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Full text of "Science progress in the twentieth century : a quarterly journal of scientific work & thought"

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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. 

*9 J 3 



NOTICE 

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postage-paid to The Editor of Science Progress, 18, Cavendish 
Square, London, W. They must be accompanied by the full name, 
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All possible care will be taken of scripts ; but responsibility 
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not be published elsewhere without the Editor's permission. 

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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. 

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ments should be addressed to the Publisher of 'Science Progress, 
50A, Albemarle Street, London, W. 



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- 3 3-7» l 9 l °) 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); an d 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- 



i 4 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- 6 37-66, 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 an d 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 = %u 2 . 
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 %u 2 = RT, and hence 
that the temperature and the mean velocity are very closely 
related. Also that, where T = / (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, 273 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 — 273 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 zero C. = 273 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 
io 20 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 5 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 — 240 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 3 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 45 . 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 zero 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 a 1 and b l 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/v 4 + 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 io 3 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 3 7 

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£ ! X 2 + D'/<£ 4 \* + etc. 

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

(9) B' = 6x6 -{■ b 2 + 6J6 + b t J6* + 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'W 2 ^) 2 + etc; 

where B" etc. = b y + b 2 /0 + b 3 /6~ + b x \8' + b b j6\ 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 



ey 



■**$*"" A f'~& 



Ti ' 
-ti~ ■ 



/ / 'I ! 



I i\. 



-U 



/ ' ' i ' ' ' 

' / ' i ' " 
i ( , ■ 






i 



T 






/ / 
/ 
/ 



1 / . 1 1 1 J i 
iii i 
1 1 ' ' 









/ 1 ' ' / 






i\< riii < 



-A—t- 



I '"I : 

K //I i!V.'- 



iii < 



i*- 



+ r 






' ' i / 
/ / / i 



;•■ V ! »'- <^- ?> 



.- -U 






-^jr-'-'' -.-■- 






.vG^f^"**" 1 ' 






\ v 



\ 
\ 



*> S v 



\e- 



I*.-' 



Q.tO- 

e- •£- 



4Ly / / 7 v •- 



; 



' ¥ i \ i i 

/ 1 / : 

— ^ H M- 



1/ fi 



t- 



t \ i l 

/ v ' 

t I 



I ' 



3>'-. 



V.C 



I 



■"" 



>» *•.•'•>*■ ~^ „..,/„ 



i / ' 






/ * 

/ ( 



*>R >6- 



"' 



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 = - 2 f 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 2 (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 = 



4 o SCIENCE PROGRESS 

15 At, and taking B = o*i and hence 7r=r5 atmospheres, then 
= 6*3 1 which makes T = 189*3 K. From this to about = 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 15 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 = 6'6, whence T = 1023 K. = 750 C, while, where 
8 = 1*5; 7T = 5 '9 ; so that at a temperature of — 40 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 100 9 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 
zero 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 

T 



= — — ^- and hence 



As 



a con- 



T-T v T """ - T 

sequence, if the perfect gas state can be assumed at very small 
pressures and densities, the absolute value of zero 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. 


IO 3 Bioo . 


+ 0-673 


+ 0-86316 


+ 0*44303 


IO 3 B„ . 


+ 0*512 


+ 0-5800I 


-037215 


io 6 Co . 


+ OI2 


+ 0-670 


+ 2-62170 


o : . . 


0*0036616 


0*0036629 


0-0036744 


At pressure/. 


1000 


1090 


1000 


a v limit .... 


o"oo366i7 


0-0036617 


00036618 


1 -T 

1 a . . . 


- 273-10 C. 


