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BRITISH ASSOCIATION

FOR THE ADVANCEMENT OF SCIENCE

REPORT

of the
EIGHTY - EIGHTH MEETING

CARDIFF-—1920
AUGUST 24—28

LONDON
JOHN MURRAY, ALBEMARLE STREET

OFFICE OF THE ASSOCIATION
BURLINGTON HOUSE, LONDON, W.1

1920

3 ait Ye eee
OQWMITHIM HTHOIM - YEH.

6so1--AMGAAD
SsEs T2EUOUA- =

_ TaaATe s.ARAMSE th

“——

CONTENTS.

PAGE
MIRRORS AND! COUNUI, PO20—2U = GR Ne. is Meets ledivchaes vooulsuven teens iv
OFFICERS OF SECTIONS, CARDIFF, 1920...........0.0. ccc cccceeseeeeseceeeees euneee vi
OFKICERS OF CONFERENCE OF DELEGATES .....c.cc0scccccccscccccescscceceusecs Vii

AnnuaL MEETINGS: PiLacEsS AND DatEs, PRESIDENTS, ATTENDANCES,
Receipts, SUMS PAID’ ON ACCOUNT OF GRANTS FOR SCIENTIFIC

IPEEPOSES: (18d L020 \reeeactenscnch cate deaass siceebocadeieatienessecseecorsasegnes Vili
REPORT OF THE COUNCIL TO THE GENERAL CoMMITTEE (1919-20)......... xii
CreneEan MEETINGS HA CARDIFE 50's) 5 spidecsn cbuicess 0 s0cceaasesictiacssoveceslsteute xvii
PUBLIC, LROTURESMAT CARDIBE 8 oe eee ade ties eceosaseeeass xvii
GENERAL TREASURER’S ACCOUNT (1919-20)...........c..cccsceereecenceceeeensecs xviii
RESEARCH CoMMITTEES' (1920-21) 200... eee llcceeectucebenssaecceasqene XX
RESOLUTIONS AND RECOMMENDATIONS (CARDIFF MEETING) ............0..008 XXVi
CATRDATIUND PSS CUARE, Bee MINES oa van RSS aod Le TO PERE RRA ol XXX
Sep AI CONE RAT, WBE TUNG rer crnicge cb ccbacs sence ape rmarenascaidaane wanes XXxi

ADDRESS BY THE PRESIDENT, Pror. W. A. HeRpMAN, C.B.E., F.R.S.... 1

SECTIONAL PRESIDENTS’ ADDRESSES:

A,—(Pror. A. S. EppINGTon, FIR.S.) soe sdapet edad s cc eeen aes aa ceel CaM 34
[can ap! Ms 3 Hrn' 604 ead Op oc 9 AR Seabee aetna ah 50
lie Helvetia AH MCLs.) scene tveressvaaes. sviaxstarscer recsies 61
D.—(Pror. J. STANLEY GARDINER, WURIS.)..........cccccsesseseeeeeeece 87
HBS Gliey VGA AINE MN On ect as sna nsesenssvesavenenerssaneneeders 98
F.—(Dr. J. H. Cuapnam, C.B.E.).........00+ Rion Sarde ax dake obo du dac bene ae 114
Gi (PRO; ©. B. SENKIN, CBSE) scscascccacagsiress o-0ccercseseucuchocss 125
Et ——(EROK., KARL PEARSON) ES. eae. oo. scc0cess sveniesoneebegeene 135
Meant Ae EA OH UE lel vrs) ales aioe cieitnclne's aalehie's er aleie se nslaivelvc semis asc anied 152
Ke (Miss Hi. Ri. SAUNDERS)\-sas: visaqeasaaaocscocrseeneccecnedudvelwcces 169
(Sik ROBERTI BrAtR poMrAn)s ..5.36 15 Sk Wades ket lash eccsevcnes 191
Rie (Ronen, (We kenbor, ©.B.Bi, BORG). tcc. ecsecntgee anctansias 200
REPORTS ON THE STATE OF SCIENCE, &C.....c.ccccecscscccsceee seseeveceecesceees 215
IERANGACTIONS" OFT THE "SECTIONS wc .w th scuttle dee wereateoas sodeeveedaevarwecniges 351

REFERENCES TO PUBLICATION OF COMMUNICATIONS TO THE SECTIONS ... 380

EVENING DISCOURSES .........cccseceesseeeee EL : IIT t airs, cceeiteterawnsaoneses 384
CORRESPONDING SOCIETIES COMMITTEE...........0.0sesccceecestssscceccescnssecees 391
REE Eire paper eM PEM scat C oly Une ivnniag's a's aussi acecenenspieelne ncaa vss SGM aNecle ne wsigeresine 436
APPENDIX—THIRD REPORT ON COLLOID CHEMISTRY! ........ccccseeeeeeee ees 1-154

1 Printed and published separately by H.M. Stationery Office.

OFFICERS AND COUNCIL, 1920-21.

PATRON.
HIS MAJESTY THE KING,

PRESIDENT.
Professor W. A. HerpMAN, C.B.E., D.Sc., LL.D., F.R.S.

PRESIDENT ELECT.
Sir T. EDWARD THorPE, O.B., D.Sc., Sc.D., LL.D., F.R.S.

VICE-PRESIDENTS FOR THE CARDIFF MEETING.
The Right Hon. the Lorp MAyor or CARDIFF | The Right Hon. Lorp TrepEGAR, D.L.

(Councillor G. F. Forspike, J.P.). E. H. GRIFFITHS, D,Sc., F.R.S.

The Most Noble the Marquis or BUTE. Sir J. Herbert Oory, Bart., M.P.

The Right Hon. the EARL oF PLyMourTH, P.O. | Principal A. H. Trow, D.Sc. (Principal of Uni-
(Lord-Lieutenant of the County of Glamorgan). versity College of S. Wales and Monmouthshire ;

Major-Gen. the Right Hon. LorD TREOWEN, O.B., President, Cardiff Naturalists’ Society).
C.M.G. (Lord-Lieutenant of the County of | J. Dyer Lewis (President, South Wales Institute

Monmouth). of Engineers).
The Right Hon. LorD ABERDARE, D.L. R. O. SANDERSON (President, Oardiff Chamber of
The Right Hon. Lonp PoNTYpRIDD, D.L, Commerce).

VICE-PRESIDENTS ELECT FOR THE EDINBURGH MEETING.
The Right Hon, the LorD Provost OF EDIN- Sir ALFRED EwinG, F.R.S. (Principal of the

BURGH. University of Edinburgh).

The Right Hon. R. Munro, P.O. (H.M. Secretary The Right Hon. Viscount LINLITHGOW,
of State for Scotland). Sir E. SHARPEY SCHAFER, F.R.S.

The Right Hon. Lorp CLYDE (Lord Justice Sir Roperr Usner (Convener of Midlothian
General), County Council).

Sir IsAAc BAYLEY BALFounR, F.R.S.

GENERAL TREASURER.
E, H. Grirrirus, Se.D., D.Sc., LL.D., F.R.S,

GENERAL SECRETARIES.
Professor H. H. TURNER, D.Sc., D.O.L., F.R.S. | Professor J. L. Myris, O.B.E., M.A., F.S.A.

ASSISTANT SECRETARY.
0. J. R. HowartH, O.B.E., M.A., Burlington House, London, W. 1.

ORDINARY MEMBERS OF THE COUNCIL.

ARMSTRONG, Dr. E. F., F.R.S. HADFIELD, Sir R., Bart., F.R.S. | Morris, Sir D., K.0.M.G.
BARCROFT, J., F.R.S. HALL, Sir DANIEL, K.O.B., F.R.S. | Pops, Sir W. J., F.R.S.
Bonk, Professor W. A., F.R.S. | HARMER, Sir S. F., K.B.E., F.R.S. | Rivers, Dr. W. H. R., F.R.S.
Drxey, Dr. F. A., F.R.S. JEANS, J. H., F.R.S. SAUNDERS, Miss E. R.
Dyson, Sir F. W., F.R.S. KEITH, Professor A., F.R.S. Scott, Professor W. R.
Fowl Ler, Professor A., F.R.S. KE TIRE, Sir J. Scorr. STRAHAN, Sir AUBREY, F.R.S.
GARDINER, Professor J. SrANLEY,| KIRKALDY, Professor A. W. WHITAKER, W., F.R.S.

F.R.S. MITCHELL, Dr. P. CHALMERS, WoopwarD, Dr. A. SMITH,
GrReGoRY, Sir R. A. F.RB.S. F.R.S.

LOCAL TREASURER FOR THE MEETING AT EDINBURGH.
Councillor T. B. WHITSON.

LOCAL SECRETARIES FOR THE MEETING AT EDINBURGH.
ANDREW GRIERSON, Town Clerk of EDINBURGH. | Professor J, H, ASHWORTH, F.R.S,

4 io

— Te

OFFICERS AND COUNCIL. Vv

EX-OFFICIO MEMBERS OF THE COUNCIL.

The Trustees, past Presidents of the Association, the President and Vice-Presidents for the year, the

President and Vice-Presidents Elect, past and present General Treasurers and General Secretaries, past

Assistant General Secretaries, and the Local Treasurers and Local Secretaries for the ensuing Annual
Meeting.

TRUSTEES (PERMANENT).

Major P. A. MacManon, D.Sce., LL.D., F.R.S., F.R.A.S. | Sir ARTHUR EVANS, M.A.,LL.D.,F.R.S., F.S.A.
Hon, Sir CHARLES PARSONS, K.C.B., M.A., LL.D., D.Sc., F.R.S.

PAST PRESIDENTS OF THE ASSOCIATION.

Sir A. Geikie, K.0.B.,0.M., F.R.S, |Sir Francis Darwin, F.R.S. | Professor W. Bateson, F.R.S.

Sir James Dewar, F.R.S. Sir J.J. Thomson,O.M., Pres.R.S. Sir Arthur Schuster, F.R.S,

Arthur J. Balfour, O.M., F.R.S. Professor T. G. Bonney, F.R.S, Sir Arthur Evans, F.R.S.

Sir E. Ray Lankester, K.O.B., | Sir E. Sharpey Schafer, F.R.S. |Hon. Sir C. Parsons, K.O.B.,
F.R.S. Sir Oliver Lodge, F.R.8. \ ERS.

PAST GENERAL OFFICERS OF THE ASSOCIATION.

Professor T. G. Bonney, F.R.S. Dr. D. H. Scott, F.R.S. Major P. A, MacMahon, F.R.S.
Sir E. Sharpey Schafer, F.R.S. Dr. J. G@. Garson. Professor W. A. Herdman, C.B.E.,
F.R.S.

HON. AUDITORS.
Sir EDWARD BRABROOK, C.B. l Professor A. BOWLEY,

OFFICERS OF SECTIONS AT THE CARDIFF
MEETING, 1920.

A.—MATHEMATICAL AND PHYSICAL SCIENCE.

President.— Prof. A. 8. Epp1neton, M.Sc., F.R.S.

Vice-Presidents.—_K. H. Grirritus, Se.D., D.Se., LL.D., F.R.S.;
Prof. G. H. Harpy, M.A., F.R.S.; Prof. A. L. Senpy, M.A.

Secretaries —_W. Maxower, M.A., D.Sc. (Recorder); H. R. Hagst;
J. Jackson ; A. O. Ranxrne, D.Se.; *Capt. J. H. SHaxsy, B.Sc.

B,—CHEMISTRY.

President.—C. T. Hrycock, M.A., F.R.S.

Vice- Presidents.—Prof. P. Partiturrs Brepson, D.Sc.; Prof. C. M.
THompson, D.Sc.

Secretaries—Prof. C. H. Dzscu, D.Se., Ph.D. (Recorder); H. F.
Cowarp, D.Se. (Acting); *Prof. E. P. Penman, D.Se.

C.—GEOLOGY.

President.—F. A. BaTuEer, D.Sc., F.R.S.

Vice-Presidents.—J. W. Evans, LL.B., D.Sc., F.R.S.; H. K. Jorpan,
D.Sc.; Principal T. Franxurn Srpry, D.Se.

Secretaries—A. R. DwerrynHouse, T.D., D.Se. (Recorder); W. T.
Gorpon, D.Se.; G. Hickiine, D.Sc.; *Prof. A. HusErt Cox, Ph.D.

D.—ZOOLOGY.

President.—Prof. J. STANLEY GARDINER, M.A., F.R.S.

Vice-Presidents—I’. A. Dixry, M.A., M.D., F.R.S.; Prof. G. Greson ;
Prof. E. S. Goopricu, M.A., F.R.S.; W. Evans Hoyuez, D.Sce.;
CRESSWELL SHBARER, D.Sc., F.R.S.

Secretaries.—Prof. J. H. Asuwortu, D.Sc., F.R.S. (Recorder) ;
F. Batrour Browns, M.A.; R. D. Lauriz, M.A.; *H. Epgar Satmon.

E.—GHOGRAPHY.

President.—J. McFaruang, M.A.

Vice-Presidents.—Rev. W. J. Barton, M.A.; H. O. Becxit, M.A.;
J. Bouton, M.A.; G. G. CutsHotm, M.A.; D. Lururer THomas.

Secretaries.—_R. N. Rupmosse Brown, D.Se. (Recorder); C. B.
Fawcett; *A. E. L. Hupson.

F.—ECONOMICS.

President.—J. H. Cuapuam, C.B.E., Litt.D.

Vice-Presidents.—Sir Hucu Berut,- Bart., C.B., D.L.; Sir E.
Brasrook, C.B.; Prof. A. W. Kirkanpy, M.A., M.Com.

Secretaries—C. R. Fay, M.A. (Recorder); J. Cunntson; Miss L.
GRIER; *Prof. W. J. Roperts, M.A.

* Local Sectional Secretaries.

OFFICERS OF sECTIONS, 1920. vii

G.—ENGINEERING.

President.—Prof. C. F. Jenkin, C.B.E., M.A.

Vice-Presidents.—J. Dyer Lewis; Davip E. Ropers.

Secretaries.—Prof. G. W. O. Howr, D.Se. (Recorder); Prof. F. C.
Lea, D.Se.; Prof. W. H. Watkinson ; *Prof. F. Bacon, M.A.

H.—ANTHROPOLOGY.

President.—Prof. Karu Pearson, M.A., F.R.S.

Vice- Presidents.—Prof. D. Hrrsurn, C.M.G., M.D.; Epwarp Owen,
M.A.; H. J. E. PEAKE.

Secretaries.—E. N. Fauuaizz, B.A. (Recorder); Rey. E. O. JAMES;
F. C. Surupsat, M.D.; *Prof. H. J. Finurs, D.Sc.

I.—PHY SIOLOGY.

President.—J. Barcrort, B.Sc., F.R.S.

Vice-Presidents.—S. Moncxton Copeman, F.R.S; Prof. J. B.
Haycorart, M.D., B.Sc.; T. Lewis, M.D., D.Se., F.R.S.; C. S. Myers,
D.S8e., F.R.S.

Secretaries.—Prof. H. E. Roar, M.D., D.Se. (Recorder); C. L. Burr;
e Lovatr Evans, D.Se.; Prof. P. T. Herrine, M.D.; *T. H. BuRLEND,

pats

K.— BOTANY.

President.—Miss E. R. SAUNDERS.

Vice-Presidents.—Prof. R. CHopat; Sir Danret Morris, K.C.M.G.,
D.Se., D.C.L., LL.D.; Prof. R. W. Paruips; Prof. A. C. SEwarD, D.Sc.,
F.R.S.; Principal A. H. Trow, D.Sc.; Prof. J. Luoyp WILLIAMs.

Secretaries-—Miss E. N. Mites Tuomas, D.Sc. (Recorder); TP. T.
Brooks; W. E. Hitry; *Miss KE. VAcHELL.

L.—EDUCATION.

President.—Sir Ropert Buarr, M.A.

Vice-Presidents.—Principal J. C. Maxwetn Garnett, M.A.; Sir
R. A. Gregory; Miss E. P. Hueues, LL.D.; Sir Naprer Suaw, M.A,,
Se.D., F.R.S.; Herpert M. THompson.

Secretaries.—D. BernipGs, M.A. (Recorder); C. E. Browns, B.Sc.
E. H. Trrep, Ph.D.; *Stanney H. Warxins, M.A., Ph.D.

M.—AGRICULTURE.

President.—Prof. F. W. Krenz, C.B.E., Se.D., F.R.S.

Vice-Presidents.—C. Crowruer, Ph.D.; C. Bryner Jones, C.B.E.

Secretaries—A. Lauprer, D.Sc. (Recorder); C. G. T. Morison ;
H. G. Toornton; *H. ALEXANDER.

CONFERENCE OF DELEGATES OF CORRESPONDING
SOCIETIES.

President.—T. SHrerPparD, M.Sc., F.G.S.
Vice-President.—T. W. SOWERBUTTS.
Secretary.—W. Mark WEBB.

* Local Sectional Secretaries

Vili ATTENDANCES AND RECEIPTS.

Table showing the Attendances and Receipts

. . Old Life | New Life.

Date of Meeting Where held Presidents MentuersulaMembers
1831, Sept. 27...... Viscount Milton, D.O.L., F.R.S. ...... _ _
1832, June 19....., ..| The Rev. W. Buckland, F.R.S. _ _—
1833, June 25...... ..| The Rev. A. Sedgwick, F.R.S. _ _
1834, Sept. 8 ...... ..| Sir T. M. Brisbane, D.O.L., F. R. 3.) _ _
1835, Aug. 10...... ..| The Rev. Provost Lloyd,LL.D., F.R. s. —_ —
1836, Aug. 22....., .| The Marquis of Lansdowne, F.R.S.... — —
1837, Sept. 11...... The Earl of Burlington, F.R.S.......... = 7
1838, Aug. 10...... Newcastle-on-Tyne,..| The Duke of Northumberland, F.RS,) = —
1839, Aug. 26 ...... Birmingham .,,...... The Rey. W. Vernon Harcourt, F.R.S.) = _ |
1840, Sept.17...... ..| The Marquis of Breadalbane, F.R.S. = _
1841, July 20 ...... ..| The Rev. W. Whewell, F.R.S. ......... 169 65
1842, June 23,,, .| The Lord Francis Egerton, F.GS. ... 303 169
1843, Aug. 17.. The Earl of Rosse, F.R.S. ............... 109 28
1844, Sept. 26 ..| The Rev. G. Peacock, D.D., F.RB.S. 226 150
1845, Junel9....., .| Sir John F. W. Herschel, Bart. » FR. 8. 313 36
1846, Sept. 10...... Sir Roderick I. Murchison ‘Bart. sF.R.S. 241 10
1847, June 23 ...... .| Sir Robert H. Inglis, Bart., FERS. 314 18
1848, Aug.9 ...... 3 TheMarquis ofNorthampton, Pres.R.S. 149 3
1849, Sept. 12...... Birmingham .,....... The Rey. T. R. Robinson, D.D., F.R.8. 227 12
1850, July 21 ...... Edinburgh ,.,........ Sir David Brewster, K.H., F. RS....... 235 9
1851, July 2..,,......| Ipswich ..... | G. B. Airy, Astronomer Royal, F.R.S. 172 8
1852, Sept.1 ...... IBOLEASG oii ccsselececsess Lieut.-General Sabine, F.R.S. .., 164 10
1853, Sept.3 Han 3.5 5;, ...| William Hopkins, F.RS.......... 141 13
1854, Sept. 20...... Liverpool ., ...| The Earl of Harrowby, F.R.S. 238 23
1855, Sept. 12......| Glasgow..... ..| The Duke of Argyll, F.R.S. ; 194 33
1856, Aug.6 ......) Cheltenham ..| Prof. 0. G. B. Daubeny, M.D., F.R.S.... 182 14
1857, Aug. 26 .| Dublin .. ..| The Rey. H. Lloyd, D.D., F.R.S. 236 15
1858, Sept. 22...... Leeds ........ ..| Richard Owen, M.D., D. 0. Ea, FBS... 222 42
1859, Sept.14...... Aberdeen ., ..| H.R.H. The Prince Consort maanenannaa 184 27
1860, June 27 ...... Oxford ..... ..| The Lord Wrottesley, M.A., F.R.S. . 286 21
1861, Sept.4 0... Manchester . ..| William Fairbairn, LL.D., F.B.S....... 321 113
1862, Oct.1 ...... Cambridge ............ The Rey. Professor Willis,M.A.,F.R.S. 239 15
1863, Aug. 26...... Newcastle-on-Tyne...| SirWilliam G. Armstrong,O.B., F.R.S. 203 36
1864, Sept.13...... Bath 4. ccd fe die cased Sir Oharles Lyell, Bart., M.A., F.R.S. 287 40
1865, Sepr6 oe: Birmingham., ..| Prof, J. Phillips, M.A., LL.D. a "ERS. 292 44
1866, Aug. 22"... Nottingham, ":| William R. Grove, Q.0., F.R.S 207 31
1867, Sept.4 ...... Dundee ...,..... ..| The Duke of Buccleuch, K.0.B 167 25
1868, Aug. 19 Norwich Dr. Joseph D. Hooker, BRS. was 196 18
1869, Aug. 18 Exeter . .| Prof. G. G. Stokes, D. 0. L., F.R.S....... 204 21
1870, Sept. 14,.,...) Liverpool .. ..| Prof. T. H. Huxley, LL. D. ERS. ... 314 39
A871, Aug. 2) 5.) Edinbur gh Ey .| Prof. Sir W. Thomson, LL. D. ay ERS s. 246 28
1872, Aug.14...... Brighton ..... ..| Dr. W. B. Carpenter, F.R.S. 245 36
1873, Sept.17...... Bradford ., ..| Prof. A. W. Williamson, F.R.S. 212 27
1874, Aug. 19 |... Belfast ... ""| Prof. J. Tyndall, LL.D., F.R. 162 13
1875, Aug. 25...... Bristol .., .| Sir John Hawkshaw, FRS. 239 36
1876, Sepi.6 0.0... Glasgow ., .| Prof. T. Andrews, M.D., F.R.S. 221 35
1877, Aug. 15...... Plymouth .. :| Prof. A. Thomson, M.D., F.R. 173 19
1878, Aug. 14...... Dublin ., 224) Rs FEA ee M.A., 201 18
1879, Aug. 20.,,.... Sheffield. .| Prof. G. J. Allman, M.D., F.R. 184 16
1880, Aug. 25 ...... Swansea... ainenc| une Cle Ramsay, LL.D., F.R. 144 ll
1881, Aug. 31 ...... SE QER 5 iteas .| Sir John Lubbock, Ba Pay 272 28
1882, Aug. 23 ......) Southampton Dr. O. W. Siemens, F.R 178 17
1883, Sept. 19 Southport .| Prof. A. Cayley, D.O.L., 203 60
1884, Aug. 27......) Montreal .. .| Prof. Lord Rayleigh, F. 235 20
1885, Sept.9 ...... Aberdeen .....,..,......| Sir Lyon Playfair, K.O. 225 18
1886, Sept.1 ....., Birmingham ,, .| Sir J. W. Dawson, O.M. 314 25
1887, Aug. 31...... Manchester ..... ‘| Sir H. E. Roscoe, D.O.L., rhe 428 86
1888, Sept.5\.i2.| Bath ....0 cctv cca Sir F. J. Bramwell, F.R.S. ......... 266 36
1889, Sept. 11 ......) Newcastle-on-Tyne...| Prof. W. H. Flower, O.B., F.R.S. 277 20
1890, Sept. 3 1", MGGOUN 57.55. .stetecsotees Sir F. A. Abel, O.B., F.R.S. 259 21
1891, Aug.19.,,,...| Oardiff ...., ‘| Dr. W. Huggins, F.R.S. 189 24
1892, Aug.3 ...... Edinburgh .,. .| Sir A. Geikie, LL.D., F. R. iS: 280 14
1893, Sept. 13,,.... Nottingham... ....| Prof. J. 8. Burdon Sanderson, F.R.S. 201 17
1894, Aug. 8 .| The Marquis of Salisbury,K. G. .F.R.S. 327 21
1895, Sept. 11 .| Sir Douglas Galton, K.C.B., BR. Ss. 214 13
1895, Sept.16 ...... .| Sir Joseph Lister, Bart., Pres. Riso 330 31
1897, Aug. 18, .| Sir John Evans, K.C.B., F.R.S. ......... 120 8
1898, Sept.7 , ...| Sir W. Orookes, F.R.S. ............. ss 281 19
1899, Sept. 13 .| Sir Michael Foster, K.C.B., Sec.R.S.... 296 20
1900, Sept. 5 ...... | Bradford’ 768.0482 Sir William Turner, D.O. Ly F.R. 3. 267 13

Ladies were not admitted by purchased tickets until 1843. + Tickets of Admission to Sections only.
[Continued on p. x.

ATTENDANCES AND RECEIPTS. 1X

at Annual Meetings of the Association.

j | Sums paid

Old New hes enone on account
Annual | Annual mites Ladies |Foreigners| Total anvine the of Grants Year

Members | Members M fore for Scientific

8 Purposes
— — — — — 353 _— — 1831
— _— _ _ _ _ _ _ 1832
_ —_— _ => —_ 900 —_ _ 1833
—_ _ _ _ _ 1298 _ £20 0 0 1834
—_ _— _— _ — —_ —_ 167 0 0 1835
—_ = _ — _ 1350 _— 435 0 0 1836
_ — — — — 1840 | — 922 12 6 1837
25 = = 1100* = 2400 | — 932 2 2| 1838
= — _— — 34 1438 _ 1595 11 0 1839
_ — —_ —_ 40 1353 _— 1546 16 4 1840
46 317 _— 60* — 891 = 1235 10 11 1841
75 376 33t 331* 28 1315 = 144917 8 1842
71 185 = 160 — — — 1565 10 2 1843
45 190 9 260 _— — _ 98112 8 1844
94 22 407 172 35 1079 =— 831.9 °9 1845
65 39 270 196 36 857 _ 685 16 0 1846
197 40 495 203 53 1320 — 208 5 4 1847
54 25 376 197 15 819 £707 0 0 275 1 8 1848
93 33 447 237 22 1071 963 0 0} 15919 6 1849
128 42 510 273 44 1241 1685 0 0| 34518 0 1850
61 47 244 141 37 710 620 0 0 391 9 7 1851
63 60 510 292 9 1108 1085 0 0| 304 6 7 1852
56 57 367 236 6 876 903 0 0} 205 0 0 1853
121 121 765 524 10 1802 1882 0 0} 38019 7 1854
142 101 1094 543 26 2133 2311 0 0} 48016 4 1855
104 48 412 346 9 1115 1098 0 0 73413 9 1856
156 120 900 569 26 2022 2015 0 0} 50715 4 1857
111 91 710 509 13 1698 19231 0 0} 61818 2 1858
125 179 1206 821 22 2564 2782 0 0 68411 1 1859
177 59 636 463 47 1689 1604 0 0 76619 6 1860
184 125 1589 791 15 3138 3944 0 0/1111 510 1861
150 57 433 242 25 1161 1089 0 0| 129316 6 1862
154 209 1704 1004 25 3335 3640 0 0/| 1608 3 10 1863
182 103 1119 1058 13 2802 2965 0 0/| 128915 8 1864
215 149 766 508 23 1997 2227 0 0| 1591 7 10 1865
218 105 960 771 11 2303 2469 0 0/175013 4 1866
193 118 1163 771 7 2444 2613 0 0) 1739 4 0 1867
226 117 720 682 45t 2004 2042 0 0} 1940 0 0 1868
229 107 678 600 17 1856 1931 0 0/| 1622 0 0 1869
303 195 1103 910 14 2878 3096 0 0/1572 0 0 1870
311 127 976 754 21 2463 2575 0 0| 1472 2 6 1871
280 80 937 912 43 2533 2649 0 0/| 1285 0 0 1872
237 99 796 601 11 1983 2120 0 0/| 168 0 0 1873
232 85 817 630 12 1951 1979 0 0| 115116 0 1874
307 93 884 672 17 2248 2397 0 0] 960 0 0 1875
331 185 1265 712 25 2774 3023 0 0| 1092 4 2 1876
238 59 446 283 11 1229 1268 0 0/1128 9 7 1877
290 93 1285 674 17 2578 2615 0 0} 72516 6 1878
239 74 529 349 13 1404 1425 0 0O| 1080 11 11 1879
] 171 41 389 147 12 915 899 0 O| 731 7 7 1880
313 176 1230 514 24 2557 2689 0 0| 476 8 1 1881
253 79 516 189 21 1253 1286 0 0] 1126 111 1882
: 330 323 952 84 5 2714 3369 0 0/| 1083 3 3 1883
j 317 219 826 74 |26&60H.§) 1777 1855 0 0| 1173 4 0 1884
332 122 1053 447 6 2203 2256 0 0| 1385 0 O 1885
| 428 179 1067 429 11 2453 2532 0 0} 995 0 6 1886
510 244 1985 493 92 3838 4336 0 0| 118618 0 1887
399 100 639 509 12 1984 2107 0 0/1511 0 5 1888
412 113 1024 579 21 2437 2441 0 0/1417 O11 1889
368 92 680 334 12 1775 1776 0 0O| 78916 8 1890
341 152 672 107 35 1497 1664 0 0} 102910 0 1891
413 141 733 439 50 2070 2007 0 0 864 10 0 1892
328 57 773 268 17 1661 1653 0 0 907 15 6 1893
435 69 941 451 77 2321 2175 0 0 683 15 6 1894
290 31 493 261 22 1324 1236 0 0 977 15 5 1895
383 139 1384 873 41 3181 3228 0 0| 1104 6 1 1896
286 125 682 100 41 1362 1398 0 0/ 105910 8 1897
327 96 1051 639 33 2446 2399 0 0| 1212 0 0 1898
324 68 548 120 27 1403 1328 0 0O| 1430 14 2 1899
297 45 801 482 9 1915 1801 0 0] 107210 0 1900

_t Including Ladies. § Fellows ofthe American Association were admitted as Hon. Members for this Meeting.

[Continued on p. xi.

xX ATTENDANCES AND RECEIPTS.

Table showing the Attendances and Receipts

| 3901, Sept. ul. Glasgow .| Prof. A. W. Riicker, D.Sc., Sec.R.S. ... 310 37
| 1902; Sept. 10......| Belfast .| Prof. J. Dewar, LL.D., F.R.S. ......... 243 21
1903, Sept. 9 ......) Southport ...| Sir Norman Lockyer, K.C.B., F.R.S. 250 | 21
1904, Aug. 17..,...| Oambridge......... ...| Rt. Hon, A. J. Balfour, M.P., F.R.S. 419 32
1905, Aug. 15...... South Africa ..,......| Prof.@.H. Darwin, LL.D.,F.R.S. ... 115 40
1906, Ang.1 1.00] York os... ...| Prof. E, Ray Lankester, LL.D., F.R.S. 322 10
1907, July 31...... Leicester . ...| Sir David Gill, K.0.B., F.R.S. 0.0.0... 276 19
1908, Sept. 2 ...,..} Dublin .., .! Dr. Francis Darwin, F. R.S. as 294 | 24
1909, Aug. 25,,,...) Winnipeg . ...| Prof, Sir J. J. Thomson, F.R.S. ...... Ls Sh eS
1910, Aug. 31 ...... Sheffield... ...| Rev. Prof, T. G. Bonney, F.R.S. 293 26
1911, Aug. 30...... Portsmouth , ...| Prof. Sir W. Ramsay, K.C.B. 284 21
1912, Sept. 4 .,,...| Dundee ......... Prof, E. A. Schifer, F.R.S........ cece 288 14
1913, Sept. 10 ...... Ee enenem ° .| Sir Oliver J. Lodge, F.R.S sd 376 40
1914, af aly-Sept... Australia .... Prof. W. Bateson, F.R.S. 172 13
1915, Sept. 7 ..,...) Manchester .. ........ Prof, A. Schuster, F.R.S. ..... 5! 242 19
| 1916, Sept.5 ...... Newcastle-on-Tyne... 164 12
1917 (No Meeting) i Sir Arthur Evans, F.R.S. ... ..... = 2
1918 (No Meeting) .........) ai a
1919, Sept.9 ..,... Bournemouth | Hon, Sir O. Parsons, K.O.B., F.R.S..., 235 47
1920, Aug. 24..,... PALO at ve canew css sanens | Prof. W. A. Herdman, C.B.E., F.R.S. 288 11

| |

q Including 848 Members of the South African Association.
tt Grants from the Caird Fund are not included in this and subsequent sums.

ATTENDANCES AND RECEIPTS. Xl

at Annual Meetings of the Association—(continued).

{ / Sums paid
Old New Neaoe pe on account
Annual = Annual cates Ladies Foreigners) Total |a ring the of Grants Year
Members Members i | Meetin for Scientific
H | 1n8 | Purposes
| 374 131 794 246 20 1912 £2046 0 |£920 9 11 1901 |
314 86 647 305 6 1620 1644 0 | 947 0 O 1902 |
319 90 688 365 21 1754 | 1762 0 | 84513 2 1903 |
449 113 1338. a7 3) ) 121 2789 2650 0 | 887 18 11 1904 |
9377 | 411 430 181 | 16 2130 2492 0 | 928 2 2 1905
356 | 93 817 352 22 1972 1811 0 | 882 0 9 1906
339 / 61 659 951 | - 42 1647 1561 0 | 757 12 10 1907 |
465 | 112 1166 222 | 14: 2297 2317 0 |1157.18 8 1908 |
290¢* =| 162 789 90)24} 7 1468 1623 0 |1014 9 9 1909.. |
379 | 57 563 123) | 8 1449 | 1439 0 | 96317 0 1910
J 349 61 414 81 | 31 1241 1176 0 | 922 0 0 1911 |
368 | 95 1292 359 88 | 2504 | 2349 0 | 845 7 6 1912
480 | 149 1287 291 20 2643 «©2756 0 | 97817 1ft 1913
139 41605 539 || _— 21 | 6044|| 4873 0 |1086 16 4 1914 |
| 287 116 §28* 141 | 8 | 1441 | 1406 0 1159 8 1915
250 76 251* (cecal _— | 826 821 0 | 715 18 10 1916
| — = a = —wiihvateedos a 42717 2 1917
_ _ _— — _ — | —_ 220 13 3 1918
254 102 688 * 153 | 3 1482 | 1736 0 | 160 uv O 1919
| |
; Annual Members |
_ Ola inde
Anpaal Tee liesce Students’ |
aid eeeing | Meeting | Tiekets | Tekets | | | |
\ Report ; only |
138 192 | atl. | 49 ed ee a | 1272 10 | 959 13 9 1920
|

** Including 137 Members of the American Association,
|| Special arrangements were made for Members and Associates joining locally in Australia, see
Report, 1914, p.686. The numbers include 80 Members who joined in order to attend the Meeting of
L’ Association Francaise at Le Havre.
* * Including Students’ Tickets, 10s.

REPORT OF THE COUNCIL, 1919-20.

I. Sir T. E. Thorpe, C.B., has been unanimously nominated
by the Council to fill the office of President of the Association for the
year 1921-22 (Edinburgh Meeting).

II. Resolutions referred by the General Committee, at the Bourne-
mouth Meeting, for consideration, and, if desirable, for action, were
dealt with as follows :—

(a) The Council adopted a resolution from Section D, that in the
case of persons applying for membership of the General Committee
who are not known to the Council, the matter should be referred to
the Organising Committee of the Section concerned.

(b) The Council collaborated with the Conjoint Board of Scientific
Societies in laying before the Prime Minister, H.M. Secretaries of
State for the Colonies and for India, and the Governments of the
Australian Commonwealth and the Union of South Africa, proposals
for the collection and publication of scientific data relating to ex-German
colonies (Resolutions of Sections E and H).

approval of the proposal to establish a British Institute of Archeology
in Egypt. (Resolution of Section H.)

(d) The Council forwarded to the Board of Agriculture a represen-
tation on the desirability of securing the uniform description and nomen-
clature of ancient remains on Ordnance Survey Maps, and after
correspondence with the Director-General of the Ordnance Survey have
learnt that measures have been taken to this end. (Resolution of
Section H.)

(e) The Council referred back to the Committee of Section I a
proposal that that Section should be entitled ‘ Physiology and
Psychology,’ and that the Presidents in alternate years should represent
the two branches of the Section.

(f) The Council, after enquiry, felt unable to take action recom-
mended by the Conference of Delegates in the matter of a representa-
tion to H.M. Government on the use of taxes derived from motor-spirit
and carriages for the improvement of roads.

———w

REPORT OF THE COUNCIL, 1919-20. Xlil

(g) A proposal from the Conference of Delegates, that the Board
of Education should be asked to hold an enquiry on the teaching of
geography, was referred to Section E.

(h) The General Officers, on the instruction of the General Com-
mittee, forwarded resolutions urging upon H.M. Government the
necessity for supporting an organised scheme of scientific research to

_ the Prime Minister, the Chancellor of the Exchequer, the First Lord of
the Admiralty, the Secretary of State for War, the President of the

Board of Trade, the Food Controller, and the Minister of Health.

The Council have received from the Admiralty and from the War
Office information on proposals for research. At the invitation of the
Master-General of the Ordnance, the General Officers attended a Con-

_ ference at the War Office, at which the Master-General, Lieut.-General
Sir J. P. Du Cane, the Quarfermaster-General, Lieut.-General Sir T. E.

Clarke, and the Director of Medical Services, Lieut.-General Sir T.

- Goodwin, explained the organisation which has been adopted for scien-
- tific research in connection with military services.

teenie i tilt tinal

III. The Council nominated as their representatives on the Joint
Committee of the General Committee and Council on Grants, under
the chairmanship of the President (Sir C. Parsons), Profs. W. A.
Herdman, J. Perry, H. H. Turner, and J. L. Myres. This Committee
was directed to report to the General Committee as well as to the
Council, and its report, which the Council has approved, is appended:

The Committee would favour the following procedure: That Re-

_ search Committees proposed by the Sectional Committees of the British ~

Association and approved by the Committee of Recommendations be
recommended by the Council for support by the Department of Scien-
tific and Industrial Research, the Medical Research Board, or other

_ bodies entrusted with the distribution of public funds, and that all Com-

mittees, the work of which may be aided by such bodies, remain
Committees of the Association responsible as before to the Sectional
Committees.

IV. The Council resumed consideration (deferred owing to the War)
of certain resolutions referréd to them by the General Committee
in Australia in 1914. e

(2) The Council forwarded to the Australian Government a resolu-
tion urging the need for legalising in Australia the metric system of
weights and measures as an alternative (optional) system. (Resolution
of Section A.)

_ (0) The Council found it inexpedient to forward a resolution propos-
ing a gravity survey in Australia. (Resolution of Section C.)

X1V REPORT OF THE COUNCIL, 1919-20.

(c) The Council forwarded to the Australian Government a resolu-
tion urging the early production of the Australian sheets of the Carte
du Monde au Millioniéme. (Resolution of Section E.)

(d). The Council has still under consideration the proposal for the
establishment of Bench-marks on Coral Islands, in the. Pacific.
(Resolutions of Sections C and E.)

V. The Department of Scientific and Industrial Research made a
grant of £600 to the Association to meet the cost of certain specified
researches for which Committees were appointed at the Sear
Meeting.

VI. The Research Fund initiated at Bournemouth now amounts to
£1,888 16s. 6d.

VII. Carrp Funp.—The Council made the following grants during
the year, additional to annual grants previously made :—

Fuel Economy Committee (additional to grant made by

General Committee at Bournemouth) ie =< tod
Committee on Training in Citizenship ; ‘ 10
Geophysical Committee of Royal Astronomical Society 10
Conjoint Board of Scientific Societies... he aif 10

VIII. CoNFERENCE oF DELEGATES and CoRRESPONDING SOCIETIES
CoMMITTEE :—

The following Nominations are made by the Council :—

Conference of Delegates.—Mr. T. Sheppard (President), Mr. T. W.
Sowerbutts (Vice-President), Mr. W. Mark Webb (Secretary).

Corresponding Societies Commiltee.—Mr. W. Whitaker (Chair-
man), Mr. W. Mark Webb (Secretary), Mr. P. J. Ashton, Dr. F. A.
Bather, Rev. J. O. Bevan, Sir Edward Brabrook, Sir H. G. Fordham,
Mr. A. L. Lewis, Mr. T. Sheppard, Rev. T. R. Stebbing, Mr. Mark
L. Sykes, and the President and General Officers of the Association.

On the proposal of a sub-committee of the Corresponding Societies
Committee the Council, in the interests of economy, propose that the
bibliography of scientific publications in the transactions of Correspond-
ing Societies be not printed in future ir the Annual Report, and there-
fore recommend the following change in the Rules :—

Rule Chap, XI., 3 (u.):—

*“There shall be inserted in the Annual Report of the Association
a list of the papers published by the Corresponding Societies . . .”’
to read as follows :—

“A list. shall be prepared of the papers published by the Corre-
sponding Societies.

REPORT OF THE COUNCIL, 1919-20. XV

IX. The Council have received reports from the General Treasurer
during the past year. His accounts have been audited and are presented
to the General Committee.

The Hon. Sir Charles Parsons has been nominated a Trustee of the
Association, in the room of the late Lord Rayleigh.

X. Power having been delegated to the Council by the General
Committee to appoint ordinary members of Council to the vacancies
caused by the resignation of Sir E. F. im Thurn and the appointment of
Prof. J. lL. Myres as General Secretary, Sir R. Hadfield and Sir J.

Scott Keltie were appointed.

The retiring members of the Council are :—
By seniority.—Sir Dugald Clerk, Prof. A. Dendy.

By least attendance.—Prof. W. H. Perkin, Dr. E. J. Russell, Prof.
E. H. Starling.
The Council nominated the following members :—

Mr. J. Barcroft,
Prof. J. Stanley Gardiner,
Sir W. J. Pope,

leaving two vacancies to be filled by the General Committee without
nomination by the Council.
The full list of nominations of ordinary members is as follows :—

Dr. E. F. Armstrong. Prof. A. Keith.
Mr. J. Barcroft. Sir J. Scott Keltie.

Prof. W. A. Bone.

‘Dr, F. A. Dixey.

Sir F. W. Dyson.

Prof, A. Fowler.

Prof. J. Stanley Gardiner.
Sir R. A. Gregory.

Dr. E. H. Griffiths.

Sir R. Hadfield.

Sir S. F. Harmer.

Prof. J. H. Jeans.

Prof. A. W. Kirkaldy.
Sir Daniel Morris.

Sir W. J. Pope.

Dr. W. H. R. Rivers.
Miss E. R. Saunders.
Prof. W. R. Scott.

Sir A. Strahan.

Mr. W. Whitaker.

Dr. A. Smith Woodward.

XI. Tue Genera Secretartes have been nominated by the Council

as follows :—

Prof. H. H. Turner.
Prof, J. L. Myres.

XII. The Genera] Treasurer and one or other of the General Secre-
taries have been appointed representatives of the Association on the
Conjoint Board of Scientific Societies.

XIII. Prof. H. A. Lorentz has been appointed an Honorary Corre-
sponding Member of the Association.

Xvi REPORT OF THE COUNCIL, 1919-20.

XIV. The following have been admitted as members of the General

Committee :—

Mr. W. B. Brierley.
Dr. F. D. Chattaway.
Mr. W. N. Cheesman.
Miss M. C. Crosfield.
Miss A. C. Davies.
Prof. J. E. Duerden.
Prof. A. J. Ewart.
Mr. C. B. Fawcett.
Dr. A. Holmes.

Prof. F. Horton.

Mr. A. Pearse Jenkin.
Prof. W. Neilson Jones.

Prof. A. A. Lawson.
Prof. J. W. MacBain.
Dr. R. MacDowall.
Dr. J. 8. Owens.

Mr. H. J. E. Peake.
Dr. Mabel C. Rayner.
Prof. E. W. Skeats.
Mr. C. E. Stromeyer.
Dr. W. M. Tattersall.
Mr. Edwin Thompson.
Lieut.-Col. Marett Tims.

XV. A Meeting of Recorders and Local Sectional Secretaries for the

Cardiff Meeting, together with the General Secretaries and Dr. W. E.
Hoyle, Local Secretary, was held in New College, Oxford, on April 10-
12,1920. Though of an informal character, it was fruitful in discussion
of arrangements at Cardiff and of other details in the working of the
Association, and the Council hope that such a meeting may become ap
annual institution.

XVI. The Council received from the General Secretaries a detailed
memorandum on the increased cost of printing, showing that the Asso-
ciation could not hope to maintain printing at the level maintained before
the war. The Council have put into force a number of alterations in the
practice of the Association in this connection, and hope that the General
Committee, after experience, will approve fhem. Taken together, it is
hoped that they will save the Association over £600 a year.

XVII. Finally, the Council record with deep regret the death of
Mr. H. C. Stewardson, on May 1, 1920, after a short illness. His
devoted service to the Association began in 1873, and being in his
eightieth year he had intended to retire at the close of the financial
year 1919-20.

The Council have instructed the Assistant Secretiary to carry on
the financial duties undertaken by Mr. Stewardson as Assistant
Treasurer.

ADDENDUM.

A verbal addition was made to the above report, when it was pre-
sented to the General Committee, expressing the profound regret of
the Council at the death of Prof. J. Perry, General Treasurer, which
took place on August 4, 1920.*

The Council, at the same time, recorded their regret at the death
of Sir Norman Lockyer, President of the Association in 1903.

* The General Committee, after receiving this report and expressing
concurrence with the sentiments of the Council, delegated to the Council the
appointment of a General Treasurer for the year 1920-21, and appointed Prof.
H. H. Turner as Acting Treasurer in the meantime.

The Council, at its meeting on November 5, 1920, elected Dr. E. H.
er Sc.D., D.Sc., LL.D., F.R.S., to be General Treasurer for the year

GENERAL MEETINGS AT CARDIFF. XVii

GENERAL MEETINGS AT CARDIFF.

On Tuesday, August 24, at 8 p.m., in the Park Hall, the Hon. Sir
Charles Parsons, K.C.B., F.R.S., resigned the office of President to
Prof. W. A. Herdman, C.B.E., F.R.S. (See p. xxxi.)

Prof. W. A. Herdman then assumed the chair and delivered an
address, for which see p. 1.

On Wednesday, August 25, at 8 p.m., a Reception was given in the
City Hall by the Right Hon. the Lord Mayor of Cardiff.

On Thursday, August 26, at 5 p.m., a Conference took place in the
Assembly Hall, Technica] College, on Science Applied to Public Ser-
vices, arising out of communications which had passed between the
Association and Government Departments as the result of resolutions
adopted by the General Committee at the Bournemouth Meeting (see
Report, 1919, pp. Ixxiii-iv). The Conference was addressed by Mr.
F. E. Smith, O.B.E., Director of Scientific Research, Admiralty, and
others.

On Thursday, August 26, at 8 p.m., in the Park Hall, Sir R. T.
Glazebrook, K.C.B., F.R.S., delivered a discourse on ‘ Some Require-
ments of Modern Aircraft.’ (See p. 384.)

On Friday, August 27, at 8 p.m., the concluding General Meeting
was held in the Park Hall.

Sir Daniel Hall, K.C.B., F.R.S., delivered a discourse on ‘ A
Grain of Wheat from the Field to the Table.’ (See p. 389.)

After the above discourse the following resolution was unanimously
adopted on the motion of the President :— ;

That the cordial thanks of the British Association be extended to the Rt.
Hon, the Lord Mayor and Corporation and the citizens of the city of Cardiff
for their hearty welcome and for the facilities so generously afforded to the
Association at the City Hall; to the Governing Bodies of the University of

_ Wales, the University College of South Wales and Monmouthshire, the Tech-

nical College, the South Wales Institute of Engineers, and other institutions
which have kindly placed their buildings and resources at the disposal ot the
Association ; and, finally, to the Local Executive Committee, the Loca] Treasurers
and Secretaries for their exertions in collecting the necessary funds and for
the hospitality which has been freely offered to many members of the Associa-
tion, as well as for the admirable arrangements made for the eighty-eighth
annual meeting of the Association.

PUBLIC OR CITIZENS’ LECTURES.

The following public lectures were given in the Park Hall at 8 P.M.
on the days stated :—
August 23, Prof. J. Lloyd Williams on ‘ Light and Life.’
August 25, Prof. A. W. Kirkaldy on ‘ Present Industrial Conditions.’
August 28, Dr. Vaughan Cornish on ‘The Geographical Position
f the British Empire,’

XVlli GENERAL TREASURER’S ACCOUNT.

Dr. THE GENERAL TREASURER IN ACCOUNT
ADVANCEMENT OF SCIENCE,

RECEIPTS.
See ey ote ie, pees ne
To Balance brought forward :—
Lloyds Bank, Birmingham ..............++8 Bebey conus voasasaskenasnaie Sesaa 1,728 17 3
Bank of England—Western Branch :—
On ‘ Caird Fund’ ............6 deciapacsamenscoconcesccuccaccevocenial v. 50819 8
y General ACCOUN,,.......seessseeceeeeees Bence EE Perecee ERC iccc0 wage 4 12
———_ 681 310
Cash in hand ......... ety SS Miseaaegsbaaeauevasghoccesaiiesesteee 0 1i1
2,410 3 0
Less Petty Oash overdrawn.,,,..,........++ peetecessretysteechntowe more 25 2
; ———_ 2,407 17 10
Life Compositions (including Transfers) ..,............ Neh cnes ety hesaeuginexhaannnet 734 0 0
Annual Subscriptions . fh 707 0 0
New Annual Members 216 0 0
Sale of Associates’ Tickets . eons x 645 10 0
Sale of Ladies’ Tickets.....,..........+ (eee oats a) 152 0 0
Life Members (old) Additional Subscriptions ..,.......scscccsssersecsrcereesseees 446 13 0
Donations for Research :—
C.Read,.2...6...-.,500 PR « 35 aenkbaah aarceseadahs stones sussh tena soapegens Neem 010 0
Rev. F. Smith, hice 2 2 0
Sir Hugh Bell............. vee, LOCHORO
Sir Richard Robinson . ‘ 25 0 0
Sir Robert Hadfield .... 250 0 0
Sir Charles Parsons ,,.. v. 1,000 0 0
Sir Alfred Yarrow, . 500 0 0
Sir C. Bright .......... De cue cede deer eet ee eerate a 110
Scientific and Indust: Research Depar 600 0 0
Scientific Research Association ......., snadabbbse de : 1013 6
—— 2,489 6 6
Sale of Publications ..,.........+ Ronstcnceaerntepud’eanssSanncca en Se: nadeaee an srgtir Oo 224 11 10
Interest on Deposits :—
Lloyds Bank, Birmingham ...............+« aeveesebatace aps abatycemunreses wastaadaced 17 20
ue ¥ ‘Oaird Gift’,....... ie 36 5 1
London County Westminster and Parr’s Bank............-..+ 36 3 9
8911 9
Unexpended Balances of Grants returned ...,....ssccceeerseeee Ghiksapt tee depenauees 5119 3
” » Emir UM eee tera gs cnasptanesadaays seers ceak eactiacur cae OU Ont
101 19 3
Dividends on Investments :—
Consols 24 per Cent. .., 81 8 0
India 3 per Cent. ........... ei 75 12.0
Great Indian Peninsula Railway A FF fe ae
War Stock 5 per Cent. .....ci.cccesseteeesesceeeeee se 43 3 0
War Bonds 5 per Oent. ..,.... bitgdhesmeb thaeeeened BT ORE RE arte PI aupuddvesundveee 49 0 0
——_ 272 10 2
Dividends on ‘Caird Fund’ Investments :—
India 34 per Cent. ..... PRTG | AUELIE, ectertccvecssauthsocvescctcosestsoten Aen 64 7 4
Oanada 34 per Cent, (including extra 4 per Cent.) ...........ssecceseeeeeees 70 0 0
London and South-Western Railway Consolidated4 per Oent. Preference
TOO ot eens treet enn er'e tine pee viva tee as tapemanmnnepiaxs resp vaucenksosnceos= 9s eeceaye ater 70 0 0
Londonand North-Western Railway Consolidated 4 per Oent. Preference
Stock 4.5... igloos sbdeetuitbar ca dueneeaes vehetaeeed dan ach Caduchbdddabivesspdaabeos i 58 16 0
——— 263 3 4
Investments.
£ s. ad.
4,651 10 5 Consolidated 24 per Oent. Stock
3,600 0 O India 3 per Cent. Stock
879 14 9 Great Indian Peninsula Railway £43 ‘B’ Annuity
2,627 010 India 3} per Cent. Stock, ‘ Oaird Fund’
2,100 0 0 London and North-Western Railway Consolidated 4 per Cent.
Preference Stock, ‘Caird Fund’
2,500 0 O Oanada 3} per Cent. (1930-50) Registered Stock ‘Caird Fund :
2,500 0 0 London and South-Western Railway Consolidated 4 per Cent.
Preference Stock, ‘Oaird Fund’
100 19 3 Sir Frederick Bramwell’s Gift of 2} per Cent. Self-Oumulating
Consolidated Stock
863 210 War Loan 5 per Cent. Stock
1,400 0 O War Loan 5 per Cent., 1929-47
1,000 0 0 Lloyds Bank, Birmingham—Deposit Account, Sir J. Caird’s Gift
for Radio-Activity Investigation, included in Balance at Bank
£22,222 8 1 £8,750 3 8
—

Value at 30th June, 1920, £13,416 8s, 1d,

O_O OL <<<

GENERAL TREASURER’S ACCOUNT. X1x

WITH THE BRITISH ASSOCIATION FOR THE Cr.
July 1, 1919, to June 30, 1920.
PAYMENTS.
S, 4. d.
By Rent and Office Expenses ...........cccccccceeeeee Recetcccedtessetevesadtcers *OS3 RON MELEE Lea ee . 29214 8
Salaries and Travelling Expenses,, ee 7 f7
Printing, Binding, etc.................ccceeceeeeeeees Peneaestrarteg eaten ertncachinceeretentiteieveieieti ets 859 15 3
Grants to Research Oommittees :— Sls
Liverpool Tidal Institute ............. SigarsavsccenisphadeesHapisses dbwendiee -. 150 0
Bronze Implements Committee .., SP 1LO® 0
Mathematical Tables .....,...... 30 0
Geology of Coal Seams .,,.............4. mig
Free Places in Secondary Education 10
Stress Distribution ...............ssseescecees 80
Effects of War on Credit . nee 100
Replacement of Men by Women......... 30
Breeding Experiments on @nothera, & Pane
Radiotelegraph Investigations,,,......... ... 100

Palaeolithic Site in Jersey...
Rude Stone Monuments
Annual Tables of Constants,
Museums Committee ..........

Railway Committee... 5
Heredity Committee ..........

Palaeozoic Rocks Oommittee . 30
Committee on Lepidoptera ,...... 50
Absorption Spectra Committee ...... 10

International Language Committee
Charts and Pictures Committee .
Kiltorcan Rocks Committee.,,. i
Zoological Bibliography....... aed
Seismological Committee . nf

essscooscososesooscoeSecooSoOCoCooOR

ee
i—)
oeoocococecoococoococooscooocoso

Stone Circles Committee .. tery HO
RISROHASIUC ene token ceevevatsneseasuscevanscais roneere eco certer| Wareaaevnene oe » , 20
= One 130
Expenses Bournemouth Meeting ...... initrd peceorcereaee tc AG POLED STE SEE ; 260 8 7
F Oxford Meeting.............. 55 50 5 4
Grants made from ‘Caird Fund’ ................cc0-eceeee0s See consdaonsaae hbteeoepy te ite 240 U0 0

Balance at Lloyds Bank, Birmingham (with Interest accrued), includin,
Sir James Caird’s Gift, Radio-Activity Investigation, of £1,000 and

Interest accrued thereon .., _ .......sccccee « cesceecees .. 1,782 5 3
London Oounty Westminster and Parr’s Bank, Ltd... .ceeccccceceeececeeuee 1,854 10 9
Balance at Bank of England, Western Branch :—
On ‘Caird Fund’ ............ Poasteectect cans ni Re’ hee-caseises’ | OGRE Se 0
gs LGrerieral Aceouamtiys; JA... ccesscsthe=-ctiWavtiecebdesseccencoese . 938 7 1
———— 1,520 10 1
5,157 6 1
PPE EVG CAA BALANCE, «0, ccs tse ssacecaarcesestasavesccnactcesecsects As CARPE rt cr PEAS 109

——— 5,158 6 10

£8,750 3 8

I have examined the above Account with the Books and Vouchers of the Association, and certify the
same to be correct. I have also verified the Balances at the Bankers, and have ascertained tbat the Invest-
ments are registered in the names of the Trustees, or held by the Bank of England on account of the
Association.

APPROVED—
EDWARD BRABROOK A
ARTHUR L. Bow Ley, } Auditors. W. B, Kuen, Chartered Accountant,
23 Queen Victoria Street, E.C. 4,
August 13, 1920,

XxX RESEARCH COMMITTEES.

RESEARCH COMMITTEES, Etc.,

APPOINTED BY THE GENERAL COMMITTEE, MEETING IN CARDIFF:
Avaust, 1920.

1. (a) Receiving grants of money from the Association for expenses
connected with research. (b) Receiving grants of money from the Associa-
tion specifically for cost of printing Report. (e) Grant to be applied for
from Public Funds.

SECTION A.—MATHEMATICS AND PHYSICS.

Seismological Investigations.—-Prof. H. H. Turner (Chairman), Mr. J. J. Shaw
(Secretary), Mr. C. Vernon Boys, Dr. J. E. Crombie, Sir H. Darwin, Dr. C. Davison,
Sir F. W. Dyson, Sir R. T. Glazebrook, Prof. C. G. Knott, Prof. H. Lamb, Sir
J. Larmor, Prof. A. E. H. Love, Prof. H. M. Macdonald, Prof. H. C. Plummer,
Mr. W. E. Plummer, Prof. R. A. Sampson, Sir A. Schuster, Sir Napier Shaw,
Dr. G. T. Walker, Mr. G. W. Walker. (b) £10, (c) £90. {

To assist work on the Tides.—Prof. H. Lamb (Chairman), Dr. A. T. Doodson (Secretary),
Colonel Sir C. F. Close, Dr. P. H. Cowell, Sir H. Darwin, Dr. G. H. Fowler,
Admiral F. C. Learmonth, Sir J. E. Petavel, Prof. J. Proudman, Major G. I.
Taylor, Prof. D’Arcy W. Thompson, Sir J. J. Thomson, Prof. H. H. Turner.
(b) £35, (c) £165.

Annual Tables of Constants and Numerical Data, chemical, physical, and technological.
—Sir E. Rutherford (Chairman), Prof. A. W. Porter (Secretary), Mr. A. FE. G.
Egerton. (a) £40.

Determination of Gravity at Sea.—Prof. A. E. H. Love (Chairman), Dr. W. G. Duffield
(Secretary), Mr. 'T. W. Chaundy, Sir H. Darwin, Prof. A. S, Eddington, Major E, O.
Henrici, Sir A. Schuster, and Prof. H.H. Turner. (a) £10.

Calculation of Mathematical Tables.—Prof. J. W. Nicholson (Chairman), Dr. J. R.
Airey (Secretary), Mr. T. W. Chaundy, Prof. L. N. G. Filon, Sir G. Greenhill,
Colonei Hippisley, Prof. E. W. Hobson, Mr. G. Kennedy, and Profs. Alfred
Lodge, A. E. H. Love, H. M. Macdonald, G. B. Mathews, G. N. Watson, and

G. Webster. (a) £30, (c) £270.

SECTION B.—CHEMISTRY.

Colloid Chemistry and its Industrial Applications.—Prof. F. G. Donnan (Chairman),
Mr. W. Clayton (Secretary), Mr. E. Ardern, Dr. E. F. Armstrong, Prof. W. M.
Bayliss, Prof. C. H. Desch, Dr. A. E. Dunstan, Mr. H. W. Greenwood, Mr. W.
Harrison, Mr. E. Hatschek, Mr. G. King, Prof. W. C. McC. Lewis, Prof. J. W.
McBain, Dr. R. 8. Morell, Profs. H. R. Proctor and W. Ramsden, Dr. E. J.
Russell, Mr. A. B. Searle, Dr. S. A. Shorter, Dr. R. E. Slade, Mr. Sproxton,
Dr. H. P. Stevens, Mr. H. B. Stocks, Mr. R. Whymper. (a) £5, (c) For
printing Report.

Fuel Economy ; Utilisation of Coal; Smoke Prevention.—Prof. W. A. Bone (Chair-
man), Mr. H. James Yates (Vice- Chairman), Mr. Robert Mond (Secretary), Mr.
A. H. Barker, Prof. P. P. Bedson, Dr. W. S. Boulton, Mr. E. Bury, Prof. W. E.
Dalby, Mr. E. V. Evans, Dr. W. Galloway, Sir Robert Hadfield, Bart., Dr.
H. 8. Hele-Shaw, Mr. D. H. Helps, Dr. G. Hickling. Mr. D. V. Hollingworth,
Mr. A. Hutchinson, Principal G. Knox, Mr. Michael Longridge, Prof. Henry
Louis, Mr. G. E. Morgans, Mr. W. H. Patchell, Mr. E. D. Simon, Mr. A. T. Smith,
Dr. J. E. Stead, Mr. C. E. Stromeyer, Mr. G. Blake Aide Sir Joseph Walton,
Prof. W. W. Watts, Mr. W. B. Woodhouse, and Mr. C. H. Wordingham.
(a) £15, (b) £20.

T The Committee receives a grant of £100 from the Caird Fund.

RESEARCH COMMITTEES. XXl

Absorption Spectra and Chemical Constitution of Organic Compounds.—Sir J. J.
Dobbie (Chairman), Prof. E. E. C. Baly (Secretary), Dr. A. W. Stewart.
(a) £10, (b) £25.

Research on Non-Aromatic Diazonium Salts.—Dr. F. D. Chattaway (Chairman),
Prof. G T. Morgan (Secretary), Mr. P. G. W. Bayly and Dr. N. V. Sidgwick.
(a) £10.

To report on the present state of knowledge in regard of Infra-red Spectra.—Prof.
E. E. C. Baly (Chairman), (vacant) (Secretary), Prof. W. C. McC. Lewis,
Prof. F, A. Lindemann, Prof. T. W. Lowry, Prof. T. R. Merton. (a) £5.

SECTION C.—GEOLOGY.

The Old Red Sandstone Rocks of Kiltorcan, Ireland.—Prof. Grenville Cole (Chair-
man), Prof. T. Johnson (Secretary), Dr. J. W. Evans, Dr. R. Kidston, and Dr.
A. Smith Woodward. (a) £15.

To excavate Critica] Sections in the Paleozoic Rocks of England and Wales.—Prof.
W. W. Watts (Chairman), Prof. W. G. Fearnsides (Secretary), Prof. W. 8. Boulton,
Mr. E. 8. Cobbold, Prof. E. J. Garwood, Mr. V. C. Illing, Dr. Lapworth, Dr. J. E.
Marr, and Dr. W. K. Spencer. (a) £30, (b) £12.

To consider the Nomenclature of the Carboniferous, Permo-carboniferous, and Per
mian Rocks of the Southern Hemisphere.—Prof. T. W. Edgeworth David (Chair-
man), Prof. E. W. Skeats (Secretary), Mr. W. S. Dun, Prof. J. W. Gregory, Sir
T. H. Holland, Messrs. W. Howchin, A. E. Kitson, and G. W. Lamplugh, Dr. A. W.
Rogers, Prof. A. C. Seward, Mr. D. M. 8. Watson, and Prof. W. G. Woolnough.
(a) £25, (b) £5.

SECTION D.—ZOOLOGY.

To nominate competent Naturalists to perform definite pieces of work at the Marine
Laboratory, Plymouth.—Prof. A. Dendy (Chairman and Secretary), Prof. E. 8.
Goodrich, Prof. J. P. Hill, Prof. 8. J. Hickson, Sir E. Ray Lankester. (a) £200.

Experiments in Inheritance in Silkworms.—Prof. W. Bateson (Chairman), Mrs. Merritt
Hawkes (Secretary), Dr. F. A. Dixey, Prof. E. B. Poulton, Prof. R. C. Punnett.
(a) £17 2s. 1d.

Experiments in Inheritance of Colour in Lepidoptera.—Prof. W. Bateson (Chairman),
The Hon. H. Onslow (Secretary), Dr. F. A. Dixey, Prof. E. B. Poulton. (a) £24,
(b) £1.

Zoological Bibliography and Publication.—Prof. E. B. Poulton (Chairman), Dr. F. A.
Bather (Secretary), Mr. E. Heron-Allen, Dr. W. E. Hoyle, and Dr. P. Chalmers
Mitchell. (a) £1.

To summon meetings in London or elsewhere for the consideration of matters affecting
the interests of Zoology, and to obtain by correspondence the opinion of Zoologists
on matters of a similar kind, with power to raise by subscription from each
Zoologist a sum of money for defraying current expenses of the organisation.—
Prof. 8. J. Hickson (Chairman), Dr. W. M. Tattersall (Secretary), Profs. G. C.
Bourne, A. Dendy, J. Stanley Gardiner, W. Garstang, Marcus Hartog, W. A.
Herdman, J. Graham Kerr, R. D. Laurie, RF. W. MacBride, A. Meek, Dr. P.
Chalmers Mitchell, and Prof. E. B. Poulton. (b) £20.

Section F.—ECONOMIC SCIENCE AND STATISTICS.

The Effects of the War on Credit, Currency, Finance, and Foreign Exchanges.— Prof.
W. R. Scott (Chairman), Mr. J. E. Allen (Secretary), Prof C. F. Bastable, Sir E.
Brabrook, Prof. L. R. Dicksee, Mr. B. Ellinger, Mr. E. L, Franklin, Mr. A. H.
Gibson, Mr. C. W. Guilleband, Mr. F. W. Hirst, Prof. A. W. Kirkaldy,
Mr. F. Lavington, Mr. E. Sykes, Sir J. C. Stamp, Mr. Hartley Withers,
Mr. Hilton Young. (a) £50.

XXli RESEARCH COMMITTEES.

Section G.—ENGINEERING,

To report on certain of the more complex Stress Distributions in Engineering Materials.
—Prof. E. G. Coker (Chairman), Prof. L. N. G. Filon and Prof. A. Robertson
(Secretary), Prof. A. Barr, Dr. Chas. Chree, Dr. Gilbert Cook, Prof. W. E. Dalby,
Sir J. A. Ewing, Messrs. A. R. Fulton and J. J. Guest, Dr. B. P. Haigh, Profs.
Sir J. B. Henderson, C. E. Inglis, F. C. Lea, A. E. H. Love, and W. Mason,
Sir J. E. Petavel, Dr. F. Rogers, Dr. W. A. Scoble, Mr. R. V. Southwell,
Dr. T. E. Stanton, Mr. C. E. Stromeyer, and Mr. J. S. Wilson. (b) £50.

The Investigation of Gaseous Explosions, with special reference to temperature.—
Sir Dugald Clerk (Chairman), (Vacant) (Secretary), Profs. W. A. Bone, F. W.
Burstall, H. L. Callendar, and EH. G. Coker, Mr. D. L. Chapman, Prof. H. B.
Dixon, Prof. A. H. Gibson, Sir R. T. Glazebrook, Dr. J. A. Harker, Colonel Sir
H. C. L. Holden, Sir J. KE. Petavel, Mr. D. R. Pye, Mr. H. R. Ricardo, Captain
H. R. Sankey, Prof. A. Smithells, and Mr. H. Wimperis. (b) £50.

Srction H.—ANTHROPOLOGY.

To excavate Early Sites in Macedonia.—Prof. Sir W. Ridgeway (Chairman), Mr. A.
J. B. Wace (Secretary), Prof. R. C. Bosanquet, Mr. L. H. D. Buxton, Mr. 8. Casson,
Dr. W. L. H. Duckworth, Prof. J. L. Myres. (a) £50.

To excavate a Paleolithic Site in Jersey.—Dr. R. R. Marett (Chairman), Mr. G. de
Gruchy (Secretary), Dr. C. W. Andrews, Mr. H. Balfour, Prof, A. Keith, and
Colonel Warton. (b) £1.

To report on the Classification and Distribution of Rude Stone Monuments.—Dr. R.
R. Marett (Chairman), Prof. H. J. Fleure (Secretary), Mr. L. H. D. Buxton, Prof.
J. L. Myres, Mr. H. Peake. (a) £25, (b) £1.

To report on the Distribution of Bronze Age Implements.—Prof. J. L. Myres (Chair-
man), Mr. H. Peake (Secretary), Dr. E. C. R. Armstrong, Dr. H. A. Auden, Mr.
H. Balfour, Mr. L. H. D. Buxton, Mr. O. G. 8. Crawford, Sir W. Boyd Dawkins,
Prof. H. J. Fleure, Mr. G. A. Garfitt, Dr. R. R. Marett, Mr. R. Mond, Sir C. H.
Read, Sir W. Ridgeway. (a) £100, (b) £1.

To conduct Archeological Investigations in Malta.—Prof. J. L. Myres (Chairman),
Prof. A. Keith (Secretary), Dr. T. Ashby, Mr. H. Balfour, Dr. A. C. Haddon,
Dr. R. R. Marett, and Mr. H. Peake. (a) £50.

Section I.—PHYSIOLOGY.

Ductless Glands.—Sir E. Sharpey Schafer (Chairman), Prof. Swale Vincent (Secretary),
Dr. R. J. 8. McDowall. (c) £30.

Section K.—BOTANY.

Experimenta! Studies in the Physiology of Heredity.—Dr. F. F. Blackman (Chairman),
Miss E. R. Saunders (Secretary), Profs. Bateson and Keeble. (a) £10, (c) £90.

To continue Breeding Experiments on QOenothera and other Genera.—Dr. A. B.
Rendle (Chairman), Dr. R. R. Gates (Secretary), Prof. W. Bateson, Mr. W.
Brierley, Prof. O. V. Darbishire, Dr. M. C. Rayner. (a) £25.

Primary Botanical Survey in Wales.—Dr. E. N. Miles Thomas (Chairman), Miss
Wortham (Secretary), Miss Davey, Prof. F. W. Oliver, Prof. Stapledon, Principal
A. H. Trow. (a) £20.

RESEARCH COMMITTEES. XXill

SECTION L.—EDUCATIONAL SCIENCE.

Training in Citizenship.—Rt. Rev. J. E. C, Welldon (Chairman), Lady Shaw (Secretary),
Sir R. Baden-Powell, Mr. C. H. Blakiston, Mr. G. D. Dunkerley, Mr. W. D. Eggar,
Mr. C. R. Fay, Principal J. C. Maxwell Garnett, Sir R. A. Gregory, and Sir T.
Morison. (a) £15, (b) £10, (c) £50.

To inquire into the provision of Educational Pictures for display in schools.—Sir R. A.
Gregory (Chairman), Mr. G. D. Dunkerley (Secretary), Mr, C. E. Browne, Miss
L. J. Clarke, Mr. C. B. Fawcett, Mr. E. N. Fallaize, Prof. 8. J. Hickson,
Mr. O. J. R. Howarth, Mr. C. G. T. Morison, Mr. H. J. E. Peake. Prof. 8S. H.
Reynolds, Prof. H. E. Roaf, Sir Napier Shaw, Dr. T. W. Woodhead.
(a) £6. 10s., (b) £16.

To inquire into the work being done by University bureaux in furthering the inter-
change of Students (particularly post-graduates) between home and foreign
Universities, and to consider what steps can be taken to increase their spheres
of action.—Mr. D. Berridge (Secretary). (a) £5.

To inquire into the Practicability of an International Auxiliary Language.—Mr. W.
B. Hardy (Chairman), Dr. E. H. Tripp (Secretary), Mr. E. Bullough, Prof. J. J.
Findlay, Sir Richard Gregory, Dr. C. W. Kimmins, Dr. H. Foster Morley, Sir
E. Cooper Perry, Prof. W. Ripman, Mr. F. Nowell Smith, Mr. A. E. Twentyman.
(a) £7. 10s., (b) £15. ,

CORRESPONDING SOCIETIES.

Corresponding Societies Committee for the preparation of their Report.—Mr. W.
Whitaker (Chairman), Mr. W. Mark Webb (Secretary), Mr. P. J. Ashton, Dr. F. A.
Bather, Rev. J. O. Bevan, Sir Edward Brabrook, Sir H. G. Fordham, Mr. A. L.
Lewis, Mr. T. Sheppard, Rey. T. R. R. Stebbing, Mr. Mark L. Sykes, and the
President and General Officers of the Association. (a) £40, (b) £30.

2. Not receiving Grants of Money.

SECTION A.—MATHEMATICAL AND PHYSICAL SCIENCE.

Radiotelegraphic Investigations.—Sir Oliver Lodge (Chairman), Dr. W. H. Eccles
(Secretary), Mr. S. G. Brown, Dr. C. Chree, Sir F. W. Dyson, Prof. A. S. Eddington,
Dr. Erskine-Murray, Profs. J. A. Fleming, G. W. O. Howe, H. M. Macdonald,
and J. W. Nicholson, Sir H. Norman, Captain H. R. Sankey, Sir A. Schuster, Sir
Napier Shaw, and Prof. H. H. Turner.

Inyestigation of the Upper Atmosphere.—Sir Napier Shaw (Chairman), Mr. C. J. P.
Cave (Secretary), Prof. S. Chapman, Mr. J. S. Dines, Mr. W. H. Dines, Sir R. T.
Glazebrook, Col. E. Gold, Dr. H. Jeffreys, Sir J. Larmor, Mr. R. G. K. Lemp-
fert, Prof. F. A. Lindemann, Dr. W. Makower, Sir J. E. Petavel, Sir A. Schuster,
Dr. G. C. Simpson, Mr. F. J. W. Whipple, Prof. H. H. Turner.

To aid the work of Establishing a Solar Observatory in Australia.—Prof. H. H. Turner,
(Chairman), Dr. W. G. Duffield (Secretary), Rev. A. L. Cortie, Dr. W. J. 8. Lockyer,
Mr. F. McClean, and Sir A. Schuster.

SECTION C.—GEOLOGY.

The Collection, Preservation, and Systematic Registration of Photographs of Geo-
logical Interest.—Prof. E. J. Garwood (Chairman), Prof. 8. H. Reynolds (Secretary),
Mr. G. Bingley, Dr. T. G. Bonney, Messrs. C. V. Crook, R. Kidston, and A. 8.
Reid, Sir J. J. H. Teall, Prof. W.W. Watts, and Messrs. R. Welch and W. Whitaker.

XXi1V RESEARCH COMMITTBES.

To consider the preparation of a List of Characteristic Fossils.—Prof. P, F. Kendall
(Chairman), Dr. W. T. Gordon (Secretary), Prof. W.S. Boulton, Dr. A. R. Dwerry-
house, Profs. J. W. Gregory, Sir T. H. Holland, and 8. H. Reynolds, Dr. Marie
C. Stopes, Dr. J. E. Marr, Prof. W. W. Watts, Mr. H. Woods, and Dr. A. Smith
Woodward.

To investigate the Flora of Lower Carboniferous times as exemplified at a newly-
discovered locality at Gullane, Haddingtonshire.—Dr. R. Kidston (Chairman),
Dr. W. T. Gordon (Secretary), Dr. J. 8. Flett, Prof, E. J. Garwood, Dr. J. Horne,
and Dr. B. N. Peach.

SECTION D.—ZOOLOGY.

To aid competent Investigators selected by the Committee to carry on definite pieces
of work at the Zoological Station at Naples.— Mr. E. 8. Goodrich (Chairman),
Prof. J. H. Ashworth (Secretary), Dr. G. P. Bidder, Prof. F. 0. Bower, Drs. W. B.
Hardy, Sir S. F. Harmer, Prof. 8. J. Hickson, Sir E. Ray Lankester, Prof. W. C.
McIntosh, Dr. A. D, Waller.

The collection of Marsupials for work upon (a) the reproductive apparatus and
development, (b) the brain.--Prof. A. Dendy (Chairman), Dr. G. E. Nicholls
(Secretary), Profs. W. J. Dakin, T. Flynn, J. P. Hill, E. B. Poulton, and G,
Elliot Smith, Dr. Marett Tims.

Section F.—ECONOMIC SCIENCE AND STATISTICS.

Replacement of Men by Women in Industry.—Prof. W. R. Scott (Chairman), Miss
Grier (Secretary), Miss Ashley, Mr. J. Cunnison, Mr. Daniels, Mr. C. R. Fay, Mr.
J. E. Highton, and Professor A. W. Kirkaldy.

Sxction H.—ANTHROPOLOGY.

The Collection, Preservation, and Systematic Registration of Photographs of Anthro-
pological Interest.—Sir C. H. Read (Chairman), Mr. E. N. Fallaize (Secretary),
Dr. G. A. Auden, Dr. H. O. Forbes, Mr. E. Heawood, and Prof. J. L. Myres.

To conduct Explorations with the object of ascertaining the Age of Stone Circles.—
Sir C. H. Read (Chairman), Mr. H. Balfour (Secretary), Dr. G. A. Auden, Prof.
Sir W. Ridgeway, Dr. J. G. Garson, Sir Arthur Evans, Sir W. Boyd Dawkins,
Prof. J. L. Myres, Mr. A. L. Lewis, and Mr. H. Peake.

To conduct Archeological and Ethnological Researches in Crete.—Mr. D. G. Hogarth
(Chairman), Prof. J. L. Myres (Secretary), Prof. R. C. Bosanquet, Dr. W. L. H.
Duckworth, Sir A. Evans, Sir W. Ridgeway, Dr. F. C. Shrubsall.

To conduct Anthropometric Investigations in the Island of Cyprus.—Prof. J. L.
Myres (Chairman), Dr. F. C. Shrubsall (Secretary), Mr. L. H. Dudley Buxton, Dr.
A. C. Haddon.

To co-operate with Local Committees in excavation on Roman Sites in Britain.—
Sir W. Ridgeway (Chairman), Mr. H. J. E. Peake (Secretary), Dr. T. Ashby, Mr.
Willoughby Gardner, Prof. J. L. Myres.

To report on the present state of knowledge of the Ethnography and Anthropology
of the Near and Middle East.—Dr. A. C. Haddon (Chairman), Mr. L. H. Dudley
Buxton (Secretary), Mr. 8S. Casson, Prof. H. J. Fleure, Mr. H. J. E. Peake.

t Grant of £100 from Caird Fund : see p. xxx.

RESEARCH COMMITTEES, XXV

To report on the present state of knowledge of the relation of early Palzolithic
Instruments to Glacial Deposits.—Mr. H. J. E. Peake (Chairman), Mr. E. N.
Fallaize (Secretary), Mr. H. Balfour.

Section I.—PHYSIOLOGY.

Electromotive Phenomena in Plants.—Dr. A. D. Waller (Chairman), Mrs. Waller
(Secretary), Prof. J. B. Farmer, Mr. J. C. Waller.

Food Standards and Man-power.—Prof. W. D. Halliburton (Chairman), Dr. A. D.
Waller (Secretary), Prof. E. H. Starling.

Section K.—BOTANY.

To consider the possibilities of investigation of the Ecology of Fungi, and assist Mr.
J. Ramsbottom in his initial efforts in this direction.—Mr. H. W. T. Wager
(Chairman), Mr. J. Ramsbottom and Miss A. Lorrain Smith (Secretaries), Mr.
W. B. Brierley, Mr. F. T. Brooks, Mr. W. N. Cheesman, Prof. T. Johnson, Prof.
M. C. Potter, Mr. L. Carleton Rea, and Mr. E. W. Swanton.

Section L.—EDUCATION.

The Influence of School Books upon Eyesight.—Dr. G. A. Auden (Chairman), Mr.
G. F. Daniell (Secretary), Mr. C. H. Bothamley, Mr. W. D. Eggar, Sir R. A.
Gregory, Dr. N. Bishop Harman, Mr. J. L. Holland, Dr. W. E. Sumpner,
and Mr. Trevor Walsh.

CORRESPONDING SOCIETIES COMMITTEE.

To take steps to obtain Kent’s Cavern for the Nation.—Mr. W. Whitaker (Chairman),
Mr. W. M. Webb (Secretary), Prof. Sir W. Boyd Dawkins, Mr. Mark L. Sykes.

Research Committees ‘in Suspense.’

The work of the following Committees is in suspense until further
notice. The personnel of these Committees will be found in the Report
for 1917. .

SECTION D.-—ZOOLOGY.

An investigation of the Biology of the Abrolhos Islands and the North-west Coast
of Australia (north of Shark’s Bay to Broome), with particular reference to the
_ Marine Fauna.

Nomenclator Animalium Genera et Sub-genera.

SECTION H.—ANTHROPOLOGY.

To investigate the Physical Characters of the Ancient Egyptians.
To prepare and publish Miss Byrne’s Gazetteer and Map of the Native Tribes
of Australia.

To investigate the Lake Villages in the neighbourhood of Glastonbury in connec-
tion with a Committee of the Somerset Archzological and Natural History Society.

SECTION K.—BOTANY.
The Renting of Cinchona Botanic Station in Jamaica.

XXVi RESOLUTIONS AND RECOMMENDATIONS.

RESOLUTIONS AND RECOMMENDATIONS.

The following Resolutions and Recommendations were referred to
the Council (unless otherwise stated) by the General Committee at
Cardiff for consideration and, if desirable, for action :—

From Section A.

That H.M. Stationery Office be asked to print the Tables on Congruence
Solutions prepared by Lieut.-Col. A. Cunningham and Mr. T. G. Creak.

From Sections A and E.

(1) That this joint meeting of Sections A and E strongly urges upon the
General Committee the desirability of printing in the report of the Association
the paper read before it by Principal E. H. Griffiths and Major E. O. Henrici
on ‘The Need for a Central British Institute for Training and Research in
Surveying, Hydrography, and Geodesy’ *; and (2) that the meeting calls the
attention of the Council to the urgency of the question at the present time, and
begs that the Council will again give attention to the subject.

From Section B.

That Section B requests the Council to recommend to the appropriate autho-
rities the great desirability of continuing the experiments on the production of
industrial alcohol now in progress, by aid of the installations now existing in
Government establishments.

From Section C.

That the Committee of Section C intimate to the Council that it regards the
forecasting of the length of Committee reports as in many cases impossible.

From Section D.

Unanimously agreed by the Committee of Section D (thirty-nine present) that
it be a recommendation to the Zoology Organisation Committee that no scheme
of payment of professional zoologists in the service of the State is satisfactory
which places them on a lower level than that of the higher grade of the Civil
Service.

(The above Resolution received the support of representatives of other
Sections, and the General Committee directed that its consideration and any
action upon it should take account of the position of workers in other branches
of science.)

From Section D.

That Section D is profoundly impressed with the importance of urging the
initiation of a further National Expedition for the Exploration of the Ocean,
and requests the Council of the British Association to appoint a Committee to
take the necessary steps to impress this need upon His Majesty’s Government
and the nation. ;

(The above Resolution was supported by the Committees of all Sections
concerned.)

* This Recommendation was sanctioned by the General Committee.

RESOLUTIONS AND RECOMMENDATIONS. XXVil

From Section E.

That this meeting of Section E of the British Association, being convinced
by the results already obtained of the value as an educational instrument and
as a work of national importance of the scheme recently initiated by the Welsh
Department of the Board of Education for the collection of Rural Lore and
Regional Survey material through the medium of the elementary and secondary
schools and colleges, heartily approves the same, and expresses the earnest hope
that the scheme may be widely taken up throughout the country.

From Section H (see preceding Resolution).

That the Committee of Section H, Cardiff, August 1920, views with interest
and appreciation the scheme of the Welsh Department of the Board of Educa-
tion for the collection of Rural Lore through the agency of the schools, and hopes
that steps may be taken to apply the scheme, mutatis mutandis, to other parts
of Great Britain.

From Section EH.

That the Committee of Section E (Geography) of the British Association for
the Advancement of Science begs leave to ask the President of the Board of
Education to give schools permission to include geography as a subject on a
level with the other subjects in advanced courses of suitable type in mathematics
and science, in classics, and in modern studies.

From Section E.

The Committee of Section E of the British Association meeting at Cardiff
(1920) expresses its appreciation of the opportunity of co-operation in the wor
of the National Committee on Geographical Research afforded by the Royal
Society, but it begs leave to suggest that the purpose might be served more fully
if the Section were permitted to nominate a representative for a period of two
or three years in place of the nomination of the President of the Section who

retires annually.
The Committee begs to suggest, if their recommendation be adopted, that

Prof. J. L. Myres be nominated as their representative.

From Section H.

That the following Committees be authorised to obtain financial assistance
from sources other than the Association * :

(a) Archeological Investigations in Malta.
(6) Bronze Age Implements.

(d) Rude Stone Monuments.

From Section H.

That this Association urges upon the Government of the Union of South
Africa the desirability of instituting an Ethnological Bureau for the purpose
of studying the racial characteristics, languages, institutions, and beliefs of the
native population of South Africa, in order that any attempt which may be made
to bring this population into closer touch with the course of social and economic
development in South Africa may be based upon a scientific knowledge and an
understanding of its psychology, mode of life, and institutions.

* This Recommendation was sanctioned by the General Committee.

XXVill RESOLUTIONS AND RECOMMENDATIONS.

From Section H.

That this Association would urge upon the Government of Western Australia
the desirability of instituting forthwith an anthropological survey of the
aboriginal population now living under Government protection on Government
reservations, stations, and elsewhere in Western Australia, in order that a record
may be made of the physical measurements, languages, customs, and beliefs of
these tribes, before this material, of great scientific importance, is lost by the
death of the older members of the tribes or impaired in value by contact with
civilisation.

From Section H.

That the attention of this Association having been called to the present
deplorable condition of the aboriginal population of Central Australia, it would
urge upon the Federal Government of the Commonwealth of Australia, the
Government of South Australia, and the Government of Western Australia the
necessity for (1) the declaration of an absolute reservation on some part of the
lands at present inhabited by these tribes, such as, for instance, the Musgrave,
Mann, and Tomkinson Ranges, upon which all may be located under State pro-
tection and supervision; and (2) the institution of a medical service for the
aborigines to check the ravages of tuberculosis and other diseases now rife
among them.

From Section H.

That in future years Associations for the Advancement of Science in the
Dominions and in Foreign Countries be invited to send official representatives to
attend the annual meetings of this Association.

From Section H.

Recommendations * in reference to printing of reports of Research Committees
1919-20 :

(a) Archeological Investigations in Malta :—That the Government of Malta
be asked to contribute £50 towards the cost of printing this report in the Journal
of the Royal Anthropological Institute on the condition that copies of the report
will be available for sale in the Island of Malta.

(6) That Mr. Willoughby Gardner’s report on the Excavations at Dinorben
in 1919-20 be printed, in abstract only, as an appendix to the report of the
Roman Sites Committee for 1919-20.

From Sections H and L.

That this Association, while viewing with approbation the recent regulation
of the Board of Education (Circular 1153, March 31, 1908), where anthropo-
metric observations may be included in the medical inspection of Continuation
Schools, would urge upon the Board the desirability of extending this provision
to all schools in receipt of Government grant for a limited period of, say, five
years, in order that, as a result of such a survey, standards of comparison may
be available in the future for the purpose of both medical inspection and
scientific investigation.

From Section I.

The Committee of Section I recommend to the General Committee of the
British Association that a separate Section of Psychology be formed.
(The above Recommendation was supported by representatives of Section L,
aoe se approved by the General Committee subject to the approval of the
ouncil.

* These Recommendations were sanctioned by the General Committee.

RESOLUTIONS AND RECOMMENDATIONS. XXiX

From Section K.

That Government support is desired for the afforestation experiments on
pit-mounds being conducted by the Midland Reafforesting Committee.

From Section L.

Section L ask the Council to give power to the Organising Committee of
Section L, if they think fit, to allow a book upon Citizenship, based. upon the
syllabus in Appendix I. of the 1920 Report of the Committee upon Training
in Citizenship, to be published, with a foreword to the effect that the book has
the approval of the Organising Committee of Section L of the British Asso-
ciation.

From Section L.

That 500 short copies of the Reports on Museums and on Training in Citizen-
ship (1920) be printed from the standing type.*

* This Recommendation was sanctioned by the General Committee.

»:0:0.4 THE CAIRD FUND.

THE CAIRD FUND.

An unconditional gift of 10,000. was made to the Association at the
Dundee Meeting, 1912, by Mr. (afterwards Sir) J. K. Caird, LL.D., of
Dundee.

The Council, in its report to the General Committee at the Bir-
mingham Meeting, made certain recommendations as to the administra-
tion of this Fund. These recommendations were adopted, with the
Report, by the General Committee at its meeting on September 10, 1913.

The following allocations have been made from the Fund by the
Council to August 1920 :-—

Naples Zoological Station Committee (p. xxiv).—501. (1912-13) ; 1001.
(1913-14) ; 100/. annually in future, subject to the adoption of the Com-
mittee’s report. (Reduced to 501. during war.)

Seismology Committee (p. xx).—100/. (1913-14) ; 1007. annually in
future, subject to the adoption of the Committee’s report.

Radiotelegraphic Committee (p. xxiii).—500/. (1913-14).

Magnetic Re-survey of the British Isles (in collaboration with the
Royal Society).—250/.

Committee on Determination of Gravity at Sea (p. xx).—1001.
(1914-15).

Mr. F. Sargent, Bristol University, in connection with his Astro-
nomical Work.—101. (1914).

Organising Committee of Section F' (Economics), towards expenses of
an Inquiry into Outlets for Labour after the War.—100l. (1915).

Rev. T. HE. R. Phillips, for aid in transplanting his private observa-
tory.—20/. (1915).

Committee on Fuel Economy (p. xx).—251. (1915-16), 107. (1919-20).
Committee on Training in Citizenship (p. xxiii).—10/. (1919-20).
Geophysical Committee of Royal Astronomical Society.—101. (1920).
Conjoint Board of Scientific Societies.—10I. (1920).

Sir J. K. Caird, on September 10, 1913, made a further gift of 1,000/.
to the Association, to be devoted to the study of Radio-activity.

INAUGURAL GENERAL MEETING. XXxl

INAUGURAL GENERAL MEETING.
Tuesday, August 24, 1920.

In the course of his speech introducing his successor, the President,
the Hon. Sir Charles Parsons, K.C.B., F.R.S., said:—

The General Committee have authorised me to send the following telegram
to His Majesty the King :—

Your Maszsty,

The members of the British Association for the Advancement of Science
desire to express their loyal devotion to your Majesty, and at this their meeting
in the Principality of Wales hope that they may be permitted to congratulate
your Majesty on the splendid work done by the Prince of Wales, which has
drawn towards him the thoughts and the hearts of the whole Empire.

We have to record with deep regret that since our meeting at Bournemouth
last year the Association has lost two of its most devoted and valued officers.

Professor John Perry, F.R.S., General Treasurer of the Association since 1904,
died at his London residence on August 4 at the age of seventy. He had only
returned two months ago from a long voyage round South America, undertaken
for the benefit of his health. It had, however, not produced the desired result ;
the affection of his heart increased, and the end came suddenly. Professor
Perry was widely known as an eminent mathematician, and as one who had
directed most of his life to introducing mathematics as a practical science—
his numerous books are well known in this country and America, and have
been translated into many foreign languages. He was at one time assistant
to Lord Kelvin, and helped in the perfecting of the Kelvin electrostatic volt-
meter. In association with Ayrton he was a pioneer in the early developments
of electrical instruments, storage batteries, and on the applications of elec-
tricity. He was a Past-President of the Institute of Electrical Engineers and
of the Physical Society. One of his most famous lectures was on ‘ Spinning
Tops,’ delivered at the British Association meeting at Leeds in 1890, and his
recent work in the perfecting of the gyroscopic compass is well known. His
genial, warm-hearted kindness endeared him not only to his wide circle of
friends, but also to his colleagues and students, and there are few members of
this Association who do not feel a blank that it is difficult to fill.

Henry Charles Stewardson, Assistant Treasurer of the British Association
for many years, entered the services of the Association in 1873 in a clerical
capacity, but, through his ability for finance, soon became Assistant Treasurer,
and the Association undoubtedly owes much to his careful economies and to
his accurate forecasts of the balance available for grants to research, which
guided the Committee of Recommendations each year. He missed no annual
meeting, and many members gratefully remember his help and courtesy in the
Reception Room. His health was failing at the last meeting, but he continued
to discharge his duties until within four days of his death, on May 1 last,
in his eightieth year.

The death of Sir Norman Lockyer, F.R.S., on Monday of last week, deprives
the world of a great astronomer, and the nation of a force which it can ill
afford to lose. By applying the spectroscope to the sun he furnished the means
of studying its surface without waiting for an eclipse; revealed in 1868 the
prominences as local disturbances in the chromosphere ; and observed in the
sun the gas, named by him helium, and afterwards identified on the earth by
Sir William Ramsay. More than half a century ago Sir Norman founded that
admirable scientific journal ‘Nature.’ He also founded the British Science

XXXii INAUGURAL GENERAL MEETING.

Guild in 1905. His Presidential Address to the British Association at South-
port sixteen years ago, on ‘ The Influence of Brain Power on History,’ attracted
wide attention, but it has taken the greatest war in history to awaken national
consciousness to its significance.

I have now the pleasure of introducing to you my successor in this chair,
an eminent biologist who has directed his great talents with indefatigable
energy to the study of the life that exists in the vast spaces and depths of the
ocean, which covers nearly three-fourths of our globe. Few people give much
thought to the ocean beyond the fact that it carries our ships and is the source
of most of the fish which we eat. But the work of investigating what goes on
within the ocean, a work in which Professor Herdman has taken so arduous
and prominent a part, has revealed a life within it, both vegetable and animal,
of great complexity and of enormous magnitude, but governed by laws chemical
and physical which are being gradually discovered. It is indeed difficult to
realise, as Professor Herdman has stated, that in some seas a cubic mile of
water may contain as much as 30,000 tons of living organisms whose life history
depends on the light of the sun, thermal currents in the ocean, and seasonal
changes, and that those organisms form the staple food of the fishes which we
eat. The difficulties of these investigations must have been enormous, requir-
ing the resources of science, consummate skill, and indefatigable energy to
overcome them. Many years ago Professor Herdman created a fisheries labora-
tory in the University of Liverpool, created and brought into co-operation with
it. a biological station at Port Erin, and arranged periodical ocean trips for
dredging and collecting marine organisms. A year ago he endowed a chair of
oceanography at Liverpool, the first on this subject in the British Isles. He
also founded, two years earlier, the chair of geology in memory of his only
son George Herdman, one of those young men of brilliant promise killed in the
war. His enthusiasm and sympathy have made him beloved by his pupils, as
indeed by zoologists in general, and his work has led to the throwing of much
additional light on the marine life of our globe.

The President-Elect, Professor W. A. Herdman, C.B.E., D.Sc.,
LL.D., F.R.S., then took the chair, and delivered the Presidential
Address, which is printed below (pp. 1-33).

The following gracious reply was received from His Majesty the
King to the telegram quoted on p. xxxi:—

I have received with much pleasure and satisfaction the message which you
have addressed to me on behalf of the members of the British Association,
and in thanking them for their loyal assurances to myself I feel greatly touched
at the kind references to my son, which are the more appreciated coming as
these do from the members of this distinguished Society assembled in the
Principality of Wales. I shall follow your deliberations with close interest,
and I gratefully recognise all that is being done for the advancement of
civilisation by the men of science. Gerorce R.I.

CARDIFF: 1920.

ADDRESS

WILLIAM A. HERDMAN, C.B.E., D.Sc., Sc.D., LL.D., F.R.S.,
Professor of Oceanography in the University of Liverpool,

PRESIDENT.
Oceanography and the Sea-Fisheries.

Ir has been customary, when occasion required, for the President to
offer a brief tribute to the memory of distinguished members of the
Association lost to Science during the preceding year. These, for the
most part, have been men of advanced years and high reputation, who
had completed their life-work and served well in their day the Associa-
tion and the sciences which it represents. Such are our late General
Treasurer, Professor Perry, and our Past-President, Sir Norman
Lockyer, of whom the retiring President has just spoken.‘ We have
this year no other such losses to record; but it seems fitting on
the present occasion to pause for a moment and devote a grateful
thought to that glorious band of fine young men of high promise in
science who, in the years since our Australian meeting in 1914,
gave, it may be, in brief days and months of sacrifice, greater service
to humanity and the advance of civilisation than would have been
possible in years of normal time and work. A few names stand
out already known and highly honoured—Moseley, Jenkinson, Geoffrey
Smith, Keith Lucas, Hopkinson, Gregory, and more recently Leonard
Doncaster—all grievous losses; but there are also others, younger
members of our Association, who had not yet had opportunity for
showing accomplished work, but who equally gave up all for a great
ideal. I prefer to offer a collective rather than an individual tribute.
Other young men of science will arise and carry on their work—but
the gap in our ranks remains. Let their successors remember that it
serves as a reminder of a great example and of high endeavour worthy
of our gratitude and of permanent record in the annals of Science.

