised.     Prices  should  always  be  notified. 

The  Editor  will  be  glad  to  receive  notice  of  scientific 
meetings  and  lectures;  of  public  appeals  for  scientific  purposes; 
of  new  scientific  instruments  and  apparatus ;  and  of  all  matters 
concerned  with  the  interests  of  science  and  of  scientific  workers. 

Correspondence  concerning  sales,  exchanges,  and  advertise- 
ments should  be  addressed  to  the  Publisher  of  Science  Progress, 
50A,  Albemarle  Street,  London,  W. 


c 


CONTENTS 


PAGE 


i.     SWEATING   THE   SCIENTIST       . 599 

2.  PHYSICS   IN    1913 608 

E.    N.    da    C.    Andrade,     B.Sc,     Ph.D.,    University, 
Manchester. 

3.  VERTEBRATE   PALEONTOLOGY   IN    1913       .         .         .626 

R.  Lydekker,  F.R.S. 
(Illustrated) 

4.  THE   NATURE   OF  THE   ARGON   FAMILY   OF   GASES     654 

Frederick  Soddy,  F.R.S.,  University,  Glasgow. 

5.  MOLECULAR  VOLUME  THEORIES   AND   THEIR   RE- 

LATION TO  CURRENT   CONCEPTIONS   OF  LIQUID 
STRUCTURE 663 

Gervaise  le  Bas,  B.Sc.  (Lond.). 

6.  ORGANIC   DERIVATIVES   OF    METALS   AND    METAL- 

LOIDS   ...........     690 

Prof.  G.   T.    Morgan,   D.Sc,    F.I.C.,    A.R.C.S.,    Royal 
College  of  Science,  Dublin. 

7.  PROF.   JOHN   MILNE 713 

Charles  Davison,  Sc.D.,  F.G.S. 

8.  THE     CORPUS     LUTEUM,     ITS     STRUCTURE     AND 

FUNCTION 721 

Charles  H.  O'Donoghue,  D.Sc. 

9.  THE   INFLUENCE   OF  THE  SCIENTIFIC  MOVEMENT 

ON    MODERN    POETRY 738 

E.  A.  Fisher. 

10.     CRITICISMS   OF    PSYCHICAL   RESEARCH      .        .         .755 

I.  J.  A.  Hill. 
II.  REPLY.     H.  S.  Shelton,  B.Sc. 

iii 


PAGE 


iv  CONTENTS 

ii.     REVIEWS  AND   BOOKS   RECEIVED. 

Translated  by  B.  Ethel  Meyer,   "  Encyclopaedia  of  the  Philo- 
sophical Sciences."     Vol.  i.  Logic.     (Macmillan)      .         .770 

F.  W.  Westaway,  "Scientific  Method."      (Blackie  &  Son,  Ltd.)     771 

C.     Lloyd     Morgan,    "Spencer's     Philosophy    of    Science." 

(Clarendon  Press) 772 

Harold  Jakoby,  "  Astronomy."     (Macmillan)    .         .         .         .773 

Max  B.  Weinstein,  "Die  Physik  der  bewegten  Materie  und  die 
Relativitatstheorie."     (Johann  Ambrosius  Barth)  .         .         .     773 

Sir  J.  J.  Thomson,  "  Rays  of  Positive  Electricity,  and  their 
Application  to  Chemical  Analysis."     (Longmans,  Green) 

E.  S.  A.  Robson,  "  Practical  Exercises  in  Heat."      (Macmillan)     776 

H.  Stanley  Allen,  "Photoelectricity."  (Longmans,  Green) .         .     777 

Karl  Eugen  Guthe,  "  Definitions  in  Physics."      (Macmillan) 

Frederick  Soddy,  "The    Chemistry   of  the    Radio-elements.' 
(Longmans,  Green)  ....... 

Sir  Edward  Thorpe,   "A  Dictionary  of  Applied  Chemistry' 
(Longmans,  Green) 

Sir  William  A.  Tilden,  "  The  Progress  of  Scientific  Chemistry.' 
(Longmans,  Green)  .         .  ..... 

"  American  Chemical  Journal."     (Ira  Remsen) 

W.  M.  Bayliss,  "  The  Nature  of  Enzyme  Action."     (Longmans 
Green)      ......... 

Cecil  H.  Desch,  "Metallography."     (Longmans,  Green)  . 

G.  W.  Walker,  "Modern  Seismology."    (Longmans,  Green) 

F.  H.    Hatch   and   R.    H.    Rastall,   "The    Petrology  of  the 

Sedimentary  Rocks."     (G.  Allen) 784 

F.    H.    Hatch,    "The    Petrology    of    the    Igneous    Rocks." 

(G.  Allen) 785 

Edited  by  Charles  R.  Eastman,  "  Text-book  of  Paleontology." 

(Macmillan)      .........     785 

William  Bateson,  "  Problems  of  Genetics."    (Oxford  University 

Press) 787 

C.  Timiriazeff,  "A  Possible  Physical  Aspect  of  the  Trichromatic 

Vision  Theory." 790 

Max  Verworn,  "  Irritability."     (Oxford  University  Press)  .     790 

J.  Duncan,  "Applied  Mechanics  for  Engineers."     (Macmillan)     791 

Books  Received 792 

794 
795 
795 

796 


12.     NOTES.     The  Sale  of  Honours  . 

The  Royal  Society      .... 
The  British  Association 

NOTICE.     The  Emoluments  of  Scientific  Workers 


778 
778 
780 

78i 
782 

782 

783 
783 


SWEATING  THE   SCIENTIST 

In  the  four  last  numbers  of  Science  Progress  a  notice  has 
been  inserted  asking  for  information  on  the  emoluments  of 
scientific  workers ;  and  a  considerable  number  of  interesting 
replies  have  been  received.  They  are  not  numerous  enough 
to  form  a  basis  for  any  statistical  investigation  of  the  subject — 
which  it  is  hoped  may  be  attempted  later  on  when  more 
evidence  has  been  collected;  but  the  replies  received,  combined 
with  information  which  may  be  otherwise  obtained,  suffice  to 
prove  the  low  scale  of  payment  given  throughout  the  British 
Empire  for  such  work. 

The  term  "  scientific  worker "  includes,  according  to  the 
notice,  all  salaried  workers — that  is,  men  of  all  grades,  namely, 
research  students,  assistants,  professors,  directors  of  labora- 
tories, and  other  fully  paid  workers,  and  also  half-time  and 
whole-time  workers.  The  duties  generally  include  teaching 
and  the  administrative  charge  of  university  departments, 
museums,  and  special  laboratories.  The  lowest  scale  of  pay 
mentioned  in  the  replies  is  £85  a  year  for  half-time  work ;  but 
it  is  notorious  that  a  large  number  of  such  workers,  especially 
in  medical  subjects,  are  paid  nothing  at  all.  The  pay  of  junior 
posts  (which  are  also  sometimes  unpaid)  rises  from  about  £120 
to  £200,  £250,  and,  rarely,  £300  a  year.  These  are  of  course 
not  so  important  as  the  upper  scales  of  pay  for  full-time  pro- 
fessorships and  permanent  appointments.  For  the  latter,  the 
highest  pay  mentioned  in  the  replies  amounts  to  ^850  a  year, 
with  a  small  pension  (Ceylon).  The  next  highest  are  salaries 
°f  £75°j  b°th  in  South  Africa,  and  one  of  .£500  in  Canada, 
with  small  pensions  generally  contributed  to  by  the  holders 
of  the  appointments.  It  is  well  known  that  many  professor- 
ships in  Britain  yield  £600  a  year,  with  very  small  con- 
tributory pensions.  In  no  cases  do  there  appear  to  be  any 
arrangements  for  family  pensions  in  the  event  of  the  holders' 
death — such  as  are  often  provided  in  the  public  services ;  nor 
insurance  against  illness  or  accident.      Notoriously,  very  few 

39  5" 


600  SCIENCE  PROGRESS 

even  of  the  highest  posts  receive  a  salary  touching  or  exceeding 
;£i,ooo  a  year;  and  in  nearly  all  cases  the  pensions  are  con- 
tributory and  are  of  a  very  small  amount — retirement  being 
often  compulsory  at  the  age  of  60  or  65  years.  Progressive 
rises  of  pay  are  also  seldom  provided  for ;  so  that  a  man  who 
obtains  an  appointment  when  comparatively  young  can  seldom 
hope  for  any  increase  during  the  rest  of  his  life.  Lastly,  pay- 
ment is  laid  down  at  many  universities  according  to  a  flat  rate, 
or  according  to  fixed  endowments  which  depend  upon  the 
funds  originally  allotted — so  that  no  provision  is  made  for  re- 
taining specially  good  men.  In  some  cases  holders  of  fully 
paid  appointments  are  able  to  increase  their  emoluments  by 
outside  work.     Many  medical  professorships  are  quite  unpaid. 

The  rates  of  pay  must  be  judged  by  the  locality  in  which 
they  are  given.  Thus  £y$o  in  South  Africa  is  worth  very 
much  less  than  that  sum  in  Britain,  the  cost  of  living  being 
perhaps  twice  as  great.  A  correspondent  from  Canada  remarks 
that  a  salary  of  £800  a  year  in  England  is  equivalent  only  to 
about  £600  a  year  there,  and  is  not  sufficient  for  a  professor. 
"  A  member  of  a  learned  community,"  he  says,  "  cannot  live 
in  a  back  street  like  a  labourer,  and  if  he  takes  an  unfurnished 
house  in  a  good  locality  here  the  rent  will  be  about  a  quarter 
of  his  income.  .  .  .  The  smallness  of  income  results,  in  my 
case,  in  my  being  unable  to  buy  books,  subscribe  to  scientific 
journals,  or  join  all  the  learned  societies  I  ought,  or  to  travel 
to  see  other  universities."  Similar  complaints  are  made  from 
elsewhere;  and  the  conditions  in  Britain  are  notorious. 

Of  course,  very  junior  posts  are  generally  financed  by 
scholarships ;  and  are  naturally  not  highly  paid  because  the 
holders  are  young  men  who  are,  practically,  being  apprenticed 
to  their  labours.  The  senior  posts  are  those  which  must  be 
considered  in  drawing  any  comparison  between  the  pa}^ment 
for  scientific  work  and  other  lines  of  effort ;  and  even  in  this 
respect  other  conditions  besides  the  payment  must  be  taken 
into  account.  On  the  whole,  however,  such  comparison  leads 
to  a  very  unfavourable  conclusion  regarding  the  present  pay- 
ment of  scientific  workers  in  Britain.  It  is  bad,  compared  even 
with  the  Church.  In  middle  posts,  the  salaries  may  be  slightly 
higher ;  but  in  academical  life  the  incumbents  are  obliged  to 
live  in  towns  and  are  rarely  provided  with  housing.  The 
highest  appointments  open   in  science  certainly  seem    to    be 


SWEATING  THE   SCIENTIST  60 1 

paid  much  less  than  the  highest  appointments  in  the  Anglican 
Church — though  the  latter  figures  cannot  be  very  easily  ascer- 
tained ;  and,  at  least,  no  scientific  men  have  a  seat  in  the  House 
of  Lords  by  virtue  of  their  office  or  work.  The  highest  salaries 
for  scientific  work  are  very  much  less  than  those  given  in 
the  Army  and  Navy — which  reach  to  £4,000  or  £5,000  a  year, 
and  probably  more  when  certain  allowances  are  added.  The 
scientific  and  academical  sides  of  the  medical  profession  show 
a  similar  state  of  affairs  when  compared  with  the  clinical  side — 
the  incomes  of  the  former  seldom  if  ever  exceeding  £1,000  a 
year,  while  those  of  the  latter  are  well  known  to  run  to  many 
times  that  amount,  especially  in  surgery.  Compared  with  the 
law,  science  stands  nowhere  at  all  in  Britain,  either  in  pay- 
ment or  in  position.  The  disparity  is  still  greater  in  comparison 
with  "  business " ;  and  the  enormous  fortunes  made  in  in- 
numerable directions  by  manufacturers,  shipowners,  retail  and 
wholesale  traders,  vendors  of  registered  articles,  financiers,  and 
so  on,  would  in  many  single  cases  cover  the  whole  funds 
allotted  to  science  throughout  the  great  British  Empire.  Even 
certain  branches  of  art,  such  as  the  drama,  singing,  and  acting, 
have  a  large  advantage  compared  with  scientific  work. 

It  is  in  no  grudging  spirit  that  men  of  science  will  draw  such 
comparisons.  That  good  pay  should  be  given  for  good  work 
is  an  elementary  principle  governing  all  lines  of  effort ;  but 
another  principle  must  be  held  in  view — that,  if  possible,  pay- 
ment should  bear  some  proportion  to  the  value  of  the  kind  of 
work  done.  We  pay  an  architect  or  a  general  more  than  we 
pay  the  bricklayer  or  the  soldier,  because  the  labours  of  the 
former  are  the  more  important ;  and  the  same  principle  should 
carry  weight  in  comparisons  of  the  emoluments  of  the  several 
professions.  In  the  two  previous  numbers  of  Science  Progress, 
a  survey  of  the  value  of  scientific  work  to  the  world  has  been 
attempted.  It  is  probably  of  greater  advantage  to  the  world 
than  any  other  line  of  effort.  Science  has  become  our  premier 
industry,  and  governs  every  other  industry  just  as  the  work 
of  the  architect  governs  that  of  the  individual  bricklayers.  The 
world  receives  not  only  "  fairy  tales "  from  science,  but  also 
the  most  wonderful  fairy  gifts — a  greater  knowledge  of  the 
universe  in  which  we  live,  a  greater  power  over  nature  and 
over  barbarism,  greater  precision  in  invention,  in  the  treatment 
and  prevention  of  disease,  and  in  our  manner  of  judging  re- 


602  SCIENCE   PROGRESS 

garding  all  matters  under  discussion.  Can  it  be  truly  said  that 
the  labours  of  any  other  professions  are  so  valuable  to  mankind  ? 
Where  the  priest,  the  clinician,  and  the  lawyer  do  good  service 
to  the  few  people  surrounding  them,  and  the  soldier,  sailor, 
and  politician  do  good  service  for  their  country,  the  discoverer 
confers  benefits  upon  the  whole  world,  and  not  for  the  present 
generation  only,  but  for  all  times.  We  have  already  argued 
the  case.  Mathematics,  chemistry,  physics,  physiology,  and  patho- 
logy have  practically  built  up  all  those  great  and  wonderful 
additions  which  modern  civilisation  has  added  to  the  civilisation 
of  the  past,  and,  with  their  sisters  of  the  arts,  have  made  a 
fitting  palace  for  what  ought  to  be  a  higher  race.  Yet  the 
payment  of  the  highly  qualified  men  who  formed  these  sciences 
in  the  past  and  who  are  still  perfecting  them  is  less  than  that 
given  to  all  the  other  professions,  and,  compared  with  the 
value  of  the  work,  is  almost  infinitely  less.  Indeed  it  would 
appear  that  the  second  principle  enunciated  above  is  just  the 
opposite  of  the  truth — that  work  is  paid  for  in  the  inverse  ratio 
of  its  value  :  and  this  is  not  a  mere  cynical  gibe,  but  the 
actual  truth.  The  greatest  benefits  which  the  world  has  ever 
received,  that  is,  those  which  it  has  received  from  science, 
literature,  art,  and  invention,  have  generally  been  paid  for  not 
at  all. 

But  it  may  now  be  said  that  the  scale  of  payment  for  science 
is  purely  a  question  of  supply  and  demand.  That  is  so — and 
the  same  principle  governs  the  case  of  sweated  industries  of 
all  kinds.  -  In  the  latter,  the  employer  exploits  the  necessities 
of  a  crowded  and  poor  population  in  order  to  have  his  work 
done  at  the  cheapest  rate.  As  regards  science,  however, 
the  employer  is  the  public  itself,  and  the  sweated  labourer  is 
the  highest  type  of  intellect  in  the  country.  The  process  by 
which  the  sweating  is  rendered  possible  is  something  as  follows  : 
Young  graduates,  fired  with  enthusiasm  for  science  or  with 
the  desire  of  investigating  some  question  which  has  occurred  to 
them,  take  scholarships  or  poorly  paid  research-studentships. 
At  first,  while  they  are  young,  everything  goes  well  with  them  ; 
but  after  some  years  they  find  that  the  shoe  begins  to  pinch. 
Then,  unfortunately,  it  is  too  late.  They  have  lost  the  time 
which  they  should  have  used  in  perfecting  themselves  for  their 
proper  profession,  whatever  that  may  be — in  which  they  have 
already  been  outpaced  by  men  of  the  same  age  who  were  not 


SWEATING  THE  SCIENTIST  603 

so  unwise  or  so  high-minded  as  themselves.  The  opening 
which  they  may  have  taken  five  years  previously  is  now  closed 
to  them ;  and  they  are  compelled  to  spend  the  rest  of  their  life 
under  the  paralysing  influences  described  above.  This  also  is 
the  actual  fact ;  and  it  must  evidently  produce  a  disastrous 
influence,  not  only  on  the  men  who  suffer,  but  also  upon  the 
great  studies  to  which  they  devote  themselves.  The  most 
capable  graduates  are  already  beginning  to  perceive  the  truth 
and  to  avoid  the  toils.  The  elder  men,  seeing  that  investigation 
leads  to  nothing,  tend  to  interest  themselves  only  in  teaching, 
compilation  of  text-books,  and  attendance  upon  committees. 
The  enthusiasm  and  concentration  which  when  found  together 
are  called  genius  become  impossible ;  and  we  look  almost  in 
vain  for  that  high  devotion  to  science  which  is  the  only  quality 
she  rewards  with  success.  And  the  punishment  does  not  really 
fall  so  heavily  upon  the  worker  himself — his  enthusiasm  for 
science  may  quite  possibly  compensate  him  for  such  troubles 
as  those  mentioned  above.  But  the  punishment  falls  upon  his 
family ;  it  falls  upon  the  institution  which  employs  him ;  it  falls 
upon  the  nation  which  allows  such  a  thing;  and  it  falls  upon 
science  herself. 

Besides  the  low  rate  of  pay  given,  there  are,  in  this  country 
at  least,  many  small  abuses  attached  to  high  intellectual  work. 
Even  such  funds  as  may  be  allotted  are  not  used  to  the  best 
advantage.  Large  portions  of  the  income  of  many  institutions 
are  given  to  the  maintenance  of  more  or  less  useless  pursuits — 
which  were  useful  pursuits  in  the  past,  but  no  longer  serve  the 
world,  or  indeed  serve  it  only  in  a  negative  sense.  Originality 
and  success  in  research  do  not  receive  their  due  place  in  selec- 
tion for  appointments.  The  best  paid  posts  are  seldom  given 
for  the  best  work  done,  but  rather  for  qualities  which  are 
of  little  account — popularity,  eloquence,  text-book  knowledge, 
private  influence,  and  skill  in  the  arts  of  time-service.  For 
obvious  reasons  it  is  impossible  to  cite  examples,  but  the  fact 
remains.  Of  the  few  Britons  of  to-day  who  have  done  world- 
service,  how  many  hold  the  leading  public  posts  even  in  their 
own  domain  ?  We  appear  to  judge  men,  not  by  the  work  which 
they  have  done,  but  by  the  work  which  we  may  imagine,  from 
their  appearance,  that  they  may  do  if  we  give  them  an  oppor- 
tunity. How  many  of  our  most  distinguished  writers,  for 
example,  have  received  academic  posts  for  teaching  their  own 


6o4  SCIENCE   PROGRESS 

art  ?    And  how  many  of  our  most  distinguished  men  of  science 
are  now  heads  of  British  universities? 

Many  other   disabilities   are   frequently  complained   of  and 
resented   by  scientific  workers.     The  whole   system   of  filling 
appointments  requires  careful  reconsideration.     Some  years  ago 
an  excellent  article  on  the  subject  of  advertising  vacant  appoint- 
ments appeared  in  the  University  Review.     The  advertisements 
are   often   issued   when  the  post   has  already  been  practically 
allotted — simply  as  a  kind  of  show  to  prove  impartiality  on  the 
part  of  the  advertising  body.     The  result  is  that  numbers  of 
candidates  are  tempted  to  put  themselves  to  great  trouble  and 
some  expense,  and  are  kept  upon  the  tenterhooks  of  doubt  for 
months.     Another  abuse,  still  allowed  for  academical  and  hos- 
pital posts,  is  the  necessity  of  canvassing  for  appointments — 
a   very   objectionable   system   which   compels   the   unfortunate 
applicant  to  visit  a  number  of  persons  with  whom  he  is  not 
acquainted  and  who  often  have  no  knowledge  of  his  subject, 
and  to  parade  his  virtues  before  them  in  competition  with  other 
unfortunates  who  are  in  the  same  case.     We  heard  some  time 
ago  of  a  distinguished  mathematician  who  was  obliged  to  sue 
humbly  for  a  poorly-paid  post  before  two  local  tradespeople — 
and  who  was  not  accepted.     Can  anything  show  more  clearly 
than  such  a  state  of  affairs  the  low  position  held  by  high  work 
in   Britain  ?     Indeed   the  whole  system  so  frequently  adopted 
here    of    allowing   scientific    institutions,    hospitals,   and   even 
universities,    to    be   governed    by    committees    of    persons    of 
whom  many  have  no  qualifications  for  the  work,  who  are  often 
not  even  moderately  distinguished  in  any  line,  but  who  find 
their  profit  in   the  position,   is   thoroughly  discreditable ;   and 
recent  disputes  in  the  management  of  certain  hospitals  have 
illustrated  the  defect. 

We  have  recently  started  the  habit  of  giving  our  rare  pro- 
fessorships to  foreigners — not  really  because  the  foreigners  are 
the  best  men  for  the  posts,  but  because  the  institution  concerned 
likes  to  obtain  a  reputation  for  magnanimity.  Yet  foreign 
nations  are  not  so  generous  to  us.  As  a  matter  of  fact  we 
buy,  not  in  the  cheapest  market,  but  in  the  dearest  one;  and 
do  so,  not  from  motives  of  business,  but  merely  out  of  osten- 
tation. The  same  indifference  to  work  done  is  often  manifested 
in  the  honours  given  by  many  learned  bodies.  We  see  the 
academic  laurel  placed  upon  the  brows  of  soldiers,  sailors,  and 


SWEATING  THE   SCIENTIST  605 

politicians — men  who  have  perhaps  done  great  service  in  their 
own  line,  though  not  in  the  line  for  which  such  honours  should 
be  reserved.  The  case  can  of  course  be  argued — as  all  bad 
cases  can ;  but  it  is  really  a  matter  of  clean  taste.  Academic 
honours  are  meant  to  promote  great  world-service  ;  and  it  is  a 
sign  of  national  degeneracy  when  they  are  given  for  anything 
lower.  One  would  think  that  our  universities  would  lead  the 
way  in  this  respect,  but  it  is  not  so.  Some  years  ago  a  dis- 
tinguished Colonial  Premier  refused  an  academic  honour  on 
these  grounds,  and  attained  greater  honour  by  doing  so.  Few 
are  the  struggling  workers  or  the  struggling  causes  which  have 
benefited  by  the  powers  in  the  hands  of  the  great  learned  bodies. 
To  add  grist  to  their  own  mill  by  subserviency  to  popular  idols 
appears  too  often  to  be  their  chief  desire ;  and  where  a  great 
worker  is  honoured  by  them,  he  is  generally  a  foreigner.  A 
still  lower  stage,  however,  has  already  been  reached — where 
a  learned  body  decorates  itself! 

We  may  now  ask,  what  exactly  does  the  British  Empire  do, 
as  a  State,  for  science,  or  indeed  for  any  of  the  higher  forms  of 
intellectual  effort  ?  Parliament  allots  £4,000  a  year  to  one 
learned  society,  and  another  £1,000  a  year  for  publications — a 
magnificent  endowment !  It  allows  also  occasional  small  grants 
to  other  institutions  ;  and  all  these  are  doled  out  for  the  expenses 
of  special  researches.  The  larger  grants  which  it  gives  to 
universities  are  devoted  chiefly  to  teaching — a  very  small  pro- 
portion ever  being  really  available  for  investigation.  Very  little 
of  the  money  goes  to  the  workers  themselves,  either  to  increase 
their  pay  or  to  reward  them  for  services  rendered ;  and  the 
State  seems  to  think  that  if  it  provides  their  test  tubes  and 
microscopes  it  has  done  enough.  In  many  countries  the  govern- 
ment wisely  pays  members  of  certain  academies ;  but  in  Britain, 
not  only  is  this  not  done,  but  the  State  actually  exacts  gratuitous 
services  from  such  members.  For  example,  a  Government 
department  wishes  for  expert  advice  on  some  matter — it  ought 
to  form  a  commission  of  its  own  and  honestly  pay  the  expert 
members  of  it.  Instead  of  doing  this  the  Government  depart- 
ment goes  to  some  learned  society  and  asks  it  to  advise  on  the 
scientific  question  at  issue.  The  society  is  honoured  by  the 
request,  and  obtains  the  advice  gratis  from  its  own  members. 
Thus  the  Government  gets  what  it  requires  for  nothing;  the 
learned  body  is  overpowered  with  the  honour  rendered  to  it; 


6o6  SCIENCE   PROGRESS 

and  the  unfortunate  worker  is  the  loser.  Such  action  is  very 
common  ;  unpaid  Government  committees  are  now  becoming 
the  rule,  and  even  reimbursement  of  travelling  expenses  is  often 
boggled  at.  We  heard  the  other  day  of  a  man  who  was  actually 
found  fault  with  for  not  attending  a  committee  of  this  nature  for 
which  he  was  not  paid.  In  other  words,  the  State  exploits  the 
man  of  science  on  account  of  his  enthusiasm  for  his  work  and 
his  patriotism.  The  thing  might  be  excused  if  the  State  were 
to  give  large  funds  for  scientific  work,  but  as  it  does  not  do  so 
such  action  is  extraordinary  in  its  meanness  and  impropriety. 

Many  similar  points  may  be  cited.  The  Board  of  Education 
expends  annually  an  enormous  sum,  amounting  to  nearly  twenty 
millions  a  year,  on  low-class  education  ;  but  what  does  it  do  for 
the  greatest  of  educators — science,  literature,  art,  drama,  explora- 
tion, discovery,  invention  ?  As  was  pointed  out  in  the  last  issue 
of  Science  Progress,  the  Patent  Acts  do  not  cover  those  whom 
they  should  most  carefully  protect,  namely  the  men  upon  whose 
investigations  nearly  all  inventions  are  founded.  Quite  recently 
the  House  of  Commons  has  given  itself  payment  amounting  to 
over  a  quarter  of  a  million  pounds  a  year.  Perhaps  this  is  quite 
right;  but  may  we  not  ask  whether  a  small  fraction  of  the  money, 
properly  devoted  to  scientific  investigation  in  many  lines,  would 
not  be  of  much  greater  benefit  to  the  people  than  are  the  wrang- 
lings  of  party  politicians  over  questions  which  will  never  be 
honestly  decided  because  they  are  never  honestly  considered  ? 
Still  more  recently  the  State  has  given,  very  wisely,  £57,000 
a  year  out  of  the  Insurance  Fund  for  medical  researches.  It  was 
suggested  at  the  committee  which  organised  the  management 
of  this  expenditure  that  a  large  prize  should  be  available  out  of 
the  fund  for  important  discoveries ;  but  the  money  actually 
offered  has  now  been  reduced  to  a  maximum  of  £1,000.  In  other 
words,  if  a  private  medical  man  were  to  discover  the  means  of 
prevention  or  cure  of  tuberculosis  or  cancer — which  he  would 
not  be  likely  to  do  without  spending  years  of  study  over  the 
theme,  and  probably  losing  his  practice  in  consequence  of  his 
work — his  only  reward  would  be  £1,000!  The  discoverer  will 
not  be  paid  ;  and  yet  the  country  hopes  to  have  discoveries 
achieved  !  And  this  brings  us  to  what  is  really  the  crowning 
defect  of  the  national  attitude  towards  high  effort  of  such  kinds, 
namely  that  it  makes  no  attempt  whatever  to  pay  for  any  benefits, 
however  great,  which  it  receives  from  individuals.     A  successful 


SWEATING  THE  SCIENTIST  607 

soldier  may  indeed  receive  a  handsome  donation,  and  many 
politicians  obtain  large  pensions ;  but  the  highest  services  in  the 
domains  of  science,  literature,  and  art  are  not  deserving  of 
reward  ! 

The  net  result  may  of  course  be  foretold  from  these  data. 
There  is  much  petty  science,  petty  literature,  and  petty  art ; 
but  the  more  arduous  labours  which  require  the  devotion  of 
a  lifetime  are  becoming  increasingly  difficult.  The  man  of 
science  is  now  exactly  in  the  position  in  which  writers  and 
inventors  found  themselves  before  the  Copyright  and  Patent 
Acts  were  passed.  He  is  never  the  master  in  his  own  house ;  he 
is  the  slave  to  institutions  which  "  run  him  "  for  what  he  is 
worth ;  and  is  seldom  able  to  spend  his  time  in  the  exercise 
of  the  lofty  gift  which  nature  has  given  him.  Still  worse,  the 
most  capable  minds  are  at  the  outset  turned  away  from  fields 
in  which  their  efforts  are  likely  to  be  of  the  highest  value  to 
humanity. 

All  this  really  springs  from  the  curious  and  stupid  attitude 
of  the  public  towards  all  forms  of  intellectual  effort.  It  seems 
to  take  no  interest  in  such  effort.  Politics,  game-playing,  and 
picture-shows  are  the  things  which  amuse  it.  The  great  worker 
is  a  mere  bookworm,  or  a  plodder,  or  a  crank.  But  the  truth 
is  that,  just  as  individuals  have  duties  to  perform  to  their 
country,  so  have  countries  duties  to  perform  to  the  civilised 
world.  It  is  the  duty  of  every  nation  to  participate  in  the 
discovery  of  the  laws  of  nature,  to  ascertain  the  cause  of 
disease,  to  enhance  the  powers  of  man,  and  to  widen  the 
range  of  his  vision.  What  does  Britain  do  to  fulfil  this  duty? 
She  still  has  great  workers,  it  is  true ;  but  their  work  springs 
from  themselves,  and  not  from  the  nation.  The  country  does 
not  perform  the  duty  referred  to.  It  has  become  like  a  trades- 
man who  has  reached  great  wealth  by  the  exercise  of  inferior 
arts,  but  who  spends  it  on  amusements,  pleasures,  and  the 
ostentation  of  charity,  without  sparing  a  penny  for  higher 
objects.  This  figure  may  at  least  be  reached  as  a  rough 
integration  of  the  general  complex  formulas  of  our  present 
condition.  Behind  all  there  is  a  shadow :  for  nations,  like 
individuals,  must  remain  efficient. 


PHYSICS    IN    1913 

WITH  SPECIAL  REFERENCE  TO  THE  DIFFRACTION 
OF  X-RAYS   BY  CRYSTALS 

By  E.  N.  da  C.  ANDRADE,  B.Sc,  Ph.D. 
{John  Harling  Fellow  of  the  University  of  Manchester) 

Perhaps  the  most  important,  certainly  the  most  striking,  advance 
in  physics  during  the  period  of  the  last  year  or  so  is  the  demon- 
stration of  the  regular  diffraction  of  X-rays,  the  experimental 
confirmation,  that  is,  of  a  theory  often  tentatively  put  forward, 
that  X-rays  are  a  disturbance  of  the  same  nature  as  light, 
differing  only,  as  far  as  we  can  judge,  in  their  wave-length  from 
visible  light.  While  evidence  for  this  was  being  accumulated, 
however,  the  nature  of  light  radiation  itself  has  become  more 
and  more  mysterious,  and  the  recent  investigations  as  to  the 
laws  and  nature  of  radiant  energy  have  rather  served  to  demon- 
strate the  defects  of  present  theories  than  to  provide  us  with 
any  very  convincing  and  comprehensive  ideas  on  the  subject. 
Planck's  theory  of  quanta,  which  assumes  that  radiant  energy  is 
emitted  not  continuously  but  in  discrete  units  whose  magnitude 
depends  only  on  the  frequency  of  the  radiation  in  question,  still 
provides  the  reigning  hypothesis,  although  the  conception  of 
the  discontinuous  absorption  of  energy  in  such  units  has  been 
abandoned  on  account  of  the  insuperable  difficulties  it  presents. 
Many  atom  models  have  been  put  forward,  most  of  which 
have  a  very  limited  application,  and  would  seem  designed  with 
a  view  of  imitating  one  set  of  phenomena  only.  Apart  from 
these  ephemeral  fancies  is  Rutherford's  nucleus  atom,  consisting 
of  a  small  positive  nucleus,  surrounded  by  rings  of  electrons  at 
distances  from  it  very  large  compared  to  the  dimensions  of  the 
nucleus  itself.  This  has  shown  itself  very  successful  so  far,  and 
a  mathematical  treatment  by  Bohr,  based  on  an  application  of 
the  quantum  theory  to  the  radiation  from  an  atom  of  this  type 
has  attracted  considerable  attention,  and  will  be  described  in 
more  detail  in  the  following  account.    Two  sensational  announce- 

608 


PHYSICS   IN    1913  609 

merits  which  await  confirmation  are  Aston's  separation  of  a  new 
gas  of  atomic  weight  22,  very  closely  allied  to  neon,  from  this 
gas,  and  Stark's  splitting  up  of  the  hydrogen  lines  by  the  appli- 
cation of  an  intense  electric  field,  corresponding  to  the  Zeeman 
effect  in  a  magnetic  field.  The  effect  of  small  traces  of  gas  on 
some  of  the  electric  properties  of  metals  has  been  brought  into 
prominence,  and  the  very  existence  of  the  photoelectric  effect 
for  absolutely  gas-free  metals  has  been  questioned.  Several 
other  researches  of  importance  are  described  in  the  following 
pages,  and  we  may  say  that  the  discoveries  of  the  past  year 
have  opened  up  more  than  one  field  of  research  which  promises 
rich  results. 

The  first  experiments  on  the  diffraction  of  X-rays  by  a 
crystal  were  described  in  June  191 2  by  Friedrich,  Knipping,  and 
Laue  in  a  paper  entitled  "  Interference  Phenomena  with  the 
Roentgen  Rays."  In  these  experiments  a  fine  pencil  of  rays 
from  an  ordinary  X-ray  bulb  was  passed  through  a  slip  of 
crystal  and  received  on  a  photographic  plate  placed  behind  the 
crystal  at  right  angles  to  the  incident  beam.  The  plate  on  de- 
velopment showed  not  only  a  very  dark  spot,  corresponding  to  the 
direct  beam,  but  also  a  series  of  other  fainter  spots  surrounding 
it  in  a  complicated  geometrical  pattern  of  high  symmetry. 
These  spots  are  formed  by  beams  of  X-rays  scattered  in  definite 
directions  from  the  crystal,  and  making,  in  some  cases,  angles  as 
large  as  450  with  the  direct  beam.  Laue's  theory,  which  led  to 
the  experiments,  was  that  the  crystal,  because  of  the  regularity 
of  its  structure,  formed  a  natural  diffraction  grating,  which 
differed  from  the  ordinary  ruled  grating  firstly  in  having  a  very 
much  smaller  grating  space,  and  secondly  in  being  an  arrange- 
ment in  three  dimensions,  analogous  to  a  set  of  plane  gratings 
placed  one  behind  the  other.  Each  molecule  he  supposed  to  be 
capable  of  emitting  secondary  wavelets  when  struck  by  the 
incident  ray,  and  by  assuming  the  molecules  to  be  arranged  in  a 
simple  system,  each  one  being  at  the  corner  of  an  elementary 
cube,  he  accounted  for  the  positions  of  the  spots  on  the  plate : 
to  explain  the  absence  of  other  spots  which  might  be  expected 
he  had  to  assume  that  the  incident  pencil  of  X-rays  did  not 
contain  a  continuous  range  of  wave-lengths,  but  a  certain  five 
wave-lengths  which  he  calculated.  The  order  of  magnitude 
found  for  them  was  from  1  to  4  times  io-9  cms.  This  is  about 
the  same  order  as  the  length  previously  suggested   by  Walter 


610  SCIENCE  PROGRESS 

and  Pohl  from  attempts  to  obtain  diffraction  with  a  wedge- 
shaped  slit,  and  a  similar  estimate  had  been  formed  from  the 
ratio  of  the  intensity  of  the  X-rays  to  that  of  the  cathode  rays 
excited  by  them. 

Soon  after  Laue's  discovery,  W.  L.  Bragg,  the  son  of  W.  H. 
Bragg,  suggested  a  different  way  of  regarding  the  phenomenon. 
He  considered  the  crystal  as  containing  different  series  of 
parallel  planes  in  which  the  atoms  are  closely  packed ;  from 
these  reflection  of  the  rays  takes  place,  for  by  Huygen's  principle 
a  number  of  points  arranged  regularly  on  a  plane  will  give  rise 
to  secondary  wavelets  which  build  up  a  wave  reflected  at  the 
angle  of  incidence.  Now  in  a  crystal  supposed  built  up  of  the 
so-called  face-centred  cubes  1  a  system  of  series  of  parallel  planes 
rich  in  atoms  can  be  picked  out,  from  which  such  reflection, 
obeying  the  ordinary  laws  of  optical  reflection,  takes  place. 
W.  L.  Bragg  obtained  a  simple  geometrical  construction  for  the 
points  that  would  result  from  reflection  from  such  planes,  and 
the  diagrams  he  obtained  agreed  excellently  with  photographs 
taken  by  Laue's  method.  There  is  no  need  to  assume  the 
incident  radiation  homogeneous,  or  consisting  of  a  few  definite 
wave-lengths  ;  the  crystal  structure  will  account  for  the  sorting 
out  of  the  general,  or  "  white,"  radiation,2  or,  in  other  words,  will 
impress  the  regularity  on  it. 

Bragg  confirmed  his  theory  of  reflection  by  throwing  a 
beam  of  X-rays  on  a  cleavage  face  of  mica,  cleavage  faces  of 
crystals  being  rich  in  atoms  ;  he  obtained  reflection  according  to 
optical  laws.  W.  H.  and  W.  L.  Bragg  then  examined  in  more 
detail  the  reflection  of  the  rays,  making  use,  not  of  the  photo- 
graphic plate,  but  of  the  ionisation  produced  by  the  reflected 
rays  in  order  to  detect  them.  The  apparatus  resembled  a 
spectroscope  in  form,  in  which  the  collimator  was  replaced  by 
a  lead  slit  through  which  the  incident  rays  passed,  the  tele- 
scope by  an  ionisation  chamber  to  which  the  rays  obtained 
access  through  a  second  narrow  slit.  They  found  that  reflection 
took  place  always  in  accordance  with  the  law  of  equal  angles  of 
incidence  and  reflection,  but  that  with  different  angles  of  incidence 
the  intensity  of  the  reflected  ray,  measured  by  the  ionisation 
produced,   varied   markedly,   showing  a   series   of  pronounced 

1  A  cube  with  a  point  at  each  corner  and  one  in  the  centre  of  each  face. 

2  By  analogy  from  white  light,  which  can  be  resolved  into  a  continuous  group 
of  wave-lengths. 


PHYSICS  IN    1913  611 

maxima  at  definite  angles.  These  maxima  correspond  to  homo- 
geneous rays  of  wave-length  X,  given  by  nX  =  2d  sin  0,  where  0 
is  the  angle  of  incidence,  n  an  integer,  and  d  the  distance 
between  successive  planes,  for  only  at  such  an  angle  will  the 
waves  reflected  from  the  successive  planes  reinforce  one  another. 
Some  of  the  radiation  from  an  X-ray  bulb  is  "  white  "  radiation, 
and  accordingly  contains  components  reflected  at  any  angle ; 
in  addition  there  are  strong  homogeneous  beams  reflected  only 
at  certain  angles,  the  angle  depending  on  the  wave-length  of 
the  particular  radiation  in  the  way  described.  The  homogeneous 
radiations  are  the  "  characteristics "  of  the  metal  of  the  anti- 
cathode,  investigated  by  Barkla  by  measurements  of  their  absorp- 
tions ;  the  target,  or  anticathode  used  by  the  Braggs  in  their 
earlier  experiments  was  of  platinum,  and  they  determined  the 
wave-length  of  the  characteristics  of  platinum  from  the  formula 
already  given,  d  being  worked  out  from  the  weight  of  the  atom, 
the  assumed  structure  of  the  crystal,  and  its  density. 

Moseley  and  C.  G.  Darwin  about  the  same  time  examined 
the  radiation  from  a  tube  with  a  platinum  target  by  reflecting 
it  from  the  principal  cleavage-planes  of  different  crystals,  rock- 
salt,  selenite,  and  potassium  ferrocyanide  being  used.  They 
detected  the  reflected  beam  by  means  of  the  ionisation  produced, 
and  showed  that  the  primary  and  reflected  beams  contained 
the  same  constituents,  present,  however,  in  different  proportions 
in  the  two  beams,  in  other  words  that  the  crystal  did  not 
manufacture  a  special  type  of  radiation,  but  picked  out  radia- 
tions already  present.  They  detected  five  homogeneous 
radiations,  reflected  at  definite  angles  from  each  of  the 
crystals,  and  measured  each  radiation  in  three  different  orders, 
that  is,  they  found  for  each  radiation  successive  values  of  0, 
the  angle  of  reflection,  corresponding  to  the  values  1,  2,  3 
for  n  in  the  formula  nX  —  2d  sin  0.  The  reflection  theory  was 
strongly  confirmed  both  by  comparing  the  results  with  the 
different  crystals,  which  showed  d  a  constant  for  the  given 
face  in  each  crystal,  but  differing  from  crystal  to  crystal,  and 
by  the  obtaining  of  each  line  in  different  orders.  Thus  a 
homogeneous  X-radiation  is  reflected  from  a  crystal  plane 
rich  in  atoms  at  certain  definite  angles,  whose  sines  are  simple 
multiples  of  one  another ;  this  corresponds  to  the  different 
orders  in  the  grating  spectra  of  visible  light.  To  the  grating 
space    corresponds  not  the   distance   between   the   atoms  in  a 


612  SCIENCE   PROGRESS 

single  plane,  but  the  distance  between  two  adjacent  planes  of 
the  series  of  parallel  planes  in  question.  Of  course,  part  of 
a  heterogeneous  radiation  will  be  reflected  at  any  angle.  In 
Bragg's  explanation  of  the  Laue  patterns  the  position  of  the 
spots  depends  on  the  existence  of  several  series  of  parallel 
planes  rich  in  atoms ;  the  incident  radiation  is  supposed  hete- 
rogeneous, and  from  this  the  planes  pick  out  the  wave-length 
required  for  reflection  to  take  place  for  the  fixed  angle  of 
incidence. 

More  recently  Moseley  has  examined,  using  the  method  of 
the  X-ray  spectrometer  described,  the  characteristic  radiation 
from  all  the  metals  whose  atomic  weights  lie  between  40  and 
65,  by  employing  them  successively  as  the  targets  in  an  X-ray 
tube ;  the  characteristics  are  excited  by  the  fast  cathode  rays. 
The  metals  were  mounted  on  a  little  truck,  so  that  they  could 
be  brought  at  will  in  the  path  of  the  cathode  rays  ;  the  X-rays 
produced  were  reflected  from  a  crystal  of  potassium  ferro- 
cyanide  and  detected  photographically.  The  X-ray,  or  high 
frequency,  spectrum  of  each  element  he  found  to  consist  of 
two  lines,  one  stronger  than  the  other,  which  he  calls  the  a 
(strong),  and  the  fi  line ;  Bragg  also  found  two  lines  for  the 
rhodium  spectrum.  The  wave-length  of  each  line  was  found 
in  terms  of  the  spacing  of  the  planes  in  the  rocksalt  crystal, 
known   from    Bragg's   researches,   and   it  was    found   that  the 

quantity  Q  =  s\J  3—  (where  v  is  the  frequency  of  the  a  radiation, 

v0  a  constant,  the  fundamental  frequency  of  ordinary  line 
spectra)  was  a  whole  number,  increasing  by  one  for  each 
successive  element  taken  in  the  order  of  their  atomic  weights. 
If  N  be  the  atomic  number,  the  number,  that  is,  of  the  place 
occupied  by  the  element  in  the  periodic  system  (H  =  I,  He  =  2, 
Li  =  3,  .  .  .  ,  Ca  =  20,  etc.),  Moseley  found  that  Q  =  N  —  I.  or  v, 
the  frequency,  varies  as  (N  —  I)2.  This  suggests  that  the  atomic 
number  is  perhaps  more  important  for  physical  processes 
than  the  atomic  weight;  the  point  will  be  referred  to  again 
later. 

Rutherford  and  Andrade  are  investigating  the  7  rays  from 
radium  by  the  method  of  reflection  from  crystals,  and  have  in 
a  preliminary  note  announced  that  they  have  photographed 
groups  of  lines  given  by  the  7  rays  from  radium  B  and 
radium  C ;  hence  the  7  radiation  from  these  substances  is  not 


PHYSICS   IN    1913  613 

of  one  wave-length,  but  complex.  De  Broglie  has  taken 
excellent  photographs  by  the  reflection  method  by  arranging 
the  crystal  to  rotate  very  slowly  by  means  of  clockwork,  and 
letting  a  narrow  beam  of  X-rays  strike  the  crystal  face  where 
the  axis  of  rotation  passes  through  it.  As  the  correct  angle 
for  any  homogeneous  ray  present  is  reached,  the  ray  is 
reflected  and  recorded  on  a  fixed  photographic  plate. 

By  the  experiments  described  much  light  has  been  thrown 
upon  the  nature  of  X-radiation ;  the  Braggs  have  applied  these 
results  to  study   the   structure  of  crystals.      For  this  purpose 
X-ray  photographs  are  taken  with  the  crystal  to  be  examined, 
either  by  the  Laue  method  of   transmission,  or  the   reflection 
method ;   for   the   former  heterogeneous   radiation  is  required, 
for  the  latter  a   homogeneous   beam,   such   as   that   found  to 
be     emitted     from    a     rhodium     anticathode.      The     reflection 
method   gives  the  more   direct   information ;    photographs   are 
taken  by  reflection   from   the  planes   richest  in  atoms   in   the 
crystal,  the   so-called  (100),  (no),  (in)   planes,  and  the   given 
line,   corresponding  to   the   homogeneous  radiation,   is  sought 
at  the  series  of  angles  corresponding  to  the  first,  second,  and 
subsequent    orders.     In  general  the   line  cannot   be  found  in 
all  the   orders;   for  instance,  for 'the  (in)   planes  in  diamond 
there   is  no    second  order  spectrum,  although  first,  third,  and 
fourth   are  found.      There   is  no  space   here  to  enter  into  the 
details   of  the    deductions    which    can    be    drawn    from    such 
evidence  ;  it  will  suffice  to  state  that  for  a  crystal  of  an  element, 
such  as  the  diamond,  the  absence  of  certain  orders  indicates  that 
the  series  of  parallel   planes    from  which   the   reflection  under 
consideration    takes    place   are    not   equally   spaced    from   one 
another,  but  a  series  of  equally  spaced  planes  are  separated  by 
another   series    of  equally   spaced    planes    arranged    so    as    to 
divide   the  spaces    between   the   first   set  unequally.     By  con- 
siderations of  this  kind,  the   Braggs  have   obtained  a  detailed 
model  of  the  spacing  of  the  carbon  atoms  in  the  diamond,  which 
they  checked   by  photographs  of  the   Laue   type;    the   model 
shows  the  atoms  arranged  at  the  points  of  two  interpenetrating 
space  lattices ;  between  a  series  of  planes  equally  spaced  other 
planes  are  placed  so  as  to  divide  the  distance  between  them  in 
the  ratio  of  one  to  three. 

Further  very  interesting  information  has  been  obtained  as  to 
the  arrangements  of  the  atoms  of  different  kinds  in  crystals  of 


614  SCIENCE  PROGRESS 

chemical  compounds,  such  as  the  simple  halogen  salts  of  potas- 
sium. Assuming  that  the  atoms  of  a  crystal  are  arranged  as 
points  in  a  space  lattice,  W.  L.  Bragg  has  shown  that  a  structure 
the  same  in  all  cases  can  explain  the  transmission  patterns 
obtained  with  this  series  of  salts,  the  differences  in  the  patterns 
being  due  to  the  fact  that  the  efficiency  of  an  atom  as  a  diffracting 
centre  increases  rapidly  with  its  atomic  weight.  If  the  atoms 
are  of  nearly  equal  atomic  weights,  as  in  K  CI,  they  are  nearly 
equivalent  as  centres;  if  one  is  at  least  twice  as  heavy  as  the 
other,  as  in  K  Br  or  K  I,  the  lattice  formed  by  the  heavy  atoms 
alone  gives  the  pattern.  The  experiments  also  point  to  the 
single  atoms  acting  as  diffracting  centres,  the  lighter  atoms  not 
being  associated  in  any  special  way  with,  or  grouped  closely 
round,  the  heavier  atoms,  but  occupying  intermediate  positions 
between  the  neighbouring  heavy  atoms,  so  that  they  can  equally 
well  be  considered  as  belonging  to  different  ones.  For  instance, 
an  atom  of  sodium  is  equally  close  to  six  chlorine  atoms  in  a 
crystal  of  rocksalt.  Thus  in  such  a  crystal  a  molecule  cannot 
be  considered  as  having  any  individual  existence;  rather  the 
whole  crystal  constitutes  one  huge  molecule.  There  can  be  no 
doubt  that  the  method  is  likely  to  prove  very  valuable  in 
examining  further  the  structure  of  crystals. 

It  would  be  expected  that  the  heat  motions  of  the  atoms 
would  influence  the  diffraction  pattern  formed  by  the  X-rays. 
That  the  heat  vibrations  do  not  disturb  the  patterns  at  room 
temperature  might  be  immediately  explained  by  Lindemann's 
conclusion  that  at  such  temperature  the  distance  of  the  centres 
of  the  molecules — or  atoms — only  varies  a  few  per  cent,  owing 
to  heat  agitation.  In  an  extended  mathematical  paper  Debye 
has  come  to  the  conclusion  that  the  heat  motions  will  not  affect 
the  positions  of  the  spots  of  the  patterns,  or  their  sharpness, 
but  only  their  intensity,  increasing  agitation  causing  the  spots 
to  become  fainter  and  fainter.  The  independence  of  the  positions 
and  sharpness  of  the  temperature  have  been  experimentally 
confirmed  by  de  Broglie,  the  weakening  of  the  spots  at  high 
temperature  by  Laue  and  van  der  Lingen,  so  that  Debye's 
theory  has  been,  at  least  qualitatively,  confirmed. 

A  good  deal  of  rather  more  random  work  has  been  already 
done  on  the  diffraction  of  the  X-rays  by  substances  other  than 
crystals.  Keene  has  shown  that  ordinary  rolled  metal  sheets 
give  X-ray  patterns  owing  to  the  metal  possessing  a  crystalline 


PHYSICS  IN    1913  615 

structure,  and  Nishikawa  and  Ono  have  shown  that  many 
fibrous  substances,  such  as  asbestos  and  bamboo,  give  patterns 
of  a  rather  different  type. 

Not   very    much   progress   has   been   made   in   the    general 
theory  of  radiation  during  the  past   year.     Since  Poincare   in 
191 2   showed   that   no   law  of  continuous  emission   of  radiant 
energy  could   account  for  the   form  of  the   radiation  curve  in 
the   short   wave-lengths,   all   attention   has    been    concentrated 
on  the  application  of  Planck's  quantum  theory,  which  asserts 
that  radiant  energy  cannot  be  emitted  continuously  in  amounts 
of  a  completely  arbitrary  magnitude,  but  only  in  whole  numbers 
of  discrete  units,  or  quanta,  of  energy,  whose  magnitude  is  a 
constant,  h,  times  the  frequency  number  of  the  given  radiation. 
The    universal    constant   h   is    often    referred    to   as   Planck's 
constant.      In   its   present   form   the   theory  does  not   exclude 
continuous   waves   of  energy  in  the   ether,  or  the  continuous 
absorption   of  energy,  as   without  waves   in  the   ether  of  the 
nature  assumed  in  the  classical  electromagnetic  theory  it  seems 
impossible  at  present  to  account  for  the  phenomena  of  polarisa- 
tion and   interference.      The  polarisation   of  light   by  crystals 
would   seem   to  depend  on  an  interaction  between  the  matter 
and  radiant  energy  which  does  not  take  place  quantum  fashion. 
The  quantum  theory  presents  grave  difficulties  in  the  way  of 
a     satisfactory     physical     interpretation,    especially    over     the 
question  of  absorption,  but  its  justification  lies  in  the  brilliant 
agreement  which  many  of  its  consequences  show  with  experi- 
mental  results   at   present  inexplicable  on   the   older   theories. 
The    older   Hamiltonian   equipartition    of    energy   among    the 
degrees  of  freedom  has  proved  insufficient;  Jeans  has  abandoned 
his   idea   that   its   predictions   fail   because  the  steady  state   is 
never  realised.    The  simplest  of  the  present  methods  of  deducing 
the   radiation   formula   is   to  count  the  number  of  degrees   of 
freedom  of  the  equilibrium  radiation  by  means  of  the  number  of 
different   stationary  waves   set  up   in   an    enclosure   with    re- 
flecting  walls    (Jeans,    Rayleigh),   and    distribute    the    energy 
among    them    in    quanta    of    magnitude    proportional    to    the 
frequencies    according    to    a    probability   law.     Debye,   by   an 
extension  of  this   method,  has  obtained  a  formula  connecting 
the  specific  heat  of  metals  with  the  temperature,  agreeing  re- 
markably well  with   experiment.      He   assumes   that   the   heat 
energy  consists  of  elastic  vibrations  of  the  atoms  about  positions 
40 


6i6  SCIENCE   PROGRESS 

of  equilibrium,  and  calculates  the  number  of  such  possible 
vibrations  from  the  elastic  constants  of  the  body.  The  quanta 
being  distributed  among  these  degrees  of  freedom  as  above, 
the  formula  for  the  heat  energy  can  be  calculated. 

On  Planck's  second  theory,  since  the  absorption  of  radiant 
energy  can  take  place  continuously,  and  an  atom  cannot  emit 
less  than  an  amount  hv  of  energy,  there  must  always  remain 
in  the  atom   an  amount  of  energy  varying   from  O   to  h^,  or 

a  mean  amount  of  energy  — .     This  energy  is  the  latent  energy 

of  the  atom,  which  Wien  ascribes  to  the  energy  of  electrons  in 
the  atom.     He  distinguishes  between  the  electronic  energy  and 

the  energy  of  the  atom  ;  this  mean  amount  —  does  not  belong 

to  the  atomic  energy  considered  by  Debye  in  his  treatment 
of  the  specific  heat  problem,  and  so  does  not  interfere  with 
the  deduction  of  his  formula. 

The  theory  of  the  electrical  and  thermal  conductivities 
presents  still  many  problems  which  await  solution.  Drude's  old 
theory  seems  to  be  almost  universally  given  up,  since  it  stands 
in  contradiction  to  the  radiation  results,  as  demonstrated  by 
Lorentz,  and  also  to  the  experiments  on  specific  heats  at  low 
temperatures.  Lenard  has  worked  out  a  theory  based  on  the 
assumption  that  the  electrons  in  the  metal  are  not  gas-kinetically 
reflected  from  the  atoms,  which  seems  impossible  in  the  face 
of  recent  experiment,  but  are  absorbed  by  the  atoms  and  sub- 
sequently liberated,  the  liberation  depending  on  the  proximity 
of  the  atoms  (Nahewirkung).  This  gives  the  velocity  of  the 
electron  independent  of  the  temperature,  which  is  the  assumption 
favoured  by  Wien,  who  connects  it  with  the  latent  energy 
of  the  atoms  mentioned  above,  which  is  independent  of  the 
temperature.  Many  of  the  observed  results  are  given  by 
Lenard's  treatment ;  it  involves,  however,  in  its  present  form 
too  many  indeterminate  factors  to  be  very  useful,  and  it  is 
doubtful  if  it  will  give  the  abnormally  high  conductivity  of 
metals  at  temperatures  near  the  absolute  zero  found  by  Kammer- 
lingh  Onnes.  Wien,  using  Debye's  assumptions  made  for  the 
specific  heat,  has  obtained  a  formula  which  gives  a  good  agree- 
ment with  experiment  in  this  direction,  even  for  the  very  low 
temperatures.  But  in  both  the  electric  and  thermal  conductivities 
there   are    many   points    still    unsatisfactorily    explained,    and, 


PHYSICS   IN    1913  617 

in  general,  the  physical  properties  of  the  elements  at  low 
temperatures  are  inadequately  accounted  for  by  present  theories. 

The  quantum  theory  has  recently  received  a  rather  more 
direct  confirmation  than  is  afforded  by  the  work  on  the  radiation 
formula  or  the  specific  heats.  Bjerrum  put  forward  a  new 
conception  of  the  mechanism  of  the  absorption  of  radiations 
in  the  infra  red  region.  The  charged  atoms  in  the  molecule, 
which  are  the  resonators  accounting  for  the  absorption,  are 
supposed  not  only  to  execute  linear  vibrations  of  frequency  vu 
but  also  to  rotate  with  a  frequency  of  rotation  v.,.  If  they 
vibrate  in  a  direction  normal  to  the  axis  of  rotation  there  are 
resultant  vibrations  of  frequency  vx-^-v^  vx  —  v2 ;  if  along  the  axis 
of  rotation,  the  movements  are  independent.  There  will  thus 
result  the  four  frequencies  vu  v2}  vv  +  v2,  vx  —  v%.  This  will  give 
three  periods  in  the  short  infra  red  and  one  in  the  long  infra 
red.  Supposing  the  rotation  frequencies  continuously  dis- 
tributed according  to  the  Maxwell  probability  law,  this  would 
give  three  near  absorption  bands  in  the  shorter  infra  red  for 
a  gas,  and  Burmeister  found  experimentally  that  the  absorption 
in  this  part  of  the  spectrum  always  occurred  in  broad  double 
bands,  the  midway  absorption  line  predicted  by  the  theory 
being  too  narrow  to  detect.  Now  on  the  quantum  theory  the 
rotation  frequencies  are  not  continuously  distributed,  but  in- 
crease in  jumps  ;  according  to  this  the  double  absorption  bands 
should  not  be  smooth,  but  show  a  serrated  edge,  the  series 
of  maxima  corresponding  to  a  series  of  separate  absorption 
frequencies.  E.  von  Bahr  has,  by  increasing  the  resolving 
power  of  the  infra  red  spectroscope  used,  actually  found  a 
series  of  jagged  irregularities  in  the  absorption  bands,  of  the 
kind  predicted  by  the  theory  indicated.  This  furnishes  striking 
evidence  for  the  physical  existence  of  quanta  of  energy,  at  any 
rate  in  some  cases.  Eucken  has  further  pointed  out  that  the 
measurements  of  the  infra  red  absorption  spectrum  of  water 
vapour  present  exactly  the  irregularities  required  by  Bjerrum's 
theory  if  the  rotational  energy  is  distributed  in  quanta.  The 
band  in  the  longer  infra  red  has  likewise  been  experimentally 
found. 

In  the  matter  of  the  specific  heats  at  low  temperature 
Dewar's  latest  results  are  of  considerable  interest.  He  has 
measured  the  mean  atomic  heat  over  a  range  of  6o°  C.  for 
fifty-five  elements  at  50°  absolute  (the  temperature  fall   being 


6i8  SCIENCE   PROGRESS 

from  80'  to  200  absolute),  and  plotted  them  against  atomic 
weight.  The  atomic  heats,  ranging  from  6*82  for  Caesium  to 
0*03  for  diamond,  then  reveal  a  definite  periodic  variation 
resembling  the  Lothar  Meyer  curve  for  atomic  volumes  in 
the  solid  state.  If  experiments  were  made  between  the  boiling 
point  of  liquid  hydrogen  and  that  of  liquid  helium,  the  atomic 
specific  heats  would  probably  be  all  nearly  equal  and  very 
small. 

Turning  to  theories  on  the  structure  of  the  atom,  Bohr's  work 
claims  attention ;  it  is  a  mathematical  treatment  of  Rutherford's 
nucleus  atom,  which  has  been  very  successful.  Bohr's  atom 
gives  a  theoretical  account  of  the  line  spectra  of  the  elements, 
especially  those  of  the  relatively  simple  hydrogen  and  helium 
atoms.  It  is  interesting  as  referring  the  discontinuities  of  wave- 
length in  the  line  spectrum  of  a  gas  back  to  the  discontinuities 
of  energy  emission  postulated  by  the  theory  of  quanta.  As  a 
result  of  experiments  on  the  scattering  of  a  particles  by  matter 
Rutherford  in  191 1  put  forward  the  theory  that  the  atom 
consists  of  a  central  positive  nucleus,  of  dimensions  very  small 
compared  to  the  atomic  radius,  in  which  practically  all  the  mass 
of  the  atom  is  concentrated,  this  nucleus  being  surrounded  by 
a  distribution  of  electrons  making  the  atom  neutral  as  a  whole. 
The  number  of  electrons  was  deduced  to  be  about  half  the 
atomic  weight;  it  is  now  considered  likely  that  it  is  the  "atomic 
number  "  already  mentioned.  To  get  the  spectral  lines  which 
would  be  emitted  by  such  an  atom  Bohr  makes  the  assumption 
that  the  electrons  are  rotating  round  the  nucleus  in  circular 
orbits ;  there  is  no  energy  emitted  when  the  electrons  are 
rotating  steadily  in  a  stationary  state.  An  electron  can,  how- 
ever, pass  from  one  such  stationary  state  to  another,  changing 
the  radius  of  its  orbit ;  during  this  transition  a  homogeneous 
radiation  is  emitted,  whose  frequency  v  is  determined  from  the 
change  of  energy  between  the  two  stationary  states  by  the 
equation  E  =  hv,  where  h  is  Planck's  constant,  and  E  is  the 
energy  change.  The  amount  of  energy  emitted  is  thus  always 
a  whole  quantum,  and  a  further  assumption  as  to  the  connection 
between  the  total  energy  of  formation  of  the  system  and  the 
frequency  of  rotation  of  the  electron  in  the  system  formed  leads 
to  the  conclusion  that  the  angular  momentum  of  any  electron 

round  the  nucleus  is  an  entire  multiple  of  the  quantity  — ;  in 


PHYSICS   IN    1913  619 

the    most   stable   system   consequent  on   the   emission   of  the 

maximum   amount   of  energy   the   angular   momentum    is    — . 

This  is  probably  closely  connected  with  Weiss'  magneton,  or 
elementary  unit  of  magnetism.  Balmer's  and  Rydberg's  laws 
follow  from  these  assumptions,  and,  considering  the  case  of 
hydrogen  as  represented  by  a  central  nucleus  with  one  rotating 
electron,  that  of  helium  as  a  nucleus  with  two  electrons,  Bohr 
has  calculated  a  value  for  Rydberg's  constant  in  close  agree- 
ment with  the  empirical  value.  His  theory  gives  all  the 
hydrogen  spectra  observed ;  in  connection  with  the  spectral 
lines  calculated  by  him  for  helium  the  question  has  arisen 
whether  certain  lines  observed  from  hydrogen  contaminated 
with  helium,  and  previously  attributed  to  hydrogen,  are  not 
due  to  helium.  Fowler  attributed  the  lines  to  hydrogen ;  but 
the  recent  work  of  Evans  points  to  these  lines  being  part 
of  the  helium  spectrum  as  required  by  Bohr's  theory.  It  may 
be  noted  that  Bohr  finds  that  the  charge  on  the  nucleus,  or 
the  number  of  electrons  present  in  the  neutral  atom,  is  equal 
to  the  atomic  number  of  the  element;  this  has  also  been  sug- 
gested by  van  der  Broek,  and  agrees  with  Moseley's  X-ray 
spectrum  results,  as  already  mentioned. 

Bohr's  atom  is  satisfactory  as  agreeing  with  Rutherford's 
postulates  required  by  the  scattering  experiments,  and  giving 
a  good  account  of  the  spectral  series  in  a  way  much  more  in 
accord  with  modern  ideas  on  radiation  than  Ritz's  atom  ;  the 
numerical  agreement  is  especially  good.  It  remains  to  be 
seen  if  the  atom  will  give  the  Zeeman  effect,  and  a  new  effect 
discovered  by  Stark — the  resolution  of  a  spectral  line  into 
components  in  an  electric  field — which  will  be  described  later. 
Warburg  has  very  recently  worked  out  that  such  an  atom 
model  will  not  give  the  required  resolution  into  lines,  but 
merely  a  broadening  of  the  spectral  line  ;  however,  these  results 
obviously  depend  upon  the  nature  of  the  special  assumptions 
made,  as  further  assumptions  are  necessary,  and  we  await 
further  work  from  Bohr  himself  upon  this  point. 

The  new  effect  discovered  by  Stark,  just  mentioned,  is  the 
resolution  of  the  chief  hydrogen  and  helium  lined  into  com- 
ponents by  means  of  a  strong  electric  field,  corresponding  to 
the  Zeeman  effect  in  the  magnetic  field.  The  great  difficulty 
in  such   experiments  is  to  obtain  a  strong  electric  field  in  a 


620  SCIENCE   PROGRESS 

luminous  gas ;  owing  to  the  strong  ionisation  taking  place  an 
arc  tends  to  set  in.  The  principle  employed  by  Stark  was 
to  use  canal  rays,  and  apply  the  potential  difference  between 
the  pierced  cathode  and  a  subsidiary  electrode  behind  it,  that 
is,  on  the  side  remote  from  the  anode.  If  the  cathode  dark 
space  is  adjusted  to  be  much  greater  than  the  distance  between 
these  electrodes  (about  2  mm.),  a  potential  difference  corre- 
sponding to  a  field  up  to  31,000  volts/cm.  can  be  applied  without 
arcing.  The  canal  rays  were  observed  in  a  direction  normal  to 
their  path  (and  so  normal  to  the  electric  field),  to  avoid  the 
Doppler  effect.  The  hydrogen  lines  Hp  and  Hy  were  resolved 
for  this  transversal  effect  into  five  components,  the  three  middle 
ones  polarised  normal  to,  the  two  outer  ones  parallel  to,  the 
electric  field.  The  extreme  separation  obtained  with  a  field  of 
estimated  strength  of  30,000  volts/cm.  was  nearly  as  great  as 
that  of  the  two  sodium  D  lines  (under  normal  circumstances). 
The  helium  lines  were  also  resolved,  but  into  different  com- 
ponents, the  effect  varying  with  the  series  to  which  the  line 
belonged.  The  separation  of  the  components  seems  to  be 
proportional  to  the  field.  The  effect  is  obviously  of  the  first 
importance,  and,  as  the  author  points  out,  may  have  disturbed 
the  finer  observations  of  the  Zeeman  effect,  as  the  application 
of  the  magnetic  field,  by  diminishing  the  cross  section  of  the 
positive  column,  increases  the  longitudinal  electric  field,  perhaps 
sufficiently  to  cause  the  Stark  effect  to  appear. 

J.  J.  Thomson  has  continued  his  work  on  the  positive  rays, 
examining  them  by  his  well-known  method  of  photographing 
the  trace  of  the  rays  simultaneously  deflected  in  an  electric 
and  a  magnetic  field  on  a  plate  placed  at  right  angles  to  the 
undeflected  beam.     The  form  of  the  curve  obtained  on  the  plate 

gives  the  ratio  —  for  the  rays  causing  any  particular  curve,  and, 

further,  information  concerning  the  velocities  of  the  particles 
constituting  the  ray  in  question.     The  most  recent  results  are 

those  which  concern  the   lines  which   correspond   to  —  =  22, 

and  —  =  3.1     The  former  line  was  obtained  when  the  residual 
e       J 

gas   in   the   tube   consisted   of  the   lighter   constituents  of  the 

atmosphere ;   a  molecule  of  C02  with  a  double  charge  would 

1  --  is  taken  as  unity  for  the  singly  charged  atom  of  hydrogen. 


PHYSICS  IN    1913  621 

give  a  line  coinciding  with  this  line,  but  the  C02  can  be  removed 
without  influencing  the  line.  J.  J.  Thomson  came  to  the  con- 
clusion that  it  corresponded  to  a  new  gas  of  atomic  weight  22, 
closely  allied  to  neon  (atomic  weight  20),  with  a  single  charge. 
After  many  attempts  Aston,  working  in  the  Cavendish  labo- 
ratory, has  apparently  succeeded  in  isolating  such  a  gas  by 
allowing  the  mixed  gases  (neon  and  the  supposed  new  gas) 
to  diffuse  repeatedly  through  a  porous  wall ;  owing  to  the 
difference  in  rates  of  diffusion  consequent  on  the  heavier  atom 
of  the  new  gas,  a  separation  would  be  expected.  In  this  way 
Aston  obtained  two  gaseous  components  which  showed  the  22 
line  in  different  intensities,  and  also  gave  differences  of  density 
when  weighed  on  a  specially  constructed  quartz  balance.  The 
two  gases,  however,  gave  the  same  spectrum,  and  in  other 
respects  showed  like  chemical  properties,  so  that  on  the  present 
evidence  it  appears  they  differ  in  atomic  weight,  but  not  in 
chemical  properties ;  this  is  the  case  with  some  of  the  radio- 
active elements.  On  Rutherford's  nucleus  atom  theory  such  a 
state  of  things  is  quite  possible,  since  the  chemical  and  physical 
properties  of  an  atom  depend  on  the  charge  on  the  nucleus, 
while  the  atomic  weight  depends  on  the  inner  structure  of  the 
nucleus,  and  may  not  be  proportional  to  the  charge. 

As  regards  the  unknown  substance  "  X3  "  causing  the  line  for 

which  —  =  3,  J.  J.  Thomson  has  come  to  the  conclusion  that  it 

is  triatomic  hydrogen  with  one  charge.  He  has  shown  that 
it  cannot  be  a  carbon  atom  with  four  charges,  and  the  fact  that  it 
can  be  obtained  by  the  bombardment  by  cathode  rays  from  salts 
containing  hydrogen,  but  not  from  those  which  contain  no 
hydrogen,  the  salts  in  both  cases  being  previously  freed  from 
absorbed  gases,  lends  support  to  the  hydrogen  hypothesis. 
J.  J.  Thomson  has  also  been  examining  by  the  positive  ray 
method  the  gases  given  off  from  a  great  variety  of  substances 
when  they  are  exposed  to  the  bombardment  by  cathode  rays, 
with  special  reference  to  the  production  of  helium,  found  by 
Ramsay  in  old  X-ray  bulbs,  and  neon.  He  finds  that  in  all  cases 
small  amounts  of  helium  are  liberated,  even  when  the  bombarded 
salts  have  been  dissolved  and  dried  several  times  to  free  them 
from  occluded  gases.  The  experiments  are  still  in  progress,  and 
the  source  of  the  helium  must  be  regarded  as  still  in  question. 
Very  recently  Strutt  has  published  an  account  of  attempts  made 


622  SCIENCE   PROGRESS 

to  observe  the  production  of  neon  or  helium  by  electric  dis- 
charge :  his  results  were  negative. 

In  connection  with  J.  J.  Thomson's  work  on  the  positive  rays, 
which  seem  to  offer  a  new  and  very  sensitive  method  of  chemical 
analysis,  it  may  be  mentioned  that  Moseley  found  that  the  X-ray 
spectra  already  described  gave  good  evidence  of  traces  of  foreign 
metals  in  some  of  the  metals  used,  the  strong  line  in  the  spectrum 
of  the  impurity  appearing  distinctly  along  with  the  spectrum  of 
the  metal  itself.  The  X-ray  spectrum,  being  apparently  so  much 
simpler  in  character  than  the  ordinary  spectra,  may  in  this  way 
afford  a  very  powerful  method  of  chemical  analysis. 

Two  very  interesting  papers  have  appeared  which  trace  effects 
previously  assumed  to  be  of  purely  electronic  origin  to  the  pre- 
sence of  small  quantities  of  gas.  The  effects  in  question  are  the 
photoelectric  effect  and  the  thermionic  effect,  which  have  been 
the  object  of  so  much  study  in  recent  years,  and  concerning 
which  so  many  inconsistent  results  have  been  obtained.  From 
a  careful  study  of  the  behaviour  of  purified  carbon  Pring  has 
come  to  the  conclusion  that  the  emission  of  electrons  by  this 
substance  ordinarily  observed  when  it  is  raised  to  a  high  tem- 
perature is  due  largely,  if  not  entirely,  to  the  presence  of  traces 
of  gas.  He  has  shown  that  by  very  carefully  purifying  the 
carbon  and  reducing  the  pressure  of  the  surrounding  gas  as 
much  as  possible  the  discharge  of  negative  electricity  can  be 
diminished  to  an  enormous  extent,  that  on  the  admission  of  a 
little  gas  the  thermionic  current  gradually  increases  correspond- 
ing to  the  occlusion  of  the  gas,  and  that  the  effect  depends  in  a 
high  degree  on  the  nature  of  the  traces  of  residual  gas,  being 
very  small  indeed  with  the  inactive  gases  helium  and  argon,  and 
relatively  considerable  with  carbon  dioxide,  which  is  known  to 
react  with  carbon  at  high  temperatures.  These  and  other  results 
furnish  a  strong  presumption  that  the  so-called  thermionic  effect 
is  due  to  the  presence  of  traces  of  gas,  which  react,  probably  in 
a  cyclic  process,  with  the  carbon,  the  reaction  resulting  in  the 
liberation  of  electrons ;  the  effect  is  thus  probably  a  chemical 
one.  Freydenhagen  came  to  similar  conclusions  in  191 2  with 
respect  to  sodium  and  potassium  in  a  high  vacuum,  after  Pring 
had  already  published  preliminary  results  on  carbon.  It  remains 
to  be  seen  if  there  is  a  residual  true  thermionic  effect,  which 
must  be  in  any  case  very  small,  and  if  the  effect  in  different 
metals  is  due  to  traces  of  gas.     Considered  in  conjunction  with 


PHYSICS   IN    1913  623 

the  work  described  in  the  next  paragraph  it  seems  likely  that 
the  whole  effect  is  due  to  traces  of  gas. 

At  the  suggestion  of  Freydenhagen  a  student  of  his,  Kiistner, 
has  studied  the  photoelectric  effect  in  zinc,  one  of  the  metals 
hitherto  supposed  to  be  particularly  active  in  this  respect,  which 
had  been  carefully  purified  and  scraped  by  means  of  a  magnetic- 
ally actuated  blade  while  actually  in  a  vacuum.     Special  means 
were  resorted  to  in  order  to  obtain  a  very  high  vacuum,  and  to 
rid  the  zinc  of  the  last  traces  of  the  gas ;   Freydenhagen  had 
come  to  the  conclusion  that  under  these  circumstances  the  photo- 
electric effect  would  cease.     It  was  found  experimentally  that  by 
prolonged  scraping  in  vacuo  and  exhaustion  the  effect  could  be 
reduced  until  it  was  not  detectable  ;   further,  that  the  various 
types  of  photoelectric  fatigue  and  abnormal  initial  effects  were 
easily  explained  on  the  assumption  that  they  were  due  to  the 
occlusion  of  residual  gases,  and  could  be  imitated  at  will.     The 
results  are  striking  enough,  and  present  remarkable  similarities 
throughout  with   those  of  Pring  on  the  different  effect.     The 
work  is  being  extended  in  both  directions,  and,  while  it  is  as  yet 
too   early  to   dogmatise,  it   certainly  seems   probable   that   the 
emission  of  electrons  due  to  the  action  of  both  heat  and  illumina- 
tion by  ultraviolet  light  is  bound  up  with  and  dependent  on  the 
presence  of  occluded  gases.     The  many  irregularities  observed 
by  workers  in  these  fields  confirm  this  belief. 

The  foregoing  does  not  pretend  to  be  a  complete  record  of 
all  work  of  any  importance  done  during  the  past  year,  but  rather 
an  account  of  certain  pieces  of  work  performed,  and  theories  put 
forward,  during  that  period,  selected  because  they  seem  likely  to 
prove  of  far-reaching  importance  and  to  modify  and  extend  our 
existing  ideas.     Thus  there  can  be  no  doubt  that  the  methods 
of  investigating  the  X-rays  opened  up  by  Laue  and  the  Braggs, 
father  and  son,  have  already  led  to  results  of  fundamental  import- 
ance, and  are  likely  to  lead  to  many  more.     Much  careful  work 
done  in  elaboration  of  older  lines  of  research  has  been  passed 
over  without  mention,  not  because  the  author  is  possessed  of 
that  passion  for  the  new  which  to-day  seems  in  so  many  cases  to 
express  itself  in  a  desire  rather  to  tear  down  than  to  build  up, 
but  because  considerations  of  space  have  prohibited  an  adequate 
treatment  of  more  than  a  relatively  few  selected  themes.     It  is 
to  be  hoped  that  the  work  here  described  will  all  of  it  prove  of 
permanent  value  to  the  progress  of  physics. 