- 273'io 


- 273'09 


<1 V 1 









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 





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 + 500 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 


T B 


T K 


pc 


Tc/pc 


T B /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 


N 2 


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 


co 2 


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 


I 7 -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 


C 6 H S F 


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, T B , T F are the absolute values of the 
critical, boiling and freezing point temperatures, and pc is 
the critical pressure in atmospheres. Tc/pc = v c /\ 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 T B /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 v c 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{v l - 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 16 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 5 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 500 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 



5 8 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 

p 

Y 



\A— 




^wSk^ 



Or Lu 



P 



100 



300 



(.00 



Fig. 1 



500 



6oojiji 



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 Ca x Cu y S z , 
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 14 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 14 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 6 7 

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,H 12 O s 

(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 papers 2 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. Armstrong 1 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 Wolff 1 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- 



i2 4 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 



i 4 2 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 



i 4 6 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. Jessup 1 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- 



i 7 2 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 



i 7 8 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 

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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 



t 9 4 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 



i 9 8 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 c 1 and c, 

u 2 = 3 P = 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) = -mu 2 . . (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 = e 1 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^ 


^^ 


c c 


• 

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 

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 "" pw J = " " " Gy = W cosecos( i> ~ Y 

Yldf + pv ~ qu ) = " " " Gz = " Wcos sin( £ - 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 X u etc., due to gusts of wind. 
We start with the assumption that X 1( etc., are zero — i.e. that the 
air is still. 

Assuming that the plane is descending uniformly at an angle 
6 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 X , Y , etc., represent the initial resistances. 



.-. O = Wsin0 o + H - X = Wcos0 o - Y = Z Q 
= - L = - M Q = - H h - N 

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 = Wsin0 o + H cos>7 - X 
O = Wcos0 o + H sin»7 - Y . 

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 = X + X u u + X v v + X r r + X w w + X p p + X q q 

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 = O + £ . 
(S small) and cos# = cos# — £ sin# , sin0 = sin0 o + £ cos0 o . <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. 

= Wcos0 o £ + 8H - uX u - vX v - rX r 
Y\dT + r U ) = " Wsin^ £ - uY u - vY v - rY r 
~g{ dl - qU/ = - W<£cos0 o - wZ w - pZ p - qZ q (Z = o) 3 

A |rt ~ F Ju = - wL w - p l p - q L q ( L o = °) 4 

B £dt ~ F &t = " WM « - P M P - <l M q < M o = °) 5 

C dr 

-y t =-8Hh-uN u - vN v -rN r 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 e Kt (\ 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^ + X u )u + X v v + (X r - y cos0 o )r = 8H = O 
Y u u + (w| + Y v )v + (^sin0 o + Ym. + y r )r = O 
f u u+N v v + (c| + N r )r = 



N, 



212 



SCIENCE PROGRESS 



X is therefore given by 



Wj+X a 



X. 



w 

x r - x cos ^> 



wx „ „ wu w . . 

~^ + Y v Y r + — + T sintf fl 



N. 



CX 



+ N r 



= O. 



Multiplying the last column by \ we have on expanding an 
equation of the fourth degree in X. 

Asymmetrical Oscillations l 

<£cos0 o = pcos# — qsin0 o 
but 

<£= -^ = \<p (assumed) 
.'. \<f>cosd = pcos# - qsin0 o . 

The equations 3, 4, and 5 on p. become 

wu w . a \ n 

in0 o Jq = O 



Gj + Z w)w + (^ cos* + Z p ) p + (Z c 



su 



g 



L w w + (A^+L p )p + (-F^ + L q )q = 
M w w+(M p -F^)p + (B^ + M q )q = 0. 

Again we have an equation of the fourth degree to find \ by 
expanding the following : 



WX _ _ , w a „ WU W . a 
— + Z W , Z p + T cos^ , Z q --j^- T sm6 a 



M 



w 



A X T 

g P 

- F- + M 



g 



P> 



g q 

B- + M q 
g q 



= O. 



In both types of oscillations we have u, v, w, etc., of the form 
a^' 1 + a 2 e A -* 1 + a s e A » l + a 4 e^ or 2(a s e* st ). 

For stability then X s must be such that the real part is negative 
or zero. If the real part is positive there is instability. 