At the last Cardiff Meeting of the British Association in 1891 you had
as your President the eminent astronomer Sir William Huggins, who
discoursed upon the then recent discoveries of the spectroscope in
relation to the chemical nature, density, temperature, pressure and even
the motions of the stars. From the sky to the sea is a long drop; but
the sciences ia both have this in common, that they deal with

} See p, Xxx., ante,
1920 B

2 PRESIDENT’S ADDRESS.

fundamental principles and with vast numbers. Over three hundred
years ago Spenser in the ‘ Faerie Queene ’ compared ‘ the seas abundant
progeny ’ with ‘ the starres on hy,’ and recent investigations show that a
litre of sea-water may contain more than a hundred times as many living
organisms as there are stars visible to the eye on a clear night.

During the past quarter of a century great advances have been
made in the science of the sea, and the aspects and prospects of sea-
fisheries research have undergone changes which encourage the hope
that a combination of the work now carried on by hydrographers and
biologists in most civilised countries on fundamental problems of the
ocean may result in a more rational exploitation and administration
of the fishing industries.

And yet even at your former Cardiff Meeting thirty years ago there
were at least three papers of oceanographic interest—one by Professor
Osborne Reynolds on the action of waves and currents, another by
Dr. H. R. Mill on seasonal variation in the temperature of lochs and
estuaries, and the third by our Honorary Local Secretary for the present
meeting, Dr. Evans Hoyle, on a deep-sea tow-net capable of being opened
and closed under water by the electric current.

It was a notable meeting in several other respects, of which I shall
merely mention two. In Section A, Sir Oliver Lodge gave the historic
address in which he expounded the urgent need, in the interests of both
science and the industries, of a national institution for the promotion
of physical research on a large scale. Lodge’s pregnant idea put forward
at this Cardiff Meeting, supported and still further elaborated by Sir
Douglas Galton as President of the Association at Ipswich, has since
borne notable fruit in the establishment and rapid development of the
National Physical Laboratory. The other outstanding event of that
meeting is that you then appointed a committee of eminent geologists
and naturalists to consider a project for boring through a coral reef, and
that led during following years to the successive expeditions to the
atoll of Funafuti in the Central Pacific, the results of which, reported
upon eventually by the Royal Society, were of great interest alike to
geologists, biologists, and oceanographers.

Dr. Huggins, on taking the Chair in 1891, remarked that it was over
thirty years since the Association had honoured Astronomy in the
selection of its President. It might be said that the case of Oceano-
graphy is harder, as the Association has never had an Oceanographer
as President—and the Association might well reply ‘ Because until very
recent years there has been no Oceanographer to have.’ If Astronomy
is the oldest of the sciences, Oceanography is probably the youngest.
Depending as it does upon the methods and results of other sciences,
it was not until our knowledge of Physics, Chemistry, and Biology was

PRESIDENT’S ADDRESS. 3

relatively far advanced that it became possible to apply that knowledge
to the investigation and explanation of the phenomena of the ocean.
No one man has done more to apply such knowledge derived from various
other subjects and to organise the results as a definite branch of
science than the late Sir John Murray, who may therefore be regarded
as the founder of modern Oceanography.

It is, to me, a matter of regret that Sir John Murray was never
President of the British Association. I am revealing no secret when I
tell you that he might have been. On more than one occasion he was
invited by the Council to accept nomination, and he declined for reasons
that were good and commanded our respect. He felt that the
necessary duties of this post would interfere with what he regarded
as his primary life-work—oceanographical explorations already planned,
the last of which he actually carried out in the North Atlantic in
1912, when over seventy years of age, in the Norwegian steamer
Michael Sars, along with his friend Dr. Johan Hjort.

Anyone considering the subject-matter of this new science must be
struck by its wide range, overlapping as it does the borderlands of several
other sciences and making use of their methods and facts in the solution
of its problems. It is not only world-wide in its scope but extends
beyond our globe and includes astronomical data in their relation to tidal
and certain other oceanographical phenomena. No man in his work,
or even thought, can attempt to cover the whole ground—although Sir
John Murray, in his remarkably comprehensive ‘ Summary ’ volumes
of the Challenger Expedition and other writings, went far towards
doing so. He, in his combination of physicist, chemist, geologist and
biologist, was the nearest approach we have had to an all-round Oceano-
grapher. The International Research Council probably acted wisely
at the recent Brussels Conference in recommending the institution of
two International Sections in our subject, the one of physical and the
other of biological Oceanography—although the two overlap and are so
interdependent that no investigator on the one side can afford to neglect
the other.*

On the present occasion I must restrict myself almost wholly to the
latter division of the subject, and be content, after brief reference to the

2 The following classification of the primary divisions of the subject may
possibly be found acceptable :—

Ag hae

|
Oceanography Geography
|

I | | |
Hydrography Metabolism Bionomics Tidology
(Physics, &¢.) (Bio-Chemistry) (Biology) (Mathematics)

4 PRESIDENT’S ADDRESS.

founders and pioneers of our science, to outline a few of those investi-
gations and problems which have appeared to me to be of fundamental
importance, of economic value, or of general interest.

Although the name Oceanography was only given to this branch of
science by Sir John Murray in 1880, and although according to that
veteran oceanographer Mr. J. Y. Buchanan, the last surviving member
of the civilian staff of the Challenger, the science of Oceanography
was born at sea on February 15, 1873,* when, at the first official
dredging station of the expedition, to the westward of Teneriffe, at
1525 fathoms, everything that came up in the dredge was new and led to
fundamental discoveries as to the deposits forming on the floor of the
ocean, still it may be claimed that the foundations of the science were
laid by various explorers of the ocean at much earlier dates. Aristotle,
who took all knowledge for his province, was an early oceanographer on
the shores of Asia Minor. When Pytheas passed between the Pillars
of Hercules into the unknown Atlantic and penetrated to British seas in
the fourth century B.c., and brought back reports of Ultima Thule and
of a sea to the North thick and sluggish like a jelly-fish, he may have
been recording an early planktonic observation. But passing over all
such and many other early records of phenomena of the sea, we come
to surer ground in claiming, as founders of Oceanography, Count
Marsili, an early investigator of the Mediterranean, and that truly
scientific navigator Captain James Cook, who sailed to the South Pacific
on a Transit of Venus expedition in 1769 with Sir Joseph Banks as
naturalist, and by subsequently circumnavigating the South Sea about
latitude 60° finally disproved the existence of a great southern
continent; and Sir James Clerk Ross, who, with Sir Joseph Hooker as
naturalist, first dredged the Antarctic in 1840.

The use of the naturalist’s dredge (introduced by O. F. Miller, the
Dane, in 1799) for exploring the sea-bottom was brought into promin-
ence almost simultaneously in several countries of North-West Europe
—by Henri Milne-Edwards in France in 1830, Michael Sars in Norway
in 1835, and our own Edward Forbes about 1832.

The last-mentioned genial and many-sided genius was a notable
figure in several sections of the British Association from about 1836
onwards, and may fairly be claimed as a pioneer of Oceanography.
In 1839 he and his friend the anatomist, John Goodsir, were dredging

° Others might put the date later. Significant publications are Sir John
Murray’s Summary Volumes of the Challenger (1895), the inauguration of
the ‘Musée Océanographique’ at Monaco in 1910, the foundation of the
‘Institut Océanographique’ at Paris in 1906 (see the Prince of Monaco’s
letter to the Minister of Public Instruction), and Sir John Murray’s little book
The Ocean (1913), where the superiority of the term ‘Oceanography ’ ‘to
‘Thalassography ’ (used by Alexander Agassiz) is discussed,

he ,PRESIDENT’S ADDRESS. 5
in the Shetland seas, with results which Forbes made known to. the
meeting of the British Association at Birmingham that summer, with
such good effect that a “Dredging Committee’ * of the Association was
formed to continue the good work. Valuable reports on the discoveries
of that Committee appear in our volumes at intervals during the subse-
quent twenty-five years.

It has happened over and over again in history that the British
Association, by means of one of its research committees, has led the
way in some important new research or development of science and has
shown the Government or an industry what wants doing and how it
can be done. We may fairly claim that the British Association has
inspired and fostered that exploration of British seas which through
marine biological investigations and deep-sea expeditions has led on to
modern Oceanography. Edward Forbes and the British Association
Dredging Committee, Wyville Thomson, Carpenter, Gwyn Jeffreys,
Norman, and other naturalists of the pre-Challenger days—all these men
in the quarter-century from 1840 onwards worked under research com-
mittees of the British Association, bringing their results before successive
meetings; and some of our older volumes _enshrine classic reports on
dredging by Forbes, McAndrew, Norman, Brady, Alder, and other
notable naturalists of that day. These local researches paved the way
for the Challenger and other national deep-sea expeditions. Here,
as in other cases, it required private enterprise to precede and stimulate
Government action.

It is probable that Forbes and his fellow-workers on this ‘ Dredging
Committee’ in their marine explorations did not fully realise that they
were Opening up a most comprehensive and important department of
knowledge. But it is also true that in all his expeditions—in the British
seas from the Channel Islands to the Shetlands, in Norway, in the
Mediterranean as far as the Algean Sea—his broad outlook on the
problems of nature was that of the modern oceanographer, and he was
the spiritual ancestor of men like Sir Wyville Thomson of the
Challenger Expedition and Sir John Murray, whose accidental death
a few years ago, while still in the midst of active work, was a grievous
loss to this new and rapidly advancing science of the sea. *

Forbes in these marine investigations worked at border-line
problems, dealing for example with the relations of Geology to Zoology.

4 “For researches with the dredge, with a view to the investigation of
the marine zoology of Great Britain, the illustration of the geographical distri-
bution of marine animals, and the more accurate determination of the
fossils of the pieistocene period: under the superintendence of Mr. Gray, Mr.
Forbes, Mr. Goodsir, Mr. Patterson, Mr, Thompson of Belfast, Mr. Ball of
Dublin, Dr. George Johnston, Mr. Smith of Jordan Hill, and Mr. A. Strickland,
£60.’ Report for 1839, p. xxvi.

6 PRESIDENT’S ADDRESS. *

and the effect of the past history of the land and sea upon the distri-
bution of plants and animals at the present day, and in these respects
he was an early oceanographer. For the essence of that new subject is
that it also investigates border-line problems and is based upon and
makes use of all the older fundamental sciences—Physics, Chemistry
and Biology—and shows for example how variations in the great ocean
currents may account for the movements and abundance of the migratory
fishes, and how periodic changes in the physico-chemical characters
of the sea, such as variations in the hydrogen-ion and hydroxyl-ion
concentration, are correlated with the distribution at the different seasons
of the all-important microscopic organisms that render our oceanic
waters as prolific a source of food as the pastures of the land.

Another pioneer of the nineteenth century who, I sometimes think,
has not yet received sufficient credit for his foresight and initiative, is
Sir Wyville Thomson, whose name ought to go down through the ages
as the ieader of the scientific staff on the famous Challenger Deep-Sea
Exploring Expedition. It is due chiefly to him and to his frend
Dr. W. B. Carpenter that the British Government, through the
influence of the Royal Society, was induced to place at the disposal of

-a committee of scientific experts first the small surveying steamer
Lightning in 1868, and then the more efficient steamer Porcupine
in the two succeeding years, for the purpose of exploring the deep water
of the Atlantic from the Faroes in the North to Gibraltar and beyond
in the South, in the course of which expeditions they got successful
hauls from the then unprecedented depth of 2435 fathoms, nearly three
statute miles.

It will be remembered that Edward Forbes, from his observations in
the Mediterranean (an abnormal sea in some respects), regarded depths
of over 300 fathoms as an azoic zone. It was the work of Wyville
Thomson and his colleagues Carpenter and Gwyn Jeffreys on these
successive dredging expeditions to prove conclusively what was
beginning to be suspected by naturalists, that there is no azoic zone in
the sea, but that abundant life belonging to many groups of animals
extends down to the greatest depths of from four to five thousand
fathoms—nearly six statute miles from the surface.

These pioneering expeditions in the Lightning and Porcupine—
the results of which are not even yet fully made known to science—
were epoch-making, inasmuch as they not only opened up this new
region to the systematic marine biologist, but gave glimpses of world-
wide problems in connection with the physics, the chemistry and the
biology of the sea which are only now being adequately investigated by
the modern oceanographer. These results, which aroused intense
interest amongst the leading scientific men of the time, were so rapidly
surpassed and overshadowed by the still greater achievements of the

PRESIDENT’S ADDRESS, 7

Challenger and other national exploring expeditions that followed
in the ’seventies and ’eighties of last century, that there is some danger
of their real importance being lost sight of; but it ought never to be
forgotten that they first demonstrated the abundance of life of a varied
nature in depths formerly supposed to be azoic, and, moreover, that
some of the new deep-sea animals obtained were related to extinct forms
belonging to the Jurassic, Cretaceous and Tertiary periods.

It is interesting to recall that our Association played its part in
promoting the movement that led to the Challenger Expedition.
Our General Committee at the Edinburgh Meeting of 1871 recom-
mended that the President and Council be authorised to co-operate with
the Royal Society in promoting ‘a Circumnavigation Expedition,
specially fitted out to carry the Physical and Biological Exploration of
the Deep Sea into all the Great Oceanic Areas ’; and our Council subse-
quently appointed a committee consisting of Dr. Carpenter, Professor
Huxley and others to co-operate with the Royal Society in carrying out
these objects.

It has been said that the Challenger Expedition will rank in history
with the voyages of Vasco da Gama, Columbus, Magellan and Cook.
Like these it added new regions of the globe to our knowledge, and the
wide expanses thus opened up for the first time, the floors of the oceans,
though less accessible, are vaster than the discoveries of any previous
exploration. Has not the time come for a new Challenger expedition?

Sir Wyville Thomson, although leader of the expedition, did not live
to see the completed results, and Sir John Murray will be remembered
in the history of science as the Challenger naturalist who brought
to a successful issue the investigation of the enormous collections and
the publication of the scientific results of that memorable voyage: these
two Scots share the honour of having guided the destinies of what is still
the greatest oceanographic exploration of all times.

In addition to taking his part in the general work of the expedition,
Murray devoted special attention to three subjects of primary import-
ance in the science of the sea, viz.: (1) the plankton or floating life
of the oceans, (2) the deposits forming on the sea bottoms, and (8) the
origin and mode of formation of coral reefs and islands. It was
characteristic of his broad and synthetic outlook on nature that, in place
of working at the speciography and anatomy of some group of
organisms, however novel, interesting and attractive to the naturalist
the deep-sea organisms might seem to be, he took up wide-reaching
general problems with economic and geological as well as biological
applications.

Hach of the three main lines of investigation—deposits, plankton
and coral reefs—which Murray undertook on board the Challenger
has been most fruitful of results both in his own hands and those of

8 PRESIDENT’S ADDRESS.

others: His plankton work has led on to those modern planktonic
researches which are closely bound up with the scientific investigation
of our sea-fisheries.

His work on the deposits accumulating on the floor of the ocean
resulted, after years of study in the laboratory as well as in the field,
in collaboration with the Abbé Renard of the Brussels Museum, after-
wards Professor at Ghent, in the production of the monumental * Deep-
Sea Deposits’ volume, one of the Challenger Reports, which first
revealed to the scientific world the detailed nature and distribution
of the varied submarine deposits of the globe and their relation to the
rocks forming the crust of the earth.

These studies led, moreover, to one of the romances of science
which deeply influenced Murray’s future life and work. In accumu-
lating material from all parts of the world and all deep-sea exploring
expeditions for comparison with the Challenger series, some ten
years later, Murray found that a sample of rock from Christmas Island
in the Indian Ocean, which had been sent to him by Commander (now
Admiral) Aldrich, of H.M.S. Egeria, was composed of a valuable
phosphatic material. This discovery in Murray’s hands gave rise to a
profitable commercial undertaking, and he was able to show that some
years ago the British Treasury had already received in royalties and
taxes from the island considerably more than the total cost of the
Challenger Expedition.

That first British circumnavigating expedition on the Challenger
was followed by other national expeditions (the American Tuscarora
and Albatross, the French Travailleur, the German Gauss,
National, and Valdivia, the Italian Vettor Pisani, the Dutch
Siboga, the Danish Thor and others) and by almost equally cele-
brated and important work by unofficial oceanographers such as
Alexander Agassiz, Sir John Murray with Dr. Hjort in the Michael
Sars, and the Prince of Monaco in his magnificent ocean-going yacht,
and by much other good work by many investigators in smaller and
humbler vessels. One of these supplementary expeditions I must refer
to briefly because of its connection with sea-fisheries. The Triton,
under Tizard and Murray, in 1882, while exploring the cold and warm
areas of the Faroe Channel separated by the Wyville-Thomson ridge,
incidentally discovered the famous Dubh-Artach fishing-grounds, which
have been worked by British trawlers ever since.

Notwithstanding all this activity during the last forty years since
Oceanography became a science, much has still to be investigated in
all seas in all branches of the subject. On pursuing any line of investi-
gation one very soon comes up against a wall of the unknown or a maze
of controversy. Peculiar difficulties surround the subject. The

PRESIDENT’S ADDRESS. 9

matters investigated are often remote and almost inaccessible.
Unknown factors may enter into every problem. The samples required
may be at the other end of a rope or a wire eight or ten miles long,
and the oceanographer may have to grope for them literally in the dark
and under other difficult conditions which make it uncertain whether
his samples when obtained are adequate and representative, and whether
they have undergone any change since leaving thew natural environ-
ment. It is not surprising then that in the progress of knowledge
mistakes have been made and corrected, that views have been held on
what seemed good scientific grounds which later on were proved to
be erroneous. For example, Edward Forbes, in his division of life in
the sea into zones, on what then seemed to be sufficiently good obser-
vations in the Algean, but which we now know to be exceptional, placed
the limit of life at 300 fathoms, while Wyville Thomson and his fellow-
workers on the Porcwpine and the Challenger showed that there is no
azoic zone even in the great abysses.

Or, again, take the celebrated myth of ‘Bathybius.’ In tthe
‘sixties of last century samples of Atlantic mud, taken when surveying
the bottom for the first telegraph cables and preserved in alcohol, were
found when examined by Huxley, Haeckel and others to contain what
seemed to be an exceedingly primitive protoplasmic organism, which
was supposed on good evidence to be widely extended over the floor of the
ocean. The discovery of this Bathybius was said to solve the problem
of how the deep-sea animals were nourished in the absence of sea-
weeds. Here was a widespread protoplasmic meadow upon which other
organisms could graze. Belief in Bathybius seemed to be confirmed
and established by Wyville Thomson’s results in the Porcupine
Expedition of 1869, but was exploded by the naturalists on the Chal-
lenger some five years later. Buchanan in his recently published
“Accounts Rendered ’ tells us how he and his colleague Murray were
keenly on the look-out for hours at a time on all possible occasions
for traces of this organism, and how they finally proved, in the spring
of 1875 on the voyage between Hong-Kong and Yokohama, that the
all-pervading substance like coagulated mucus was an amorphous
precipitate of sulphate of lime thrown down from the sea-water in the
mud on the addition of a certain proportion of alcohol. He wrote to
this effect from Japan to Professor Crum Brown, and it is in evidence
that after receiving this letter Crum Brown interested his friends in
Edinburgh by showing them how to make Bathybius in the
chemical laboratory. Huxley at the Sheffield Meeting of the British
Association in 1879 handsomely admitted that he had been mistaken, and
it is said that he characterised Bathybius as ‘ not having fulfilled the
promise of its youth.’ Will any of our present oceanographic beliefs

10 PRESIDENT’S ADDRESS.

share the fate of Bathybius in the future? Some may, but even if they
do they may well have been useful steps in the progress of science.
Although like Bathybius they may not have fulfilled the promise of their
youth, yet, we may add, they will not have lived in the minds of man
in vain.

Many of the phenomena we encounter in oceanographic investi-
gations are so complex, are or may be affected by so many diverse
factors, that it is difficult, if indeed possible, to be sure that we are
unravelling them aright and that we see the real causes of what we
observe.

Some few things we know approximately—nothing completely. We
know that the greatest depths of the ocean, about six miles, are a
little greater than the highest mountains on land, and Sir John Murray
has calculated that if all the land were washed down into the sea the
whole globe would be covered by an ocean averaging about two miles in
depth.° We know the distribution of temperatures and salinities over
a great part of the surface and a good deal of the bottom of the oceans,
and some of the more important oceanic currents have been charted
and their periodic variations, such as those of the Gulf Stream, are being
studied. | We know a good deal about the organisms floating or
swimming in the surface waters (the epi-plankton), and also those
brought up by our dredges and trawls from the bottom in many parts
of the world—although every expedition still makes large additions
to knowledge. The region that is least known to us, both in its physical
conditions and also its inhabitants, is the vast zone of intermediate
waters lying between the upper few hundred fathoms and the bottom.
That is the region that Alexander Agassiz from his observations with
closing tow-nets on the Blake Expedition supposed to be destitute of
life, or at least, as modified by his later observations on the Albatross,
to be relatively destitute compared with the surface and the bottom, in
opposition to the contention of Murray and other oceanographers that
an abundant meso-plankton was present, and that certain groups of
animals, such as the Challengerida and some kinds of Meduse, were
characteristic of these deeper zones. I believe that, as sometimes
happens in scientific controversies, both sides were right up to a point,
and both could support their views upon observations from particular
regions of the ocean under certain circumstances.

But much still remains unknown or only imperfectly known even
in matters that have long been studied and where practical applications

° It was possibly in such a former world-wide ocean of ionised water that
according to the recent speculations of A. H. Church (Zhalassiophyta, 1919) the
first living organisms were evolved to become later the floating unicellular
plants of the primitive plankton.

Ag PRESIDENTS ADDRESS, << ee 11
of great value are obtained—such as the investigation and prediction
of tidal phenomena. We are now told that theories require re-inyesti-
gation and that published tables are not sufficiently accurate. To
take another practical application of oceanographic work, the ultimate
causes of variations in the abundance, in the sizes, in the movements
and in the qualities of the fishes of our coastal industries are still to
seek, and notwithstanding volumes of investigation and a still greater
volume of discussion, no man who knows anything of the matter is
satisfied with our present knowledge of even the best-known and
economically most important of our fishes, such as the Herring, the
Cod, the Plaice and the Salmon.

Take the case of our common fresh-water eel as an example of how
little we know and at the same time of how much has been discovered.
All the eels of our streams and lakes of N.-W. Europe live and feed
and grow under our eyes without reproducing their kind—no spawning
eel has ever been seen. After living for years in immaturity, at last
near the end of their lives the large male and female yellow eels
undergo a change in appearance and in nature. They acquire a silvery
colour and their eyes enlarge, and in this bridal attire they commence
the long journey which ends in maturity, reproduction and death. From
all the fresh waters they migrate in the autumn to the coast, from
the inshore seas to the open ocean and still westward and south to the

mid-Atlantic and we know not how much further—for the exact
locality and manner of spawning has still to be discovered. The
youngest known stages of the Leptocephalus, the larval stage of eels,
have been found by the Dane, Dr. Johs. Schmidt, to the west of
the Azores where the water is over 2000 fathoms in depth. These
_ were about one-third of an inch in length and were probably not long
hatched. I cannot now refer to all the able investigators—Grassi,
_ Hjort and others—who have discovered and traced the stages of growth
_ of the Leptocephalus and its metamorphosis into the ‘ elvers ’ or young
eels which are carried by the North Atlantic drift back to the coasts of
Europe and ascend our rivers in spring in countless myriads; but no
‘man thas been more indefatigable and successful in the quest than
‘Dr. Schmidt, who in the various expeditions of the Danish Investigation
‘Steamer Thor from 1904 onwards found successively younger and
younger stages, and who is during the present summer engaged in a
traverse of the Atlantic to the West Indies in the hope of finding the
missing link in the chain, the actual spawning fresh-water eel in the
intermediate waters somewhere above the abysses of the open ocean.°®

® According to Schmidt’s results the European fresh-water eel, in order to

be able to propagate, requires a depth of at least 500 fathoms, a salinity of
oe an 35.20 per mille and a temperature of more than 7° C. in the required
epth.

12 PRESIDENT’S ADDRESS.

Again, take the case of an interesting oceanographic observation
which, if established, may be found to explain the variations in time
and amount of important fisheries. Otto Pettersson in 1910 discovered
by his observations in the Gullmar Fjord the presence of periodic sub-
marine waves of deeper salter water in the Kattegat and the fjords
of the west coast of Sweden, which draw in with them from the Jutland
banks vast shoals of the herrings which congregate there in autumn.
The deeper layer consists of ‘bankwater’ of salinity 32 to 34 per |
thousand, and as this rolls in along the bottom as a series of huge ©
undulations it forces out the overlying fresher water, and so the
herrings living in the bankwater outside are sucked into the Kattegat
and neighbouring fjords and give rise to important local fisheries.
Pettersson connects the crests of the submarine waves with the phases
of the moon. Two great waves of salter water which reached up to the
surface took place in November 1910, one near the time of full moon
and the other about new moon, and the latter was at the time when
the shoals of herring appeared inshore and provided a profitable fishery.
The coincidence of the oceanic phenomena with the lunar phases is
not, however, very exact, and doubts have been expressed as to the
connection; but if established, and even if found to be due not to the
moon but to prevalent winds or the influence of ocean currents, this
would be a case of the migration of fishes depending upon mechanical
causes, while in other cases it is known that migrations are due to
spawning needs or for the purpose of feeding, as in the case of the
cod and the herring in the west and north of Norway and in the
Barents Sea.

Then, turning to a very fundamental matter of purely scientific
investigation, we do not know with any certainty what causes the great
and all-important seasonal variations in the plankton (or floating minute
life of the sea) as seen, for example, in our own home seas, where there
is a sudden awakening of microscopic plant life, the Diatoms, in early
spring when the water is at its coldest. In the course of a few days
the upper layers of the sea may become so filled with organisms that a
small silk net towed for a few minutes may capture hundreds of
millions of individuals. And these myriads of microscopic forms, after
persisting for a few weeks, may disappear as suddenly as they came,
to be followed by swarms of Copepoda and many other kinds of minute
animals, and these again may give place in the autumn to a second
maximum of Diatoms or of the closely related Peridiniales. Of course
there are theories as to all these more or less periodic changes in the
plankton, such as Liebig’s ‘law of the minimum,’ which limits the
production of an organism by the amount of that necessity of existence
which is present in least quantity, it may be nitrogen or silicon or

4 PRESIDENTS ADDRESS. 13

phosphorus. According to Raben it is the accumulation of silicie acid
in the sea-water that determines the great increase of Diatoms in spring
and again in autumn. Some writers have considered these variations
in the plankton to be caused largely by changes in temperature supple-
mented, according to Ostwald, by the resulting changes in the viscosity
of the water; but Murray and others are more probably correct in
attributing the spring development of phyto-plankton to the increasing
power of the sunlight and its value in photosynthesis.

Let us take next the fact—if it be a fact—that the genial warm
waters of the tropics support a less abundant plankton than the cold
polar seas. The statement has been made and supported by some
investigators and disputed by others, both on a certain amount of evi-

dence. This is possibly a case like some other scientific controversies

where both sides are partly in the right, or right under certain con-
ditions. At any rate there are sealed exceptions to the generalisation.
The German Plankton Expedition in 1889 showed in its results that

much larger hauls of plankton per unit volume of water were obtained
in the temperate North and South Atlantic than in the tropics between,
and that the warm Sargasso Sea had a remarkably scanty microflora.
Other investigators have since reported more or less similar results.
Lohmann found the Mediterranean plankton to be less abundant than

that of the Baltic, gatherings brought back from tropical seas are fre-
quently very scanty, and enormous hauls on the other hand have been
recorded from Arctic and Antarctic seas. There is no doubt about the
large gatherings obtained in northern waters. I have myself in a
few minutes’ haul of a small horizontal net in the North of Norway
collected a mass of the large Copepod Calanus finmarchicus sufficient
to be cooked and eaten like potted shrimps by half a dozen of the
yacht’s company, and I have obtained similar large hauls in the cold
Labrador current near Newfoundland. On the other hand, Kofoid and
Alexander Agassiz have recorded large hauls of plankton in the Humboldt
current off the west coast of America, and during the Challenger
Expedition some of the largest quantities of plankton were found in the
equatorial Pacific. Moreover, it is common knowledge that on occa-
sions vast swarms of some planktonic organism may be seen in tropical
waters. The yellow alga Trichodesmium, which is said to have given
ts name to the Red Sea and has been familiarly known as ‘ sea-sawdust ’
since the days of Cook’s first voyage,’ may cover the entire surface over
considerable areas of the Indian and South Atlantic Oceans; and some
elagic animals such as Salpe, Meduse and Ctenophores are also
ommonly present in abundance in the tropics. Then, again, American

7 See Journal of Sir Joseph Banks. This and other swarms were also
joticed by Darwin during the voyage of the Beagle,

14 PRESIDENT’S ADDRESS.

biologists * have pointed out that the warm waters of the West Indies
and Florida may be noted for the richness of their floating life for
periods of years, while at other times the pelagic organisms become
rare and the region is almost a desert sea.

It is probable, on the whole, that the distribution and variations
of oceanic currents have more than latitude or temperature alone to do
with any observed scantiness of tropical plankton. These mighty
rivers of the ocean in places teem with animal and plant life, and may
sweep abundance of food from one region to another in the open sea.

But even if it be a fact that there is this alleged deficiency in tropical
plankton there is by no means agreement as to the cause thereof.
Brandt first attributed the poverty of the plankton in the tropics to the
destruction of nitrates in the sea as a result of the greater intensity of
the metabolism of denitrifying bacteria in the warmer water; and
various other writers since then have more or less agreed that the
presence of these denitrifying bacteria, by keeping down to a minimum
the nitrogen concentration in tropical waters, may account for the
relative scarcity of the phyto-plankton, and consequently of the
’ zoo-plankton, that has been observed. But Gran, Nathansohn, Murray,
Hjort and others have shown that such bacteria are rare or absent
in the open sea, that their action must be negligible, and that Brandt’s
hypothesis is untenable. It seems clear, moreover, that the plankton
does not vary directly with the temperature of the water. Furthermore,
Nathansohn has shown the influence of the vertical circulation in the
water upon the nourishment of the phyto-plankton—by rising currents
bringing up necessary nutrient materials, and especially carbon dioxide
from the bottom layers; and also possibly by conveying the products of
the drainage of tropical lands to more polar seas so as to maintain the
more abundant life in the colder water.

Piitter’s view is that the increased metabolism in the warmer water
causes all the available food materials to be rapidly used up, and so
puts a check to the reproduction of the plankton.

According to Van’t Hoff’s law in Chemistry, the rate at which a
reaction takes place is increased by raising the temperature, and this
probably holds good for all bio-chemical phenomena, and therefore for
the metabolism of animals and plants in the sea. This has been
verified experimentally in some cases by J. Loeb. The contrast
between the plankton of Arctic and Antarctic zones, consisting of large
numbers of small Crustaceans belonging to comparatively few species,
and that of tropical waters, containing a great many more species
generally of smaller size and fewer in number of individuals, is to be

® A. Agassiz, A. G. Mayer, and H, B. Bigelow.

PRESIDENT’S ADDRESS. 15

accounted for, according to Sir John Murray and others, by the rate
of metabolism in the organisms. ‘The assemblages captured in cold
polar waters are of different ages and stages, young and adults of
several generations occurring together in profusion,’ and it is supposed
that the adults ‘ may be ten, twenty or more years of age.’ At the
low temperature the action of putrefactive bacteria and of enzymes
is very slow or in abeyance, and the vital actions of the Crustacea
take place more slowly and the individual lives are longer. On the
other hand, in the warmer waters of the tropics the action of the
bacteria is more rapid, metabolism in general is more active, and the
various stages in the life-history are passed through more rapidly,
so that the smaller organisms of equatorial seas probably only live for
days or weeks in place of years.

This explanation may account also for the much greater quantity
of living organisms which has been found so often on the sea floor
in polar waters. It is a curious fact that the development of the
polar marine animals is in general ‘ direct’ without larval pelagic stages,
the result being that the young settle down on the floor of the ocean
in the neighbourhood of the parent forms, so that there come to be
enormous congregations of the same kind of animal within a limited
area, and the dredge will in a particular haul come up filled with
hundreds, it may be, of an Echinoderm, a Sponge, a Crustacean, a
Brachiopod, or an Ascidian; whereas in warmer seas the young pass
through a pelagic stage and so become more widely distributed over
the floor of the ocean. The Challenger Expedition found in the
Antarctic certain Echinoderms, for example, which had young in
various stages of development attached to some part of the body of the
parents, whereas in temperate or tropical regions the same class of
animals set free their eggs and the development proceeds in the open
water quite independently of, and it may be far distant from, the
parent.

Another characteristic result of the difference in temperature is that
the secretion of carbonate of lime in the form of shells and skeletons
proceeds more rapidly in warm than in cold water. The massive shells
of molluscs, the vast deposits of carbonate of lime formed by corals
and by calcareous seaweeds, are characteristic of the tropics ; whereas
in polar seas, while the animals may be large, they are for the most
part soft-bodied and destitute of calcareous secretions. The calcareous
pelagic Foraminifera are characteristic of tropical and sub-tropical

. plankton, and few, if any, are found in polar waters. Globigerina

_ * Whether, however, the low temperature may not also retard reproduction
is worthy of consideration.

16 PRESIDENT’S ADDRESS.

ooze, a calcareous deposit, is abundant in equatorial seas, while in the
Antarctic the characteristic deposit is siliceous Diatomaceous ooze.

The part played by bacteria in the metabolism of the sea is very
important and probably of wide-reaching effect, but we still know very
litfle about it. A most promising young Cambridge biologist, the late
Mr. G. Harold Drew, now unfortunately lost to science, had already
done notable work at Jamaica and at Tortugas, Florida, on the effects
produced by a bacillus which is found in the surface waters of these
shallow tropical seas and in the mud at the bottom ; and which denitrifies
nitrates and nitrites, giving off free nitrogen. He found that this
Bacillus calcis also caused the precipitation of soluble calcium salts
in the form of calcium carbonate (‘ drewite ’) on a large scale, in the
warm shallow waters. Drew’s observations tend to show that the
great calcareous deposits of Florida and the Bahamas previously known
as ‘coral muds’ are not, as was supposed by Murray and others,
derived from broken-up corals, shells, nullipores, &c., but are minute
particles of carbonate of lime which have been precipitated by the
action of these bacteria.*°

The bearing of these observations upon the formation of oolitic
limestones and the fine-grained unfossiliferous Lower Paleozoic lime-
stones of New York State, recently studied in this connection by R. M.
Field,’? must be of peculiar interest to geologists, and forms a notable
instance of the annectant character of Oceanography, bringing the
metabolism of living organisms in the modern sea into relation with —
paleozoic rocks.

The work of marine biologists on the plankton has been in the
main qualitative, the identification of species, the observation of struc-
ture, and the tracing of life-histories. The oceanographer adds to that
the quantitative aspect when he attempts to estimate numbers and
masses per unit volume of water or of area. Let me lay before you
a few thoughts in regard to some such attempts, mainly for the
purpose of showing the difficulties of the investigation.. Modern quanti-
tative methods owe their origin to the ingenious and laborious work
of Victor Hensen, followed by Brandt, Apstein, Lohmann, and others
of the Kiel school of quantitative planktologists. We may take their
well-known estimations of fish eggs in the North Sea as an example
of the method.

The floating eggs and embryos of our more important food fishes
may occur in quantities in the plankton during certain months in
spring, and Hensen and Apstein have made some notable calculations

+9 Journ. Mar. Biol. Assoc., October 1911.
1 Carnegie Institute of Washington, Year Book for 1919, p, 197,

PRESIDENT’S ADDRESS. 17

based ‘on the occurréncé of these in certain hauls taken at intervals
across the North Sea, which led them to the conclusion that, taking
six of our most abundant fish, such as the cod and some of the flat
fish, the eggs present were probably produced by about 1200 million
spawners, enabling them to calculate that the total fish population
of the North Sea’ (of these six species), at that time (spring of 1895),
amounted to about 10,000 millions. Further calculations led them
to the result that the fishermen’s catch of these fishes amounted
to about one-quarter of the total population: Now all this is not only
of scientific interest, but also of great practical importance if we could
be sure that the samples upon which the calculations are based were
adequate and representative, but it will be noted that these samples
only represent one square metre in 3,465,968,354. Hensen’s state-
ment, repeated in various works in slightly differing words, is to the
effect that, using a net of which the constants are known hauled
vertically through a column of water from a certain depth to the
surface, he can calculate the volume of water filtered by the net and
so estimate the quantity of plankton under each square metre of the
surface; and his whole results depend upon the assumption, which
he considers justified, that the plankton is evenly distributed over
large areas of water which are under similar conditions. In these
calculations in regard to the fish eggs he takes the whole of the North
Sea as being an area under similar conditions, but we have known
since the days of P. T. Cleve and from the observations of Hensen’s
own colleagues that this is not the case, and they have published chart-
diagrams showing that at least three different kinds of water under
different conditions are found in the North Sea, and that at least five
different planktonic areas may be encountered in making a traverse
from Germany to the British Isles. If the argument be used that
wherever the plankton is found to vary there the conditions cannot
be uniform, then few areas of the ocean of any considerable size remain
as cases suitable for population-computation from randem samples.
It may be doubted whether even the Sargasso Sea, which is an area
of more than usually uniform character, has a ‘sufficiently evenly
distributed plankton to be treated by Hensen’s method of estimation
of the population.

In the German Plankton Expedition of 1889 Schiitt reports that
in the Sargasso Sea, with its relatively high temperature, the twenty-
four catches obtained were uniformly small in quantity. His analysis
of the volumes of these catches shows that the average was 3:33 c.c.,
but the individual catches ranged from 1:5 c.c. to 65 ¢.c., and the diver-
gence from the average may be as great as + 3°2'c.c. ; and, after deduct-

ing 20 per cent. of the divergence as due to errors of the experiment,
1920 a

18 PRESIDENT’S ADDRESS.

Schiitt estimates the mean variation of the plankton at about 16 per
cent. above or below. This does not seem to me to indicate the
uniformity that might be expected in this ‘ halistatic’’ area occupying
the centre of the North Atlantic Gulf Stream circulation. Hensen
also made almost simultaneous hauls with the same net in quick
succession to test the amount of variation, and found that the average
error was about 13 per cent.

As so much depends in all work at sea upon the weather, the con-
ditions under which the ship is working, and the care taken in the
experiment, with the view of getting further evidence under known
conditions I carried out some similar experiments at Port Erin on four
occasions during last April and on a further occasion a month later,
choosing favourable weather and conditions of tide and wind, so as
to be able to maintain an approximate position. On each of four days
in April the Nansen net, with No. 20 silk, was hauled six times from
the same depth (on two occasions 8 fathoms and on -two occasions
20 fathoms), the hauls being taken in rapid succession and the catches
being emptied from the net into bottles of 5 per cent. formaline, in
which they remained until examined microscopically.

The results were of interest, for although they showed considerable
uniformity in the amount of the catch——for example, six successive
hauls from 8 fathoms being all of them 0:2 c.c. and four out of five
from 20 fathoms being 0°6 ¢.c.—the volume was made up rather
differently in the successive hauls. The same organisms are present
for the most part in each haul, and the chief groups of organisms are
present in much the same proportion. For example, in a series where
the Copepoda average about 100 the Dinoflagellates average about 300
and the Diatoms about 8000, but the percentage deviation of indi-
vidual hauls from the average may be as much as plus or minus 50.
The numbers for each organism (about 40) in each of the twenty-six
hauls have been worked out, and the details will be published elsewhere,
but the conclusion I come to is that if on each occasion one haul only,
in place of six, had been taken, and if one had used that haul to
estimate the abundance of any one organism in that sea-area, one
might have been about 50 per cent. wrong in either direction.

Successive improvements and additions to Hensen’s methods in
collecting plankton have been made by Lohmann, Apstein, Gran, and
others, such as pumping up water of different layers through a hose-
pipe and filtering it through felt, filter-paper, and other materials
which retain much of the micro-plankton that escapes through the
meshes of the finest silk. Use has even been made of the extraordinarily
minute and beautifully regular natural filter spun by the pelagic animal
Appendicularia for the capture of its own food. This grid-like trap,

PRESIDENT’S ADDRESS. 19

when dissected out and examined under the microscope, reveals a
surprising assemblage of the smallest protozoa and protophyta, less
than 30 micro-millimetres in diameter, which would all pass easily
through the meshes of our finest silk nets.

The latest refinement in capturing the minutest-known organisms
of the plankton (excepting the bacteria) is a culture method devised
by Dr. E. J. Allen, Director of the Plymouth Laboratory.’ By diluting
half a cubic centimetre of the sea-water with a considerable amount
(1500 ¢.c.) of sterilised water treated with a nutrient solution, and
distributing that over a large number (70) of small flasks in which
after an interval of some days the number of different kinds of organisms
which had developed in each flask were counted, he calculates that
the sea contains 464,000 of such organisms per litre; and he gives
reasons why his cultivations must be regarded as minimum results,

‘and states that the total per litre may well be something like a million.
Thus every new method devised seems to multiply many timés the
probable total population of the sea. As further results of the quan-
titative method it may be recorded that Brandt found about 200 diatoms
per drop of water in Kiel Bay, and Hensen estimated that there are
several hundred millions of diatoms under each square metre of the
North Sea or the Baltic. It has been calculated that there is approxi-
mately one Copepod in each cubic inch of Baltic water, and that the
annual consumption of these Copepoda by herring is about a thousand
billion; and that in the 16 square miles of a certain Baltic fishery
there is Copepod food for over 530 millions of herring of an average
weight of 60 grammes.

There are many other problems of the plankton in addition to
quantitative estimates—probably some that we have not yet recognised—
and various interesting conclusions may be drawn from recent planktonic
observations. Here is a case of the introduction and rapid spread of
a form new to British seas.

Biddulphia sinensis is an exotic diatom which, according to Osten-
feld, made its appearance at the mouth of the Elbe in 1903, and spread
during successive years in several directions. It appeared suddenly
in our plankton gatherings at Port Erin in November 1909, and has
been present in abundance each year since. Ostenfeld, in 1908, when
tracing its spread in the North Sea, found that the migration to the
north along the coast of Denmark to Norway corresponded with the
rate of flow of the Jutland current to the Skagerrak—viz., about 17 cm.
per second—a case of plankton distribution throwing light on hydro-
graphy—and he predicted that it would soon be found in the English

2 Journ. Mar, Biol. Assoc. xii, 1, July 1919.

20 PRESIDENT’S ADDRESS.

Channel. Dr. Marie Lebour, who recently examined the store of
plankton gatherings at the Plymouth Laboratory, finds that as a matter
of fact this form did appear in abundance in the collections of October
1909, within a month of the time when according to our records it
reached Port Erin. Whether or not this is an Indo-Pacific species
brought accidentally by a ship from the Far East, or whether it is
possibly a new mutation which appeared suddenly in our seas, there
is no doubt that it was not present in our Irish Sea plankton gatherings
previous to 1909, but has been abundant since that year, and has
completely adopted the habits of its English relations—appearing with
B. mobiliensis in late autumn, persisting during the winter, reaching a
maximum in spring, and dying out before summer.

The Nauplius and Cypris stages of Balanus in the plankton form
an interesting study. The adult barnacles are present in enormous |
abundance on the rocks round the coast, and they reproduce in winter,
at the beginning of the year. The newly emitted young are sometimes
so abundant as to make the water in the shore pools and in the sea
close to shore appear muddy. The Nauplii first appeared at Port Erin,
in 1907, in the bay gatherings on February 22 (in 1908 on Feb-
ruary 13), and increased with ups and downs to their maximum on
April 15, and then decreased until their disappearance on April 26.
None were taken at any other time of the year. The Cypris stage
follows on after the Nauplius. It was first taken in the bay on
April 6, rose to its maximum on the same day with the Nauplii, and
was last caught on May 24. Throughout, the Cypris curve keeps
below that of the Nauplius, the maxima being 1740 and 10,500 respec-
tively. Probably the difference between the two curves represents the
death-rate of Balanus during the Nauplius stage. That conclusion I
think we are justified in drawing, but I would not venture to use the
result of any haul, or the average of a number of hauls, to multiply by
the number of square yards in a zone round our coast in order to
obtain an estimate of the number of young barnacles, or of the old
barnacles that produced them—the irregularities are too great. ;

To my mind it seems clear that there must be three factors making
for irregularity in the distribution of a plankton organism :—

1. The sequence of stages in its life-history—such as the Nauplius
and Cypris stages of Balanus. ;

2. The results of interaction with other organisms—as when a
swarm of Calanus is pursued and devoured by a shoal of herring.

3. Abnormalities in time or abundance due to the physical environ-
ment—as in favourable or unfavourable seasons.

And these factors must be at work in the open ocean as well as in
coastal waters.

PRESIDENT’S ADDRESSs 21

In many oceanographical inquiries there is a double object. There
is the scientific interest and there is the practical utility—the interest,
for example, of tracing a particular swarm of a. Copepod like Calanus,
and of making out why it is where it is at a particular time, tracing it
back to its place of origin, finding that it has come with a particular
body of water, and perhaps that it is feeding upon a particular assem-
blage of Diatoms ; endeavouring to give a scientific explanation of every
stage in its progress. Then there is the utility—the demonstration
that the migration of the Calanus has determined the presence of a
shoal of herrings or mackerel that are feeding upon it, and so have
been brought within the range of the fisherman and have constituted
a commercial fishery.

We have evidence that pelagic fish which congregate in shoals,
such as herring and mackerel, feed upon the Crustacea of the plankton
and especially upon Copepoda. A few years ago when the summer
herring fishery off the south end of the Isle of Man was unusually near
the land, the fishermen found large red patches in the sea where the
fish were specially abundant. Some of the red stuff, brought ashore
by the men, was examined at the Port Erin Laboratory and found to
be swarms of the Copepod Temora longicornis; and the stomachs of
the herring caught at the same time were engorged with the same
organism. It is not possible to doubt that dnring these weeks of the
herring fishery in the Irish Sea the fish were feeding mainly upon this
species of Copepod. Some ten years ago Dr. E. J. Allen and Mr.
G. E. Bullen published ** some interesting work, from the Plymouth
Marine Laboratory, demonstrating the connection between mackerel
and Copepoda and sunshine in the English Channel; and Farran'
states that in the spring fishery on the West of Ireland the food of the
mackerel is mainly composed of Calanus.

Then again at the height of the summer mackerel fishery in the
Hebrides, in 1913, we found” the fish feeding upon the large Copepod
Calanus finmarchicus, which was caught in the tow-net at the rate of
about 6000 in a five-minutes’ haul, and 6000 was also the average
number found in the stomachs of the fish caught at the same time.

These were cases where the fish were feeding upon the organism
that was present in swarms—a monotonic plankton—but in other cases
the fish are clearly selective in their diet. If the sardine of the French
coast can pick out from the micro-plankton the minute Peridiniales in
preference to the equally minute Diatoms which are present in the sea

at the same time, there seems no reason why the herring and the

18 Journ. Mar. Biol. Assoc. vol. viii. (1909), pp. 394-406.
M4 Conseil Internat. Bull, Trimestr, 1902-8, ‘ Planktonique,’ p, 89.
18 * Spolia Runiana,’ iii. Linn. Soc. Journ., Zoology, vol. xxxiv. p. 95, 1918.

oo PRESIDENT’S ADDRESS.

mackerel should not be able to select particular species of Copepoda
or other large organisms from the macro-plankton, and we have
evidence that they do. Nearly thirty years ago the late Mr. Isaac
Thompson, a constant supporter of the Zoological Section of this Asso-
ciation and one of the Honorary Local Secretaries for the last Liver-
pool meeting, showed me in 1893 that young plaice at Port Erin were
selecting one particular Copepod, a species of Jonesiella, out of many
others caught in our tow-nets at the time. H. Blegvad*® showed in
1916 that young food fishes and also small shore fishes pick out certain
species of Copepoda (such as Harpacticoids) and catch them individually
—either lying in wait or searching for them. A couple of years later *’
Dr. Marie Lebour published a detailed account of her work at Plymouth
on the food of young fishes, proving that certain fish undoubtedly do
prefer certain planktonic food.

These Crustacea of the plankton feed upon smaller and simpler
organisms—the Diatoms, the Peridinians, and the Flagellates—and the
fish themselves in their youngest post-larval stages are nourished by
the same minute forms of the plankton. Thus it appears that our sea-
fisheries ultimately depend upon the living plankton which no doubt
in its turn is affected by hydrographic conditions. A correlation seems
to be established between the Cornish pilchard fisheries and periodic
variations in the physical characters (probably the salinity) of the
water of the English Channel between Plymouth and Jersey.** Appa-
rently a diminished intensity in the Atlantic current corresponds with
a diminished fishery in the following summer. Possibly the connection
in these cases is through an organism of the plankton.

It is only a comparatively small number of different kinds of
organisms—both plants and animals—that make up the bulk of the
plankton that is of real importance to fish. One ean select about half-
a-dozen species of Copepoda which constitute the greater part of the
summer zoo-plankton suitable as food for larval or adult fishes, and
about the same number of generic types of Diatoms which similarly
make up the bulk of the available spring phyto-plankton year after
year. This fact gives great economic importance to the attempt to
determine with as much precision as possible the times and conditions
of occurrence of these dominant factors of the plankton in an average
year. An cbvious further extension of this investigation is an inquiry
into the degree of coincidence between the times of appearance in the
sea of the plankton organisms and of the young fish, and the possible
effect of any marked absence of correlation in time and quantity.

Just before the war the International Council for the Exploration

6 Rep. Danish Biol. Stat. xxiv. 1916.

17 Journ, Mar. Biol. Assoc. May 1918.
18 See E. C. Jee, Hydrography of the English Channel, 1904-17.

PRESIDENT’S ADDRESS. 23

of the Sea’*® arrived at the conclusion that fishery investigations indi-
cated the probability that the great periodic fluctuations in the fisheries
are connected with the fish larve being developed in great quantities
only in certain years. Consequently they advised that plankton work
should be directed primarily to the question whether these fluctuations
depend upon differences in the plankton production in different years.
It was then proposed to begin systematic investigation of the fish
larvee and the plankton in spring and to determine more definitely the
food of the larval fish at various stages.

About the same time Dr. Hjort*® made the interesting suggestion
that possibly the great fluctuations in the number of young fish observed
from year to year may not depend wholly upon the number of eggs
produced, but also upon the relation in time between the hatching of
these eggs and the appearance in the water of the enormous quantity
of Diatoms and other plant plankton upon which the larval fish after
the absorption of their yolk depend for food. He points out that if
even a brief interval occurs between the time when the larve first
require extraneous nourishment and the period when such food is
available, it is highly probable that an enormous mortality would result.
In that case even a rich spawning season might yield but a poor result
in fish in the commercial fisheries of successive years for some time to
come. So that, in fact, the numbers of a year-class may depend not
so much upon a favourable spawning season as upon a coincidence
between the hatching of the larve and the presence of abundance of
phyto-plankton available as food.**

The curve for the spring maximum of Diatoms corresponds in a
general way with the curve representing the occurrence of pelagic fish
eggs in our seas. But is the correspondence sufficiently exact and
constant to meet the needs of the case? The phyto-plankton may still
be relatively small in amount during February and part of March in
some years, and it is not easy to determine exactly when, in the open
sea, the fish eggs have hatched out in quantity and the larve have
absorbed their food-yolk and started feeding on Diatoms.

If, however, we take the case of one important fish—the plaice—we
can get some data from our hatching experiments at the Port Erin
Biological Station which have now been carried on for a period of
seventeen years. An examination of the hatchery records for these
years in comparison with the plankton records of the neighbouring sea,
which have been kept systematically for the fourteen years from 1907

19 Rapports et Proc. Verb. xix. December 1913.

20 Rapports et Proc. Verb. xx. 1914, p. 204.

21 For the purpose of this argument we may include in ‘ phyto-plankton ’
the various groups of Flagellata and other minute organisms which may be
present with the Diatoms,

94 PRESIDENT’S ADDRESS.

to 1920 inclusive, shows that in most of these years the Diatoms were
present in abundance in the sea a few days at least before the fish
larvee from the hatchery were set free, and that it was only in four
years (1908, 09, ’18, and ‘14) that there was apparently some risk of
the larve: finding no phyto-plankten food, or very little. The evidence
so far seems to show that if fish larve are set free in the sea as late as
March 20, they are fairly sure of finding suitable food;** but if they
are hatched as early as February they run some chance of being
starved.

But this does not exhaust the risks to the future fishery. C. G.
Joh. Petersen and Boysen-Jensen in their valuation of the Limfjord*
have shown that in the case not only of some fish but also of the larger
invertebrates on which they feed there are marked fluctuations in the
number of young produced in different seasons, and that it is only at
intervals of years that a really large stock of young is added to the
population.

The prospects of a year’s fishery may therefore depend primarily
upon the rate of spawning of the fish, affected no doubt by hydrographic
and other environmental conditions, secondarily upon the presence of a
sufficient supply of phyto-plankton in the surface layers of the sea at
the time when the fish larve are hatched, and that in its turn depends
upon photosynthesis and physico-chemical changes in the water, and
finally upon the reproduction of the stock of molluscs or worms at the
bottom which constitute the fish food at later stages of growth and
development.

The question has been raised of recent years—Is there enough
plankton in the sea to provide sufficient nourishment for the larger
animals, and especially for those fixed forms such as sponges that are
supposed to feed by drawing currents of plankton-laden water through
the body? Ina series of remarkable papers from 1907 onwards Piitter
and his followers put forward the views (1) that the carbon require-
ments of such animals could not be met by the amount of plankton
in the volume of water that could be passed through the body in a
given time, and (2) that sea-water contained a large amount of dis-
solved organic carbon compounds which constitute the chief if not
the only food of a large number of marine animals. These views
have given rise to much controversy and have been useful in stimu-
lating further research, but I believe it is now admitted that Piitter’s
samples of water from the Bay of Naples and at Kiel were probably
polluted, that his figures were erroneous, and that his conclusions

22 All dates and statements as to occurrence refer to the Irish Sea round
the south end of the Isle of Man. For further details see Report Lancs. Sea-

Fish, Lab. for 1919.
23 Report of Danish Biol. Station for 1919.

PRESIDENT’S ADDRESS. 25

must be rejected, or at least greatly modified. His estimates of the
plankton were minimum ones, while it seems probable that his figures
for the organic carbon present represent a variable amount of organic
matter arising from one of the reagents used in the analysis.** The
later experimental work of Henze, of Raben, and of Moore shows that
the organic carbon dissolved in sea-water is an exceedingly minute
quantity, well within the limits of experimental error. Moore puts it,
at the most, at one-millionth part, or 1 mgm. ina litre. At the Dundee
meeting of the Association in 1912 a discussion on this subject took
place, at which Piitter still adhered to a modified form of his hypothesis
of the inadequacy of the plankton and the nutrition of lower marine
animals by the direct absorption of dissolved organic matter. Further
work at Port Erin since has shown that, while the plankton supply
as found generally distributed would prove sufficient for the nutrition
of such sedentary animals as Sponges and Ascidians, which require ta
filter only about fifteen times their own volume of water per hour,
it is quite inadequate for active animals such as Crustaceans and Fishes.
These latter are, however, able to seek out and capture their food, and
are not dependent on what they may filter or absorb from the sea-
water. This result accords well with recorded observations on the
irregularity in the distribution of the plankton, and with the variations
in the occurrence of the migratory fishes which may be regarded as
_ following and feeding upon the swarms of planktonic organisms.
. This then, like most of the subjects I am dealing with, is still a
_ matter of controversy, still not completely understood. Our need, then,
is Research, more Research, and still more Research.
Our knowledge of the relations bétween plankton productivity and
_ variation and the physico-chemical environment is still in its infancy,
but gives promise of great results in the hands of the bio-chemist and
_ the physical chemist.
4 Recent papers by Sérensen, Palitzsch, Witting, Moore, and others
have made clear that the amount of hydrogen-ion concentration as
indicated by the relative degree of alkalinity and acidity in the sea-
water may undergo local and periodic variations and that these have
an. effect upon the living organisms in the water and can be correlated
with their presence and abundance. To take an example from our
own seas, Professor Benjamin Moore and his assistants in their work
at the Port Erin Biological Station in successive years from 1912
onwards have shown** that the sea around the Isle of Man is a good
deal more alkaline in spring (say April) than it is in summer (say
24 See Moore, etc., Bio.-Chem. Journ. vi. p. 266, 1912.
4 *5'* Photosynthetic phenomena in sea-water,’ Z'rans. Liverpool Biol. Soc.
_ ~XX1xX. 233, 1915.

26 PRESIDENTS ADDRESS.

July). The alkalinity, which gets low in summer, increases somewhat
in autumn, and then decreases rapidly, to disappear during the winter ;
and then once more, after several months of a minimum, begins to
come into evidence again in March, and rapidly rises to its maximum
in April or May. This periodic change in alkalinity will be seen to
correspond roughly with the changes in the living microscopic contents
of the sea represented by the phyto-plankton annual curve, and the
connection between the two will be seen when we realise that the
alkalinity of the sea is due to the relative absence of carbon dioxide.
In early spring, then, the developing myriads of diatoms in their
metabolic processes gradually use up the store of carbon dioxide accumu-
lated during the winter, or derived from the bi-carbonates of calcium
and magnesium, and so increase the alkalinity of the water, till the
maximum of alkalinity, due to the fixation of the carbon and the reduc-
tion in amount of carbon dioxide, corresponds with the crest of the
phyto-plankton curve in, say, April. Moore has calculated that the
annual turnover in the form of carbon which is used up or converted
from the inorganic into an organic form probably amounts to some-
thing of the order of 20,000 or 30,000 tons of carbon per cubic mile
of sea-water, or, say, over an area of the Irish Sea measuring 16 square
miles and a depth of 50 fathoms; and this probably means a production
each season of about two tons of dry organic matter, corresponding to
at least ten tons of moist vegetation, per acre—which suggests that
we may still be very far from getting from our seas anything like the
amount of possible food-matters that are produced annually.

Testing the alkalinity of the sea-water may therefore be said to be
merely ascertaining and measuring the results of the photosynthetic
activity of the great phyto-plankton rise in spring due to the daily
increase of sunlight.

The marine biologists of the Carnegie Institute, Washington, have
made a recent contribution to the subject in certain observations on
the alkalinity of the sea (as determined by hydrogen-ion concentration),
during which they found in tropical mid-Pacific a sudden change to
acidity in a current running eastwards. Now in the Atlantic the Gulf
Stream, and tropical Atlantic waters generally, are much more alkaline
than the colder coastal water running south from the Gulf of St.
Lawrence. ‘That is, the colder Arctic water has more carbon dioxide.
This suggests that the Pacific easterly set may be due to deeper water,
containing more carbon dioxide (=acidity), coming to the surface at
that point. The alkalinity of the sea-water can be determined rapidly
by mixing the sample with a few drops of an indicator and observing
the change of colour; and this method of detecting ocean currents by
observing the hydrogen-ion concentration of the water might be useful
to navigators as showing the time of entrance to a known current.

— Er

PRESIDENT’S ADDRESS. 27

Oceanography has many practical applications—chiefly, but by no
means wholly, on the biological side. The great fishing industries of
the world deal with living organisms, of which all the vital activities
and the inter-relations with the environment are matters of scientific
investigation. Adquiculture is as susceptible of scientific treatment as
agriculture can be; and the fisherman who has been in the past too
much the nomad and the hunter—if not, indeed, the devastating raider—
must become in the future the settled farmer of the sea if his harvest
is to be less precarious. Perhaps the nearest approach to cultivation
of a marine product, and of the fisherman reaping what he has actually
sown, is seen in the case of the oyster and mussel industries on the
west coast of France, in Holland, America, and to a less extent on
our own coast. Much jas been done by scientific men for these and
other similar coastal fisheries since the days when Professor Coste
in France in 1859 introduced oysters from the Scottish oyster-beds to
start the great industry at Arcachon and elsewhere. Now we buy
back the descendants of our own oysters from the French ostreicul-
turists to replenish our depleted beds.

It is no small matter to have introduced a new and important food-
fish to the markets of the world. The remarkable deep-water ‘tile-
fish,’ new to science and described as Lopholatilus chameleonticeps,
was discovered in 1879 by one of the United States fishing schooners
to the south of Nantucket, near the 100-fathom line. Several thousand
pounds weight were caught, and the matter was duly investigated by
the United States Fish Commission. For a couple of years after that
the fish was brought to market in quantity, and then something unusual
happened at the bottom of the sea, and in 1882 millions of dead tile-
fish were found floating on the surface over an area of thousands of
square miles. The schooner Navarino sailed for two days and a night
through at least 150 miles of sea, thickly covered as far as the eye

could reach with dead fish, estimated at 256,000 to the square mile.

The Fish Commission sent a vessel to fish systematically over the
grounds known as the ‘ Gulf Stream slope,’ where the tile-fish had
been so abundant during the two previous years, but she did not catch
a single fish, and the associated sub-tropical invertebrate fauna was
also practically obliterated.

This wholesale destruction was attributed by the American oceano-
graphers to a sudden change in the temperature of the water at the
bottom, due in all probability to a withdrawal southwards of the warm
Gulf Stream water and a flooding of the area by the cold Labrador
current.

I am indebted to Dr. C. H. Townsend, Director of the celebrated
New York Aquarium, for the latest information in regard to the

98 PRESIDENT’S ADDRESS.

yeappearance in quantity of this valuable fish upon the old fishing grounds
off Nantucket and Long Island, at about 100 miles from the coast to
the east and south-east of New York. It is believed that the tile-fish
is now abundant enough to maintain an important fishery, which will
add an excellent food-fish to the markets of the United States. It is
easily caught with lines at all seasons of the year, and reaches a
length of over three feet and a weight of 40 to 50 pounds. During
July 1915 the product of the fishery was about two and a half million
pounds weight, valued at 55,000 dollars, and in the first few months
of 1917 the catch was four and a half million pounds, for which the
fishermen received 247,000 dollars.

We can scarcely hope in European seas to add new food-fishes to our
markets, but much may be done through the qp-operation of scientific
investigators of the ocean with the Administrative Departments to bring:
about a more rational conservation and exploitation of the national
fisheries.

Earlier in this address I referred to the pioneer work of the dis-
tinguished Manx naturalist, Professor Edward Forbes. There are
many of his writings and of his lectures which I have no space to
refer to which have points of oceanographic interest. Take this, for
example, in reference to our national sea fisheries. We find him in
1847 writing to a friend: ‘ On Friday night I lectured at the Royal
Institution. The subject was the bearing of submarine researches and
distribution matters on the fishery question. I pitched into Govern-
ment mismanagement pretty strong, and made a fair case of it. It
seems to me that at a time when half the country is starving we are
utterly neglecting or grossly mismanaging great sources of wealth
and food. . . . Were I arich man I would make the subject a hobby,
for the good of the country and for the better proving that the true
interests of Government are those linked with and inseparable from
Science.’ We must still cordially approve of these last words, while
recognising that our Government Department of Fisheries is now being
organised on better lines, is itself carrying on scientific work of national
importance, and is, I am happy to think, in complete sympathy with
the work of independent scientific investigators of the sea and desirous
of closer co-operation with University laboratories and _ biological
stations.

During recent years one of the most important and most frequently
discussed of applications of fisheries investigation has been the pro-
ductivity of the trawling grounds, and especially those of the North
Sea. It has been generally agreed that the enormous increase of fishing
power during the last forty years or so has reduced the number of
large plaice, so that the average size of that fish caught in our home

PRESIDENT’S ADDRESS. 29

waters has become smaller, although the total number of plaice landed
had continued to increase up to the year of the outbreak of war. Since
then, from 1914 to 1919, there has of necessity been what may be
described as the most gigantic experiment ever seen in the closing of
extensive fishing grounds. It is still too early to say with any certainty
exactly what the results of that experiment have been, although some
indications of an increase of the fish population in certain areas have
been recorded. For example, the Danes, A. C. J ohansen and Kirstine
Smith, find that large plaice landed in Denmark are now more abun-
dant, and they attribute this to a reversal of the pre-war tendency,
due to less intensive fishing. But Dr. James Johnstone has pointed out
that there is some evidence of a natural periodicity in abundance of such
fish and that the results noticed may represent phases in a cyclic change.
If the periodicity noted in Liverpool Bay*® holds good for other
grounds it will be necessary in.any comparison of pre-war and post-
war statistics to take this natural variation in abundance into very
careful consideration.

In the application of oceanographic investigations to sea-fisheries
problems, one ultimate aim, whether frankly admitted or not, must
be to obtain some kind of a rough approximation to a census or valua-
tion of the sea—of the fishes that form the food of man, of the lower
animals of the sea-bottom on which many of the fishes feed, and of
the planktonic contents of the upper waters which form the ultimate
organised food of the sea—and many attempts have been made in
different ways to attain the desired end.

Our knowledge of the number of animals living in different regions
of the sea is for the most part relative only. We know that one haul
of the dredge is larger than another, or that one locality seems richer
than another, but we have very little information as to the actual
numbers of any kind of animal per square foot or per acre in the sea.
Hensen, as we have seen, attempted to estimate the number of food-
fishes in the North Sea from the number of their eggs caught im a
comparatively small series of hauls of the tow-net, but the data were
probably quite insufficient and the conclusions may be erroneous. It
is an interesting speculation to which we cannot attach any economic
importance. Heincke says of it: ‘This method appears theoretically
feasible, but presents in practice so many serious difficulties that no
positive results of real value have as yet been obtained.’

All biologists must agree that to determine even approximately the
number of individuals of any particular species living in a known area

is a contribution to knowledge which may be of great economic value

26 See Johnstone, Report Lancs. Sea-Fish Lab; for 1917, p. 60; and Daniel,
Report for 1919, p. 51.

30 PRESIDENT’S ADDRESS. aac

in the case of the edible fishes, but it may be doubted whether Hensen’s
methods, even with greatly increased data, will ever give us the
required information. Petersen’s method, of setting free marked plaice
and then assuming that the proportion of these recaught is to the total
number marked as the fishermen’s catch in the same district is to the
total population, will only hold good in circumscribed areas where there
is practically no migration and where the fish are fairly evenly dis-
tributed. This method gives us what has been called ‘the fishing
coefficient,’ and this has been estimated for the North Sea to have a
probable value of about 0°33 for those sizes of fish which are caught by
the trawl. Heincke,*’ from an actual examination of samples of the
stock on the ground obtained by experimental trawling (‘ the catch
coefficient ’), supplemented by the market returns of the various
countries, estimates the adult plaice at about 1,500 millions, of which
about 500 millions are caught or destroyed by the fishermen annually.

It is difficult to imagine any further method which will enable us
to estimate any such case as, say, the number of plaice in the North
Sea where the individuals are so far beyond our direct observation and
are liable to change their positions at any moment. But a beginning
can be made on more accessible ground with more sedentary animals,
and Dr. C. G. Joh. Petersen, of the Danish Biological Station, has
for some years been pursuing the subject in a series of interesting
Reports on the ‘ Evaluation of the Sea.’?* He uses a bottom-sampler,
or grab, which can be lowered down open and then closed on the
bottom so as to bring up a sample square foot or square metre (or in
deep water one-tenth of a square metre) of the sand or mud and its
inhabitants. With this apparatus, modified in size and weight for
different depths and bottoms, Petersen and his fellow-workers have
made a very thorough examination of the Danish waters, and especially
of the Kattegat and the Limfjord, have described a series of ‘ animal
communities ’ characteristic of different zones and regions of shallow
water, and have arrived at certain numerical results as to the quantity
of animals in the Kattegat expressed in tons—such as 5,000 tons of
plaice requiring as food 50,000 tons of ‘ useful animals’ (mollusca and
polychaet worms), and 25,000 tons of starfish using up 200,000 tons
of useful animals which might otherwise serve as food for fishes, and
the dependence of all these animals directly or indirectly upon the
great beds of Zostera, which make up 24,000,000 tons in the Kattegat.
Such estimates are obviously of great biological interest, and even if
only rough approximations are a valuable contribution to our under-

*7 F. Heincke, Oons. Per. Internat. Explor. de la Mer, ‘Investigations on
the Plaice,’ Copenhagen, 1913.

28 See Reports of the Danish Biological Station, and especially the Report
for 1918 ‘ The Sea Bottom and its Production of Fish Food,’ E

a PRESIDENT’S ADDRESS, 31

standing of the metabolism of the sea and of the possibility of increasing
the yield of local fisheries.
But on studying these Danish results in the light of what we know
of our own marine fauna, although none of our seas have been examined
in the same detail by the bottom-sampler method, it seems probable that
the animal communities as defined by Petersen are not exactly applicable
on our coasts and that the estimates of relative and absolute abundance
may be very different in different seas under different conditions. The
work will have to be done in each great area, such as the North Sea, the
English Channel, and the Irish Sea, independently. This is a necessary
_ investigation, both biological and physical, which lies before the oceano-
graphers of the future, upon the results of which the future preservation
and further cultivation of our national sea-fisheries may depend.
: It has been shown by Johnstone and others that the common edible
animals of the shore may exist in such abundance that an area of the
sea may be more productive of food for man than a similar area of
_ pasture or crops on land. A Lancashire mussel bed has been shown
to have as many as 16,000 young mussels per square foot, and it is
estimated that in the shallow waters of Liverpool Bay there are from
twenty to 200 animals of sizes varying from an amphipod to a plaice
on each square metre of the bottom.”*
From these and similar data which can be readily obtained, it is
not difficult to calculate totals by estimating the number of square
_ yards in areas of similar character between tide-marks or in shallow
water. And from weighings of samples some approximation to the
number of tons of available food may be computed. But one must
not go too far. Let all the figures be based upon actual observation.
_ Imagination is necessary in science, but in calculating a population
; of even a very limited area it is best to believe only what one can
see and measure.
Countings and weighings, however, do not give us all the informa-
tion we need. It is something to know even approximately the number
of millions of animals on a mile of shore and the number of millions
of tons of possible food in a sea-area, but that is not sufficient. All
food-fishes are not equally nourishing to man, and all plankton and
bottom invertebrata are not equally nourishing to a fish. At this
point the biologist requires the assistance of the physiologist and the
bio-chemist. We want to know next the value of our food matters
in proteids, carbohydrates, and fats, and the resulting calories. Dr.
Johnstone, of the Oceanography Department of the University of
Liverpool, has already shown us how markedly a fat summer herring

—

29 Conditions of Life in the Sea, Cambridge Univ. Press. 1908.

32 PRESIDENT’S ADDRESS.

differs in essential constitution from the ordinary white fish, euck.; as
the cod, which is almost destitute of fat.

Professor Brandt, at Kiel, Professor Benjamin Moore, at Port
Erin, and others have similarly shown that plankton gatherings may
vary greatly in their nutrient value according as they are composed
mainly of Diatoms, of Dinoflagellates, or of Copepoda. And, no doubt,
the animals of the ‘ benthos,’ the common invertebrates of our shores,
will show similar differences in analysis.*° It is obvious that some
contain more solid flesh, others more water in their tissues, others
more calcareous matter in the exoskeleton, and that therefore weight
for weight we may be sure that some are more nutritious than the others ;
and this is probably at least one cause of that preference we see in
some of our bottom-feeding fish for certain kinds of food, such as
polychaet worms, in which there is relatively little waste, and thin-
shelled lamellibranch molluscs, such as young mussels, which have a
highly nutrient body in a comparatively thin and brittle shell.

My object in referring to these still incomplete investigations is to
direct attention to what seems a natural and useful extension of faunistic
work, for the purpose of obtaining some approximation to a quantitative
estimate of the more important animals of our shores and shallow
water and their relative values as either the immediate or the ultimate
food of marketable fishes.

Each such fish has its ‘ food-chain’ or series of alternative chains,
leading back from the food of man to the invertebrates upon which it
preys and then to the food of these, and so down to the smallest and
simplest organisms in the sea, and each such chain must have all
its links fully worked out as to seasonal and quantitative occurrence
back to the Diatoms and Flagellates which depend upon physical con-
ditions and take us beyond the range of biology—but not beyond that
of oceanography. The Diatoms and the Flagellates are probably more
important than the more obvious sea-weedg not only as food, but also
in supplying to the water the oxygen necessary for the respiration
of living protoplasm. Our object must be to estimate the rate of pro-
duction and rate of destruction of all organic substances in the sea.

To attain to an approximate census and valuation of the sea—
remote though it may seem—is a great aim, but it is not sufficient.
We want not only to observe and to count natural objects, but also
to understand them. We require to know not merely what an organism
is—in the fullest detail of structure and development and affinities—

80 Moore and others have made analyses of the protein, fat, etc., in the soft
parts of Sponge, Ascidian, Aplysia, Fusus, Echinus and Cancer at Port Erin,
and find considerable differences—the protein ranging, for example, from 8 to

51 per cent., and the fat from 2 to 14 per cent. (see Bio-Chemical Journ. vi.
p. 291).

PRESIDENT’S ADDRESS. 33

and also where it occurs—again in full detail—and in what abundance
under different circumstances, but also how it lives and what all its
relations are to both its physical and its biological environment, and that
is where the physiologist, and especially the bio-chemist, can help us.
In the best interests of biological progress the day of the naturalist
who merely collects, the day of the anatomist and histologist who
merely describe, is over, and the future is with the observer and the
experimenter animated by a divine curiosity to enter into the life
of the organism and understand how it lives and moves and has its
being. ‘ Happy indeed is he path has been able to discover the causes
of things.’

Cardiff is a sea-port, and a great sea-port, and the Bristol Channel
is a notable sea-fisheries centre of growing importance. The explorers
and merchant venturers of the South-West of England are celebrated in
history. What are you doing now in Cardiff to advance our knowledge
of the ocean? You have here an important university centre and a
great modern national museum, and either or both of these homes of
research might do well to establish an oceanographical department,
which would be an added glory to your city and of practical utility to
the country. This is the obvious centre in Wales for a sea-fisheries
institute for both research and education. Many important local move-
ments have arisen from British Association meetings, and if such a
notable scientific development were to result from the Cardiff meeting
of 1920, all who value the advance of knowledge and the application of
science to industry would applaud your enlightened action.

But in a wider sense, it is not to the people of Cardiff alone that I
appeal, but to the whole population of these Islands, a maritime people
who owe everything to the sea. I urge them to become better informed
in regard to our national sea-fisheries and take a more enlightened
interest in the basal principles that underlie a rational regulation and
exploitation of these important industries. National efficiency depends
to a very great extent upon the degree in which scientific results and
methods are appreciated by the people and scientific investigation is
promoted by the Government and other administrative authorities.
The principles and discoveries of science apply to aquiculture no less
than to agriculture. To increase the harvest of the sea the fisheries
must be continuously investigated, and such cultivation as is possible
must be applied, and all this is clearly a natural application of the
biological and hydrographical work now united under the science of
Oceanography.

1920 D

SECTION A: CARDIFF, 1920.

ADDRESS

MATHEMATICAL AND PHYSICAL SCIENCE SECTION

Proressor A. 8. EDDINGTON, M.A., M.8c., F.B.S.,

PRESIDENT OF THE SECTION.

The Internal Constitution of the Stars.

Last year at Bournemouth we listened to a proposal from the President
of the Association to bore a hole in the crust of the earth and discover
the conditions deep down below the surface. This proposal may
remind us that the most secret places of Nature are, perhaps, not
10 to the n-th miles above our heads, but 10 miles below our feet.
In the last five years the outward march of astronomical discovery has
been rapid, and the most remote worlds are now scarcely safe from
its inquisition. By the work of H. Shapley the globular clusters, which
are found to be at distances scarcely dreamt of hitherto, have been
explored, and our knowledge of them is in some respects more com-
plete than that of the local aggregation of stars which includes the Sun.
Distance lends not enchantment but precision to the view. Moreover,
theoretical researches of Hinstein and Weyl make it probable that the
space which remains beyond is not illimitable; not merely the
material universe, but space itself, is perhaps finite; and the explorer
must one day stay his conquering march for lack of fresh realms to
invade. But to-day let us turn our thoughts inwards to that other
region of mystery—a region cut off by more substantial barriers, for,
contrary to many anticipations, even the discovery of the fourth
dimension has not enabled us to get at the inside of a body. Science
has material and non-material appliances to bore into the interior, and
I have chosen to devote this address to what may be described as
analytical boring devices—absit omen!

The analytical appliance is delicate at present, and, I fear, would
make little headway. against the solid crust of the earth. Instead of
letting it blunt itself against the rocks, let us look round for something
easier to penetrate. The Sun? Well, perhaps. Many have struggled
to penetrate the mystery of the interior of the Sun; but the difficulties
are great, for its substance is denser than water. It may not be quite
so bad as Biron makes out in Love’s Labour’s Lost: — |

The heaven’s glorious sun,
That will not be deep-searched with saucy looks;
Small have continual plodders ever won
Save base authority from others’ books.

¢
i
(

A.—MATHEMATIUS AND PHYSICS. 35

But it is far better if we can deal with matter in that state. known
as a perfect gas, which charms away difficulties as by magic... Where
shall it be found? . is

A few years ago we should have been puzzled to say where, except
perhaps in certain nebula; but now it is known that abundant material
of this kind awaits investigation. Stars in a truly gaseous state exist
in great numbers, although at first sight they are scarcely to be dis-
criminated from dense stars like our Sun. Not only so, but the
gaseous stars are the most powerful light-givers, so that they force
themselves on our attention. Many of the familiar stars are of this
kind—Aldebaran, Canopus, Arcturus, Antares; and it would be safe
to say that three-quarters of the naked-eye stars are in this diffuse
state. This remarkable condition has been made known through the
researches of H. N. Russell! and E. Hertzsprung; the way.in which
their conclusions, which ran counter to the prevailing thought of the
time, have been substantiated on all sides by overwhelming evidence,
is the outstanding feature of recent progress in stellar astronomy. _

The diffuse gaseous stars are called giants, and the dense stars are
ealled dwarfs. During the life of a star there is presumably a gradual
merease of density through contraction, so that these terms distinguish
the earlier and later stages of stellar history.. It appears that a star
begins its effective life as.a giant of comparatively low temperature—
a red or M-type star. As this diffuse mass of gas contracts its tem-
perature must rise, a conclusion long ago pointed out by Homer Lane.
The rise continues until the star becomes too dense, and ceases to
behave as a perfect gas. A maximum temperature is attained, depend-
ing on the mass, after which the star, which has now become a dwarf,
cools and further contracts. Thus each temperature-level is passed
through twice, once in an ascending and once in a descending stage—
once as a giant, once as a dwarf. ‘Temperature plays so predominant
a part in the usual spectral classification that the ascending and
descending stars were not originally discriminated, and the customary.
classification led to some perplexities. The separation of the two series
was discovered through their great difference in luminosity, particularly
striking in the case of the red and yellow stars, where the two stages
fall widely apart in the star’s history. The bloated giant has a far
larger surface than the compact dwarf, and gives correspondingly
greater light. The distinction was also revealed by direct determina-
tions of stellar densities, which are possible in the case of. eclipsing
variables like Algol. Finally, Adams and Kohlschiitter have set the
seal on this discussion by showing that there are actual spectral differ-
ences between the ascending and descending stars at the same tem-
aie which are conspicuous enough—when they are looked
or.
‘Perhaps we should not too hastily assume that the direction of

evolution is necessarily in the order of increasing density, in view of

our ignorance of the origin of a star’s heat, to which I must allude

later. But, at any rate, it is a great advance to have disentangled what

! Nature, vol. 93, pp. 227, 252, 281.
D2

36 SECTIONAL ADDRESSES.

is the true order of continuous increase of density, which was hidden
by superficial resemblances.

The giant stars, representing the first half of a star’s life, are
taken as material for our first boring experiment. Probably, measured
in time, this stage corresponds to much less than half the life, for
here it is the ascent which is easy and the way down is long and slow.
Let us try to picture the conditions inside a giant star. We need not
dwell on the vast dimensions—a mass like that of the Sun, but swollen
to much greater volume on account of the low density, often below
that of our own atmosphere. It is the star as a storehouse of heat
which especially engages our attention. In the hot bodies familiar to
us the heat consists in the energy of motion of the ultimate particles,
flying at great speeds hither and thither. So too in the stars a great
store of heat exists in this form; but a new feature arises. A large
proportion, sometimes more than half the total heat, consists of
imprisoned radiant energy—ether-waves travelling in all directions
trying to break through the material which encages them. The star
is like a sieve, which can only retain them temporarily ; they are turned
aside, scattered, absorbed for a moment, and flung out again in a new
direction. An element of energy may thread the maze for hundreds
of years before it attains the freedom of outer space. Nevertheless the
sieve leaks, and a steady stream permeates outwards, supplying the
light and heat which the star radiates all round.

That some ethereal heat as well as material heat exists in any hot
body would naturally be admitted; but the point on which we have
here to lay stress is that in the stars, particularly in the giant stars,
the ethereal portion rises to an importance which quite transcends our
ordinary experience, so that we are confronted with a new type of
problem. In a red-hot mass of iron the ethereal energy constitutes
less than a billionth part of the whole; but in the tussle between matter
and ether the ether gains a larger and larger proportion of the energy
as the temperature rises. This change in proportion is rapid, the
ethereal energy increasing rigorously as the fourth power of the tem-
perature, and the material energy roughly as the first power. But even
at the temperature of some millions of degrees attained inside the stars
there would still remain a great disproportion; and it is the low density
of material, and accordingly reduced material energy per unit volume
in the giant stars, which wipes out the last few powers of 10. In all
the giant stars known to us, widely as they differ from one another, the
conditions are just reached at which these two varieties of heat-energy
have attained a rough equality; at any rate one cannot be neglected
compared with the other. Theoretically there could be conditions in
which the disproportion was reversed and the ethereal far out-weighed
the material energy; but we do not find them in the stars. It is as
though the stars had been measured out—that their sizes had been
determined—with a view to this balance of power; and one cannot
refrain from attributing to this condition a deep significance in the
evolution of the cosmos into separate stars.

To recapitulate. We are acquainted with heat in two forms—the
energy of motion of material atoms and the energy of ether waves. In

OE ———

A.—MATHEMATICS AND PHYSICS. 37

familiar hot bodies the second form exists only in insignificant quanti-
ties. In the giant stars the two forms are present in more or less equal
proportions. That is the new feature of the problem.

On account of this new aspect of the problem the first attempts to
penetrate the interior of a star are now seen to need correction. In
saying this we do not depreciate the great importance of the early
researches of Lane, Ritter, Emden, and others, which not only pointed
the way for us to follow, but achieved conclusions of permanent value.
One of the first questions they had to consider was by what means the
heat radiated into space was brought up to the surface from the low
level where it was stored. They imagined a bodily transfer of the hot
material to the surface by currents of convection, as in our own
atmosphere. But actually the problem is, not how the heat can be
brought to the surface, but how the heat in the interior can be held
back sufficiently—how it can be barred in and the leakage reduced to the
comparatively small radiation emitted by the stars. Smaller bodies
have to manufacture the radiant heat which they emit, living from
hand to mouth; the giant stars merely leak radiant heat from their
store. I have put that much too crudely; but perhaps it suggests the
general idea.

The recognition of ethereal energy necessitates a twofold modifi-
cation in the calculations. In the first place, it abolishes the supposed
convection currents; and the type of equilibrium is that known as
radiative instead of convective. This change was first suggested by
R. A. Sampson so long ago as 1894. The detailed theory of radiative
equilibrium is particularly associated with K. Schwarzschild, who
applied it to the Sun’s atmosphere. It is perhaps still uncertain whether
it holds strictly for the atmospheric layers, but the arguments for its
validity in the interior of a star are far more cogent. Secondly, the
outflowing stream of ethereal energy is powerful enough to exert a
direct mechanical effect on the equilibrium of a star. It is as though
a strong wind were rushing outwards. In fact we may fairly say that
the stream of radiant energy is a wind; for though ether waves are not
usually classed as material, they have the chief mechanical properties
of matter, viz. mass and momentum. This wind distends the star
and relieves the pressure on the inner parts. The pressure on the gas
in the interior is not the full weight of the superincumbent columns,
because that weight is partially borne by the force of the escaping
ether waves beating their way out. This force of radiation-pressure,
as it is called, makes an important difference in the formulation of the
conditions for equilibrium of a star.

Having revised the theoretical investigations in accordance with
these considerations,? we are in a position to deduce some definite
numerical results. On the observational side we have fairly satis-
factory knowledge of the masses and densities of the stars and of the
total radiation emitted by them; this knowledge is partly individual and
partly statistical. The theoretical analysis connects these observational
data on the one hand with the physical properties of the material inside

2 Astrophysical Journal, vol. 48, p. 205.

38 SECTIONAL ADDRESSES.

the star on the other hand. We can thus find certain information as to
the inner material, as though we had actually bored a hole. So far as
can be judged there are only two physical properties of the material
which can concern us—always provided that it is sufficiently rarefied
to behave as a perfect gas—viz. the average molecular weight and
the transparency or permeability to radiant energy. In connecting
these two unknowns with the quantities given directly by astronomical
observation we depend entirely on the well-tried principles of conserva-
tion of momentum and the second law of thermodynamics. If any
element of speculation remains in this method of investigation, I think
it is no more than is inseparable from every kind of theoretical-advance.

We have, then, on the one side the mass, density and output of
heat, quantities as to which we have observational knowledge; on the
other side, molecular weight and transparency, quantities which we
want to discover.

To find the transparency of stellar material to the radiation
traversing it, is of particular interest because it links on this
astronomical inquiry to physical investigations now being carried on in
the laboratory, and to some extent it extends those investigations to
conditions unattainable on the earth. At high temperatures the
ether waves are mainly of very short wave-length, and in the stars we
are dealing mainly with radiation of wave-length 3 to 30 Angstrém
units, which might be described as very soft x-rays. It is interesting,
therefore, to compare the results with the absorption of the harder
a-rays dealt with by physicists. To obtain an exact measure of this
absorption in the stars we have to assume a value of the molecular
weight; but fortunately the extreme range possible for the molecular
weight gives fairly narrow limits for the absorption. The average
weight of the ultimate independent particles in a star is probably
rather low, because in the conditions prevailing there the atoms would
be strongly ionised; that is to say, many of the outer electrons of the
system of the atom would be broken off; and as each of these free
electrons counts as an independent molecule for the present purposes,
this brings down the average weight. In the extreme case (probably
not reached in a star) when the whole of the electrons outside the
nucleus are detached the average weight comes down to about 2,
whatever the material, because the number of electrons is about half
the atomic weight for all the elements (except hydrogen). We may,
then, safely take 2 as the extreme lower limit. For an upper limit we
might perhaps take 200; but to avoid controversy we shall be generous
and merely assume that the molecular weight is not greater than—
infinity. Here is the result :—

For molecular weight 2, mass-coefficient of absorption=10

©.G.8. units.

For molecular weight co , mass-coefficient of absorption =130

C.G.§. units.

The true value, then, must be between 10 and 130. Partly from
thermodynamical considerations, and partly from further comparisons
of astronomical observation with theory, the most likely value seems
to be about 35 C.G.S. units, corresponding to molecular weight 3°5.

Dll it i ee a

A.—MATHEMATICS AND PHYSICS. 39

Now this is of the same order of magnitude as the absorption of
a@-rays measured in the laboratory. I think the result is in itself of
some interest, that in such widely different investigations we should
approach the same kind of value of the opacity of matter to radiation.
The penetrating power of the radiation in the star is much like that of
x-rays; more than half is absorbed in a path of 20 cms. at atmospheric
density. Incidentally, this very high opacity explains why a star is so
nearly heat tight, and can store vast supplies of heat with comparatively
little leakage.

So far this agrees with what might have been anticipated; but there
is another conclusion which physicists would probably not have foreseen.
The giant series comprises stars differing widely in their densities and
temperatures, those at one end of the series being on the average
about ten times hotter throughout than those at the other end. By
the present investigation we can compare directly the opacity of the
hottest stars with that of the coolest stars. The rather surprising
result emerges that the opacity is the same for all; at any rate there
is no difference large enough for us to detect. There seems no room
for doubt that at these high temperatures the absorption-coefficient is
approaching a limiting value, so that over a wide range it remains
practically constant. With regard to this constancy, it is to be noted
that the temperature is concerned twice over: it determines the character
and wave-length of the radiation to be absorbed, as well as the physical
condition of the material which is absorbing. From the experimental
knowledge of x-rays we should have expected the absorption to vary
very rapidly with the wave length, and therefore with the temperature.
it is surprising, therefore, to find a nearly constant value.

The result becomes a little less mysterious when we consider more
closely the nature of absorption. Absorption is not a continuous
process, and after an atom has absorbed its quantum it is put out of
action for a ‘time until it can recover its original state. We know
very little of what determines the rate of recovery of the atom, but it
seems clear that there is a limit to the amount of absorption that can
be performed by an atom in a given time. When that limit is reached
no increase in the intensity of the incident radiation will lead to any
more absorption. There is in fact a saturation effect. In the
laboratory experiments the radiation used is extremely weak; the atom
is practically never caught unprepared, and the absorption is propor-
tional to the incident radiation. But in the stars the radiation is very
intense and the saturation effect comes in.

Even granting that the problem of absorption in the stars involves
this saturation effect, which does not affect laboratory experiments, it
is not very easy to understand theoretically how the various conditions
combine to give a constant absorption-coefficient independent of tem-
perature and wave-length. But the astronomical results seem con-
clusive. Perhaps the most hopeful suggestion is one made to me a
few years ago by C. G. Barkla. He suggested that the opacity of
the stars may depend mainly on scattering rather than on true atomic
absorption. In that case the constancy has a simple explanation, for
it is known that the coefficient of scattering (unlike true absorption)

40 SECTIONAL ADDRESSES.

approaches a definite constant value for radiation of short wave-length.
The value, moreover, is independent of the material. Further, scat-
tering is a continuous process, and there is no likelihood of any
saturation effect; thus for very intense streams of radiation its value is
maintained, whilst the true absorption may sink to comparative
insignificance. The difficulty in this suggestion is a numerical dis-
crepancy between the known theoretical scattering and the values
already given as deduced from the stars. The theoretical coefficient
is only 0°2 compared with the observed value 10 to 130. SBarkla further
pointed out that the waves here concerned are not short enough to give
the ideal coefficient ; they would be scattered more powerfully, because
under their influence the electrons in any atom would all vibrate in the
same phase instead of haphazard phases. This might help to bridge
the gap, but not sufficiently. It must be remembered that many of the
electrons have broken loose from the atom and do not contribute to the
increase.* Making all allowances for uncertainties in the data, it seems
clear that the astronomical opacity is definitely higher than the theoretical
scattering. Very recently, however, a new possibility has opened up
which may possibly effect a reconciliation. Later in the address I shall
refer to it again.

Astronomers must watch with deep interest the investigations of
these short waves, which are being pursued in the laboratory, as well
as the study of the conditions of ionisation both by experimental and
theoretical physics, and I am glad of this opportunity of bringing before
iheke who deal with these problems the astronomical bearing of their
work.

I can only allude very briefly to the purely astronomical results
which follow from this investigation ;* it is here that the best oppor-
tunity occurs for checking the theory by comparison with observation,
and for finding out in what respects it may be deficient. Unfortunately,
the observational data are generally not very precise, and the test is not
so stringent as we could wish. It turns out that (the opacity being
constant) the total radiation of a giant star should be a function of its
mass only, independent of its temperature or state of diffuseness. The
total radiation (which is measured roughly by the luminosity) of any
one star thus remains constant during the whole giant stage of its
history. This agrees with the fundamental feature, pointed out by
Russell in introducing the giant and dwarf hypothesis, that giant stars
of every spectral type have nearly the same luminosity. From the
range of luminosity of these stars it is now possible to find their range
of mass. The masses are remarkably alike—a fact already suggested
by work on double stars. Limits of mass in the ratio 3: 1 would cover
the great majority of the giant stars. Somewhat tentatively we are able
to extend the investigation to dwarf stars, taking account of the

3 E.g., for iron non-ionised the theoretical scattering is 5.2, against an
astronomical value 120. If 16 electrons (2 rings) are broken off the theoretical
coefficient is 0.9 against an astronomical value 35. For different assumptions
as to ionisation the values chase one another, but cannot be brought within
reasonable range.

4 Monthly Notices, vol. 77, pp. 16, 596; vol. 79, p. 2.

A.—MATHEMATICS AND PHYSICS. 41

deviations of dense gas from the ideal laws and using our own Sun to
supply a determination of the unknown constant involved. We can
calculate the maximum temperature reached by different masses; for
example, a star must have at least + the mass of the Sun in order to
reach the lowest spectral type, M; and in order to reach the hottest
type, B, it must be at least 24 times as massive as the Sun. Happily
for the theory no star has yet been found with a mass less than
4 of the Sun’s; and it is a well-known fact, discovered from the study
_ of spectroscopic binaries, that the masses of the B stars are large com-
_ pared with those of other types. Again, it is possible to calculate the
_ difference of brightness of the giant and dwarf stars of type M, i.e. at
the beginning and end of their career ; the result agrees closely with the
observed difference. In the case of a class of variable stars in which
the light changes seem to depend on a mechanical pulsation of the
star, the knowledge we have obtained of the internal conditions enables
us to predict the period of pulsation within narrow limits. For example,
for 8 Cephei, the best-known star of this kind, the theoretical period
is between 4 and 10 days, and the actual period is 53 days. Correspond-
ing agreement is found in all the other cases tested.

Our observational knowledge of the things here discussed is chiefly

of a rather vague kind, and we can scarcely claim more than a general
agreement of theory and observation. What we have been able to do
in the way of tests is to offer the theory a considerable number of
opportunities to ‘make a fool of itself,’ and so far it has not fallen
into our traps. When the theory tells us that a star having the mass
of the Sun will at one stage in its career reach a maximum effective
temperature of 9,000° (the Sun’s effective temperature being 6,000°)
we cannot do much in the way of checking it; but an erroneous theory
might well have said that the maximum temperature was 20,000° (hotter
than any known star), in which case we should have detected its error.
Tf we cannot feel confident that the answers of the theory are true, it
must be admitted that it has shown some discretion in lying without
being found out.
_ It would not be surprising if individual stars occasionally depart
considerably from the calculated results, because at present no serious
attempt has been made to take into account rotation, which may modify
the conditions when sufficiently rapid. That appears to be the next
step needed for a more exact study of the question.

Probably the greatest need of stellar astronomy at the present day,
in order to make sure that our theoretical deductions are starting on the
right lines, is some means of measuring the apparent angular diameters
ofstars. At present we can calculate them approximately from theory,
but there is no observational check. We believe we know with fair
accuracy the apparent surface brightness corresponding to each spectral
type; then all that is necessary is to divide the total apparent brightness
by this surface brightness, and the result is the angular area subtended
by the star. The unknown distance is not involved, kecause surface
brightness is independent of distance. Thus the estimation of the
angular diameter of any star seems to be a very simple matter. For
instance, the star with the greatest apparent diameter is almost certainly

:
|
:
|

42 SECTIONAL ADDRESSES.

Betelgeuse, diameter 051”. Next to it comes Antares, 043”. Other
examples are Aldebaran “022”, Arcturus “020”, Pollux 013”. Sirius
comes rather low down with diameter 007”. The following table may
be of interest as showing the angular diameters expected for stars of
various types and visual magnitudes :—

Probable Angular Diameters of Stars.

Vis. Mag. | A | F | G | K | M
eee | eS
m. | iad | 7 | ” wt | mr
0-0 - | -0034 | -0054 -0098 0219 -0859
2-0 -0014 -0022 | -0039 -0087 | -0342
| +0016 0035 «| +0136

4-0 | “0005 0009

However confidently we may believe in these values, it would be
an immense advantage to have this first step in our deductions placed
beyond doubt. If the direct measurement of these diameters could be
made with any accuracy it would make a wonderfully rapid advance
in our knowledge. The prospects of accomplishing some part of this
task are now quite hopeful. We have learnt with great interest this
year that work is being carried out by interferometer methods with the
100-inch reflector at Mount Wilson, and the results are most promising,
At present the method has only been applied to measuring the separation
of close double stars, but there seems to be no doubt that an angular
diameter of “05” is well within reach. Although the great mirror is
used for convenience, the interferometer method does not in principle
require great apertures, but rather two small apertures widely separated
as in a range-finder. Prof. Hale has stated, moreover, that success-
ful results were obtained on nights of poor seeing. Perhaps it would
be unsafe to assume that ‘ poor seeing’ at Mount Wilson means quite
the same thing as it does for us, and I anticipate that atmospheric
disturbance will ultimately set the limit to what can be accomplished,
But even if we have to send special expeditions to the top of one of the
highest mountains in the world the attack on this far-reaching problem
must not be allowed to languish.

I spoke earlier of the radiation-pressure exerted by the outflowing
heat, which has an important effect on the equilibrium of a star. It is
quite easy to calculate what proportion of the weight of the material
is supported in this way; it depends neither on the density nor opacity,
but solely on the star’s total mass and on the molecular weight. No
astronomical data are needed ; the calculation involves only fundamental
physical constants found by laboratory researches. Here are the
figures, first for average molecular weight 3:0 :—

For mass } x Sun, fraction of weight supported by radiation-
pressure = "044.