624  SCIENCE   PROGRESS 


References  to  Literature 

A  list  of  the  chief  papers  describing  the  work  mentioned  in 
the  foregoing  article.  Further  references  will  in  many  cases  be 
found  in  the  papers  here  cited. 

Diffraction  of  X-rays  by  Crystals,  and  Allied  Work 

FRIEDRICH,    KNIPPING,   and    M.    Laue,    Sitzungsber.   der  Kais.    Bayer.   Akad. 

Miinchen,  1912,  p.  303.  Reprinted,  Annalen  der  Physik,  (iv.)  41, 191 3,  p.  971. 
M.  LAUE,  A?malen  der  Physik,  (iv.)  41,  1913,  p.  989. 

and  J.  VAN  DER  LlNGEN,  Physikalische  Zeitschr.  15,  1914,  p.  75. 

W.  L.  Bragg,  Proc.  Cambridge  Phil.  Soc.  xvii.  Part  I.  p.  43  ;  Proc.  Roy.  Soc.  A,  89, 

1913,  p.  248. 
W.  H.  Bragg  and  W.  L.  Bragg,  Proc.  Roy.  Soc.  A,  88,  1913,  p.  428  ;  Proc.  Roy. 

Soc.  A,  89,  1913,  p.  277. 
W.  H.  Bragg,  Proc.  Roy.  Soc.  A,  89,  p.  246. 

H.  G.  J.  Moseley  and  C.  G.  Darwin,  Phil.  Mag.  July  191 3,  p.  210. 
H.  G.  J.  Moseley,  Phil.  Mag.  December  191 3,  p.  1024. 
P.  Debye,  Ber.  der  Deutschen  Phys.  Gesellschaft,  15,  1913,  p.  738. 
M.  DE  BROGLIE,  Le  Radium,  10,  1913,  pp.  186,  245. 
E.  Rutherford  and  E.  N.  da  C.  Andrade,  Nature,  October  30,  1913,  p.  266. 

See  also  various  letters  in  Nature  for  the  end  of  19 12  and  for  191 3,  all  indexed 
there  under  X-rays 

Theory  of  Radiation,  a?id  its  Applications 

H.  POINCARE,  Journal de  Physique,  (v.)  2,  1912,  p.  5. 

M.  PLANCK,  Theorie  der  Wiirmestrahlung,  Second  Edition,  Leipzig,  191 3. 

W.  Wien,  Neuere  Probleme  der  theoretischen  Physik.  Leipzig,  Teubner,    1913, 

which  gives  further  references. 
P.  LENARD,  Annalen  der  Physik,  (iv.)  40,  1913,  p.  393,  and  (iv.)  41,  1913,  p.  53. 
N.  BjERRUM,  Nernst  Festschrift,  1912,  p.  90. 

E.  von  Bahr,  Ber.  der  Deutschen  Phys.  Gesellschaft,  15,  1913,  pp.  710,  1150. 
J.  Dewar,  Proc.  Roy.  Soc.  A,  89,  191 3,  p.  158. 

See  also  discussion  at  the  British  Association,  Birmingham,  1913.     J.  H.  Jeans 
and  others. 

Structure  of  the  Atom 

E.  Rutherford,  Phil.  Mag.  May  191 1,  p.  669. 

Also  H.  Geiger  and  E.   Marsden,  Phil.  Mag.  April   1913,   p.   604  ;   and 
E.  Rutherford  and  J.  M.  Nuttall,  Phil.  Mag.  Oct.  191 3,  p.  702. 
N.  Bohr,  Phil.  Mag.  1913,  July,  p.  1  ;  Sept.  p.  476  ;  Nov.  p.  857. 
E.  Warburg,  Ber.  der  Deutschen  Phys.  Gesellschaft,  15,  191 3,  p.  1259. 

Also  E.  J.  Evans,  A.  Fowler,  N.  Bohr,  letters  in  Nature  during  Sept.  and 
Oct.  191 3,  and  subsequent  letters  by  others  in  Nature. 

Effect  of  Electric  Field  on  Spectral  Lines 
J.  STARK,  Sitzungsber.  der  Kais.  Preuss.  Akad.,  Berlin,  Nov.  191 3,  p.  932. 


PHYSICS  IN    1913  625 

Positive  Rays,  Production  of  Helium,  etc. 

J.  J.  Thomson,  Proc.  Roy.  Soc.  A,  89,  1913,  p.  1. 

See  also  Rays  of  Positive  Electricity,  Longmans,  1913. 
F.  W.  Aston,  Proc.  Roy.  Soc.  A,  89,  1914,  P-  439- 
R.  J.  Strutt,  Proc.  Roy.  Soc.  A,  89,  1914,  P-  499- 

Thermionic  and  Photoelectric  Effect 

J.  N.  Pring,  Proc.  Roy.  Soc.  A,  89,  1913,  P-  344- 

K.  FREYDENHAGEN,  Physikalische  Zeitschrift,  15,  1914,  P-  65. 

H.  Kustner,  Physikalische  Zeitschrift,  15,  19141  P-  68. 


VERTEBRATE   PALEONTOLOGY   IN   1913 

By  R.  LYDEKKER,  F.R.S. 

The  first  point  to  notice  is  that  the  complete  paper,  by  Messrs. 
Dawson  and  Smith  Woodward,  on  the  famous  Piltdown  skull 
appeared  in  vol.  lxix.,  pp.  1 17-51,  of  the  Quarterly  Journal  of  the 
Geological  Society,  where  the  full  name,  Eoanthropus  dawsoni,  was 
for  the  first  time  published,  thus  dating  from  191 3.  As  so  much 
space  was  devoted  to  this  subject  in  my  review  of  vertebrate 
palaeontology  in  191 2,  published  in  last  year's  volume  of  this 
journal,  it  might  well  have  been  thought  that  there  was  little  or 
nothing  to  add  on  the  present  occasion.  Additional  material — 
in  the  shape  of  a  lower  canine  tooth — has,  however,  been 
brought  to  light  since  the  publication  of  the  original  memoir; 
and  a  regrettable  controversy  has  taken  place  with  regard  to 
Dr.  Smith  Woodward's  restoration  of  the  skull,  and  the  nature 
and  affinities  of  the  being  to  whom  it  pertained.  Into  the 
details  of  this  controversy  I  have  no  intention  of  entering ;  and 
I  shall  content  myself  with  quoting  certain  extracts  from  the 
report  of  an  evening  discourse  delivered  by  Dr.  Woodward 
before  the  Royal  Institution  on  September  16,  191 3,  in  which 
the  criticisms  of  his  work  are  discussed  and,  for  the  most  part, 
refuted. 

As  regards  the  discovery  of  the  aforesaid  tooth  Dr.  Wood- 
ward spoke  as  follows : 

"  Fortunately,  Mr.  Dawson  has  continued  his  diggings  during 
the  past  summer,  and  on  August  30  Father  P.  Teilhard,  who 
was  working  with  him,  picked  up  the  canine  tooth  which 
obviously  belongs  to  the  half  of  the  mandible  originally  dis- 
covered. In  shape  it  corresponds  exactly  with  that  of  an  ape, 
and  its  worn  face  shows  that  it  worked  upon  the  upper  canine 
in  the  true  ape-fashion.  It  only  diners  from  the  canine  of  my 
published  restoration  in  being  slightly  smaller,  more  pointed, 
and  a  little  more  upright  in  the  mouth.  Hence,  we  have  now 
definite  proof  that  the  front  teeth  of  Eoanthropus  resembled 
those  of  an  ape." 

626 


VERTEBRATE  PALEONTOLOGY   IN    1913        627 

In  regard  to  the  question  whether  the  lower  jaw  pertains  to 
the  same  individual  as  the  cranium,  or  skull  proper,  the  lecturer 
expressed  his  views  in  the  following  words : 

"  We  can  only  state  that  its  molar  teeth  are  typically  human, 
its  muscle-markings  are  such  as  might  be  expected,  and  it  was 
found  in  the  gravel  near  to  the  skull.  The  probabilities  are 
therefore  in  favour  of  its  natural  association.  If  so,  it  is  reason- 
able to  suppose  that  the  skull  will  prove  to  be  that  of  a  very 
lowly  kind,  not  that  of  a  highly  civilised  man.  I  have  accord- 
ingly made  a  new  study  of  the  specimen  .  .  .  and  find  that  the 
only  alteration  necessary  in  our  original  model  is  a  very  slight 
displacement  of  the  occipital  and  right  parietal  bones." 

Finally,  he  sums  up  by  remarking  that  "in  Eoanthropus  we 
have  a  human  being  with  a  distinct  remnant  of  ape-like  ancestors 
in  his  jaws  ;  and  in  the  human  mandible,  probably  of  the  same 
period,  found  near  Heidelberg,  we  have  a  slightly  more  advanced 
stage  with  teeth  which  are  distinctly  human.  When  the  Plio- 
cene forerunners  of  these  species  are  found,  they  will  probably 
fall  rather  into  the  category  of  apes  than  of  man. 

"  Next,  in  connection  with  the  remarks  I  have  made  about 
the  evolution  of  the  brain  in  mammals,  it  is  interesting  to  notice 
that  the  brain  of  Eoanthropus  makes  a  much  nearer  approach  to 
that  of  modern  man  than  his  face.  It  therefore  appears  that  the 
excessive  development  of  the  brain  preceded  the  loss  by  the 
mouth  of  its  functions  as  a  weapon.  Increase  of  intelligence 
removed  the  necessity  for  so  much  brute  force,  and  the  face  then 
became  reduced  in  size,  while  the  familiar  weakness  of  the  jaws 
of  man  was  the  result." 

It  should  be  added  that  in  the  Geological  Magazine  for 
October  191 3  (decade  5,  vol.  x.  pp.  433-4)  Dr.  Smith  Woodward 
published  a  short  supplementary  note  on  Eoanthropus,  with  a 
figure  of  the  amended  restoration  of  the  whole  skull,  together 
with  one  of  the  lower  jaw  containing  the  newly  found  canine  in 
position. 

Many  years  ago  Dr.  Ameghino  described  a  small  monke}^ 
from  the  Patagonian  Miocene  under  the  name  of  Homun- 
culus,  and  considered  that  it  showed  affinity  to  the  human 
phylum.  Mr.  H.  Bluntschli  {Verh.  Anat.  Ges.  191 3,  pp.  33-43) 
has  now  shown  that  Homunculus,  together  probably  with 
Anthropops  and  Pitheculus,  is  nearly  allied  to  the  existing 
South  American  douroucolis  (Nyctipithecus).     On  the  other  hand, 


628  SCIENCE   PROGRESS 

a  number  of  other  Patagonian  genera  referred  by  Ameghino  to 
the  Primates  do  not  belong  to  that  order,  some,  such  as  Pithe- 
culites  and  Homunculites,  being  apparently  marsupials,  while 
others,  like  Archceopithecus  and  Henricosbornia,  seem  to  be 
ungulates. 

In  this  place  attention  may  be  directed  to  a  few  faunistic 
mammal  papers,  among  which  reference  may  first  be  made  to 
one  by  Mr.  J.  W.  Gidley  (Proc.  U.S.  Nat.  Mus.  vol.  xlvi. 
pp.  29-102),  recording  the  results  of  the  exploration  of  a  cavern 
near  Cumberland,  Maryland,  U.S.A.  The  remains  include  those 
of  a  bear  closely  related  to  the  existing  Ursus  americanus,  but 
with  larger  tusks,  which  has  been  named  U.  vitabilis,  and  also 
of  a  dog,  Canis  ambusteri,  of  the  size  of  a  wolf,  but  with  lower 
carnassial  teeth  resembling  those  of  a  coyote. 

Brief  reference  may  also  be  made  to  a  popular  article  con- 
tributed by  Dr.  W.  D.  Matthew  to  the  American  Museum  Journal 
for  November  1903  on  the  vertebrate  remains  discovered  in 
the  great  asphalt-springs  of  Rancho  La  Brea,  California,  which 
formed  during  the  later  part  of  the  Tertiary  period  a  death-trap 
for  the  fauna  of  the  adjacent  country.  Remains  of  fully  fifty 
species  of  birds  have  been  identified,  and  there  were  probably 
as  many  mammals ;  remains  of  wolves,  lion-like  cats,  sabre- 
toothed  tigers,  eagles,  and  vultures  being  the  most  common, 
while  next  in  abundance  are  those  of  bisons,  horses,  and  gigantic 
ground-sloths,  as  well  as  of  wading-birds.  On  the  other  hand, 
bones  of  the  smaller  mammals  and  birds  are  comparatively  rare. 
The  obvious  corollary  from  this  is  that  the  aforesaid  large 
mammals  ventured  heedlessly  on  to  the  apparently  solid  surface 
of  the  treacherous  asphalt,  in  which  they  soon  became  hopelessly 
bogged  and  condemned  to  a  lingering  death  by  suffocation  or 
starvation.  While  thus  hopelessly  trapped,  they  served  as  lures 
to  attract  all  the  beasts  and  birds  of  prey  within  sight,  which  in 
their  turn  became  enmired,  and  thus  drew  others  of  their  kin 
to  the  fatal  snare.  So  things  went  on  from  year  to  year  and 
from  century  to  century,  with  the  result  that  the  palaeontologist 
has  now  a  rich  museum  of  the  remains  of  the  old  fauna  of  the 
country  ready  to  his  hand. 

In  connection  with  cavern  and  other  superficial  formations, 
reference  maybe  made  to  the  identification  by  Mr.  J.  W.  Jackson 
{Geol.  Mag.  decade  5,  vol.  x.  pp.  259-62)  of  remains  of  the  lynx 
from  caves  in  North  Wales  and  Derbyshire.     Here,  too,  may  be 


VERTEBRATE   PALEONTOLOGY   IN    1913        629 

mentioned  a  paper  by  Dr.  J.  C.  Merriam  {University  of  Cali- 
fornia Publications,  Bull.  Dep.  Geol.  vol.  vii.  pp.  373-85)  on  the 
vertebrate  fauna  of  the  Orindan  and  Siestan  beds  of  California, 
which  are  of  Miocene  age. 

Another  faunistic  paper  is  one  by  Mr.  H.  G.  Stehlin  {Bull. 
Soc.  Geol.  France,  ser.  4,  vol.  xii.  pp.  198-212,  191 2)  on  the 
palaeontology  of  the  Tertiary  sands  of  Rosieres,  near  St.  Florent, 
Cher.     A  new  species  of  Cervus  is  described. 

Of  wider  interest  is  an  article  by  Dr.  Ernst  Stromer  {Zeits. 
deutsch.  Geol.  Ges.  vol.  lxv.  pp.  350-72)  on  the  Middle  Pliocene 
fauna  of  the  Wadi  Natrun,  Egypt,  in  which,  among  numerous 
other  forms,  an  extinct  otter  is  described  as  new,  under  the  name 
of  Lutra  libyea. 

Reverting  to  systematic  work  on  mammals,  the  next  paper 
for  notice  is  one  by  Dr.  W.  D.  Matthew  {Bull.  Amer.  Mus.  Nat. 
Hist.  vol.  xxxi.  pp.  307-14),  on  the  skull  of  a  new  type  of  the 
Insectivora — Palceoryctes puercensis — from  the  Puerco,  or  Lowest, 
Eocene  of  New  Mexico.  It  is  referred  to  the  primitive  and 
scattered  group  now  represented  by  the  solenodons  {Solenodont- 
idce)  of  the  West  Indies,  the  otter-shrew  {Potamogale)  and  the 
golden  moles  {Chrysochloridcc)  of  Ethiopian  Africa — a  convenient 
term  to  denote  that  part  of  the  African  continent  lying  to  the 
south  of  the  northern  tropic — and  the  tenrecs  {Centctidai)  of 
Madagascar ;  the  affinity  with  the  last  being  so  close  that 
Dr.  Matthew  is  inclined  to  include  the  extinct  genus  in  the  same 
family.  Here  it  should  be  mentioned  that  although  the  group  is 
now  unknown  on  the  continent  of  America,  it  was  represented 
in  Patagonia  during  the  Miocene  by  Nccrolestes,  which  appears 
to  have  been  nearly  related  to  the  golden  moles,  and  also  by 
four  more  or  less  closely  related  genera  in  North  America.  The 
problem  now  awaiting  solution  is  whether  the  living  and  extinct 
southern  members  of  these  Zalamdodont  Insectivora,  as  the 
whole  group  is  called,  reached  their  respective  habitats  by  means 
of  one  or  more  land-bridges  between  the  great  southern  conti- 
nents, which  were  almost  certainly  in  existence  during  the  early 
part  of  the  Tertiary  period,  or  whether  they  travelled  southwards 
from  the  northern  hemisphere  by  independent  routes. 

Be  this  as  it  may,  the  newly  described  genus  seems  to  indicate 
that  the  Centetidm  are  the  oldest  existing  family  of  placental 
mammals.  It  likewise  points  to  the  great  antiquity  of  the 
triangular,  or  tritubercular,  type  of  molar  tooth,  which  forms  a 


630  SCIENCE   PROGRESS 

distinctive   feature    of    all   the    members   of    the   group    under 
consideration. 

Mention  of  the  tritubercular  type  of  dentition  leads  con- 
veniently on  to  a  paper  by  Mr.  K.  S.  Bardenfleth  (Vidensk. 
Meddel.  Dank,  naturh.  Fpren,  vol.  lxv.  pp.  6i-m)  on  the  form 
and  structure  of  the  carnassial  teeth  of  Carnivora — this  paper 
being,  of  course,  only  in  part  palaeontological.  Its  chief  interest, 
from  the  latter  standpoint,  is  concentrated  on  a  discussion  as  to 
the  possibility  of  the  tritubercular  molar  being  formed  by  a 
rotation  of  two  of  the  three  longitudinally  arranged  cusps  of 
a  tooth  like  that  of  the  Mesozoic  Triconodon.  The  author  adduces 
evidence  to  show  that,  in  the  first  place,  such  a  rotation  of  the 
cusps  could  not  have  taken  place,  and,  secondly,  if  it  did,  the 
cusps  are  not  respectively  homologous  with  those  of  the 
tritubercular  molar.  He  adds  that  "  if  this  holds  good,  the 
whole  nomenclature  and  theory  of  Osborn  falls  to  the  ground." 

Turning  to  the  Carnivora,  it  may  be  noticed  that  Dr.  Merriam 
has  considerably  extended  our  knowledge  of  fossil  Canidce  by  a 
study  of  the  osteology  and  dentition  of  the  North  American 
Tertiary  genus  Tephrocyon  in  a  paper  issued  in  the  Publications 
of  California  University,  Bull.  Dep.  Geol.  vol.  vii.  pp.  359-72. 
In  the  opinion  of  the  author,  the  genus  in  question  was  to  a 
considerable  extent  intermediate  in  dental  and  skeletal  structure 
between  the  extinct  American  ALlurodon  and  modern  wolves  and 
jackals  (Canis) ;  its  range  extending  from  the  middle  portion  of 
the  Miocene  to  the  early  part  of  the  Pliocene  period. 

Remains  of  the  small  bear  known  as  Ursus  etruscus,  or 
arvernensis,  from  the  Pliocene  of  Tegelen-sur-Meuse,  form  the 
subject  of  a  paper  by  Mr.  E.  T.  Newton,  published  in  the 
Verhand  Geol.-Mijnbouw,  Genuots.  Nederl.  en  Kolon.  Geol.  ser.  1, 
191 3,  pp.  249-54.  Hyaena  remains  from  the  Pleistocene  of  the 
Lower  Rhine  in  the  neighbourhood  of  Mosbach  have  been 
referred  by  Dr.  H.  Pohlig  {Bull.  Soc.  beige  Geol.  vol.  xxvii.  Proc- 
Verb.  p.  147)  to  a  new  race  of  the  striped  species  {Hycena  striata 
trogontherii). 

The  only  paper  on  fossil  rodents  that  has  come  under  my 
notice  is  one  by  Dr.  T.  Studer  {Mitt,  naturfor.  Ges.  Bern,  1913, 
8  pp.)  on  remains  of  marmots  from  the  European  Diluvium. 
Many  of  these  belong  to  the  large  form  of  the  Alpine  species 
known  as  Arctomys  marmotta  primigenia,  but  those  from  Bohemia 
are  identified  with  A.  bobac  of  Eastern  Europe. 


VERTEBRATE  PALEONTOLOGY  IN   1913        631 

Among  the  numerous  papers  on  fossil  ungulates  which  have 
been  published  during  the  year,  the  first  place  may  be  accorded 
to  one  by  Dr.  O.  P.  Hay  (Proc.  U.S.  Nat.  Mus.  vol.  xlvi.  pp. 
161-200)  on  the  extinct  North  American  bisons.  After  a  review 
of  the  large  number  of  previously  described  species,  with  figures 
of  the  skulls  of  many  of  them,  the  author  describes  a  new  one, 
on  the  evidence  of  a  Kansas  skull,  as  Bison  regius.  This  skull 
(fig.  1)  differs  from  that  of  its  near  relative  B.  latifrons,  from  the 
Pleistocene  formation  of  Ohio,  by  the  longer,  more  slender,  and 
more  highly  curved  horn-cores.  Such  a  difference  might,  indeed, 
be  merely  sexual,  but  as  the  enamel-islets  in  the  crowns  of  the 
upper  molars  display  a  folding  which  is  not  found  in  those  of  the 


www 


Fig.   I. — Front  and  back  views  of  skull  of  the  extinct  Kansas 
Bison  {Bison  regius). 


Ohio  species,  the  author  feels  justified  in  regarding  the  Kansas 
bison  as  distinct.  Remains  of  cattle  from  the  Pleistocene  of 
Pianosa  Island,  Italy,  are  referred  by  Mr.  G.  de  Stefano,  Bull. 
Soc.  Geol.  Hal.  ser.  3,  vol.  xii.  pp.  50  and  70,  to  the  new  species 
Bos  bubaloides  and  B.  intermedins. 

In  vol.  lx.  No.  27  of  the  Smithsonian  Miscellaneous  Collections 
Mr.  J.  W.  Gidley  refers  an  associated  series  of  five  upper  cheek- 
teeth of  a  large  ruminant  from  a  Pleistocene  cave-deposit  near 
Cumberland,  Maryland,  U.S.A.,  to  the  existing  African  genus 
Taurotragus,  under  the  name  of  T.  americanus.  Although 
elands  are  now  restricted  to  Ethiopian  Africa ;  the  present 
writer  (see  Cat.  Siwalik  Vert,  lnd.  Mus.  part.  i.  p.  18,  1885)  has 
provisionally  referred  certain  teeth  from  the  Indian  Siwaliks  to 
4i 


632  SCIENCE   PROGRESS 

Taurotragus  {  =  Oreas),  and  if  this  identification  be  correct,  it 
would  tend  to  show  how  elands  might  have  reached  America 
from  Asia  by  the  Bering  Sea  route.  Mr.  Gidley  refers,  more- 
over, to  the  occurrence  in  the  Pleistocene  of  Nevada  of  remains 
of  certain  ruminants  {Ilingoceros  and  Sphenophalus)  as  corrobo- 
rative evidence  of  the  former  existence  of  tragelaphine  or 
eland-like  antelopes  in  America,  although  omitting  to  mention 
that  these  genera  are  regarded  by  Dr.  Merriam  {Univ.  California 
Publications,  Bull.  Dep.  Geol.  vol.  vi.  p.  292)  as  akin  to  the 
American  family  Antilocapridce ;  and  if  this  be  correct,  it  does 
not  seem  impossible  that  the  supposed  eland  represents  another 
member  of  the  same  group,  as  on  distributional  grounds  it  is 
highly  improbable  that  Taurotragus  should  occur  in  America. 
This  is  also  the  opinion  of  Dr.  P.  Matschie,  who,  when 
describing  a  new  African  race  of  eland  {Sitzber.  Ges.  nat. 
Freunde,  Berlin,  191 3,  p.  294),  takes  occasion  to  state  that 
he  can  see  nothing  particularly  eland-like  in  the  Maryland 
teeth. 

In  connection  with  elands,  it  may  be  mentioned  that,  in  an 
article  on  the  association  of  man  with  extinct  mammals  in  South 
Africa,  Dr.  R.  Broom  {Ann.  S.  African  Museum,  vol.  xii.  pp. 
13-16)  has  described  remains  of  certain  antelopes  apparently 
representing  extinct  species  of  existing  African  genera.  One  of 
these,  Connochajtes  antiquus,  is  of  particular  interest  on  account 
of  being,  in  the  opinion  of  its  describer,  intermediate  between 
the  two  existing  species  of  gnus. 

An  important  memoir  by  Dr.  J.  Chomenko  (Khomenko)  on 
the  Tertiary  ruminants  of  Taraklia,  Bessarabia,  is  published 
in  the  Annuaire  geol.  et  min.  Russ.  vol.  xv.  pp.  107-43,  with  a 
French  translation  of  the  first  part.  Antelopes,  gazelles, 
sivatheroids,  and  giraffes  are  abundantly  represented  in  this 
fauna,  which  serves  to  connect  that  of  Pliocene  India  with 
modern  Africa.  In  the  hollow-horned  group,  Criotherium, 
typically  from  the  Pliocene  of  Samos,  is  placed  with  the  harte- 
beests,  while  further  indications  of  African  affinities  are 
displayed  by  Procobus,  a  genus  of  antelopes  akin  to  Cobus. 
Three  species  of  deer  are  also  assigned  to  new  genera,  namely, 
Cervocerus,  Cervavitus,  and  Damacerus;  the  first  two  of  these 
being  apparently  related  to  the  Asiatic  rusine  group,  while 
the  third  is  considered  to  be  allied  to  the  Mesopotamian  fallow 
group.    All  three  are  referred  to  an  extinct  subfamily,  for  which 


VERTEBRATE   PALEONTOLOGY   IN    1913        633 

the  name  Pliocervince  is  suggested,  but  as  there  is  no  such  genus 
as  Pliocervus,  this  is  obviously  inadmissible. 

Reverting  to  America,  it  may  be  noticed  that  in  the  Publi- 
cations of  California  University,  Bull.  Dep.  Geol.  vol.  vii.  pp. 
335—9,  Dr.  Merriam  has  described  a  peculiar  type  of  horn  or 
antler  from  the  Orindan  Miocene  of  California,  which  he 
tentatively  assigns  to  the  extinct  genus  Merycodus,  that  genus 
being  apparently  more  or  less  closely  allied  to  the  modern 
prongbuck  {Antilocapra). 

For  two  short  papers  on  deer  {Cervidce),  one  by  Mr.  L.  Joleaud 
{Bull.  Soc.  Geol.  France,  ser.  4,  vol.  xii.  pp.  468-71)  on  the 
systematic  position  of  Cervus  pachygenys,  of  the  Algerian 
Pleistocene,  and  the  other,  by  Mr.  E.  Kiernik  {Bull.  Ac.  Sci. 
Cracovie,  19 13,  pp.  449-69),  on  antlers  of  Dicrocerus  from  Poland, 
bare  mention  will  suffice.  Reference  has  already  been  made 
to  Mr.  Stellin's  description  of  a  new  Tertiary  Cervus  from 
France. 

More  interest  attaches  to  a  couple  of  papers  on  fossil  North 
American  camels,  in  the  first  of  which  Mr.  Gidley  {Smithson. 
Misc.  Collect,  vol.  lx.  No.  26)  records  the  occurrence  of  a  toe- 
bone  of  a  camel  in  a  superficial  deposit  at  the  mouth  of  the  Old 
Crow  River,  in  the  Yukon  Territory,  in  association  with  remains 
of  mammoth,  horse,  and  bison.  The  occurrence  of  the  camel- 
bone  confirms,  to  quote  the  author's  own  words,  "  the  theory  of 
the  existence  of  a  wide  Asiatic-Alaskan  land-connection  of  com- 
paratively recent  date,  which  for  a  very  considerable  length  of 
time  served  as  a  great  highway  for  the  free  transmission  of 
mammals  between  America  and  the  Old  World."  In  discussing 
the  question  whether  the  Pleistocene  North  American  camels 
described  as  Camelops,  of  which  seven  species  are  recognised, 
are  really  distinct  from  the  South  American  llamas  {Lama,  or 
Auchenia),  Dr.  O.  P.  Hay  {Proc.  Amer.  Mus.  Nat.  Hist.  vol.  xlvi. 
pp.  161-200)  points  out  that  the  northern  forms  lack  the  vertical 
ridges  at  the  antero-external  angles  of  the  last  two  lower  molars 
distinctive  of  their  southern  cousins,  while  their  skulls  are  also 
longer  and  narrower,  with  the  upper  part  of-the  nasal  bones  less 
expanded,  the  crowns  of  their  upper  molars  have  larger  grinding 
surfaces,  and  the  lower  incisors  are  less  proclivous.  It  may  be 
mentioned  that  the  ridge  in  the  lower  molars  of  the  llama  group 
is  also  developed  in  the  corresponding  teeth  of  the  true  camels 
of  the  Pliocene  of  the  Siwalik  Hills,  Northern  India. 


634  SCIENCE   PROGRESS 

It  has  for  some  time  been  known  that  the  brain  of  the  African 
aardvark  (Orycteropus)  exhibits  a  distinct  approximation  to  the 
ungulate  type ;  and,  in  a  paper  contributed  to  the  Proceedings 
of  the  Zoological  Society  for  1913  (pp.  878-93),  Mr.  R.  W.  Palmer 
has  shown  that  this  resemblance  is  most  pronounced  when  the 
brain  of  Orycteropus  is  compared  with  the  cast  of  that  of  the 
Oligocene  artiodactyle  genus  Anoplotherium.  So  marked, 
indeed,  is  the  general  similarity  of  the  two  structures  as  to  lead 
the  author  to  remark  that  "if  cerebral  anatomy  be  of  any 
systematic  value,  the  view  that  Anoplotherium  and  Orycteropus 
arose  from  a  common,  though  necessarily  remote,  ancestry 
can  hardly  be  doubted." 

The  pig-like  Anthracotheriidce  of  the  Miocene  or  Oligocene 
strata  of  the  Bugti  Hills,  Baluchistan,  form  the  subject  of  a 
preliminary  communication  from  Mr.  C.  Forster-Cooper,  pub- 
lished in  the  Annals  and  Magazine  of  Natural  History,  ser.  8, 
vol.  xii.  pp.  514-22.  These  are  referred  to  several  new  species 
and  one  new  genus.  Personally  the  present  writer  is  much 
interested  in  the  reference  of  one  of  these  to  Hemimeryx,  a  genus 
established  by  himself,  with  a  certain  degree  of  trepidation, 
some  thirty  years  ago,  on  the  evidence  of  a  single  upper  molar 
tooth  from  the  Siwaliks  of  the  Punjab.  The  great  numerical 
abundance  of  members  of  the  anthracothere  group,  especially  of 
the  genus  Brachyodus,  is  a  notable  feature  of  the  fauna  of  the 
Bugti  beds. 

In  connection  with  the  above  reference  may  be  made  to  a 
note  by  Mr.  Guy  Pilgrim  in  the  Records  of  the  Geological  Survey  of 
India,  vol.  xliii.  pp.  74  and  75,  amending  the  generic  designations 
of  certain  Bugti  mammals.  The  most  interesting  item  in  con- 
nection with  the  Bugti  fauna  is,  however,  the  description  by 
Mr.  Forster-Cooper  (Ann.  Mag.  Nat.  Hist.  ser.  8,  vol.  xii.  pp. 
376-81)  of  a  gigantic  perissodactyle  ungulate,  which  must 
apparently  have  exceeded  an  ordinary  elephant  in  bulk.  Un- 
fortunately the  generic  name  Thaumastotherinm,  proposed  in 
the  original  description,  proved  to  be  pre-occupied,  and  it  was 
accordingly  replaced  later  on  in  the  same  volume  by  Balu- 
chitherium,  with  the  specific  affix  osborni.  The  skull  and 
dentition  of  this  monster  are  not  yet  known,  certain  jaws  and 
molars  described  as  Paraceratherium  bugtiense,  which  are  of 
a  rhinoceros-like  type,  being  relatively  small  in  comparison  with 
the   huge  dimensions  of  the  vertebrae  and  limb-bones.     Never- 


VERTEBRATE   PALEONTOLOGY   IN    1913        635 

theless,  I  am  inclined  to  think  some  of  them  pertain  to  the  new 
genus.     The  femur  lacks  a  third  trochanter. 

In  a  paper  published  in  vol.  xxii.  (pp.  407-20)  of  the  Bulletin 
of  the  American  Museum  of  Natural  History  Prof.  H.  F.  Osborn 
makes  a  further  contribution  to  his  favourite  study  of  the 
skulls  of  the  horned  ungulates  of  the  families  Uintathcriidoc, 
and  Titanotheriidce,  dealing  in  this  instance  with  species  from  the 
Wind  River  Lower  Eocene  of  Wyoming.  A  very  interesting  point 
is  that  in  the  members  of  the  family  Uintatheriida:  characteristic 
of  this  stage,  such  as  Bathyopsis,  the  skull  lacks  the  great  bony 
horn-cores  of  the  later  types,  their  place  being  taken  by  small 
insignificant  bony  knobs.  In  the  perissodactyle  family 
Titanotheriidce  it  has  been  found  that  two  phyla  of  the  genus 
Eotitanops  are  recognisable,  one  comprising  relatively  small, 
persistently  primitive  light-limbed  species,  and  the  other  animals 
of  a  larger  and  more  progressive  type.  Several  new  species 
are  named  in  the  course  of  the  article. 

From  the  point  of  view  of  geographical  distribution  special 
interest  attaches  to  the  description  by  Mr.  E.  de  L.  Niezabitowski 
{Bull.  Ac.  Sci.  Cracovie,  1913,  pp.  223-5)  of  Part  of  the  skull  of 
a  rhinoceros  from  the  Tertiary  of  Odessa,  which  is  referred  to 
the  extinct  American  genus  Teleoceras,  under  the  name  of  T. 
ponticus.  It  is  one  more  instance  of  the  affinity  between  the 
Tertiary  faunas  of  Eastern  Europe  and  North  America. 

A  Pleistocene  rhinoceros  from  the  Lower  Rhine  in  the 
neighbourhood  of  Mosbach  has  been  made  the  type  of  a  new 
race  by  Dr.  Hans  Pohlig  (Bull.  Soc.  beige  Geol.  vol.  xxvii.  Proc- 
Verb.  p.  145),  under  the  name  of  Rhinoceros  mercki  mosbachensis, 
Falconer's  R.  etruscus  being  also  regarded  as  a  race  of  the  same 
species. 

North  American  Tertiary  horses  belonging  to  the  modern 
genus  Equus  form  the  subject  of  a  paper  by  Dr.  Hay,  published 
in  the  Proceedings  of  the  U.S.  National  Museum,  vol.  xliv.  pp. 
569-94.  Four  species  are  described  as  new,  two  of  these  being 
based  on  teeth  alone,  while  each  of  the  other  two  is  represented 
by  the  skull.  As  this  paper  is  very  technical,  and  therefore  of 
interest  only  to  specialists,  fuller  notice  would  be  out  of  place 
on  the  present  occasion,  but  the  following  passage  in  reference 
to  the  difficulties  incidental  to  the  study  of  fossil  horses  may  be 
quoted  : 

"  It    may     be     perfectly     obvious    that     two     species     are 


636  SCIENCE  PROGRESS 

present,  and  that  they  differed  in  size ;  but  the  teeth  of  the 
larger  individuals  of  the  smaller  species  may  equal  in  size 
the  teeth  of  the  smaller  individuals  of  the  larger  species.  The 
matter  is  likewise  complicated  by  the  fact  that  [in  all  horses] 
the  premolars  are  larger  than  the  molars  of  the  same  individual." 

As  the  result  of  the  acquisition  of  additional  remains,  Dr. 
Broom  (Bull.  Amer.  Mus.  Nat.  Hist  vol.  xxxii.  pp.  437-9)  has 
been  enabled  to  give  further  particulars  with  regard  to  the 
affinities  of  the  extinct  South  African  horse  described  by  himself 
in  1909  under  the  name  of  Equus  capensis.  These  are  stated  to 
indicate  a  heavily  built,  short-legged  species,  standing  about  four- 
teen hands,  and  apparently  distinct  from  all  the  existing  South 
African  members  of  the  genus,  as  well  as  from  the  Arab  stock. 

The  only  literature  relating  to  extinct  tapirs  published 
during  the  year  appears  to  be  a  note  by  Dr.  Merriam  {Pub.  Cali- 
fornia Univ.,  Bull.Dep.  Geol.  vol.  vii.  pp.  169-75)  on  a  lower  molar 
of  a  tapir  obtained  many  years  ago  from  the  auriferous  gravels 
of  California.  It  is  considered  to  represent  a  new  race  of  a 
species  described  by  Leidy  from  the  Pleistocene  of  South 
Carolina.  To  this  race  (Tapirus  haysii  californicus)  is  also 
provisionally  referred  a  set  of  three  upper  molars  from  the  late 
Tertiary  of  Oregon.  T.  haysii  appears  to  be  nearly  related  to 
the  existing  Central  American  T.  bairdi. 

Several  papers  on  extinct  elephants  have  appeared  during 
the  year,  notably  one  in  the  Palceontographica  (vol.  lx.  pp.  1-114) 
by  Mr.  Wolfgang  Soergel  on  the  relationship  and  phylogeny  of 
Elephas  trogontherii  and  E.  antiquus,  and  their  value  in  the  matter 
of  zoning  the  German  Diluvium.  The  fossil  elephants  of  the 
Pleistocene  of  St.  Acheul  and  Montieres  form  the  subject  of  a 
paper  of  six  pages  by  Mr.  V.  Commont,  published  in  Bull.  Soc. 
Linn.  Nord  France  for  191 2  (19 13);  they  included  trogontherii 
antiquus,  and  primigenius,  the  first  of  these  being  regarded  as  a 
race  of  meridionalis.  In  a  third  paper,  by  Mr.  H.  Pohlig  (Bull. 
Soc.  beige  Geol.  vol.  xxvii.  P.V.  pp.  142-7),  the  occurrence  of 
trogontherii  (regarded  as  a  race  of  primigenius)  on  the  Lower 
Rhine  near  Mosbach  is  recorded. 

Stegodont  elephants  from  the  Kendeng  beds  of  Java  form 
the  subject  of  a  memoir  by  Mr.  Soergel  in  the  Palceontographica, 
suppl.  iv.  pp.  1-24,  most  of  which  are  referred  to  Stegodon 
airawana  and  S.  trigonocephalus. 

The  phylogeny  of  the  whalebone-whales  is  discussed  in  an 


VERTEBRATE   PALAEONTOLOGY   IN    1913        637 

article  by  Dr.  O.  Abel  which  I  have  not  yet  seen  ;  the  subject 
being  as  much  zoological  as  palaeontological,  bare  mention 
of  the  communication  must  suffice.  Nearly  as  brief  notice  must 
also  suffice  for  an  article  by  Mr.  Gidley  {Proc.  U.S.  Nat.  Mus. 
vol.  xliv.  pp.  649-54)  on  a  remarkably  fine  skeleton  of  a 
zeuglodont  recently  set  up  in  the  American  Museum.  For 
these  primitive  whales  the  author  retains  the  extremely  inappro- 
priate name  Basilosaurns,  despite  the  fact  that  it  was  replaced  by 
its  sponsor,  Sir  R.  Owen,  by  Zeuglodon  when  the  mammalian 
nature  of  the  remains,  which  were  at  first  regarded  as  per- 
taining to  a  reptile,  became  apparent. 

In  an  article  on  the  ancestry  of  the  mammals  of  the  order 
Edentata,  published  in  the  American  Museum  Journal  (vol.  xii. 
pp.  300-3),  Dr.  Matthew,  after  mentioning  that  armadillos  are 
probably  the  most  primitive  existing  members  of  the  whole 
group,  and  that  remains  of  "armadillos  without  armour"  occur 
in  the  early  North  American  Tertiary,  observes  that  although 
neither  the  latter  nor  the  rodent-like  taeniodonts  of  the  North 
American  Eocene  can  be  regarded  as  direct  ancestors  of  the 
typical  South  American  edentates,  such  as  sloths  and  anteaters, 
yet  they  suggest  the  possibility  that  the  group  originally  came 
from  North  America,  penetrated  to  South  America  about  the 
beginning  of  the  Tertiary  period,  where  they  developed  into  a 
host  of  new  forms,  which  constituted  a  most  important  element 
in  the  fauna  of  the  country. 

Remains  of  ground-sloths  of  the  genera  Nothrotherium  and 
Megalonyx  from  the  Pleistocene  of  Southern  California  form  the 
subject  of  an  article  by  Mr.  Chester  Stock  {Univ.  California  Pub., 
Bull.  Dep.  Geol.  vol.  vii.  pp.  341-50),  in  which  a  new  species  of 
each  genus  is  named  and  described ;  most  of  the  bones  being 
from  the  asphalt-beds  of  Rancho  La  Brea,  referred  to  in  an  earlier 
paragraph  of  the  present  review.  As  Megalonyx  is  typically  from 
the  North  American  Pleistocene,  while  Nothrotherium  (formerly 
Ccelodon)  is  Brazilian,  Southern  California  is  precisely  the  locality 
where  the  two  might  be  expected  to  be  found  in  association. 
Remains  of  both  genera  are  much  less  abundant  at  Rancho  La 
Brea  than  are  those  of  Mylodon. 

As  regards  marsupials,  the  only  paper  that  has  come  under 
my  notice  is  one  by  Dr.  E.  C.  Stirling  {Mem.  R.  Soc.  S.  Australia, 
a,  vol.  i.  pp.  128-78),  in  which  conclusive  evidence  is  adduced  to 
show  that  the  upper  incisors   described  by  Sir  R.   Owen   as 


638  SCIENCE  PROGRESS 

Sceparnodon  really  pertain,  as  first  suggested  by  myself,  to  the 
giant  wombat,  Phascolonus  gigas. 

Two  articles  by  Dr.  R.  W.  Shufeldt  on  fossil  birds  have 
appeared  during  the  year.  The  most  interesting  item  in  the 
first  of  these  {Bull.  Amer.  Mus.  Nat.  Hist.  vol.  xxxii.  pp.  285-306) 
relates  to  certain  bones  of  the  gigantic  Eocene  birds  originally 
described  by  the  late  Prof.  E.  D.  Cope  as  Diatryma,  the  type 
species  being  from  New  Mexico.  The  new  specimens,  for  which 
the  name  D.  ajax  is  suggested,  are  from  the  Wasatch  Eocene  of 
Wyoming,  and,  with  the  exception  of  a  couple  of  toe-bones,  are 
in  a  fragmentary  condition.  Nevertheless,  the  author  considers 
himself  justified  in  making  the  astounding  statement  that  the 
bird  to  which  they  pertained  was  "  fully  double  the  size  of 
Diatryma  gigantea  of  Cope,  and  that  it  may  possibly  have 
attained  a  height  of  over  thirty  feet,"  or  nearly  five  times  that  of 
a  big  ostrich !  The  other  bones  described,  which  are  from 
various  horizons,  are  referred  for  the  most  part  to  birds  of  prey 
and  game-birds  ;  a  new  genus,  Palceophasianus,  of  the  latter  group 
being  named  on  the  evidence  of  imperfect  bones  from  the 
Wasatch  Eocene  of  Wyoming. 

In  the  second  communication  {Journ.  Geol.  vol.  xxi.  pp.  628- 
52)  Dr.  Shufeldt  discusses  fossil  specimens  in  which  the 
imprints  of  birds'  feathers  are  preserved,  commencing  with  those 
of  Arch&opteryx.  Such  impressions,  accompanied  by  one  leg, 
on  slabs  from  the  well-known  Green  River  Shales  of  Wyoming 
are  made  the  type  of  a  new  genus  and  species  of  perching-bird, 
under  the  crude  name  of  Yalavis  lenuipes,  with  the  significant 
remark  that  "  birds  of  the  same  genus  and  species  may  or 
may  not  be  still  in  existence ;  the  probabilities  are  that  they 
are  not." 

To  vol.  i.  (pp.  1 1 1-26)  of  the  Memoirs  of  the  Royal  Society  of 
South  Australia  Dr.  E.  C.  Stirling  contributes  an  account  of 
additional  remains  of  the  giant  Australian  bird,  Genyornis  newtoui, 
from  Lake  Cadibona. 

Papers  on  reptiles,  especially  those  of  South  Africa,  have 
been  unusually  numerous  during  the  year.  The  first  for  con- 
sideration is  one  by  Mr.  R.  W.  Hooley  (Quart.  Journ.  Geol.  Soc. 
vol.  lxix.  pp.  372-422)  on  the  skeleton  of  a  large  pterodactyle 
from  the  Wealden  of  Atherfield,  Isle  of  Wight,  referred  to  the 
genus  Ornithodesmus,  under  the  name  of  O.  latidens.  Whether 
Jhis  reference  is  correct  seems  open  to  doubt,  as  it  is  stated  iji 


VERTEBRATE  PALAEONTOLOGY   IN    1913        639 

the  report  of  the  discussion  following  the  reading  of  the  paper 
that  the  generic  name  Oniithodesmns  was  "  applied  originally  to 
a  number  of  fused  vertebrae  which  differ  materially  from  either 
of  the  two  groups  of  fused  vertebrae  in  the  specimen  under 
consideration."  It  is  accordingly  quite  probable  that  the 
generic  designation  may  have  to  be  changed,  although  this 
will  in  no  wise  detract  from  the  value  of  the  communication  as 
illustrating  an  altogether  peculiar  type  of  the  ornithosaurian 
order.  So  markedly  distinct,  indeed,  is  this  Wealden  ptero- 
dactyle  that,  in  the  opinion  of  the  author,  it  should  be  regarded 
as  the  representative  of  a  distinct  family,  the  serial  position 
of  which  is  indicated  in  the  following  revised  classification  of 
the  Ornithosauria  proposed  by  Mr.  Hooley : 

I.  Suborder  Scaphognathoidea. 

1.  Family  Scaphognathidae. 

Genera  Scaphognathus  and  Dimorphodon. 

2.  Family  Ornithodesmidae. 

Genus  Omithodesmus. 

II.  Suborder  Pterodactyloidea. 

Family  Pterodactylidae. 

Genera  Pterodactylus  and  Ptenodraco. 

III.  Suborder  Rhamphorhynchoidea. 

1.  Family  Rhamphorhynchidae. 

Genera  Rhamphorhynchus,  Dorygnathus,  etc. 

2.  Family  Ornithostomatidae. 

Genera  Ornithostoma  (=  Pteranodori)  and  Nycto- 
saurus  (=  Nyctodadylus). 

3.  Family  Ornithochiridae. 

Genus  Ornithochirus. 

For  the  distinctive  character  of  the  new  Wealden  species 
and  its  probable  relationships,  reference  must  be  made  to  the 
original  paper,  in  which  the  osteology  is  described  in  great 
detail. 

Turning  to  dinosaurs,  the  first  papers  for  notice  are  two  by 
Mr.  Barnum  Brown  {Bull.  Amer.  Mus.  Nat.  Hist.  vol.  xxxii. 
pp.  387-407)  on  the  skeletons  of  Saurolophus  osbornt,  a  duck- 
billed dinosaur  of  the  family  Trac/iodontidcu,  and  of  Hypacro- 
saurus  altispinus,  a  new  genus  and  species  of  the  same  family, 


640 


SCIENCE  PROGRESS 


both  from  the  Upper  Cretaceous  beds  of  Edmonton,  Alberta, 
Canada.  The  type  skeleton  of  the  first  of  these,  which  measures 
about  32  ft.  in  length,  or  nearly  the  same  as  that  of  the  con- 
temporaneous Trackodon  mirabilis,  has  been  mounted  on  a 
slab  for  exhibition  in  the  American  Museum.  This  genus,  it 
appears,  is  much  more  numerously  represented  in  the  Edmonton 
beds  than  is  its  cousin  Trackodon.     The  skeleton  of  the  second 


Fig.  2. — Lateral  (A)  and  posterior  (B) 
aspects  of  dorsal  vertebrae  of 
Hypacrosaurus  alttspinis. 

(From  Bull.  Amer.  Mus.  Nat.  Hist.) 


Fig.  3. — Skeleton  of  the  left  hind 
limbs  of  Trackodon  (A)  and 
Hypacrosaurus  (B). 

(From  Bull.  Amer.  Mus.  Nat.  Hist.) 


genus,  Hypacrosaurus,  is  characterised  by  the  great  height  of 
the  spines  of  the  dorsal  vertebrae  (fig.  2),  coupled  with  the 
presence  of  nine  vertebras  in  the  sacrum,  against  eight  in  the 
allied  genus.  In  all  the  members  of  the  family  the  hind  limbs 
were  tridactylate  ;  the  distinctive  features  of  those  of  Trackodon 
and  Hypacrosaurus  being  shown  in  fig.  3. 

The  skeleton  of  the  fore-limb  of  a  species  of  Trackodon  from 


VERTEBRATE   PALEONTOLOGY   IN    1913        641 

the  Edmonton  Cretaceous  forms  the  subject  of  a  note  by 
Mr.  L.  M.  Lambe  in  the  Ottazva  Naturalist,  vol.  xxvii.  p.  21. 
In  a  second  article  in  the  same  volume  (pp.  109-16) 
Mr.  Lambe  describes  a  new  generic  type  of  horned  dinosaur, 
Styracosaurus  albcrtensis,  from  the  Edmonton  beds,  in  which  the 
margin  of  the  great  posterior  flange  of  the  skull  carries  a  series 
of  long  spines. 

Reference  in  this  place  may  be  made  to  a  note  in  vol.  ix. 
No.  11  of  The  South  African  Journal  of  Science,  relating  to  the  dis- 
covery in  the  Lower  Cretaceous  marls  of  Bushman's  River,  South 
Africa,  of  the  broken  femur  of  a  presumably  dinosaurian  reptile 
fully  as  large  as  the  corresponding  bone  of  Diplodocus,  and, 
when  complete,  measuring  about  5  ft.  in  length.  Here  it  may 
be  mentioned  that  the  preoccupied  generic  name  Gigantosaurus 
used  by  Dr.  Fraas  for  the  gigantic  dinosaur  from  the  Cretaceous 
of  German  East  Africa  has  been  replaced  by  Tomicria  (Sternfeld, 
Sitzber.  Ges.  Nat.  Freunde,  191 1,  p.  398). 

In  the  Parasuchia  (Belodontia)  remains  of  a  new  species 
of  the  genus  Rutiodon,  from  the  Upper  Triassic  beds  of  Fort 
Lee,  New  Jersey,  at  the  base  of  the  "  Palisades,"  opposite  New 
York,  are  described  by  Prof.  H.  von  Huene  {Bull.  Amer. 
Mus.  Nat.  Hist.  vol.  xxxii.  pp.  275-83),  under  the  name  of 
R,  manhaitanensis.  In  the  opinion  of  the  describer,  the  members 
of  the  genera  Rutiodon  and  Mystriosuchus,  on  account  of  the 
taller  spines  of  their  vertebrae  and  their  more  compressed 
bodily  form,  were  probably  better  swimmers  than  those  of  the 
typical  genus  Phytosaurus.  The  species  of  both  the  American 
Rutiodon  and  the  European  Mystriosuchus  were  long-snouted 
reptiles  of  larger  bodily  size  than  Phytosaurus ;  the  newly 
described  representative  of  the  first  of  these  being  the  biggest 
of  the  whole  group. 

More  or  less  nearly  related  to  the  Parasuchia  is  the  group 
of  early  reptiles  known  as  the  Pseudosuchia,  certain  members 
of  which  form  the  subject  of  a  paper  contributed  by  Dr.  Broom 
to  the  Proceedings  of  the  Zoological  Society  for  191 3  (pp.  619-33). 
The  main  object  of  this  communication  is  the  description  of 
the  skull  and  skeleton  of  a  rhynchocephalian-like  reptile  from 
the  Trias  of  Aliwal  North,  South  Africa,  for  which  the  author 
had  previously  proposed  the  new  generic  and  specific  designa- 
tion Euparkeria  capensis.  The  opportunity  is,  however,  taken 
of  discussing  the   osteology  of  the  genera   Ornithosuchus  and 


642  SCIENCE   PROGRESS 

Herpetosuchus,  from  the  Trias  of  Elgin,  with  the  description  of 
a  new  species  of  the  former ;  and  likewise  of  considering  the 
affinities  of  the  South  African  Mesosuc/ms,  which  it  is  suggested 
may  not  be  parasuchian  at  all.  The  paper  concludes  with  a 
discussion  of  the  affinities  of  the  Pseudosuchia  as  a  whole,  in 
the  course  of  which  the  writer,  after  alluding  to  the  views  of 
other  palaeontologists,  expresses  himself  as  follows : 

"  There  cannot,  I  think,  be  the  slightest  doubt  that  the 
Pseudosuchia  have  close  affinities  with  the  dinosaurs,  or  at 
least  with  the  Theropoda.  ...  In  fact  there  seems  to  me  little 
doubt  that  the  ancestral  dinosaur  was  a  pseudosuchian.  The 
skulls  of  such  types  as  Enparkeria  or  Ornithosuchus  are 
practically  dinosaurian  even  in  detail,  and  the  skulls  of  the 
early  dinosaurs,  such  as  Anchisaurus,  differ  less  from  the  skulls 
of  pseudosuchians  than  do  those  of  the  early  dinosaurs  from 
many  of  the  later  types.  And  there  is  nothing  in  the  post- 
cranial  skeleton  that  is  not  just  what  we  should  expect  to  find 
in  the  dinosaur  ancestor.  .  .  . 

"Another  group  to  which  the  pseudosuchians  seem  to  have 
affinities  ...  is  the  Ornithosauria.  In  general  proportions  the 
pterodactyles  differ  very  greatly,  but  the  form  from  which  they 
arose  must  have  been  very  much  like  that  seen  in  the  pseudo- 
suchians. The  pterodactyle  and  pseudosuchian  skull  are  almost 
exactly  similar  in  essentials.  .  .  . 

"  There  is  still  another  group  to  which  some  pseudochian 
has  probably  been  ancestral,  namely,  the  birds." 

Crocodiles  of  the  families  Teleosauridce  and  Geosauridce  form 
the  subject  of  the  second  half  of  vol.  ii.  of  the  British  Museum 
"  Catalogue  of  the  Marine  Reptiles  of  the  Oxford  Clay,"  the 
genera  included  being  Steneosaurus,  Mycterosuchus  (new),  and 
Metriorhynch  us. 

In  a  communication  which  did  not  come  under  notice  when 
writing  the  palaeontological  review  for  1912,  Mr.  C.  W.  Gilmore 
described  {Proc.  U.S.  Nat.  Mas.  vol.  xli.  pp.  479  et  seq.  191 2) 
a  new  generic  type  of  mosasaur,  or  "  sea-serpent,"  from  the 
Cretaceous  of  Alabama,  remarkable  for  having  teeth  of  a 
blunted  character  adapted  for  crushing  hard  substances ;  this 
feature  being  expressed  in  the  generic  name  Globidens,  to  which 
is  added  the  specific  title  alabamaensis.  About  a  year  later 
Prof.  L.  Dollo  was  enabled  to  record  (Archiv  Biol.  vol.  xxviii. 
pp.  609-20)  the  occurrence  of  a  very  similar  mosasaur  in  the 
Maestrict  Cretaceous,   which   he   referred   to  the   same  genus, 


VERTEBRATE  PALEONTOLOGY  IN   1913        643 

under  the  name  of  G.  fraasi.  It  differs  from  the  American 
species  by  the  teeth  being  laterally  compressed,  instead  of 
hemispherical.  In  both  cases  the  food  probably  consisted, 
according  to  Prof.  Dollo,  of  echinoderms ;  such  a  diet  being, 
of  course,  indicative  of  diving  habits.  In  the  allied  genus 
Plioplatecarpus,  belemnites  and  other  cephalopods  may  have 
constituted  the  staple  food,  in  which  case  these  reptiles  would 
likewise  have  been  divers.  On  the  other  hand,  the  members 
of  the  typical  genus  Mosasaurus,  in  which  the  dentition  is  of 
a  highly  carnivorous  type,  were  probably  fish-eating  surface- 
swimmers. 

In  connection  with  this  part  of  the  subject,  reference  may 
be  made  to  a  paper  by  Dr.  R.  Broom  (Bull.  Amer.  Mus.  Nat. 
Hist.  vol.  xxii.  pp.  507-8)  on  the  squamosal  and  associated 
bones  of  mosasaurs  and  lizards,  in  which  the  author  endorses 
the  view  that  the  outermost  of  the  two  bones  which  have 
been  alternately  regarded  as  representing  the  squamosal  is 
really  that  element.  This  view  is  strongly  supported  by  the 
condition  obtaining  in  the  carnivorous  anomodonts,  in  which 
the  structure  of  this  region  is  so  mammal-like  as  to  leave  no 
doubt  which  bone  is  the  squamosal,  and  the  outermost  of  the 
two  bones  in  the  corresponding  region  of  the  skulls  of  lizards 
and  mosasaurs  appears  to  be  the  homologue  of  the  former. 
If  this  be  correct,  the  inner  bone  will  apparently  represent 
the  tabulare ;  and  as  this  is  a  primitive  element,  it  would 
seem  to  follow  that  lizards  are  really  a  very  ancient  group. 

The  preceding  paragraph  naturally  leads  to  the  consideration 
of  a  letter  from  Dr.  Broom,  published  in  Nature  on  the  vomer 
of  dicynodonts.  After  referring  to  the  fact  that  a  pair  of 
bones — the  prevomers — in  the  fore  part  of  the  palate  of  lizards 
seem  to  represent  the  two  elements  in  the  mammal  Ornitho- 
rhynchus  which  eventually  unite  to  form  the  so-called  dumb-bell 
bone,  the  author  proceeds  to  observe  that  while  some  of  the 
carnivorous  anomodonts  seem  to  have  a  single  mammal-like 
vomer  and  a  pair  of  bones  in  front,  in  the  dicynodonts  only 
the  former  element  is  present ;  other  carnivorous  forms  (thero- 
cephalians),  on  the  contrary,  have  a  pair  of  large  anterior 
elements  and  no  median  bone.  To  solve  the  problem  a  specimen 
showing  a  large  median  true  vomer  and  a  pair  of  prevomers 
was  essential,  and  this  has  turned  up  in  the  shape  of  a  dicy- 
nodont  skull  in  which  the  median  element  lying  between  the 


644  SCIENCE   PROGRESS 

posterior  paired  bones  represents  the  anchylosed  prevomers. 
Above,  and  completely  concealed  by  this  element,  is  a  large, 
well-developed,  typically  mammalian  median  vomer  extending 
from  the  basisphenoid  behind  to  the  premaxillse  in  front. 
Along  its  upper  side  the  vomer  is  grooved  for  the  large 
basal  and  ethmoidal  cartilage  ;  while  posteriorly  it  is  closely 
united  to  the  basisphenoid.  This  confirms  the  view  that  the 
mammalian  vomer  is  the  reptilian  parasphenoid,  and  thus  quite 
different  from  the  prevomers. 

Passing  on  to  Chelonia,  it  may  first  be  noticed  that  a 
remarkable  new  generic  type  of  the  side-necked  or  pleurodiran 
group  from  the  Keuper,  in  the  neighbourhood  of  Stuttgart, 
has  been  described  by  Prof.  O.  Fraas  in  the  Jahresheft  Ver. 
Naturkunde  Wiirttemberg,  191 3,  No.  80,  under  the  name  of 
P  rote  roc  hersis  robusta.  Its  most  striking  peculiarity  consists  in 
the  presence  of  two  complete  pairs  of  mesoplastral  bones  in  the 
lower  shell,  which  is  believed  to  be  a  unique  feature  in  the 
order.  As  a  mesoplastron  seems  to  be  a  primitive  feature,  its 
duplication  may  perhaps  represent  a  still  more  archaic  type. 

Two  tortoises  from  the  Oligocene  of  Wyoming  form  the 
subject  of  an  article  by  Mr.  L.  M.  Lambe  in  the  Ottazva  Naturalist 
(vol.  xxvii.  pp.  57-63).  The  first  represents  a  new  species  of 
land  tortoise  {Testudo  prceexstans),  characterised  by  the  great 
development  of  the  horn-like  epiplastra  on  the  front  edge  of 
the  lower  half  of  the  shell — a  feature  displayed  to  a  minor 
degree  in  T.  thomsoni  of  the  Oligocene  of  South  Dakota.  The 
second  is  referred  to  a  well-known  Tertiary  species,  Stylemys 
nebrascensis. 

Reference  may  also  be  made  to  a  paragraph  in  Nature  based 
on  a  cutting  from  the  Daily  Malta  Chronicle  of  February  17, 
1913,  in  which  Mr.  N.  Tagliaferro  records  the  discovery  in 
a  rock-fissure  at  Corradino  of  a  large  series  of  remains  of 
giant  land-tortoises.  Many  of  these,  it  is  stated,  are  referable 
to  Testudo  robusta  and  the  smaller  T  spratti  of  Leith  Adams ; 
but  one  specimen  indicates  a  tortoise  nearly  half  as  large 
again  as  the  biggest  described  example  of  the  former,  and 
may,  it  is  suggested,  represent  a  third  species.  These  and 
other  deposits  have  been  deposited  in  the  museum  at  Valletta. 
Leurospondylus  ultimus  is  the  name  proposed  by  Mr.  Barnum 
Brown  {Bull.  Amer.  Mus.  Nat.  Hist.  vol.  xxxii.  pp.  605-15)  for  a 
new  generic  type  of  plesiosaurian  from  the  Edmonton  Creta- 


VERTEBRATE   PALEONTOLOGY   IN    1913        645 

ceous  of  Alberta,  Canada,  which  is  of  more  than  ordinary 
interest  on  account  of  being  the  latest  representative  of  the 
Sauropterygia  at  present  known,  the  Edmonton  beds  being 
separated  from  the  Eocene  Tertiary  series  only  by  another 
set  of  Cretaceous  rocks.  Nearly  related  to  the  long-necked 
Elasmosaurus,  the  new  type  has  a  neck  of  medium  length,  and 
very  short  centra  to  the  vertebrae ;  the  total  length  of  the 
vertebral  column  being  about  seven  feet.  The  author  gives 
a  synopsis  of  the  chief  structural  features  by  which  it  is  dis- 
tinguished from  five  other  genera  of  American  plesiosaurians. 
The  plesiosaurians  of  the  genus  Murcenosaurus  form  the  subject 
of  a  paper  by  Dr.  E.  Koken,  published  in  the  Neues  Jahrbuch 
fiir  Min.  1913,  voi.  i.  pp.  101-15. 

The  first  portion  of  the  above-mentioned  "  Catalogue  of  the 
Marine  Reptiles  of  the  Oxford  Clay"  deals  with  the  pliosaurs  of 
the  genera  Pliosaurus,  Sitnolestcs,  and  Pelonenstes,  of  the  skeletons 
of  some  of  which  Dr.  Andrews  gives  almost  complete  restorations. 

As  skulls  of  ichthyosaurs  which  have  escaped  the  effects 
of  crush  are  comparatively  rare,  considerable  interest  attaches 
to  an  uncrushed  specimen  of  Ichthyosaurus  acutirostris,  from  the 
Lias  of  Holzmaden,  described  and  figured  by  Dr.  E.  Fraas  in 
the  Jahresheft  Verh.  Naturkunde  Wiirttemberg,  19 13,  12  pages. 

A  large  series  of  papers,  chiefly  from  the  pen  of  Dr.  R.  Broom, 
on  the  mammal-like  anomodont,  or  theromorphous,  reptiles 
of  the  Permo-Trias  of  South  Africa,  have  appeared  during  the 
year.  Before  considering  those  of  the  author  just  mentioned 
reference  may,  however,  be  made  to  an  ingenious  attempt  by 
Miss  I.  J.  B.  Sollas  and  Prof.  W.  J.  Sollas  to  solve  some  of 
the  problems  connected  with  the  structure  of  the  skull  of  the 
well-known  genus  Dicynodon  by  means  of  a  series  of  sections. 
The  results  of  this  investigation  are  embodied  in  a  report  pub- 
lished in  the  Philosophical  Transactions  (ser.  A,  vol.  cciv.  pp.  201- 
25).  No  analysis  of  such  an  extremely  technical  communication 
can,  however,  be  attempted  on  the  present  occasion,  and  it 
must  suffice  to  refer  to  a  very  interesting  restoration  of  the 
canals  of  the  labyrinth  of  the  internal  ear. 

Brief  mention  may  be  made  in  this  place  of  a  paper  by 
Mr.  D.  M.  S.  Watson  (Geol.  Mag.  decade  5,  vol.  x.  pp.  388-93) 
on  the  beds  of  the  South  African  Karru  series,  which,  although 
mainly  stratigraphical,  deals  to  some  extent  with  palaeontology. 

Among  the  series  of  papers  by  Dr.  Broom  reference  may 


646  SCIENCE  PROGRESS 

be  made  first  to  one  in  the  Bull.  Amer.  Mus.  Nat.  Hist.  (vol. 
xxxii.  pp.  441-57)  in  which  are  described  a  number  of  remains 
of  dicynodonts ;  many  of  these  being  regarded  as  representing 
new  species  of  the  typical  Dicynodon,  while  others  are  assigned 
to  new  genera.  It  is  interesting  to  note  that  a  skull  described 
by  Huxley  as  that  of  a  lizard,  under  the  name  of  Pristerodon 
mackayi,  really  represents  a  dicynodont  with  cheek-teeth. 
Two  other  new  species  of  Dicynodon  are  described  by  Messrs. 
Broom  and  Haughton  in  vol.  xii.  pp.  36-9  of  the  Annals  of  the 
South  African  Museum. 

In  the  first  of  three  papers  by  Dr.  Broom  in  part  6  of  the 
viith  of  the  serial  just  quoted x  it  is  shown  that  while  in 
Pariasaurus  the  digital  formula  is  2.3.3.4.3,  in  the  allied 
Propappus  it  is  probably  2.3.4.5.3,  thus  affording  another  point 
of  distinction  between  them.  In  the  second  he  describes,  as 
Noteosaurus  africanus,  a  new  genus  allied  to  Mesosaurus,  of 
which  three  of  the  known  species  are  South  African,  while  the 
fourth  is  Brazilian.  The  third  paper  contains  a  systematic 
list  of  the  early  Mesozoic  reptiles  of  South  Africa,  which,  apart 
from  dinosaurs,  crocodiles,  rhynchocephalians,  etc.,  are  arranged 
in  no  fewer  than  nine  ordinal  groups,  brigaded  in  three  so-called 
superorders. 

In  vol.  xii.  of  the  Annals  of  the  South  African  Museum 
(pp.  17-24)  Messrs.  Broom  and  Haughton  describe  the  im- 
perfect skeleton  of  a  new  generic  type  of  pariasaurian  from 
Beaufort  West,  under  the  name  of  Pareiasuchus  peringueyi. 
One  of  the  points  of  difference  from  the  typical  genus  consists 
in  the  larger  size  of  the  temporal  roof  of  the  skull,  which 
descends  below  the  quadrate,  in  a  manner  also  found  in  the 
Russian  pariasaurians,  which  may,  however,  represent  another 
genus.  In  the  same  issue  (pp.  43-5)  Mr.  H.  S.  Haughton 
describes  a  new  species  of  the  allied  genus  Propappus ;  while 
he  also  communicates  {op.  cit.  pp.  40-42)  a  note  on  a  very  fine 
skull  of  the  gigantic  Tapinocephalus  atherstonei  from  Beaufort 
West,  the  locality  of  the  type  specimen  described  by  Sir 
Richard  Owen. 

If  his  conclusions  are  well  founded,  Dr.  Broom,  in  2.  paper 
published  in  the  Bulletin  of  the  American  Museum  of  Natural 
History  (vol.    xxxii.   pp.   465-6),    adduces    an    important    piece 

1  It  may  be  well  to  mention  that  instalments  of  vii.  and  ot  vol.  xii.  of  this 
serial  were  published  during  the  year. 


VERTEBRATE  PALEONTOLOGY  IN    191 3        647 

of  evidence  in  regard  to  the  affinity  between  certain  carnivorous 
(cynodont)  anomodonts  and  mammals.  For  he  describes  and 
figures,  under  the  new  specific  name  of  Diademodon  plaiyrhinus, 
a  lower  jaw  of  an  anomodont  which  is  stated  to  furnish 
evidence  of  a  single  successional  replacement  of  the  teeth 
similar  to  that  of  mammals.     "  We  may  thus  safely  conclude," 


^-  ««*&*. 


Fig.  4. — Skull,  without  lower  jaw,  of  Ictidorhinus  martinsi. 

(From  Bull.  Amer.  Mus.  Nat.  Hist.) 

he  observes,  "  that  as  the  cynodont  approaches  full  maturity 
the  incisors,  canines,  and  premolars  are  replaced  as  in  mammals, 
and  as  no  completely  adult  specimen  has  ever  shown  any  trace 
of  a  later  succession,  we  may  conclude  as  probable  that  there 
is  only  a  single  succession." 

New  carnivorous  South  African  anomodonts  of  the  group 


FlG.  5. — Skull  of  Scymnognathus  angusticebs. 
(From  Bull.  Amtr.  Mus.  Nat.  Hist.) 

Therapsida  form  the  subject  of  an  article  by  Dr.  Broom  (Bull. 
Amer.  Mus.  Nat.  Hist.  vol.  xxxii.  pp.  537-61)  in  which  four 
species  are  described,  one  referable  to  a  new  genus,  under  the 
name  of  Ictidorhinus  martinsi.  Of  the  latter  the  skull  (fig.  4) 
is  altogether  unique  in  shape ;  the  peculiarity  being  in  great 
part  due  to  the  unusually  large  size  of  the  orbits,  and  the 
42 


648  SCIENCE    PROGRESS 

consequent  crater-like  elevation  of  the  pineal  foramen,  which 
is  situated  in  the  median  line  between  and  above  them.  As  an 
example  of  the  skull  and  dentition  of  a  more  normal  type  of 
these  most  mammal-like  reptiles  Dr.  Broom's  figure  of  the 
skull  of  the  new  species  Scymnognathus  angusticeps  is  repro- 
duced in  fig.  5.  Both  genera  are  related  to  Gorgonops.  Two 
new  species  of  Scymnognathus  are  described  in  this  paper,  and 
a  third  is  added  in  an  article  by  Messrs.  Broom  and  Haughton 
in  the  Annals  of  the  S.  African  Museum,  vol.  xii.  pp.  26-35. 

In  the  same  issue,  pp.  8-12,  Dr.  Broom  describes  a  skull 
from  Beaufort  West  as  a  new  species  of  Gorgonopsis,  a  genus 
originally  proposed  by  the  late  Prof.  H.  G.  Seeley  for  a  reptile 
allied  to  Gorgonops,  and  now  revived  by  Dr.  Broom,  who  seems, 
however,  to  have  omitted  to  confer  a  specific  name  on  the  new 
form. 

In  a  subsequent  paper  {Proc.  Zool.  Soc.  1913,  pp.  225-30) 
Dr.  Broom  reviews  the  structure  and  affinities  of  the  group 
Gorgonopsia,  which  is  taken  to  include  Scymnognathus  as  well 
as  Gorgonops  and  Gorgonopsis.  "  Most  of  the  characters,"  he 
observes,  "  in  which  the  Gorgonopsia  differ  from  the  Thero- 
cephalia  are  characters  in  which  they  agree  with  the  [typical] 
Anomodontia.  The  Therocephalia  are  unquestionably  the 
more  primitive  group,  but  there  are  also  some  early  characters 
in  the  Gorgonopsia  and  also  in  the  [typical]  Anomodontia.  Of 
course  we  only  know  well  one  or  two  of  the  later  gorgo- 
nopsians,  and  we  have  good  reason  to  believe  that  the  group 
is  very  early." 

The  structure  of  the  gorgonopsid  palate  forms  an  important 
item  in  a  paper  by  Mr.  Watson  {Ann.  Mag.  Nat.  Hist.  ser.  8, 
vol.  xii.  pp.  65-72)  on  certain  features  in  the  skulls  of  the 
therocephalians ;  the  same  author  {op.  cit.  pp.  217-28)  also  con- 
tributing an  article  on  the  skull,  brain,  nose,  and  internal  ear 
of  Diademodon.  The  special  interest  attaching  to  the  sense- 
organs  in  this  genus  is  that  they  appear  to  indicate  the  com- 
mencement of  a  change  from  the  lowly  reptilian  to  the  higher 
mammalian  type,  and  it  is  hence  possible  that  Diademodon  may 
have  been  warm-blooded. 

The  work  of  Dr.  Broom  has  not  been  altogether  restricted 
to  the  early  reptiles  of  South  Africa,  for  he  has  contributed  two 
articles  to  vol.  xxxii.  of  the  Bidletin  of  the  American  Museum  of 
Natural  History  on  some  of  those  of  North  America.     In  the 


VERTEBRATE  PALAEONTOLOGY   IN    1913        649 

first  of  these  (pp.  509-16)  are  discussed  the  structure  and 
affinities  of  Bolosaurus,  a  genus  originally  described  by  Prof. 
Cope  on  the  evidence  of  a  skull  from  the  Lower  Permian  of 
Texas,  who  regarded  it  as  representing  a  distinct  family  of  the 
Cotylosauria,  more  or  less  nearly  related  to  the  Diadectidce.  In 
the  light  of  new  material  and  fresh  investigations,  Dr.  Broom 
is  of  opinion  "that  the  Bolosanridce  represent  a  primitive  group 
of  theromorphs  near  to  the  common  ancestors  of  the  pely- 
cosaurs,  varanosaurids,  and  dromasaurians.  Even  without 
knowing  anything  of  the  Bolosauridce,  we  know  that  these 
three  groups  had  a  common  post-cotylosaurian  ancestor,  and 
while  the  bolosaurids  are  too  specialised  to  have  been  ancestral, 
they  are  probably  members  of  the  suborder  that  included  the 


Fig.  6.— Skull  of  Pantylus  cordahts,  to  show  the  closed  temporal  region  of 

the  Cotylosauria. 

(From  Bull.  Amer.  Mns.  Nat.  Hist.     It  has  not  been  considered  necessary  to  give  the 
names  of  the  constituent  bones  indicated  by  letters.) 

common  ancestor.  If  we  place  the  Bolosauridce  in  this  central 
position  we  get  a  satisfactory  explanation  of  its  seeming  varied 
affinities."  It  is  added  that  a  suggested  affinity  between  Bolo- 
sciurus  and  the  European  Permian  genus  P alceohatteria  has 
been  rendered  the  more  probable  by  the  discovery  of  sclerotic 
plates  in  the  orbits  of  the  former,  which  have  long  been  known 
in  those  of  the  latter. 

In  the  second  article  {pp.  cit.  pp.  527-32)  the  author  considers 
the  cotylosaurian  genus  Pantylus,  likewise  described  by  Cope 
on  the  evidence  of  remains  from  the  Permian  of  Texas.  Dr. 
Broom's  paper  is  of  too  technical  a  nature  to  be  referred  to 
in  any  more  than  an  incidental  manner.  At  present  the  genus 
is  known  only  by  the  skull  (fig.  6) ;  but  even  from  this  evidence 


6$o  SCIENCE  PROGRESS 

alone  Dr.  Broom  is  of  opinion  that  "  we  may  safely  conclude 
that  it  is  a  cotylosaur,  and  in  the  meantime  it  may  be  safest 
to  follow  Case  in  keeping  it  as  the  type  of  a  distinct  suborder — 
the  Pantylosauria." 

As  containing  descriptions  both  of  primitive  reptiles  and 
of  stegocephalian  amphibians,  mention  may  be  made  of  an 
important  and  exhaustive  memoir  on  the  vertebrate  fauna  of 
the  Permo-Carboniferous  beds  of  north-central  New  Mexico 
by  Messrs.  Case,  Williston,  and  Mehl,  issued,  as  Publication 
No.  181,  by  the  Carnegie  Institution  of  Washington.  The  total 
number  of  species  from  this  horizon  at  present  identified 
includes  a  shark  akin  to  Pleuracanthus,  five  amphibians,  and 
ten  reptiles  of  a  low,  although  in  some  cases  specialised,  type. 
The  most  noteworthy  of  the  amphibian  remains  is  a  skull 
described  as  the  representative  of  a  new  genus  and  species, 
under  the  name  of  Chenoprosopus  milleri ;  the  generic  title 
referring  to  the  superficial  resemblance  of  the  specimen  to 
the  skull  of  a  goose  {Chen).  This  genus  belongs  apparently 
to  the  temnospondylous  amphibians,  in  spite  of  certain  indi- 
cations of  affinity  with  reptiles.  Among  undoubted  reptiles 
special  interest  attaches  to  the  restoration  of  the  skeleton  of 
the  pelycosaurian  described  by  O.  C.  Marsh  as  Ophiacodon 
minis,  on  account  of  the  enormous  size  of  the  skull  as  compared 
with  that  of  the  trunk.  According  to  the  figures,  the  shoulder 
and  pectoral  girdles  of  this  and  certain  allied  forms  present 
a  striking  resemblance  to  the  corresponding  elements  of  African 
anomodonts. 