For stability \ = - a s ± i& {a s = or > o}. If & is zero 
there is subsidence, and if & is not zero there is oscilla- 
tion and subsidence, two of the terms 2(a s e Ast ) reducing to 

e~° st (acos/3 s t + bsin£ s t) 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 : A Q X 4 + B X 3 + C X 2 + D X + E = O 
Asymmetrical oscillations : A' \* + B' X 3 + C' X 2 + D' X + E' = O. 

For stability l A , B , C , D , and E must all be positive and 
B C D — E B 2 — A D 2 > O, and similarly for the values A' etc. 

Forced Oscillations 

Those forces, — X„ — Y lf — Z lt — L*, — M„ — N x 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) 

= lP s e- k s t cos(X s t + a s ),' 

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 X lf etc., 
are now : 

(w| + X u )u + X v v + (X r - ™ cos0 o )r = - IX^e'Vcos (p^t + g^) 

Y u u + (Y v + ^) v + (Y r + ^U + W s . n ^ r = _ ?y ^ - » Vcos^t + ^ 

N u u + N v v + ((£ + N r )r = - f N^e'" "• t cos(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 + ^ + ^ > f Y =. e ~ nVc ° s( pv + £ y + 

^ ? N,e-"".'co s (^t +B y] 

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"°*' W s . + *y + 



;)p s e-v cos(p » Sit + sv ] 



A(S) s 



- -Clf ? I v" Vcos(i v + ^> + w^V^W,. + e v + 



^p S0 e-°'V cos(pV+£ . 3i )] 



where 



A(8) 



™ + x t 
g 



N. 



X, 



y„ + 



N, 



g 



w 

X r - -ycos0 o 
Wsinfl WU 



g 



N r + 



g 



and UtCS), U 2 (8), U 3 (S) ; V.(8), V 2 (S), V 3 (S) ; and R^S), R 2 (8) and 
R 3 (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)X S e ' cos(p s t + £ s ) 



as a type. We have 
Let 



F(S) . Pe mt = F(m) . Pe mt . 
m s = - n s + ip s and P s = Q s 4- iR s 5 



-n B t 



ms, 1 



and X s e ' cos(p s t + S s ) = real part of P s e ' 



e S| (Q s cos p 3 1 - R s sin p s t) ; 



whence we have 



i i 



Qs. = X s cosS: s.> R s. = X s sin£ s 



i£ 5 



X s (cos£ s + i sin£ s ) = X s e '. 



Similarly under the same conditions of solution 



P' = Y c e S2 andP" = N,e 



.-. u = - real part of [~2F (fi)P s eV + 2F S (8)P' S 



nv_ t n" t-i 

^3(8)P" S3 e S 'J 



e s '-' + 2F 3 



s. 



+ free vibrations 



Ui(m, ) 



= - the real part of [s 1 !V P s e m « ( l 



A(m s ) 



t , ,. U,(m' s ) TJ , m' a ,t 

s„ 



3 A(m' ) 



+ fjW*2v» s e m 'V] 



THE DISTURBED MOTION OF AN AEROPLANE 215 

+ the real part of 2{(a s e x s t ). U,(X S )} 

r V,(m s) m t V 2 (m' ) m , t 

v = - the real part of 2 —, V P, e * + a 2 A/ , \ P' e 2 

* Ls, A(m s ) s i s 3 A(m' Sj ) s 2 

V 3( m \) m " s t-1 

+ s A(m" r ) P " s 3 e 3 J 

s .1 

+ the real part of 2{(a s e Xst )V,(X s )} 



R-(m s .) m . t R 2 (m' s ) 



e s 2' 



r = - the real part of [ « ^ P., e . + S ^-y P' s < 

+ the real part of ^{(ase^). R,(X S )} 

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 a s . 

Where X s is complex we have the free vibrations given by 

\ = — a* ± i&. 

These are 

(a s cos/3 s t + b s sin/3 s t). 

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 X s is real we see that the free vibrations are propor- 
tional to 

U,(X S ) : V^) : R^) or U (X s ) : V (X g ) : R 2 (X S ) or U (X s ) : V (X s ) : R/X,). 