For mass 5 x Sun, fraction of weight supported by radiation-
pressure =°457.

For molecular weight 5:0 the corresponding fractions are “182 and
"645.

A.—MATHEMATICS AND PHYSICS. 43

The molecular weight can scarcely go beyond this range,*» and
for the conclusions [ am about to draw it does not much mattér which
limit we take. Probably 90 per cent. of the giant stars have masses be-
tween 4 and 5 times the Sun’s, and we see that this is just the range in
which radiation-pressure rises from unimportance’ to importance. «It
seems clear that a globe of gas of larger mass, in which radiation-pres-
sure and gravitation are nearly balancing, would be likely to be unstable.
The condition may not be strictly unstable in itself; but’a small rotation
or perturbation would make it so. It may therefore be conjectured
that, if nebulous material began to concentrate into a mass much greater
than 5 times the Sun’s, it would probably break up, and continue to
redivide until more stable masses resulted. Above the upper limit the
chances of survival are small; when the lower limit is approached the
danger has practically disappeared, and there is little likelihood of any
further breaking-up. Thus the final masses are left distributed almost
entirely between the limits given. To put the matter slightly differently,
we are able to predict from general principles that the material of the
stellar universe will aggregate primarily into. masses chiefly lying
between 10°° and 10% grams; and this is just the magnitude of the
masses of the stars according to astronomical observation.*®

This study of the radiation and internal conditions of a star brings
forward very pressingly a problem often debated in this Section:
What is the source of the heat which the Sun and stars are continually
squandering? The answer given is almost unanimous—that it is
obtained from the gravitational energy converted as the star steadily
contracts. But almost as unanimously this answer is ignored in its
practical consequences. Lord Kelvin showed that this hypothesis, due
to Helmholtz, necessarily dates the birth of the Sun about 20,000,000
years ago; and he made strenuous efforts to induce geologists and
biologists to accommodate their demands to this time-scale. I do not
think they proved altogether tractable. But it is among his own col-
leagues, physicists and astronomers, that the most outrageous violations
of this limit have prevailed. I need only refer to Sir George Darwin’s
theory of the earth-moon system, to the present Lord Rayleigh’s deter-
mination of the age of terrestrial rocks from occluded helium, and to all
modern discussions of the statistical equilibrium of the stellar system.
No one seems to have any hesitation, if it suits him, in carrying back
the history of the earth long before the supposed date of formation
of the solar system ; and in some cases at least this appears to be justified

> As an illustration of these limits, iron has 26 outer electrons ; if 10 break
away the average molecular weight is 5; if 18 break away the molecular weight
is 3. Eggert (Phys. Zeits. 1919, p. 570) has suggested by thermodynamical]
reasoning that in most cases the two outer rings (16 electrons) would break away
in the stars. The comparison of theory and observation for the dwarf stars
also points to a molecular weight a little greater than 3.

6 By admitting plausible assumptions closer limits could be drawn. Taking
the molecular weight as 3.5, and assuming that the most critical, condition is
when 4 of gravitation is counterbalanced (by analogy with the case of rotating
spheroids, in which centrifugal force opposes gravitation and creates instability),
we find that the critical mass is just twice that of the Sun, and stellar masses
may be expected to cluster closely round this value,

44 SECTIONAL ADDRESSES.

by experimental evidence which it is difficult to dispute. Lord Kelvin’s
date of the creation of the Sun is treated with no more respect than
Archbishop Ussher’s.

The serious consequences of this contraction hypothesis are particu-
larly prominent in the case of giant stars, for the giants are prodigal
with their heat and radiate at least a hundred times as fast as the
Sun. The supply of energy which suffices to maintain the Sun for
10,000,000 years would be squandered by a giant star in less than
100,000 years. The whole evolution in the giant stage would have to
be very rapid. In 18,000 years at the most a typical star must pass
from the initial M stage totype G. In 80,000 years it has reached type
A, near the top of the scale, and is about to start on the downward
path. Even these figures are probably very much over-estimated.’
Most of the naked-eye stars are still in the giant stage. Dare we
believe that they were all formed within the last 80,000 years? The
telescope reveals to us objects not only remote in distance but remote
in time. We can turn it on a globular cluster and behold what was
passing 20,000, 50,000, even 200,000 years ago—unfortunately not all
in the same cluster, but different clusters representing different epochs
of the past. As Shapley has pointed out, the verdict appears to be
‘nochange.’ This is perhaps not conclusive, because it does not follow
that individual stars have suffered no change in the interval; but it is
difficult to resist the impression that the evolution of the stellar universe
proceeds at a slow, majestic pace, with respect to which these periods of
time are insignificant.

There is another line of astronomical evidence which appears to
show more definitely that the evolution of the stars proceeds far more
slowly than the contraction hypothesis allows ; and perhaps it may ulti-
mately enable us to measure the true rate of progress. There are
certain stars, known as Cepheid variables, which undergo a regular
fluctuation of light of a characteristic kind, generally with a period of a
few days. This light change is not due to eclipse. Moreover, the
colour quality of the light changes between maximum and minimum,
evidently pointing to a periodic change in the physical condition of the
star. Although these objects were formerly thought to be double
stars, it now seems clear that this was a misinterpretation of the
spectroscopic evidence. There is in fact no room for the hypothetical
companion star; the orbit is so small that we should have to place it
inside the principal star. Everything points to the period of the light
pulsation being something intrinsic in the star; and the hypothesis
advocated by Shapley, that it represents a mechanical pulsation of the
star, seems to be the most plausible. I have already mentioned that the
observed period does in fact agree with the calculated period of
mechanical pulsation, so that the pulsation explanation survives one
fairly stringent test. But whatever the cause of the variability,
whether pulsation or rotation, provided only that it is intrinsic in the

7 I have taken the ratio of specific heats at the extreme possible value, $;
that is to say, no allowance has been made for the energy needed for ionisa-
tion and internal vibrations of the atoms, which makes a further call on the
scanty supply available.

EE — a

A.—MATHEMATICS AND PHYSICS. 45

star, and not forced from outside, the density must be the leading factor
in determining the period. If the star is contracting so that its density
changes appreciably, the period cannot remain constant. Now, on the
contraction hypothesis the change of density must amount to at least
1 per cent. in 40 years. (I give the figures for § Cephei, the best-
known variable of this class.) The corresponding change of period
should be very easily detectable. For 6 Cephei the period ought to
decrease 40 seconds annually.

Now & Cephei has been under careful observation since 1785, and
it is known that the change of period, if any, must be very small.
S. Chandler found a decrease of period of 4, second per annum, and in a
recent investigation E. Hertzsprung has found a decrease of #4, second
perannum. The evidence that there is any decrease at all rests almost
entirely on the earliest observations made before 1800, so that it is not
very certain; but in any case the evolution is proceeding at not more
than 33, of the rate required by the contraction hypothesis. There
must at this stage of the evolution of the star be some other source
of energy which prolongs the life of the star 400-fold. The time-scale
so enlarged would suffice for practically all reasonable demands.

I hope the dilemma is plain. Hither we must admit that whilst the
density changes 1 per cent. a certain period intrinsic in the star can
change no more than z3, of 1 per cent., or we must give up the con-
traction hypothesis.

If the contraction theory were proposed to-day as a novel hypothesis
IT do not think it would stand the smallest chance of acceptance. From all
sides—biology, geology, physics, astronomy—it would be objected that
the suggested source of energy was hopelessly inadequate to provide the
heat spent during the necessary time of evolution; and, so far as it is
possible to interpret observational evidence confidently, the theory would
be held to be definitely negatived. Only the inertia of tradition keeps
the contraction hypothesis alive—or rather, not alive, but an unburied
corpse. But if we decide to inter the corpse, let us frankly recognise
the position in which we are left. A star is drawing on some vast
reservoir of energy by means unknown to us. This reservoir can
scarcely be other than the sub-atomic energy which, it is known, exists
abundantly in all matter; we sometimes dream that man will one day
learn how to release it and use it for his service. The store is well-nigh
inexhaustible, if only it could be tapped. There is sufficient in the Sun
to maintain its output of heat for 15 billion years.

Certain physical investigations in the past year, which I hope we
may hear about at this meeting, make it probable to my mind that some
portion of this sub-atomic energy is actually being set free in the stars.
F. W. Aston’s experiments seem to leave no room for doubt that all the
elements are constituted out of hydrogen atoms bound together with
negative electrons. The nucleus of the helium atom, for example,
consists of 4 hydrogen atoms bound with 2 electrons. But Aston has
further shown conclusively that the mass of the helium atom is less
than the sum of the masses of the 4 hydrogen atoms which enter into
it; and in this at any rate the chemists agree with him. There is a
loss of mass in the synthesis amounting to about 1 part in 120, the.

46 . SECTIONAL ADDRESSES.

atomic weight of hydrogen being 1008 and that of helium just 4. I
will riot dwell on his beautiful proof of this, as.you will no doubt be
able to hear it from himself. Now mass cannot be annihilated, and the
deficit can only represent the mass of the electrical energy set free in
the transmutation. We can therefore at once calculate the quantity of
energy liberated when helium is made out of hydrogen. If 5 per cent.
of a star’s mass consists initially of hydrogen atoms, which are gradually
being combined to form more complex elements, the total heat liberated
will more than suffice for our demands, and we need look no further
for the source of a star’s energy.

But is it possible to admit that such a transmutation is occurring?
It is difficult to assert, but perhaps more difficult to deny, that this is
going on. Sir Ernest Rutherford has recently been breaking down the
atoms of oxygen and nitrogen, driving out an isotope of helium from
them ; and what is possible in the Cavendish laboratory may not be
too difficult in the Sun. I think that the suspicion has been generally
entertained that the stars are the crucibles in which the lighter atoms
which abound in the nebule are compounded into more complex
elements. In the stars matter has its preliminary brewing to prepare
the greater variety of elements which are needed for a world of life.
The radio-active elements must have been formed at no very distant
date; and their synthesis, unlike the generation of helium from
hydrogen, is endothermic. If combinations requiring the addition of
energy can occur in the stars, combinations which liberate energy ought
not to be impossible.

We need not bind ourselves to the formation of helium from
hydrogen as the sole reaction which supplies the energy, although it
would seem that the further stages in building up the elements involve
much less liberation, and sometimes even absorption, of energy. It is
@ question of accurate measurement of the deviations of atomic weights
from integers, and up to the present hydrogen is the only element for
which Mr. Aston has been able to detect the deviation. No doubt we
shall learn more about the possibilities in due time. The position may
be summarised in these terms: the atoms of all elements are built of
hydrogen atoms bound together, and presumably have at one time been
formed from hydrogen; the interior of a star seems as likely a place
as any for the evolution to have occurred ; whenever it did occur a great
amount of energy must have been set free; in a star a vast quantity
of energy is being set free which is hitherto unaccounted for. You
may draw ‘a conclusion if you like.

lf, indeed, the sub-atomic energy in the stars is being freely used
to maintain their great furnaces, it seems to bring a little nearer to
fulfilment our dream of controlling this latent power for the well-being
of the human race—or for its suicide.

So far as the immediate needs of astronomy are concerned, it is
not of any great consequence whether in this suggestion-we have actually
laid a finger on the true source of the heat. It is sufficient if the
discussion opens’ our eyes to the wider possibilities: We can get rid
of the obsession that there is no other conceivable supply besides con-
traction, buf we need not again cramp ourselves by adopting prematurely

iit ni

A.—-MATHEMATICS AND PHYSICS. 47

what is perhaps a still wilder guess. Rather we should admit that the
source is not certainly known, and seek for any possible astronomical
evidence which may help to define its necessary character. One piece
of evidence of this kind may be worth mentioning. It seems clear that
it must be the high temperature inside the stars which determines the
liberation of energy, as H. N. Russell has pointed out.® If so the
supply may come mainly from the hottest region at the centre. I have
already stated that the general uniformity of the opacity of the stars
is much more easily intelligible if it depends on scattering rather than
on true absorption ; but it did not seem possible to reconcile the deduced
stellar opacity with the theoretical scattering coefficient. | Within
reasonable limits it makes no great difference in our calculations at what
parts of the star the heat energy is supplied, and it was assumed that

it comes more or less evenly from all parts, as would be the case on
_ the contraction theory. The possibility was scarcely contemplated that

the energy is supplied entirely in a restricted region round the centre.
Now, the more concentrated the supply, the lower is the opacity requisite
to account for the observed radiation. I have not made any detailed
calculations, but it seems possible that for a sufficiently concentrated
source the deduced and the theoretical coefficients could be made to
agree, and there does not seem to be any other way of accomplishing
this. Conversely, we might perhaps argue that the present discrepancy
of the coefficients shows that the energy supply is not spread out in the
way required by the contraction hypothesis, but belongs to some new
source only available at the hottest, central part of the star.

I should not be surprised if it is whispered that this address has at
times verged on being a little bit speculative; perhaps some outspoken
friend may bluntly say that it has been highly speculative from
begimning to end. I wonder what is the touchstone by which we may
test the legitimate development of scientific theory and reject the idly
speculative. We all know of theories which the scientific mind in-
stinctively rejects as fruitless guesses; but it is difficult to specify their
exact defect or to supply a rule which will show us when we ourselves
do err. It is often supposed that to speculate and to make hypotheses
are the same thing; but more often they are opposed. It is when we
let our thoughts stray outside venerable, but sometimes insecure,
hypotheses that we are said to speculate. Hypothesis limits speculation.
Moreover, distrust of speculation often serves as a cover for loose
thinking ; wild ideas take anchorage in our minds and influence our out-

look; whilst it is considered too speculative to subject them to the
scientific scrutiny which would exorcise them.

If we are not content with the dull accumulation of experimental
facts, if we make any deductions or generalisations, if we seek for any
theory to guide us, some degree of speculation cannot be avoided. Some
will prefer to take the interpretation which seems to be most imme-
diately indicated and at once adopt that as an hypothesis; others will
rather seek to explore and classify the widest possibilities which are
not definitely inconsistent with the facts. Hither choice has its dangers ;

8 Pub. Act. Soc. Pacific. August 1919.

48 SECTIONAL ADDRESSES.

the first may be too narrow a view and lead progress into a cul-de-sac ;
the second may be so broad that it is useless as a guide, and diverges
indefinitely from experimental knowledge. When this last case
happens, it must be concluded that the knowledge is not yet ripe for
theoretical treatment and speculation is premature. The time when
speculative theory and observational research may profitably go hand
in hand is when the possibilities, or at any rate the probabilities, can
be narrowed down by experiment, and the theory can indicate
the tests by which the remaining wrong paths may be blocked up one
by one.

f The mathematical physicist is in a position of peculiar difficulty.
He may work out the behaviour of an ideal model of material with
specifically defined properties, obeying mathematically exact laws, and
so far his work is unimpeachable. It is no more speculative than
the binomial theorem. But when he claims a serious interest for
his toy, when he suggests that his model is like something going on in
Nature, he inevitably begins to speculate. Is the actual body really
like the ideal model? May not other unknown conditions intervene?
He cannot be sure, but he cannot suppress the comparison; for it is by
looking continually to Nature that he is guided in his choice of a sub-
ject. A common fault, to which he must often plead guilty, is to use
for the comparison data over which the more experienced observer
shakes his head; they are too insecure to build extensively upon. Yet
even in this, theory may help observation by showing the kind of data
which it is especially important to improve.

I think that the more idle kinds of speculation will be avoided if
the investigation is conducted from the right point of view, When the
properties of an ideal model have been worked out by rigorous mathe-
matics, all the underlying assumptions being clearly understood, then
it becomes possible to say that such and such properties and laws lead
precisely to such and such effects. If any other disregarded factors
are present, they should now betray themselves when a comparison is
made with Nature. There is no need for disappointment at the failure
of the model to give perfect agreement with observation; it has served
its purpose, for it has distinguished what are the features of the actual
phenomena which require new conditions for their explanation. A
general preliminary agreement with observation is necessary, otherwise
the model is hopeless ; not that it is necessarily wrong so far as it goes,
but it has evidently put the less essential properties foremost. We
have been pulling at the wrong end of the tangle, which has te be un-
ravelled by a different approach. But after a general agreement with
observation is established, and the tangle begins to loosen, we should
always make ready for the next knot. I suppose that the applied
mathematician whose theory has just passed one still more stringent test
by observation ought not to feel satisfaction, but rather disappointment
—‘ Foiled again! This time I had hoped to find a discordance which
would throw light on the points where my model could be improved.’
Perhaps that is a counsel of perfection; I own that I have never felt
very keenly a disappointment of this kind.

Our model of Nature should not be like a building—a handsome

A.—MATHEMATICS AND PHYSICS. 49

structure for the populace to admire, until in the course of time someone
takes away a corner-stone and the edifice comes toppling down. It
should be like an engine with movable parts. We need not fix the
position of any one lever; that is to be adjusted from time to time as
the latest observations indicate. The aim of the theorist is to know
the train of wheels which the lever sets in motion—that binding of the
parts which is the soul of the engine.

In ancient days two aviators procured to themselves wings.
Deedalus flew safely through the middle air across the sea, and was duly
honoured on his landing. Young Icarus soared upwards towards the
Sun till the wax melted which bound his wings, and his flight ended
in fiasco. In weighing their achievements perhaps there is something
to be said for Icarus. The classic authorities tell us that he was only
‘ doing a stunt,’ but I prefer to think of him as the man who certainly
brought to light a constructional defect in the flying-machines of his
day. So too in science... Cautious Dedalus will apply his theories
where he feels most confident they will safely go; but by his excess of
caution their hidden weaknesses cannot be brought to light. Icarus
will strain his theories to the breaking-point till the weak joints gape.
For a spectacular stunt? Perhaps partly; he is often very human.
But if he is not yet destined to reach the Sun and solve for all time the
riddle of its constitution, yet he may hope to learn from his journey
some hints to build a better machine.

1920 z

SECTION B: CARDIFF, 1920.

ADDRESS

TO THE Y

CHEMICAL SECTION

C. T. HEYCOCK, M.A., F.B.S.,
PRESIDENT OF THE SECTION.

During its past eighty-nine years of useful life the British Association
has, in the course of its evolution, established certain traditions ; among
these is the expectation that the sectional President shall deliver an
address containing a summary of that branch of natural knowledge with
which he has become especially acquainted.

The rapid accumulation of experimental observations during the
last century, and the consequent necessity for classifying the observed
facts with the aid of hypotheses and theories of ever-increasing com-
plexity, make such summaries of knowledge essential, not only to the
student of science, but also to the person of non-specialised education
who desires to realise something of the tendencies and of the results
of modern science.

At the present moment, when the whole world is in pause after
having overcome the greatest peril which has ever threatened civilisa-
tion; when all productive effort, social, artistic, and scientific, is under-
going reorganisation preparatory to an advance which will eclipse in
importance the progress made during the nineteenth century, such
attempts to visualise the present condition of knowledge as are made
in our Presidential Addresses are of particular value. It is, therefore,
hardly necessary for me to apologise for an endeavour to place before
you a statement upon the particular branch of science to which I have
myself paid special attention; whatever faults may attend the mode
of presentation, such a survey of a specific field of knowledge cannot
but be of value to some amongst us.

I propose to deal to-day with the manner in which our present rather
detailed knowledge of metallic alloys has been acquired, starting from
the sparse information which was available thirty or forty years ago;

B.—CHEMISTRY. 51

to show the pitfalls which have been avoided in the theoretical inter-
pretation of the observed facts, and to sketch very briefly the present
position of our knowledge.

The production of metals and their alloys undoubtedly constitutes
the oldest of those chemical arts which ultimately expanded into the
modern science of chemistry, with all its overwhelming mass of experi-
mental detail and its intricate interweaving of theoretical interpretation
of the observed facts. Tubal-Cain lived during the lifetime of our
common ancestor, and was ‘an instructor of every artificer in brass
and iron’; and although it may be doubted whether the philologists
have yet satisfactorily determined whether Tubal-Cain was really
acquainted with the manufacture of such a complex metallic alloy as
brass, it is certain that chemical science had its beginnings in the
reduction of metals from their ores and in the preparation of useful
alloys from those metals. In fact, metallic alloys, or mixtures of
metals, have been used by mankind for the manufacture of implements
of war and of agriculture, of coiage, statuary, cooking vessels, and the
like from the very earliest times.

In the course of past ages an immense amount of practical informa-
tion has been accumulated concerning methods of reducing metals, or
mixtures of metals, from their ores, and by subsequent treatment,
usually by heating and cooling, of adapting the resulting metallic
product to the purpose for which it was required. Until quite recent
times, however, the whole of this knowledge was entirely empirical
in character, because it had no foundation in general theoretical prin-
ciples ; it was collected in haphazard fashion in accordance with that
method of trial and error which led our forerunners surely, but with
excessive expenditure of time and effort, to valuable results.

To-day I purpose dealing chiefly with the non-ferrous alloys, not
because any essential difference in type exists between the ferrous and
non-ferrous alloys, but merely because the whole field presented by the
chemistry of the metals and their alloys is too vast to be covered in
any reasonable length of time.

_ The earliest recorded scientific investigations on alloys were made
in 1722 by Reaumur, who employed the microscope to examine the
fractured surfaces of white and grey cast iron and steel.

In 1808 Widmanstatten cut sections from meteorites, which he
polished and etched.

The founder, however, of modern metallography is undoubtedly
H. C. Sorby, of Sheffield. Sorby’s early petrographic work on the
examination of thin sections of rock under the microscope led him to
a study of meteorites and of iron and steel, and in a paper read before
the British Association in 1864 he describes briefly (I quote his own
words) how sections ‘of iron and steel may be prepared for the
microscope so as to exhibit their structure to a perfection that leaves
little to be desired. They show various mixtures of iron, and two
or three well-defined compounds of iron and carbon, graphite, and
slag; these constituents being present in different proportions and
arranged in various manners, give rise to a large number of varieties
of iron and steel, differing by well-marked and very striking peculiarities

ct
to

SECTIONAL ADDRESSES.

of structure.’ The methods described by Sorby for polishing and
etching alloys and his method of vertical illumination (afterwards
improved by Beck) are employed to-day by all who work at this branch
of metallography.

The lantern-slides, now shown, were reproduced from his original
photographs; they form a lasting memorial to his skill as an investi-
gator.and his ability as a manipulator. In 1887 Dr. Sorby published
a paper on the microscopical structure of iron and steel in the Journal
of the Iron and Steel Institute. This masterpiece of clear writing
and expression, even with our present knowledge, needs but little
emendation. In this paper he describes Free Iron (ferrite) carbon as
graphite, the pearly constituent as a very fine laminar structure (pearlitic
structure), combined iron as the chief constituent of white cast iron
(cementite), slag inclusions, effect of tempering steel, effect of working
iron and steel, cementation of wrought iron, and the decarbonisation
of cast iron by haematite. A truly remarkable achievement for one
man.

From 1854-68 Mattheisen published in the Reports of the British
Association and in the Proceedings and Transactions of the Royal
Society, a large number of papers on the electrical conductivity,
tenacity, and specific gravity of pure metals and alloys. He concluded
that alloys are either mixtures of definite chemical compounds with an
excess of one or other metal, or solutions of the definite alloy in the
excess of one of the metals employed, forming, in their solid condition,
what he called a solidified solution. This idea of a solidified solution
has developed into a most fruitful theory upon which much of our
modern notions of alloys depends. Although, at the time, the experi-
ments on the electrical conductivity did not lead to very definite con-
clusions, the method has since been used with great success in testing
for the presence of minute quantities of impurities in the copper used
for conductors.

In the Philosophical Magazine for 1875, F. Guthrie, in a
remarkable paper, quite unconnected with alloys, gave an account of
his experiments on salt solutions and attached water. He was led to
undertake this work by a consideration of a paper by Dr. J. Rea, the
Arctic explorer, on the comparative saltness of freshly formed and of
older ice floes. Guthrie showed that the freezing-point of solutions was
continuously diminished as the percentage of common salt increased,
and that this lowering increased up to 23.6 per cent. of salt, when the
solution’ solidified as a whole at about 229 C. He further showed,
and this is of great importance, that the substance which first separated
from solutions more dilute than 23.6 was pure ice. To the substance
which froze as a whole, giving crystals of the same composition as the
mother liquor, he gave the name cryohydrate. At the time he thought
that the cryohydrate of salt containing 23.6 per cent. NaCl and 76.4 per
cent. of water was a chemical compound 2NaCl.21H,0. In suc-
ceeding years he showed that a large number of other salts gave solu-
tions which behaved in a similar manner to common salt. He
abandoned the idea that the cryohydrates were chemical compounds.

How clear his views were will be seen by quotations from his

B.—CHEMISTRY. 53)

paper in the Phil. Mag. (5) 1. and II., 1876, in which he states:
(i.) When a@ solution weaker than the cryohydrate loses heat, ice is
formed. (ii.) Ice continues to form and the temperature to fall until’
the cryohydrate is reached. (iii.) At’the point of saturation ice and:
salt separate simultaneously and the solid and liquid portions are
identical in composition. ins

These results can be expressed in the form of a simple diagram as’
shown in the slide.

In a subsequent paper, Phil. 'Mag. (5) 17, he extends his experi- ,
ments to solvents other than water,, and states that the substances
which separate at the lowest temperature are neither atomic nor mole-
cular; this lowest melting-point mixture of two bodies he names the:
eutectic mixture. In the same paper he details the methods of obtain-
ing various eutectic alloys of bismuth, lead, tin, and cadmium.

We have, in these papers of Guthrie’s, the first important clue to
what occurs on cooling a fused mixture of metals. The researches of -
Sorby and Guthrie, undertaken as they were for the sake of investigat-
ing natural phenomena, are a remarkable example of how purely
scientific experiment can lead to most important practical results. It is
not too much to claim for these investigators the honour of being the
originators of all our modern ideas of metallurgy. Although much
valuable information had been accumulated, no rapid advance could be
made until some general theory of solution had been developed. In
1878 Raoult first began his work on the depression of the freezing-
point of solvents due to the addition of dissolved substances, and he
continued, at frequent intervals, to publish the results of his experi-
ments up to the time of his death in 1901. He established for organic’
solvents certain general laws: (i.) that for moderate concentrations the:
fall of the freezing-point is proportional to the weight of the dissolved
substance present in a constant weight of solvent; (ii.) that when the
falls produced in the same solvent by different dissolved substances are
compared, it is found that a molecular weight of a dissolved substance
produces the same fall of the freezing-point, whatever the substance is.
When, however, he applied the general laws which he had established
for organic solvents to aqueous solutions of inorganic acids, bases, and
salts, the results obtained were hopelessly discrepant. In a paper in
the Zeit. Physikal. Chem. for 1888 on ‘Osmotic Pressure in the
analogy between solutions and gases,’ Van’t Hoff showed that the
experiments of Pfeffer on osmotic pressure could be explained on
the theory that dissolved substances were, at any rate for dilute solu-
tions, in a condition similar to that of a gas; that they obeyed the laws
of Boyle, Charles, and Avogadro, and that on this assumption the:
depression of the freezing-point of a solvent could be calculated by
means of a simple formula. He also showed that the exceptions which
occurred to Raoult’s laws, when applied to aqueous solutions of
electrolytes, could’ be explained by the assumption, first made by
Arrhénius, that’ these latter in solution are partly dissociated into their
ions. The result of all this work was to establish a general theory
applicable to all solutions which has been widespread in its appli- .
eations. It is true that Van’t Hoff’s theory has been violently attacked ; .

64 SECTIONAL ADDRESSES.

but it enables us to calculate the depression of the freezing-points of a
large number of solvents. To do this it is necessary to know the latent
heat of fusion of the pure solvent and the absolute temperature of the
freezing-point of the solution. That the numbers calculated are in very
close accord with the experimental values constitutes a strong argu-
ment in favour of the theory. From this time the study of alloys
began to make rapid progress. Laurie (Chem. Soc. Jour. 1888), by
measuring the potential difference of voltaic cells composed of plates
of alloy and the more negative element immersed in a solution of a salt
of one of the component metals, obtained evidence of the existence
of compounds such as CuZn,.Cu,Sn. In 1889 F. H. Neville and I,
whilst repeating Raoult’s experiments on the lowering of the freezing-
point of organic solvents, thought that it was possible that the well-
‘known fact that alloys often freeze at a lower temperature than either
of their constituents might be explained in a similar way. In a pre-
Jiminary note communicated to the Chemical Society on March 21,
1889, on the same evening that Professor Ramsay read his paper on the
molecular weights of metals as determined by the depression of the
vapour pressure, we showed that the fall produced in the freezing-
point of tin by dissolving metals in it was for dilute solutions directly
proportional to the concentration. We also showed that the fall pro-
duced in the freezing-point of tin by the solution of one atomic weight
of metal in 100 atomic weights of tin was a constant.

G. Tannman about the same time (Zeit. Physikal. Chemie, III., 44,
1889) arrived at a similar conclusion, using mercury as a solvent.

These experiments helped to establish the similarity between the
behaviour of metallic solutions or alloys and that. of aqueous and other
solutions of organic compounds in organic solvents. That our experi-
ments were correct seemed probable from the agreement between the
observed depression of the freezing-point and the value calculated from
Van’t Hoff’s formula for the case of those few metals whose latent
heats of fusion had been determined with any approach to accuracy.

Our experiments, subsequently extended to other solvents, led to
the conclusion that in the case of most metals dissolved in tin the
molecular weight is identical with the atomic weight; in other words,
that the metals in solution are monatomic. This conclusion, however,
involves certain assumptions. Prof. Ramsay’s experiments on the
lowering of the vapour pressure of certain amalgams point to a similar
conclusion.

So far our work had been carried out with mercury thermometers,
standardised against a platinum resistance pyrometer, but it was evident
that, if it was to be continued, we must have some method of extend-
ing our experiments to alloys which freéze at high temperatures. The
thermo couple was not at this stage a reliable instrument; fortunately,

however, Callendar and Griffiths had brought to great perfection the
electrical resistance pyrometer (Phil. Trans. A, 1887 and 1891). Dr.
BE. H. Griffiths kindly came to our aid, and with his help we installed
a complete electrical resistance set. As at this time the freezing-points
of pure substances above 300° were not known with any degree of
accuracy, we began by making these measurements :—

B.—CHEMISTRY.

crt
cr

Table of Freezing-poimts.

| { Burgess &
‘Camenty’s| Holborn | Callendar | Neville Berek
— Tables | & Wien, & Griffiths, & Heycock,| 11,7) mn,
| 1892 1892 | 1895 Be OP
perature
| Measure-
és iodyesy tn ask joa | ments
Tm , 3 5 —_ — 231-7 | -231°9 231°9
Zine . q - ~~ 433 — 4176 | 419°0 419°4
Lead . A - “ — _ — 327°6 327°4
Antimony. . . | 432 — | ~~ | 6295 | 630-7 &
| | | | | 629-2
Magnesium. 3 . oo Se 1632°6 650
| Aluminium il 700 —_— : _ *654'5 658
Silver : 4 af 954 968 | 972 960°7 960°9
Gold . $ . | 1,045 1,072 1,037 1,061°7 1,062°4
Copper . . .| 1,054 1,082 ie, 1,080°3 | 1,083
| SulphurB.P. . . | 448 — | 44453 is 444-7
' Contaminated with silicon. 2 Known to be impure.

With the exception of silver and gold, these metals were the purest
obtainable in commerce.

Two facts are evident from the consideration of this table: (a) the
remarkable accuracy of Callendar’s formula connecting the Tempera-
ture Centigrade with the change of resistance of a pure platinum wire ;
(b) the accuracy of Callendar and Griffiths’ determination of the boiling-
point of sulphur. Although the platinum resistance pyrometer had at
this time only been compared with the air thermometer up to 600° C.,
ib will be noted that the exterpolation from 600° to nearly 1,100 was
justified.

I cannot leave the subject of high-temperature measurements with-
out referring to the specially valuable work of Burgess, and also to
Eza Griffiths’ book on high-temperature measurements, which contains
an excellent summary of the present state of our knowledge of this
important subject.

During the period that the above work on non-ferrous alloys was
being done, great progress was being made in the study of iron and
steel by Osmond and Le Chatelier. In 1890 the Institute of Mechanical
Engineers, not apparently without considerable misgivings on the part
of some of its members, formed an Alloys Research Committee. This
Committee invited Professor (afterwards Sir William) Roberts-Austen
to undertake research work for them. The results of his investigations
are contained in a series of five valuable reports, extending from 1891
to 1899, published in the Journal of the Institute. The first report
contained a deseription of an improved form of the Le Chatelier record-
ing pyrometer, and the instrument has since proved a powerful weapon
of research. In the second report, issued in 1893, the effects on the
properties of copper of small quantities of arsenic, bismuth, and
antimony were discussed. Whilst some engineers advocated, others
as strongly controverted, the beneficial results of small quantities of

56 SECTIONAL ADDRESSES.

arsenic on the copper used for the fireboxes of locomotives. The
report showed that the presence of from °5-1 per cent. of arsenic was
highly beneficial. The third report dealt with electric welding and
the production of alloys of iron and aluminium. The fourth report
is particularly valuable, as it contains a résumé of the Bakerian Lecture
given by Roberts-Austen on the diffusion of metals in the solid state,
in which he showed that gold, even at as low a temperature as 100°,
could penetrate into lead, and that iron became carbonised at a low
red heat by contact with a diamond in a vacuum. In 1899 the fifth
report appeared, on the effects of the addition of carbon to iron. This
report is of especial importance, because, besides a description of the
thermal effects produced by carbon, which he carefully plotted and
photographed, he described the microscopical appearance of the various
constituents of iron. The materials of this report, together with the
work of Osmond and others on steel and iron, provided much of the
material on which Professor Bakhuis Roozeboom founded the iron
carbon equilibrium diagram. Reference should also be made to the
very valuable paper by Stansfield on the present position of the solution
theory of carbonised iron (Journ. Iron and Steel Inst., 11, 1900,
p. 317). It may be said of this fifth report, and the two papers just
referred to, that they form the most important contribution to the study
of iron and steel that has ever been published. Although the diagram
for the: equilibrium of iron and carbon does not represent the whole
of the facts, it affords the most important clue to these alloys, and
undoubtedly. forms the basis of most of the modern practice of steel
manufacture. (Slide showing iron carbon diagram.)

Many workers, both at home and abroad, were now actively engaged
in metallurgical work—Stead, Osmond, Le Chatelier, Arnold, Hadfield,
Carpenter, Ewing, Rosenhain, and others too numerous to mention.

In 1897 Neville and I determined the complete freezing-point curve
of the copper-tin alloys, confirming and extending the work of Roberts-
Austen, Stansfield, and Le Chatelier; but the real meaning of the
curve remained as much of a mystery as ever. Early in 1900 Sir G.
Stokes suggested to us that we should make a microscopic examination
of a few bronzes as an aid to the interpretation of the singularities
of the freezing-point curve. An account of this work, which occupied
us for more than two years,-was published as the Bakerian Lecture
of the Royal Society in February 1903. Whilst preparing a number
of copper-tin alloys of known composition we were struck by the fact
that the crystalline pattern which developed on the free surface of the
slowly cooled alloys was entirely unlike the structure developed by
polishing and etching sections cut from the interior; it therefore
appeared probable that changes were going on within the alloys as
they cooled. In the hope that, as Sorby had shown in the case of
steel, we could stereotype or fix the change by sudden cooling, we
melted small ingots of the copper-tin alloys and slowly cooled them
to selected temperatures and then suddenly chilled them in water.’ The
results of this treatment were communicated to the Royal Society and
published in the Proceedings, February 1901. (Slides showing effects
of chilling alloys.)

B.—CHEMISTRY. 57

To apply this method to a selected alloy we first determined its
cooling curve by means of an automatic recorder, the curve usually
showing several halts or steps in it. The temperature of the highest
of these steps corresponded with a point on the liquidus, i.e., when
solid first separated out from the molten mass. To ascertain what
occurred at the subsequent halts, ingots of the melted alloy were slowly
cooled to within a few degrees above and below the halt and then
chilled, with the result just seen on the screen.

The method of chilling also enabled us to fix, with some degree
of accuracy, the position of points on the solidus. If an alloy, chilled
when it is partly solid and partly liquid, is polished and etched, it
will be seen to consist of large primary combs embedded in a matrix
consisting of mother liquor, in which are disseminated numerous small
combs, which we called ‘ chilled primary.’ By repeating the process
at successively lower and lower temperatures we obtained a point at
which the chilled primary no longer formed, i.e., the upper limit of
the solidus.

Although we made but few determinations of the physical properties
of the alloys, it is needless to say how much they vary with the
temperature and with the rapidity with which they are heated or cooled.

From a consideration of the singularities in the liquidus curve,
coupled with the microscopic examination of slowly cooled and chilled
alloys, we were able to divide the copper-tin alloys into certain groups
having special qualities. It would take far too long to discuss these
divisions. In interpreting our result we were greatly assisted not only
by the application of the phase rule, but also by the application of
Roozeboom’s theory of solid solution (unfortunately Professor Rooze-
boom’s letters were destroyed by fire in June 1910) and by the advice
he kindly gave us. At the time the paper was published we expressly
stated that we did not regard all our results as final, as much more
work was required to clear up points still obscure. Other workers—
Shepherd and Blough, Giolitti and Tavanti—have somewhat modified
the diagram. (Slides shown.)

Neither Shepherd and Blough nor Hoyt have published the photo-
micrographs upon which their results are based, so that it is impos-
sible to criticise their conclusions. Giolitti and Tavanti have published
some microphotographs, from which it seems that they had not allowed
sufficient time for equilibrium to be established. In this connection I
must call attention to the excellent work of Haughton on the con-
stitution of the alloys of copper and tin (Journ. Institute of Metals,
March 1915). He investigated the alloys rich in tin, and illustrated
his conclusions by singularly beautiful microphotographs, and has done
much to clear up doubtful points in this region of the diagram. I
have dwelt at some length on this work, for copper-tin is probably the
first of the binary alloys on which an attempt had been made to
determine the changes which take place in passing from one pure
constituent to the other. I would again call attention to the fact that
without a working theory of solution the interpretation of the results
would have been impossible.

Since 1900, many complete equilibrium diagrams have been pub-

58 SECTIONAL ADDRESSES.

lished ; amongst them may be mentioned the work of Rosenhain and
Tucker on the lead-tin alloys (Phil. Trans., 1908), in which they describe
hitherto unsuspected changes on the lead rich side which go on when
these alloys are at quite low temperatures, also the constitution of the
alloys of aluminium and zinc; the work of Rosenhain and Archbutt
(Phil. Trans., 1911), and quite recently the excellent work of Vivian,
on the alloys of tin and phosphorus, which has thrown an entirely
new light on this difficult subject.

So far I have called attention to some of the difficulties encountered
in the examination of binary alloys. When we come to ternary alloys
the difficulties of carrying out an investigation are enormously increased,
whilst with quaternary alloys they seem almost insurmountable; in the
case of steels containing always six, and usually more, constituents, we
can only hope to get information by purely empirical methods.

Large numbers of the elements and their compounds which originally
were laboriously prepared and investigated in the. laboratory and
remained dormant as chemical curiosities for many years have, in the
fulness of time, taken their places as important and, indeed, essential
articles of commerce. Passing over the difficulties encountered by
Davy in the preparation of metallic sodium and by Faraday in the
production of benzene (both of which materials are manufactured in
enormous quantities at the present time), I may remark that even
during my own lifetime I have seen a vast number of substances trans-
ferred from the category of rare laboratory products to that which
comprises materials of the utmost importance to the modern metal-
lurgical industries. A few decades ago, aluminium, chromium, cerium,
thorium, tungsten, manganese, magnesium, molybdenum, nickel,
calcium and calcium carbide, carborundum, and acetylene were un-
known outside the chemical laboratory of the purely scientific inyesti-
gator; to-day these elements, their compounds and alloys, are
amongst the most valuable of our industrial metallic products. They
are essential in the manufacture of high-speed steels, of armour-plate,
of filaments for the electric bulb lamp, of incandescent gas mantles, and
of countless other products of modern scientific industry.

All these metallic elements and compounds were discovered, and
their industrial uses foreshadowed, during the course of the purely
academic research work carried out in our Universities and Colleges ; all
have become the materials upon which great and lucrative industries
have been built up. Although the scientific worker has certainly not ex-
hibited any cupidity in the past—although he has been content to rejoice
in his own contributions to knowledge, and to see great. manufacturing
enterprises founded upon his work—it is clear that the obligation
devolves upon those who have reaped in the world’s markets the fruit
of scientific discovery to provide from their harvest the financial aid
without which scientific research cannot be continued.

The truth of this statement is well understood by those of our great
industrial leaders who are engaged in translating the results of scientific
research into technical practice. As evidence of this I may quote the
magnificent donation of 210,0001. by the British Oil Companies towards
the endowment: of the School of Chemistry in the University of Cam-

B.—CHEMISTRY. 59

bridge, the noble bequest of the late Dr. Messel, one of the most en-
lightened of our technical chemists, for defraying the cost of scientific
research, the gifts of the late Dr. Ludwig Mond towards the upkeep
and expansion of the Royal Institution, one of the strongholds of British
chemical research, and the financial support given by the Goldsmiths’
and others of the great City of London Livery Companies (initiated
largely by the late Sir Frederick Abel, Sir Frederick Bramwell, and

_ Mr. George Matthey), to the foundation of the Imperial College of

Science and Technology. The men who initiated these gifts have been
themselves intimately associated with developments both in ‘science
and industry; they have understood that the field must be prepared
before the crop can be reaped. Fortunately our great chemical indus-
triés are, for the most part, controlled and administered by men fully
conversant with the mode in which technical progress and prosperity
follow upon scientific achievement ; and it is my pleasant duty to reeord
that within the last few weeks the directors of one of our greatest
chemical-manufacturing concerns have, with the consent of their
shareholders, devoted £100,000 to research. Doubtless other chemical
industries will in due course realise what they have to gain by an ade-
quate appreciation of pure science.

Tf the effort now being made to establish a comprehensive scheme
for the resuscitation of chemical industry within our Empire is to
succeed, financial support on a very liberal scale must be forthcoming,
from the industry itself, for the advancement of purely scientific
research. This question has been treated recently in so able a fashion
by Lord Moulton that nothing now remains but to await the results of
his appeal for funds in aid of the advancement of pure science.

In order to prevent disappointment, and a possible reaction in the
future, in those who endow pure research, it is necessary to give a word
of warning. It must be remembered that the history of science abounds
in illustrations of discoveries, regarded at the time as trivial, which have
in after years become epoch-making.

In illustration I would cite Faraday’s discovery of electro-magnetic
induction. He found that when a bar magnet was thrust into the
core of a bobbin of insulated copper wire, whose terminals were con-
nected with a galvanometer, a momentary current was produced;
whilst on withdrawing the magnet a momentary reverse current
occurred; a purely scientific experiment destined in later years to
develop into the dynamo and with it’ the whole electrical industry.
Another illustration may be given: Guyton de Morveau, Northmore,
Davy, Faraday and Cagniard Latour between 1800 and 1850 were
engaged in liquefying many of the gases. Hydrogen, oxygen, nitrogen,
marsh gas, carbon-monoxide, and nitric oxide, however, resisted all
efforts, until the work of Joule and Andrews gave the clue to the causes
of failure. Some thirty years later by careful application of the
theoretical considerations all the gases were liquefied. The liquefaction
of oxygen and nitrogen now forms the basis of a very large and
important industry.

_Such cases can be multiplied indefinitely in all branches of
science.

60 SECTIONAL ADDRESSES.

Perhaps the most pressing need of the present day lies in the
cultivation of a better understanding between our great masters of
productive industry, the shareholders to whom they are in the first.
degree responsible, and our scientific workers; if, by reason of any
turbidity of vision, our large manufacturing corporations fail to discern :
that, in their own interest, the financial support of purely scientific
research should be one of their first cares, technical advance will slacken
and other nations, adopting a more far-sighted policy, will forge ahead
in science and technology. It should, I venture to think, be the
bounden duty of everyone who has at heart the aims and objects of
the British Association to preach the doctrine that in closer sympathy
between all classes of productive labour, manual and intellectual, lies
our only hope for the future. I cannot do better than conclude by
quoting the words of Pope, one of our most characteristically British
poets :
‘ By mutual confidence and mutual aid

Great deeds are done‘and great discoveries made.’

SECTION C: CARDIFF, 1920.

ADDRESS

TO THE

GEOLOGICAL SECTION

BY
FRANOIS ARTHUR BATHER, M.A., D.Sc., F.RB.S.,

PRESIDENT OF THE SECTION.

FOSSILS AND LIFE.

Or the many distinguished men who have preceded me in this chair
only eight can be described as essentially palaeontologists ; and among
them few seized the occasion to expound the broader principles of their
science. I propose, then, to consider the Relations of Palaeontology to
the other Natural Sciences, especially the Biological, to discuss its
particular contribution to biological thought, and to inquire whether its
facts justify certain hypotheses frequently put forward in its name.
Several of those hypotheses were presented to you in his usual masterly
manner by Dr. Smith Woodward in 1909, and yet others are clearly
elucidated in two Introductions to Palaeontology which we have been
delighted to welcome as British products: the books by Dr. Morley
Davies and Dr. H. L. Hawkins. If I subject those attractive specula-
tions to cold analysis it is from no want of admiration or even sympathy,
for in younger days I too have sported with Vitalism in the shade
and been caught in the tangles of Transcendental hair.

The Differentia of Palaeontology.

Like Botany and Zoology, Palaeontology describes the external
and internal form and structure of animals and plants; and on this
description it bases, first, a systematic classification of its material ;
secondly, those broader inductions of comparative anatomy which con-
stitute morphology, or the science of form. Arising out of these studies
are the questions of relation—real or apparent kinship, lines of descent,
the how and the why of evolution—the answers to which reflect their
light back on our morphological and classificatory systems. By a
different approach we map the geographical distribution of genera and
species, thus helping to elucidate changes of land and sea, and so barring
out one hypothesis of racial descent or unlocking the door to another.
Again, we study collective faunas and floras, unravelling the interplay
of their component animals and plants, or inferring from each assem-
blage the climatic and other physical agents that favoured, selected, and
delimited it.

62 SECTIONAL ADDRESSES.

All this, it may be said, is nothing more than the Botany and
Zoology of the past. True, the general absence of any soft tissues, and
the obscured or fragmentary condition of those harder parts which alone
are preserved, make the studies of the palaeontologist more difficult, and
drive him to special methods. But the result is less complete: in short,
an inferior and unattractive branch of Biology. Let us relegate it to
Section C!

Certainly the relation of Palaeontology to Geology is obvious. It is
a part of that general history of the Earth which is Geology. And it is
an essential part even of physical geology, for without life not merely
would our series of strata have lacked the coal measures, the mountain
limestones, the chalks, and the siliceous earths, but the changes of land
and sea would have been far other. To the scientific interpreter of
Earth-history, the importance of fossils lies first in their value as date-
markers ; secondly, in the light which they cast on barriers and currents,
on seasonal and climatic variation. Conversely, the history of life has
itself been influenced by geologic change. But all this is just as true of
the present inhabitants of the globe as it is of their predecessors. It
does not give the differentia of Palaeontology.

That which above all distinguishes Palaeontology—the study of
ancient creatures, from Neontology—the study of creatures now living,
that which raises it above the mere description of extinct assemblages of
life-forms, is the concept of Time. Not the quasi-absolute time of the
clock, or rather, of the sun; not various unrelated durations; but an
orderly and related succession, coextensive, in theory at least, with
the whole history of life on this planet. The bearing of this obvious
statement will appear from one or two simple illustrations.

Effect of the Time-concept on Principles of Classification.

Adopting the well-tried metaphor, let us imagine the tree of life
buried, except for its topmost twigs, beneath a sand-dune. The neontolo-
gist sees only the unburied twigs. He recognises certain rough group-
ings, and eonstructs a classification accordingly. From various hints
he may shrewdly infer that some twigs come from one branch, some
from another; but the relations of the branches to the main stem are
matters of speculation, and when branches have become so interlaced
that their twigs have long been subjected to the same external influences,
he will probably be led to incorrect conclusions. The palaeontologist
then comes, shovels away the sand, and by degrees exposes the true
relations of branches and twigs. His work is not yet accomplished, and
probably he never will reveal the root and lower part of the tree; but
already he has corrected many natural, if not inevitable, errors of the
neontologist.

I could easily occupy the rest of this hour by discussing the pro-
found changes wrought by this conception on our classification. It is
not that Orders and Classes hitherto unknown have been discovered,
not that some erroneous allocations have been corrected, but the whole
basis of our system is being shifted. So long as we were dealing with

C.—GEOLOGY. 63

& horizontal section across the tree of life—that is to say, with an assem-
blage of approximately contemporaneous forms—or even with a number
of such horizontal sections, so long were we confined to simple descrip-
tion. Any attempt to frame a causal connection was bound to be
speculative. Certain relations of structure, as of cloven hooves with
horns and with a ruminant stomach, were observed, but, as Cuvier him-
self insisted, the laws based on such facts were purely empirical.
Huxley, then, was justified in maintaining, as he did in 1863 and for
long after, that a zoological classification could be based with profit on
‘ purely structural considerations’ alone. ‘ Every group in that [kind
of] classification is such in virtue of certain structural characters, which
are not only common to the members of that group, but distinguish it
from all others; and the statement of these constitutes the definition of
the group.’ In such a classification the groups or categories—from
species and genera up to phyla—are the expressions of an arbitrary in-
tellectual decision. From Linnaeus downwards botanists and zoologists
have sought for a classification that should be not arbitrary but natural,
though what they meant by ‘ natural ’ neither Linnaeus nor his succes-
sors either could or would say. Not, that is, until the doctrine of
descent was firmly established, and even now its application remains
impracticable, except in those cases where sufficient proof of genetic
connection has been furnished—as it has been mainly by palaeontology.
In many cases we now perceive the causal connection ; and we recognise
that our groupings, so far as they follow the blood-red clue, are not
arbitrary but tables of natural affinity.

Fresh difficulties, however, arise. Consider the branching of a tree.
Tt is easy to distinguish the twigs and the branches each from each,
but where are we to draw the line along each ascending stem? To con-
vey the new conception of change in time we must introduce a new set
of systematic categories, called grades or series, keeping our old cate-
gories of families, orders, and the like for the vertical divisions between
the branches. Thus, many crinoids with pinnulate arms arose from
others in which the arms were non-pinnulate. We cannot place them
in an Order by themselves, because the ancestors belonged to two or
three Orders. We must keep them in the same Orders as their respec-
tive ancestors, but distinguish a Grade Pinnata from a Grade Impin-
nata.

This sounds fairly simple, and for the larger groups so it is. But
when we consider the genus, we are met with the difficulty that many
of our existing genera represent grades of structure affecting a number
of species, and several of those species can be traced back through
previous grades. This has long been recognised, but I take a modern
instance from H. F. Osborn’s ‘ Equidae’ (1918, Mem. Amer. Mus.
N.H., ns. II. 51): ‘The line between such species as Miohippus
(Mesohippus) meteulophus and M. brachystylus of the Leptauchenia
zone and M. (Mesohippus) intermedius of the Protoceras zone is purely
arbitrary. It is obvious that members of more than one phylum [i.e.,
lineage] are passing from one genus into the next, and Mesohippus
meteulophus and M. brachystylus may with equal consistency be
referred. to Miohippus.’

64 SECTIONAL ADDRESSESs

The problem is reduced to its simplest elements in the -following
scheme :— | 4

Big Dr tC, AO Cink Italics.

IE CHT: RP Lower-case Roman.
ABCDEF Capitals Roman.
a By Si €o Greek.

Our genera are equivalent to the forms of letters: ~ Italics, Raintin;
Greek, and so forth. The successive species are the letters themselves.
Are we to make each species a genus? Or would it not be better to
confess that here, as in the case of many larger groups, our basis of
classification is wrong? For the palaeontologist, at any rate, the lineage
a, A, a, a, is the all-important concept. Between these forms he finds
every gradation ; but between a and 6 he perceives no connection.

. Inthe old classification the vertical divisions either were arbitrary,
or were gaps due to ignorance. We are gradually substituting a
classification in which the vertical divisions are based» on knowledge,
and the horizontal divisions, though in some degree: arbitrary, often
coincide with relatively sudden or physiologically important changes) of
form.

This brings us to the last point of contrast. Quix Ji fanaa can
no longer have the rigid character emphasised by Huxley. They are
no longer purely descriptive. When it devolved on me to draw up
a definition of the great group Echinoderma, a definition that should
include all the fossils, I found that scarcely a character given in the
textbooks could certainly be predicated of every member of the group.
The answer to the question, ‘ What is an Echinoderm?’ (and you may
substitute Mollusc, or Vertebrate, or what name you please) has to
be of this nature: An HEchinoderm is an animal descended: from an
ancestor possessed of such-and-such characters differentiating it from
other animal forms, and it still retains the imprint ofthat ancestor,
though modified and obscured in various ways according to the class,
order, family, and genus to which it belongs. The etindibibean given
by Professor Charles Schuchert in his classification of the Brachiopoda
(1913, Eastman’s ‘ Zittel’) represent an interesting attempt to put
these principles into practice. The Family Porambonitidae, for instance,
is thus defined: ‘ Derived (out of Syntrophiidae), progressive, semi-
rostrate Pentamerids, with the deltidia and chilidia vanishing more
and more in. time. Spondylia and cruralia present, but the - former
tends to thicken and unite with the ventral valve.’

The old form of diagnosis was per genus et differentiam. The new
form is per proavum et modificationem.

Even the conception of our fundamental unit, the species, is in-
secure owing to the discovery of gradual changes. But this is a
difficulty which the palaeontologist shares with the neontologist.

Let us consider another way in which the time-concept has affected
biology.

Effect of the Time-concept on Ideas of Relationship.

Etienne Geoffroy-Saint Hilaire was the first to. compare the embryonic
stages of certain animals with the adult stages of animals considered

0.-—GEOLOGY. 65

inferior. Through the more precise observations of Yon Baer, Louis
Agassiz, and others, the idea grew until it was crystallised by the
poetic imagination of Haeckel in his fundamental law of the reproduction
of life—namely, that every creature tends in the course of its individual
development to pass through stages similar to those passed through
in the history of its race. This principle is of value if applied with
the necessary safeguards. If it was ever brought into disrepute, it
was owing to the reckless enthusiasm of some embryologists, who
unwarrantably extended the statement to all shapes and_ structures
observed in the developing animal, such as those evoked by special
conditions of larval existence, sometimes forgetting that every con-
ceivable ancestor must at least have been capable of earning its own
livelihood. Or, again, they compared the early stages of an individual
with the adult structure of its contemporaries instead of with that of
its predecessors in time. Often, too, the searcher into the embryology
of creatures now living was forced to study some form that really was
highly specialised, such as the unstalked Crinoid Antedon, and he
made matters worse by comparing its larvae with forms far too remote
in time. Allman, for instance, thought he saw in the developing
Antedon a Cystid stage, and so the Cystids were regarded as the ancestors
of the Crinoids; but we now find that stage more closely paralleled
in some Crinoids of Carboniferous and Permian age, and we realise
that the Cystid structure is quite different.

Such errors were due to the ignoring of time relations or to lack
of acquaintance with extinct forms, and were beautifully illustrated
in those phylogenetic trees which, in the ’eighties, every dissector of
a new or striking animal thought it his duty to plant at the end of
his paper. The trees have withered, because they were not rooted in
the past.

A similar mistake was made by the palaeontologist who, happening
on a new fossil, blazoned it forth as a jink between groups previously
unconnected—and in too many cases unconnected still. This action,
natural and even justifiable under the old purely descriptive system,
became fallacious when descent was taken as the basis. In those days
one heard much of generalised types, especially among the older fossils ;
animals were supposed to combine the features of two or three classes.
This mode of thought is not quite extinct, for in the last American
edition of Zittel’s ‘ Palaeontology ’ Stephanocrinus is still spoken of as
a Crinoid related to the Blastoids, if not also to the Cystids. Let it
be clear that these so-called ‘ generalised’ or ‘ annectant’ types are
not regarded by their expositors as ancestral. Of course, a genus
existing at a certain period may give rise to two different genera of a
succeeding period, as possibly the Devonian Coelocrinus evolved into
Agaricocrinus, with concave base, and into Dorycrinus, with convex
base, both Carboniferous genera. But, to exemplify the kind of state-
ment here criticised, perhaps I may quote from another distinguished
writer of the present century: ‘The new genus is a truly annectant
form uniting the Melocrinidae and the Platycrinidae.” Now the genus
in question appeared, so far as we know, rather late in the Lower
Carboniferous, whereas both Platycrinidae and Melocrinidae were already

1920 2

66 SECTIONAL, ADDRESSES.

established in Middle Silurian time, How is it possible that the far
later form should unite these two ancient families? Even a mésalliance
is inconceivable. In a word, to describe any such forms as ‘ annectant’
is not merely to misinterpret structure but to ignore time.

As bold suggestions calling for subsequent proof these speculations
had their value, and they may be forgiven in the neontologist, if not
in the palaeontologist, if we regard them as erratic pioneer tracks blazed
through a tangled forest, As our acquaintance with fossils enlarged,
the general direction became clearer, and certain paths were seen to
be impossible. In 1881, addressing this Association at York, Huxley
could say: ‘ Fifty years hence, whoever undertakes to record the
progress of palaeontology will note the present time as the epoch in
which the law of succession of the forms of the higher animals was
determined by the observation of palaeontological facts. He will point
out that, just as Steno and as Cuvier were enabled from their knowledge
of the empirical laws of co-existence of the parts of animals to conclude
from a part to a whole, so the knowledge of the law of succession of
forms empowered their successors to conclude, from one or two terms
of such a succession, to the whole series, and thus to divine the existence
of forms of life, of which, perhaps, no trace remains, at epochs of
inconceivable remoteness in the past.’

Descent Not a Corollary of Succession.

Note that Huxley spoke of succession, not of descent. Succession
undoubtedly was recognised, but the relation between the terms of the
succession was little understood, and there was no proof of descent.
Leti us suppose all written records to be swept away, and an attempt
made to reconstruct English history from coins. We could set out our
monarchs in true order, and we might suspect that the throne was
hereditary; but if on that assumption we were to make James I. the
son of Hlizabeth—well, but that’s just what palaeontologists are con-
stantly doing. The famous diagram of the Evolution of the Horse which
Huxley used in his American lectures has had to be corrected in the
light of the fuller evidence recently tabulated in a handsome volume
by Professor H. F. Osborn and his coadjutors. Palaeotherium, which
Huxley regarded as a direct ancestor of the horse, is now held to be
only a collateral, as the last of the Tudors were collateral ancestors
of the Stuarts. The later Anchitheriwum must be eliminated from the
true line as a side-branch—a Young Pretender. Sometimes an apparent
succession is due to immigration of a distant relative from some other
region-—‘ The glorious House of Hanover and Protestant Succession.’
It was, you will remember, by such migrations that Cuvier explained
the renewal of life when a previous fauna had become extinct. He
admitted succession but not descent. If he rejected special creation,
he did-not accept evolution.

Descent, then, is not a corollary of succession. Or, to broaden the
statement, history is not the same as evolution. History is a succession
of events. Evolution means that each event has sprang’ from the pre-
ceding one. .Not that the preceding event was the active cause of its
successor, buf that it was a necessary condition of if. For the evolu-

trat

| 0.—GEOLOGY. 67

tionary biologist, a species contains in itself and its environment the
possibility of producing its successor. ‘The words ‘its environment ’
are necessary, because a living organism cannot be conceived apart
from its environment. They are important, because they exclude from
the idea of organic evolution the hypothesis that all subsequent forms
were implicit in the primordial protoplast alone, and were manifested
either through a series of degradations, as when Thorium by successive
disintegrations transmutes itself to Lead, or through fresh develop-
ments due to the successive loss of inhibiting factors. I say ‘a species
contains the possibility ’ rather than ‘ the potentiality,’ because we
cannot start by assuming any kind of innate power.

Huxley, then, forty years ago, claimed that palaeontologists had
proved an orderly succession. To-day we claim to have proved evolution
by descent. But how do we prove it? The neontologist, for all his
experimental breeding, has scarcely demonstrated the transmutation
of a species. The palaeontologist cannot assist at even a single birth.
The evidence remains circumstantial.

Recapitulation as Proof of Descent.

Circumstantial evidence is convincing only if inexplicable on any
other admissible theory. Such evidence is, I believe, afforded by
palaeontological instances of Haeckel’s law—1.e., the recapitulation by
an individual during its growth of stages attained by adults in the
previous history of the race. You all know how this has been applied
to the ammonites ; but any creatures with a shell or skeleton that grows
by successive additions and retains the earlier stages unaltered can be
studied by this method. If we take a chronological series of apparently
related species or mutations, a’, a?, a°, a*, and if in a* we find that
' the growth stage immediately preceding the adult resembles the adult
a*, and that the next preceding stage resembles a?, and so on; if this
applies mutatis mutandis to the other species of the series; and if,
further, the old age of each species foreshadows the adult character
of its successor; then we are entitled to infer that the relation between
the species is one of descent. Mistakes are liable to occur for various
reasons, which we are learning to guard against. For example, the
perennial desire of youth to attain a semblance of maturity leads often
to the omission of some steps in the orderly process. But this and
other eccentricities affect the earlier rather than the later stages, so
that it is always possible to identify the immediate ancestor, if it can
be found. Here we have to remember that the ancestor may not have
lived in the same locality, and that therefore a single cliff-section does
not always provide a complete or simple series. An admirable example
of the successful search for a father is provided by R. G. Carruthers
in his paper on the evolution of Zaphrentis delanouei (1910, Quart.
Journ. Geol, Soc., lxvi., 523). Surely when we get a clear case of
this kind we are entitled to use the word ‘ proof,’ and to say that we
have not merely observed the succession, but have proved the filiation.

_ It has, indeed, been objected to the theory of recapitulation that
the stages of individual growth are an inevitable consequence of an
¥3

68 SECTIONAL ADDRESSES.

animal’s gradual development from the embryo to the adult, and there-
fore prove nothing. Even now there are those who maintain that the
continuity of the germ-plasm is inconsistent with any true recapitula-
tion. Let us try to see what thismeans. Take any evolutionary series,
and consider the germ-plasm at any early stage in it. The germ, it is
claimed, contains the factors which produce the adult characters of that
stage. Now proceed to the next stage of evolution. The germ has
either altered or it has not. If it has not altered, the new adult
characters are due to something outside the germ, to factors which may
be in the environment but are notin the germ. In this case the animal
must be driven by the inherited factors to reproduce the ancestral form ;
the modifications due to other factors will come in on the top of this,
and if they come in gradually and in the later stages of growth, then
there will be recapitulation. There does not seem to be any difficulty
here. You may deny the term ‘ character’ to these modifications, and
you may say that they are not really inherited, that they will disappear
entirely if the environment reverts to its original condition. Such lan-
guage, however, does not alter the fact, and when we pass to subsequent
stages of evolution and find the process repeated, and the recapitulation
becoming longer, then you will be hard put to it to imagine that the
new environment produces first the effects of the old and then its own
particular effect.

Even if we do suppose that the successive changes in, say, an
ammonite as it passes from youth to age are adaptations to successive
environments, this must mean that there is a recapitulation of environ-
ment. If is an explanation of structural recapitulation, but the fact
remains. There is no difficulty in supposing an individual to pass
through the same succession of environments as were encountered in
the past history of its race. Every common frog is an instance. . The
phenomenon is of the same nature as the devious route followed in their
migrations by certain birds, a route only to be explained as the repetition
of past history. There are, however, many cases, especially among
sedentary organisms, which cannot readily be explained in this way.

Let us then examine the other alternative and suppose that every
evolutionary change is due to a change in the germ—how produced we
need not now inquire. Then, presumably, it is claimed that at each
stage of evolution the animal will grow from the egg to the adult along
a direct path. For present purposes we ignore purely larval modifications,
and admit that the claim appears reasonable. The trouble is that it
does not harmonise with facts. The progress from youth to age is not
always a simple advance. The creature seems to go out of its way to
drag in a growth-stage that is out of the straight road, and can be ex-
plained only by the fact that it is inherited from an ancestor. Thus,
large ammonites of the Xipheroceras planicosta group, beginning
smooth, pass through a ribbed stage, which may be omitted, through
unituberculate and bituberculate stages, back to ribbed and smooth
again. The anal plate of the larval Antedon, which ends its course
and finally disappears above the limits of the cup, begins life in that
lower position which the similar plate occupied in most of the older
crinoids.

we %

‘C.—GEOLOG Y. 69

Here, then, is a difficulty. It can be overcome in two ways. A
view held by many is that there are two kinds of characters: first, those
fhat arise from changes in the germ, and appear as sudden or discon-
tinuous variations; second, those that are due to external (i.e., non-
germinal) factors. It seems a corollary of this view that the external
characters should so affect the germ-plasm as ultimately to produce in
it the appropriate factors. This is inheritance of acquired characters.
The other way out of the difficulty is to suppose that all characters
other than fluctuations or temporary modifications are germinal; that
changes are due solely to changes in the constitution of the germ; and
that, although a new character may not manifest itself till the creature
has reached old age, nevertheless it was inherent in the germ and latent
through the earlier growth-stages. This second hypothesis involves
two further difficulties. It is not easy to formulate a mechanism by
which a change in the constitution of the germ shall produce a character
of which no trace can be detected until old age sets in; such acharacter,
for instance, as the tuberculation of the last-formed portion of an
ammonite shell. Again, it is generally maintained that characters due
to this change of germinal factors, however minute they may be, make
a sudden appearance. They are said to be discontinuous. They act
as integral units. Now the characters we are trying to explain seem
to us palaeontologists to appear very gradually, both in the individual
and in the race. Their beginnings are small, scarcely perceptible; they
increase gradually in size or strength; and gradually they appear at
earlier and earlier stages in the life-cycle. It appears least difficult to
suppose that characters of this kind are not initiated in the germ, and
that they, if no others, may be subject to recapitulation. It may not
yet be possible to visualise the whole process by which such characters
are gradually established, or to refer the phenomena of recapitulation
back to more fundamental principles. But the phenomena are there,
and if any hypothesis is opposed to them so much the worse for the
hypothesis. However they be explained, the instances of recapitula-
tion afford convincing proof of descent, and so of genetic evolution.

The ‘ Line upon Line’ Method of Palaeontology.

You will have observed that the precise methods of the modern
palaeontologist, on which this proof is based, are very different from the
slap-dash conclusions of forty years ago. The discovery of Archae-
opteryx, for instance, was thought to prove the evolution of Birds from
Reptiles. No doubt it rendered that conclusion extremely probable,
especially if the major premiss—that evolution was the method of
nature—were assumed. But the fact of evolution is precisely what
men were then trying to prove. These jumpings from Class to Class
or from Era to Era, by aid of a few isolated stepping-stones, were what
Bacon calls Anticipations, ‘ hasty and premature ’ but ‘ very effective,
because as they are collected from a few instances, and mostly from
those which are of familiar occurrence, they immediately dazzle the
intellect and fill the imagination ’ (Nov. Org. I. 28). No secure step
was taken until the modern palacontologist began to affiliate mutation
with mutation and species with species, working his way back, literally

70 | SECTIONAL ADDRESSES.

inch by inch, through a single small group of strata. Only. thus could
he base on the laboriously collected facts a single true Interpretation ;
and to. those who preferred the broad path of generality his Interpreta-
tions seemed, as Bacon says they always ‘must. seem, harsh and
discordant—almost like mysteries of faith.’

It is impossible to read these words without thinking of one
‘naturae minister et interpres,’ whose genius was the first in_ this
country to appreciate and apply to palaeontology the Novum Organon.
Devoting his whole life to abstruse research, he has persevered with
this method in the face of distrust and has produced a, series of brilliant
studies which, whatever their defects, have illuminated the problems of
stratigraphy and gone far to revolutionise systematic palaeontology.
Many are the workers of to-day who acknowledge a master in Sydney
Savory Buckman.

I have long believed that the only safe mode of advance in palae-
ontology is that which Bacon counselled and Buckman has practised,
namely, ‘ uniformly and step by step.’ Was this not indeed the prin-
ciple that guided Linnaeus himself? Not till we have linked species
into lineages, can we group them into genera; not till we have un-
ravelled the strands by which genus is connected with genus can we
draw the limits of families. Not till that has been accomplished can
we see how the lines: of descent. diverge or converge, so as to warrant
the establishment of Orders. Thus by degrees we reject the old slippery
stepping-stones that so often toppled us into the stream, and foot by foot
we build a secure bridge over the waters of ignorance.

The work is slow, for the material is not always to hand, but as we
build we learn fresh principles and test our current hypotheses. To
some of these I would now direct your attention.

Continuity in Development.

Let us look first at this question of continuity. Does an evolving
line change by discontinuous steps (saltations), as when a man mounts
a ladder; or does it change continuously, as when a wheel rolls up-
hill? The mere question of fact is extraordinarily difficult to determine.
Considering the gaps in the geological record one would have expected
palaeontologists to be the promulgators of the hypothesis of discon-
tinuity. They are its chief opponents.‘ The advocates of discon-
tinuity maintain that palaeontologists are misled: that the steps are so
minute as to escape the observation of workers handicapped by the
obscurities of their material; that many apparent characters are com-
pound and cannot, in the case of fossils, be subjected to Mendelian

1 As Dr. W. D. Matthew (1910, Pop. Sci. Monthly, p. 473) has well
exemplified by the history of the Tertiary oreodont mammals in North America,
the known record, taken at its face value, leads to ‘the conclusion that new
species, new genera and even larger groups have appeared by saltatory evolution,
not by continuous development.’ But a consideration of the general conditions
controlling evolution and migration among jand mammals shows him that such
a conclusion is unwarranted. ‘The more complete the series of specimens,
the more perfect the record in successive strata, and the nearer the hypothetic
centre of dispersal, the closer do we come. to a phyletic series whose. intergrading
stages are we!] within the limits of observed variation of the race.’

C.— GEOLOGY. TA

analysis; that no palaeontologist can guarantee the genetic purity of the
assemblages with which he works, even when his specimens are collected
from a single locality and horizon. It is difficult to reply to such
negative arguments. One can but give examples of the kind of obser-
vation on which palaeontologists rely.

Since Dr. Rowe’s elaborate analysis of the species of Micraster
occurring in the Chalk of $.E. England, much attention has been
concentrated on the gradual changes undergone by those sea-urchins
in the course of ages. ‘The changes observed affect many characters ;
indeed, they affect the whole test, and all parts are doubtless correlated.
The changes come in regularly and gradually; there is no sign of
discontinuity. It is convenient to give names to the successive forms,
but they are linked up by innumerable gradations. There does not
seem here to be any question of the sudden appearance of a new
character, in one or in many individuals; or of the introduction of
any character and the gradual extension of its range by cross-breeding
until it has become universal and in turn gives way to some new
step in advance. The whole assemblage is affected and moves forward
in line, not with an advanced scout here and a straggler there. Slight
variation between contemporaneous individuals occurs, no doubt, but
the ‘limits are such that a trained collector can tell from a single fossil
the level at which it has been found. The continuity of the changes is
also inferred from such a fact as that in occasional specimens of
Micraster cor-bovis the distinctness of the ambulacral sutures (which
is one of these characters) is greater on one side of the test than on
the other.

Such changes as these may profitably be compared with those which
Professor Duerden believes to be taking place in the ostrich. He too
finds a slow continuous change affecting innumerable parts of the bird,
a change that is universal and within slight limits of variation as
between individuals. Even on the hypothesis that every barb of every
feather is represented by a factor in the germ, he finds it impossible
to regard the changes as other than continuous, and he is driven to
the supposition (on the hypothesis of germinal factors) that the factors
themselves undergo a gradual change, which he regards as due to old
age. It is interesting also that he finds an occasional lop-sided change,
such as we noted in Micraster cor-bovis.

Whatever may be the explanation, the facts do seem to warrant
the statement that evolutionary change can be, and offen is, continuous.
Professor De Vries has unfortunately robbed palaeontologists of the
word ‘ mutation,’ by which, following Waagen, they were accustomed
to denote such change. I propose, therefore, to speak of it as
‘transition.’ But here the question may be posed, whether such transi-
tions can progress indefinitely, or whether they should not be compared
to those divergences from the norm of a species which we call fluctua-
tions, because, like the waves of the sea piled up by a gale, they return
to their original level when the external cause is removed. If every
apparent transition in time is of the latter nature, then, when it reaches
a limit comparable to that circumscribing contemporary fluctuation,
there must, if progress is to persist, be some disturbance provoking

72 SECTIONAL ADDRESSES.

a saltation, and so giving a new centre to fluctuation and a fresh limit
to the upward transition. Those who maintain such an hypothesis
presumably regard transition as the response of the growing individual
body to gradual change of the physical environment (somatic modifica-
tion). But saltation they ascribe to a change in the composition of
the germ. That change may be forced on the germ by the condition
of the body, and may therefore be in harmony with the environment,
and may produce a new form along that line. The new form may be
obviously distinct from its predecessor, or the range of its fluctuation
may overlap that of its predecessor, in which case it will be impossible
to decide whether the change is one of transition or of saltation. This
succession of hypotheses involves a good many difficulties; among
others, the mechanism by which the germ is suddenly modified in
accordance with the transition of the body remains obscure. But the
facts before us seem to necessitate either perpetual transition or salta-
tion acting in this manner. ‘Transition, we must admit, also involves
a change of the germ pari passu with the change of the body. Conse-
quently the difference between the two views seems to be narrowed
down to a point which, if not trivial, is at any rate minute.

The particular saltation-hypothesis which I have sketched may
remind some hearers of the ‘ expression points ’ of E. D. Cope. That
really was quite a different conception. Cope believed that, in several
cases, generic characters, after persisting for a long time, changed
with relative rapidity. This took place when the modifications of adult
structure were pushed back so far prior to the period of reproduction
as to be transmitted to the offspring. The brief period of time during
which this rapid change occurred in any genus was an expression-point,
and was compared by Cope to the critical temperature at which a gas
changes into a liquid, or a liquid into a solid. The analogy is not
much more helpful than Galton’s comparison of a fluctuating form to
a rocking polyhedron, which one day rocks too much and topples over
on to another face. It is, however, useful to note Cope’s opinion that
these points were ‘ attained without leaps, and abandoned without
abruptness.’ He did not believe that ‘ sports’ had ‘ any considerable
influence on the course of evolution ’ (1887, ‘ Origin of Fittest,’ pp. 39,
79; 1896, ‘ Factors Org. Evolution,’ pp. 24, 25).

The Direction of Change: Seriation.

The conception of connected change, whether by transition or by
scarcely perceptible saltation, or by a combination of the two processes,
leads us to consider the Direction of the Change.

Those who attempt to classify species now living frequently find
that they may be arranged in a continuous series, in which each species
differs from its neighbours by a little less or a little more; they find
that the series corresponds with the geographical distribution of the
species; and they find sometimes that the change affects particular
genera or families or orders, and not similar assemblages subjected,
apparently, to the same conditions. They infer from this that the
series represents a genetic relation, that each successive species is the
descendant of its preceding neighbour ; and in some cases this inference

C.—GEOLOGY. 73

is warranted by the evidence of recapitulation, a fact which further
indicates that the change arises by addition or subtraction at the end
of the individual life-cycle. So far as I am aware this phenomenon,
at least so far as genera are concerned, was first precisely defined
by Louis Agassiz in his ‘ Hssay on Classification,’ 1857. He called
it ‘ Serial Connection,’ a term which connotes the bare statement of
fact. Cope in his ‘ Origin of Genera,’ 1869, extended the observation,
in a few cases, to species, and introduced the term ‘ Successional
Relation,’ which for him implied descent. We may here use the brief
and non-committal term ‘ Seriation.’

The comparison of the seriation of living species and genera to the
seriation of a succession of extinct forms as revealed by fossils was,
it seems, first definitely made by Cope, who in 1866 held the zoological
regions of to-day to be related to one another ‘as the different sub-
divisions of a geologic period in time’ (Journ. Acad. Nat. Sct. Phila-
delphia, 1866, p. 108). This comparison is of great importance. Had
we the seriations of living forms alone, we might often be in doubt
as to the meaning of the phenomenon. In the first place we might
ascribe it purely to climatic and similar environmental influence, and
we should be unable to prove genetic filiation between the species.
Even if descent were assumed we should not know which end of the
series was ancestral, or even whether the starting point might not
be near the middle. But when the palaeontologist can show the same,
or even analogous, seriation in a time-succession, he indicates to the
neontologist the solution of his problem.

Here it is well to remind ourselves that all seriations are not exact.
There are seriations of organs or of isolated characters, and the trans-
ition has not always taken place at the same rate. Hence numerous
examples of what Cope called Inexact Parallelism. The recognition of
such cases is largely responsible for the multiplication of genera by some
modern palaeontologists. This may or may not be the best way of
expressing the facts, but it is desirable that they should be plainly
expressed or we shall be unable to delineate the actual lines of genetic
descent.

Restricting ourselves to series in which descent may be considered
as proved or highly probable, such as the Micrasters of the Chalk, we
find then a definite seriation. There is not merely transition, but trans-
ition in orderly sequence such as can be represented by a graphic curve
of simple form. If there are gaps in the series as known to us, we can
safely predict their discovery ; and we can prolong the curve backwards
or forwards, so as to reveal the nature of ancestors or descendants.

Orthogenesis: Determinate Variation.

The regular, straightforward character of such seriation led Eimer
to coin the term Orthogenesis for the phenomenon as a whole. If this
term be taken as purely descriptive, it serves well enough to denote
certain facts. But Orthogenesis, in the minds of most people, connotes
the idea of necessity, of determinate variation, and of predetermined
course. Now, just as you may have succession without evolution, so
you may have seriation without determination or predetermination.

74 SECTIONAL ADDRESSES.

Let us be clear as to the meaning of these terms. | Variation is
said to be determinate, or, as Darwin called it, ‘ definite,’ when all the
offspring vary in the same direction. Such definite variation may be
determined by a change in the composition of the germ, due perhaps
to some external influence acting on all the parents; or it may express
the direct action of an external influence on the growing offspring. The
essential feature is that all the changes are of the same kind, though
they may differ in degree. For instance, all may consist in some addi-
tion, as a thickening of skeletal structures, an outgrowth of spines or
horns; or all may consist in some loss, as the smaller size of outer
digits, the diminution of tubercles, or the disappearance of feathers.
A succession of such determinate variations for several generations pro-
duces seriation ; and when the seriation is in a plus direction it is called
progressive (anabatic, anagenetic), when in a minus direction, retro-
gressive (catabatic, catagenetic). When successive additions appear
late in the life-cycle, each one as it were pushing its predecessors back
to earlier stages, then we use Cope’s phrase—acceleration of develop-
ment. When subtraction occurs in the same way, there is retardation
of development. Now it is clear that if a single individual or genera-
tion produces offspring with, say, plus variations differing in degree,
then the new generation will display seriation. Instances of this are
well known. You may draw from them what inferences you please,
but you cannot actually prove that there is progression. Breeding-
experiments under natural conditions for a long series of years would
be required for such proof. Here, again, the palaeontologist can point
to the records of the process throughout centuries or millennia, and
can show that there has been undoubted progression and retrogression.
I do not mean to assert that the examples of progressive and retrogres-
sive series found among fossils are necessarily due to the seriation of
determinate variations ; but the instances of determinate variation known
among the creatures now living show the palaeontologist a method that
may have helped to produce his series. Once more the observations of
neontologist and palaeontologist are mutually complementary.

Predetermination.

So much for determination: now for Predetermination. This is a
far more difficult problem, discussed when the fallen angels

* reasoned high
Of providence, foreknowledge, will, and fate,
Fixed fate, free will, foreknowledge absolute,
And found no end in wandering mazes lost.’

—and it is likely to be discussed so long as a reasoning mind persists.
For all that, it is a problem on which many palaeontologists seem to
have made up their minds. They agree (perhaps unwittingly) with
Aristotle * that ‘Nature produces those things which, being con-

* pioer yap [ylvovra] boa ad Tivos ev abtois dpxiis ouvexas kwotmeva aikverra
els tt TéAos. Phys, Il., 199b, 15, ed. Bekker.

C.— GEOLOGY. "5

tinuously moved by a certain principle inherent in themselves, arrive
at a certain end.’ In other words, a race once started on a certain
course, will persist in that course; no matter how conditions may
change, no matter how hurtful to the individual its own changes
may be, progressive or retrogressive, up hill and down hill, straight
as a Roman road, it will go on to that appointed end. Nor is
it only palaeontologists who think thus. Professor Duerden has
recently written, ‘The Nagelian idea that evolutionary changes have
taken place as a result of some internal vitalistic force, acting altogether
independently of external influences, and proceeding along definite lines,
irrespective of adaptive considerations, seems to be gaining ground at
the present time among biologists ’ (1919, Journ, Genetics, vii. p. 193).

The idea is a taking one, but is it really warranted by the facts at our
disposal? We have seen, I repeat, that succession does not imply
evolution, and (granting evolution) I have claimed that seriation can
occur without determinate variation and without predetermination. It
is easy to see this in the case of inanimate objects subjected to a con-
trolling foree. The fossil-collector who passes his material through a
series of sieves, picking out first the larger shells, then the smaller,
and finally the microscopic foraminifera, induces a seriation in size by
an action which may be compared to the selective action of successive
environments. ‘There is, in this case, predetermination imposed by an
external mind; but there is no determinate variation. You may see in
the museum at Leicester a series beginning with the via strata of the
Roman occupants of Britain, and passing through all stages of the
tramway up to the engineered modern railroad. The unity and
apparent inevitability of the series conjures up the vision of a world-
mind consciously working to a foreseen end. An occasional experiment
along some other line has not been enough to obscure the general trend ;
indeed, the speedy scrapping of such failures only emphasises the idea
of a determined plan. But closer consideration shows that the course
of the development was guided simply by the laws of mechanics and
economies, and by the history of discovery in other branches of science.
That alone was the nature of the determination; and predetermination,
there was none. From these instances we see that selection can, indeed
must, produce just that evolution along definite lines which is the
supposed feature of orthogenesis.

The arguments for orthogenesis are reduced to two: first, the diff-
culty of accounting for the incipient stages of new structures before
they achieve selective value; second, the supposed cases of non-adaptive
or even—as one may term it—counter-adaptive growth.

The earliest discernible stage of an entirely new character in an
adaptive direction is called by H. F. Osborn a ‘ rectigradation ’ (1907),
and the term implies that the character will proceed to develop in a
definite direction. As compared with changes of proportion in exist-
ing characters (‘ allometron,’ Osborn), rectigradations are rare. Osborn
applies the term to the first signs of folding of the enamel in the teeth
of the horse. Another of his favourite instances is the genesis of horns
in the Titanotheres, which he has summarised as follows: ‘ (a) from
excessively rudimentary beginnings, i.e. rectigradations, which can

76 SECTIONAL ADDRESSES.

hardly be detected on the surface of the skull; (b) there is some pre-
determining law or similarity of potential which governs their first
existence, because (c) the rudiments arise independently on the same
part of the skull in different phyla [i.e. lineages] at different periods of
geologic time; (d) the horn rudiments evolve continuously, and they
gradually change in form (i.e. allometrons) ; (e) they finally become the
dominating characters of the skull, showing marked variations of the
form in the two sexes; (f) they first appear in late or adult stages of
ontogeny, but are pushed forward gradually into earlier and earlier
ontogenetic stages until they appear to arise prenatally.’

Osborn says that rectigradations are a result of the principle of
determination, but this does not seem necessary. In the first place,
the precise distinction between an allometron and a rectigradation fades
away on closer scrutiny. When the rudiment of a cusp or a horn
changes its form, the change is an allometron; the first swelling is a
rectigradation. But both of these are changes in the form of a pre-
existing structure; there is no fundamental difference between a bone
with an equable curve and one with a slight irregularity of surface.
Why may not the original modification be due to the same cause as the
succeeding ones? The development of a horn in mammalia is prob-
ably a response to some rubbing or butting action which produces
changes first in the hair and epidermis. One requires stronger evidence
than has yet been adduced to suppose that in this case form precedes
function. As Jaekel has insisted, skeletal formation follows the changes
in the softer tissues as they respond to strains and stresses. In the
evolution of the Echinoid skeleton, any new structures that appear,
such as auricles for the attachment of jaw-muscles or notches for the
reception of external gills, have at their inception all the character of
rectigradations, but it can scarcely be doubted that they followed the
growth of their correlated soft parts, and that these latter were already
subject to natural selection. But we may go further: in vertebrates
as in echinoderms the bony substance is interpenetrated with living
matter, which renders it directly responsive to every mechanical force,
and modifies it as required by deposition or resorption, so that the
skeleton tends continually to a correlation of all its parts and an adapta-
tion to outer needs.

The fact that similar structures are developed in the same positions
in different stocks at different periods of time is paralleled in probably all
classes of animals; Ammonites, Brachiopods, Polyzoa, Crinoids, Sea-
urchins present familiar instances. But do we want to make any
mystery of it? The words ‘predisposition,’ ‘ predetermining law,’
‘similarity of potential,’ ‘inhibited potentiality,’ and ‘ periodicity,’ all
tend to obscure the simple statement that like causes acting on like
material produce like effects. When other causes operate, the result is
different. Certainly such facts afford no evidence of predetermination,
in the sense that the development must take place willy-nilly. Quite
the contrary: they suggest that it takes place only under the influence
of the necessary causes. Nor do they warrant such false analogies as
‘ Environment presses the button: the animal does the rest.’

The resemblance of the cuttle-fish eye to that of a vertebrate has

C.— GEOLOGY. i7

been explained by the assumption that both creatures are descended,
longo intervallo no doubt, from a common stock, and that the flesh or
the germ of that stock had the internal impulse to produce this kind of
eye some day when conditions should be favourable. It is not ex-
plained why many other eyed animals, which must also have descended
from this remote stock, have developed eyes of a different kind. Never-
theless I commend this hypothesis of Professor Bergson to the advo-
eates of predisposition. To my mind it only shows that a philosopher
may achieve distinction by a theory of evolution without a secure know-
ledge of biology.

When the same stock follows two quite different paths to the same
goal, it is impossible to speak of a predetermined course. In the Wen-
lock beds is a crinoid whose stalk has become flattened and coiled, and
the cirri or tendrils of the stalk are no longer set by fives all round it,
but are reduced to two rows, one along each side. In one species these
cirri are spaced at irregular intervals along the two sides, but as the
animal grows there is a tendency for them to become more closely set. In
another species, in various respects more developed, the cirri are set quite
close together, and the tightly coiled stalk looks like a ribbed ammonite.
Closer inspection shows that this species includes two distinct forms.
In one each segment of the stalk bears but a single cirrus, first on the
right, then on the left; but the segments taper off to the opposite side so
that the cirri are brought close together. In the other form two cirri
are borne by a single segment, but the next segment bears no cirri.
These intervening segments taper to each side, so that here also the
cirri are brought close together. Thus the same appearance and the
same physiological effect are produced in two distinct ways. Had one
ofthese never existed, the evolution of this curious stem would have
offered as good an argument for orthogenesis as many that have been
advanced. So much for similarity !

The argument for orthogenesis based on a race-history that marches
to inevitable destruction, heedless of environmental factors, has always
seemed to me incontrovertible, and so long as my knowledge of
palaeontology was derived mainly from books I accepted this premiss
as well founded. Greater familiarity with particular groups has led
me to doubt whether such cases really occur, for more intensive study
generally shows that characters at first regarded as indifferent or
detrimental may have been adapted to some factor in the environment
or some peculiar mode of life.

Professor Duerden’s jnteresting and valuable studies of the ostrich
(1919, 1920, Journ. Genetics) lead him to the opinion that retrogressive
changes in that bird are destined to continue, and ‘ we may look for-
ward,’ he says, ‘ to the sad spectacle of a wingless, legless, and feather-
less ostrich if extinction does not supervene.’ Were this so we might
at least console ourselves with the thought that the process is a very
slow one, for Dr. Andrews tells me that the feet and other known
bones of a Pliocene ostrich are scarcely distinguishable from those of
the present species. But, after careful examination of Dr. Duerden’s
arguments, I see no ground for supposing that the changes are other
than. adaptive. Similar changes.occur in other birds of other stocks

78 SECTIONAL ADDRESSES.

when subjected to the requisite conditions, as the flightless birds of
diverse origin found on ocean islands, the flightless and running rails,
geese, and other races of New Zealand, the Pleistocene Genyornis of
the dried Lake Callabonna, which, as desert conditions came on, began
to show a reduction of the inner toe. Among mammals the legs and
feet have been modified in the same way in at least three distinct
orders or suborders, during different periods, and in widely separated
regions, Living marsupials in Australia have the feet modified accord-
ing to their mode of life, whether climbing on trees or running over
hard ground; and among the latter we find a series indicating how
the outer toes were gradually lost and the fourth digit enlarged. 1
need scarcely remind you of the modifications that resulted in the
horse’s hoof with its enlarged third digit, traceable during the Tertiary
Epoch throughout the Northern Hemisphere, whether in one or more
than one stock. I would, however, recall the fact that occasional
races, resuming from time to time a forest habitat, ceased to progress
along the main line. Lastly, there are those early hoofed animals
from South America, made known by Ameghino under the name
Litopterna, which underwent a parallel series of changes and attained
in Thoatherium from the Upper Miocene of Patagonia a one-toed foot
with elongate metacarpals essentially similar to that of the horse. In
all these cases the correlation of foot-structure with mode of life (as
also indicated by the teeth) is such that adaptation by selection has
always been regarded as the sole effective cause.

My colleague, Dr. W. D. Lang, has recently published a most
thoughtful paper on this subject (1919, Proc. Geol. Assoc. xxx. 102).
His profound studies on certain lineages of Cretaceous Polyzoa
(Cheilostomata) have led him to believe that the habit of secreting
calcium carbonate, when once adopted, persists in an increasing degree.
Thus in lineage after lineage the habit ‘has led to a brilliant but
comparatively brief career of skeleton-building, and has doomed the
organism finally to evolve but the architecture of its tomb.’ These
creatures, like all others which secrete calcium carbonate, are simply
suffering from a gouty diathesis, to which each race will eventually
succumb. Meanwhile the organism does its best to dispose of the
secretion ; if usefully, so much the better; but at any rate where it
will be least in the way. Some primitive polyzoa, we are told, often
sealed themselves up; others escaped this self-immurement by turning
the excess into spines, which in yet other forms fused into a front
wall. But the most successful architects were overwhelmed at last
by superabundance of building-material.

_.__ While sympathetic to Dr. Lang’s diagnosis of the disease (for in
1888 I hazarded the view that in Cephalopoda lime-deposition was
uncontrollable by the animal, and that its extent was inversely relative
to the rate of formation of chitin or other calcifiable tissue), still I
think he goes too far in postulating an ‘insistent tendency.’ He
speaks of living matter as if it were the over-pumped inner-tube of
a bicycle tyre, ‘tense with potentiality, curbed by inhibitions’ fof
the cover] and ‘ periodically breaking out as inhibitions are removed ’
{by broken glass]. A race acquires the lime habit or the drink habit,

0.—GEOLOGY, 79

and, casting off all restraint, rushes with accelerated velocity down
the easy slope to perdition.

A melancholy picture! But is it true? The facts in the case of
the Cretaceous Polyzoa are not disputed, but they can be’ interpreted
as a reaction of the organism to the continued abundance of lime-salts
in the sea-water. If a race became choked off with lime, this perhaps
was because it could not keep pace with its environment. Instead of
‘irresistible momentum’ from within, we may speak of irresistible
pressure from without. Dr. Lang has told us (1919, Phil. Trans.
B. ecix.) ‘that in their evolution the individual characters in a
lineage are largely independent of one another.’ It is this independ-
ence, manifested in differing trends and differing rates of change, that
originates genera and species. Did the evolution follow some inner
impulse, along lines ‘ predetermined and limited by innate causes,’
one would expect greater similarity, if not identity, of pattern and
of tempo.

Many are the races which, seeking only ornament, have (say our
historians) perished like Tarpeia beneath the weight of a less welcome
cift: oysters, ammonites, hippurites, crinoids, and corals. But I see
no reason to suppose that these creatures were ill-adapted to their
erivironment—until the situation changed. This is but a special case
of increase in size. In creatures of the land probably, and in creatures
of the water certainly (as exemplified by A. D. Mead’s experiments
on the starfish, 1900, Amer. Natural. xxxiv. 17), size depends on
the amount of food, including all body- and skeleton-building con-
stituents. When food is plentiful larger animals have an advantage
over small. Thus by natural selection the race increases in size until
a balance is reached. Then a fall in the food-supply handicaps the
larger creatures, which may become extinct. So simple an explana-
tion renders it quite unnecessary to regard size as in itself indicating
the old age of the race.

Among the structures that have been most frequently assigned to
some blind growth-force are spines or horns, and when they assume
a grotesque form or disproportionate size they are dismissed as evidences
of senility. Let us take a case.

The Trilobite family Lichadidae is represented in Ordovician and
Silurian rocks by species with no or few spines, but in the early
part of the Devonian, both in America and in Europe, various unrelated
groups in this family begin to grow similarly formed and situated
spines, at first short and straight, but soon becoming long curved horns,
until the climax is reached in such a troll-like goat-form as Ceratarges
armatus of the Calceola-beds in the Hifel.

Dr. J. M. Clarke (1913, Monogr. Serv. Geol. Brazil, i. p. 142)
is among those who have regarded this parallel development as a sign
of orthogenesis in the most mystical meaning of the term. Strange
though these little monsters may be, I cannot, in view of their con-
siderable abundance, believe that their specialisation was of no use
to them, and I am prepared to accept the following interpretation by
Dr. Rudolf Richter (1919, 1920).

Such spines haye their first origin in the tubercles which form so

80 SECTIONAL ADDRESSES.

common an ornament in Crustacea and other Arthropods and which
serve to stiffen the carapace. A very slight projection of any of these
tubercles further acts as a protection against such soft-bodied enemies
as jelly-fish. Longer out-growths enlarge the body of the trilobite in
such a way as to prevent its being easily swallowed. When, as is
often the case, the spines stretch over such organs as the eyes, their
protective function is obvious. This becomes still more clear when
we consider the relation of these spines to the body when rolled up,
for then they are seen to form an encircling or enveloping chevauz-
de-frise. But besides this, the spines in many cases serve as balancers ;
they throw the centre of gravity back from the weighty head, and
thus enable the creature to rise into a swimming posture. Further,
by their friction, they help to keep the animal suspended in still water
with a comparatively slight motion of its numerous oar-like limbs.
Regarded in this light, even the most extravagant spines lose their
mystery and appear as consequences of natural selection. A com-
parison of the curious Marrella in the pelagic or still-water fauna
of the Middle Cambrian Burgess shale with Acidaspis radiata of the
Calceola-beds certainly suggests that both of these forms were adapted
to a similar life in a similar environment.

The fact that many extreme developments are followed by the
extinction of the race is due to the difficulty that any specialised organism
or machine finds in adapting itself to new conditions. A highly
specialised creature is one adapted to quite peculiar circumstances;
very slight external change may put it out of harmony, especially if the
change be sudden. It is not necessary to imagine any decline of vital
force or exhaustion of potentiality.

When people talk of certain creatures, living or extinct, as obviously
unadapted for the struggle of life, I am reminded of Sir Henry de Ja
Beche’s drawing of a lecture on the human skull by Professor
Ichthyosaurus. ‘ You will at once perceive,’ said the lecturer, ‘ that
the skull before us belonged to one of the lower orders of animals;
the teeth are very insignificant, the power of the jaws trifling; and
altogether it seems wonderful how the creature could have procured
food.’

What, then, is the meaning of ‘momentum’ jn evolution? Simply
this, that change, whatever its cause, must be a change of something
that already exists. The changes in evolving lineages are, as a rule,
orderly and continuous (to avoid argument the term may for the
moment include minute saltations). Environment changes slowly and
the response of the organism always lags behind it, taking small heed
of ephemeral variations.” Suppose a change from shallow to deep water

2 The conception of dag in evolution is of some importance. On a hypothesis
of selection from fortuitous variations the lag must be considerable. If the
variations be determinate and in the direction of the environmental change, the
lag will be reduced; but according as the determination departs from the
environmental change, the lag will increase. If a change of environment acts on
the germ, inducing either greater variation or variation in harmony with the
change, there will still be lag, but it will be less. On this hypothesis the lag
will depend on the mechanism through which the environment affects the germ.
If, with Osborn, we imagine an action on the body, transmitted to the various

C.—GEOLOGY. 81

—either by sinking of the sea-floor or by migration of the organism.
Creatures already capable of becoming acclimatised will be the majority
of survivors, and among them those which change most rapidly will
soon dominate. Place your successive forms in order, and you will get
the appearance of momentum; but the reality is inertia yielding with
more or less rapidity to an outer force.