In  close  connection  with  the  above  is  an  article  by  Dr. 
Broom  (Bull,  Anier.  Mus.  Nat.  Hist.  vol.  xxxii.  pp.  563-5)  on 
the  temnospondylous  stegocephalians  of  the  North  American 
Permian,  which  is  chiefly  devoted  to  the  further  elucidation  of 
the  structure  and  affinities  of  genera,  such  as  Cricotus,  Trimero- 
rhachis,  Eryops,  and  Zatrac/iys,  described  by  previous  writers. 
New  species  of  the  second  and  third  of  these  are,  however, 
named ;  and  the  communication  is  of  special  value  on  account 
of  the  excellent  figures  of  the  skulls  of  all  four. 

In  another  communication  (Ann.  S.  African  Mus.  vol.  xii. 
pp.  6  and  7)  Dr.  Broom  describes  the  skull  and  skeleton  of 
a  comparatively  small  stegocephalian  from  the  Permo-Trias 
of  the  Fraserburg  district  of  South  Africa,  under  the  name  of 
Phrynosuclius    ivhaitsi;    the    generic    designation    (as   well,    of 


VERTEBRATE   PALEONTOLOGY   IN    1913        651 

course,  as  the  specific)  being  apparently  new,  although  this  is 
not  definitely  stated  to  be  the  case.  The  broad  flattened  head, 
coupled  with  the  short  and  nearly  straight  ribs,  suggests 
relationship  to  the  Protritonidce  (Branchiosauridce). 

In  Europe  Dr.  E.  Fraas  has  described  {Palccontographica, 
vol.  lx.  pp.  275-94)  several  new  species  of  large  labyrinthodont 
stegocephalians  from  the  Swabian  Trias,  one  of  which  is 
referred  to  Cyclotosaurus,  as  typified  by  Meyer's  Capitosaurus 
robustus ;  the  genus  also  including  the  so-called  Capitosaurus 
stantonensis  of  the  Warwickshire  Keuper.  And  from  the  Trias 
of  Heligoland  Mr.  H.  Schroeder  has  described  and  figured 
(K.  preuss.  Geol.  Landesanstalt  for  1913)  a  beautifully  preserved 
skull  of  a  member  of  the  same  group  as  a  new  species  of  the 
genus  typified  by  Meyer's  Capitosaurus  nasutus,  from  the  Trias 
of  Bernberg,  under  the  name  of  C.  heligolandi. 

Yet  another  paper  on  stegocephalians  is  to  be  found  in  the 
Proceedings  of  the  Zoological  Society  for  191 3  (pp.  949-62),  in 
which  Mr.  D.  M.  S.  Watson  discusses  the  osteology  and  rela- 
tionships of  Batrachiderpeton  lineatum,  a  genus  and  species  from 
the  Coal  Measures  of  Northumberland  originally  described  by 
Messrs.  Hancock  and  Atthey.  Its  nearest  known  relative 
appears  to  be  Ceraterpeton  of  the  Kilkenny  and  Staffordshire 
Coal  Measures,  from  which  it  differs  by  certain  features  in  the 
structure  of  the  skull — notably  the  greater  development  of  the 
posterior  "horns";  all  such  points  of  distinction  being  in 
the  direction  of  greater  specialisation.  A  still  more  specialised 
type  is  represented  by  Diplocaulus,  in  which  not  only  are  the 
"  horns "  still  longer  than  in  Batrachiderpeton,  but  the  nasal 
bones,  which  are  small  in  the  latter,  have  altogether  disappeared. 

Mr.  Watson  {Geol.  Mag.  decade  5,  vol.  x.  pp.  340-46)  has 
also  reviewed  in  the  light  of  recent  knowledge  the  skull  of  the 
small  South  African  temnospondylous  amphibian  described  by 
Prof.  Huxley  in  1859  as  Micropholis  stowi. 

Finally,  remains  of  two  stegocephalians  from  the  Permian  of 
Texas  are  described  by  Mr.  F.  Broili  in  the  Neues  Jahrbuch  fur 
Min.  1913,  vol.  i.  pp.  96-100;  one  of  them,  apparently  allied  to 
Diplocaultis,  being  referred  to  a  new  genus  and  species  under 
the  name  of  Goniocephalus  willistoni,  while  the  second  is  made 
the  type  of  the  new  species  Acheloma  casei. 

Premising  that  as  my  acquaintance  with  the  year's  literature 
relating  to  fossil  fishes  is  very  imperfect,  my  review  of  this 


652  SCIENCE  PROGRESS 

portion  of  the  subject  must  be  extremely.brief,  the  first  papers  for 
notice  are  connected  with  the  structure  and  origin  of  the  primi- 
tive types  of  fin-structure,  and  the  evolution  therefrom  of  the 
tetrapod  limbs  of  the  higher  vertebrates.     In  the  first  of  these 
Mr.    Watson   (Anat.   Anzeiger,   vol.    xliv.    pp.    24    et   seq.)    ex- 
presses   the   opinion   that    the    limbs    of   the   Tetrapoda   have 
been   evolved  from  a  reduced  archipterygium  such  as   occurs 
in  the  crossopterygian  genus  Eusthcnopteron.     Dr.  Broom  {Bull. 
Amer.   Mus.   Nat.   Hist.  vol.   xxxii.    pp.  459-64),  on    the   other 
hand,  favours  the  view  that  the   chiropterygium,  as  found   in 
Sauripteris,  is  nearer  the  type  from  which  the  tetrapod  limb  was 
developed  ;  this  form  of  fin  being  of  particular  interest  from  the 
fact  that  it  was  used  partly  for  progression  on  land.     It  is,  how- 
ever, of  a  too  specialised  type  to  have  given  rise  to  the  tetrapod 
limb,  and  the  author  accordingly  surmises  the  existence  of  a 
"  presauripterid  "  type  of  fin,  from  which  the  original  tetrapod 
limb  was  evolved  by  the  loss  of  the  fin-rays  and  the  disappear- 
ance   of   a    considerable    portion    of    the   hinder  or  postaxial 
elements   of  the   skeleton   proper.     A   diagram — scarcely  very 
convincing — illustrates  the  mode  in  which  the  author  believes 
the   five  digits   of  the  tetrapod   limb   to  have  been  produced. 
"  Had  six  or  seven  [digits]  been  retained  for  a  time,"  remarks 
the  author,  "  they  would  have  been  found  too  feeble  to  usefully 
reach  the  preaxial  border.     Even  as  it  is,  the  aquatic  Amphibia 
found  the  fifth  useless,  and  it  accordingly  disappeared." 

In  a  paper  on  four  new  species  of  North  American  Palaeozoic 
fishes  Mr.  L.  Hussakof  {Bull.  Amer.  Mus.  Nat.  Hist.  vol.  xxxii. 
pp.  245-50)  remarks  that  one  is  an  arthrodire  of  the  genus  Dino- 
my lo stoma )  of  which  it  is  the  second  known  species ;  the  second, 
provisionally  assigned  to  Apateacanthus,  is  represented  by  a 
spine  with  large  denticules  remarkable  for  increasing  (in  place 
of  diminishing)  in  size  towards  the  tip.  The  third  and  fourth 
belong  to  Stenacanthus. 

In  1906  Dr.  Ameghino  described  certain  sharks'  teeth  from 
the  Tertiaries  of  Patagonia  as  the  representatives  of  the  new 
generic  type  Carcharoides ;  the  name  alluding  to  the  fact  that 
these  teeth  have  sharply  acuminate  crowns  like  those  of  Lamna, 
associated  with  the  serrated  margins  of  those  of  Carcharodon. 
Teeth  of  a  similar  type  from  the  Tertiaries  of  Victoria  are 
described  in  The  Victorian  Naturalist  (vol.  xxx.,  pp.  i42-3)  by 
Mr.  F.  Chapman.    The  discovery  affords  additional  evidence  of 


VERTEBRATE   PALAEONTOLOGY   IN    1913        653 

the  affinity  between  the  Tertiary  littoral  faunas  of  Patagonia, 
New  Zealand,  and  Australia,  which  appear  to  have  inhabited 
different  portions  of  a  single  sea-bed. 

An  appendix  to  a  previous  memoir  on  fossil  sharks  is  com- 
municated by  Messrs.  Jordan  and  Bell  to  the  Publications  of the 
University  of  California,  Bull.  Dep.  Geol.  vol.  vii.  pp.  243-56,  in 
which  several  species  are  described  as  new. 

During  the  last  few  years  a  number  of  papers  have  been  pub- 
lished on  fish-remains  from  various  horizons  in  different  parts 
of  Africa,  a  list  of  which  is  given  by  Dr.  E.  Henning  in  an  article 
on  remains  of  this  nature  from  Equatorial  and  South  Africa 
issued  in  the  Sitzber.  Ges.  naturfor.  Freunde,  191 3,  pp.  305-18. 
In  this  communication  the  bearing  of  these  remains  on  the 
physiography  and  former  connections  of  the  African  continent  is 
discussed  at  some  length.  Of  the  aforesaid  papers,  those  pub- 
lished during  the  year  under  review  include,  in  addition  to  the 
one  just  cited,  the  following:  The  Older  Eocene  Fishes  of 
Landana,  Congo,  by  Mr.  Leriche,  Ann.  Mus.  Congo  Beige,  Geol. 
Pal.  ser.  3,  pp.  69-80 ;  a  second  communication  on  West  African 
Tertiary  fishes  by  the  same  author,  op.  cit.  pp.  81-91 ;  new  Mesozoic 
vertebrate  remains  from  the  Cameruns  by  Dr.  Henning  {K.  preuss. 
geol.  Landesanstalt,  1913);  Tertiary  fish-remains  from  Spanish 
Guinea,  by  Dr.  C.  H.  Eastman,  Ann.  Carnegie  Mus.  19 13,  pp.  370- 
78 ;  and,  lastly,  fish-remains  from  the  Karru  beds  of  South 
Africa,  by  Dr.  Broom,  published  in  the  Annals  of  the  S.  African 
Museum,  vol.  xii.  pp.  1-5.  Space  does  not  permit  of  fuller  notice 
of  these,  but  in  the  case  of  Dr.  Broom's  paper  it  may  be  men- 
tioned that  five  species  are  described  as  new,  four  being  referable 
to  the  Palaoniscidce  and  one  to  the  Platysomatidce.  The  last 
represents  a  new  generic  type,  for  which  the  atrocious  name 
Caruichthys  is  proposed. 

An  unusually  fine  example  of  the  gigantic  Portheus  molossus, 
from  the  Cretaceous  of  Kansas,  recently  acquired  by  the  Natural 
History  Branch  of  the  British  Museum,  forms  the  subject  of  a 
note,  accompanied  by  a  plate,  contributed  by  Dr.  Smith  Wood- 
ward to  the  December  number  of  the  Geological  Magazine 
(decade  5,  vol.  x.  pp.  529-31). 

Lastly,  it  may  be  mentioned  that  five  new  American 
Cretaceous  pycnodonts,  referable  to  Microdon  (recorded  for  the 
first  time  in  America),  Ccelodus,  and  Anomceodus,  are  described 
by  Mr.  Gidley  in  vol.  xlvi.  (pp.  445-9)  of  the  Proc.  U.S.  Nat.  Mus. 


THE  NATURE  OF  THE  ARGON  FAMILY 

OF  GASES 

By  FREDERICK    SODDY,    F.R.S. 

University,  Glasgow 

The  question  of  the  nature  of  the  argon  family  of  gases   has 

recently  been   discussed   by   Prof.  Armstrong  and  Sir  Oliver 

Lodge  (Science   Progress,    191 3,  April,    p.   648;   and   October, 

p.   197).     Sir  Oliver  Lodge  defends  the  accepted  view  that  the 

molecules  of  these  gases  consist  of  single  atoms  against  Prof. 

Armstrong's  view  that  the  molecules  are  polyatomic.     Although 

I   regard   the   evidence   in   favour   of  the  monatomicity  of  the 

molecule  in  the  case  of  these  gases  as  beyond  dispute,  I  think 

something  can  be  said  also  for  Prof.  Armstrong's   theory  that 

these  gases  have  an  intense  affinity — "  an  affinity  so  intense  that 

it  is  far  beyond  anything  we  have  experienced  in  the  case  of 

any  other  element."     Where   I   should  join   issue   with   Prof. 

Armstrong  is  on  the  question  exactly  what  it  is  for  which  the 

argon  gases  have  intense  affinity.     He  regards  it  as  exercised 

between  the  constituent   parts   of  the   molecule,  and   in    1895, 

when  the  view  was  first  suggested,  no  other  result  was  possible 

than  that  the  molecule  must  therefore  necessarily  be  polyatomic, 

and  that  the  atomic  weight  and  position  of  the  inert  gases  in 

the   periodic   table  cannot  be  determined.     I  will  try  to  show 

that,  whilst  modern  progress  seems   to   leave   no   loophole  of 

escape  from  the  conclusion  that  the  argon  gases  have  molecules 

composed  of  single  atoms,  and  that  these  elements  are  correctly 

represented   as   occupying  a   new  zero  family  in   the   periodic 

table,    we    can    reconcile    this    with    the    essentials    of    Prof. 

Armstrong's   view  with  a  distinct  gain  in  clearness  as   to  the 

chemical   character   of  these   gases,    and   the   meaning   of    the 

numbers  of  the  families  of  the  periodic  table. 

It  is,  of  course,  as  Prof.  Armstrong  is  well  aware,  even  more 
difficult  to  demonstrate  convincingly  that  the  molecule  of  an 
element  consists  of  a  single  atom,  and  is  not  merely  an 
hitherto  undecomposed  collection  of  atoms,  than  it  is  to  prove 

654 


THE  ARGON   FAMILY  OF  GASES  655 

convincingly  that  a  substance  is  an  element,  and  not  merely 
an  undecomposed   compound.     In   neither  case   is  any   single 
proof  absolutely  satisfying.      In  both  cases  a  review  must  be 
made  of  all  the  available  evidence.     I  shall  use  the  word  mole- 
cule generally  to  indicate  a  single  particle,  whatever  its  com- 
plexity, whether  mon-atomic  or  not,  which  is  capable  of  existing 
an  appreciable  time,  long  enough  to  be  studied,  and  the  word  atom 
only  for  the  smallest  particle  that,  as  in  a  chemical  change,  has 
an  existence  so  momentary  that  it   cannot   be   studied   alone. 
Thus  the  hydrogen   atom,    H,  cannot  yet,   under  any   known 
circumstances,   properly   be    termed    a    molecule,    though    no 
doubt  extension   of  our   means   of  high  temperature  research 
would    result    in    its    becoming    experimentally    known    as    is 
the   case   for  the   single   iodine   or    bromine    atoms   which    at 
high  temperatures  exist  as  molecules.      But  the  hydrogen  ion 
(H+),  the  a-particle  (He++),  the  various  positive-ray  ions  studied 
by  Sir  J.  J.  Thomson  recently,  are  molecules,  in  the  strict  sense 
of  the  definition,  and  whether  they  are  also  single  atoms  or  not, 
need  not  be  prejudged  by  the  name  by  which  they  are  called. 
They  exist,  unchanged   in  mass,  for   periods   long  enough   to 
enable  their  mass  to  be  determined.     I  shall  treat  it  as  beyond 
dispute,  that  from  Avogadro's  Law,  the  molecular  weight  of  a 
gas  in  terms  of  hydrogen  is  identical  with  that  of  its  density  in 
terms  of  the  same  unit,  and  shall  follow  the  usual  convention  that 
the  unit  of  gaseous  density  is  H  =  1,  and  the  unit  of  molecular 
weight  H2  =  2.     The  molecular  weight  of  helium  is  thus  4,  and 
that  of  the  radium  emanation,  from  diffusion,  effusion,  and  direct 
density  determinations   by   the   micro-balance,   is   222   (±   say 
10  per  cent,  at  most).     The  molecular  weight  of  the  a-particle 
is  experimentally  found  by  comparing  the  value  of  the  ratio  of 
its  mass  to  its  charge,  m/e,  as  determined  by  electrostatic  and 
electromagnetic  deviation,  with  that  of  the  hydrogen  ion,  and 
by  comparing  the  charge  on  the  single  a-particle  (which  it  is 
possible   to    determine    experimentally    since   the    number    of 
a-particles  can  be  counted  and  their  total  charge  measured)  with 
that  on  the  hydrogen  ion.     As  Perrin  has  shown  the  value  for 
the  single  atomic  charge    carried    by  the    hydrogen    ion — or 
what  is  the  same  thing,  experimentally,  the  determination  of 
Avogadro's   constant,   the    number    of   molecules    in    a    cubic 
centimetre  of  gas  at   N.T.P. — can   be   determined  by  at  least 
nine  independent  methods,  with  results  in  agreement  far  closer 


656  SCIENCE   PROGRESS 

than  is  necessary  for  this  kind  of  calculation,  where  it  is  the 
magnitude  of  a  small  whole  number  which  is  in  question.  The 
value  of  the  ratio  m/e  for  the  a-particle  and  the  value  of  its 
charge  are  both  twice  that  of  the  hydrogen  ion.  So  the  mole- 
cular weight  of  the  a-particle  is  4,  in  terms  of  that  of  the 
hydrogen  ion  as  unity.  That  is,  the  a-particle  has  a  molecule 
identical  with  that  of  helium  gas  and  not  a  fraction  of  it.  In 
this  respect  it  is  unlike  the  hydrogen  ion,  which,  as  is  everywhere 
accepted,  has  a  molecular  weight  one-half  of  that  of  hydrogen 
gas.  Sir  J.  J.  Thomson  finds  that  the  positive  ray  in  helium  is 
the  same  as  the  a-particle,  though  he  has  indications  of  a  more 
complex  molecule  (He3)+,  which  is  a  highly  interesting  and  may 
be  very  significant  observation. 

From  Avogadro's  constant,  known  certainly  to  ±  20  per 
cent,  the  number  of  molecules  of  radium  chloride  in  a  gram  is 
easily  calculated,  the  molecular  weight  of  radium  chloride  being 
known.  The  number  of  a-particles  expelled  from  it  per  second 
in  its  first  disintegration  in  which  the  emanation  is  produced  has 
been  determined  by  Rutherford,  as  is  well  known,  by  direct 
counting  measurements.  We  shall  get  a  different  value  for  the 
period  of  average  life  of  radium,  or  its  reciprocal,  the  fraction 
disintegrating  per  unit  of  time,  if  we  suppose  that  one  molecule 
of  radium  chloride  gives  rise  to  one,  two,  three  and  so  on 
rt-particles.  The  period  of  average  life  found  by  several  quite 
independent  methods  is  about  2,500  years,  whereas  that  found 
by  assuming  that  one  a-particle  results  per  molecule  of  radium 
chloride  disintegrating  in  the  first  change  is  2,560  years.  Hence 
one  molecule  of  radium  chloride  gives  in  its  first  change  one 
a-particle,  identical  in  mass  with  one  whole  molecule  of  gaseous 
helium,  one  also  in  each  of  its  four  later  a-ray  changes,  and 
never  less  than  the  single  whole  molecule  of  helium.  Again, 
the  experimental  value  for  the  volume  of  helium  produced  per 
gram  of  radium  per  year  (Dewar)  is  0*164  c.c,  whereas  the 
calculated  value  on  the  assumption  that  each  a-particle  is  a 
whole  molecule  of  helium  is  0*158  c.c,  calculated  to  the  same 
radium  standard  in  each  case.  This,  in  itself,  constitutes  a 
simple  independent  proof  of  the  point  being  argued. 

Now  consider  the  radium  emanation  also  produced.  Again 
we  find  it  is  produced  in  molecules  of  the  same  mass  as  exist  in  the 
state  of  gas,  one  whole  molecule  per  molecule  of  radium  chloride 
disintegrating.    The  volume  of  emanation  in  equilibrium  with 


THE   ARGON   FAMILY  OF  GASES  657 

1  gram  of  radium,  o'6  cu.  mm.  at  N.T.P.,  is  almost  exactly  that 
calculated,  0*585  cu.  mm.,  on  the  assumption  that  one  whole 
molecule  of  emanation  results  in  the  disintegration  of  one  mole- 
cule of  radium  chloride. 

There  is,  therefore,  something  like  direct  proof  that  in  the 
decomposition  of  a  single  molecule  of  radium  chloride  "  the 
disintegration  of  a  single  atom  of  radium  of  mass  226,"  as  I 
should  prefer  to  say,  one  molecule  of  radium  emanation  of 
molecular  weight  222  and  one  molecule  of  helium  of  molecular 
weight  4  is  produced.  Must  it  not  be  admitted  that  this  is  dead 
against  Prof.  Armstrong's  theory  that  "  proto-helium,"  the  hypo- 
thetical single  constituent  atom  of  the  known  polyatomic  helium 
molecule,  is  the  wondrous  material  at  the  root  of  radioactivity? 
The  radium  atom  is  not  decomposing  into  proto-helium  and 
something  else,  but  into  whole  molecules  of  helium  and 
emanation.  The  view,  therefore,  that  it  is  the  intense  affinity  of 
proto-helium  and  the  single  atoms  of  the  complex  molecules  of 
the  inert  gases  generally,  which  is  the  cause  of  the  peculiarities 
and  extraordinary  energy  of  the  radioactive  changes,  does  not, 
in  itself,  help  towards  the  explanation  of  the  facts. 

The  logic  of  events  has  manoeuvred  Prof.  Armstrong  out  of 
his  formerly  impregnable  position  that,  since  the  argon  gases  do 
not  form  compounds  or  enter  into  chemical  changes,  their  true 
atomic  weight  must  remain  unknown.  For  radioactive  changes 
now  give  precisely  the  same  kind  of  evidence  as  chemists  rely 
on  in  the  determination  of  atomic  weights,  and  this  evidence 
shows  that  the  smallest  particle  taking  part  in  a  radioactive 
change  is  a  whole  molecule  of  helium  or  of  emanation.  In 
deciding  atomic  weights  the  periodic  law  is  the  final  court  of 
appeal.  Can  the  elements  be  properly  accommodated  therein, 
or  must  the  multiple  of  the  equivalent  be  altered  before  a  vacant 
place  can  be  found  for  them  ?  I  need  only  mention  the  periodic 
law  generalisation,  that  in  an  a-ray  change  the  group  number  of 
the  element  is  reduced  by  two,  whereas  in  a  /3-ray  change  the 
group  number  of  the  element  is  increased  by  one.  The  non- 
valent  emanation  results  from  radium  in  one  a-ray  change,  from 
thorium  in  three  a-ray  and  two  /3-ray  changes,  from  actinium  in 
two  a-ray  and  one  /3-ray  change,  in  full  accord  with  the  accepted 
group  numbers  II,  IV,  and  III  for  radium,  thorium,  and  actinium 
respectively.  Moreover,  if  radium  emanation  had  a  polyatomic 
molecule,  since  its  molecular  weight  is  220,  its  atomic  weight 


658  SCIENCE  PROGRESS 

could  not  be  greater  than  1 10.  Yet  its  products,  radium  B  and 
radium  C,  are  respectively  chemically  identical  and  non-separable 
from  lead  and  bismuth  respectively,  which  is  easy  enough  to 
understand  if  the  atomic  weight  is  also  220  and  impossible  to 
explain  if  it  is  no  or  less.  The  fact  that,  in  the  final  chemical 
court  of  appeal,  the  rare  gases  fit  beautifully  into  the  periodic 
law,  as  a  new  family  of  zero  group  number,  only  if  their 
molecules  are  considered  monatomic,  and  cannot  be  fitted  in  at  all 
if  their  molecules  are  considered  polyatomic,  has  been  strikingly 
extended  in  the  case  of  the  radioactive  emanations.  The 
sequence  radium,  (vacant),  emanation,  (vacant),  polonium,  bis- 
muth, lead  of  the  last  two  horizontal  rows  is  completely 
analogous  to  the  other  sequences — barium,  caesium,  xenon, 
iodine,  tellurium,  antimony,  tin;  strontium,  rubidium,  krypton, 
bromine,  selenium,  arsenic,  germanium ;  calcium,  potassium, 
argon,  chlorine,  sulphur,  phosphorus,  silicon ;  magnesium, 
sodium,  neon,  fluorine,  oxygen,  nitrogen,  carbon. 

Now  let  us  turn  to  the  physical  evidence.  This  is  not  so 
logical  in  argument,  perhaps,  because  the  underlying  causes  are 
not  always  clear.  In  the  first  place  I  would  put  the  stopping 
power  of  helium  to  the  a-rays.  Though  helium  is  twice  as  dense 
as  hydrogen,  it  stops  the  a-ray  to  nearly  the  same  extent  as 
hydrogen.  The  range  of  the  a-particle  of  polonium  in  hydrogen 
is  15*95  and  in  helium  167  cms.  at  N.T.P.  (T.  S.  Taylor,  Phil. 
Mag.,  191 3  (vi.)  26,  402).  This  would  be  unexpected  but  for 
Prof.  Bragg's  generalisation.  He  found  the  stopping  power  of 
matter  to  be  purely  an  additive  or  colligative  property,  and  to 
depend  only  on  the  numbers  and  kinds  of  atoms  and  not  of  the 
molecules  into  which  the  atoms  are  combined.  The  stopping 
power  of  any  atom  is  approximately  proportional  to  the  square 
root  of  its  mass,  not  directly  to  its  mass  as  might  be  supposed. 
If  helium  be  monatomic,  then,  since  hydrogen  is  diatomic,  at  the 
same  pressure  the  number  of  atoms  of  hydrogen  in  the  path  of 
the  a-ray  will  be  twice  the  number  of  helium  atoms,  but  the 
stopping  power  of  each  helium  atom  will  be  approximately  ^4 
times  that  of  each  hydrogen  atom,  so  that  the  stopping  power  of 
equal  thicknesses  of  the  two  gases  at  the  same  temperature  and 
pressure  will  be  approximately  the  same.  Lest  it  should  be 
thought  that  helium  is  peculiar,  because  the  a-particle  is  a 
helium  molecule,  it  may  be  said  that  argon,  like  helium,  also 
obeys   the  square-root  law,  only  on   the  assumption   that  its 


THE  ARGON   FAMILY  OF  GASES  659 

molecule  is  monatomic.  The  generalisation  affords  a  powerful 
means  of  checking  the  chemist's  value  of  the  atomic  weights,  and 
it  is  at  least  very  satisfactory  that  no  discrepancies  have  so  far 
been  encountered. 

1  should  be  inclined  to  give  the  specific  heat  evidence  rather 
less  weight  than  Sir  Oliver  Lodge  does,  not  on  account  of  its 
relative  importance,  but,  rather,  because  it  involves  other  and 
more  important  issues  which  cannot  yet  be  held  to  be  satisfac- 
torily decided.  At  bottom,  the  first  question  at  issue  is  whether, 
during  changes  of  temperature,  heat  energy  is  communicated  to 
the  structure  of  the  atom  or  not.  Has  the  atom  a  structure,  that 
is,  that  can  absorb  thermal  energy  from  without  and  be  put  into 
vibration  or  caused  to  "  squirm  "  with  thermal  energy  ?  If  it  has, 
then  one  never  ought  to  get  the  S/3rds  ratio  for  the  specific 
heats.  If  it  has  not,  this  value  should  be  given  by  monatomic 
gases,  provided,  but  only  provided,  that  one  further  and  rather 
unexpected  assumption  is  made. 

The  first  assumption  that  the  atom,  in  addition  to  being  the 
chemical  unit  of  matter,  is  also  the  physical  unit  as  regards  the 
degradation  or  deco-ordination  of  the  energy  of  motion  of  matter, 
may  now  be  generally  admitted.  It  certainly  was  not  admitted 
for  all  temperatures,  I  remember,  by  Prof.  Schuster  in  a  dis- 
cussion at  the  Manchester  University  Physical  Society,  which 
I  had  the  honour  to  take  part  in  some  years  ago ;  and  whether 
it  does  apply  for  temperatures  at  which  the  atom  radiates  its 
characteristic  spectrum  is  a  matter  which  still  may  be  con- 
sidered open  to  discussion.  But  for  ordinary  ranges  of 
temperature  a  closely  allied  assumption  is  made  in  the  kinetic 
theory  of  gases  in  the  form  that  the  molecules  are  perfectly 
elastic.  The  assumption  is  really  a  far  more  important  one 
than  the  thesis  of  the  monatomicity  of  certain  molecules,  and 
though  one  might  employ  the  latter  in  discussing  the  former, 
the  opposite  process  is  hardly  safe. 

On  the  second  point,  I  have  sought  light  and  leading  from 
physical  friends  in  vain.  The  5/3rds  ratio  involves  the  further 
assumption  that  the  thermal  energy  of  rotation  of  a  monatomic 
molecule  is  zero.  The  monatomic  molecule,  in  fact,  possesses 
one  degree  of  freedom  less  than  it  ought  to  have  if  it  were 
merely  a  molecule  and  nothing  more.  For  the  rotation  of 
spherical  granules  under  Brownian  movement  has  been  ob- 
served   by    Perrin,   and   the   equipartition    of  energy    for   this 


660  SCIENCE  PROGRESS 

degree  of  freedom  experimentally  established.  In  fact,  the 
meaning  of  the  5/3rds  ratio  of  the  specific  heats  involves  a 
knowledge  first  of  the  monatomicity  of  the  gas  molecule  before 
it  can  be  used  to  discuss  the  larger  questions  of  the  absence 
of  rotational  energy  and  the  thermal  isolation  of  the  atomic 
structure  from  its  environment. 

Let  us  now  turn  to  the  other  side  of  the  shield,  and  consider 
the  progress  of  knowledge  in  other  directions  since  Prof. 
Armstrong  made  his  suggestion  in  1895.  The  electron,  as  the 
atom  of  negative  electricity  first  definitely  proved  to  be  capable 
of  existence  apart  from  matter  by  Sir  J.  J.  Thomson,  has  to 
be  reckoned  with,  together  with  the  evidence  that  the  electron 
is  a  constituent  of  all  atoms,  and  is  responsible  for  their  chemical 
affinities  and  the  vast  majority  of  their  physical  properties.  Do 
the  argon  gases  contain  these  electrons?  It  might  be  thought 
that  the  absence  of  chemical  affinities  and  the  zero  number  of 
this  family  in  the  periodic  grouping  indicated  complete  absence 
of  electrons,  or,  at  least,  of  electrons  capable  of  being  detached 
from  the  atom.  Whereas  the  fact  that  the  a-particle  has  two 
atomic  charges  of  positive  electricity  is  proof  that  the  helium 
atom  has  two  electrons  capable  of  being  detached,  at  least 
during  radioactive  changes.  It  is,  in  this  respect,  analogous 
to  an  element  of  the  alkaline-earth  family,  and  the  question 
arises,  therefore,  why  compounds  of  the  type  ACL  and  HeCl2 
are  not  possible. 

Nor  is  it  only  in  the  more  drastic  changes  of  radioactivity 
that  this  valency  is  manifested.  The  positive  ray  in  helium, 
for  example,  shows  that  the  atom  carries  two  positive  charges. 
Helium,  when  it  is  specially  pure,  exhibits  what  may  be  de- 
scribed as  a  peculiar  electrical  inertness,  in  that  at  low  pressure 
it  conducts  the  discharge  with  great  difficulty.  In  the  purest 
helium  all  the  phenomena  of  a  high  vacuum — production  of 
cathode-rays  and  of  X-rays — are  exhibited  under  the  discharge 
at  a  pressure,  0*5  mm.  of  mercury,  when  other  gases  conduct 
with  the  maximum  facility.  At  first  it  appeared  possible  that 
absolutely  pure  helium  might  not  conduct  the  discharge  at  all, 
but  a  careful  investigation  showed  that  this  inertness  is  rela- 
tive only.  Five  to  ten  molecules  of  helium  are  electrically 
equivalent  to  one  of  a  common  gas  like  hydrogen  and  nitrogen, 
so  that  if  the  discharge  in  pure  helium  is  compared  at  any 
pressure  with  that  in  a  common  gas,  not  at  the  same  pressure 


THE  ARGON  FAMILY  OF  GASES  661 

but  at  a  pressure  five  to  ten  times  less,  the  same  discharge 
phenomena  are  observed  in  the  two  cases.  This  explains  the 
original  observation  of  Sir  William  Ramsay  and  Prof.  Collie 
that  helium  at  atmospheric  pressure  conducts  the  discharge  with 
far  greater  facility  than  other  gases.  (Soddy  and  Mackenzie, 
Proc.  Roy.  Soc,  1908,  80  A,  92.)  The  fact,  though  it  has  never 
been  adequately  accounted  for,  shows  clearly  that  the  electrical 
inertness  of  helium  is  relative  only,  and  therefore  one  may 
conclude  that  its  chemical  inertness  is  also  only  relative.  The 
molecule  possesses  detachable  electrons,  but  no  chemical  agency 
has  yet  succeeded  in  detaching  them. 

The  recognition  of  detachable  electrons  as  a  normal  con- 
stituent of  the  atom  alters  the  significance  of  the  latter  term. 
The  term  atom,  as  it  is  used  by  chemists,  now  signifies  a  complex 
of  one  material  particle — the  positive  ion  of  the  element — 
together  with  a  certain  number  of  electrons.  The  single  un- 
combined  material  particle  is  the  positive  ion,  not  the  atom. 
It  would  be  idle  to  pretend,  in  spite  of  the  now  generally 
accepted  dictum,  that  "  the  forces  of  chemical  affinity  and  elec- 
tricity are  one  and  the  same,"  that  we  have  yet  a  complete 
explanation  of  the  nature  of  chemical  affinity  in  terms  of  the 
electron.  But  the  numbers  of  the  families  in  the  Periodic  Table 
from  O  to  VII,  representing  the  maximum  positive  valency  of 
the  elements,  do  probably  represent  also  the  maximum  number 
of  electrons  in  the  ring  systems  detachable  in  chemical  changes. 
That  they  do  not  always  represent  the  whole  number  of  detach- 
able electrons  in  any  change  is  shown  by  the  case  of  the  inert 
gases.  They  are  of  relative  rather  than  absolute  significance, 
and  represent  how  one  atom  will  behave  with  regard  to  another. 
If  an  electrically  neutral  atom,  that  is,  the  complex  of  the  positive 
ion  with  its  electrons,  is  the  most  stable  compound  of  that  ion 
which  can  exist,  the  atom  will  appear  to  be  chemically  inert  or 
devoid  of  affinity,  as  in  the  case  of  the  gases  of  the  zero  group. 
In  proportion  as  this  electrically  neutral  complex  is  unstable, 
so  will  the  chemical  activity  of  the  element  increase.  Just  as 
chemists  suppose  that  the  peculiar  inertness  of  nitrogen  is  best 
accounted  for  on  the  view  that  the  elementary  nitrogen  molecule, 
the  complex,  N2,  is  the  most  stable  and  readily  formed  compound 
of  all  compounds  containing  nitrogen,  and  that  the  single 
nitrogen  atoms  have  intense  affinity  for  one  another,  so  it 
seems  reasonable  to  regard  the  helium  molecule,  the  compound 


662  SCIENCE  PROGRESS 

of  the  helium  ion  with  two  electrons,  as  the  most  stable  and 
readily  formed  of  all  compounds  of  helium.  The  intense  affinity 
of  helium,  "  an  affinity  far  beyond  anything  we  have  experience 
of  in  the  case  of  any  other  element,"  is,  on  this  view,  exerted  not 
between  hypothetical  smaller  material  atoms  within  the  helium 
molecule,  as  Prof.  Armstrong  originally  proposed,  but  between 
the  elementary  material  particle  as  a  whole  and  its  electrons. 
This  affinity  is  so  intense  that  the  compound  has  never  been 
decomposed  by  chemical  agencies,  and,  in  consequence,  other 
compounds  than  the  monatomic  complex  containing  two  electrons 
have  never  been  obtained. 


MOLECULAR  VOLUME  THEORIES  AND 
THEIR  RELATION  TO  CURRENT  CON- 
CEPTIONS  OF   LIQUID   STRUCTURE 

By  GERVAISE  LE  BAS,  B.Sc.  (Lond.) 

There  can  be  no  doubt  that  of  all  the  Properties  of  Matter 
which  have  been  correlated  with  the  Chemical  Structure  of 
the  Molecules,  Molecular  Volumes  have  been  of  little  use  to 
the  chemist  in  his  endeavour  to  determine  the  manner  in 
which  the  atoms  are  arranged  in  these  structures.  Many 
successful  attempts  have  been  made  with  other  physical  pro- 
perties, such  as  Optical  Refractivity,  the  Magnetic  Rotatory 
Power,  Viscosity,  and  so  on,  but  this  success  has  not  attended 
the  study  of  Molecular  Volumes.  The  reason  for  this  seems 
to  be  that  the  introduction  of  the  conception  of  a  co-volume 
or  molecular  vibration  volume  into  modern  theories  has  exer- 
cised a  retarding  effect,  in  that  it  has  side-tracked  the  subject 
from  the  main  line  of  its  historical  development.  It  is  possible 
to  show  that,  even  supposing  such  a  theory  of  liquid  structure 
as  we  have  indicated  should  turn  out  to  be  based  on  fact,  no 
possible  reason  exists  why  the  original  point  of  view  of  Kopp 
should  be  abandoned,  for  in  any  case,  as  Kopp  supposed,  the 
volumes  of  the  molecules  at  the  normal  boiling  point  are 
approximately  equal  multiples  of  their  real  molecular  volumes. 
In  these  circumstances,  important  results  from  the  point  of 
view  of  molecular  structure  may  be  expected  if  constitutive 
influences  be  considered. 

Two  types  of  Liquid  Structure  may  be  considered. 

(a)  Space  completely  filled  by  matter. — This  condition  assumes 
that  the  atoms  of  a  molecule  are  in  constant  vibration  about 
a  mean  position,  which  is  determined  by  the  combined  influ- 
ence of  the  chemical  forces  of  affinity  and  the  expanding  heat 
forces.  The  atoms  are  regarded  as  those  separate  entities 
which  by  combination  make  up  the  molecules,  but  which  are  in 
actual  contact  at  —  2730  C.  The  effect  of  the  vibratory  motion 
43  663 


664  SCIENCE   PROGRESS 

just  mentioned  is  to  cause  the  atom  to  occupy  a  space  consider- 
ably larger  than  that  of  its  own  substance,  so  that  the  volume 
of  the  molecule  at  any  temperature  above  absolute  zero  is 
greater  than  XA.  V._273.  The  enlarging  effect  of  the  heat  forces, 
combined  with  the  attractive  intermolecular  forces,  still  pre- 
serves the  compact  arrangement,  but  in  such  a  way  as  to  allow 
of  the  slow  diffusion  of  the  molecules  through  the  mass.  One 
possibility  of  this  unstable  equilibrium  is  the  alternate  formation 
and  dissolution  of  molecular  aggregates.  At  any  rate,  this  view 
accounts  for  the  undoubted  rigidity  which  has  been  found 
characteristic  of  liquids,  the  possibility  of  the  formation  of 
liquid  crystals,  and  the  enormous  resistances  to  pressure  which 
distinguish  the  liquid  from  the  vapour  states. 

The  passage  of  a  substance  into  the  solid  state  is  easily 
accounted  for,  because  the  diminishing  temperature  causes  the 
intermolecular  forces  to  assume  greater  relative  importance, 
owing  to  the  gradual  approximation  of  the  molecular  centres. 
Under  such  conditions  a  point  is  found  where  the  relative 
movement  which  involves  slipping  becomes  impossible,  and 
there  may  also  result  an  orientation  of  the  molecules. 

This  compact  condition  of  matter  is  involved  in  the  theory 
of  Barlow  and  Pope  on  the  Morphotropic  Relationships  of 
Crystalline  Structures,  and  it  has  been  deduced  by  Richards 
as  a  result  of  his  work  on  the  Compressibilities  of  Solids  and 
Liquids. 

(b)  As  an  alternative  to  the  above,  there  exists  the  con- 
ception of  space  only  partly  occupied  by  matter.  The  molecules 
under  the  circumstances  are  not  in  contact,  but  are  separated 
from  each  other  by  a  molecular  vibration  space,  which  is 
maintained  against  the  enormous  internal  attractions  by  com- 
paratively feeble  vibratory  movements.  This  space  is  called 
the  co-volume — a  term  borrowed  from  Van  der  Waals'  theory. 

(i)  Co-volume  Constant  at  Equal  Temperatures. — Traube  con- 
siders that  the  co-volume  is  the  same  for  all  non-associated 
substances  at  the  same  temperature  (Ueber  den  Raum  der 
A  tome,  Stuttgart,  1899,  and  Berichte,  1892-5). 

Thus  Vm  =  £nVa  -f  <£,  <f>  being  constant  at  t°  say.  At  150,  <£  is 
25  —  26  for  different  non-associated  compounds.  This  volume  is 
a  considerable  fraction  of  the  total  volume,  and  it  is  difficult  to 
make  this  circumstance  coincide  with  the  existence  of  the  Law 
of  Coincident  States. 


MOLECULAR  VOLUME 


665 


If,  as  Traube  assumes,  the  constitution  of  liquids,  and  even 
solids,  resembles  in  some  respects  that  of  vapours,  it  is  logical 
to  suppose  that  the  co-volume  would  be  the  same  for  all  sub- 
stances under  similar  physical  conditions.  Facts  are,  however, 
against  this  supposition.  The  following  diagram,  which  gives 
the  volumes  of  the  normal  Paraffins  at  the  different  temperatures, 
shows  this. 

The  Volumes  of  the  n-Paraffins  at  the  Different  Temperatures 

(Data  due  to  Young) 


Temperature  in  degrees  absolute. 

An  inspection  of  the  curve  shows  that  the  molecular  critical 
volumes  lie  on  a  curve  represented  by  the  dotted  line  c5c6c7. 
The  molecular  volumes  at  the  B.P.  lie  along  another  dotted 
line  a/3. 

The  volumes  at   the   reduced  pressure   P/P^o'011796  are 


666  SCIENCE   PROGRESS 

represented  by  points  along  a  third  dotted  line  78.  The  tem- 
peratures at  which  the  pressures  are  equal  are  known,  and  thus 
the  line  can  be  drawn. 

A  remarkable  feature  of  these  three  dotted  lines  is  that  they 
are  all  in  the  same  direction,  a  fact  which  indicates  that  the 
volumes  represented  by  points  of  intersection  of  the  dotted  and 
the  full  lines  are  all  similar  functions  of  the  molecular  magni- 
tudes or  the  complexities.  Moreover,  if  the  molecular  critical 
volumes  of  the  different  compounds  are  equimultiples  of  the 
molecular  volumes  at  absolute  zero,  the  molecular  volumes  at 
the  boiling  point,  and  the  reduced  pressure  P/P*  =  o,oii796  are 
also  equimultiples  of  the  real  molecular  volumes  : 

Thus     VK     =  xV0  =  4V0  approx. 
VB.P.  =  yV0  =  |V0      „ 
VP/P    =  zV2  =  1  '46V0  approx. 

x,  y,  and  z  are  constants  under  the  different  conditions  for  the 
most  various  substances. 

It  is  owing  to  this  fact — one  which  involves  the  Law  of 
Coincident  States — that  an  investigation  of  Molecular  Volumes 
from  the  point  of  view  of  Kopp  is  justified,  independently  of  the 
fact  of  the  existence  or  non-existence  of  a  molecular  vibration 
space  or  co-volume. 

The  Law  of  Coincident  States  is  fatal  to  Traube's  hypo- 
thesis. 

(ii)  Co-volume  Proportional  to  M.V!s  under  Conditions  of  Equal 
Pressure. — Prideaux,  who  also  favours  the  conception  of  a  co- 
volume  or  molecular  vibration  space  {Trans.  Chem.  Soc.  1910, 
Nov.  577,  2032),  concludes  that  it  is  proportional  to  the  real 
molecular  volumes  under  the  conditions  laid  down  by  Young, 
at  equal  fractions  of  the  critical  pressures,  or  below  the  normal 
boiling  point  equal  pressures.  He  connects  the  vibration 
volume  with  the  existence  of  a  vapour  pressure  above  the  sur- 
face. The  co-volume  and  vapour  pressures  are  zero  at  a  certain 
point  (not  —  273) ;  and  as  the  vapour  pressure  increases,  the 
co-volume  also  increases.  They  are  both  functions  of  the 
temperature,  and  thus  the  increase  in  co-volume  may  be 
expressed  as  a  function  of  the  pressure. 

If  Vp  and  V0  represent  the  volumes  of  liquid  at  "  p  "  and 
"  o  "  pressure 

Vp  =  V0  [1  +  <£(p)]  =  Vol.  at  o  press.  +  co-vol.  at  zero  pressure. 


MOLECULAR  VOLUME  667 

For  another  liquid 

Vp-V.[i  +  *'(p)1 

At  a  higher  pressure  pi  the  volumes  become 

Vo[i  +  0(Px)]  and  V'0[i  +  £'(Px]  respectively. 

In  the  case  of  normal  liquids 

Vq  [1  +  *(P,)]  _  V'o  [1  +  ^(P1)] 
V0  [1  +  <Mp)]      V0  [i  +  *'(Pl)] 

V„  [t  +  0'(p.)]  =  Vq  [1  +  *'(p)] 
"  V0[i  +  *(Pl)J        V0[i  +<£(?)] 

•'.  <*>(p)  =  *'(p)  and  <f>  =  4! 

The  function  <£  may,  however,  change  towards  the  critical  point. 
He  concludes  that:  (1)  The  increase  in  co-volume  is  the  same 
function  of  p  for  all  these  liquids,  assuming  the  same  law  of 
expansion  holds  down  to  the  lowest  and  eventually  to  zero 
pressure. 

Vq  [I  +  *'(p)j        Vq 

V0  [1  +  </>(p)]       v0 

(2)  The  co-volumes  V'o0'(p)  and  V0<£(p)  at  any  pressure  are 
proportional  to  the  actual  volumes  of  the  molecules  V'0  and  V0. 

(3)  The  ratios  between  the  volumes  of  the  liquids  at  equal  vapour 
pressures  are  equal  to  the  ratios  between  the  actual  volumes  of 
the  molecules. 

These  conditions  are  all  that  is  necessary  to  justify  the 
investigation  of  molecular  volumes  from  the  point  of  view  of 
Kopp.  This  is,  however,  no  proof  that  the  space  V</>(p)  is 
actually  a  molecular  vibration  space,  and  can  be  equally  well 
explained  on  another  assumption. 

(i)  In  the  first  place,  no  account  is  taken  of  the  vibration  of 
the  atoms,  which  is  certainly  a  fact.  The  reason  it  does  not  do 
this  is  owing  to  a  particular  conception  of  the  atom  which  pre- 
vails, and  which  tends  to  regard  it  as  merely  a  central  nucleus 
which  is  measured  by  the  Refractivity.  Prideaux,  like  Traube, 
believes  that  the  vibration  space  of  the  atom  is  the  external 
shell  of  dielectric,  and  thus  the  internal  vibrations  of  the  mole- 
cule are  within  the  space  b0  or  V0.  The  central  nuclei  are 
spoken  of  as  the  atoms  themselves,  and  the  shell  of  bound  ether, 
which  is  impenetrable  to  other  atoms,  is  not  considered  as  a 
fundamental  part  thereof. 


668  SCIENCE   PROGRESS 

We  believe  that  both  the  central  nuclei  and  the  external 
dielectric  shells  together  constitute  the  physical  atoms,  and  that 
it  is  this  physical  atom  which  vibrates  as  a  whole  when  the 
temperature  is  raised. 

It  is  quite  possible  that,  as  Traube  shows,  both  the  sum  of 
these  central  nuclei  which  make  up  MRa,  and  the  sum  of  the 
external  shells  b0  —  MRa,  are  proportional  to  n  the  number  of 
valencies : 

MRa      .„  ,b0-MR0  .. 

=  790  ana  — =  175  on  the  average. 

At  any  rate,  MRa,  b0,  VK,  VBP,  and  the  molecular  volumes  under 
equally  reduced  pressures,  show  constant  relations  with  each 
other  in  the  different  substances  examined,  and  thus  the  additive 
relations  which  apply  to  one  apply  to  all. 

It  consequently  seems  one-sided  to  refer  to  MRa  only 
when  for  spatial  relations  volumetric  standards  are  available. 
Moreover,  as  just  indicated,  it  does  not  seem  justifiable  to 
consider  the  atom  as  being  just  that  portion  which  happens 
to  be  impermeable  to  light  and  is  conducting,  and  to  neglect  the 
remainder  b0  —  MRa.  It  leads  to  results  which  are  imperfect, 
although  in  themselves  of  utility  and  interest.  Molecular 
Volume  relations  introduce  another  aspect  which  is  of  equal 
importance. 

(ii)  In  the  second  place,  the  existence  of  the  co-volume  has 
been  shown  to  be  connected  with  an  external  vapour  pressure. 
T\\e  vapour  and  solid  phases  can,  however,  exist  together 
independently  of  the  liquid  phase,  and  the  solid  can  even  be 
transformed  into  the  vapour  without  the  appearance  of  liquid. 
Are  we,  then,  to  suppose  that  a  vibration  space  separates  the 
molecules  in  solids,  which  manifest  the  property  of  rigidity? 
This  is  inconceivable,  and  we  conclude  that  in  the  solid  state 
the  molecules  are  in  contact. 

Since  expansion  is  a  well-known  property  of  solids,  we  must 
suppose  that  augmentations  in  volume  with  temperature  are 
due  to  the  increased  vibration  spaces  of  the  atoms.  It  cannot 
be  supposed  that  this  mode  of  expansion  extends  only  as  far  as 
the  melting  point,  but  must  persist  in  the  liquid  state. 

We  are  thus  left  with  the  alternative  of  supposing  that  the 
extra-atomic  space  is  occupied  partly  by  vibrating  atoms,  which 
increase  the  molecular  magnitude,  and  partly  by  a  molecular 


MOLECULAR  VOLUME  669 

vibration  space,  or  by  the  more  simple  one  of  compact  structure. 
The  latter  is  capable  of  explaining  all  the  known  properties  of 
liquids,  many  of  which  are  inconsistent  with  the  first  alternative. 

Since     V°  =  2n(V°)  =  the  sum  of  the  combined  A.V.'s 
Vpm  =  V°  [1  +  eftp)]  -  2n(V°)  [1  +  ftp)]. 

The  space  V£,  —  £n(V°)  is  thus  a  function  of  the  composition  and 
constitution  of  the  molecules  because  it  is  proportional  to 
2n(V°). 

So  also  is  the  whole  volume  V^  proportional  to  2n(V°). 

On  the  assumption  of  compact  structures 

V^       2n(V°)       L    ^9{y,i 
and  (VS)  =  (V°)  [1  +  <£(?)]. 

If  p  represents  some  fraction  of  the  critical  pressure,  or  when  the 
pressure  is  sufficiently  low  some  common  pressure,  then  we  suppose 
that  the  atomic  volumes  change  under  the  different  physical  conditions 
in  the  same  ratio  as  the  whole  molecular  volumes.  This  constitutes, 
at  least  in  part,  a  physical  interpretation  of  the  Law  of  Coincident 
States  as  it  applies  to  liquids. 

Such  a  ratio  is  probably  independent  of  the  chemical  com- 
position and  constitution  of  the  substances,  and  depends  mainly 
on  the  physical  conditions  of  comparison. 

A 

This  is  the  first  of  three  lines  of  investigation  which  form 
the  experimental  basis  of  this  theory,  and  may  be  called  a  proof 
of  the  existence  of  the  Law  of  Coincident  States  in  liquids. 

Suppose  that  the  two  reference  points  for  the  volumes  of  a 
number  of  liquids  are  the  equal  or  reduced  pressure  p  and  plf 

Then  for  Substance  I. 

V£_Vm[i  +  4>'(Pi)]_[i  +  4>'(Pi)] 
V&       V£[i+#p)]        [i+*(p)] 

For  Substance  II. 

V'£  _  VS,  [1  +  *'(Pi)]  _  [1  +  *'(Pi)] 

vg, "    v°  [1  +  </>(?)]      [i  +  <Kp)]     (Re§ularity  1.) 

and  so  on  for  a  number  of  substances. 

These  ratios  are  thus  the  same  for  all. 

(a)  Young  has  made  the  Critical  Molecular  Volume,  or  rather 
Density,   the   basis    of   comparison,   and    has   shown    that   the 


670 


SCIENCE  PROGRESS 


densities  at  equal  fractions  of  the  critical  pressures  are  equal 
multiples  of  the  critical  densities. 

Owing  to  certain  irregularities  which  occur  at  or  near  the 
critical  points,  the  author  has  indicated  {Phil.  Mag.  S.  6,  vol.  xiv. 
No.  81,  Sept.  1907,  pp.  340-4;  vol.  xvi.  No.  91,  July  1908, 
pp.  87-9)  the  advantage  of  making  the  densities  or  volumes 
at  some  reduced  pressure  like  P/P*  =  '01 1795  the  basis  of 
comparison. 

Comparison  of  the  Volumes  of  a  number  of  Hydrocarbons  at 
Corresponding  Pressures. 


P/Pk- 

C5H12. 

C6H14. 

CrHie. 

C8HI8. 

CgHg. 

CeHi2. 

•OI 1 795 



,^_ 

.,     . 







044232 

I0614 

I0614 

10617 

1-0636 

I  0609 

10610 

•144744 

II594 

I  1604 

11620 

n638 

II593 

1-1587 

•58978 

1-4696 

1-4684 

1-4695 

1-4798 

1-4674 

1-4620 

•82568 

1712 

I7I5 

1715 

I736 

1713 

1700 

■97313 

2'IIO 

2-II2 

2- 106 

— 

— 

2-089 

I  OOOOO 

2731 

2740 

2754 

2780 

2-741 

2715 

The  Law  of  Coincident  States  is  thus  approximately  realised, 
as  Young  has  shown.  The  divergences  therefrom  have  been 
connected  by  him  with  differences  in  constitution. 

(b)  Prideaux,  as  already  stated,  has  given  some  data  under 
conditions  of  equal  pressure  (normal  atmospheric),  showing  that 
the  volumes  or  densities  are  comparable  with  similar  data  for 
a  pressure  of  200  mm.  in  the  case  of  non-associated  compounds. 


Thus 


Vm(76o) 

Vm(200) 

CeHg 

PCI3 

HC1 

02 

C2HUBr 


const. 

1-050 
1-050 
1-049 
1-048 
1*048. 


It  appears  that  constant  relations  are  also  obtained  by  sum- 
ming the  atomic  volumes  of  the  free  elements  under  the  two  or 
more  equal  pressures  and  comparing  them  : 

Vm(76o)  2Va(76o) 


Vra(200) 


PCh 
ICl' 


1-050 

]  "041 


2Va(2oo) 
P  +  Cl3     1-050 
I  +  CI       1 -043 


MOLECULAR  VOLUME 

It  follows  that  the  relation 


671 


2Va 


=  const. 


holds  at  various  equal  pressures  for  all  normal  substances.     In 
the  following  cases  100  volumes  become  on  combination  : 


P  860  mm. 

760  mm. 

560  mm. 

HgCl.,     Hg  +  2CI  . 
HgBr2    Hg  +  2Br 
Hgl,      Hg  +  2I     . 

101-9 
I075 
IO95 

ior8 

107-4 
IO95 

IOI7 
107*3 
109*6 

Table  illustrating  the  Law  of  Coincident  States  among  the  Complex 

Paraffins  near  the  M.P. 


M.P.  +n  x  10. 

C14H30. 

Ratio. 

CijH32. 

Ratio. 

C16H34. 

Ratio. 

Ci7H36. 

Ratio. 

M.P.   . 

„      +  30  . 
„      +  60  . 
„      +  80  . 

255'4 
262*45 
270*01 
275'34 

I'OOOO 
1*028 
1*057 
1*078 

273*2 
28o*8 
288*94 
294*47 

I'OOO 
I*028 
1*057 
1*078 

291*2 

299' 34 
30773 
31371 

I'OOO 
I'028 
1*056 
I*077 

309*00 

3I7'54 
326*31 

332'37 

I'OOO 
I*028 
1*056 
1*076 

(From  Krafft's  observations,  Ber.  15,  1687.) 
Under  the  above  conditions  the  molecular  volumes  are  equal 
multiples  of  the  molecular  volumes  at  the  melting  point. 

(c)  It  is  possible  to  go  a  step  farther,  and  to  trace  the  Law  of 
Corresponding  States  into  the  solid  state.  The  data  which 
furnish  evidence  for  this  are  due  to  Vincentini  and  Omodei 
{Beibl.  12,  178),  and  are  from  observations  on  certain  Pb-Sn 
alloys.  The  compounds  were  examined  in  the  solid  state  from 
200  C.  up  to  the  melting  point  (1820  C.  approx.),  and  in  the  liquid 
state  up  to  3560  C.  As  in  the  previous  case,  the  conditions  for 
comparison  are  met  with  at  equal  intervals  of  temperature  above 
and  below  the  respective  melting  points. 

Comparison  of  the   Volumes  of  certain  Pb-Sn  Alloys  under 

Various  Conditions. 


Alloys. 

Solid 

20°  C 

Solid  M.P.  (182° C). 

Liquid  3560  C. 

M  P 

vra 

Ratio. 

vm 

Ratio. 

vm 

Ratio. 

SnPb 
Sn,Pb 
Sn3Pb       . 
Sn4Pb 

34*49 
50-67 

66-So 

83*06 

I'OOO 
I'OOO 
I'OOO 
1*000 

35*02 
5i'36 
67*63 
84*10 

I*Ol5 
I*OI3 
I'OI2 

roi2 

36*69 
53*76 
70*87 
88-13 

1*064 

1*061 
1*061 
ro6i 

181*8° 
182*3° 
182*9° 

183*3* 

672  SCIENCE  PROGRESS 

The  ratios  which  have  been  given  in  the  above  tables  are 
indications  of  the  changes  in  the  physical  states  simply,  and  are 
independent  of  the  nature  of  the  substances.  They  show  the 
increases  in  the  vibration  spaces  from  one  physical  condition  to 
another. 

If  the  space  were  a  molecular  vibration  space,  there  is  no 
reason  why  it  should  be  practically  constant.  Indeed,  it  would 
be  likely  to  diminish  with  increasing  complexity,  because  the 
greater  molecular  weight  of  the  more  complex  compounds 
would  tend  to  diminish  the  amplitudes  of  the  vibrations  and  so 
diminish  the  co-volumes.  The  constancy  of  the  ratio  must 
therefore  be  connected  with  the  atomic  vibrations,  which  show 
similar  amplitudes  of  vibration  under  similar  physical  conditions. 

B 

After  tracing  the  Law  of  Coincident  States  in  the  two  states — 
the  Solid  and  the  Liquid — we  are  led  to  a  Second  Regularity. 
This  refers  to  the  relations  between  the  volumes  of  the  com- 
pounds under  particular  physical  conditions. 

Since  it  is  likely  that  the  effects  of  differences  in  constitution 
would  show  themselves  in  the  ratios,  care  must  be  taken  to 
compare  chemically  similar  substances.  Suppose  the  conditions 
be  equal  or  reduced  pressure  p. 

Then  for  a  number  of  substances  which  are  structurally 
similar  and  which  form  a  homologous  series  or  one  characterised 
by  some  constant  difference  in  composition : 

(Vm  =  V0[i  +  *(p)]    ) 
At  pressure)  V'm  =  V'0  [i  +  *(p)]    L.         ,        ,,       ,„ 

P  V'WUx-^p)]  [Since*-*-*    = 

Comparing  the  volumes  of  the  second  and  the  third  with  the 
first  we  find : 

fV'm_V'o[i  +  *(p)]__V0 


At  pressure 
P 


Vm  V0  [i  +  *(p)]       V, 

V^  V' 

v       V 

v  m 

V"'  v 


i  +  nx 
=  i  +  (n  +  i)x 

2  =  i  +  (n  +  2)x 


Vm                                      V0 
(Regularity  II.) 

x  being  some  difference  and  n  a  number  which  is  usually  unity. 


MOLECULAR  VOLUME 


$73 


All  these  ratios  are  similar  to  the  ratio  of  the  volumes  at 
absolute  zero,  and  if  the  compounds  differ  in  composition  by  a 
similar  constituent,  the  ratios  are  likely  to  form  an  arithmetical 
series.  Differences  in  constitution  would  interfere  with  this 
regularity  somewhat. 

Such  a  regularity  as  the  above  is  very  significant,  because  it 
indicates  what  are  the  ratios  of  the  volumes  at  absolute  zero, 
which  is  a  condition  where  atomic  vibration  is  absent.  Thus 
a  study  of  M.V.'s,  as  ordinarily  understood,  leads  to  the  detection 
of  constant  relations  between  the  combined  volumes  of  the 
atoms. 

The  law  which  is  involved  in  Relation  II.  may  be  called  the 
Laiv  of  Constant  Volume  Relations.  This  relation,  while  true  in 
principle,  may  be  interfered  with  by  Constitutive  Influences  to 
some  extent. 

(a)  The  Law  of  Constant  Volume  Relations  in  the  Normal  Paraffins 
under  Equally  Reduced  Pressures 


p/pk- 

C.sHi8. 

Ratio. 

C7Hl6. 

Ratio. 

C6HU. 

Ratio. 

C5H12. 

Ratio. 

C6H6 

Ratio. 

C6H12. 

Ratio. 

•01179s 

1 75 '83 

1 '000 

I54'58 

•8792 

133-65 

■7601 

113*20 

•6436 

93 '5 

I'OOO 

112*97 

I '208 

■044232 

187*02 

I'OOO 

l64'02 

•8770 

141-95 

■7596 

120-15 

•6425 

99*19 

I'OOO 

119*82 

1-208 

•144744 

204'62 

I'OOO 

179*62 

•8778 

i55'o9 

•7580 

I3I'2S 

•6414 

108  "49 

I'OOO 

130*89 

I '207 

•5C978 

260*3 

I'OOO 

227*17 

•8728 

196*25 

"7539 

166-35 

•6386 

137*20 

I'OOO 

165*17 

1*204 

•82568 

305-2 

I'OOO 

26525 

•869 

229'20 

'751 

ig3-8o 

•63S 

160-19 

I'OOO 

191*74 

1-197 

1 '00000 

488-9 

I'OOO 

427-7 

•8707 

366-3 

•7490 

309*2 

•632s 

2563 

I'OOO 

306*7 

1*196 

of  Va- 

lencies 

59 

50 

i"ooo 

n 

•880 

u 

•760 

13 

"640 

no 

a  11 

I'OOO 

M 

l'2Q 

The  ratios  are  seen  to  form  an  approximate  arithmetic  series, 
comparing  the  paraffins  with  C8H,8,  and  C6Hi3  with  C6HG.  Thus 
in  the  case  of  the  Molecular  Critical  Volumes 

CsHig  i*ooo  C7H16 1  —  1  x  0*1293  CeH14 1  -  2  x  0*1255  C5H41  1  —  3  x  0-1225 

P/PK  -011795 
CgHis  i'ooo  C7HK3  1  —  1  x  0*1218  CeH14  1  — 2  x  0*1200  CsHi2  1—3  x  0*1188 

CeH6  1*000  C6H12  1  +  1  X  0*1208. 


Also,  if  we  compare  compounds  belonging  to  the  same  class, 
we  see  that  the  volumes  are  nearly  in  the  same  ratio  as  that  of 
the  sum  of  the  valencies.  This  relation  must  consequently  obtain 
at  absolute  zero,  and  represent  a  constant  relation  between  the 
volumes  of  the  constituent  atoms  C  and  H. 

The  ratio  holds  more  accurately  the  further  away  from  the 


674 


SCIENCE  PROGRESS 


Critical  Point  that  observation  is  made.     The  following  table 
emphasises  this : 

The  Law  of  Constant  Volume  Relations  among  the  Complex 
n- Paraffins  near  the  Melting  Point 


M.P.  +n  x  io°C. 

CuH30. 

C15H33. 

C16H34 . 

cnHj6. 

M.P 

„        +  30° 
„       +  6o° 
„      +  8o° 
Ratio  of  Valency  Numbers 

I'OOO 
I'OOO 
I'OOO 
I'OOO 
|f    I'OOO 

I '070 
1*070 
I '070 
1*070 

II  1-070 

I '140 
i'i4o 
1*140 
1 '140 
II  1 '140 

I'2IO 
I'2IO 
I'209 
I '204 

ss-    I  2IO 

The  relations  between  the  molecular  volumes  near  the  melting 
point  are  similar  to  those  for  such  compounds  near  the  critical 
point. 

It  will  be  now  useful   to   compare  the  volumes  of  normal 
paraffins  at  the  Normal  Boiling  Point : 


C4H, 

C5H„. 

C6H)4. 

C7HI6. 

C8H18. 

vm- 

Ratio. 

vm. 

Ratio. 

vm. 

Ratio. 

vm. 

Ratio. 

vm- 

Ratio. 

Ratio   of 
Valencies 

96-0 

2  R 
2^ 

I'OOO 
I -OOO 

II7-8 

32 
TS 

1*227 
I-23I 

139-93 

88 

1-458 
1*462 

162-56 
44 

1-694 
1-693 

186-26 

50 
TT5 

1-940 
1*923 

The  rule  is  very  closely  followed  at  the  boiling  point.  Diver- 
gences therefrom  can  be  ascribed  to  differences  in  constitution ; 
e.g.  lengthening  of  the  Hydrocarbon  chain. 

We  now  discuss  a  similar  relation  in  the  Sn-Pb  alloys — a 
series  of  similar  substances  differing  in  composition  by  Sn. 

The  Laiv  of  Constant  Volume  Relations  in  the  Sn-Pb  Alloys 

near  the  Melting  Point. 


Alloys. 

Solid  20°. 

Solid  M.P. 

Liquid  3560  C 

SnPb. 

vm. 

Ratios. 

vm. 

Ratios. 

vm. 

Ratios. 

SnPb     . 
Sn.,Pb   . 
Sn,Pb    . 

Sn.Pb    . 

34'49 
50-67 
66- 80 
83-06 

I'OOO 

i  +  i  x  0*469 

I   +  2   X   C469 

i  +  3  x  0*469 

35-02 

67-63 
84-10 

I'OOO 

1  +  1  x  '467 

I   -(-  2   X    '466 

i  +  3  x  '467 

36*69 
53-76 
70-87 

88*13 

I'OOO 

1  +  1  x  '465 

I    +  2    X    '466 

i  +  3  x  '467 

MOLECULAR  VOLUME  675 

The  results  show  that  the  series  is  an  additive  one  under  the 
various  conditions,  a  fact  which  agrees  with  the  arrangement  of 
the  substances  in  series.  It  follows  that  the  volumes  of  the 
atoms  maintain  their  relative  values  under  the  different  con- 
ditions. This  is  because  the  changing  physical  conditions  affect 
the  atoms  Sn  and  Pb  similarly — that  is,  change  of  temperature, 
and,  what  is  more  important,  change  of  state. 

C 

The  symbolical  relations  previously  given  enable  us  to  arrive 
at  a  third  regularity,  which  is  suggested  by  the  above  tables. 
We  have  seen  that 

**  P"  =  P  =  const-  t1  +  ^p)l 

which  suggests  unchanging  internal  volume  relations  because 

V.       V^0       Sn'(Va), 
Vm        V0        2n(Va)0  * 

We  also  see  that  since 

5s  =  S*  - [1  +  *(p>] 

*  o  *    o 

2n(Va)a        2n'(Va)0  L    +  9WJ 

and  (Va)p  =  (Va)0  [1  +  *(p)]. 

At  any  pressure  p,  we  have  thus  to  do  with  a  number  of  atomic 
vibration  volumes,  which  bear  the  same  relation  to  each  other 
as  their  volumes  do  at  absolute  zero ;  for  if  (V'a)p  and  (Va)p  be 
two  combined  atoms  at  pressure  p, 

(V.)P     (Va)o[i  +  <Mp)]  =  (va 

(V.)p       (Va)0  [1  +  0(p)]       (V.). 

For  the  above  reason  the  investigation  of  molecular  volumes 
from  the  point  of  view  of  Kopp  is  justified. 

The  Third  Regularity  is  the  Law  of  Additive  and  Constitutive 
Relations  in  molecular  volumes.  The  investigation  is  possible, 
because  we  choose  conditions  such  that  the  molecular  volumes 
are  equimultiples  of  the  volumes  at  absolute  zero,  or  the  real 
molecular  volumes. 

'In  accordance  with  the  above  ideas,  we  note  the  unchanging 
relation   which    exists  between  the  volumes  of  C  and  H,  viz. 


676 


SCIENCE   PROGRESS 


C :  H  =4:1,  which  is  at  the  bottom  of  the  valency  rule  met  with 
in  the  Hydrocarbons. 

The  change  in  structure  involved  in  passing  from  Hexane, 
CGHi4,  to  Benzene,  CcHc,  does  not  prejudice  the  relation  men- 
tioned. 

The  explanation  of  this  on  the  basis  of  a  co-volume  or 
molecular  vibration  volume  is  not  apparent. 


The  Law  of  Additivity  in  the  Simple  Normal  Paraffins,  etc., 
at  Corresponding  Pressures 


CsH,8. 

C7H16. 

C6HI4. 

QH,2. 

CBH6. 

C0Hi2. 

W  =  5o. 

w=44. 

W=38. 

W  =  32. 

W  =  3o. 

W=36. 

P/PK 

vm 

vra 

W 

vm 

w 

vm 

w 

vm 

vra 
w 

vra 

w 

vm 

vm 

W 

•01179s  . 

I75'83 

3'Si7 

154-58 

3-513 

'33-65 

3'5i7 

113-20 

3-537 

93-5 

3-12 

II2'C7 

3'M 

•044232  . 

187-02 

3'74Q 

164-02 

3728 

Mi  '95 

3'736 

120-15 

3'755 

99-19 

3' 30 

1198s 

3'33 

•144744  . 

204'62 

4-092 

179-62 

4-082 

I55"09 

4-082 

131-25 

4-101 

108-49 

3'6i 

130-89 

3'64 

•S8978    . 

260-3 

5-206 

227-17 

5-163 

196-25 

5'i64 

166-35 

5-198 

137-20 

4-57 

165-17 

4' 59 

•82568    . 

3°5'2 

6"  10 

265.25 

6-03 

229*20 

6-03 

193-80 

6-05 

160*19 

5'34 

191-74 

5-32 

I  'ooooo 

488-9 

9'77 

427-7 

9-67 

366-3 

964 

309-2 

9-66 

256-3 

8-54 

306-7 

8-52 

The  ratios  ^  give  the  volumes  of  one  valency  or  the  atom  of 

combined  Hydrogen  under  the  different  conditions.  The  volume 
of  combined  Carbon  is  four  times  this  value.  Such  differences 
as  we  find  are  due  to  differences  in  constitution. 

The  accurate  investigation  of  molecular  volumes  is  thus 
greatly  facilitated  by  a  recognition  of  the  Law  of  Constant 
Volume  Ratios : 

The  Additive  Rule  in  the  Complex  n-Paraffins  near  the 

Melting  Point 


M.P. +  nio. 

C14H30. 

Wm  =  86. 

CI5H32. 
W  =  92. 

C16H34. 
W=  98. 

W  =  104. 

vm 

w 

vm 

w 

vra 

vm 
w 

vm 

w 

M.P. 

»      +  30°       . 
„     +6o°      . 
„     +800     . 

255'4 
262*45 
270*01 
275*34 

2*970 

3*05* 
3*139 

3*201 

273-2 
28o*8 
288-94 

294*47 

2*970 

3*052 
3*140 

3'2oo 

291*2 
299*34 
3°7*73 
3I37I 

2*971 

3'o54 
3*!4o 
3*200 

309*0 

317*54 
326-31 

332*37 

2*971 

3"o53 
3*i38 
3 '200 

The  atomic  volumes  are  practically  constant  under  the  cir- 
cumstances. 


MOLECULAR  VOLUME 


677 


The  rule  C :  H  =  4 : 1  has  been  traced  from  the  Critical  to  the 
Melting  Point  or  throughout  the  liquid  state. 

According  to  the  Prideaux's  result  it  should  also  be  noticed 
at  the  Boiling  Point. 


C8H.8 

C7Hl6. 

C6HU. 

C5H„ 

C4H9. 

v,„ 

V 

w 

vm 

vra 
w 

vm 

vm 
w 

vm 

vm 
w 

V 

vm 
w 

186-26 

3-725 

162*56 

3-695 

139-93 

3-682 

117-8 

3-681 

96-0 

3-693 

We  cannot  doubt  that  at  absolute  zero  the  relative  volumes 
of  bound  C  and  H  is  as  4 : 1  in  each  compound  and  approximately 
for  different  compounds. 

Similarly,  it  is  probable  that  a  constant  relation  exists 
between  the  volumes  of  other  atoms. 

It  is  to  be  expected  also,  that  additive  relations  exist  in  the 
volumes  of  the  Sn-Pb  alloys  in  both  the  solid  and  liquid  states. 

The  Additive  Ride  in  the  Sn-Pb  Alloys  near  the  Melting  Point 


Solid  20°. 

Solid  M.P.  (182)°. 

Liquid  356°  C. 

Alloys. 

vm 

2A.V. 

vm 

2A.V. 

V£ 

2A.V. 

SnPb      . 
Sn,Pb     . 
Sn3Pb     . 
Sn4Pb     . 

34'49 
50-67 
66-8o 
83-06 

Sn  16-176, 

34*49 
50-66 

66-84 

83*02 

Pb  18*313 

35-02 

5I-36 

67-63 
84*10 

Sn  16-354, 

35-02 

51*37 
67-72 
84-08 

Pb  18-665 

36*69 
53-76 
70-87 
8813 

Sn  17*097 

36*69 
53-78 
70-88 
87*98 
,  Pb  19*592 

n  the  free  state: 

A.V.*  . 

.     Sn  16*186 

A.V.I82 

.     Sn  16-375 

A.V.  M.P.   . 

.     Sn  16*426 

M.P.   . 

2260  C. 

Pb  18-259 
Pb  18-565 
Pb  18-818 
3260  C. 

We  note  from  the  above  table  that  the  additive  rule  holds  in 
the  three  conditions  above  mentioned — one  in  the  liquid,  and 
two  in  the  solid  state. 

Expansion  in  both  states  takes  place  owing  to  the  increase 
in  the  spheres  of  activity  of  the  atoms,  and  there  is  no  reason  to 
suppose  that  any  change  in  this  respect  occurs  owing  to  change 
of  state. 

On  comparing  the  atomic  volumes  in  the  free  and  combined 
states,  we  see  that  they  are  nearly  the  same  at  the  same 
temperatures. 


678  SCIENCE   PROGRESS 

The  Molecular  Volume  {and  A.V.),  a  Function  of  the  Chemical 

Constitution  of  the  Molecules 

The  Law  of  Additivity  has  been  suggested  by  the  foregoing 
Tables,  and  thus  we  notice  the  probability  of  the  M.V.'s  being 
also  functions  of  the  Constitution  of  the  Substances.  We  start 
with  a  substance  like  Hexane,  C6H14,  and  by  a  series  of  chemical 
changes  illustrate  the  different  varieties  of  structure. 

I.  Straight  Chains :  The  Di-substitution  of  Hexane. 

Hexane  CH3 .  CH2 .  CH2  .  CH2 .  CH2  .  CH3     M.V.  139-93  observed. 
3A.V.  6  x  147  +  14  x  37  =     140  o    calculated, 

(i)  CH3 .  CH  2 .  CH2 .  CH2 .  CH2 .  CH3  +  Cl2 

=  CH3  .  CH2 .  CH2  •  CH2  .  CH2 .  CH2  [5]  4-  HC1 
C6H13C1     M.V.  158-5 
2A.V.  6XC  +  13XH  +C1=  1590 

This  compound  has  thus  a  straight  chain,  like  Hexane. 

(ii)  CH3 .  CH2 .  CH2 .  CH2 .  CH2 .  CH2C1  4-  Cl2 

=  |5|  CH2 .  CH2 .  CH2 .  CH2 .  CH2 .  CH2 .  |a|  +  HC1 
C6Hi2Cl2     M.V.  162-4     (Extrapolated  value) 

2A.V.  6  x  CH2  +  2CI  =  177-4 

A  —    i5'o     Possibly  somewhat  less 

There  is  thus  a  large  difference  in  volume  between  the  two 
results.  It  has  been  shown  by  experiment  that  1 : 1  di-substitu- 
tion products  are  normal  and  involve  no  contraction.  1  : 2 
compounds  show  a  contraction  of  3*0,  and  1:3a  contraction  of 
6-o,  and  so  on  successively.  (See  paper  read  before  Brit.  Assoc. 
Portsmouth,  191 1,  Section  B;  and  also  Chemical  News,  vol.  civ. 
191 1,  p.  151  et  seq.) 