If m s be a root of A(m) = o, the denominators of the forced 
vibrations become indefinitely small. This gives, however, a 
value of m s 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 — a a of 
the exponential. a s , a positive quantity, is the co-efficient of 
decay or subsidence. 

The Limits of the Forced Vibrations 

If m s = \ 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 (m s ) 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. 

A l 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 

U 1 (S){|X s e- n s t cos(p s t+E s )> =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 m { = — n -f- ip } and Ui(8) — taking a type — has /? roots 
equal to m . a and /3 cannot be greater than 4. 
[N.B. — Do not confuse a and ft with a s and /3 S in X s = — a s 

± iA.] 

Let m = m + h, where h is ultimately zero. Expanding we 
have : 

VjP#r* + £ {U,(m )e"»'! . h + . . . g£, JD ^J . e™«' } j* 

— j^ gmt. = - '-= 

M) A(m ) + A'(m ) + A»(m ) £ 

., . & a A(m ) 
where A°(m ) = -^J-^. 

Since there are a roots equal to m in A(m ) = o, then A(m ) = o 
= A'(m ) = A"(m ) = A a_I (m ). Similarly, 

U > (m ° ) = °-^rn7 rr ~ 
and U^-'Cm,,) = U^- 3 (m ) = . . . . U',(m ) = U/mJ = o. 

. . A(8) e - (a + a, t + . . . . a a _^_ x t )e + ^ A<x(mo) 

on putting h equal to zero. 

We also see that the coefficient of e mot is infinite, containing 

powers of [j-j- It may, however, be absorbed into the free 

vibrations — A(x) = o, where X = m — which are 

(a + a 1 t + ...a a _^ I t*-e- I )e m ot ? 

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 X and roots m as above. The terms containing 
X are similar to those containing m 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 m and X , or X 8> 
or m s . The roots for the forced vibrations are m s such that 
A(m s ) £ o and m as above. 



218 SCIENCE PROGRESS 

u - real part of [2 {a s e^ . U (X s )} + 2(a "+ a"t+ . . . . a" a _^_ 1 t n -^ I )e ni ot . tj (m )] 
-real part of 2^^[u;(m ) + aU;" 1 ^). t + Si^i) u;- 2 (m ) . t 3 + . . ..+ 

+ .. ^-^^-) U>o) ,;^] 

r U,(m s ) m t U : (m' s ) m - t U 3 (m" s ) m » t .-. 

- real part of 2 ■ ' P s e s ' +2 , ■ P' e s » +2 A , „\ P" s e 3 . 

r L s i A(m s ) s i s 2 A(m' s ) s » s 3 A(m s ) s 3 J 



a s , a ", a"i, etc., are arbitrary, giving the free vibrations. Of 
course there may be free vibrations of the type given by X = m 
when there are no forced vibrations of that type (m = m ) ; but 
if there are forced vibrations of the type (m = m ) 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 m . The signs ', ", '", etc., are 
merely symbols when used with " a's " and " /3's " and not 
symbols of operation. V^m,,), Ri(m ) are taken as possessing 
/3' and /3" roots respectively. Hence 

v = the real part of [S{a s eV . V,(X S )} + S(a* +a' l ' | t 
+ ...a" a _^- 1 t a ^'- I )e m o t .V l (m ).] 

p„e m o t r 

- the real part of 2 ^__ [^(m,) + aV.-'K)! 

4- ^""gl/ +l) V/(m p )t^] 

- the real part of [2 ^ P s .V +1 ^ P ; e »V 

L s, A(m s ) s i s 2 A(m' s ) s j 



V 3 (m" s ) m . t -. 