Sometimes a change is exhibited to a greater or less extent by every
member of some limited group of animals, and this change may seem
to be correlated with the conditions of life in only a few of the genera
or species, while in others it manifests no adaptive character and no
selective value. Thus the loss of the toes or even limbs in certain
lizards is ascribed by Dr. G. A. Boulenger to an internal tendency,
although, at any rate in the Skinks, which furnish examples of all stages
of loss, it certainly seems connected with a sand-loving and burrowing
life. Recently Dr. Boulenger (1920, Bull. Soc. Zool. France, xlv.
68) has put forward the East African Testudo loveridgei, a ribless
tortoise with soft shell that squeezes into holes under rocks, and swells
again like an egg in a bottle, as the final stage of a regressive series.
The early stages of this regression, such as a decrease in size of the
vertebral processes and rib-heads, were long since noticed by him in
other members of the same family; but, since they did not occur in
other families, and since he could perceive no adaptive value in them,
he regarded them as inexplicable, until this latest discovery proved them
to be prophetic of a predestined goal. The slightness of my acquaint-
ance with tortoises forbids me to controvert this supreme example of
teleology as it appears to so distinguished an authority. But in all
these apparent instances we should do well to realise that we are still
incompletely informed about the daily life of these creatures and of
their ancestors in all stages of growth, and we may remember that
structures once adaptive often persist after the need has passed or
has been replaced by one acting in a different direction.

The Study of Adaptive Form.

This leads us on to consider a fruitful field of research, which would
at first seem the natural preserve of neontologists, but which, as it
happens, has of late been cultivated mainly to supply the needs of
palaeontology. That field is the influence of the mode of life on the
shape of the creature, or briefly, of function on form; and, conversely,
the indications that form can give as to habits and habitat. For many
a long year the relatively simple mechanics of the vertebrate skeleton
have been studied by palaeontologists and anatomists generally, and
have been brought into discussions on the effect of use. The investiga-
tion of the mechanical conditions controlling the growth of organisms has
recently been raised to a higher plane by Professor D’Arcy Thompson’s

parts through catalysera and hormones, then the process will involve lag varying
with the physico-chemical constitution of the organism. Slight differences in
this respect between different races may have some bearing on the rate of
change (vide infra ‘The Tempo of Evolution’), on the correlation of characters,
and so on the diversity of form.

1920 q

82 SECTIONAL ADDRESSES.

suggestive book on ‘ Growth and Form.’ These studies, however,
have usually considered the structure of an animal as an isolated
machine, We have to realise that an organism should be studied in
relation to the whole of its environment, and here form comes in as
distinct from structure. That mode of expression, though loose and
purely relative, will be generally understood. By ‘form’ one means
those adaptations to the surrounding medium, to food, to the mode of
motion, and so forth, which may vary with outer conditions while the
fundamental structure persists. Though all structures may, conceiy-
ably, have originated as such adaptations, those which we call ‘ form’
are, as a rule, of later origin. Similar. adaptive forms are found in
organisms of diverse structure, and produce those similarities which we
know as ‘ convergence.’ To take but one simple instance from the
relations of organisms to gravity. A stalked echinoderm naturally
grows upright, like a flower, with radiate symmetry. But in the late
Ordovician and in Silurian rocks are many in which the body has a
curiously flattened leaf-like shape, in which the two faces are distinct,
but the two sides alike, and in which this effect is often enhanced by
paired outgrowths corresponding in shape if not in structure. Expan-
sion of this kind implies a position parallel to the earth’s surface, .7.e.
at right angles to gravity. The leaf-like form and the balancers are
adaptations to this unusual position. Recognition of this enables us to
interpret the peculiar features of each genus, to separate the adaptive
form from the modified structure, and to perceive that many genera
outwaraly similar are really of quite different origin.

Until we understand the principles governing these and other adapta-
tions—irrespective of the systematic position of the creatures in which
they appear—we cannot make adequate reconstructions of our fossils,
we cannot draw correct inferences as to their mode of life, and we cannot
distinguish the adaptive from the fundamental characters. No doubt
many of us, whether palaeontologists or neontologists, have long recog-
nised the truth in a general way, and have attempted to describe our
material—whether in stone or in aleohol—as living creatures; and not
as isolated specimens but as integral portions of a mobile world. It is,
however, chiefly to Louis Dollo that we owe the suggestion and the
example of approaching animals primarily from the side of the environ-
ment, and of studying adaptations as such. The analysis of adaptations
in those casés where the stimulus can be recognised and correlated with
its reaction (as in progression through different media or over different
surfaces) affords sure ground for inferences concerning similar forms of
whose life-conditions we are ignorant. Thus Othenio Abel (1916) has
analysed the evidence as to the living squids and cuttle-fish and has
applied it to the belemnites and allied fossils with novel and interesting
results. But from such analyses there have been drawn wider con-
clusions pointing to further extension of the study. It was soon seen
that adaptations did not come to perfection all at once, but that har-
monisation was gradual, and that some species had progressed further
than others. But it by no means follows that these represent chains of
descent. The adaptations of all the organs must be considered, and one
seriation checked by another. Thus in 1890, in sketching the probable

0.— GEOLOGY. 83

history of certain crinoids, I pointed out that the seriation due to the
migration of the anal plates must be checked by the seriation due to the
elaboration of arm-structure, and so on. .

In applying these principles we are greatly helped by Dollo’s thesis
of the Irreversibility of Evolution. It is not necessary to regard this as
an absolute Law, subject to no conceivable exception. It is a simple
statement of the facts as hitherto observed, and may be expressed
thus:

1. In the course of race-history an organism never returns exactly
to its former state, even if placed in conditions of existence identical with
those through which it has previously passed. Thus, if through adap-
tation to a new mode of life (as from walking to climbing) a race loses
organs which were highly useful to it in the former state, then, if it ever
reverts to that former mode of life (as from climbing to walking), those
organs never return, but other organs are modified to take their place.

2. But (continues the Law), by virtue of the indestructibility of the
past, the organism always preserves some trace of the intermediate
stages. Thus, when a race reverts to its former state, there remain the
traces of those modifications which its organs underwent while it was
pursuing another mode of existence.

The first statement imposes a veto on any speculations as to descent
that involve the reappearance of a vanished structure. It does not
interfere with the cases in which old age seems to repeat the characters
of youth, as in Ammonites, for here the old-age character may be
similar, but obviously is not the same. The second statement furnishes
a guide to the mode of life of the immediate ancestors, and is applicable
to living as well as to fossil forms. It is from such persistent adaptive
characters that some have inferred the arboreal nature of our own
ancestors, or even of the ancestors of all mammals. ‘To take but a
single point, Dr. W. D. Matthew (1904, Amer. Natural. xxxyiil.
813) finds traces of a former opposable thumb in several early Eocene
mammals, and features dependent on this in the same digit of all
mammals where it is now fixed,

The Study of Habitat.

The natural history of marine invertebrata is of particular interest
to the geologist, but its study presents peculiar difficulties. The marine
zoologist has long recognised that his early efforts with trawl and dredge
threw little light on the depth in the sea frequented by his captures. The
surface floaters, the swimmers of the middle and lower depths, and the
crawlers on the bottom were confused in a single haul, and he has
therefore devised means for exploring each region separately. The
geologist, however, finds all these faunas mixed in a single deposit.
He may even find with them the winged creatures of the air, as in the
insect beds of Gurnet Bay, or the remains of estuarine and land animals.

Such mixtures are generally found in rocks that seem to have been
deposited in quiet land-locked bays. Thus in a Silurian rock near
Visby, Gotland, have been found creatures of such diverse habitat as
a scorpion, a possibly estuarine Pterygotus, a large barnacle, and a
_ erinoid of the delicate form usually associated with clear deep water.
a 2

84 SECTIONAL. ADDRESSES.

The lagoons of Solenhofen have preserved a strange mixture of land and
sea life, without a trace of fresh or brackish water forms. Archae-
opteryx, insects, flying reptiles, and creeping reptiles represent the air
and land fauna; jelly-fish and the crinoid Saccocoma are true open-
water wanderers; sponges and stalked crinoids were sessile on the
bottom; starfish, sea-urchins, and worms crawled on the sea-floor ;
king-crabs, lobsters, and worms left their tracks on mud-flats ; cephalo-
pods swam at various depths; fishes ranged from the bottom mud to the
surface waters. The Upper Ordovician Starfish bed of Girvan contains
not only the crawling and wriggling creatures from which it takes its
name, but stalked echinoderms adapted to most varied modes of life,
swimming and creeping trilobites, and indeed representatives of almost
all marine levels.

In the study of such assemblages we have to distinguish palieen
the places of birth, of life, of death, and of burial, since, though these
may all be the same, they may also be different. The echinoderms
of the Starfish bed further suggest that closer discrimination is needed
between the diverse habitats of bottom forms. Some of these were, I
believe, attached to sea-weed; others grew up on stalks above the
bottom ; others clung to shells or stones; others lay on the top of the
sea-floor ; others were partly buried beneath its muddy sand; others may
have grovelled beneath it, connected with the overlying water by
passages. Here we shall be greatly helped by the investigations of
C. G. J. Petersen and his fellow-workers of the Danish Biological
Station. (See especially his summary, ‘The Sea Bottom and its
Production of Fish Food,’ Copenhagen, 1918.) They have set an
example of intensive study which needs to be followed elsewhere. By
bringing up slabs of the actual bottom, they have shown that, even in
a small area, many diverse habitats, each with its peculiar fauna, may
be found, one superimposed on the other. Thanks to Petersen and
similar investigators, exact comparison can now take the place of in-
genious speculation. And that this research is not merely fascinating
in itself, but illuminatory of wider questions, follows from the con-
sideration that analysis of faunas and their modes of life must be a
necessary preliminary to the study of migrations and geographical
distribution.

The Tempo of Evolution.

We have not yet done with the results that may flow from an analysis
of adaptations. Among the many facts which, when considered from
the side of animal structure alone, lead to transcendental theories with
Greek names, there is the observation that the relative rate of evolution
is very different in races living at the same time. Since their remains
are found often side by side, it is assumed that they were subject to the
same conditions, and that the differences of speed must be due to a
difference of internal motive force. After what has just been said you
will at once detect the fallacy in this assumption. Professor Abel has
recently maintained that the varying tempo of evolution depends on the
changes in outer conditions. He compares the evolution of whales,
sirenians, and horses during the Tertiary Epoch, and correlates it with

0.—a@koLoey. 85

the nature of the food. Roughly to summarise, he points out that
from the Eocene onwards the sirenians underwent a steady, slow change,
because, though they migrated from land to sea, they retained their
habit of feeding on the soft water-plants. The horses, though they
remained on land, display an evolution at first rather quick, then
slower, but down to Pliocene times always quicker than that of the
sirenians ; and this is correlated with their change into eaters of grain,
and their adaptation to the plains which furnish such food. The whales,
like the sirenians, migrated at the beginning of the Tertiary from land to
sea; but how different is their rate of evolution, and into what diverse
forms have they diverged! At first they remained near the coasts, keep-
ing to the ancestral diet, and, like the sirenians, changing but slowly.
But the whales were flesh-eaters, and soon they took to hunting fish, and
then to eating large and small cephalopods; hence from the Oligocene
onwards the change was very quick, and in Miocene times the evolution
was almost tempestuous. Finally, many whales turned to the swallow-
ing of minute floating organisms, and from Lower Pliocene times,
having apparently exhausted the possibilities of ocean provender, they
changed with remarkable slowness.

Whether such changes of food or of other habits of life are, in a
sense, spontaneous, or whether they are forced on the creatures by
changes of climate and other conditions, makes no difference to the
facts that the changes of form are a reaction to the stimuli of the outer
world, and that the rate of evolution depends on those outer changes.

Whether we have to deal with similar changes of form taking place
at different times or in different places, or with diverse changes affect-
ing the same or similar stocks at the same time and place, we can see
the possibility that all are adaptations to a changing environment.
There is then reason for thinking that ignorance alone leads us to assume
some inexplicable force urging the races this way or that, to so-called
advance or to apparent degeneration, to life or to death.

The Rhythm of Life.

The comparison of the life of a lineage to that of an individual is,
up to a point, true and illuminating; but when a lineage first starts on
its independent course (which really means that some individuals of a
pre-existing stock enter a new field), then I see no reason to predict
that it will necessarily pass through periods of youth, maturity, and
old age, that it will increase to an acme of numbers, of variety, or of
specialisation, and then decline through a second childhood to ultimate
extinction. Still less can we say that, as the individuals of a species
have their allotted span of time, long or short, so the species or the
lineage has its predestined term. The exceptions to those assertions
are indeed recognised by the supporters of such views, and they are
explained in terms of rejuvenescence, rhythmic cycles, or a grand
despairing outburst before death. This phraseology is delightful as
metaphor, and the conceptions have had their value in promoting search
for confirmatory or contradictory evidence. But do they lead to any
broad and fructifying principle? When one analyses them.one is per-
petually brought up against some transcendental assumption, some

86 SECTIONAL ADDRESSES.

unknown entelechy that starts and controls the machine, but must for
eyer evade the methods of our science.

The facts of recurrence, of rhythm, of rise and fall, of marvellous
efflorescences, of gradual decline, or of sudden disappearances, all are
incontestable. But if we accept the intimate relation of organism and
environment, we shall surmise that on a planet with such a geological
history as ours, with its recurrence of similar physical changes, the
phenomena of life must reflect the great rhythmic waves that have
uplifted the mountains and lowered the deeps, no less than every
smaller wave and ripple that has from age to age diversified and
enlivened the face of our restless mother.

To correlate the succession of living forms with all these changes
is the task of the palaeontologist. To attempt it he will need the aid of
every kind of biologist, every kind of geologist. But this attempt is not
in its nature impossible, and each advance to the ultimate goal will,
in the future as in the past, provide both geologist and biologist with
new light on their particular problems. | When the correlation shall
have been completed, our geological systems and epochs will no longer
be defined by gaps in our knowledge, but will be the true expression
of the actual rhythm of evolution. Lyell’s great postulate of the uni-
form action of nature is still our guide; but we have ceased to confound
uniformity with monotony. We return, though with a difference, to
the conceptions of Cuvier, to those numerous and _ relatively sudden
revolutions of the surface of the globe which have produced the corre-
sponding dynasties in its succession of inhabitants.

The Future.

The work of a systematic palaeontologist, especially of one dealing
with rare and obscure fossils, often seems remote from the thought and
practice of modern science. I have tried to show that it is not really
so. But still it may appear to some to have no contact with the urgent
problems of the world outside. That also is an error. Whether the
views I have criticised or those I have supported are the correct ones is
a matter of practical importance. If we are to accept the principle of
predetermination, or of blind growth-force, we must accept also a
check on our efforts to improve breeds, including those of man, by any
other means than crossings and elimination of unfit strains. In spite
of all that we may do in this way, there remain those decadent races,
whether of ostriches or human beings, which ‘ await alike the inevit-
able hour.’ If, on the other hand, we adopt the view that the life-
history of races is a response to their environment, then it follows,
no doubt, that the past history of liying creatures will have been deter-
mined by conditions outside their control, it follows that the idea of
human progress as a biological law ceases to be tenable; but, since man
has the power of altering his environment and of adapting racial
characters through conscious selection, it also follows that progress will
not of necessity be followed by decadence; rather that, by aiming at a
high mark, by deepening our knowledge of ourselyes and of our world,
and by controlling our energy and guiding our efforts in the light of
that knowledge, we may prolong and hasten our ascent to ages and to
heights as yet beyond prophetic vision.

SECTION D: CARDIFF, 1920.

ADDRESS

LOOLOGICAL SECTION

BY
Professor J. STANLEY GARDINER, M.A., F.RB.S.,

PRESIDENT OF THE SECTION,

Where do we stand?

Tue public has the right to consider and pass judgment on all that
affects its civilisation and advancement, and both of these largely
depend on the position and advance of science. I ask its consideration
of the science of Zoology, whether or not it justifies its existence as
such, and, if it does, what are its needs? It is at the parting of the
ways. It either has to justify itself as a science or be altogether starved
out by the new-found enthusiasm for chemistry and physics, due to the
belief in their immediate application to industries.

It is a truism to point out that the recent developments in chemistry
and physics depend, in the main, on the researches of men whose
names are scarcely known to the public: this is equally true for all
sciences. A list of past Presidents of the Royal Society conveys
nothing to the public compared with a list of Captains of Industry who,
to do them justice, are the first to recognise that they owe their position
and wealth to these scientists. These men of science are unknown to
the public, not on account of the smallness of their discoveries, but
rather on account of their magnitude, which makes them meaningless
to the mass.

Great as have been the results in physical sciences applied to
industry, the study of animal life can claim discoveries just as great.
Their greatest value, however, lies not in the production of wealth, but
rather in their broad applicability to human life. Man ig an animal and
he is subject to the same laws as other animals. He learns by the
experience of his forebears, but he learns, also, by the consideration of
other animals in relationship to their fellows and to the world at large:
The whole idea of evolution, for instance, is of indescribable value; it
permeates all life to-day ; and yet Charles Darwin, whose researches did
more than any others to establish its facts, is too often only known to
the public as ‘the man who said we came from monkeys.’

88 SECTIONAL ADDRESSES.

Whilst first and foremost I would base my claim for the study of
animal life on this consideration, we cannot neglect the help it has given
to the physical welfare of man’s body. It is not out of place to draw
attention to the manner in which pure zoological science has worked
hand in hand with the science of medicine. Harvey’s experimental
discovery of the circulation of the ‘blood laid the foundation for that
real knowledge of the working of the human body which is at the basis
of medicine; our experience of the history of its development gives us
good grounds to hope that the work that is now being carried out by
numerous researchers under the term ‘ experimental’ will ultimately
elevate the art of diagnosis into an exact science. Harvey’s work, too,
mostly on developing chicks, was the starting-point for our knowledge
of human development and growth. Instances in medicine could be
multiplied wherein clinical treatment has only been rendered possible
by laborious research into the life histories of certain parasites preying
often on man and other animals alternately. In this connection there
seems reason at present for the belief that the great problem of medical
science, cancer, will reach its solution from the zoological side. A
pure zoologist has shown that typical cancer of the stomach of the rat
can be produced by a parasitic threadworm (allied to that found in
pork, Trichina), this having as a carrying host the American cock-
roach, brought over to the large warehouses of Copenhagen in sacks of
sugar. Our attack on such parasites is only made effective by what we
know of them in lower forms, which we can deal with at will. Millions
of the best of our race owe their lives to the labours of forgotten men
of science, who laid the foundations of our knowledge of the generations
of insects and flat-worms, the modes of life of lice and ticks, and the
physiology of such lowly creatures as Ameba and Paramecium; parasitic
disease—malaria, Bilharziasis, typhus, trench fever and dysentery—
was as deadly a foe to us as was the Hun.

Of immense economic importance in the whole domain of domestic
animals and plants was the rediscovery, early in the present century,
of the complefely forgotten work of Gregor Mendel on cross-breeding,
made known to the present generation largely by the labours of a
former President of this Association, who, true man of science, claims
no credit for himself. We see results already in the few years that
lave elapsed in special breeds of wheat, in which have been combined
with exactitude the qualities man desires. The results are in the
making—and this is true of all things in biology—but can anyone doubt
that the breeding of animals is becoming an exact science? We have
got far, perhaps, but we want to get much further in our understand-
ing of the laws governing human heredity; we have to establish
immunity to disease. Without the purely scientific study of chromo-
somes (the bodies which carry the physical and mental characteristics
of parents to children) we could have got nowhere, and to reach our
goal we must know more of the various forces which in combination
make up what we term life.

In agricultural sciences we are confronted with pests in half a
dozen different groups of animals. We have often to discover which
of two or more is the damaging form, and the difficulty is greater

D.—-ZOOLOGY. 89

where the damage is due to association between plant and animal pests.
Insects are, perhaps, the worst offenders, and our basal knowledge of
them as living organisms—they can do no damage when dead, and
perhaps pinned in our showcases—is due to Redi, Schwammerdam,
and Réaumur in the middle of the seventeenth century. Our present
successful honey production is founded on the curiosity of these men in
respect to the origin of life and the generations of insects. The fact
that most of the dominant insects have a worm (caterpillar or maggot)
stage of growth, often of far longer duration than that of the inseets,
has made systematic descriptive work on the relation of worm and
insect of peculiar importance. I hesitate, however, to refer to catalogues
in which perhaps a million different forms of adults and young are
described. Nowadays we know, to a large degree, with what pests we
deal and we are seeking remedies. We fumigate and we spray, spending
millions of money, but the next remedy is in the use of free-living
enemies or parasites to prey on the insect pests. The close correlation
of anatomy with function is of use here in that life histories, whether
parasitic, carnivorous, vegetarian, or saprophagous, can be foretold in
fly maggots from the structure of the front part of their gut (pharynx) ;
we know whether any maggot is a pest, is harmless, or is beneficial.

I won’t disappoint those who expect me to refer more deeply to
science in respect to fisheries, but its operations in this field are less
known to the public at large. The opening up of our north-western
grounds and banks is due to the scientific curiosity of Wyville Thomson
and his confréres as to the existence or non-existence of animal life
in the deep sea. It was sheer desire for knowledge that attracted
a host of inquirers to investigate the life history of river eels. The
wonder of a fish living in our shallowest pools and travelling two
or three thousand miles to breed, very likely on the bottom in 2,000
fathoms, and subjected to pressures varying from 14 lb. to 2 tons per
square inch, is peculiarly attractive. It shows its results in regular
eel farming, the catching and transplantation of the baby eels out of
the Severn into suitable waters, which cannot, by the efforts of Nature
alone, be sure of their regular supply. Purely scientific observations
on the life histories of flat fish—these were largely stimulated by the
scientific curiosity induced by the views of Lamarck and Darwin as
to the causes underlying their anatomical development—and on the
feeding value and nature of Thisted Bredning and the Dogger Bank,
led to the successful experiments on transplantation of young plaice
to these grounds and the phenomenal growth results obtained, particu-
larly on the latter. Who can doubt that this ‘ movement of herds’
is one of the first results to be applied in the farming of the North
Sea as soon as the conservation of our fish supply becomes a question
of necessity ?

The abundance of mackerel is connected with the movements of
Atlantic water into the British Channel andthe North Sea, movements
depending on complex astronomical, chemical, and physical conditions.
‘They are further related to the food of the mackerel, smaller animal
life which dwells only in these Atlantic waters. These depend, as
indeed do all animals, on that living matter which possesses chlorophyll

50 SECTIONAL ADDRESSES.

for its nutrition and which we call plant. In this case the plants
are spores of algae, diatoms, etc., and their abundance as food again
depends on the amount of the light of the sun—the ultimate source,
it might seem, of all life.

A method of ascertaining the age of fishes was sought purely to
correlate age with growth in comparison with the growth of air-living
vertebrates. This method was found in the rings of growth in the
scales, and now the ascertaining of age-groups in herring shoals enables
the Norwegian fishermen to know with certainty what possibilities and
probabilities are before them in the forthcoming season. From the
work on the blending together of Atlantic with Baltic and North Sea
water off the Baltic Bight and of the subsequent movements of this
Bank water, as it. is termed, into the Swedish fiords can be understood,
year by year, the Swedish herring fishery. It is interesting that these
fisheries have been further correlated with cycles of sun spots, and
also with longer cycles of lunar changes.

The mass of seemingly unproductive scientific inquiries undertaken
by the United States Bureau of Fisheries, thirty to fifty years ago,
was the forerunner of their immense fish-hatching operations, whereby
billions of fish eggs are stripped year by year and the fresh waters
of that country made into an important source for the supply of food.
The study of the growth stages of lobsters and crabs has resulted in
sane regulations to protect the egg-carrying females, and in some
keeping up of the supply in spite of the enormously increased demand.
Lastly, the study of free-swimming larval stages in mollusea, stimu-
lated immensely by their similarity to larval stages in worms and
starfishes, has given rise to the establishment of a successful pearl-
shell farm at Dongonab, in the Red Sea, and of numerous fresh-water
mussel fisheries in the southern rivers of the United States, to supply
small shirt buttons.

Fishery inyestigation was not originally directed to a more ambitious
end than giving a reasonable answer to a question of the wisdom or
unwisdom of compulsorily restricting commercial fishing, but it was
soon found that this answer could not be obtained without the aid
of pure zoology. The spread of trawling—and particularly the intro-
duction of steam trawling during the last century—gave rise to grave
tears that the stock of fish in home waters might be very seriously
depleted by the use of new methods. We first required to know the
life histories of the various trawled fish, and Sars and others told
us that the eggs of the vast majority of the European marine food
species were pelagic; in other words, that they floated, and thus could
not be destroyed, as had been alleged. Trawl fishing might have to
be regulated all the same, for there might be an insufficient number
of parents to keep up the stock. It was clearly necessary to know
the habits, movements, and distribution of the fishes, for all were
not, throughout their life; or at all seasons. found on the grounds it
was practicable to fish. A North Sea plaice of 12 in. in length, a
quite moderate size, is usually five years old. The fact that of the
female plaice captured in the White Sea, a virgin ground, the vast
majority are mature, while less than half the plaice put upon our —

D.—ZOOLOGY. 91

markets from certain parts of the southern North Sea in the years
immediately before the war had ever spawned, is not only of great
interest, but gives rise to grave fears as to the possibility of unrestricted
fishing dangerously depleting the stock itself. There is, however,
another group of ideas surrounding the question of getting the maximum
amount of plaice-meat from the sea; it may be that the best size for
catching is in reality below the smallest spawning size. I here merely
emphasise that in the plaice we have an instance of an important food
fish whose capture it will probably be necessary to regulate, and that
in determining how best the stock may be conserved, what sizes should
receive partial protection, on what grounds fish congregate and why,
and in all the many cognate questions which arise, answers to either
can only be given by the aid of zoological science.

But why multiply instances of the applications of zoology as a pure
science to human affairs? Great results are asked for on every side of
human activities. The zoologist, if he be given a chance to live and
to hand on his. knowledge and experience to a generation of pupils,
can answer many of them. He is increasingly getting done with the
collection of anatomical facts, and he is turning more and more to the
why and how animals live. We may not know in our generation nor
in many generations what life is, but we can know enough to control
that life. The consideration of the fact that living matter and water
are universally associated opens up high possibilities. The experi-
mental reproduction of animals, without the interposition of the male,
is immensely interesting; where it will lead no one can foretell. The
association of growth with the acidity and alkalinity of the water is a
matter of immediate practical importance, especially to fisheries. The
probability of dissolved food material in sea and river water, indepen-
dent of organised organic life and absorbable over the whole surfaces of
animals, is clearly before us. Is it possible that that dissolved material
may be even now being created in nature without the assistance of
organic life? The knowledge of the existence in food of vitamines,
making digestible and usable what in food would otherwise be wasted,
may well result in economies of food that will for generations prevent the
necessity for the artificial restriction of populations. The parallel
between these vitamines and something in sea-water may quite soon
apply practically to the consideration of all life in the sea. Finally,
what we know of the living matter of germ cells puts before us the not
impossible hope that we may influence for the better the generations yet

to come.

If it is the possibility in the unknown that makes a science, are
there not enough possibilities here? Does Zoology, with these prob-
lems before it, look like a decayed and worked-out science? Is it not
worthy to be ranked with any other science, and is it not worthy
of the highest support? Is it likely to show good value for the
money spent upon it? Should we not demand for it a Professorial
Chair in every University that wishes to be regarded as an educational
institution? And has not the occupant of such a Chair a task at least
equal in difficulty to that of the occupant of any other Chair? Surely
the zoologist may reasonably claim an equal position and pay to that

92 SECTIONAL ADDRESSES.

of the devotee of any other science! The researcher is not a huckstet'
and will not make this claim on his own behalf, but the occupant of
this Chair may be allowed to do so for him.

So far I have devoted my attention primarily, in this survey of the
position of Zoology, to the usefulness of the subject. Let us now note
where we stand in respect to other subjects and in meeting the real need
for wide zoological study.

All sciences are now being reviewed, and zoology has to meet month
by month the increasingly powerful claim of physics and chemistry for
public support. Both of these sciences are conspicuously applicable
to industry, and this, perhaps, is their best claim. The consideration
of life as a science would itself be in danger were it not for the economic
applications of physiology to medicine. This is the danger from
without, but there is another from within, and this lies in the splitting
up of the subject into a series of small sections devoted to special
economic ends. They are a real danger in that they are forming
enclosures Within a science, while research is more and more breaking
down the walls between sciences. Zoology in many Universities
scarcely exists, for what is assimilated by agriculturists and medical
men are catalogued lists of pests, while medical students merely acquire
the technique of observing dead forms of animals other than human—
not the intention of the teachers, it is true, but a melancholy fact all
the same. The student, I say again, is merely acquiring in ‘ Zoology ’
a travesty of a noble subject, but to this point I return later.

Let me now give a few facts which have their sweet and bitter for
us who make Zoology our life work. During the war we wanted men
who had passed the Honours Schools in Zoology—and hence, were pre-
sumably capable of doing the work—to train for the diagnosis of proto-
zoal disease. We asked for all names from 1905 to 1914 inclusive, and the
average worked out at under fourteen per year from all English
Universities: an average of one student per University per year. In
the year 1913-14 every student who had done his Honours Course in
Zoology in 1913 could, if he had taken entomology as his subject, have
been absorbed into the economic applications of that subject. Trained
men were wanted to undertake scientific fishery investigations and they
could not be found. Posts were advertised in Animal Breeding, in
Helminthology, and in Protozoology, three other economic sides of
the subject. The Natural History Museum wanted systematists and
there were many advertisements for teachers. How many of these
posts were filled I don’t know, but it is clear that not more than one-
half—or even one-third—can have been filled efficiently. Can any
zoologist say that all is well with his subject in the face of these
deficiencies?

The demands for men in the economic sides of zoology are con-
tinually growing, and it is the business of Universities to try and meet
these demands. There are Departments of Government at home and
in our Colonies, which, in the interests of the people they govern, wish
to put into operation protective measures but cannot do so because
there are not the men with the requisite knowledge and common sense
required for Inspectorates. There are others that wish for research

D.—ZOOLOGY. 938

t to develop seas, to conserve existing industries as well as to discover new

:
.
|

b
.
‘
:

ones, and they, too, are compelled to mark time.

In default, or in spite of, the efforts of the schools of pure zoology,
attempts are being made to set up special training schools in fisheries,
in entomology, and in other economic applications of zoology. Hach
branch is regarded as a science and the supporters of each suppose
they can, from the commencement of a lad’s scientific training, give
specialised instruction in each. The researcher in each has to do the
research which the economic side requires. But he can’t restrict his
education to one science; he requires to know the principles of all
sciences; he must attempt to understand what life is. Moreover, his
specialist knowledge can seldom be in one science. The economic
entomologist, however deep his knowledge of insects may be, will find
himself frequently at fault in distinguishing cause and effect unless he
has some knowledge of mycology. The protozoologist must have an
intimate knowledge of unicellular plants, bacterial and other. The
animal-breeder must know the work on cross-fertilisation of plants.
The fisheries man requires to understand physical oceanography. The
helminthologist and the veterinary surgeon require an intimate know-
ledge of a rather specialised ‘ physiology.’ All need knowledge of the
comparative physiology of animals in other groups beyond those with
which they deal, to assist them in their deductions and to aid them to
secure the widest outlook. It is surely a mistake, while the greatest
scientific minds of the day find that they require the widest knowledge,
to endeavour to get great scientific results out of students whose train-
ing has been narrow and specialised. Such specialisation requires to
come later, and can replace nothing. ‘This short cut is the longest way
round. The danger is not only in our science, but in every science.

In face of this highly gratifying need for trained zoologists, indepen-
dently of medical schools, I ask my colleagues in the teaching of zoology,
‘What is wrong with our schools of zoology that they are producing
so few men of science? It is not the subject! Can it be our presenta-
tion of it, or is it merely a question of inadequate stipends? ’

In science schools there can be no standing still. Progress or
retrogression in thought, technique, and method are the two alterna-
tives. If we are to progress we must see ever wider vistas of thought,
and must use the achievements of cur predecessors as the take-off for
our own advances. The foundations of our science were well and truly
laid, but we must not count the bricks for ever, but add to them.
Par be it from me to decry the knowledge and ideas our predecessors

_haye given to us. To have proved the possibility, nay, probability, that

all life is one life and that life itself is permanent is an immense achieve-
ment. To have catalogued the multitudinous forms that life takes in
each country was a herculean task. To have studied with meticulous
eare the shapes, forms, and developments of organs in so many bodies
was equally herculean. It was as much as could be expected in the
nineteenth century, during most of which zoology was in advance of
all other sciences. But surely for these pioneer workers this docket-
ing, tabulating, and collecting was not the object of their research,
but the means to its attainment, The prize they sought was the under-

4 SECTIONAL ADDRESSES.

standing of life itself, the intangible mystery which makes ourselves
akin to all these specimens, the common possession which gives to man,
as to the lowest creature, the power of growth and reproduction.

To my colleagues I say, let us no longer, in the reconstruction
immediately before us, tie ourselves down to the re-chewing of our dry
bones. They are but dead bones, and the great mystery which once
lived in them has passed from them, and it is that we must now
seek. Not in bones, in myriads of named specimens, does that mystery
dwell, but in the living being itself, in the growth and reproduction of
live creatures. Observation and experiment rather than tabulation and
docketing are our technique. What is that life, common to you, to me,
to our domestic pets, to animals and to plants alike? Surely this is
our goal, and the contents of our museums, means to this end, are
in danger of being regarded as the end. There is hope now. Those
of us who have the will to look can see zoology in its proper plaéé,
the colleague of botany in applying physics and chemistry to the under-
standing of life itself. The study of life is the oldest of all sciences;
it is the science in which the child earliest takes an interest; its study
has all the attributes required for education of the highest type, for the
appreciation of the beauty of form and of music, of unselfishness, of
self-control, of imagination, of love, and constancy. The more we know
of life, the more we appreciate its wonders and the moré we want t
know ; it is good to be alive.

Surely the time has now come for us to lift our eyes from our
tables of groups and families, and, on the foundations of the know-
ledge of these, work on the processes going on in the living body,
the adaptation to environment, the problems of heredity, and of many
another fascinating hunt in unknown country. Let us teach our
students not only what is known, but, still more, what is unknown, for
in the pursuit of the latter we shall engage eager spirits who care nought
for collections of corpses. My own conviction is that we are in danger
of burying our live subject along with our specimens in museums.

We see the same evil at work in the teaching of zoology from the
very beginning. Those of us who are parents know that the problems
of life assail a child almost as soon as it can speak, and that it is the
animal side of creation which makes the most natural and immediate
appeal to its interest and curiosity. Where such interest is intelligent
and constant it is safe to educate truly in the desired direction. You
will notice that the child’s questions are very fundamental and that,
according to my experience, the facts elicited are applied widely, and
with perfect simplicity. ‘Thus my own small daughter, having elicited
where the baby rabbits came from, said ‘ Oh! just like eggs from hens.’

The child’s own desires show up best what his mind requires for
its due development, and I fear no contradiction in claiming that it is
animal life in all its living aspects. Yet what is he given? Schools
encourage ‘natural history,’ as it is termed. In some it is nature; but
too often it consists in a series of prizes for dates—when the first
blooms of wild flowers were found; the first nests, eggs, and young of
birds ; the records of butterflies and moths, etc. Actual instruction, if
there is any beyond this systematic teaching of destruction, frequently

D.—ZOOLOGY. 95

_ lies solely in a few sheets of the life histories of the cabbage butterfly

1
,

and other insects. Fossil sea urchins and shells are curiosities and

are used to teach names. The whole is taught—there are some striking
exceptions—with the minimum requirements of observation and intelli-
gence. Plants too often dominate. The lad can pluck flowers and
tear up roots; there is a certain cruelty to be discouraged if animals
are treated similarly, but here there is none, for ‘they are not alive’ as

_weare. Which one of us would agree to this, and say that there is
not a similar ‘ cruelty’ in tearing up plants? The method is the

—

negation of science. The boy must be taught from the other end, from
fhe ohe animal about which he does know a little, viz., himself. From
the commencement he must associate himself with all living matter.
The child—boy or girl—shows us the way in that he is invariably keener
on the domestic pets, while he has to be bribed by pennies to learn
plant names.

As a result of the wrong teaching of zoology we see proposals to
make so-called “nature study’ in our schools purely, botanical. Is
this proposal made in the interests of the teacher or the children? It
surely can’t be for ‘ decency ’ if the teaching is honest, for the pheno-
mena are the same, and there is nothing ‘indecent’ common to all
life. ‘The proper study of mankind is man,’ and the poor child,
athirst for information about himself, is given a piece of moss or duck-
weed, or even a chaste buttercup. Is the child supposed to get some
knowledge it can apply economically? Whatever the underlying ideas
may be, this course will not best develop the mind to enable it to
grapple with all phenomena, the aim of education. If necessary, the
scliool teacher must. go to school; he must bring himself up to date in

_ his own time, as every teacher in science has to do; it is the business

of Universities to help him, for nothing is more important to all science
than the foundations of knowledge.

Into schools is now moving the teaching required for the first
professional examination in medicine, and this profoundly affects the

_ whole attitude of teachers. It has a syllabus approved by the Union

of Medicine, the ‘ apprenticeship ’ to which is as real and as difficult to

alter as that of any expert trade with its own union. It compels the

remembering of a number of anatomical facts relating to a miscellaneous
seléction of animals and plants, and the acquirement of a certain
amount of technique. However it may be taught, its examination can
almost invariably be passed on memory and manual dexterity ; it implies

no standard of mental ability. Anatomy without function and know-

ledge of an organism without reference to its life is surely futile. And
yet, too often, this is what our colleagues concerned with the second
year of this apprenticeship directly or indirectly compel us to teach
in the first year. Surely it is time for us to rebel and insist that what
is required is education as to the real meaning of what life is. We
shall never reach complete agreement as to a syllabus, but probably
we are all at one in regarding reproduction as the most interesting
biological phenomenon, and water and air as the most important environ-
ments.

Unfortunately most Universities have adopted this in many ways

96 SECTIONAL ADDRESSES.

unscientific and rather useless first Medical Examination as part. of
their first examination for the B.Sc. degree and for diplomas and
degrees in agriculture, dentistry, and other subjects. Zoology is part
of a syllabus in which half a dozen professors are concerned, and it
cannot change with the times without great difficulty. Our colleagues
of other sciences do not want it to change, preferring that a rival subject
to attract pupils should remain in a backwash; to be just, each has
a firm belief in the subject he knows. For our continuation courses,
having choked out the more thinking students, we have to go on as
we have begun, and we survey the animal kingdom in a more or less
systematic manner. We carefully see that all our beasts are killed
before we commence upon them; we deal solely with their compara-
tive anatomy, to which are often added some stories of ‘ evolution,’
fhe whole an attempted history of the animal kingdom. There are
great educational merits in the study of the comparative anatomy of
a group of similar animals, but too often we go to group after group,
the student attaining all that is educational in the first, only securing
from each subsequent group more and more facts which might just
as well be culled from text-books.

Students who continue further and take the final honours in zoology
specialise in most Universities in their last year in some branch of
their science. Such students are usually thinking of the subject from
the point of view of their subsequent livelihood. They have to think
of what will pay and in what branches there is, in their University,
some teacher from whom they can get special instruction. They read
up the most modern text-book, examine a few specimens, and are often
given the class they desire by examiners who know less of their
speciality than they do. They are then supposed to be qualified both
to teach and research in zoology. They teach on the same vicious
lines, and in research many are satisfied to become mere accumulators
of more facts in regard to dead creatures.

I have called this address ‘ Where do we stand?’ and I hope all
who are interested will try to answer this question. Personally I feel
that we stand in a most uncomfortable position, in which, to use a
colloquialism, we must either get on or get out. I am certain that the
progress of humanity requires us to ‘ get on.’

Of you in my audience who are not workers in science I ask a
final moment of consideration. There is no knowledge of which it
is possible to answer the question, ‘ What is the use of it?’ for only
time can disclose what are the full bearings of any piece of know-
ledge. Let us not starve pure research because we do not see its
immediate application. I often think that if Sir Isaac Newton, at
the present day, discovered the law of gravity as a result of watching
the apples fall, someone would say, ‘ Oh! interesting, no doubt: but
my money will go to the man who can stop the maggots in them.’

On the one side leads the path of economic research, offering more
obvious attractions in the way of rapid results and of greater immediate
recognition. That path is one trodden by noble steps, full of sacrifice
and difficulty, worthy of treading. But let us view with still greater
sympathy and understanding the harder path which leads workers,

D.— ZOOLOGY. 97

through years of seemingly unproductive toil, to strive after the solution
of the great basal problems of life. Such workers forfeit for themselves
the hope of wealth, leisure, and public recognition. As a rule they die
in harness, and leave not much beyond honoured names. ‘These are
they who worship at the Altar of the Unknown, who at great cost
wrest from the darkness its secrets, not recking of the boon they may
bring to humanity. It is for these I plead, not for themselves as
individuals, but for the means wherewith to keep the flame of pure
research burning, for the laboratories and equipment that all Universities
need.

1920 H

SECTION E: CARDIFF, 1920.

ADDRESS

TO THE

GEOGRAPHICAL SECTION

BY
JOHN McFARLANE, M.A,
PRESIDENT OF THE SECTION.

SincE the last meeting of the British Association, Treaties of Peace
have been signed with Austria, Hungary, Bulgaria, and Turkey; and,
although there is still much which is unsettled, especially in the East,
it 1s now possible to obtain some idea of the changes wrought on the
map of Europe by the Great War. These changes are indeed of the
most profound and far-reaching description. Old States have in some
cases either disappeared or suffered an enormous loss of territory, and
new States, with the very names of which we are but vaguely familiar,
have been brought into existence. It has seemed to me, therefore,
that it might not be altogether inappropriate to inquire into the prin-
ciples upon which these territorial changes have been made, and to
consider how far the political units affected by them possess the elements
of stability. A learned but pessimistic historian to whom I confided
my intention shook his head and gravely remarked, ‘ Whatever you
say on that subject will be writ in water.’ But the more I consider
the matter the more do I feel convinced that certain features in the
reconstructed Europe are of great and even of permanent value, and
it is in that belief that I have ventured to disregard the warning which
was given me.

In the rearrangement of European States which has taken place,
geographical conditions have perhaps not always had the consideration
which they deserve, but in an inquiry such as that upon which we are
engaged they naturally occupy the first place. And by geographical
conditions I am not thinking primarily, or even mainly, of defensive
frontiers. It may be true, as Sir Thomas Holdich implies, that they
alone form the true limits of a State. But if they do we ought to
carry our theory to its logical conclusion and crown them with barbed-
wire entanglements. Whether mankind would be happier or even safer
if placed in a series of gigantic compounds I greatly doubt. It is to the
land within the frontier, and not to the frontier itself, that our main
consideration should be given. The factors which we have to take
into account are those which enable a people to lead a common national

E.—GEOGRAPHY. 99

life, to develop the economic resources of the region within which they
dwell, to communicate freely with other peoples, and to provide not
only for the needs of the moment, but as far as possible for those
arising out of the natural increase of the population.

The principle of self-determination has likewise played an important,
if not always a well-defined, part in the rearrangement of EKurope. The
basis upon which the new nationalities have been constituted is on
the whole ethnical, though it is true that within the main ethnical
divisions advantage has been taken of the further differentiation in
racial characteristics arising out of differences in geographical environ-
ment, history, language, and religion. But no more striking illustration
could be adduced of the strength of ethnic relationships at the present
time than the union of the Czechs with the Slovaks, or of the Serbs
with the Croats and the Slovenes. Economic considerations, of course,
played a great part in the settlement arrived at with Germany, but on
the whole less weight has been attached to them than to ethnic condi-
tions. In cases where they have been allowed to influence the final
decision the result arrived at has not always been a happy one. Nor
can more be said for those cases where the motive was political or
strategic. Historical claims, which have been urged mainly by Powers
anxious to obtain more than that to which they are entitled on other
grounds, may be regarded as the weakest of all claims to the possession
of new territory.

When we come to examine the application of the principles which
I have indicated to the settlement of Europe we shall, I think, find that
the promise of stability is greatest in those cases where geographical and
ethnical conditions are most in harmony, and least where undue weight
has been given to conditions which are neither geographical nor ethnical.

The restoration of Alsace-Lorraine to France has always been treated
as a foregone conclusion in the event of a successful termination of the
war against Germany. From the geographical point of view, however,
there are certainly objections to the inclusion of Alsace within French
territory. The true frontier of France in that region is the Vosges, not
necessarily because they form the best defensive frontier, but because
Alsace belongs to the Rhineland, and the possession of it brings France
into a position from which trouble with Germany may arise in the
future.

Nor can French claims to Alsace be justified on ethnical grounds.
The population of the region contains a strong Teutonic element, as
indeed does that of Northern France, and the language spoken by over
90 per cent. of the people is German. On the other hand, it must
be borne in mind that during the period between the annexation of
Alsace by France in the seventeenth century and its annexation by
Germany in the nineteenth French policy appears to have been highly
successful in winning over the sympathies of the Alsatians, just as
between 1871 and 1914 German policy was no less successful in alienat-
ing them. The restoration of Alsace must therefore be defended, if
at all, on the ground that its inhabitants are more attached to France
than to Germany. That attachment it will be necessary for France to
preserve in the future, as economic conditions are not altogether favour-

100 SECTIONAL ADDRESSES.

able. The cotton industry of Alsace may perhaps attach itself to that
of France without great difficulty ; but the agricultural produce of the
Rhine plain will as before be likely to find its best and most conyenient
market in the industrial regions of Germany.

With regard to Lorraine the position is somewhat different. Physi-
cally that region belongs in the main to the country of the Paris basin,
and is therefore in a sense part of France. Strategically it commands
the routes which enter France from Germany between Belgium and
the Vosges, and from that point of view its possession is of the utmost
importance to her. Of the native population about one-third speak
French, and the German element is mainly concentrated in the more
densely populated districts of the north-east. But although in these
various aspects Lorraine may be regarded as belonging to France in a
sense in which Alsace does not, the real argument for the restoration
of the ceded provinces is in both cases the same. Lorraine, no. less
than Alsace, is French in its civilisation and in its sympathies.

From the economic point of view, however, the great deposits of
iron ore in Lorraine constitute its chief attraction for France to-day,
just as they appear to have constituted its chief attraction for Germany
half a century ago. But the transfer of the province from Germany,
which has built up a great industry on the exploitation of its mines,
to France, which does not possess in sufficient. abundance coal for
smelting purposes, together with other arrangements of a territorial or
quasi-territorial nature made partly at least in consequence of this
transfer, at once raises questions as to the extent to which the economic
stability of Germany is threatened. The position of that country, with
regard to the manufacture of iron and steel will be greatly affected, for
not only does she lose, in Lorraine and the Saar, regions in which these
manufactures were highly developed, but she loses in them the sources
from which other manufacturing regions still left to her, notably the
Ruhr, drew considerable quantities either of raw materials or of semi-
manufactured goods. For example, in 1913 the Ruhr, which produced
over 40 per cent. of the pig iron of the German Empire, obtained 15 per
cent. of its iron ore from Lorraine, and it also obtained from there
and from the Saar a large amount of pig iron for the manufacture of
steel. Unless, therefore, arrangements can be made for a continued
supply of these materials a number of its industrial establishments will
have to be closed down.

In regard to coal, the position is also serious.. We need not, perhaps,
be unduly impressed by the somewhat alarmist attitude of Mr. Keynes,
who estimates that on the basis of the 1913 figures Germany, as she
is now constituted, will require for the pre-war efficiency of her rail-
ways and industries an annual output of 110,000,000 tons, and that
instead she will have in future only 100,000,000 tons, of which
40,000,000 will be mortgaged to the Allies. In arriving at these figures
Mr. Keynes has made an allowance of 18,000,000 tons for decreased
production, one-half of which is caused by the German miner having
shortened his shift from eight and a half to. seven hours per day.
This is certainly a deduction which we need not take into account.
Mr. Keynes also leaves out of his calculation the fact that previous to the

B.—-GEOGRAPHY. 101

war about 10,000,000 tons per year were sent from Upper Silesia to
other parts of Germany, and there is no reason to suppose that this
amount need be greatly reduced, especially in view of Article 90 of the
Treaty of Versailles, which provides that ‘for a period of fifteen years
Poland will permit the produce of the mines of Upper Silesia to be
available for sale to purchasers in Germany on terms as favourable
as are applicable to like products sold under similar conditions in Poland
or in any other country.’ We have further to take into account the
opportunities for economy in the use of coal, the reduction in the
amount which will be required for bunkers, the possibility of renewing
imports from abroad—to a very limited extent indeed, but still to some
extent—and the fact that the French mines are being restored more
rapidly than at one time appeared. possible. (On the basis of the
production of the first four months of 1920 Germany could already
reduce her Treaty obligations to France by 1,000,000 tons per year.)
Taking all of these facts into account, it is probably correct to say that
when Germany can restore the output of the mines left to her to the
1913 figure, she will, as regards her coal supply for industrial purposes,
be in a position not very far removed from that in which she was in
1910, when her total consumption, apart from that at the mines, was
about 100,000,000 tons.

The actual arrangements which have been made, it is true, are in
some cases open to objection. The Saar is not geographically part of
France, and its inhabitants are German by race, language, and sym-
pathy. It is only in the economic necessities of the situation that a
defence, though hardly a justification, of the annexation of the coal-
field can be found. The coal from it is to be used in the main for the
same purposes as before, whereas if it had been left to Germany much
of it might have been diverted to other purposes. In 1913 the total
production of Alsace-Lorraine and the Saar amounted to about
18,000,000. tons, while their consumption was about 14,000,000 tons.
There is thus apparently a net gain to France of about 4,000,000 tons,
but from that must be deducted the amount which the North-Hast of
France received from this field in pre-war days. Switzerland also will
probably in future continue to draw part of its supplies from the Saar.

The stipulation that Germany should for ten years pay part of her
indemnities to France, Belgium, and Italy in kind also indicates an
attempt to preserve the pre-war distribution of coal in Europe, though
in some respects the scales seem to have been rather unfairly weighted
against Germany. France, for example, requires a continuance of
Westphalian coal for the metallurgical industries of Lorrainé and the
Saar, while Germany requires a continuance of Lorraine ore if her iron-
works on the Ruhr are not to be closed down. There was therefore
nothing unreasonable in the German request that she should be secured
her supplies of the latter commodity. Indeed, it would have been to
the advantage of both countries if a clause similar to Article 90, which
I have already quoted, had been inserted in the Treaty. It is true
that temporary arrangements have since been made which will ensure
to Germany a considerable proportion of her pre-war consumption of
minette ores. But some agreement which enabled the two separate

102 SECTIONAL ADDRESSES.

but complementary natural regions of the Saar and the Ruhr to exchange
their surplus products on a business basis would have tended to an
earlier restoration of good feeling between the two countries.

One other question which arises in this connection is the extent
to which the steel industry of Germany will suffer by the loss of the
regions from which she obtained the semi-manufactured products neces-
sary for it. On this subject it is dangerous to prophesy, but when we
take into consideration the length of time required for the construction
of modern steelworks, the technical skill involved in their management,
and the uncertainties with regard to future supplies of fuel, it seems
unlikely that France will attempt any rapid development of her steel
industry. In that case the Ruhr will still continue to be an important
market for Lorraine and the Saar.

Our general conclusion, then, is that the territorial arrangements
which have been made do not necessarily imperil the economic stability
of Germany. The economic consequences of the war are really much
more serious than the economic consequences of the peace. Germany
has for ten years to make good the difference between the actual and
the pre-war production of the French mines which she destroyed. Her
own miners are working shorter hours, and as a result her own pro-
duction is reduced, and as British miners are doing the same she is
unable. to import from this country. For some years these deductions
will represent a loss to her of about 40,000,000 tons per annum, and
will undoubtedly make her position a serious one. But to give her
either the Saar or the Upper Silesian coalfields would be to enable her
to pass on to others the debt which she herself has incurred. The re-
duction of her annual deliveries of coal to France, Belgium, and Italy
was, indeed, the best way in which to show mercy to her.

The position of Poland is geographically weak, partly because its
surface features are such that the land has no well-marked individuality,
and partly because there are on the east and west no natural boundaries
to prevent invasion or to restrain the Poles from wandering
far beyond the extreme limits of their State. Polish geographers
themselves appear to.be conscious of this geographical infirmity,
as ‘Vidal de la Blache would have termed it, and in an
interesting little work Nalkowski has endeavoured to show that
the very transitionality of the land between east and west entitles
it to be regarded as a geographical entity. But transitionality is rather
the negation of geographical individuality than the basis on which it
may be established. And indeed no one has pointed out its dangers
more clearly than Nalkowski himself. ‘The Polish people,’ he says,
‘living in this transitional country always were, and still are, a prey
to a succession of dangers and struggles. They should be ever alert
and courageous, remembering that on such a transitional plain, devoid
of strategic frontiers, racial boundaries are marked only by the energy
and civilisation of the people. If they are strong they advance those
frontiers by pushing forward ; by weakening and giving way they promote
their contraction. So the mainland may thrust out arms into the sea,
or, being weak, may be breached and even overwhelmed by the ocean
floads.’ If we bear in mind the constant temptation to a people which

E.—GEOGRAPHY. 108

is strong to advance its political no less than its racial frontiers, and
the constant danger to which a weakening people is exposed of finding
its political frontier contract even more rapidly than its racial, we shall
yealise some of the evils to which a State basing its existence on
transitionality is exposed.

It is, then, to racial feeling, rather than to geographical environ-
ment, that we must look for the basis of the new Polish State, but
the intensity with which this feeling is likely to operate varies consider-
ably in different parts of the region which it is proposed to include.
In the plébiscite area of Upper Silesia there were, according to the
census of 1900, which is believed to represent the facts more accurately
than that of 1910, seven Poles to three of other nationalities. In
Prussian Poland, apart from the western districts which have not been
annexed to Poland and the town and district of Bromberg, the Poles
number at least 75 per cent. of the total population, and in the ceded
and plébiscite areas of East and West Prussia 52 per cent. Russian
Poland, which contains rather more than two-thirds of the entire popula-
tion of what we may call ethnic Poland, has 9,500,000 Poles and over
3,000,000 Jews, Germans, Lithuanians, and others, while West Galicia
is almost solidly Polish. Thus out of a total population of 21,000,000
within the regions mentioned the Poles number 15,500,000, or about
75 per cent.

Bearing these facts in mind, it is possible to consider the potentialities
of the new State. The population is sufficiently large and the Polish
element within it is sufficiently strong to justify its independence on
ethnical grounds. Moreover, the alien elements which it contains are
united neither by racial ties nor by contiguity of settlement. In Posen,
for example, there is in the part annexed to Poland a definitely Polish
population with a number of isolated German settlements, while in
Russian Poland the Jews are to be found mainly in the towns. Con-
sidered as a whole, Poland is at least as pure racially as the United
States.

When we consider the economic resources of Poland we see that
they also make for a strong and united State. It is true that in the
past the country has failed to develop as an economic unit, but this
is a natural result of the partitions and of the different economic
systems which have prevailed in different regions. HEyen now, however,
we can trace the growth of two belts of industrial activity which will
eventually unite these different regions together. One is situated on
the coalfield running from Oppeln in Silesia by Cracow and Lemberg,
and is engaged in mining, agriculture, and forestry; while the other
extends from Posen by Lodz to Warsaw, and has much agricultural
wealth and an important textile industry. Moreover, the conditions,
geographical and economic, are favourable to the growth of international
trade. If Poland obtains Upper Silesia she will have more
coal than she requires, and the Upper Silesian fields will,
as in the past, export their surplus produce to the surrounding
countries, while the manufacturing districts will continue to find
their best markets in the Russian area to the east. The outlets
of the State are good, for not only has it for all practical purposes

104 SECTIONAL ADDRESSES.

control of the port of Danzig, but it is able to share in the navigation
of the Oder and it has easy access to the south by way of the Moravian
Gap.

It seems obvious, therefore, that Poland can best seek compensation
for the weakness of her geographical position by developing the natural
resources which lie within her ethnic frontiers. By such a policy the
different parts of the country will be more closely bound to one another
than it is possible to bind them on a basis of racial affinity and national
sentiment alone. Moreover, Poland is essentially the land of the
Vistula, and whatever is done to improve navigation on that river will
similarly tend to have a unifying effect upon the country as a whole.
The mention of the Vistula, however, raises one point where geo-
graphical and ethnical conditions stand in marked antagonism to one
another. The Poles have naturally tried to move downstream to the
mouth of the river which gives their country what little geographical
individuality it possesses, and the Polish corridor is the expression of
that movement. On the other hand, the peoples of Hast and West
Prussia are one and the same. The geographical reasons for giving
Poland access to the sea are no doubt stronger than the historical reasons
for leaving Hast Prussia united to the remainder of Germany, but
strategically the position of the corridor is as bad as it can be, and the
solution arrived at may not be accepted as final.

Lastly, we may consider the case of Hast Galicia, which the Poles
claim not on geographical grounds, because it is in reality part of the
Ukraine, and not on ethnical grounds, because the great majority of
the inhabitants are Little Russians, but on the ground that they are
and have for long been the ruling race in the land. It may also be
that they are not uninfluenced by the fact that the region contains
considerable stores of mineral oil. But as the claim of the Poles to
form an independent State is based on the fact that they form a separate
race, it is obviously unwise to weaken that claim by annexing a land
which counts over 3,000,000 Ruthenes to one-third that number of
Poles. Further, the same argument which the Poles use in regard to
East Galicia could with no less reason be used by the Germans in
Upper Silesia. Mr. Keynes, indeed, suggests that the Allies should
declare that in their judgment economic conditions require the inclusion
of the coal districts of Upper Silesia in Germany unless the wishes of
the inhabitants are decidedly to the contrary. It is not improbable
that Kast Galicia would give a more emphatic vote against Polish rule
than Upper Silesia will give for it. If Poland is to ensure her position
she must forget the limits of her former empire, turn her back on the
Russian plain, with all the temptations which it offers, and resolutely
set herself to the development of the basin of the Vistula, where alone
she can find the conditions which make for strength and safety.

Czecho-Slovakia is in various ways the most interesting country in
the reconstructed Kurope. Both geographically and ethnically it is
marked by some features of great strength, and by others which are
a source of considerable weakness to it. Bohemia by its physical
structure and its strategic position seems designed by Nature to be
the home of a strong and homogeneous people. Moravia attaches itself

E.— GEOGRAPHY. 105

more or less naturally to it, since it belongs in part to the Bohemian
massif and is in part a dependency of that massif. Slovakia is Carpathian
country, with a strip of the Hungarian plain. Thus, while Bohemia
‘possesses great geographical individuality and Slovakia is at least
‘strategically strong, Czecho-Slovakia as a whole does not possess geo-
graphical unity and is in a sense strategically weak, since Moravia,
‘which unites the two upland wings of the State, lies across the great
route which leads from the Adriatic to the plains of Northern Europe.
The country might easily, therefore, be cut in two as the result of a
successtul attack, either from the north or from the south. Later I
‘shall endeavour to indicate certain compensations arising out of this
diversity of geographical features, but for the moment at least they do
not affect our argument.

We have, further, to note that the geographical and ethnical con-
ditions are not altogether concordant. In Bohemia there is in the
basin of the Eger in the north-west an almost homogeneous belt of
German people, and on the north-eastern and south-western border-
lands there are also strips of country in which the Germanic element
is in a considerable majority. It is no doubt true, as Mr. Wallis has
shown, that the Czechs are increasing in number more rapidly than
the Germans, but on ethnical grounds alone there are undoubtedly
strong reasons for detaching at least the north-western district from
the Czecho-Slovak State. We feel justified in arguing, however, that
here at least the governing factors are and must be geographical. To
partition a country which seems predestined by its geographical features
to be united and independent would give rise to an intolerable sense
of injustice. I do not regard the matter either from the strategic or
from the economic point of view, though both of these are no doubt
important. What I have in mind is the influence which the geographical
conditions of a country exercise upon the political ideas of its inhabi-
tants. It is easy to denounce, as Mr. Toynbee does, ‘ the pernicious
doctrine of natural frontiers,’ but they will cease to appeal to the human
taind only when mountain and river, highland and plain cease to appeal
to the human imagination. With good sense on both sides the difficulties
in this particular case are not insurmountable. The Germans of the
‘Eger valley, which is known as German Bohemia, have never looked
to Germany for leadership nor regarded it as their home, and their
main desire has hitherto been to form a separate province in the Austrian
‘Empire. A liberal measure of autonomy might convert them into
et citizens, and if they would but condescend to learn the Czech

imguage they might come to play an important part in the government
of the country.

_ In Slovakia also there are racial differences. Within the mountain
area the Slovaks form the great majority of the population, but in the
Valleys, and on the plains of the Danube to which the valleys open out,
the Magyar element. predominates. Moreover, it is the Magyar element
Which is racially the stronger, and before which the Slovaks are
radually retiring. Geographical and ethnical conditions therefore
unite in fixing the political frontier between Magyar and Slovak at the
meeting place of hill and plain. But on the west such a frontier would

106 - SECTIONAL ADDRESSES.

have been politically inexpedient because of its length and irregularity,
and economically disadvantageous because the river valleys, of which
there are about a dozen, would have had no easy means of communi-
cation with one another or with the outside world. Hence the frontier
was carried south to the Danube, and about 1,000,000 Magyars were
included in the total population of 3,500,000. Nor is the prospect of
assimilating these Magyars particularly bright. The Germans in
Bohemia are cut off from the Fatherland by mountain ranges, and, as
we have seen, it does not appear to present any great attraction to them.
It is otherwise in Slovakia, where the Magyars of the lowland live in
close touch with those of the Alfold, and it may be long ere they
forget their connection with them. The danger of transferring terri-
tory not on geographical or ethnical, but on economic, grounds could
not be more strikingly illustrated.

With regard to economic development, the future of the new State
would appear to be well assured. Bohemia and Moravia were the most
important industrial areas in the old Austrian Empire, and Slovakia,
in addition to much good agricultural land, contains considerable stores
of coal and iron. But if Czecho-Slovakia is to be knit together into a
political and economic unit, its communications will have to be
developed. We have already suggested that the geographical diversity
of the country offers certain compensations for its lack of unity, but
these cannot be taken advantage of until its different regions are more
closely knit together than they are at present. The north of Bohemia
finds its natural outlet both by rail and water through German ports.
The south-east of Bohemia and Moravia look towards Vienna. In
Slovakia the railways, with only one important exception, converge upon
Budapest. The people appear to be alive to the necessity of remedying
this state of affairs, and no fewer than fifteen new railways have been
projected, which, when completed, will unite Bohemia and Moravia
more closely to one another and Slovakia. Moreover, it is proposed
to develop the waterways of the country by constructing a canal from
the Danube at Pressburg to the Oder. From this canal another will
branch off at Prerau and run to Pardubitz on the Elbe, below which
point that river has still to be canalised. If these improvements are
carried out the position of Czecho-Slovakia will, for an inland State,
be remarkably strong. It will have through communication by water
with the Black Sea, the North Sea, and the Baltic, and some of the
most important land routes of the Continent already run through it.
On the other hand, its access to the Adriatic is handicapped by the —
fact that in order to reach that sea its goods will have to pass through
the territory of two, if not of three, other States, and however well the
doctrine of economic rights of way may sound in theory, there are
undoubted drawbacks to it in practice. Even with the best intentions,
neighbouring States may fail to afford adequate means of transport,
through defective organisation, trade disputes, or various other reasons.
It is probable, therefore, that the development of internal communica-
tions will in the end be to the advantage of the German ports, and
more especially of Hamburg. But the other outlets of the State will
certainly tend towards the preservation of its economic independence.

E.—GEOGRAPHY. 107

The extent to which Rumania has improved her position as a result
of the war is for the present a matter of speculation. On the one hand
she has added greatly to the territory which she previously held,
and superficially she has rendered it more compact; but on the other
she has lost her unity of outlook, and strategically at least weakened
her position by the abandonment of the Carpathians as her frontier.
Again, whereas before the war she had a fairly homogeneous popula-
tion—probably from 90 to 95 per cent. of the 7,250,000 people in the
country being of Rumanian stock—she has, by the annexation of
Transylvania, added an area of 22,000 square miles of territory, in
which the Rumanians number less than one and a half out of a total
of two and two-third millions. In that part of the Banat which she
has obtained there is also a considerable alien element. It is in this
combination of geographical division and ethnic intermixture that we
may foresee a danger to Rumanian unity. That part of the State which
is ethnically least Rumanian is separated from the remainder of the
country by a high mountain range, and in its geographical outlook no
less than in the racial sympathies of a great number of its inhabitants
is turned towards the west, while pre-war Rumania remains pointed
towards the south-east. Economically also there is a diversity of
interest, and the historical tie is perhaps the most potent factor in
binding the two regions together. It is not impossible, therefore, that
two autonomous States may eventually be established, more or less
closely united according to circumstances.

The position in the Dobruja is also open to criticism. Geographi-
cally the region belongs to Bulgaria, and the Danube will always be
regarded as their true frontier by the Bulgarian people. Ethnically its
composition is very mixed, and whatever it was originally, it certainly
was not a Rumanian land. But after the Rumanians had rather un-
willingly been compelled to accept it in exchange for Bessarabia, filched
from them by the Russians, their numbers increased and their economic
development of the region, and more especially of the port of Con-
stanza, undoubtedly gave them some claims to the northern part of it.
As so often happens, however, when a country receives part of a natural
region beyond its former boundaries, Rumania is fertile in excuses for
annexing more of the Dobruja. To the southern part, which she
received after the Balkan wars, and in the possession of which she
has been confirmed by the peace terms with Bulgaria, she has neither
ethnically nor economically any manner of right. The southern
Dobruja is a fertile area which, before its annexation, formed the
natural hinterland of the ports of Varna and Ruschuk. Her occupation
A it will inevitably draw Rumania on to further intervention in Bulgarian
affairs.

The arrangements which have been made with regard to the Banat
must be considered in relation to the Magyar position in the Hungarian
plain. The eastern country of the Banat, Krasso-Szérény, has a
population which is in the main Rumanian, and as it belongs to the
Carpathian area it is rightly included with Transylvania in Rumanian
territory. In the remainder of the Banat, including Arad, the
Rumanians form less than one-third of the total population, which also

108 SECTIONAL ADDRESSES.

comprises Magyars, Germans, and Serbs. The Hungarian plain is a
great natural region, capable of subdivision no doubt, but still a great
natural region, in which the Magyar element is predominant. The
natural limit of that plain is the mountain region which surrounds it,
and to that limit at least the Magyar political power will constantly
press. But Rumania has been permitted to descend from the moun-
tains and Jugo-Slavia to cross the great river which forms her natural
boundary, and both have obtained a foothold on the plain where it may
be only too easy for them to seek occasion for further advances. And it
cannot be urged that the principle of self-determination would have
been violated by leaving the Western Banat to the Magyars. No
plébiscite was taken, and it is impossible to say how the German element
would have given what in the circumstances would have been the
determining vote. Finally, as it was necessary to place nearly a mil-
lion Magyars in Transylvania under Rumanian rule, it might not have
been altogether inexpedient to leave some Rumanians on Hungarian
soil.

For the extension of Jugo-Slavia beyond the Danube two pleas have
been advanced, one ethnical and the other strategic. Neither is really
valid. It is true that there is a Serbian area to the north of Belgrade,
but the total number of Serbs within the part assigned to Jugo-Slavia
probably does not much exceed 300,000. ‘The strategic argument that
the land which they occupy is necessary for the defence of the capital
is equally inconclusive. From the military point of view it does not
easily lend itself to defensive operations, and when we consider the
political needs of the country we cannot avoid the conclusion that a
much better solution might have been found in the removal of the
capital to some more central position. ‘The Danube is certainly a better
defensive frontier than the somewhat arbitrary line which the Supreme
Council has drawn across the Hungarian plain.

In fact, it is in the treatment of the Hungarian plain that we feel
most disposed to criticise the territorial settlements of the Peace
Treaties. Geographical principles have been violated by the dismem-
berment of a region in which the Magyars were in a majority, and in
which they were steadily improving their position. Hthnical principles
have been violated, both in the north, where a distinctly Magyar region
has been added to Slovakia, and in the south, where the eastern Banat
and Backa have been divided between the Rumanians and the Jugo-
Slavs, who together forma minority of the total population. For the
transfer of Arad to Rumania and of the Burgenland to Austria more
is to be said, but the position as a whole is one of unstable equilibrium,
and can only be maintained by support from without. In this part of
Europe at least a League of Nations will not have to seek for its troubles.

When we turn to Austria we are confronted with the great tragedy in
the reconstruction of Europe. Of that country it could once be said
‘Bella gerant alii, tu felix Austria nube,’ but to-day, when dynastic
bonds have been loosened, the constituent parts of the great but hetero-
geneous empire which she thus built up have each gone its own way.
And for that result Austria herself is to blame. She failed to realise
that an empire such as hers could only be permanently retained on a

E.—GEOGRAPHY,. 109

basis of-common political and economic interest. Instead of adopt-
ing such a policy, however, she exploited rather than developed the
subject. nationalities, and to-day their economic, no less than their
political, independence of her is vital to their existence. Thus it is that
the Austrian capital, which occupies a situation unrivalled in Kurope,
and. which before the war numbered over 2,000,000 souls, finds herself
with her occupation gone. For the moment Vienna is not necessary
either to Austria or to the so-called Succession States, and she will not
be necessary to them until she again has definite functions to perform.
I do not overlook the fact that Vienna is also an industrial city, and
that it, as well as various other towns in Lower Austria, are at present
unable to obtain either raw materals for their industries or foodstuffs
for their inhabitants. But there are already indications that this state
of affairs. will shortly be ameliorated by economic treaties with the
neighbouring States. . And what I am particularly concerned with
is not the temporary but the permanent effects of the change which has
taken place... The entire political re-orientation of Austria is necessary
if she is to emerge successfully from her present trials, and such a
re-orientation must be brought about with due regard to geographical
and ethnical conditions, The two courses which are open to her lead
in opposite directions. On the one hand she may become a member
of a Danubian confederation, on the other she may throw in her lot
with the German people. The first would really imply an attempt to
restore the economic position which she held before the war, but it is
questionable whether it is either. possible or expedient for her to make
such an attempt... A Danubian confederation twill inevitably be of
slow growth, as it is only under the pressure of economic necessity
that it will. be. joined by the various. nationalities of south-
eastern Europe. The suggestions made by Mr. Asquith, Mr.
Keynes, and others, for a compulsory free-trade union would, if carried
into effect, be provocative of the most intense resentment among most,
if not all, of the States concerned. But even if a Danubian confedera-
tion were established it does not follow that Austria would be able to
play a part in it similar to that which she played in the Dual Monarchy,
With the construction of new railways and the growth of new com-
mercial centres it is probable that much of the trade with the south-
east of Europe which formerly passed through Vienna will in future go
to the east of that city, Even now Pressburg, or Bratislava, to give it
the name, by which it will hence be known, is rapidly developing at the
expense alike of Vienna and Budapest. Finally, Austria has,in the
past shown little capacity to understand the Slay peoples, and in any
ease her position in what would primarily be a Slav confederation would
be an invidious one. For these reasons we turn to the suggestion that
Austria should enter the German Empire, which, both on geographical
and on ethnical grounds, would appear to be her proper place. _ Geo-
graphically she is German, because the bulk of the territory left to her
belongs either to, the Alpine range or to the Alpine foreland. It is
only when we reach the basin of Vienna that we leave the mid-world
mountain system and look towards the south-east of Europe across
the great Hungarian plain. Ethnically, of course, she is essentially

110 SECTIONAL ADDRESSES.

German. Now although my argument hitherto has rather endeavoured
to show that the transfer of territory from one State to another on
purely economic grounds is seldom to be justified, it is equally indefen-
sible to argue that two States which are geographically and ethnically
related are not to be allowed to unite their fortunes because it would
be to their interest to do so. And that it would be to their interest
there seems little doubt. Austria would still be able to derive some
of her raw materials and foodstuffs from the Succession States, and she
would have, in addition, a great German area in which she would find
scope for her commercial and financial activities. Even if Naumann
were but playing the part of the Tempter, who said ‘ All these things
will I give thee if thou wilt fall down and worship me,’ he undoubtedly
told the truth when he said ‘ The whole of Germany is now more open
to the Viennese crafts than ever before. The Viennese might make
an artistic conquest extending to Hamburg and Danzig.’ But not only
would Austria find a market for her industrial products in Germany, she
would become the great trading centre between Germany and south-east
Europe, and in that way would once more be, but in a newer and
better sense than before, the Ostmark of the German people.

The absorption of Austria in Germany is opposed by France, mainly
because she cannot conceive that her great secular struggle with the
people on the other side of the Rhine will ever come to an end, and
she fears the addition of 6,500,000 to the population of her ancient
enemy. But quite apart from the fact that Germany and Austria
cannot permanently be prevented from following a common destiny if
they so desire, and apart from the fact that politically it is desirable
they should do so with at least the tacit assent of the Allied Powers
rather than in face of their avowed hostility, there are reasons for
thinking that any danger to which France might be exposed by the
additional man-power given to Germany would be more than compen-
sated for by the altered political condition in Germany herself. Vienna
would form an effective counterpoise to Berlin, and all the more so
because she is a great geographical centre, while Berlin is more or
less a political creation. The South German people have never loved
the latter city, and to-day they love her less than ever. In Vienna
they would find not only a kindred civilisation with which they would
be in sympathy, but a political leadership to which they would readily
give heed. In such a Germany, divided in its allegiance between Berlin
and Vienna, Prussian animosity to France would be more or less
neutralised. Nor would Germany suffer disproportionately to her gain,
since in the intermingling of Northern efficiency with Southern culture
she would find a remedy for much of the present discontents. When
the time comes, and Austria seeks to ally herself with her kin, we
hope that no impassable obstacle will be placed in her way.

The long and as yet unsettled controversy on the limits of the
Italian Kingdom illustrates very well the difficulties which may arise
when geographical and ethnical conditions are subordinated to con-
siderations of military strategy, history, and sentiment in the deter-
mination of national boundaries. The annexation of the Alto Adige
has been generally accepted as inevitable. It is true that

E.— GEOGRAPHY. 111

the population is German, but here, as in Bohemia, geographical
conditions appear to speak the final word. Strategically also the
frontier is good, and will do much to allay Italian anxiety with regard
to the future. Hence, although ethnical conditions are to some extent
ignored, the settlement which has been made will probably be a lasting
one.

On the east the natural frontier of Italy obviously runs across the
uplands from some point near the eastern extremity of the Carnic
Alps to the Adriatic. The pre-war frontier was unsatisfactory for one
reason because it assigned to Austria the essentially Italian region of
the lower Isonzo. But once the lowlands are left on the west the
uplands which border them on fhe east, whether Alpine or Karst,
mark the natural limits of the Italian Kingdom, and beyond a position
on them for strategic reasons the Italians have no claims in this direc-
tion except what they can establish on ethnical grounds. To these,
therefore, we turn. In Carniola the Slovenes are in a large majority,
and in Gorizia they also form the bulk of the population. On the
other hand, in the town and district of Trieste the Italians predominate,
and they also form a solid block on the west coast of Istria, though
the rest of that country is peopled mainly by Slovenes. It seems to
follow, therefore, that the plains of the Isonzo, the district of Trieste,
and the west coast of Istria, with as much of the neighbouring upland
as is necessary to secure their safety and communications, should be
Italian and that the remainder should pass to the Jugo-Slavs. The
so-called Wilson line, which runs from the neighbourhood of Tarvis
fo the mouth of the Arsa, met these requirements fairly
well, though it placed from 300,000 to 400,000 Jugo-Slavs under
Italian rule, to less than 50,000 Italians, half of whom are
in Fiume itself transferred to the Jugo-Slavs. Any additional
territory must, by incorporating a larger alien element, be a
source of weakness and not of strength to Italy. To Fiume the
Italians have no claim beyond the fact that in the town itself they
slightly outnumber the Croats, though in the double town of Fiume-
‘Sushak there is a large Slav majority. Beyond the sentimental reasons
which they urge in public, however, there is the economic argument,
which, perhaps wisely, they keep in the background. So long as
Trieste and Fiume belonged to the same empire the limits within
which each operated were fairly well defined, but if Fiume become
Jugo-Slav it will not only prove a serious rival to Trieste, but will
prevent Italy from exercising absolute control over much of the trade
of Central Europe. For Trieste itself Italy has in truth little need,
and the present condition of that city is eloquent testimony of the
extent to which it depended for its prosperity upon the Austrian and
German Empires. In the interests, then, not only of Jugo-Slavia
buf of Europe generally, Fiume must not become Italian, and the
idea of constituting it a Free State might well be abandoned. Its
development is more fully assured as the one great port of Jugo-Slavia
than under any other form of government.

With regard to Italian claims in the Adriatic, little need be said.
fp the Dalmatian coast Italy has no right either on geographical or on

|
\

112 SECTIONAL ADDRESSES.

ethnical grounds, and the possession of Pola, Valona, and some of the
islands gives her all the strategic advantages which she has reason to
demand. But, after all, the only danger which could threaten her in
the Adriatic would come from Jugo-Slavia, and her best insurance
against that danger would be an agreement by which the Adriatic should
be neutralised. The destruction of the Austro-Hungarian fleet offers
ltaly a great opportunity of which she would do well to take advantage.

Of the prospects of Jugo-Slavia it is hard to speak with any feeling
of certainty. | With the exception of parts of Croatia-Slavonia and of
Southern Hungary, the country is from the physical point of view
essentially Balkan, and diversity rather than unity is its most pro-
nounced characteristic. From this physical diversity there naturally
results a diversity in outlook which might indeed be all to the good if
the different parts of the country were linked together by a well-
developed system of communication. Owing to the structure of the
land, however, such a system will take long to complete.

Ethnic affinity forms the real basis of union, but whether that
union implies unity is another matter. It is arguable that repulsion
from the various peoples—Magyars, Turks, and Austrians—by whom
they have been oppressed, rather than the attraction of kinship, is the
foree which has brought the Jugo-Slavs together. In any case the |
obstacles in the way of the growth of a strong national feeling are many.
Serb, Croat, and Slovene, though they are all members of the Slav —
family, have each their distinctions and characteristics which political
differences may tend to exaggerate rather than obliterate. In Serbian :
Macedonia, again, out of a total population of 1,100,000, there are
400,000 to 500,000 people who, though Slavs, are Bulgarian in their
sympathies, and between Serb and Bulgarian there will long be bitter
enmity. Religious differences are not wanting. The Serbs belong to
the Orthodox Church, but the Croats are Catholics, and in Bosnia there
is a strong Mohammedan element. Cultural conditions show a wide
range. The Macedonian Serb, who has but lately escaped from
Turkish misrule, the untutored but independent Montenegrin, the Dal-—
matian, with his long traditions of Italian civilisation, the Serb of the
kingdom, a sturdy fighter but without great political insight, and the
Croat and Slovene, whose intellectual superiority is generally admitted, ©
all stand on different levels in the scale of civilisation. To build up out —
of elements in many respects so diverse a common nationality without
destroying what is best in each will be a long and laborious task. —
Heonomic conditions are not likely to be of much assistance. It is true
that they are fairly uniform throughout Jugo-Slavia, and it is improbable
that the economic interests of different regions will conflict to any great
extent. On the other hand, since each region is more or less self-
supporting, they will naturally unite into an economic whole less easily
than if there had been greater diversity. What the future holds for
Jugo-Slavia it is as yet impossible to say; but the country is one of
great potentialities, and a long period of political rest might render
possible the development of an important State.

This brings me to my conclusion. I have endeavoured to consider
the great changes which have been made in Europe not in regard to

E.—GEOGRAPHY. 118

the extent to which they do or do not comply with the canons of
boundary-making, for after all there are no frontiers in Europe which
can in these days of modern warfare be considered as providing a sure
defence, but in regard rather to the stability of the States concerned.
A great experiment has been made in the new settlement of Europe,
and an experiment which contains at least the germs of success. But
in many ways it falls far short of perfection, and even if it were
perfect it could not be permanent.. The methods which ought to be
adopted to render it more equable and to adapt it to changing needs
it is not for us to discuss here. But as geographers engaged in the
study of the ever-changing relations of man to his environment we can
play an important part in the formation of that enlightened public
opinion upon which alone a society of nations can be established,

1920 J

SECTION F: CARDIFF, 1920.

ADDRESS

TO THE

SECTION OF ECONOMIC SCIENCE AND STATISTICS

BY
J. H. CLAPHAM, C.B.E., Litt.D.,
PRESIDENT OF THE SECTION.

Ir is, I think, a President’s first duty to record the losses which
economic science has sustained since the Association last met. A year
ago we had just lost, on the academic side, Archdeacon Cunningham,
and on the side of affairs, Sir Edward Holden. This year, happily, I
have no such losses to record in either field. But it is right to name
the death of a late enemy, Professor Gustav Cohn, of Gdttingen, an
economist of the first rank, who had made a special study of English
affairs. I believe that no student of our railway history would fail to
place Cohn’s ‘ Inquiries into English Railway Policy,’ published (in
German) so long ago as 1873, first on the unfortunately very short list
of scientific works devoted to that side of history. Kven when supple-
mented by an additional volume, issued ten years later, it covers only
what seems to-day the prehistoric period of our policy—before the
Act of 1888 and very long before our present uncertainties—but it is
not yet out of date. Cohn died full of years. He was nearly eighty.
I may mention, perhaps, with his name that of a much younger, and
possibly more brilliant, German economist, Max Weber, of Munich,
who has died at the age of fifty-six. He once tried to explain, by a
study of Puritan theology, the economic qualities of the Nonconformist
business man—a very fascinating study. But his work as a whole has
not roused much interest in England.

By an accident the three scholars whose names I have mentioned
were all best known, in England at any rate, as historians. And, with
your indulgence, I will do what I think has seldom been done from
this chair, in making my address largely historical. History has been
my main business in life; and it has occurred to me that some com-
parisons between the economic condition of Europe after the great
wars of a century ago and its condition to-day may not be without
interest. Historical situations are never reproduced, even approxi-
mately; but it is at least interesting to recall the post-war problems
which our grandfathers or great-grandfathers had to face, and how
they handled them; to ask how far our sufferings and anxieties have
had their parallels in the not remote past; and to note some danger

F.—ECONOMICS. 115

signals. By ‘we’ I mean not the British only, but all the peoples of
Western and Central Europe. Of Eastern Europe I will only speak
incidentally ; for I am unable as yet to extract truth from the conflicting
and biassed evidence as to its economic condition. Moreover, there is
still war in the Kast.

In 1815 France had been engaged in almost continuous wars for
twenty-three, England for twenty-two, years. The German States
had been at war less continuously; but they had been fought over,
conquered, and occupied by the French. Prussia, for instance, was
overthrown in 1806. When the final struggle against Napoleon began,
in 1812, there was a French army of occupation of nearly 150,000 men
in Prussia alone. From 1806 to 1814 Napoleon’s attempt to exclude
English trade from the Continent had led to the English blockade—
with its striking resemblances to, and its striking differences from, the
blockade of 1914-19. Warfare was less horribly intense, and so less
economically destructive, than it has become in our day; but what it
lacked in intensity it made up in duration.

Take, for instance, the loss of life. For England it was relatively
small—because for us the wars were never people’s wars. In France
also it was relatively small in the earlier years, when armies of the
old size were mainly employed. But under Napoleon it became enor-
mous. Exact figures do not exist, but French statisticians are disposed
to place the losses in the ten years that ended with Waterloo at fully
1,500,000. Some place them higher. As the population of France
grew about 40 per cent. between 1805-15 and 1904-14, this would
correspond to a loss of, say, 2,100,000 on the population of 1914. The
actual losses in 1914-18 are put at 1,370,000 killed and missing; and
I believe these figures contain some colonial troops.

Or take the debts accumulated by victors and the requisitions or
indemnities extorted from the vanquished. The wars of a century ago
left the British debt at 848,000,000/. According to our success or
failure in securing repayment of loans made to Dominions and Allies,
the Great War will have left us with a liability of from eight to nine
times that amount. Whether our debt-carrying capacity is eight or nine
times what it was a century ago may be doubted, and cannot be
accurately determined. But it is not, I would venture to say, less than
Six or seven times what it was, and it might well be more. A good
deal depends on future price levels. At least the burdens are com-
parable ; and we understand better now where to look for broad shoulders
to bear them.

After Waterloo France was called upon to pay a war indemnity of
only 28,000,0001., to be divided among all the victors. With this figure
Prussia was thoroughly dissatisfied. Not, I think, without some
reason. She reckoned that Napoleon had squeezed out of her alone,
between 1806 and 1812, more than twice as much—a tremendous exac-
tion, for she was in those days a very poor land of squires and peasants,
whose treasury received only a few millions a year. England, who
was mainly responsible—and that for sound political reasons—for the
low figure demanded of France, found herself, the victor, in the curious
position of being far more heavily burdened with debt than France, who

116 SECTIONAL ADDRESSES.

had lost. England, of course, had acquired much colonial territory ;
but on the purely financial side the comparison between her and France
was most unequal. England’s total national debt in 1817 was
848,000,0001. France’s debt did not reach 200,000,0001. until 1830.

The reasons why France came out. of the wars so well financially
were four. First, she had gone bankrupt during the Revolution, and
had wiped out most of her old debt. Second, under Napoleon she had
made war pay for itself, as the case of Prussia shows. Third, there
was No financial operation known to the world in 1815 by which
England’s war debt, or even half of it, could have been transferred to
France. Fourth, England never suggested any such transference, or,
so far as I know, ever even discussed it.

France’s financial comfort, immediately after her defeat, extended
to her currency. During the Revolution she had made a classical experi-
ment in the mismanagement of credit documents, with the assignats
issued on the security of confiscated Church property ; but after that she
had put her currency in good order. Her final defeat in 1812-14, and
again in 1815, did not seriously derange it. Indeed, the English
currency was in worse order than the French, owing to the suspension
of cash payments by the Bank of England; and so rapidly did France’s
credit recover after 1815 that in 1818 French 5 per cents stood at
almost exactly the present-day price of British 5 per cent War Loan.
That year she finished the payment of her war indemnity, and the last
armies of oceupation withdrew.

She had no doubt gained by waging war, and eventually suffering
defeat, on foreign soil. No French city had been burnt like Moscow,
stormed like Badajoz, or made the heart of a gigantic battle ike Leipzig.
Napoleon fought one brilliant defensive campaign on French soil, in
the valleys of the Marne and the Seine, in 1814. In 1815 his fate was
decided in Belgium. Hardly a shot was fired in France; hardly a French
cornfield was trampled down. But France, as in 1918, was terribly
short of men, and, again as in 1918, her means of communication had
suffered. Napoleon’s magnificent roads—he was among the greatest
of road engineers—had gone out of repair; his great canal works had
been suspended. ‘These things, however, were soon set right by the
Government which followed him.

France’s rapid recovery brings us to one of the essential differences
between Western Europe a century ago and Western Europe to-day.
In spite of Paris and her other great towns, the France of 1815 was a
rural country, a land of peasants and small farmers. Only about 10 per
cent, of her population lived in towns of 10,000 inhabitants or more.
The town below 10,000, in all countries, is more often a rural market
town, ultimately dependent on the prosperity of agriculture, than an
industrial centre. Parallels for France’s condition must be sought
to-day in Eastern Europe—in Serbia or Russia. It is a condition which
makes the economics of demobilisation easy. The young peasant goes
back from the armies to relieve his father, his mother, and his sisters,
who have kept the farm going. Moreover, France maintained a stand-
ing army of 240,000 men after 1815; and her losses in the Waterloo
campaign had been so heavy that the actual numbers demobilised were

F.—ECONOMICS. 117

relatively small. Demobilisation left hardly a ripple on the surface of
her economic life.

The German States were far more rural in character even than
France. There were a few industrial districts, of a sort, in the West
and in Saxony; a few trading towns of some size, like Hamburg and
Frankfurt ; but there was nowhere a city comparable to Paris. In 1819
the twenty-five cities which were to become in our day the greatest
of the modern German Empire had not 1,250,000 inhabitants between
them. Paris alone at that time had about 700,000. German statesmen,
when peace came, were occupied not with problems arising from the
situation of the urban wage-earner, though such problems existed, but
with how to emancipate the peasants from the condition of semi-servility
in which they had lived during the previous century. Here, too, demo-
bilisation presented few of the problems familiar to us. Probably not
one man in ten demobilised was a pure wage-earner. The rest had
links with the soil. The land, neglected during the war, was crying out
for labour, and every man had his place, even if it was a servile place,
in rural society.

Things were different in England; but our demobilisation problem
was smaller than that of our Continental allies or enemies, who had
mobilised national armies, though not of the modern size. On the other
hand, we had kept an immense fleet in commission, the crews of which
were rapidly discharged. arly in 1817 Lord Castlereagh stated in
Parliament that 300,000 soldiers and sailors had been discharged since
the peace. In proportion to population, that would be equivalent, for
the whole United Kingdom, to nearly 750,000 to-day. For these men
no provision whatever was made. They were simply thrown on the
labour market; and the vast majority of them were ex-wage-earners or
potential wage-earners, industrial, mercantile, or agricultural. The
United Kingdom was not urbanised as it is to-day; but the census of
1821 showed that 21 per cent. of the population lived in cities of 20,000
inhabitants and upwards, and probably about 27 per cent. (as compared
with France’s 10 per cent.) lived in places of 10,000 and upwards. As
industry in various forms, especially coal-mining, spinning, and weaving,
was extensively carried on in rural or semi-rural districts, it is certain
that at least one demobilised man of working age in every three was a
potential wage-earner of industry or commerce. And as Great Britain
had lost most of her peasant-holders, whether owners or small working
farmers, the remainder of the demobilised rank and file were nearly all
of the agricultural labourer class. They had to find employment ; there
was not a place in rural society waiting for them, as there was for the
average French or German peasant soldier. It is not surprising that
the years from 1815 to 1820 were, both economically and politically,
inane the most wretched, difficult, and dangerous in modern English

istory.

Things were at their worst in 1816-17, both for England and for her
Continental neighbours. Western Europe was very near starvation.
Had the harvest of 1815 not been excellent, so providing a carry-over
of corn, or had the harvest of 1817 been much below the average,
there must have been widespread disaster; so thorough and universal

118 SECTIONAL ADDRESSES.

was the harvest failure of 1816. In the latter part of 1816 (Decem-
ber) wheat fell in England to 55s. 7d., although no grain imports were
allowed, except of oats. LHarly in 1816 the United Kingdom was
actually exporting a little wheat. Then came a terrible spring—a long
frost; snow lying about Edinburgh in May; all the rivers of Western
Europe in flood. An equally disastrous summer followed. There was
dearth, in places amounting to real famine, everywhere—worst of all in
Germany. Unlike France, the German States of a century ago were
extraordinarily ill-provided with roads. What roads there were had
gone to pieces in the wars. In winter even the mails could hardly get
through with sixteen and twenty horses. Food supplies could not be
moved over long distances by land; and the slightly more favoured
regions could not help the most unfortunate. There was a far wider
gap between prices in Kastern and Western Germany in 1816 than there
had been in the last bad famine year (1772). Hach German State, in
its. anxiety, began to forbid export early in 1816, thus making things
worse. At Frankfurt, the representatives of the German States,
gathered for the Diet, could hardly feed their horses. Prices rose
amazingly and quite irregularly, with the varying food conditions of the
various provinces. In the spring of 1817 pallid, half-starved people
were wandering the fields, hunting for and grubbing up overlooked and
rotten potatoes of the last year’s crop.

In England the harvest failure of 1816 drove wheat up to 103s. 7d.
a quarter for December of that year, and to 112s. 8d. for June of
1817. In Paris the June price in 1817 was equivalent to 122s. dd.
At Stuttgart the May price was equivalent to 138s. 7d. These are
only samples. Think what these figures mean at a time when an
English agricultural labourer’s wage was about 9s. 6d., and a French
or German unskilled wage far less. It must be recalled that there
were no special currency causes of high prices either in France or
Germany. ‘These were real dearth prices. In the spring of 1817 the
French Government was buying corn wherever it could find it—in
England, North Africa, America—as another bad harvest was feared.
Happily, the 1817 harvest was abundant, here and on the Continent.
By September the Mark Lane price of wheat was 77s. 7d., and the
Paris price 71s. Od.

I have gone into price details for the purpose of drawing a contrast
between a century ago and to-day. Except for the damage done to
the German roads, the wars had very little to do with these food
troubles of 1816-17. High and fluctuating food prices were the natural
consequence of the general economic position of Western Europe a
century ago. It was only in the most comfortable age in all history—
the late nineteenth and early twentieth centuries—that low and stable
food prices came to be regarded as normal. In the eighteenth century,
when England fed herself and often had an exportable surplus, fluctua-
tions were incessant. Take the ten years 1750-1760. The mean price
of wheat at Eton in 1752 was 45 per cent. above the mean price in 1750.
The mean price in 1757 was nearly 100 per cent. above the mean price
of 1750. On Lady Day 1757 the price was 60s. 5jd. On Lady Day
1759 it was 37s. 4d. On Lady Day 1761 it was 26s. 8d. The 1761
mean price was exactly half the 1757 mean price.

F.—ECONOMICS. 119

Highteenth-century England was too well organised economically
to be in much risk of actual famine, but for Ireland and large parts of
the Continent famine was a normal risk, War and its effects had only
accentuated, not created, that risk. Imports might reduce it, but could
not avert it, because Western Europe tends to have approximately the
same harvest conditions throughout, and it was impossible to draw
really large supplementary supplies from anywhere else. So unim-
portant were overseas supplies that the Continent suffered very much
more from the harvest failure of 1816, in time of peace, than from the
eight years’ English blockade in time of war. If overseas supplies
could be got they were hard to distribute, owing to defective transport
facilities. Thanks to the work of the nineteenth century, the most
terrific of all wars was required to bring Western Europe face to face
with what had been both a war-time and a peace-time risk a century
earlier,

But the old Europe, if it had the defects, had also the elasticity of
a rather primitive economic organism. Given a couple of good harvests,
and a land of peasants soon recovers from war. Serbia had a good
harvest last year (1919), and was at once in a state of comparative
comfort, in spite of her years of suffering. A second good harvest
this year, for which fortunately the prospects are favourable, would
almost restore her. So it was with France and, to a less extent,
Germany in 1816-18. In France acute distress in 1816-17 had been
confined to the towns and to those country districts where the harvest
failure was worst. The harvest of *17 put an end to it. One gets the
impression that in Germany distress among the peasants themselves
had been more widespread. Worse communications and the absence of
a strong central Government seem to have been the chief causes of
this, though perhaps the harvest failure was more complete. In
Trance, as we have seen, the central Government took such action
as was possible in the interests of the whole country. A parallel
might be drawn between the German situation in 1815-17 and that
of the States which have arisen from the break-up of the old Austro-
Hungarian Empire since 1918. Freed from French domination, and
then from the urgent necessity of co-operating against a common
enemy, the German States relapsed into their ancient jealousies and
conflicting economic policies, just as the new States, which were
once subject to the Hapsburgs, have been forbidding exports of food
and fuel and disputing with one another.

An excellent harvest in 1817 averted the risk of famine in Germany
also; but anything that could be called prosperity was long delayed,
whereas France was indisputably prosperous, judged by the standards
of the day, and far more contented than England, by 1818-20. Germany
had been so exhausted by the wars and incessant territorial changes
of the Napoleonic age, and was politically so divided, that her economic
life remained stagnant and her poverty great until at least 1830. It
was all that the various Governments could do to find money for the
most essential of all economic measures—the repair and construction
of roads—whereas France had her splendid main roads in order again
and had resumed work on her canals before 1820. But France had

120 SECTIONAL ADDRESSES.

cut her losses nearly twenty years before, and had enjoyed continuous
treedom from war on her own territory between 1794 and 1814, as we
have seen. She had been well, if autocratically , governed, and her war
indemnity was but a trifling burden. Jer peasants were free and, as
a class, vigorous and hopeful. She was united and conscious of her
leadership in Europe, even through her ultimate defeats.