Such  di-substituted  compounds  as  the  above,  however,  mark 
a  structure  different  from  that  of  straight-chain  compounds. 
Owing  to  residual  affinity,  arising  from  the  terminal  chlorine 
atoms,  the  curvature  of  the  Hydrocarbon  chain  is  effected  and 
a  Partial  Ring  is  formed. 

CHj  —  CHj  —  CHo  —  CI 

CI .  CH2 .  Cri2  .  CH2 .  CH2 .  CH2 .  CH2C1  = 

Crl2  —  CH2  —  CH2  —  CI 

The  difference,  i5'o,  is  an  expression  of  this  change  in  con- 
stitution. 


MOLECULAR   VOLUME 
II.  A  Closing  of  the  Partial  Ring. 

i 
i 

CH2  -  CH2  -  CH2  -  CI  +  Na 


679 


Complete 
Hings. 


CH2  -  CH2  -  CH2  -  CI  +  Na 


CH, 


CH2  —  CHc 


CH2  —  CH2  —  CH; 

Hexamethylene. 


L12- 


CH2 


CH  =  CH  -  CH 


M.V.  C6H12  116-3 

6  x  CH2  =  6  x  22*2  =  133*2 
A  —  16-9 
This  large  difference  is  an  expression  of  the  difference  in  struc- 
ture between  Hexamethylene  and  Hexane  or  Hexylene,  C6Hj 

III.  The  Formation  of  Benzene  from  Hexamethylene. 

CH2  -  CH2  -  CH2  CH  =  CH  -  -  CH 

-  6H2  = 

CH2  —  CH2 
M.V.  of  Benzene  C6H6     96-0 

V.  C6H12  -  V6H  =  116-3  -6x3-2  =  97-1  =  C6H6 
or  Hexane  CeH12     139*93 

Hexylene       C6Hi2     132-4       ^  ^3 
Dipropargyl  C6H6      139*93  -4x7-5 

=  l39'9    —  3°'°  =  k>9'9 
A  =  109*9  —  96  =  —  13-9  or  14*0  approx. 

In   this  case    again    we    notice    a    large   contraction   for  ring 
structure. 

IV.  Substitutions  in  the  Benzene  Ring. 

(i)  Nitrobenzene  C0H5NO2 

CH  CH 

S   \  *   V 


Volume 
Anomaly, 


CH 

I 
CH 

\  / 
CH 


CH 


CH    CH 


CH 


+  HNO3 


CH 

%  / 
CH 


CH  -  N03 


+  etc. 


C6H6  V.  96-0  C6H5N02  V.  i22-i 

Vol.  of  2N02  is  64-0  N02  =  32-0 

V.  CeH5N02  =  V.  (C6H6  -  H  +  N02) 
=  96  —  3*2  +  32*0  =  124*8 
A  between  calculated  and  observed  results 
124-8  —  i22*i  =  —  2-7 

This   small   difference  expresses   the  effect    of   an  interaction 
between  the  unsaturated  —  N02  group  and  the  nucleus.    This 
44 


680  SCIENCE   PROGRESS 

has  been  called  the  Volume  Anomaly,  by  analogy  with  the  similar 

Optical  Anomaly.     It  is  expressed  graphically  thus  : 

CH 

S     \ 
CH       CH 

I  II 

CH       C— N02 

%      /•...    / 

CH 

If  the  group  be  saturated,  this  anomaly  disappears, 
(ii)  Meta  Xylene  i  :  3  C0H4(CH3)     M.V.  140-0. 
We  find  that  the  CH3  group  is  equal  to  25-5. 

Toluene  C6H5CH3  V.  118-3. 
x  CH3.  =  C6H5 .  CH3  -  C6H5  =  118-3  -92-8  =  25-5 


0.  M.  and  P. 

CH 

s  \ 

CH       CH 

C— CH3 
CH    CH 

Arrangements 
of  Substituents . 

I           II        +  2CH3  = 
CH       CH 

%     / 
CH 

II                +H2 
CH    C— CH3 

%/ 
CH 

Vol.  C6H4        89-6 
2CH3      51*0 

Calculated     140*6 

Observed  140-0 

Para  Xylene  is  140-6,  and  O  Xylene  138-4. 

The  close  approximation  of  the  two  groups  CH3  causes  a 
contraction  owing  to  residual  affinity. 

C— CH3  C— CH3  CH 

t,  CH    CH       , ,  (      CH    CH  ~  f,      CH      C— CH3-. 

Para        ,         ,,  Meta      ,         ,,  Ortho    .  .,  s    •. 

14        CH    CH        I3     CH    CH— CH3     J  ' 2    CH      C— CH3..-' 

%  /  %/  X    / 

C— CH  CH  CH 

M.V.  140-6  M.V.  140-0  M.V.  138-4 

Calculated  140-6  on  supposition  of  independence  of  groups. 
The  dotted  line  illustrates  this  effect. 

Value  for  O  Nitrotoluene  1  :  2  C6H4CH3N02  is  142-7 

CH  C6H4  118-3  —  3-2  =  115-1 

S    \  N02    +  32-0 

CH       CH  

I  ||  QH4CH3N02       147-1 

CH       C — CHj--.       Vol.  an.  +  o.  corr.  i42'7 


C NCy..-'  Obsd.  -4-4 


MOLECULAR  VOLUME  68 1 

Nitro  m.  Xylene  C6H3(CH3)2N02  1:3:4 

C CH3  O.  Nitrotoluene     1427 

jf  \                                            M.  Nitrotoluene     144*3 
CH    CH  


I         II  -  i'6 

CH    C— CH3-..  Vol.  anom.  -4*4  +  i'6  =  2*8 

"\  /  \  which  is  similar  to  that  of  nitro  benzene. 


C NO 


2. 


m.  Xylene  1 :  3C6H4(CH3)2       140*0 

less  H 


NO 


■2 


More  simply 

O  Nitrotoluene 

1427  less  vol.  an. 

less  H         3*2 


139-5  less  °-  struct. 

+  CH3      25-5 

Calculated  Vol. 


J  2 

136-8 

+  32"° 

168-8 
-2-8 

i66'o 
-  r6 

164*4 
164-8 

165*0  Observed 


The  result  that  the  constitutive  features  which  are  observed 
in  the  separate  compounds  are  united  in  this  compound. 

For  Nitro  m.  Xylene  :  (1)  ring  structure,  (2)  volume  anomaly, 
and  (3)  ortho  position.  Each  of  these  is  indicated  by  a  definite 
influence  on  the  volume. 

Besides  all  this,  there  is  an  additive  effect  due  to  its 
composition. 

A  similar  striking  series  of  reactions  to  the  above  may  be 
made  up  from  the  following : 

Hexane  Hexyl  chloride 

CH3.CH2.CH2.CH2.CH2.CH2.  ->  CH3  CH2.CH2.CH2.CH2.CH,C1  -> 
contr.  o  contr.  o 

Hexylene  chloride 

CH2  -  CH2  -  CH2  -  CI 

I  II 

Cri2  —  CH2  —  CH2  —  CI 

contr.  —  15  about 

Hexymethylene  Benzene 

->CH2.CH2.CH2  ->  CH=CH-CH 

II  I  II 

CH2.CH2.CH2  CH  =  CH-CH 


682 


SCIENCE   PROGRESS 


Benzoic  Acid 

CH 

S     \ 
CH      CH 


Methyl  Benzoate 

CH 

s   \ 

CH   CH 


CH 

CH 
M.V.  126-9 


C— COOH 


CH 

%  / 
CH 

M.V 


C— COOCH3  _>  Methyl 

Salicylate 


CeH5 
COOH 


92-8 
37"o 


2VA     129-8 


C6H5 
COOH 

CH2 


i5°'3 

92-8 

37'° 

22'I 


A 2-9 

Large  volume 
anomaly  owing 
to  the  reactive 
group  -  COOH. 

CH 

S  V 

CH      C- 

I  II 

CH      C- 

\    / 
CH 

Phenol  C6H5  -  OH 

C6H5       92-8 
OH       in 


is1^ 

A     -  1 '6 

Anomaly  has 
nearly  disap- 
peared. Ethyl 
Benzoate  shows 
a  value  o  for  this. 


CH       ... 

S  V 

CH      C— OH  \ 

I  I! 

CH      C— COOCH; 

\    / 
CH 

Anomaly  has  again 
appeared  owing  to 
unsat.  —  OH  group. 


OH"\ 

■ 

•COOCH3 


C8H803 


M.V.  Methyl  Salicylate  157-0 
Dipropargyl     iii'o 
Ring   —15-0 


Calculated     103-9 
Observed     10 1-9 


Benzene  CeH6       96*0 
less  H2     —  6-4 


A  for  anom. 


2-0 


C6H4       896 
OH    +ii-i 


1  :  2  Cresol  C6H4CH3 .  OH 

I2I-8 

1  :  4  Cresol     123-8 


1007 
COOH    +370 


—  2*0 


137*7 
CH2     +  22'I 


For  ortho.  correction. 


1  o'  has  been  taken  to  be  7*4,  but  in  the 
aliphatic  alcohols  it  is  only  6'3.  This  is  i'i 
less.  It  follows  that  the  calculated  volume 
of  Methyl  Salicylate  should  be  on  this  basis 
=  156-9. 


159.8 
less  vol.  anom.     —2*0 


157-8 
less  o.  corr.     —2*0 


Calculated     155*8 
Observed     157*0 


MOLECULAR  VOLUME 


68^ 


These  examples  show  that  the  molecular  volume  is  very 
sensitive  to  changes  in  constitution.  Such  a  result  does  not 
seem  possible  except  on  the  basis  of  compact  structure. 

Incidentally,  these  results  confirm  the  Theory  of  the  Atomic 
Structure  of  Matter  and  of  the  existence  of  Proximate  Con- 
stituents, because  molecular  volumes  show  that  parts  of  a 
molecule  are  outside  the  range  of  each  other's  action,  while 
others  evidently  influence  one  another. 


The  Molecular  Volumes  {and  A.V.)  Functions  of  the  Physical 

State  of  Compounds 

It  follows  from  the  Theory  of  Compact  Structure  herein  set 
forth  that  the  Atomic  Volumes  are  likely  to  reflect  the  Physical 
State  of  substances.  The  idea  is  that  the  nature  of  the  intra- 
molecular cohesive  forces  upon  the  particular  character  of 
which  the  different  Physical  Modifications  depend  are  functions 
of  the  internal  conditions  and  arrangements.  Changes  in  the 
Molecular  Volumes  due  to  differences  in  mode  of  arrangement 
of  the  molecules  are  accompanied  by  changes  in  the  atomic 
volumes.  Thus  the  A.V.'s  have  been  found  to  vary  with  tem- 
perature and  pressure. 

They  also  vary  with  the  Solid  or  Liquid  condition  in  which 
they  are  examined.  If  the  assumptions  which  we  have  made  be 
correct,  then  we  are  justified  in  speaking  of  the  Liquid  and  Solid 
Atom,  because  an  atom  in  a  liquid  is  essentially  different  from 
an  atom  in  the  solid  molecule. 

This  is  emphasised  by  an  examination  of  the  abrupt  changes 
in  volume,  which  usually  occur  at  the  M.P.  when  change  of 
state  occurs,  and  illustrated  by  the  volumes  of  the  Pb-Sn  alloys 
already  referred  to. 


Free  Atoms : 

Sb. 

Pb. 

At  M.P.  (solid)  .... 
„       (liquid) 

A  in  liquefaction 

16-42 
16*91 

+  0-49 

18-82 
19-44 

+  0'62 

684 


SCIENCE   PROGRESS 


In  Combination : 


No.  of  atoms  n. 

Alloy. 

M.P. 

+  A. 

Solid. 

Liquid. 

n  x  '44. 

2      . 

j     •                  • 

4  • 

5  .        .        .        . 

13    ... 

SnPb 

Sn.,Pb 

Sn3Pb 

Sn4Pb 

Sn,.,Pb 

35-02 

5I"36 
67-63 
84-10 

216-8 

35'4o 
52-65 
69-81 
86-34 

221*9 

+  0*38 
+   1*29 
+   178 
+  2-24 

+  5'io 

3  x  °"43 

4  x  o'44 

5  x  0-45 
13  x  0-39 

The  Table  shows  conclusively  that  the  augmentations  in  volume 
on  liquefaction  depend  on  the  number  of  atoms.  The  expan- 
sion is  the  same  for  a  Pb  as  for  a  Sn  atom,  for  Sn  =  Pb  =  +  0*44 ; 
but  in  the  free  state  they  are  different,  for  Sn  =  +  0*49  and 
Pb  =  +  0*62.  A  modification  of  this  space  augmentation  per 
atom  has  occurred,  in  a  similar  manner  to  the  variation  or 
modification  of  the  M.P.  on  combination.  That  there  has  been 
an  alteration  in  the  volume  of  each  atom  individually,  and  not 
an  indirect  variation  due  to  the  change  in  the  amount  of  play 
space  of  the  whole  molecule,  seems  very  probable. 

A  study  of  the  amounts  of  heat  absorbed  by  100  grammes  of 
the  substance  as  the  temperature  has  been  raised  from  ioo°  to 
3600  has  been  shown  by  Spring  {Bull.  Acad.  Belg.  [3],  11,  355, 
1886)  to  be  greater  than  that  absorbed  by  an  amount  of  matter 
in  the  free  state  equivalent  to  the  sum  of  the  constituents.  The 
excess  varies  with  the  composition.  The  results  may  be  ex- 
plained by  assuming  that  the  metals  form  unstable  compounds, 
which,  on  being  heated,  break  down  into  their  constituents. 
The  result  of  Magies'  work  on  "  Specific  Heats  "  {Bull,  of  Amer. 
Phys.  Soc,  April  27, 1 901)  greatly  favours  our  view  of  the  question, 
for  even  in  solution  salt  molecules  and  ions  are  able  to  exert  an 
attracting  influence  on  molecules  of  the  solvent  for  some  con- 
siderable distance,  so  that  possibly  complex  aggregations  of 
molecules  about  the  ions  result. 

If  this  be  so,  the  Additive  rule  already  noticed  is  independent 
of  whether  the  substance  is  solid  or  liquid,  or  whether  the  atoms 
are  associated  or  dissociated. 


Modifications  in  Volume  associated  with  Physical  Changes  in 

Compounds 

It  is  extremely  probable  that  ma^r  differences  occur  in  the 
nature   of    alloys    which   are   indicated    by   their   thermal   and 


MOLECULAR  VOLUME 


685 


electrical  properties.  So  too  do  molecular  volumes  show  con- 
clusively that  changes  have  taken  place.  Several  writers  show 
this  to  be  the  case  by  summing  up  the  A.V.'s  in  the  free  state 
and  finding  out  the  nature  of  the  differences,  M.V.  —  5"Va. 
This  certainly  indicates  that  changes  have  taken  place,  but  we 
are  left  in  the  dark  regarding  the  nature  of  such  changes.  This, 
no  doubt,  is  because  these  writers  are  unwilling  to  make  the 
assumption  that 

M.V.  =  S(A.V.) 

Thus  E.  Vanstone,  in  a  paper  entitled  "  A  Physico-chemical 
Study  of  the  Mercury-sodium  Alloys  or  Amalgams,"  and  read 
before  the  Faraday  Society,  March  14,  191 1,  gives  data  which 
show  the  existence  of  the  compounds  Na3Hg,  Na3Hg2,  NaHg, 
Na7Hg8,  NaHg2,  and  NaHg4  as  crystalline  solids.  Volumetric 
evidence  is  here  given  that  they  are  divisible  into  two  classes. 
The  first  four  are  additive  as  regards  volume,  and  made  up  from 
the  combined  volumes  of  Na  =  21*64  and  Hg  =  9*04.  The  free 
values  are  Na  =  23*786  and  Hg  =  1476.  Na  thus  contributes 
23*786  —  21*64  =  — 2*146  to  the  contraction,  and  Hg  14*76  — 
904  =  —  5*72,  per  gramme  atom. 

The  remaining  compounds,  NaHg2  and  NaHg4,  are  different. 
The  columns  marked  *  are  additional  to  those  given  by  the 
author  of  the  paper  (E.  Vanstone),  and  are  based  upon  the  prin- 
ciples set  forth  in  the  present  one  : 


M.P.  compound. 

M.V. 

2(A.V0* 

2A.V2  (free). 

M.V-  2A.V. 

Calc* 

Na3Hg    . 
Na3Hg2   . 
NaHg     . 
Na7Hg8  . 

73'97 
83*01 

3° '99 

221*88 

73'96 

83  OO 

30-68 

223-80 

86*12 
100*87 

38-54 
284-57 

-  12*14 

-  17*86 

-  7-54 

-  62*69 

-  12*14 

-  1786 

-  786 

-  60-74 

The  observed  and  calculated  values  agree  so  well,  that  it  cannot 
be  doubted  that  the  explanation  given  of  the  reason  for  the 
changes  in  volume  is  the  correct  one. 

The  combined  volume  of  Na  is  very  similar  to  that  in  the 
free  state,  but  the  free  and  combined  volumes  of  mercury  are 
very  different. 

In  the  next  group  the  state  of  things  is  very  different : 

M.P.  [NaHg2]  43*14  =  3  x  14*38 

M.P.  [NaHg4]  =  [NaHg]  .  3Hg  =  30*99  +  3  x  14*38  =  74-13 

Observed  74-07 


686 


SCIENCE  PROGRESS 


In  the  first  case  Hg  seems  to  impose  its  value  on  Na,  and  in  the 
second  there  seems  to  be  association  of  NaHg  in  the  former 
with  three  atoms  of  mercury. 

The  M.P.'s  show  that  NaHg2  is  quite  different  from  all  the 
others,  because  its  M.P.  is  considerably  higher  than  those  of 
NaHg  and  NaHg4,  whereas  it  should  be  intermediate. 

It  is  evident  from  this  that  considerable  modifications  of  the 
free  atomic  volumes  can  occur,  even  in  such  loose  combinations 
as  alloys,  and  that  in  spite  of  such  changes  the  Additive 
Principle  holds. 

(ii)  The  Chlor-Brom-Iodides  of  Silver,  which  have  been  studied 
by  Rodwell  {Phil.  Trans.  1882,  1140),  present  some  remarkable 
examples  of  the  modification  of  volumes  in  conformity  with  a 
simple  numerical  relationship. 

We  give  first  of  all  the  following,  which  illustrate  the  prin- 
ciple of  addivity  without  great  modification  of  the  free  values 
(Rodwell,  Phil.  Trans.  1882,  1160). 


Compound. 

vm. 

2A.V. 

2C11I  .  Agl      .... 

107*1 

107-1 

2C11I  .  2AgI    .... 

148-4 

148-4 

2C11I  .  3AgI   .... 

189-6 

189-7 

2C11I  .  4AgI   .... 

231-1 

231-0 

2C11I  .  I2AgI 

561-8 

561-4 

The  combined  volumes  of  Cul  and  Agl  are  respectively  32-9 
and  41-3. 

Free  Volumes: 

Cul  33-3        Agl  415 
The  volumes  of  both  are  diminished  slightly  in  the  above  com- 
binations, but  the  volumes  are  perfectly  additive. 

As  before  stated,  great  modifications  can  occur,  either  so  as 
to  conform  with  some  simple  spatial  relation,  or  even,  as  in  the 
case  of  the  amalgams  previously  studied,  in  what  seems  an 
arbitrary  manner. 

They  may  be  studied  at  o°  and  at  their  respective  M.P.'s. 

The  data  for  the  free  simple  salts  are : 


Compounds. 

V0 

v 

M.P. 

AgCl    .... 
AgBr   .... 
Agl       .... 

26-07 

30'  14 
41-52 

29-I7 
33*60 

44*59 

451 
427 

527 

Rodwell,  P.  T. 
1182         1125 

MOLECULAR  VOLUME 
If  we  tabulate  the  Chlor-Brom-Iodides  we  find 


687 


Compounds. 

V0 

2A.V. 

v 

mp 

M.P. 

Agl  .  2AgBr  .  2AgCl 
Agl  .  AgBr  .  Agl 
2AgI  .  AgBr  .  Agl 
3AgI  .AgBr.  Agl       . 
4AgI  .  AgBr  .  Agl       . 

147*6 
92*56 
123*25 
173*6 
215*2 

i53'94 
97-73 
i39'25 
18077 
222*29 

l62*9 

ior8 
140-7 

183-5 
223*9 

383 

331 
326 

354 
380 

The  volumes  at  o°  show  considerable  changes,  as  judged  by 
the  differences  V0  —  2A.V.,  but  these  cannot  be  made  out  at 
this  point.  Probably  there  is  considerable  heterogeneity  in  the 
composition  of  the  substances. 

At  the  M.P.'s  the  results  are,  however,  surprisingly  regular. 

Rodwell's  Chlor-Brom-Iodides  at  the  M.P. 


Substance. 

M.P. 

V 

•  mp 

n 

n  x  2o'36. 

i  Agl  .  2AgBr.2AgCl 

2  Agl.  AgBr.  AgCl  . 

3  2AgI  .  AgBr  .  AgCl 

4  3AgI  .  AgBr  .  AgCl 

5  4AgI  .  AgBr  .  AgCl        . 

383 
331 

326 

354 
380 

162*9 

ioi-8 
140-7 

I83-5 
223*9 

8 

5 
7 

9 
11 

8  x  20*36  =  162-9 
5  x  20*36  =  101*8 
7  x  20*36  =  142*5 

9  x  20-36  =  183*2 
11  x  20*36  =  2239 

A  (1)  —  (2)  =  AgBr  +  AgCl   6i*i  —  3  x  20-36  =      6ri 
A  (4)  —  (2)  =  3AgI  i22'i  —  6  x  20*36  =  121*1 

Thus  Ag  I  =  2  x  20*36  Ag  Br  =  2  x  20*36  and  AgCl  =  1  x  20*36. 

These  three  Halogen  Compounds  of  Silver  in  the  above  complex 
compounds  possess  volumes  which  stand  to  each  other  in  the 
simple  relationship  of 

Ag  I :  AgBr  :  AgCl  =  2:2:1. 
This  occurs  at  the  M.P.     We  note  that 

Vol.  of  Agl  at 

o°d  -5673  is  41*42 
max.  dens.  1630  d  '5771  is  40*72  =  2  x  20*36 
mol.  den.    527    d  '5522  is  42*56 

This  compound  diminishes  in  volume  from  o°  to  1630,  and  then 
increases  to  the  M.P. 

It  is  thus  remarkable  that,  in  combination  at  the  M.P.,  the 
volume  of  Agl  is  the  same  as  its  volume  at  the  maximum 
density  when  free.     Not  only  is  this  the  case,  but  Agl  imposes 


688 


SCIENCE   PROGRESS 


its  volume  on  AgBr  and  AgCl.     The  considerable  differences 
met  with  at  o°  are  thus  easily  understood. 

The  half  of  20*36  (io'iS)  is  very  similar  to  the  volume  of  Ag 
in  the  solid  state,  so  that  we  must  attribute  to  CI,  Br,  or  I  this 
volume  or  one  twice  as  great.  Since  Ag  and  the  Halogens  are 
typically  monovalent,  we  have  perhaps  here  an  example  of 
the  operation  of  Barlow  and  Pope's  Valency  Law. 


The  Effect  of  Physical  Modification  in  Solid  State  on  the  A.V. 

In  the  solid  state  we  find  that  differences  in  physical  modi- 
fication affect  the  atomic  volumes.  This  is  well  illustrated  by  a 
number  of  Complex  Felspars,  studied  by  Day  and  Allen  of  the 
U.S.  Geological  Survey  {The  Isomorphism  and  Thermal  Proper- 
ties of  Felspars,  Part  I.). 

Volumes  of  Certain  Complex  Felspars 


Felspar 
Anorthite  An. 

M.P. 

M.V.  (cryst.) 

2V. 

M.V.  (glass). 

sv. 

{Al,Ca(Si04)J       . 

1532 

IOO76 

,. 

IO3T9 

_ 

AbiAn5 

1500 

605-9 

605-3 

626T 

626-4 

Ab,An2 

H63 

302*6 

302-5 

3I6-5 

316-7 

Ab,Am 

1419 

20I '9 

2017 

2I3-8 

2i3'5 

AbaAni 

1367 

3°2'4 

302-4 

323'9 

323"9 

Ab3Ani 

I340 

402-9 

4037 

434'2 

434'3 

Albite  Ab    . 

— 

100-92 

— 

110-37 

(AlNaSi308) 

In  the  case  of  both  crystalline  and  glassy  varieties  the  additive 
law  strictly  holds — the  volumes  of  the  Simple  Felspars  being 
preserved  in  the  Complex  Felspars.  In  the  glassy  state  we  may 
suppose  that  amorphous  structure  is  the  true  one,  and  in  the 
crystalline  varieties  we  have  orientation  of  the  molecules.  This 
arrangement  of  the  molecules,  although  it  involves  a  certain 
amount  of  compression  as  compared  with  those  which  show 
want  of  arrangement,  yet  does  not  prejudice  the  principle  of 
additivity.  If  molecular  interspaces  existed  this  would  not  be 
so.  We  must  suppose  that  in  the  amorphous  condition  the 
structure  is  compact  in  the  sense  already  stated,  because  the 
vibrating  atoms,  held  together  by  the  forces  of  affinity,  fully 
occupy  the  space.  When  arrangement  of  the  molecules  takes 
place,  owing  to  the  action  of  intermolecular  forces,  it  may  well 
be  that  the  molecules  are  in  the  most  favourable  position  for 


MOLECULAR  VOLUME  689 

the  action  of  these  forces,  so  that  there  results  a  certain  com- 
pression. This  in  the  first  instance  affects  the  Simple  Felspathic 
constituents,  but  ultimately  the  constituent  atoms  also. 

It  follows  that  the  individual  atoms  have  different  volumes  in 
the  two  modifications,  owing  to  the  difference  in  the  constraint 
imposed  by  the  attracting  forces. 

We  can  speak  of  a  crystalline  atom  and  a  glassy  atom,  for 
they  are  different.  Crystalline  and  glassy  modifications  of  sub- 
stances have  their  origin  in  the  peculiarities  of  intermolecular 
forces.  These  are  in  reality  residual  affinities  due  to  the  atomic 
constituents  of  the  molecules  and  their  special  arrangements. 
We  are,  consequently,  led  to  look  for  the  ultimate  cause  of  physical 
modifications  in  the  nature  and  arrangement  of  the  atoms. 

In  conclusion  we  see  that  a  study  of  the  Molecular  Volumes 
of  Substances  gives  us,  as  it  were,  an  external  view  of  the 
structures.  From  the  peculiarities  noticed,  by  a  process  of 
analysis  of  the  data  for  known  substances,  we  proceed  induc- 
tively to  arrive  at  conclusions  concerning  the  internal  conditions 
and  the  modes  of  arrangement  of  the  atoms  in  the  molecules. 
By  the  opposite— or  deductive — method  R.  Kleeman  {Phil.  Mag. 
vi.  19,  840-46)  has  recently  studied  the  question.  This  author 
concludes  that  the  range  of  action  of  the  molecular  forces  is 
equal  to  the  distance  between  the  molecular  centres.  The 
molecules  are  thus  strongly  attracted.  In  opposition  to  these, 
the  kinetic  heat-forces  act.  By  supposing  that  the  intervening 
space  is  occupied  by  matter,  then  owing  to  the  extensive  motion 
of  the  vibrating  atoms  the  resistances  to  compression  which 
Richards  has  studied  would  be  represented  by  the  mechanical 
resistance  occasioned  by  this  motion.  The  molecular  kinetic 
forces  are  so  far  reduced  as  compared  with  vapours  that  only 
slow  diffusion  is  possible. 


ORGANIC  DERIVATIVES  OF  METALS  AND 

METALLOIDS 

By  PROF.  GILBERT  T.  MORGAN,  D.Sc,  F.I.C.,  A.R.C.S. 

Royal  College  of  Science  for  Ireland,  Dublin 

Taken  in  its  widest  sense,  the  title  of  this  paper  x  embraces  a 
very  large  and  miscellaneous  series  of  substances  divisible  into 
several  distinct  classes.  For  since  carbon  is  the  essential  element 
of  all  organic  compounds,  there  should  fall  within  the  category 
of  organic  derivatives  of  metals  and  metalloids  all  those  combina- 
tions which  contain  carbon  in  direct  association  with  these 
elements.  The  scope  of  the  present  paper  is,  however,  restricted 
to  a  consideration  of  the  compounds  containing  not  merely 
carbon  but  the  carbon  of  hydrocarbon  radicals.  This  restriction 
at  once  excludes  two  very  important  classes  of  substances  which 
would  otherwise  deserve  special  reference.  The  first  of  these 
classes  is  that  of  the  metallic  carbides,  an  outcome  of  Moissan's 
famous  researches  on  the  electric  furnace,  of  which  calcium 
carbide  is  the  best  known  example.  The  other  class  includes 
the  metallic  carbonyl  derivatives  which  were  discovered  by 
Mond,  who  made  use  of  the  remarkable  properties  of  nickel 
carbonyl  in  the  technical  production  of  pure  nickel. 

The  substances  discussed  in  the  sequel  contain  a  metal  or 
metalloid  combined  with  one  or  more  hydrocarbon  radicals,  and 
for  the  purpose  of  this  paper  the  hydrocarbons  themselves,  com- 
pounds consisting  entirely  of  carbon  and  hydrogen,  may  be 
illustrated  by  the  following  two  types :  the  paraffins  with 
methane  CH4,  ethane  C2Ha,  and  propane  C3H8,  as  simplest 
members,  and  the  aromatic  hydrocarbons  represented  by 
benzene  C6H6. 

The  paraffinoid  or  alkyl  radicals  are  methyl  CH3,  ethyl  C2H5, 
propyl  C3H5,  and  generally  CnH2n+i,  obtained  by  removing  one 
hydrogen  from  the  paraffin  hydrocarbon  itself.     These  radicals 

1  This  paper  formed  the  subject  of  the  opening  address  to  the  Dublin  University 
Experimental  Science  Association  delivered  on  November  11,  1913. 

690 


METALS  AND   METALLOIDS  691 

do  not  exist  in  the  free  state,  but  can  pass  from  one  compound  to 
another  in  chemical  interchanges. 

The  typical  benzenoid  or  aryl  radical  is  phenyl  C6H5,  obtained 
by  the  abstraction  of  one  hydrogen  from  the  aromatic  hydro- 
carbon, benzene.  This  radical,  again,  is  only  known  in  combina- 
tion. 

Perhaps  in  passing  I  should  attempt  to  define  the  inorganic 
portion  of  my  title.  The  metals  are  those  elements  which  can 
function  as  simple  cations  in  electrolysis  and  which  do  not 
furnish  volatile  hydrides,  i.e.  compounds  with  hydrogen.  The 
metalloids  are  a  small  group  of  elements  having  certain  metallic 
characteristics  and,  in  addition,  the  property  of  yielding  vaporis- 
able  hydrides  like  the  non-metals.  Arsenic,  antimony,  and 
tellurium  may  be  regarded  as  metalloids,  and  possibly  also 
boron  and  selenium,  although  the  last  two  are  much  more  closely 
allied  to  the  non-metals  than  to  the  metals. 

In  many  instances  chemical  research  has  progressed  along 
utilitarian  lines.  The  employment  in  medicine  of  various  plant 
extracts  has  encouraged  investigations  on  alkaloids  and  other 
active  products  of  vegetable  life.  The  art  of  dyeing  has  led  to 
the  study  of  natural  and  artificial  colouring  matters,  lakes,  and 
mordants.  But  the  activities  of  pioneers  have  never  been 
restricted  by  purely  utilitarian  considerations,  and  if  science  is 
to  continue  its  healthy  and  beneficial  growth  it  is  to  be  hoped 
that  these  activities  will  always  be  afforded  the  widest  scope. 
Many  laboratory  investigations,  at  first  apparently  quite  devoid 
of  any  practical  utility,  have  led  to  results  of  fundamental 
importance  from  both  the  theoretic  and  practical  standpoints. 
The  pioneering  experiments  of  Cavendish  on  the  fixation  of 
atmospheric  nitrogen  is  a  classical  example,  and  I  hope  to 
show  that  the  early  study  of  organic  derivatives  of  metals  and 
metalloids  is  another  case  in  point.  Of  no  branch  of  human 
activity  can  it  be  predicted  with  greater  certainty  than  of 
chemistry,  "  Cast  thy  bread  upon  the  waters  and  thou  shalt 
find  it  after  many  days." 

1.  Early  Researches 

So  singular  are  the  properties  of  the  first  discovered  organo- 
metallic  compounds  that  in  taking  up  their  study  chemists 
appeared  to  be  turning  their  backs  on  the  realities  of  ordinary 
terrestrial  phenomena.    It  would  tax  the  genius  of  a  Jules  Verne 


692  SCIENCE  PROGRESS 

or  a  Wells  to  conceive  a  world  in  which  these  substances  might 

form  the  materials  of  everyday  life.     Many  of  them  are  intensely 

poisonous,  others  are  decomposed  by  traces  of  moisture,  and 

others  again  are  spontaneously  inflammable  or  even  explosive 

in  air. 

Cacodyl  Derivatives 

The  first  worker  in  this  field  was  Bunsen,  who  during  the 
period  1837 — 1843  undertook  the  study  of  organic  derivatives  of 
arsenic.  It  had  long  been  known  that  by  distilling  a  mixture 
of  white  arsenic  (arsenious  oxide)  and  potassium  acetate  a  fuming 
oily  liquid  was  obtained  having  very  poisonous  properties  and  a 
most  disagreeable  odour.  This  uninviting  product,  known  as 
Cadet's  liquid,  was  examined  systematically  by  Bunsen,  who 
showed  that  the  pungent  constituents  of  the  mixture  were  two 
substances  containing  arsenic. 

The  main  constituent  contained  the  metalloid  associated 
with  carbon,  hydrogen,  and  oxygen ;  the  compound  present  in 
smaller  amount  consisted  of  the  three  elements,  arsenic,  carbon, 
and  hydrogen.     Both  compounds  were  extremely  poisonous. 

Bunsen's  analyses  showed  that  the  oxygenated  compound 
had  a  composition  indicated  by  the  formula  As2C4H120.  The 
non-oxygenated  compound  had  the  empirical  formula  AsC2H6, 
but  the  vapour  density  gave  its  molecular  formula  as  As2C4H12. 
The  former  of  these  substances  when  distilled  with  hydrochloric 
acid  yielded  a  volatile  oil  with  the  molecular  formula  AsC2H6Cl, 
and  this  compound,  when  heated  with  zinc  in  an  inert  atmo- 
sphere, lost  its  chlorine  and  became  converted  into  the  compound 
As2v^4.ri12. 

x/VsoC4H120  < As2C4H12 

(02) 

On  examining  the  foregoing  formulae  it  will  be  seen  that 
there  is  a  group  [AsC2He]  common  to  all.  Such  a  group  is  now 
called  a  compound  radical,  and  this  particular  group  was  among 
the  first  compound  radicals  to  be  definitely  recognised. 

At  first  the  group  was 'called  by  Bunsen  alkarsin,  but  later, 
at  the  suggestion  of  Berzelius,  the  name  of  cacodyl  was  adopted. 
This  discovery  of  a  compound  metal  afforded  at  the  time  a 
striking  confirmation  of  the  radical  theory  according  to  which 
organic  substances  are  composed  of  these  groups  or  compound 


METALS  AND  METALLOIDS  693 

radicals  combined  with  elementary  radicals.  Berzelius  wrote 
of  Bunsen's  work,  "  The  research  is  a  foundation  stone  of  the 
theory  of  compound  radicals  of  which  cacodyl  is  the  only  one 
the  properties  of  which  in  every  particular  correspond  with 
those  of  the  simple  radicals." 

The  analogy  between  the  compound  metal,  cacodyl,  and 
two  of  the  metallic  elements,  sodium  and  thallium,  may  be 
illustrated  as  follows : 

Cacodyl.  Cacodyl  oxide.  Cacodyl  chloride. 

As2C4H12  =  [AsC2H6]2  (AsC2H6)20  AsC«>H6Cl 

Kd2  Kd20  KdCl 

Metal.  Metallic  oxide.  Metallic  chloride. 

2Na .  Na20  NaCl 

Tl2  T120  T1C1 . 

From  the  large  series  described  by  Bunsen,  two  other 
cacodyl  derivatives  may  be  selected  for  special  mention.  On 
distilling  cacodyl  oxide  with  mercuric  cyanide  a  well-defined 
crystalline  substance,  cacodyl  cyanide,  was  obtained.  This 
product  is  of  interest,  as  consisting  of  a  combination  of  two 
of  the  first  compound  radicals  (cacodyl  and  cyanogen,  CN)  to  be 
definitely  recognised. 

Kd20  +  Hg(CN)2  =  HgO  +  2Kd .  CN. 

Cacodyl  cyanide  is  a  terribly  poisonous  substance,  a  few 
grains  left  to  evaporate  in  a  large  room  speedily  attack  the 
occupants,  producing  tingling  and  numbness  of  hands  and 
feet,  giddiness  and  finally  unconsciousness.  In  addition  to 
this  disagreeable  property,  the  vapour  of  the  compound  is 
explosive,  and  in  attempting  to  determine  the  vapour  density 
Bunsen  lost  the  sight  of  one  eye.  Nevertheless,  he  persisted 
in  the  investigation  and  left  on  record  a  complete  description  of 
this  deadly  substance. 

Cacodyl  itself  is  spontaneously  inflammable  in  air,  but  if 
allowed  only  a  moderate  amount  of  free  oxygen,  or  preferably  if 
oxidised  with  moist  mercuric  oxide,  it  changes  successively  into 
cacodyl  oxide  Kd20  and  then  to  an  extremely  soluble  compound 
Kd  O .  OH  which,  having  acidic  properties,  is  termed  cacodylic 
acid.  When  compared  with  the  cacodyl  derivatives  already 
mentioned,  it  may  seem  extraordinary  that  this  oxidised  com- 
pound, although  containing  54  per  cent,  of  soluble  arsenic,  is 
nevertheless  non-poisonous.  Bunsen  first  observed  this  differ- 
ence in  1843,  and  his  observation  remained  fallow  until  seventy 


694  SCIENCE  PROGRESS 

years  afterwards,  when  in  191 3  Ehrlich  unfolded  to  the  Seven- 
teenth International  Congress  of  Medicine  assembled  in  London 
his  wonderful  story  of  the  therapeutic  application  of  the  organo- 
arsenic  compound  "  salvarsan  "  or  "  606." 

Cacodylic  acid,  in  the  form  of  its  sodium  salt,  has  been 
suggested  for  medicinal  use,  but  at  present  it  is  largely  super- 
seded by  arsenical  preparations  based  on  atoxyl. 

It  should   be   pointed    out    that   at    the   time    of  Bunsen's 

researches  the  hydrocarbon  radicals  themselves  had    not  been 

recognised.      Subsequent    researches     by    Kolbe,     Frankland, 

Cahours,  v.  Baeyer  and  others  elucidated  the  inner  constitution 

of  cacodyl,  and  it  is  now  known  that   this   compound   radical 

consists  of  tervalent  arsenic  associated  with  two  methyl  radicals: 

CH3x  /CH3  CH3x 

>As  -  As<  >As  -  CI 

ch/  N:h3  CH/ 

Cacodyl  b.p.  1700.  Cacodyl  chloride  b.p.  1090. 

CH3x  /CH3  CH3x        ,.0 

>As  -  O  -  As<  >As/ 

ch/  x:h3        ch/     xoh 

Cacodyl  oxide  b.p.  120°  Cacodylic  acid. 

In  all  these  compounds  but  the  last  the  arsenic  is  tervalent ;  in 
cacodylic  acid  it  is  quinquevalent. 

Cahours  found  that  an  alloy  of  arsenic  and  sodium  when 
heated  with  methyl  iodide  yielded  cacodyl  and  another  arsenical 
compound,  trimethylarsine  (I)  containing  arsenic  associated  with 
three  methyl  groups.  This  substance  gives  rise  to  a  large 
number  of  derivatives,  of  which  I  shall  only  mention  two. 

The  direct  addition  of  methyl  iodide  yields  a  salt-like 
compound,  tetramethylarsonium  iodide  (II.),  and  from  this  product 
by  the  action  of  moist  silver  oxide  one  obtains  the  base 
tetramethylarsonium  hydroxide  (III.),  which  is  a  strong  caustic 
alkali  having  properties  resembling  those  of  potassium 
hydroxide  : 

CH3X  CH3v        yCH3  CH3\       yCH3 

CHa>-CH,     -*     CH3)As/  -     CH:7A<qh 

I.  II.  HI. 

Zinc  and  Mercury  Alky  Is 
A  few  years  after  Bunsen's  investigations  E.  Frankland  found 
that  on  heating  the  alkyl  iodides  with  zinc,  especially  when  the 
metal  is  rendered  more  active  by  the  addition  of  a  small  amount 


METALS   AND   METALLOIDS  69$ 

of   sodium,   the  iodine   and  alkyl   radicals   became   separately 
attached  to  zinc : 

2C2H5I  +  2Z11  =  Znl2  +  Zn(C2H5)2. 

Zinc  ethyl  is  a  liquid  boiling  at  1 180  and  solidifying  at  —  280 ; 
it  is  spontaneously  inflammable  in  air,  and  is  decomposed 
violently  by  water.  It  is  a  remarkably  energetic  substance 
and  a  most  valuable  reagent  in  research,  as  it  reacts  with  a  great 
variety  of  inorganic  or  organic  materials. 

The  organo-mercury  derivatives  next  discovered  were  pre- 
pared either  through  the  agency  of  zinc  alkyls  or  directly  by 
the  action  of  alkyl  iodides  on  sodium  amalgam : 
Hg(2Na)  +  2C2H5I  =  2NaI  +  Hg(C2H5)2. 

With  zinc  ethyl  and  mercuric  chloride  an  intermediate 
compound  is  formed : 

2HgCl2  +  Zn(C2H5)2  -  ZnCla  +  2Hg(C2H5)Cl. 
This  mercury  ethyl  chloride  gives  rise  to  an  iodide  in  which 
moist  silver  oxide  replaces  iodine  by  hydroxyl.  The  product, 
mercury  ethyl  hydroxide,  is  a  strongly  caustic  base  like  potassium 
hydroxide ;  it  liberates  ammonia  from  ammonium  salts,  and 
precipitates  alumina  and  other  metallic  oxides  from  their 
soluble  salts. 

By  the  agency  of  the  zinc  and  mercury  alkyls  it  has  been 
found  possible  in  many  instances  to  combine  the  alkyl  radicals 
with  other  metals,  but  the  reaction  is  by  no  means  general,  and 
some  metals  have  not  as  yet  yielded  organo-metallic  derivatives. 
It  might  therefore  be  profitable  at  this  stage  to  consider  in 
which  cases  favourable  results  are  obtained. 

2.  The  Position  of  Elements  in  the  Periodic  Scheme  in 
Relation  to  their  Capacities  for  Forming  Organic 
Derivatives 

The  periodic  classification  due  to  Newlands  and  Mendeleef 
is  now  too  well  known  to  need  detailed  description.  It  is  based 
on  the  principle  that  the  physical  and  chemical  properties  of 
the  elements  are  periodic  functions  of  their  atomic  weights. 
Starting  with  the  elements  of  least  atomic  weight,  excluding 
hydrogen,  it  is  found  that  during  two  periods  recurrence  occurs 
at  the  ninth  element,  subsequently  the  periodicity  becomes 
doubled,  but  nevertheless  all  the  elements  can  be  arranged  in 
eight  vertical  series,  each  of  these  vertical  series  being  divisible 

45 


696  SCIENCE  PROGRESS 

into  two  natural  families,  the  successive  members  of  which  occur 
alternately. 

The  most  rational  way  of  representing  the  arrangement  is 
not  on  a  sheet,  but  on  a  cylinder  or  octagonal  prism.  A  spiral 
or  solid  helix  is  traced  down  the  cylinder  or  prism,  each  turn 
of  the  screw  corresponding  with  the  addition  of  eight  or  ten 
elements  arranged  in  their  appropriate  vertical  columns. 

The  doubling  of  the  periodicity  indicated  by  Mendeleef 
leads  to  the  arrangement  of  two  natural  families  in  each  vertical 
series.  Let  us  examine  a  pair  of  these  related  families  as  re- 
gards their  capacities  for  yielding  organic  derivatives. 

(a)  The  Silicon  Family 

It  will  be  most  convenient  to  start  with  the  fourth  vertical 
series.  Here  we  find,  as  the  initial  member,  carbon  itself,  the 
essential  element  of  organic  compounds.  Following  this'element 
is  silicon,  which  exhibits  certain  points  of  resemblance,  but  also 
many  points  of  difference. 

Silicon  is  followed  successively  by  titanium  and  germanium, 
and  the  question  arises  which  of  these  is  to  be  placed  in  the 
same  family  as  silicon. 

Germanium  and  tin,  the  next  metal  of  the  series,  resemble 
silicon  in  forming  feebly  acidic  hydroxides  existing  in  colloidal 
forms ;  their  oxides  have  the  same  general  formula  R02  as  silica, 
and  they  yield  volatile  chlorides  RC14  decomposable  by  water. 

Titanium  and  zirconium  also  resemble  silicon  in  many  of 
their  naturally  occurring  compounds ;  they  likewise  form  feebly 
acidic  gelatinous  hydroxides  and  yield  volatile  chlorides  and 
bromides  decomposed  by  water. 

Silicon  evidently  has  affinities  with  both  series,  but  the  best 
criterion  of  relationship  is  the  capacity  for  forming  organic 
derivatives.  This  non-metal  readily  yields  organic  derivatives, 
and  a  large  number  of  these  compounds  have  been  described 
by  Friedel,  Ladenburg,  Emerson  Reynolds,  and  more  recently 
by  Kipping. 

Titanium  and  zirconium  have,  however,  evaded  all  attempts 
to  combine  them  with  hydrocarbon  radicals ;  they  are  found 
directly  associated  with  carbon  in  their  carbides,  but  these 
compounds  are  excluded  from  the  present  consideration. 

Turning  to  the  germanium-tin  series,  we  find  that  all  the 
elements  of  this  group  yield  organic  derivatives,  and  this  pro- 


METALS  AND  METALLOIDS  697 

perty  forms  the  distinctive  family  trait  for  this  group  of  elements, 
in  which  we  may,  by  straining  a  point,  include  carbon,  since 
this  element  is  known  to  possess  in  the  highest  degree  the 
property  of  combining  with  hydrocarbon  radicals.  Hence  the 
fourth  vertical  series  of  the  periodic  scheme  may  be  divided 
into  two  families,  the  former  of  which  yields  organic  derivatives 
but  the  latter  does  not : 

Silicon  family      .     C  Si  Ge  Sn  Pb 

Titanium  family .  Ti  Zr  Ce  Th 

It  will  be  sufficient  to  consider  the  following  two  series  of 
alkyl  derivatives  to  see  the  family  likeness  of  the  five  members 
of  the  silicon  family  : 


c 

Si 

Ge 

Sn 

Pb 

C(CH3)4 

Si(CH3)4 

— 

Sn(CH3)4 

Pb(CH3)4 

b.p  +  9S° 

30-31° 

— 

78° 

no° 

— 

Si(C2Hs)4 

Ge(C2H5)4 

Sn(C2H5)4 

Pb(C2H5> 

b.p 

iS3° 

160° 

1810 

200 

The  first  member  of  the  series,  C(CH3)4,  regarded  from  our 
present  standpoint  as  an  organic  derivative  of  carbon,  is  a 
hydrocarbon  of  the  paraffin  series,  but  it  does  not  occur  in 
mineral  oils.  Like  its  homologues,  the  organo-metallic  com- 
pounds of  tin  and  lead,  it  is  produced  through  the  agency  of 
zinc  methyl,  the  other  reagent  in  this  instance  being  the 
dichloride  of  the  well-known  solvent  acetone,  (CH3)2CO  : 

(CH3)2  CC12  +  Zn(CH3)2  =  ZnCl2  +  C(CH3)4. 

Similarly  silicon  tetramethyl  and  tetrethyl  are  produced  by 
the  interaction  of  zinc  alkyls  and  silicon  tetrachloride.  Tin 
tetramethyl  is  obtained  from  methyl  iodide  and  an  alloy  of 
tin  and  sodium.  Lead  tetramethyl  and  tetrethyl  are  prepared 
by  the  general  process  from  the  zinc  alkyls  and  lead  chloride. 
It  is  interesting  to  note  the  exaltation  in  the  valency  of  lead 
produced  in  these  condensations  : 

II.  IV. 

2PbCl2  +  2Zn(CH3)2  =  Pb  +  2ZnCl2  +  Pb(CH3)4. 

Silicon,  tin,  and  lead  yield  also  organic  derivatives  containing 
aryl  radicals. 

By  surrounding  silicon  or  tin  with  four  dissimilar  radicals, 
three  being  organic  groups,  it  has  been  demonstrated  that  the 
product  is  a  racemic  combination  containing  two  optically  active 
components  related  to  one  another  as  object  and  image. 


698  SCIENCE  PROGRESS 

The  case   of  silicon  was  worked    out  by  Kipping  on   the 
sulphonic  acid  of  benzylethylpropylsilicyl  oxide  : 

C2H5 

O 


SO3H  .  C6H4  .  CH2 .  Si . 

C8H7J. 


by  crystallising  the  salts  of  this  acid  with  optically  active  d- 
and  /-methylhydrindamines.  Pope  and  Peachy  demonstrated 
the  case  of  tin  with  the  compound  methylethyl-w-propyl- 
stannic  iodide,  the  dextrorotatory  component  being  isolated 
through  the  agency  of  */-camphorsulphonic  acid. 

This  resolution  of  silicon  and  tin  asymmetric  compounds 
into  optically  active  components  shows  that  these  compounds 
have  the  tetrahedral  structure  characteristic  of  carbon  com- 
pounds, and  that  in  all  probability  the  above  series  of  tetra- 
alkyl  derivatives  are  all  constituted  on  the  tetrahedral  type. 

Such  relationships  as  these  afford  ample  justification  for 
including  carbon,  silicon,  germanium,  tin,  and  lead  in  the 
same  natural  family. 

The  points  of  difference  between  carbon  and  silicon  are 
also  illustrated  by  investigations  of  the  organic  derivatives  of 
the  latter.  Kipping  and  Robison  showed  that  silicones  differed 
from  the  ketones  in  having  polymerised  molecules ;  they  worked 
this  difference  out  in  the  case  of  benzyl  ethyl  silicone,  which 
has  a  trimeric  molecule 


[ 


CeHs .  CH2\  — l 


/SiO 

C2H5/       J 


3 


unlike  the  non-polymerised  molecule  of  the  ketones  RR'CO. 
This  fact  helps  to  explain  the  difference  between  the  refractory 
solid  oxide,  silica  [Si02]x,  and  the  gaseous  carbon  dioxide  C02. 

(b)  The  Aluminium  Family 

The  third  vertical  series  is  similarly  divisible  into  two  natural 
families,  and  taking  again  the  capacity  for  forming  organic 
derivatives  as  the  important  criterion  of  relationship,  we  find 
that  boron,  the  initial  member  of  the  series,  falls  into  line  with 
aluminium  and  its  homologues  in  yielding  organic  derivatives  : 

Aluminium  family  .     B  Al  Ga  In  Tl 

Rare  earth      „  Sc  Y  La,  etc. 

The  other  family  containing  scandium,  yttrium,  and  some 
other    twelve    or  thirteen   elements   of   the   rare   earth   series 


METALS  AND  METALLOIDS  699 

including  lanthanum,  do  not  give  rise  to  organo-metallic 
derivatives.  In  this  vertical  series,  therefore,  as  in  the  fourth, 
the  two  families  show  very  different  capacities  for  forming 
compounds  containing  hydrocarbon  radicals. 

The  boron  compounds  with  alkyl  radicals  are  produced 
by  the  general  method  from  zinc  alkyls  : 

2BCI3  +  3Zn(C2H5)2  -  3ZnI2  +  2B(C2H5)3. 

The  corresponding  boron  trimethyl  is  made  by  similar  means 
from  ethyl  borate. 

These  alkyl  boron  compounds  are  possessed  of  somewhat 
remarkable  properties,  one  might  even  say  inconvenient  pro- 
perties, regarded  from  the  standpoint  of  the  conventional  theories 
of  valency.  The  existence  of  the  great  majority  of  boron  com- 
pounds can  be  readily  explained  on  the  assumption  that  the 
element  is  uniformly  tervalent,  corresponding  with  the  chloride 
BCI3  and  the  oxide  B2Os.  But  if  this  degree  of  combining 
power  represented  all  the  chemical  affinity  possessed  by  boron, 
then  the  boron  trialkyls  should  be  as  inert  as  the  paraffins, 
for  example,  tertiary  pentane  (carbon  tetramethyl,  C(CH3)4),  in 
which,  as  we  have  already  seen,  the  carbon  is  surrounded  by 
four  methyl  radicals  situated  at  the  apices  of  a  regular  tetra- 
hedron containing  the  carbon  atom  at  its  centre.  The  boron 
trialkyls  behave,  however,  as  highly  unsaturated  compounds ; 
they  combine  additively  with  ammonia,  and  are  readily  absorbed 
by  the  caustic  alkalis.  The  compound  [B(CH3)3,  NH3]  is 
possessed  of  considerable  stability,  melting  at  510  and  boiling 
at  1100.  The  compound  with  caustic  potash  has  the  composition 
B(CH3)3,  KOH. 

If  instead  of  regarding  valency  as  being  always  entirely 
integral  we  consider  it  as  partly  fractional  and  depending  to 
a  large  extent  on  the  possibilities  of  arrangemert,  we  can  obtain 
an  explanation  for  the  existence  of  these  additive  compounds. 

The  most  symmetrical  mode  of  arranging  three  methyl 
groups  round  a  central  boron  atom  is  at  three  points  1200  apart 
on  a  great  circle  of  the  boron  sphere  of  influence.  This  would 
also  be  the  most  symmetrical  way  of  arranging  the  atoms  in  a 
molecule  of  ammonia.  This  arrangement  is,  however,  less 
symmetric  than  the  tetrahedral  structure  which  could  be  pro- 
duced by  adding  another  associating  unit  to  either  of  these 
molecules.    The  boron  and  the  nitrogen  of  the  ammonia  have 


;oo  SCIENCE  PROGRESS 

sufficient  residual  affinity  to  make  this  addition  possible,  and 
accordingly  rearrangement  occurs  in  both  molecules  with  the 
setting  up  of  the  more  symmetric  tetrahedral  configurations : 

H 


i 


■L   ;•      — > 


Hv  7H 


In  this  additive  compound  the  three  methyl  groups  are  held  in 
position  by  the  principal  valencies  of  the  boron  atom,  while  the 
ammonia  group  is  held  in  position  by  the  mutual  action  of  the 
residual  affinity  of  the  boron  and  nitrogen  atoms. 

The  addition  of  ammonia  to  tertiary  pentane,  C(CH3)4  would 
destroy  and  not  increase  the  existing  symmetry  of  the  molecule, 
and  hence  this  combination  does  not  occur.  In  the  struggle  for 
existence  among  chemical  compounds  the  most  symmetrical 
types  tend  to  survive. 

Boron  combines  with  aryl  radicals,  and  phenylboron  di- 
chloride  results  from  the  interaction  of  boron  trichloride  and 
mercury  diphenyl.  This  dichloride  is  decomposed  by  water, 
3'ielding  phenylboric  acid,  C6H5.  B(OH)2,  which  is  an  antiseptic 
far  more  powerful  than  boric  acid.  Both  acids  are  volatile 
in  steam. 

The  alkyl  derivatives  of  aluminium  obtained  by  the  action 
of  the  metal  on  mercury  alkyls  are  spontaneously  inflammable 
in  air  and  are  at  once  decomposed  by  water  : 

A1(C2H5)3  +  3H20  =  Al(OH)8  +  3C2H6. 

Aryl  derivatives  have  not  been  obtained.1 
Gallium  and  indium  are  extremely  rare  metals,  and  hitherto 
only  alkyl  derivatives  of  the  latter  have  been  studied. 

Thallium  readily  yields  both  alkyl  and  aryl  derivatives  : 

TICI3  +  Zn(C2H5)3  =  ZnCl2  +  T1(C2H5)2C1. 
The  product,  thallic  diethyl  chloride,  can  be  converted  into 

1  Aluminium  triphenyl  has  recently  been  prepared  {Ber.  1912,45,  2828)  from 
aluminium  foil  and  mercury  diphenyl  as  a  very  unstable  solid  decomposed  by 
water  and  not  distillable  even  in  vacuo. 


METALS  AND   METALLOIDS  701 

thallic   diethyl  hydroxide,   T1(C2H5)2.  OH,   a   strongly  alkaline 
base. 

Thallium  diphenyl  bromide,  Tl(C6H6)2Br,  is  an  example  of  an 
aryl  derivative  obtained  through  the  agency  of  the  Grignard 
reaction,  a  process  which  is  explained  in  the  following  section. 

(c)  The  Glucinum  Family 

In  the  vertical  periodic  series  containing  the  typical  bivalent 
metals  we  come  across  a  family  possessing  in  a  very  marked 
degree  the  property  of  yielding  organic  derivatives.  This  is  the 
glucinum  family,  including  zinc  and  mercury,  the  organic 
derivatives  of  which  have  already  been  discussed. 

The  other  natural  family  of  this  series  contains  the  metals  of 
the  alkaline  earths  and  radium  : 

Gl  Mg  Zn  Cd  Hg 

Ca  Sr  Ba  Ra 

The  organic  derivatives  of  calcium  have  been  mentioned  as 
substitutes  for  the  corresponding  compounds  of  magnesium  in 
the  Grignard  reaction,  but  do  not  appear  to  have  met  with  any 
considerable  degree  of  success.  Very  little  is  known  concerning 
the  organic  derivatives  of  strontium  and  barium,  the  metals  of 
the  alkaline  earths  showing  little  or  no  tendency  to  combine 
with  hydrocarbon  radicals.  Radium  is  the  final  member  of  this 
family,  and  it  therefore  seems  unlikely  that  organic  derivatives 
of  this  remarkable  element  will  be  readily  obtained. 

In  the  glucinum  family  cadmium  shows  the  least  tendency 
to  unite  with  hydrocarbon  radicals.  Cadmium  dimethyl  and 
diethyl  have  been  obtained,  but  only  in  very  small  yield  ;  they 
are  fuming  liquids  spontaneously  inflammable  in  air  and 
energetically  decomposed  by  water. 

The  glucinum  compounds  are  prepared  by  the  interaction  of 
this  metal  and  mercury  alkyls.  Glucinum  dimethyl  and  diethyl 
are  fuming  liquids  decomposed  by  water  but  not  spontaneously 
inflammable  in  air. 

The  Grignard  Reagents. — To  the  early  workers  in  this  field 
the  organic  compounds  of  magnesium  did  not  appear  to  be  very 
promising  materials  for  synthetic  purposes.  But  as  the  result  of 
modern  researches,  all  carried  out  within  the  last  thirteen  years, 
the  organo-magnesium  derivatives  have  proved  to  be  the  most 
general  synthetic  agents  hitherto  discovered  in  organic  chemistry. 

In   1899  Barbier  found  that  a  mixture   of  magnesium   and 


7o2  SCIENCE   PROGRESS 

methyl  iodide  in  the  presence  of  dry  ether  behaved  towards 
certain  ketones  in  the  same  way  as  zinc  methyl.  Grignard  took 
up  the  study  of  this  reaction  in  1900  and  discovered  the  impor- 
tant reagents  which  now  bear  his  name. 

It  is  possible  to  obtain  as  white  solids  the  so-called  individual 
magnesium  compounds,  composed  only  of  magnesium  and  alkyl 
groups.  But  in  the  presence  of  dry  ether  this  solvent  enters 
into  reaction  and  the  Grignard  reagents  are  additive  compounds 
of  ether  with  the  individual  magnesium  alkyl  or  aryl  halide, 
MgRI,  (C2H6)20. 

V.  Baeyer  regards  these  compounds  as  derivatives  of  quadri- 
valent oxygen  (I.),  and  Grignard  proposes  the  alternative 
formula  (II.) : 

CsHs^    /MgR  CoHss^    /Mgl 

c2n/  ^1  C2H5/  Nr 

1.  11. 

Whichever  of  these  two  configurations  be  accepted,  it  will  be 
seen  that  the  same  general  principle  is  at  work,  namely  the 
grouping  of  four  radicals  round  a  central  atom — in  this  case 
oxygen — with  possibly  a  development  of  tetrahedral  symmetry. 

Similar  compounds  are  known  in  the  case  of  zinc, 
Zn(CH3)2)  (C2H5)20,  and  Tschelinzeff  has  isolated  magnesium 
compounds  with  two  and  four  molecular  proportions  of  ether 
and  this  solvent  may  in  certain  cases  be  replaced  by  tertiary 
amines,  MgRI,  NX3. 

These  Grignard  reagents  are  not  spontaneously  inflammable 
in  air,  and  being  readily  soluble  in  many  anhydrous  organic 
solvents  are  much  more  easily  handled  than  the  inflammable 
zinc  alkyls.  Accordingly,  these  reagents  have  already  received 
a  very  wide  application,  and  in  the  hands  of  Acree,  Behal, 
W.  H.  Perkin,  jun.,  Zelinsky  and  numerous  other  investigators 
have  facilitated  many  valuable  syntheses  which  could  not  other- 
wise have  been  effected.  Perkins  synthesis  of  terpineol  may  be 
cited  as  a  prominent  example  of  the  use  of  magnesium  methiodide. 

In  this  paper  attention  will  be  confined  to  the  use  of  the 
Grignard  reagents  in  preparing  organo-metallic  and  metalloidal 
derivatives. 

(d)  The  Alkali  Metals 

In  the  first  vertical  series  of  the  periodic  table  we  find  the 
well-defined  family  of  alkali  metals  which  are  typically  univalent 


METALS  AND  METALLOIDS  703 

metals.  The  tendency  for  these  metals  to  unite  with  hydro- 
carbon radicals  is  very  slight.  Organic  derivatives  of  sodium 
and  potassium  were  indicated  by  Frankland  and  Wanklyn 
but  not  isolated  as  individual  compounds.  Here,  as  in  the 
case  of  magnesium,  residual  affinity  plays  an  important  part 
in  increasing  the  stability  of  the  organic  derivatives.  Sodium 
ethyl,  although  not  isolated  as  such,  has  been  obtained  in  an 
additive  compound  with  zinc  ethyl  containing  the  two  metals  in 
atomic  proportions,  Na  .  C2H5,  Zn(C2H5)2. 

The  metals  of  the  alkalis  resemble  those  of  the  alkaline 
earths  as  regards  their  feeble  affinity  for  hydrocarbon  radicals. 

(e)  The  Gold-Platinum  Group 

Alternating  with  the  alkali  metals  in  the  first  vertical  series, 
we  find  the  currency  metals,  copper,  silver,  and  gold.  Although 
researches  are  even  now  in  progress,  only  one  of  these,  namely 
gold,  has  been  definitely  combined  with  hydrocarbon  groups. 
This  combination  was  successfully  accomplished  by  Pope  and 
Gibson  in  1907,  by  acting  on  auric  bromide  with  the  Grignard 
reagent,  magnesium  ethiodide  : 

AuBr3  +  2MgC2H6I  =  Au(C2H5)2Br  +  Mgl2  +  MgBr2. 

The  product,  diethylauric  bromide,  which  was  obtained  in 
colourless  needles,  reacted  with  bromine  to  yield  ethylauric 
dibromide,  Au(C2H5)Br2,  a  ruby-red  crystalline  compound  com- 
bining additively  with  ammonia,  and  in  this  respect  resembling 

boron  trimethyl : 

NH,s  /Br 

Au(C2Hg)Br2  +  NH3  =  >Au< 

C2H/         \Br 

In  this  reaction  the  general  tendency  to  form  the  compound  with 
four  associating  units  is  again  apparent. 

The  metal  platinum,  closely  allied  in  many  respects  to  gold, 
occurs  in  the  periodic  scheme  as  the  final  member  of  the  metals 
of  the  eighth  vertical  series,  which  contains  nine  metals  arranged 
in  three  sets  each  with  three  members.  Pope  and  Peachy  have 
successfully  applied  the  Grignard  reagent  to  platinic  chloride 
dissolved  in  dry  ether  : 

PtCU  +  3Mg(CH3)I  =  (CH3)sPtI  +  Mgl2  +2MgCl2. 

Trimethylplatinic  iodide  (bright  yellow  crystals)  is  con- 
verted by  moist  silver  oxide   into  trimethylplatinic  hydroxide 


704  SCIENCE  PROGRESS 

(colourless  needles),  a  basic  substance  insoluble  in  water,  but 
soluble  in  nitric  acid  to  the  corresponding  nitrate,  (CH3)3  Pt .  N03. 
The  original  iodide  combines  additively  with  two  molecules 
of  ammonia,  a  combination  which  in  all  probability  involves 
the  formation  of  a  molecule  having  octahedral  symmetry: 

NH3 
CH3X      /CH3  2NH3  CH3      j  CH3 


CH; 


/'  Ni 


CH,        j 

NH; 


At  present  very  little  is  known  regarding  the  organic 
derivatives  of  the  other  metals  of  the  platinum  family.  Both  in 
this  series  and  in  the  first  vertical  series,  including  the  alkali 
and  currency  metals,  it  is  significant  that  it  is  the  metal  of 
highest  atomic  weight — platinum  in  one  case,  gold  in  the  other — 
which  has  combined  most  readily  with  alkyl  radicals. 

Generalisations 

1.  Influence  of  Atomic  Weight  on  the  Stability  and  Ease 
of  Formation  of  Organic  Derivatives 

In  the  natural  families  of  elements  thus  far  considered  the 
capacity  for  forming  organic  derivatives  appears  to  increase 
with  the  rise  in  atomic  weight.  Gold  and  platinum,  the  final 
members  of  their  respective  groups,  have  just  been  cited  as  a 
case  in  point.  Thallium,  the  final  member  of  the  aluminium 
family,  is  the  only  one  yielding  readily  both  alkyl  and  aryl 
derivatives.  Iodine,  although  a  non-metal,  may  be  quoted,  as 
it  furnishes  iodinium  bases  such  as  I(C6H5)2 .  OH  containing  two 
phenyl  or  other  aryl  groups,  a  property  which  is  not  possessed 
by  the  halogens  of  lower  atomic  weight. 

Organo-Mercuric  Compounds 

Mercury,  the  final  member  of  the  glucinum  family,  affords  a 
striking  illustration  of  the  great  capacity  for  combining  with 
organic  groups  possessed  by  metals  and  metalloids  of  high 
atomic  weight.  This  metal  possesses  a  very  marked  affinity 
for  carbon,  and  enters  into  combination  with  a  large  number  of 
organic  substances  of  very  varied  type. 

In  many  instances  the  attachment  of  mercury  to  carbon  can 
be  effected  merely  by  boiling  the  organic  substance  with 
mercuric  acetate  in  a  suitable   solvent.      This   is   notably  the 


METALS  AND   METALLOIDS  705 

case  with  phenols  and  aromatic  amines.  The  mercury  enters 
the  amine  molecule  in  two  stages,  the  mercuri-acetate  group 
first  attaches  itself  to  the  amino-nitrogen,  and  then  swings  into 
the  aromatic  nucleus  either  into  para-  or  the  ortho-position  in 
accordance  with  the  law  governing  substitution  in  the  benzene 
series.  This  process  can  be  repeated,  and  in  the  case  of ///^fa- 
toluidine  as  many  as  three  mercuri-acetate  groups  can  be  intro- 
duced into  the  molecule : 

NH2 

CH3 .  COOHgj-^-HgOOC  .  CH3 

HgOOC .  CH3 

This  compound  contains  93  per  cent,  of  mercury  and  is  extremely 
soluble  in  water. 

By  heating  mercuric  acetate  with  aromatic  compounds  at 
high  temperatures,  products  are  obtained  containing  mercury 
attached  to  two  organic  radicals. 

Meta-nitrobenzoic  acid  and  mercuric  acetate  yield  such  a 
compound  which  on  reduction  furnishes  an  amino-acid,  the 
sodium  salt  of  which  has  the  following  formula : 

Hg[C6H3(NH2).C02Na]2. 

2.  The  Masked  or  Hidden  Condition  of  Metals  and 
Metalloids  in  their  Organic  Derivatives 

The  above  sodium  salt  of  the  mercury  derivative  of  meta- 
aminobenzoic  acid  is  soluble  in  water,  but  owing  to  its  double 
attachment  to  carbon  the  mercury  present  in  the  salt  does  not 
show  its  ordinary  analytical  reactions.  Before  the  mercury  can 
be  detected  by  the  usual  tests  for  the  metal,  its  attachment  to 
the  two  aromatic  rings  must  be  destroyed.  This  masked  con- 
dition of  the  mercury  extends  to  the  physiological  action  of  the 
compound,  which  is  thirty  times  less  toxic  than  mercuric 
chloride.  The  substance  has  marked  bactericidal  and  spiro- 
chaetocidal  properties,  and  can  be  tolerated  in  large  doses.  A 
rabbit  weighing  about  5  lb.  was  not  injured  by  a  one-gram  dose 
of  this  sodium  salt. 

Mercury  compounds  with  aromatic  amines  are  likely  to  prove 
of  therapeutic  value,  as  the  amino  groups  have  the  property 
of  entering  into  combination  with  certain  constituents  of  the 
parasitic  organisms  binding  drug  and  organism  together, while  the 
poisonous  metal  does  its  work  on  the  bacterium  or  spirochaete, 


7o6  SCIENCE  PROGRESS 

Organic  Arsenic  Derivatives 

In  1865  Bechamp  discovered  among  the  products  of  the 
interaction  of  aniline  and  arsenic  acid  a  compound  which  he 
supposed  was  an  anilide  of  arsenic  acid,  that  is,  a  substance  in 
which  carbon  and  arsenic  are  not  joined  directly  but  through 
the  intermediary  of  oxygen.  Experiments  on  animals  showed 
that  this  compound  was  much  less  toxic  than  the  ordinary 
inorganic  compounds  of  arsenic,  and  it  was  found  safe  to 
administer  forty  times  as  much  arsenic  in  the  form  of  the 
supposed  arsanilide  as  in  potassium  arsenite  (Fowler's  solution). 
The  compound,  which  was  accordingly  called  atoxyl,  came  into 
increasing  demand  as  the  result  of  the  discovery  that  it  had 
considerable  germicidal  powers  and  could  be  used  in  the  treat- 
ment of  sleeping  sickness  and  other  diseases  of  protozoal  origin. 

In  1907  Ehrlich  and  Bertheim  showed  that  atoxyl  was  a 
true  organo-metalloidal  compound,  the  arsenic  being  directly 
attached  to  carbon.  The  compound  therefore  furnishes  another 
striking  example  of  the  masked  or  hidden  state  of  metals  and 
metalloids  in  their  organic  derivatives,  this  intimate  state  of 
combination  with  carbon  leading  to  a  modification  in  the 
analytical  and  physiological  reactions  of  these  elements. 

Although  destroying  trypanosomes  in  vivo,  atoxyl  has  no 
effect  on  these  organisms  in  vitro.  A  preliminary  change,  which 
takes  place  in  the  tissues  of  the  host,  appears  to  be  necessary 
before  the  drug  becomes  effective.  The  arsenic  in  atoxyl  (I.)  is 
in  the  same  saturated  quinquevalent  condition  as  it  was  in 
Bunsen's  non-poisonous  cacodylic  acid  (II.) 

v.  v. 

NH2.C6H4.  AsO(OH)2  (CH3)2AsO  .  OH. 

1.  11. 

The  substance  which  actually  destroys  the  trypanosomes 
in  the  body  of  the  host  is  in  all  probability  a  compound  of 
tervalent  arsenic.  Following  up  this  hypothesis,  Ehrlich  after 
many  trials  ultimately  arrived  at  the  compound,  salvarsan 
(III.),  or  "606,"  this  number  indicating  the  series  of  substances 
which  had  been  examined  before  success  was  attained : 
OH       OH  OH       OH 

HCl.NHg^      r^NHs,  HC1     NHjf^      ^jNH  .  CH2.  S02Na 

As  =  As  As  =  As 

in.  IV. 


METALS  AND  METALLOIDS  707 

Salvarsan  inhibits  the  growth  of  trypanosomes  in  a  test-tube  as 
well  as  in  the  body  of  the  host.  It  contains  the  two  contiguous 
0^0-aminohydroxyl  groups  which  serve  as  "  haptophores " 
for  attaching  the  molecule  to  the  parasitic  organism.  Ehrlich 
compares  the  compound  to  the  poisoned  arrows  used  by 
savages,  the  amino- phenol  complex  being  the  barbed  arrow- 
head, the  two  benzene  nuclei  serving  as  the  shaft  of  the  arrow, 
while  the  two  unsaturated  arsenic  atoms  are  the  poison  smeared 
on  the  arrow. 

The  drug  is  made  up  in  the  form  of  its  dihydrochloride 
(III.),  and  the  practical  difficulties  attending  its  use  are  its 
great  oxidisability  and  the  careful  preparation  needed  to  secure 
a  neutral  solution,  which  is  especially  necessary  when  the 
substance  is  administered  intravenously.  To  obviate  the  latter 
difficulty  a  modified  drug  has  been  devised,  known  as  Neo- 
salvarsan  (IV.),  which  is  prepared  by  treating  salvarsan  with 
formaldehyde  sulphoxylate,  the  result  being  that  one  or  two 
CH2.  S02H  groups  become  attached  to  aminic  nitrogen,  so  that 
the  product  becomes  distinctly  acidic  and  capable  of  forming 
a  stable  neutral  sodium  salt  (IV.). 

Organic  Derivatives  of  Antimony 

Antimony  has  long  been  administered  therapeutically  in  the 
form  of  its  salts,  especially  as  potassium  antimonyl  tartrate, 
the  well-known  tartar  emetic.  It  would  be  of  great  interest 
to  ascertain  what  modification  in  the  action  of  the  metalloid 
would  be  effected  by  combining  it  with  hydrocarbon  radicals. 

Many  organic  derivatives  of  antimony  are  known  containing 
alkyl  or  aryl  radicals,  or  both.  I  do  intend  discussing  these 
beyond  showing  the  steps  by  which  quite  recently  the  antimony 
analogue  of  atoxyl  has  been  reached.  We  may  expect  the 
antimony  analogue  of  salvarsan  to  follow,  although  its  advent 
has  not  yet  been  recorded. 

The  best  general  method  of  attaching  aromatic  radicals  to 
antimony  is  through  the  Grignard  reaction,  as,  for  example, 
with  antimony  trichloride  and  magnesium  phenyl  bromide, 
this  condensation  leading  to  triphenylstibine.  From  this  product 
three  series  of  aromatic  antimony  compounds  can  be  obtained 
containing  one,  two,  and  three  phenyl  radicals  attached  to 
antimony.     By  chlorination  followed  by  hydrolysis  the  corre- 


7o8 


SCIENCE  PROGRESS 


sponding  organic  stibinic  acids  are  produced,  and  these  three 
substances  were  shown  by  Miss  Micklethwait  and  the  author 
to  yield  meta-mtro  derivatives,  from  which,  on  reduction, 
aromatic  amino-compounds  containing  antimony  were  obtained. 
These  amines  had  some  trypanocidal  action,  but  were  also 
very  irritant  on  injection.  Their  production  is  shown  in  the 
following  diagram,  which  illustrates  the  genesis  of  the  series 
from  the  Grignard  reagent  and  antimony  trichloride  : 

6Mg(C6H5) .  Br  +  2SbCl3 


'(C6H5)3Sb- 
C6H5 .  SbCl4  (C6H6)2SbCl3 

C6H5 .  SbO(OH)2      (C6H5)2SbO(OH) 


{^SbO(OH)2 
N02 

(      )sbO(OH)2 

NH2 

_    * 
<_)sb(OH)2 

NH2 


L    N02   J 

L     NH2    J 


(C6H5)3SbCl2 
(C6H5)3Sb(OH)2 


SbO.OH 


Sb.OH 


L      NQ2      J* 

L   NH2    J 


Sb. 


Owing  to  the  fact  that  the  oxidised  antimony  radical  induces 
nitration  in  the  meta-position,  all  the  foregoing  amines  are  meta- 
derivatives,  differing  in  this  respect  from  atoxyl,  which  is  a 
para-compound.  But  within  the  last  few  months  the  isolation 
of  para-aminophenylstibinic  acid  has  been  accomplished.  The 
starting-point  is  acetyl-^-phenylenediamine  (V.),  which  when 
diazotised  combines,  as  was  shown  by  P.  May,  with  antimony 
chloride  ;  this  double  salt  (VI.)  when  gently  warmed  with  dilute 
alkali  and  copper  powder  yields  antimony -atoxyl,  sodium  para- 
aminophenylstibinate  (VII.) : 

CH3CO.NH/"  "\nH2    ->    CH3CO.NH./"  ~\N2Cl.SbCl3 

v.  vi. 