+ 2 — ^- P" e 3 



r = the real part of [Ka^s 1 . R(A S )} + 2(a" + a",t 
+ a" a _^_ 1 t a -^"- I )e m o t . R,(m )] 



- the real part of 2 ^— } |_R »(m ) + aR x °- \m )t 

+ ... g(a -^J^ 0+l) R^(mo)t^"] 

t R i(m s ) m . t R^Cm'g ) m < t 
5 -D rP e ' +2 A , , x P'e 2 
s i A(m sl ) . s 2 A(m a ) s 2 



s g A(m s 3 ) s 3 



'} 



THE DISTURBED MOTION OF AN AEROPLANE 219 

The free and forced vibrations contain the term t a ~^, being 
magnified to the (a — /3)th degree, thus confirming the conclusion 
previously inferred as to the indefinite increase — A(m s ) = o— of 
the forced vibrations. 

The solution for the symmetrical vibrations is now complete. 
U^m), U 2 (m), U 3 (m) ; V^m), V 2 (m), V 3 (m) ; and R^m), R 2 (m), 
R 3 (m) are known, and their derivations with respect to m 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 + z wJ w + (t cos ^ + z pJ p + l z q ~ ~Y~ ~ T * m6 oh 

- S Z s e" D "' t cos(p s t + B ) 



s i 



L w w + (a| + L p ) p + ( - Fg + L q )q - - S L S2 e~ n V C os(p' S2 t + S^) 
M w w + (M p - F|)p + (f£ + M )q = - i M s e" n " s 4os(p" s t + & ). 

N.B.— The values n , n' s , n" s ; p s , 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 



P Sl =Z s e ' 

» E 's 
P's =L s e s * 

P" s = M s e' £ s * 
3 3 



and m s = -n s + ip s ; m' = - n' s + ip' s ; and m" s = - n" s -f 

1112 22 «» 3 

ip" s then 

, W ,KJ m st W ,( m 's) m' s t 

w=-therealpartof{s- ? -rTP Si e ' +l-X7 r CT I V 2 + 



% A (m Si ) s . T s 2 A(m' S2 ) 

W,(m" s ) m , st 
, A(m' s ) s 3 



+ the real part of S{(a s e v )W,(X,)}, 



220 



SCIENCE PROGRESS 



X s being a root as on page 212, and the last term containing four 
terms which are the free vibrations. 



A«t x 



p =the real part of 2(a s e s )P (X s ). 



the real part of {2 -^Pe s ' +2 — - ^P'e W^-^P'e 9 * } 



A(m s ) 



1 



s 2 A(m' s ) s 2 



s 3 A(m" s ) s 3 



q =the real part of S^eV). Q/Xg)}. 



the real part of { 2 SjS^P ,***<+ 2 |^P' Si e ra V + 2 %^P'' S3 e m V}. 
* s,A(m Si ) s > s„A(m' S2 ) s ' s 3 A(m' S3 ) s » '■ 



Instead of the free vibrations being proportional to W^X), 
Pi(^-)i Qi(^)» they could have been taken proportional to W 2 (A<), 
PA), QM or W s (\), P s (\), Q 3 (V). 

Note that 



A(m) = 



Wm 
g + w 



M 



w 



W 
Z P + m C0S ^o 

g p 

- F™ + M p 
g p 



7 wu w . 



g 



m 



- F-4-L 
g q 



and that W,(m), W 2 (m), W 3 (m); P^m), P 2 (m), P 3 (m) ; and 
Qi(m), Q2(m), Q 3 (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 
m (= — n + ip ) and W^S), say, may have fi roots also equal 



THE DISTURBED MOTION OF AN AEROPLANE 221 

to m . 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 [2 s (a s e A s l ) . W,(Xs) + 2(a" + a/'t + 
...a'* a _^_ I t a - e - I )e m ot.w,(m )] 

P oe m o t r 

- the real part of 2^^j[ W,«(m ) + oW^-^m^t . + 

- the real part of {2 A'"»i' P e m s ,t , 2 » v y p , e m' S2 t 



s 3 A(m" S3 ) 



2 * v ^p",e m Vt 



Again' /? may be zero. 

p = the real part of [2{(a s e Ast ) . P/X,). } + 2(a " + a/'t 
+ ...a" a _^_ I t a -^- I )e m otp i(mo )] 

P e m o t ( 

- the real part of 2^^- ) |P l a (m ) + aP* -1 ^)! 