If the experience of Hurope after Waterloo is, on the whole, of good
augury for agricultural States, and especially for agricultural States
with a competent central Government, for the industrialised modern
world that experience is less encouraging. Great Britain alone was
partially industrialised in 1815-20, and Great Britain, though victorious,
suffered acutely. Mismanagement was largely responsible for her
sufferings—mismanagement of, or rather, complete indifference to,
problems of demobilisation; mismanagement of taxes (the income tax
was abandoned at the clamour of interested parties, and the interest on
the huge debt paid mainly from indirect taxes, which bore heavily
on the poor); mismanagement of food supplies, by the imposition of the
Corn Law; and so on. But suffering due to international economic dis-
location followmg war could not have been avoided by management,
however good. The situation was unique. England alone of the Kuro-
pean Powers had developed her manufactures to some extent on what
we call modern lines. During the wars she had accumulated also great
stores of colonial and American produce, which could only get into
Kurope with difficulty—by way of smuggling. In 1813, before Napo-
leon’s first fall, her manufacturers and merchants were eagerly awaiting
peace. In 1814 manufactures and colonial produce were rushed over,
only to find that, much as Europe desired them, it could not pay the
price. It had not enough to give in exchange; and England, being
rigidly protectionist. was not always prepared to buy even what Europe
had to give. There was no machinery for international buying credits.
Merchants shipped at their own risks, usually as a venture, not against
a firm order as to-day, and they had to bear their own losses—often up
to 50 per cent. Continental economic historians have hardly yet for-
given us for this ‘dumping,’ which both drained away the precious
metals to Kngland—as there was not much else to pay with—and did
a great deal of harm to the struggling young factory industries which
had begun to grow up under the protection of Napoleon’s anti-English
commercial policy.

British exporters were so badly bitten in 1814 that, when peace
finally came next year, after Waterloo, they were nervous of giving
orders at home—which was very bad for the manufacturing industries
and for the men who sought employment in them. There was the
curious situation in 1816 that, while the price of wheat was rushing
up, most other prices were falling, the bottom of the market being
often reached at the end of the year, when the confidence of buyers
and shippers began to revive. Raw cotton, for instance, which had
touched 2s. 6d. a lb. in 1813-14, fell to a minimum of 1s. 2d. in
1816—although Europe was open and cotton badly needed.

It is as yet too early to work out a parallel between this post-war
sommercial and industrial slump. and the slump that followed the Great,

eee

T.—ECONOMICS. 121

War of 1914-18, for we have not yet had it. But it is coming. More
certainly, I am inclined to believe, in the United States than in Eng-
land; but pretty certainly here also. I say more certainly in the United
States because her position bears most resemblance to that of Hngland
in 1815-17. Consider that position. What before the war was, on
the balance, a debtor country has become a creditor country. That
creditor is equipped to export both raw materials and manufactures—
iron and steel goods particularly—on a huge scale. It is true she is a
heavy importer of some foods, such as sugar, coffee, and tea, and of
certain raw materials, such as rubber, timber, and wool. But, owing
to her tariff system and her general policy, she is reluctant to take many
things which her debtors have to offer. Her recent ‘ dry’ policy, for
example, has shut her markets to one of France’s most valuable
exports, an export with which France has always been in the habit
of paying her creditors. Already, I notice, American business men
are beginning to point out what English business men stated clearly
in a famous document, the Petition of the London Merchants, a
century ago—that the country which will not buy, neither shall it sell.
This was the most solid of all free-trade arguments in the early nine-
teenth century, and it has lost none of its force. No doubt America
is, and will be, glad to take part payment in gold, just as England
was in 1814-16. But that is not a permanent solution. If she remains
a creditor nation—and there is no present reason to think that she
will not—she must in time arrange to take more goods from outside.
Her political processes, however, are slow; and it seems unlikely that
she will have adjusted her policy before the post-war slump is upon
her.

The United Kingdom, which, on the whole, still takes freely what
its customers have to offer it, is in a better position, provided its
customers can go on offering. This may prove an important proviso.
Customers who have been litile hurt or even helped by the war—Spain,
perhaps, or Egypt, or India, or New Zealand—should continue good
buyers. But the uncertainty gives cause for anxious thought in the
ease of the war-damaged nations, allied and ex-enemy. Modern financial
and commercial organisation has postponed the critical moment in
a way that was impossible a century ago. When Europe was hungry
in 1816 there were not food surpluses available anywhere on the earth,
nor shipping enough on the seas, nor means of transport good enough
on land, to relieve her need. If, per impossibile, there had been all
these things, there would have been no country or group of business
men anywhere ready to give her the necessary credit on a large scale.
The Rothschilds, a young firm in those days, did something. They
advanced money to a few German princes to buy corn for their people
at the Baltic ports, for there was some corn to spare from Poland and
Russia. But the huge food-financing operations of 1918-20 would have
been as unthinkable as the actual handling of the foodstuffs would
‘have been impossible. Had two harvests like that of 1816 come in
succession, there would have been famine and food riots everywhere,
past hope of cure.

Similarly modern finance is postponing the critical moment for the

122 SEUTIONAL ADDRESSES.

international trade in manufactures. _ British business men in 1919-20
have not, I believe, often sent their goods abroad in hope of finding
a vent for them, and then been forced to content themselves with
prices far below cost of production, as their grandfathers were in 1814-16.
Every kind of financial device—long private credit, assistance from
banks, credits given by Governments—has been called in, so that trade
may be resumed before the war-damaged nations are in a position to
pay for what they need by exporting the produce of their own labour.
The more industrial the damaged nation is, the more complex is the
restarting of her economic activity. Corn grows in nine months, and
pigs breed fast. The start once given, countries like Denmark and
Serbia, both of which are normally great exporters of pigs or bacon,
could soon pay for necessary imports of machinery or fertilisers bought
on long credit to restart their rural industries. The United Kingdom,
the least damaged of all the combatants except America, is believed
by the Chancellor of the Exchequer to be now rather more than paying
its way. That may be sanguine, but at the worst our accounts are
nearly balanced. What might not have happened in 1919 if modern
methods for postponing payment had not been applied internationally ?
The other chief combatants are far from paying their way. Italy is
importing abnormal quantities of food and also her necessary raw
materials with the aid of American and English credits, while Germany,
who can get little in the way of credit, has hardly begun even to import
the raw materials to make the goods by the export of which she may
eventually pay her way, not to mention her indemnities. I have in
mind such materials as cotton, wool, rubber, copper, oil-seeds, and
hides—all of which she imported heavily in 1913. Some materials,
of course, she possesses in abundance, but the working up even of these
is hampered by her coal position. I make no political pleas: I merely
illustrate the complexity of the restarting of industry under present-
day conditions. France has the first claim to assistance in restarting, a
claim which we all recognise; but for the comfort and peace of the
world a universal restart is desirable.

The central problem is one which I can only indicate here, not
discuss. Its discussion is for experts with full inside knowledge from
month to month, and the answer varies for every country. It is—when
will the inability of the war-damaged nations to pay for all that they
want, in food and materials, in order to restart full economic activity,
make itself felt by the nations who are supplying them, primarily, that
is, the United States and ourselves? In 1814-16, when the problem
was, of course, infinitely smaller because nations were so much more
self-sufficing, the reaction came at once for lack of long organised
eredits. Conceivably, all other combatants might do in turn what we
seem to have done—that is, adjust their trade balance within a reason-
able period and so avoid renewal of special credits. In that case the
post-war trade slump would come, not as an international crisis, but as a
gradual decline, when the first abnormal demand for goods of all kinds
to replenish stocks is over. Already this type of demand is slackening
‘n certain quarters. We shall do very well if we have nothing worse
than that gradual decline, which would be eased, in our case, by our

! ,— ECONOMICS, 123

extensive connections with undamaged countries, and by our willingness
to buy most things which any nation has to offer. The situation would
be still further eased if countries such as Germany and Russia were to
develop in turn what might. be called a reconstruction demand, to take
the place of the satisfied reconstruction demands of our Allies. But the
fear, as I think the quite reasonable fear, expressed in some well-
informed quarters, is that, in view of the complicated and dangerous cur-
rency position in many countries ; in view of the difficulty which the war-
damaged nations have in collecting taxes enough to meet their obliga-
tions; in view of the slowness with which some of them are raising
production to the level of consumption ; in view of the complete uncer-
tainty of the political and economic future in much of Central and
Bastern Europe—that in view of these things, and quite apart from pos-
sible political disturbances, we shall have to go through a genuine crisis,
as distinct from a depression ; a crisis beginning in the field of finance,
when some international obligation cannot be met or some international
credit cannot be renewed, spreading to industry and giving us a bad spell
ef unemployment, comparable with the unemployment of the post-war
period a century ago, and more dangerous because of the high standard
of living to which the people in this and some other countries is becom-
ing accustomed.

Personally, I am less apprehensive for the industries of this country
than are many whose opinions I should ordinarily be disposed to prefer
to my own. A demand, an effective demand, exists for many things
that we can supply in great regions outside the war area—in China,
for instance, where there is said to be at this moment a keen demand
for machinery which the United Kingdom is too much preoccupied with
other work to supply. Nor do I fear that a crisis will originate here,
as I am disposed to think that our currency and taxation position is
already relatively sound. But we should be bound to feel the reactions
of acrisis which might occur elsewhere ; to what extent is, however, quite
impossible to foresee.

One final comparison. An extraordinary feature of the great wars
of a century ago was that they coincided with a steady growth of popu-
lation, and were followed by a period of rapid growth. For the
United Kingdom that fact is well known and not surprising. We
lost relatively few men in war. But the official French figures,
97,500,000 in 1801 and 29,500,000 in 1816, are so remarkable that
one is tempted to doubt the first enumeration. Though remarkable,
the figures are, however, not impossible; and it must be recalled that
the losses were spread over many years. British population has grown
a little since 1914 ; in spite of separations of man and wife and our three-
quarters of a million dead. A main reason has, however, been the
suspension of emigration, which was proceeding at a rate of over 200,000
a year just before the war. France estimates a dead loss of over
3,000,000 (on 39,700,000) between 1913 and 1918 on her old territory.
Her census is due next year. Comparatively early in the war the
German civilian death rate was above the birth rate; so presumably she
is in much the same position as France. But, owing to changes of
frontier and continued unrest, it is as yet too early to estimate the total

124 SECTIONAL ADDRESSES.

effect of the Great War on population. For Western and Central Europe
it must, I think, have produced a considerable net loss. For Russia
one can hardly guess ; but her population is so largely rural and grew so
amazingly fast before 1914, that it would not surprise me very much to
learn that, with all her miseries, it had been maintained.

The growth of population in Europe after 1815 coincided with the
spread of the first industrial and agricultural revolution outwards from
the United Kingdom. The world was learning new ways to feed and
clothe itself; and it continued to learn all through the century. I
myself do not suppose that the age of discovery is at an end, so our
troubles may be eased as time goes on; and although I have not the
slightest wish that population should ever again grow so fast as it grew
in Europe during the nineteenth century, I see no reason why a moderate
rate of growth should not be resumed, in a few years at latest. But
perhaps I have already committed prophecy, or half prophecy, more
than is altogether wise for one in my position.

SECTION G; CARDIFF, 1920,

ADDRESS

TO THE

ENGINEERING SECTION

Proressor C. F. JENKIN, C.B.E., M.A.,
PRESIDENT OF THE SECTION.

Tue importance of research in all branches of industry is now becoming
fully recognised. It is hardly necessary to point out the great possi-
bilities of the Board of Scientific and Industrial Research, formed
just before the war, or to lay stress on the attention which has been
called to the need for research by events during the war. Probably
in no branch of the Services was more research work done than in
the Air Service, and the advances made in all directions in connection
with flying were astonishing. My own work was confined to problems
connected with materials of construction, and as a result of that work
I have come to the conclusion that the time has come when the funda-
mental data on which the engineering theories of the strength and
suitability of materials are based require thorough overhauling and
revision. I believe that the present is a favourable time for this work,
but I think that attention needs to be drawn to it, lest research work
is all diverted to the problems which attract more attention, owing
to their being in the forefront of the advancing engineering knowledge,
and lest the necessary drudgery is shirked in favour of the more
exciting new discoveries.

Tt has been very remarkable how again and again in aeroplane
engineering the problems to be solved have raised fundamental ques-
tions in the strength and properties of materials which had never been
adequately solved. Some of these questions related to what may be
termed theory, and some related to the physical properties of materials.

I propose to-day to describe some of these problems, and to suggest
the direction in which revision and extension of our fundamental
theories and data are required and the lines on which research should
be undertaken. Let us consider first one of the oldest materials of
construction—timber. Timber was of prime importance in aircraft
construction. The first peculiarity of this material which strikes us
is that it is anisotropic. Its grain may be used to locate three principal
axes—along the grain, radially across the grain, and tangentially across
the grain. It is curious that there do not appear to be generally
recognised terms for these three fundamental directions. A very few

126 SECTIONAL ADDRESSES.

tests are sufficient to show that its strength is enormously greater
along the grain than across it. How, then, is an engineer to calculate
the strength of a wooden member? There is no theory, in a form
available for the engineer, by which the strength of members made
of an anisotropic material can be calculated.

I fancy I may be told that such a theory is not required—that
experience shows that the ordinary theory is quite near enough. How
utterly misleading such a statement is I will try to show by a few
examples. Suppose a wooden tie or strut is cut from the tree obliquely
so that the grain does not lie parallel to its length. In practice it
is never possible to ensure that the grain is accurately parallel to the
length of the member, and often the deviation is considerable. How
much is the member weakened? This comparatively simple problem
has been of immense importance in aeroplane construction, and, thanks
to the researches made during the war, can be answered. The solution
has thrown a flood of light on many failures which before were obscure.
If the tensile strengths of a piece of timber are, say, 18,000 lb./sq. in.
along the grain and 800 lb./sq. in. across it (radially or tangentially)
and the shear strength is 900 lb./sq. in. along the grain—these figures
correspond roughly with the strengths of silver spruce—then if a
tensile stress be applied at any angle to the grain the components
of that stress in the principal directions must not exceed the above
strengths, or failure will occur. Thus we can draw curves limiting
the stress at any angle to the grain, and similar curves may be drawn
for compression stresses. These theoretical curves have been checked
experimentally, and the results of the tests confirm them closely, except
in one particular. The strengths at small inclination to the grain fall
even faster than the theoretical curves would lead us to expect. The
very rapid drop in strength for quite small deviations is most striking.

Similar curves have been prepared for tensile and compressive
stresses inclined in each of the three principal planes for spruce, ash,
walnut, and mahogany, so that the strengths of these timbers to resist
forces in any direction can now be estimated reasonably accurately.

As a second example consider the strength of plywood. Plywood
is the name given to wood built up of several thicknesses glued
together with the grain in alternate thicknesses running along and
across the plank. he result of this crossing of the grain is that the
plywood has roughly equal strength along and across the plank. Ply-
wood is generally built up of thin veneers, which are cut from the
log by slicing them off as the log revolves in a lathe.

Owing to the taper in the trunk of the tree and to other irregularities
in form, the grain in the veneer rarely runs parallel to the surface,
but generally runs through the sheet at a more or less oblique angle.
As a consequence the strength of plywood is very variable, and tests
show that it is not possible to rely on its having more than half the
strength it would have if the grain in the veneers were not oblique.
It is therefore obviously possible to improve the manufacture enor-
mously by using veneers split off, following the grain, in place of the
present sliced veneers. The superiority of split or riven wood over
cut wood has been recognised for ages. I believe all ladders and ladder

G.—ENGINEERING. 127

rungs are riven. Hurdles, hoops, and laths are other examples. Knees
in ships are chosen so that the grain follows the required outline.

Owing to the enormous difference in strength in timber along and
across the grain, it is obviously important to get the grain in exactly
the right direction to bear the loads it has to carry. The most perfect
example I ever saw of building up a plywood structure to support all
the loads on it was the frame of the German Schutte-Lanz airship,
which was made entirely of wood. At the complex junctions of the
various girders and ties the wood, which was built up of very thin
yeneers—hardly thicker than plane shavings—layers were put on most
ingeniously in the direction of every stress.

During the war I have had to reject numerous types of built-up
struts intended for aeroplanes, because the grain of the wood was in
the wrong direction to bear the load. The example shown—a McGruer
strut—is one of the most elegant designs, using the grain correctly.

Many of the tests applied to timber are wrong in theory and conse-
quently misleading. For example, the common method of determining
Young’s modulus for timber is to measure the elastic deflection of a
beam loaded in the middle and to calculate the modulus by the ordinary
theory, neglecting the deflection due to shear, which is legitimate in
isotropic materials ; but in timber the shear modulus is very small—for
example, in spruce it is only about one-sixtieth of Young’s modulus—
and consequently the shear deflection becomes quite appreciable, and
the results obtained on test pieces of the common proportions lead to
errors in the calculated Young’s modulus of about 10 per cent.

The lantern plates show three standard tests; the first is supposed
to give the shearing strength of the timber, but these test pieces fail
by tension across the grain—not by shearing. Professor Robertson
has shown that the true shear strength of spruce is about three times
as great as the text-book figures, and has designed a test which gives
fairly reliable results. The second figure represents a test intended to
give the mean strength across the grain, but the concentration of stress
at the grooves is so great that such test pieces fail under less than half
the proper load. This fact was shown in a striking manner by narrow-
ing a sample of this shape to half its width, when it actually bore a
greater total load—i.e., more than double the stress borne by the
original sample. The third figure represents a test piece intended to
measure the rather vague quality, ‘strength to resist splitting.’ The
results actually depend on the tensile strength across the grain, on the
elastic constants, and on the accidental position of the bottom of the
groove relatively to the spring or autumn wood in the annular rings.
Unless the theory is understood, rational tests cannot be devised.

There are some valuable tropical timbers whose structure is far
more complex than that of our ordinary northern woods. The grain in
these timbers grows in alternating spirals—an arrangement which at
_ first sight is almost incredible. The most striking example of this type
of wood I have seen is the Indian ‘ Poon.’ The sample on the table
has been split in a series of tangential planes at varying distances from
the centre of the tree, and it will be seen that the grain at one depth
is growing in a right-hand spiral round the trunk; a little farther out

128 SECTIONAL ADDRESSES,

it grows straight up the trunk; further out again it grows in a left-
hand spiral, and this is repeated again and again, with a pitch of about
two inches. The timber is strong and probably well adapted for use
in large pieces—it somewhat resembles plywood—but it is doubtful
whether it is safe in small pieces. No theory is yet available for esti-
mating its strength, and very elaborate tests would be needed to
determine its reliability in all positions. I had to reject it for aero-
planes during the war for want of accurate knowledge of its
properties.

These examples show how necessary it is to have a theory for the
strength of anisotropic materials before we can either understand the
causes of their failure or make full use of their properties or even test
them rationally.

The second material we shall consider is steel, and in dealing with
it I do not wish to enter into any of the dozen or so burning questions
which are so familiar to all metallurgists and engineers, but to call
your attention to a few more fundamental questions. Steel is not
strictly isotropic—but we may consider it to be so to-day. The first
obvious question the engineer has to answer is, ‘ What is its strength? ’
The usual tests give the Ultimate Strength, Yield Point, Elastic Limit,
the Elongation, the Reduction of Area, and perhaps the Brinell and
Izod figures. On which of these figures is the dimension of an engine
part, which is being designed, to be based? If we choose the Ultimate
Strength we must divide it by a large factor of safety—a factor of
ignorance. If we choose the Yield Point we must remember that none
of the higher-grade steels have any Yield Point, and the nominal Yield
Point depends on the fancy of the tester. This entirely imaginary
point cannot be used for accurate calculation except in a very few
special cases. Can we base our calculation on the Elongation—the
Reduction of Area—the Izod test? If we face the question honestly we
realise that there is no known connection between the test results and
the stress we can safely call on the steel to bear. The only connecting
link is that cloak for our ignorance—the factor of safety.

I feel confident that the only reliable property on which to base
the strength of any engine part is the suitable Fatigue Limit. We
have not yet reached the position of being able to specify this figure,
but a considerable number of tests show that in a wide range of steels
(though there are some unexplained exceptions) the Fatigue Limit for
equal + stresses is a little under half the Ultimate Strength, and is
independent of the Elastic Limit and nominal Yield Point, so that the
Ultimate Strength may be replaced as the most reliable guide to true
strength, with a factor—no longer of ignorance, but to give the fatigue
limit—of a little over 2.

If the Fatigue Limit is accepted as the only sound basis for strength
calculation for engine parts, and it is difficult to find any valid objection
to it, then it is obvious that there is urgent need for extensive researches
in fatigue, for the available data are most meagre. The work is
laborious, for there is not one Fatigue Limit, but a continuous series,
as the signs and magnitudes of the stresses change. Many problems in
connection with fatigue are of great importance and need much fuller

G.—ENGINEERING. 129

investigation than they have jso far received—e.g., the effect of speed
of testing; the effect of rest and heat treatment in restoring fatigued
material; the effect of previous testing at higher or lower stresses on
the apparent fatigue limit of a test piece. Some observers have found
indications that the material may possibly be strengthened by subject-
ing it to an alternating stress below its fatigue limit, so that the results
of fatigue tests may depend on whether the limit is approached by
increasing the stress or by decreasing it.

Improved methods of testing are also needed—particularly methods
which will give the results quickly. Stromeyer’s method of measur-
ing the first rise of temperature, which indicates that the fatigue limit
is passed, as the alternating load is gradually increased, is most promis-
ing; it certainly will not give the true fatigue limit in all cases, for it
has been shown by Bairstow that with some ranges of stress a finite
extension occurs at the beginning of a test and then ceases, under
stresses lower than the fatigue limit. But the fatigue limit in that
case would not be a safe guide, for finite changes of shape. are not
permissible in most machines, so that in that case also Stromeyer’s
test may be exactly what is wanted. It can probably be simplified in
‘detail and made practicable for commercial use. Better methods of
testing in torsion are also urgently needed, none of those at present
used being free from serious defects. Finally, there is a fascinating
field for physical research in investigating the internal mechanism of
fatigue failure. Some most suggestive results have already been
obtained, which extend the results obtained by Ewing.

For members of structures which are only subjected to ‘steady loads
I suggest ‘that the safe stress might be defined by limiting the corre-
‘sponding permanent set to a small amount—perhaps 4 per cent. or
per cent. This principle has been tentatively adopted in some.of \the
aircraft material specifications by specifying a Proof Load which must
be sustained without a permanent extension of more than 4 per cent.
Whether this principle is suitable for all materials and how it will
answer in practice remains to be proved by experience. It is at any
rate a possible rational ‘basis for determining the useful strength of a
material under steady loads.

The relation between the proof stress and ‘the shape of the stress-
‘strain diagram is shown in the lantern slide. The curve is the record
of an actual test on a certain copper alloy. Ifa length A B correspond-
ing'to 4 per cent. elongation be set off along the base line and a line BP
be drawn through the point B parallel to the elastic line, to cut the curve
in P, then the stress at P is the stress which will give 4 per cent.
permanent set. Though 4 per cent. may appear rather a large
permanent set to allow it will be seen from the figure that it is less
than the elastic elongation would have been at the same stress, and we
do not usually find elastic elongations serious.

As a commercial test the proof load is very easily applied. For this
alloy the ‘specified proof load is shown by the horizontal line so labelled.
This load is to (be applied and released, and the permanent extensicn is
required by the specification to be less than 4 per-cent. This sample
passes the test easily. On the figure the condition for complying with

1920 K

130 SECTIONAL ADDRESSES.

the specification is that the curve shall fall above Q. But the test does
not require the curve to be determined.

If we admit that the fatigue limit is the proper basis for engine-
strength calculations, there are a number of interesting modifications
required in the common theory of the strength of materials. It will
no longer be possible to neglect, as has been so general in the past, the
uneven distribution of stress in irregularly shaped parts of machines.
It has been generally recognised that sharp corners should be avoided
when possible, but no theory is available to enable the stresses at corners
to be calculated or to enable their effect on the strength of the member
to be estimated. If fatigue is the critical factor in failure under fluc-
tuating stresses such theory is most necessary. Hven the roughest
guide would be of great value. The nature and magnitude of the con-
centrations of stress which occur in practice have been investigated
experimentally by Professor Coker by his elegant optical method which
has given most valuable results, some of which are already being used
in designing offices. If the mathematical theory is too difficult, it may
be possible to lay down practical rules deduced from such experimental
results—but the method still has many limitations, perhaps the most
serious being that it can only be used on flat models. I believe Professor
Coker expects to be able to extend the method to round models.

As a simple example to show the importance of the subject let us
consider the effect of a groove round a straight round bar subject to
alternating tension and compression—such a groove as a screw thread.
There will be a concentration of stress at the bottom of the groove.
The ratio of the stress at the bottom of a groove to the mean stress in
the bar has been worked out mathematically by Mr. A. A. Griffith, and
his calculations have been confirmed experimentally by his elegant soap-
bubble method. The ratio depends on the relation between the depth
of the groove, the radius at the bottom, and slightly on the
angle between the sides. For a Whitworth form of thread the ratio
will be about 3. If the Fatigue Limit is exceeded at the bottom of the
groove the metal will fail and a minute crack will form there; this crack
will soon spread right across the bar and total failure will result. Thus
we see that the safe mean stress in the bar will be reduced to one-third
what a plain bar will bear. The truth of this theory regarding the
importance of concentrations of stress has still to be proved experi-
mentally ; if true, it is of far-reaching importance, since it applies to all
concentrations of stress in machine parts subject to fluctuating loads.

The theory does not apply to steadily loaded members; in these the
local excess of stress is relieved by the stretching of the minute portion
which is overloaded, and no further consequences follow.

The theory appears to apply to grooves however small, and has an
important bearing on the smoothness of the finish of machine parts.
The surface of any engine part finished by filing is certainly entirely
covered with scratches. Emery likewise leaves the surface scratched—
though the scratches are smaller. If, however, polishing be carried
further the surface may ultimately be freed from scratches and left in a
burnished condition. In this condition amorphous metal has been
smeared over the surface—the smooth appearance is not simply due

ae G.—ENGINEERING. 131

to the scratches being too small to see. The strength—under alternat-
ing stresses—appears to depend on the form of the scratches, and if the
ratio of radius at the bottom of the scratch to its depth is fairly large,
very little weakening occurs. It seems probable in the ordinary engineer-
ing finish produced by emery and oil that the scratches are broad and
shallow. This subject is being investigated. A considerable amount of
evidence has been collected from practical experience pointing to the
important effect which a smooth finish has on the strength of heavily
stressed engine parts.

Fatigue is probably the cause of failure of wires in wire ropes. A
good deal of valuable experimental work has been done on the life of
ropes, but so far as I am aware there is no satisfactory theory of their
strength. This subject also requires research, and it seems probable
that valuable practical results might follow if the true explanation of
the cause of the breakages of the wires was determined.

These are only examples, but they may be sufficient to show how
much work both experimental and theoretical requires to be done to
give the engineer a really sound basis for the simplest strength calcula-
tions on any moving machinery. But there are more fundamental
questions still which must be tackled before the simplest questions of
all which meet the engineer can be answered scientifically. The two
most urgent and most important questions which I met with during the
war in connection with aircraft were always the same—Why did some
part break? and, What is the best material to use for that part? It was
most disconcerting to find how inadequate one’s knowledge was to
answer these two simple questions. The common answers are: To the
first: ‘It broke because it was too weak, make it stronger,’ and to the
second: ‘ General practice indicates such a material as the best—better
not try any other or you may have trouble.’ In aircraft weight is
paramount, and to make a part stronger—t.e., heavier—had to be the
last resort, and when used was almost a confession of failure. ‘ General
practice’ was no guide in aeroplane engines, which are built of the
strangest materials. The origins of fractures were traced to many
causes, often lying far away from the site of the breakage; but with
these I am not concerned to-day. I wish to confine our consideration to
the actual fracture and to ask, ‘ What stress caused the fracture?’ and
“What property of the metal was absent which would have enabled
it to withstand that stress?’ And again, ‘ What other material pos-
sesses suitable properties to withstand the stresses better?’ These are
the fundamental questions which I have referred to—and which urgently
need answers.

As an example I will take a broken propeller shaft. It has broken
in a beautiful spiral fracture. What stress causes that? T have failed
to explain it by any of the facts I know about the steel it is made of.
It is, of course, a fatigue fracture—i.e., it spread gradually. The
questions to be answered are, Did it fail under tension, bending or

torsion? and, Why was a spiral direction followed by the failure as it
spread ? riety
_ It may be objected that the question is unimportant. TI think not.
For example, till we can determine the nature of the stress we cannot

Kk 2

132 SECTIONAL ADDRESSES.

indicate the nature of the load—thus I cannot say if it broke under
a torsional load (possibly torsional vibration) or under a bending load
(possibly due to some periodic variation of thrust on one of the pro-
peller blades as it passed an obstruction). Until the nature of the load
which caused the failure is known, it is very difficult to take steps to
guard against similar accidents. For the most urgent reasons, there-
fore, we require to be able to understand the fracture, as in nearly all
aircraft problems men’s lives hang on the answer.

Turning now to the question of the most suitable material, I will
take as an example the material for the crankshaft of an aeroplane
engine. A few months before the Armistice there were difficulties in
gefting sufficient supplies of the high-grade nickel-chrome steel forgings
then in general use for shafts, and proposals were made to use a plain
carbon steel. Such a steel would be about 30 per cent. weaker, accord-
ing to the ordinary tests. A conference of leading metallurgists and
engineers was held to discuss the suggestion. No one present ventured
to predict whether the weaker steel would answer or not, or whether
the dimensions would have to be increased or not. It was pointed out
that a French engine was now using 50-ton steel with better results
than when using the 100-ton steel for which it was designed, no
changes in dimensions having been made. Such a reduction of strength
might be understood in ordinary engineering where there are large
margins of safety, but in an aeroplane engine, in which every ounce
of metal is cut off which can be spared, they show how completely
ignorant engineers are of what the suitability of material depends on.

As another example, Why are oxygen cylinders annealed—repeat-
edly? Annealing reduces the steel to its weakest condition. I believe
the fondness for annealing is due to our ignorance of the properties
we require. Perhaps the quality of steel which an engineer fears most
is brittleness. He believes that annealing will soften it and reduce the
brittleness; so he anneals, blindly. The fact is that we do not know
what brittleness is—we cannot define it—we cannot measure it—
though there are endless empirical tests to detect it. Till we know
what it means and can measure it we are in a miserable position.
During the war I was consulted on what could be done to reduce the
enormous weight of oxygen cylinders, and I advised that experiments
should be made on the high-quality alloyed steel tubes we were using
in aircraft construction. The department dealing with these tubes
took the matter up, and alloyed steel cylinders, properly heat-treated,
were made. These were, I believe, a success, and only weighed a
small fraction of the old-fashioned cylinders. But my suggestion was
little more than a guess, and no means was known of accurately testing
the suitability of the material, so they were only accepted after passing
any number of empirical tests, consisting of various kinds of rough
usage, to see if they would crack or burst. Surely an engineer should
be able to sav whether a cylinder. is safe without dropping it from
the roof or rolling it down the front-door steps to see if it breaks.

These examples refer only to different grades of the same material—
steel—but how far worse off we are when the problem is whether some
other alloy would be suitable to replace steel. Proposals have been —

_@,=-ENGINEERING. 133.

made, for example, to, replace the very hard steel used at present
for connecting-rods by duralumin or some other forged aluminium
alloy. It seems worth trying; but who, in our present state of ignorance
of the real properties of metals, will say if the experiment will be a
success ?

How difficult it is to prophesy may be illustrated by the results of
two empirical tests on duralumin and steel sheets of the same thick-
nesses. ‘he ultimate strengths and elongations of the steel and the
duralumin were roughly equal. ‘Ihe lantern slides show that under
reverse-bend tests they both follow the same law, the steel being the
better. But under the cupping test they follow opposite laws.

The suitability of different materials presumably depends on their
fundamental physical properties. These may be many, but some
physicists think that they are probably really very few, and that,
knowing these few, it may be possible to deduce all the complex
properties required by the engineer and to state with certainty how
materials will behave under any conditions of service. This is the most
fundamental problem which needs solution to enable the knowledge
of the strength of materials to be put on a sound foundation. It will
need the co-operation of able physicists, metallurgists, and engineers
to solve it.

While urging the importance of research in the fundamental theories
of stress and fundamental properties of materials, I wish to lay special
stress on the nature of the researches required. Engineers are intensely
practical men, and their practice has generally been ahead of their
theory. The difficulties they have met have been dealt with, often with
the greatest ingenuity and skill, as special problems. They have seldom
had time or opportunity to solve the general problems, and as a result
they are used to making their experiments and trials as close a copy—
usually on a smaller scale—of the real thing as possible. The results
obtained in this way, while they are applicable to the particular
problem, are of little general use. They depend on many factors. The
researches I am now advocating must be of a diametrically opposite
description. They must be absolutely general, and the results must
depend on one factor only at a time, so that general laws may be
established which will be applicable to all special problems.

There are many other similar gaps in our knowledge to which I
have not time to refer to to-day. I have tried to show that we need
most of all a real knowledge of the fundamental properties of materials,
from which we shall be able to deduce their behaviour in any condition
of service, so that we may be able to compare the relative merits of
diverse materials for any particular purpose.

_ Secondly, that we need a practical method of calculating the stresses
in parts of any form, so that concentrations of stress may be avoided
or that their magnitudes may be known and allowed for.

Thirdly, that we need a rational connecting link between the tests
made on materials and the stresses they will bear in service, to replace
the factor of safety. I have suggested two tests, the Proof Load and
the Fatigue Limit, which might be used directly in estimating the allow-
able working stress.

184 SECTIONAL ADDRESSES.

Fourthly, that we need a mathematical theory for the strength of
anisotropic materials, of which timber is an extreme and important
example.

When the notes for this address were first drafted I ended by an
appeal to the Board of Scientific and Industrial Research to undertake
the necessary research work. Since then the Aeronautical Research
Committee has been constituted, and a sub-committee has been
appointed to deal with ‘ Materials.’ I have great hopes that the
committee will tackle many of these problems. I will therefore conclude
by appealing to all who can help to assist that committee in their
endeavour to solve these most important and fascinating, but most
difficult, problems.

SECTION H: CARDIFF, 1920.

ADDRESS

TO THE

ANTHROPOLOGICAL SECTION

Pror. KARL PEARSON, M.A., LL.D., F.RB.S.,
PRESIDENT OF THE SECTION,

Anthropology—the Understanding of Man—should be, if Pierre
Charron were correct, the true science and the true study of mankind.*
We might anticipate that in our days—in this era of science—anthro-
pology in its broadest sense would occupy the same exalted position
that theology occupied in the Middle Ages. We should hail it ‘ Queen
of the Sciences,’ the crowning study of the academic curriculum.
Why is it that we are Section H and not Section A? If the answer
be given that such is the result of historic evolution, can we still be
satisfied with the position that anthropology at present takes up in our
British Universities and in our learned societies? Have our univer-
sities, one and all, anthropological institutes well filled with enthusi-
astic students, and are there brilliant professors and lecturers teaching
them not only to understand man’s past, but to use that knowledge to
forward his future? Have we men trained during a long life of study
and research to represent our science in the arena, or do we largely
trust to dilettanti—to retired civil servants, to untrained travellers or
colonial medical men for our knowledge, and to the anatomist, the sur-
geon, or the archeologist for our teaching? Needless to say, that for the
study of man we require the better part of many sciences, we must
draw for contributions on medicine, on zoology, on anatomy, on
archeology, on folk-lore and travel-lore, nay, on history, psychology,
geology, and many other branches of knowledge. But a hotch-
potch of the facts of these sciences does not create anthropology. The
true anthropologist is not the man who has merely a wide knowledge
of the conclusions of other sciences, he is the man who grasps their
bearing on mankind and throws light on the past and present factors
of human evolution from that knowledge.

1 “‘Ta vraye science et le vray estude de l’homme c’est l’Homme.’’ Pierre
Charron, De la Sagesse, Préface du Premier Livre, 1601.. Pope, with his ‘‘ The
proper study of mankind is Man,” 1733, was, as we might anticipate, only a
plagiarist.

136 wis * SECTIONAL ADDRESSES. |
I am afraid I am a scientific heretic—an outcast from the true ortho-
dox faith—I do not believe in science for its own sake. I believe only in
science for man’s sake. You will hear on every side the argument that
it is not the aim of science to be utile, that you must pursue scientific
studies for their own sake and not for the utility of the resulting dis-
coveries. I think that there is a great deal of obscurity about this
attitude, I will not say nonsense. [I find the strongest supporters of
‘science for its own sake ’ use as the main argument for the pursuit
of not immediately utile researches that these researches will be useful
some day, that we can never be certain when they will turn out to be
of advantage to mankind. Or, again, they will appeal to non-utile
branches of science as providing a splendid intellectual training—as if
the provision of highly trained minds was not itself a social function
of the greatest utility! In other words, the argument from utility is
in both cases indirectly applied to justify the study of science for its
own sake. In the old days: the study of hyperspace—space of higher
dimensions than that of which we have physical cognisance—used to
be cited as an example of! a non-utile scientific research. In view of
the facts: (i.) that our whole physical outlook on the universe—and
with it I will add our whole philosophical and theological outlooks—are
taking new aspects under the theory of Einstein; and (ii.) that study
of the relative influences of Nature and Nurture in Man can be
reduced to the trigonometry of polyhedra in hyperspace—we see how
idle it is to fence off any field of scientific investigation as non-utile.
Yet are we to defend the past of anthropology—and, in particular,
of anthropometry—as the devotion of our science to an immediate non-
utile which one day is going to be utile in a glorious and epoch-making
manner, like the Clifford-Hinstein suggestion of the curvature of our
space? I fear we can take no such flattering unction to our souls.
I fear that ‘the best is yet to be’ cannot be said of our multitudinous
observations on ‘ height-sitting’ or on the censuses of eye or hair
colours of our population. These things are dead almost from the day
of their record. It is not only because the bulk of their recorders were
untrained to observe and measure with scientific accuracy, it is not only
because the records in nine out of ten cases omit the associated factors
without which the record is valueless. It is because the progress of
mankind in its present stage depends on characters wholly different
from those which have so largely occupied the anthropologist’s atten-
tion, Seizing the superficial and easy to observe, he has let slip the
more subtle and elusive qualities on which progress, on which national
fitness for this or that task essentially depends. The pulse-tracing,
the reaction-time, the mental age of the men under his control are far
more important to the commanding officer—nay, I will add, to the
employer of labour—than any record of span, of head-measurement,
or pigmentation categories. The psycho-physical and psycho-physio-
logical characters are of far greater weight in the struggle of nations
to-day than the, superficial measurements of man’s body. Physique,
im the: fullest. sense, counts; something still, but. it is. physique as
méasured by health, not by stature or eye-colour. But character,
strength of will, mental quickness count more, and if anthropometry

7. . H.—ANTHROPOLOGY. Brie 137
is to be useful to the State it must turn from these rusty old weapons,
these measurements of stature and records of eye-colour to more
certain appreciations of bodily health and mental apfitude—to what we
may term ‘ vigorimetry ’ and to psychometry.

Some of you may be inclined to ask: And how do you know that
these superficial size-, shape-, and pigment-characters are not closely
associated with measurements of soundness of body and soundness of
mind? The answer to this question is twofold, and I must ask you
to follow me for a moment into what appears a totally different sub-
ject. I refer to a‘ pure race.’ Some biologists apparently believe
they can isolate a pure race, but in the case of man, I feel sure that
purity of race is a merely relative term. For a given character one
race is purer than a second, if the scientific measure of variation of
that character is less than it is in the second. In loose wording, for
we cannot express ourselves accurately without mathematical symbols,
that race is purer for which on the average the individuals are: closer to
type for the bulk of ascertainable characters than are the characters
in a second race. But an absolutely pure race in man defies definition.
The more isolated a group of men has remained, the longer it has
lived under the same environment, and the more limited its habitat,
the less variation from type it will exhibit, and we can legitimately
speak of it as possessing greater purity. We, most of us, probably
believe in a single origin of man. But as anthropologists we are
inclined to speak as if at the dawn of history there were a number of
pure races, each with definite physical and mental characteristics; if
this were true, which I do not believe, it could only mean that up: to
that period there had been extreme isolation, extremely differentiated
environments, and so marked differences in the direction and rate of
mental and physical evolution. But what we know historically of
folk-wanderings, folk-mixings, and folk-absorptions have undoubtedly
been going on for hundreds of thousands of years, of which we know
only a small historic fragment. Have we any real reason for suppos-
ing that ‘ purity of race’ existed up to the beginning of history, and
that we have all got badly mixed up since?

Let us, however, grant that there were purer races at the beginning
of history than we find to-day. Let us suppose a Nordic race with
a certain stature, a given pigmentation, a given shape of head, and a
given mentality. And, again, we will suppose an Alpine race, differ-
ing markedly in type from the Nordic race. What happens if we cross
members of the two races and proceed to a race of hybrids? <A
_ Mendelian would tell us that these characters are sorted out like: cards
from a pack in all sorts of novel combinations. A Nordic mentality
will be found with short stature and dark eyes. A tall but brachy-
cephalic individual will combine Alpine mentality with blue eyes.
Without accepting fully the Mendelian theory we can at least accept
the result of mass observations, which show that the association
between superficial physical measurements and mentality is of the
slenderest kind. If you keep within one class, my own measurements
show me that there is only the slightest relation between intelligence
and the size and shape of the head. Pigmentation in this country seems

138 SECTIONAL ADDRESSES.

to have little relation to the incidence of disease. Size and shape of
head in man have been taken as a rough measure of size and shape of
brain. They cannot tell you more—perhaps not as much as brain-
weight—and if brain-weight were closely associated with intelligence,
then man should be at his intellectual prime in his teens.

Again, too often is this idea of close association of mentality and
physique carried into the analysis of individuals within a human group,
i.e. of men belonging to one or another of the many races which have
gone to build up our population. We talk as if it was our population
which was mixed, and not our germplasm. We are accustomed to speak
of a typical Englishman. For example, Charles Darwin; we think of
his mind as a typical English mind, working in a typical English
manner, yet when we come to study his pedigree we seek in vain
for ‘ purity of race.’ He is descended in four different lines from
Irish kinglets; he is descended in as many lines from Scottish and
Pictish kings. He had Manx blood. He claims descent in at least
three lines from Alfred the Great, and so links up with Anglo-Saxon
blood, but he links up also in several lines with Charlemagne and the
Carlovingians. He sprang also from the Saxon Emperors of Germany,
as well as from Barbarossa and the Hohenstaufens. He had Nor-
wegian blood and much Norman blood. He had descent from the
Dukes of Bavaria, of Saxony, of Flanders, the Princes of Savoy, and
the Kings of Italy. He had the blood in his veins of Franks, Alamans,
Merovingians, Burgundians, and Longobards. He sprang in direct
descent from the Hun rulers of Hungary and the Greek Emperors of
Constantinople. If I recollect rightly, Ivan the Terrible provides a
Russian link. There is probably not one of the races of Europe con-
cerned in the folk-wanderings which has not a share in the ancestry
of Charles Darwin. If it has been possible in the case of one English-
man of this kind to show in a considerable number of lines how impure
is his race, can we venture to assert that if the like knowledge were
possible of attainment, we could expect greater purity of blood in any
of his countrymen? What we are able to show may occur by tracing
an individual in historic times, have we any valid reason for supposing
did not occur in prehistoric times, wherever physical barriers did not
isolate a limited section of mankind? If there ever was an association
of definite mentality with physical characters, it would break down
as soon as race mingled freely with race, as it has done in historic
Europe. Isolation or a strong feeling against free inter-breeding—as
in a colour differentiation—could alone maintain a close association
between physical and mental characters. Europe has never recovered
from the general hybridisation of the folk-wanderings, and it is only
the cessation of wars of conquest and occupation, the spread of the
conception of nationality and the reviving consciousness of race, which
is providing the barriers which may eventually lead through isolation
to a new linking-up of physical and mental characters.

In a population which consists of non-intermarrying castes, as in
India, physique and external appearance may be a measure of the type
of mentality. In the highly and recently hybridised nations of Europe
there are really but few fragments of ‘ pure races’ left, and it is

ii.— ANTHROPOLOGY. 199

hopeless to believe that anthropometric measurements of the body or
records of pigmentation are going to help us to a science of the psycho-
physical characters of man which will be useful to the State. The
modern State needs in its citizens vigour of mind and vigour of body,
but these are not characters with which the anthropometry of the past
has largely busied itself. In a certain sense the school medical officer
and the medical officer of health are doing more State service of an
anthropological character than the anthropologists themselves.

These doubts have come very forcibly to my notice during the last
few years. What were the anthropologists as anthropologists doing
during the war? Many of them were busy enough and doing valuable
work because they were anatomists, or because they were surgeons,
or perhaps even because they were mathematicians. But as anthropo-
logists, what was their position? The whole period of the war pro-
duced the most difficult problems in folk-psychology. There were
occasions innumerable when thousands of lives and most heavy expen-
diture of money might have been saved by a greater knowledge of
what creates and what damps folk-movements in the various races
of the world. India, Egypt, Ireland, even our present relations with
Italy and America, show only too painfully how difficult we find it to
appreciate the psychology of other nations. We shall not surmount
these difficulties until anthropologists take a wider view of the material
they have to record, and of the task they have before them if they
wish to be utile to the State. It is not the physical measurement of
native races which is a fundamental feature of anthropometry to-day ;
it is the psychometry and what I have termed the vigorimetry of white-
as well as of dark-skinned men that must become the main subjects
of our study.

Some of you may consider that I am overlooking what has been
contributed both in this country and elsewhere to the science-offolk-
psychology. I know at least that Wilhelm Wundt’s ? great work runs
to ten volumes. But I also know that in its 5452 pages there is
not a single table of numerical measurements, not a single state-
ment of the quantitative association between mental racial characters,
nor, indeed, any attempt to show numerically the intensity of
association between folk-mentality and folk customs and institutions.
It is folk-psychology in the same stage of evolution as present-day
sociology is in, or as individual psychology was in before the advent
of experimental psychology and the correlational calculus. It is

purely descriptive and verbal. I am not denying that many sciences
must for a long period still remain in this condition, but at the same
time I confess myself a firm disciple of Friar Roger Bacon® and of
Leonardo da Vinci,* and believe that we can really know very little

2 Its last volume also bears evidence of the non-judicial mind of the writer,
who expresses strong opinions about recent events in the language of the party
historian rather than the man of science.

3 He who knows not Mathematics cannot know any other science, and what
is more cannot discover his own ignorance or find its proper remedies.

4 Nissuna humana investigatione si po dimandare vera scientia s’essa non
passa per le mathematiche dimostratione,

140) SECTIONAL ADDRESSES.

about a phenomenon until we can actually measure. it- and express: its
relations to other phenomena in quantitative form. Now you will
doubtless suggest that sections of folk-psychology like Language,
Religion, Law, Art—much that forms the substance of cultural
anthropology—are incapable of quantitative treatment. I am not con-
vinced that this standpoint is correct. Take only the first of these sec-
tions—Language. I am by no means certain that there is not a mich
harvest to:be reaped by the first man who can give unbroken time and
study to the statistical analysis of language. Whether he start with
roots or with words to investigate the degree of resemblance in
languages of the same family, he is likely, before he has done, to
learn a great deal about the relative closeness and order of evolution
of cognate tongues, whether those tongues be Aryan or Sudanese.
And the methods’ applicable in the case of language will apply in the
same manner to cultural habits and ideas. Strange as the notion may
seem at first, there is a wide field in cultural anthropology for the use
of those same methods which have revolutionised psychometric tech-
nique, to say nothing of their influence on osteometry.

The problems of cultural anthropology are subtle, but so indeed
are the problems of anthropometry, and no instrument can be too
fine if our analysis is to be final. The day is past when the arithmetic
of the kindergarten sufficed for the physical anthropologist; the day
is. coming when mere verbal discussion will prove inadequate for the
cultural anthropologist.

I do not say this merely in the controversial spint. I say it because
I want to find a remedy for the present state of affairs. I want to
see the full recognition of anthropology as a leading science by the
State. I want to see the recognition of anthropology by our manu-
facturers and commercial men, for it should be at least as important
to them as chemistry or physics—the foundations of the Anthropo-
logical Institutes with their museums and professors in Hamburg
and.Frankfurt have not yet found their parallels in commercial centres
here. I want to see a fuller recognition of anthropology in our great
scientific societies, both in their choice of members and in the memoirs
published. If their doors are being opened to psychology under its new
technique, may not anthropology also seek for fuller recognition ?

It appears to me that if we are to place anthropology in its true
position as the queen of the sciences, we must work shoulder to.shoulder
and work without intermittence in the following directions: anthropolo-
gists must not cease:

(i) To insist that our recorded material shall be such that it is
at present or likely in the near future to be utile to the State, using the
word ‘State’ in its amplest sense.

(ii) To insist that there shall be institutes of anthropology, each
with a full staff of qualified professors, whose whole energy and time
shall be devoted to the teaching of and research in anthropology,
ethnology and prehistory. At least three of our chief universities
should be provided with such institutes.

(iii) To insist that our technique shall not consist in the mere state-
ment of opinion on the facts observed, but shall follow, if possible

H.—ANTHROPOLOGY. 141

“with greater insight, the methods which are coming into use in
epidemiology and psychology.

I should like to enlarge a little further on these three insistencies,
the fundamental ‘ planks’ of the campaign I have in view.

(i) Insistence on the Nature of the Material to be dealt with.

I have already tried to indicate that the problems before us to-day,
the grave problems that are pressing on us with regard to the future,
cannot be solved by the old material and by the old methods. We have
to make anthropology a wise counsellor of the State, and this means
a counsellor in political matters, in commercial matters, and in social
matters.

The Governments of Europe have had military advisers, financial
advisers, transport and food experts in their service, but they have
not had:ethnological advisers; there have been no highly trained anthro-
pologists at their command. You have only to study the Peace of
Versailles to see that it is ethnologically unsound and cannot be per-
manent. It is no good asking why our well-meaning rulers did not
consult our well-meaning anthropologists. I for one confess that
we have not in the past dealt with actuality, or if we did deal with
actuality, we have not treated it in a manner likely to impress either
the executive or the public at large. There lacked far too largely
the scientific attitude and the fundamental specialist training. 1 will
not go so far as to say that, if the science of man had been developed
to the extent of physical science in all HKuropean countries, and had
then had its due authority recognised, there would have been no war,
but I will venture to say that the war would have been of a different
character, and we should not have felt that the fate of European society
and of European culture hung in the balance, as at this moment they
certainly do.

No one can allow individual inspiration to-day, and you may justly
cry a Daniel has no right to issue judgment from the high seat of
the feast. Daniel’s business is that of the outsider, the stranger, the
unwelcome person interpreting, probably his own, scrawling on the wall.

Well, if it be hard to learn from friends, let us at least study
impassionately from our late foes. Some of my audience may have
read the recent manifesto of the German anthropologists, their clarion
ery for a new and stronger position of the science of man in academic
studies. But the manifesto may have escaped some, and so closely
does it fit the state of affairs here that I venture to quote certain portions
of it. After reciting the sparsity of chairs for the study of physical and
cultural anthropology in the German universities and how little academic
weight has been given to such studies, it continues: ‘ Where these
sciences have otherwise found recognition in the universities, they are
not represented by specialists, so that anthropology is provided for by
the anatomists, ethnology by the geographers, and prehistory by
Germanists, archeologists and geologists, and this although, in the
present extent of these three sciences, the real command of each one of
them demands the complete working powers of an individual. This want

{

142 SECTIONAL ADDRESSES. 1

of teaching posts had made itself felt long before the war, so that the
number of specialists and of those interested in our science has
receded.’ *

And again:

‘During the war we have often experienced how in political
pamphlets ethnology and ethnography—even as in the peace treaty of
Brest-Litovsk—were used too often as catchwords without their users
being clear about the ideas those words convey. The sad results of
our foreign policy, the collapse of all our calculations as to national
frames of mind, were based in no small degree on ethnographic ignor-
ance ; one has only to take for example the case of the Turks. Ethnology
should not embrace only the spears and clubs of the savages, but also
the psychology and demography of the white races, the European
peoples. At this very moment, when the right of self-determination
has become a foremost question of the day, the scientific determination
of the boundaries of a people and its lands has become a task of the first
importance. But our Government of the past knew nothing of the
activity of the ethnologists, and the Universities were not in the condition
to come {o their aid, for ethnological chairs and institutes were wanting.
The foundation of such must be the task of the immediate future.’ ®

And once more:

“The problems of the military fitness of our people, of the physical
constitution of the various social classes, of the influence of the social
and material environment upon them, the problems of the biological
grounds for the fall in the birth-rate and its results, of the racial com-
position of our people, of the eventual racial differences and the accom-
panying diverse mental capacities of the individual strata, and finally
the racial changes which may take place in a folk under the influences
of civilisation, and the bearing of all these matters on the fate of a
nation, these are problems which can alone be investigated and brought
nearer to solution by anthropology. Even now after the war population-
problems stand in the forefront of interest, the question of folk-increase
and of the falling birth-rate is the vital question of the future.’ 7

I must ask your pardon for quoting so much, but it seems so strongly
to point the moral of my tale. If you will study what Germany is
feeling and thinking to-day do not hope to find it in the newspaper
reports, seek it elsewhere in personal communication or in German
writings. Then, I think, you will agree with me that rightly or wrongly
there is a conviction spreading in Germany that the war arose and that
the war was lost because a nation of professed thinkers had studied all
sciences, but had omitted to study aptly the science of man. And in
a certain sense that is an absolutely correct conviction, for if the science
of man stood where we may hope it will stand in the dim and distant
future, man would from the past and the surrounding present have
some grasp of future evolution, and so have a greater chance of guiding
its controllable factors.

5 Correspondenz Blatt, u.s.w., Jahrg. 1., S. 37.
® Tbid. 8. 41.
* Thid. 8, 38.

ints

H.—ANTHROPOLOGY. 148

We are far indeed from that to-day; but it befits us none the less
to study what this new anthropological movement in Germany connotes.
It means that the material of anthropology is going to change, or rather
that its observations will be extended into a study of the mental as
well as the physical characters, and these of the white races as well as of
the dark. It means that anthropologists will not only study individual
psychology, but folk-psychology. It means—and this is directly said—
that Germany, having lost her colonies, will still maintain her trade by
aid of consuls, missionaries, traders, travellers, and others trained
academically to understand both savage and civilised peoples. This is a
perfectly fair field, and if the game be played squarely can solely lead
to increased human sympathy, and we shall only have ourselves to
blame if other nations are before us in their anthropological knowledge
and its practical applications. The first condition for State support
is that we show our science to be utile by turning to the problems
of racial efficiency, of race-psychology, and to all those tasks that
Galton described as the first duty of a nation—‘in short, to make
every individual efficient both through Nature and by Nurture.’

Does this mean that we are to turn our backs on the past, to
desert all our prehistoric studies and to make anthropology the servant
of sanitation and commerce? Not in the least; if you think this is my
doctrine I have indeed failed to make myself even roughly clear to-day.
Such teaching is wholly opposed to my view of the function of science.
I feel quite convinced that you cannot understand man of to-day, savage
or civilised, his body or his mind, unless you know his past evolution,
unless you have studied fully all the scanty evidence we have of the
stages of his ascent. I should like to illustrate this by an incident
which came recently to my notice, because it may indicate to some
of those present the difficulties with which the anthropologist has to
contend to avoid misunderstanding.

Looking into the ancestry of man and tracing him backward to a
being who was not man and was not ape, had this prot-simio-human,
in the light of our present knowledge, more resemblance to the gibbon
or to the chimpanzee as we know them to-day? Some naturalists
link man up to the apes by a gibbonlike form, others by a troglodyte
type of ancestor. Some would make a push to do without either. But
granted the alternative, which is the more probable? This is the
problem of the hylobatic or the troglodyte origin of man. I had given
a lecture on the subject, confining my arguments solely to characters
of the thigh-bone. Now there chanced to be a statesman present, a
man who has had large responsibilities in the government of many races.

I have been honoured by seeing his comments on my lecture. ‘I am
not,’ he says, ‘ particularly interested in the descent of man. I do
not believe much in heredity, and this scientific pursuit of the dead
bones of the past does not seem to me a very useful way of spending
‘life. I am accustomed to this mode of study; learned volumes have
_been written in Sanscrit to explain the conjunction of the two vowels
“‘a’’ and ‘‘u.’’ It is very learned, very ingenious, but not very help-
ful. . . . I am not concerned with my genealogy so much as with my
future. Our intellects can be more advantageously employed than in

144 SECTIONAL ADDRESSES. a

finding our diversity from the ape... There may be noispirit, no
soul: there is no proof of their existence. If that is so, let us do
-away with shams and live like animals. If, on the other hand, there
is a soul to be looked after, let us all strain our nerves to the task;
there is no use in digging into the sands of time for the skeletons of
the past: build your man for the future.’

What is the reply of anthropology to this indictment of the states-
man? You cannot brush it lightly aside. It is the statement of a
good man and a strong man who is willing to spend his life in the service
of his fellows. He sees us handling fossils and potsherds and cannot
perceive the social utility of our studies. He does not believe any
enthusiasm for human progress can lie beneath the spade and callipers
of the scientific investigator. He has never grasped that the man of
to-day is precisely what heredity and his genealogy, his past history
and his prehistory, have made him. He does not recognise that it is
impossible to build your man for the future until you have studied the
origin of his physical and mental constitution. Whence did he draw
his good and evil characteristics—are they the product of his nature or
his nurture? Man has not a plastic mind and body which the enthu-
silastic reformer can at will mould to the model of his golden age ideals.
He has taken thousands of years to grow into what he is, and only by
like processes of evolution—intensified and speeded up, if we work
consciously and with full knowledge of the past—can we build his
future.

It does matter in regard to the gravest problems before mankind
to-day whether our ancestry was hylobatic or troglodyte. For five years
the whole world has been a stage for brutality and violence. We ‘have
seen a large part of the youth who were best fitted mentally and
physically to be parents of future generations perish throughout Europe :
the dysgenic effect of this slaughter will show itself each twenty ‘to
twenty-five years for centuries to come in the census returns of half
the countries of the world. Science undertook work which national
feeling bade it do, but-on which it will ever look back with a shuddering
feeling of distaste, an uneasy consciousness of having soiled its hands.
And as aftermath we see in almost every land an orgy of violent crime,
a sense of lost security, and at times we dread that our very civilisation
may perish owing to the weakening of the social ties, a deadening of
the responsibilities of class to class. This outbreak of violence which
has so appalled the thinking world, is it the sporadic appearance of an
innate-passion for the raw and brutal in mankind, or is it the outcome
of economic causes forcing the nations of the world to the combat for
limited food and material supplies? I wish we could attribute it to
the latter source, for then we could eradicate the spirit of violence by
changing environmental conditions. But if the spirit of violence ‘be
innate in man, if there be times when he not only sees red but rejoices
in it—and that was the strong impression I formed when T crossed
Germany on August 1, 1914—then outbreaks of violence will not cease
till troglodyte mentality is bred out of man. ‘That is why the question
of troglodyte or hylobatic ancestry ‘is nota ‘pursuit of dead bones. It
is @ vital problem en which turns much of folk-psychology. Tt is a

H.—ANTHROPOLOGY. 145

problem utile to the State, in that it throws light on whether nature
or nurture is the more likely to build up man’s future—and save him
from the recurrence of such another quinquennium.

The critic to whom I have referred was not idle in his criticism.
He had not been taught that evolutionary doctrine has its bearings on
practical life. The biologist and the anthropologist are at fault; they
have too often omitted to show that their problems have a very close
relation to those of the statesman and the social reformer, and that the
problems of the latter cannot be solved without a true insight into
man’s past, without a knowledge of the laws of heredity, and without a
due appreciation of the causes which underlie great folk-movements.

(ii) Insistence on Institutes of Anthropology.

The anthropological problems of the present day are so numerous
and so pressing that we can afford to select those of the greatest
utility. Indeed, the three university institutes of anthropology I have
suggested would have to specialise and then work hard to keep abreast
of the problems which will crowd upon them. One might take the
European races, another Asia and the Pacific, and a third Africa.
America in anthropology can well look after itself. In each case we
need something on the scale of the Paris Ecole d’Anthropologie, with
its seventeen professors and teachers, with its museums and journals.
But we want something else—a new conception of the range of
problems to be dealt with and a new technique. From such schools
would pass out men with academic training fit to become officials,
diplomatic agents, teachers, missionaries, and traders in Europe, in
Asia, or in Africa, men with intelligent appreciation of and sympathy
with the races among whom they proposed to work.

But this extra-State work, important as it is, is hardly comparable
in magnitude with the intra-State work which lies ready to hand for
the anthropological laboratory that has the will, the staff, and the
equipment to take it up efficiently. In the present condition of affairs
it is only too likely that much of this work, being psychometric, will
fall into the hands of the psychologist, whereas it is essentially the
fitting work of the anthropologist, who should come to the task, it
fitly trained, with a knowledge of comparative material and of the
past history, mental and physical, of mankind, on which his present
faculties so largely depend. The danger has arisen because the anthro-
pometer has forgotten that it is as much his duty to measure the
human mind as it is his duty to measure the human body, and that it is
as much his duty to measure the functional activities of the human
body—its dynamical characters—as its statical characters. By dyna-
mical characters I understand such qualities as resistance to fatigue,
facility in physical and mental tasks, immunity to disease, excitability
under stimuli, and many kindred properties. If you tell me that we are
here trenching on the field of psychology and medicine, I reply: Cer-
tainly ; you do not suppose that any form of investigation which deals
with man—body or mind—is to be omitted from the science of man? If
you do you have failed to grasp why anthropology is the queen of the
sciences. The University anthropological institute of the future will

1920 u

146 SECTIONAL ADDRESSES.

have attached to it a psychologist, a medical officer, and a biologist.
They are essential portions of its requisite staff, but this is a very
different matter from lopping off large and important branches of its
fitting studies, to lie neglected on the ground, or to be dragged away,
as dead wood, to be hewn and shapen for other purposes by scientific
colleagues in other institutes. Remember that I am emphasising that
side of anthropology which studies man in the service of the State—
anthropology as a utile science—and that this is the only ground
on which anthropology can appeal for support and sympathy from
State, from municipality, and from private donors. You will notice
that I lay stress on the association of the anthropological institute
with the university, and the reasons for this are manifold. In the
first place, every science is stimulated by contact with the workers in
allied sciences; in the second place, the institute must be a teaching
as well as a researching body, and it can only do this effectively in
association with an academic centre—a centre from which to draw
its students and to recruit its staff. In the third place, a great university
provides a wide field for anthropometric studies in its students and
its staff. And the advantages are mutual. It is not of much service
to hand a student a card containing his stature, his weight, his eye
colour, and his head length! Most of these he can find out for himself !
But it is of importance to him to know something of how his eye, heart,
and respiration function ; it is of importance to him to know the general
character of his mental qualities, and how they are associated with
the rapidity and steadiness of muscular responses. Knowledge on
these points may lead him to a fit choice of a career, or at any rate
save him from a thoroughly bad. choice.

In the course of my life I have often received inquiries from school-
masters of the following kind: We are setting up a school anthropo-
metric laboratory, and we propose to measure stature, weight, height
sitting, &c. Can you suggest anything else we should measure?

My invariable reply is: Don’t start measuring anything at all until,
you have settled the problems you wish to answer, and then just
measure the characters in an adequate number of your boys, which
will enable you to solve those problems. Use your school as a labora-
tory, not as a weighhouse.

And I might add, if I were not in dread of giving offence: And
most certainly do not measure anything at all if you have no problem
to solve, for unless you haye you cannot have the true spirit of the
anthropologist, and you will merely increase that material up and down
in the schools of the country which nobody is turning to any real use.

Which of us, who is a parent, has not felt the grave responsibility
of advising a child on the choice of a profession? We have before us,
perhaps, a few meagre examination results, an indefinite knowledge
of the self-chosen occupations of the child, and perhaps some regard
to the past experience of the family or clan. Possibly we say John is
good with his hands and does not care for lessons; therefore he should
be an engineer. That may be a correct judgment if we understand
by engineer, the engine-driver or mechanic. It is not true if we think of
the builders of Forth Bridges and Avsuan Dams. Such men work

‘H.—-ANTHROPOLOGY. 147

with the head and not the hand. One of the functions of the anthro-
pological laboratory of a great university, one of the functions of a
school anthropometric laboratory, should be to measure those physical
and mental characters and their inter-relations upon which a man’s
success in a given career so much depends. Its function should be to
guide youth in the choice of a calling, and in the case of a school to
enable the headmaster to know something of the real nature of indi-
vidual boys, so that that much-tried man does not feel compelled to
hide his ignorance by cabalistic utterances when parents question him
on what their son is fitted for.

Wide, however, as is the anthropometric material in our universities
and public schools, it touches only a section of the population. The
modern anthropologist has to go further; he has to enter the doors of
the primary schools; he has to study the general population in all its
castes, its craftsmen, and its sedentary workers. Anthropology has to
be useful to commerce and to the State, not only in association with
foreign races, but still more in the selection of the right men and women
for the staff of factory, mine, office, and transport. ‘The selection of
workmen to-day by what is too often a rough trial and discharge method
is one of the wasteful factors of production. Few employers even ask
what trades parents and grandparents have followed, nor consider the
relation of a man’s physique and mentality to his proposed employment.
T admit that progress in this direction will be slow, but if the work
undertaken in this sense by the anthropologist be well devised, accurate,
and comprehensive, the anthropometric laboratory will gradually obtain
an assured position in commercial appreciation. As a beginning, the
anthropologist by an attractive museum, by popular lectures and demon-
strations, should endeavour to create, as Sir Francis Galton did at
South Kensington, an anthropometric laboratory frequented by the
general population, as well as by the academic class. Thus he will
obtain a wider range of material. But the anthropologist, if he is to
advance his science and emphasise its services to the State, must pass
beyond the university, the school, and the factory. He must study
what makes for wastage in our present loosely organised society; he
must investigate the material provided by reformatory, prison, asylums
for the insane and mentally defective; he must carry his researches into
the inebriate home, the sanatorium, and the hospital, side by side with
his medical collaborator. Here is endless work for the immediate
future, and work in which we are already leagues behind our American
colleagues. For them the psychometric and anthropometric laboratory
attached to asylum, prison, and reformatory is no startling innovation,
to be spoken of with bated breath. It is a recognised institution of the
United States to-day, and from such laboratories the ‘ fieldworkers ’
pass out, finding out and reporting on the share parentage and environ-
ment have had in the production of the abnormal and the diseased, of
the anti-social of all kinds. Some of this work is excellent, some in-
different, some perhaps worthless, but this will always be the case in the
expansion of new branches of applied science. The training of the
workers must be largely of an experimental character, the technique has
to be devised as the work develops. Instructors and directors have to be

L 2

148 SECTIONAL ADDRESSES.

appointed, who have not been trained ad hoc. But this is remedying
itself, and if indeed, when we start, we also do not at first limp some-
what lamely along these very paths, it will only be because we have
the advantage of American experience.

There is little wonder that in America anthropology is no longer the
stepchild of the State. It has demanded its heritage, and shown that
it can use it for the public good.

Tf I have returned to my first insistence that the problems handled
by the anthropologist shall be those useful to the State, it is because
I have not seen that point insisted upon in this country, and it is
because my first insistence, like my third, involves the second for its
effectiveness—the establishment in our chief universities of anthro-
pological institutes. A's Gustay Schwalbe said of anthropology in 1907
—and he was a man who thought before he spoke, and whose death
during the war is a loss to anthropologists the whole world over— a
lasting improvement can only arise if the State recognises that anthro-
pology is a science pre-eminently of value to the State, a science which
not only deserves but can demand that chairs shall be officially estab-
lished for it in every university. . . Only this spread of officially
authorised anthropology in all German universities can enable it to fulfil
its task, that of trainmg men who, well armed with the weapon of
anthropological knowledge, will be able to place their skill at the service
of the State, which will ever have need of them in increasing numbers.’ ®

Our universities are not, as in Germany, Government-controlled
institutions, although such control is yearly increasing. Here we have
first to show that we are supporting the State before the State somewhat
grudgingly will give its support to us. Hence the immediate aim of the
anthropologist should be—not to suggest that the State should a priori
assist work not yet undertaken, but to do what he can with the limited
resources in his power, and when he has shown that what he has
achieved is, notwithstanding his limitations, of value to the State, then
he is in a position to claim effective support for his science.

I have left myself little time to place fairly before you my third
insistence.

(iii) Insistence on the Adoption of a New Technique.

What is it that a young man seeks when he enters the university—
if we put aside for a moment any social advantages, such as the forma-
tion of lifelong friendships associated therewith? He seeks, or ought
to seek, training for the mind. He seeks, or ought to seek, an open
doorway to a calling which will be of use to himself, and wherein he
will take his part, a useful part, in the social organisation of which
he finds himself a member. Much as we may all desire it, in the
pressure of modern life, it is very difficult for the young man of moderate
means to look upon the university training as something apart from
his professional training. Men more and more select their academic
studies with a view to their professional value.. Wecan no longer com-
bine the senior wranglership with the pursuit of a. judgeship; we cannot

§ Correspondenz Blatt, Jahrg, xxxyiil., 8. 68.

“ge _ .H.— ANTHROPOLOGY: 149

pass out in the classical tripos and aim at settling down in life as a
Harley Street consultant; we cannot take a D.Sc. in chemistry as a
preliminary to a journalistic career. It is the faculties which provide
professional training that are crowded, and men study nowadays physics
or chemistry because they wish to be physicists or chemists, or seek by
their knowledge of these sciences to reach commercial posts. Even the
very Faculty of Arts runs the danger of becoming a professional school
for elementary school teachers. I do not approve this state of affairs; I
would merely note its existence. But granted it, what does anthro-
pology offer to the young man who for a moment considers it as a
possible academic study? ‘There are no professional posts at present
open to him, and few academic posts.* ‘There is little to attract the
young man to anthropology as a career. Is its position as a training
of mind any sironger? The student knows if he studies physics or
chemistry or engineering that he will obtain a knowledge of the prin-
ciples of observation, of measurement, and of the interpretation of data,
which will serve him in good stead whenever he has to deal with pheno-
mena of any kind. But, alas! in anthropology, while he finds many
things of surpassing interest, he discovers no generally accepted methods
of attacking new problems, quot homines, tot sententie. The type of
man we want in anthropology is precisely the man who now turns to
mathematics, to physics, and to astronomy—the man with an exact
mind who will not take statements on authority and who believes in
testing all things. To such a man anthropometry—in all its branches,
craniometry, psychometry, and the wide field in which body and mind
are tested together under dynamic conditions—forms a splendid training,
provided his data and observations are treated as seriously as those of
the physicist or astronomer by adequate mathematical analysis. Such a
type of man is at once repelled from our science if he finds in its
text-books and journals nothing but what has been fitly termed ‘ kinder-
garten arithmetic.’ Why, the other day I saw in a paper by a dis-
tinguished anthropologist an attempt to analyse how many individual
bones he ought to measure. Headopted the simple process of comparing
the results he obtained when he took 10, 20, 30 individuals. He was
not really wiser at the end of his analysis than at the beginning, though
he thought he was. And this, notwithstanding that the whole matter
had been thrashed out scientifically by John Bernoulli two centuries
ago, and that its solution is a commonplace of physicist and astronomer !

How can we expect the scientific world to take us seriously and
to treat anthropology as the equal of other sciences while this state
of affairs is possible? What discipline in logical exactness are we
offering to academic youth which will compare with that of the older
sciences? What claim have we to advise the State until we have intro-
duced a sounder technique and ceased to believe that anthropometry is
a science that any man can follow, with or without training? As I
have hinted, the problems of anthropology seem to me as subtle as

® In London, for example, there is a reader in physical anthropology who is
a teacher in anatomy, and a professorship in ethnology, which for some
mysterious reason is included in the faculty of economics and is, I believe, not
a full-time appointment. :

150 SECTIONAL ADDRESSES,

those of physical astronomy, and we are not going to solve thei with
rusty weapons, nor solve them at all unless we can persuade the
“brainy boys ’ of our universities that they are worthy of keen minds.
Hence it seems to me that the most fertile training for academic pur-
poses in anthropology is that which starts from anthropometry in its
broadest sense, which begins to differentiate caste and class and race,
bodily and mental health and disease, by measurement and by the
analysis of measurement. Once this sound grounding has been reached
the trained mind may advance to ethnology and sociology, to prehistory
and the evolution of man. And I shall be surprised if equal accuracy
of statement and equal logic of deduction be not then demanded in
these fields, and I am more than half convinced, nay, I am certain,
that the technique the student will apply in anthropometry can be
equally well applied in the wider fields into which he will advance in
his later studies. Give anthropology a technique as accurate as that
of physics, and it will forge ahead as physics have done, and then
anthropologists will take their due place in the world of science and
in the service of the State.

Francis Galton has a claim upon the attention of anthropologists
which I have not. He has been President of your Institute, and he
spoke just thirty-five years ago from the chair I now occupy, pressing
on you for the first time the claims of new anthropological methods.
in Galton’s words: ‘ Until the phenomena of any branch of knowledge
have been submitted to measurement and number it cannot assume the
status and dignity of a Science.’ Have we not rather forgotten those
warning words, and do they not to some extent explain why our
universities and learned societies, why the State and statesmen, have
turned the cold shoulder on anthropology ? .

This condition of affairs must not continue; it is good neither for
anthropology, nor for the universities, nor for the State if this funda-
mental science, the science of man, remains in neglect. It will not
continue if anthropologists pull together and insist that their problems
shall not fail in utility, that their scientific technique shall be up to
date; and that anthropological training shall be a reality in our univer-
sities—that these shall be fully equipped with museums, with material,
with teachers and students.

it is almost as difficult to reform a science as it is to reform a
réligion; in both cases the would-be reformer will offend the sacrosanct
upholders of tradition, who find it hard to discard the faith in which
they have been reared. But it seems to me that the difficulties of our
time plead loudly for a broadening of the purpose and a sharpening of
the weapons of anthropology. If we elect to stand where we have
done a new science will respond to the needs of State and Society; it
will spring from medicine and psychology, it will be the poorer in
that it knows little of man’s development, little of his history or pre-
history. But it will devote itself to the urgent problems of the day.
The future lies with the nation that most truly plans for the future,
that studies most accurately the factors which will improve the racial
qualities of future generations either physically or mentally. Is
anthropology to lie outside this essential function of the science of .

: H.—ANTHROPOLOGY. 151
man? If I understand the recent manifesto of the German anthropo-
logists, they are determined it shall not be so. The war is at an end,
but the critical time will be with us again, I sadly fear, in twenty
to thirty years. How will the States of Hurope stand then? It
depends to no little extent on how each of them may have cultivated
the science of man and applied its teaching to the improvement of
national physique and mentality. Let us take care that our nation
is not the last) in this legitimate rivalry. The organisation of existing
human society with a view to its future welfare is the crowning task
of the science of man; it needs the keenest-minded investigators, the
most stringent technique, and the utmost sympathy from all classes
of society itself. Have we,-as anthropologists, the courage to face this
greatest of all tasks in the light of our knowledge of the past and
with our understanding of the folk of to-day? Or shall we assert that
anthropology is after all only a small part of the science of man, and
retreat to our study of bones and potsherds on the ground that science
is to be studied for its own sake and not for the sake of mankind? I
do not know what answer you will give to that question, yet I am
convinced what the judgment of the future on your answer is certain
to be. It will be similar to Wang Yang Ming’s reproof of the com-
placency of the Chinese cultured classes of his day: “Thought and
Learning are of little value, if they be not translated into Action.’

SECTION I: CARDIFF, 1920.

ADDRESS

TO THE

PHYSIOLOGICAL SECTION

J. BARCROFT, C.B.E., M.A., F.R.S.,
PRESIDENT OF THE SECTION.

ProMINENT among the pathological conditions which claimed attention
during the war was that of insufficient oxygen supply to the tissues, or
anoxemia. For this there were several reasons; on the one hand,
anoxeemia clearly was a factor to be considered in the elucidation of such
conditions as are induced by gas-poisoning, shock, &. On the other
hand, knowledge had just reached the point at which it was possible to
discuss anoxzemia on a new level. It is not my object in the present
address to give any account of war-physiology—the war has passed, and
I, for one, have no wish to revive its memories, but anoxemig remains,
and, as it is a factor scarcely less important in peace than in war
pathology, I think I shall not do wrong in devoting an hour to its
consideration.

The object of my address, therefore, will be to inquire, and, if pos-
sible to state, where we stand; to sift, if I can, the knowledge from
the half-knowledge; to separate what is ascertained as the result of
unimpeachable experiment from what is but guessed on the most likely
hypothesis. In war it was often necessary to act on defective informa-
tion, because action was necessary and defective information was the
best that was to be had. In this, as in many other fields of know-
ledge, the whole subject should be reviewed, the hypotheses tested ex-
perimentally, and the gaps filled in. The sentence which lives in my
mind as embodying the problem of anoxeemia comes from the pen of
one who has given more concentrated thought to the subject than per-
haps any other worker—Dr. J. §. Haldane. It runs, ‘ Anoxeemia. not
only stops the machine but wrecks the machinery.’ This phrase puts
the matter so clearly that I shall commence by an inquiry as to the
limits within which it is true.

Anything like complete anoxemia stops the machine with almost
incredible rapidity. It is true that the breath can be held for a con-
siderable time, but it must be borne in mind that the lungs have a
volume of about three litres at any moment, that they normally
contain about half a litre of oxygen, and that this will suffice for the
body at rest for upwards of two minutes. But get rid of the residual
oxygen from the lungs only to the very imperfect extent which is

1 See References, page 168.

I.— PHYSIOLOGY. 153

possible by the breathing of some neutral gas, such as nitrogen, and you
will find that only with difficulty will you endure half a minute. Yet
even such a test gives no real picture of the impotence of the machine
—which is the brain—to ‘ carry on’ in the absence of oxygen. For,
on the one hand, nearly a quarter of a minute elapses before the reduced
blood gets to the capillary in the brain, so that the machine has only
carried on for the remaining quarter of a minute; on the other hand,
the arterial blood under such circumstances is far from being com-
pletely reduced—in fact, it has very much the composition of ordinary
venous blood, which means that it contains about half its usual quotum
of oxygen. It seems doubtful whether complete absence of oxygen
would not bring the brain to an instantaneous standstill. So convincing
are the experimental facts to anyone who has tested them for himself
that I will not further labour the power of anoxemia to stop the
machine. I will, however, say a word about the assumption which I
have made that the machine in this connection is the brain.

It cannot be stated too clearly that anoxzemia in the last resort must
affect every organ of the body directly. Stoppage of the oxygen supply
is known, for instance, to bring the perfused heart to a standstill, to
cause a cessation of the flow of urine, to produce muscular fatigue, and
at last immobility, but from our present standpoimt these effects of
anoxemia seem to me to be out of the picture, because the brain is so
much the most sensitive to oxygen want. Therefore, if the problem is
the stoppage of the machine due to an insufficient general supply of
oxygen, I have little doubt that the machine stops because the brain
stops, and here at once I am faced with the question how far is this
assumption and how far is it proven fact? I freely answer that research
in this field is urgent; at present there is too great an element of assump-
tion, but there is also a certain amount of fact.

To what extent does acute anoxemia in a healthy subject wreck the
machinery as well as stop the machine? By acute anoxemia I mean
complete or almost complete deprivation of oxygen which, in the
matter of time, is too short to prove fatal. It is not easy to obtain
quite clear-cut experiments in answer to the above question. No
doubt many data might be quoted of men who have recovered from
drowning, &c. Such data are complicated by the fact that anoxemia
has only beer a factor in their condition; other factors, such as
accumulation of carbonic acid, may also have contributed to at.
The remarkable fact about most of them, however, is the slight-
ness of the injury which the machine has suffered. These data,
therefore, have a value in so far as they show that a very great degree
of anoxemia, if acute and of short duration, may be experienced with
but little wreckage to the machine. They have but little value in show-
ing that such wreckage is due to the anoxemia, because the anoxsemia
has not been the sole disturbance. Of such cases I will quote two.

The first is that of a pupil of my own who received a gunshot
wound in the head, to the prejudice of his cerebral circulation. I
can give you the most perfect assurance that neither intellectually
nor physically has the catastrophe which befell him caused any
permanent injury. For the notes of the case I am indebted to

154 SECTIONAL ADDRESSES.

Colonel Sir William Hale White. My pupil fell wounded at 6.50 a.m.’
on 20th of November 1917. As far as is known, he lay insensible
for about two hours. Picked up five hours after the wound, he
could not move either upper or lower extremity. Thirty-six hours
after the wound he underwent an operation which showed that the
superior sagittal sinus was blocked, happily not by a thrombus, but by
being torn and having pieces of the inner table of the skull thrust into
it, so that for this period of time the motor areas on both sides down
to the face area were asphyxiated, the right being much more affected
than the left. Six days after the wound the cerebration was still slow,
with typically vacant look.

In the left upper extremity the muscular power was much improved ;
he could raise his arm to his mouth, but he preferred to be fed.

In the right upper extremity there were no movements in the
shoulder, elbow, or wrist, but he could flex and extend the fingers
weakly.

In the left lower extremity there were fair movements of hip and

knee, no movements of ankle and toes.

In the right lower extremity there were no movements of hip, knee,
ankle, or toes.

Six weeks after the wound he first walked, although with difficulty ;
absolutely the last place in which the paresis remained was in the
muscles of the right toes. Four months after the injury these toes
were spread out and could not be brought together voluntarily.
Gradually this has become less, but even now, two and a-half years
later, all these muscles are weaker than those on the other side. ~~

Such, then, is the wreckage of the machine caused by thirty-six
hours’ blockage of the blood-flow through the motor areas of the brain;
wreckage enough but not irreparable.

I pass to the second case. It is that of the child of a well-known
Professor of Physiology and a first authority on the subject of respira-
tion. I am indebted to him for the following notes:

In this child, a male twin, born about twelve weeks too early; it was
noticed about twenty-four hours after birth that the breathing during
sleep was irregular and of a very pronounced Cheyne Stokes type, six to
ten breaths being followed by a pause during which no respiratory move-
ment occurred. Usually the pauses were of fifteen to twenty seconds’
duration, but occasionally (two to ten times a day) the breathing remained
suspended for a prolonged period, extending in some cases to ten and
fifteen minutes, and in one accurately observed case even to twenty-five
minutes, interrupted by one single breath and a cry about the middle of

the period. The breathing invariably started again before the heart-'

beats ceased.

Cases in which the anoxemia has been uncomplicated are to be
found among those who have been exposed to low atmospheric pres-
sures; for instance, balloonists and aviators. Of these quité a con-
siderable number have suffered from oxygen want to the extent of being
unconscious for short intervals of time.

No scientific observer has pushed a general condition of anoxeemia:
either on himself or on ‘his fellows to ths extent of complete unconscious-:

wwe dk

ay hemes

. 1—Prvsioioay. 155

ness. ‘The most severe experiments of this nature are those carried out
by Haldane and his colleagues. One experiment in particular demands
attention. Dr. Haldane and Dr, Kellas* together spent an hour in
a chamber in which the air was reduced to between 320 and 295 mm.
Tt is difficult to say how far they were conscious. Clearly each
believed the other to be complete master of his own faculties, but it is
evident that Dr. Haldane was not so. I gather that he has no recollec-
tion of what took place, that whenever he was consulted about the
pressure he gave a stereotyped answer which was the same for all
questions, that, even with a little more oxygen present, he was suffi-
ciently himself to wish to investigate the colour of his lips in the glass,
but msufficiently himself to be conscious that he was looking into the
back and not the front of the mirror. Dr. Kellas, who could make
observations, never discovered Dr. Haldane’s mental condition, though
boxed up with him for an hour, and went on consulting him auto-
matically. A somewhat similar experiment was performed on the other
two observers, with results differing only in degree.

Yet the after-effects are summed up in the following sentence:
“All four observers suffered somewhat from headache for several hours
after these experiments, but there was no nausea or loss of appetite.’

Of real importance in this connection are the results of carbon
monoxide poisoning. Of these a large number might. be cited. Those
interested will find some very instructive cases described in a volume
entitled ‘The Investigation of Mine Air,’ by the late Sir C. Le Neve
Foster and Dr. Haldane.* The cases in question were those of a
number of officials who went to investigate the mine disaster on
Snaefell, in the Isle of Man, in May 1897. Of the five cases cited all
suffered some after-effects, by which I mean that by the time the blood
was restored sufficiently to its normal condition for the tissues to get
the amount of oxygen which they required, the effects of the asphyxia
had not passed off and to this extent the machine suffered, e.g.

Mr. W. H. Kitto says: ‘On reaching terra firma I felt very ill and
wanted to vomit . . . through the night. I had severe palpitation of the heart,
a thing I have never felt in my life before or since. On the day following,
Thursday, the pain in my knees was so great that I could not stand properly,
and for fully a week I had great pain when walking, and still (a month
later) feel slight effects of the poisoning.’

_ Of the five whose experiences were given, the one who received the
most permanent damage was Sir Clement Foster himself.

_ A few days after I got back from the island the first time, about the
21st or 22nd of May, I noticed my heart; it could scarcely be called palpitation,
as 1 understand palpitations to be, for there did not seem to be any increased
ety of the action, but I was conscious of its beating; as a rule, I am not.
This passed off, and then on the Ist and 2nd of June I noticed it very decidedly

ain, 80 much so that I went to my doctor. He sounded me, and said the
heart was all right, though there was one sound which was not very distinct.

is consciousness of having a heart still returns from time to time, though’
only to a slight extent. On the 19th May I suffered much from headache, not
pgularly, but intermittently. The headache lasted for several days, and the
feeling in the legs was very apparent; it was an aching in the legs from the
knees to the ankles. A coldness from the knees to the soles of the feet
wag ‘also noticeable; it came on occasionally for a considerable time. The

156. SECTIONAL ADDRESSES,

headaches continued at intervals for some time, and lasted certainly for some:
months after the accident; indeed, I cannot say that they have disappeared
altogether.

To sum up, then, what may be said of the permanent damage caused
by acute anoxemia, it seems to me to be as follows: No degree of
anoxemia which produces a less effect than that of complete uncon-
sciousness leaves anything more than the most transient effects; if the
anoxeemia be pushed to the point at which the subject is within a
measurable distance of death, the results may take days or weeks to get
over, but only in the case of elderly or unsound persons is the machine
wrecked beyond repair.

Chronic Anozemia.

And now to pass to the consideration of what I may call chronic
anoxemia ; that is to say, oxygen want which perhaps is not very great
in amount—and I shall have to say something later about the measure-
ment of anoxeemia in units—but which is continued over a long time:
weeks, months, or perhaps years. We have to ask ourselves, how far
does chronic anoxeemia stop the machinery; how far does it wreck the
machine? Here we are iaced with a much more difficult problem, for
the distinction between stopping the machinery and wrecking the
machine tends to disappear. In fact so indistinct does it become that
you may ask yourself, with some degree of justice, does chronic
anoxemia stop the machine in any other way than by wrecking it?

The most obvious instances of men subject to chronic anoxemia
are the dwellers at high altitudes. Now, it is quite clear that in many
instances of mountain-dwellers the anoxemia does not wreck the
machine. On what I may call the average healthy man anoxemia
begins to tell at about 18,000 feet. At lower altitudes no doubt he
will have some passing trouble, but it seems to me from my own
experience that this altitude is a very criticalone. Yet there are mining
camps at such heights in South America at which the work of life
is carried on. Under such circumstances the machine is kept going
by a process Of compensation. ‘This is in part carried out by a modifi-
cation in the chemical properties of the blood. It would appear that
both the carbonic acid in the blood and the alkali diminish. The
result, according to my interpretation of my own observations on the
Peak of Teneriffe, which appeared to be confirmed by the experi-
ments in a chamber in Copenhagen* from which the air was partially
exhausted, was this: The hydrogen ion concentration of the blood
increased slightly, the respiratory centre worked more actively, and the
lung became better ventilated with oxygen, with the natural result that.
the blood became more oxygenated than it would otherwise have been.

The difference which this degree of acclimatisation made was very
great. Take as an example one of my colleagues, Dr. Roberts. On
Monte Rosa in his case, as in that of the rest of the party, 15 mm. of
oxygen pressure were gained in the lungs. To put the matter another
way, the amount of oxygen in our lungs at the summit was what it
would otherwise have been 5,000 or 6,000 feet lower down. No actual
analyses of the oxygen in Roberts’ arterial blood were made, but from
what we now know it seems probable that his blood was about 82 per

I.—PHYSIOLOGY. 157

cent. saturated; that is to say, that for every hundred grams of
hemoglobin in the blood 82 were oxyhemoglobin and 18 reduced
hemoglobin ; had this degree of acclimatisation not taken place his blood
would have contained as many as 38 parts of unoxidised hemoglobin
out of every hundred, and this would probably have made all the differ-
ence between the machine stopping and going on.

The body, then, had fought the anoxeemia and reduced it very much
in degree, but at the same time the anoxemia had, in a subtle way,
done much to stop the powers of the body, for this very acclimatisation
is effected at the expense of the ultimate reserve which the body has
at its disposal for the purpose of carrying out muscular or other work.
The oxygen in the lungs was obtained essentially by breathing at rest
as you would normally do when taking some exercise. Clearly, then, if
you are partly out of breath before you commence exercise you cannot
undertake so much as you otherwise would do. As a friend of mine,
who has, I believe, camped at a higher altitude than any other man,
put it to me, ‘ So great was the effort that we thought twice before we
turned over in bed.’

One of the interesting problems with regard to chronic anoxemia
is its effect upon the mind. Working from the more acute type of
anoxeemia to the more chronic, the following quotation will give an
account of the condition of a person in the acute stage. It is Sir
Clement Le Neve Foster’s account of himself during CO poisoning, and
shows loss of memory, some degree of intelligence, and a tendency to
repeat what is said:

How soon I realised that, we were in what is commonly called ‘a tight place’
1 cannot say, but eventually, from long force of habit, I presume, I took out
my note-book. At what o'clock I first began to write I do not. know, for
the few words written on the first page have no hour put to them. They were
simply a few words of good-bye to my family, badly scribbled. The next page
is headed ‘2 p.m.,’ and I perfectly well recollect taking out my watch from
time to time. As a rule I do not take a watch underground, but I carried
it on this occasion in order to be sure that I left the rat long enough when
testing with it. In fact, my note on the day of our misadventure was
“Sth ladder. Rat two minutes at man,’ meaning by the side of the corpse.
My notes at 2 p.m. were as follows: ‘2 p.m., good-bye, we are all dying, your
Clement, I feel we are dying, good-bye, all my darlings all, no help coming, good-
bye we are dying, good-bye, good-bye we are dying, no help comes, good-bye,
good-bye.” Then later, partly scribbled over some ‘ good-byes’ I find, ‘We
saw a body at’ 1.30 and then all became affected by the bad air, we have got tothe
115 and can get no further, the box does not come in spite of our ringing for help.
It does not come, does not come—I wish the box would come. Captain R. is
shouting. my legs are bad, and I feel very1, my knees are 1.’ The so-called
‘ringing’ was signalling to the surface by striking the air-pipe with a hammer
or bar of iron. We had agreed upon signals before we went down. There is
writing over other writing, as if I did not see exactly where I placed my
pencil, and then: ‘I feel as if I were dreaming, no real pain, good-bye,
good-bye, I feel as if I were sleeping.’ ‘2.15 we are all done. No 1, or
searcely any, we are done, we are done, godo-bye my darlings.’ Here it is
rather interesting to note the ‘ godo’ instead of ‘good.’ Before very long the
fresh men who had climbed down to rescue us seemed to have arrived, and
explained that the ‘box’ was caught in the shaft. Judging by my notes I did
not realise thoroughly that we should be rescued. Among them occur the words
“No pain, it is merely like a dream, no pain.” TI frequently wrote the same
sentence over and over again. My last note on reaching the surface tells of

1 in the above quotation indicates an illegible word in the notes,

158 SECTIONAL ADDRESSES.

that resistance to authority which likewise appears to be a symptom of the
poisoning.

These notes afford ample confirmation of the effect produced by carbonic
oxide poisoning of causing reiteration, I wrote the same words over and over
again unnecessarily. The condition I was in was rather curious. JT had
absorbed enough of the poison to paralyse me to a certain extent and dull my
feelings, but at the same time my reason had not left me.

The whole train of symptoms strongly suggests some form of
intoxication, and is not dissimilar to that produced by alcoholic excess.
Here it may be noted that, as far as isolated nerves are concerned, there
is pretty good evidence that alcohol and want of oxygen produce
exactly the same effects, i.e. they cause a decrement in the conducting
power of the nerve. And herein lies a part of its interest, for pharma-
cologists of one school at all events tell me that the corresponding
effects of alcohol are really due to an inhibition of the higher centres of
the mind; you can therefore conceive of the mental mechanism of self-
control being knocked out either because it has not oxygen enough with
which to ‘carry on,’ or because it is drugged by some poison as a
secondary result of the anoxeemia.

And now to pass to the results of more chronic anoxemia. If I
were to try to summarise them in a sentence I should say that, just as
acute anoxemia simulates drunkenness, chronic anoxemia simulates
fatigue.

The following slide shows you a photograph taken from a page in
my note-book written at the Alta Vista Hut, at an altitude of 12,000
feet. You will see that the page commences with a scrawl which is
crossed out, then ‘6 Sept.,’ the word ‘ Sept.’ is crossed out and
‘March ’ is inserted, ‘March’ shares the same fate as ‘ Sept.,’ and
“ April,’ the correct month, is substituted, and so on, more crossings
out and corrections. All this you might say with justice is the action
of a tired man. The other pages written at lower altitudes do not,
however, bear out the idea that I was out of health at the time, and
there was no reason for tiredness on that particular day. . Another
symptom frequently associated with mental fatigue is irritability.
Anyone who has experience of high altitudes knows to his cost that life
does not run smoothly at 10,000 feet. If the trouble is not with one’s
own temper, it is with those of one’s colleagues: and so it was in many
cases of gas-poisoning and in the case of aviators. In these subjects
the apparent fatigue sometimes passed into a definitely neurasthenic
condition. At this point an issue appeared to arise between the
partisans of two theories. One camp said that the symptoms. were
definitely those of anoxeemia, the other that they were due to nerve
strain. As I have indicated later on, it is not clear that these tw6
views are mutually exclusive. It takes two substances to make an
oxidation, the oxygen and the oxidised material. If the oxidation does
not take place, the cause may lie in the absence of either or of both, in
each case with a similar effect. The subject really is not ripe for
controversy, but it is amply ripe for research, research in which both
the degree of anoxemia and the symptoms of fatigue are clearly
defined.

So much, then, for the injury to the machine wrought by chronic
anoxemia.

I.— PHYSIOLOGY. 159

Types of Anoxemia.

And now to pass to the consideration of the various types of
anoxeemia.

Anozemia is by derivation want of oxygen in the blood.

Suppose you allow your mind to pass to some much more homely
substance than oxygen—such, for instance, as milk—and consider the
causes which may conspire to deprive your family of milk, three
obvious sources of milk deficiency will occur to you at once:

(1) There is not enough milk at the dairy;

(2) The milk is watered or otherwise adulterated so that the fluid
on sale is not really all milk; and

(3) The milkman from that particular dairy does not come down your
road.

These three sources of milk deficiency are typical of the types of
oxygen deficiency.

The first is insufficient oxygen dispensed to the blood by the lungs.
An example of this type of anoxeemia is mountain-sickness. The
characteristic of it is insufficient pressure of oxygen in the blood. In
mountain-sickness the insufficiency of pressure in the blood is due to
insufficient pressure in the air, for, according to our view at all events,
the pressure in the blood will always be less than that in air. But
this type of anoxemia may be due to other causes. The sufferer may
be in a normal atmosphere, yet for one reason or another the air may
not have access to his whole lung. In such cases, either caused by
obstruction, by shallow respiration, or by the presence of fluid in the
alveoli, the blood leaving the affected areas will contain considerable
quantities of reduced hemoglobin. This will mix with blood from un-
affected areas which is about 95 per cent. saturated. The oxygen will
then be shared round equally among the corpuscles of the mixed blood,
and if the resultant is only 85-90 per cent. saturated the pressure of
oxygen will only be about half the normal, and, as I said, deficiency of
oxygen pressure is the characteristic of this type of anoxemia.

The second type involves no want of oxygen pressure in the arterial
blood ; it is comparable to the watered milk: the deficiency is really in
the quality of the blood and not in the quantity of oxygen to which the
blood has access. The most obvious example is anemia, in which
from one cause or other the blood contains too low a percentage of
hemoglobin, and because there is too little hemoglobin to carry the
oxygen too little oxygen is carried. Anemia is, however, only one
example which might be given of this type of anoxeemia. There may
be sufficient hemoglobin in the blood, but the hemoglobin may be
useless for the purpose of oxygen transport; it may be turned in part
into methemoglobin, as in several diseases, e.g. among workers in the
manufacture of some chemicals, and in some forms of dysentery con-
tracted in tropical climates, or it may be monopolised by carbon
monoxide, as in mine-air.

Thirdly, the blood may have access to sufficient oxygen and may
contain sufficient functional hemoglobin, but owing to transport trouble
it may not be circulated in sufficient quantities to the tissues. The
quantity of oxygen which reaches the tissue in unit time is too small.