CH3CO .  NH/"  ~\sbO(OH)2    -»    NH2/"  AsbO(OH) .  ONa 


VII. 


METALS  AND   METALLOIDS  709 

Some  of  these  aromatic  amino-derivatives  of  antimony  may 
find  therapeutic  application,  and  already  triphenylstibine  sulphide, 
(C6H6)3SbS  ("  sulphoform  "),  has  been  used  in  the  treatment  of 
skin  diseases. 

3.  Influence  of  Valency  on  the  Stability  of  Organo- 
metallic  and  metalloidal  compounds 

Reference  has  already  been  made  to  the  influence  of  valency 
in  the  formation  of  organic  compounds  of  metals  and  metalloids. 
There  is  no  well-authenticated  case  where  a  univalent  metal 
furnishes  an  organic  derivative  capable  of  existence  as  an 
individual  compound.  Sodium  ethyl  is  only  known  in  com- 
bination with  zinc  ethyl.  When  a  metal  has  several  valencies 
the  tendency  is  for  the  organic  compound  to  contain  the  metal 
in  its  highest  state  of  valency.  Mercury,  thallium,  gold,  and  lead 
exhibit  this  tendency,  as  is  shown  by  their  organic  derivatives 
already  cited.  A  series  of  comparative  experiments  with 
camphor  and  the  elements  of  the  arsenic  family  show  the  same 
tendency  at  work.  Sodium  camphor  was  condensed  with  the 
trichlorides  of  phosphorus,  arsenic,  and  antimony  containing 
the  non-metal  or  metalloid  in  the  tervalent  condition,  the 
products  as  shown  by  the  following  table,  contained  these 
elements  in  the  quinquevalent  state  : 

Condensation  Products  from  Sodium  Camphor  and  the  Trichlorides  of 

the  Phosphorus  Group 

Products.            Phosphorus  trichloride.  Arsenic  trichloride.               Antimony  trichloride. 

Dicamphoryl   (Cl0Hl5O)2PO  .  OH,    di-  (Cl0H,sO),2AsO  .  OH,  di-                     

derivatives.         camphorylphosphinic  camphorylarsinic  acid, 

acid,  stable  in  concen-  stable    in    hot     dilute 

trated    aqueous    alkali  aqueous  alkali  hydrox- 

hydroxides  ;       decom-  ides  ;    decomposed  by 

posed   by  fused  alkali  very  strong  solutions  of 

hydroxides.  these  alkalis. 

Tricamphoryl  (C|0H15O)3As(OH)2,  tri-  (Ci0HlsO)3SbCl2,  tricam- 

derivatives.  camphorylarsinic  acid,      phorylstibinic  chloride, 

is    as    stable    towards     slowly  resolved  by  water 
alkalis  as  the  above  di-      into 
camphoryl  derivative.        (Cl0H15O)3Sb(OH)2, 

trie  am  phorylstibinic 
acid,  very  unstable,  de- 
composed by  dilute 
aqueous  sodium  hydrox- 
ide and  even  by  boiling 
water. 

This    very  general    tendency  affords   confirmation  for   the 
view  that  valency  is  largely  a  question  of  arrangement  in  space. 


7io  SCIENCE  PROGRESS 

The  atomic  volume  of  carbon  is  less  than  that  of  other  elements, 
and  accordingly  when  a  metal  or  metalloid  unites  directly 
with  carbon  there  is  room  for  the  maximum  number  of 
associating  units. 

Organic  Derivations  of  Selenium  and  Tellurium 

Considerable  attention  is  now  being  given  to  the  study  of 
organic  compounds  of  selenium  and  tellurium  owing  to  a  recent 
statement  made  by  v.  Wassermann  to  the  effect  that  com- 
binations containing  these  elements  had  been  noticed  to  induce 
diminution  in  the  growth  of  malignant  tumours.  Bearing  in 
mind  the  beneficial  results  obtained  with  atoxyl  and  salvarsan, 
it  seems  likely  that  the  most  promising  field  for  research  lies 
in  the  study  of  the  aromatic  derivatives  of  these  two  elements. 
The  Grignard  reaction  is  available  for  both,  and  recently  it 
has  been  found  that  selenium  can  be  introduced  into  aromatic 
nuclei  through  the  agency  of  the  diazo-reaction.  The  following 
series  has  been  completed  by  Mr.  Elliott  of  the  Royal  College 
of  Science,  Dublin.  Starting  with  diazotised  para-nitraniline, 
selenium  is  introduced  by  the  action  of  potassium  selenocyanide 
KCNSe  : 

N02/~  ~\N2C1    ->        N02       ^^>Se.CN    -> 

N°2(      )~ Se-Se~ C  ^)NQ2    -» 

NH2/~  ~\— Se  .  Se— f  ~\  NH2  (VIII.) 

The  organic  selenocyanide  when  hydrolysed  yields 
di-^>-nitrophenyldiselenide ;  this  on  reduction  furnishes 
di-/>-aminophenyldiselenide  (VI II.),  an  oxidisable  base  which, 
like  salvarsan,  can  be  utilised  in  the  form  of  its  more  stable 
dihydrochloride.1 

1  Alternating  in  the  periodic  scheme  with  the  arsenic  and  selenium  families, 
we  find,  as  in  other  cases,  two  other  groups  of  elements  showing  little  or  no 
capacity  for  yielding  organic  derivatives  ;  these  are  the  vanadium  family  (with 
columbium  and  tantalum)  and  the  chromium  family  (with  molybdenum,  tungsten, 
and  uranium).  It  was  formerly  supposed  that  tungsten  had  yielded  organic 
derivatives,  but  this  statement  has  since  been  contradicted. 


METALS  AND  METALLOIDS  711 

4.  Organo-metallic  and  Organometalloidal  Radicals 
behaving  as  complex  alkali  metals 

A  necessarily  brief  and  imperfect  survey  has  now  been  made 
of  all  the  families  of  metals  and  metalloids  capable  of  yielding 
organic  derivatives.  It  will  have  been  noticed  that  in  several 
instances,  for  example  with  certain  derivatives  of  arsenic, 
mercury,  and  thallium,  it  is  possible  to  obtain  complex  alkaline 
hydroxides  having  the  properties  of  caustic  soda  or  potash. 

The  alkali  metals,  potassium,  lithium,  sodium,  rubidium, 
and  caesium,  are  distinguished  from  most  other  metals  by 
their  univalency  and  by  their  property  of  yielding  very 
soluble  alkaline  hydroxides.  Moreover,  they  are  distinguished 
from  all  other  elements  by  having  each  in  its  own  horizontal 
series  the  maximum  atomic  volume.  When  this  property 
(atomic  volume)  is  plotted  for  all  the  elements  against  the 
atomic  weight  as  was  done  by  Lothar  Meyer,  it  is  seen  that  the 
alkali  metals  occupy  points  of  maxima  on  the  curve. 

The  study  of  organic  derivatives  of  metals,  metalloids,  and 
non-metals  shows  that  one  can  synthesise  a  compound  alkali 
metal  by  associating  with  many  polyvalent  elements  sufficient 
alkyl  or  aryl  radicals  to  reduce  the  principal  valency  to  unity. 
If  the  remaining  valency  is  satisfied  by  iodine,  the  result  is  a 
saline  iodide  in  which  the  iodide  ion  can  be  replaced  by 
hydroxyl,  usually  through  the  agency  of  moist  silver  oxide, 
giving  rise  to  a  basic  hydroxide  which  in  the  majority  of  cases 
is  soluble  in  water  to  a  caustic  alkaline  solution.  The  following 
series  of  organo-metallic,  organo-metalloidal,  and  organo-non- 
metallic  hydroxides  illustrates  this  principle  : 

N(CH3)40H,  P(C2H5)4OH,     As(C7H7)4OH,  Sb(CH3)4OH, 
Se(CH3)3OH,  Sn(C2H5)3OH,  Pb(C2H5)3OH,  Pt(CH3)3OH, 

I(CGH5)2OH,    Tl(CH3)2OH, 

Hg(C2H5)OH    Hg(C6H5)OH. 

All  these  substances,  with  the  exception  of  trimethyl- 
platinic  hydroxide,  are  soluble  in  water,  giving  rise  to  strongly 
alkaline  solutions,  which  absorb  carbon  dioxide,  precipitate  the 
heavy  metals  from  their  soluble  salts,  and  saponify  fats,  thus 
behaving  quite  like  the  strong  caustic  alkalis,  sodium  and 
potassium  hydroxides. 

Providing  that  the  univalent  complex  organo-metallic  or 
46 


712  SCIENCE  PROGRESS 

metalloidal  ion  has  a  sufficiently  large  molecular  volume,  it 
resembles  the  bulky  elementary  ion  of  sodium  or  potassium  in 
furnishing  ionisable  halides  (chlorides,  bromides,  and  iodides) 
and  soluble  strongly  alkaline  hydroxides. 

Nowadays,  when  elementary  atoms  are  regarded  as  having  a 
composite  structure,  this  synthesis  of  compound  alkali  radicals 
in  the  manner  just  indicated  is  a  fact  of  great  significance. 

Conclusions 

The  investigations  in  the  wide  field  of  organic  derivatives  of 
metals  and  metalloids  on  which  I  have  touched  so  very  super- 
ficially have  amply  justified  themselves  in  a  variety  of  ways. 

On  the  theoretic  and  doctrinal  side  of  chemistry  they  have 
proved  to  be  of  fundamental  importance  in  establishing  the 
theory  of  compound  radicals.  They  have  greatly  enlarged  our 
conceptions  of  stereo-chemistry  and  the  structure  of  molecules, 
and  have  thrown  much  additional  light  on  the  manifestations  of 
chemical  affinity  and  valency. 

From  the  practical  standpoint  these  researches  have  endowed 
chemists  with  the  Grignard  reagents  and  other  synthetic  agents 
of  a  most  general  type. 

To  the  physician  they  have  furnished  several  valuable  series 
of  synthetic  drugs  in  which  a  close  connection  can  be  traced 
between  chemical  constitution  and  physiological  action,  and  the 
combined  chemical  and  clinical  study  of  these  materials  has 
given  rise  to  a  new  science — "  Chemiotherapy." 

At  the  outset  an  apparently  fantastic  development  of  chemical 
synthesis,  these  experimental  researches  have  vindicated  the 
cogency  in  chemistry  of  Bamberger's  bold  assertion,  "  Ohne 
Phantasie  kommen  wir  nicht  weiter." 


PROF.  JOHN  MILNE 

By  CHARLES  DAVISON,  Sc.D.,  F.G.S. 

To  three  Englishmen,  living  almost  in  three  different  centuries, 
we  are  chiefly  indebted  for  the  advances  which  have  culminated 
in  the  new  science  of  seismology.  John  Michell  (1724-1793), 
one  of  the  early  Woodwardian  professors  at  Cambridge,  wrote 
the  first  important  memoir  on  a  great  earthquake,  that  of  Lisbon 
in  1755,  and,  in  endeavouring  to  account  for  its  various  pheno- 
mena, foresaw  some  of  the  main  lines  on  which  the  science 
has  since  developed.  Robert  Mallet  (1810-1881),  a  Dublin 
engineer,  with  unfailing  industry  codified  our  knowledge  of  the 
nature  of  earthquakes  and  devised  new  methods  of  investigation 
which  he  applied  to  the  Neapolitan  earthquake  of  1857.  Much 
of  Mallet's  work  remains,  but  his  methods  and  theoretical  views 
are  to  a  great  extent  superseded,  and  the  instruments  which  he 
devised  for  the  registration  of  earthquakes  are  of  little  value.  It 
was  reserved  for  John  Milne  (1850-1913)  to  advance  far  beyond 
the  limits  to  which  Michell  and  Mallet  attained.  His  influence 
and  energy  were  such  that,  at  the  close  of  his  life,  when  the  study 
of  earthquakes  has  attracted  a  host  of  workers  and  its  practical 
importance  is  fully  recognised,  we  may  yet  claim  for  him  the 
chief  share  in  the  growth  of  the  science. 

Of  the  three,  Milne  received  the  training  best  adapted  to  his 
future  career.  Born  at  Liverpool  on  December  30,  1850,  he  was 
educated  as  a  mining  engineer  under  Warington  Smyth  at  the 
Royal  School  of  Mines.  After  gaining  experience  in  the  mines 
of  Cornwall,  Lancashire,  and  Central  Europe,  he  spent  two 
summers  in  ascertaining  the  mineral  resources  of  Newfoundland, 
while  his  interest  in  geology  was  manifested  by  the  valuable 
remains  of  the  great  auk  which  he  brought  home  from  Funk 
Island.  In  1874'  he  acted  as  geologist  in  Beke's  expedition  to 
north-west  Arabia  ;  and,  a  year  later,  received  the  appointment 
which  determined  the  bent  of  his  future  life,  that  of  consulting 
mining  engineer  and  geologist  to  the  Government  of  Japan. 

It  was  characteristic  of  Milne's  energy  and  wide  interests 

713 


7i4  SCIENCE  PROGRESS 

that  he  preferred  to  approach  his  new  home  by  a  solitary  and 
toilsome  journey  overland.  Crossing  Asia,  almost  along  the  line 
of  the  present  Siberian  Railway,  and  making  many  geological 
observations  on  the  way,  he  arrived  at  Tokyo  after  the  lapse  of 
nearly  a  year.  On  the  first  night  spent  in  that  city,  he  began 
his  acquaintance  with  Japanese  earthquakes.  A  strong  shock 
made  his  house  creak  and  pictures  sway,  and  it  is  said  that,  from 
that  moment,  the  main  interest  of  his  life  was  fixed. 

In  its  early  days,  the  Tokyo  University  depended  largely  on 
foreign  aid.  On  his  arrival  in  1876,  Milne  found  among  its  pro- 
fessors the  late  W.  Ayrton  as  well  as  J.  Perry  and  J.  A.  Ewing, 
all  of  whom  became  interested  in  the  construction  of  accurately 
recording  seismographs.  Milne's  opportunity,  however,  came 
with  the  destructive  earthquake  of  February  22,  1880,  when  the 
neighbouring  port  of  Yokohama  was  laid  in  ruins.  In  a  country 
visited  by  a  thousand  earthquakes  a  year,  the  materials  are  too 
abundant  for  solitary  workers,  and  Milne  realised  that  it  was 
only  by  the  co-operation  of  many  students  and  observers  that 
substantial  advances  could  be  made.  As  the  result  of  a  public 
meeting  due  to  his  initiative,  the  Seismological  Society  of  Japan 
— the  first  society  devoted  exclusively  to  the  study  of  earth- 
quakes and  volcanoes — was  founded  in  the  spring  of  1880,  with 
Mr.  J.  Hattori  as  president  and  Milne  as  secretary. 

In  later  years  Milne  often  claimed  that  the  formation  of  this 
society  marks  an  epoch  in  the  history  of  seismology,  and  all 
will  admit  the  justice  of  the  claim.  Little,  it  was  recognised, 
could  be  done  without  the  aid  of  an  accurate  seismograph,  the 
essential  feature  of  which  is  that  a  part  should  remain  at  rest  or 
nearly  so  while  the  ground  to  which  it  is  attached  is  in  constant 
motion.  The  problem  was  solved  satisfactorily  by  members  of 
the  Seismological  Society,  and  it  is  to  them,  and  especially 
to  Ewing,  Milne,  and  Gray,  that  we  are  indebted  for  the  first 
instruments  deserving  of  the  name  of  seismographs.  The  fre- 
quent earthquakes  of  Japan  soon  offered  the  materials  for 
registration,  and  the  diagrams  of  these  early  seismographs 
represented  with  precision  the  movements  of  the  ground  during 
earthquakes  both  great  and  small.  The  Seismological  Society 
lasted  for  about  twelve  years,  and  ceased  to  exist  in  1892,  mainly 
because  its  work  could  be  carried  on  more  completely  under 
official  guidance  and  control.  During  the  greater  part  of  the 
time   Milne  might  almost   have   said   that   he  himself  was  the 


JOHN   MILNE  715 

Seismological  Society.  He  certainly  did  most  of  its  work. 
Of  the  sixteen  volumes  of  Transactions  published  by  the  Society 
and  of  the  four  volumes  of  the  Seismological  Journal  which  he 
afterwards  edited,  he  wrote  not  less  than  two-thirds.  But  his 
labours  did  not  end  with  his  actual  contributions.  It  was  under 
his  guidance  and  led  by  his  enthusiasm  that  many  of  the  other 
papers  were  written,  and  that  native  investigators,  and  in  par- 
ticular the  present  eminent  professor  of  seismology  at  Tokyo, 
were  trained  to  carry  on  the  work  after  his  return  to  Europe. 

The  papers  which  Milne  contributed  to  these  twenty  volumes 
vary  widely  in  their  subjects.  There  were  indeed  few  branches 
of  the  science  with  which  he  did  not  at  some  time  or  other  deal. 
Occasionally  he  would  touch  on  the  lighter  side,  such  as  the 
effects  of  earthquakes  on  animals  and  the  emotional  and  moral 
effects  of  earthquakes  on  human  beings.  He  made  many  experi- 
ments on  artificial  earthquakes  caused  by  the  fall  of  heavy  iron 
balls  or  by  explosions  of  dynamite.  The  minute,  and  some- 
times almost  incessant,  tremors  of  the  ground  attracted  much  of 
his  attention,  and  he  was  probably  correct  in  attributing  them, 
in  part  at  least,  to  the  pressure  of  the  wind  on  the  mountains  of 
Central  Japan.  He  soon  recognised  that  the  vibrations  of  a 
given  earthquake  varied  in  strength  and  period  in  different  parts 
of  Tokyo,  and  this  led  him  to  carry  out  what  he  called  a  seismic 
survey  of  that  city.  Of  still  greater  importance  were  his  survey 
of  the  whole  of  Japan  and  his  determination  of  the  districts 
in  which  the  principal  earthquakes  originated.  His  mode  of 
working  was  characteristic.  Enlisting  the  aid  of  numerous 
observers  in  all  parts  of  the  country,  he  provided  them  with 
bundles  of  postcards,  one  of  which  with  the  necessary  details 
was  sent  to  him  whenever  an  earthquake  was  felt.  In  this  way 
he  was  able  to  determine  the  region  beneath  which  each  earth- 
quake occurred,  and  thus  to  ascertain  and  map  those  parts  of 
the  country  that  were  most  liable  to  be  shaken.  But  the  method 
had  other  and  more  permanent  results,  for  it  led  to  the  forma- 
tion of  the  network  of  nearly  a  thousand  observing  stations 
which  are  now  scattered  over  the  empire  of  Japan.  Of  this 
valuable  system  Milne  was  able  to  avail  himself  in  the  last  work 
which  he  published  before  leaving  the  country.  The  concluding 
volume  of  the  Seismological  Journal  consists  of  his  great  catalogue 
of  8,331  Japanese  earthquakes  during  the  years  1885-92.  The 
volume,  however,  is  no  mere  list  of  dates.     For  each  earthquake 


716  SCIENCE   PROGRESS 

it  gives,  in  addition  to  other  elements,  the  dimensions  of  the 
disturbed  area  and  the  approximate  position  of  its  centre.  The 
illustrative  map  which  Milne  prepared  shows  the  positions  of 
these  centres  and  incidentally  reveals  the  great  law  of  their  dis- 
tribution, namely,  that  earthquakes  are  most  numerous  on  the 
side  of  Japan  facing  the  Pacific  Ocean,  and  especially  beneath 
the  ocean  bed  shelving  steeply  into  the  Tuscaroora  Deeps. 

Shortly  after  Milne  began  the  study  of  earthquakes,  he 
received  aid  from  the  British  Association  in  the  construction 
of  seismographs  and  for  other  allied  purposes.  Money-grants 
are  made  by  the  Association  to  committees  and  never  to 
individuals.  But  when  the  chairman  of  the  committee  lives  in 
England,  and  the  secretary  who  does  the  work  in  Japan,  the 
committee  becomes  identified  with  the  secretary.  Thus,  the 
fifteen  valuable  reports  of  the  committee  were  the  work  of  Milne 
alone.  They  gave  brief,  and  readily  accessible,  summaries  of 
the  many  investigations  which  he  carried  out  in  Japan. 

Milne  remained  in  Japan  for  nearly  twenty  years,  and 
during  this  time  collected  an  extensive  library  of  earthquake- 
literature  and  furnished  his  observatory  with  numerous 
instruments  mostly  of  his  own  design.  The  close  of  his 
residence  in  the  country  was  i  marked  by  a  deep  feeling  of 
animosity  among  the  Japanese  towards  foreigners  generally. 
Though  it  was  by  the  action  of  Russia,  France,  and  Germany 
alone  that  they  were  afterwards  deprived  of  the  principal  fruits 
of  the  war  with  China,  there  can  be  little  doubt  that  it  was 
from  political  motives  that  almost  the  whole  of  his  property  was 
destroyed  in  February  1895.  Early  one  Sunday  morning,  a 
fire  broke  out  in  a  pile  of  wood  in  an  outhouse  and  spread  so 
rapidly  that,  in  half  an  hour,  Milne  was  standing  in  his  night- 
dress looking  at  the  smoking  ruins  of  his  home,  with  some 
papers  and  a  few  books  at  his  feet  to  represent  all  that  was 
saved  of  the  accumulations  of  twenty  years.  Great  as  it  was, 
the  loss,  though  uncovered  by  insurance,  was  not  wholly 
irreparable.  The  library  was  in  part  at  least  replaced,  and 
Milne  with  his  usual  energy  at  once  set  about  the  construction 
of  two  new  pendulums,  so  as  to  lose  no  time  in  renewing 
observations  when  he  arrived  in  England. 

Milne  reached  this  country  and  began  the  third  period  of 
his  life  in  July  1895.  With  his  Japanese  wife,  he  made  his  home 
at  Shide   Hill   House,   near   Newport,   in  the   Isle  of  Wight. 


JOHN   MILNE  7i7 

He  at  once  constructed  pillars  on  which  to  erect  the  pendulums 
he  had  brought  from  Japan,  and  in  three  weeks  he  began  the 
long  series  of  records  which  have  made  his  name  and  observa- 
tory so  widely  known.  As  far  back  as  1883  he  had  predicted 
that  with  suitable  instruments  every  great  earthquake  might 
be  recorded  in  all  parts  of  the  globe.  Within  the  next  twelve 
years,  observations  in  Germany  and  England,  as  well  as  in 
Japan,  fulfilled  the  prediction  and  at  the  same  time  showed 
that  the  horizontal  pendulum,  in  one  or  other  of  its  various 
forms,  was  admirably  adapted  for  the  purpose.  Milne  preferred 
his  own  form  of  pendulum,  with  photographic  registration  ;  and 
this  form,  with  some  improvements,  still  holds  the  field  in 
British,  as  well  as  in  some  foreign,  observatories. 

During  his  last  years  in  Japan,  Milne's  interest  in  the 
phenomena  of  local  earthquakes  gave  place  to  that  in  the 
phenomena  of  what  he  called  "  world-shaking  earthquakes  " ; 
and  in  his  new  home  it  was  only  natural  that  the  later  interest 
should  prevail.  At  the  first  meeting  of  the  British  Association 
held  after  his  return,  the  committee  on  the  earthquake  and 
volcanic  phenomena  of  Japan,  which  had  naturally  ceased  to 
exist,  was  merged  in  that  on  earth  tremors,  and  the  joint 
seismological  committee  took  up  the  great  task  of  organising 
a  seismic  survey  of  the  world.  As  a  similar  task  had  also  been 
undertaken  at  about  the  same  time  by  the  International  Seismo- 
logical Association,  with  its  headquarters  in  Strasburg,  Milne's 
work  became  almost,  though  not  entirely,  confined  to  British 
colonies.  Beginning  with  his  observatory  at  Shide,  the  network 
of  stations  extended  year  by  year,  until  the  number  of  stations 
contributing  records  to  the  Seismological  Committee  now 
amounts  to  thirty-four.  In  this  country,  in  addition  to  Shide, 
there  are  ten  other  stations  furnished  with  the  Milne  seismo- 
graph or  similar  instruments.  In  the  British  possessions  they 
are  to  be  found  in  Canada  and  British  Columbia,  in  Ascension 
Island  and  the  Cape  of  Good  Hope,  and  in  various  parts  of 
India,  Australia,  and  New  Zealand.  Records  are  also  sent  to 
the  committee  from  several  observatories  in  foreign  countries, 
in  Spain,  the  Azores,  and  Syria,  and  from  such  distant  island 
stations  as  Fernando  Noronha  and  Honolulu.  Since  1899  the 
records  have  been  published  twice  a  year  in  Circulars;  while 
from  1896  onwards  the  results  have  been  discussed  in  the 
valuable  reports  presented   annually  at  the  meetings  of   the 


7i8  SCIENCE  PROGRESS 

British  Association.  These  reports  are  not  entirely  the  work 
of  the  late  secretary,  for  Milne  always  welcomed  the  co- 
operation of  other  members  of  the  committee ;  but  the 
portions  of  chief  and  abiding  interest  are  those  in  which  he 
determined  the  origins  of  the  sixty  or  more  world-shaking 
earthquakes  recorded  every  year  in  the  observatories  associated 
with  the  committee.  It  is  one  of  the  most  valuable  results  of 
recent  work  that  such  determinations  should  be  possible  whether 
the  earthquakes  originate  in  civilised  countries,  beneath  the 
ocean,  or  under  lands  inhabited  by  illiterate  and  wandering 
tribes.  They  show  that  the  destructive  earthquakes  of  the 
world  are  confined  to  about  a  dozen  seismic  regions,  the  more 
important  of  which  lie  along  the  steeply  sloping  margins  of 
the  Pacific  Ocean. 

In  the  physical  history  of  the  globe,  however,  an  interval 
of  fourteen  years  is  but  as  one  day.  No  fact  of  seismology  is 
more  clearly  established  than  the  continual  migration  of  seismic 
activity.  From  month  to  month,  even  from  hour  to  hour,  the 
centre  of  action  ranges  along  the  line  or  lines  of  fault  which 
give  birth  to  a  series  of  earthquakes.  In  larger  districts  the 
same  displacement  occurs  over  greater  distances  and  at  longer 
intervals  of  time.  Thus  the  interesting  maps  which  Milne 
published  annually  in  his  reports  show  only  the  region  in  which 
the  earth's  crust  is  being  deformed  at  the  present  time.  In  past 
centuries  the  seats  of  chief  activity  may  have  been  very  different. 
What  they  were  Milne  sought  to  determine  in  one  of  his  latest 
contributions  to  seismology — his  "  Catalogue  of  Destructive 
Earthquakes,  a.d.  7  to  a.d.  1899."  As  complete  probably  as  such 
a  catalogue  can  now  be  made,  it  is  inevitably  defective.  The 
total  number  of  entries  in  it  is  4,151,  and  many  of  the  earth- 
quakes recorded  in  it  would  fall  far  short  of  the  intensity  of  a 
world-shaking  earthquake.  Yet  if  the  latter  occurred  through- 
out the  Christian  era  at  the  present  rate  of  sixty  a  year,  the 
total  number  would  be  more  than  113,000;  that  is  to  say,  ninety- 
six  out  of  every  hundred  great  earthquakes  in  the  past  nineteen 
centuries  may  remain  for  ever  unknown  to  us.  Nevertheless, 
Milne's  second  great  catalogue  of  earthquakes  possesses  a  value 
that  will  only  be  fully  known  after  a  careful  analysis  of  its 
contents  has  been  made. 

From  what  has  been  already  said  it  will  be  obvious  that 
Milne  was  a  student  of  earthquake  phenomena  rather  than  of 


JOHN   MILNE  719 

individual  earthquakes.  With  one  exception  he  never  made 
a  detailed  study  of  any  shock.  The  nature  of  earthquake  motion 
in  general,  the  relations  between  earthquakes  and  other  pheno- 
mena, the  peculiarities  of  their  distribution  in  time  and  space, 
presented  greater  attractions  to  him  than  the  investigation  of 
an  earthquake  unit. 

It  has  been  said  of  Milne  that  he  was  a  man  who  never 
perfected  anything;  and  in  a  very  limited  sense  this  was  true. 
He  preferred  sometimes  to  start  an  inquiry  and  to  leave  others 
to  finish  it.  His  two  great  catalogues,  of  Japanese  earthquakes 
and  of  destructive  earthquakes,  are  monuments  of  detailed  and 
patient  labour ;  but,  in  both  cases,  his  own  analysis  was  slight. 
He  was  content  to  provide  the  materials  which  others  were  to 
use  in  building.  He  was  a  man  of  large  views.  He  cannot  be 
held  to  have  proved  that  the  frequency  of  great  earthquakes  is 
connected  with  the  small  migrations  of  the  earth's  pole  or  that 
there  is  any  bond  between  the  occurrence  of  earthquakes  in 
regions  so  remote  as  the  east  and  west  margins  of  the  Pacific. 
But  it  is  something  to  have  imagined  such  relations,  to  have 
tested  their  reality  as  far  as  his  materials  would  allow,  and  thus 
to  provide  promising  subjects  of  inquiry  for  a  future  of  wider 
knowledge. 

Several  chapters  of  seismology,  if  they  do  not  owe  their  origin 
to  Milne,  were  largely  written  by  him.  His  part  in  the  construc- 
tion of  seismographs  was  a  prominent  one,  and  the  extent  and 
precision  of  our  knowledge  as  to  the  nature  of  earthquake  motion 
were  to  no  slight  extent  the  result  of  his  labours.  He  was  the 
first  to  realise  that  the  vibrations  of  a  great  earthquake  may  be 
recorded  in  any  part  of  the  globe,  the  first  also  to  carry  a  world- 
wide seismic  survey  into  execution.  What  all  this  means,  we 
shall  only  fully  understand  when  the  accumulation  of  many 
records  shall  enable  us  to  unravel  the  mystery  of  the  nature  of 
the  earth's  interior. 

The  practical  applications  of  his  science  always  possessed  a 
charm  for  a  man  so  human  as  Milne.  He  devised  a  form  of 
seismograph  for  registering  the  vibrations  of  railway-trains,  and 
for  discovering  any  defects  that  may  exist  in  the  engine  or 
permanent  way.  His  study  of  the  fracture  of  deep-sea  cables  by 
earthquakes  and  other  earth-movements  is  unique.  But  it  was 
by  his  design  of  houses,  bridges,  etc.,  that  will  withstand  the 
rough  and  sudden  touch  of  earthquakes  that  he  has  chiefly  earned 


720  SCIENCE  PROGRESS 

the  gratitude  of  the  present  and  future  generations.  It  may  not 
always  be  possible  to  use  the  best  sites  for  dwelling-houses — the 
neighbourhood  of  a  great  harbour  may  prevail  over  other 
considerations — but  it  is  at  least  possible,  by  following  the 
principles  which  Milne  has  laid  down,  to  lessen  very  materially 
the  destructive  power  of  a  great  shock. 

After  a  brief  illness,  Milne  died  on  July  31.  By  his  will,  he 
has  left  all  his  seismographs  and  his  books  and  papers  relating 
to  earthquakes  to  the  British  Association,  together  with  a  sum 
of  £1,000  subject  to  the  life-interest  of  his  wife.  He  has  also  left 
behind  him  property,  intangible  it  may  be,  but  still  more  valuable. 
He  has  left  an  organisation  for  the  study  of  earthquakes  that  is 
practically  co-extensive  with  the  British  empire.  It  is  satisfac- 
tory to  learn  that  this  work  of  Milne's  creation  will  not  be 
allowed  to  lapse,  that  it  will  be  continued  as  far  as  possible  by 
other  if  less  capable  hands.  A  more  worthy  memorial  to  our 
late  leader  in  seismology  we  could  not  offer  than  by  continuing 
and  extending  his  work  in  the  way  that  he  would  probably  have 
done  had  he  remained  among  us. 


THE  CORPUS   LUTEUM,  ITS  STRUCTURE 

AND   FUNCTION 

By  CHAS.   H.  O'DONOGHUE,  D.Sc. 

Beit  Memorial  Felloiv,  Zoological  Laboratory ,  University  College,  London 

Introduction 

Long  ago  it  was  known  that  in  the  mammalian  ovary  sometimes 
a  well-marked  bright  yellow  body,  the  corpus  luteum,  appeared, 
easily  recognisable  with  the  naked  eye  ;  and  its  nature  and 
function  were  the  subjects  of  much  speculation.  In  recent  years 
a  great  deal  of  attention  has  been  paid  to  this  structure,  and 
some  light  has  been  thrown  on  its  histology  and  function.  It 
is  hoped  it  will  be  of  interest  therefore  to  set  out  the  facts  and 
theories  recently  brought  forward  regarding  this  body,  which 
we  now  recognise  as  a  ductless  gland,  and  the  part  it  plays  in 
the  chemical  co-ordination  of  the  body. 

It  is  now  generally  known  that  in  the  female  mammal  the 
ovary  is  in  a  state  of  activity  during  the  years  intervening 
between  puberty  and  senescence.  This  activity  varies  in 
intensity,  and  becomes  very  strongly  marked  at  recurring 
intervals.  The  time  elapsing  between  two  periods  of  maximum 
activity  varies  from  about  a  year  {e.g.  Monotremes,  Mar- 
supials (9),  etc.)  to  about  a  month  {e.g.  Primates,  etc.).  The 
ovarian  changes  are  frequently  accompanied  by  well-marked 
alterations  in  the  external  appearance  or  behaviour  of  the 
animal,  and  these  latter  have  long  been  recognised  by  the 
breeder  under  the  name  of  "heat"  or  "rut."  The  climax  of 
the  period  of  ovarian  activity  is,  in  general,  marked  by  the 
liberation  of  a  ripe  ovum  or  ova,  and  this  is  immediately 
followed  by  the  formation  of  corpora  lutea. 

Before  passing  on  to  consider  the  corpus  luteum  itself  it  is 
necessary  to  glance,  albeit  quite  briefly,  at  the  structures  present 
in  the  ovary  prior  to  the  setting  free  of  the  eggs. 

The  mammalian  ovary  consists  of  a  mass  of  connective 
tissue,  the  stroma,  which  contains  some  plain  muscular  fibres 

721 


;22  SCIENCE  PROGRESS 

and  numerous  blood  vessels.  It  is  surrounded  by  a  single  layer 
of  columnar  cells,  the  germinal  epithelium,  and  has  embedded 
in  it  a  large  number  of  ova  in  all  stages  of  growth,  each  sur- 
rounded by  an  epithelium.  The  ovum,  together  with  its 
enveloping  epithelium,  is  termed  a  Graafian  follicle,  and  such 
follicles  are  present  in  all  stages  of  development  from  the  early 
"  primordial "  follicles  up  to  those  that  are  mature.  Here  only 
the  latter  need  be  considered. 

The  ripe  follicle  is  a  vesicular  structure  containing  a  large 
central  cavity  filled  with  a  fluid,  the  liquor  folliculi,  which 
appears  in  section  as  a  lightly  staining  coagulum.  The  ovum 
is  situated  within  the  cavity  and  usually  towards  one  side.  The 
wall  of  the  follicle  is  formed  by  an  epithelium  several  cells  deep, 
known  as  the  membrana  granulosa,  and  a  special  part  of  the 
membrana,  the  discus  proligerus,  surrounds  the  ovule.  In 
fairly  small  follicles  mitotic  figures  are  by  no  means  uncommon 
in  the  cells  of  the  membrana  granulosa,  but  they  appear  to  be 
entirely  absent  in  the  ripe  follicle. 

The  thickness  of  the  membrana  granulosa  varies  in  different 
parts  of  the  follicle.  It  may  be  six  to  ten  or  even  more  cells 
thick  on  the  inner  side  or  at  the  point  where  it  meets  the  discus 
proligerus,  while  at  its  outer  edge  it  is  thinner,  and  at  the  point 
where  it  will  rupture,  i.e.  the  stigma,  it  is  not  more  than  two  or 
three  cells  thick.  The  outer  limit  of  the  membrana  granulosa 
is  marked  by  a  clear  homogeneous  basal  membrane.  Outside 
this  again  the  follicle  is  surrounded  by  a  fibrous  structure,  the 
theca  folliculi,  derived  from  the  ovarian  stroma.  This  is 
divisible  in  the  Eutheria  into  two  parts,  an  inner  coat  of  more 
or  less  granular  cells,  the  theca  interna,  which  is  very  vascular, 
and  an  outer  coat  of  more  fibrous  nature,  the  theca  externa. 
In  one  of  the  Marsupials  (Dasyurus),  however,  as  Sandes(i9) 
pointed  out,  the  two  layers  of  the  theca  folliculi  cannot  be 
distinguished  one  from  the  other. 

Usually  several  of  these  follicles  attain  maturity  at  the  same 
time  and  burst,  discharging  their  contained  ova,  together  with  a 
certain  amount  of  the  liquor  folliculi  and  some  blood.  The 
cause  of  this  rupture  is  obscure,  and  although  it  has  been 
suggested  that  it  is  due  to  a  rise  of  blood  pressure  or  to  the 
stimulation  of  erectile  tissue  in  the  ovary,  a  satisfactory 
explanation  is  not  yet  forthcoming. 

The  mammals  fall  into  two  classes,  according  to  the  manner 


THE  CORPUS  LUTEUM  723 

of  their  ovulation,  which  may  be  either  spontaneous  or  not. 
According  to  Ancel  and  Bouin  (1)  in  animals  in  which  ovulation 
is  not  spontaneous,  i.e.  it  requires  the  additional  stimulus  of 
coition  to  provoke  it,  only  one  kind  of  corpus  luteum  is  to  be 
found,  the  "  corpus  luteum  gestative"  and  this  body,  however 
produced,  always  becomes  fully  grown  and  is  of  long  duration. 
In  the  remaining  mammals,  where  ovulation  occurs  spon- 
taneously, two  varieties  of  corpora  are  encountered.  Firstly, 
during  each  pregnancy  a  "  corpus  luteum  gestative "  is  formed 
similar  to  that  in  the  preceding  group.  Secondly,  in  non- 
pregnant females  at  each  heat  period  corpora  lutea  are  formed. 
These  do  not  become  full-grown  and  have  but  a  transitory 
existence  and  are  termed  "  corpora  lutea  pe'riodiques."  This  does 
not  appear  to  apply  universally  however,  for  in  a  Marsupial 
(Dasyurus  (15)),1  although  the  ovulation  is  spontaneous,  it  is 
not  possible  to  distinguish  between  the  corpora  lutea  in  the 
pregnant  and  non-pregnant  females. 

It  is  perhaps  better  to  retain  the  terminology  in  use  before 
the  work  of  Ancel  and  Bouin,  as  it  applies  equally  well  to  either 
group  of  mammals.     Thus  : 

The  corpus  luteum  verum  is  the  structure  that  forms  in  the 
ruptured  follicle  in  the  ovary  of  a  female  when  pregnancy  follows 
ovulation. 

The  corpus  luteum  spurium  is  the  structure  that  forms  in  the 
ruptured  follicle  in  the  ovary  of  a  female  when  ovulation  is  not 
followed  by  pregnancy. 

Still  another  term  is  to  be  found  in  older  works,  namely 
corpus  luteum  atreticum.  It  is  applied  to  an  ////ruptured  follicle 
undergoing  atrophy,  i.e.  an  atresic  follicle,  and  as  it  is  not 
comparable  in  structure  with  either  of  the  foregoing  it  will  not 
be  dealt  with  here. 

Growth  and  Structure  of  the  Corpus  Luteum  Verum 

Immediately  after  the  discharge  of  the  ovum  the  follicle 
shrinks  considerably.  In  some  animals  the  cells  of  the 
membrana  granulosa  come  together  so  as  to  close  the  point 
of  rupture  by  a  plug  of  epithelial  cells  (Bouchon  epithelial), 
while  in  others  apparently  the  opening  may  persist  for  some 
time.     The  interior  of  the  body  which  is  now  a  corpus  luteum 

1  This  has  since  been  shown  to  be  the  case  in  certain  other  marsupials  (i6a). 


724  SCIENCE  PROGRESS 

contains  a  large  space  filled  with  liquor  folliculi  and  in  some 
cases  a  certain  amount  of  extravasated  blood.  All  parts  of  the 
follicular  wall  now  take  part  in  the  changes  leading  to  the 
formation  of  the  fully  grown  corpus  luteum.  The  membrana 
propria  is  burst  through  in  a  large  number  of  places  by  active 
irruptions  of  the  theca  folliculi,  which  sends  shoots  of  connective 
tissue  towards  the  centre.  With  these  connective  tissue 
sprouts,  new  blood  vessels  enter  the  corpus  luteum,  and  in 
their  immediate  neighbourhood  the  membrana  propria  becomes 
lost,  although  in  other  places  it  persists  for  some  time. 
Simultaneously  with  this  invasion  the  cells  of  the  membrana 
granulosa  gradually  become  transformed  into  lutein  cells  and 
start  to  fill  up  the  central  cavity. 

On  account  of  the  ingrowths  from  the  theca,  the  membrana 
granulosa  cells  become  divided  up  into  groups,  so  that  the  young 
corpus  luteum  presents  a  lobulated  appearance.  Very  soon, 
however,  the  irruptions  burst  through  the  membrana  cells  and 
reach  the  central  cavity,  where  they  form  ultimately  a  plug  of 
connective  tissue. 

In  the  ripe  follicle  the  epithelial  cells  are  small  and  crowded 
together  as  if  under  pressure.  During  the  invasion  of  the  thecal 
ingrowths  these  cells  undergo  a  great  hypertrophy  both  of  the 
nucleus  and  the  cell  body  and  become  much  less  tightly  packed 
together.  Their  cytoplasm  also  becomes  more  and  more  granu- 
lar, the  granules  giving  to  the  cells  that  intense  yellow  colour 
so  characteristic  of  this  body,  and  the  granulation,  which  be- 
comes more  marked  as  the  formation  proceeds,  certainly  sug- 
gests a  secretory  activity  on  the  part  of  the  lutein  cells. 

The  matrix  of  the  fully  developed  corpus  luteum,  then, 
contains  two  distinct  kinds  of  cells,  the  lutein  cells  and  the  con- 
nective tissue  network  and  central  plug.  Opinion  is  divided  as 
to  the  origin  of  both  of  these,  and  it  will  be  convenient  to  deal 
with  each  of  them  separately. 

With  regard  to  the  lutein  cells  two  main  theories  have  been 
advanced.  On  the  one  hand,  Von  Baer  in  1827  (22)  suggested 
that  the  entire  corpus  luteum  was  derived  from  connective  tissue 
and  that  the  membrana  granulosa  took  no  part  in  its  formation, 
and  was  either  discharged  with  the  ovum  or  degenerated  in  situ. 
On  the  other  hand,  Bischoff  in  1842  (4)  stated  that  the  lutein  cells 
were  formed  by  the  hypertrophy  of  the  cells  of  the  membrana 
granulosa  and   not   from   the   theca,  which   only  supplied   the 


THE  CORPUS  LUTEUM  725 

connective  tissue.  Both  views  have  received  a  considerable 
number  of  supporters,  but  largely  owing  to  the  work  of  Sobotta 

(20)  the  balance  is  in  favour  of  Bischoff's  view.     Van  der  Stricht 

(21)  has  put  forward  yet  another  theory,  that  the  lutein  cells 
were  derived  not  only  from  the  cells  of  the  membrana  granulosa, 
but  also  in  small  part  from  the  cells  of  the  theca  interna. 
On  the  whole,  then,  it  appears  that  the  lutein  cells  are 
derived  from  the  cells  of  the  membrana  granulosa,  although 
in  some  cases  perhaps  some  of  them  may  also  be  derived  from 
the  theca  interna.  Moreover,  although  certain  investigators 
(e.g.  Sobotta  and  Van  der  Stricht)  have  described  the  very 
occasional  appearance  of  mitotic  figures  in  the  lutein  cells  of  the 
growing  corpus  luteum,  there  is  no  doubt  that  by  far  the  greater 
number  of  these  cells  are  simply  the  transformed  and  hyper- 
trophied  cells  of  the  membrana  granulosa. 

All  investigators  agree  that  the  connective  tissue  network  is 
derived  from  the  theca  folliculi,  but  differ  in  describing  the  parts 
taken  by  its  constituent  layers.  It  is  stated  that  the  network  is 
derived  from  the  theca  interna  alone  or  from  this  and  also  from 
the  theca  externa.  In  the  Marsupial,  Dasyurus,  one  cannot  dis- 
tinguish between  these  two  layers  of  the  theca.  The  part 
played  by  each  layer  is  not  yet  decided  or  may  perhaps  vary  in 
different  species. 

The  blood  vessels  of  the  corpus  luteum  appear  to  take  their 
origin  from  the  vessels  of  the  theca  interna  and  have  walls  com- 
posed of  a  single  layer  of  flattened  endothelial  cells.  They  form 
a  network  of  cavities  and  resemble  the  "sinusoids  "  in  the  liver 
and  kidney  of  an  Amphibian.  Definite  blood  vessels  with  the 
structure  of  venules  or  arterioles  are  not  found  in  the  corpus 
luteum. 

The  duration  of  this  body  is  not  known  accurately ;  it  takes 
but  a  few  days  to  form  and  is  generally  stated  to  reach  its 
maximum  development  about  the  middle  of  pregnancy,  and  after 
that  period  to  decrease  gradually,  lasting  about  three  months  in 
the  rabbit,  and  also  in  Dasyurus.  During  the  later  stages  of  its 
degeneration  it  loses  its  characteristic  yellow  colour  and  be- 
comes fibrous  and  white,  whence  it  is  known  as  the  corpus 
albicans.  It  finally  undergoes  fatty  degeneration  and  is  ab- 
sorbed by  the  aid  of  leucocytes,  while  according  to  some 
observers  a  number  of  its  cells  become  transformed  into 
interstitial   cells. 


?26  SCIENCE   PROGRESS 

The  Corpus  Luteum  Spurium 

According  to  Ancel  and  Bouin,  the  corpus  luteum  spurium 
does  not  assume  the  characters  of  the  corpus  luteum  verum  and 
has  but  a  transitory  existence.  It  is  stated,  however,  that  in 
man  the  false  corpus  is  similar  in  structure  to  the  true  corpus 
and  originates  in  the  same  way,  although  it  has  but  a  short  life 
and  in  two  months  has  entirely  disappeared.  In  other  animals 
also  it  does  not  appear  possible  to  find  any  difference  in 
structure  between  the  two  corpora  lutea.  Among  the  Eutheria, 
then,  the  corpus  luteum  spurium  is  similar  to  the  corpus  luteum 
verum,  but  may  not  last  for  so  long  a  time.  The  Marsupial, 
Dasyttrus,  also  has  the  two  varieties  of  corpora  lutea  which 
cannot  be  distinguished  in  size  or  structure,  and,  moreover, 
there  does  not  appear  to  be  such  a  marked  difference  in  the 
duration  of  the  two  bodies  (15). 

The  foregoing  statements  apply  on  the  whole  to  the  corpus 
luteum  in  the  Eutherian  mammals,  although,  as  has  been  pointed 
out,  they  apply  equally  well  to  Dasyurus.  According  to  certain 
authors,  the  corpus  luteum  does  not  exist  or  remains  rudi- 
mentary in  vertebrates  whose  eggs  develop  outside  the  mother 
and  in  the  aplacental  mammals  (i.e.  Monotremes  and  Mar- 
supials). In  so  far  as  this  remark  applies  to  the  Monotremes 
and  Marsupials  it  is  not  correct,  for  Platypus  certainly  possesses 
well-marked  corpora  lutea,  as  do  also  the  Marsupials.  In 
Dasyurus,  the  only  Marsupial  that  has  been  investigated  as 
yet,  the  corpus  luteum  is  similar  to  that  of  a  Eutherian  mammal.1 

The  Nature  of  the  Corpus  Luteum 

It  has  been  pointed  out  previously,  but  may  be  reiterated 
here,  that  the  corpus  luteum  has  a  very  glandular  appearance. 
Indeed,  in  the  fully  formed  structure  the  lutein  cells  strongly 
resemble  the  cells  of  an  ordinary  gland  in  a  state  of  secretory 
activity  and  are  epitheloid  in  origin  and  character.  Then,  too, 
the  whole  body  has  a  very  efficient  blood  supply,  by  means  of 
which  the  blood  is  brought  into  close  proximity  with  the  lutein 
cells. 

Many  workers  have  remarked  that  the  ovary,  apart  from  the 

fact  that  it  is  the  seat  of  origin  of  the  female  reproductive  cells, 

is   a   structure  of  great   importance  in  the  metabolism  of  the 

animal  as  a  whole.     Knauer(io)  indeed,  as  the  result  of  a  long 

1  This  is  also  true  of  a  number  of  other  Marsupials  ;  vide  (i6a). 


THE  CORPUS  LUTEUM  727 

series  of  experiments,  came  to  the  conclusion  that  it  is  only  so 
long  as  there  is  a  functional  ovary  present,  that  is  one  that  is 
capable  of  producing  ripe  ova,  that  it  influences  the  general 
metabolism  of  the  body. 

To  Prennant  (17),  in  1898,  belongs  the  honour  of  being  the 
first  to  suggest  that  the  corpus  luteum  was  an  actively  secreting 
gland  of  the  variety  we  now  call  ductless  glands,  i.e.  a  gland  in 
which  the  secretion,  instead  of  being  conveyed  to  a  definite  place 
by  a  duct,  is  transferred  from  the  cells  of  the  gland  into  the 
blood  stream.  Three  years  later  Regaud  et  Policard  (18) 
demonstrated  that  by  means  of  a  special  method  of  staining, 
specific  droplets  of  secretion  can  be  found  in  the  lutein  cells. 
These  droplets  are  coloured  readily  by  Weigert's  stain,  and 
although  similar  to  are  yet  different  from  fat  globules.  Cohn  (5), 
again,  working  on  the  ovary  of  the  rabbit,  found  that  the 
Plessen-Rabonowicz  method  of  staining  brought  out  in  the 
lutein  cells  vesicles  surrounded  by  a  kind  of  capsule  and 
containing  a  substance  resembling  fat  but  not  identical  with  it. 
Other  authors  have  described  an  osmophile  substance  in  these 
cells,  and,  again,  granules  of  a  doubly  refracting  substance. 

As  a  result  of  chemical  analysis  various  substances  are  stated 
to  be  present,  a  substance  sui  generis,  lutein,  cholesterin,  or 
.again  lipoids  with  or  without  phosphorus,  and  also  ethers  of 
cholesterin.  In  his  latest  paper  Van  der  Stricht  gives  a  full 
review  of  the  chemical  aspect  of  the  problem  and  the  reader  is 
referred  thereto  for  further  details. 

The  evidence  available  is  strongly  in  favour  of  regarding  the 
corpus  luteum  as  a  ductless  gland  that  produces  a  specific 
secretion  which  may  be  a  lipoid  or  a  mixture  of  lipoids. 

Thus  we  see  that  in  the  mammalian  ovary  at  recurring  periods 
a  highly  specialised  glandular  structure  producing  a  specific 
secretion  is  developed  which,  after  a  period  of  activity  very 
short  compared  with  the  life  of  the  animal,  disappears  only  to 
be  replaced  subsequently  by  another  similar  body.  Further, 
it  is  noteworthy  that  it  is  present  at  those  times  when  either 
the  animal  becomes  pregnant  or  there  is  a  possibility  of  preg- 
nancy. In  other  words  it  appears  immediately  after  ripe  ova 
have  been  discharged  from  the  ovary.  It  is  perhaps  not  unnatural 
therefore  that  we  should  look  for  some  connection  between  it 
and  the  changes  marking  the  beginning  of  pregnancy.  The 
extent  and  nature  of  these  connections  will  now  be  considered. 
47 


728  SCIENCE  PROGRESS 

The  Functions  of  the  Corpus  Luteum 

Various  views  have  been  advanced  as  to  the  functions  of  this 
gland,  and  it  is  proposed  to  deal  briefly  with  some  of  the  older 
ones  before  passing  to  the'  two  most  recent. 

The  first  is  that  the  corpus  luteum  forms  a  plug  of  tissue  to 
fill  up  the  cavity  of  the  ruptured  follicle  and  so  compensate  for 
the  disturbance  in  the  circulatory  system  caused  by  the  rupture. 
A  second  view,  really  a  modification  of  the  former,  is  that  it 
provides  a  soft  tissue  which  favours  the  growth  of  the  succeeding 
follicles  and  allows  of  the  regrowth  of  blood  vessels  instead  of 
leaving  hard  fibrous  scar  tissue.  These  views  have  met  with 
little  support.  Although  just  after  rupture  the  corpus  luteum  is 
smaller  than  the  follicle,  it  ultimately  grows  and  becomes  a  great 
deal  larger  and  also  possesses  an  elaborate  and  highly  specialised 
histological  structure.  Again,  no  blood  vessel  with  the  structure 
of  an  arteriole  or  venule  is  ever  found  in  the  corpus.  In  view 
of  these  facts  the  foregoing  explanations  of  its  functions  are 
obviously  insufficient. 

Another  theory  that  has  received  a  considerable  amount  of 
support  owes  its  origin  to  Beard  (3).  In  an  interesting  paper  in 
1897  ne  suggested  that  the  function  of  the  corpus  luteum  Was 
to  suppress  ovulation  during  pregnancy  by  causing  the  degenera- 
tion of  the  nearly  ripe  follicles  and  retarding  the  maturation  of 
the  others.  He  stated  also  that  it  disappeared  prior  to  parturi- 
tion in  order  to  allow  of  ovulation  at  that  time,  but  it  only 
effected  a  temporary  suppression  in  the  absence  of  pregnancy, 
hence  the  difference  in  duration  between  the  corpus  luteum 
verum  and  the  corpus  luteum  spurium.  In  a  large  number  of 
animals,  however,  the  corpus  luteum  has  not  disappeared  before 
parturition.  The  suggestion  is  open  to  several  other  criticisms, 
however.  Follicles  may  mature  in  an  ovary  that  has  large  and 
active  corpora  lutea.  The  rabbit  can  ovulate  shortly  after 
parturition,  indeed  by  some  observers  it  is  stated  to  do  so 
spontaneously  at  that  time,  but  well-marked  corpora  lutea  are 
still  present  in  the  ovary.  Again,  in  the  rabbit  and  sometimes 
also  in  the  sheep  and  ferret  and  probably  in  other  mammals  the 
follicles  do  not  burst  spontaneously,  and  in  the  absence  of 
copulation  degenerate  on  their  own  account  without  ever  coming 
under  the  influence  of  a  corpus  luteum.  In  certain  mammals 
only  one  batch  of  follicles  reach  maturity  during  the  breeding 


THE  CORPUS  LUTEUM  729 

season,  so  that  only  one  heat  period  or  oestrus  occurs  instead  of 
a  succession  of  such  periods  as  in  the  higher  mammals  ;  these 
animals  are  termed  moncestrous.  Moncestrous  mammals  have 
a  long  quiescent  period,  in  some  cases  lasting  about  eleven 
months,  and  the  corpora  lutea  have  disappeared  months  before 
another  set  of  follicles  starts  to  mature,  and  so  the  inhibitory 
influence  throughout  this  period  cannot  be  regarded  as  due  to 
the  corpus  luteum.  As  then  follicles  can  mature,  while  corpora 
lutea  are  present  and  in  the  absence  of  such  bodies  the  follicles 
in  some  cases  degenerate  and  in  others  do  not  mature,  this 
theory  of  Beard  is  also  unsatisfactory. 

Loeb  (12)  investigated  this  point  in  guinea-pigs.  He  first 
ascertained  the  time  elapsing  between  two  successive  ovulations, 
the  first  following  coition  and  the  second  spontaneous,  and 
found  that  in  no  case  was  it  less  than  fifteen  days  and  in  the 
majority  it  was  more  than  nineteen.  A  second  series,  in  which 
the  corpora  lutea  were  extirpated  during  the  first  day  of  their 
growth,  was  examined,  and  it  was  found  that  after  sixteen  days 
all  those  in  which  the  extirpation  had  been  complete  had 
ovulated.  On  the  other  hand,  in  a  certain  number  of  cases  in 
which  the  extirpation  was  incomplete  and  some  of  the  corpus 
luteum  tissue  was  left,  ovulation  had  not  occurred  eighteen  or 
twenty  days  after.  It  has  been  claimed  that  these  experiments 
support  Beard's  hypothesis  that  the  function  of  the  corpus 
luteum  is  to  prevent  ovulation.  What  they  do  show,  however, 
is  that  the  removal  of  these  structures  tends  to  hasten  the  next 
ovulation.  The  criticisms  advanced  above  apply  also  in  this 
case  and  in  the  moncestrous  mammals  a  suppression  of  ovulation 
takes  place  without  the  intervention  of  corpora  lutea.  So  that 
although  it  may  be  said  that  the  presence  of  a  corpus  luteum 
tends  to  retard  ovulation  it  cannot  be  claimed  that  this  is  its 
main  function. 

Two  hypotheses  now  remain,  which,  in  the  light  of  our 
present  knowledge,  appear  more  satisfactory,  and  it  is  proposed 
to  deal  with  them  separately. 

Uterine  Changes  in  Early  Pregnancy 

The  first  concerns  the  changes  in  the  uterus  during  the  first 
stages  of  pregnancy,  and  owes  its  origin  to  Gustav  Born.  It  is 
that  the  corpus  luteum  provides  an  internal  secretion  which 
assists  in  the  attachment  of  the  embryo  to  the  lining  of  the 


730  SCIENCE  PROGRESS 

uterus,  i.e.  to  the  uterine  mucosa.  The  experimental  examina- 
tion of  this  hypothesis  was  first  made  by  Fraenkel  and  Cohn  (6), 
who  found  that  the  removal  of  both  ovaries  from  rabbits  at 
various  times  during  the  first  six  days  of  pregnancy  brought 
about  its  cessation.  Since  then  a  number  of  observers  have 
conducted  similar  experiments  on  various  animals,  dogs,  rats, 
and  guinea-pigs.  Although  different  times  were  obtained  in  the 
separate  species,  all  the  results  confirm  that  for  rabbits,  namely, 
that  if  the  two  ovaries  be  removed  during  the  first  part  of 
pregnancy,  it  is  invariably  stopped.  Removal  of  the  ovaries  at 
a  later  stage  did  not  have  any  effect. 

It  is  clear,  then,  that  the  presence  of,  at  any  rate,  one  ovary 
is  absolutely  necessary  to  the  implantation  and  maintenance  of 
the  embryo  during  the  early  stages  of  that  process. 

These     investigations     were     pressed     still     further,     and 

Fraenkel  (7)  tried  the  result  of  removing  the  corpora  lutea  by 

electric  cautery.      Control   animals   were   employed   in  which 

some  of  the  corpora  lutea  were  left  untouched.     It  was  found 

that  the  complete  removal  of  all  the  corpora  lutea  from  both 

ovaries  resulted  in  the  termination  of  pregnancy  if  performed 

within  the   first  six  days,  whereas,  so  long  as  some  of  these 

-structures  were  left,  pregnancy  as  a  general  rule  pursued  its 

normal  course.      Similar  experiments   have  been  repeated   by 

'Other  workers,  and  the  results  fully  confirm  the  previous  ones. 

Further  evidence  of  a  less  direct  nature,  but  also  bearing  on 
this  point,  is  forthcoming.  It  is  found  that  in  the  rabbit,  if 
•ovulation  be  provoked  by  sterile  coitus,  the  formation  of  corpora 
ilutea  takes  place,  and  simultaneously  there  occur  an  enlarge- 
ment and  vascularisation  of  the  uterus.  After  the  thirteenth 
day  repression  begins  in  the  uterus,  and  by  this  time  also  the 
corpus  luteum  is  on  the  wane. 

The  placenta,  by  means  of  which  the  embryo  is  attached  to 
the  uterine  wall,  is  composed  of  two  parts,  one  of  embryonic 
and  one  of  maternal  origin.  Loeb  (13)  found  that  he  could 
produce  deciduomata,  the  maternal  part  of  the  placenta,  by 
making  a  series  of  transverse  cuts  in  the  uterus,  by  injecting 
paraffin  wax,  and  by  inserting  pieces  of  glass  or  platinum. 
These  structures,  however,  could  only  be  produced  from  one 
to  ten  days  after  ovulation,  that  is,  only  during  the  time  that 
young,  active  corpora  lutea  are  present  in  the  ovary,  but  can 
be  produced  during  that  time  even  though  the  discharged  ova 


THE  CORPUS  LUTEUM  731 

be  excluded  from  the  uterus.  As  the  uterine  growth  did  not 
take  place  in  the  absence  of  mechanical  stimulation,  it  appears 
as  if  the  formation  of  the  maternal  part  of  the  placenta  is  due 
to  two  causes :  Firstly,  the  presence  of  corpora  lutea  in  the 
ovary  conditions  the  possibility  of  its  formation,  and  secondly, 
a  mechanical  stimulus,  supplied  normally  by  the  fertilised  ovum, 
calls  forth  the  response. 

The  experimental  evidence  therefore  shows  that  there  is  an 
intimate  connection  between  the  corpora  lutea  and  the  early 
uterine  changes.  The  nature  of  this  connection  will  now  be 
discussed. 

During  the  above  inquiry  into  the  production  of  deciduomata 
it  was  noticed  that  if  the  corpora  lutea  were  all  removed  the 
first  day  or  two  after  ovulation  no  response  could  be  obtained. 
If  they  were  removed  six  days  afterwards  the  response, 
although  obtained,  was  not  so  marked  as  if  the  ovaries  were 
left  intact,  so  that  the  effect  of  the  corpora  lutea  is  cumulative. 
Again,  portions  of  the  uterus  transplanted  to  the  sub-cutaneous 
tissue  also  produced  deciduomata  if  the  transplantation  was 
carried  out  from  five  to  seven  days  after  ovulation.  If  when 
the  uterine  tissue  was  transplanted  the  ovaries  were  also 
extirpated,  it  was  found  that  the  response  was  not  nearly  so 
marked  as  if  the  transplantation  alone  had  been  effected  but 
the  ovaries  not  interfered  with.  These  transplanting  experi- 
ments appear  to  exclude  the  possibility  of  the  stimulation  being 
nervous  in  nature,  and  the  fact  that  it  is  cumulative,  even  when 
the  uterus  is  removed  to  another  part  of  the  body,  suggests 
that  the  stimulus  is  a  chemical  one  carried  by  the  blood. 

To  sum  up  briefly,  then :  The  presence  of  a  corpus  luteum 
is  essential  to  the  uterine  changes  connected  with  the  implanta- 
tion of  the  ovum;and  its  maintenance  during  the  early  stages 
of  pregnancy.  Under  the  influence  of  the  corpus  luteum  the 
uterine  mucosa  becomes  so  sensitised  that  it  will  form  the 
maternal  part  of  the  placenta  in  response  to  a  certain  stimulus 
normally  provided  by  the  fertilised  ovum,  but  which  may  be 
replaced  by  a  mechanical  one.  Some  evidence  is  also  available  to 
show  that  the  stimulus  is  a  chemical  one  carried  by  the  blood. 

The  Mammary  Gland  Growth  in  Early  Pregnancy 

The  second  of  the  two  hypotheses  concerns  the  relation 
existing  between  the  corpus  luteum  and  the  mammary  glands. 


732  SCIENCE   PROGRESS 

The  credit  of  being  the  first  to  conduct  "an  experimental 
inquiry  into  the  factors  which  determine  the  growth  and 
activity  of  the  mammary  glands"  belongs  to  Lane-Claypon 
and  Starling  (u),  who  in  1906  tried  the  effect  of  the  injection 
of  extracts  of  ovaries,  placentae,  and  foetuses.  They  came  to 
the  conclusion  that  the  growth  of  the  mammary  gland  during 
pregnancy  is  due  to  the  action  of  a  specific  chemical  stimulus 
produced  in  the  fertilised  ovum.  Similar  experiments  have  been 
repeated  without  a  uniformity  of  the  results. 

These  authors  further  state  that  the  source  of  the  stimulus 
during  early  pregnancy  may  be  located  in  the  chorionic  villi, 
i.e.  a  part  of  the  placenta.  Halban  (8),  who  gathered  a  great 
deal  of  clinical  evidence,  also  considers  the  placenta  as  the 
tissue  in  which  the  chemical  stimulus  inciting  growth  in  the 
mammary  glands  is  produced.  This  view,  however,  is  open 
to  criticism.  In  Dasyurus,  a  Marsupial  (14),  the  main  growth 
of  the  glands  has  occurred  before  the  attachment  of  the  embryo, 
which  does  not  take  place  until  late,  and  therefore  before  the 
formation  of  the  placenta.  In  the  Monotremes,  the  egg-laying 
mammals,  of  course  no  placenta  is  ever  formed  :  although  in 
both  these  cases  there  is  a  growth  of  the  mammary  glands.  A 
full  functional  development  of  these  glands  may  be  experienced 
by  virgins,  and  therefore  without  any  stimulus  from  a  foetus. 
In  hunting  kennels  also  it  is  not  very  uncommon  for  a  bitch 
that  has  failed  to  become  pregnant  to  experience  such  a  growth 
of  the  breasts  that  she  is  able  to  suckle  the  pups  of  another 
mother  who  for  some  reason  or  other  is  unable  to  do  so  herself. 
In  Dasyurus  the  mammary  glands  in  the  non-pregnant  female 
undergo  a  growth  identical  with  those  in  the  pregnant  female, 
and  reach  a  state  of  development  comparable  with  that  in  the 
mother  thirty-six  hours  after  the  birth  of  the  young. 

Although  it  is  not  improbable  that  the  presence  of  a  foetus  and 
its  attachment  may  influence  the  very  great  growth  and  activity 
of  the  mammary  gland  in  the  pregnant  female,  the  foregoing 
facts  show  that  neither  fertilised  ovum  nor  placenta  is  necessary, 
and  therefore  neither  of  these  can  be  regarded  as  primarily 
responsible  for  the  production  of  the  stimulus.  Halban  himself, 
although  looking  to  the  placenta  in  pregnancy,  admits  that  at 
puberty,  at  the  menstrual  periods,  and  in  pathological  cases, 
that  is  to  say,  cases  of  abnormal  growths  in  the  ovary,  it  is  in 
the  ovary   that  the  stimulus  inciting   growth  in  the  mammary 


THE  CORPUS  LUTEUM  733 

glands  is  produced.     It  is  hard  to  see  why  if  the  ovary  may  be 
effective  at  one  time  it  should  not  also  be  effective  at  another. 

Several  authors  have  pointed  out  that  the  removal  of  both 
ovaries  before  puberty  prevents  its  onset  with  the  accompanying 
growth  of  the  mammary  glands.  It  is  well  known  too  that  there 
is  a  growth  of  these  glands  at  puberty  and  again  at  each  cestral 
period.  In  connection  with  the  latter  an  interesting  case  has 
been  cited  of  a  woman  with  supernumerary  mammary  glands 
which  not  only  enlarge  but  actually  secrete  milk  at  each  cestral 
period.  All  these  enlargements  of  course  synchronise  with 
periods  of  ovarian  activity  which  include  ovulation  and  the 
formation  of  corpora  lutea. 

In  the  course  of  their  experiments  Lane-Claypon  and  Starling 
noted  that  if  the  ovaries  and  uteri  were  removed  from  a  rabbit 
before  the  fourteenth  day  of  pregnancy  the  mammary  glands 
return  to  a  state  of  rest  without  giving  milk.  If  the  same 
operation  were  performed  after  that  time  milk  was  expressible 
within  two  days,  that  is  to  say,  the  glands  had  reached  a  stage 
of  development  at  which  they  could  become  functionally  active. 
But  the  corpora  lutea  have  also  reached  their  maximum  growth 
by  the  fourteenth  day  and  after  that  time  begin  to  diminish. 

All  these  points,  considered  in  the  light  of  what  is  already 
known  of  the  connection  between  the  uterine  changes  and  the 
corpora  lutea,  suggest  the  probability  of  a  relation  between  these 
bodies  and  the  mammary  glands. 

Turning  now  to  consider  the  condition  in  the  Marsupial, 
Dasyurus  viverrimis,  we  find  that  the  adult  resting  gland 
consists  of  six  main  ducts  lined  with  an  epidermis  four  or  five 
cells  thick.  Some  distance  below  the  epidermis  each  duct 
breaks  up  into  a  number  of  branching  tubules,  lined  with  an 
epidermis  two  cells  thick.  The  growth  of  the  gland  falls  into 
two  distinct  phases.  Firstly,  the  stage  of  actual  formative 
growth  during  which  the  glandular  cells  lining  the  mammary 
tubules  increase  rapidly  by  mitotic  division  and  in  which  the 
total  number  of  cells  is  increased  many  times.  As  a  result  of 
this  growth  the  mammary  tubules  become  much  more  ramified 
and  throughout  their  length  hollow  bud-like  outgrowths,  the 
primitive  alveoli,  are  formed.  Towards  the  end  of  this  period 
the  lumina  of  the  tubules  and  their  outgrowths  begin  to  enlarge 
and  the  cells  lining  them  begin  to  arrange  themselves  in  a  single 
layer.     Secondly,    a  stage   of  enlargement,   during  which   the 


734  SCIENCE   PROGRESS 

epithelial  cells  no  longer  multiply  and  mitoses  are  absent  from 
them,  but  each  individual  cell  increases  markedly  in  size  and 
commences  to  secrete.  The  cells  of  alveoli  and  tubules  become 
arranged  in  a  single  layer,  and  as  a  result  of  their  secretory 
activity  the  alveoli  and  ducts  become  greatly  distended.  It  is  this 
second  stage  that  is  the  more  noticeable  in  external  examination. 

An  interesting  correlation  is  seen  between  the  formation  and 
growth  of  the  corpus  luteum  and  the  growth  phase  of  the 
mammary  glands.  As  soon  as  the  corpus  luteum  is  formed  the 
mammary  gland  starts  to  grow.  This  growth  is  noticeably 
increased  after  the  body  is  fully  formed,  a  stage  characterised  by 
the  presence  of  plentiful  granules  in  the  lutein  cells.  Later  the 
corpus  luteum  reaches  its  maximum  and  remains  constant,  and 
shortly  after  the  cells  of  the  mammary  gland  cease  to  multiply. 
This  correlation,  which  holds  good  whether  the  female  be 
pregnant  or  not,  suggested,  taking  into  account  the  other  evidence, 
that  it  was  very  probable  that  the  corpus  luteum,  in  addition  to 
its  other  functions,  is  intimately  connected  with  if  not  indeed 
the  point  of  origin  of  the  stimulus  inciting  growth  in  the 
mammary  glands. 

Other  evidence  regarding  the  relation  of  the  two  structures 
was  already  in  existence  when  the  foregoing  conclusion  was 
independently  arrived  at.  Ancel  and  Bouin  (2)  showed  that  if 
corpora  lutea  are  produced  in  the  rabbit,  either  by  copulation 
with  a  male  previously  rendered  sterile  or  by  artificial  rupture 
of  the  follicle,  a  growth  of  the  mammary  gland  follows.  This 
growth,  very  noticeable  about  the  fourth  day,  ceases  about 
the  fourteenth  day  and  regression  then  takes  place. 

Similar  experiments  have  been  performed  (16)  which  confirm 
these  results  in  their  essential  points.  It  was  found,  however, 
that  the  rupture  of  the  ripe  follicles  was  not  invariably  followed 
by  the  formation  of  corpora  lutea,  but  this  provided  a  strong 
piece  of  negative  evidence.  The  results  may  be  summarised  as 
follows.  1.  If  the  rupture  of  the  follicle  was  followed  by  the 
formation  of  corpora  lutea  there  was  also  a  growth  of  the 
mammary  glands.  The  amount  of  growth  in  fourteen  or  fifteen 
days  was  about  equal  to  that  in  the  normal  pregnant  animal  of 
twelve  days.  2.  On  the  other  hand,  if  the  follicular  rupture  was 
not  succeeded  by  the  formation  of  corpora  lutea,  there  was  no 
growth  of  the  mammary  glands,  although  the  operation  per- 
formed was  precisely  similar  in  the  two  cases. 


THE  CORPUS  LUTEUM  735 

As  in  the  case  of  the  uterine  changes,  so  also  here  the 
experimental  evidence  points  strongly  to  a  connection  between 
the  corpora  lutea  and  mammary  gland  growth.  Again  also  the 
facts  indicate  that  the  connection  is  a  chemical  one. 

The  nerves  supplying  the  mammary  gland  in  the  goat  were 
cut  without  interfering  with  the  growth  of  the  gland  during 
pregnancy  or  consequent  lactation.  In  ,the  dog  the  spinal  cord 
was  severed  above  the  point  of  origin  of  the  ovarian  nerves,  and 
a  similar  lesion  resulting  from  an  accident  is  also  recorded  in  a 
woman,  and  in  neither  case  were  the  growth  and  activity  of  the 
mammary  gland  interfered  with.  These  seem  to  exclude  the 
possibility  of  any  nervous  stimulation.  In  the  guinea-pig, 
however,  single  mammary  glands  have  been  transplanted  to 
the  subcutaneous  tissue  behind  the  ear  without  the  growth 
during  pregnancy  being  interfered  with,  so  that  the  stimulus- 
in  these  cases  must  have  been  a  chemical  one  carried  by  the 
blood. 

The  use  of  the  term  hormone  has  been  carefully  avoided 
because  as  yet  no  definite  evidence  has  been  adduced  to  show 
that  the  corpora  lutea  produce  a  specific  secretion  which  when 
poured  into  the  blood  stream  directly  influences  the  mammary 
glands.  As  has  been  indicated  above,  the  presumptive  evidence 
is  strongly  in  favour  of  such  a  direct  chemical  stimulus,  but  the 
experiments  of  injecting  corpus  luteum  extract  that  have  been 
tried  up  to  the  present  have  yielded  only  negative  results.  This 
failure,  however,  may  simply  be  because  the  technique  was  at 
fault. 

It  has  been  attempted  in  the  foregoing  to  set  out  the  evidence 
now  available  to  show  that  the  corpus  luteum  is  a  well-marked,, 
glandular  body  with  a  very  definite  and  characteristic  histological 
structure  that  periodically  forms  and  disappears  in  the  mamma- 
lian ovary — that  it  secretes  a  substance  of  lipoid  nature. 
While  present  in  the  ovary  corpora  lutea  may  retard  subsequent 
ovulation.  Its  principal  work  appears  to  be  that  by  means  of  a 
chemical  stimulus  acting  directly  or  indirectly  it  controls  the 
uterine  changes  necessary  for  the  attachment  of  the  embryo  in 
the  early  stages  of  pregnancy  and  also  incites  the  formative 
growth  of  the  mammary  glands  during  the  same  and  at  other 
times. 

The  corpus  luteum,  then,  is  a  gland  that  is  present  in  a  well- 
developed  condition  in  the  three  sub-classes  of  the  Mammalia,, 


736  SCIENCE  PROGRESS 

and  we  must  conclude  therefore  either  that  it  took  its  origin 
de  novo  in  that  class  or  that  its  representative  is  to  be  found  in 
lower  classes  of  the  Vertebrata.  Little  is  known  with  certainty 
concerning  the  follicular  changes  following  ovulation  in  the 
lower  vertebrates,  for  the  accounts  given  by  the  few  workers 
who  have  investigated  these  phenomena  do  not  agree.  Wallace 
(23)  describes  an  enlargement  of  the  epithelial  cells  accompanied 
by  a  more  or  less  marked  invasion  of  the  connective  tissue  and 
blood  vessels  in  certain  fish,  although  according  to  some  preced- 
ing workers  no  such  hypertrophy  occurs.  It  is  also  stated  that 
a  somewhat  similar  series  of  changes  takes  place  in  certain 
reptiles,  and  so  here  perhaps  we  may  have  the  morphological 
forerunner  of  the  corpus  luteum. 

For  the  origin  of  its  two  main  functions  described  above  we 
shall  have  to  search  within  the  limits  of  the  class  Mammalia 
itself,  for  both  are  concerned  with  processes  that  are  character- 
istically and  exclusively  mammalian.  Indeed  the  formation  of 
a  placenta  is  a  process  that  itself  originates  among  the  mammals, 
for  it  is  not  found  in  the  lowest  sub-class,  the  Monotremata. 
These  animals  (Monotremes)  possess  corpora  lutea,  however, 
which  therefore  furnish  an  example  of  a  gland  taking  on  a  further 
and  new  function  within  the  same  class  of  animals.  Moreover, 
the  mammary  glands  are  found  in  all  three  sub-classes  of  the 
Mammalia  and  are  so  characteristic  that  from  their  presence  the 
name  of  the  whole  class  is  derived. 