+ a(a " I / ) ;:/ ,+I) -p,^o)t a -^} 

- the real part of [_ 2 ^-g- P Si e ., . + \ % ^q • P s ,e « 

+ 2 S3 A(m" S3 )^^ 3 J 
q = the real part of[2 s {(a s e x s l ). Q/Xg)} + 2( a " + a/'t 

+ . . . a" a _/r-it a -' 5 "- 1 ) • e m o l . Q,(m ) .] 

Poe^r 

- the real part of 2 £=7^-)\Q, a ( m o) + a Q. a Vo) 1 • 

+ ••• /a-/3" ^> ^ mo)t J 

- th e re a, P a r ,o f [7|^P«,e-,. + ^?gp^V 

Again the coefficients P" s (not cofactors), the m's, m , \ , 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 
P s , 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 — a s ± i/3 s or 
— n s ± ip s , 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) = KSU 2 f(a) + ^ Su + ~ 6a 

= KSU 2 f(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 

f rW (=^.u)and*r W (=^)u 
the rotary derivatives. 

X = Rsina, Y = Rcosa, N = R£. 

We then find that 



X Q = KSU 2 f(a)sina, 
X u = 2KSUf(a)sina, 
X,; = KSUf'(a)sina, 



Y = KSU»f(a)cosa, 
Y u = 2KSUf(a)cosa, 
Y v = KSUf'(a)C0Sa, 



X r = KSU{xf'(a) + f r (a) - 2yf(a)}sina, Y r = KSU{f r (a) + xf'(a) - 2yf(a)}cosa. 
N = KSU>f(«)£, N v = KSU {f'(a)£ + af(a)(/)'(a)}, 
N u = 2KSUf(a)£, N r = KSU{f'(a)x - 2yf(a) + f r (a)j£, + 

KSUf(a) . {xa(£'(a) + a«/) r (a)j. 

See Prof. Bryan's work (p. 41). 



224 SCIENCE PROGRESS 

f r (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=2R 9°'7+ 1 sin'a = 2l V sina (approximately). 

Prof. Bryan then obtains f(a) <x R, f(a) = sina. 

H = X = SKSlPsin'a, - Hh = N Q - U 2 2KS£'sina, 
W = Y = SKSU 2 cosasina, 

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 — f r (a), a<£ r (a), and 
a(f>'(a) are negligible. 



X 


2KSsin 2 a, 


x u 
u 


= 22KSsin 2 a, 


x v 
u 


= SKSsinacosa, 


^J= SKS^'sina, 


Y 
U»~ 


SKSsinacosa, 


Y„ 
U 


= 22KSsinacosa, 


Y v 
U 


= SKScos 2 a, 


^j = SKSrcosa, 


N 
IP " 


SKSrsina, 


N u 
U 


= 2SKSsinar, 


N v 
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 =/Kl 2 U 2 dS + 2Uu/Kl 2 dS + Uv/lmKdS + Ur/l(mx - 2ly)KdS 

Y = IP/KmldS + 2Uu/KlmdS + Uv/m 2 KdS + Ur/m(mx - 2ly)KdS 

Z = Uw/n 2 KdS + Up/Kn(ny - mz)dS + Uq/n(2lz - nx)KdS 

L = U\v/Kn(ny - mz)dS + Up/(ny - mz) 2 KdS + 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 X u , Y u , 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 =/z 2 dS. 

L p = KUIcos 2 a, L = - 2KUIcosa sina, 

M p = -KU I sina cosa, M q - 2KUIsin 2 a. 

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, y l( z x 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, 

Z w = - K'TU, Z p = K'TUy,, Z q = - 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} 

M P = - K'U {product of inertia} 

Mq = K'U /moment of inertia with respect to x = o] 

L w = K'TUy, ; M w = - K'TU Xl . 

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. 