160 SECTIONAL ADDRESSES.
Literally, according to the strict derivation of the word ‘ anoxeemia,’
the third type should perhaps be excluded from the category of con-
ditions covered by that word, but, as the result is oxygen starvation
in the tissues, it will be convenient to include it. Indeed, it would be
an act. of pedantry not to do so, for no form of anoxemia has any
significance apart from the fact that it prevents the tissues from obtain-
ing the supply of oxygen requisite for their metabolic processes.

The obvious types of anoxeemia may therefore be classified in some
such scheme as the following, and, as it is difficult to continue the dis-
cussion of them without some sort of nomenclature, I am giving a name

to each type:

ANOX MIA,

1. Anowic Type.

The pressure of oxygen
in the blood is too low.
The hemoglobin is not
saturated to the normal
extent.
The blood is dark.
“Examples :
1. Rare atmospheres.
2. Areas of lung par-
tially unventilated.
3. Fluid or fibrin on
surface of cells.

2. Anemic Type.

The quantity of functional
hemoglobin is _ too
small.

The oxygen pressure is
normal.

The blood is normal in
colour.
Examples:

1. Too little
globin.

2. CO hemoglobin.

3. Methemoglobin.

hemo-

1
3. Stagnant Type.

The blood is normal, but
is supplied to the
tissues in. insufficient
quantities.

Examples:
1. Secondary result of
histamine shock.
2. Hemorrhage.
3. Back pressure:

Anoxic anoxemia is essentially a general as opposed to a local con-
dition. Not only is the pressure of oxygen in the blood too low, but
the lowness of the pressure and not the deficiency in the quantity is
the cause of the symptoms observed.

Proof of the above statement is to be found in the researches of most
workers who have carried out investigations at low oxygen pressures,
and it can now be brought forward in a much more convincing way than
formerly that oxygen secretion is, for the time at all events, not a
factor to be counted with.

The workers on Pike’s Peak, for instance, emphasised the fact that
the increase of red blood corpuscles during their residence at 14,000 feet
was due to deficient oxygen pressure. No doubt they were right, but
the point was rather taken from their argument by their assertion in
another part of the paper that the oxygen pressure in their arterial blood
was anything up to about 100 mm. of mercury. Let me therefore
take my own case, in which the alveolar pressures are known to be an
index of the oxygen pressures in the arterial blood. I will compare my
ccndition on two occasions, the point. being that on these two occasions
the quantities of oxygen united with the hemoglobin were as nearly as
may be the same, whilst the pressures were widely different.

As I sit here the hemoglobin value of my blood is 96-97, which
corresponds to an oxygen capacity of ‘178 c.c. of O, per c.c. of blood.
In the oxygen chamber on the last day of my experiment, to which I
refer later,® the oxygen capacity of my blood was ‘201 c.c. Assuming
the blood to be 95 per cent. saturated now and 84 per cent. saturated

1.—PHYSIOLOGY. 161

then, the actual quantity of oxygen in the blood on the two occasions
would be:

Oxygen Capacity. Percentage Saturation. Oxygen Content.
“178 95 "169
201 84 “169

Here, I am in my usual health. In the chamber, I vomited; my
pulse was 86—it is now 56; my head ached in a most distressing fashion,
it was with the utmost difficulty that I could carry out routine gas
analyses, and when doing so the only objects which I saw distinctly
were those on which my attention was concentrated.

In the anoxic type of anoxeemia there may then be quite a sufficient
quantity of oxygen in the blood, but a sufficient quantity does not avail
in the face of am insufficient pressure. Indeed, as I shall show
presently, the anoxic type of anoxemia is the most serious. We are
therefore confronted with something of a paradox in that the mosi
severe type of anoxemia is one in which there is not necessarily an
insufficient quantity of oxygen in the blood at all.

And here let me justify fhe statement that the anoxic type is the
most to be feared. I can justify it on either or both of two grounds.
Firstly, of the three types it places the tissues at the greatest disadvan-
tage as regards oxygen supply, and secondly, it is of the three the least
easy type for the organism to circumvent.

Let me dwell for a moment upon the efficiency of the blood as a
medium for the supply of oxygen to the tissue in the three types. The
goal of respiration is to produce and maintain as high an oxygen pres-
sure in the tissue fluids as possible. For the velocity of any particular
oxidation in the tissues must depend upon the products of the concen-
trations (active masses) of the material to be oxidised and of the oxygen.
Now the concentration of oxygen in the tissue is proportional to its
partial pressure, and the highest partial pressure in the tissue must,
other things being equal, be the result of that type of anoxeemia in
which there is the highest partial pressure in the blood plasma.

It is interesting and not uninstructive to try to calculate the degree
to which the tissues are prejudiced by being subjected to various types
of anoxeemia. Let us suppose that we have a piece of tissue, muscle for
instance, which normally is under the following conditions :

(a) One cubic centimetre of blood per minute runs through it.
(b) The total oxygen capacity of this blood is 188 c.c. of oxygen
per c.c. of blood.

(d) The oxygen pressure is 100 mm.

(e) The oxygen used is 059 c.c.

(f) The oxygen pressure in the tissues is half of that in the veins,
in this case 19 mm.

Compare with this a severe case of anoxic anoxemia, one in which
the blood-flow is the same as above, and also the oxygen capacity value
of the blood, but in which the oxygen pressure is only 31 mm. and the
percentage saturation of the arterial blood 66 per cent. Let us further

retain the assumption that the oxygen pressure in the tissues is half
1920 , M

162 SECTIONAL ADDRESSES.

that in the veins. It is possible to calculate, as indeed has been done
by my colleague, Mr. Roughton, what the amount of oxygen leaving
the capillaries is. The answer is not ‘059, as in the case of the normal,
but ‘026—less than half the normal. So, other things being equal,
cutting down the oxygen pressure in the arterial blood to 31 and the
percentage saturation to 66 would deprive the tissues of half. their
oxygen. With this compare an example of the anemic type. The
arterial blood shall have the same total quantity of oxygen as in the
anoxic case, but instead of being 66 per cent. saturated it shall contain
66 per cent. of the total hemoglobin, which shall be normally saturated.
The amount of oxygen which would pass to the tissues under these
conditions is ‘041 c.c.—more than half as much again as from the
anoxic blood laden with the same quantity of oxygen.

And thirdly, let us take for comparison a case of stagnant anoxeemia
in which the same quantity of oxygen goes to the tissue in the cubic
centimetre of blood as in the anoxic and anemic types. On the assump-
tion which we have made the quantity ie oxygen which would leave
the blood would be °045 c¢.c.

In round numbers therefore the ot to the tissues may be
expressed by the following comparison. In this case both of the
oxygen going to the blood and going into the tissues I have called the
normal 100. This does not, of course, mean that the two amounts are
the same: The former in absolute units is about three times the latter.
The figure 100 at the top of each column is merely a standard with
which to compare the figures beneath it.

Oxygen in blood going Oxygen leaving the blood
to vessels of tissue. to supply the tissues.
Per cent, Per cent.
Normal 5 - 5 ; 100 100
Anoxic . : 66 42
Anoxamin | Anemic . ¢ 66 66
Stagnant . F 66 75

Measurement of Anoxemia.

In the study of all physical processes there comes a point, and that
very early, when it becomes necessary to compare them one with
another, to establish some sort of numerical standard and have some
sort of quantitative measurements. The study of anoxemia has reached
that point. By what scale are we to measure oxygen want?

Let us take the anoxic type first. There are two scales which
might be applied to it, both concern the arterial blood; the one is the
oxygen pressure in it, the other is the actual percentage of the hemo-
globin which is oxyhemoglobin. A third possibility suggests itself,
namely, the actual amount of oxygen present, but this would be in-
fluenced as much by the anemic as by the anoxic conditions. Of the
two possibilities—that of measuring the pressure, and that of measuring
the saturation of the blood with oxygen—the latter is the one which is
likely to come into vogue, because it is susceptible of direct measurement.

Two conyerging lines of work have within the last few years brought
us nearer to being able to state the degree of anoxeemia in man in terms
of the percentage saturation of oxygen in his blood. The first,. intro-

I.— PHYSIOLOGY. 163

duced by the American researcher Stadie,* is the method of arterial
puncture. It had long been the wish of physiologists to make direct
examinations of the gases in human arterial blood, yet, as far as I know,
this had only once been accomplished, namely, ‘by Dr. Arthur Cooke
and myself in a case in which the radial artery was opened for the pur-
pose of transfusion. But the matter now seems to be relatively
simple. The needle of a hypodermic syringe can be put right into the
radial artery and arterial blood withdrawn. I am not sure that the
operation is less painful than that of dissecting out the radial artery
and opeuing it—and in this matter I speak with experience—but it is
less alarming, and it has the great merit that it does not injure the
artery.

Another method of determining the percentage saturation of arterial
Blood has invited the attention of researchers, appearing like a will-
o’-the-wisp, at one time within grasp, at another far off. That method
is to deduce the percentage saturation from the composition of the
alveolar air. Into the merits of the rival methods for the determina-
tion of the oxygen in alveolar air I will not go: the method of Haldane
and Priestley will suffice for persons at rest. Granted, then, that a
subject has a partial pressure of 50 mm. of oxygen in his alveolar air,
what can we infer as regards his arterial blood? A long controversy has
raged about whether or no any assumption could be made about the
condition of the arterial blood from that of the alveolar air, for it was
an article of faith with the school of physiologists which was led by
Haldane that when the oxygen pressure in the alveolar air sank, the
oxygen in the arterial blood did not suffer a corresponding reduction.
The experimental evidence at present points in the opposite direction,
and unless some further facts are brought to light it may be assumed
that the oxygen pressure in the arterial blood of a normal person at
rest is some five millimetres below that in his alveolar air. And having
obtained a figure for the pressure of oxygen in the arterial blood, where
do we stand as regards the percentage of saturation? The relation
between the one and the other is known as the oxygen dissociation
curve. It differs but slightly in normal individuals, and at different
times in the same individual. To infer the percentage saturation from
the oxygen pressure, no doubt the actual dissociation curve should be
determined, but in practice it is doubtful whether as a first approxi-
mation this is necessary, for a curve determined as the result of a few
observations is unlikely to be much nearer the mark than a standard
curve on which twenty or thirty points have been determined.
Therefore an approximation can be made for the percentage saturation
as follows: In a normal individual take the oxygen in the alveolar air,
subtract five millimetres, and lay the result off on the mean dissociation
curve for man.

Whether measured directly or juarentae the answer is a statement
of the relative quantities of oxyhemoglobin and. of reduced hemoglobin
in the arterial blood. The important thing is that there should be as
little reduced hemoglobin as possible. The more reduced hemoglobin
there is present the less saturated is the blood, or, as the American
authors say, the more unsaturated is the blood. | They emphasise

164 SECTIONAL ADDRESSES.

the fact that it is the quantity of reduced hemoglobin that is the index
of the anoxic condition. They speak not of the percentage saturation,
but of the percentage of unsaturation. A blood which would ordinarily
be called 85 per cent. saturated they speak of as 15 per cent. unsaturated.

Anoxic anoxemia, in many cases of lung affection, should be
measured by the direct method of arterial puncture, for the simple
reason that the relation between the alveolar air and the arterial blood
is quite unknown. Such, for instance, are cases of many lung lesions
of pneumonia in which the lung may be functioning only in parts, of
pneumothorax, of pleural effusions, of emphysema, of multiple pul-
monary embolism, in phases of which the arterial blood has been found
experimentally to be unsaturated. In addition to these definite lung
lesions, there is another type of case on which great stress has been
laid by Haldane, Meakins, and Priestley, namely, cases of shallow
respiration.? A thorough investigation of the arterial blood in such
cases is urgently necessary. Indeed, in all cases in which it is prac-
ticable, the method of arterial puncture is desirable. But in the cases
of many normal persons—as, for instance, those airmen at different
altitudes—alveolar-air determinations would give a useful index.

The anemic type of anoxemia is gauged by the quantity of oxy-
hemoglobin in the blood. In the case of simple anemias this is
measured by the scale in which the normal man counts as 100 and the
hemoglobin in the anemic individual is expressed as a percentage of
this. This method has been standardised carefully by Haldane, and we
now know that the man who shows 100 on the scale has an oxygen
capacity of 185 c.c. of oxygen for every c.c. of blood. We can therefore,
in cases of carboxyhemoglobin, or methemoglobin poisoning, express
the absolute amount of oxyhemoglobin pressure either by stating the
oxygen capacity and so getting an absolute measurement, or in relative
units by dividing one hundred times the oxygen capacity by °185, and
thus getting a figure on the ordinary hemoglobin metre scale.

The Mechanism of Anoremia.

Perhaps the most difficult phase of the discussion is that of how
anoxeemia produces its baneful results. In approaching this part of
the subject I should like to warn my readers of one general principle
the neglect of which seems to be responsible for a vast dissipation of
energy. Before you discuss whether a certain effect is due to cause A or
cause B, be clear in your own mind that A and B are mutually exclusive.

Let me take an example and suppose

(1) That the energy of muscular contraction in the long run
depends in some way on the oxidation of sugar ;

(2) That in the absence of an adequate supply of oxygen the
reaction

C.H,,0, +.6 0,=6 CO,+ 6 H,0

cannot take place in its entirety ;
(3) That under such circumstances some lactic acid is formed as
well as carbonic acid;

f,
‘

—_- -

I.— PH YSIOLOG Ys 165

(4) ‘That the hydrogen ion concentration of the blood rises and
the total ventilation increases. On what lines are you to
discuss whether the increased ventilation is due to
‘ acidosis,’ by which is meant in this connection the increased
hydrogen ion concentration of the blood, or to ‘ anoxzemia ’?
Clearly not on the lines that it must be due to one or other.

In the above instance anoxemia and acidosis are to some extent
dependant variables. I have chosen the above case because measure-
ments have been made throughout which make the various assump-
tions fairly certain, and tell us pretty clearly in what sort of chain
to string up the events, what is cause and what is effect. Clearly
it would be ridiculous to start a discussion as to whether the breath-
lessness was due to ‘ acidosis’ or ‘ anoxemia.’ Hach has its place
in the chain of events. But I have heard discussions of whether other
phenomena of a more obscure nature were due to oxygen want or to
acidosis. Such discussions tend to no useful end.

Nor is this the only problem with regard to oxygen want concerning
which my warning is needed. Oxygen want may act immediately in
at least two ways:

(1) In virtue of absence of oxygen some oxidation which otherwise
might take place does not do so, and therefore something
which might otherwise happen may not happen. For
instance, it may be conceived that the respiratory centre can
only go through the rhythmic changes of its activity as the
result of the oxidation of its own substance.

(2) A deficient supply of oxygen may produce, not the negation
of a chemical action, but an altered chemical action which
in its turn produces toxic products that have a secondary
effect. on such an organism as the respiratory centre.

Now these effects are not mutually exclusive. In the same category
are many arguments about whether accumulations of carbonic acid
act specifically as such or merely produce an effect in virtue of their
effect on the hydrogen ion concentration.. Here again the two points
of view are not, strictly speaking, alternatives, and, in some cases at
all events, both actions seem to go on at the same time.

It will be evident that in any balanced action in which CO, is
produced its accumulation will tend to slow the reaction; but, on the
other hand, the same accumulation may very likely raise the hydrogen
ion concentration, and in that way produce an effect.

The relation of oxygen to hemoglobin seems to furnish a case in
point. Carbonic acid is known to reduce the affinity of haemoglobin
for oxygen, and other acids do the same. On analogy, therefore, it
might have, and has, been plausibly argued that CO: acts in virtue of the
change in reaction which it produces. Put into mathematical language,
the relation of the percentage saturation of oxygen to the oxygen
pressure of the gas dissolved in the hemoglobin solution is expressed
by the equation

A ORS 0) )) sO hen COL
100~ 1 + Ka" DL paw? WOT 4 SR’

166 SECTIONAL? ADDRESSES.

where y is the percentage saturation and a the oxygen pressure. ‘The
value of K is the measure of the affinity of oxygen for hemoglobin:
the less the value of K the less readily do the two substances unite.

Now a has been shown by Laurence J. Henderson,* and indepen-

dently by Adair, to vary directly with the concentration of CO,. The
value of this constant is, according to Henderson, too great to be a
direct effect of the CO, on the hemoglobin, and involves as well the
assumption that the hemoglobin in blood is in four forms—an acid
and a salt of reduced hemoglobin and an acid and a salt of
oxyhemoglobin. The presence of CO, alters the balance of these four
substances.

- It is rather fashionable at present to say that ‘the whole question
of acidosis and anoxeemia is in a hopeless muddle.’ To this I answer
that, if it is in a muddle, I believe the reason to be largely because
schools of thought have rallied round words and have taken sides under
the impression that they have no common ground. The ‘ muddle,’
in so far as it exists, is not, I think, by any means hopeless; but I
grant freely enough that we are rather at the commencement than at
the end of the subject, that much thought and much research must
be given, firstly, in getting accurate data, and, secondly, on relating
cause and effect, before the whole subject will seem simple. No effort
should be spared to replace indirect by direct measurements. My own
inference with regard to changes of the reaction of the blood, based
on interpretations of the dissociation curve, should be checked by actual
hydrogen ion measurements, as has been done by Hasselbach and is
being done by Donegan and Parsons.* Meakins also is, [ think,
doing great work by actually testing the assumptions made by Haldane
and himself as regards the oxygen in arterial blood.

The Compensations for Anoxemia.

For the anoxic type of anoxemia two forms of compensation at
once suggest themselves. ‘The one is increased hemoglobin in the
blood; the other is increased blood-flow through the tissues. Let us,
along the lines of the calculations already made, endeavour to ascertain
how far these two types of compensation will really help. To go back
to the extreme anoxic case already cited, in which the hemoglobin
was 66 per cent. saturated, let us, firstly, see what can be accomplished
by an increase of the hemoglobin value of the blood. ‘Such an increase
takes place, of course, at high altitudes. Let us suppose that the
increase is on the same grand scale as the anoxeemia, and that it is
sufficient to restore the actual quantity of oxygen in one c.c. of blood
to the normal. This, of course, means a rise in the hemoglobin value
of the blood from 100 to 150 on the Gowers’ scale. Yet even so great
an increase in the hemoglobin will only increase the oxygen taken
up in the capillary from each c.c. of blood from ‘031 to ‘036 c.c., and
will therefore leave it far short of the ‘06 c.c. which every cubic centi-
metre of normal blood was giving to the tissue. So much, then, for
increased hemoglobin. It gives a little, but only a little, respite. Let
us turn, therefore, to increased blood-flow.

I.— PHYSIOLOGY. 167

In the stagnant type of anoxemia the principal change which is
seen to take place is an increase in the quantity of hemoglobin per
eubic millimetre of blood.

This increase is secondary to a loss of water in the tissues, the
result in some cases, as appears from the work of Dale, Richards, and
Laidlaw,’ of a formation of histamine in the tissues. Whether this
increase of hemoglobin is to be regarded as merely an accidental occur-
rence or as a compensation is difficult to decide at present. Roughton’s
calculations rather surprised us by indicating that increased hemoglobin
acted less efliciently as a compensatory mechanism than we had
expected. This conclusion may have been due to the inaccuracy of
our assumptions. I must therefore remind you that much experimental
evidence is required before the assumptions which are made above are
anything but assumptions. But, so far as the evidence available at the
present time can teach any lesson, that lesson is this: The only way
of dealing satisfactorily with the anoxic type of anoxeemia is to abolish
it by in some way supplying the blood with oxygen at a pressure suffi-
cient to saturate it to the normal level.

Tt has been maintained strenuously by the Oxford school of physio-
logists that Nature actually did this; that when the partial pressure in
the air-cells of the lung was low the cellular covering of that organ
could clutch at the oxygen and force it into the blood at an unnatural
pressure, creating a sort of forced draught. This theory, as a theory,
has much to recommend it. Iam sorry to say, however, that I cannot
agree with it on the present evidence. I will only make a passing
allusion to the experiment which I performed in order to test the theory,
living for six days in a glass respiration-chamber in which the partial
pressure of oxygen was gradually reduced until it was at its lowest—
about 45 mm. Such a pressure, if the lung was incapable of creating
what I have termed a forced draught, would mean an oxygen pressure
of 38-40 mm. of mercury in the blood, a change sufficient to make
the arterial blood quite dark in colour, whereas, did any considerable
forced draught exist, the blood in the arteries would be quite bright in
colour. Could we but see the blood in the arteries, its appearance alone
would almost give the answer as to whether or no oxygen was forced,
or, in technical language, secreted, through the lung wall. And, of
course, we could see the blood in the arteries by the simple process of
cutting one of them open and shedding a little into a closed glass tube.
To the surgeon this is not a difficult matter, and it was, of course, done.
The event showed that the blood was dark, and the most careful analyses
failed to discover any evidence that the body can force oxygen into
the blood in order to compensate for a deficiency of that gas in the air.

Yet the body is not quite powerless. It can, by breathing more
deeply, by increasing the ventilation of the lungs, bring the pressure
of oxygen in the air-cells closer to that in the atmosphere breathed
than would otherwise be the case. I said just now that the oxygen
in my lungs dropped to a minimal pressure of 45 mm. ; but it did not
remain at that level. When I bestirred myself a little it rose, as the
result of increased ventilation of the lung, to 56 mm., and at one time,
when I was breathing through valves, it reached 68 mm. Nature will

168 SECTIONAL ADDRESSES.

do something, bul what Nature does not do should be done by artifice.
Exploration of the condition of the arterial blood is only in its infancy,
yet many cases have been recorded in which in illness the arterial blood
has lacked oxygen as much as or more than my own did in the respira-
tion chamber when I was lying on the last day, with occasional vomit-
ing, racked with headache, and at times able to see clearly only as an
effort of concentration. A sick man, if his blood is as anoxic as mine
was, cannot be expected to fare better as the result, and so he may
be expected to have all my troubles in addition to the graver ones
which are, perhaps, attributable to some toxic cause. Can he be spared
the anoxemia? The result of our calculations, so far, points to the fact
that the efficient way of combating the anoxic condition is to give
oxygen. During the war it was given with success in the field in cases
of gas-poisoning, and also special wards were formed on a small scale
in this country in which the level of oxygen in the atmosphere was
kept up to about 40 per cent., with great benefit to a large percentage
ot the cases. The practice then inaugurated is being tested at Guy’s
Hospital by Dr. Hunt, who administered the treatment during the war.

Nor are the advantages of oxygen respiration confined to patho-
logical cases. One of the most direct victims of anoxic anoxemia is
the airman who flies at great heights. Everything in this paper tends
to show that to counteract the loss of oxygen which he sustains at high
altitudes there is but one policy, namely, to provide him with an
oxygen equipment which is at once as light and as efficient as possible—
a consummation for which Haldane has striven unremittingly. And
here I come to the personal note on which I should like to conclude.
In the pages which I have read views have been expressed which differ
from those which he holds in matters of detail—perhaps in matters
of important detail. But Haldane’s teaching transcends mere detail.
He has always taught that the physiology of to-day is the medicine
of to-morrow. The more gladly, therefore, do I take this opportunity
of saying how much I owe, and how much [ think medicine owes
and will owe, to the inspiration of Haldane’s teaching.

References.
1. HaAupane.
2. Hatpanz, Kenuas, and Kennaway. Journal of Physiology, liii.
3. Foster and Haupanr. .The Investigation of Mine Air. Griffin & Co.
1905.

4. Krocu and Linpuarp, quoted by Bainbridge.

5. Barcrort, Cooke, Harrripce, Parsons and Parsons. Journal of
Physiology, liii. p. 451, 1920.

6. Stapre. Journal of Experimental Medicine, xxx. p. 215. 1919.

7. Hanpanr, Meakins, and Prirsrury. Journal of Physiology, lii. p. 420.
1918-19.

8. L. J, Henperson. The Journal of Biological Chemistry, vol. xli, p. 401.
1920.
9. Dongcan and Parsons. Journal of Physiology, lii. p. 315. 1919.
10. Dave and Rrcuarps. Journal of Physiology, lii. p. 110. 1919. Daze
and Larptaw. Ibid. p. 355.

SECTION K: CARDIFF, 1920.

ADDRESS

TO THE

BOTANICAL SECTION

BY
Miss E. R. SAUNDERS, F.L.S.,

PRESIDENT OF 'THE SECTION.

Year by year we see the meetings of the Association recur, pursuing a
course which neither geographer nor astronomer would venture to
predict and leaving traced out behind them a figure unknown to the
mathematician. Nevertheless the path of its journeyings is ever return-
ing upon itself. As this recurrence is brought afresh to one’s mind,
there is a natural impulse to reflect upon the progress which has
been made in the intervening period in the science which one here finds
oneself called upon to represent. Not quite thirty years have elapsed
since the last occasion on which the Association was welcomed to
Cardiff. Curiosity to learn whether the matter of the discourse
delivered by my predecessor on that occasion had a connection, close
or remote, with the particular subject with which I proposed to deal
in this Address led me to refer to the Annual Report of the Association
for 1891. I thus became aware how recent was the occurrence of the
mutation—or should I rather say of the dichotomy ?—which led to the
appearance of a Botanical Section, for twenty-nine years ago Section K
had not yet come into existence. At that period the problems relating
to living organisms, whether concerned with plant or animal, whether
of a morphological or physiological nature, were all embraced within
the wide field of Section D, the Section of Biology. Though in succeeding
years discovery at an ever-increasing rate and in many new fields
of investigation has made inevitable the separation first of Physiology,
and then of Botany from their common parent, we may with advantage
follow the precedent set by the Association as a whole, and, as a Section,
return from time to time upon our course of evolution. I shall there-
fore invite your attention to a subject which lies within the wide province
of Biology and makes its appeal alike to the botanist, zoologist and
physiologist—the subject of Heredity.

By the term Inheritance we are accustomed to signify the obvious

fact of the resemblance displayed by all living organisms between

offspring and parents, as the direct outcome of the contributions received
from the two sides of the pedigree at fertilisation: to indicate, in fact,

170 SECTIONAL ADDRESSES.

owing to lack of knowledge of the workings of the hereditary process,
merely the visible consequence—the final result of a chain of events.
Now, however, that we have made a beginning in our analysis of the
stages which culminate in the appearance of any character, a certain
looseness becomes apparent in our ordinary use of the word Heredity,
covering as it does the two concomitant essentials, genetic potentiality
and somatic expression—a looseness which may lead us into the para-
doxical statement that inheritance is wanting in a case in which never-
theless the evidence shows that the genetic constitution of the children
is precisely like that of the parents. When we say that a character is
inherited no ambiguity is involved, because the appearance of the
character entails the inheritance of the genetic potentiality. But when
a character is stated not to be inherited it is not thereby indicated whether
this result is due to environmental conditions, to genetic constitution,
or to both causes combined. That we are now able in some measure
to analyse the genetic potentialities of the individual is due to one of
those far-reaching discoveries which change our whole outlook, and
bring immediately in their train a rapidly increasing array of new facts,
falling at once into line with our new conceptions, or by some orderly
and constant discrepancy pointing a fresh direction for attack. An
historical survey of the steps by which we have advanced to the present
state of our knowledge of Heredity has so frequently been given during
the last twenty years that the briefest reference to this part of my
subject will suffice.

The earliest attempts to frame some general law which would co-
ordinate and explain the observed facts of inheritance were those of
Galton and Pearson. Galton’s observations led him to formulate two
principles which he believed to be capable of general application—the
Law of Ancestral Heredity and the Law of Regression. The Law of
Ancestral Heredity was intended to furnish a general expression for the
sum of the heritage handed on in any generation to the succeeding off-
spring. Superposed upon the working of this law were the effects of
the Law of Regression, in which the average deviation from the mean
of a whole population of any.fraternal group within that population
was expressed in terms of the average deviation of the parents. These
expressions represent statements of averages which, in so far as they
apply, hold only when large numbers are totalled together. They afford
no means of certain prediction in the individual case. These and all
similar statistical statements of the effects of inheritance take no account
of the essentially physiological nature of this as of all other processes
in the living organism. They leave us unenlightened on the funda-
mental question of the nature of the means by which the results we
witness came to pass. We obtain from them, as from the melting-pot,
various new products whose properties are of interest from other view-
points, but, corresponding to no biological reality, they have failed to
bring us nearer to our goal—a fuller comprehension of the workings
of the hereditary mechanism. Progress in this direction has resulted
from the opposite method of inquiry—the study of a single character
in a single line of descent, the method which deals with the unit im
place of the mass. The revelation came with the opening of the present

* Fs

K.—BOTANY. 171

century, for in 1900 was announced the rediscovery of Mendel’s work,
actually given to the world thirty-five years earlier, but at the time
leaving no impress upon scientific thought. The story of the Austrian
monk and the details of his experiments carried out in the monastery
garden upon races of the edible pea are now familiar history, and |
need not recount them here. Having formed the idea that in order

_ to arrive at a clearer understanding of the relation of organisms to

their progeny the problem must be studied in its simplest form, Mendel
came to see that a scheme of analysis must deal not with mass popula-

tions but with a smaller unit—the family, and that each character of
_ the individual must be separately investigated.

Selecting for his experiments races which showed themselves to be

pure-breeding and mating together those exhibiting characters of such
- opposite nature as to constitute a pair—e.g., tall with short, yellow-

seeded with green-seeded—he obtained results which could be accounted
for if it were supposed that these opposite, or as we should now term
them allelomorphic, characters were distributed unaltered and in equal
proportion to the reproductive cells of the cross-bred organism. It is
this conception of the pure nature of the germ-cells, irrespective of
whether the organism forming them be of pure-bred or cross-bred
descent, which revolutionised our conceptions of Heredity and laid the
foundations upon which we build to-day. For the intervening years
have seen the instances in which the Mendelian theory is found to
hold mount steadily from day to day, furnishing a weight of evidence
in its support which is incontrovertible.

It chanced that in each pair of characters selected by Mendel for
experiment the opposites are related to each other in the following

simple manner: An individual which had received both allelomorphs,

one from either parent, exhibited one of the two characteristics, hence
called the dominant, to the exclusion of the other. Among the offspring
of such an individual both characteristics appeared, the dominant in
some, its opposite, the recessive, in others, in the proportion approxi-
mately of three to one. This is the result which might be expected

from random pairing in fertilisation of two opposites, where the mani-

festation in the zygote of the one completely masks the presence of the
other. As workers along Mendelian lines increased and the field of
inquiry widened, it soon, however, became apparent that the dominant-
recessive relationship is not of universal occurrence. It likewise

became clear that the simple ratios which obtained in Mendel’s experi-

ments are not characteristic of every case. Mendel’s own results were
all, as it happened, explicable on the supposition that the two alterna-
tive forms of each character were dependent on a single element or
factor. By a fortunate accident none of the complex factorial inter-
‘relations which have since been brought to light in other cases obscured
the expression in its simplest form of the results of germ purity. It
is our task, in the light of this guiding principle, to attempt to elucidate
these more complicated types of inheritance.
We now know, for example, that many characters are not con-
trolled by one single factor, but by two or more. One of the most
familiar instances of the two-factor character is the appearance of the

172 SECTIONAL ADDRESSES.

colouring matter anthocyanin in the petals of plants such as the Stock
and Sweet Pea. Our proof that two factors (at least) are here involved
is obtained when we find that two true breeding forms devoid of colour
yield coloured offspring when mated together. In this case the two
complementary factors are carried, one by each of the two crossed
forms. When both factors meet in the one individual, colour is
developed. We have in such cases the solution of the familiar, but
previously unexplained, phenomenon of Reversion. Confirmatory evi-
dence is afforded when among the offspring of such cross-bred indi-
viduals we find the simple 3 to 1 ratio of the one-factor difference
replaced by a ratio of 9 to 7. Similarly we deduce from a ratio of
27 to 37 that three factors are concerned, from a ratio of 81 to 175
four factors, and so on. The occurrence of these higher ratios proves
that the hereditary process follows the same course whatever the
number of factors controlling the character in question.

And here I may pause to dwell for a moment upon a point of which
it is well that we should remind ourselves from time to time, since,
though tacitly recognised, it finds no explicit expression jn our ordinary
representation of genetic relations. The method of factorial analysis
based on the results of inter-breeding enables us to ascertain the least
possible number of genetic factors concerned in controlling a particular
somatic character, but what the total of such factors actually is we
cannot tell, since our only criterion is the number by which the forms
we employ are found to differ. How many may be common to these
forms remains unknown. In illustration I may take the case of sur- —
face character in the genera Lychnis and Matthiola. In L. vespertina
the type form is hairy; in the variety glabra, recessive to the type,
hairs are entirely lacking. Here all glabrous individuals have so far
proved to be similar in constitution, and when bred with the type give a
3 to 1 ratio in F,.1| We speak of hairiness in this case, therefore, as —
being a one-factor character. In the case of Matthiola incana v. |
glabra, of which many strains are in cultivation, it so happened that —
the commercial material originally employed in these investigations
contained all the factors since identified as present in the type and —
essential to the manifestation of hairiness except one. Hence it
appeared at first that here also hairiness must be controlled, as in
Lychnis, by a single factor. But further experiment revealed the fact
that though the total number of factors contained in these glabrous
forms was the same, the respective factorial combinations were not
identical. By inter-breeding these and other strains obtained later,
hairy F, cross-breds were produced giving ratios in F, which proved
that at least four distinct factors are concerned.2 Whereas, then, the
glabrous appearance in Lychnis always indicates the loss (if for con-
venience we may so represent the nature of the recessive condition)
of one and the same factor, analysis in the Stock shows that the
glabrous condition results if any factor out of a group of four is repre-
sented by its recessive allelomorph. Hence we describe hairiness in
the latter case as a four-factor character.

Pe a

eer ee eS ee

1 Report to the Evolution Committee, Royal Society, i., 1902.
2 Proc. Roy. Soc. B, vol. 85, 1912.

K.—BOTANY. 173

It will be apparent from the cases cited that we cannot infer from
the genetic analysis of one type that the factorial relations involved
are the same for the corresponding character in another. That this
should be so in wholly unrelated plants is not perhaps surprising, but
we find it to be true also where the nature of the characteristic and
the relationship of the types might have led us to expect uniformity.
This is well seen in the case of a morphological feature distinctive of
the N.O. Graminez. ‘The leaf is normally ligulate, but individuals are
occasionally met with in which the ligule is wanting. In these plants,
as a consequence, the leaf blade stands nearly erect instead of spread-
ing out horizontally. Nilsson-Ehle* discovered that in Oats there are
at least four and possibly five distinct factors determining ligule forma-
tion, all with equal potentialities in this direction. Hence, only when
the complete series is lacking is the ligule wanting. In mixed families
the proportion of ligulate to non-ligulate individuals depends upon the
number of these ligule-producing factors contained in the dominant
parent. Emerson* found, on the other hand, that in Maize mixed
families showed constantly a 3 to 1 ratio, indicating the existence of
only one controlling factor.

From time to time the objection has been raised that the Mendelian
type of inheritance is not exhibited in the case of specific characters.
That no such sharp line of distinction can be drawn between the
behaviour of varietal and specific features has been repeatedly demon-
strated. As a case in point and one of the earliest in which clear
proof of Mendelian segregation was obtained, we may instance Datura.
The two forms, D. Stramonium and D. Tatula, ave ranked by all
systematists as distinct species. Among other specific differences 1s
the flower colour. The one form has purple flowers, the other pure
white. In the case of both species a variety inermis is known in which
the prickles characteristic of the fruit in the type are wanting. It has
been found that in whatever way the two pairs of opposite characters
are combined in a cross between the species, the F, generation is mixed,

comprising the four possible combinations in the proportions which
we should expect in the ‘case of two independently inherited pairs of
characters, when each pair of opposites shows the dominant-recessive
relation. Segregation is as sharp and clean in the specific character
flower colour as in the varietal character of the fruit. Among the
latest additions to the list of specific hybrids showing Mendelian inheri-
tance, those occurring in the genus Salix are of special interest, since
heretofore the data available had been interpreted as conflicting with
the Mendelian conception. The recent observations of Heribert-
Nilsson * show that those characters which are regarded by systematists
as constituting the most distinctive marks of the species are referable
to an extremely simple factorial system, and that the factors mendelise
in the ordinary way. Furthermore, these specific-character factors

® Kreuzungsuntersuchungen an Hafer und Weizen, Lund, 1909.
4 Annual Report of the Agricultural Experiment Station of the University of
Nebraska, 1912.
5 Hxperimentelle Studien iiber Variabilitdit, Spaltung, Arthildung und
Bvolution in der Gattung Salix, 1918.

174 SECTIONAL ADDRESSES.

control not only the large constant morphological features, but funda-
mental reactions such as those determining the condition of physio-
logical equilibrium and vitality in general. In so far as any distinction
can be drawn between the behaviour of factors determining the varietal
as opposed to the specific characters of the systematist, Heribert-
Nilsson concludes that the former are more localised in their action,
while the latter produce more diffuse results, which may affect almost
all the organs and functions of the individual, and thus bring about
striking alterations in the general appearance. S. caprea, for example,
is regarded as the reaction product of two distinct factors which together
control the leaf-breadth character, but which also affect, each separately
and in a different way, leaf form, leaf colour, height, and the periodicity
of certain phases. We cannot, however, draw a hard-and-fast line
between the two categories. The factor controlling a varietal charac-
teristic often produces effects in different parts of the plant. For
example, the factors which lead to the production of a coloured flower
no doubt also in certain cases cause the tinging seen in the vegetative
organs, and affect the colour of the seed. MHeribert-Nilsson suggests
that fertility between species is a matter of close similarity in genotypic
(factorial) constitution rather than of outward morphological resem-
blance. Forms sundered by the systematist on the ground of gross
differences in certain anatomical features may prove to be more akin,
more compatible in constitution, than others held to be more nearly
related because the differentiating factors happen to control less
conspicuous features.

Turning to the consideration of the more complex types of inheri- —

tance already referred to, we find numerous instances where a somatic

character shows a certain degree of coupling or linkage with another —
perhaps wholly unrelated character. This phenomenon becomes still

further complicated when, as is now known to occur fairly frequently,

somatic characters are linked also with the sex character. The results :

of such linkages appear in the altered proportions in which the various
combinations of the several characters appear on cross-breeding.

Linkage of somatic characters can be readily demonstrated in the garden —
Stock. Some strains have flowers with deeply coloured sap, e.g., full —

red or purple; others are of a pale shade such as a light purple or
flesh-colour. In most commercial strains the ‘eye’ of the flower is
white owing to absence of colour in the plastids, but in some the plastids
are cream-coloured, causing the sap colour to appear of a much richer
hue and giving a cream ‘eye.’ Oream plastid colour is recessive to
white and the deep sap colours are recessive to the pale. When a
cream-eyed strain lacking the pale factor is bred with a white-eyed
plant of some pale shade, the four possible combinations appear in

F. but not, as we should expect in the case of two independently

inherited one-factor characters, in the proportions 9: 3: 3:1, with the

double recessive as the least abundant of the four forms. We find

instead that the double dominant and the double recessive are both
in excess of expectation, the latter being more abundant than either
of the combinations of one dominant. character with one recessive.
The two forms which preponderate are. those which exhibit the

K.— BOTANY. 175

combinations seen in the parents, the two smaller categories are those
representing the new combinations of one paternal with one maternal
characteristic. In the Sweet Pea several characters are linked in this
manner, viz.: flower colour with pollen shape, flower colour with
form of standard, pollen shape with form of standard, colour of leaf
axil with functioning capacity of the anthers. If in these cases the
cross happens to be made in such a way that the two. dominant
characters are brought in one from each side of the pedigree instead
of both being contributed by one parent, we get again a result in which
the two parental combinations occur more frequently, the two recom-
binations or ‘crossovers’ less often than we should expect. In the
first case the two characters appear to hang together in descent to a
certain extent but not completely, in the latter similarly to repel each
other. This type of relationship has been found to be of very general
occurrence. The linked characters do not otherwise appear to be con-
nected in any way that we can trace, and we therefore conclude that
the explanation must be sought in the mechanism of distribution. Two
main theories having this fundamental principle as their basis but
otherwise distinct have been put forward, and are usually referred to
as the reduplication and the chromosome view respectively. The
reduplication view, proposed by Bateson and Punnett,* rests on the idea
that segregation of factors need not necessarily occur simultaneously
at a particular cell division. The number of divisions following the
segregation of some factors being assumed to be greater than those
occurring in the case of others, there would naturally result a larger
number of gametes carrying some factorial combinations and fewer
earrying others. If this differential process is conceived as occurring
in an orderly manner it would enable us to account for the facts
observed. We could imagine how it came about that gametic ratios
such as 3: 1: 1: 3,7: 1:1: 7,15: 1: 1: 15, and so on arose giving the
series of linkages observed. It has, however, to be said that we cannot
say why segregation should be successive nor at what moments, on
this view, it must be presumed to occur. On the other hand, the
conceptions embodied in the chromosome hypothesis as formulated by
Morgan and his fellow-workers’ are, in these respects, quite precise.
They are built around one cardinal event in the life cycle of animals —
and plants (some of the lowest forms excepted), viz.: the peculiar type

of cell division at which the number of chromosomes is reduced to
half that to be found during the period of the life cycle extending
backwards from this moment to the previous act of fertilisation. In
the large number of cases already investigated the chromosome number
has been found as a rule to be the same at each division of the somatic
cells. We can, in fact, take it as established that it is ordinarily con-
stant for the species. These observations lend strong support to the
view that the chromosomes are persistent structures; that is to say,
‘that the chromatin tangle of the resting nucleus, whether actually
composed of one continuous thread or not, becomes resolved into

*® Proc. Roy. Soc., 1911. } .
7-The Mechanism of Mendelian Heredity (Morgan, Sturtevant, Muller,
Bridges), 1915.

176 SECTIONAL ADDRESSES.

separate chromosomes at corresponding loci at each successive mitosis.
The reduction from the diploid to the haploid number, according to
the more generally accepted interpretation of the appearances during
the meiotic phase, is due to the adhering together in pairs of homologous
chromosomes, each member of the set originally received from one
parent lying alongside and in close contact with its mate received from
the other. Later these bivalent chromosomes are resolved into their
components so that the two groups destined one for either pole consist
of whole dissimilar chromosomes, which then proceed to divide again
longitudinally to furnish equivalent half chromosomes to each of the
daughter nuclei. According to the view of Farmer the homologous
chromosomes do not lie alongside, but become joined end to end. The
longitudinal split seen in the bivalent structure is interpreted as a
separation not of whole chromosomes but of half chromosomes already
formed in anticipation of the second division of the meiotic phase. As
however on either interpretation the same result is ultimately secured,
viz.: the distribution of whole paternal and maternal chromosomes to
different nuclei which now contain the haploid number, it is not essen-
tial to our present purpose to discuss the cytological evidence in support
of these opposing views in further detail. Nor, indeed, would it
be practicable within the limits of this Address. The obvious close
parallel between the behaviour of the chromosomes—their pairing and
separation—and that of Mendelian allelomorphs which similarly show
pairing and segregation, first led to the suggestion that the factors
controlling somatic characters are located in these structures. The
ingenious extension of this view which has been elaborated by Morgan
and his co-workers presumes the arrangement of the factors in linear
series after the manner of the visible chromomeres—the bead-like
elements which can be seen in many organisms to compose the
chromatin structure—each factor and its opposite occupying correspond-
ing loci in homologous chromosomes. From this conception follows
the important corollary of the segregation of the factors during the
process of formation and subsequent resolution of the bivalent chromo-
somes formed at the reduction division. We should suppose, according
to Morgan, in the case of characters showing independent inheritance
and giving identical Mendelian ratios whichever way the mating is
made, and however the factorial combination is brought about, that the
factors controlling the several characters are located in different
chromosomes. Thus, in the case of Datura already mentioned, the two
factors affecting sap colour and prickliness respectively would be pre-
sumed to be located so far apart in the resting chromatin thread that
when separation into chromosomes takes place they become distributed
to different members. Where unrelated characters show a linked
inheritance the factors concerned are held on the other hand to lie so
near together that they are always located in one and the same chromo-
some. Furthermore, and here we come to the most debatable of the
assumptions in Morgan’s theory, when the bivalent chromosome com-
posed of a maternal and a paternal component gives rise at: the reduction
division to two single dissimilar chromosomes, these new chromosomes
do not always represent the original intact maternal and paternal

K.—BOTANY. 177

components. It has been observed in many forms that the bivalent struc-
ture has the appearance of a twisted double thread. Already in 1909
cytological study of the salamander had led Janssen* to conclude
that fusion might take place at the crossing points, so that when the
twin members ultimately draw apart each is composed of alternate
portions of the original pair. Morgan explains the breeding results
obtained with Drosophila by a somewhat similar hypothesis. He also
conceives that. in the process of separation of the twin lengths of
chromatin cleavage between the two is not always clean, portions of
the one becoming interchanged with corresponding segments of the
other, so that both daughter chromosomes are made up of comple-
mentary sections of the maternal and paternal members of the duplex
chromosome. To picture this let us imagine that two bars of that
delectable substance, Turkish Delight, one pink and one white, are laid
alongside and are then given a half twist round each other and pressed
together. If, with a knife inserted between the two pieces at one
end, the double bar is now sliced longitudinally down the middle neither
of the two halves will be wholly pink or wholly white. Each half will be
particoloured, the pink portion in one and the portion which is white in
the other representing corresponding regions of the original bars. If
the complete twist is made, or if the number of turns is still further
increased before the slicing, the number of alternately coloured por-
tions will naturally be increased correspondingly. Though the precise
manner in which the postulated chromosomal interchange is brought
about in Janssen’s ‘chiasmatype’ and Morgan’s ‘ crossing-over ’
scheme is different, the resulting gametic output would be the same.
A critical examination by Wilson and Morgan,’ from different aspects,
of Janssen’s interpretation of the cytological evidence including dis-
cussion of his latest suggestion that in the case of compound ring
chromosomes cleavage in one plane would result in the separation of
homologous elements in one ring but not in another has just appeared.
These authors are not disposed to accept Janssen’s conclusions,*® but
reserve their final statement pending the appearance of his promised
further contribution. Should Janssen’s view of the evolutions of these
complex chromosome structures be upheld, the process of segregation
might in such cases become extended over more than one mitosis, as
on the reduplication theory is conceived to be the case at some point,
though evidence in this direction has hitherto been lacking. Bisection
of a bivalent chromosome in this fashion might, moreover, yield the
class of results to explain which Morgan has found it necessary to
have recourse to hypothetical lethal factors. On the main issue, how-
ever, both schemes are in accord. A physical basis for the phenomenon
of linkage is found in the presumed nature and behaviour of the
chromosomes, viz.: their colloidal consistency, their adhesion after
pairing at the points of contact, when in the twisted condition, and
their consequent failure to separate cleanly before undergoing the
succeeding division.

8 La Cellule, xxv.
9 Am. Nat., vol. 54, 1920.
10 See Comptes Rendus Soc. Belg. Biol., 1919
1920 N

178 SECTIONAL ADDRESSES.

According to Morgan the frequency of separation of linked
characters is a measure of the distance apart in the chromosome of the
loci for the factors concerned, and it becomes possible to map their
position in the chromosome relatively to one another. In this attempt
to find in cytological happenings a basis for the observed facts of
inheritance our conception of the material unit in the sorting-out
process has been pushed beyond the germ cell and even the entire
chromosome to the component sections and particles of the latter
structure.

To substantiate the ‘ chromosome’ view the primary requisite was
to obtain proof that a. particular character is associated with a particular
chromosome. With this object in view it was sought to discover a
type in which individual chromosomes could be identified. | Several
observers working on different animals found that a particular chromo-
some differing in form from the rest could be traced at the maturation
division, and that this chromosome was always associated with the sex
character in the following manner. The female possessed an even
number of chromosomes so that each egg received an identical number,
including this particular sex-chromosome. The male contained an
uneven number, having one fewer than the female, with the result
that half the sperms received the same number as the egg including
the sex-chromosome, and half were deficient in this particular chromo-
some. Hggs fertilised with sperms containing the full number of
chromosomes developed into females, while those fertilised with sperms
lacking this distinctive chromosome produced males. Morgan made
the further discovery in the fruit fly Drosophila ampelophila that certain
factors controlling various somatic characters were located in the sex-
chromosome. The inheritance of these characters and of sex evidently
went together. A male exhibiting the dominant condition of such a
sex-linked character bred to a recessive female gave daughters all
dominant and sons all recessive (fig. 2), but in the reciprocal cross both
sons and daughters proved to be all dominants (fig. 1). Since the
mother with the dominant factor contributed it to all her children
(fig. 1), whereas, where the father bore it, it descended only to his
daughters (fig. 2), it was apparent that the female was homozygous
and the male heterozygous for the somatic character. Further,
although no distinction is observable in this species between the sperms,
the occurrence of this sex-linked form of inheritance indicated that here,
as in the other cases mentioned, it is the female which behaves as a
homozygote for the ser character and the male as a heterozygote, the
sex-chromosomes of some sperms differing presumably in character,
though not in appearance, from those of others. The sperms. of
Drosophila are therefore conceived as of two kinds, one containing the
same sex-chromosome as the eggs, the so-called X chromosome, and
the other a mate of a different nature, the Y chromosome, which
appears to be inert and unable to carry the dominant allelomorphs.
If, now, we suppose the factor for the sex-linked somatic character
to be located in the X chromosomes we understand why the dominant
female, which is XX, and therefore furnishes an X chromosome
to every egg, should contribute the dominant character to all her

K.— BOTANY. 179

offspring. And conversely, why the dominant male, which is XY, when
bred to a recessive female, produces offspring which are either female
and dominant or male and recessive.

Tracing the chromosomes into the next (F,) generation we see also
the reason for the different result obtained from the reciprocal matings
if the F, individuals are inbred. When the female parent has the
dominant sex-linked character half the eggs of the daughters and half
the sperms of the sons receive this character. As the sperms receive
it along with the X chromosome fertilisation of either kind of egg by
these X sperms will cause the character to descend to each grand-
daughter. The grandsons, on the other hand, since they arise from
fertilisation by the sperms lacking the dominant character—i.e., by the
Y sperms—will be dominant or recessive according as these sperms
unite with the one type of egg or with the other. Thus we get the
Mendelian F, ratio 3D to 1R (fig. 1), but so linked with sex that the
dominant class comprises half the males and all the females, while
the remaining half of the males make up the recessive class. Where
it is the male parent that carries the dominant, and where therefore
the dominant character passes along with the X chromosome only
to the daughters in F,, their eggs, as in the reciprocal cross, are of
two kinds, but the sons’ sperms all carry the recessive allelomorphs.
Both kinds of eggs being fertilised with both X sperms and Y sperms,
the dominant and recessive characters will occur equally in both sexes
among the grandchildren, and we get the Mendelian ratio of 1D to
1R (fig. 2). Muller ** puts the number of factors already located in the
X chromosome of Drosophila at not less than 500, and in those that
have so far been investigated this form of inheritance has been found
to hold.

Instances of sex-linked inheritance are now known in many animals,
some of which are strictly comparable with Drosophila, others follow
the same general principle, but have the relations of the sexes reversed,
as exemplified by the moth Abraxas, which has been worked out by
Doncaster,'? whose sudden death we have so recently to deplore. Here
the female is the heterozygous sex, and contains the dummy mate of
the sex-chromosome.

The behaviour of the sex-chromosomes as here outlined suffices to
account for the occurrence of sex-linked inheritance, but the relations
found to hold between one sex-linked character and another need
further explanation. If a cross is made involving two sex-linked
characters, the F, females when tested by a double recessive male are
found to produce the expected four classes of gametes, but not in equal
proportions, nor in the same proportions in the case of different pairs of
sex-linked characters. Partial linkage (coupling) occurs of the kind
which has already been described for the Stock and the Sweet Pea.
The parental combinations predominate, the recombinations (‘ cross-
overs *) comprise the smaller categories. The strength of the linkage
varies, however, for different characters, but is found to be constant
for any given pair. Since the sex-linked factors are by hypothesis

11 Am. Nat., vol. liv., 1920.
Rep, Evolution Committee, iv., 1908.

Fig.|

Parents.

Sperms @

Parents

182 SECTIONAL ADDRESSES.

carried in the sex-chromosomes, a clean separation of homologous
members at meiosis should result in the characters which were asso-
ciated in the parents remaining strictly in the same combination in
each succeeding generation. The fact that this is not the case has
led Morgan to conclude that an interchange of chromosome material
must take place at this phase among a proportion of the gametes, and
that the percentage of these ‘ cross-overs’ will depend on the distance
apart of the loci of the factors concerned. This phenomenon of linkage
may also be exhibited by pairs of characters which show uo sex-
linkage in their inheritance. The factors involved in these latter cases
must presumably, therefore, be disposed in one of the chromosomes
which is not the sex-chromosome.

To this brief sketch of the main points of Morgan’s chromosome
theory must be added mention of the extremely interesting
relation which lends strong support to his view, and the significance of
which seems scarcely to admit of question, viz.: that in Drosophila
ampelophila there are four pairs of chromosomes, and that the linkage
relations of the hundred and more characters investigated indicate that
they form four distinct groups. It is hardly possible to suppose that
the one fact is not directly connected with the other. The interesting
discovery of Bridges ** that the appearance of certain unexpected cate-
gories among Drosophila offspring, where females of a particular
strain were used, coincided with the presence in these females of an
additional chromosome adds another link in the chain of evidence. On
examination it was found that in these females the X chromosome pair
occasionally failed to separate at the reduction division, and conse-
quently that the two XX chromosomes sometimes both remained in the
egg, and sometimes both passed out into the polar body. Hence there
arose from fertilisation of the XX eggs some individuals containing
three sex-chromosomes, with the resulting upset of the expectation in
regard to. sex-limitation of characters which was observed.

It, however, remains a curious anomaly that in the cross-bred
Drosophila male no corresponding crossing-over of linked characters,
whether associated with the sex character or not, has yet been ob-
served. His gametes carry only the same factorial combinations
which he received from his parents. For this contrast in the behaviour
between the sexes there is at present no explanation. The reverse con-
dition has been described by Tanaka’ in the silkworm. Here inter-
change takes place in the male but not in the female.

It must then be acknowledged that Morgan’s interpretation of the
cytological evidence has much in its favour. The striking parallel
between the behaviour of the chromosomes and the distributional rela-
tions of Mendelian allelomorphs is obvious. The existence in Droso-
phila ampelophila of four pairs of chromosomes and of four sets of
linked characters can hardly be mere coincidence. The employment of
the smaller physical unit in accounting for the reshuffling of characters
in their transmission commends itself in principle. The necessity for
postulating the occurrence of some orderly irregularity in the hereditary

13 J. Hap. Zool., xv., 1913.
14 J. Coll. Agr., Sapporo, Japan, 1913-14.

K.—BOTANY. 183

process in order to explain the phenomenon of partial linkage is, it
will be seen, inherent alike in both theories. When, however, we come
to examine the general applicability of Morgan’s theory we are con-
fronted with a considerable body of facts among plants which we find
difficult to reconcile with the requirement that factorial segregation is
accomplished by means of the reduction division. An instance in
which this is particularly clearly indicated is that of the sulphur-white
Stock. I have chosen this example because here we have to do with
two characters which are distinguished with the utmost sharpness,
viz.: plastid colour and flower form. The peculiar behaviour of this
strain is due to the fact that not only are the two factors for flower form
(singleness and doubleness) differently distributed to the male and
female sides of the individual, as in all double-throwing Stocks, but the
factor controlling plastid colour likewise shows linkage with the sex
nature of the germ cells. As a result every individual, even though
self-fertilised, yields a mixed offspring, consisting chiefly of single
whites and double creams, but including a small percentage of double
whites. So far as the ovules are concerned, the mode of inheritance can
be accounted for on either theory. According to the reduplication
hypothesis the factors X Y ** producing singleness and W giving white
plastids are partially coupled so as to give the gametic ratio on the
female side 7 WXY: 1WXy: lwxY: 7wxy.'® On the chromosome
scheme the factorial group WXY must be assumed to be disposed in
one member of the bivalent chromosome formed at meiosis, the corre-
sponding recessive allelomorphs wxy in the other. If the three factors
be supposed to be arranged in the chromosome in alphabetical order,
and if, on separation, a break takes place between the loci of the two
factors for flower form (as shown), so as to give ‘ cross-overs’ of Y

Ovules Pollen,

** The letters X and Y are used here to denote particular factors, not, as in
Morgan’s scheme, the entire sex-chromosomes.
18 Or possibly 15:1:1:15.

184 SECTIONAL ADDRESSES.

and y in about 12 per cent. of the gametes, the occurrence of such
‘ cross-overs ’ would fulfil the required conditions. But the case of the
pollen presents a distinct difficulty on this latter view. This Stock is
distinguished both from the Drosophila and the Abraxas type by the
fact that none of the male germs carry either of the dominant charac-
ters. In place of the XX—xXY form of sex-linked inheritance in
the former type and the WZ—ZZ in the latter, we should need to
regard this form as constituting a new class, which we might represent
as DR—RR, thus indicating that both members of the bivalent chromo-
some on the male side appear to be inert and able to carry only the
recessive characters, and hence are represented as RR, in contrast with
the DR pair of the female side. By this formula we can indicate the
behaviour of the several double-throwing strains. It is, besides, becom-
ing clear, I think, from recent results that there is no ‘ crossing over ’ of
these factors on the male side in the F, cross-breds. But the real
difficulty is to explain why these factors are confined to the female side
in the ever-sporting individual. This may result from aberrant
behaviour or loss of chromosomes at some point in pollen development.
On this point I hope that evidence will shortly be available. Failing
such evidence the presumption is that the elimination of XY (and in one
strain of W) must have taken place prior to, and not at, the
moment of the maturation division. Morgan’s proposal to fit
the pollen into his scheme for Drosophila by having recourse to hypo-
thetical lethal factors does not appeal to the observer, who finds the
pollen all uniformly good and every ovule set. Zygotic lethals are
clearly not in question under these circumstances. The supposition of
gametic lethals confined to the pollen appears far-fetched, seeing
that of the missing combinations two, viz.: single white, the double
dominant, and double white a dominant-recessive, occur in the
ovules, and the third, the single cream, the other dominant-recessive,
exists as a pure strain, so that the homozygous condition is evidently
not in itself a cause of non-development. Other examples suggesting
premeiotic segregation can be quoted, notably cases among variegated
plants and plants showing bud sports, where somatic segregation appears
to be of regular occurrence. Among the Musciniae the present evidence
appears to show that the sex potentiality segregates in some forms at
the division of the spore mother cells, so that already the spores possess
a sex character; while in other species this separation takes place later,
during the development of the gametophyte, the spores being then all
alike and undifferentiated in this respect. In Fumaria hygrometrica,
an example of the latter class, an attempt has been made by E. J.
Collins** to ascertain the stage at which sex segregation takes place
by inducing the growth of new individuals from isolated portions of the
vegetative tissues of the gametophyte. No doubt when the evidence
is derived from experiments in which a portion of the plant has been
severed from the rest, it is possible to urge that the result obtained
is not necessarily indicative of the potentizlity in the intact organism.
Phenotypic appearance is the product of a reaction system, in which
the internal as well as the external environment plays its part. We

17 Journal of Genetics, vol. viii., 1919.

K.—BOTANY. 185

have, for example, evidence that the manifestation of a character may
be dependent upon the variation of internal conditions with age; in
other words, a time relation may be involved.** Or, again, upon the
state of general internal equilibrium resulting from the relation of one
morphological member or region to another. Thus removal of the
lamina of the leaf, so as to leave only the midrib, may cause the
mutilated individual to develop hairs on the stems and petioles in the
same environment in which the intact individual remains hairless.
Injury from attack by insects in a glabrous form may in like manner
lead to the production of hairs which, by their resemblance to those
of an allied species, show that the pathological condition set up has
caused genetic potentiality to become actual. But even if we exclude
the class of evidence to which objection on these grounds might be
made, there still remain various cases of normal types, where, unless
the behaviour of the chromosomes should point to a different explana-
tion, it seems mosi natural to assume that segregation takes place before
the reduction division.
It has been argued from time to time that any scheme representing
the mechanism of Heredity which leaves out of account the cytoplasm
must prove inadequate. This general statement has been expressed in
more definite form by Loeb,’® who holds that the egg cytoplasm
is to be looked upon as determining the broad outlines, in fact as
standing for the embryo ‘in the rough,’ upon which are impressed in
the course of development the characteristics controlled by the factors
segregated in the chromosomes. The arguments in fayour of the view
that the cytoplasm, apart from its general functions in connection with
growth and nutrition, is the seat of a particular hereditary process are
mainly derived from observation upon embryonic characters in certain
animals, chiefly Echinoderms, where the inheritance appears to be
purely maternal. It has been shown, however, that such female
prepotency is no indication that inheritance of the determining factors
takes place through the cytoplasm. Other causes may lead to this
result. It has been observed, for example, that hybrid sea-urchin larvae,
which at one season of the year were maternal in type, at another
_ were all paternal in character, showing that the result was due to some
effect of the environment. Again, where the hybrid plutei showed purely
maternal characters it was discovered by Baltzer ?° that in the earliest
mitoses of the cross-fertilised eggs a certain number of chromosomes
fail to reach the poles, and are consequently left out of the daughter
nuclei. The chromosomes thus lost probably represent those contributed
_by the male gamete, for in both parents certain individual chromosomes
can be identified owing to differences in shape and size. After this
_ process of elimination those characteristic of the male parent could
not be traced, whereas the one pair distinctive of the female parent

was still recognisable. In the reciprocal cross where the first mitosis

8 As in the case of characters which exhibit a regular change of phase,
€.g., the colour of white and cream Stocks is indistinguishable in the bud, and
a yellow-seeded Pea 1s green at an earlier stage.

%° The Organism as a Whole, 1916.

*° Archiv fiir Zellforschung, v., 1910.

186 SECTIONAL ADDRESSES.

follows a normal course the embryos are intermediate in regard to
character of the skeleton, thus affording proof of the influence of the
male parent. Another type of case is found in the silkworm. Here
a certain rate character determining the time of hatching out of the
eggs has been shown to exhibit normal Mendelian inheritance, the
appearance that it is transmissible by the female through the cytoplasm
alone being delusive. The eggs are always laid in the spring. Accord-
ing as they hatch out immediately so that a second brood is obtained
in the year, or do not hatch out for twelve months, the female parent
laying the eggs is described as bivoltin or univoltin. Now the length
of interval before hatching is obviously an egg character, and therefore
maternal in origin. Consequently when a cross is made between a
univoltin female and a bivoltin male the eggs laid are not cross-bred
in respect of this character, any more than the seed formed as a result
of a cross is cross-bred in respect of its seed coat, which is a maternal
structure. The silkworm mother being univoltin, the eggs will not
hatch out until the following spring. The F, mother will in turn
lay eggs which again take twelve months to hatch, since the long-
period factor is the dominant. It is not until the eggs of the F,
generation are laid that we see the expression of the character introduced
by the bivoltin father. For some of the egg batches hatch at once,
others not for twelve months, showing that of the F. females some
were uni- and some bi-voltin, and hence that the egg character in any
generation depends upon both the maternal and the paternal antecedents
of the female producing the eggs. Consequently, in the case of an
egg character the effects of inheritance must be looked for in the genera-
tion succeeding that in which the somatic characteristics of the zygote
become revealed. We find in fact that in almost all instances where
the evidence is suggestive of purely cytoplasmic inheritance, fuller
investigation has shown that the explanation is to be found in one of
the causes here indicated. The case of some plants where it has been
established that reciprocal hybrids are dissimilar still, however, remains
to be cleared up. Among such may be cited certain Digitalis hybrids.
Differences in the reciprocal hybrids of D. grandiflora and D. lutea
were described by Gaertner, and in the earlier literature dealing with
Digitalis species hybrids other cases are to be found. In more recent
years J. H. Wilson *! has repeated the crossing of D. purpurea and
D. lutea, and states that the reciprocals are indistinguishable during
the vegetative period, but that they differ in size and colouring of the
flowers, the resemblance being the greater in each case to the seed
parent. A detailed comparison of the differential characters of the
reciprocal hybrids of D. purpurea and D. grandiflora has been set out
by Neilson Jones,?* who similarly finds in both matings a greater
resemblance to the mother species. We know nothing as yet of the
cytology of these cases, and it is not improbable that the interpretation
may be found in some aberrant behaviour of the chromosomes. An
instance in a plant type where a definite connection appears traceable
between chromosome behaviour and somatic appearance has been

21 Rep. Third International Congress on Genetics, R.H.S, 1906.
22 J. of Genetics, vol. ii., 1912.

K.—-BOTANY. 187

recently emphasised by Gates,** who attributes the peculiarity of the
lata mutation in Gnothera (which has arisen as a modification at
different times from each of three distinct species) to an irregularity
‘in meiosis in the germ mother cells whereby one daughter cell receives
an extra duplicate chromosome while the sister cell lacks this chromo-
some. The cell with the extra chromosome fertilised by a normal germ
produces a lata individual. On the chromosome view every normal
fertilised egg contains a double set of chromosomes, each carrying a
complete set of the factor elements. Hence, if some of the one set
become eliminated we can still imagine that a normal though under-
sized individual might develop. The converse relation where increased
‘size goes with multiplication of chromosomes was discovered by
Gregory,” in a Primula, and occurs also in @nothera gigas, a mutant
‘derived from G@. Lamarckiana. Gregory found in his cultures giant
individuals which behaved as though four instead of two sets of factors
were present, and upon examination these individuals were found to
contain twice the normal number of chromosomes. It is interesting
‘in this connection to recall the results obtained by Nemec?® as the
result of subjecting the root tips of various plants to the narcotising
action of chloral hydrate. Under this treatment cells undergoing
division at the time were able to form the daughter nuclei, but the
production of a new cell wall was inhibited. The cells thus became
binucleate. If on recovery these cells were to fuse before proceeding
to divide afresh a genuine tetraploid condition would result. So few
cases of natural tetraploidy have so far been observed that we have as
yet no clue to the cause which leads to this condition.
_ The conclusions to which we are led by the considerations which
have here been put forward are, in the main, that we have no warrant
‘in the evidence so far available for attributing special hereditary pro-
cesses to the cytoplasm as distinct from the nucleus. On the other
hand, there is a very large body of facts pointing to a direct connection
‘between phenotypic appearance and chromosomal behaviour. In
animals the evidence that the chromosomes constitute the distributional
“mechanism may be looked upon as almost tantamount to proof; in
‘plants the observations on Drosera, Primula, Ginothera, Spherocarpus
‘are in harmony with this view. When we come, however, to the
‘question of linkage and general applicability of the conception of
crossing over’ as adopted by Morgan and his school we are on less
‘certain ground. In Drosophila itself, the case which the scheme was
framed to fit, the entire absence of ‘ crossing over’ in the male remains
‘unaccounted for, while the evidence from certain plant types appears
to be definitely at variance with one of its fundamental premises. If
Segregation at the recognised reduction division is definitely established
for animal types, then we must conclude that the sorting-out process
may follow a different course in the plant.
' The question as to what is the precise nature of the differences for

_ 73 New Phytologist, vol. xix., 1920.

_ *4 Proc. Roy. Soc., vol. 1xxxvii. B, 1914.

#5 Jahrb. f. wiss. Bot., xxxix., 1904, ‘Das Problem der Begruchtungsvor-
gange,’ 1910.

188 SECTIONAL ADDRESSES.

which the Mendelian factors stand is constantly before the mind of the
breeder, but we are only now on the threshold of investigation in this
direction, and it is doubtful whether we can as yet give a certain answer
in any single instance. Still less are we able to say what the actual
elements or units which undergo segregation may be. In the case of
such allelomorphic pairs as purple and red sap colour or white or
cream plastid colour it may be that the difference is wholly qualitative,
consisting merely in the formation or non-formation of some one
chemical substance. But the majority of characteristics are not of
this hard-and-fast type. Between some the distinction appears to be
one of range—to be quantitative rather than, or as well as, qualitative
in nature, and range must mean, presumably, either cumulative effect
or a force or rate difference. It may well be, for example, that with
some change in physiological equilibrium accompanying growth and
development, factorial action may be enhanced or accelerated, or, on
the other hand, retarded or even inhibited altogether, and a regional
grading result in consequence. Range in a character is not confined to,
though a common characteristic of, individuals of cross-bred origin. It
may be a specific feature, both constant and definite in nature. For
example, a change as development proceeds from a glabrous or nearly
glabrous to a hairy condition is not of unusual occurrence in plants.
In the Stock such a gradational assumption of hairiness is apparent no
less in the homozygous form containing a certain weak allelomorph
controlling surface character, when present with the factors for sap
colour, than in those heterozygous for this or some other essential
component. We see a similar transition in several members of the
Scrophulariacee—e.g., in various species of Digitalis, in Antirrhinum
majus, Antirrhinum Orontium, Anarrhinum pedatum, Pentstemon, and
Nemesia. In perennials an annual recurrence of this change of phase
may be seen, as in various species of Viola and in Spirea Ulmaria.
It is somewhat curious that the transition may be in the same direction
—from smoothness to hairiness—in forms in which the dominant-reces-
sive relation of the two conditions is opposite in nature, as in Matthiola
on the one hand and Digitalis purpurea nudicaulis on the other. Mani-
festation of the dominant characteristic gradually declines in the Fox-
glove, while it becomes more pronounced in the Stock. In some, per-
haps all, of these cases the allelomorphs may stand for certain states
of physiological equilibrium, or such states may be an accompanying
feature of factorial action. A change of phase may mean an altered
balance, a difference of rhythm in interdependent physiological pro-
cesses. In the case, for instance, of a certain sub-glabrous strain of
Stock in which the presence of a single characteristically branched
hair or hair-tuft over the water-gland terminating the midrib in a_
leaf otherwise glabrous is an hereditary character, it is hardly conceiv- —
able that there is a localisation in this region of a special hair-forming
substance. It seems more probable that some physiological condition

intimately connectea with the condition of water-content at some

critical period is a causal factor in hair production, and that this con-

dition is set up over the whole leaf in the type, but in the particular

strain in question is maintained only at the point which receives the

K.—BOTANY. 189

largest and most direct supply. In this same strain a leaf may now
and again be found lacking this hydathode trichome in an otherwise
continuous hair-forming series, an occurrence which may well result
from a slight fluctuation in physiological equilibrium such as is inherent
in all vital processes—a fluctuation which, when the genetic indicator
is set so near to the zero point, may well send it off the scale altogether.
If, as is not improbable in this and similar cases, we are concerned with
a complex chain of physiological processes, investigation of the nature
of the differences for which the allelomorphs stand may present a more
difficult problem than where the production of a particular chemical
compound appears to be involved. In such a physiological conception
we have probably the explanation of the non-appearance of the recessive
character in certain dominant cross-breds.

Up to this point we have treated of the organism from the aspect
of its being a wholly self-controlled, independent system. As regards
some characteristics, this may be regarded as substantially the case.
That is to say, the soma reflects under all observed conditions the
genetic constitution expressed in the Mendelian formula. Corre-
spondence is precise between genotypic potentiality and phenotypic
reality, and we have so far solved our problem that we can predict cer-
tainly and accurately the appearance of offspring, knowing the consti-
tution of the parents. In such cases we may say that the efficiency
of the genetic machine works out at 100 per cent., the influence of
external environment at 0. Our equation somatic appearance=factorial
constitution requires no correction for effect of conditions of tem-
perature, humidity, illumination, and the like. But most somatic
characters show some degree of variability. Phenotypic appearance
is the outcome primarily of genotypic constitution, but upon this are
superposed fluctuations, slight or more pronounced, arising ag the
result of reaction to environmental conditions. In the extreme case
the genetic machinery may, so to speak, be put out of action; geno-
typic potentiality no longer becomes actual. We say that the character
is not inherited. We meet with such an example in Ranunculus
aquatilis. According to Mer,*® the terrestrial form of this plant has no
hairs on the ends of the leaf segments, but in the aquatic individual the
segments end in needle-shaped hairs. That is to say, hairs of a definite
form are produced in a definite region. Again, Massart?7 finds that
in Polygonum amphibium the shoot produces characteristic multi-
cellular hairs when exposed to the air, but if submerged it ceases to form
them on the new growth. Every individual, however bred, behaves
in the same manner, and must therefore have the same genetic con-
stitution. In an atmospheric environment genotypic expression is

achieved, in water it becomes physiologically impossible. A limitation
to genotypic expression may in like manner be brought about by the
internal environment, for the relation of the soma to the germ elements
may be looked upon in this light. Thus in the case of a long-pollened
and round-pollened Sweet Pea Bateson and Punnett ?* found that the

26 Bull. Soc. Bot. de France, i. 27, 1880.
°7 Bull. Jard. Bot. Bruxelles, i. 2, 1902.
28 Report to the Hvolution Committee, Roy. Soc., ii., 1905.

190 SECTIONAL ADDRESSES.

F, pollen grains are all long, yet half of them carry the factor for
roundness. If we take the chromosome view, and if it be presumed
that the factor for roundness is not segregated until the reduction
division, the cytoplasm of the pollen mother cells may be supposed to
act as a foreign medium owing to a mixture of qualities having been
impressed upon it through the presence of the two opposite allelomorphs
before the moment of segregation. We should consequently infer that
the round pollen shape is only produced when the round-factor-bearing
chromosome is surrounded by the cytoplasm of an individual which
does not contain the long factor. If, further, we regard the result in
this case as indicative of the normal inter-relation of nucleus and
cytoplasm in the hereditary process, we shall be led to the view that
whatever the earlier condition of mutual equilibrium or interchange
between these two essential cell constituents may be, an ultimate stage
is reached in which the réle of determining agent must be assigned to
the nucleus. To pursue this theme farther, however, in the present
state of our knowledge would serve no useful purpose.

Before bringing this Address to a conclusion I may be permitted to
add one word of explanation and appeal. In my remarks I have
deliberately Ieft on one side all reference to the immense practical
value of breeding experiments on Mendelian lines. To have done so
adequately would have absorbed the whole time at my disposal. It is
unnecessary to-day to point out the enormous social and economic gain
following from the application of Mendelian methods of investigation
and of the discoveries which have resulted therefrom during the last
twenty years, whether we have in mind the advance in our knowledge
of the inheritance of ordinary somatic characters and of certain patho-
logical conditions in man, of immunity from disease in races of some
of our most important food plants, or of egg-production in our
domestic breeds of fowls.

My appeal is for more organised co-operation in the experimental
study of Genetics. It is a not uncommon attitude to look upon the
subject of Genetics as a science apart. But the complex nature of the
problems confronting us requires that the attacking force should be a
composite one, representing all arms. Only the outworks of the
fortress can fall to the vanguard of breeders. Their part done, they
wait ready to hand over to the cytologists with whom it lies to con-
solidate the position and render our foothold secure. This accom-
plished, the way is cleared for the main assault. To push this home
we urgently need reinforcements. It is to the physiologists and to the
chemists that we look to crown the victory. By their co-operation
alone can we hope to win inside the citadel and fathom the meaning of
those activities which take shape daily before our eyes as we stand
without and observe, but the secret of which is withheld from our
gaze.

anew oe eee

past

SECTION L: CARDIFF, 1920.
ADDRESS |
TO THE

EDUCATIONAL SCIENCE SECTION

BY
Sm ROBERT BLAIR, LL.D.,

PRESIDENT OF THE SECTION.

Introduction.

THE requirements of the Act of 1918 and the endeavour to frame
scales of salaries for teachers on a national basis are, at present, absorb-
ing so much of the energy of those engaged in educational administra-
tion that I have thought it advisable to turn our attention from the
immediate needs of the day to two of the wider aspects of our educa-
tional activities, which belong to the spirit rather than to the form of
our educational system.

It is natural that in this meeting of the British Association for the
Advancement of Science I should take first the Science of Education.

The value to education of science and the scientific method has
hitherto been for the most part indirect and incidental. It has con-
sisted very largely in deductions from another branch of study, namely,
psychology, and has resulted for the most part from the invasion into
education of those who were not themselves educationists. A moment
has now been reached when education itself should be made the subject
of a distinct department of science, when teachers themselves should
become scientists.

There is in this respect a close analogy between education and
medicine. Training the mind implies a knowledge of the mind, just
as healing the body implies a knowledge of the body. Thus, logically,
education is based upon psychology, as medicine is based on anatomy
and physiology. And there the text-books of educational method are
usually content to leave it. But medicine is much more than applied
physiology. It constitutes an independent system of facts, gathered
and analysed, not by physiologists in the laboratory, but by physicians
working in the hospital or by the bedside. In the same way, then,
education as a science should be something more than mere applied
psychology. It must be built up not out of the speculations of
theorists, or from the deductions of psychologists, but by direct,
definite, ad hoc inquiries concentrated upon the problems of the class-

192 SECTIONAL ADDRESSES.

room by teachers themselves. When by their own researches teachers
have demonstrated that their art is, in fact, a science, then, and not
till then, will the public allow them the moral, social, and economic
status which it already accords to other professions. The engineer
and the doctor are duly recognised as scientific experts. |The educa-
tionish should see to it that his science also becomes recognised, no
longer as a general topic upon which any cultured layman may dog-
matise, but as a technical branch of science, in which the educationist
alone, in virtue of his special knowledge, his special training, his special
experience, is the acknowledged expert.

Educational science has hitherto followed two main lines of investiga-
tion: first, the evaluation and improvement of teachers’ methods;
secondly, the diagnosis and treatment of children’s individual capacities.

I. The Psychology of the Individual Child.

It is upon the latter problem, or group of problems, that experi-
mental work has in the past been chiefly directed, and in the imme-
diate future is likely to be concentrated with the most fruitful results.
The recent advances in ‘ individual psychology "—the youngest branch
of that infant science—haye greatly emphasised the need, and assisted
the development, of individual teaching. The keynote of successful
instruction is to adapt that instruction to the individual child. But
before instruction can be so adapted, the needs and the capacities of
the individual child must first be discovered.

A. Diagnosis.

Such discovery (as in all sciences) may proceed by two methods,
by observation and by experiment.

(1) The former method is in education the older. At one time,
in the hands of Stanley Hall and his followers—the pioneers of the
Child-Study moyernent—observation yielded fruitful results. And it
is perhaps to be regretted that of late simple observation and descrip-
tion have been neglected for the more ambitious method of experi-
mental tests. There is much that a vigilant teacher can do without
using any special apparatus and without conducting any special ex-
periment. Conscientious records of the behaviour and responses of
individual children, accurately described without any admixture of in-
ference or hypothesis, would lay broad foundations upon which subse-
quent investigators could build. The study of children’s temperament
and character, for example—factors which have not yet been accorded
their due weight in education—must for the present proceed upon
these simpler lines.

(2) With experimental tests the progress made during the last
decade has been enormous. The intelligence scale devised by Binet for
the diagnosis of mental deficiency, the mental tests employed by the
American army, the vocational tests now coming into use for the selec-
tion of employees—these have done. much to familiarise, not school
teachers and school doctors only, but also the general public, with the
aims and. possibilities of psychological measurement. More recently
an endeavour has been made to assess directly the results of school

L..—-EDUCATION. 193

instruction, and to record in quantitative terms the course of progress
from year to year, by means of standardised tests for educational attain-
ments. In this country research committees of the British Association
and of the Child-Study Society have already commenced the standardisa-
tion of normal performances in such subjects as reading and arithmetic.
In America attempts have been made to standardise even more elusive
subjects, such as drawing, handwork, English composition, and the
subjects of the curriculum of the secondary school.

B. Treatment.

This work of diagnosis has done much to foster individual and
differential teaching—the adaptation of education to individual children,
or at least to special groups and types. It has not only assisted the
machinery of segregation—of selecting the mentally deficient child at one
end of the scale and the scholarship child at the other end; but it has
also provided a method for assessing the results of different teaching
methods as applied to these segregated groups. Progress has been most
pronounced in the case of the sub-normal. The mentally defective are
now taught in special schools, and receive an instruction of a specially
adapted type. Some advance has more recently been made in differen-
tiating the warious grades and kinds of so-called deficiency, and in dis-
criminating between the deficient and the merely backward and dull.
With regard to the morally defective and delinquent little scientific work
has been attempted in this country, with the sole exception of the new
experiment initiated by the Birmingham justices. In the United States
some twenty centres or clinics have been established for the psycho-
logical examination of exceptional children; and in England school
medical officers and others have urged the need for ‘ intermediate’
classes or schools not only to accommodate backward and borderline
cases and cases of limited or special defect (e.g., ‘ number-defect ’ and
so-called ‘ word-blindness ’) but also to act as clearing-houses.

In Germany and elsewhere special interest has been aroused in
super-normal children. The few investigations already made show
clearly that additional attention, expenditure, study, and provision will
yield for the community a far richer return in the case of the super-
normal than in the sub-normal.

At Harvard and elsewhere psychologists have for some time been
elaborating psychological tests to select those who are best fitted for
different types of vocation. The investigation is still only in its initial
stages. But it is clear that if vocational guidance were based, in part
at least, upon observations and records made at school, instead of being
based upon the limited interests and knowledge of the child and his
parents, then not only employers, but also employees, their work, and
the community as a whole, would profit. A large proportion of the
vast wastage involved in the current system of indiscriminate engage-
ment on probation would be saved.

The influence of sex, social status, and race upon individual differ-
ences in educational abilities has been studied upon a small scale.
The differences are marked: and differences in sex and social status,
when better understood, might well be taken into account both in

1920 0

194 SECTIONAL ADDRESSES.

diagnosing mental deficiency and in awarding scholarships. As a rule,
however, those due to sex and race are smaller than is popularly sup-
posed. How far these differences, and those associated with social
status, are inborn and ineradicable, and how far they are due to
differences in training and in tradition, can hardly be determined without
a vast array of data.

II. Teaching Methods.

The subjects taught and the methods of teaching have considerably
changed during recent years. In the more progressive types of schools
several broad tendencies may be discerned. All owe their acceptance
in part to the results of scientific investigators.

(1) Far less emphasis is now laid upon the disciplinary value of
subjects, and upon subjects whose value is almost solely disciplinary.
Following in the steps of a series of American investigators, Winch and
Sleight in this country have shown very clearly that practice in one
kind of activity produces improvements in other kinds of activities, only
under very limited and special conditions. The whole conception of
transfer of training is thus changed, or (some maintain) destroyed;
and the earlier notion of education as the strengthening, through exer-
cise, of certain general faculties has consequently been revolutionised.
There is a tendency to select subjects and methods of teaching rather
for their material than their general value.

(2) Far less emphasis is now laid upon an advance according to strict
logical sequence in teaching a given subject of the curriculum to children
of successive ages. The steps and methods are being adapted rather to
the natural capacities and interests of the child of each age. This
genetic standpoint has received great help and encouragement from
experimental psychology. Binet’s own scale of intelligence was in-
tended largely as a study in the mental development of the normal child.
The developmental phases of particular characteristics (e.g., children’s
ideals) and special characteristics of particular developmental phases
(e.g., adolescence) have been elaborately studied by Stanley Hall and his
followers. Psychology, indeed, has done much to emphasise the im-
portance of the post-pubertal period—the school-leaving age, and the
years that follow. Such studies have an obvious bearing upon the
curriculum and methods for our new continuation schools. But it is,
perhaps, in the revolutionary changes in the teaching methods of the
infants’ schools, changes that are already profoundly influencing the
methods of the senior department, that the influence of scientific study
has been most strongly at work.

(3) Increasing emphasis is now being laid upon mental and motor
activities. arly educational practice, like early psychology, was ex-
cessively intellectualistic. Recent child-study, however, has em-
phasised the importance of the motor and of the emotional aspects of
the child’s mental life. As a consequence, the theory and practice
of education have assumed more of the pragmatic character which has
characterised contemporary philosophy. grt

The progressive introduction of manual and practical subjects, both
in and for themselves, and as aspects of other subjects, forms the most

L.— EDUCATION. 195

notable instance of this tendency. The educational process is assumed
to start, not from the child’s sensations (as nineteenth-century theory
was so apt to maintain), but rather from his motor reactions to certain
perceptual objects—objects of vital importance to him and to his species
under primitive conditions, and therefore appealing to certain instinctive
impulses. Further, the child’s activities in the school should be, not
indeed identical with, but continuous with, the activities of his subse-
quent profession or trade. Upon these grounds handicraft should now
find a place in every school curriculum. It will be inserted both for
its own sake, and for the sake of its connections with other subjects,
whether they be subjects of school life, of after life, or of human life
generally.

(4) As a result of recent psychological work, more attention is now
being paid to the emotional, moral, and esthetic activities. This is a
second instance of the same reaction from excessive intellectualism.
Education in this country has ever claimed to form character as well as
to impart knowledge. Formerly, this aim characterised the Public
Schools rather than the public elementary schools. Recently, however,
much has been done to infuse into the latter something of the spirit of
the Public Schools. The principle of self-government, for example, has
been applied with success not only in certain elementary schools, but
also in several colonies for juvenile delinquents. And, in the latter
case, its success has been attributed by the initiators directly to the
fact that it is the corollary of sound child-psychology.

Bearing closely upon the subject of moral and emotional training
is the work of the psycho-analysts. Freud has shown that many forms
of mental inefficiency in later life—both major (such as hysteria,
neurosis, certain kinds of ‘ shell-shock,’ &c.) and minor (such as lapses
of memory, of action, slips of tongue and pen)—are traceable to the
repression of emotional experiences in earlier life. The principles
themselves may, perhaps, still be regarded as, in part, a matter of
controversy. But the discoveries upon which they are based vividly
illustrate the enormous importance of the natural instincts, interests,
and activities inherited by the child as part of his biological equip-
ment; and, together with the work done by English psychologists such
as Shand and McDougall upon the emotional basis of character, havé
already had a considerable influence upon educational theory in this
country. y

(5) Increasing emphasis is now being laid upon freedom for indi-
vidual effort and initiative. Here, again, the corollaries drawn from the
psycho-analytic doctrines as to the dangers of repression are most sug-
gestive. Already a better understanding of child-nature has led to the
substitution of ‘internal ’ for ‘ external’ discipline ; and the pre-deter-
mined routine demanded of entire classes is giving way to the growing
recognition of the educational value of spontaneous efforts initiated by
the individual, alone or in social co-operation with his fellows.

In appealing for greater freedom still, the new psychology is in line
with the more advanced educational experiments, such as the work done
by Madame Montessori and the founders of the Little Commonwealth.

(6) The hygiene and technique of mental work is itself being based

196 SECTIONAL ADDRESSES.

upon scientific investigation. Of the numerous problems in the con-
ditions and character of mental work generally, two deserve especial
mention—fatigue, and the economy and technique of learning.

But of all the results of educational psychology, perhaps the most
valuable is the slow but progressive inculcation of the whole teaching
profession with a scientific spirit in their work, and a scientific attitude
towards their pupils and their problems. Matter taught and teaching
methods are no longer exclusively determined by mere tradition or mere
opinion. They are being based more and more upon impartial observa-
tion, careful records, and statistical analysis—often assisted by labora-
tory technique—of the actual behaviour of individual children.

I turn now to the second aspect.

So much of our educational system is voluntary that it is often
called a dual system. But in speaking of a dual system only the
primary stage is, as arule,in our minds. Yet to foreign students some
parts of our higher education, e.g., the Public Schools, appear as that
which is most definitely English in character. The Public Schools,
however, form no part of the system of public (i.e. of State and muni-
cipal) education and are not directly associated with it.

The reasons are fairly obvious. Many of the Public Schools are
centuries old; our public system began but fifty vears ago. The Act of
1870 gave us only public elementary schools. More than thirty years
elapsed before we had the beginnings of a system of secondary schools.
Even to-day, with the comprehensive Act of 1918, whose primary
object is to establish a national system of education, the Public Schools.
owing largely to the fact that the Act is administered by 318 Local
Education Authorities, retain a ‘ non-local’ character.

The Public Schools of England have no parallel. They have their
defects and their critics; but they have had a paramount influence on
the intellectual and social life of the country. They are admired less
for the intellectual severity of the class-room than for their traditions,
their form of self-government, and as training places of a generous
spirit. In the past the Public Schools in the education of the aristocracy
achieved a national purpose. They were the nurseries of English
thought and action. Now that the predominant power in the State
has passed to the nation as a whole, it would only be in keeping with
their long-cherished traditions if the Public Schools were to seek a
share in the education of democracy. Moreover, the problems of Local
Education Authorities are of such absorbing interest that the profes-
sional svirit of the Public Schoolmaster must be longing to assist in
their solution,

The two older Universities have had a history, and have borne a
part in the national life, analogous to, but on a much larger scale than,
the Public Schools. They also are ‘ non-local’: they serve the Empire.
The newer Universities are much more local in character. Yet as a
whole it can hardly be said that they exercise an important influence
on the work of the Local Education Authorities. I am not overlooking
the fact that the Universities, like the Public Schools, play their own

L.--EDUCATION. 197

part in providing the most advanced education; nor that they place
their best at the disposal of the Local Education Authorities’ scholars
and contribute a part of the teaching staff. I am, however, to-day
suggesting a closer association with Local Education Authorities, and of
bringing to bear more immediately on local and public education the
wealth of their long experience and the riches of their accumulated
knowledge.

There is a third group of institutions which have had a large
share in English education, I refer to the endowed Grammar Schools.
Partly of choice, partly through stress of circumstances, many of
these schools have joined forces with the Local Education Authorities.
With the recent rapid growth in the cost of maintenance and with in-
adequacy of other sources of income they have received ‘aid’ from
the Authority. Some have. become municipal schools: others have
undertaken to bear their share in local work, but have retained their
individuality of character and independence of Government, to both of
which they are passionately attached. All have contributed much to
the general storehouse of ideas, and the local system has been enriched
by the co-operation of forces of different origin, methods, and historical
significance, —

All three groups of institutions were founded by the few whose spirit
in so far as it sought the spread of education has now passed to the
multitude. They are ali national institutions, but, with the exceptions
to which I have referred, they form no part of the national system
administered by Local Education Authorities and supervised by the
Board of Education. I do not, of course, suggest control. That is
obviously impossible in the case of two of the groups. Nor am I
to-day thinking of making constructive proposals as to the forms of
associations. Such proposals will, I hope, be put forward later in the
week. For the moment it will be sufficient to add that the association
desired is direct and close rather than indirect and remote, and in
teaching rather than in administration.

There is one further group which I cannot pass in silence: the
priyate schools. Each Local Education Authority must, under Section 1
of the Act of 1918, submit a scheme for the progressive and compre-
hensive organisation of education within its area. Presumably, each
Local Education Authority will include the local ‘places’ in efficient
private schools as part of the accommodation already provided in the
area. All such efficient private schools, whether run for private profit
or not, reduce the provision to be made by the Authority. To the
extent to which they relieve the burden on the Authority they are
therefore contributing to the public service. In return the Authority,
while it cannot financially assist schools conducted for private profit,
can confer advantages through close association with its organisation.
All. private schools doing local work, at all events all which claim to
be efficient, would therefore serve their own interests and render public
seryice by entering into communication with the Authority and getting
the lines of local co-operation satisfactorily adjusted.

198 SECTIONAL ADDRESSES.

It would not be possible to exhaust the possibilities of co-operation of
voluntary endeavour with the public system, even if my whole paper
had been devoted to this subject. JI am anxious, however, to carry
my suggestions one step further. It is of the essence of voluntary
effort that it is constantly evolving new forms. 1n most large towns
within the last ten years Care Committees have been established, some
merely to assist the Authorities in carrying out the more social powers
and duties conferred on them by the Act; others with the higher
ambition of ‘building up the homes.’ Such Care Committees have
rendered a great service to their areas not only in work actually done
under the direction of the Authority, but in the fact that they have
frequently introduced new and opposite points of view from those of
the administration. The Act of 1918 offers wider opportunities, and
many social workers are beginning to realise it. During the last
twelve months, in connection with the establishment of Day Continua-
tion Schools, I have met in consultation, or addressed meetings, of
social workers, trades-union representatives, club leaders, employers,
clergy of various denominations, and parents; together and separately.
I have met with opposition and criticism and divergent points of view,
but what has gratified me most has been the general and eager desire
for an increase in educational facilities and an improvement in social
conditions. No subject for discussion has been so well received as that
of training our young workers to use their leisure wisely. There has
been the fullest recognition that all must join up in the common task ;
that the greatest opportunity of our time for joint endeavour in a wider
educational effort has come; to miss it would be something in the
nature of a betrayal of our several functions. If our continuation
schools are to become national, not only in the sense of being universal
and comprehensive, but in the generous nature of the spirit which
inspires them, all that is best in our trade, social, and sports organisa-
tions must be brought to bear on their external and internal activities.
On this ground alone I feel sure that there was general satisfaction
that the guidance of the Juvenile Organisation Committees, and al!
that they stand for, was transferred from the Home Office, which has
the great credit of having consolidated them, to the Board of Education,
which is the official foster-mother of our educational system. In the
London area the Juvenile Organisation Committees have gradually be-
come representative in the widest sense of all social organisations,
and it is anticipated that before long lines of co-operation with the
Authority will be established. 'The task in all areas is so large that
there is ample room for all; it is so complex that there is need for all
and it is of such importance to the future that it would be a national
misfortune not to welcome the service of all.

It is difficult for this generation to estimate with true insight the
after-effects of the war. But it would seem as if there had rarely been
a time when the minds of men were so much loosened from great
principles. Such a condition is no doubt partly a reaction from a
period of tense anxiety in which suppression of the individual and
sacrifice for the community were the demands of a struggle for existence.
But the general mental attitude may also be a reaction, accentuated by the

L.— EDUCATION. | 199

war, against the interpretation of the great principles which has hitherto
directed us, to continue to deserve universal adherence. The outlook is
yet clouded. Will the present individualistic point of view continue, or
are we but being carried through a transition phase until the coming
of a new rallying cry which will restate the brotherhood of man in
some new and captivating form? However that may be, our course
seems clear: it is to develop the intelligence and the spirit of social
. service in our whole population in complete confidence that the solidity
of the English character fortified with such weapons will maintain and
expand that civilisation which has brought us so far, and which we
owe it to posterity to hand on not only unimpaired, but broadened and
deepened by new streams of thought and action. It is in this sense that
the. spread of educational advantages is the hope of all, and that I
have made this appeal for all educational and social forces to concen-
trate in one national effort. In the words of one of our greatest poets:

Give all thou canst—high Heaven rejects the lore
Of nicely calculated less or more.

SECTION M: CARDIFF, 1920,

ADDRESS

AGRICULTURAL SHCTION

BY
PROFESSOR FREDERICK KEEBUH, C.B.E., Sc.D., F.R.S.,

PRESIDENT OF THE SECTION.
Intensive Culitvation.

THERE is, so far as I can discoyer, no reason—save one—why I
should have been called upon to assume the presidency of the Agri-
cultural Section of the British Association, or why I should have been
temerarious enough to accept so high an honour and such a heavy load
of responsibility. For upon the theme of Agriculture as commonly
understood I could speak, were I to speak at all, but as a scribe and
not as one in authority. The one reason, however, which must have
directed the makers of presidents in their present choice is, I believe,
so cogent that despite my otherwise unworthiness I dared not refuse
the invitation. It is that, in appointing me, agriculturists desired to
indicate the brotherhood which they feel with intensive cultivators. As
properly proud sisters of an improved tale they have themselves issued
an invitation to the Horticultural Cinderella to attend their party, and
in conformity with present custom, which requires each lady to bring
her partner, I am here as her friend.

Nor could any invitation give me greater pleasure: for my devotion
to Horticulture is profound and my affection that of a lover. My only
fear is lest I should weary my hosts with her praises, for in conformity
with this interpretation I propose to devote my Address entirely to
Horticulture—to speak of its performance during the war and of its
immediate prospects.

Although that which intensive cultivators accomplished during the
war is small in comparison with the great work performed by British
agriculturists, yet nevertheless it is in itself by no means incon-
siderable, and is, moreover, significant and deserves a brief record.
That work may have turned and probably did turn the scale between
scarcity and sufficiency; for, as I am informed, a difference of 10 per
cent. in food supplies is enough to convert plenty into dearth. Seen
from this standpoint the war-work accomplished by the professional
horticulturist—the nurseryman, the florist, the glass-house cultivator,
the fruit-grower and market gardener, and by the professional and
amateur gardener and allotment holder assumes a real importance,
albeit that the sum-total of the acres they cultivated is but a fraction
of the land which agriculturists put under the plough.

M.—AGRICULTURE. 201

As a set-off against the relative smallness of the acreage brought
during the war under intensive cultivation for food purposes, it is to be
pemembered that the yields per acre obtained by intensive cultivators
are remarkably high. For example, skilled onion-growers compute
their average yield at something less than 5 tons to the acre. A
chrysanthemum-grower who turned his resources from the production
of those flowers to that of onions obtained over an area of several acres
a yield of 17 tons per acre. The average yield of potatos
under farm conditions in England and Wales is a little over 6 tons to
the acre, whereas the army gardeners in France produced, from Scotch
seed of Arran Chief which was sent to them, crops of 14 tons to
the acre. Needless to say, such a rate of yield as this is not remarkable
when compared with that obtained by potato-growers in the
Lothians or in Lincolnshire, but it is nevertheless noteworthy as an
indication of what I think may be accepted as a fact, that the average
yields from intensive cultivation are about double those achieved by
extensive methods.