Bibliography 

It  is  not  possible  or  desirable  to  give  here  a  full  list  of  the 
extensive  literature  of  this  subject.  Certain  outstanding  papers 
have  been  referred  to,  and  these,  together  with  some  of  the 
latest  investigations  on  the  subject,  are  given  below.  In  most 
of  these  is  to  be  found  a  list  of  references  to  other  works.  The 
reader  is  also  referred  to  The  Physiology  of  Reproduction,  by 
F.  H.  A.  Marshall  (London,  1910). 

1.  Ancel  et  Bouin,  Sur  les  Homologies  et  la  Signification  des  Glandes  a  Secre- 

tion interne  de  l'ovaire,  Comptes  Rend,  de  la  Soc.  Biol.  t.  lxvii.  1909. 

2.  ,  Le  developpement  de  la  Glande  mammaire  pendant  la  Gestation  est 

determine  par  le  Corps  jaune,  Comptes  Rend,  de  la  Soc.  Biol.  t.  lxvii.  1909. 

3.  Beard,  Rhythm  of  Reproduction  in  Mammalia,  Anal.  Anzeig.  Bd.  iv.  1897  ; 

The  Span  of  Gestation  and  the  Cause  of  Birth,  Jena,  1897. 

4.  Bischoff,  Entwickelungsgeschichte  des  Kanenchenseies,  Braunschweig,  1842. 


THE  CORPUS  LUTEUM  737 

5.  COHN,  Zur  Histologic  und  Histogenese  des  Corpus  luteum  und  des  inter- 

stitiellen  Ovarialgewebes,  Inaug.  Dissert.,  Breslau,  1903  ;  under  the  same 

title  in  Arch.  f.  mikr.  Anat.  Bd.  lxii.  1903. 
•6.  Fraenkel  und  Cohn,  Experimentelle  Untersuchungen  iiber  den  Einfluss 

des  Corpus  luteum  auf  die  Insertion  des  Eies,  Anat.  Anzeig.  Bd.  xx.  1901. 
7.  Fraenkel,  Die  Function  des  Corpus  luteum,  Arch.  f.  Gynakol.  Bd.  lxviii. 

1903. 
S.  Halban,  Die  innere  Secretion  von  Ovarium  und  Placenta  und  ihre  Bedeutung 

fur  die  Function  der  Milchdriise,  Archiv  f.  Gynakol.  Bd.  lxxv.  1905. 
9.  Hill  and  O'Donoghue,  The  Reproductive  Cycle  of  the  Marsupial,  Dasyums 

viver  rimes,  Quart.  J  our.  Micro.  Sci.  vol.  lix.  19 13. 
no.  Knauer,  Die  Ovarientransplantation,  Archiv f.  Gynakol.  Bd.  lx.  1900. 
31.  Lane-Claypon  and  STARLING,  An  Experimental    Inquiry  into  the  Factors 

which  Determine  the  Growth  and  Activity  of  the  Mammary  Glands,  Proc. 

Roy.  Soc.  B.  vol.  lxxvii.  1906. 

12.  LOEB,    Ueber  die    Bedeutung   des    Corpus  luteum   fur  die    Periodizitat   des 

sexuellen   Zyklus   beim  Weiblichen   Sangetierorganismus,   Deutsch.   Med. 
Woch.  i9ii,xxvii.  17. 

13.  ,  The  Experimental  Production  of  the  Maternal  Placenta  and  the  Function 

of  the  Corpus  Luteum,  Jour.  Amer.  Med.  Assoc.  1909,  liii.  1471. 

.14.  O'DONOGHUE,  The  Growth-changes  in  the  Mammary  Apparatus  of  Dasyums 
and  the  Relation  of  the  Corpora  lutea  thereto.  Quart.  Jour.  Micro.  Sci. 
vol.  lvii.  191 1  ;  also  the  Relation  between  the  Corpus  luteum  and  the 
Growth  of  the  Mammary  Gland,  Proc.  Physiol.  Soc.  ;  Journal  of  Physiol. 
vol.  xliii.   191 1. 

35.  ,  The    Corpus   luteum  in   the  Non-pregnant  Dasyums  and   Polyovular 

Follicles  in  Dasyurus,  Anat.  A?ts.  Bd.  41,  1912. 

36.  ,  The  Artificial   Production  of  Corpora  lutea  and  their  Relation  to  the 

Mammary  Gland,  Proc.  Physiol.  Soc,  Feb.  15,  191 3,  Jour,  of  Physiol. 
xlvi.  1913. 

J6a.  ,  Ueber  die  Corpora  lutea  bei  einigen  Benteltieren,  Archiv  f.  mikroskof. 

Anat.  Bd.  84,  abt.  ii.  1913. 

17.  Prenant,    La  Valeur  morphologique   du    Corps  jaune,  etc.,  Rev.   Gen.  des 

Sciences  Pures  et  Appliquecs,  1898. 

18.  Regaud  et  Policard,  Function  glandulaire  de  l'Epithelium  ovarique  chez 

la  chienne,  Comptes  Rend,  de  la  Soc.  Biol.  t.  liii.  1901. 

19.  Sandes,  The  Corpus  luteum  of  Dasyurus  viverrinus,  with  Observations  on 

the  Growth  and  Atrophy  of  the  Graafian  Follicle,  Proc.  Linn.  Soc.  New 
South  Wales,  1903. 

20.  SOBOTTA,  Numerous  papers,  reference  to  which  may  be  found  in  the  latest, 

viz.  :  Ueber  die  Bildung  des  Corpus  luteum  beim  Meerschweinchen, 
Anat.  Hefte.  Bd.  xxxii.  1906. 

21.  Van  der  Stricht,  Sur  le  processus  de  l'excretion  des  glandes  endocrines: 

Le  Corps  jaune  et  la  glande  interstitielle  de  l'ovaire,  Archiv  de  Biol. 
t.  xxvii.  191 2.  Contains  a  full  literature  list  with  references  to  the  author's 
other  papers. 

22.  VON  Baer,  De  Ovi  Mammalium  et  Hominis  Genesi  Epistola,  Lipsice,  1827. 

23.  Wallace,  Observations  on  Ovarian  Ova,  etc.,  Quart.  Jour.  Micro.  Sci. 
vol.  xlvii.  1903.  ^<£TF«  i 

v   ° 

■J*  .^  *._. 


THE    INFLUENCE   OF  THE   SCIENTIFIC 
MOVEMENT   ON   MODERN   POETRY 

By   E.   A.   FISHER 

Balliol  College,  Oxford  ;  and  S.E.  Agricultural  College,  Wye 

11  Poetry,"  says  Leigh  Hunt,  "  is  the  utterance  of  a  passion  for 
truth,  beauty,  and  power,  embodying  and  illustrating  its  con- 
ceptions by  imagination  and  fancy,  and  modulating  its  language 
on  the  principle  of  variety  in  uniformity.  Its  means  are  what- 
ever the  Universe  contains ;  and  its  ends,  pleasure  and  exaltation. 
Poetry  stands  between  nature  and  convention,  keeping  alive 
among  us  the  enjoyment  of  the  external  and  the  spiritual  worlds  ; 
and,  next  to  Love  and  Beauty,  which  are  its  parents,  is  the 
greatest  proof  to  man  of  the  pleasure  to  be  found  in  all  things, 
and  of  the  probable  riches  of  infinitude.  .  .  .  Poetry,"  he  con- 
tinues, '!  begins  where  matters  of  fact  or  of  science  cease  to  be 
merely  such,  and  it  exhibits  a  further  truth  ;  that  is,  the  connec- 
tion science  has  with  the  world  of  emotion,  and  its  power  of 
producing  imaginative  pleasure.  Inquiring  of  a  gardener,  for 
instance,  what  flower  it  is  we  see  yonder,  he  answers,  '  a  lily.' 
This  is  a  matter  of  fact.  The  botanist  pronounces  it  to  be  of  the 
order  Hexandria  monogynia.  This  is  a  matter  of  science.  It  is 
the  'lady'  of  the  garden,  says  Spenser;  and  here  we  begin  to 
have  a  poetical  sense  of  its  fairness  and  grace.  It  is  '  the  plant 
and  flower  of  light,'  says  Ben  Jonson  ;  and  poetry  then  shows  us 
the  beauty  of  the  flower  in  all  its  mystery  and  splendour."  This 
was  written  some  eighty  years  ago,  when  science  was  in  its 
infancy,  or  rather  in  that  embryo  stage  in  which  all  science  is 
purely  descriptive,  but  it  shows  us  clearly  enough  that,  even  in 
those  early  days  of  scientific  thought,  the  best  literary  minds  of  the 
time  saw  clearly  that  in  matters  of  poetry,  as  in  matters  of  fact 
and  of  science,  we  see  "  the  same  feet  of  nature  treading  in 
different  ways  " ;  that  the  most  scornful  and  dullest  disciple  of 
fact  should  be  cautious  how  he  betrays  the  shallowness  of  his 
philosophy  by  discerning  no  poetry  in  its  depths.     It  is  indeed 

738 


SCIENCE  AND  MODERN   POETRY  739 

not  too  much  to  say  that  science  and  poetry  are  twin  sisters,  so 
intimately  bound  up  are  they  each  with  the  other. 

That  there  is  some  real  connection  between  science  and 
poetry — some  direct  and  real  influence  of  what  we  call  the 
scientific  movement  upon  poetry — is  easily  discernible  and  be- 
comes very  evident  when  we  remember,  as  we  must,  that  although 
the  poet,  like  all  genius,  is  born,  not  made,  that  is,  although 
genius  is  largely  independent  of  time  and  place,  he  is  never- 
theless and  necessarily,  and  to  no  inconsiderable  extent,  a  pro- 
duct of  his  age,  both  as  regards  form  and  content.  For  example, 
Mrs.  Browning,  Tennyson,  Robert  Browning,  Matthew  Arnold — 
to  take  a  few  at  random  of  the  greatest  of  the  Victorian  poets — 
have  indelibly  impressed  the  poetry  of  their  era.  But  it  must 
not  be  forgotten  that  their  greatness — even  though  it  be  the 
greatness  of  genius — does  not  alter  the  fact  that  what  they 
thought  and  what  they  wrote  was  in  large  measure  determined 
for  them  by  the  circumstances  and  ideas  of  the  time  in  which 
they  lived.  This  fact,  though  obvious,  is  often  obscured  in  the 
minds  of  those  people  who  talk  of  great  men  as  being  not  of  an 
age,  but  for  all  time.  It  is  undoubtedly  true  that  great  poets, 
philosophers,  artists,  statesmen,  and  great  men  of  all  kinds,  if  they 
are  only  great  enough,  are  for  all  time  ;  but  it  is  equally  true  that 
they  are,  in  a  sense,  of  their  own  age  first  of  all.  Shakespeare  is 
perhaps  the  first  example,  as  well  as  the  best,  that  comes  to  one's 
mind.  His  literary  form,  the  atmosphere  of  his  poetry — what 
one  might  call  the  mental  dialect  in  which  it  was  written ;  that 
is,  the  presuppositions  which  he  carried  with  him  to  his  work  and 
which  he  owed  entirely  to  his  education  and  environment — 
many  of  his  characteristic  interests  are  Elizabethan.  His 
morality,  too,  is  essentially  that  of  the  age  of  the  later  Tudors 
— so  much,  indeed,  is  this  the  case  that  there  are  not  wanting 
Mrs.  Grundys  at  the  present  day  who  would  willingly  banish 
some  of  his  plays  altogether  from  the  stage.  Again,  the  drama 
was  the  most  popular  form  of  literature ;  and  he  wrote  mainly 
dramas.  Subjects  from  English  History  possessed  a  special 
interest  for  his  audience  and  had  a  special  fascination  for 
writers  of  his  time  ;  and  he  wrote  English  historical  plays. 
The  fact,  therefore,  that  Shakespeare  is  for  all  time  does  not 
prevent  his  being,  in  a  very  real  sense,  of  an  age,  and  of  his 
own  age.  Similar  considerations  apply  to  all  writers  of  every 
age  and  clime.     However  great  a  man  may  be,  the  world  is 


740  SCIENCE  PROGRESS 

greater,  and  we  can  only  hope  to  understand  the  man  and  his- 
work  in  so  far  as  we  view  him  in  his  relation  to  the  spirit 
and  thought  of  his  age.  This  being  so,  it  is  easy  to  see  that 
the  influence  of  science  on  poetry  is  not  a  mere  figment  of  a 
perverted  imagination,  but  is  as  real  as  it  is  lasting ;  for  the 
spirit  of  the  nineteenth  and  twentieth  centuries  was,  and 
is,  essentially  scientific;  and  by  "scientific"  one  must  not  be 
understood  to  mean  "  materialistic,"  which  is  a  philo- 
sophical and  not  a  scientific  term,  and  so  outside  the 
scope  of  this  article.  By  the  scientific  spirit  is  meant 
merely  submission  to  the  conception  of  universal  law.  The 
greatest  intellectual  triumph  of  the  early  part  of  the  nine- 
teenth century  was  the  establishment  of  the  two  laws  of  the 
uniformity  of  Nature  and  of  universal  causation  on  a  firm 
basis  of  experience,  and  the  consequent  elimination  of  the 
supernatural  from  natural  phenomena.  Such  an  intellectual 
revolution  could  not  fail  in  leaving  its  mark  upon  contemporary 
literature,  for  the  simple  reason  that  it  altered  our  whole  con- 
ception of  the  relation  of  man  to  the  Universe. 

This  influence  has  sometimes  been  deplored  on  the  ground 
that  science  means  the  disappearance  of  mystery  and  of  super- 
stition and  so  takes  away  from  the  poet  a  great  deal  of  his  raw 
material.     The  idea  is  quite  a  wrong  one.     It  is  true,  indeed,  it 
is  universally  admitted  that  natural  science  has  had  the  greatest 
possible  influence  in  the  extirpation  of  superstition ;   but  this 
in  no  way  limits  the  activity  of  the  poet.     The  error  is  based  on 
a  confusion  in  thought.     Superstition  is  not  a  necessary  nor  a 
permanent  possession  of  mankind  ;  it  is  but  a  phase — although 
an   inevitable   one — in   human   history.     During   the   period  of 
infancy — alike  of  the  race  as  of  the  individual — in  which  the 
power  of  thought  is  but  slightly   developed,   and   the  reason 
hardly  more  than  a  rudiment,  the  form  given  by  this  faculty  of 
thought  to  the  impressions  of  the  senses  is  very  imperfect  and 
only   superficially   correct.     But   during  his   development  man 
acquires  a  considerable   knowledge  of  himself,  and  his  know- 
ledge of  himself  has,  and  must  necessarily  have,  an  immense 
influence  on  his  comprehension  of  the  world.     He  embodies  all 
his  feelings,  his  desires,  his  fancies  into  the  sensible  world,  and 
imagines   that   everything   around   him   is   living,  feeling,    and 
desiring   as   he   is.      He,   in   fact,   does   and   can    only    regard 
phenomena  in  terms  of  his  own  consciousness.     He  does   the 


SCIENCE  AND  MODERN   POETRY  741 

same  in  religion.  It  was  once  said  by  a  Frenchman — I  forget 
his  name — "  In  the  beginning  God  created  man  in  His  own 
image,  and  since  then  man  has  returned  the  compliment  by 
creating  God  in  his."  The  jibe — for  jibe  it  was— is  really  the 
expression  of  a  fundamental  truth  :  among  all  the  lower  and 
early  religions,  even  as  in  our  own,  the  conception  of  God  is 
essentially  anthropomorphic  like  primitive  man's  conception 
of  Nature.  This  inner  world,  which  man  thus  creates  for 
himself,  is  a  world  of  poetry  and  is  very  different  from  that 
which  he  afterwards  acquires  from  his  thoughts,  but  neverthe- 
less this  childish  comprehension  of  the  world  is  in  peculiar 
harmony  with  things  as  they  appeared  to  our  ingenuous 
ancestor.  We  may  say,  in  fact,  that  if  poetry  could  be  the  pre- 
vailing sentiment  in  the  world,  the  life  of  man  would  be  one 
harmonious  whole,  but  at  the  same  time  his  comprehension  of 
the  world  would  be  vague  and  dreamy.  He  would  not  be  fully 
conscious,  if  at  all,  of  the  rational  connection  between 
phenomena.  He  has  to  be  led,  so  to  speak,  by  knowledge — that 
is,  by  science,  which  is  only  organised  knowledge — to  the 
point  where  thought  and  poetry  will  no  longer  be  opposed. 
This  intellectual  development  is  forced  upon  man  by  the  very 
constitution  of  Nature.  Nature  does  not  permit  man  to  bury 
himself  in  a  world  of  poetry  and  he  is  prevented  from  doing 
so  by  external  influences  ;  objects  intrude  themselves  which 
require  his  constant  consideration.  Irresistible  impressions 
and  thoughts  appear  in  prominent  distinctness,  and  oblige  him 
to  look  at  things  in  a  new  manner.  This  induces  one  of  two 
opposite  sensations  :  either  joy  and  satisfaction  at  the  new  idea 
that  he  finds  revealed  to  his  ken,  or  discontent  at  the  encroach- 
ment which  has  been  made  into  his  habitual  view  of  the  world. 
Either  will  have  a  direct  influence  on  the  expression  of  his 
thoughts  and  ideas  in  poetic  form.  It  is  the  latter  idea  that 
dominates  those  who  deplore  the  disappearance  of  mystery  and 
superstition  on  the  plea  that  it  means  a  serious  loss  to  the  poet, 
and  hence  to  the  world.  It  is  not  so.  The  muse  of  the  poet  is 
the  eternal  beautiful — and,  surely,  truth  is  the  highest  expression 
of  the  beautiful ;  as  Browning  has  it : 

Ah  !  world  as  God  has  made  it  !      Truth  is  beauty, 
And  knowing  this  is  love,  and  love  is  duty. 

I  think  we  may  say,  then,  that  the  poet  not  only  cannot,  but 


.742  SCIENCE   PROGRESS 

ought  not  even  to  attempt  to,  get  away  from  contemporary  life 
and   activity  on   the  mistaken  idea  that  he  serves  the  eternal 
beautiful ;  or,  rather,  under  a  misapprehension  as  to  what  the 
eternal   beautiful   is.     Whatever  men  think,  do,  suffer,  hope  is 
the  poet's  theme.     Poetry  therefore  must  change  with  life  and 
grow   with   thought  and  will  never  suffer   from   a   scarcity   of 
subject-matter  until  life  and  thought  alike  have  disappeared.     It 
is  true  that  only  recently  have  we  begun   to  awaken   to   this 
conception   of  the  function   of  poetry.     In   the   middle   of  the 
nineteenth  century  a  materialistic  anti-poetic  movement  swept 
over  the  intellectual  world   to   the  great  detriment   of  poetic 
expression.     One  must  always  be  thankful  that  such  a  move- 
ment was  transient,  even  evanescent,  in  its  nature  and  in  its 
effects  on  poetry ;  but  this  movement  again  was  an  inevitable 
phase  in  the  intellectual  development  of  mankind,  and  to  it  we 
owe  our  present  firm  belief  in  the  universality  of  law  and  our 
rejection    of   the    old    theological  ideas   of  the  causeless,   the 
arbitrary,  the  capricious  in  the  government  of  Nature.     It  arose 
out  of  an  attempt  to  correct  the  false  perspective  of  previous 
generations,  and  like  all  attempts  at  re-adjustment  erred  through 
its  very  exaggeration ;  we  find  the  same  exaggeration  to-day  in 
the  ideas  of  such  writers  as  Tolstoi  and  G.  B.  Shaw.     We  see 
then  that  there  are  two  ways  of  regarding  the  natural  world — 
first,  as  it  appears  to  the  bodily  eye  and  to  the  normal  untutored 
imagination  ;  secondly,  as  we  know  it  actually  is,  having  sought 
out  the  truth  of  its  phenomena,  and  the  laws  which  underlie 
their  beauty  or  repulsiveness.     The  former,   although   purely 
empirical,   was   formerly  the   raw  material  on  which  the  poet 
worked  ;  the  latter  is  due  to  that  spirit  of  inquiry  which  we  call 
the  scientific  movement. 

The  materialism  of  the  middle  nineteenth  century  was  due 
to  an  attempted  transition  from  one  point  of  view  to  the  other — 
an  attempt,  however,  which  from  its  very  violence  carried  the 
intellectual  pendulum  far  beyond  its  point  of  equilibrium  into  a 
position  in  which  it  was  as  unstable  as  it  was  before.  Thus 
Huxley  in  a  lecture  on  "  Scientific  Education"  in  1869  deplored 
the  fact  that  "  at  present,  education  is  almost  entirely  devoted  to 
the  cultivation  of  the  power  of  expression  and  of  the  sense  of 
literary  beauty."  The  spirit  of  the  conflict  is  aptly  summed  up 
by  another  writer  who  says  :  "  The  truth  is  that  our  school-girls 
and  spinsters  wander  down  the  lanes  with  Darwin,  Huxley,  and 


SCIENCE  AND  MODERN   POETRY  743 

Spencer  under  their  arms  ;  or  if  they  have  Tennyson,  Longfellow, 
or  Morris,  read  them  in  the  light  of  Spectrum  Analysis  or  test 
them  by  the  economics  of  Mill  and  Bain."  Such  a  conflict, 
however  inevitable,  was  necessarily  short-lived.  Many  of  the 
greater  minds  of  the  time  regretted  it  and  looked  forward  to  the 
day  when  reconciliation  should  come  and  "  so  far  from  being 
unfriendly  to  the  poetic  imagination,  science  will  breathe  into  it 
a  higher  exaltation."  The  poets  themselves  recognised  the 
necessity  of  the  struggle,  while  looking  forward  with  calmness, 
serenity,  and  certain  hope  to  reconciliation  and  mutual  help. 
The  poets'  feelings  did  not  belie  them — we  are  growing  to 
recognise  the  fact  that  poetry  is  largely  the  expression  of 
thoughts,  ideas,  feelings,  many  of  which  are  founded  and 
generated  by  science.  The  essays  of  Tyndall  and  Huxley  are, 
the  question  of  form  apart,  poems  in  themselves  ;  and  there  are 
both  philosophers  and  poets  who  feel  that  no  absolute  antagon- 
ism can  exist  between  them.  The  mission  of  science  is  to 
struggle  against  the  unknown  ;  while  in  letters  it  is  enough  to 
give  an  expression,  and  in  art  a  body,  to  the  conceptions  of  the 
mind  or  the  beauties  of  Nature.  In  other  words,  science  kindles 
the  imagination  with  new  conceptions  and  new  beauties  which 
it  has  wrested  from  the  unknown,  and  thus  becomes  the  ally  of 
poetry. 

On  the  other  hand,  although,  as  has  been  pointed  out,  science 
is  the  ally  of  poetry,  it  must  not  be  forgotten  that  poetry  is,  in  no 
less  real  a  sense,  the  ally  of  science.  The  intuition  of  the  poet 
often  anticipates  scientific  discoveries  ;  we  see  this  in  fiction  in 
the  novels  of  Victor  Hugo,  Jules  Verne,  and  in  those  of  H.  G. 
Wells.  In  poetry  a  single  example  will  suffice:  when  the  theory 
of  Evolution  had  been  definitely  established  in  science  it  was 
regarded  merely  as  the  process  by  which  man  and  the  Universe 
in  general  had  arrived  at  their  present  condition,  and  inferences 
from  it  with  regard  to  the  future  were  put  forward  in  a  purely 
tentative  manner,  merely  as  suggestions  containing  perhaps  a 
certain  amount  of  speculative  interest.  The  poet,  however,  with 
his  prophetic  insight  seized  on  the  theory  and  pushed  it  at  once 
to  its  logical  conclusion  ;  he 

Dipt  into  the  future  far  as  human  eye  could  see  ; 

Saw  the  vision  of  the  world  and  all  the  wonder  that  would  be  ; 

and  many  of  his  speculations  are  now  accepted  as  beliefs  by  men 
of  science,  if  not  as  scientists  at  any  rate  as  thinkers. 
48 


744  SCIENCE  PROGRESS 

One  must  not  forget, in  passing,  the  independence  of  the  poet — 
as  the  scientist  has  his  own  independent  field  of  work,  the  investi- 
gation of  the  laws  of  Nature,  so  also  has  the  poet.     In  his  case 
it  is  the  expression  of  the  spirit  of  Nature.    It  is  where  these  two 
spheres  of  activity — the  investigation  of  the  laws  of  Nature  and 
the  expression  of  the  spirit  of  Nature — overlap  that  we  find  the 
common  ground  of  science  and  poetry;  but  whereas  science 
reaches  it  by  an  analysis  of  natural  phenomena,  poetry  attains  it 
by  that  direct  intuition  which  is  the  poetic  characteristic  par 
excellence.    Then  again  this  common  ground,  where  science  and 
poetry  meet  and  join  hands,  is  an  elusive  thing,  which  though 
easy  to  recognise  is  by  no  means  easy  to  describe  without  taking 
personal   factors   into   account ;    it   is    so   largely   a   matter   of 
temperament.     It  has  been  said  that  "  visible  beauty  exalts  our 
emotions  far  more  than  a  dissection  of  the  wondrous  and  intricate 
systems  beneath  it.     The  sight  of  a  star  or  of  a  flower,  or  the 
story  of  a  single  noble  action,  touches  our  humanity  more  nearly 
than  the  greatest  discovery  or  invention  could  ever  do  and  does 
the  soul  more  good."    The  passage  is  a  striking  one  and  expresses 
a  belief  that  is  all  too  general ;  but  though  true  in  a  sense  it 
contains  a  confusion  in  thought  which  it  is  not  difficult  to  point 
out.     Although  a  noble  action  may  appeal   to  us  and  to  our 
human  sympathy  more  strongly  than  the  latest  scientific  dis- 
covery, say  that  of  aerial  locomotion,  it  is  because  its  very  nature 
is  human,  it  pertains  of  the  very  essence  of  humanity  ;  while  the 
latter  is  something  extraneous,  without  which  the  world  would 
probably  be  as  well  off.     The  world  was  no  less  beautiful  in  the 
days  before  artificial  means  of  locomotion  came  into  being,  but 
we  can  scarcely  conceive  a  world  so  ugly,  so  repulsive,  so  utterly 
devoid  of  beauty  that  nobility  of  thought,  word,  and  deed  was 
unknown  ;  we  cannot  conceive  a  humanity  so  inhuman  as  to  be 
devoid  of  human  sympathy  and  utterly  unresponsive  to  nobility 
and  beauty  of  thought   and   action.     The   former   part   of  the 
argument,  however,  belongs  to  quite  another  plane,  and  I  think 
one  may  say  safely  that  "  the  sight  of  a  star  or  of  a  flower  "  does 
not  "  touch  our  humanity  more   nearly,"  or   anything   like   as 
nearly,  as  a  "  dissection  of  the  wondrous  and  intricate  systems  " 
that  lie  beneath  the  object ;  or  as  an  analysis  of  the  processes 
underlying  its  growth  and  development ;  for  by  the  very  act  of 
dissection    or   analysis   new   beauties  and   fresh   wonders  are 
revealed  to  our  ken  which   far   surpass   those  laid   bare   by  a 


SCIENCE  AND   MODERN   POETRY  745 

mere  sight  of  the  object.  The  poets  themselves  realise  this  ; 
when  Tennyson  said, 

Flower  in  the  crannied  wall, 
I  pluck  you  out  of  the  crannies  ; — 
Hold  you  here,  root  and  all,  in  my  hand, 
Little  flower — but  if  I  could  understand 
What  you  are,  root  and  all,  and  all  in  all, 
I  should  know  what  God  and  man  is, 

it  was  not  the  mere  sight  of  the  beauty  of  the  flower  that  touched 
him,  but  the  thought  that  that  same  little  flower  was  an  integral 
part,  however  small  a  one,  in  a  more  wondrous  whole  we  call 
Nature ;  it  was  the  innumerable  beauties  laid  bare  by  thought 
and  reflection  founded  on  investigation  and  knowledge  that 
touched  the  poet's  nature  and  enriched  our  language  with  a 
poetic  gem  of  such  surpassing  beauty  ;  and  it  is  the  same  know- 
ledge in  us,  likewise  based  on  a  study  of  Nature's  laws  and 
processes,  that  alone  enables  us  to  recognise  its  beauty. 

But  enough  of  the  general  nature  of  the  influence  of  the 
scientific  movement  on  poetry.  One  comes  naturally  to 
inquire  into  some  of  the  more  direct  effects  of  scientific 
ideas  on  the  form  and  expression  adopted  in  modern  poetry. 
Such  an  inquiry  can  only  be  carried  out  by  an  appeal  to  the 
poets  themselves  and  by  a  study  of  their  works.  For  this 
purpose  we  will  take  Tennyson  as  our  chief  example,  since  it  is 
better  to  make  a  detailed  examination  of  one  poet  than  a  diffusive 
and  cursory  glance  at  many.  Moreover,  besides  being  one 
of  the  greatest  and  one  of  the  most  typical  of  modern  poets, 
Tennyson  was  a  scientific  observer  of  no  mean  order  and  his 
scientific  knowledge,  if  not  profound,  was  at  least  exact  and  of 
unusual  width  ;  while  he  enjoyed  the  extra  advantage  (for  our 
present  purpose,  at  any  rate)  of  being  a  friend  of  Darwin's — of 
all  modern  scientists  the  one  most  deficient  in,  I  had  almost  said 
devoid  of,  poetic  feeling ;  a  defect  which  no  one  deplored  more 
than  he  did  himself. 

Perhaps  the  first  real  scientific  idea  introduced  into  poetry 
was  the  idea  of  vastness — vastness  of  space,  and  later  still  the 
vastness  of  time.  One  might  at  first  think  that  the  conception 
of  mere  immensity  is,  emotionally  speaking,  a  barren  one  ;  it  is 
not  so  in  reality.  Who  does  not  know,  who  has  not  felt  the  awe 
and  wonderment,  the  subdued  reverence  with  which  we  gaze  up 
at  the  starry  heavens  in  the  darkness  and  silence  of  the  night ! 


746  SCIENCE   PROGRESS 

How  insignificant  and  even  humble  we  ourselves  are  compelled 
to  feel,  even  against  our  wills,  when  we  realise  how  small  a  part 
we,  and  our  earth  on  which  we  live,  play  in  the  totality  of  things  ! 
Or,  to  change  the  point  of  view,  how  happy  we  feel,  what  a  quiet 
sense  of  pleased  satisfaction  we  get  when  we  realise  that  the  part 
we  play,  even  though  it  be  so  small,  is  an  essential  one  and  that 
we  form  an  integral  part  of  that  scheme  of  things  we  call  the 
Universe.  This  sense  of  awe  is  admirably  expressed  by  Byron 
in  his  dramatic  poem  Cain  ;  Cain  is  being  borne  through 
space  by  Lucifer  and  is  overcome  with  awe  as  millions  of  stars 
seem  to  flash  past  him  and  he  loses  sight  of  earth — 

O  thou  beautiful 

And  unimaginable  ether  !  and 

Ye  multiplying  masses  of  increased 

And  still  increasing  lights  !  what  are  ye  ?     What 

Is  this  blue  wilderness  of  interminable 

Air,  where  ye  roll  along,  as  I  have  seen 

The  leaves  along  the  limpid  streams  of  Eden  ? 

Is  your  course  measured  for  ye  ?     Or  do  ye 

Sweep  on  in  your  unbounded  revelry 

Through  an  aerial  universe  of  endless 

Expansion — at  which  my  soul  aches  to  think — 

Intoxicated  with  eternity? 

O  God  !  O  Gods  !  or  whatsoe'er  ye  are  ! 

How  beautiful  ye  are  !  how  beautiful 

Your  works,  or  accidents  !  or  whatsoe'er 

They  may  be  !     Let  me  die  as  atoms  die 

(If  that  they  die),  or  know  ye  in  your  might 

And  knowledge  !     My  thoughts  are  not  in  this  hour 

Unworthy  what  I  see,  though  my  dust  is  ; 

Spirit,  let  me  expire,  or  see  them  nearer  ; 
Lucifer.   Art  thou  not  nearer  ?     Look  back  to  thine  earth  ! 
Cain.   Where  is  it  ?     I  see  nothing  save  a  mass 

Of  most  innumerable  lights. 
Lucifer.  Look  there  ! 

Cain.    I  cannot  see  it. 

Lucifer.  Yet  it  sparkles  still  ! 

Cain.   That  !    Yonder  ! 
Lucifer.  Yea. 

Cain.  And  wilt  thou  tell  me  so  ? 

Why  I  have  seen  the  fire-flies  and  fire-worms 
Sprinkle  the  dusky  groves  and  the  green  banks 
In  the  dim  twilight,  brighter  than  yon  world 
Which  bears  them. 

The  idea  of  the  vastness  of  space  was  first  introduced  into 
science   by  Copernicus  and  was   afterwards  extended  by   such 


SCIENCE  AND   MODERN   POETRY  747 

intellectual  giants  as  Galileo,  Kepler,  and  Newton.  To  the 
immensity  of  space  was  added  the  immensity  of  time  by  Darwin 
and  his  co-workers.  Perhaps  no  scientific  idea  has  been  so 
fruitful  of  results  in  its  effects  upon  philosophy  and  religion, 
for  it  was  a  discovery  which  at  once  caused  a  vague  disquietude 
in  the  minds  of  men.  The  universe  ceased  suddenly  to  be 
homocentric.  Man  seemed  to  become  at  once  utterly  insig- 
nificant ;  a  mere  speck  of  animated  dust ;  a  parasite  of  one  of 
the  meanest  of  the  planets.     As  Tennyson  says  : 

What  are  men  that  He  should  heed  us?  cried  the  King  of  sacred  song; 
Insects  of  an  hour,  that  hourly  work  their  brother-insects  wrong, 
While  the  silent  Heavens  roll,  and  suns  along  their  fiery  way, 
All  their  planets  whirling  round  them,  flash  a  million  miles  a  day. 

And  again,  in  that  awful,  gloomy,  pessimistic  poem  Despair, 
he  says : 

And  the  suns  of  the  limitless  Universe  sparkled  and  shone  in  the  sky, 
Flashing  with  fires  as  of  God,  but  we  knew  that  their  light  was  a  lie — 
Bright  as  with  deathless  hope — but  however  they  sparkled  and  shone, 
The  dark  little  worlds  running  round  them  were  worlds  of  woe  like  our  own- 
No  soul  in  the  heaven  above,  no  soul  on  the  earth  below, 
A  fiery  scroll  written  over  with  lamentation  and  woe. 

And  yet  again,  in  a  more  cheerful  vein,  he  writes : 

For  tho'  the  Giant  Ages  heave  the  hill 
And  break  the  shore,  and  evermore 
Make  and  break,  and  work  their  will ; 
Tho'  world  on  world  in  myriad  myriads  roll 
Round  us,  each  with  different  powers, 
And  other  forms  of  life  than  ours, 
What  know  we  greater  than  the  soul? 

The  immensity  of  time,  too,  is  realised  : 

Many  an  aeon  moulded  earth  before  her  highest,  Man,  was  born, 
Many  an  aeon  too  may  pass  when  earth  is  manless  and  forlorn. 

It  is  small  wonder  indeed  that  the  greatest  minds  have  been 
frightened  and  have  recoiled  in  blank  dismay  from  the  concep- 
tion of  such  immensity  as  this !  "  Man  began  to  wonder  how 
far  he  could  still  maintain  moral  laws  and  ideals  of  life  formu- 
lated under  other  and  different  conditions,  conditions  when  he 
was  able  to  regard  himself  not  only  as  the  centre  but  as  the 


748  SCIENCE   PROGRESS 

object  of  creation.  '  The  heavens  declare  the  glory  of  God  and 
the  firmament  showeth  His  handiwork,'  said  the  Psalmist ;  '  the 
heavens  declare  no  glory  but  that  of  Newton  and  Kepler' 
seemed  to  be  the  conclusion  of  modern  science ;  and  Laplace,  in 
his  great  treatise  Mecanique  Celeste,  admitted  that  in  his  system 
he  could  find  no  place  for  a  God."  The  situation  has  been  aptly 
summed  up  by  Haeckel  when  he  said,  "We  have  learnt  to  look 
upon  the  sun  shining  out  of  a  godless  heaven  upon  a  soulless 
earth."  It  is  quite  evident  that  our  apprehension  of  man's 
littleness  and  the  greatness  of  the  Universe  has  a  disquieting 
effect  upon  the  human  mind  and  tends  to  point  out  the  futility 
of  moral  effort  and  the  absurdity  of  mental  speculation. 

All  these  questions  and  problems  were  raised  and  suggested 
by  this  one  scientific  idea.  The  answers,  if  answers  there  are, 
must  be  sought  in  philosophy  and  in  the  works  of  the  poets ; 
this  is  neither  the  place  nor  the  time  for  such  philosophical 
disquisitions — the  object  of  this  article  is  to  point  out  that  such 
questions  were  raised  by  science ;  we  must  go  to  the  poets  for 
an  answer. 

The  next  idea  which  has  been  introduced  by  science  is  the 
conception  of  law  and  order  in  the  Universe.  This  question 
has  already  been  touched  upon,  so  we  may  pass  it  over  here, 
and  proceed  at  once  to  a  consideration  of  its  greatest  offspring — 
that  master  thought  of  the  nineteenth  century  the  idea  of 
Evolution.  This  idea,  more  perhaps  than  any  other  scientific 
conception,  has  had  most  influence  on  modern  thought ;  it,  more 
than  anything  else,  has  altered  man's  outlook  on  life.  The 
reason  is  obvious — it  revolutionised  men's  conception  of  life, 
and  their  chief  interest,  whether  scientist,  poet,  or  philosopher, 
must  necessarily  be  life.  It  meant  the  substitution  of  a  dynamic 
for  a  static  conception  of  the  Universe ;  it  meant  the  replace- 
ment of  the  idea  of  a  product  by  the  idea  of  a  process.  The 
idea  itself  is  by  no  means  the  exclusive  property  of  science ; 
on  the  contrary,  the  earliest,  widest,  and  most  satisfactory 
expression  of  it  was  given  in  philosophy.  Nevertheless,  the 
idea  would  not  have  had  a  tithe  of  the  influence  it  now  possesses 
if  it  had  not  been  put  on  a  firm  scientific  foundation  by  Darwin 
and  his  successors. 

It  is  really  very  difficult  for  us  to  realise  fully  the  whole 
effect  of  Evolution  on  modern  thought ;  we  are  so  used  to  the 
idea,  having  grown  up,  as  it  were,  in  its  shadow,  that  it  has 


SCIENCE  AND   MODERN   POETRY  749 

almost  become  a  part  of  our  mental  constitution ;  it  has  become 
one  of  the  presuppositions  which  the  human  mind  carries  with 
it  in  its  onward  march.  We  can  scarcely  imagine  the  intel- 
lectual outlook  of  people,  including  the  poets,  who  lived  before 
the  inception  of  this  idea.  We  have  to  imagine  an  intellectual 
atmosphere  in  which  the  law  of  the  uniformity  of  Nature  and 
the  law  of  universal  causation  were  only  accepted  to  a  very 
limited  degree.  Law  itself  was  hardly  more  than  partially 
recognised.  Theories  of  the  special  creation  of  species  held 
general  sway,  and  immutability,  rather  than  mutability,  was 
regarded  as  their  main  characteristic.  In  man  the  idea  of 
development,  of  social  and  intellectual  progress,  was  of  academic 
rather  than  of  practical  interest.  Many,  indeed,  believed  that 
retrogression  had  set  in ;  that  the  highest  attainment  of 
humanity  had  occurred  in  some  Golden  Age  of  the  past.  If 
there  was  any  social  progress  at  all  it  was  looked  upon  as  the 
result  of  an  artificial  social  machinery ;  the  idea  that  that  social 
machinery  itself  was  the  result  of  a  natural  development  of  the 
race  was  only  dimly  perceived,  if  at  all.  Evolution  changed  all 
this.  Society  must  be  regarded  as  continuous  from  age  to 
age — it  is  an  organism,  not  a  manufacture.  The  idea  of  the 
individual  being  "  the  heir  of  all  the  ages "  was  seen  to  be 
merely  the  expression  of  a  fact.  Moreover,  the  philosophy  of 
development  is  essentially  a  hopeful  one— it  finds  for  a  large 
amount  of  pain  and  evil  a  place  and  a  significance  more  satis- 
factory to  the  reason  than  most  of  the  arbitrary  theological 
explanations  of  previous  generations,  and  affords  a  natural 
incentive  to  moral  effort. 

Of  all  modern  poets  Tennyson  was  the  one  who  perhaps 
made  most  use  of  this  conception,1  though  all  were  under  its 
influence.  In  fact  Tennyson's  principal  point  of  contact  with 
science  was  his  acceptance  of  evolution  as  a  fact.  All  his  philoso- 
phical and  nature  poetry  is  written  from  this  point  of  view.  His 
most  emphatic  references  to  evolution  are  in  the  two  poems 
Locksley  Hall  and  its  sequel.     In  Maud  too  we  find  it — 

He  (man)  felt  himself  in  his  force  to  be  Nature's  crowning  race. 
As  nine  months  go  to  the  shaping  an  infant  ripe  for  his  birth, 
So  many  a  million  of  ages  have  gone  for  the  making  of  man  ; 
He  now  is  first,  but  is  he  the  last  ?  is  he  not  too  base  ? 


1  For  a  more  extended  treatment  of  this  part  of  the  subject  see  Mr.  Master- 
man's  book  on  Tennyson,  to  which  I  must  acknowledge  my  indebtedness. 


750  SCIENCE  PROGRESS 

And  again  in  The  Princess  : 

This  world  was  once  a  fluid  haze  of  light, 

Till  toward  the  centre  set  the  starry  tides, 

And  eddied  into  suns,  that  wheeling  cast 

The  planets  :  then  the  monster,  then  the  man  ; 

Tattoo'd  or  woaded,  winter-clad  in  skins, 

Raw  from  the  prime,  and  crushing  down  his  mate  ; 

As  yet  we  find  in  barbarous  isles,  and  here 

Among  the  lowest. 

This  evolutionary  faith  runs  all  through  Tennyson's  works  ; 
In  Memoriam  is  permeated  with  it.  In  one  part  of  this  poem 
he  speaks  of  the  succession  of  types  in  Nature  and  speaks  of 
a  gradual  development  from  age  to  age,  man  being  but  an 
intermediate  link  in  the  chain  of  progress  to  higher  and  higher 
types : 

Star  and  system  rolling  past, 
A  soul  shall  draw  from  out  the  vast 
And  strike  his  being  into  bounds, 

And,  moved  thro'  life  of  lower  phase, 

Result  in  man,  be  born  and  think, 

And  act  and  love,  a  closer  link 
Betwixt  us  and  the  crowning  race 


*& 


Of  those  that,  eye  to  eye,  shall  look 
On  knowledge  ;  under  whose  command 
Is  Earth  and  Earth's,  and  in  their  hand' 

Is  Nature  like  an  open  book  ; 

No  longer  half-akin  to  brute, 
For  all  we  thought  and  loved  and  did, 
And  hoped  and  suffered  is  but  seed 

Of  what  in  them  is  flower  and  fruit. 


It  is  significant  that  though  this  was  written  before  the 
Origin  of  Species  was  published,  the  ideas  expressed  are 
practically  identical  with  those  in  Prof.  Ray  Lankester's  Romanes 
Lecture  on  "  Nature  and  Man  " — the  latest  word  that  science 
has  yet  said  on  man's  position  in  the  Universe.  After  the 
appearance  of  the  Origin  Tennyson's  grasp  of  the  principle  of 
Evolution  became  much  firmer.  Henceforth  two  main  points 
in  the  theory  seem  to  have  struck  him  with  special  force.  One 
was  the  slowness  of  the  change  combined  with  the  fact  that 
though  slow  there  seems  to  be  no  logical  limit  to  its  power; 


SCIENCE  AND   MODERN   POETRY  751 

so  that  man  may   develop  into  something   much   higher  than 
he  is— 

Man  as  yet  is  being  made,  and  ere  the  crowning  Age  of  ages, 
Shall  not  aeon  after  aeon  pass  and  touch  him  into  shape. 

Or,  on  the  other  hand,  he  may  pass  away  altogether  : 

Many  an  aeon  moulded  earth  before  her  highest,  Man,  was  born, 
Many  an  aeon  too  may  pass  when  earth  is  manless  and  forlorn. 

The  other  point  that  seems  to  have  struck  Tennyson  was 
the  possibility  of  a  reversion.  This  becomes  much  more  marked 
in  his  later  poems  in  which  he  looks  back  on  life ;  they  are 
naturally  less  optimistic  than  the  earlier  ones.  In  the  earlier 
poems  he  regards  man  as  being  an  intermediate  link  in  a  chain 
of  an  ever-progressing  development.  Later  he  is  less  confident, 
and  his  lack  of  confidence  is  due  to  his  wider  experience  and 
completer  knowledge  of  the  complex  relationships  of  life.  In 
Locksley  Hall,  Sixty  Years  After,  we  find  this  conception  of 
reversion  quite  clearly  stated  : 

Evolution  ever  climbing  after  some  ideal  good, 
And  Reversion  ever  dragging  Evolution  in  the  mud. 

He  then  goes  on  and  gives  the  idea  in  its  full  significance  : 

All  the  full-brain,  half-brain  races,  led  by  Justice,  Love,  and  Truth  ; 
All  the  millions  one  at  length,  with  all  the  visions  of  my  youth  ? 

All  diseases  quench'd  by  Science,  no  man  halt,  or  deaf,  or  blind  ; 
Stronger  ever  born  of  weaker,  lustier  body,  larger  mind  ? 

Earth  at  last  a  warless  world,  a  single  race,  a  single  tongue — 
I  have  seen  her  far  away — for  is  not  Earth  as  yet  so  young? 

Every  tiger  madness-muzzled,  every  serpent  passion-killed, 
Every  grim  ravine  a  garden,  every  blazing  desert  till'd, 

Robed  in  universal  harvest  up  to  either  pole  she  smiles, 
Universal  ocean  softly  washing  all  her  warless  isles. 

Warless  ?  when  her  tens  are  thousands,  and  her  thousands  millions,  then — 
All  her  harvests  all  too  narrow— who  can  fancy  warless  men  ? 

Warless  ?  war  will  die  out  late  then.     Will  it  ever  ?  late  or  soon  ? 
Can  it,  till  this  outworn  Earth  be  dead  as  yon  dead  world  the  moon? 

And    this    reversion,   he    fears,  has  even   now  set   in,  for  he 
continues — 

Is  it  well  that  while  we  range  with  Science,  glorying  in  the  Time, 
City  children  soak  and  blacken  soul  and  sense  in  city  slime  ? 


752  SCIENCE  PROGRESS 

There  among  the  gloomy  alleys  Progress  halts  on  palsied  feet, 
Crime  and  hunger  cast  our  maidens  by  the  thousand  on  the  street. 

There  the  master  scrimps  his  haggard  sempstress  of  her  daily  bread, 
There  a  single  sordid  attic  holds  the  living  and  the  dead. 

There  the  smouldering  fire  of  fever  creeps  across  the  rotted  floor, 
And  the  crowded  couch  of  incest  in  the  warrens  of  the  poor. 

And  yet  in  spite  of  all  this  he  realises  that  it  is  a  possibility 
only  and  no  more,  and  that  we  are  really  quite  ignorant  as  to 
the  future — 

Far  away  beyond  her  myriad  coming  changes  Earth  will  be 
Something  other  than  the  wildest  modern  guess  of  you  and  me. 

Earth  may  reach  her  earthly-worst,  or  if  she  gain  her  earthly-best, 
Would  she  find  her  human  offspring  this  ideal  man  at  rest? 

On  the  whole,  however,  he  agrees  that  Evolution  instils  hope 
into  the  human  heart ;  his  last  word  is  one  of  exhortation,  and 
he  ends  the  poem  by  pointing  out  the  necessity  of  hoping  and 
striving : 

Follow  you  the  star  that  lights  a  desert  pathway,  yours  or  mine, 
Forward,  till  you  see  the  highest  Human  Nature  is  divine. 

Follow  Light,  and  do  the  Right — for  man  can  half-control  his  doom — 
Till  you  find  the  deathless  Angel  seated  in  the  vacant  tomb. 

Forward,  let  the  stormy  moment  fly  and  mingle  with  the  Past. 

I  that  loathed  have  come  to  love  him.     Love  will  conquer  at  the  last. 

Tennyson,  as  we  have  seen,  kept  pace  with  the  advances  of 
modern  thought.  He  of  all  the  poets  made  most  use  of  the 
results  arrived  at  by  modern  science  without  making  his  work 
at  all  prosaic,  or  anything  other  than  the  highest  and  the  best. 
It  is,  in  fact,  this  advance  of  Tennyson  in  keeping  pace  with  the 
strides  of  modern  science  and  modern  thought  that  makes  him 
the  best  example  one  can  offer  of  the  influence  of  science  on 
poetry ;  from  an  examination  of  his  work  we  can  trace  the 
development  of  his  mind  with  increasing  years  and  that  know- 
ledge, wider  experience,  and  fuller  understanding  that  advancing 
years  alone  can  bring. 

It  has  been  said  that  Browning  had  a  firmer  grasp  of  the 
principle  of  Evolution,  and  that  the  science  and  philosophy  of 
the  time  probably  made  a  deeper  impression  on  him  than  it  did 
on  Tennyson.     Be  this  as  it  may,  at  any  rate  it  is  less  apparent, 


SCIENCE  AND   MODERN   POETRY  753 

for  Browning  never  advanced  beyond  the  position  taken  up  in 
his  first  really  great  poem,  Paracelsus,  which  he  published  at  the 
age  of  twenty-three.     It  is  remarkable  that  although  this  poem 
was  written  a  quarter  of  a  century  before  Darwin's  Origin  was 
published,   yet   it   contains   what   is   perhaps   one  of  the  most 
precise,  complete  and  satisfactory  expressions  of  the  principle  of 
Evolution  that  has  ever  been  put  forward.    As  far  as  regards  his 
position  towards  this  theory  and  towards  contemporary  thought 
in  general,  his  mind  was  as  fully  developed  at  this  time  as  it  was 
in  any   of  his  later  poems,  and  his  whole  conception  of  the 
Universe  was  ruled  by  this  one  idea.     Thus  at  the  close  of  the 
poem,  the  speaker  Paracelsus  shows  how  God  is  immanent  in 
all  Nature  and  how  finally  all  leads  up  to  man  ;  and  yet  how 
"  man  is  not  Man  as  yet,"  but  must  develop  into  something  far 
higher  and  nobler.     The  whole  poem  is  wonderfully  conceived 
and  still  more  wonderfully  expressed ;  it  is  one  of  the  wonders 
of  the  English  language ;  one  of  those  precious  things  of  litera- 
ture  that   humanity   cannot   afford   to   be    without.     It  is   also 
interesting  from   another  point    of   view.      It   shows   us   that 
Browning  arrived  at  the   conception   of   evolution,  not  from 
science  alone,  but  from  the   whole  of  contemporary  thought, 
whereas  Tennyson  arrived  at  it  mainly  from  the  scientific  side. 
It  points   out  to  us  exactly  the  nature  of  any  influence  that 
science  may  have  had  on  modern   poetry.      Science  is  not  an 
extraneous  thing  which  casts  a  halo,  like  some  divine  effulgence, 
over  everything  that  comes  within  its  influence.     It  is  merely  a 
mode   of  thought.      It  is  one  of  the  forms  in  which  thought 
expresses  itself.     Philosophy  is  another,  and  so  also  to  a  large 
extent  are  poetry  and  art.     All  these  are  merely  expressions  of 
thought ;  merely  forms  in  which  is  expressed  man's  outlook  on 
life  and  on  the  Universe.    As  such  they  are  bound  to  influence 
each  other,  to  overlap,  as  it  were,  and  collectively  they  represent 
that  "  spirit  of  the  age  "  which  we  are  so  prone  to  objectify  and 
make  the  standard  by  which  we  judge  and  are  judged,  and  by 
which,  to  use  Hegel's  phrase,  we  "  re-evaluate  all  values  "  as 
human  exigencies   demand.     This   "  spirit  of  the  age,"  which 
is  thus   in   reality  but  another  name  for  modern  thought,  is 
itself  a  product  of  the  human  mind — like  science,  poetry,  and 
art — and   must  therefore  change   with   progress.     This   brings 
one  naturally  to  the  idea  of  the  relativity  of  human  knowledge 
and   the  impossibility  of  setting  up  absolute  standards.    This 


754  SCIENCE  PROGRESS 

conception  is  a  product  of  evolutionary  science,  in  fact  it 
follows  from  it  as  a  necessary  corollary  and  is  perhaps  the 
latest  scientific  idea  that  is  old  enough  to  have  influenced 
poetry  in  any  definite  manner. 

The  more  one  thinks  about  it  the  more  is  one  convinced 
that  the  scientific  movement  must  necessarily  from  its  very 
nature  have  had  a  profound  and  lasting  influence  on  modern 
poetry.  In  tracing  such  influence  one  can  only  generalise, 
pointing  out  tendencies  and  directions  that  the  thoughts  of 
men — poets  in  particular — have  taken.  The  real  meeting-point 
of  the  poet  and  the  scientist  is  in  the  imagination  and  the 
emotions  of  men.  We  have  too  long  been  accustomed  to 
regard  these  as  being  the  exclusive  happy  hunting  ground  of 
the  poet  and  as  being  but  a  sterile  desert  to  the  scientific  investi- 
gator except  in  so  far  as  he  regards  them  objectively  as  parts  of 
that  Nature  which  it  is  his  function  to  study.  This,  in  fact,  was 
the  feeling  in  the  materialistic  philosophy  of  last  century,  but  it 
has  happily  given  place  to  another.  Science  can  play  on  the 
imagination  and  emotions  of  men  to  an  extent  scarcely  inferior 
to  that  of  poetry,  and  it  is  only  by  so  doing  that  science  can 
become  and  remain  a  living  thing  and  of  real  and  lasting  interest 
to  mankind. 


CRITICISMS    OF    PSYCHICAL    RESEARCH 

I.— By  J.  ARTHUR  HILL 

Mr.  Shelton's  paper  in  Science  Progress  for  January  may 
perhaps  give  erroneous  impressions  regarding  certain  points  in 
psychical  research.  Without  in  the  least  wishing  to  be  cen- 
sorious, or  to  adopt  anything  but  the  most  friendly  attitude,  I 
venture  to  make  a  few  remarks  on  the  paper  in  question  ;  follow- 
ing up  those  remarks  with  a  review  of  the  main  features  of 
the  subject,  in  the  hope  that  the  interest  of  some  few  hitherto- 
indifferent  men  of  science  may  be  enlisted  in  the  work  upon 
which  we  are  engaged.  In  the  first  and  more  critical  part  I  will 
be  as  brief  as  possible,  and  hope  that  brevity  will  not  be  taken 
as  discourtesy. 

Mr.  Shelton  says,  with  commendable  candour,  that  about 
psychical-research  evidence  he  "  knows  little  and  cares  less." 
He  has  read  (some  years  ago)  F.  W.  H.  Myers's  Human  Person- 
ality, "  that  monumental  volume,"  which  as  a  matter  of  fact  is 
two  volumes,  unless  he  means  the  abridged  edition,  which  is 
not  particularly  "  monumental,"  if  "  large "  is  the  meaning  in- 
tended. This,  plus  "common  sense"  and  "some  knowledge 
of  psychology,"  represents  his  equipment  for  attacking  a  very 
distinguished  man  of  science  who  has  worked  at  psychical 
research — experimentally,  and  not  merely  by  reading — for  the 
last  thirty  years.  It  is  usually  found,  in  scientific  and  all  other 
matters,  that  those  who  are  ignorant  of  a  subject  are  not  capable 
of  expressing  wise  opinions  on  it. 

Mr.  Shelton  has  found  nothing  in  Myers's  book  or  "  else- 
where "  which  could  "  carry  conviction  to,  or  even  merit  serious 
consideration  by,  any  one  not  naturally  predisposed  to  form  the 
spiritualist  conclusions."  Well,  as  to  what  merits  serious  con- 
sideration, that  is  a  matter  of  individual  opinion ;  but  I  wish  to 
say  that  though  I  am  not  a  spiritualist,  and  am  not  predisposed 
to  form  spiritualist  conclusions  (for  I  do  not  want  a  future  life), 
I  have  nevertheless  found  in  Myers's  book,  and  elsewhere,  very 
much  that  seems  to  me  worthy  of  the  most  serious  considera- 

755 


756  SCIENCE  PROGRESS 

tion.  Of  course  mere  reading  probably  does  not  convince 
anybody.  It  certainly  would  not  convince  me.  It  is  experi- 
ment, personal  investigation,  that  is  required.  But  if  a  man 
will  not  investigate — if  he  will  persist  in  sitting  in  an  armchair, 
reading  books  and  complaining  that  they  do  not  convince  him — 
what  can  we  do  with  him  ?  We  can  only  exhort  him  to  be  more 
scientific,  to  give  up  talking,  and  investigate  for  himself.  I  am 
reminded  of  a  clerical  acquaintance  of  mine  who  "could  see  no 
evidence  for  evolution."  There  are  none  so  blind  as  those  who 
won't  see. 

Mr.  Shelton  says  that  a  well-known  conjurer  "  has  never  yet 
failed  to  reproduce  every  phenomenon  credited  to  '  spirits '  that 
has  been  brought  before  him."  A  very  wild  statement !  Mr. 
Maskelyne  (who  I  suppose  is  meant)  can  do  remarkable  things, 
on  his  own  stage  and  with  all  his  concealed  apparatus,  but  I  am 
not  aware  that  he  has  offered  to  reproduce  the  phenomena  of 
Florence  Cook  in  the  house  of  the  President  of  the  Royal 
Society.  I  should  like  to  see  the  conjurer  who  could  produce 
a  Katie  King  in  my  house  (still  more  in  the  house  of  an  F.R.S.), 
with  half  a  dozen  of  my  intimate  friends  present,  with  a  good 
light,  and  the  key  of  the  locked  door  in  my  pocket. 

As  to  telepathy,  which  is  "  not  proven  "  (that  is  a  matter  of 
opinion,  depending  partly  on  what  is  meant  by  "  proven  "),  we 
know  well  enough  that  it  is  a  possible  alternative  (as  regards 
some  of  the  evidence)  to  the  survival  hypothesis,  and  that,  if  it 
is  a  fact,  it  may  be  material  or  etherial  in  its  process.  But  I 
agree  very  cordially  that  it  is  "  rash  folly  "  to  admit  an  ether- 
wave  telepathy  except  as  a  mere  guess — a  guess,  moreover, 
which  the  details  of  the  evidence  seem  to  render  probably  mis- 
taken. Is  it  not  equally  rash  folly  for  Mr.  Shelton  to  say  that, 
when  telepathy  has  explained  all  it  can,  "the  residuum  ceases 
to  be  worth  investigating"?  No  doubt  this  is  so,  to  one  who 
"knows  little  and  cares  less"  about  the  subject.  But  there  are 
others  who  think  that  even  small  residua  do  not  cease  to  be 
worth  investigating.  Rayleigh  and  Ramsay  discovered  argon  by 
following  up  the  small  residual  difference  between  atmospheric 
nitrogen  and  nitrogen  obtained  from  other  sources.  And  as 
telepathy  is  "  not  proven,"  the  spiritistic  residuum  is  not  proven 
to  be  small.  It  may  turn  out  very  large.  It  depends  on  the 
scope  of  telepathy.     And  this  is  a  matter  for  investigation. 

As  to  Mr.  Shelton's  suggestion  that  Sir  Oliver  Lodge  should 


PSYCHICAL  RESEARCH  757 

"  see  what  Rome  has  to  teach  him,"  because  the  Roman  Catholic 
Church  has  had  a  lot  of  experience — well,  I  suppose  this  is  a 
joke.  Scientific  method  is  a  modern  thing;  the  stringent 
psychical-research  canons  of  evidence  are  only  about  thirty 
years  old ;  the  evidence  of  pre-scientific  days  does  not  come 
up  to  our  standard.  The  Virgin  of  the  Pillar,  at  Saragossa,  is 
said  to  have  restored  a  worshipper's  amputated  leg.  Spanish 
theologians  regard  this  as  a  specially  well-attested  case.1  But 
the  "evidence,"  such  as  it  is,  would  leave  an  S.P.R.  investi- 
gator unmoved,  and  I  tremble  to  think  with  what  ferocious  joy 
the  late  Mr.  Podmore  would  have  hewed  it  in  pieces  before  the 
Lord. 

The  Roman  Catholic  Church  says  that  our  investigations 
"  are  better  not  attempted."  I  rather  think  she  has  said  some- 
thing like  that  to  every  science  in  its  turn.  She  tried  to  dis- 
courage Galileo — tried  rather  strenuously,  we  may  remember, 
for  there  is  some  evidence  (not  conclusive)  that  he  was  put  to 
the  torture.  Fortunately  science  has  now  won  its  freedom  from 
ecclesiastical  control. 

Now  to  the  more  congenial  positive  side.  First  as  to  general 
considerations. 

The  question,  "  Does  this  or  that  alleged  but  not  generally 
accepted  thing  really  happen  ?  "  is  to  be  answered  by  observa- 
tion and  inference.  It  is  a  question  of  evidence.  No  scientific 
man  believes  without  evidence,  but,  on  the  other  hand,  neither 
does  he  say  a  priori  that  any  alleged  occurrence  is  impossible. 
J.  S.  Mill  in  his  Three  Essays  on  Religion,  and  Huxley  in  his 
Hume  and  elsewhere,  sufficiently  demolished  the  "  impossibility  " 
dogma.     Says  the  latter,  in  Science  and  Christian  Tradition  : 

"  Strictly  speaking,  I  am  unaware  of  anything  that  has  a 
right  to  the  title  of  an  impossibility,  except  a  contradiction  in 
terms.  There  are  impossibilities  logical,  but  none  natural.  A 
\  round  square,'  a  '  present  past,'  '  two  parallel  lines  that 
intersect,'  are  impossibilities,  because  the  ideas  denoted  by  the 
predicates  '  round,'  '  present,'  '  intersect,'  are  contradictory  of 
the  ideas  denoted  by  the  subjects  '  square,'  •  past,'  •  parallel.' 
But  walking  on  water,  or  turning  water  into  wine,  are  plainly 
not  impossibilities  in  this  sense"  (p.  197). 

In   matters   of  alleged    objective  fact,   it    is    a   question    of 

1  Lecky's  Rise  and  Influence  of  Rationalism  in  Europe,  vol.  i.  p.  141. 


758  SCIENCE  PROGRESS 

evidence.  The  incomprehensible  and  incredible  may  turn  out 
true,  when  we  have  learned  more.  The  African  king  would  not 
believe  that  water  could  ever  take  the  form  of  solid  lumps,  for 
he  had  always  seen  it  liquid.  An  elderly  agricultural  labourer 
said  to  a  friend  of  mine  a  few  years  ago,  concerning  the  alleged 
electric  trams  of  the  town:  "  Don't  talk  silly!  How  can  they 
go  without  'osses  ?  "  The  Greeks  did  not  believe  the  circum- 
navigators of  Africa  when  these  latter  said  they  had  seen  the 
sun  in  the  north.  Even  so  romantic  an  historian  as  Herodotus 
declined  to  accept  such  an  obvious  "  traveller's  story."  "  I  for 
my  part  do  not  believe  them,"  he  says  (History,  book  iv.).  Yet 
all  these  unbelievers  were  in  error,  because  of  their  ignorance. 
They  should  have  said  :  "  I  do  not  know  ;  I  suspend  judgment 
until  I  learn  more."  The  lesson  of  scientific  experience  is  that 
when  a  thing  seems  inexplicable,  or  when  two  theories  clash, 
what  is  wanted  is  more  investigation,  more  facts.  The  dis- 
covery of  radioactivity  has  enabled  physicists  to  concede  the 
geologists'  claim  concerning  the  age  of  the  earth ;  indeed  we 
now  want  more  facts  to  help  us  to  see  why  the  earth  is  not 
hotter  than  it  is !  Further  knowledge  always  tends  to  fit  things 
in,  though  until  we  see  just  where  to  fit  them,  the  facts  are 
naturally  distrusted.  The  hypnotic  trance  was  long  looked  on 
as  a  delusion  of  Elliotson's,  and  Esdaile's,  and  it  was  even 
hazarded  that  the  Calcutta  natives  who  underwent  severe 
operations  at  the  hands  of  the  latter  were  shamming  anaesthesia ! 
But  the  a  priori  objections  of  the  ignorant  had  to  give  way 
before  the  hail  of  further  facts.  For  example,  Mr.  Mayo  Robson 
performed  evulsion  of  the  great  toe-nail,  and  removal  of  part  of 
the  first  phalanx  (for  exostosis)  on  a  hypnotised  patient  of  Dr. 
Bramwell's  in  Leeds,  March  25,  1890,  and  no  pain  was  felt. 
Another  patient  had  sixteen  teeth  extracted  :  no  pain,  no  corneal 
reflex,  and  the  pulse  slowed  during  the  operation.  About  sixty 
medical  men  were  present  by  invitation,  to  see  these  and  other 
operations.  Anaesthesia  in  the  hypnotic  trance  of  a  good 
subject  is  now  a  medical  commonplace.  Explanation  may  not 
yet  be  fully  attained,  though  we  are  as  near  it  as  we  are  to 
explanation  of  ordinary  sleep ;  but  at  least  the  system  of 
orthodox  science  had  to  make  room  for  the  new  facts.  May  it 
not  be  the  same  with  other  psychical  phenomena  ?  I  think 
it  will. 

Psychical   research   covers   a  wide  field.     It   is  rather    un- 


PSYCHICAL  RESEARCH  759 

fortunate  that  the  popular  interest  in  "  spirits  "  causes  attention 
to  be  focussed  on  the  Society's  activities  in  the  survival  direc- 
tion ;  for  it  is  quite  possible  that  its  investigations  in,  e.g., 
hypnotism,  multiple  personality,  etc.,  if  pushed  farther,  might 
yield  data  more  important  to  our  conceptions  of  human 
personality  than  the  more  immediately  attractive  phenomena 
of  definitely  spiritistic  type.  Anyhow,  let  me  emphasise  the 
fact  that  the  Society  exists  to  investigate,  without  prejudice, 
all  apparently  supernormal  faculty,  not  merely  those  alleged 
phenomena  which  point  directly  to  survival.  The  Society  has 
no  creed,  except  perhaps  the  belief  that  there  is  something 
worth  investigating ;  and  consequently  no  one  has  any  right  to 
speak  for  it  as  regards  the  conclusions  reached — the  facts  and 
theories  which  are  or  are  not  established.  Each  member  must 
speak  for  himself;  and,  as  I  am  perhaps  a  fairly  average  member, 
half-way  between  Dr.  Bramwell  who  does  not  believe  in  telepathy, 
and  Dr.  Ochorowicz  who  (after  long  and  laborious  investigation) 
has  arrived  at  belief  in  various  queer  telergic  and  teleplastic 
phenomena,  it  may  not  be  out  of  place  if  I  indicate  my  own 
attitude  towards  the  main  features  of  the  subject. 

Telepathy 

I  believe  that  communication  between  mind  and  mind, 
through  channels  other  than  the  known  sensory  ones,  is  a  fact. 
My  belief  is  based  on  the  voluminous  and  carefully  recorded 
evidence  in  the  forty  volumes  of  Proceedings  and  Journal  S.P.R., 
plus  my  own  experience.  I  have  carried  out  long  series  of  experi- 
ments with  distant  friends — not  professional  mediums,  and  not 
spiritualists — with  impressive  if  not  conclusive  results.  There 
is  always  a  mixture  of  hit  and  miss  in  these  experiments,  and 
it  is  difficult  to  know  how  much  to  allow  for  chance  coincidence. 
However,  by  using  a  shuffled  pack  of  cards,  and  drawing  one 
for  each  attempt,  the  chances  can  be  mathematically  determined. 
It  may  here  be  mentioned  that,  in  a  series  carried  out  by  Sir 
Oliver  Lodge,  the  odds  can  be  shown  to  be  ten  millions  to  one 
against  the  results  being  due  to  chance.1  Mr.  Shelton  may  say 
that  telepathy  is  "  not  proven,"  but  I  think  that  in  certain  walks 
of  life  such  odds  as  ten  millions  to  one  would  indicate  what  I 
believe  is  known  as  a  "  dead  cert." 

1  Survival  of  Matt,  p.  65. 
49 


76o  SCIENCE  PROGRESS 

The  experimental  evidence  is  the  best  adapted  to  exact 
statement  and  safe  inference,  but  a  provisional  telepathic 
hypothesis  is  indicated— as  the  doctors  say — by  other  phenomena 
such  as  are  often  observed  in  trance  mediums  and  normal 
clairvoyants.  Few  if  any  serious  investigators  have  remained 
unconvinced  that  some  supernormal  agency  or  mode  of  function 
is  occasionally  concerned  in  these  curious  happenings.  Says 
the  late  William  James,  who  investigated  these  things,  off  and 
on,  for  about  thirty  years,  without  accepting  any  particular 
theory : 

11  Knowing  these  trances  at  first  hand,  I  cannot  escape 
the  conclusion  that  in  them  the  medium's  knowledge  of  facts 
increases  enormously,  and  in  a  manner  impossible  of  explana- 
tion by  any  principles  of  which  our  existing  science  takes 
account.  .  .  .  The  trances  I  speak  of  (Mrs.  Piper's)  have  broken 
down  for  my  own  mind  the  limits  of  the  admitted  order  of 
nature.  Science,  so  far  as  science  denies  such  exceptional 
facts,  lies  prostrate  in  the  dust  for  me ;  and  the  most  urgent 
intellectual  need  which  I  feel  at  present  is  that  science  be  built 
up  again  in  a  form  in  which  such  facts  shall  have  a  positive 
place." 

That  expresses  the  feelings  of  many  of  us. 

Trance-Phenomena  and  Normal  Clairvoyance 

It  is  fairly  common  for  a  trance-control  to  give  information 
about  the  sitter's  deceased  relatives,  quite  beyond  what  any 
amount  of  inquiry  would  account  for.  So  long  as  the  informa- 
tion given  is  within  the  knowledge  of  the  sitter,  telepathy  is  a 
possible  explanation;  and  even  if  he  has  no  conscious  recollection 
of  it,  the  knowledge  may  exist  in  his  subliminal  memory — where 
"  forgotten  "  things  go — and  may  be  "  telepathing"  itself  from 
that  dim  abode,  or  may  be  accessible  to  the  medium's  foraging 
mind.  This  is  a  permissible  guess,  but  nothing  more.  Some- 
times, however,  evidential  communications  are  received  from 
soi-disant  spirits  who  are  quite  unconnected  with  the  sitter,  and 
who  were,  indeed,  unknown  to  him  in  life  ;  and  these  messages 
have  been  verified  by  inquiry  of  the  spirit's  relatives,  who  did 
not  even  know  of  the  medium's  existence.  This  requires  an 
extension  of  telepathy — if  telepathy  is  urged  at  all — far  beyond 
what  experiment  justifies.  I  cordially  agree  with  Mr.  Shelton 
about  the  rash  folly  of  experimentally  unsupported  speculation. 


PSYCHICAL  RESEARCH  761 

Premature  guesses  often  retard  discovery,  by  turning  our  eyes 
in  wrong  directions.  I  doubt  very  much  if  the  telepathy  guess 
is  the  true  explanation  of  these  cases. 

And  sometimes  telepathy  seems  almost  or  quite  excluded.   A 
soi-disant  spirit  has  been  known  to  refer  to  something  which,  so 
far  as  could  be  ascertained,  was  known  to  no  living  mind,  e.g. 
something  written  in  an  MS.  note-book  just  before  death,  and  not 
looked   at   by   surviving   relatives   until   the  mediumistic  com- 
munication came,  alluding  to  the  book  and  the  entry  as  a  test 
of  identity.1     Nevertheless,  though  telepathy   seems   excluded, 
this  does  not  give  us  proof  of  the  spiritistic  hypothesis.     There 
are  several  alternatives.    It  may  be  a  case  of  deferred  telepathy — 
i.e.  the  person  may  have  "  telepathed "  the  information  before 
she  died,  and  the  medium  (a  non-professional  one)  may  have 
picked  up  its  reverberations,  or  indeed  may  have  received  it  at 
once  and  stored  it  up  for  later  emergence.     Or  it  may  be  that 
objects  which  have  been  handled  and  thought  about  by  human 
beings  somehow  retain  a  sort  of  dim   mentality  or  memory  of 
their   owner,   and  can  afford    information   about   the  latter    to 
any  one  possessing  the  necessary  sensitiveness.     Personally,  I 
am  convinced  by  my  own  experiments  that  something  of  the 
sort  is  true.     A  medium  whom  I  have  known  for  many  years 
can  describe  living  people,  and  can  often  give  the  most  intimate 
details   of  their  lives,   by  handling  a  lock  of  hair   or  a  worn 
garment  taken  by  some  other  person  ;  and  the  explanation  is 
not  telepathy  from  the  sitter,  for  the  evidence  given  often  goes 
far  beyond  the  sitter's  knowledge.     And  if  objects  do  thus  carry 
some  sort  of  memory,  an  old  glove  may  enable  a  medium  to 
produce  any  amount  of  evidence  about  its  deceased  owner.  How 
it  comes  about,  the  medium  does  not  know,  nor  do  I.     Perhaps 
dead   people's  memories   stick   together    for    a  while,   in    the 
psychical    world,   without   any   self-conscious   survival,   as  the 
physical   body  sticks    together    for    a  while    in    the   physical 
world  ;     and     the    worn     object     may     somehow    tell     the 
medium's  subliminal  where  to  cast  its  line  to  fish  up  some  of 
these  recollections.      But   this   is    only  ingenious    guesswork, 
devised  as  an  alternative  to  "  spirits."     I  state  it  in  order  that 
all  sides  of  the  question  may  be  seen.     We  cheerfully  admit  that 

1  Proceedings  S.P.R.,  vol.  xvii.  p.  183.  The  whole  report  (by  Mrs.  Verrall, 
classical  lecturer  at  Newnham,  and  translator  of  Pausanias)  should  be  read.  It 
is  an  admirable  example  of  what  reports  of  this  kind  should  be. 


762  SCIENCE  PROGRESS 

coercive  proof  is  not  possible — it  never  is  in  inductive  science — 
and  that  alternative  hypotheses  may  always  be  devised.  No  one 
need  be  afraid  of  having  to  believe  against  his  will ! 

These  trance-phenomena  are  closely  paralleled  by  the  "normal 
clairvoyance  "  of  a  medium  well  known  to  me  for  many  years. 
This  man,  apparently  quite  normal,  and  certainly  not  in  trance, 
will  sometimes  reel  off  correct  descriptions  and  names  of  one's 
deceased  relatives  as  fast  as  they  can  be  taken  down  in  short- 
hand ;  also  intimate  family  details  of  the  sitter's  history  which 
he  could  not  have  obtained  by  detective  work ;  also,  sometimes, 
things  which  the  sitter  did  not  know,  and  never  had  known — so 
far  as  he  was  aware — but  which,  on  inquiry,  turned  out  true. 
My  friends  and  1  have  carried  out  long  series  of  experiments 
with  this  medium,  introducing  strangers  from  distant  towns — 
non-spiritualists,  people  with  no  interest  in  these  matters — and 
devising  various  other  tests.  We  began  as  unbelievers,  but  the 
facts  beat  us.  Something  out  of  the  common  is  at  work,  of  that 
we  are  sure.  What  it  is  we  do  not  know.  Perhaps  it  is  partly 
telepathy,  but  some  of  the  evidence  seems  to  go  beyond  that.1 

Automatic  Writing 

Of  late  years  the  main  interest  of  the  Society  has  centred  in 
the  automatic  scripts  of  certain  persons,  mostly  of  high  social 
and  academic  position,  and  not  spiritualists  or  mediums  in  any 
current  sense  of  that  objectionable  and  question-begging  word, 
who  receive  messages  purporting  to  come  from  the  surviving 
minds  of  some  former  leaders  of  the  S.P.R.,  notably  Edmund 
Gurney,  Richard  Hodgson,  F.  W.  H.  Myers,  and  Henry 
Sidgwick.  Once  more  we  may  say  that  much  of  this  may  be 
due  to  subliminal  fabrication  plus  telepathy,  so  I  waive  the 
portion  which  is  possibly  thus  explicable.  But  the  more  recent 
developments  cannot  be  ascribed  to  any  telepathy  that  I  can 
believe  in.  In  the  cross-correspondences,  fragmentary  and  in- 
comprehensible messages  came  through  Mrs.  Verrall  at  Cam- 
bridge, Mrs.  Holland  in  India,  Mrs.  Forbes  in  the  North  of 
England,  and  Mrs.  Piper  in  America,  but  when  the  bits  were 
pieced  together  by  the  Society's  Research  Officer,  they  were 
found  to  "  make  sense,"  and  sense  characteristic  of  the  ostensible 

1  For  details  of  this  and  other  cases  I  may  mention  my  New  Evidences  in 
Psychical  Research  (Rider,  London)  and  Spiritualism  and  Psychical  Research 
(T.  C.  &  E.  C.  Jack's  "People's  Books"). 