M lf M 2 , 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 

L p = K'U{Ty 2 +M 1 }, M p = - K'U{Txy + P} 
L q = - K'U{Txy+P}, M q = K'U{T5c 2 + M 3 } 

and Z W| Z P , Z q , L w , and Mw hold good as in the last paragraph. 
15 



226 SCIENCE PROGRESS 

Asymmetrical Derivatives for Two Transverse Planes 

Let a lf a 2 be the angles of attack, and l u I 2 the moments of 
inertia of the planes respectively. 

Let (I, 2a) be the vector sum of (I„ 2a x ) and (I 2 , 2a 2 ). 

Then Z w = Z y = Z q = L w = M w = 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 

L p - KUIcos'a + KU{Ty» + M, + \{h + L - I)} 

L q =- 2KUIcosasina -KU{Txy+P} 

M p = - KUIcosasina -KU{Txy + P} 

M q = 2KUIsin 3 a + KU{Tx 2 + M 2 + A(h + U- 0} 

[Note that, from page 225, 
L w = KTUy, M w = - KTUx, Z w = -- KTU, Z p = + KTUy, Z q = - KTUx 

are due to the fins.] 

Ii + I 2 — I may be proved to be positive. Prof. Bryan points 
out that M 2 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 Sohncke 2 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. 



2 3 o 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,a 3 ,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) Ca 3 b, (2) Ca 2 b 2 , and 
(3) Ca 2 bc. 

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 Ca 2 , 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 \ ' ,/V N / 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 C 6 H 6 (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 

Ladenburg 1 was the first to draw attention to what he 
thought to be the exceptional character of a configuration like 
this : 

a / x y x 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-, /CH 2 CH 2 \ /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 Everest 1 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. 



2 4 o SCIENCE PROGRESS 

Van't Hoff 1 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,H 5 s. /C fi H 5 

>C : C : C;' 
C 10 H 7 / * - 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 (CH 2 )/ 



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 /(CH 2 ) n x 
NCH,)/ X (CH 2 ) 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 Werner 1 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 : 

H x /CH, CH 2X 

>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^ v d 



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. Jones 1 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 
Na 3 bx 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. 



2 4 8 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 Na 2 bcx, 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 Collie 1 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 Meisenheimer 2 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 Meisenheimer 3 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. 



2 6o 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 . 



2 8o 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 
fragment 1 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 bigger 2 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 



2 9 o 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 I 1 

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 M 1 , 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, M 1 , 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 M 1 with a second motor neurone element M 2 , which 
innervates another muscle that is antagonistic in its action to 
that supplied by M 1 . Stimulation of the sensory nerve in the 
skin may give rise not only to reflex contraction of the muscle 
supplied by M 1 , but also through the association neurone A, to 
relaxation by inhibition of contraction of the muscle supplied 
by M 2 . 

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 

Hi P- 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 



3 oo 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 



3 o2 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 



30 4 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"* *** 
FL ECHSIG'S AS SO CIATION 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 
e gg S — 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 



3 i2 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, 



3 i4 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 



3 i6 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 ' nurture 1 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 's 2 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 Rahlmann 1 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 Mouton 2 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. Ulelah 4 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. 

Gaidukov 2 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, /, r t y, 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 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 i t 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 f t 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. 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. 

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 ; 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 



37 o 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. 



3 8o 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, 34 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 





O 


O 


I 


1 


41-8 


4. Denmark . 


27 





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 








1 





1 


267 


8. Belgium 


7'A 













1 


I3"5 


9. Britain 


45'4 


2 


2 


1 




6 


i3'3 


10. Spain. 


I9"6 








1 




2 


IO'2 


11. Italy . 


347 


1 





1 






8-6 


12. Poland (Russian) 


I2 '5 













1 


8-o 


13. United States . 


92*0 


1 











1 


ri 


14. Russia 


I20 - 6 








1 





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^yNH 2 
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 



3 9 o 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 ADDRESS 1 
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 



4 oo 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 



4 04 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 



4 o6 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 



4 io 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- 



4 i4 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- 



4 i6 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 



4 i8 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 



4 20 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 



4 2 4 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