The reduction of the acreage under soft fruits—strawberries, rasp-
berries, currants, and gooseberries—which took place during the
war gives some measure of the sacrifices—partly voluntary, partly
involuntary—made by fruit-growers to the cause of war-food produc-
tion. The total area under soft fruits was 55,560 acres in 19138,
by 1918 it had become 42,415, a decrease of 13,145 acres, or about
24 per cent. As would be expected, the reduction was greatest in the
case of strawberries, the acreage of which fell from 21,692 in 1913 to
13,143 in 1918, a decrease of 8,549 acres, or about 40 per cent. It is
unfortunate that bad causes often have best propagandas, for were the
public made aware of such facts as these they would realise that the
present high prices of soft fruits are of the nature of deferred premiums
on war-risk insurances with respect to which the public claims were
paid in advance and in full.

I should add that the large reduction of the strawberry acreage is a
measure no less of the short-sightedness of officials than of the public
spirit of fruit-growers; for in the earlier years of the war many
counties issued compulsory orders requiring the grubbing up and
restriction of planting of fruit, and I well remember that one of my
first tasks as Controller of Horticulture was to intervene with the object
of convincing the enthusiasts of corn production that, in war, some
peace-time luxuries become necessaries and that, to a sea-girt island

beset by submarines, home-grown fruit most certainly falls into this
category.

Those who were in positions of responsibility at that time will not
readily forget the shifts to which they were put to secure and preserye
supplies of any sorts of fruit which could be turned into jam—the
collection of blackberries, the installation of pulping factories which
Mr. Martin and I initiated, and the rushing of supplies of scarcely set
jam to great towns, the populace of which, full of a steadfast fortitude
in the face of military misfortune, was ominously losing its sweetness
of disposition owing to the absence of jam and the dubiousness of the
supply and quality of margarine.

202 SECTIONAL ADDRESSES.

But though the public lost in one direction it gained in another,
and the reduction of the soft-fruit acreage meant—reckoned in terms of
potatos—an augmentation of supplies to the extent of over 100,000
tons. Equally notable was the contribution to food production made
by the florists and nurserymen in response to our appeals. An indication
of their effort is supplied by figures which, as president of the British
Florists’ Federation, Mr. George Munro—whose invaluable work for
food production deserves public recognition—caused to be collected.
They relate to the amount of food production undertaken by 100 leading
florists and nurserymen. These men put 1,075 acres, out of a total of
1,775 acres used previously for flower-growing, to the purpose of food
production, and they put 142 acres of glass out of a total of 218 acres
to like use. I compute that their contribution amounted to considerably
more than 12,000 tons of potatos and 5,000 tons of tomatos.

The market growers of Evesham and other districts famous for inten-
sive cultivation also did their share by substituting for luxury crops,
such as celery, those of greater food value, and even responded to our
appeals to increase the acreage under that most chancy of crops—the
onion, by laying down an additional 4,000 acres and thereby doubling
a crop which more than any other supplies accessory food substances
to the generality of the people.

In this connection the yields of potatos secured by Germany and
this country during the war period are worthy of scrutiny.

The pre-war averages were: Germany 42,450,000 tons, United
Kingdom 6,950,000 tons; and the figures for 1914 were: Germany
41,850,000 tons, United Kingdom 7,476,000 tons.

Germany’s supreme effort was made in 1915 with a yield of
49,570,000 tons, or about 17 per cent. above average. In that year our
improvement was only half as good as that of Germany: our erop of
7,540,000 tons bettering our average by only 8 per cent. In 1916
weather played havoc with the crops in both countries, but Germany
suffered most. The yield fell to 20,550,000 tons, a decrease of more
than 50 per cent., whilst our yield was down to 5,469,000 tons, a
falling off of only 20 per cent. In the following year Germany could
produce no more than 39,500,000 tons, or a 90 per cent. crop, whereas
the United Kingdom raised 8,604,000 tons, or about 24 per cent. better
than the average. Finally, whereas with respect to the 1918 crop in
Germany no figures are available, those for the United Kingdom indi-
cate that the 1917 crop actually exceeded that of 1918.

There is much food for thought in these figures, but my immediate
purpose in citing them is to claim that of the million and three-quarter
tons increase in 1917 and 1918 a goodly proportion must be put to the
éredit of the intensive cultivator.

I regret that no statistics are available to illustrate the war-time food
production by professional and amateur gardeners. That it was great
I know, but how great I am unable to say. This, however, I can
state, that from the day before the outbreak of hostilities, when, with
the late Secretary of the Royal Horticultural Society, I started the in-
tensive food-production campaign by urging publicly the autumn sowing
of vegetables—a practice both then and now insufficiently followed—the

M.—AGRICULTURE. 908

amateur and professional gardeners addressed themselves to the work
of producing food with remarkable energy and success. No less remark-
able and successful was the work of the old and new allotment holders,
so much so indeed that at the time of the Armistice there were nearly
a million and a-half allotment holders cultivating upwards of 125,000
acres of land: an allotment for every five households in England and
Wales. It is a pathetic commentary on the Peace that Vienna should
find itself obliged to do now what was done here during the war—
namely, convert its parks and open spaces into allotments in order to
supplement a meagre food supply.

This brief review of war-time intensive cultivation would be in-
complete were it to contain no reference to intensive cultivation by the
armies at home and abroad. From small beginnings, fostered by the
distribution by the Royal Horticultural Society of supplies of vegetable
seeds and plants to the troops in France, army cultivation assumed
under the direction of Lord Harcourt’s Army Agricultural Committee
extraordinarily large dimensions: a bare summary must suffice here,
but a full account may be found in the report presented by the Com-
mittee to the Houses of Parliament and published as a Parliamentary
Paper.

Th 1918 the armies at home cultivated 5,869 acres of vegetables. In
the summer of that year the camp and other gardens of our armies in
France were producing 100 tons of vegetables a day. These gardens
yielded, in 1918, 14,000 tons of vegetables, worth, according to my
estimate, a quarter of a million pounds sterling, but worth infinitely
more if measured in terms of benefit to the health of the troops.

As the result of General Maude’s initiative, the forces in Meso-
potamia became great gardeners, and in 1918 produced 800 tons of
vegetables, apart altogether from the large cultivations carried out by
His Majesty’s Forces in that wonderfully fertile land. In the same
year the forces at Salonika had about 7,000 acres under agricultural and
horticultural crops, and raised produce which effected a saving of over
50,000 shipping tons.

Even from this brief record it will, I believe, be conceded that
intensive cultivation played a useful and significant part in the war:
what, it may be asked, is the part which it is destined to play in the
future? So far as I am able to learn, there exist in this country two
schools of thought or opinion on the subject of the prospects
of intensive cultivation, the optimistic and the pessimistic school.
The former sees visions of large communities of small cultivators
colonising the countryside of England, increasing and multiplying both
production and themselves, a numerous, prosperous and happy people
and a sure shield in time of war against the menace of submarines and
starvation. Those on the other hand who take the pessimistic view,
point to the many examples of smallholders who ‘ plough with pain
their native lea and reap the labour of their hands’ with remarkably
small profit to themselves or to the community—smallholders like
those in parts of Warwickshire, who can just manage by extremely
hard labour to maintain themselves, or like those in certain districts of
Norfolk, who have let their holdings tumble down into corn and who’

204. SECTIONAL ADDRESSES.

produce no more and indeed less to the acre than do the large farmers
who are their neighbours.

Before making any attempt to estimate the worth of these rival
opinions it may be observed that the war has brought a large reinforce-
ment of strength to the rank of the optimists. A contrast of personal
experiences illustrates this fact. When in the early days of the war
I felt it my duty to consult certain important county officials with the
object of securing their support for schemes of intensive food production,
1 carried away from the conference one conclusion only: that the
counties of England were of two kinds, those which were already doing
much and were unable therefore to do more, and those which were
doing little because there was no more to be done. In spite of this close
application of the doctrine of Candide—that all is for the best in the
best of all possible worlds—I was able to set up some sort of county
horticultural organisation, scrappy, amateurish, but enthusiastic, and
the work done by that organisation was on the average good; so much
so indeed that when after the Armistice I sought to build up a per-
manent county horticultural organisation I was met by a changed
temper. The schemes which the staff of the Horticultural Division had
elaborated as the result of experience during the war were received
and adopted with a cordiality which I like to think was evoked no less
by the excellence of the schemes themselves than by the promise of
liberal financial assistance in their execution. Thus it came about that
when the time arrived for me to hand over the controllership of Horti-
culture to my successor, almost every county had established a strong
County Horticultural Committee, and the chief counties from the point
of view of intensive cultivation had provided themselves with. a staff
competent to demonstrate not only to cottagers and allotment holders,
but also to smallholders and commercial growers, the best methods of
intensive cultivation. In the most important counties horticultural
superintendents with knowledge of commercial fruit-growing were being
appointed, and demonstration fruit and market-garden plots, designed
on lines laid down by Captain Wellington and his expert assistants,
were in course of establishment. The detailed plans for these links
in a national chain of demonstration and trial plots haye been published,
and anyone who will study them will, I believe, recognise that they
point the way to the successful development of a national system of
intensive cultivation.

By means of these county stations the local cultivator may learn
how to plant and maintain his fruit plantation and how to crop his
vegetable quarters, what stock to run and what varieties to grow.

Farm stations—with the Research stations established previously
by the Ministry ; Long Ashton and East Malling for fruit investigations ;
the Lea Valley Growers’ Association and Rothamstead for investigation
of soil problems and pathology; the Imperial College of Science for
research in plant physiology, together with a couple of stations, con-
templated before the war, for local investigation of vegetable cultiya-
tion; an alliance with the Royal Horticultural Society’s Research
Station at Wisley, and with the John Innes Horticultural Institute for
research in genetics; the Ormskirk Potato Trial Station; a Poultry

M.—AGRICULTURE. 205

Tnstitute ; and, most important of all from the point of view of educa-
tion, the establishment at Cambridge of a School of Horticulture—con-
stitute a horticultural organisation which, if properly co-ordinated and—
dare I say it?—directed, should prove of supreme value to all classes
of intensive cultivators. To achieve that result, however, something
more than a permissive attitude on the part of the Ministry is required,
and in completing the design of it I had hoped also to remain a part
of that organisation long enough to assist in securing its functioning as

a living, plastic, resourceful, directive force—a horticultural cerebrum.
Thus developed, it is my conviction that this instrument is capable of
bringing Horticulture to a pitch of perfection undreamed of at the present
time either in this country or elsewhere.

In my view Horticulture has suffered in the past because the foster-
ing of it was only incidental to the work of the Ministry. In spite of
the fact that it had not a little to be grateful for—as for example the
research stations to which I have referred—Horticulture had been
regarded rather as an agricultural side-show than as a thing in itself.
My intention, in which I was encouraged by Lord Ernle, Lord Lee,
and Sir Daniel Hall, was to peg out on behalf of Horticulture a large
and valid claim and to work that claim. The conception of Horticulture
which I entertained was that comprised in the ‘ petite culture’ of the
French. It included crops and stock, fruit and vegetables, flower and
bulb ana seed crops, potatos, pigs and poultry and bees. [I held
the view, and still hold it, that the small man’s interests cannot be
fostered by the big man’s care; that Horticulture is a thing in itself
and requires constant consideration by horticulturists and not occasional
help from agriculturally minded people, however distinguished and
capable.

I had to include the pig and poultry, for the smallholder and
commercial grower will have to keep the one and may with profit
keep both, and he will have to modify his system of cultivation accord-
ingly. The adoption of this conception of the scope of intensive culti-
vation opens up an array of new problems which require investigation,
and it was my intention to endeavour to secure the experimental solu-
tion of these many problems at the Research Stations and elsewhere.
Beside these problems—of green manuring, cropping, horticultural
rotations—horticultural surveys would be made, ‘ primeur’ lands
demarked for colonisation. and existing orchard lands ascertained and
classified, as indeed we had begun to do in the West of England.
But. above all, with this measure of independence for Horticulture we,
having the good will and support of the fraternity of horticulturists,
aimed at putting to the test the certain belief which I hold that education
—sympathetic and systematic—is an instrument the power of which,
for our purpose. scarcely vet tried, is in fact of almost infinite potency.
I believe with Mirabean that, ‘ after bread, education is the first need
‘of thé people,’ and I know that the people themselves are ready to
receive it.

Contrast this horticultural prospect with the fast that a group of
smallholders in an outlying district informed one of my inspectors that

2.06 SECTIONAL ADDRESSES.

his was the first visit that they had received for many years, or with
the fact that remediable diseases are still rife in hundreds of gardens,
or that few small growers understand the principles which should guide
them in deciding whether or not to spray their potatos, or that West
Country orchardists exist who let dessert fruit tumble to the ground
and sell it in ignorance of its true value, or that unthrifty fruit-trees
may be top-grafted but are not, or that it is often ignored that arsenate
of lead as a spray fluid for fruit pays over and over again for its use,
or even that growers in plenty still do not know that Scotch or Irish
or once-grown Lincolnshire seed potatos are generally more profitable
than is home-grown or local seed. The truth is that great skill and
sure knowledge exist among small cultivators side by side with much
ignorance and moderate practical ability. Herein lies the opportunity
of the kind of education which I have in mind. But for any such
intensive system of education to prevail the isolation both of cultivators
and of Government Departments must be abolished. Out of that isola-
tion hostility arises, in which medium no seed of education will
germinate. It is troublesome, but not difficult, to abolish hostility.
It vanishes when direct relations are established and maintained between
a Department and those whose affairs jt administers. The paternal
method will not do it. The official life, lived ‘ remote, unfriendly,
alone,’ with only underlings as missionaries to the heathen public,
will not do it.

There is only one way to prepare the ground for the intensive
cultivation of education, and that is to secure the full co-operation of
officials and cultivators. If this be not done the official must continue
to bear with resignation the unconcealed hostility of those he wishes
to assist. That a state of confidence and co-operation may be esta-
blished is proved by the record of the Horticultural Advisory Committee
which was set up by Lord Ernle during my controllership. The Com-
mittee consisted of representatives of all the many branches of Horti-
culture—fruit-growers, nurserymen, market gardeners, growers under
glass, salesmen, researchers, and so forth. That Committee became,
as it were, the Deputy-Controller of Horticulture. To it all large ques-
tions of policy were referred, and to its disinterested service Horticulture
owes a great debt. That its existence has been rendered permanent
by Lord Lee is of good augury for the future of intensive cultivation.
As an instance of the judicial temper in which this Committee attended
to its business I may mention that when an Order—the Silver Leaf
Order—was under discussion the only objection to its terms on the
part of the fruit-growers on the Committee was that the restrictive
measures which it contemplated were not drastic enough: a noteworthy
example of assent to a self-denying ordinance.

It may be asked What are the subjects in which growers require
education? To answer that question: fully would require an Address in
itself. Among those subjects, however, mention may be made of. a
few: the extermination or top-grafting of unthrifty fruit, the proper
spacing and pruning of fruit-trees, the use of suitable stocks, -sys-
tematic orchard-spraying, the use of thrifty varieties of bush fruit and
the proper manuring thereof, the choice of varieties suitable to given

M.—AGRICULTURE. 207

soils and districts and for early cropping, the better grading and packing
of fruit.

Of all methods of instruction in this last subject the best is that
provided by Fruit Exhibitions. Those interested in the promotion of
British fruit-growing will well remember the object-lesson in good and
bad packing provided by the first Eastern Counties Fruit Show, held
afi Cambridge in 1919. That exhibition, organised by the East Anglian
fruit-growers with the assistance of the Horticultural Division of the
Ministry of Agriculture, demonstrated three things: first, that fruit of
the finest quality is being grown in Hast Anglia; second, that ‘this
district may perhaps become the largest fruit-growing region in Eng-
land; and, third, that among many growers profound ignorance exists
with respect to the preparation of fruit for market.

The opinions which I have endeavoured to express on the organisa-
tion of intensive cultivation may be summarised thus :—

1. The object of the organisation is to improve local and general
cultivation, the former by demonstration, the latter by research.

2. The method of organisation must provide for co-operation between
the horticultural officers of the State and the persons engaged in the
industry. ‘This co-operation must be real and complete. Dummy
Committees are silly devices adopted merely by second-rate men and
merely clever administrators. The co-operation must embrace the policy
as well as the practice of administration. Nevertheless the horti-
cultural officers of the State must be leaders. They can, however, lead
only by the power of knowledge. Wherefore an administrator who
lacks practical knowledge and scientific training is not qualified to act
as the executive head of a horticultural administration. The head
must of course possess administrative capacity, but this form of
ability is by no means uncommon among Britons, although it is a
custom to represent it as something akin to inspiration and the attribute
of the otherwise incompetent. The directing head must possess a wide
practical knowledge of Horticulture; that alone can fire the train of
his imagination to useful and great issues. His right-hand man, how-
ever, must be one versed in departmental and interdepartmental intrica-
cies—the best type of administrator—of sober and cool judgment and
keen intelligence, unused perhaps to enthusiasm, but not intolerant of
nor immune from it. Similarly in each sub-department for cultivation,
disease-prevention, small stock, &c., the head must be a trained prac-
tical man with an administrator as his chief assistant. The outdoor
officers, the intelligence officers of the organisation, must also be men
of sound and wide practical knowledge and must know that their
reports will be read by someone who understands the subjects whereof
they speak.

It was on these lines that the Horticultural Division was organised
under Lord Ernle, Lord Lee, and Sir Daniel Hall. The work accom-
plished justified the innovation.

_ This is the contribution which I feel it my duty to make on the
vexed question of the relation between expert and administrator in
Departments of State which deal with technical and vital problems.

I
:
i

I believe that no administrator, save the rare genius, can direct the

208 SECTIONAL ADDRESSES.

expert, whereas the expert with trained scientific mind and possessed
of a fair measure of administrative ability can direct any but a génius
for administration. If the work of a Government office is to be and
remain purely administrative no creative capacity is required, and it
may be left in the sure and safe and able hands of the trained adminis-
trator; but if the work is to be creative it must be under the direction
of minds turned as only research can turn them—in the direction of
creativeness. To the technically initiated initiation is easy and attrac-
tive, to the uninitiated it is difficult and repugnant.

The useful work that such a staff as I have indicated would find
to do is well-nigh endless. It would become a bureau of information
in national horticulture. and the knowledge which it acquired would be
of no less use to investigators than to the industry. Diseases ravage
our orchards and gardens, some are known to be remediable and yet
persist, others require immediate and vigorous team-wise investiga-
tion and yet continue to be investigated by solitary workers or single
research institutions.

Certain new varieties of some soft fruits are known to be better
than the older varieties, and yet the latter continue to be widely culti-
vated. The transport and distribution of perishable fruit is often in-
adequate—‘ making a famine where abundance lies.’ The informa-
tion gathered in during the constant survey of the progress of Horticul-
ture would serve not only to direct educational effort into useful channels.
but to stimulate and assist research. For the headquarters staff of
trained men learns in the course of its administrative work many things,
which, albeit unknown to the researcher, are of first importance to him
who is bent on advancing horticultural knowledge.

For example, it is known that the trade of raisers of seed potatos
for export to Jersey or Spain is in some places menaced by the presence
of a plot of land a mile or two away in which wart disease has appeared.
It may be that the outbreak occurred on only a single plant, yet never-
theless the seed-potato grower may be inhibited from exporting the
seed grown by him on clean land. The prohibition is just, but the man
who refuses to issue a licence to export, if he be a trained horticulturist
in touch with research, will know that there is research work to hand
and that immediately, and will bring the problem to the urgent notice
of the researchers. Thus the scientifically trained administrator be-
comes, although not himself witty in research, the cause of wit in
others. To ask the researcher, who must inevitably be to some extent
like Prospero ‘ wrapt in secret studies and to the State grown stranger,’
to discover problems which arise out of administrative embarrassments
is unreasonable ; on the other hand. the scientifically trained administra-

tor acts naturally as liaison officer between the laboratory and the land, —
passing on the problems which arise out of administrative necessities —

or expedients.
In this connection it is interesting to recall the fact that the im-

portance of the existence of varietiés of potatos immune from wart

disease was observed years ago by an officer of the Ministry, Mr. Gough,

who is also a man possessed of a scientific training, and I believe ~
also that I am right in saying that either this officer or another suggested —

M.—AGRICULTURE. 209

long ago that the clue to the spread of wart disease in England was
to be sought in the potato fields of Scotland. Mr. Taylor will, I hope,
give us the latest and most interesting chapter in the story of wart
disease, and I will not therefore spoil his story by anticipation of its
conclusions.

The tacit assumption which has so far underlain my Address is that
an extension of intensive cultivation in this country is desirable. I
have indicated that areas are to be discovered where soil and climate
are favourable to this form of husbandry, and that by the establishment
of a proper form of research—administrative—and educational organisa-
tion the already high standard reached by intensive cultivators may be
surpassed. It remains to inquire whether any large increase in the
area under intensive cultivation is in fact either desirable or probable.

The dispassionate inquirer will find his task by no means easy.
He should, as a preliminary, endeavour to discern in the present welter
of cosmic disturbance what are likely to be the economic conditions of
the politician’s promised land—the new world which was to be created
from the travail of war. In the first place, and no matter how academic
he may be, he cannot fail to recognise the fact that costs of production.
including labour, are at least twice and probably 24 times those of
pre-war days, and he must assume that the increase is permanent and
not unlikely to augment. What this means to the different forms of
cultivation may be judged from the following estimates of capital costs
of cultivation of different kinds :—

Labour and Capital for Farming and Intensive Cultivation.

Labour per 100 Capital per Acre

sures Pre-War Present
Men™ £ £
Mixed Farming : ’ : "3-577 10 20-25
Fruit and Vegetable growing f 20-30 50 100-125
Intensive Cultivation in the open 200 750 ~1,500-1,875"
(French Gardening) AT
Cultivation under glass. ‘ 200-300 2,000 |"4,000-5,000

In the second place the inquirer is bound to assume that the inten-
sive cultivator of the future, like his predecessor in the past, will have
to be prepared to face the competition of the world. He may, I believe,
look for no artificial restriction of imports, and therefore he must be
prepared to find that higher costs of production will not necessarily
be accompanied by increased receipts for intensively cultivated com-
modities.

But, on the other hand, he may find some comfort in the fact that
both immediately before and, still more, subsequently to the war,
the standard of living both in this country and throughout the world
was, and is still, rising. Hence he may perhaps expect a less severe
competition from foreign growers and also a better market at home.

He may also derive comfort from the reflection that the increased
cost of production which he must bear must also, perhaps in no less

1920 P

910 SECTIONAL ADDRESSES.

measure, be borne by his foreign competitors. Even before the war
the cost of production of one of the chief horticultural crops—apples—
was no higher in this country than in that of our main competitors.
There are also certain other apparently minor but really important
reasons for optimism with regard to the prospects of intensive cultiva-
tion. Among these is the increasing use of road in lieu of rail
transport for the marketing of horticultural produce. The advantages
of motor over rail transport for the carriage of perishable produce for
relatively short distances—say up to 75 miles from market—lie in its
greater punctuality, economy of handling, and elasticity. Only a poet
native of a land of orchards could have written the lines: ‘ When T
consider everything that grows holds in perfection but a single moment.’
Fruit crops ripen rapidly and more or less simultaneously throughout a
given district. They must be put on the market forthwith or are
useless. A train service, no matter how well organised, does not seem
able to cope with gluts, and hence it arises that a season of abundance
in the country rarely means a Jike plenty to the consumer. I am aware
that the problem of gluts is by no means simple and that the railways
are sometimes blamed unjustly for failing to cope with them, but
nevertheless I believe that, as Kent has discovered, the motor-lorry
will be more and more called in to redress the balance between the
home growers and the foreign producers in favour of the former; for
by its use the goods can be delivered with certainty in time to catch
the market and thus give the home producer the advantage due to
propinquity which should be his. Increasing knowledge of food values,
together with the general rise in the standard of living, also present
features of good augury to the intensive cultivator. Jam and tomatos
and primeurs may be taken as texts.

In 1914 the consumption of jam in the United Kingdom amounted
to about a spoonful a day per person. The more exact figures are
2 oz. per week, or 126,000 tons per annum.

It is difficult to estimate the area under jam fruit—plums, straw-
berry, raspberry, currants, &c.—required to produce this tonnage, but
it may be put at between 10,000 and 20,000 acres.

By 1918, thanks to the wisdom of the Army authorities in insisting
on a large ration of jam for the troops, and thanks also to the scarcity
and quality of margarine, the consumption of jam had more than
doubled. From 126,000 tons of 1914 it reached 340,000 tons in 1918.
To supply this ration would require the produce of from 25,000 to
50,000 acres of orchard, which in turn would directly employ the labour
of say from 5,000 to 10,000 men. ‘Yet even the tonnage consumed
in 1918 only allows a meagre ration of little more than a couple of
spoonfuls a day. It may therefore be anticipated that if, as is probable,
albeit only because of the immanence of margarine, the new-found public —
taste for jam endures, fruit-growers in this country will find a con-
siderable and profitable extension in supplying this demand.

The remarkable increase in ‘consumption which the tomato has
achieved would seem to support this conclusion. Fifty years ago, as
Mr. Robbins has mentioned in his paper on ‘ Intensive Cultivation ’
(Journal of Board of Agriculture, xxy. No. 12, March 1919), this

M.—AGRICULTURE. 211

fruit was all but unused as a food. To-day one district alone, the Lea
Valley, produces 30,000 tons per annum. The total production in
this country amounts to upwards of 45,000 tons. Yet the demand for
tomatos has increased so rapidly—the appetite growing by what it
feeds upon—that the imports in 1913 from the Channel Islands,
Holland, France, Portugal, Spain, Canary Islands, and Italy amounted
to nearly double the home crop, viz. 80,000 tons, making the total
annual consumption not less than 14 tons or about 2 pounds per week
per head of population. Is it too fanciful to discern in this rapidly
growing increase in the consumption of such accessory foodstuffs as jam
and tomatos, not merely an indication of a general rise in the standard
of living and a desire on the part of the community as a whole to share
in the luxuries of the rich, but also a sign that in a practical, instinctive,
unconscious way the public has discovered simultaneously with the
physiologists that a monotonous diet means malnutrition, and that even
in a dietetic sense man cannot live by bread alone? As lending support
to this fancy and as indicating that the value of vitamines was dis-
covered by people before vitamines were discovered by physiologists,
I may mention the curious fact that the general public has always shown
a wise greediness for an accessory food which, though relatively poor
in calories is rich in vitamines—namely the onion. Even in pre-war
times the annual value of imported onions amounted to well over one
million pounds sterling; and, when the poverty of the winter diet of
the people of England and Wales is considered, it must be admitted
that this expenditure represented a sound investment on the part of
the British public. It is a curious fact also that the genius of Nelson
led him to alike conclusion. He took care, during the long years when
his blockading fleet kept the seas, to provide his sailors with plenty of
exercise and onions. ;

If, as I think, the increasing consumption of the accessory foods
which intensive cultivation provides represents not merely a craving
for luxuries, but an instinctive demand for the so-called accessory food
bodies which are essential to health, then it may be expected that, as
has been illustrated in the case of jam and tomatos, consumption will
continue to increase. If this be so, the demand both for fresh fruit
and also for ‘ primeurs ’—early vegetables—should grow and should
be supplied at least in part by the intensive cultivators of this country.

If the home producer can place his wares on the market at a price
that can compete with imported produce—and it is not improbable that
he will be able to do so—he need not, even with increased production,
apprehend more loss from lack of demand than he has had to face in
the past. Seasonal and other occasional gluts he must, of course,
expect.

Even when judged by pre-war values, his market, as indicated bv
imports, is a capacious one. Thus in 1913 the imports into the United
Kingdom of soil products from smallholdings were of the value of
about 50 million pounds sterling. To-day it is safe to compute them
at over 100 millions. To that sum—of 50 millions—imported vegetables
contributed 54 million pounds sterling, apples 24 millions, other fruits
nearly 3 millions, eggs and poultry over 10 millions, rabbits and rabbit-

912 SECTIONAL ADDRESSES.

skins a million and a half, and bacon and pork over 22 millions.
No one whose enthusiasm did not altogether outrun both his discretion
and knowledge would suggest that the home producer could supply the
whole or even the greater part of these commodities. But, on the other
hand, few of those who have knowledge of the skill and resources of
our intensive cultivators, and of the suitability of favoured parts of this
country for intensive cultivation, will doubt but that a modest proportion,
say, for example, one fifth, might be made at home. This on a post-
war basis would amount in value to over 20 million pounds, would
require the use of several hundred thousand acres of land and provide
employment for something like 100,000 men. The fact that Kent has
found it profitable to bring one-fifth of its total arable land under fruit
and other forms of intensive cultivation is significant and a further
indication that intensive cultivation offers real prospects to the skilful
and industrious husbandman. The present reduced acreage under fruit,
due partly to war conditions, but mainly to the grubbing of old orchards,
enhances the prospects of success.
The estimated acreage under fruit in England and Wales is :—

Acres
Apples , ¢ é : S 5 : . 170,000
Pears . , . 3 5 3 . : f 10,000
Plums. 4 : * 3 : . : : 17,000
Cherries ‘4 i i s a E . s 10,000
Strawberries 4 : ; f 3 3 - 13,000
Raspberries : : : : i Ae 6,000
Currants and Gooseberries . 5 ; . 22,000

248,000

exclusive of mixed orchards and plantations.

These figures are, however, well-nigh useless as indicating the areas
devoted to the intensive cultivation of fruit for direct consumption. Of
the 170,000 acres of apples, cider fruit probably occupies not less than
100,000, and of this area much ground is cumbered with old and
neglected trees. Of the 10,000 acres in pears some 8,000 are devoted
to perry production, and hence lie outside our immediate preoccupation.
Having regard, however, to the reduction of acreage under fruit, to the
increasing consumption of fruit and jam, and to the success which has
attended intelligent planting in the past, it may be concluded that a
good many thousand acres of fruit might be planted in this country with
good prospects of success.

Lastly, it remains to consider what results are likely to occur if ©

intensive cultivation comes to be more generally practised in this country.

T am indebted to one of our leading growers for an example of the —

results which have attended the conversion of an ordinary farm into
an intensively cultivated holding.

The farm—of 150 acres and nearly all arable—was taken over in
1881. At that date it found regular employment for three men and
a boy—with the usual extra help at harvest. The rate of wages paid
to the farm hand was 15s. a week.

In 1853, two years after the farm had been taken over and converted

M.—AGRICULTURE. 913

to the uses of a horticultural holding, from 20 to 25 men and 80 to 100
women, according to season, were at work on it, and the minimum
wage for men was 20s. per week. The holding was increased gradually
to 310 acres, and at the present time gives employment on an average
to 90 men and 50 women during the winter months and 110 men and
200 women during the summer months. In 1913 the wages bill was
7,9811., and in 1918 10,0002. per annum, that is, over 34l. per acre.

Another concrete example of the effect of intensity of cultivation
on density of population is provided by the comparison of two not far
distant districts—Rutland and the Isle of Ely. ‘The rich soil and in-
dustrious temperament of the inhabitants of the Isle have justly brought
it prosperity and fame. ‘The Isle of Ely comprises 236,961 acres, of
which number 170,395 are arable; Rutland 97,087 acres with 35,000
arable. The land of Rutland is occupied by 475 persons, that of the
Isle by 2,002; the average acreage per occupier in Rutland is 206, in
the Isle 118. The total number of agricultural workers in Rutland is
2,146, and in the Isle 13,382. The density of agricultural population
in terms of total acreage is in Rutland 2.5 per 100 acres, and in the
Isle 5.6, or 20 more cultivators to the square mile in the Isle of Ely
than in Rutland; from which the curious may estimate the possibility
of home colonisation by introducing as a supplement to extensive
agriculture such an amount of intensive cultivation as may be practised
in districts similar in climate and soil to the Isle.

The immediate object of the comparison is to show, however, that
the difference between the closeness of colonisation of the two lands
is accurately presented by the difference between the acreages amenable
to intensive cultivation which by reason of soil must, however, always
remain relatively larger in the Isle than in Rutland. Thus in Rut-
land the area under fruit is 204 acres, and in the Isle 7,126. If
these areas and the workers thereon be deducted from the total
arable in the two districts, the respective agricultural populations
in terms of 100 acres of arable become almost identical, viz. 6.7
for Rutland and 6.9 for the Isle. The difference of agricultural
populations is measured by the area under intensive cultivation.
The agricultural workers engaged on the 7,126 acres of fruit in the
Isle of Ely are almost as numerous as those engaged in doing all the
agricultural work of Rutland—say, about 2,000 as compared with 2,416.

It may of course be true that a chance word, a common soldier,
a girl at the door of an inn, have changed, or almost changed,
the fate of nations, but it is probable that the genius of peoples
and the pressure of economic and social forces are more potent. Is
there then, it may be asked, any indication that the people of this
country will seek in intensive cultivation a means of colonising their
own land rather than continue to export their surplus man-power?
The problem is too complex and too subtle for me to solve, but I will
conclude by citing a curious fact which may have real significance in
indicating that if a nation so wills it may retain its surplus population
on the land by adjusting the intensity of its cultivation to the density of
its population. Ifa diagram be made combining the intensity of pro-

914 SECTIONAL ADDRESSES.
duction of a given erop, e.g., the potato, as grown in the chief indus-

trial countries of the world, it will be found that the curve of production
coincides closely with that of density of population.

Density of Population and Intensity of Production. Potatos.

cote, stat Yield in

ensity of | Porontase | poreentage goin Pe

Square Mile. | Population. , Average

1911-13.

United States : : 31 10 33 1:3
France ; 5 : 193 62 56 2:2
Germany , ‘ ; 311 100 100 39
U.K... : b ; 374 120 110 4:3
England and Wales : 550 177 128 5
Belgium : ‘ : 658 212 155 6°04

From these facts we may take comfort, for they indicate that as:a
population increases so does the intensity of its cultivation: the tide
which flows into the towns may be made to ebb again into the country.
The rate of return, however, must depend on many factors: the proclivi-
ties of peoples, the relative attractiveness of urban and rural life and of
life at home and abroad, but ultimately the settlement or non-settlement
of the countryside must be determined by the degree of success of the
average intensive cultivator. The abler man can command success;
whether the man. of average ability and industry can achieve it, will,
T believe, depend ultimately on education. He can look for no assistance
in the form of restricted imports. He must be prepared to face open
competition. Wherefore he should receive all the help which the State
can render; and the measure of success which he, and hence the State,
achieves will be determined ultimately by the quality and kind of
education which he is able to obtain.

REPORTS ON THE STATE OF SCIENCE, ETc.

Seismological Investigations.—Twenty-fifth Report of the Committee,
consisting of Professor H. H. Turner (Chairman), Mr. J. J.
Suaw (Secretary), Mr. C. Vernon Boys, Dr. J. E. Crompir,
Sir Horace Darwin, Dr. C. Davison, Sir F. W. Dyson, SirR. T.
GLAZEBROOK, Professors C. G. Knorr and H. Lams, Sir J.
Larmor, Professors A. E. H. Love, H. M. Macponatp, J. Perry,
and H. C. Puummer, Mr. W. E. Puummer, Professor R. A.
Sampson, Sir A. ScuustTsEr, Sir Naprer Suaw, Dr. G. T. WaKer,
and Mr. G. W. WALKER.

General.

Tue transference of the Milne books and apparatus from Shide to the University
Observatory at Oxford was completed in September last. Mrs. Milne sailed
for Japan, after some shipping delays, on September 27, and news of her safe
arrival on November 13 has been received. The greater part of the books,
records, cards, and the two globes for preliminary calculations are conveniently
housed in a room in the Students’ Observatory, apart from the main building :
the remainder of the material is for the present stored in an outbuilding. But
by a timely benefaction of 400/. from Dr. Crombie, a small house has been
acquired near the Observatory, of which it is hoped to get occupation in
September, and this will easily hold all that is required, and serve at the same
time as a dwelling for the seismological assistant. These arrangements have
been made in accordance with the spirit of Professor Schuster’s resolution
(quoted in the last report), offering to establish a Central Bureau at Oxford,
which could not be exactly carried into effect at the moment owing to circum-
stances there mentioned. Further, in pursuance of this plan, the Cambridge
Committee entrusted with the appeal for a Geophysical Institute which should
include Seismology, finding their appeal unsuccessful, passed the following
resolution on March 10, 1920 :—

it was agreed that Professor Turner should be informed that no objection
could be taken by the Committee to a seismological station and establish-
ment at Oxford.

This resolution, with a letter from the Chairman of the Committee and a
summary of other information, was next reported to the University of Oxford
through the Board of Visitors in May last, and approved. Finally, these facts
were reported to this Committee (B.A. Seismology) at its meeting on July 2,
and the plan of locating the work at Oxford approved. It remains to obtain
the funds necessary for the salary of a full-time director and for replacing the
grants temporarily made by the British Association and the Royal Society. A
Royal Commission is at present reviewing the finances of the Universities of
Oxford and Cambridge, and a note has been addressed to this Commission on
the subject of Seismology, in the first instance by the Board of Faculty of
tag Science, supplemented by a more particular note from Professor

urner.

Instrumental.

The Milne-Shaw seismograph erected in the basement of the Clarendon
Laboratory has worked well through the year. Professor Lindemann has given
formal sanction to the arrangement, and included the basement in his general

216 REPORTS ON THE STATE OF SCIENCE, ETC.—1920.

installation of electric light in the laboratory. This has much facilitated the
operations of changing films, comparing clocks, &c., but the gas-jet is retained
for the photography. The room has further been cleaned and whitewashed, ana
an outer door has been added shutting it off from draughts. It is now a very
convenient laboratory, and is large enough for the erection of at least one
more machine, when one is available.

The Milne-Shaw machine formerly erected at Eskdalemuir for direct com-
parison with Galitzin records’ has been now transferred (on loan) to the Royal
Observatory, Edinburgh, and readings have been received from July 4, 1919.
The situation seems peculiarly liable to microseismic disturbance, obviously
connected with wind.

The instrument mounted in the ‘dug-out’ near West Bromwich has given
some interesting results as regards these microseisms on which Mr, Shaw writes
a special note at the end of this report.

Various other instruments are being constructed as rapidly as present difficul-
ties permit.

Milne-Shaw machines have recently been dispatched to Cape Town, Montreal,
Honolulu, and Aberdeen. Others are being made for India, China, Egypt, New
Zealand, Canada, and Ireland.

Bulletins and Tables.

‘The Large Earthquakes of 1916’ have been collated and published as a
single pamphlet of 116 pages, but there are great difficulties in obtaining satis-
factory determinations of epicentres for the later war years, which have delayed
further publication. ,

The corrections to adopted tables have not yet been completed.

Earthquake Periodicity.

The study of long periods in the ‘Chinese Earthquakes’ directed attention
to a period near 260 years. This was in the first instance identified as 240 years
(‘Mon, Not. R.A.S.,’ lxxix., p. 531) as mentioned in the last report, and Mr, De
Lury pointed out that this value also suited tree-records (Pub, Amer, Ast.
Soc. 1919). But an investigation on the secular acceleration of the Moon by Dr.
Fotheringham recalled attention to a value nearer 260 years, which was also
found to suit the tree-records (‘ Mon. Not. R.A.S.,’ lxxx., p. 578) over the same
period. Ultimately a much longer series of tree-records was obtained (Mr. A. EB.
Douglass’s compilation from 1180 8.c.) and a full analysis of these, now in the
press (‘ Mon. Not. R.A.S.,’ 1920 Supp. No.), suggests a double periodicity, with
components of approximate lengths 284 and 303 years. Long as it is, the series
of tree-records is not long enough to separate these components themselves : the
evidence for separation is provided by the harmonics, especially the third
harmonic, which shows components of 101 years and 94°4 years clearly separated,
the former and longer being the stronger, whereas in the main terms the shorter
period is the stronger. The second harmonic of the longer period, 7.e., half 303,
or, say, 152 years, is quite possibly the 156-year period referred to in the last
report.

These results have been obtained so recently that their full relation to the
earthquake records have not yet been worked out. But a welcome confirmation
may be mentioned. In the ‘Bull. Seism. Soc. of America,’ vol. ii., No. 1, Miss
Bellamy found a later list of ‘Chinese Earthquakes’ compiled by N. F. Drake.
It is not entirely independent of the catalogue already studied (compiled by
Shinobu Hirota in 1908 and mentioned by Drake as having been received too
late for inclusion or comparison), but it differs from it in one important respect,
being copious in the later centuries where Hirota’s catalogue is scanty. Further,
it is confined to ‘ destructive or nearly destructive’ earthquakes, so that the
records are probably more precisely comparable inter se, although they still
show a large increase about A.D. 1300, which must be attributed to greater

SEISMOLOGICAL INVESTIGATIONS. 217

completeness of the later records, or rather imperfection in the earlier years.
The following table gives the analysis in periods of 284 years :—

Tas_e I.
Numbers of Chinese Destructive Harthquakes (Drake).

Initia] 2081 B-c.| 93 B.c. | 191 | 475 | 759 | 1043 | 1327 | 1611 a
vpn to to to to to to to Total | - a
94 zc. | a.v.190| 474 | 758 | 1042 | 1326 | 1610 | 1894 mag
0 1 2 1 2 2 3 28 27 66 48
24 2 2 1 5 2 7 21 12 52 58
48 0 3 2 0 3 2 1 11 22 25
71 1 2 4 0 2 5 0 2 16 28
95 0 0 5 1 3 0 7 8 24 27
119 0 2 10 1 2 1 9 5 30 39
142 2 0 0 3 0 4 26 7 42 37
166 3 3 4 1 1 7 30 4 53 53
190 4 5 0 0 1 0 23 9 42 42
213 0 7 2 0 2 4 22 12 49 39
237 1 7 1 1 9 9 23 15 66 68
261 0 3 1 4 3 18 22 14 65 63
Total] 14 36 31 18 30 60 | 212 | 126 | 527 | 527

The totals in the last column but one are governed chiefly by the later
cycles. To minimise this effect the eight columns were all reduced to the
same total 66, using one place of decimals until the sums were formed. The
results are given under the heading ‘ Revised,’ and it will be seen that they
give substantially the same curve, with pronounced minimum extending from
the 48th year to the 118th, and a pronounced maximum at the end. The 48th
year of the present cycle will be 1942, so that we are approaching the time of
minimum quakes and have passed the maximum. But it is not yet clear whether
these figures for China apply unmodified to the whole earth. It may be possible
to observe this decline in the near future, but up to the present the records are
affected by so many uncertainties, owing partly to the novelty of the science,
partly to the war, and to other causes, that it is very difficult to compare one
year with another. Thus the Eskdalemuir records show the following fotal
numbers of earthquakes :—

1911 1912 1913 1914 1915 1916 1917 1918
236 393 287 278 184 163 166 192

which at first sight might be interpreted as a notable falling-off in earthquake
activity, but is probably chiefly due to a change of method in 1915. The point
will, however, be further examined. Analysing the last two columns of Table I.
harmonically we get from the simple totals

20 cos (@ — 301°) + 11 cos (26 — 348°) + 1 cos (38 — 304°) + 5 cos (40 — 98°)
from the revised
14 cos (8 — 304°) + 8 cos (20 — 340°) + 3 cos (3@— 211°) + 8 cos (40 — 138°).

The third harmonic is small—smaller than the fourth, for instance. But on
analysing the results in 101 years a larger term is obtained. The totals are
(for twelve groups to the cycle, which gives nearly the same mean as above)

48 41 45 41 31 53 38 37 33 656 43 54

which gives a term 5 cos (@— 331°).
This is in accordance with the results found from trees—that the 101-year term
should exceed the 94 year.

218 REPORTS ON THE STATE OF SCIENCE, ETC.—1920.

Microseisms. By J. J. SHAw.

Microseisms appear to have been a much neglected study. A few observers
have counted them, measured their frequency and amplitude, and noted their
seasonal character, but beyond this little seems to have been done. This is all
the more remarkable in view of the fact that microseisms, unlike earthquakes,
are always more or less available for investigation.

In 1911 the International Seismological Congress in Manchester allotted 5000.
for their investigation, and as a result the Central Bureau at Strasbourg tabulated
a number of observations, and, but for the European War, would probably
have reported at Petrograd in 1914, If any conclusions were arrived at they
do not appear to have been published.

In the 1917 report of this Committee attention was drawn to the readiness
with which a microseismic wave could be identified at two adjacent stations (in
that case, in separate buildings 60 feet apart).

The two machines, arranged with precisely similar constants, produced
identical records of the microseisms; but an interesting feature was observed,
that, when keeping the nominal magnifications of the two machines the same, and
at the same time varying the relative sensitivity to tilt of one machine to as much
as four times the other, the amplitude shown on the film remained the same on each
machine, This seems to indicate that a microseismic wave is purely horizontal
and compressional rather than of an undulating gravitational character.

In, the same report it was suggested that, by gradually increasing the distance
between the recording stations (but only so long as it was possible to identify the
individual waves), it might be possible to trace the origin and cause of these
movements.

With this object in view two suitable stations were secured. The one was
the writer’s household cellar at West Bromwich, the other a ‘dug-out’ in a
pit bank at Millpool Colliery situated two miles away, and kindly placed
at our disposal by T. Davis, Esq., of the Patent Shaft and Axletree Co., of
Wednesbury.

The dug-out was a tunnel 60 feet into the mound and 15 feet below the
surface. It lay 17° west of north of the ‘home’ station.

The first observations were made in March and April 1919, when for a few
weeks two Milne-Shaw machines were available.

It was at once seen that at stations two miles apart the records of the
microseismic waves were almost identical.

The clock in use at the dug-out was not of a sufficiently high standard to
obtain the precise difference in time of arrival at the respective stations.

Several seismograms were obtained during this time and were seen to be
similar in every detail.

In March and April of the present year a first-class timing clock was substi-
tuted, and two more machines installed with the intention of timing the
microseismic wave over this two-mile base line.

The usual means of synchronising were not available, therefore the clocks
were adiusted as follows :—

A watch with an excellent hourly rate was chosen and carried per motor-cycle
between the stations. Two observations, with 30-minute intervals, were made
on the home clock, two on the dug-out clock, and two more on the home clock.
It was estimated that on favourable occasions the two clocks were set alike
within one-tenth of a second. The clocks were checked once per day, and the
waves timed by measuring on the film from a minute eclipse to the nearest. apex
at the extreme of an excursion.

This first method was continued from January 31 to February 15. As differ-
ences of 14 to 2 seconds were shown—being probably erroneous—an effort was
made during March to secure a closer comparison.

Firstly, the clocks were checked twice per day. Secondly, as, on a closer
scrutiny, small fluctuations in the peripheral speed of the recording drums
could be detected, it was seen to be inadvisable to measure any intermediate
point during a minute, but to rely only upon the moment when the eclipsing
shutter opened or closed.

SEISMOLOGICAL INVESTIGATIONS. 219

The duration of the eclipse was 4°7 seconds in each case, so that opening or
closing were equally serviceable as datum points. Therefore a new method of
comparing the films was devised as follows :—

The eclipsing shutter was provided with a narrow slit through which a small
percentage of light could pass when the shutter was closed. ‘This feeble beam
produced a ghost-like trace during the interval of each eclipse.

In making comparisons instances were chosen where the amplitude was not
only large but also where the shutter had opened or closed near the middle
or zero position of the wave.

The change of intensity of the trace was sharp and easily measured, whilst
the extremity of the excursion could be seen in the ghost.

The period of the wave and its phase at the datum point having been deter-
mined, it was then possible to resolve the harmonic motion, and so obtain the
difference in time to one-tenth of a second.

It is interesting to note that by either method the average difference was
0°8 second, but the second method gave much more consistent readings.

A further object was to note to what extent the direction of propagation,
the amplitude, or the period were affected by meteorological conditions, particu-
larly the direction and force of the wind.

We were indebted to A. J. Kelly, Esq., Director of the Birmingham and
Midland Institute Observatory (four miles distant), for his help in this matter.

The force of the wind and the amplitude did appear to be co-related, inasmuch
that the microseisms were small during calm spells and vice versa, but there was
a notable exception on March 10. During March 9 and 10 the air movement
had been small, 178 and 272 miles in each 24 hours respectively, yet on the
evening of the 10th nearly the largest waves of the series were recorded.

Within a period of 24 hours, March 12 to 13, the velocity of the wind
ranged from 37 to 12 and back to 37 miles per hour in-three nearly equal periods,
but there was no corresponding fluctuation in the amplitude of the microseisms.
Similar fluctuations on other dates were equally ineffective to produce sudden
change in the ground movement.

There was little variation in period. It was usually 6 to 7 seconds. On
a few occasions it fell to 4°5 seconds, but never exceeded 8 seconds. It will
be observed that the period appears to increase with the amplitude.

The outstanding, and we venture to think important, discovery was that
the microseismic waves always arrived from the same direction. On every. film
they were seen to arrive at the ‘dug-out’ or northerly station first,

During the period of observation the wind blew from all points, except
north to east, but no quarter seemed to affect the regularity with which the
waves arrived from the north.

Column two in the following table gives the time in seconds by which the
waves arrived at the dug-out first :—

By First Method.

>
4
0
&
i)
oe)
~I
Ln
i)
or
oO
o
=)

Daily Horl. Wave
Date Difference, Wind Motion of |Amplitude P sod
F Sec. Direction the Wind, & ‘Seo ;
Miles ra
1920
Jan. 31 0-0 S—WSW 427 58 73
Feb. 2 0:0 SW—S 587 4:0 7°5
» 6 15 SSE 295 2°8 67
” 9 10 WSW 491 3:2 63
» 10 10 SW 670 95 8:0
» 12 0:0 WNW —S 354 3°6 6:2
» 15 15 8 423 5:0 62
tl el ak brill peel te eT mat ede Al co sgl AO beh Nl bata ate

220 REPORTS ON THE STATE OF SCIENCE, ETC.—1920.

By Second Method.

Daily Horl. ee
Dat Difference, Wind Motion of | Amplitude Pe ie d
Ve Sec. Direction the Wind, Ie Saline
Miles BAG:
1920
March 4 1:0 WSW—S 260 4:9 75
Ss 5 1:0 8 285 16 6-7
” 6 0°75 NS) 476 4:5 6°0
:° 9 ==" W 178 = a7
» 10 07 SSW 272 7:0 7:0
rer sii 11 NW 257 4:9 6°5
babe, plies 0:5 W 541 57 6:0
elisa) 1:0 S) 377 4:5 6°2
he les 0:8 WwW 500 4:0 67
» 20 — W 131 08 5:5
pee a 08 Sy 348 4:0 7°3
9», 20 07 s 613 53 73
» 28 08 rs) 498 32 57
Average 83 371 3°9 6°5

It will be observed that the time in column two is generally about one second,
which is the approximate time required for a surface wave to travel two miles,
thus indicating that the direction of propagation was more or less constant and
approximately from north to south.

On the other hand there are differences ranging between 0°7 sec. and 1°1 sec.
Remembering the method of synchronising the clocks it is possible many of the
irregularities are due to personal and instrumental error. To what extent they
indicate that the azimuth wanders round the northern semicircle it is difficult
to determine, but from the fact that the southern half was never indicated, it
would seem feasible to presume that the waves came generally from the north.

More precise information is very desirable, and can only be obtained from
not less than three stations with preferably a longer base of operation, and
with better timing facilities.

It is hoped, at some future date, when three machines are simultaneously
available and suitable quarters and observers found, to make the experiment
on a ten-mile triangle.

An attempt was made to identify the microseisms recorded at Oxford with
those of West Bromwich (80 miles apart), but unfortunately the booms are
oriented 90° from each other. From some measures made by Professor Turner
there was a suggestion of agreement, but nothing really tangible has at present
been. detected.

A fruitful investigation for observatories would be to determine whether this
unidirectional character of microseisms is general, and whether the azimuth
depends upon the contour or physical features of a country.

From the foregoing it is clear that microseisms are real travelling waves of
the same character as those propagated by earthquake shocks, and if a
seismograph fails to perceive them then it is not recording all that is passing.

Two stations where Milne-Shaw instruments are installed, viz., Bidston and
Edinburgh, seem to be very liable to microseisms. Both stations are near the
sea, and both stand upon the crest of a hill.

Shide was within six miles of the open sea, but did not stand upon a hill.
This station did not find the microseisms more prevalent than an average station.

Oxford and West Bromwich are well removed from the sea. They record
microseisms as freely as Shide. It has yet to be determined whether the sea.
board is more liable to these movements : the evidence points to that conclusion.

SEISMOLOGICAL INVESTIGATIONS. 221

The P phase of a seismogram sometimes, but not often, begins with a sharp
kick—denoted i P; but sensitive machines show that much more frequently this
sharp kick is preceded by two or three waves of smaller amplitude and higher
frequency. When the frequency is distinctly quicker than that of the prevail-
ing microseisms, and the amplitude of the latter is not too great, it is easy to
detect the true P as a superimposed wave, but if the period of these small
precursors approximate to that of the microseisms, then it is difficult to deter-
mine the true inception of the earthquake record.

Machines which do not record the microseisms will not record these minute
waves. With such machines probably more uniformity, by reading the bigger
kick, will result, but misguided uniformity will not be conducive to obtaining
the true rate of propagation of the P phase.

It is to sensitive machines and careful scrutiny of the record that we
must look for data for the perfecting of seismological tables.

929, REPORTS ON THE STATE OF SCIENCE.—1920.

Absorption Spectra of Organic Compounds.—Report of Committee
(Sir J. J. Dossiz, Chairman; Professor E. E. C. Baty, Secretary;
and Dr. A. W. Stewart). Drawn up by the Secretary.

Various theories have been advanced from time to time to explain the absorption
bands exhibited by organic compounds, and it would seem advisable at this time
to deal with these and to state the position that has been reached in this branch
of scientific investigation. There is no doubt that the pioneer in this field of
work was the late Sir Walter Noel Hartley. He was the first to undertake a
detailed investigation on scientific lines of the absorption exerted by organic
compounds in the visible and ultra-violet regions of the spectrum. He was the
first to recognise the fact that isolated measurements of the absorption spectrum
of a substance in solution are valueless, and he devised the method whereby com-
plete records of the absorption could be obtained. Hartley’s method consisted
in measuring the oscillation frequencies of the light for which complete absorption
is shown by definite thicknesses of a solution of known strength of the sub-
stance. The observations were repeated with the same thicknesses of more and
more dilute solutions until no measurable absorption was observed. By plotting
the oscillation frequencies against the thicknesses expressed as equivalent thick-
nesses of some selected concentration an absorption curve was obtained, called by
Hartley a molecular curve of absorption.

At the present time this method of observation has been displaced by the
quantitative measurement of the light absorbed. The absorptive power exhibited
by a given substance for light of a given frequency is expressed in terms of the
molecular extinction coefficient, log Io/I+dc, where Io/I is the ratio of the
intensities of the incident and emergent light as observed with a layer d cms
thick of a solution containing c¢ gram molecules of the absorbing substance
dissolved in a litre of some diactinic solvent.

Reference may: be made to the use of a solution of the substance under
examination. In general it may be said that the absorptive power exerted
by compounds is large, with the result that it is necessary to use very thin layers
for purposes of observation. This is impossible of realisation with solid sub-
stances, and indeed with many liquids the thickness required is so small that
without very accurate and expensive apparatus the necessary thin layers cannot
be obtained. By common consent, therefore, solutions of known strength in
diactinic solvents are employed. It must be remembered, however, that the
influence of a solvent on the absorptive power of a compound is often very
marked, and due allowance must be made for this effect. The question of the
influence of a solvent will be discussed later.

The region of the spectrum dealt with by Hartley extended from the red
end to the limit of the ultra-violet as set by a quartz spectrograph working in
air, that is to say, between the limits of wave-length 6000 and 2100 Angstroms.
He showed in the first place that substances can in general be divided into two
classes, namely, those which exhibit selective absorption, z.e., absorption bands
between the above spectral limits, and those which exhibit only general absorp-
tion. It is not necessary here to detail the whole of Hartley’s work, but one
important fact was established, namely, that, providing no disturbing factor
intervenes, the absorption curves shown by compounds of similar constitution are
themselves similar. This fact was made use of in determining the constitution
of a few substances with reference to which the chemical arguments at the time
were at fault. It was shown for instance that phloroglucinol is a true trihydroxy-
benzene and not ketonic since its absorption curve is very similar to that of its

trimethyl ether.' Similarly the constitution of isatin CoH Seo,
NH

1 See references, p. 243,

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 223

CH=CH

O
carbostyril? ON and 0-oxycarbanii® oHK Seo, was determined
NH

NH—CO

by comparison of their absorption curves with those of their nitrogen and oxygen
methyl derivatives.

It may readily be understood that high hopes were engendered that this
method might prove to be of immense value to the chemist as independent evi-
dence in the determination of the constitution of compounds, but it may be
said at once that these high hopes have not been realised. A very brief account
may be given of the various attempts that have been made to co-ordinate consti-
tution and absorption of light, because all of these attempts have some importance
in relation to more recent developments. Following on Hartley’s successful
work an attempt was made to determine the constitution of ethyl acetoacetate
and its metallic derivatives by comparison with its two ethyl derivatives, ethyl
B-ethoxycrotonate and ethyl ethylacetoacetate.* It was found, however, that
the parent ester and its metallic derivatives differ in absorptive power very
materially from the two isomeric ethyl derivatives. The two latter do not show
selective absorption, whilst the metallic derivatives show well-marked absorption
bands. The deduction was made from this that the origin of the absorption
bands is to be found not in any specific structure but in a tautomeric equilibrium
between the two forms, that is to say, the selective absorption of light is due to

O OM

tl |
the change of linking involved in the process—C—CHM—+—C=CH_, where

M stands for hydrogen or a metal.

This theory was extended to aromatic compounds where the selective absorp-
tion was considered to be due to the oscillation of linking supposed to be present
in the benzene ring. The absence of selective absorption observed with some
benzenoid compounds was considered to be due to the restraint on the oscillation
exercised by certain strongly electro-negative substituent groups such as NO,,
&e.> i

Without question one of the most important theories connoting absorption and
structure is that known as the quinonoid theory which connected visible colour
with a structure analogous to that of either para- or ortho-benzoquinone. This
theory has found great favour on account of the undoubted fact that when a
quinonoid structure is possible the substance in the majority of cases is visibly
coloured, whilst in the case of an isomeric substance in which a quinonoid struc-
ture is not possible the colour is in general less intense or indeed very slight.
It was a simple matter to apply the oscillation theory in explaining the visible

-colour of the quinonoid compounds. The oscillation was suggested as that
between the two forms

oO o——
I |
——
er
5
O |
o——
Similarly the visible colour of the o-diketones was explained by the oscillation
00 o-0O

ol jy ar
between the two forms —C—C— Pil —C=C-—, which after all is only a slight varia-
tion of the quinonoid conception. This particular type of oscillating linking was
named isorropesis.®
It was soon pointed out, however, that this theory was open to serious

objection because certain compounds in which no oscillation seemed possible

99.4 REPORTS ON THE STATE OF SCIENCE.—1920.

CH,

exhibit strong selective absorption. For example camphor 7 CoB. shows
; CO
a marked band, as also does the disubstituted compound 8

is
Gi] Dre
Co

in which no tautomeric equilibrium seems possible. Again, azo-iso-butyronitrile
shows marked selective absorption.

aah Sega
C—-N=N-
Pleas sf a

CH,
CN NC

The most interesting example of a compound which exhibits an absorption band is
chloropicrin, CC1,NO,, which does not contain any hydrogen atoms at all. It
may be noted that Hantzsch has taken up the position that there is a definite
correlation between constitution and absorption, and he has published very many
papers in support of his theory. The starting-point of the theory is the
derivatives of ethyl acetoacetate which have already been referred to. He
showed that ethyl dimethylacetoacetate, which is an absolutely definite ketonic
compound, exhibits only slight general absorption. The enolic derivative ethyl
B-ethoxycrotonate at equal molecular concentration exhibits more strongly marked
general absorption. Hantzsch assumes® that the absorption curves are truly
characteristic of the ketonic and enolic forms respectively. He then assumes
that the absorption band shown by the metallic derivatives of ethyl acetoacetate
is due to the constitution where M stands for a monovalent metal. The novelty

bs
C
yh io,
H,C

oO
|

|
C M
Ge ee

of the conception lies in the mutual influence of the secondary valencies or
residual affinities of the metal and oxygen atoms, this influence being denoted
by the dotted line in the formula. It will be seen that this explanation of
selective absorption does not involve any liable atoms but attributes the
phenomenon to secondary valencies. Starting from this original assumption
Hantzsch has built up a complete theory of a direct correlation between absorp-
tion and constitution which states that if a substan¢e exhibits different absorption
curves under different conditions of solvent, &c., this is due to a definite
change in constitution. It is not worth while to describe in detail the conclusions
which Hantzsch arrives at as regards the specific compounds examined by him,?°
such, for instance, as the variety of absorption bands shown by compounds of
an acid type when dissolved in different basic solvents, each different absorption
band being attributed to a different structure of the compound. It is perhaps
worthy of mention that Hantzsch finds it necessary to confess that in some cases
the variations in absorption shown by certain compounds are more numerous
than can be accounted for by changes in constitution.

It may be stated at once that there are several very grave objections to

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 995

Hantzsch’s theory, and indeed these are so fundamental that it becomes impos-
sible to accept the theory as it stands. In the first place, as was pointed out
above, the cardinal assumption on which the whole theory rests is that the absorp-
tion band shown by the metallic derivatives of ethyl acetoacetate is due to the
secondary valencies of the metallic atom and the carbonyl oxygen of the
carboxyl group. There are many cases of compounds in which secondary
valencies must be postulated in order to explain their very existence, and these
compounds do not generally show absorption bands in the visible and ultra-
violet. Some peculiar merit must therefore be attributed to the six-membered
‘ring’ of Hantzsch’s formula, and it is difficult to accept this since the selective
absorption of such compounds as the alkaline nitrates and chloropicrin obviously
cannot have any relation to a six-membered ring.

More important still are two facts which appear to have escaped the notice
of Hantzsch. First, ethyl dimethylacetoacetate in the presence of alkali shows
an absorption band very similar to that shown by ethyl acetoacetate in the
presence of alkali. Second, ethyl B-ethoxycrotonate shows an incipient absorp-
tion band in the presence of acid. It is obvious that these two observations are
in direct opposition. to the Hantzsch formula as the correct explanation of the
selective absorption shown by the metallic derivatives of ethyl acetoacetate.

Still more cogent arguments against the theory of correlation between
structure and absorption in the visible and ultra-violet are to be found in such
cases as pyridine and piperidine. Pyridine in the homogeneous state and in
solution in various solvents exhibits an absorption band with centre at
1/A = 3910, but in the vapour state it shows an entirely different band with
centre at 1/A = 3587.1! Piperidine vapour shows a well-marked absorption band,
but in solution and in the homogeneous state it is completely diactinic. Analogous
dissimilarities between the molecular absorptive powers of liquid and vapour have
been observed with other compounds, and clearly on the structure-absorption
theory the structure of the molecules in the liquid and vapour phases must be
different. This would seem to be impossible at any rate in the case of
symmetrical molecules such as pyridine and piperidine.

The evidence against the direct structure-absorption correlation theory as
developed by Hantzsch is overwhelmingly great, and this is equally true of the
quinonoid explanation of visible colour. The evidence of numerous colourless
compounds which cannot be quinonoid in structure is sufficient to condemn this
theory, even were there no other evidence against it. One of the most often
quoted instances in which the quinonoid theory is invoked is the well-known
case of aminoazobenzene. This compound gives with hydrochloric acid (one
equivalent) a salt which is more highly coloured than it is itself. This is
universally accepted as being due to the salt having the structure

==,

because the colour and absorption spectrum is entirely different from that of
benzeneazophenyltrimethylammonium iodide.

lin
Bot pea

which of course corresponds to the normal form of the hydrochloride.

H,;
OD

_ On the other hand, the trimethylammonium compound also gives a salt which

is more highly coloured than it is itgelf, and obviously this cannot be due to a

quinonoid structure, It is clearly unjustifiable to explain the one case of colour
1920 ee ; Q

996 REPORTS ON THE STATE OF SCIENCE.—1920.

change by the quinonoid configuration when the other case of exactly analogous
colour change cannot be so explained.

Another well-known application of the quinonoid hypothesis is to the alkali
metal salts of the nitrophenols which are highly coloured. It is stated, for
example, that the sodium salt of p-nitrophenol has the constitution

O
O= == xt

ONa

If that is so, what is the constitution of the nitrophenol when in solution in
concentrated sulphuric acid, for it is equally coloured under these conditions? A
similar coloured solution is obtained when p-nitroanisole is dissolved in sulphuric
acid. Many other instances could be quoted, and there is no doubt that the
evidence against a direct structure-absorption correlation is overwhelmingly
great.

There are two general objectives to any of the theories that have been referred
to. In the first place, no theory can be sound which is limited to a very minute
section of the spectrum such as the visible and ultra-violet, and in the second
place, no theory can hold good unless it rests on a quantitative physical basis.
There is also another aspect of the phenomenon of absorption, namely, its un-
doubted connection with the phenomena of fluorescence and phosphorescence.
Just as the selective absorption of light must be due to specific properties of
molecules, so also must the emission of light by molecules be due to similar
properties. It is evident that any theory must take cognisance of both
phenomena. It is true that many theories were advanced to explain the
fluorescence of organic compounds, but none of these can be said to hold the
field. Devised to explain visible fluorescence they fail entirely to offer any
explanation of the ultra-violet fluorescence shown by many compounds,

In general it may be said that the most recent work on the absorption by
organic compounds has increasingly shown that there is some relation between
the absorption bands shown by a substance and its reactivity. Perhaps the first
observations which supported this view were those of certain amino-aldehydes
and -ketones of the aromatic series and their salts with hydrogen chloride.12_ It
was found that alcoholic solutions of these compounds exhibit well-marked
absorption bands. On the addition of small quantities (0°1 to 0°5 eq.) of hydro-
chloric acid to these solutions a new absorption band, situated nearer to the red,
is developed in each case. On the addition of more acid this band disappears
and gives place to the absorption characteristic of the hydrochloride of the
original base. This shows that the base as it exists in alcohol solution does not
react with the acid to give the salt, but that it is first converted into an inter-
mediate or reactive phase which then reacts with more acid to give the salt.

These observations were extended to many substances, notably certain
phenolic compounds including the nitrophenols.1* The compounds in alcoholic
solution exhibit well-marked absorption bands which are not appreciably changed
when sulphuric acid is added. When dissolved in concentrated sulphuric acid
they develop visible colour due to absorption bands in the visible region. The
compounds in sulphuric acid solution, on being allowed to remain, slowly
undergo sulphonation to give colourless sulphonic acids. Clearly. therefore,
these phenols in the condition in which they exist in alcoholic solution do not
react with sulphuric acid. When dissolved in strong sulphuric acid they are
changed into a reactive phase which slowly reacts with the sulphuric acid to give
the sulphonic acid. They are therefore exactly analogous to the amino-aldehydes
and -ketones alreadv mentioned.

It might easily be said that the coloured reactive modifications have under-
gone a change in structure. but further evidence shows that no change of
structure has taken place. The majority of these compounds in alcoholic solu-
tion exhibit fluorescence when exposed to light of frequency equal to that of
their absorption bands. The frequency of this fluorescent emission has been
accurately measured, and it has been found in every case of the above-mentioned
substances that the frequency of the fluorescence of the compound in alcoholic

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 227

solution is equal to that of the absorption band shown by that compound when
in the reactive phase. The same frequency therefore is characteristic of a given
substance in two solvents, in one of which it is exhibited as emission and in the
other as absorption. It is evident, therefore, that the constitution of each
compound is the same in the two cases.

Very important conclusions may be drawn from these observations, namely,
that a given compound can exist in at any rate two phases which differ in
their reactivity and which are characterised by different absorption bands.
Also the absorption bands shown by the reactive phases are nearer to the red
end of the spectrum. It is therefore an obvious deduction that a definite
absorption band is associated with a definite type of reactivity.

The next question to consider is whether an explanation of these facts can
be found. In the theories of absorption spectra given above no reference is
made to the ultimate destination of the light which is being absorbed. It is
perfectly obvious that, unless the absorbing compound undergoes a photochemical
change, the total amount of energy absorbed must again be radiated. It is
equally evident that just as the light energy is absorbed at frequencies which
are characteristic of the absorbing substance, so also must this energy be
radiated at frequencies characteristic of the substance. Careful experiments
have proved that, provided the absorbing substance or its solution is free from
dust, there is no evidence of radiation at the frequencies which lie within the
absorption band. Clearly, therefore, the phenomenon of absorption is not one of
optical resonance, that is to say, the light energy absorbed by a substance is
radiated at frequencies which are not the same as those at which it has been
absorbed. Except in those cases where fluorescence or phosphorescence is
observed, the whole of the absorbed energy is radiated at frequencies which lie
in the infra-red region of the spectrum, and we have therefore—

Energy absorbed (visible or ultra-violet) = energy radiated (infra-red),

This necessarily establishes a relationship between the various frequencies
exhibited by a substance in the infra-red, visible, and ultra-violet regions, and,
indeed, invites investigation of this relationship.

It will be remembered that Planck formulated the theory that absorption
and radiation of energy are not continuous processes, but are discontinuous in
the sense that the energy is absorbed or emitted in a series of fixed amounts.
To these fixed amounts he gave the name of energy quanta, and he showed that
the size of the quantum is given by the product of the frequency into a universal
constant, the most recent value of which is 656 x 1027. According to this
theory, therefore, if a substance is absorbing light with a frequency of, say,
9 x 1014, the process is not continuous, but each molecule absorbs a series of
quanta, each of which is 9 x 10!4 x 656 x 107, or 5:904 x 107 ergs.
Without discussion of the fundamental basis of this quantus theory it may be
applied to the problem of the absorption and radiation of energy by a molecule
when, as already explained, the total quantity of energy absorbed is radiated
at another and smaller frequency. Let a molecule absorb one quantum of light
energy at its absorbing frequency. This energy is then radiated at another
‘and smaller frequency, but it must be radiated as a whole number of quanta at
‘that frequency. It follows, therefore, that when a molecule is absorbing at
one frequency and radiating at another and smaller frequency, one quantum of
energy at the larger frequency must be equal to a whole number of quanta at
‘the smaller frequency. Finally, since the quantum is the product of the fre-
‘quency into the universal constant, the conclusion is reached that the absorbing
frequency must be an exact multiple of the radiating frequency. In other words,
‘the frequencies of each absorption band shown by a substance. in the visible
‘and ultra-violet must, on the basis of Planck’s theory, be an exact multiple of a
frequency characteristic of that substance in the infra-red. It was not difficult
‘to test the validity of this deduction since the existence of characteristic
frequencies in the infra-red possessed by a substance can be proved by the
method of absorption spectra observations in that region, and indeed a creat
number of substances had already been in vestigated in this manner. .

Tt may be stated’ at once that the relation has been found to be true in the

Q 2

228 REPORTS ON THE STATE OF SCIENCE.—1920.

case of every substance examined.‘ Further than this, it is well known that
certain substances exhibit more than one absorption band in the visible or ultra-
violet, and it has been found that the frequencies of each,of these absorption
bands are exact multiples of one and the same frequency characteristic of that
substance in the infra-red. It follows, therefore, that when a substance shows
more than two absorption bands in the visible or ultra-violet there must exist a
constant difference between the frequencies of consecutive bands, and this
difference must equal the fundamental infra-red frequency. This has also been
proved to be true.

The application of the Planck theory has led to the discovery of relationships
between the frequencies of the absorption bands shown by a substance, relation-
ships which are of considerable importance because they form a quantitative
basis of molecular frequencies. It is not possible here to give the mathematical
development of Planck’s theory, and the theory is only mentioned because it led
to the discovery of the relation between the frequencies.

It is advisable at this point to discuss in some detail what is meant by the
frequency of an absorption band and also the influence of a solvent upon that
frequency. It is common knowledge that in many instances under high resolving
power an absorption band is found to possess a structure. The most common
phenomenon is when an absorption band consists of a series of sub-groups. In
this case one sub-group always exhibits a maximum absorptive power, and those
on either side exhibit decreasing absorptive power the farther they are situated
from the principal sub-group. Then, again, it is generally found by the
examination of the vapour of the substance that each of the sub-groups is
resolved into fine absorption lines, and that the arrangement of these lines as
regards their intensity is analogous to that of the sub-groups themselves. There
is always in each sub-group one line of maximum intensity, and the other lines
are arranged in series of decreasing intensity with regard to this central line.

Now when a substance is cooled to low temperatures it is found that its
absorption bands become narrower, this being due to the suppression of the
outermost sub-groups. With further fall of temperature more and more sub-
groups disappear, and finally there is left only the principal line of the principal
sub-group. This absorption line persists even at the lowest temperatures yet
reached. It is perfectly evident therefore that this single frequency is truly
characteristic of the molecules, and that the other frequencies which make up
the breadth of the band are due to some cause connected with the temperature
of the molecules. There is, of course, no necessity to cool a substance to low
temperatures in order to recognise the true molecular frequency, because this
frequency is always that one for which the absorptive power is the greatest in
the absorption band. In the quantitative relationships given above it is this
true molecular frequency which is referred to.

It is perhaps not out of place to refer to the confusion that has arisen from
time to time from carelessness in nomenclature in dealing with absorption
spectra observations. The term ‘band’ is applied to the whole region covered by
one set of associated groups or sub-groups. In the literature the word band
has been used when a sub-group of a band is meant, and thus considerable
confusion has been caused.

The next point to be dealt with is the variation in absorption caused by a
solvent, a fact that is of material importance in connection with the quantitative
relations between the molecular frequencies exhibited by a compound. Hartley
was the first to observe the difference in frequency of a particular absorntion band
according to whether a substance is examined in the vapour state or in solution

in a solvent, and he noted that there is always a small shift towards the red in:

passing from vapour to solution. There are, in fact, two different effects of a

solvent npon the absorption spectrum of a substance as observed in-the vapour

state. One of these has already been mentioned, namely, the appearance of an
entirely different absorption band when the substance is dissolved. In this
case the vapour exhibits a molecular frequency which is one multiple of the
infra-red frequency, whilst the solution exhibits a molecular frequency which
is another multiple of that infra-red freauency. In the case of some comnounds
it has been shown that bv the nse of different solvents a number of different
multiples of the infra-red fundamental are called into play.

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 229

The second effect of a solvent is when the same molecular frequency is
common to vapour and solution, but the measurements of this frequency with
vapour and solution do not give exactly the same values. 1t is this particular
eftect which requires discussion, because unless the phenomenon is understood
the relationships between the infra-red fundamental frequency and the visible
and ultra-violet frequencies will apparently not hold good. Without going
fully into the quantitative measurements it may be stated that the change in
the value of the molecular frequency in passing trom vapour to solution depends
on the nature of the solvent and on the concentration in that solvent.’° As
regards the effect of concentration, the difference between values of the molecular
frequency as observed with vapour and solution is greatest with concentrated
solutions. As the solution is diluted the value more and more nearly approaches
the value for the vapour until at very great dilution the value for the solution
equals that for the vapour. This change in the molecular frequency in passing
from vapour to solution is not due to the fact that the quantitative relation
between visible or ultra-violet bands and the intra-red fundamental does not
hold, but to the fact that the infra-red fundamental itself varies slightly
in position with the nature of the solvent and the concentration in that solvent.
Another important fact to be recorded is that a compound in the liquid state
does not show exactly the same molecular frequency as it does in the state of
vapour. This, again, is due to a small difference in the infra-red fundamental
frequency in the two states. It is obvious, therefore, that in making measure-
ments ot molecular frequencies the true values are those obtained with the
vapour. If, as frequently happens, measurements cannot be made with the
vapour, then very dilute solutions must be used. Above all, in comparing
together the various molecular frequencies shown by a given substance it is
necessary: that all the measurements be made with the substance under the same
conditions.

In connection with the effect of solvents on the absorption exerted by a sub-
stance, a brief reference may be made to the variation in the absorptive power
with concentration. Measurements have as yet only been made for frequencies
in the ultra-violet region. At first sight it might be expected that Beer’s
law would hold good, namely, that the molecular absorptive power would be
independent of the concentration. It is, however, rarely the case that Beer’s
law holds good, and in the great majority of cases the absorptive power in-
creases with dilution up to a constant) maximum. It has been found that if
K isthe maximum absorptive power shown by a substance at very great dilution
in a given solvent, and k is the absorptive power at a definite concentration
k/K=1—e-4V, where V is the volume in litres containing one gram molecule
of the absorbing substance and a is a constant. A more convenient form of the
above is log (K / K-k) =aV.

The quantitative relationships between the various frequencies shown by a
molecule may now be further considered. It has already been stated that the
principal frequencies of all the absorption bands shown by a compound in the
visible and ultra-violet are always exact multiples of the principal frequency
of an important absorption band shown by that substance in the infra-red.
This is true of all the absorption bands which are shown by a substance in
different solvents, and which Hantzsch attempted to explain by assigning a
different formula for each band. Other quantitative relationships have also
been discovered, and these may briefly be described, because it has been
found possible from a knowledge of them to formulate a quantitative theory
which would seem capable of explaining all the observations that have been
made on absorption spectra.

In the first place it may be noted that the examination of the absorption
exerted by a compound in the infra-red reveals the existence of many more
bands than the important one which has been called the infra-red fundamental,
and’ which determines the frequencies of the visible and ultra-violet bands. ,
Purther, in every case yet examined the infra-red fundamental lines were in the
short wave infra-red region, i.e., between the wave-lengths limits of 8 and 3p.
Tf the principal frequencies of all the infra-red bands are examined additional

interesting relationships are found. Thus the fundamental infra-red frequency

either ig the least common multiple of certain of the long wave infra-red

230 REPORTS ON THE STATE OF SCIENCE.—1920.

frequencies or is a multiple of that least common multiple, and indeed this rela-
tionship gives the key to the whole of the system of frequencies exhibited by a
moiecule. Again, the whole of the principal frequencies.in the infra-red are
derived from certain constants, and these constants are characteristic of the
elementary atoms of which the absorbing molecules are composed. These con-
stants or elementary atomic frequencies lie in the very long wave infra-red
region, and the corresponding wave-lengths are of the order of 1000p.

The whole of the principal frequencies shown by a molecule are determined
as follows: The fundamental infra-red frequency either is the least common
multiple of all the elementary atomic frequencies which are active in the mole-
cule or is an exact multiple of that least common multiple. The principal
frequencies of all the visible or ultra-violet absorption bands shown by that
molecule under various conditions are exact multiples of that fundamental infra-
red frequency, and therefore are characteristic of that molecule. In addition
to all these frequencies which are true molecular frequencies, there also exist
frequencies which are the least common multiples of some (not all) of the
elementary atomic frequencies, and these are due to specific groups of atoms in
the molecule, and are called intra-molecular frequencies.

The question might be asked as to how these relationships have been proved
within a very high degree of accuracy in view of the fact that measurements
of absorption in the infra-red have not reached a high level of accuracy. It
has been found that if a molecule exhibit a principal frequency F in the infra-
red, visible, or ultra-violet, there will be associated with that frequency sub-
sidiary frequencies F+.A, where A stands for either the intra-molecular fre-
quencies or the elementary atomic frequencies. Indeed, it is to this cause that
the breadth of the absorption bands is due. As the result of this it is possible
to arrive at highly accurate determinations of the intra-molecular and ele-
mentary atomic frequencies by analysis of the absorption bands, especially
those in the ultra-violet where the accuracy of measurement is very high.

The most usual arrangement of the subsidiary frequencies within an absorp-
tion band is as follows : The band consists of a series of sub-groups symmetrically
arranged with respect to the principal sub-group with the greatest absorptive
power. These sub-groups each possess a principal line for which the absorptive
power is a maximum, and all these principal lines form a series of constant
frequency difference.. This frequency difference is an intra-molecular frequency
and is characteristic of a specific group of atoms within the molecule.

Then, again, each sub-group is exactly similar in structure and consists of
two or more series of lines, each with constant frequency difference and
symmetrically arranged with respect to the principal line. These constant
frequency differences are the elementary atomic frequencies characteristic of
the atoms composing the specific group within the molecule, and the least common
multiple of these is the intra-molecular frequency characteristic of that group
of atoms.

Two instances may be given which exemplify very fully these relationships,
The complete absorption system of sulphur dioxide has been found to be based
on three elementary atomic frequencies.1¢ Of these, two, 819 x 104! and
1:296 x 10!2, are characteristic of the sulphur atom because they also form

the basis of the infra-red frequencies of hydrogen sulphide, and the third, |

24531 x 1011, is characteristic of the oxygen atom. Krom direct measurement
the two possible intra-molecular frequencies of the water molecule have been
found to be 75 x 10! and 1:7301 x 10%. Obviously if 2:4531 x 1011 is
characteristic of the oxygen atom it should form one of the fundamental constants
of the water molecule. From these three values alone it has been found
possible?” to calculate the whole of the structure of the infra-red bands of
water, and the values obtained agree absolutely with those observed.1®

Again, in one of the ultra-violet bands of naphthalene there exists a constant
frequency difference of 1-4136 x 101° between the sub-groups, which is therefore
an intra-molecular frequency, and thus must be characteristic of a definite
group of atoms within the naphthalene molecule. The two most obvious groups
of atoms are the phenyl group and the olefine group, and therefore the frequency
1:4136 x 101% should be the true molecular frequency of either benzene or one
of the olefines, the olefines being very similar in their characteristic frequencies.

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 231

This was found to be true for the olefines since ethylene shows a series of bands
in the short wave infra-red, the principal frequencies of which are exact multiples
of 14136 x 101°,

In formulating a theory of absorption spectra the following relationships
which have been established must be considered.}*

1. Every elementary atom possesses one or more frequencies which are
characteristic of the element.

2. When atoms of different elements enter into combination the resulting
molecule is endowed with a new frequency which is the least common multiple
of the frequencies of the atoms it contains. This is called the true molecular
frequency.

3. lhe central frequencies of all absorption bands, that is, those frequencies
for which the absorptive power is greatest, are molecular frequencies
characteristic of the molecules, since these alone persist when the substance
is cooled to low temperatures.

4. The molecular frequencies in the visible and ultra-violet regions are exact
multiples of a molecular frequency in the short wave infra-red, which is called
the infra-red fundamental frequency.

5. The infra-red fundamental frequency either is the true molecular frequency
or is an exact multiple of the true molecular frequency.

6. The breadth of an absorption band as observed at ordinary temperatures
is due to the combination of the molecular central frequency with subsidiary
frequencies.

The first question which arises is the meaning of the characteristic atomic
frequencies which are the fundamental constants trom which the whole system
of trequencies shown by a molecule is derived. Presumably they are connected
with the shift of an electron from one stationary orbit to another, a change
which must require a definite amount of energy depending upon the electro-
magnetic force field of the atom. Indeed, it would seem that, if a possibility
be allowed of the shift of an electron from one stationary orbit to another, it
becomes necessary at once to accept the conclusion that a definite and fixed
amount of energy is involved in the change. It is proposed, therefore, to start
from this assumption, that in any elementary atom it is possible to shift an
electron from one stationary orbit to another, that a definite amount of energy
is required to effect the change, and that this fixed quantity of energy is
connected with the frequency by the relation—

Fixed Quantity of Energy
Constant

= Frequency.

This is readily to be understood if the constant involves a function of the time
taken in the actual operation, which is the same for every atom and is a universal
constant.

This elementary quantum of energy involved in the electron shift is without
doubt the basis of the whole energy quantum hypothesis as applied to absorption
and radiation, for it can be shown that the whole can be built up from the
original assumption of the elementary quantum as a specific property of the
atom. For the sake of convenience only it will be necessary to make use of a
value for the constant, and the most recent value for this, based on Planck’s
theory, is 656 x 10°’. Using this value, the elementary quanta already
calculated, namely, those of hydrogen, oxygen, and sulphur, lie between
525 x 1076 and 1:65 x 107° erg, corresponding with frequencies between
819 x 101° and 2°54 x 10!?.

The difference between this conception and Planck’s theory may be
emphasised. Whereas according to the latter the frequency is accepted as a
characteristic of the atom and the quantum is the result of discontinuous
absorption or emission at that frequency, the present theory assumes the quantum
of energy as being due to a specific process taking place in the atom and hence
a fundamental characteristic of the atom, and that the frequency exhibited by
the atom is established and determined by that process. The present theory,
therefore, gives a simple physical basis to the energy quantum,

232, REPORTS ON THE STATE OF SCIENCE.—1920,

The first fact to be dealt with is that when two or more atoms unite together
the resulting molecule becomes endowed with a new frequency which is the
least common multiple of the frequencies characteristic of the atoms. Leaving
on one side the cause of the chemical combination, the energy lost in the process
may be considered. The simplest possible assumption to make is that in the
synthesis of any one molecule each of the component atoms contributes an equal
amount of the total energy lost. An elementary atom ex hypothesi can only
gain or lose energy in elementary quanta, and, further, can only’ enter into
chemical combination if it already contains energy that can be evolved. Let
the case be considered of two elementary atoms, the characteristic frequencies
of which are 9 x 10° and 1°5 x 10", or in wave numbers (1/A) 3 and 5.
The smallest equal amounts of energy that the two atoms can lose are five ele-
mentary quanta at the frequency 9 x 101° in the one case, and three elementary
quanta at the frequency 1°5 x 10% in the other. These two amounts are each
equal to one quantum measured at the frequency 45 x 101", which is the least
common multiple of the two atomic frequencies. In this is doubtless to be found
the key to the first problem—namely, that the true molecular frequency is the
least common multiple of the frequencies of the atoms in the molecule.

Further, the gain or loss of energy by a molecule as a whole must be equally
shared in by the component atoms. When a molecule absorbs or loses energy
as a whole, it must do so by means of the elementary quanta characteristic of
its atoms. In the case of the molecule specified above, the smallest amount
of energy it can gain or lose as a whole ig the sum of five quanta at the frequency
9 x 10!° and three quanta at the frequency 15 x 10!!. This minimum amount
of molecular energy is two quanta at the true molecular frequency, and in this
again is to be found an explanation of the fact that the true molecular frequency
is the least common multiple of the atomic frequencies.

It is evident, therefore, that starting from the conception of the elementary
energy quantum required to shift one electron and making the simple assumption
that the combining atoms share equally in the energy loss on combination and
in the future energy changes of the resulting molecule, we arrive at the con-
ception of molecular quanta, and hence molecular frequency, the latter being
the least common multiple of the atomic frequencies.

It can be shown that, when molecules under normal conditions are dealt with,
one of the most important frequencies they possess is the infra-red fundamental
frequency, which is an exact multiple of the true molecular frequency. In the
case of sulphur dioxide the infra-red fundamental is fourteen times the true
molecular frequency, and in the case of water it is eight times the true molecular
frequency. It was stated above that the smallest possible equal amounts of
energy which two or more atoms can evolve when combining together are equal
to one quantum measured at the frequency which is the least common multiple
of their atomic frequencies. It does not follow, of course, that the reacting
atoms only evolve this smallest possible amount of energy. They may evolve
an amount of energy which is 2, 3, 4, &c., times this smallest quantity, with
the result that the smallest frequency truly characteristic of the molecule may
be a multiple of the true molecular frequency. Indeed, it would seem that the
infra-red fundamental is the frequency which is truly characteristic of the
freshly synthesised molecule.

At the commencement the simplest possible case was considered of the com-
bination of two atoms, each characterised by a single elementary quantum.
There is no necessity to restrict the conditions in this way, and it is to be
expected that, at any rate in the atoms of some elements, there will exist more
than one possibility of shift of the electrons, and that there will be elementary
quanta of different sizes associated with such atoms. It has already been found
that two different elementary quanta are associated with the atom of oxygen
in the water molecule and with the atom of sulphur in the molecule of sulphur
dioxide. :

Whilst the establishment of molecular quanta, and hence of molecular
frequency, is a simple deduction from the conception of elementary atomic
quanta, it cannot be denied that the molecule may also exhibit those frequencies
which are characteristic of its component atoms. Although these atoms have
united together to form the molecule, there is no reason to expect that they have

Be) eq.

ON ABSORPIION SPECTRA OF ORGANIC COMPOUNDS. £83

thereby lost their individuality as far as their powers of absorbing or radiating
energy are concerned. ‘he conception of the molecular quantum 1s based on
the assumption that the component atoms can gain or lose elementary quanta
when in combination. In addition to this, there is definite evidence that the
molecule exhibits the specific frequencies of its atoms, since, although these
atomic frequencies have not yet been observed in the long-wave infra-red, they
are found in combination with the molecular frequencies as subsidiary frequencies
within the absorption band groups in the intra-red, visible, and ultra-violet
regions. The question then arises as to the course of events when a molecule
is exposed to radiation of a frequency that is the same as one of its characteristic
atomic frequencies which may be active in the extreme infra-red. Let it be
supposed that the molecule formed by the combination of two elementary atoms
haying the characteristic frequencies 9 x 10'° and 15 x 101 is exposed to
monochromatic radiation of the frequency 9 x 10!°. The atom haying this
frequency will absorb this energy in elementary quanta of 9 x 656 x 10% erg:
and further, let it be supposed that this atom absorb five such quanta. The
total quantity of energy now absorbed is equal to the minimum quantity of
energy which that atom evolves when combining with the atom with characteristic
frequency 1°5 x 10", and is equal to one molecular quantum at the true molecular
frequency. If the postulate made at the beginning as to the combination of
atoms be accepted, then it would seem to follow as a natural consequence that
the total energy absorbed by the atom can be transferred to or taken over by the
whole molecule as exactly one true molecular quantum, In fact the molecule
can obtain one true molecular quantum by the absorption of a whole number of
elementary quanta by its atoms, the whole number being of course determined
by the frequencies of the other atoms in the molecule and the least common
multiple of all the atomic frequencies. Further, there is no reason against
this process being continuous in the sense that a molecule will be able to gain
more true molecular quanta than the single one by absorption of the specified
number of elementary quanta by its atoms.

Again, this process will be reversible : that is to say, a molecule will be able
to radiate one or more true molecular quanta in the form of the specified
number of elementary quanta characteristic of one of its atoms.

It will be seen that this leads to the conception of critical amounts of energy
associated with elementary atoms in combination, the critical amount of energy
of an atom being a whole number of elementary quanta characteristic of that
atom which in their sum equal one true molecular quantum characteristic of the
molecule of which that atom forms a part. When an atom is exposed to
radiation of a frequency equal to its own frequency, it can absorb its elementary
quanta until its critical quantity is reached, when this critical quantity becomes
merged into the molecular energy content as one true molecular quantum.

Amongst the quantitative relationships detailed above was mentioned the fact
that the central frequencies of all absorption bands, that is to say, all molecular
frequencies exhibited by a molecule in the visible and ultra-violet, are exact
multiples of the infra-red fundamental. It is therefore evident that one
molecular quantum absorbed at one of the molecular frequencies in the visible
or ultra-violet is equal to an exact number of quanta at the infra-red funda-
mental. If a molecule absorbs one quantum at one of these higher frequencies,
this amount of energy can be radiated again as a whole number of quanta at the
infra-red fundamental, or partly as quanta at this frequency and partly as
elementary atomic quanta. This is the process underlying the phenomena of
phosphorescence and fluorescence, and in this particular case the phosphorescence
will be in the form of infra-red quanta. Further, it is obvious that the
fluorescence emission need not of necessity be evolved as a whole number of
molecular quanta at the infra-red fundamental, but may be radiated as one
molecular quantum at a molecular frequency which is a multiple of the infra-red
fundamental, the remainder being radiated as molecular quanta at the infra-red
fundamental or as elementary atomic quanta, For example, if the molecule
absorbs one molecular quantum at the frequency which is ten times the infra-red
fundamental, this energy may be evolved as one quantum at the frequency which
is nine times the infra-red fundamental and one quantum at the infra-red funda-
mental itself. In such a case the fluorescence will be in the visible or ultra-

934 REPORTS ON THE STATE OF SCTENCE.—1920.

violet region of the spectrum. The factors governing these various alternatives
are determined by the conditions under which the molecules exist. It will be
seen from this that a molecule can acquire one or more molecular. quanta at the
infra-red fundamental in three different ways: by exposure to radiation equal
to its atomic frequencies, by exposure to radiation of frequency equal to the
infra-red fundamental, or by exposure to radiation of a frequency which is an
exact multiple of the infra-red fundamental.

The next point to be considered is the structure of the absorption bands, that
is to say, the system of subsidiary frequencies which are always found asso-
ciated with the true molecular frequency when the absorbing or radiating power
of molecules is examined at ordinary temperatures. These subsidiary frequencies
have been attributed by Bjerrum *° to the rotation of the molecules and by
Kriger?! to their precessional motions. Without discussion in detail it may
be pointed out that both these theories break down. In the first place neither
theory takes account of the fact that the subsidiary frequencies are due to the
atomic frequencies, and in the second place it is necessary for the purpose of
these theories to postulate impossibly large variations in the values of the
molecular rotation or molecular precession.

On the other hand, the conception now put forward of elementary atomic
quanta of energy, whereby definite atomic frequencies are established, would
seem capable of affording a very simple and straightforward explanation. More-
over, this conception leads to the establishment of exact frequencies without
any possibility of variation. The case may again be considered of the molecule
formed by the combination of the two elementary atoms for which the elementary
quanta are 9 X 6:56 x 1077 and 1:°5 x 6°56 x 1016 erg,and which therefore exhibit
the characteristic frequencies 9 x 101° and 1:5 x 10! respectively. Hx hypothesi
the elementary quantum is associated with the shift of one electron from one.
stationary orbit to another, and, of course, there is no reason to assume that
only one electron can be so shifted. There may be many such electrons which
can be so shifted, the amount of energy being the same for each; and conse-
quently it will be possible for one atom to absorb 1, 2, 3, &c., elementary quanta
in the same unit of time. The atom will therefore exhibit frequencies which
are 1, 2, 3, &c., times its fundamental frequency. The two atoms specified
above will in the free state exhibit frequencies of n x 9 x 10!°and n x 1'5 x 10%
respectively, where n= 1, 2, 3, &c. The molecule formed by the combination
of these two atoms can also exhibit these frequencies, but now the upper limit
of n will be fixed by the critical quantity previously defined. Since the least
common multiple of the two atomic frequencies is 4°5 x 1011, the upper limits
of n for the two atomic frequency series shown by the molecule will be 4 and 2
respectively, since when 7 = 5 and 3, the two atomic frequency series will con-
verge in the true molecular frequency. Perhaps, therefore, the true molecular
frequency will be better understood as the convergence frequency of the atomic
frequency series than as the least common multiple of the atomic frequencies.

We may now consider one of the true molecular frequencies. Since the
molecule can absorb as a whole one quantum at that frequency, and since also
each atom within the molecule can absorb one or more elementary quanta,
there is no reason why the two processes should not be simultaneous. The
molecule will then absorb in one unit of time an amount of energy equal to the
sum of one true molecular quantum and one or more elementary quanta. This
will result in the establishment of the subsidiary frequencies M + nA, where
M is the true molecular frequency, A is the atomic frequency, and n = 1, 2, 8, &c.,
the upper limit of n being fixed by the critical value as already explained.

Similarly there will be established the subsidiary frequencies M—nA, for
the following reason. Let the molecule which is in radiant equilibrium with
its surroundings absorb one quantum of energy at one of its atomic frequencies.
In order for it to gain a molecular quantum at one of its true molecular
frequencies it will now only be necessary for it to absorb the molecular quantum,
less the atomic quantum already absorbed. It has already been shown how on
the present conception summation of atomic quanta can take place to form
molecular quanta ; so it would follow that, after the absorption of a given number
of elementary quanta beyond that associated with the radiant equilibrium, the
molecule will be able to absorb the balance necessary to form one molecular

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 235

quantum. In other words, the molecule will be endowed with the frequencies
M—7nA.

Emphasis may be laid on the fact that, under normal conditions, when the
molecule is in radiant equilibrium with its surroundings the subsidiary frequencies
M+7A are actually observed; and further, that in these series of subsidiary
frequencies the maximum observed value of 7 is one Jess than the critical value ;
that is to say, the subsidiary frequencies associated with two consecutive values
of the molecular frequency do not overlap. Obviously, if the molecule is screened
from all external radiation with frequency equal to its atomic frequencies—that
is to say, it is cooled to low temperatures—the whole of the above deductions
as to subsidiary frequencies fail, and the subsidiary frequencies must therefore
vanish. This has been observed, since at very low temperatures only the central
molecular frequencies remain.