PSYCHICAL  RESEARCH  7^ 

sender.  Here,  then,  is  no  mere  sticking  together  of  unconscious 
memories  in  a  cosmic  reservoir ;  for  the  evidence  suggests  in- 
telligence, initiative,  and  will  on  "  the  other  side."  Admittedly, 
here  again,  the  evidence  does  not  amount  to  knock-down  proof. 
It  never  can.  We  can  always  say,  "  there  must  have  been  some 
fraud  or  error  somewhere,"  even  though  we  cannot  find  it. 
Lavoisier  had  settled  it  in  his  own  mind  that  there  were  "no 
stones  in  the  sky,"  therefore  the  celestial  origin  of  meteoric 
stones  was  palpably  wrong.  The  scholastic  philosopher  had 
read  several  times  through  Aristotle,  and  had  found  no  mention 
of  sun-spots  ;  therefore  the  astronomer  who  thought  he  saw 
them  must  be  mistaken.  We  moderns  are  not  yet  emancipated 
from  prejudice,  but  we  may  at  least  learn  from  such  instructive 
examples  that  it  is  better  to  investigate  for  ourselves  than  to 
deny  a  priori  the  observations  of  others. 

Veridical  Sensory  Automatisms 

These  are  not  producible  to  order,  but  they  can  be  studied 
when  they  do  turn  up,  like  volcanic  eruptions  and  earthquakes, 
which  are  similarly  beyond  our  control. 

It  happens  fairly  often  that  when  a  person  is  undergoing 
some  particularly  stressful  experience  some  friend  at  a  distance 
becomes  more  or  less  aware  of  the  fact  by  experiences  varying 
from  vague  emotions  to  full-blown  hallucinations.  When  a  full 
record  is  written  out  and  placed  in  the  hands  of  some  respon- 
sible person  before  verification,  this  constitutes  evidence  of  some- 
thing supernormal,  particularly  if  the  percipient  had  no  reason 
to  expect  or  imagine  any  occurrence  of  the  kind,  and  was 
therefore  not  predisposed.  Usually  this  signifies  telepathy,  and 
is  sufficiently  interesting  as  such.  But  sometimes  it  seems  to 
signify  more.  It  often  happens  that  the  apparent  sender  of  the 
telepathic  message  is  found  to  have  died  just  about  the  time. 
And,  of  course,  even  if  the  hallucination  (or  whatever  it  may  be) 
occurred  after  the  time  of  death  this  would  not  prove  survival, 
for  it  may  be  "  deferred "  telepathy,  the  dying  person  having 
sent  his  psychical  wave-message  out  before  dissolution.  There 
may  be  cases,  however,  in  which  this  seems  unlikely,  as  when 
the  death  is  so  sudden  that  the  individual  has  next  to  no  time 
for  thinking  about  it.  If  I  see  an  apparition  of  my  brother, 
with  a  bleeding  wound  in  his  right  temple,  and  if  it  turns  out 


764  SCIENCE   PROGRESS 

that  he  was  killed  by  a  bullet  in  the  right  temple  a  few  hours 
before  I  saw  the  apparition,  it  certainly  suggests  the  activity  of 
his  surviving  mind.  It  does  not  prove  it,  for  it  is  impossible 
to  prove  that  death  was  instantaneous,  which,  indeed,  it  pro- 
bably never  is.  He  might,  therefore,  have  time  to  send  the 
message  before  death  occurred.  But  such  cases  warn  us  to  be 
careful  about  too  airily  disposing  of  everything  of  the  kind  by 
a  reference  to  telepathy.  The  illustrative  case  just  given  actually 
happened  to  Captain  Colt.  He  was  in  Scotland  when  he  saw 
the  apparition,  and  his  brother  was  killed  in  Russia.  Two 
more  points  are  worth  noting:  (i)  Captain  Colt  had  asked  his 
brother  to  let  him  know  by  "appearing"  to  him  if  possible 
should  anything  happen  to  him ;  (2)  he  saw  the  figure  in  a 
kneeling  position,  and  that  was  the  posture  in  which  the  body 
was  actually  found.1 

The  S.P.R.  has  made  laborious  collections  of  such  cases, 
instituting,  e.g.,  a  census  in  which  17,000  persons  were 
questioned.  The  report  of  the  Committee,  which  worked  at 
the  data  for  several  years,  concludes  with  the  short  but  weighty 
statement  that  "  between  deaths  and  apparitions  of  the  dying 
person  a  connexion  exists  which  is  not  due  to  chance  alone." 
This  was  signed,  among  others,  by  Prof.  Sidgwick,  who  was — 
according  to  William  James — "  the  most  exasperatingly  critical 
mind  in  England." 

The  Report,  in  vol.  x  of  Proceedings  S.P.R.,  is  worth  careful 
study.  All  the  possibilities  of  error  that  could  be  thought  of 
by  acute  and  experienced  investigators  were  duly  considered 
and  allowed  for.  Some  hasty  critics  have  revealed  their  ignor- 
ance of  the  Report  by  advancing  various  elementary  objections 
which  the  Committee  had  already  exhaustively  dealt  with. 
Verb.  sap. 

Physical  Phenomena 

Of  these  there  are  various  alleged  kinds.  Small  objects — 
stools,  chairs,  tables  sometimes — are  said  to  move  without 
discoverable  application  of  force.  Percussive  sounds  ("  raps  ") 
are  said  to  be  produced  in  some  similarly  inexplicable  fashion. 
Objects  are  said  to  be  brought  from  a  distance  (apports)  by 
supernormal  means, ;as  when  a  bell  appears  in  the  seance  room 
without  any  door  having  been  opened — the  bell  being  usually 

1  Myers's  Human  Personality  and  its  Survival  of  Bodily  Death,  vol.  ii.  p.  348. 


PSYCHICAL  RESEARCH  7^5 

located  on  a  shelf  in  another  room.  In  this  particular  case 
the  experimenter  at  once  went  to  the  other  room  to  investigate. 
His  two  boys  were  working  there.  He  asked  where  the  bell 
was.  One  of  the  boys  looked  up  at  the  shelf,  and  said,  aston- 
ished, that  it  was  there  a  few  minutes  ago.  The  experimenter 
was  Sir  William  Crookes,  now  President  of  the  Royal  Society, 
who  also  testifies  to  raps,  movement  of  objects  without  contact, 
and  materialisation.  The  medium  who  gave  him  the  greatest 
range  of  results  was  D.  D.  Home,  who,  contrary  to  Browning's 
assertion,  now  disproved,  was  never  caught  in  trickery,  or 
anything  like  it.  Sir  William's  materialisations,  however,  were 
mostly  produced  by  the  medium  Florence  Cook.  All  the  ex- 
periments were  carried  out  in  Sir  William  Crookes's  own  house 
or  that  of  a  friend,  and  all  the  sitters  were  his  close  relatives 
or  friends.  Usually  he  did  not  decide  which  room  to  use  for 
the  seance  until  the  last  minute,  so  that  preparation  by  a 
hypothetical  trickster  was  rendered  impossible.  It  is  useless 
to  discuss  this  evidence  in  detail,  but  any  one  who  will  read  it 
with  a  really  open  mind  will  probably  find  it  rather  impressive. 

The  performances  of  the  Rev.  Stainton  Moses  seem  to  have 
equalled  those  of  Home.  Unfortunately,  Mr.  Moses  gave  sittings 
to  his  own  friends  only,  and  the  evidence  is  therefore  less  good. 
But  he  was  certainly  a  very  highly  respected  man — a  teacher  of 
English  for  eighteen  years  at  University  College  School,  after 
throat  trouble  compelled  relinquishment  of  his  curacy — and  no 
evidence  of  fraud  or  anything  incompatible  with  complete 
integrity  has  ever  been  brought  against  him. 

The  most  famous  physical  medium  of  modern  times,  however, 
is  Eusapia  Palladino,  who  is  still  living.  For  thirty  years  this 
Neapolitan  peasant  woman  has  provided  material  for  the  psycho- 
logical savants  of  Western  Europe  to  puzzle  over.  She  was 
certainly  caught  tricking  in  the  Cambridge  sittings  of  1895,  held 
by  Dr.  Hodgson,  Sir  Oliver  Lodge,  Mr.  Myers,  and  Prof.  Sidg- 
wick ;  also,  perhaps,  in  some  recent  sittings  in  America.  It  is 
admitted,  even  by  those  who  believe  in  her  genuine  powers,  that 
she  cheats  sometimes,  perhaps  in  a  trance-state,  which  absolves 
her  of  moral  responsibility.  But  it  is  a  fact,  on  the  other  hand, 
that  she  had  in  1894  convinced  Sir  Oliver  Lodge,  Mr.  Myers, 
and  Prof.  Richet  (the  recent  recipient  of  the  191 3  Nobel  prize 
for  physiology)  of  her  supernormal  faculty.  After  the  Cambridge 
sittings,  Mr.  Myers  further  confirmed  his  good  opinion  by  some 


766  SCIENCE  PROGRESS 

more  sittings  in  Paris.  Most  impressive  of  all  (to  those  who, 
like  Mr.  Shelton's  conjurer,  have  no  opinion  of  F.R.S.'s),  she 
completely  upset  the  scepticism,  in  a  series  of  eleven  sittings  at 
Naples  in  1908,  of  three  of  the  ablest  investigators  now  living, 
two  of  them  expert  conjurers,  and  all  of  them  old  hands  at  the 
game  of  showing  up  fraudulent  mediums.1 

But,  once  more  and  for  the  last  time,  conclusions  are  not  to 
be  arrived  at  by  proxy.  We  cannot  get  convictions  second- 
hand. Each  must  investigate  for  himself.  The  mind  is  natur- 
ally inhospitable  to  statements  alleging  occurrences  which  have 
no  parallel  in  its  own  experience.  And  this  natural  conservatism 
is  a  good  thing.  It  saves  us  from  superstition  and  foolish 
credence  of  various  kinds.  I  greatly  prefer  excessive  scepticism 
to  excessive  credulity,  and  should  be  sorry  to  think  that  any  one 
believed  these  things  on  my  authority.  We  do  not  expect  to 
produce  belief  by  our  reports ;  we  do  not  even  wish  to  do  so. 
The  most  that  we  expect  or  wish  to  do  is  to  "  modify  the  atmo- 
sphere," to  dissolve  away  negative  assumptions,  to  change 
popular  opinion  from  a  state  of  ignorant  denial  to  a  state  of 
open-minded  tolerance  and  suspense  of  judgment ;  while  at  the 
same  time  insisting  on  adherence  to  careful  scientific  methods 
and  on  ruthless  rejection  of  anything  that  is  not  based  on  solid, 
carefully  amassed,  and  tested  evidence.     To  quote  James  again  : 

"  Is  it  then  likely  that  the  science  of  our  own  day  will  escape 
the  common  doom,  that  the  minds  of  its  votaries  will  never  look 
old-fashioned,  to  the  grandchildren  of  the  latter?  It  would  be 
folly  to  suppose  so.  Yet,  if  we  are  to  judge  by  the  analogy  of 
the  past,  when  our  science  once  becomes  old-fashioned  it  will  be 
more  for  its  omissions  of  fact,  for  its  ignorance  of  whole  ranges 
and  orders  of  complexity  in  the  phenomena  to  be  explained,  than 
for  any  fatal  lack  in  its  spirit  and  principles."2 

Oliver  Cromwell  once  said,  when  getting  rather  impatient 
with  some  bigoted  theologians  :  "  For  God's  sake,  gentlemen, 
consider  that  you  may  just  possibly  be  mistaken."  I  would  say 
to  orthodox  scientific  men  :  "  For  Truth's  sake,  gentlemen,  con- 
sider that  Hamlet's  famous  remark  to  Horatio,  though  now  too 
hackneyed  for  quotation,  may  nevertheless  be  true." 

1  Proceedings  S.P.R.,  vol.  xxiii.  pp.  309  et  seq.  •  Report  by  Baggally, 
Carrington,  and  Feilding.  See  also  Carrington's  book,  Eusapia  Palladino  and 
her  Phenomena,  and  Morselli's  Psicologia  e  Spiritismo. 

*  Proceedings  S.P.P.,  vol.  xii.  p.  10. 


PSYCHICAL  RESEARCH  767 

II.    REPLY.— By  H.  S.  SHELTON,  B.Sc. 

Mr.  J.  Arthur  Hill,  who  has  the  opportunity  to  place  before 
the  readers  of  Science  Progress  evidence  concerning  the 
survival  of  human  personality  beyond  the  grave,  would  have 
done  better  to  have  used  the  space  at  his  disposal  in  presenting 
his  evidence,  instead  of  paying  so  much  attention  to  my  few 
cursory  remarks  published  in  the  last  issue.  By  so  doing  he 
would  have  been  able  to  give  a  clearer  idea  of  what  the  evidence 
is  supposed  to  be,  and  he  would  not  have  given  an  entirely  false 
impression  of  the  content  of  my  article.  Readers  of  Mr.  Hill's 
paper  would  imagine  that  I  had  written  a  paper  in  criticism 
of  psychical  research,  whereas  my  article  was  a  criticism  of 
Sir  Oliver  Lodge's  presidential  address,  concentrated  mainly 
on  the  scientific  side,  and  the  object  of  the  paper  was  to  show 
that,  on  that  side,  there  was  a  valuable  contribution  to  the 
philosophy  of  science  which  was  liable  to  be  forgotten  because 
criticism  had  been  concentrated  on  the  few  remarks  Sir  Oliver 
did  make  on  survival  after  death  and  on  other  matters  of 
religion.  The  details  of  the  evidence  for  psychical  research 
I  did  not  attempt  to  discuss.  Certainly  I  expressed  the  opinion 
that  the  evidence  did  not  convince  me,  but  the  point  of  my 
remarks  consisted,  not  in  discussion  of  the  evidence,  but  in 
a  statement  of  the  methodological  principles  which  would  apply 
to  any  attempt  to  prove  anything  of  the  kind  from  the  scientific 
standpoint. 

Concerning  my  remarks,  and  Mr.  Hill's  criticisms,  the  follow- 
ing short  explanation  will  suffice.  The  book  of  the  late  F.  W. 
H.  Myers  referred  to  was  the  original  edition  in  two  volumes. 
The  term  monumental  was  intended  to  apply,  not  so  much  to 
the  length,  as  to  mass  of  material  contained  therein,  and  to 
the  industry,  ability,  and  research  shown  by  the  author.  The 
conjuror  was  Mr.  Maskelyne,  and  the  reference  was  to  a 
challenge  by  him  to  reproduce,  under  similar  conditions,  any 
physical  phenomena  credited  to  "spirits"  which  he  had  the 
opportunity  of  witnessing.  I  believe  the  challenge  has  not 
been  withdrawn,  and  Mr.  Hill  would  do  well  to  refer  to  Mr. 
Maskelyne  for  further  information.  I  seem  to  remember  also 
that  Mr.  Maskelyne  was  present  on  one  occasion  at  a  stance 
with  Eusapia  Palladino. 

Whether  Mr.  Hill  has  said   anything  likely  to  carry  con- 


768  SCIENCE  PROGRESS 

viction,  or  to  induce  any  one  not  at  present  interested  to  think 
there  is  evidence  worthy  of  investigation,  is  a  question  on  which 
I  do  not  think  it  necessary  to  express  an  opinion.  I  am 
perfectly  well  content  to  leave  that  matter,  as  Mr.  Hill  has 
stated  it,  to  the  readers  of  Science  Progress. 

The  suggestion  concerning  the  Roman  Catholic  Church  is 
emphatically  not  a  joke.  It  is,  perhaps,  the  most  serious  state- 
ment in  the  preliminary  remarks  of  my  article,  before  I  reached 
the  more  strictly  scientific  side.  The  suggestion  had  reference 
not  only  to  survival  after  death.  Sir  Oliver  Lodge  made 
remarks  on  survival  after  death,  on  Theism,  and,  if  my  memory 
does  not  fail  me,  also  on  miracles.  I  strongly  objected  to  the 
introduction  of  such  matters  into  a  presidential  address  to  the 
British  Association.  I  did  so,  in  the  first  place,  because  I 
thought  that  he  would  have  done  better  to  have  concentrated 
on  the  scientific  side.  I  did  so,  in  the  second  place,  because  I 
thought  that  his  patronising  attitude  towards  the  exponents 
of  orthodox  Christianity  was  somewhat  inconsistent  with  his 
statement  of  belief  in  some  of  their  most  important  fundamental 
doctrines,  as  if  the  belief  in  them  were  a  remarkable  new 
discovery  of  his  own.  He  seemed  entirely  ignorant  how  power- 
ful, and  how  logical,  is  the  case  for  orthodox  Christianity,  and 
particularly  for  Roman  Catholicism,  if  once  you  admit  the 
premises.  To  those  who  have  a  strong  interest  in  religion, 
as  Sir  Oliver  Lodge  appears  to  have,  and  who  are  personally 
convinced  on  the  three  dogmas  of  God,  immortality,  and 
miracles,  I  repeat,  the  most  logical  course  is  to  go  and  see 
what  Rome  has  to  teach  them. 

But  all  this  is  more  or  less  a  side-issue.  I  am  not,  and  make 
no  pretence  to  be,  an  authority  on  ghosts,  on  religion,  or  even 
on  telepathy.  Concerning  the  latter,  it  is  sufficient  for  me 
that  Mr.  Arthur  Hill's  "  dead  cert "  has  not  convinced  a 
prominent  member  of  his  own  Psychical  Research  Society. 
And,  moreover,  if  you  succeed  in  proving  it,  as  Mr.  Hill  has 
admitted,  a  mechanical  explanation  is  available.  The  subject 
is  of  considerable  scientific  interest,  but  it  lies  within  the  sphere 
of  experimental  psychology  rather  than  within  that  of  my 
own  subject — logic  and  methodology,  and  general  philosophy. 
Any  one  who  wishes  to  continue  the  discussion  concerning 
ghosts,  would  do  well,  so  far  as  they  refer  to  me,  to  note 
my   statements   concerning  the   methods   of  interpreting  such 


PSYCHICAL  RESEARCH  769 

evidence   as   is  available,  rather  than   my  opinion   concerning 
its  value. 

What  I  desire  most  emphatically  to  repeat  is  that  the  most 
important  part  of  my  article,  as  is  stated  in  the  article,  is  to 
be  found  in  the  latter  part.  And  it  is  the  scientific  side  of 
Sir  Oliver  Lodge's  address  to  which  I  wished  to  attract 
attention.  In  my  criticism  of  his  remarks,  I  expressed  views 
on  metageometry,  on  the  principle  of  relativity,  on  the  principles 
of  mathematical  method  and  their  application  to  scientific 
theories,  which  are  somewhat  at  variance  with  those  commonly 
held  among  men  of  science.  On  several  disputed  points,  I 
was  glad  to  note  that  Sir  Oliver  Lodge  held  similar  views, 
and  I  greatly  regretted  that  the  value  of  his  support  was  dis- 
counted by  the  introduction  of  what  could  hardly  be  described 
as  legitimate  scientific  matter.  I  would  repeat  that,  in  my 
opinion,  to  concentrate  criticism  on  the  "spiritualistic"  side 
is  an  injustice  to  Sir  Oliver  Lodge.  That,  however,  is  a  matter 
for  Sir  Oliver  rather  than  for  me.  With  regard  to  my  article, 
I  followed  him,  on  that  side,  with  great  reluctance,  because  it 
was  my  duty,  as  a  critic,  to  deal  with  the  address.  But,  so 
far  as  I  am  personally  concerned,  I  would  most  emphatically 
say  that,  to  concentrate  criticism  on  that  side  of  my  article, 
is  an  injustice  to  me 


REVIEWS 

Encyclopaedia  of  the  Philosophical   Sciences.    Vol.  i.  Logic.    By  Arnold 

RUGE,     WlLHELM     WlNDLEBANK,     JOSIAH      ROYCE,     LOUIS     COUTURAT, 

Benedetto  Croce,  Ferderigo  Enriquez,  and  Nicolaj  Losskij. 
Translated  by  B.  Ethel  Meyer.  [Pp.  vi  +  268.]  (London  :  Macmillan 
&  Co.,  1913.) 

The  title-page  is  strongly  reminiscent  of  "Widdecombe  Fair."  The  volume 
consists  of  an  article  on  the  scope  and  purpose  of  Logic  by  each  of  the  authors 
named.  Each  presents  the  subject  in  a  slightly  different  personal  aspect.  All 
the  articles  are  well  written.  The  object  of  the  series  of  volumes  is  expressed  by 
the  editor  in  a  few  well-chosen  words  :  "  .  .  .  each  volume  will  consist  .  .  . 
of  original  and  relatively  exhaustive  discussions  of  fundamental  aspects  of 
each  main  subject."  This  is  carried  out  thoroughly  well.  Another  ideal,  which 
the  present  volume  purports  to  subserve,  and  which  is  also  said  by  the  editor 
to  be  the  mission  of  philosophy,  is  to  correct  the  surface  tendency  of  present-day 
human  thought  towards  divergency.  "  The  field  of  the  thinker's  inquiry  is 
becoming  ever  narrower,  and  the  function  of  the  practical  man  ever  more 
particular.  .  .  .  The  theoretic  and  speculative  intercourse  of  civilised  peoples  is 
always  becoming  more  intimate  and  full.  .  .  .  The  promoters  of  the  Encyclo- 
paedia have  set  themselves  the  most  difficult,  but  also  the  most  significant  task 
of  giving  expression  to  this  unity  by  means  of  the  very  freedom  and  variety  of 
the  writers  whom  they  have  enlisted  in  the  service." 

The  reviewer  is  not  disposed  to  deny  the  truth  of  the  view  expressed  in  the 
first  part  of  the  quotation,  having  himself,  on  several  occasions,  asserted  the  same 
thing.  The  last  part  is  an  unwarrantable  and  meaningless  paradox.  Regretfully 
it  must  be  stated  that,  so  far  as  the  present  volume  is  concerned,  the  writers 
have  not  given  expression  to  this  unity  in  any  matter  whatever.  If  this  is  the 
object  we  must  be  definite  in  saying  that  there  are  high-sounding  words  and 
promises,  but  no  achievement.  The  volume  will  be  of  interest  to  that  small 
class  of  people,  those  absurd  contradictions  in  terms,  who,  like  Mr.  Chesterton's 
rhinoceros,  exist  but  look  as  if  they  didn't,  the  specialists  in  philosophy.  To 
these,  and  to  amateur  dabblers,  the  book  will  appeal,  but  to  no  one  else. 

To  readers  of  this  journal  the  main  point  of  interest  is  that,  by  several  writers, 
considerable  space  is  given  to  the  treatment  of  methodology.  What  is  metho- 
dology ?  It  is  supposed  to  have  something  to  do  with  scientific  method,  and 
consequently,  might  be  expected  to  have  some  interest  for  men  of  science.  As 
usually  presented  it  emphatically  has  not.  But  the  potential  scientific  interest 
of  the  subject,  as  it  might  conceivably  be  presented,  will  be  sufficient  excuse 
for  devoting  the  remainder  of  the  space  at  our  disposal  to  the  methodological 
aspect. 

Prof.  Windlebank  contributes  very  little  of  interest.  "  Strictly  speaking, 
methodology  has  no  principles  of  its  own.  Its  principles  are  to  be  found  in 
pure  Logic,  and  methodology  has  only  to  deal  with  their  application  to  the 
different  aims  of  the  special  sciences  "  (p.  43).     Very  admirable,  but  it  does  not 

770 


REVIEWS  77t 

do  it.  The  methodologists  are  like  the  chorus  of  policemen  in  the  Pirates  of 
Penzance;  their  song  sounds  well,  but,  in  the  words  of  Major-General  Stanley, 
they  don't  go.  Prof.  Windlebank  occupies  eleven  pages  but  says  little  more. 
He  concludes  by  informing  us  that  "  the  knowledge  of  reality  of  the  empirical 
sciences  .  .  .  possesses  immanent  truth  in  the  agreement  of  the  theory  with  the 
facts"  (p.  54,  italics  his).  Most  of  us  will  be  of  the  opinion  that  we  were  aware 
of  this  already. 

Prof.  Royce  makes  an  attempt  to  depart  from  the  conventional  view  that 
methodology  is  a  division  or  extension  of  general  or  formal  logic.  He  regards 
formal  logic  as  a  very  subordinate  part  of  methodology.  The  idea  may  be  said 
to  be  in  the  air.  Dr.  Schiller  and  the  pragmatists  would  certainly  not  repudiate 
it.  The  reviewer  expressed  a  similar  but  less  extreme  opinion  several  years  ago. 
Prof.  Royce  can  thus  make  no  claim  to  originality  in  the  idea  itself.  Everything 
depends  on  the  manner  in  which  he  carries  it  out  in  detail.  A  methodology  of 
which  formal  logic  is  only  a  part  should,  at  least,  be  substantial  in  its  content. 
It  would  not  be  reasonable  to  expect  any  considerable  detail  in  Prof.  Royce's 
twenty-seven  pages.  And  such  general  ideas  as  he  has  stated  are  so  condensed 
in  exposition  as  hardly  to  admit  of  summary  or  criticism.  Very  great 
prominence  is  given  to  Mr.  Charles  S.  Pierce's  logic  of  induction.  He  brings 
into  strong  relief  the  presupposition  that  every  set  of  facts  has  some  definite 
constitution.  "  That  is,  according  to  our  presupposition,  there  are  possible 
assertions  to  be  made  about  these  facts  which  are  either  true  or  false  of  each 
individual  fact  of  the  set  in  question."  " '  A  is  a  man '  is  either  true  or  is  not 
true  of  A."  On  this  supposition,  which  is  said  not  to  be  self-evident,  all  induction 
and  scientific  inquiry  is  based.  This  is  interesting  and  plausible,  but  what  is 
meant  by  "  fact."  A  "  fact  "  concerning  which  nothing  could  be  asserted  as  true 
or  false  would,  indeed,  be  a  curious  phenomenon.  If  it  is  not  self-evident  that 
"  fact "  implies  definite  constitution,  what  is  self-evident  ?  There  is  the  usual 
discussion  concerning  definition,  classification,  and  stages  in  the  growth  of 
science.  The  specialist  in  logic  will  find  the  discussion  well  written,  interesting, 
and  highly  controversial.  It  contains  just  those  elements  so  dear  to  the  formal 
logician. 

The  few  methodological  pages  of  M.  Couturat  contain  a  glaring  example  of 
pyrrhonism.  All  axioms  other  than  the  "common  axioms  which  are  the 
principles  of  logic  "  (what  are  they  ?)  are  merely  primary  and  true  for  the  par- 
ticular theory  under  consideration.  "  We  are  guided  in  our  choice  of  fundamental 
data  by  quasi-aesthetic  reasons."  This  is  pragmatism  with  a  vengeance  and, 
as  such,  well  worth  noting.  Any  one  interested  must  refer  to  the  original  for  the 
manner  in  which  it  is  worked  out. 

The  whole  volume  is  an  admirable  compilation  in  its  way  and  will  greatly 
interest  logicians.  It  is  a  pity,  however,  that  its  object  should  be  stated  to  be  to 
give  expression  to  the  fundamental  unity  of  thought  underlying  the  theoretical 
and  speculative  intercourse  of  civilised  peoples.  It  is  merely  logical  specialism, 
one  more  specialised  science,  added  to  the  rest. 

H.  S.  Shelton. 

Scientific   Method.      Its  Philosophy  and  Practice.      By  F.   W.   Westaway. 
[Pp.  xx  +  439.]    (London  :  Blackie  &  Son,  Ltd.,  1912.     Price  6s.) 

The  volume  is  divided  into  four  books  entitled  respectively  :  The  Philosophy  of 
Scientific  Method,  The  Logic  of  Scientific  Method,  Famous  Men  of  Science  and 
Their  Methods,  Scientific  Method  in  the  Classroom. 


772  SCIENCE  PROGRESS 

The  first  two  books  call  for  very  brief  comment.  They  are  lengthy,  encyclo- 
paedic, and  seemingly  without  any  guiding  principle,  central  idea,  or  original  point 
of  view.  The  author  has  evidently  read  carefully  the  works  of  many  of  the  great 
ancient  and  modern  philosophers,  and  is  also  well  acquainted  with  the  current 
text-books  on  logic.  The  views  of  all  and  sundry  are  duly  noted  and  are  discussed 
at  some  length.  The  volume  cannot  be  regarded  seriously  as  a  contribution 
either  to  the  logic  or  to  the  philosophy  of  science,  nor  can  it  be  recommended  as  a 
text-book  for  those  wishing  to  acquire  a  clear  knowledge  of  the  current  methodology. 
That  being  so,  it  is  to  be  regretted  that  the  first  two  sections  are  not  condensed  to 
a  brief  introduction. 

In  the  latter  part  of  the  work  the  author  is  on  his  own  ground,  and  his  treat- 
ment of  the  principles  of  pedagogics  is  worthy  of  serious  consideration.  The 
preface  indicates  that  the  volume  is  intended  mainly  for  the  practical  teacher,  and 
Mr.  Westaway's  opinions  on  that  subject  should  be  treated  with  the  respect  due  to 
an  expert  in  school  routine.  Mr.  Westaway  is  an  ardent  advocate  of  heuristic 
methods,  especially  those  of  Prof.  Armstrong.  A  somewhat  fuller  treatment  of 
this  point  would  have  been  welcome.  Unfortunately  the  discussion  is  scanty 
and,  moreover,  exceedingly  didactic.  Whether  or  no  and  to  what  extent  school 
children  in  the  process  of  learning  the  elementary  principles  of  science  and 
mathematics  can  be  put  into  the  position  of  discoverers  is  a  problem  which 
deserves  fuller  and  more  impartial  consideration  than  it  has  yet  received.  Every 
teacher  of  every  subject  will  probably  say  that  his  main  object  is  to  train  the  pupil 
to  use  his  own  intelligence,  but  whether  or  no  this  object  will  be  served  by  turning 
a  science  lesson  into  a  peculiar  ritual  yclept  heuristic  is  a  controversial  question. 

What  Mr.  Westaway  does  not  appear  to  realise  is  that  the  teacher  to  whom 

his  remarks  are  addressed  has  no  option  but  to  proceed  by  the  experimental 

method.     If  he  attempts  to  adopt  Prof.  Armstrong's  and  Mr.  Westaway's  ideas 

the  attempt  can  be  nothing  else  but  an  experiment,  and  one,  moreover,  of  which 

the  standard  of  success  is  uncertain.     It  is  so  easy,  on  insufficient  grounds,  to  call 

a  fad  a  great  discovery.     But  the  matter  dealt  with  is  of  great  interest  to  a  large 

professional  class.     It  is  unfortunate,  therefore,  that  Mr.  Westaway  did  not  write 

a  book  on  the  practical  teaching  of  science,  a  subject  on  which  he  is  specially 

competent  to  speak,  and  that  he  did  not  discuss  these  current  controversies  clearly, 

fully  and  with  the   minimum  of  dogmatism.     The   exponents   of  the   heuristic 

method  show  small  disposition  to  be  heuristic  in  the  presentation  of  their  own 

pedagogics.     The  author's  attempt  to  combine  in  a  single  volume  a  treatise  on 

pedagogics  and  an  account  of  the  philosophy  of  scientific  method  is  not  very 

successful. 

H.  S.  S. 

Spencer's  Philosophy  of  Science.    By  C.  Lloyd  Morgan,  F.R.S.    [Pp.  52.] 
(Oxford:  Clarendon  Press,  1913.     Price  2s.  net.) 

Prof.  Lloyd  Morgan,  who  is,  or  has  been,  a  competent  specialist  in  at  least 
the  three  subjects  biology,  geology,  and  psychology,  is  eminently  fitted  to  be  a 
Herbert  Spencer  lecturer  and  to  pass  judgment  on  the  work  of  the  great  synthetic 
philosopher.  The  lecture,  however,  is  disappointing.  The  lecturer  tries  to  cover 
too  much  ground  and  conveys  no  very  clear  impression.  Moreover,  he  greatly 
overstates  the  importance  of  "  the  Unknowable  "  in  Spencer's  system.  There  are 
a  number  of  interesting  points,  but  the  content  of  the  lecture  is  not  well  indicated 
by  the  title. 

H.  S.  S. 


REVIEWS  773 

Astronomy.  A  popular  handbook.  By  Harold  Jakoby,  Professor  of  Astronomy, 
Columbia.  [Pp.  xi  +  435,  with  32  plates  and  many  figures  in  the  text.] 
(New  York  :  The  Macmillan  Co.     Price  10^.  6d.  net.) 

In  the  preface  to  this  volume  the  author  states  that  it  has  been  written  primarily 
for  "  the  ordinary  reader  who  may  desire  to  inform  himself  as  to  the  present  state 
of  astronomical  science,  or  to  secure  a  simple  explanation  of  the  many  phenomena 
constantly  exhibiting  themselves  in  the  Universe  about  him."  Such  a  reader  will 
find  the  second  of  these  desires  amply  satisfied  by  this  book,  the  greater  part 
of  which  is  occupied  with  elementary  and  lucid  explanations  of  some  of  the 
problems  of  spherical  and  gravitational  astronomy.  The  explanation  of  the 
differences  between  sidereal,  true  solar,  and  mean  solar  times,  of  the  principles 
of  the  sundial,  of  the  methods  of  determination  of  the  shape,  size,  and  mass  of  the 
earth  and  of  the  shape  and  dimensions  of  its  orbit,  and  of  the  differences  between 
the  Julian  and  Gregorian  calendars  are  given.  The  methods  by  which  the  masses 
and  distances  of  the  sun,  moon,  and  planets  have  been  determined  are  described, 
as  are  also  the  methods  by  which  the  position  of  a  ship  at  sea  may  be  found.  The 
phenomena  of  the  precession  of  the  equinoxes,  and  of  the  librations  of  the  moon, 
and  the  causes  of  the  production  of  tides,  eclipses,  and  kindred  phenomena  are 
also  expounded  in  a  simple  manner.  The  variety  of  the  subjects  here  mentioned 
will  sufficiently  indicate  the  comprehensive  nature  of  this  portion  of  the  book. 
Wherever  possible,  the  derivations  of  the  mathematical  results  which  are  assumed 
in  the  course  of  the  arguments  are  given  for  the  benefit  of  those  readers  who 
possess  a  knowledge  of  elementary  mathematics,  these  elementary  explanations 
being  collected  together  separately  in  an  appendix. 

The  portion  of  the  book  dealing  with  descriptive  astronomy  is  not  nearly  so 
successful,  being  very  sketchy,  incomplete,  and  disjointed ;  and  the  author  would 
have  succeeded  better  had  he  not  attempted  to  cover  so  much  ground.  The 
beginner  who  may  wish  to  study  this  part  of  the  subject  is  recommended  to  turn 
to  other  books  where  it  is  treated  in  a  much  more  satisfactory  manner. 

The  author  also  intended  that  this  volume  should  serve  as  a  text-book  for  high 
schools  and  colleges.  It  does  not  appear  to  be  suitable  for  this  purpose  :  much 
is  included  that  would  be  beyond  the  grasp  of  young  students,  whilst  in  the  case 
of  more  advanced  students,  the  subjects  here  dealt  with  can  be  studied  to  much 
greater  advantage  by  a  more  free  use  of  mathematics.  The  requirements  of  the 
student  are  so  different  from  those  of  the  ordinary  reader  that  it  is  impossible 
to  meet  adequately  the  needs  of  both  by  one  and  the  same  volume. 

A  few  incorrect  or  misleading  statements  may  be  mentioned.  On  p.  125  it  is 
asserted  that  "  so  far  as  gravitational  forces  alone  are  concerned,  the  solar  system 
may  endure  for  ever."  The  researches  of  Henri  Poincare  have  negatived  this 
conclusion,  which  Laplace  and  Poisson  erroneously  believed  to  follow  from  their 
mathematical  investigations.  On  p.  181  the  lunar  mountains  are  stated  to  be  from 
1,000  to  2,000  feet  high,  whereas  some  of  the  large  mountain  rings  rise  to  ten 
times  this  amount.  Also  on  p.  240  the  velocity  of  light  is  given  as  186,000  miles 
per  sec,  whereas  on  p.  333  the  value  183,000  miles  per  sec.  is  used. 

H.  S.  J. 

Die  Physik  der  bewegten  Materie  und  die  Relativitatstheorie.  By  Max  B. 
Weinstein.  [Pp.  xii  +  424.]  (Leipzig:  Johann  Ambrosius  Barth,  191 3. 
Price  17  marks  ;  bound,  19  marks.) 

This  book  gives  a  careful  and  laborious  account  of  the  work  done  on  electro- 
dynamics  in  recent  years,  divided  into  two  parts,  the  first  presenting  the  pre- 


774  SCIENCE  PROGRESS 

Einstein  treatment  of  the  optical  and  electrical  phenomena  in  moving  systems  ; 
the  second  the  work  of  Einstein,  Minkowski,  and  their  disciples  on  the  theory  of 
relativity.  Thus  the  author  devotes  considerably  more  than  half  of  his  work  to 
setting  out  the  classical  work  of  Maxwell,  Hertz,  and  Heaviside.  His  object,  as 
stated  by  himself,  is  somewhat  in  the  nature  of  a  protest  against  the  haste  of 
some  of  the  ultra-moderns  to  throw  the  powerful  theories  of  the  great  physicists 
of  the  last  generation  overboard  ;  he  warns  them  lest,  having  driven  out  the  old 
gods,  they  be  compelled  to  bring  them  back,  should  those  who  have  replaced 
them  not  fulfil  expectation.  We  think  that  most  physicists  will  be  able  to 
sympathise  with  this  point  of  view,  but  at  the  same  time  we  do  not  consider  that 
the  presentation  of  the  older  work  is  sufficiently  original  or  convenient  to  justify 
the  amount  of  space  devoted  to  it.  A  competent  knowledge  of  the  work  of  the 
Maxwell-Hertz  school,  and  a  clear  realisation  of  the  points  in  which  it  comes  into 
conflict  with  experience,  is,  of  course,  a  necessary  preliminary  to  an  understanding 
of  the  principle  of  relativity,  and  what  it  seeks  to  do  ;  but  in  view  of  the  large 
number  of  excellent  books  on  the  older  electrodynamics  we  find  the  present  book 
unnecessarily  diffuse. 

The  second  part  of  the  book  deals  with  the  modern  theory  of  relativity,  and 
seeks  in  particular  to  reduce  the  brilliant  work  of  Minkowski  to  a  form  more 
easily  understandable  than  that  of  the  original  papers.  Einstein's  concept  of 
simultaneity  and  the  fundaments  of  his  theory  are  clearly  exposed.  The  author 
finds  an  objection  to  the  theory  in  the  assumption  which  makes  co-ordination  of 
times  dependent  on  so  arbitrary  a  thing  as  the  velocity  of  light — a  difficulty  which 
must  have  struck  every  one  on  their  first  approach  to  the  principle.  It  is  hard  to 
answer  the  objection  ;  probably  the  best  justification  of  the  whole  theory  is  the 
way  in  which  it  gives  the  dragging  coefficient  required  by  Fresnel's  formula  and 
the  Fiseau  experiment,  the  negative  results  of  the  Michelson-Morley  and  all 
allied  experiments,  and  the  appeal  of  a  transformation  which  makes  the  equations 
invariant.  Minkowski's  mechanics  and  electrodynamics  are  developed  in  two 
sections,  but,  while  adequately  exposed,  are  not  made  much  clearer  than  in  the 
original  papers. 

The  book  has  all  the  thoroughness  of  a  German  work  of  the  old  school,  and  is 

a  formidable  addition  to  the  works  on  relativity. 

E.  N.  da  C.  Andrade. 

Rays  of  Positive  Electricity,  and  their  Application  to  Chemical  Analysis. 
By  Sir  J.  J.  Thomson.  [Pp.  vi  + 132.]  (London  :  Longmans,  Green  &  Co., 
191 3.     Price  $s.  net.) 

To  the  various  series  of  scientific  monographs  now  appearing  Messrs.  Longmans, 
Green  &  Co.  now  add  their  "  Monographs  on  Physics,"  under  the  joint  editorship 
of  Sir  J.  J.  Thomson  and  Dr.  F.  Horton.  The  first  volumes  include  one  on 
positive  rays  by  Sir  J.  J.  Thomson,  and  one  on  the  photoelectric  effect  by 
Dr.  Allen,  reviewed  elsewhere. 

The  book  on  positive  rays  is  not  a  general  account  of  all  the  work  which  has 
been  done  on  the  subject,  but  rather  an  account  of  the  recent  experiments  of  the 
distinguished  author,  which  has  thrown  so  much  light  on  the  nature  and  charge 
of  the  material  carriers  of  electricity  at  low  pressure,  together  with  a  few  selected 
researches  of  other  authors  whose  results  are  of  interest  in  this  connection.  It 
is  to  be  welcomed  as  giving  an  authoritative  summary  of  the  methods  and  results 
of  his  investigation  of  the  last  seven  years  in  this  field.  The  general  method 
consists  in  subjecting  a  beam  of  positive  rays,  passing  through  a  single  fine  hole 


REVIEWS  775 

in  the  cathode,  to  the  joint  action  of  codirectional  electric  and  magnetic  fields  ; 
the  trace  of  the  deflected  rays  on  a  plane  perpendicular  to  the  undeflected  rays 

e 

will  then  be  a  straight  line  if  the  velocity  of  the  rays  is  constant,  and  the  ratio  — 

variable,  and  a  parabola  if  the  velocity  is  variable,  and  the   ratio  —  constant, 

m 

different  values  of  the  ratio  giving  different  parabolas  (e  is  the  charge  on  the 

carrier  of  mass  m).     The  trace  of  the  rays  is  detected  by  means  of  a  photographic 

plate,  and  from  its  nature  Sir  J.  J.  Thomson  is  able  to  make  a  series  of  striking 

deductions. 

The  nature  of  the  curves  on  the  plate  depends  upon  the  pressure  of  the  gas. 
When  this  is  not  very  low  (relatively  speaking),  these  are  straight  lines,  generally 
only  two,  corresponding  to  the  atom  and  molecule  of  hydrogen  ;  Wien,  how- 
ever, also  obtained  evidence  of  the  existence  of  positively  changed  oxygen 
atoms.  For  these  pressures  the  effect  is  complicated  by  the  fact  that,  owing 
to  collisions  with  the  gas  molecules,  these  positive  rays  are  not  positively  changed 
all  the  time,  but  alternate  this  condition  with  the  neutral  and  negative  state,  as 
Wien  showed.  The  effective  charge,  e,  thus  varies  according  to  the  fraction 
of  the  time  during  which  a  carrier  is  charged  with  electricity  of  one  kind.  In 
Sir  J.  J.  Thomson's  recent  series  of  experiments  this  effect  was  avoided  by  using 
very  high  vacua. 

In  these  high  vacua  experiments,  to  which  a  large  part  of  the  book  is  devoted, 
the  main  curves  are  parabolic,  to  each  parabola  corresponding  a  definite  value  of 

—  for  the  rays  producing  it.     Sir  J.  J.  Thomson  has  from  the  different  parabolic 

traces  photographed  shown  the  presence  of  atoms  of  various  elements  with 
positive  charges  of  one  or  more  units,  of  neutral  atoms,  and  of  negatively 
charged    atoms     in     the    "positive"     rays     in     different     gases.       In     addition 

he  has  found  values  of  —  which  indicate   molecules  of  various  sorts  with  one 

m 

positive  charge  :   the  number  of  molecules  of  different  kinds  present  in  the  case 

of  a  complex  gas  may  be  very  large  ;  for  instance,  in  the  case  of  phosgene  gas, 

COCL,    molecules   of    the   composition    CO,    CI,,    CC1   and    COCL,    were   found. 

Molecules  with  a  multiple  positive  charge  have  never  been  detected.     A  strong 

confirmation   of  the   monatomic  nature   of  helium,  argon,  and    the  other   inert 

gases  is  afforded  by  the  fact  that,  for  them,  only  curves  corresponding  to  single 

charged    atoms    have    been    observed,    while    for    oxygen    and    hydrogen,    for 

instance,   diatomic  molecules  are  easily  detected.     Another  striking  result  from 

the  photographs  is  that  all  the  atoms  except  hydrogen  can  acquire  multiple  positive 

charges,  which  agrees  with   Prof.   Rutherford's  theory  that  the  hydrogen  atom 

consists   of  a  positive  nucleus  and  only   one   electron.     Mercury,   the   heaviest 

atom  investigated,  acquires  from  one  to  eight  positive  charges  ;    the  maximum 

number   of    charges   possible   appears   to   depend,   not    on    the    valency   of    the 

atom,  but  on  the  atomic  weight. 

As  the  photographs  afford  no  indication  of  the  relative  proportions  in  which 

the  different  and  differently  charged  atoms  and  molecules  are  present,  Sir  J.  J. 

Thomson  has  measured  the  number  of  electrified  particles  of  the  various  kinds 

present  by  an  electrostatic  method,  isolating  them  by  a  parabolic  slit,  through 

which  the  rays  of  different  kinds  are  brought  to  pass  by  altering  the  strength  of 

the  magnetic  field.     In   this   way   estimates   of  the   number   of  positively   and 

negatively  charged  atoms  have  been  made  ;  consideration  of  these  results  shows 

50 


776  SCIENCE   PROGRESS 

that  the  atoms  of  the  molecule  of  a  compound  gas  are  not  charged  with  electricity 
of  opposite  signs,  but  each  atom  contains  as  much  positive  as  negative  electricity, 
a  result  of  great  importance  for  chemistry. 

The  method  is  a  very  powerful  one  for  finding  the  weights  of  the  atoms  and 
molecules  present   in  the   tube,  and   has   already  led   to  the   announcement   of 

a  new  atom  and  a  new  molecule.     A  parabola  for  which  — =  3  (taking  — =1  for 

the   singly   charged    hydrogen    atom)   is    attributed    to   triatomic   hydrogen.      A 

parabola  for  which  —  =  22,  which  accompanies  the  neon  parabolaf —  =  20  J,  indicates 

an  atom  of  weight  22.  Mr.  F.  W.  Aston  has  partially  separated  such  a  gas 
from  neon  by  diffusion  ;  differences  of  density  in  the  two  components  have  been 
actually  measured. 

Besides  the  parabolic  curves  discussed  already,  there  appear  on  the  photo- 
graphs at  lowest  pressure  straight  lines,  which  the  author  calls  "  secondaries." 
Their  origin  is  the  subject  of  an  interesting  theoretical  discussion,  in  the  course 
of  which  the  conclusion  is  reached  that  the  minimum  velocity  required  by  an 
electron  to  ionise  an  atom  of  hydrogen  is  1 1  volts  ;  this  is  the  value  obtained 
by  Lenard  in  1903,  one  of  whose  students,  F.  Mayer,  has  recently  redetermined 
it  to  be  u'5  volts.  The  discussion  on  p.  70  of  the  amount  of  ionisation  produced 
by  cathode  rays  is  not  very  clear,  as  no  explicit  mention  is  made  of  the  fact 
that  there  is  a  certain  best  velocity  of  the  primary  electron  which  produces  the 
most  secondary  electrons,  and  the  matter  is  further  obscured  by  the  misprinting 
of  "increases"  for  "decreases"  on  p.  71.  In  this  connection  reference  may  be 
made  to  a  paper  by  C.  Ramsauer  in  the  Jahrbuch  der  Radioactivitat,  ix.  1912, 
p.  515. 

Enough  has  been  said  to  indicate  the  extraordinary  interest  of  the  researches 
described.  The  book,  further,  contains  short  accounts  of  the  retrograde  and 
anode  rays,  of  Stark's  experiments  on  the  Doppler  effect  in  canal  rays,  and  of 
experiments  on  the  continuous  production  of  helium  and  neon  by  bombardment 
by  cathode  rays,  affirmed  by  Sir  William  Ramsay.  Sir  J.  J.  Thomson  does  not 
pronounce  definitely  in  favour  of  any  particular  source  of  the  gases  so  liberated. 

The  book  unfortunately  contains  many  oversights.  The  figures  are  not 
always  clear  ;  for  instance,  fig.  50  is  not  marked  with  the  letters  given  in  the 
text,  and  fig.  29  likewise.  There  are  also  misprints,  such  as  "  Kulschewski ':  for 
"  Kutschewski,"  and  misplaced  commas  sometimes  produce  odd  effects,  as  in 
the  many  cases  in  the  index  where  Doppler  (spelt  Doppler  throughout)  is  made 
to  appear  as  part  of  the  name  of  the  man  who  has  worked  on  his  effect.  These 
are  trifles,  however.  The  importance  of  the  book  is  obvious,  and  a  book  by 
Sir  J.  J.  Thomson  requires  no  recommendation. 

E.  N.  da  C.  A. 

Practical  Exercises  in  Heat.    By  E.  S.  A.  Robson.     Second  Edition.    [Pp. 
xii  +  213.]     (Macmillan  &  Co.,  1913.     Price  3^.  6d.  net.) 

This  book,  written  by  one  evidently  experienced  in  teaching,  contains  accounts 
of  a  number  of  varied  experimental  exercises  in  heat,  which  are  described  clearly 
yet  briefly.  They  are  none  of  them  very  difficult,  all  being  well  within  the  ability 
of  first  and  second  year  men  ;  the  range  is,  however,  wide,  and  includes  many 
interesting  experiments  not  usually  described  in  books  of  this  kind,  such  as 
simple  determinations  of  the  calorific  values  of  fuels,  and  the  use  of  the  resistance 


REVIEWS  777 

thermometer.  The  experiments  on  the  thermocouple  are  very  simple  and  neat. 
We  must,  however,  take  strong  exception  to  an  experiment  described  as  measuring 
the  temperature  of  the  blowpipe  flame  ;  a  brass  cylinder  is  heated  in  the  flame, 
and  its  final  temperature,  measured  calorimetrically,  taken  as  being  the  flame 
temperature.  This  is,  of  course,  wildly  wrong  ;  the  melting  point  of  brass  is 
about  900°  C,  while  the  true  temperature  of  the  ordinary  Bunsen  flame  goes  from 
1400°  C.  up  to  i8oo°C.  The  student  could  easily  convince  himself  that  the  brass 
is  only  prevented  from  melting  by  radiation  losses,  and  other  disturbing  factors, 
by  fusing  thin  brass  and  iron  wires  in  the  flame  ;  this  would  be  more  instructive 
as  to  flame  temperatures  than  the  experiment  described.  With  this  exception  we 
have  only  found  trifling  faults  in  the  book,  which  is  on  the  whole  to  be  recom- 
mended. The  working  out  of  actual  numerical  cases  is  helpful  to  the  student, 
and  there  are  some  useful  tables  at  the  end  of  the  book. 

E.  N.  da  C.  A. 

Photoelectricity.      By    H.   Stanley  Allen.      [Pp.   vii  +  221.]     (Longmans, 
Green  &  Co.,  191 3.     Price  js.  bd.  net.) 

In  1887  Hertz  observed  that  the  passage  01  a  spark  was  facilitated  it  ultraviolet 
light  fell  on  the  spark  gap  ;  and  in  the  next  year  Hallwachs  found  that  such  light 
possessed  the  power  of  discharging  plates  of  certain  metals  if  they  were  negatively 
charged,  but  not  if  they  were  positively  charged.  In  1899  Lenard,  and  a  few 
months  later  J.  J.  Thomson,  showed  that  the  action  of  the  light  was  to  set  free 
electrons  from  the  metal  thus  illuminated ;  this  effect  of  light  in  liberating 
negative  electricity  has  received  the  name  of  the  photoelectric  effect.  (It  may 
be  noted  here  that  Lenard's  fundamental  paper  first  appeared  in  the  Sitztings- 
berichte  der  Kaiserlichen  Akademie  in  Wien,  v.  19,  October  1899  ;  it  was  reprinted 
in  the  Annalen  der  Physik  in  the  following  year.  The  paper  is  quoted  by  the 
latter  date  only  in  the  book  under  review  and  other  English  books.  The  point 
is  of  some  importance  as  regards  priority.) 

Dr.  Allen  undertakes  to  give  an  account  of  the  work,  very  extensive  in 
recent  years,  which  has  been  carried  out  on  the  subject  ;  and  he  has  added 
chapters  on  the  connected  subjects  of  Phosphorescence  and  Photochemical 
Action.  The  chapter  on  phosphorescence  is  very  welcome,  as  the  recent  work 
in  this  field  has  been  much  neglected  in  English  text-books,  and  is  very  important 
for  the  information  it  affords  on  the  mechanism  of  light  emission.  As  regards 
the  photoelectric  effect  itself,  it  is  remarkable,  considering  the  number  of  papers 
published,  how  little  definite  information  has  been  won  beyond  that  contained 
in  the  early  papers  of  Hallwachs,  Elster  and  Geitel,  and,  especially,  Lenard.  So 
much  contradictory  and  indefinite  work  has  been  done  of  recent  years  that  the 
task  of  arranging  it  in  a  clear  and  connected  form  is  one  of  great  difficulty  ;  if 
Dr.  Allen  has  not  always  succeeded  in  ordering  the  material  and  criticising 
it  so  as  to  make  clear  what  are  the  most  reliable  results  at  the  present  time, 
he  has,  in  general,  given  good  summaries  of  the  results  of  the  individual 
experimenters.  At  the  same  time  we  do  not  think  that  the  amount  of  space 
devoted  to  the  different  researches  is  always  well  chosen  ;  the  work  of  Hughes, 
which  is  not  very  conclusive  {e.g.  the  distilled  metal  surfaces  do  not  seem  to  give 
such  very  satisfactory  results  as  Dr.  Allen  frequently  states.  See,  for  criticism 
on  this  and  other  points,  a  paper  by  Pohl  and  Pringsheim,  Phil.  Mag.  December 
1913),  is  treated  at  very  great  length,  while  Lenard  and  Ramsauer's  extensive 
work  on  the  photoelectric  effect  in  gases,  which  is  not  very  accessible  to  English 


778  SCIENCE   PROGRESS 

readers,  and  so  might  have  been  more  fully  described,   is  dismissed  in  a  few 
sentences. 

The  book  has  been  written  at  a  rather  unfortunate  time,  since  a  few  months 
after  its  publication  a  paper  has  appeared  which  seems  to  show  the  cause  of  many 
of  the  inconsistencies  between  different  experiments,  and  to  be  likely  to  influence 
profoundly  the  whole  field  of  research.  We  refer  to  the  work  of  Fredenhagen 
and  Kiistner,  published  in  the  Physikalische  Zeitschrift  for  January  1914,  where 
it  is  shown  that  pure  zinc,  freed  from  gases  by  scraping  in  a  very  high  vacuum, 
gives  no  photoelectric  effect  at  all.  If  this  work,  when  extended,  shows  that 
other  substances  too,  when  absolutely  free  from  gases,  give  no  photoelectric 
effect,  then  the  old  work  will  obviously  have  to  be  carefully  revised. 

Dr.  Allen's  book  is  useful  as  giving  a  correct  account  of  most  of  the  work 
which  has  been  done  on  the  subjects  he  treats,  while  leaving  criticism  of  it  largely 
to  the  reader.  In  the  treatment  of  the  photoelectric  effect  on  water  there  is  no 
mention  of  Obolensky's  paper  (Annalen  der  Physik,  iv.  39,  1912,  p.  961),  which 
contains  the  best  measurements,  and  explains  previous  inconsistencies,  Lenard's 
latest  work  on  phosphorescence  is  not  touched,  and  one  or  two  other  papers  of 
some  interest  are  neglected.  A  few  such  omissions  are  almost  inevitable  ;  on  the 
whole  the  book  is  fairly  complete,  and  can  be  recommended  to  those  interested 
in  the  subject  as  being  the  only  account  to  be  found  in  English  (excepting 
J.  J.  Thomson's  famous  book  on  the  conduction  of  electricity  in  gases,  which 
only  goes  up  to  1906)  where  the  researches  in  this  region  are  collected. 

E.  N.  da  C.  A. 

Definitions  in  Physics.  By  Karl  Eugen  Guthe,  Professor  of  Physics  in  the 
University  of  Michigan,  and  Dean  of  the  Graduate  Department.  [Pp. 
vii  -f-  107.]     (The  Macmillan  Company,  1913.     Price  y.  6d.  net.) 

The  whole  book  is  taken  up  with  a  series  of  bright  "snappy"  sentences,  giving 
in  two  or  three  lines  definitions  of  physical  conceptions  and  quantities,  such  as 
light,  surface  tension,  electron,  and  so  on.  A  few  examples  will  make  clear  the 
nature  of  the  information  supplied  :  "  Interference  is  the  destructive  or  reinforcing 
action  of  different  systems  of  waves  upon  each  other,"  "  Magnetism  is  the  name 
of  a  hypothetical  substance  producing  attraction  or  repulsion  between  magnetic 
bodies  by  action  at  a  distance,"  "  Electrolysis  is  the  decomposition  of  an  elec- 
trolyte." There  are  about  a  hundred  pages  of  this  kind  of  thing,  in  the  course 
of  which  we  are  told  that  a  rays  "are  identical  with  ordinary  canal  rays" 
(reviewer's  italics). 

We  cannot  imagine  any  useful  purpose  to  be  served  by  such  a  book,  which 
would  seem  to  encourage  as  part  of  a  scientific  education  the  parrot-like  learning 
of  a  few  hundred  "  definitions,"  necessarily  incomplete,  generally  meaningless  as 
they  stand,  and  sometimes  misleading,  if  not  actually  wrong. 

E.  N.  DA  C.  A. 

The  Chemistry  of  the  Radio-elements.  Part.  II.  The  Radio-elements  and 
the  Periodic  Law.  By  Frederick  Soddy,  F.R.S.  [Pp.46.]  (London: 
Longmans,  Green  &  Co.     Price  2s.  net.) 

The  importance  of  this  book  is  not  to  be  gauged  from  its  size  ;  for  it  embodies  a 
classification,  with  its  resulting  theories,  which  will  probably  prove  to  be  the 
greatest  stride  made  in  inorganic  chemistry  since  Mendeleeffs  time.  As  with 
other  cases  of  the  kind,  earlier  workers  had  glimpses  of  the  truth,  but  to  Fajans 


REVIEWS  779 

and  to  Soddy  belongs  the  credit  of  the  first  complete  statement  of  the  unifying 
principle.  A  little  over  a  year  ago,  chemists  regarded  the  elements  which 
had  been  discovered  through  their  radio-activity  as  being  mostly  extraneous 
to  the  periodic  law — chemical  sports,  whose  behaviour  seemed  little  likely  to 
prove  amenable  to  classification.  But  with  the  publication,  in  February  of  last 
year,  by  Fajans  and  by  Soddy,  of  the  principle  set  out  in  this  book,  the  chemical 
relations  of  the  radio-elements  with  each  other  and  with  ordinary  elements  were 
suddenly  revealed. 

The  loss  of  an  a-particle  by  an  atom  leaves  a  residual  atom  which  weighs 
four  units  less,  and  belongs  to  a  group  two  places  back  from  the  parent  in  the 
periodic  classification  ;  whilst  the  loss  of  a  /3-particle  leaves  a  residue  of  the 
same  atomic  weight  belonging  to  the  next  higher  group.  The  result  of  this  is 
that  frequently  more  radio-elements  than  one  must  be  allotted  the  same  space  in 
the  table,  and  sometimes  a  radio-element  falls  into  a  space  already  occupied  by  a 
common  element.  There  thus  arise  clusters  of  elements  of  slightly  different 
atomic  weights,  in  each  of  such  spaces  ;  and  the  author  gives  the  members  of 
such  a  cluster  the  convenient  name  "isotopes."  Moreover,  it  is  found  that  the 
members  of  an  isotopic  cluster  cannot  be  separated  chemically  from  each  other, 
at  all  events  by  the  means  which  have  been  resorted  to. 

It  therefore  becomes  necessary  to  modify  the  notion  that  in  the  Periodic  Table 
the  rule  is  "  one  space,  one  element,"  and  to  recognise  that  what  are  ordinarily 
taken  to  be  homogeneous  elements  may  in  some  cases  be  mixtures  of  stable 
isotopes.  Furthermore,  the  range  of  atomic  weights  within  a  given  isotopic 
cluster  may  be  great  enough  to  overlap  that  of  its  next-door  neighbour  ;  and  so, 
through  radio-active  instability  of  some  members  of  each  cluster,  it  could  happen 
that  the  order  of  atomic  weights  of  the  two  spaces  would  become  inverted. 
Irregularities  of  atomic  weights,  such  as  that  between  tellurium  and  iodine,  thus 
receive  a  tentative  explanation. 

On  the  radio-active  side,  it  may  readily  be  believed  that  the  classification  is  of 
great  aid  in  elucidating  the  mechanism  of  transformations. 

It  may  be  thought  by  many  chemists  who  have  followed  the  experimental 
evidences  for  the  theory  that  its  upholders  take  rather  too  rigid  a  view  of  the 
similarity  of  isotopes.  That  the  members  of  a  cluster  are  strongly  alike  in  the 
chemical  tests  to  which  they  have  been  subjected,  nobody  would  deny  ;  but  it  is 
a  bold  step  from  this  to  a  statement  that  they  are  chemically  identical.  Further, 
it  may  be  urged  that  such  a  statement  restricts  the  admittedly  great  extension  of 
our  views  which  the  general  theory  gives,  by  excluding  from  the  category  of 
isotopes  the  one  case  which  almost  any  chemist  would  now  be  willing  to  include — 
the  rare  earths.  Mr.  Soddy  mentions  this  case,  but  it  must  be  said  that  his 
discussion  of  it  is  not  quite  satisfying.  Modern  methods  of  following  rare-earth 
separations  are  extraordinarily  delicate,  yet  the  difficulties  which  are  entailed  in 
separation  necessitate  far  more  fractionations  than  have  ever  been  used  for  radio- 
element  separations  ;  and  one  might  hazard  the  remark  that  if,  let  us  say,  any  pair 
of  the  most  closely  related  rare  earths  had  been  tested  only  by  as  few  fractiona- 
tions as  have  been  carried  out  with  radio-elements,  they  might  easily  have  been 
called  "  inseparable."  The  rare  earths  are  surely  isotopes,  that  is,  they  occupy 
only  one  space  in  the  table— indeed,  Mr.  Soddy  seems  practically  to  indicate  it — 
and  they  are  extremely  alike  in  behaviour.  Whether  they  owe  their  origin  to 
some  bygone  radio-active  series  is  an  interesting  matter  for  speculation.  One 
would  have  less  doubt  of  the  absoluteness  of  the  inseparability  of  isotopes  were  it 
not  for  the  fact  that  adsorption-effects  seem  to  be  too  lightly  put  aside,  and  both 


780  SCIENCE   PROGRESS 

in  this  book  and  in  the  original  papers  differences  are  classed  as  essential  and 
definite  which  to  many  readers  seem  to  be  merely  important  differences  of  degree. 
The  curve  showing  the  concentrations  of  adsorbed  substance  in  adsorbent  and  in 
the  solution  often  approaches  the  horizontal,  in  which  case  effects  similar  to  those 
obtained  by  Fleck,  von  Hevesy,  and  others  might  be  accounted  for. 

Qualitatively  at  any  rate,  however,  the  experimental  evidence  has  undoubtedly 
shown  that  isotopes  are  extremely  similar  substances  ;  and,  although  one  could 
wish  for  a  rather  more  detailed  discussion  of  "  con  "  as  well  as  of  "  pro  "  than 
appears  in  either  volume  of  this  book,  the  author  has  certainly  demonstrated  how 
a  space  in  the  Periodic  Table  can  be  filled  by  several  elements  of  different  atomic 
weights,  and  of  at  least  very  close  chemical  similarity. 

When  other  than  chemical  properties  are  discussed,  the  evidence  as  yet 
adduced  is  of  course  scanty,  and  too  great  stress  is  not  laid  on  the  apparent 
identity  of  the  spectra  of  ionium  and  thorium,  nor  upon  the  new  gas,  Metaneon. 
If  these  and  similar  cases  turn  out  to  be  verified,  many  of  the  objections  which 
have  been  mentioned  will  naturally  be  silenced.  The  author's  case  might  almost 
have  been  strengthened  had  he  dwelt  less  upon  some  of  the  rather  doubtful 
positive  evidences,  such,  for  example,  as  the  relative  volatilies  of  the  emanations. 
The  last  adverse  remark  to  be  made  is  that  if  Uranium  X2,  as  a  unique  element, 
merits  the  special  name  of  "  Brevium,"  surely  also  Radium  Emanation,  no  less  a 
new  chemical  type,  deserves  its  name  of  Niton  ? 

Lest  it  be  thought  that  this  review  is  written  in  a  hostile  or  carping  spirit,  one 
may  emphasise  the  sentiment  of  the  opening  paragraph,  that  to  the  writer's  mind 
the  subject  of  this  book  represents  the  greatest  inorganic  advance  since 
Mendeleeff;  and  every  chemist  must  welcome  so  attractive  and  stimulating  a 
scheme,  and  will  admire  the  skill  and  ingenuity  of  its  founders. 

Irvine  Masson. 

A  Dictionary  of  Applied  Chemistry.  By  Sir  Edward  Thorpe,  C.B.,  LL.D., 
F.R.S.  [Pp.  viii  +  830.]  (London  :  Longmans,  Green  &  Co.,  1913. 
Price  45.?.). 

The  reviewer  of  chemical  books  in  his  time  plays  many  parts.  He  may  have  to 
place  himself  by  turns  in  the  frame  of  mind  of  a  university  professor,  a  schoolboy, 
a  manufacturer,  a  research  chemist,  or  the  man-in-the-street.  At  least  three  of 
these  mental  attitudes  are  required  if  one  is  to  review  properly  the  present  work  ; 
but,  failing  the  requisite  versatility,  one  may  be  content  to  look  upon  it  as  an  index 
of  the  correlation  between  scientific  research  and  industry  as  viewed  by  the  repre- 
sentatives of  each  who  contribute  to  this  dictionary.  From  this  standpoint  it  seems 
as  if  we  have  far  to  go  before  the  correlation  is  nearly  close  enough,  at  any  rate  if 
the  evidence  here  displayed  is  a  true  indication.  There  are  noteworthy  exceptions 
among  the  many  articles  in  the  volume,  but  in  the  main  the  trail  of  the  serpent 
Rule-of-thumb  is  over  them  all. 

Take,  for  example,  an  article  which  deals  with  one  of  the  greatest  industries — 
the  manufacture  of  sodium  carbonate.  In  the  whole  section  on  the  ammonia-soda 
process  we  look  in  vain  for  any  curves  or  phase-rule  diagrams,  despite  the  fact 
that  the  process  really  depends  for  its  success  and  further  progress  upon  phase- 
rule  researches  no  less  than  upon  mechanical  ingenuity.  One  might  forgive  such 
an  omission  in  the  discussion  of  the  older  Leblanc  process  on  the  ground  of  its 
evolution  having  taken  place  less  systematically  ;  but  here  again  some  of  the  very 
clear  and  admirable  descriptions  of  constructional  details  could  have  been  dispensed 


REVIEWS  781 

with  for  the  sake  of  more  space  devoted  to  theory.  An  alkali  manufacturer  is  not 
likely  to  turn  to  a  dictionary  for  information  as  to  the  mechanical  outlines  of  his 
own  business  ;  but  he  surely  ought  to  be  able  to  consult  it  for  the  purpose  of 
ascertaining  fully  the  why  and  the  wherefore.  Naturally,  this  is  the  expression 
of  a  personal  opinion,  and  it  is  given  only  for  what  it  is  worth. 

But  the  section  on  the  contact  manufacture  of  sulphuric  acid  shows  that  an 
article  dealing  with  an  industry  can  be  scientifically  interesting — that  is,  of  great 
educative  value  and  practical  heip— to  the  technical  man. 

This  is  the  true  purpose  of  a  dictionary  such  as  this — to  point  out  to  the  practical 
man  the  virtues  of  scientific  method,  and  to  show  him  that  it  is  for  him  to  instigate 
research,  not  merely  to  profit  by  it  when  he  finds  it  made  to  his  hand.  Such 
articles  as  that  on  triphenylmethane  dyes,  or  in  yet  another  field,  that  on  soils,  may 
be  quoted  as  being  likely  to  produce  this  effect. 

The  metallurgy  articles  hardly  come  up  to  the  standard,  and  would  be  much 
improved  by  a  more  "  advanced "  discussion  of  physical  and  physico-chemical 
properties;  indeed,  in  the  article  "Tin"  there  is  no  section  on  the  properties  of 
the  metal  at  all. 

The  main  criticism  to  be  levelled  at  the  work  is,  in  fact,  that  despite  the  great 
influence  which  physico-chemical  work  now  has  upon  industry,  that  side  of  the 
subject  receives  far  too  scanty  attention  ;  and  even  in  the  special  articles  there  is 
often  so  sharp  a  line  drawn  between  theory  or  practice,  or  rather  between  labora- 
tory and  works,  that  no  obvious  connection  is  manifest.  It  is  remarkable  that  the 
important  subject  of  surface-tension  should  be  ignored,  nor  is  to  be  found  under 
"Capillarity"  in  Vol.  I. 

Several  of  the  larger  articles  have  already  been  cited  as  being  of  high  value  ; 

and  among  the  others  which  call  for  special  mention  are  "  Starch,"  "  Water," 

"  Thermit,"    "  Ultramarine,"   and    many   of   the    sections    on   various   vegetable 

extracts. 

Irvine  Masson. 

The  Progress  of  Scientific  Chemistry  in  our  own  times ;  with  biographical 
notices.  By  Sir  William  A.  Tilden,  F.R.S.  Second  Edition.  [Pp.  xii 
+  366.]     (Longmans,  Green  &  Co.,  1913.     Price  ys.  6d.  net.) 

Some  fifteen  years  have  passed  since  the  first  edition  of  this  book  was  published, 
and  consequently  this,  the  second  edition,  embodies  many  additions.  Originally 
the  outcome  of  a  series  of"  Lectures  to  Working  Men,"  its  eleven  chapters  con- 
stitute a  most  interesting  survey  of  the  development  of  chemistry  during  the  past 
eighty  years.  Sir  William  Tilden  is  one  of  the  comparatively  few  who  can 
properly  claim  to  be  competent  to  pass  under  review  so  fruitful  a  period  in 
chemistry  ;  for,  even  apart  from  the  wide  scope  of  his  chemical  interests,  the  fact 
that  a  large  section  of  this  time  lies  within  his  own  recollection  gives  him  a  special 
title  to  authority,  and  confers  a  sense  of  perspective  and  proportion  which  no 
younger  chemist  can  compass.  This  is  far  from  saying  that  the  author  of  this 
work  is  laudator  temporis  acti ;  the  significance  which  he  evidently  attaches  to 
the  most  recent,  no  less  than  to  the  earlier,  developments  would  satisfy  even  the 
most  "  modern  ''  of  chemists.  The  said  modern,  however,  is  occasionally  apt  to 
forget  the  debt  of  the  past,  especially  of  the  recent  past  ;  and  such  a  book  as  this 
does  service  in  keeping  in  due  prominence  the  great  researches  which  last  century 
brought  forth. 

In  a  sense,  chemistry  may  be  said  to  have  been  made  during  the  last  three 
generations,  and  thus  it  would  be  small  wonder  if  a  history  of  this  period  were 


78z  SCIENCE   PROGRESS 

somewhat  "  confused  feeding  "  ;  but  here  the  sectional  treatment  of  the  multi- 
farious developments  conduces  rather  to  the  proper  feeling  of  unity  than  to  one 
of  complexity.  To  the  many  students  who  wish  for  a  single  volume  giving  a  clear 
purview  over  the  modern  foundations  of  chemistry,  this  book  should  prove  most 
welcome. 

I.  M. 

American  Chemical  Journal.    Vol.  50,  Nos.  4  and  5  (Baltimore). 

Of  the  six  papers  contributed  to  these  numbers,  the  longest  deals  with  work 
carried  out  by  Guy  and  H.  C.  Jones  on  absorption-spectra  of  salt  solutions  as 
measured  with  the  radio-micrometer.  Two  papers  are  concerned  with  compounds 
between  inorganic  salts  and  organic  bases  ;  another  describes  the  preparation  of 
numerous  organic  compounds.  Finally,  there  are  two  papers  on  certain  chemical 
and  physical  results  of  high-tension  discharges.  Other  matter  includes  reviews, 
and  reports  of  Royal  Institution  lectures  by  Sir  J.  J.  Thomson  and  by  Dr.  Dobbie. 
The  journal  is  now  merged  in  that  of  the  American  Chemical  Society. 

The  Nature  of  Enzyme  Action.  By  W.  M.  Bayliss,  D.Sc,  F.R.S. 
Third  Edition,  revised  and  enlarged.  [Pp.  vii+180.]  (London:  Long- 
mans, Green  &  Co.     Price  5.?.  net.) 

The  justification  for  the  series  in  which  this  monograph  takes  its  place  is  stated 
by  the  general  editors  to  be  the  facility  with  which,  in  this  method  of  publication 
the  text-book  may  keep  pace  with  our  rapidly  growing  knowledge  of  the  subject. 
This  can  only  be  accomplished  by  the  repeated  issue  of  fresh  editions  of  separate 
monographs  ;  new  editions  which  are  not  reprints,  but  have  been  carefully  revised 
to  take  account  of  more  modern  points  of  view.  It  is  from  this  standpoint  that  the 
present  edition  of  the  book  needs  to  be  regarded,  and,  as  would  be  expected  from 
its  author,  it  is  an  eminently  satisfactory  example  of  the  value  of  the  monograph 
method  of  publication. 

Attention  will  naturally  be  directed  to  the  main  alterations  in  this  third  edition. 
These  seem  to  be  significant  of  modern  trends  of  biochemical  investigation,  and  in 
particular  of  the  influence  of  pressing  biological  problems  upon  the  development  of 
biochemical  ideas. 

The  chapter  upon  reversibility  of  enzyme  action,  for  instance,  has  been 
practically  rewritten,  and  now  includes  a  valuable  discussion  of  the  conflicting 
evidence  as  to  the  part  played  by  enzymes  in  synthesis. 

Recent  work  on  the  asymmetric  synthesis  of  carbohydrates  by  enzyme  agency 
has  enabled  the  author  to  reaffirm  with  greater  confidence  the  position  he  took  up 
in  the  earlier  edition.  The  whole  chapter  is  very  valuable  for  its  insistence  that  in 
these  complex  phenomena  the  investigator  should  retain  a  clear  conception  of  the 
present  position  of  the  theory  of  catalytic  action,  and  that  assumptions  not  com- 
patible with  this  position  should  only  be  accepted  after  critical  examination  of  the 
experimental  evidence.  This  leads  the  author  to  a  conservative  position  in 
relation  to  the  so-called  "  synthetisising  enzymes  "  which  will  probably  prove  of 
more  value  to  progress  than  an  uncritical  acceptance  of  these  new  suggestions. 

It  is  generally  anticipated  that  we  may  have  to  extend  our  ideas  as  to  the 
possibilities  of  enzyme  action,  with  increased  knowledge,  but  nothing  is  to  be 
gained  by  a  rapid  solution  of  our  difficulties  through  ready  acceptance  of  new 
properties  and  new  names  for  enzyme  catalysts,  which  merely  hide  our  difficulties 
of  interpretation  under  a  cloud  of  words. 

In  this  connection  it  is  interesting  to  notice  the  growing  importance  of  Note  E 


REVIEWS  783 

in  these  editions  ;  this  note  refers  to  the  possibility  that  the  same  enzyme  may  be 
active  in  different  and  allied  reactions  which  it  accelerates  unequally.  The 
possibilities  of  the  biological  applications  of  this  hypothesis  are  fascinating,  and 
the  simplicity  of  the  statement,  one  reaction,  one  enzyme,  is  more  apparent  than 
real  when  dealing  with  actual  physiological  problems. 

J.  H.  P. 

Metallography.  By  Cecil  H.  Desch,  D.Sc,  Ph.D.  Second  Edition,  with 
14  plates  and  108  diagrams.  [Pp.  x  +  431.]  (London  :  Longmans,  Green 
&  Co.,  1913.     Price  9^.) 

THE  first  edition  of  Dr.  Desch's  book  is  so  well  known  to  metallographists  that  no 
very  detailed  review  of  the  second  edition  is  called  for.  The  new  features  do  not 
affect  the  general  plan,  although  by  bringing  the  book  up  to  date  and  by  correcting 
earlier  errors  they  naturally  enhance  the  already  high  value  of  the  work.  The 
treatment  of  the  whole  subject  might  well  serve  as  a  model  to  all  scientific  authors, 
and  the  reader  is  continually  made  to  feel  the  sense  of  satisfaction  always  imparted 
by  clear  and  logical  exposition  united  with  cogent  criticism — factors  which  diversity 
of  knowledge,  as  well  as  depth,  on  the  part  of  the  author,  alone  can  produce. 
The  correlation  between  metallographic  studies  and  research  in  other  physico- 
chemical  fields  is  an  intimate  one,  and  in  the  writer's  mind  the  greatest  value  of 
this  book  is  that  it  forces  one  to  realise  this  intimacy,  and  indicates  very  clearly 
the  mutual  benefits  which  metallography  and  the  rest  of  physical  chemistry  may 
expect  of  one  another.  In  this  way,  and  by  his  systematic  method  of  examining 
each  part  of  his  subject,  Dr.  Desch  has  produced  a  book  which  will  certainly 
continue  for  a  long  time  to  be  one  of  the  most  stimulating  works  of  its  kind,  alike 
to  workers  in  physical  chemistry  and  to  specialists  in  metallography. 

I.  M. 

Modem  Seismology.  By  G.  W.  Walker,  A.R.C.Sc,  M.A.,  F.R.S.  [Pp. 
xii-f  88.  With  13  plates  and  diagrams.]  (London  :  Longmans,  Green 
&  Co.,  1913.     Price  5^.) 

This  work  is  one  of  the  monographs  on  physics  edited  by  Sir  J.  J.  Thomson  and 
Dr.  H.  Horton,  of  the  Cavendish  Laboratory.  The  geological  aspects  of  earth- 
quakes are  purposely  avoided,  and  seismographs  and  their  records  are  treated 
from  a  mathematical  point  of  view.  The  author  has  been  profoundly  influenced 
by  the  vigorous  personality  of  John  Milne,  with  whom  he  associates  Wiechert  and 
Galitzin  as  the  most  prominent  workers  in  seismology.  Photographs  and  descrip- 
tions are  given  of  the  best  modern  types  of  seismograph,  and  the  introduction  ot 
artificial  "damping"  is  discussed.  Even  to  the  non-mathematical,  the  successive 
triumphs  over  unexpected  difficulties  must  appeal.  On  page  25  we  learn,  after  a 
discussion  of  mechanical  registration,  that  "  the  writing  point  may  remain  at  rest 
anywhere  within  a  range  of  2r,  and  discontinuities  of  the  magnitude  may  occur  in 
the  trace."  The  author's  experiments  show,  moreover,  that  r  is  not  a  constant,  but 
depends  on  the  state  of  the  smoked  surface  on  which  registration  takes  place  and 
on  the  amplitude  of  the  movement.  We  are  immediately  reassured  by  the 
statement  that  with  care  the  value  of  r  may  be  reduced  on  Wiechert  instruments 
to  "  a  few  tenth  millimetres." 

The  student  will  not  find  much  in  the  book  about  the  nature  of  earthquake- 
waves  ;  he  is  supposed  to  have  assimilated  this  in  previous  reading.  The  author's 
familiarity  with  the  appearance  and  interpretation  of  seismographic  records  leads 
him  to  be  very  concise,  even   when  he  discusses   their   interpretation.      A  few 


784  SCIENCE   PROGRESS 

practical  notes  are  given  in  Chapter  V.  on  the  installation  of  seismographs,  and 
we  are  then  asked  to  consider  the  characters  of  a  record  resulting  from  a  shock 
initiated  in  a  solid  isotropic  earth.  Though  such  an  earth  fails  to  satisfy  the  actual 
readings  of  the  instruments,  we  are  not  allowed  to  comfort  ourselves  with  the  idea 
that  these  readings  as  yet  give  us  reliable  information  about  earth-shells  and 
variations  of  density  below  the  surface. 

The  most  marked  recent  advance  appears  to  be  Galitzin's  determination  of  the 
epicentre  of  a  shock  from  observations  at  one  station  only  (p.  64).  The  science  of 
seismology,  as  distinct  from  seismoscopy,  is  so  modern  that  Mr.  Walker,  watching 
the  work  of  his  colleagues  in  this  field  of  delicate  measurement,  and  observing 
earthquakes  critically  on  his  own  account  at  Eskdalemuir,  can  look  forward 
confidently  to  successive  editions  of  his  treatise. 

The  Petrology  of  the  Sedimentary  Rocks.  A  description  of  the  Sediments 
and  their  Metamorphic  Derivatives.  By  F.  H.  Hatch,  Ph.D.,  and  R.  H. 
RASTALL.  With  an  Appendix  on  the  Systematic  Examination  of  loose 
Detrital  Sediments.  By  T.  Crook.  [Pp.  xiii  +  425.  With  60  text- 
figures.]    (London  :  G.  Allen  &  Co.,  1913.     Price  7s.  6d.  net.) 

This  book  is  divided  into  two  portions,  of  which  the  first  deals  with  unaltered 
sedimentary  rocks,  and  the  second  with  the  changes  such  deposits  may  undergo 
subsequent  to  their  deposition. 

The  first  portion  is  by  far  the  smaller,  and  treats  in  a  general  and  brief  manner 
the  processes  of  formation,  and  the  classification  of  stratified  rocks  which  are 
arranged  under  the  headings  Fragmental,  Chemical,  and  Organic.  There  is  no 
doubt  that  for  purposes  of  a  text-book  it  is  desirable  to  draw  rather  hard  and  fast 
lines  ;  but  the  division  between  chemical  and  organic  deposits  cannot  be  definite, 
and  there  can  never  be  a  strictly  logical  separation  of  the  two  groups.  The 
authors  have  shown  a  great  tendency  to  concentrate  on  the  second  portion  of 
the  work  and  to  treat  the  metamorphic  rocks  with  conspicuous  partiality ;  not  only 
this,  but  metamorphism  has  been  extended  to  the  widest  limits  placed  upon  the 
term  by  trans-Atlantic  workers,  and  has  been  made  to  embrace  all  rocks  except 
those  which  have  suffered  practically  no  change  of  any  description.  This  is  a 
departure  from  the  system  usually  adopted  in  this  country,  and  is  not  to  be 
recommended. 

The  elementary  student  and  also  the  more  advanced  worker  will  find  this  book 
of  considerable  use,  for  collected  between  its  covers  is  a  store  of  information  which 
previously  was  scattered  through  varied  and  often  obscure  publications.  The 
worker,  however,  who  turns  to  this  book  for  detailed  descriptions  of  any  particular 
type  of  sedimentary  deposit  will  be  disappointed,  for,  unlike  the  mode  of  treatment 
adopted  for  the  igneous  rocks  in  the  first  volume,  the  sediments  are  discussed 
in  general  with  special  reference  to  their  mode  of  origin  and  subsequent  changes. 
It  is  true  that  specific  examples  are  given  in  many  cases,  but  these  examples  are 
too  few  in  number  ;  and  at  the  same  time  it  is  to  be  regretted  that  so  many  have 
been  drawn  from  distant  foreign  localities  when  there  are  equally  good  examples 
which  might  have  been  quoted  from  Britain. 

A  most  useful  Appendix  has  been  drawn  up  by  Mr.  Crook  on  the  methods  of 
examination  of  loose  detrital  sediments.  It  is  an  admirably  clear  account  of  the 
methods  usually  adopted  for  the  separation  of  mineral  constituents  from  each 
other,  and  it  includes  data  for  the  determination  of  the  commoner  mineral  species 
present  in  sedimentary  deposits.     From  these  data   the   author  might  perhaps 


REVIEWS  785 

have  omitted  the  values  of  the  bi-refringence,  for  although  of  prime  importance 
in  the  case  of  cleavage  flakes  bounded  by  parallel  planes  it  is  of  little  value  for 
irregular  grains  of  which  the  thickness  cannot  be  determined.  The  author  has 
placed  in  deserved  prominence  the  determinative  methods  of  Schroder  van  du  Kolk 
and  Becke,  and  has  added  a  list  of  most  useful  oils  which  can  be  used  to  ascertain 
the  mean  refractive  index  of  the  minerals  he  mentions.  It  is  doubtful,  however, 
whether  a  solution  of  sulphur  in  methylene  iodide  can  be  made  to  attain  such 
a  high  refractive  index  as  i"83  and  retain  any  degree  of  stability.  The  usual 
figure  is  nearer  179. 

The  Petrology  of  the  Igneous  Rocks.    By  F.  H.  Hatch,  Ph.D.  [Pp.  xxiv+454.] 
Seventh  Edition.     (London  :  G.  Allen  &  Co.,  Ltd.,  1914.     Price  ys.  6d.  net.) 

The  seventh  edition  of  this  useful  textbook  differs  mainly  from  the  older  editions 
in   the   presence    of  chapters   on    the    Pyroclastic    Rocks  and    the  Metamorphic 
Derivatives  of  the  Igneous  Rocks,  which,  although  treated  very  briefly,  are  well 
done,  and  in  keeping  with  the  rest  of  the  book.       The  classification  of  Igneous 
Rocks  adopted  by  Hatch  is,  however,  still  shaped  by  the  old  qualitative  views,  in 
spite  of  the  recent  onset  of  quantitative  treatment.     It  is  based  mainly  on  silica 
percentage,  followed,  at  least  in  the  case  of  plutonic  rocks,  by  a  subdivision  into 
alkalic,  monzonitic,  and  calc-alkalic  series.     It  is  difficult  to  see  why  the  ultrabasic 
rocks  should  be  excluded  from  this  scheme  (p.  160)  if  it  is  adequate  to  the  needs 
of  students   and   petrographers.      A   rather   elaborate   quantitative   treatment    is 
accorded  to  the  acid  plutonic  rocks,  but  it  is  denied  to  the  more  basic.      Whilst 
the  volcanic  rocks  are  subdivided  on  the  same  basis  as  the  plutonic,  the  hypabyssal 
types  are  apparently  not  considered  as  susceptible  to  this  treatment,  and  are 
classified  into  five  vaguely  defined  families.       This  classification  is  a  patchwork 
consisting  of  oddly  contrasted  compartments  in  which  qualitative  and  quantitative 
treatment  is  alternately  adopted.     While  there  is,  no  doubt,  still  some  advantage 
to  be  gained  by  the  student  in  continuing  with  the  older  qualitative  classification, 
it  is  time  the  newer  quantitative  ideas  were  appearing  in  the  textbooks.      The 
description   of  the    rocks   and   the   account   of  their   distribution    is   in   general 
excellently  done.     When  Scottish  Carboniferous  basalts  are  mentioned  in  several 
places  it  is  difficult  to  understand  the  repetition  of  the  ancient  error  that  andesites 
occur  amongst  them  (p.  413).     The  terms  "texture"  and  "structure,"  which  now 
possess  well-defined  and  different  significations,  are  used  as  though  they  were 
interchangeable.      The   book   is   free   from   typographical   errors,   but   the    word 
"spilosite  "  is  used  where  "  spilite  "  is  obviously  meant  (p.  29). 

Text-Book  of  Paleontology.    Edited  by  Charles  R.  Eastman,  A.M.,  Ph.D., 
Prof,  of  Paleontology,  Pittsburg.     Adapted  from  the  German  of  KARL  A. 
VON  Zittel.     Second  Edition,  vol.  i.     [Pp.  xi-f  839,  illustrated.]    (London 
Macmillan  &  Co.,  Ltd.,  1913.     Price  25s.  net.) 

Almost  the  only  fault  we  have  to  find  with  this  admirable  volume  is  the  spelling 
of  the  title,  an  atrocious  Americanism,  which,  together  with  "Paleozoic"  in  the 
text,  is  enough  to  make  a  classically  educated  Englishman  lose  his  temper.  It  is, 
moreover,  an  insult  to  the  memory  of  the  great  German  palaeontologist  upon  whose 
work  the  present  and  previous  editions  are  based. 

The  present  volume,  which  deals  solely  with  the  invertebrates,  is  considerably 
larger  that  its  predecessor  in  the  first  edition  (1899),  containing  839,  against  706, 


786  SCIENCE  PROGRESS 

pages  of  text,  and  about  1600,  in  place  of  1476,  illustrations  :  the  increase  being 
especially  noticeable  in  the  case  of  the  sections  on  Echinodermata  and  Arthropoda, 
which  respectively  show  an  augmentation  of  38  and  45  pages. 

A  great  change,  too,  has  taken  place  in  the  list  of  specialists  responsible  for  the 
various  sections  of  this  volume  ;  only  three  out  of  the  twelve  names  in  the  first 
edition  reappearing  in  the  second,  namely,  those  of  Messrs.  J.  M.  Clarke,  W.  H. 
Dall,  and  C.  Schuchert.  In  the  present  edition  the  number  of  collaborating 
specialists  is  no  less  than  seventeen  :  the  new  ones  being  Messrs.  R.  S.  Bassler, 
W.  T.  Caiman,  A.  H.  and  H.  L.  Clark,  J.  A.  Cushman,  A.  Handlirsch,  R.  T. 
Jackson,  A.  Petrunkevitch,  P.  E.  Raymond,  R,  Ruedemann,  J.  P.  Smith,  F.  Springer, 
T.  W.  Vaughan,  and  C.  D.  Walcott.  A  better  and  more  representative  list  it 
would  be  difficult  to  bring  together  ;  each  specialist  being  eminent  in  his  own 
particular  department. 

Such  a  sweeping  change  in  the  staff,  coupled  with  the  increase  in  the  bulk  of 
the  volume,  implies  of  course  equally  radical  changes  in  the  text  ;  so  that,  as  the 
editor  remarks  in  his  preface,  the  work  can  no  longer  be  properly  styled  Zittel's 
Text-Book,  as  it  is  in  effect  a  composite  production,  although  still  modelled  on 
the  lines  of  the  famous  German  original.  Apart  from  the  importation  of  new 
blood,  such  additions  and  alterations  were  inevitable,  as  invertebrate  palaeontology 
has  not  been  standing  still  during  the  first  dozen  years  of  the  present  century  ; 
and,  as  a  matter  of  fact — to  quote  the  editor's  own  words — "  many  parts  of  the 
work  have  been  entirely  rewritten,  others  have  been  emended,  rearranged,  and 
enlarged,  and  the  classification  in  various  places  has  been  very  considerably 
altered." 

The  main  groups,  however,  stand  practically  as  they  were  in  the  first  edition, 
the  only  alteration  being  that  the  Echinodermata  and  the  Vermes  have  changed 
places,  the  latter  coming  first,  instead  of  second,  in  the  present  edition. 

In  regard  to  these  (seven)  main  groups,  the  noticeable  feature  is  the  inclusion 
(as  in  the  first  edition)  of  the  Porifera  (sponges)  in  the  Ccelenterata  ;  and  since  this 
arrangement  differs  from  that  adopted  by  the  majority  of  zoological  writers,  it 
would  have  been  well,  we  think,  if  the  reasons  for  the  departure  from  the  usual 
practice  had  been  stated  in  detail,  instead  of  the  reader  being  left  to  find  them  out 
as  best  he  may.  It  of  course  involves  a  considerable  change  in  the  usual  defini- 
tion of  the  Ccelenterata — a  change  which  is  not,  in  our  opinion,  on  the  side  of 
simplicity  and  clearness. 

Extreme  technicality,  it  need  scarcely  be  mentioned,  is  the  leading  character  of 
the  work,  which  is  intended  solely  for  more  or  less  advanced  students,  and  for 
palaeontologists  desirous  of  information  with  regard  to  groups  which  do  not  form 
the  subject  of  their  special  studies.  It  is  not,  however,  to  palaeontologists  alone 
that  the  work  should  appeal,  for  it  contains  much  valuable  information  with  regard 
to  certain  existing  species,  notably  the  nautilus  ;  and  if  it  be  thereby  the  means 
of  inducing  zoologists — in  the  restricted  sense  of  that  term — to  devote  more 
attention  (in  some  cases  we  may  say  to  devote  any)  to  palaeontology  than  is 
the  practice  with  many,  it  will  have  done  good  service  in  helping  to  place 
biology  on  a  broader  and  more  philosophical  basis. 

The  excellence  and  number  of  the  illustrations  form  an  especially  valuable 
feature  of  the  volume  ;  among  those  worthy  of  special  commendation  being  the 
figures  of  Palaeozoic  insects,  crustaceans,  arachnids,  and  other  arthropods,  which  will 
come  as  a  revelation  to  those  who  have  not  hitherto  devoted  attention  to  this  part  of 
the  subject.  Most  wonderful  of  all  these  Palaeozoic  insects  are  the  giant  dragon- 
flies  of  the  Upper  Carboniferous,  which  are  regarded   as  forming  a   group — the 


REVIEWS  787 

Protodonata— intermediate  between  the  still  more  primitive  Palaeodictyoptera  of 
the  Carboniferous  and  the  modern  Odonata,  or  dragon-flies. 

In  this  connection  reference  may  be  made  to  a  marked  defect  in  the  book, 
namely  that  the  index  does  not  include  groups  of  higher  rank  than  genera,  and 
that  when  mention  is  made  in  the  text  of  groups  other  than  those  under  considera- 
tion no  reference  is  made  to  the  pages  where  they  are  respectively  described.  In 
this  particular  instance,  for  example,  the  group  Palaeodictyoptera  is  mentioned  on 
page  809,  but  we  have  to  search  through  the  fourteen  preceding  pages  before  there 
is  any  possibility  of  finding  out  what  insects  it  represents.  And  such  waste  of 
time  is  trying  to  the  temper  !  Moreover,  is  it  not  too  absurd  to  spell  such  names 
as  Pakeodictyoptera  with  a  diphthong  in  the  second  syllable  and  Palaeontology 
and  Palaeozoic  without  it  ? 

Reverting  to  the  giant  dragon-flies  of  the  Carboniferous,  it  is  mentioned  that 
in  Meganeura  mo?iyi,  the  largest  of  them  all,  the  wing-expanse  is  no  less  than 
75  centimetres  ;  but  it  would  have  been  well  if  some  reference  had  been  made 
to  recent  speculations  with  regard  to  the  physical  conditions  necessary  to  enable 
such  monsters  to  fly,  which,  like  the  giant  pterodactyles  of  a  later  epoch,  they  could 
not  apparently  have  done  if  they  lived  under  conditions  of  atmospheric  pressure 
similar  to  those  existing  at  the  present  day. 

In  the  Introduction,  which  contains  an  excellent  summary  of  the  stratigraphical 
sequence  of  rocks  and  a  review  of  ancient  and  modern  theories  with  regard  to  the 
origin,  evolution,  and  extinction  of  species,  attention  may  be  particularly  directed 
to  the  following  thoughtful  passage  :  "  For  the  extinction  of  many  plants  .  .  . 
and  animals  ...  of  former  periods  no  adequate  explanation  has  yet  been  found. 
Changes  in  external  conditions,  especially  such  as  regards  the  distribution  of  land 
and  water,  climatal  conditions,  saltness  of  the  water,  volcanic  eruptions,  paucity 
of  food-supply,  the  encroachments  of  natural  enemies,  and  diseases,  may  have  led 
to  the  extinction  of  certain  forms,  but  such  suggestions  signally  fail  to  account  for 
the  disappearance  of  an  entire  species  or  particular  groups  of  organisms.  Often- 
times extinction  seems  to  have  been  caused  merely  by  superannuation.  Long- 
lived  forms  belong  for  the  most  part  to  persistent  types  whose  range  of  species  is 
limited.  Their  reproductive  functions  have  declined,  and,  like  an  individual  in  its 
senescence,  they  evince  the  symptoms  of  decrepitude." 

Palaeontology,  we  may  observe  in  conclusion,  has  been  decried  as  an  obsolete 
and  unnecessary  science,  which  ought  to  be  merged  in  zoology  and  botany.  But 
there  are  many  and  cogent  reasons  against  such  a  view,  not  the  least  of  these 
being  a  volume  like  the  one  before  us,  which  is  very  nearly  the  ideal  of  what  a 
manual  of  palaeontology  should  be,  and  which  displays  before  the  eyes  of  the  reader 
a  cinematographic  sketch  of  the  past  history  of  a  portion  of  the  animal  kingdom, 
the  vividness  and  compactness  of  which  would  be  utterly  and  completely  lost  if  its 
contents  were  amalgamated  with  a  volume  on  recent  zoology. 

R.  L. 

Problems  of  Genetics.  By  William  Bateson,  M.A.,  F.R.S.  [Pp.  ix  +  258, 
illustrated.]  (Yale  University  Press.  London  :  Humphrey  Milford,  Oxford 
University  Press,  1913.     Price  17s.  net.) 

Certainly  it  would  be  a  misfortune  to  the  advance  of  science  were  Darwinism 
established  as  an  orthodoxy  against  which  a  biologist  should  write  only  at  the 
peril  of  his  reputation,  and  were  the  writings  of  Darwin  accredited  with  a  plenary 
inspiration.     It  would  be  even  more  paralysing  were  the  principles  expounded  by 


;88  SCIENCE  PROGRESS 

hat  painstaking  and  luminous  genius  to  be  accepted  as  the  final  expression  and 
.nterpretation  of  natural  knowledge,  deductions  from  which  were  to  be  regarded 
as  cogent  in  themselves,  and  proper  refutations  of  the  results  of  new  observers. 
If  there  were  any  approach  to  this  state  of  affairs,  I  should  offer  Mr.  Bateson  the 
humble  tribute  of  my  sympathy,  and  even  if  I  did  not  agree  with  him,  I  should 
gladly  put  my  back  against  such  small  portion  of  his  as  it  might  cover.  But  it  is 
not  so.  Mr.  Bateson,  in  girding  at  Darwin,  is  expanding  his  wings  to  the  bland 
and  buoyant  air  of  popular  approval,  and  although  I  do  not  doubt  that  it  is  not  his 
objective,  he  has  become  an  idol  of  the  market-place.  The  irony  of  the  position 
is  that  those  who  applaud  Mr.  Bateson  on  the  rumour  that  he  is  an  opponent  or 
refuter  of  Darwin  would  take  little  comfort  were  they  at  the  pains  to  examine  for 
themselves  the  direction  in  which  Mr.  Bateson  would  lead  them.  He  believes 
that  the  fancies  of  the  living  world  came  about  by  some  evolutionary  process,  a 
proposition  which  was  first  made  credible  by  Darwin.  Whether  species  have 
come  into  existence  by  the  summation  of  minute  variations,  a  view  for  which 
Darwin  thought  there  was  just  a  balance  of  evidence,  and  Wallace  thought  greatly 
preponderating  evidence,  or  by  big  jumps,  as  Mr.  Bateson  thinks,  is  a  problem  of 
great  interest  and  great  importance,  but  its  solution  in  the  sense  of  Mr.  Bateson 
would  lessen  not  increase  the  difficulties  in  accepting  natural  selection  as  the 
fundamental  principle  of  evolution.  In  my  opinion  Mr.  Bateson  is  rash  in  de- 
parting from  Darwin's  caution  in  refusing  to  assert  that  characters  are  useful 
because  we  cannot  understand  their  utility  ;  he  does  not  allow  enough  for  the 
possible  correlation  of  useless  characters  with  useful  characters,  and  he  is  going 
far  beyond  the  book  if  he  thinks  it  a  vital  part  of  Darwin's  theory  to  suppose  that 
every  specific  character  is  useful.  But  even  if  he  were  to  succeed  in  ejecting 
every  notion  of  utility  from  our  conception  of  the  evolutionary  process,  his  dis- 
illusioned admirers  would  find  themselves  further  than  ever  from  Paley,  further 
from  teleology,  further  from  a  mystical  immanence  of  design.  The  analysis  of 
organisms  into  unit  characters  or  factors,  the  interpretation  of  the  phenomena  of 
variation  and  heredity  as  combinations  and  disintegrations  of  given  unit  factors 
according  to  numerical  law,  would  make  the  living  world  more  congruous  with 
the  inorganic  world,  and  would  not  lighten  the  task  of  those  who  propose  to 
interpret  it  in  terms  of  mind. 

These  preliminary  remarks  relate  rather  to  the  attitude  than  to  the  substance 
of  Mr.  Bateson's  lectures,  for  the  greater  part  of  the  volume  is  a  luminous  and 
quite  reasonably  impartial  account  of  many  of  the  problems  that  are  still  per- 
plexing biologists.  These  fortunately  exist  in  every  branch  of  biology  ;  it  would 
be  a  dull  world  if  we  understood  it  all.  In  his  introductory  chapter  Mr.  Bateson 
relates  the  problem  of  species  in  a  fashion  which  insists  on  the  reality  of  specific 
distinctions  apart  from  what  has  been  called  their  "  selection  value."  He  is  very 
severe  on  systematics,  contrasting  those  who  are  "engaged  in  the  actual  work  of 
naming  and  cataloguing  animals"  with  biologists.  He  points  out  that  almost 
always  the  collections  are  arranged  in  such  a  way  that  the  phenomena  of  variation 
are  masked,  that  the  causes  of  variation  are  overlooked  or  confused,  and  that  it 
is  only  by  a  minute  study  of  the  original  labels  of  specimens  and  by  redistributing 
them  according  to  locality  and  date  that  their  natural  relations  can  be  traced. 
He  might  have  added  that  the  modern  museum  system  of  attaching  to  each 
specific  name  a  "type"  specimen  duly  registered  and  labelled,  by  which  the 
species  must  in  future  stand  or  fall,  may  be  convenient  to  the  systematist,  but  has 
helped  to  divorce  systematic  work  from  any  true  understanding  of  the  natural 
facts.     It  is  conceivable  that  the  vast  labour  of  systematists  in  museums  may  not 


REVIEWS  789 

be  thrown  away,  but  it  has  been  recognised  for  long  that  their  work  will  have  to 
be  followed  by  some  attempt  to  delimit  what  have  been  called  "  master  species," 
the  real  units  into  which  the  forms  of  life  are  thrown,  and  that  their  named  species 
and  museum  types  will  at  the  most  serve  as  index  numbers.  But  at  the  least  it 
may  be  said  that  the  large  series  of  individuals,  with  localities  and  dates  carefully 
marked,  that  are  now  being  collected  in  museums,  will  be  of  great  service  when 
the  work  of  systematists  comes  to  be  translated  into  science. 

The  second  chapter  opens  with  a  statement  so  astonishing  that  it  is  difficult  to 
qualify  it  with  any  other  term  than  the  term  "  perverse."  "  Twenty  years  ago," 
declares  Mr.  Bateson,  "  in  describing  the  facts  of  variation,  argument  was  necessary 
to  show  that  these  phenomena  had  a  special  value  in  the  sciences  of  zoology  and 
botany."  I  cannot  conceive  how  this  proposition  could  be  justified,  and  it  is  an 
introduction  entirely  unnecessary  for  the  extremely  interesting  discussion  to  which 
it  leads.  Mr.  Bateson  offers  as  a  preliminary  classification  of  the  facts  of  varia- 
tion, the  distinction  between  those  which  are  the  results  of  changes  in  the  mode 
of  division,  and  those  which  relate  to  differentiation  in  the  substances  divided. 
He  suggests  that  the  first  set  of  variations  are  possibly  in  the  last  resort  dependent 
on  the  second,  and  offers  valuable  comments  on  the  nature  of  the  two  processes. 
He  is  inclined  to  think,  in  this  differing  from  perhaps  a  majority  of  modern 
writers,  that  substantive  variations,  depending  on  differentiation  of  the  substances 
divided,  are  more  easy  to  understand  than  meristic  variations.  The  former  may 
be  due  to  some  kind  of  chemical  process  ;  the  latter,  and,  indeed,  the  nature  of 
division  itself,  so  far  remain  nothing  but  observed  facts  of  life.  Two  chapters  are 
occupied  with  a  clear  description,  illustrated  by  many  examples,  of  the  different 
kinds  of  merism  and  segmentation,  and  of  the  recovery  of  symmetry  in  dividing 
parts.  In  Chapter  IV.  substantive  variations  are  discussed,  and  the  attempt 
is  made  to  correlate  them  with  the  unit  factors  of  Mendelian  analysis.  The 
suggestion  is  developed  that  recessive  characters  are  due  to  the  omission  of  a 
factor  and  dominant  characters  to  the  addition  of  a  factor,  but  this  distinction  is 
abandoned  in  an  appendix,  and  we  are  left  with  the  tentative  picture  that  all 
substantive  variation  is  due  to  the  loss  of  a  pre-existing  factor — a  conception  that 
does  not  appear  to  carry  the  argument  on  to  any  very  useful  plane.  In  Chapter  V. 
there  is  a  very  fair  account  of  the  failure  of  Mendelian  analysis  to  account  for  the 
phenomena  of  mutation  in  Oenothera. 

In  three  interesting  and  detailed  chapters  the  relations  between  geographical 
distribution  and  variation  are  discussed,  with,  however,  the  result  of  showing  that 
Mendelian  methods  are  as  yet  no  more  satisfactory  than  any  other  methods  in 
explaining  the  relation  of  geographical  races  to  species.  It  is  obvious,  as  Mr. 
Bateson  suggests,  that  no  great  advance  can  be  made  in  this  direction  until 
extensive  breeding  experiments  have  been  undertaken.  In  Chapters  IX.  and  X., 
under  the  title  "  Adaptation,"  Mr.  Bateson  discusses  recent  evidence  for  the 
inheritance  of  acquired  characters,  and  dismisses  it  partly  on  the  ground  that  it 
is  unconfirmed,  but  even  more  cogently  because  in  the  alleged  cases  the  normal 
course  of  inheritance  under  undisturbed  conditions  is  not  sufficiently  known.  The 
utmost  length  to  which  Mr.  Bateson  thinks  the  evidence  can  be  stretched  is  to 
suppose  that  in  some  parthenogenetic  forms,  variations,  produced  in  response  to 
special  conditions,  recur  in  one  or  two  generations  after  the  removal  of  those 
conditions,  and  that  violent  maltreatment  may  in  rare  cases  so  affect  the  germ 
cells  contained  in  the  parents  as  to  bring  about  in  the  offspring,  resulting  from 
the  fertilisation  of  these  germ  cells,  an  arrest  of  development  similar  to  that  which 
their  parents  underwent.     Examination  of  the  present  condition  of  knowledge  as 


790  SCIENCE   PROGRESS 

to  the  sterility  of  hybrids  leads  to  similar  negative  conclusions,  and  the  best  hope 
that  Mr.  Bateson  has  to  bring  us  is  the  expression  of  his  conviction  that  the 
prospect  of  permanent  progress  is  greater  if  science  retreats  from  the  speculative 
position  which  he  thinks  it  has  occupied.  He  states  his  belief  that  new  light  will 
most  probably  come  from  the  pursuit  of  genetic  research.  Those  who  think  that 
a  little  speculation  is  the  salt  of  experimental  work,  can  at  least  comfort  themselves 
with  the  reflection  that  there  seems  no  dissociation  of  any  radical  nature  between 

speculation  and  genetic  research  on  Mendelian  lines. 

P.  C.  M. 

A  Possible  Physical  Aspect  of  the  Trichromatic  Vision  Theory.    By  C. 

Timiriazeff,  F.M.R.S.     [Pp.  12.]     (Moscow,  1913.) 

This  pamphlet  is  an  ingenious  attempt  to  associate  Edridge-Green's  Theory  of 
Vision  with  the  Trichromatic  Theory.  The  author  suggests  that  the  distribution 
of  the  red  sensation  corresponds  to  the  perception  of  amplitudes  of  the  vibrations 
that  the  green  sensation  curve  corresponds  to  the  absorption  curve  of  the  visual 
purple,  having  its  maximum  in  the  green,  and  sloping  to  the  limits  of  the  spectrum: 
the  third  curve  having  its  maximum  in  the  violet  is  attributed  to  the  perception 
of  the  oscillation  frequencies.  It  is  difficult  to  suppose  that  the  sensation  of  red 
can  be  only  caused  by  the  perception  of  amplitude  any  more  than  a  treble  note 
should  become  a  bass  one  when  struck  very  violently.  The  author  in  support  of 
this  view  alludes  to  the  decrease  of  the  red  sensation  with  the  decrease  of  the 
intensity  of  light,  and  the  converse  effect.  This  pamphlet  will  be  interesting  to 
those  who  incline  to  the  Trichromatic  Theory,  but  to  those  who  claim  that  the 
Trichromatic  Theory  is  quite  untenable,  and  that  the  objections  to  it  have  never 
been  answered,  it  will  only  be  regarded  as  an  ingenious  speculation.  So  many 
of  the  so-called  facts  of  colour-vision  are  merely  speculations  based  upon  the 
theory,  and  do  not  bear  any  relation  to  the  actual  facts.  The  terms  red-blindness 
and  green-blindness  convey  no  meaning  to  us,  as  different  varieties  are  classed 
under  the  same  heading.  A  theory  of  colour-vision  should  be  able  to  account 
for  the  facts  as  given,  for  instance,  in  Professor  Starling's  Text-book  of 
Physiology. 

Irritability.  A  physiological  analysis  of  the  general  effect  of  stimuli  in  living 
substance.  The  Silliman  Lectures  delivered  at  Yale  University  in  1911-12. 
By  Max  Verworn,  M.D.,  Ph.D.,  Professor  at  Bonn  Physiological  Institute. 
With  Diagrams  and  Illustrations.  [Pp.  xii  +  264.]  (New  Haven:  Yale 
University  Press.  London  :  Henry  Frowde,  Oxford  University  Press, 
1913.     Price   15^.  net.) 

Prof.  Max  Verworn  is  no  mean  successor  to  those  who  have  preceded  him  in 
the  Silliman  lectureship,  the  names  of  whom  include  Sir  J.  J.  Thomson,  Professors 
Sherrington,  Bateson,  and  Svante  Avrhenius.  The  present  volume  will  add  to  the 
very  high  reputation  which  Prof.  Verworn  already  enjoys  both  as  an  investigator 
and  writer.  The  subject  which  forms  the  title  of  the  lecture  deals  with  a  property 
of  the  living  substance  which  is  perhaps  its  most  fundamental  characteristic,  and 
the  author  has  made  it  peculiarly  his  own,  for  the  volume  deals  with  his  researches 
which  have  covered  a  period  of  twenty  years. 

Those  acquainted  with  Verworn's  General  Physiology  will  know  that  the  author 
was  one  of  the  earliest  to  recognise  the  importance  of  a  study  of  the  subject  from 
the  comparative  standpoint  ;  the  muscle-nerve  preparation  from  the  frog's  leg  is 


REVIEWS  791 

still  the  sheet  anchor  of  those  who  investigate  the  phenomenon  of  irritability,  but 
fresh  light  is  shed  upon  the  problem  by  employing  other  kinds  of  excitable  proto- 
plasm such  as  are  found  in  the  protozoa.  Prof.  Verworn  emphasises  the 
importance  of  this  branch  of  work  in  the  book  just  published. 

His  first  chapter  deals  with  the  history  of  the  subject  from  the  days  of  Francis 
Glisson  onward,  and  his  second  with  the  general  principles  of  scientific  research, 
especially  in  relation  to  the  conception  of  the  word  cause.  It  is  not  until  we  reach 
Chapter  III.  that  the  author  really  launches  out  into  his  subject  proper,  and  in 
this  and  succeeding  lectures  deals  in  turn  with  the  varieties  of  stimuli  and  the 
manner  of  response.  We  have,  for  instance,  a  discussion  of  the  Weber-Fechner 
law  which  mainly  operates  in  sensory  phenomena,  and  the  "all  or  nothing"  law 
which  he  regards  as  the  rule  in  motor  responses.  It  is  pointed  out  that  stimulation 
as  a  rule  leads  to  katabolic  effects,  the  intakes  of  food  being  practically  the  only 
stimulus  which  leads  to  anabolism.  The  processes  of  induction  are  of  necessity 
included  with  those  of  irritability.  The  importance  of  a  due  supply  of  oxygen  is 
largely  dwelt  upon,  for  it  is^upon  an  interference  with  this  that  the  phenomena  of 
"  refractory  period  "  and  of  fatigue  depend.  The  concluding  chapters  deal  with 
the  "  interference "  of  stimuli,  and  with  inhibition  which  is  largely  due  to 
interference,  and  with  the  very  important  question  of  depression  of  irritability  as 
especially  illustrated  during  narcosis. 

Such  a  hasty  summary  of  the  main  contents  01  the  book  is  sufficient  to 
illustrate  the  important  nature  of  the  themes  it  treats  of,  and  one  hopes  it  will 
be  sufficient  to  induce  those  interested  in  physiological  advance  to  purchase  it.  It 
is,  however,  only  right  to  warn  intending  purchasers  that  they  are  not  to  expect 
light  and  easy  reading.  It  is  not  suited  to  beginners,  for  it  presupposes  a  ground- 
work of  physiological  knowledge.  To  the  advanced  student  or  professed 
physiologist,  especially  if  he  is  a  rapid  thinker,  some  of  the  sections,  moreover,  may 
prove  rather  "  irritating,"  for  they  labour  points  which  are  pretty  obvious. 

The  translation  has  been  admirably  carried  out  by  Frau  Verworn,  and  in  a  book 
published  in  the  United  States  one  naturally  forgives  such  Americanisms  as  center 
and  acetat.  But  the  words  functionation,  oxyclable,  and  excitate  do  not  strike 
one  as  happy ;  they  are  not  English  and  one  doubts  whether  they  are  even 
American. 

W.  D.  H. 

Applied  Mechanics  for  Engineers.     By  J.   Duncan,  Wh.Ex.,  M.I.Mech.E. 
[Pp.  xv  +  718.]     (London  :  Macmillan  &  Co.,  1913.     Price  8.r.  6d.  net.) 

This  book  deals  in  two  parts  with  Materials  and  Structures,  and  Machines  and 
Hydraulics.  There  is,  of  course,  no  logical  reason  for  not  dealing  with  heat 
engines  and  other  branches  of  engineering,  when  treating  with  mechanics  for 
engineers.  But  no  one  can  complain  that  enough  has  not  been  crowded  into  the 
seven  hundred  odd  pages  as  it  is.  It  may  be  said  at  once  that  the  book  will  be 
found  very  useful  for  students  who  have  been  properly  taught,  and  who  wish  to 
possess  in  a  concise  form  a  summary  of  the  material  dealt  with  in  the  usual 
engineering  examinations.  They  will  be  further  helped  by  the  numerous  examples, 
particularly  as  answers  to  these  questions  are  given  at  the  end  of  the  book.  All 
that  can  be  done  by  a  good  compiler  and  an  excellent  printer  has  been  achieved. 
The  formulae  and  tables  are  admirably  clear,  and  the  illustrations  throughout  are 
excellent  and  carefully  drawn.  The  student  will  find  that  the  numerous  proofs  of 
different  formulas  are  stated  in  a  concise  form,  and  the  cross  references  are  con- 
veniently given.     It  is  quite  necessary  for  a  student  to  understand  that  he  cannot 

5i 


?9*  SCIENCE   PROGRESS 

hope  from  this  book  alone  to  study  and  understand  the  very  large  number  of 
problems  that  are  dealt  with  unless  he  has  had  a  good  technical  and  mathematical 
training.  Thus  the  intimation  in  the  preface  as  to  the  amount  of  mathematics 
required  appears  to  be  misleading,  and  there  are  very  few  students  who  could 
understand  the  differential  and  integral  calculus  from  the  few  remarks  given  in 
the  first  chapter.  In  fact,  this  chapter  is  only  to  be  justified  by  the  point  of  view 
of  reference.  To  take  another  instance,  the  whirling  of  shafts,  which  is  really  a 
difficult  subject,  should  at  least  contain  a  reference  to  Prof.  Dunkerley's  original 
investigations  in  the  Phil.  Trans,  to  enable  the  student  to  understand  the  subject 
properly,  since  there  are  variations  in  whirling  which  are  dealt  wich  in  that  paper 
.vhich  might  easily  be  called  for  by  an  examiner  as  well  as  the  simple  cases 
given  by  the  writer.  Aided  by  the  instruction  of  a  good  teacher,  who  can  ref~r 
the  student  to  other  books  for  further  information  on  subjects  such  as  the  Ellipse 
of  Stress  and  various  other  problems,  the  book  might  be  safely  recommended  to 
students  of  engineering. 


BOOKS   RECEIVED 

{Publishers  are  requested  to  notify  prices') 

Chemistry  and  its  Borderland.  By  Alfred  W.  Stewart,  D.Sc,  Lecturer  on 
Organic  Chemistry  in  the  Queen's  University  of  Belfast,  Formerly  185 1 
Exhibition  Research  Scholar  and  Carnegie  Research  Fellow.  With  11  Illus- 
trations and  2  Plates.  Longmans,  Green  &  Co.,  39,  Paternoster  Row,  London, 
New  York,  Bombay,  and  Calcutta,  1914.     (Pp.  xi,  313.)     Price  5^.  net. 

Photo-Chemistry.  By  S.  E.  Sheppard,  D.Sc.  (Lond.),  Formerly  1851  Exhibition 
Research  Scholar  of  University  College,  London.  With  Illustrations  and 
Figures.  Longmans,  Green  &  Co.,  39,  Paternoster  Row,  London,  New  York, 
Bombay,  and  Calcutta,  1914.     (Pp.  ix,  461.)     Price  12s.  bd. 

Quantitative  Analysis  in  Practice.  An  Introductory  Course  designed  for  Colleges 
and  Universities.  By  John  Waddell,  B.A.  (Ualhousie  University),  B.Sc. 
(Lond.),  Ph.D.  (Heidelberg),  D.Sc.  (Edinburgh),  Formerly  Assistant  to  the 
Professor  of  Chemistry  in  Edinburgh,  Assistant  Professor  of  Chemistry 
School  of  Mining  (Queen's  University),  Kingston,  Canada.  London  :  J.  &  A. 
Churchill,  7,  Great  Marlborough  Street,  191 3.  (Pp.  vi,  162.)  Price  4-y.  bd. 
net. 

The  Great  Scourge  and  How  to  End  it.  By  Christabel  Pankhurst,  LL.B.  London: 
E.  Pankhurst,  Lincoln's  Inn  House,  Kingsway,  W.C.,  1913.  (Pp.  xi,  155.) 
Price  is. 

A  Course  of  Practical  Work  in  the  Chemistry  of  the  Garden.  For  Teachers  and 
Students  of  Horticulture,  Gardening,  and  Rural  Science.  ByD.  R.  Edwardes- 
Ker,  B.A.  (Oxon),  B.Sc.  (Lond.),  Head  of  the  Chemical  Department  and 
Lecturer  in  Agricultural  Chemistry  at  the  South-Eastern  Agricultural  College 
(University  of  London),  Wye,  Kent ;  Joint  Author  of  'k  Practical  Agricultural 
Chemistry."  London  :  John  Murray,  Albemarle  Street,  W.,  1914.  (Pp.  40.) 
Price  is.  bd.  net. 

Controlled  Natural  Selection  and  Value  Marking.  By  J.  C.  Mottram,  M.B. 
(Lond.).  Longmans,  Green  &  Co.,  39,  Paternoster  Row,  London,  New  York, 
Bombay,  and  Calcutta,  1914.     (Pp.  vii,  130.)     Price  3.s\  bd.  net. 

The  Universe  and  the  Mayonnaise,  and  Other  Stories  for  Children.  By 
T.  Brailsford  Robertson.  Illustrated  by  K.  Clausen.  London  :  John  Lane, 
the  Bodley  Head.  New  York  :  John  Lane  Company.  Toronto  :  Bell  & 
Cockburn,  1914.     (Pp.  125.) 


BOOKS  RECEIVED  793 

Health  Preservation  in  West  Africa.  By  J.  Charles  Ryan,  L.R.C.P.I.,  L.M., 
L.R.C.S.I.,  L.M.,  Diplomate  in  Tropical  Medicine,  University,  Liverpool,  Late 
M.O.  West  African  Medical  Staff.  With  Introduction  by  Sir  Ronald  Ross, 
K.C.B.,  F.R.S.,  Nobel  Laureate,  M.D.,  D.P.H.,  F.R.C.S.,  D.Sc,  LL.D. 
London  :  John  Bale,  Sons  &  Danielsson,  Ltd.,  Oxford  House,  83-91,  Great 
Titchfield  Street,  Oxford  Street,  W.,  1914.     (Pp.  xv,  96.) 

Studies  in  Water  Supply.  By  A.  C.  Houston,  B.Sc,  M.B.,  CM.,  Director  of 
Water  Examination,  Metropolitan  Water  Board.  Macmillan  &  Co.,  Ltd., 
St.  Martin's  Street,  London,  191 3.     (Pp.  ix,  203.)     Price  5^.  net. 

Artificial   Parthenogenesis  and  Fertilisation.     By  Jacques  Loeb,  Member  of  the 
Rockefeller  Institute  for  Medical  Research.     Originally  translated  from  the 
German  by  W.  O.  Redman   King,   B.A.,  Assistant   Lecturer  in  Zoology  atv 
the  University  of  Leeds,  England,  Supplemented  and  Revised  by  the  Author.  ' 
The   University   of  Chicago  Press,  Chicago,    Illinois.    Agents :     Cambridge 
University  Press,  London.     (Pp.  x,  312.)     Price  los.  net. 

A  Way  of  Life.  An  Address  to  Yale  Students,  Sunday  Evening,  April  20,  1913. 
By  William  Osier.     London  :  Constable  &  Co.,  Ltd.,  1913.     (Pp.  61.) 

Some  Main  Issues.  A  Collection  of  Essays.  By  G.  Walter  Steeves,  M.D. 
London  :  Chapman  &  Hall,  Ltd.,  191 3.     (Pp.  iii,  109.)     Price  35-.  6d.  net. 

Ancient  Egypt.  Quarterly  Journal,  Part  I.  Editor,  Prof.  Flinders  Petrie,  F.R.S., 
F.B.S.  Macmillan  &  Co.,  London  and  New  York,  and  British  School  of 
Archaeology  in  Egypt.  University  College,  London.  (Pp.  48,  Illustrated.) 
Price  2s.  net. 

A  School  Statics.  By  G.  W.  Brewster,  M.A.,  Senior  Mathematical  Master  at 
Oundle  School,  and  C.  J.  L.  Wagstaff,  M.A.,  Headmaster,  Haberdashers' 
Hampstead  School.  Cambridge  :  W.  Heffer  &  Sons,  Ltd.,  191 3.  (Pp.  viii, 
248.)  Price  2s-  net- 
Modern  Methods  of  Water  Purification.  By  John  Don,  F.I. C,  A.M.I. Mech.E., 
and  John  Chisholm,  A. M.I. Mech.E.,  Engineer  and  Manager  of  the  Airdrie, 
Coatbridge  and  District  Waterworks.  With  106  Illustrations.  Second 
Revised  and  Enlarged  Edition.  London  :  Edward  Arnold,  1913.  (Pp.  xvii' 
398.)     Price  15s.  net. 

Physical  Chemistry  :  Its  Bearing  on  Biology  and  Medicine.  By  James  C.  Philip, 
M.A.,  Ph.D  ,  D.Sc,  Assistant  Professor  in  the  Department  of  Chemistry, 
Imperial  College  of  Science  and  Technology.  Second  Edition.  London  : 
Edward  Arnold,  191 3.    (Pp.  vi,  326.)     Price  7s.  6d.  net. 

Heredity  and  Sex  :  Columbia  University  Lecture.  By  Thomas  Hunt  Morgan, 
Ph.D.,  Professor  of  Experimental  Zoology  in  Columbia  University.  Hum- 
phrey Milford,  Oxford  University  Press,  London,  E.C.,  and  at  Toronto,  Mel- 
bourne, and  Bombay.     (Pp.  ix,  282.)     Price  js.  bd.  net. 

Flies  and  Mosquitoes  as  Carriers  of  Disease.  By  Wra.  Paul  Gerhard,  C.I., 
Member  American  Society  Mechanical  Engineers,  Consulting  Engineer, 
Doctor  of  Engineering.  New  York,  191 1.  Published  by  the  Author,  39, 
Strong  Place,  Brooklyn,  New  York.     (Pp.  14.)     Price  25  cents. 

The  sub-title  of  this  paper  is  "  What  Farmers  can  do  to  Assist  in  the  Cam- 
paign against  Flies  and  Mosquitoes."  The  work  is  well  designed  for  instruc- 
tion in  this  particular,  as  regards  the  United  States,  and  farmers  even  in  this 
country  often  have  to  deal  with  mosquitoes  in  the  summer,  especially  in 
certain  parts.  The  author  does  not  appear  to  have  read  all  the  large  literature 
either  on  malaria  or  on  yellow  fever ;  but  the  instructions  for  practical  work 
will  be  useful. 

Journal  of  Ecology.  Vol.  I.  No.  4, 1913.  Edited  or  the  British  Ecological  Society 
by  Frank  Cavers,  Cambridge  University  Press.     (Pp.  64.)     Price  $s. 


NOTES 

The  Sale  of  Honours 

The  feast  of  unreason  called  party  politics  is  the  last  kind 
'of  banquet  which  men  of  science  should  attend  ;  but  neverthe- 
less men  of  science  have  definite  duties  to  perform  towar  Js 
the  State — it  should  be  their  part  to  throw  the  cold  light  of 
reason  upon  the  welter  of  clashing  interests.  As  a  matter  of 
fact,  however,  they  as  a  body  take  almost  no  part  whatever 
in  public  affairs.  The  light  of  reason  remains  unthrown ;  and 
in  the  darkness  we  hear  only  the  howls  of  the  combat  between 
the  interested  people  who  are  trying  to  rob  each  other  and 
the  time-servers  who  are  pretending  to  lead  them.  There  are, 
however,  some  signs  of  awakening  interest  among  the  more 
intelligent  people  in  the  country — combined  with  a  rapidly 
increasing  sense  of  resentment  against  the  politicians  of  both 
parties.  It  is  beginning  to  be  seen  that  these  people  are 
sacrificing  the  interests  of  the  whole  empire  in  the  pursuit  of 
the  game  which  they  play — to  their  own  profit  and  to  the  loss 
of  the  nation.  Mr.  John  Galsworthy,  the  dramatist,  has  per- 
formed a  public  duty  by  calling  attention  in  the  Times  of 
February  28  to  the  "  heartlessness  of  Parliament " — he  might 
have  said  "  inefficiency."  He  complains  that  a  large  number 
of  important  reforms  remain  quite  ignored  by  the  body  which 
is  supposed  to  govern  us ;  and  we  could  easily  add  to  his  list 
many,  and  many  more  important,  matters  which  have  been 
fruitlessly  calling  for  attention  during  the  last  century  or 
more — such  as  the  perfectioning  of  the  Common  Law,  the 
encouragement  of  the  arts  and  sciences,  and  the  removal  of 
innumerable  abuses  which  are,  if  anything,  favoured  by  the 
party  politicians.  But  the  things  which  are  most  effectually 
rousing  even  the  most  brainless  to  the  evils  of  party  govern- 
ment are,  first,  the  state  to  which  the  parties  are  bringing 
Ireland,  and,  secondly,  the  infamous  abuse  to  which  Lord 
Selborne  called  attention  in  the  House  of  Lords  on  February  24 
— the  public  sale  of  honours  to  persons  who  purchase  them 
by  subscribing  funds  to  the  parties — a  thing  which  we  should 

794 


NOTES  795 

expect  to  find  more  easily  in  Turkey  or  China  than  in  a  country 
which  thinks  that  it  possesses  the  hegemony  of  the  world. 
In  other  words,  the  great  honours  of  the  State,  which  should 
be  reserved  only  for  the  highest  services  to  the  world  or  to 
the  State,  are  given  for  perpetuating  a  disease  of  government 
which  does  not  really  belong  to  our  Constitution  at  all,  and 
which  every  person  accustomed  to  correct  reasoning  must 
look  upon  with  dislike  and  contempt.  The  world  is  beginning 
to  .perceive  that  the  next  great  reform  which  it  must  undertake' 
is  the  expulsion  of  the  party  politician  from  public  affairs. 

The  Royal  Society- 
List  of  recommendations  by  the  Council  for  the  Fellowship 
in  1914:  Dr.  E.  J.  Allen,  Mr.  R.  Assheton,  Mr.  G.  T.  Bennett, 
Prof.  R.  H.  Bififen,  Dr.  A.  E.  Boycott,  Mr.  Clive  Cuthbertson, 
Dr.  H.  H.  Dale,  Prof.  A.  S.  Eddington,  Prof.  E.  J.  Garwood, 
Mr.  T.  H.  Havelock,  Dr.  T.  M.  Lowry,  Prof.  D.  Noel  Paton, 
Mr.  S.  Ruhemann,  Dr.  S.  W.  J.  Smith,  and  Dr.  T.  E.  Stanton. 

The  British  Association 

The  Committee  for  Radiotelegraphic  Investigation  have  issued 
a  circular  asking  for  assistance  in  connection  with  the  forth- 
coming eclipse.  Communications  should  be  addressed  to  the 
Hon.  Secretary,  Dr.  W.  Eccles,  University  College,  London, 
W.C. 


NOTICE 

THE  EMOLUMENTS  OF  SCIENTIFIC  WORKERS 

It  is  proposed  to  undertake  an  inquiry  regarding  the  pay,  posi- 
tion, tenure  of  appointments,  and  pensions  of  scientific  workers 
and  teachers  in  this  country  and  the  Colonies.  The  Editor  will 
therefore  be  much  obliged  if  all  workers  and  teachers  who  hold 
such  appointments,  temporary  or  permanent,  paid  or  unpaid, 
will  give  him  the  necessary  information  suggested  below. 
The  figures  will  be  published  only  in  a  collective  form  and 
without  reference  to  the  names  ol  correspondents,  unless  they 
expressly  wish  their  names  to  be  published.  The  Editor 
reserves  the  right  not  to  publish  any  facts  communicated  to 
him.  Workers  who  are  conducting  unpaid  private  investigations 
must  not  be  included.  The  required  information  should  be 
sent  as  soon  as  possible  and  should  be  placed  under  the 
following  headings  : 

(i)  Full  name 

(2)  Date   of  birth.     Whether  married.     Number  of  family 

living 

(3)  Qualifications,  diplomas,  and  degrees 

(4)  Titles  and  honorary  degrees 

(5)  Appointments  held  in  the  past 

(6)  Appointments  now  held,  with  actual  salary,  allowances, 

fees,   and   expected   rises,  if  any.     Whether  work  is 
whole  time  or  not 

(7)  Body  under  which  appointment  is  held 

(8)  Conditions  and  length  of  tenure 

(9)  Pension,  if  any,  with  conditions 

(10)  Insurance  against  injury,  it  any,  paid  by  employers 

(11)  Family  pensions,  if  any 

(12)  Remarks 


INDEX   TO   VOL.   VIII   (1913 — 1914) 


I.   ARTICLES 

VAGE 

Aeroplane,  The  Disturbed  Motion  of  an.     W.  Beverley       ....  209 

Alcock,  Prof.   Nathaniel,  M.D.,  D.Sc 1/5 

Argon  Family  of  Gases,  Nature  of  the.     F.  Soddy 654 

Atomic  Theory  and  Radioactivity.     Sir  O.  Lodge 197 

Balfour,  Mr.,  at  the  National  Physical  Laboratory 385 

Bristol,  The  University  of I75>384 

Bristol  University 593 

Business  Affairs  of  Science,  The *77 

Corpus  Luteum,  The.     C.  H.  O'Donoghue  .......  721 

Corrosion  of  Iron,  The.     H.  E.  A.       . 72 

Corrosion,  Novel  Experiments  and  Facts  Concerning.     J.  N.  Friend         .  202 

Dark  Ground  Illumination  in  Botanical  Research,  The  Method  of.     S.  R. 

Price 343 

Differences  in  Animal  and  Plant  Life.     F.  Carrel 511 

Displacement  of  Spectral  Lines  by  Pressure,  The.     H.  S.  Jones       .         .  438 

Enzymes  as  Synthetic  Agents.     J.Priestley.    Part  I.  British  Earthworms     .  113 

M                 „                 „                 „             Part  II.  In  Protein  Metabolism  482 

Eugenics  and  War 59 l 

Genius  of  Science,  The 391 

Geologic  Time,  Some  Aspects  of.     H.  S.  Shelton 250 

Heredity,  The  Interpretation  of  Fact  in  the  Study  of.     C.  Walker    .         .  324 

Influence  of  the  Scientific  Movement  on  Modern  Poetry.     E.  A.  Fisher  .  738 

Kelvin's  Work,  Some  Views  on  Lord.     G.  Green        .  .        .        .4*9 

797 


798 


INDEX  TO  VOL.   VIII 


PACE 


Lenard's  Researches  on  Phosphorescence.     E.  N.  da  C.  Andrade    .         .  54 

Lodge,  Sir  Oliver's  Address.     I.  The  Logic  of  Science.     F.  C.  S.  Schiller,  .  398 

„              „              „            II.  The  Philosophy  of  Science.     H.  S.  Shelton  408 

Medicine,  The  International  Congress  of 386 

Mental  Development,  Nature  and  Nurture  in.     F.  W.  Mott       .         .         .  291 

„             The  Inborn  Potentiality  of  the  Child         .         .         .  307 
,,              The    Influence    of    Nutrition    and    the    Influence    of 

Education 460 

Milne,  Prof.  John.     C.  Davison 713 

Molecular  Volume  Theories  and  their  Relation  to  Current  Conceptions  of 

Liquid  Structure.     G.  le  Bas 663 


Nervous  Activity,  The  History  of  the  Views  of.     D.  F.   Harris  . 
Nobel  Prizes  during  Twelve  Years,  The  International  Distribution  of 
„      for  1913,  The 


505 


597 


Oligochseta,  A  Contribution    to    the    Bionomics    of   English.     H.    Friend 

Part  I.    British  Earthworms 

Opsonic  Experiment,  The  Physical  Aspect  of.     A.  G.   McKendrick   . 
Organic  Derivatives  of  Metals  and  Metalloids.     G.  T.   Morgan 
Outlook  for  Human  Health,  The.     B.  Houghton         .... 


99 

497 
690 

153 


Palaeontology  in  191 2,  Vertebrate.     With  Note  on  Giant  Tortoises  and  Dis 

tribution.     R.  Lydekker  .... 
Palaeontology  in  191 3,  Vertebrate.     R.  Lydekker 
Physics  in  1913.     E.  N.  da  C.  Andrade 

Piltdown  Discovery,  The  Significance  of  the.     A.  G.  Thacker 
Protection  of  Science  by  Patent,  The  . 
Psychical  Research,  Criticisms  of.     I.   J.  A.   Hill 

II.   Reply.     H.  S.  Shelton 


Radioactive  Matter,  A  Suggestion  Concerning  the  Orig 


1 
626 

608 
275 

551 

755 
767 


n  of.     H.  S.  Shelton     456 


Sale  of  Honours,  The 

Sanitary  Awakening  of  India,  The.     Sir  C.  Pardey  Lukis  . 
Science  and  the  Lay  Press    .... 
Scientific  National  Defence.     C.  Ross  . 
Scientific  Spelling.     I.  Sir  H.  Johnston 

„  „  II.  Sir  R.  Ross 

Seats  of  the  Soul  in  History,  The.     D.  F.   Harris 
Speech,  The  Relations  of,  to  Human  Progress.     L.  Robinson 
StereoTsomerism  and  Optical  Activity.     G.  S.  Agashe 

Sweating  the  Scientist 

Syphilis,  Recent  Advances  in  our  Knowledge  of.     E.  H.  Ross 


794 
181 

594 
122 

355 
367 
'45 
5i9 

227 

599 
535 


INDEX  TO  VOL.  VIII  799 

PAGE 

Temperature  and  the  Properties  of  Gases.     F.  Hyndman  ....       26 
Tropical  Medicine,  The  Finances  of 589 

Volcanoes,  Recent  Work  on.     E.  H.  L.  Schwarz 85 

Why  are  People  so  Confined,  when  Freedom  can  be  Enjoyed?    T.  Brown- 
bridge       547 

Woman's  Place  in  Nature.     I.  M.  S.  Pembrey  .         .         .         .         .         .133 

<%    »  »  ,.  II.  O.  A.  Craggs 1$ 

II.    AUTHORS   OF   ARTICLES 

Agashe,  G.  S 227 

Andrade,  E.  N.  da  C 54,  608 

Bas,  Gervaise  le 663 

Beverley,  W.  M.  S 209 

Brownbridge,  T.       ...........  547 

Carrel,  F 511 

Craggs,  O.  A 133 


Davison,  Charles 


713 


Fisher,  E.  A 738 

Friend,  Rev.  Hilderic 99 

Friend,  J.  Newton 202 

Green,  George 419 

Harris,  David  Fraser 145,  505 

H.  E.  A 72 

Hill,  J.  A 755 

Houghton,  Bernard          .         . 153 

Hyndman,  Francis 26 

Johnston,  Sir  Harry 355 

Jones,  H.  Spencer 438 

Lodge,  Sir  Oliver 197 

Lukis,  Sir  Charles  Pardey 181 

Lydekker,  R i,  626 

McKendrick,  Major  A.  G.                                  497 

Morgan,  Prof.  G.  T 690 

Mott,  F.  W 291,  307,  460 


8oo 


INDEX  TO  VOL.  VIII 


O'Donoghue,  Charles  H. 


PAGE 

721 


Pembrey,  M.  S 133 

Price,  S.  Reginald 434 

Priestley,  Prof.  J.  H 133,  482 

Robinson,  Louis 519 

"olonel  Charles 122 

£.  H 

'  -    ij 

<oss,  Sir  Ronald 

Schiller,  F.  C.  S 398 

Schwartz,  Prof.  E.  H.  L 85 

Shelton,  H.  S. 150,398,456,767 

Soddy,  Frederick 654 

Thacker,  A.  G 275 

Walker,  Charles 324 


AUTHORS   OF   BOOKS   REVIEWED 


Allen,  H.  S.,  "  Photo-Electricity"  . 
(Anonymous),  "  Life,  Light,  and  Cleanliness  " 


777 
584 


Barlow,   C.    W.    C,   "  Mathematical    Physics.      Vol.    I.    Electricity    and 

Magnetism" .  379 

Bateson,  W.,  "  Problems  of  Genetics  " 787 

Bayliss,  W.  M.,  "The  Nature  of  Enzyme  Action" 782 

Bose,  J.  Chunder,  "  Researches  on  Irritability  of  Plants"       ....  576 

Brooks,  H.  J.,  "The  Science  of  the  Sciences" 562 

Bunau-Varilla,  P.,  "  Panama,  the  Creation,  Destruction,  and  Resurrection  "  .  584 

Buttel-Reepen,  H.  v.,  "  Man  and  His  Forerunners  " 376 


Campbell,  Norman  Robert,  "  Modern  Electrical  Theory  " 
Campbell,  W.  W.,  "Stellar  Motions"     .... 
Cohen,  J.  B.,  "  Organic  Chemistry  for  Advanced  Students" 
Cumming,  A.  C,  "  Quantitative  Chemical  Analysis" 


378 
567 
570 
569 


Davies,  A.  M.,  and  H.  G.  Wells,  "Text-book  of  Zoology" 
Desch,  C.  H.,  "  Modern  Seismology"     .... 
Duncan,  J.,  "Applied  Mechanics  for  Engineers "   . 


577 
783 
791 


Eastman,  C.  E.,  "  Text-Book  of  Paleontology  " 


785 


INDEX  TO  VOL.  VIII  80* 


PAGE 


Fleming,  H.  A.,  "  The  Wonders  of  Wireless  Telegraphy  "      ....     581 
Fortescue,  C.  L.,  "  Wireless  Telegraphy" 375 


Gadow,  Hans,  "  The  Wanderings  of  Animals  "        ......  578 

Geen,  Burnard,  "  Continuous  Beams  in  Reinforced  Concrete"       .         .         .  376 

Gregory,  J.  W.,  "  The  Nature  and  Origin  of  Fiords" 574 

Guthe,  K.  E.,  "  Definitions  in  Physics" 778 


1  .r 

H,  jdane,  J,  S.,  "  Mechanism,  Life,  and  Personality" 582. 

Hartog,  Marcus,  "Problems  of  Life  and  Reproduction  "         .         .         .         .  170 

Hatch,  F.  H.,  "The  Petrology  of  Igneous  Rocks" 785 

Hatch,  F.  H.,  and  R.  H.  Rastall,  "  The  Petrology  of  the  Sedimentary  Rocks  "  784 

Holmes,  Arthur,  "  The  Age  of  the  Earth  " 168 


Jakoby,  H.,  "  Astronomy  " 773 

Jones,  R.  H.,  "  Experimental  Domestic  Science" 585 

Lyde,  L.  W.,  "  The  Continent  of  Europe  " 572 


McKready,  Kelvin,  "  A  Beginner's  Star  Book  " 374 

Mason,  A.  W.,  "A  Systematic  Course  of  Practical  Science  :  Book  I.  Intro- 
ductory Physical  Measurements.     Book  II.  Experimental  Heat "        .  562 

Mill,  H.  R.,  "The  Realm  of  Nature" 583 

Morgan,  C.  L.,  "  Spencer's  Philosophy  of  Science  " 772 

Murray,  Sir  John,  "The  Ocean" 583 

Nierenstein,   M.,  "  Organische   Arsenverbindungen   und   ihre   chemothera- 

peutische  Bedeutung" 572 

Parker,  Philip  A.  Morley,  "  The  Control  of  Water  " 375 

Paulin,  George,  "  No  Struggle  for  Existence  :  No  Natural  Selection  "   .        .  373 

Preston,  Thomas,  "The  Theory  of  Light" 168 

Remsen,  Ira,  "American  Chemical  Journal" 782 

Robson,  E.  S.  A.,  "  Practical  Exercises  in  Heat  " 776 

Ross,  E.  H.,  "Reduction  of  Domestic  Flies" 172 

Ruge,  A.,  and  others,  "  Encyclopaedia  of  the  Philosophical  Sciences.     Vol.  I. 

Logic  " 770 

Schiller,  F.  C.  S.,  "  Formal  Logic  :  A  Scientific  Social  Problem"  .        .        .  559 

Schmucker,  S.  C,  "The  Meaning  of  Evolution  " 584 

Shephard,  J.  W.,  "  Qualitative  Determination  of  Organic  Compounds"         .  374 


802  INDEX   TO  VOL.   VIII 

PAGE 

Silberstein,  L.,  "  Vectorial  Mechanics" 564 

Soddy,  F.,  "  The  Chemistry  of  the  Radio-Elements  " 778 

Southall,  J.  P.  C,  "  Principles  and  Methods  of  Geometrical  Optics"     .         .  566 

Tarde,  Gabriel,  "  Penal  Philosophy  " 578 

Thomson,  Sir  J.  J.,  "  Rays  of  Positive  Electricity" 774 

Thorpe,  Sir  E.,  "A  Dictionary  of  Applied  Chemistry  " 780 

Tilden,  Sir  W.  A.,  "The  Progress  of  Scientific  Chemistry"    . 

^'imiriazeff,  C,   "A  Possible  Physical  Aspect  of  the  Trichromatic  Vision 

Theory" 1 

Verworn,  M.,  "  Irritability" 790 

Walker,  G.  W.,  "  Modern  Seismology  " 783 

Weinstein,     M.     B.,   "  Die     Physik    der    bewegten      Materie     und     die 

Relativitatstheorie " 773 

Wells,  H.  G.,  and  A.  M.  Davies,  "Text-Book  of  Zoology"     .         .         .         .577 

Westaway,  F.  W.,  "  Scientific  Method  :  Its  Philosophy  and  Practice  "  .         .  771 

Zeeman,  P.,  "  Researches  in  Magneto  Optics  " 565 


Printed  by  Hazell,  Watson  &  Viney,  Ld.,  London  and  Aylesbury, 


SCIENCE  PROGRESS 

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CONTENTS  \*> 

1.  Vertebrate  Palaontology  in  1912.    R.  Lydekker,  F.R.8.  ^^4  ~fc 

2.  Temperature  and  the  Properties  of  Oases.    Francis  Hyndmanv* 

3.  Lenard's  Researches  on  Phosphorescence.    E.  N.  Da  C.  Andrade. 
i.  The  Corrosion  of  Iron.    H.  E.  A. 

5.  Recent  Work  on  Volcanoes.    E.  H.  L.  Schwarz. 

6.  A  Contribution  to  the  Bionomics  of  English  Oligochata. 

I.  British  Earthworms.    Hilderic  Friend. 

7.  Enzymes  as  Synthetic  Agents. 

I.  In  Carbohydrate  Metabolism.    J.  H.  Priestley. 

8.  Scientific  National  Defence.    Col.  Charles  Ross. 

9.  Woman's  Place  in  Nature.    I.  M.  S.  Pembrey:    II.  0.  A.  Craggs. 

10.  The  Seats  of  the  Soul  in  History.    David  Fraser  Harris. 

11.  The  Outlook  for  Human  Health.    Bernard  Houghton. 

12.  Reviews,  Books  Received,  and  Notes. 
Notice— The  Emoluments  of  Scientific  Workers. 


EDITOR 

SIR   RONALD   ROSS,   K.C.B.,   F.R.S.,   D.Sc, 
LL.D.,   M.D.,   F.R.C.S. 

LONDON 
JOHN   MURRAY,  ALBEMARLE   STREET,   W. 

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(  H  ) 


No.  28.    IAPRIL   1913. 


Radioactivity  Visualised.    C.  T.  R.  Wil» 

son,  M.A.,  F.R.S.     Illustrated. 
Horticultural    Research.       III.      The 

Action  of  Grass  on  Trees.     Spencer 

Pigkering,  F.R.S.     Illustrated. 
The    Exact    Determination    of    Atomic 

Weights  by  Physical  Methods.    F.  T.  V. 

Little,  A.R.C.S.,  B.Sc    Illustrated. 
The  Logic  of  Darwinism.   Archer  Wilde. 
The  Measurement  ofOsmotic  Pressure  by 

Direct  Experiment.    T.  Martin  Lowry, 

D.Sc.     Illustrated. 


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ternal Ear  of  Vertebrates.  R.  H, 
Burne.     Illustrated. 

The  Projected  Revival  of  the  Flax  In- 
dustry in  England.  J.  Vargas  Eyre, 
PhD.     Illustrated. 

The  State  Protection  of  Wild  Plants. 
A.  R.  Horwood. 

Further  Speculations  upon  the  Origin 
of  Life.     Charles  Walker,  D.Sc. 

The  Mystery  of  Radioactivity.     H.  E.  A. 

Reviews. 


THE  REDUCTION  OF 
DOMESTIC  FLIES. 

By   EDWARD    HALFORD  ROSS,    M.R.C.S.Eng., 

L.R.C.P  Lond., 

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(  xiv  ) 


SCIENCE  PROGRESS 

IN  THE  TWENTIETH   CENTURY 

A    QUARTERLY  JOURNAL    OF 
SCIENTIFIC    WORK    AND    THOUGHT 

NO.  30.     OCTOBER    1913 


CONTENTS 

1.  The  Business  Affairs  of  Science. 

2.  The  Sanitary  Awakening  of  India.    Sir  Charles  Pardey  Lukis. 

3.  Atomic  Theory  and  Radioactivity.    Sir  Oliver  Lodge. 

i.  Novel  Experiments  Concerning  Corrosion.    Dr.  J.  Newton  Friend. 
3.  The  Disturbed  Motion  of  an  Aeroplane.    W.  Beverley. 

6.  Stereo- Isomerism  and  Optical  Activity.    G.  S.  Agashe. 

7.  Some  Aspects  of  Geologic  Time.    H.  S.  Shelton. 

8.  The  Significance  of  the  Piltdown  Discovery.    A.  G.  Thacker. 

9.  I.  Nature  and  Nurture  in  Mental  Development.     II.  The  Potentiality  of 

the  Child.    Dr.  F.  W   Mott. 

10.  The  Study  of  Heredity.    Dr.  Charles  Walker. 

11.  Dark  Ground  Illumination.    S.  R.  Price. 

12.  Scientific  Spelling.    I.  Sir  Harry  Johnston:    II.  Sir  Ronald  Ross. 

13.  "No  Struggle  for  Existence,"  and  other  Reviews. 

14.  The  Nobel  Prizes  and  other  Notes. 


EDITOR 

SIR   RONALD   ROSS,   K.C.B.,   F.R.S.,   N.L., 
D.Sc,   LL.D.,    M.D.,   F.R.C.S. 

LONDON 
JOHN   MURRAY,   ALBEMARLE   STREET,   W. 

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(  ii  ) 


No.  27.     JANUARY  1913. 


The  Mechanism  of  Infection  in  Tuber- 
culosis. R.  R.  Armstrong,  B.A.,  M.B., 
B.C.  (Cantab.),  M.R.C.S.,  L.R.C.P. 

Scientific  Problems  in  Radiotelegraphy. 
J.  A.  Fleming,  M.A.,  D.Sc,  F.R.S. 

X-Rays  and  Crystals.  W.  L.  Bragg, 
B.A.     Illustrated. 

"Mathematics  and  Chemistry":  A  Reply. 
James  Riddick  Partington,  M.Sc. 

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Pruning  and  Manuring.  Spencer 
Pickering,  F.R. S.     Illustrated. 


The  Discussion  on  Animal  Nutrition  at 
Dundee.     E.  J.  Russell,  D.Sc. 


The    Spectre    of    Vitalism.' 
Elliott. 


Hugh    S. 


The  Dangers  of  Socialistic  Legislation. 
Charles  Walker,  D.Sc,  M.R.C.S., 
L.  R.C.I 

The  Detection  of  Pregnancy. 

The  Bleaching  of  Floi 


No.  28.     APRIL    1913. 


Radioactivity  Visualised.  C.  T.  R.  Wil- 
son, M.A.,  F.R.S.     Illustrated. 

Horticultural  Research.  III.  The 
Action  of  Grass  on  Trees.  Spencer 
Pigkering,  F.R.S.     Illustrated. 

The  Exact  Determination  of  Atomic 
Weights  by  Physical  Methods.  F.  T.  V. 
Little,  A.R.C.S.,  B.Sc    Illustrated. 

The  Logic  of  Darwinism.    Archer  Wilde. 

The  Measurement  of  Osmotic  Pressure  by 
Direct  Experiment.  T.  Martin  Lowry, 
D.Sc.     Illustrated. 


The  Comparative  Anatomy  of  the  In- 
ternal Ear  of  Vertebrates.  R.  H. 
Burne.     Illustrated. 

The  Projected  Revival  of  the  Flax  In- 
dustry in  England.  J.  Vargas  Eyre, 
Ph  D.     Illustrated. 

The  State  Protection  of  Wild  Plants, 
A.  R.  Horwood. 

Further  Speculations  upon  the  Origin 
of  Life.     Charles  Walker,  D.Sc. 

The  Mystery  of  Radioactivity.     H.  E.  A. 

Reviews. 


Vertebrate  Palaeontology  in  1912.  With 
Note  on  Giant  Tortoises  and  Their 
Distribution.     R.  Lydekker,  F.R.S. 

Temperature  and  the  Properties  of 
Gases.     Francis  Hyndman,  B.Sc. 

Llnard's  Researches  on  Phosphores- 
cence. E.  N.  Da  C.  Andrada,  B.Sc, 
Ph.D.     (Illustrated.) 

The  Corrosion  of  Iron.     H.  E. 

Recent  Work  on  Volcanoes.  E.  H.  L. 
Schwarz,  F.G.S. 

A  Contribution  to  the  Bionomics  of 
English  Oligoch^eta.  Part  I — British 
Earthworms.  The  Rev,  Hilderic 
Friend,  F.L.S. 


No.  29.     JULY,  1913. 

Enzymes    as    Synthetic   Agents.      J.   H. 

Priestley,  B.Sc,  F.L.S. 
Scientific   National   Defence.     Colonel 

Charles  Ross,  D.S.O. 
Woman's   Place   in    Nature.      I — M.    S. 

Pembrf.y,  M.A.,  M.D.    II — O.  A.  Craggs, 

B.Sc. 
The    Seats    of    the    Soul    in    History. 

David  Fraser  Harris,  M.D.,  B.Sc 
The  Outlook  for  Human  Health.     Ber- 
nard Houghton,  B.A.,  I.C.S. 
Reviews. 
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(   xvii  ) 


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JOHN  MURRAY,  ALBEMARLE  STREET,   W. 

(  xviii  ) 


SCIENCE  PROGRESS 

IN   THE  TWENTIETH   CENTURY 

A    QUARTERLY  JOURNAL   OF 
SCIENTIFIC    WORK    AND    THOUGHT 

NO.  31.     JANUARY    1914 


CONTENTS 

1.  The  Genius  of  Science. 

2.  Sir  Oliver  Lodge's  Address. 

I.  The  Logic  of  Science.    Dr.  Schiller. 
II.  The  Philosophy  of  Science.    H.  S.  Shelton. 

3.  Lord  Kelvin's  Work.    Dr.  George  Green. 

&  The  Displacement  of  Spectral  Lines  by  Pressure.    H.  Spencer  Jones. 
3.  The  Origin  of  Radioactive  Matter.    H.  S.  Shelton. 

6.  Nutrition  and  Education  in  Mental  Development.    Dr.  F.  W.  Mott, 

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13.  Why  are  People  so  Confined?    T.  Brownbridge. 

li.  The  Protection  of  Science  by  Patent.    By  an  Authority  on  Patent  Law. 

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16.  The  Finances   of   Tropical   Medicine,   Eugenics    and   War,   Science    and 

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IN  THE  TWENTIETH   CENTURY 

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