In the foregoing the simplest case only was dealt with of a binary molecule
formed by the combination of atoms of two different elements. Exactly the
same conditions will, of course, obtain in more complex molecules, but added
to these will be new conditions resulting from the existence of groups of atoms
within the molecule. For instance, even in the apparently simple case of the
water molectile the conditions will be more complex, owing to the undoubted
fact that in this molecule the hydroxyl group exists as an integral portion of
the molecule. Whilst, of course, the true molecular frequency will be the
convergence frequency of all the atomic frequencies, it is the subsidiary fre-
quencies that will exhibit a greater complexity. This complexity, however, is
only one of degree, and its explanation follows exactly the same principles as
were laid down for the simplest possible binary molecules. The specific case
of the water molecule may be discussed in which there are three atomic fre-
quencies, 1:0635 x 1011, 2:1159 x 1011, and 274531 x 1011. Whilst the true mole-
cular frequency of the water molecule is the convergence frequency of these
three, 6°1326 x 10!2, we have also to take into account the intra-molecular fre-
quency of the OH group. Now in the molecule H—O—H there are two
frequencies active for oxygen and one for hydrogen, and thus there are two
possible intra-molecular frequencies for the OH group, depending on which
oxygen frequency is concerned. In addition, therefore, to the three atomic
frequency series the molecule will also show intra-molecular or OH series.
Each of these intra-molecular frequencies is the convergence frequency of two
atomic series, and will be associated with subsidiary frequencies to form a
band group. If I be the intra-molecular frequency, the only subsidiary fre-
quencies associated with I will be given by I-+mA, and I+ nAg, where A, and
A> are the two atomic frequency series converging at I, and n=1, 2, 3, &c.,
with an upper limit defined by the critical value. There will also exist two
series of frequencies, I, 21: 31,1, &c., and Iz, 212, 312, &c., each associated
with its subsidiary frequencies. These intra-molecular frequencies will converge
at the true molecular frequency.

In the case of the water molecule there are two intra-molecular frequency
series, namely 7-5 x 101, which is the convergence frequency of the atomic
frequencies, 1:0635 x 101! and 2°1159 x 1011, and 1-7301 x 1012, which is the
convergence frequency of the atomic frequencies 21159 x 1011 and 2°4531 x 1011,

When the subsidiary frequencies associated with the given true molecular
frequency are considered, instead of only the subsidiary frequencies M+7A,
there will exist as subsidiary frequencies M+nI-+mA, where n and m=0, 1, 2,
&c., each having its own critical limit, I is one or other of the intra-molecular
frequencies, and A stands for the two atomic frequencies which have I as their
convergence frequency. This will obviously result in the whole group of sub-
sidiary frequencies associated with the given molecular frequency being divided
into sub-groups. The central sub-group will be given by n = 0, and the central
lines of the sub-groups will be given by m = 0. This is exactly the structure
that has been observed in the case of water and sulphur dioxide, both of which
molecules have three atomic frequencies. Perhaps the most striking experi-
mental confirmation is to be found in the fact that in any one sub-group the
subsidiary frequencies are formed from only those atomic frequencies which
have the intra-molecular frequency as their convergence frequency. None of
the previous theories are able to account for this selective association of the
atomic frequencies.

236 REPORTS ON THE STATE OF SCIENCE.—1920.

With still more complex molecules it becomes necessary to accept the exist-
ence of small atomic groupings within the principal groupings. Without going
into the resulting system in detail it may be stated that this will result in
the sub-division of the sub-groups into smajler sub-groups. It is of considerable
interest to note that the phosphorescence and absorption bands shown, by certain
uranyl compounds exhibit this type of structure.?

Before entering further into the quantitative relationships one point arising
from the foregoing discussion of energy quanta may be mentioned. It has been
shown that in the water molecule the oxygen atom exhibits two characteristic
frequencies and the hydrogen atom one, whilst in sulphur dioxide the oxygen
atoms exhibit one and the sulphur atom two characteristic frequencies. It is
difficult to avoid the conclusion that the characteristic atomic trequency is the
basis of the valency of that atom. Thus a univalent atom may be one for
which there is only one possible shift of its electrons, with a bivalent atom
there may be two possible shifts, and so on. From this it would also follow
that the numerical size of the elementary quantum associated with the atoms
of an element determines the position of that element in the series of electro-
positivity. Obviously the larger the elementary quantum associated with an
atom the greater will be the energy given out when that atom enters into
combination. Further, when a multivalent atom enters into successive com-
bination with atoms of a given univalent element, its largest elementary quantum
will be concerned when it combines with the first atom. ‘I'his will be followed
by the next largest, and so on. This will mean that the ‘strength’ of its
different valencies will be different, and the individual bonds with the various
atoms of the univalent element will require different amounts of energy to
resolve them.

There now remains to be considered the origin of chemical reaction. The
relationships between the frequencies shown by a molecule and its component
atoms have been discussed, but nothing has been said as to why atoms combine
together and why certain specific properties are associated with the molecules
produced. It would seem that the key to this problem is to be found in the
electromagnetic force fields of the atoms. It is evident that, according to
the modern view of atomic structure, a central positive nucleus with negative
electrons in rotation round it, each atom must form the centre of an electro-
magnetic field of force. These force fields were first dealt with by Humphreys,??
who showed that they are capable of giving a quantitative explanation of the
Zeeman effect and also of the pressure-shitt of spectrum lines. He deduced
the fact that two atoms will attract one another when they approach in such
a way that the direction of their electronic motions is the same, and will repel
one another when their electronic motions are in opposite directions. Each
atom therefore possesses two faces, and when one pair of faces comes together
they repel one another, and when the other pair comes together they attract
one another. In other words, an atom forms the centre of an electromagnetic
field of force, the opposite poles of which are localised in two opposite faces
of the atom.

Let it be supposed that two atoms of different elements are brought together
in such a way that their mutually attracting faces come together. They will
at once tend to form an addition complex which can lose energy in the
manner already described. ‘The two atoms radiate equal amounts of energy
as a whole number of elementary quanta whereby the resulting molecule becomes
endowed with the frequency based on the least common multiple of the atomic
frequencies. This molecule is now rendered a stable entity, and can only be
resolved into its atoms by absorbing an amount of energy equal to that lost
in its formation. This quantity of energy consists of a definite number of true
molecular quanta.

As will be noticed, however, in this suggestion, that the reactivity of atoms
for one another is due to the attraction of their respective force fields, and
that their combination consists in their joint loss of equal amounts of energy,
no account has been taken of the other faces of these combining atoms. Whereas
the combination of the atoms produces a molecule characterised by a specific
energy quantum, it is not possible to consider that the force fields due to the
external atomic faces can exist without influence on one another. These
external force lines must condense to form an external molecular force field, and

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 937

in this process energy must be evolved. It was not possible previously to deter-
mine the amount of energy lost by each molecule in this process, but the theory
of elementary and molecular quanta put forward now enables this to be done
with accuracy. It was shown above that a freshly synthesised molecule is
characterised by a definite molecular quantum, and hence by a specified frequency
in the short wave infra-red, which has been called the infra-red fundamental
frequency. When a freshly synthesised molecule loses energy as a whole it
must do so in quanta at the infra-red fundamental, and thus it would follow
that, when the external force fields of the component atoms of a freshly syn-
thesised molecule condense together to form ‘the molecular force field, the
system loses energy in quanta at the infra-red fundamental of that molecule.
Clearly, the molecule itself will not suffer any Joss of individuality as far as
its characteristic frequencies are concerned. None of the deductions from the
conception of elementary and molecular quanta made above will be contra-
dicted, and the only change accompanying the formation of the molecular force
field will be the endowment of the system with an additional molecular frequency
which is an exact multiple of the infra-red fundamental. Let it be supposed
that in the formation of its molecular force field a given molecule loses one
molecular quantum at the infra-red fundamental. If the freshly synthesised
molecule were allowed to absorb one quantum at the infra-red fundamental it
would become endowed with certain properties. If now it is required to bring
the molecule with its molecular force field established by the loss of one quantum
into this physical state it will be necessary to supply it with energy equal to
two energy quanta at the infra-red fundamental. There can be no reason against
the molecule and its force field absorbing both these quanta simultaneously.
and therefore it may be concluded that the system of molecule and force field
becomes endowed with a new and additional frequency which is exactly twice
the infra-red fundamental. Similarly, it follows that, if the force-field con-
densation proceeds to the extent defined by the loss of tao molecular quanta at
the infra-red fundamental, the molecule and its force field will be endowed with
a new and additional frequency which is exactly three times the infra-red
fundamental. Generally, if the infra-red fundamental of a freshly synthesised
molecule be denoted by M, and if in the formation of the force field 2 quanta
are evolved at that frequency. the system will be characterised by two molecular
frequencies, namely M and M(x+1). Since the external atomic fields are bound
to undergo a certain amount of condensation, it is evident that the molecule
must exist in one of a number of possible phases, each molecular phase being
defined by the number of molecular quanta lost in the force-field condensation
and characterised by a specific frequency which is an exact multiple of the
infra-red fundamental.

The initial assumption was made that the chemical reactivity of atoms is due
to the attraction exerted by their electromagnetic fields. As the result of this
attraction the atoms form an addition complex which constitutes the first stage
in the reaction between them, the second stage being the joint loss of equal
amounts of energy by all the atoms whereby the freshly synthesised molecule
is formed with its infra-red fundamental. Similarly the reactivity of molecules
will be a function of their force fields, and the first stage of any reaction between
two or more molecules will be the formation of the addition complex due to the
attraction between their respective force fields. It follows, therefore, that the
reactivity of a molecule will depend on the molecular phase in which it exists,
and, further, the creater the extent to which the condensation in the molecular
force field has taken place the smaller will be the reactivity. The phase in
which a molecule exists is governed by the nature of the external force fields
of its atoms. The more equally balanced these are the greater will be the
condensation that takes place between them. The particular phase assumed by
a molecule will depend on the external conditions, such as temperature, nature
of solvent, &c.

The experimental evidence in favour of the existence of these molecular
phases is exceedingly strong. It is not possible to give here a detailed account
of this evidence, but two or three of the most striking observations may be
mentioned. For instance, it is common knowledge that substances which pos-
sess very small reactivity are characterised by molecular frequencies which are

238 FEPORTS ON THE STATE OF SCIENCE.—1920.

large multiples of their infra-red fundamentals and lie in the extreme ultra-
violet. The converse of this is also true that substances with measurable
reactivity are characterised by frequencies which relatively are smaller multiples
of the infra-red fundamental. Again, it is possible by changing the external
conditions of temperature or solvent to change the molecular frequency ex-
hibited by a given substance, and in some cases as many as six different mole-
cular frequencies have been brought into play, each of which is an exact multiple
of the infra-red fundamental of that substance. This means that six different
molecular phases of the same compound have been observed. Then, again, it has
been proved that a particular frequency is associated with a specific chemical
reactivity, or, in other words, a particular molecular phase is endowed with its
own reactivity.

An interesting point arises at once when the force fields of free elementary
atoms are considered. It has been assumed that in a molecular force field the
force lines due to the external faces of its atoms undergo condensation to form
a condensed molecular force field. It is manifest if an atom consist of a
central positive nucleus with a single plane ring of electrons that the force
lines at the two faces of that atom will be exactly equal and opposite, that
condensation must occur to form an atomic field of force, and that this con-
densation will be very great with the evolution of a large number of atomic
quanta. Such an atom will under ordinary circumstances possess little or
no power of attracting other atoms, and hence will have no measurable chemical
reactivity. It is possible that the atoms of the inactive gases, helium, neon,
&e., are of this type. On the other hand, if there exist more than one plane
orbit of electrons, a condition of asymmetry will be set up in the atomic force
field, with the result that the complete condensation to form a non-reactive
atomic field is no longer possible. It does not seem improbable that in the
various types of asymmetry likely to exist the explanation is to be found of
the various properties of elementary molecules which are familiar to the chemist.
_ The extreme conditions resulting from this asymmetry would be (1) the non-

reactive diatomic molecule such as H,, N,, &c.: (2) the highly reactive mon-
atomic molecule such as Na, K, &c.; (3) the highly reactive diatomic molecule
such as F',; (4) the non-reactive polyatomic molecule such as those of carbon.
Apart from this possibility, which need not now be discussed, it is necessary
to take into account the fact that at any rate in the case of elementary molecules
containing more than two atoms the different molecular phases may be capable
of separate existence. Smits has put forward the theory that the different
allotropic modifications of an element are equilibrium mixtures of different
molecular species of that element. Thus the various allotropic modifications
of sulphur are equilibrium mixtures of some or all of four molecular species
of sulphur known as §,, §,, S,, and §,. There seems little doubt that
what Smits calls molecular species are in reality four different molecular
_ phases of sulphur, which differ in their energy content by a definite number
of quanta at the infra-red fundamental of sulphur. It is of considerable interest
to note that each of the four varieties of the sulphur molecule exhibits a
different molecular frequency in the visible or ultra-violet region, and that
thev therefore conform to the definition of molecular phases.

_ The molecular phase hypothesis throws a considerable light on the mechanism
of chemical reaction, and enables accurate calculations to be made of the com-
plete energy changes which are involved in any reaction. In the first place,
the calculation may be made of the total energy which is evolved during the
combination of elementary atoms to form molecules which are in radiant
equilibrium with their surroundings.

Let the case be considered of the combination of atoms of different elements,
and further let the characteristic frequencies of these atoms be 910°, 1:°2x 1011,

15 x 1011, and 2°1 x 101! respectivelv. The least common multiple of these
four frequencies is 1:26 x 1013, and this therefore will be the true molecular
frequency of the resulting molecule. On the assumption made in the preceding
paper that an equal amount of energy is contributed for each atomic frequency,
the smallest equal amount evolved for each atomic.frequency is 1:26 x 6:56 ~ 1114
or 82656 x 1074 ergs. The total quantity of. energy evolved therefore in the
actual formation of each molecule will be 4 x 82656 x 10°!4 or 330624 x 1075 ergs,

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 939

which will result in the establishment of the infra-red fundamental
5°04 x 10%. Since one quantum at this frequency equals the sum total of
energy evolved, the absorption of one energy quantum at this frequency will
result in the molecule just being resolved back again into its atoms,

The next stage in the process will be the formation of the molecular force
field, and let this be accompanied by the loss of 20 quanta at the infra-red
fundamental 5:04 x 1015. As shown above, the molecular system will now be
endowed with an additional characteristic frequency, 5-04 x 21 x 10 or
1:0584 x 101°, which lies in the ultra-violet region of the spectrum. The energy
lost by each molecule during the condensation of its force field will be
504 x 20 x 656 x 1074 or 661248 x 107% ergs. The total energy therefore
evolved in the two processes is the sum of 330624 x 10° ergs evolved in the com-
bination of the atoms and 6:61248 x 101? ergs evolved during the condensation to
form the molecular force field, which amounts to 6943104 x 107? ergs. This
amount of energy, however, is equal to one quantum at the frequency
1:0584 x 1015, which is characteristic of the molecular phase. As this is obvi-
ously true whatever may have been the number of quanta at the infra-red
fundamental lost during the formation of the molecular force field, the general
conclusion is reached that one energy quantum measured at the largest fre-
quency characteristic of the molecule is just sufficient to resolve that molecule
into its atoms. This is a general conclusion which includes Einstein’s photo-
chemical law.

The values taken above of atomic frequencies,* infra-red fundamental, and
molecular phase frequency closely approximate to those observed with many
compounds. It will be seen that the amount of energy evolved in the com-
plete process may be very large, and for a gram-molecule amounts in the above
instance to about 102,320 calories. It must, of course, be remembered that in
any reaction the observed heat evolved is less than the total amount evolved
in the formation of the molecular systems of the products by the amount
necessary to resolve the initial substance or substances into atoms.

An important deduction from this molecular phase theory may be made as
regards the energy changes involved in chemical reaction. It is obvious that
in any reaction in which the first stage is the resolution of the molecule into
its atoms the energy necessary for this first stage can at once be found from
the frequency of the phase in which that molecule exists. | Unfortunately,
there does not seem to be known at present a single instance of a simple
reaction in which the molecular phase frequencies have been accurately
measured, both for the original substance and the products, and consequently
it is not possible at the present time accurately to calculate the net change of
energy observed in any reaction. On the other hand, in the vast majority of
chemical reactions the reacting molecules are not resolved into their atoms in
the first stage of the process. It has been shown in a number of cases that it
is only necessary to bring the molecules into a particular phase in order to
enable them to enter into the desired reaction. A very typical example of the
difference in reactivity shown by the different molecular phases of the same
molecule is afforded by benzaldehyde. In alcoholic solution this substance ex-
hibits two molecular frequencies in the ultra-violet, and therefore two mole-
cular phases co-exist. It is well known that in alcoholic solution benzaldehyde
is readily oxidised by gaseous oxygen to benzoic acid, and that it is not con.
verted to benzaldehydesulphonic acid when sulphuric acid ig added to the

% In the example given simple numbers have been used for the atomic fre-
quencies in order to avoid complexity in calculation. It is perhaps worth
while to point out here that there are certain indications that the fundamental
frequencies of the atoms of different elements are possibly connected by simple
arithmetical relations. A sufficient number of these atomic frequencies has not
yet been computed, owing to the dearth of accurate measurements of the
subsidiary frequencies of simple molecules, to justify any conclusions being
made. It is of some interest, however, to note that in sulphur dioxide the
oxygen frequency 2-4531 x 10! is almost exactly three times the sulphur
frequency 8:19 x 10!°. and that in the case of the water molecule the atomic
frequency 2°1159 x 101! is very nearly twice the atomic frequency 1:0635 x 1011,

940 REPORTS ON THE STATE OF SCIENCE.—1920.

solution. The reaction with oxygen, therefore, is characteristic of one or both
of the two molecular phases present in alcoholic solution. If benzaldehyde is
dissolved in concentrated sulphuric acid it exhibits two new molecular fre-
quencies, one in the visible and the other in the ultra-violet region. T:wo
further molecular phases, therefore, exist in solution in sulphuric acid. In this
case the benzaldehyde is no longer oxidised by oxygen, but is readily converted
to the sulphonic acid.

Now the question arises as to the amount of energy necessary to convert
one molecular phase into another and the mechanism whereby this energy is
supplied. ‘The amount of energy required per molecule is readily calculated,
and is equal to one or more quanta measured at the infra-red fundamental of
that molecule. If the frequency characteristic of the first phase is « times
the infra-red fundamental and the required phase is characterised by a frequency
which is 7 times the infra-red fundamental, then the energy required for each
molecule is x—y quanta at the infra-red fundamental. Obviously the molecular
system can absorb this energy when exposed to radiation of a frequency equal
to its infra-red fundamental, or, as explained above, it may absorb it at any of
the frequencies characteristic of its component atoms. Lastly, the molecule
mav absorb one quantum at its characteristic phase frequency, and under
ordinary circumstances this energy will again be entirely radiated as quanta
at a lower phase frequency, the infra-red fundamental, or the atomic frequencies.
If there is present a substance capable of reacting with a less condensed phase.
then the molecule is converted into that phase and reacts, the balance of
energy being evolved as infra-red radiation. The essential point is that the
necessary amount of energy to change the molecular phase is x—y quanta at
the infra-red fundamental, and that when one quantum is absorbed at the phase
frequency the excess energy over and above that required is radiated. The
change of molecules from one phase to another under the influence of light is
readily enough shown experimentally, but it is necessary to stabilise the second
phase in some way, since otherwise it returns instantaneously to the first phase.
An interesting example is furnished by trinitrobenzene. an alcoholic solution
of which contains a molecular phase characterised by a frequency in the ultra-
violet. A piperidine solution contains a molecular phase of trinitrobenzene
which is characterised by a frequency in the blue and the solution is deep red
in colour. This second phase, therefore, is favoured by piperidine. Tf to an
alcoholic solution of trinitrobenzene a small quantity of piperidine is added, not
more than one molecule of piperidine to 10 molecules of trinitrobenzene, the
solution remains perfectly colourless. On exposure to light of the frequency
characteristic of the phase in alcohol the solution turns red, owing to the
formation of the second molecular phase, and the solution slowly becomes
colourless again when placed in the dark.

There is no need to enter into a discussion of the application in detail of
this theory to the quantitative relations involved in the energy changes of
chemical reaction. It is obvious that the theory renders possible the calcula-
tion of the complete energy changes, and this aspect of the phenomena may be
left. on one side. From the point of view of absorption spectra the essential
fact is that the theory leads to the conclusion that a molecule must exist in one
of a number of possible phases, each of which is characterised by its own
absorption band in the visible or ultra-violet region of the spectrum. It has
been proved that a molecule can be brought from one phase to another by the
gain of a whole number of fundamental infra-red quanta and that this can be
brought about by exposure to radiant energy at a frequency characteristic of the
molecule. Reference has already been made to the fact that it is possible to
change the nhase in which a molecule exists by the use of a suitable. solvent,
and indeed it is to this effect of a solvent that the variation in the absorption
spectra of many compounds is due.

In order to understand this effect of a solvent. it is necessary to consider the
condensation of the molecular force fields a little more in detail. From what
has already been said it is clear that this condensation will proceed to the
farthest possible extent. In the case of a molecule in which the external force
fields of the atoms are well balanced the condensation will proceed far with
the establishment of a highly eondensed field characterised by an absorption
hand in the extreme ultra-violet. On the other hand, if the external force fields

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 241

are not balanced the condensation will not be so great, and a balance of force
lines of one type will remain uncompensated. If this balance be removed in
some way then there will be nothing to prevent the condensation from proceed-
ing further with the escape of more fundamental infra-red quanta and the
formation of a more highly condensed phase. It may be noted in passing that
an uncompensated balance of force lines remaining after the condensation of
the force field has take place is in all probability the origin of what is known
to chemists as residual affinity. Let the case be considered of a molecule which
possesses residual affinity of an acid type, and let this molecule be brought
into the neighbourhood of another molecule which possesses a force field basic
in type. The two will together form a complex, and since the residual affinity
of the first is now compensated there is no reason why its force field should
not undergo further condensation with the evolution of one or more funda-
mental infra-red quanta. Provided that the fundamental infra-red frequencies
of the two molecules are similar, these quanta may be absorbed by the second
molecule, which is thereby converted into a Jess condensed phase. The
similarity of the infra-red fundamental frequencies necessary for this trans-
ference of energy quanta is very probable. because, in the first place, observa-
tion shows that the fundamental infra-red frequencies of at any rate organic
compounds are very near together. In the second place, it has been found
that when two substances with not very different fundamental infra-red fre-
quencies form a complex, this complex becomes endowed with a new funda-
mental infra-red. frequency of its own which lies between those of its com-
ponents. This is of material importance, not only because it shows that the
complex is a definite entity, but also because the mechanism for transference
of fundamental infra-red quanta from one component to the other is perfect.
Tt, would seem that in this process is to be found the explanation of the change
of phase which frequently takes place when organic compounds pass into
solution.

It is not possible to avoid mentioning the bearing of this upon the whole
problem of catalysis. It has already been stated that each phase of a given
molecule is endowed with its own reactivity, and that in order to cause
a molecule to enter into a specific reaction it is necessary to bring it into
the proper phase. This. change of phase may be produced by the action of
light, in which case the reaction is called a nhotochemical one. On the other
hand. the change in phace may be produced by a material substance which
is called a catalyst. The substance is a catalyst because it increases the
velocity of the particular reaction. owing to the fact that it brings more
molecules into the reactive nhase than would otherwise exist in that phase.
Not the least interesting anvlication of the nresent theory is to the phenomenon
of catalvsis, a phenomenon which has not hitherto found a completely satisfactory
explanation.

After what has been stated of the existence of molecular phases, each with
its own characteristic frequency in the visible or ultra-violet. a frequency
which is an exact multiple of the infra-red fundamental, it is perhaps scarcelv
necessary to discuss many of the observations of the absorption snectra of
organic compounds, since the application of the theorv is obvious. Tn order
to illustrate this avplication, however, some of the observations recorded in
the earlier nages of this report may he considered, and the case of ethyl aceto-
acetate and its derivatives may be selected first. Jt was shown quite clearly
that neither the oricinal theory of tautomeric equilibrium nor the Hantzsch
six-membered ‘ring’ formula can exnlain the absorvtion band shown by the
sodium salt. The absorption band-is due to the fact that the substance in
the presence of a basic solvent is changed into a phase the characteristic
absorption band of which lies in the ultra-violet region. This alteration of
phase is ‘characteristic of the ketonic form. since the disubstituted compound.
ethyl dimethvlacetoacetate, shows the same band when dissolved in a basic
solvent. ' It is noteworthv that exactly the same bands are shown when these
compounds are dissolved in piperidine.

The reason why the two derivatives, ethyl B-ethoxycrotonate and ethvl
dimethylacetoacetate, show only general ahsorption in alcoholic solution is
because they exist in a phase the characteristic band of which lies in the extreme

1920 »

242 ' REPORTS ON THE STATE OF SCIENCE.—1920.

ultra-violet region beyond that reached with a quartz spectrograph working
in air. Lastly, the incipient or very shallow absorption band shown by ethyl
B-ethoxycrotonate in the . presence of acid 1s due to the fact that relatively
few molecules are brought into a less condensed! phase. by the action of the
ak must be clearly understood that the statement that a compound only
shows general absorption is very misleading, because it only means that no
absorption band is exhibited by that compound between the spectral limits of
7000 and 2100 Angstréms. Such substances will certainly be found to exhibit
selective absorption when investigations are made in the very extreme ultra-
violet. There is a very fertile field of research in this direction by the use
of a vacuum spectrograph with a fluorite prism or a grating, in order to
obviate the absorption due to air and quartz. Some preliminary investigations
have already been made by Stark, who found evidences of selective absorption
in this region by some of the so-called diactinic substances. .

Again, the explanation of the results recorded in the examination of the
aromatic aminoaldehydes and aminoketones is very simple. These compounds
show one absorption band. in alcoholic solution, a second in the presence of a
trace of acid, and a third in the presence of a great mass of acid, the frequency
of the second being the smallest and that of the third being the greatest. The
molecules exist in three different phases under the three conditions.. Similarly
the variety of absorption bands which Hantzsch found certain substances to
exhibit in different solvents is due to a variety of phases of the same molecule.
Thus diphenylyioluric acid can be brought into several different phases by
alkali according to the chemical strength of LiOH, NaOH, KOH, RbOH,
CsOH. Further, a considerable variety of phases of trinitrobenzene, picric acid
and its ether trinitroanisole, can be produced by the use of solvents of different
basicity, such as water, alcohol, pyridine, piperidine, dimethylaniline, and
alcoholic sodium ethoxide.24 The case of trinitrobenzene and also of trinitro-
toluene is interesting, for it is possible with these two compounds not. only
to obtain them in highly coloured molecular phases by solution in_ basic
solvents, but also to prepare these phases in the pure state. The coloured
liquid phase of trinitrotoluene is well known to those engaged in the manu
facture of this compound. The corresponding phase of trinitrobenzene can be
obtained by dissolving the compound in piperidine. On pouring this solution
into excess af hydrochloric acid the trinitrobenzene is precipitated as a red
solid, and after drying the colourless form may be dissolved in ether or benzene,
leaving the red form. A solution of this in alcohol shows the same absorption
band as does the piperidine solution of trinitrobenzene.

There indeed is little doubt that the existence of a compound in two or more
forms, as is frequently the case in organic chemistry, means the isolation of two
or more different molecular phases of the same compound. One of the most
interesting cases of the preparation of a molecular phase less condensed than
the ordinary phase is the so-called aci-ethers of the nitrophenols.2> These com-
pounds on the basis of the quinonoid theory were considered to have the
quinonoid formula typified by

OCH,
O= ont
\ (0)

put the only evidence on which this formula was based was the instability of the
compounds and their visible colour. They are extraordinarily unstable and
change at once under the influence of certain solvents into the normal forms.
‘In the light of present-day knowledge there is not the slightest doubt that they
are simply less condensed phases of the nitrophenol ethers, having the usually
-aecénted formule.

‘Reference was made previously to the quinonoid explanation of the highly
coloured hydrochloride of dimethylaminoazobenzene. This again is another
‘example of the conversion of a weak base into a less condensed phase by: the
-addition’ of acid ‘such as occurs with the aminoaldehydes and aminoketones. It
was ‘pointed out ‘above that the quinonoid explanation fails because a similar

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 248;

change in absorption takes place with benzeneazophenyltrimethylammonium:
iodide in the presence of acid, although the change is less obvious to the eye.”
The most serious criticism of the quinonoid explanation is to be found in the
fact that in concentrated acid the colour is not so intense as in dilute acid, for
it hardly seems scientific to state that a particular configuration is favoured by
acid and then to have to agree to a change from that configuration to another:
when more acid is added. Here again as with the aminoaldehydes three molecular:
phases exist, one in alcohol, one in dilute acid, and one in strong acid, the
primary structure of the molecule being the same in all three. A very: analogous
case is pararosaniline, which with one equivalent of acid gives a very marked
colour, but in the presence of excess of acid the colour and absorption are
different. Three phases again are formed, one in alcohol, one in dilute acid, and
one in concentrated acid. poe

In all probability the above instances are sufficient to indicate the application
of the theory of molecular phases to absorption spectra. In conclusion it may
be claimed for the theory that it attempts to co-ordinate on a definite physical
basis all absorption spectra observations over the whole spectrum between the
extreme limits of wave-length 1000u and O‘lu, and that these attempts seem
to meet with considerable success.

References.

- Hartley, Dobbie, and Lauder, ‘ Trans.,’ 81, 929 (1902).

. Hartley and Dobbie, ‘ Trans.,’ 75, 640 (1899).

. Hartley, Dobbie, and Paliatseas, ‘ Trans.,’ 77, 839 (1900).

. Baly and Desch, ‘ Trans.,’ 85, 1029 (1904) ; 87, 766 (1905).

. Baly and Collie, ‘ Trans.,’ 87, 1332 (1905).

Baly and Stewart, ‘ Trans.,’ 89, 502 (1906).

. Baly, Marsden, and Stewart, ‘ Trans.,’ 89, 966 (1906).

. Lowry and Desch, ‘ Trans.,’ 95, 807 (1909).

F ate ‘Ber.,’ 43, 3049 (1910); 44, 1771 (1911); 45, 559 (1912); 48, 772
1915).

. Hantzsch and Colleagues, ‘ Ann.,’ 384, 135 (1911); Ber., 41, 1204 (1908); 42,
68, 889, 1216, 2119, 2129 (1909) ; 43, 45, 68, 106, 1651, 1662, 1685, 2129, 2512,
3049 (1910); 44, 1771, 1783 (1911); 45, 85, 553, 559, 3011 (1912); 46, 1537,
3570 (1913); 48, 158, 167, 772, 797, 1407 (1915); 49, 213, 226, 511 (1916);
50, 1413, 1422 (1917); 52, 493, 509, 1535, 1544 (1919); ‘ Zeit. phys. Chem.,
84, 321; 86,624 (1913).

11. Purvis, ‘Trans.,’ 97, 692 (1910) ; Baly and Tryhorn, ‘Phil. Mag.,’ 31, 417 (1916).

12. Baly and Marsden, ‘ Trans.,’ 98, 2108 (1908).

13. Baly and Rice, ‘ Trans.,’ 101, 1475 (1912).

14. Baly, ‘ Phil. Mag.,’ 2, 632 (1914); ‘ Astrophys. J.,’ 742, 4 (1915).

15. Baly and Tryhorn, ‘ Phil. Mag.,’ 31, 417 (1916).

16. Garrett, ‘ Phil. Mag.,’ 31, 505 (1916) ; Baly and Garrett, ibid., 31, 512 (1916).

17. Baly, ‘ Phil. Mag.,’ 39, 565 (1920).

18. Sleator, ‘ Astrophys. J.,’ 48, 125 (1918).

19. Baly, ‘ Phil. Mag.,’ 40, 1, 15 (1920).

20. Bjerrum, ‘ Nernst Festschrift,’ page 90 (1912).

21. Kriiger, ‘ Ann. der Phys.,’ 50, 346; 51, 450 (1916).

22. Nichols and Merritt, ‘ Phys. Rev.,’ 6, 630 (1915); 9, 113 (1917).

23. Humphreys, ‘ Astrophys. J.,’ 33, 233 (1906).

24. Baly and Rice, ‘ Trans.,’ 103, 2085 (1913).

25. Hantzsch and Gorke, ‘ Ber.,’ 39, 1073 (1906).

26. Baly and Hampson, ‘ Trans.,’ 107, 248 (1915),

OMOAIRD A PWr =

—
i—)

R 2

944 REPORTS ON THE STATE OF SCIENCE.—1920.

Appendix.

List or SUBSTANCES OF WHICH THE ABSORPTION SPECTRA HAVE BEEN EXAMINED IN
THE ULTRA-VIOLET AND VISIBLE REGIONS SINCE THE PUBLICATION OF THE LAST
Report rm 1916.

Acetic acid and salts. Hantzsch. ‘ Ber.,’ 50, 1422 (1917).

Acetone. Lifschitz. ‘ Zeit. wiss. Phot.,’ 16, 140 (1916).

Acetylenedicarboxylic acid. Macbeth and Stewart. ‘ Trans.,’ 111,829 (1917).
Alizarin. Meek. ‘ Trans.,’ 111, 969 (1917).

Alizarin-blue. Meek. ‘ Trans.,’ 111, 969 (1917).

Alizarin-Bordeaux. Meek. ‘Trans.,’ 111, 969 (1917).

Alizarin-cyanine. Meek. ‘Trans.,’ 111, 969 (1917).

Aminoazobenzene. Ghosh and Watson. ‘ Trans.,’ 111, 815 (1917).
Anthragallol. Meek. ‘ Trans.,’ 111, 969 (1917).

-Aurin. Ghosh and Watson. ‘ Trans.,’ 111, 815 (1917).

Behenolic acid. Macbeth and Stewart. ‘Trans.,’ 111, 829 (1917).
Benzeneazoanthranol. Sircar. ‘Trans.,’ 109, 757 (1916).
Benzene-l-azo-4-anthrol. Sircar. ‘ Trans.,’ 109,757 (1916).
Benzeneazocatechol. Ghosh and Watson. ‘ Trans.,’ 111, 815 (1917).
Benzeneazo-1.5-dihydroxynaphthalene. Ghosh and Watson. ‘Trans.,’ 111, 815
(1917).
Benzene-l-azo-4-naphthol. Sircar. ‘Trans.,’ 109, 757 (1916).
Benzeneazo-a-naphthol. Ghosh and Watson. ‘Trans.,’ 111, 815 (1917).
Benzeneazo-8-naphthol. Ghosh and Watson. ‘Trans.,’ 111, 815 (1917).
Benzeneazo-8-naphthylamine. Ghosh and Watson, ‘'Trans.,’ 111, 815 (1917).
Benzeneazophenol. Ghosh and Watson. ‘Trans.,’ 111, 815 (1917),
Sircar. ‘ Trans.,’ 109, 757 (1916).
Benzeneazopyrogallol. Ghosh and Watson. ‘ Trans.,’ 111, 815 (1917).
Benzeneazoquinol. Ghosh and Watson. . ‘ Trans.,’ 111, 815 (1917).
Benzeneazoresorcinol. Ghoshand Watson. ‘ Trans.,’ 111, 815 (1917).
Benzene- 1-azo-1'.2'.3'.4'-tetrahydro-4-naphthol. Sircar. ‘ Trans.,’ 109, 757 (1916).
Benzoic acid. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).
p-Bromobenzene-1l-azo-4-anthrol. Sirear. ‘ Trans.,’ 109, 757 (1916).
p-Bromobenzene-]-azo-4-naphthol. Sircar. ‘ Trans.,’ 109, 757 (1916).
p- Bromobenzeneazophenol, Sirear. ‘ Trans.,’ 109,757 (1916).
p-Bromobenzene- l-azo-1’.2'.3'.4'-tetrahydro-4-naphthol. Sirear. ‘ Trans.,’ 109, 757
(1916).
Bromodinitrotriphenylmethane. Hantzsch and Hein. ‘ Ber.,’ 52, 493 (1919).

Chloranil. Lifschitz. ‘ Ber.,’ 49, 2050 (1916).
Chrysoidine. Ghosh and Watson. ‘ Trans.,’ 111, 815 (1917).
Cinnamic acid. Ley. ‘ Ber.,’ 51, 1808 (1918).
Py » Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).
a + Macbeth and Stewart. * Trans.,’ 111, 829 (1917).
65 Stobbe. ‘ Ber.,’ 52, 1021 (1919).
Cinnamylideneacetic acid. Macbeth and Stewart. ‘Trans.,’ 111, 829 (1917).
Cobalt acetate. Ley and Ficken. ‘ Ber.,’ 50, 1123 (1917).
Cobalt picolate. Ley and Ficken. ‘ Ber.,’ 50, 1123 (1917).
Crystal violet. Hantzsch. ‘ Ber.,’ 52, 509 (1919).
“9 a Kehrmann and Sandoz. ‘ Ber.,’ 51, 915 (1918).
ef SS derivatives. Kehrmann and Sandoz. ‘ Ber.,’ 51, 915 (1918).
nitrile of. Lifschitz. ‘ Ber.,’ 52, 1919 (1919).
a and Cyanopyronin Dye-stuffs. Kehrmann and Sandoz. ‘Ber.,’ 53,
63 (1920

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 245

4.4’-Diaminoazobenzene. Ghosh and Watson. ‘ Trans.,’ 111, 815 (1917).

Dibenzyl. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).

Diethylthiazin bromide. Kehrmann. ‘ Ber.,’ 49, 2831 (1916).

1.4-Dihydroxyanthraquinone. Meek. ‘ Trans.,’ 111, 969 (1917).

3.4-Dihydroxymalachite-green. Ghosh and Watson. ‘ Trans.,’ 111, 815 (1917).

Diiodoacetylene. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).

Diiodoethylene. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).

p-p'-Dimethoxyfuchsonedimethylimonium chloride. Hantzsch. ‘Ber.,’ 52, 509
(1916).

Dimethyl sulphide. Hantzsch. ‘ Ber.,’ 52, 1544 (1919).

Dimethylaminoazobenzene. Hantzsch. ‘ Ber.,’ 52, 509 (1919).

Dimethylaniline. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).

Dimethyldiacetylene. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).

Dimethylpyrone. Hantzsch. ‘ Ber.,’ 52, 1535 (1919).

Dimethylthiazin perchlorate. Kehrmann. ‘ Ber.,’ 49, 2831 (1916).

Dimethyl-o-toluidine. Ley. ‘Zeit. wiss. Phot.,’ 18, 178 (1918).

4.5-Dinitro-3-acetylaminoveratrole. Gibson, Simonsen, and Rau. ‘ Trans.,’ 111, 69
(1917).

5.6-Dinitro-3-acetylaminoveratrole. Gibson, Simonsen, and Rau. ‘ Trans.,’ 111, 69
(1917).

p.'p-Dinitrodiazoaminobenzene. Hantzsch and Hein. ‘ Ber.,’ 52, 493 (1919).

p-p'-Dinitrodiphenylamine. Hantzsch and Hein. ‘ Ber.,’ 52, 493 (1919).

s-Diphenylethane. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).

Di-cyclo-pentadiene. Stobbe and Diinnhaupt. ‘ Ber.,’ 52, 1436 (1919).

Dithioindigo. Lifschitz and Lourié. ‘ Ber.,’ 50, 897 (1917).

Doebner's violet and derivatives. Kehrmann and Sandoz. ‘ Ber.,’ 51, 915 (1918).

Elaidic acid. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).
Eosine. Miethe and Stenger. ‘ Zeit. wiss. Phot.,’ 19, 57 (1920).
Erucic acid. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).
B-Ethoxycinnamic acid. Ley. ‘ Ber.,’ 51, 1808 (1918).
a-Ethoxystyrol. Ley. ‘ Ber.,’ 51, 1808 (1918).
8-Ethoxystyrol. Ley. ‘ Ber.,’ 51, 1808 (1918).
Ethyl benzoylaretate. Ley. ‘ Ber.,’ 51, 1808 (1918).
Ethyl dinitrophenylmalonate. Hantzsch and Hein. ‘Ber.,’ 52, 493 (1919).
Ethyl nitrate. Schaefer. ‘ Zeit. wiss. Phot.,’ 17, 193 (1918).
Ethyl ortho-formate. Hantzsch. ‘ Ber.,’ 50, 1422 (1917).
” a9 » salts. Hantzsch. ‘ Ber.,’ 50, 1422 (1917).
Ethyl phenylpropiolate. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).
Ethyl trinitrophenylmalonate. Hantzsch and Hein. ‘ Ber.,’ 52, 493 (1919).
Ethylbenzene. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).
Ethylene iodide. Macbeth and Stewart. ‘Trans.,’ 111, 829 (1917).

Filter yellow. Miethe and Stenger. ‘ Zeit. wiss. Phot.,’ 19, 57 (1920).
Fluorescein. Miethe and Stenger. ‘ Zeit. wiss. Phot.,’ 19, 57 (1920).
Formic acid and salts. Hantzsch. ‘ Ber.,’ 50, 1422 (1917).

Fuchsine. Hantzsch. ‘ Ber.,’ 52, 509 (1919).
Fuchsonedimethylimonium chloride. Hantzsch. ‘ Ber.,’ 52, 509 (1919).
Fumaric acid. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).

Hexamethylbenzene. Lifschitz. ‘ Ber.,’ 49, 2050 (1916).
Hexamethyltriaminotriphenylearbinol.. Hantzsch. ‘ Ber.,’ 52, 509 (1919).
Hexatriene. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917). é
p-Hydroxybenzeneazo-1.3-dihydroxynaphthalene, Ghosh and Watson. ‘'Trans.,’
111, 815 (1917). €
_ p-Hydroxybenzeneazo-1.5-dihydroxynaphthalene. Ghosh and Watson. ‘ Trans.,’
111, 815 (1917).

246 REPORTS ON THE STATE OF sctencE.—1920.

p-Hydroxybenzeneazo-a-naphthol. Ghosh and Watson. ‘Trans.,’ 111, 815 (1917).

p-Hydroxybenzeneazo-8-naphthol. Ghosh and Watson. ‘ Trans.,’ 111, 815 (1917).

p-Hydroxybenzeneazo-#-naphthylamine. Ghosh and Watson. ‘ Trans.,’ 111, 815
(1917).

4-Hydroxymalachite-green. Ghosh and Watson. “ Trans.,’ 111, 815 (1917).

Imidovioluric acid. Lifschitz and Kritzmann. ‘ Ber.,’ 50, 1719 (1917).
3 » salts. Lifschitz and Kritzmann. ‘ Ber.,’ 50, 1719 (1917).
Indigo. Lifschitz and Lourié. ‘ Ber.,’ 50, 897 (1917).

K
Ketothiodimethylpyrone. Hantzsch. ‘ Ber.,’ 52, 1535 (1919).

Malachite-green. Ghosh and Watson. ‘Trans.,’ 111, 815 (1917).
Hantzsch. ‘ Ber.,’ 52, 509 (1919).

Kehrmann and Sandoz. ‘ Ber.,’ 51, 915 (1918).

ie a derivatives. Kehrmann and Sandoz. ‘ Ber.,’ 51, 915 (1918).
Maleic acid. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).

Martius yellow. Miethe and E. Stenger. ‘ Zeit. wiss. Phot.,’ 19, 57 (1920).
Methoxymalachite green. Hantzsch. ‘ Ber.,’ 52, 509 (1919).
a-Methylcinnamic acid. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).
8-Methylcinnamic acid. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).
Methyl.o-formate. Hantzsch. ‘ Ber.,’ 50, 1422 (1917).
Methylphenylthiazin bromide. Kehrmann. ‘ Ber.,’ 49, 2831 (1916).
@-Methylstilbene. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).
a-Methylstyrol. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).

B-Methylstyrol. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).

Methylthiazin perchlorate. Kehrmann. ‘ Ber.,’ 49, 2831 (1916).
Monochloroacetic acid and salts. Hantzsch. ‘ Ber.,’ 50, 1422 (1917).
Monosulphuryl indigo. Lifschitz and Lourié. ‘ Ber.,’ 50, 897 (1917).

9 ”

” ”

Naphthophenazoxonium derivatives. Kehrmann and Sandoz. ‘ Ber.,’ 51, 923 (1918).
p-Nitrobenzeneazoanthranol. Sircar. ‘Trans.,’ 109, 757 (1916).
p-Nitrobenzene-l-azo-4-anthrol. Sircar. ‘Trans.,’ 109, 757 (1916).
p-Nitrobenzene-l-azo-4-naphthol. Sircar. ‘ Trans.,’ 109, 757 (1916).
p-Nitrobenzene-1l-azo0-4-naphthol-3-carboxylic acid and salts. Sircar. ‘Trans.’ 109,
757 (1916).
p-Nitrobenzeneazophenol, Sircar. ‘Trans.,’ 109, 757 (1916).
p-Nitrobenzeneazosalicylic acid and salts. Sircar. ‘Trans.,’ 109, 757 (1916).
p-Nitrobenzene-1-azo-1’.2'.3'.4'-tetrahydro-4-naphthol. Sircar. ‘Trans.’ 109, 757 —
(1916).
p-Nitrodiazoaminobenzene. Hantzsch and Hein. ‘Ber.,’ 52, 493 (1919). |
p-Nitrodiphenylamine. Hantzsch and Hein. ‘ Ber.,’ 52, 493 (1919). ;
p-Nitronaphthalene-l-azophenol. Sircar. ‘Trans.,’ 109, 757 (1916). 4
4-Nitronaphthalene-1-azosalicylic acid and salts. Sircar. ‘ Trans.,’ 109, 757 (1916).
Nitrosodimethylaniline. Miethe and Stenger. ‘ Zeit. wiss. Phot.,’ 19, 57 (1920).
p-Nitrotriphenylmethane. Hantzsch and Hein. ‘ Ber.,’ 52, 493 (1919).

Parafuchsin. Kehrmann and Sandoz. ‘ Ber.,’ 51, 915 (1918).

Pararosaniline. Lifschitz. ‘ Ber.,’ 52, 1919 (1919).

cyclo-Pentadiene. Stobbe and Diinnhaupt. ‘ Ber.,’ 52, 1436 (1919).
Phenazoxonium derivatives. Kehrmann and Sandoz. ‘ Ber.,’ 50, 1667 (1917).
Phenazthionium derivatives. Kehrmann and Sandoz. ‘ Ber.,’ 50, 1673 (1917).
Phenol. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).

Phenyl benzoate. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).

a-Phenyl cinnamate. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).

ON ABSORPTION SPECTRA OF ORGANIC COMPOUNDS. 247

Phenyl salicylate. Ley. ‘Zeit. wiss. Phot.,’ 18, 178 (1918).

a-Phenyl stilbene. Ley. ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).
Phenylacetylene. Macbeth and Stewart. * Trans.,’ 111, 829 (1917).
Phenylethylene. Macbeth and Stewart. * Trans., 111, 829 (1917).
Phenylpropiolic acid. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).
B-Phenylpropionic acid. Macbeth and Stewart. ‘Trans.,’ 111, 829 (1917).
Phenylthiazin bromide. Kehrmann. ‘Ber.’ 49, 2831 (1916).

Phorone. Lifschitz. ‘Zeit. wiss. Phot.,’ 16, 140 (1916).

a-Picoline. Herrmann. ‘ Zeit. wiss. Phot.,’ 18, 253: (1919).

B-Picoline. Herrmann. ‘ Zeit. wiss. Phot.,’ 18, 253 (1919).

Picolinic acid. Ley and Ficken. ‘ Ber.,’ 50, 1123 (1917).

Piperidine. Herrmann. ‘ Zeit. wiss. Phot.,’ 18, 253 (1919).

Purpurin. Meek. ‘Trans.,’ 111, 969 (1917).

Pyridine. Herrmann. ‘Zeit. wiss. Phot.,’ 18, 253 (1919).

Pyridonium and Pyroxonium salts. Hantzsch. ‘Ber,,’ 52, 1535, 1544 (1919).

Quinizarin. Meek. ‘Trans.,’ 111, 969 (1917).
Quinone. Hantzsch and Hein.’ * Ber.,’ 52, 493 (1919).

R
Resaurin. Ghosh and’ Watson. ‘Trans.,’ 111, 815 (1917).

SS)

Salicylic acid. Ley. ‘Zeit. wiss. Phot.,’ 18, 178 (1918).
Stearic acid. Macbeth and Stewart. ‘Tramns.,’ 111, 829 (1917):
Stearolic acid. Macbeth and Stewart. ‘Trans.,’ 111, 829 (1917).
Stilbene. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).
7 Ley. ‘Zeit. wiss. Phot.,’ 18, 178 (1918).
Styrene. Macbeth and Stewart. ‘Trans.,’ 111, 829 (1917).
Styrol. Ley. ‘Ber.,’ 51, 1808 (1918). ‘ Zeit. wiss. Phot.,’ 18, 178 (1918).
Succinic acid. Macbeth and Stewart. ‘ Trans.,’ 111, 829 (1917).
p-Sulphobenzene-l-azo-4-anthrol. Sirear: ‘Trans.,’ 109, 757 (1916).
p-Sulphobenzene-1-azo-4-naphthol. Sircar. * Trans.,’ 109, 757 (1916).
p-Sulphobenzeneazophenol. Sircar. ‘Trans.,’ 109, 757 (1916).
p-Sulphobenzene-1-azo- 1’.2'.3/.4'-tetrahydro-4-naphthol. Sircar. ‘ Trans.,’ 109, 757
(1916).
Aly

Tartrazine. Miethe and Stenger. ‘ Zeit. wiss. Phot.,’ 19, 57 (1920).
Tetrabenzylarsonium iodide. Hantzsch. ‘Ber.,’ 52, 1544 (1919).
Tetraethylphosphonium iodide. Hantzsch. ‘ Ber.,’ 52, 1544 (1919).
1.2.5.8-Tetrahydroxyanthroquinone. Meek. ‘Trans.,’ 111, 969 (1917).
Tetramethyldiaminofuchsone. Hantzsch. ‘ Ber.,’ 52, 509 (1919).
Tetramethyldiaminoquinone. Hantzsch. ‘Ber.,’ 52, 509 (1919).
Tetrapropylammonium iodide. Hantzsch. ‘ Ber.,’ 52, 1544 (1919).
Thiazin chloride. Kehrmann. ‘ Ber.,’ 49, 2831 (1916).
Tolane. Macbeth and Stewart. ‘Trans.,, 111, 829 (1917).
Trialkylsulphonium haloids. Hantzsch. ‘ Ber.,’ 52, 1544 (1919).
Trichloroacetic acid and salts. Hantzsch. ‘ Ber.,’ 50, 1422 (1917).
1.2.4-Trihydroxyanthraquinone. Meek. ‘ Trans.,’ 111, 969 (1917).
Trihydroxyaurin. Ghosh and Watson. ‘Trans.,’ 111, 815 (1917).
2.3.4-Trihydroxymalachite-green. Ghosh and Watson, ‘ Trans.,’ 111, 815 (1917).
Trinitrobenzene. Hantzsch and Hein. ‘ Ber.,’ 52, 493 (1919)...
-p-Trinitrotriphenyl carbinol. Hantzsch. ‘Ber.,’ 50, 1413 (1917).
Trinitrotriphenylmethane. Hantzsch and Hein. ‘Ber.,’ 52, 493 (1919).
Triphenylearbinol. Hantzsch. ‘ Ber.,’ 52, 509 (1919)...

+s Kehrmann and Sandoz. ‘ Ber.,’ 51, 915 (1918).
Triphenylmethylphosphonium iodide. Hantzsch. ‘ Ber.,’ 52, 1544 (1919).
a-Truxillic acid. Stobbe. ‘ Ber.,’ 52, 1021 (1919).
8-Truxillic acid. Stobbe. ‘ Ber.,’ 52, 1021 (1919).

248 REPORTS ON THE STATE OF SCIENCE.—1920.

Fuel Economy. Third Report of Committee (Professor W. A. Bone *
(Chairman), Mr. H. James Yares * (Vice-Chairman), Mr. Ropert
Monn * (Secretary), Mr. A. H. Barxsr, Professor P. P. Bepson,
Dr. W. S. Bouton, Mr. E. Bury, Professor W. E. Dausy, Mr.
E. V. Evans,* Dr. W. GauLoway, Sir RoBert HapDFIELD, Bart. ,*
Dr. H. 8. Heue-SHaw,* Mr. D. H. Heures, Dr. G. Hickuina,
Mr. D. V. HouttinewortH, Mr. A. Hurouinson,* Principal G.
Knox, Professor Henry Louis,* Mr. H. M. Moraans, Mr. W. H.
PatcHety,* Mr. A. T. Smita, Dr. J. E. Sreap, Mr. C. E.
StroMEyER, Mr. G. BuakE WALKER, Sir JosEPpH Watton, M.P.,*
Professor W. W. Warts,* Mr. W. B. WoopuHovss, and Mr. C. H.
WorpDINGHAM*) appointed for the Investigation of Fuel Economy,
the Utilisation of Coal, and Smoke Prevention.

Introduction.

THe Committee has held altogether six meetings since its reappointment last
year, and is investigating (inter alia) the following matters, namely :—

(a) The present official methods of arriving at coal-mining statistics (e.g.,
outputs of coal, etc.) in thig and other coal-producing countries,

(6) The effect of the war upon the British coal export trade.

(zd) The low temperature carbonisation of coal.

(e) The thermal efficiencies at present attainable (i) in the carbonisation and
gasification of coal by various systems, (ii) in domestic fires and heating
appliances, (iii) in metallurgical and other furnaces, (iv) in steam raising and
power production, and (v) in regard to the generation of electric power in
public stations.

(f) Sources of supply of liquid fuels.

Although the Committee has made satisfactory progress with its inquiries
in certain directions during the past year, both time and opportunity have been
wanting for completing them. ‘Che present Report, therefore, is of an interim
nature, but the Committee hopes to report more fully on the above matters to
the Edinburgh Meeting next year.

Coal-maning Statistics.

The attention of the Committee having been drawn by Professor Henry
Louis to the fact that, owing to considerable variations in the modes of arriving
at the official data concerning coal outputs, etc., periodically published by
Government Departments in the various coal-producing countries, it is impossible
to regard them as being properly comparable, the Committee requested him
to prepare a Memorandum on the subject. This he subsequently did, and,
having regard to the great importance of the matter, the Committee decided
to publish the Memorandum im extenso as Appendix I. to this Report, in
the hope that it may lead to the desired: reform being effected. In particular,
the Committee endorses Professor Louis’ view concerning the importance of
summoning an International Conference for determining the precise manner in
which mineral statistics of all kinds shall be collected, tabulated, and finally
issued to the public.

* Denotes a member of the Executive Committee.

ON FUELS ECONOMY. 249

Coal Outputs and Average Pithead Prices in 1919.

According to information kindly furnished to the Committee by the Statistical
Department of the Board of Trade, the total output of coal in the United
Kingdom during the year 1919 has been provisionally estimated at 229,668,000
tons, and the total output per person employed (below and above ground) in the
mines at 197°5 tons.

Owing to abnormal circumstances during the period of coal control, it is
difficult to give strictly comparable figures for the average pithead prices of coal
in the years immediately preceding and following (respectively) the war.
According to official estimates supplied by the Statistical Department of the
Board of Trade, the pithead prices per ton of coal raised in 1913, and in July
1919, respectively, were approximately as follows :—

Average On July 16,

for 1913 1919

8. d. 8. d.

Labour . 4 : 6.4 19 53
Timber and Stores . : - HoH GO 3 2h
Other Costs . f : : : 10 SOY 1 24
Royalties : E ? ’ - O 5} 0 62
Owners’ Profits : : SORMAG 1 2
Compensation . : . : ; : — 0 3}
Administration, etc. z 3 ‘ 3 — 0 24
Total . t ’ - 10 26 04

In the Report recently made to the Prime Minister by Messrs. Alfred Tongue
& Co., Chartered Accountants, of Manchester and Glasgow, and presented to
Parliament by command of His Majesty (Cmd. 555), it was estimated that the
average cost per ton of coal raised in British mines during the year ending
March 31, 1920, was as follows :—

8. d.
Wages 4 : : : : : : Z of dD yh
Timber and Store , 2 . - . F eet S10
Other Costs : ; : 7 : - Spi A Lye)
Royalties , - ; ; ‘ : : - O 63
Administration . : : s A ‘ ; oy Ot ve
Capital Adjustments under Finance Acts . nv.
Control and Contingencies 0 2
Owners’ Profits . 1 2
Total . ‘ : : . : - 27 3f

It would thus appear that the pithead cost of coal has been nearly trebled as
the result of the war.

Coal Hxport Statistics,

The Statistical Department of the Board of Trade has also placed at the
disposal of the Committee detailed information concerning the amounts of coal
exported from the principal ports of the kingdom (a) to British possessions, and

_ (6) to foreign countries, during each of the years 1913-1919 inclusive. In view
of the importance of such statistics, the Committee has decided to publish them
in tabular form as Appendix II. to this Report. The Committee is also collecting
information as to average prices obtained at the principal ports for the coal
exported during each of the years in question. In the light of such statistics
the Committee hopes next year to be able to review the question of the effect of
the war upon the coal export trade.

“ Chemistry of Coal.

. During the year considerable progress has been made with the researches on

the chemistry of coal under the direction of Professor Bone at the Fuel

Laboratories at the Imperial College of Science and Technology, further details

250 REPORTS ON THE STATE OF SCIENCE.—1920.

of which will shortly be published. The Committee has also followed with
close. attention the work recently published (a) by Drs. Marie Stopes, R. V.
Wheeler, and Rudolph Lessing upon the four macroscopically distinguishable
portions of banded bituminous coal and their respective behaviour on car-
bonisation and oxidation, (0) by Mr. 8. R. Illingworth at the Treforest School
of Mines, and (c) by Mr. F. 8. Sinnatt and collaborators of the Lancasnrre and
Cheshire Coal Research Association.

Future Standards of Gas Supplies.

Since it reported its views on the above subject to the Bournemouth Meeting
of the Association last year, the Committee has followed up the matter, and on
February 2 last a deputation, consisting of the Chairman, Sir Robert Hadfield,
Messrs, W. H. Patchell and H. James Yates, waited upon the then President
of the Board of Trade (the Rt. Hon. Sir Auckland C. Geddes, K.C.B.) to lay
before him the views of the Committee upon the subject, with special reference
to impending legislation.

In introducing the deputation, Professor Bone called the attention of the
President to (a) the Report on Gas Standards which had been made by the Fuel
Research Board, (6) the conclusions thereon that had been arrived at as the
result of a conference between representatives of consumers, local authorities, and
gas undertakings, and (c) the announcement by the President of the Board of
Trade that a Bill would shortly be introduced in Parliament to give effect to
the recommendations of the Fuel Research Board.! He explained that the Com-
mittee had looked at the question primarily from the view of the national
interests as a whole, and particularly from that of domestic and industrial gas
consumers. It agreed with the Fuel Research Board that the future basis of
charge to the consumer should be the actual number of thermal units supplied
to him in the gas which passed through his meter, but desired that the charge
should be based upon the ‘ascertained net calorific value’ of the gas supplied
rather than its ‘ declared calorific value,’ as proposed by the Fuel Research
Board. It also endorsed the Fuel Research Board’s original recommendation that
the gas should be supplied at a pressure of ‘not less than two inches of water
at the exit of the consumer’s meter,’ but expressed its disagreement with the
Board’s subsequent view that the pressure condition might be reduced to one
of ‘ not less than two inches of water in any main or service pipe of two inches
in diameter’; because what mattered to the consumer was the adequacy of the
pressure in his own pipes rather than in the gas mains outside his premises.

It was also stated that the Committee attached great importance to the
pressure being maintained as constant as possible, as well as to gas undertakings
being required to pay greater attention than ever to the removal of cyanogen
and sulphur impurities from the gas. Finally, it was explained that the Com-
mittee, whilst agreeing generally with the proposals in regard to the new thermal
basis for the sale of gas, and to the restriction of its inert constituents, con-
sidered that its chemical composition would need some statutory regulation, and
that in particular no public gas supply should be allowed to contain less than
20 per cent. of methane or more than 20 per cent. of carbon monoxide.

After Sir Robert Hadfield had endorsed the views of the Committee from the
point of view of industrial consumers of gas, Mr. H. James Yates outlined
his views as a maker of gas fires who had for many years given much attention
to the scientific investigation of domestic heating and ventilation. He laid

stress upon the importance of maintaining a constant pressure of not less than ~

two inches water-gauge on the consumer’s side of the service pipes, and that
the gross calorific value of the gas supplied should not be allowed to fall below

450 B.Th.U. per cubic foot, stating that if gas undertakings supplied gas of |

lower calorific value a large part of the existing gas appliances would become

useless.
Sir Auckland Geddes, in his reply, promised to give full consideration to
the facts and opinions which they had laid before him. Also, he said that he

1The Bill was subsequently introduced by Sir Robert Horne in the House of
Commons on May 19, 1920.

ON FUEL ECONOMY. 251

had been impressed with the physiological side of the question and with the
danger of cyanogen and of too high a proportion of carbonic oxide in gas.

The ‘Gas Regulation Bill,’ as subsequently presented to the House of
Commons on May 19 last by Sir Robert Horne (the new President of the Board
of Trade), contained far-reaching new proposals concerning the public sale and
distribution of gas, among which the following are of especial importance ‘to
consumers :—

(a2) That the Board of Trade may, on the application of any gas undertakers,
by order, provide for the repeal of any enactments or other provisions requiring
the undertakers to supply gas of any particular illuminating or calorific value,
and for substituting power to charge for thermal units supplied in the form of

as.

F (6) That where such substitution has been decided upon, the new basis for
the sale of gas shall be 100,000 British Thermal Units (to be referred to in the
Bill as a ‘therm’). The consumer will then be charged according to the number
of ‘therms’ supplied to him in the gas, and the standard price per therm fixed by
the order shall be a price corresponding as nearly as may be to the price fixed
by former provisions for each 1,000 cubic feet, but with such additions (if any)
as appear to the Board to be reasonably required in order to meet unavoidable
increases since June 30, 1914, in the costs and charges of and incidental
to the production and supply of gas by the undertakers ; and the order may make
such modifications of any provisions whereby the rate of dividend payable by
the gas undertakers is dependent on the price of gas supplied as appear to the
Board to be necessary.

(ec) That an order under the Act shall prescribe the time when, and the
manner in which, the undertakers are to give notice of the calorific value of the
gas they intend to supply (#.e., ‘declared calorific value’), and shall require the
undertakers, before making any alteration in the declared calorific value, to
take at their own expense such steps as may be necessary to alter, adjust, or
replace the burners in consumers’ appliances in such a manner as to secure that
the gas can be burned with safety and efficiency.

(d) That the gas supplied under the Act (i) shall not contain any trace of
sulphuretted hydrogen, (ii) shall not be at a pressure of less than two inches
water-gauge in any main or service pipe of two inches diameter or upwards, and
(iii) shall not contain more than a certain permissible proportion of incombustible
constituents (namely, 20 per cent. during a period of two years after the passing
of the Act, 18 per cent. during the succeeding two years, and 15 per cent.
thereafter).

(e) That as soon as may be after the passing of the Act the Board shall cause
an inquiry to be held into the question whether it is necessary or desirable to
prescribe any limitations of the proportion of carbon monoxide which may be
supplied in gas used for domestic purposes, and may, if on such inquiry it
appears desirable, make a special order under the Act prescribing the permissible
proportion.

(f) That Gas Referees and Examiners shall be appointed for the purpose of
(i) prescribing the apparatus and method for testing the gas, and (ii) carrying
out of such prescribed tests.

During the passage of the Bill through its Committee stage in the House of
Commons, the important sub-section limiting the amount of incombustible con-
stituents permissible in gas (vide (d) (iii) above) was deleted, on the under-
standing that, subsequent to the passing of the Act, the matter shall be made
the subject of an official inquiry by the Board of Trade. The effect of this
amendment is, therefore, to put the question of ‘inerts ’ into the same category
as that of carbon monoxide, and the whole matter now stands as follows :—

The Board of Trade shall, as soon as may be after the passing of this Act,
cause inquiries to be held into the question whether it is necessary
or desirable to prescribe any limitations of the proportion of carbon
monoxide which may be supplied in gas used for domestic purposes,
and into the question whether it is necessary or desirable to prescribe
any limitations of the proportion of incombustible constituents which
may be supplied in gas so. used, and may, if on any such inquiry it
appears desirable, make one or more special orders under this Act
prescribing the permissible proportion in either case, and any such

252 REPORTS ON THE STATE OF SCIENCE.—1920.

special order may have effect either generally or as regards particular
classes of undertakings, and the provisions of the special order shall
have effect as if they were enacted in this section.

When such official inquiries are instituted by the Board of Trade this Com-
mittee will hope to be given an opportunity of presenting again its views (as
already reported) upon the matters concerned.

Alcohol from Coke-oven Gas.

During the past year a notable development has been made in connection
with the technology of by-product recovery from coal as the result of Mr. E.
Bury’s successful experimental trials, in conjunction with Mr. O. Ollander, at
the Skinningrove Iron Works, upon the absorption of ethylene from debenzolised
coke-oven gas and its conversion into ethyl alcohol. These trials have demon-
strated the possibility of obtaining on a large scale 16 gallons of absolute alcohol
per ton of the particular Durham coal carbonised. Assuming’ a similar yield
from the 15,000,000 tons (or thereabouts) of coal now annually carbonised in
British by-product coke ovens, it is claimed to be possible to obtain from coke
works alone a 95 per cent. industrial alcohol in quantities equivalent to about
24 million gallons per annum of the absolute spirit.

Although a full account of the investigation has already been given by Messrs,
Bury and Ollander in a paper before the Cleveland Institution of Engineers in
December last (vide also Iron and Coal Trades Review, December 1919), the
Committee, whilst not expressing any opinion as to the commercial prospects
of the process, considers that the technical importance of it is such as to
warrant attention being drawn in this Report to some of its salient features
(see Appendix IIT.).

The Committee recommends that it be reappointed to continue its investi-
gations, with a grant of 351.

AppENDIx [.

Memorandum upon Coal-mining Statistics.

The most important statistics concerning coal are the figures giving the
annual production of coal, the number of workers employed in the mines, the
number of fatal and of non-fatal accidents respectively. These statistics are
collected and published by the Government Departments in most coal-producing
countries, and upon these are based a number of comparative statements by
which the progress of the industry in different countries is usually estimated,
such as the production per worker employed, the accident death-rate per thousand
workers, etc. For most economic and social studies, the number of workers
employed is in several respects the most important of these figures, and un-
fortunately it would appear to be the one upon which the least dependence can
be placed. Elaborate reports have been drawn up, and legislation has even been
enacted, based upon the comparative results of these data; and it has been quite
freely assumed that the figures given for different countries or different districts
of a country are properly comparable, whilst as a matter of fact the methods of
arriving at these figures vary so widely that they come to bear quite different
meanings, and the assumption that similar headings always connote similar
interpretations is utterly without foundation.

Production.—In this country the returns of the output of coal until recently
included the stones and dirt sent up to ‘bank with the coal and picked out
on the belts or screens; since that time the weight of coal alone is supposed
kos Re returned. The instructions at present issued by the Home Office read as
follows :—

The weight given should be the net weight after screening or sorting. .. .
Where the net weight of the coal is not determined during the year
in respect of which the return is being made, it will be sufficient if a
deduction is made according to the average percentage of dirt ex-
tracted from the coal at the mine. In cases where the coal is sold as
it leaves the pit without screening or sorting it will be proper to give
the gross weight sent out of the pit as the amount of output.

ON FUEL ECONOMY. 253

It will be seen that the instructions are somewhat vague, and that. they also
leave considerable openings for guess-work and estimates instead of accurate
facts; furthermore, the instructions would in, some cases at any rate compel
the inclusion of washery dirt under the heading of output, since this dirt does
not always come under the heading of ‘ dirt extracted from the coal at the mine.’
It is by no means uncommon for one company to control two collieries not far
distant from each other and to erect at one of them a washery to which the
small coal from the first colliery is to be sent for washings; in such a case if the
instructions are literally followed, washery dirt will be included in the returns
of the coal output from the first colliery and excluded from the second.
Accordingly, it is natural that the practice in making up these returns varies
greatly from district to district, and even from colliery to colliery. In some
cases both the dirt picked out on the belts and that washed out in the washery
are deducted from the pithead weight, 7.e., from the tonnage on which the
men are paid; in other cases no deduction at all is made for washery dirt, and
in yet other cases an arbitrary percentage is deducted from the coal sent to the
washery. There is also some difference as regards the practice concerning ‘free
coal’ given to the’ miners and coal for colliery consumption. In most cases all
this coal is returned as part of the production; in some cases the coal consumed
by the pits is not included, and apparently in a few cases both the ‘free coal’
and coal for colliery consumption are deducted from the output. In some places
it is customary to give as a return of output the landlord’s tonnage, that is the
amount on which royalty is paid, which is usually the output less certain deduc-
tions allowed by the terms of the lease. In view of this wide variation, it would
be a distinct advantage if the Home Office were to issue specific instructions on
all the above points, so as to secure uniformity of method in making returns
throughout the United Kingdom. The methods used in Canada might well be
adopted here.

In Canada a more definite system is adopted; the introduction. to the
Canadian Annual Statistics states in definite language what is intended, as
follows :—

The term ‘production’ in the text and tables of this report is used to
represent the tonnage of coal actually sold. or used, by the producer, as
distinguished from the term ‘output,’ which is applied to the total coal
extracted from the mine, and which includes. in some cases, coal lost
or unsaleable or coal carried into stock on hand at the end of the year.

Apparently throughout Canada the various Provinces issue sheets which
have to be filled up every month, and which the different Provincial Govern-
ments have agreed to issue in identical form, so that returns for the Dominion
can be made by the Canadian Department of Mines or by the Dominion Bureau
of Statistics. The whole of the collection of statistics, and, in fact, the
administration of mining law, is controlled by the respective Provincial Govern-
ments. with the exception of mining lands in certain of the Western Provinces
and North-West Territories, which are controlled directly by the Dominion
Government. These monthly returns show the amount of free coal or of coal
sold to miners at a reduced price, the quantity used for colliery consumption.
specifying any used on the colliery company’s own railways, the quantity of
coal used for making coke and briquettes, the quantity stocked, and the
quantity on hand. The only fault that can be found with these returne is that
they do not specifically ask for a return of the dirt picked out and washed ont
respectively. In Canada the term ‘production’ is restricted. to marketable or
economically useful coal. whilst the term ‘output’ is the equivalent of what
we sometimes speak of in this country as ‘drawings,’ i.e., everything drawn
out from the colliery, inclusive of any dirt that may be extracted subsequently.

In the United States. the production means the total production of clean coal.
that is to say, coal with the exclusion of pickings and washerv dirt, and includ-
ing colliery consumption. Tho work is done by the Mineral Resources: Division
of the United States Geological Survey, but there is a cood deal of overlapping
and difficulty owing to some of the statistics being collected by State Bureaux
and others by Federal Bureaux: in this resnect attention may be directed to. the
Conference on this subject held at Washington in 1916. the results of which
are printed in a report of the Committee on the Standardisation of Mining

O54: REPORTS ON THE STATE OF SCIENCE.—1920.

Statistics in 1918. At present cards in the shape of card slips are issued, to be
filled up annually, and these ask for the total production, which is defined to
‘include all marketable coal, excluding only refuse from washeries and slack
coal wasted.’ It distinguishes between the coal loaded at the mine for ship-
ment, coal used locally, colliery consumption, and coal used for making coke
at the mine. It will be seen that these instructions are fairly clear and definite.

In France the production includes the whole of the drawings, deducting only
the worthless waste, 7.e., pickings and washery refuse,

In Belgium the same practice is followed, the production including colliery
consumption and coal given or sold to employees, but definitely excluding
pickings and washery waste.

It will be seen that all these producing countries are aiming at one definite
meaning for the word ‘production,’ and in this respect there is at any rate
uniformity of intention. Unfortunately the execution of the object leaves much
to be desired. The Canadian practice of monthly returns has much in its favour ;
it no doubt throws a certain amount of additional work both upon individual
collieries and upon the department collecting statistics, but, on the other hand,
it enables half-yearly and quarterly statements to be issued very shortly after
the conclusion of the respective periods, and in the same way annual statements
can be produced much more rapidly than would be the case if the whole of the
returns began to come in after the end of the year. It is quite desirable that
the returns should show definitely the total weight of drawings, the weight of
dirt picked and washed out, the weight given or sold to employees, the colliery
consumption, and the coal used for making coke. Again, there would not
be a great deal of labour involved in keeping these figures, and the information
would be of the greatest value.

Number of Employees.—In this country the only information asked for is a
return ‘ of persons ordinarily employed ’; the returns specify that it must include
all the persons employed on the mine premises, such as officials, storekeepers,
clerks, etc., those employed on the pit sidings, on private branch railways and
tramways, and in washeries adjacent to and belonging to the mine. Furthermore,
the number employed underground must be kept separate from those employed
above-ground, and there is also a separation according to age and sex. There is,
however, no information as to what is meant by ‘the number of persons
ordinarily employed.’ although this is evidently the crux of the whole matter.
The consequence is that extremely variable methods are made use of. Some pits
merely give the number of men entered on the pay sheet for the particular
day in the year on which the return is made out; others take two or three days
which they consider normal and average these. Some return the number of
employees on the books of the company, others the number on the time roll;
with the prevailing amount of absenteeism, the former number will exceed the
latter by about 25 per cent., but there is no instruction as to which of the two
is the figure intended to be given. Some of the more painstaking collieries
average the number of men employed daily, but this is apparently exceptional.
It is evident that a more definite and svstematic method would have to be
adopted before it is possible to attach anything like a precise meaning to returns
of numbers employed in this country.

In Canada, apparently, monthly returns are made, and these are averaged
for the year. The Canadian intention is to ‘show the actual amount of labour
in terms of days worked, rather than the actual number of individual men that
may have been engaged,’ and this is obviously the correct way of dealing with
the subject. The returns ask for a classification under eight different heads
and separate them into underground and above-ground workers; it may be
noted that in Canada the number of men employed at the coke ovens and
briquetting plants in connection with collieries is included in the mine employees.
whilst according to the wording of the English return these should be excluded
in this country, although there is no warranty for saying that the instructions
for making the latter returns are in all cases strictly complied with. Further-
more, in Canada there is an interesting table showing the time lost through
absenteeism, meaning thereby the fault of the men and through a series of other
reasons which may be classified as the fault of the mine or of the industry.
It would be a distinct advantage if such returns were available for this
country. j

ON FUEL ECONOMY. 255

In the United States of America the information asked for is the average
number of men employed during the year, excluding coke workers and office
force. In the exclusion of the latter item this return differs from the British
return; in the exclusion of the former item it differs from the Canadian return.
The number of hours per working day is also asked for, as well as the average
number of days lost by strikes and the number of men thereby affected. The
intention in America is to get the average number of men employed during the
year, but apparently the methods of obtaining these are about as vague as they
are in this country. In the report already referred to it is stated that ‘ without
instruction in regard to the way these averages (average number of employees)
should be computed there will be a lack of uniformity of method, and in many
cases the figures submitted will not be averages, and will not represent even
approximately the real average number of persons employed.’ No one with any
experience of the subject will doubt the accuracy of this statement, and it is
certainly applicable to countries other than the United States. In the report
in question the definition is put forward that ‘the average number of men
should be the actual number of man-hours for the year.” This obviously is a
clear and intelligible definition, and it would probably be a great advantage if it
were generally adopted.

In Belgium this principle is carried into effect; the number of employees
returned represents the quotient of the number of days’ work done in the year
divided by the number of working days. This figure is thus really the mean
number of workmen engaged during the working days.

In France, on the other hand, the number of employees is intended to be
the number of names regularly on the colliery pay roll; a column is reserved
for the number of days worked in the year. It is obvious that we are dealing
here, under the same heading, with two entirely different conceptions ; some
countries return the number of men who normally get their living by the
industry, without any regard to the amount of absenteeism or the length of time
that these men may be at work, whilst others return the number of men who
have put in a full year’s work, meaning thereby have worked on all the days
on which the mine was in operation. Obviously, these two figures differ widely
from each other, and the fact that both are returned indifferently under the
same heading vitiates many of the conclusions that have been drawn upon the
basis of these returns.

Fatal Accidents.—It is a curious fact that whereas every coal-mining country
publishes a return of fatal accidents, there appears to be in none of them any
legal definition of what constitutes a fatal accident. In the absence of legal
definition in this country the Home Office has for many years made a practice
of classifying all mine accidents which result in death within a year and a
day as fatal accidents, apparently for no better reason than that in so doing
they have followed the old Coroner’s Law.

In Canada the Mineral Resources Statistics Branch does not collect accident
statistics, and these appear to be left to the relative departments of different
Provinces. They are not asked for in the statistical returns, but are obtained
from the reports to the Inspector of Mines. In the Province of Alberta a fatal
accident is construed as an accident which causes death within a twelvemonth.
In the other Canadian Provinces there appears to be no definition at all, and it
would seem that if a man dies from the effect of a mining accident, however
long the death may be after the accident, it would apparently be reported as a
fatal accident for the year in which the death takes place.

In the United States mine-accident statistics are gathered by the various
States and are by no means as reliable as statistics gathered by the Bureau of
Mines. Mr. G. S. Rice. the chief mining’ engineer of the Bureau of Mines at
Washington. gives me the following information: ‘As to what constitutes a
definition of a fatal accident, this varies in the different States. In some States
it means immediate death, in others within a day or two, in still others, if the
man dies from the direct cause of the accident before the report is turned in,
which is in February for the preceding calendar year, which may mean from two
to thirteen months after the accident.’ Tt will be seen that these figures are
obviously vague and unreliable. It is a curious fact that in the report of the Com-
mittee on the Standardisation of Mining Statistics already referred to, the terms
fatal and non-fatal accidents are freely used, but there is no attempt at definition.

256 REPORTS ON THE STATE OF SCIENCE.—1920.

In France the principle followed is that the records of fatal accidents are
restricted to those who are mortally injured in a mine accident, that is to say,
either those killed on the spot or who die as the result of their injuries within a
few hours after the accident, or at the outside within a few months without
ever having been able to resume work. With regard to those whose death,
occurring after a considerably longer interval, is the consequence of injuries
received, they do not appear on the record, the Statistical Department not being,
as a rule, informed of their death, and being, moreover, unable to determine
its real cause.

In Belgium, on the other hand, a fatal accident is restricted to an accident
that causes death within thirty days.

Here, again, it may be pointed out that this extremely important matter
is in a chaotic condition, and that it is most urgent that an agreement be arrived
at as to what precisely is meant by a fatal accident.

Non-Fatal Accidents.—Here, again, there is a wide variation to be noted in
practice. In this country the return is asked for of non-fatal accidents within
any given year, non-fatal accidents being defined as accidents disabling the
victim for more than seven days.

In Canada the practice varies in the different Provinces. Apparently in
Nova Scotia a non-fatal accident is classified as an accident by which a man
must be disabled for at least seven days, but from which he recovers. In the
Province of Saskatchewan accidents entailing a disability of less than six days
are not recorded. In Alberta a non-fatal accident must be reported if a man
is off for more than fourteen days; apparently in some cases accidents involving
a disability of less than fourteen days are tabulated as slight accidents.

In the United States of America the question of what constitutes a non-fatal
accident is even more unsettled than the definition of a fata) accident. In some
of the States statistics are collected based on the State Compensation Acts,
under which compensation is paid for an injury causing a loss of at least two
weeks; in metal mines apparently an accident causing a loss of at least one
shift is tabulated as a slight injury, and one involving a loss of two weeks as a
serious injury.

In France injuries causing disability to work for more than twenty days are
counted as non-fatal accidents.

In Belgium all non-fatal accidents are accidents that cause permanent
disability, whether this be total or partial, accidents involving only temporary
disability not being included in the returns.

The above can only be looked upon as an attempt to supply a portion of the
information which is evidently needed before it is possible to read coal-mining
statistics at all intelligently. It will be obvious, however, from what has been
said, that attempts at comparisons, which have been so freely made without
taking into account the striking differences in interpretation given above, must
result in wholly inaccurate comparisons. I sincerely hope that the data here
given may be further extended to all coal-producing countries, and I wish to
urge again, as I: have done in more than one International Congress, the import-
ance of an International Conference for determining the precise manner in
which mineral statistics of all kinds shall be collected and tabulated, and the
precise meaning that should be attached to the various headings.

Henry Lovts.

bh mee? x

ON FUEL ECONOMY.

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REPORTS ON THE STATE OF SCIENCE.—1920.

258

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ON FUEL ECONOMY. 959

Apprnprx III,

Memorandum upon the Skinningrove Process for the Production of
Alcohol from Coke Oven Gas.

Tux following is a brief outline of the process devised by Messrs. Bury and
Ollander for the removal of ethylene from debenzolised coke oven gas and its
conversion into ethyl alcohol. )

The average amount of olefines present in a debenzolised gas from a typical
Durham coking coal is usually between 2'0 and 2°5 per cent. They consist chiefly
of ethylene with small quantities of propylene and possibly other higher members
of the series.

The process for their removal from tie gas is based upon the well-known
fact that ethylene is absorbed by concentrated sulphuric acid forming ethyl
hydrogen sulphate, which may be subsequently hydrolysed by the dilution of
the acid with water yielding ethyl alcohol and sulphuric acid. The sequence of
the reactions concerned may be represented by the following equations :—

C,H;

(a) C,H,+H,S0,= H SO.,

C,H;
(b) 80+ H,0 =C,H,OH+H,S0,.
H

The problem presented to the investigators was not only the determination
of the conditions under which 2 per cent. of ethylene in an industrial gas can
be rapidly absorbed by concentrated sulphuric acid so as to produce ethyl
hydrogen sulphate exclusively, but also how the much smaller quantities of
higher olefines contained in the gas can be removed from it prior to the desired
absorption of ethylene.

Laboratory experiments proved (i) that, although the absorption of ethylene
by concentrated sulphuric acid proceeds far too slowly at ordinary temperatures,
yet between 60° and 80° C., the time of contact required between the acid and
coke oven gas, in order to ensure the absorption of 70 per cent. of its total ethylene
content, need be no more than 2} minutes, and (ii) that under such conditions
the only product formed is ethyl hydrogen sulphate. On the other hand, if the
temperature be allowed to exceed 80°C. some decomposition occurs and ethyl
ether is produced.

The successful operation of such an absorption process on a large scale pre-
supposes the elimination from the crude gas of tars, ammonia, naphthalene, and
benzol hydrocarbons in the order named. At the Skinningrove Works the
Otto direct process is employed for this purpose.

The next step consists in the successive elimination from the cooled and
debenzolised gas of (a) sulphuretted hydrogen, and (6) higher olefines than
ethylene, together with most of its water vapour content. For the elimination
of the sulphuretted hydrogen it is proposed to make use of the well-known
reaction between sulphuretted hydrogen and sulphur dioxide gases :—

2H, +SO, ===]2H,0+38.

The advantage of such a procedure is that it would not only dispense with
the necessity of employing iron oxide purifiers (except perhaps as a final pre-
caution), but it would also enable the small amount of sulphur dioxide arising
from the reduction of the hot strong sulphuric acid during the later ethylene
absorption process to be utilised.

Propylene and other higher olefines are next removed by scrubbing the gas
with an 80 per cent. sulphuric acid at the ordinary temperature in a tower on the
counter-current principle, which also effects the removal of about 97 per cent.
of its water vapour content. The resulting cooled and dried gas is then passed

s 2

260 REPORTS ON THE STATE OF ScIENCE.—1920.

through a ‘heat exchanger’ situated so near the ovens that its temperature cat
be raised to between 60° and 80° ©. at the expense of some cf the sensible heat
in the hot crude gas leaving the ovens, The strong acid (95 per cent.) used for
the absorption is also pre-heated to the same temperature. The scrubbing
process for the removal of ethylene is carried out on the counter-current prin-
ciple, and the time of contact between the pre-heated gas and acid is 24 minutes,
which is sufficient to effect absorption of 70 per cent. of the total ethylene
present. The acid can be used until it has absorbed up to 5 per cent. of its
weight of ethylene with the formation of a corresponding quantity of ethyl
hydrogen sulphate.

The strong acid from the ethylene absorption towers containing the ethyl
hydrogen sulphate is next taken to a special form of distilling column where
it meets a current of steam which dilutes the acid to about 75 per cent. strength
and simultaneously hydrolyses the ethyl hydrogen sulphate forming ethyl alcohol
and sulphuric acid. The heat produced during the dilution is sufficient to raise
the temperature of the diluted acid to between 90° and 100° C., under which con-
ditions the resulting alcohol distils over and is subsequently condensed, finally
leaving the plant as a 95 per cent. alcohol.

The diluted acid is finally pumped to the top of a Gaillard concentration
tower where it is concentrated to a 95 per cent. strength, which is then used
ever again for the absorption of ethylene. Any smal] quantity of sulphurous
acid formed by the reducing action of the gases upon acids in the absorption
tower is, during the dilution process, decomposed, and the resulting sulphur
dioxide is (as aforesaid) utilised for the elimination of sulphuretted hydrogen
from the debenzolised gas.

From figures given in Messrs. Bury and Ollander’s paper (loc. cit.) the com-
position of the debenzolised gas from a Durham coking coal, before and after
the ates of the greater parts of its ethylene content in the manner proposed,
is as follows :—

Before After
Carbon Dioxide , . P ’ - 2:0 2:08
Carbon Monoxide . ; é ; : 54 5°61
Ethylene, &c. . : ‘ ‘ 3 : 2:0 0°62
Methane . A : 5 : . 25:0 25°96
Hydrogen : { : : - - 50°0 61°91
Nitrogen and Water Vapour, &. . . 156 13°82

100:0 100:0

Before After
Gross 5 ‘ 3 . 467°8 4589
Net * : «y ALD 402°8

W. A. Bone.

EXPERIMENTS IN INHERITANCE OF COLOUR IN LEPIDOPTERA. 261

Old Red Sandstone Rocks at Rhynie, Aberdeenshire. Final Report of
Committee (Dr. J. Horne, Chairman; Dr. W.. Mackin, Secre-
tary; Dr. J. 8. Fuerr, Dr. W. T. Gorpon, Dr. G. Hickuine,
Dr. R. Kwston, Dr. B. N. Peacu, Dr. D. M. 8S. Watson)
appointed to excavate Critical Sections therein.

Dr. W. T. Cauman and Mr. D. I. Scourfield have continued their examination
of the microscopic sections of the plant-bearing cherts discovered by Dr. Mackie
in the Old Red Sandstone at Rhynie, Aberdeenshire. The following Report on
the results of their investigations has been furnished by Dr. Calman :—‘ A large
number of sections and chips have now been studied by Mr. Scourfield, and
drawings have been made of the more important remains. It has not been
possible to discover any regularity in the way in which the specimens are
distributed in the chert, or to correlate their presence with anything visible to
the naked eye in hand specimens. Although the remains are of the most
fragmentary kind, it has been possible to determine with fair certainty the
more important characters of the body and limbs. We are now convinced that
all the remains belong to a single species which is most nearly related to the
Anostraca, although it differs in important morphological characters from the
recent representatives of that order. It is hoped to discuss these remains
at greater length in a memoir which is now in preparation. A few fragments
of limbs and body-somites of a much larger Arthropod have been observed.
There is some evidence to suggest that these may belong to a Diplopod, but it
is not proposed to discuss them unless further material should be discovered.’

As sufficient material has been collected for further examination, the balance
of the grant from the Royal Society has been returned. The Committee may
now be discharged.

Experiments in Inheritance of Colour in Lepidoptera.—First Report of
Committee (Prof. W. Batrson, Chairman; Hon. H. Onstow,
Secretary; Dr. F. A. Drxsy).

Spilosoma mendica and var. rustica.—The white variety of the male is incom-
pletely dominant. About 400 insects were raised from the following types of
mating :—DR x RR, DD x DR, and DD x RR. Eggs were obtained from a
number of pairings of DR x DR, which will emerge next year, 1921.. These,
with the previous records, should be sufficient to elucidate the nature of the
inheritance. Owing to the great colour variation of the F, generation, readings
of the colour of each individual are being made with the ‘ Tintometer’ to show
the colour distribution.

Boarmia consortaria and var. consobrinaria.—About 200 insects were reared
which confirmed the dominance of the melanic variety. The suggestion made in
the J. of Genetics, Vol. IX. No. 4, March 1920, p. 339, that the intermediate
variety is dominant to the type, was also confirmed. Ova were obtained which
should show the relationship of the intermediate to the melanic variety next year.

Hemerophila abruptaria and var. brunneata.—Ova were obtained from several
pairs in order to see whether the melanic variety behaves as a simple Mendelian
dominant. In the published experiments of Hamline and Harris there is a large
excess of melanics in matings of the type DR x RR.

Callimorpha dominula, and the yellow varietv.—About 700 insects were raised
from these crosses, which completely confirm Bateson’s suggestion that the yellow
form is recessive to the red. The insects reared will serve as material for an
examination of the pigments.

Zygena filipendule, and the yellow variety.—Larve were reared from several
pairings between red and vellow varieties and from the F, generation. The
larvee have not as yet nupated.

Abraxas grossulariata and var. varleyata.—About 409 insects were reared
from matings hetween the type and the melanic variety. Together with previous

262 REPORTS ON THE STATE OF SCIENCE.—1920,

records, they fully confirm the recessiveness of the melanic variety. In the F,
generation there appears to be a difference in the distribution of the black
pigment between the two sexes. This is being investigated by means of camera
lucida drawings of the F; generation, from which a calculation of the black
areas may be obtained by means of a planimeter.

A. grossulariata var. lacticolor and var. varleyata.—The combination of these
two characters in the same zygote produces a new and very beautifully marked
variety, named var. exquisita.

If T=type, and t=varleyata, and if G=type, and g=Tlacticolor,

then ¢ type=TTGG, 2 type=TTGg

3 varleyata= ttGG, 2 varleyata = ttGg
3 lacticolor = TTgg, 2 lacticolor = TT gg
6 exquisita = ttgg, 2 exquisita = ttgg

Therefore TtGgxTtGg should give a 9:3:3:1 ratio of type, varleyata,
lacticolor and exquisita, but, owing to the spurious allelomorphism in the F,
generation, the sex ratios will not be normal. Experiments are being made to
test this. Up to the present, though the numbers are small, owing to the
unfortunate incidence of disease, an excess of type and varleyata individuals is
indicated.

It is hoped, if possible, to complete the experiments indicated above next
year. It is also suggested that, in the event of material being procurable from
Germany, experiments might be initiated to elucidate the inheritance of Aglia tau
and its var. lugens.

Committee to co-operate with Local Committees in Excavations on
Roman Sites in Britain.—(Sir W. Ripeeway, Chairman; Mr.
H. J. E. Psaxe, Secretary; Dr. T. Asupy, Mr. WinLoucHBy
Garpner, Prof. J. L. Myrss).

Owrne to the war the Committee has been in suspense since 1914, when all
excavations in the Hill Fort in Kinmel Park, which was being explored by the
Abergele Antiquarian Association and the Cambrian Archeological Association
in co-operation with this Committee, came to an end.

Although the Committee had not been revived in 1919, and therefore no
srant was available, Mr. Willoughby Gardner reopened his investigations in
November 1919, and has supplied the Committee with a detailed report of
them.

‘The Committee asks to be reappointed.

Abstract of Report on Further Excavations in Dinorben, the Ancient
Hill-Fort in Parch-y-Meirch Wood, Kinmel Park, Abergele,
N. Wales, during 1920.

By WitLoucHpy GARDNER, F.S.A.

THE excavations in this native hill-fort (see Reports of the British Associa-
tion, 1912, 1913, and 1915) were reonened in November 1919. A first objective
was the further investigation of the huge main rampart. Attention was directed
to the cutting through it on the S.W., where archeological ‘floors’ and con-
structions belonging to two occupations,-A and B, had been previously dis-
covered, and where the top course of a wall belonging to an earlier construction
had been found beneath the lower Floor B. Before we could excavate this it
was necessary to widen our cutting considerably, thus enabling us to examine
further areas of Floors A and B. In the uppermost, A, more relics of the
fourth century were found. Below it the revetting wall excavated in 1914 was

ON FURTHER EXCAVATIONS IN DINORBEN, 263

found to be built upon an earthen surface marking a fresh floor between
Floors A and B. Upon this lay bones, pot-boilers, &c., but no pottery or coins,
differentiating it therefore from Floor A and causing us to name it Floor A2.
The core of the rampart behind this wall consisted of rubble stones in its lower
half and of layers of clay above. This clay had been visibly laid on wet, and
had afterwards dried hard like cement, so as to give a foundation for any stone
structure, such as a parapet wall, which is indicated by surviving stones seen
here and there along the crest of the rampart.

A further length of the back revetting wall of the rampart belonging to
the earlier Floor B was next uncovered. The rampart consisted of
rubble stones and was about 15 ft. thick, but its outer side and facing wall
were ruined and missing. It was built upon a similar layer of hardened clay
4 ft. thick. Behind it Floor B, of dark soil 3 ft. thick and gradually shallowing.
stretched towards the interior of the hill-fort. Upon this were found bones of
domestic animals, much charcoal, broken pot-boilers, a pounding stone, sawn
antlers, a deer-horn toggle, and an iron knife-blade. About 20 ft. from the wall
a mass of burnt limestones mixed with baked red soil and much charred wood
like burnt timbers was unearthed. also several stone-lined post-holes. Apparently
this was the ruin of a stone-and-timber building destroyed in some great con-
flagration, such as previouslv observed in and near the earliest S.E. entrance.

Having removed Floor B, it was possible to investigate the wall-top found
below it in 1914. This was followed downwards till a ruined dry masonry facing
wall, still standing in one part 5 ft. high and backed with an 8 ft. thick core
of large stones and rubble, wag revealed to view. This newly discovered rampart,
was erected upon a floor surface of dark soil 6 in. thick, which we designated
Floor C. It would appear to be a portion of the earliest defence constructed
upon the site. Keen search was therefore made for relics here. The floor was
followed up as far as practicable at the bottom of our deep cutting. revealing
charcoal, pot-boilers, broken bones of domestic animals. and sling stones, but
unfortunately nothing definitely dateable. In front of the wall the ground
was piled high with the débris of the upper half of the thrown-down rampart,
which was once, apparently. about 10 ft. high.

Search was next made for a ditch defending this ramnart. The hill slope
was followed beneath the fallen ruins and then beneath lavers of clay for a
horizontal distance of 23 ft. from the wall hefore one was found. But here a
section of a rock-cut ditch 6 ft. wide and 5 ft. deep was dug out. It was filled
with rubble mixed with a few wall-facing stones, with a 1 ft. laver of dark
soil half-way down containing animal bones and a. portion of an antler probably
used as a pick. Tt was covered at the bottom with 6 in. of silting,

As the second and third onlv of the three earth-cnt ditches beloncine to
Floor A seen along the S. side of the hill-fort were visible. though nearly filled
with débris, along the S.W. side. our cutting was extended outwards to search
for the first. This was found buried deep under silting and filled with stony
debris from the partial demolition of the Jatest main rampart. Tt was rock-
eut. 15 ft. wide and 7 ft. deep. and had but a thin layer of silting on the
hottom. The second and third ditches were then fnllv excavated. the second
heing filled with stony débris and the third with soil and a few fallen stones.
No relics were found.

Turnine from the S.W cntting. renewed attention was raid to the defences
nvon the §S. side of the hill-fort. Here a cutting had already been made across
the upper portion of the creat main ramnart and the three onter earth-cut
ditches had been excavated. The first ditch had been found to be filled with
clean quarried rubble stones mixed with wall-facing stones—the thrown-down
débris of a parapet which once stood unon the crest of the rammart and
which was approximately contemporaneous with the fonrth-century Floor A.
In order to excavate deener down, this cutting also had to be widened, at a
cost of much exnensive Jabour- hut bv this widening. additional knowledce
of the periods of occunation of the hill-fort was obtained. Here. as in the
S.W. cutting. 2 floor and construction, A2. were found intermediate between
Floors A and R. A further lencth of the hack revetting wall of the rampart
belonging to Floor B was also uncovered, built upon a similar foundation of

264 REPORTS ON THE STATE OF SCIENCE.—1920.

hardened clay. The core of this rampart was composed in places of rubble
and in places of clay, probably the work of different gangs of labourers. Here
there does not appear to be a floor in actual contact with the wall, but there
was one four feet below it. This, Floor B, was first visible as a thin layer
of soil covering the surface of a former clay rampart thrown up rather 8.
of the crest of the present one. It was followed up towards the N., 4 ft, below
the bottom of the above-named wall, 2 ft. below Floor A2, over a low bank of
made clay, till, at length, it became indistinguishable from Floor A. Along
its course animal bones, charcoal, pot-boilers, and the cut shank-bone of an ox
with four holes drilled in it (probably used for weaving) were found. Con-
siderable stony remains, apparently of buildings destroyed by fire, as in the
S.W. section, were also encountered. These ruing will require working out by
exposure of larger areas.

Floor C was next sought for in this cutting by driving in trenches at
increasing depths from the southern slope of the rampart. The floor, which
was shown to be a surface of human habitation by finds of broken animal bones
and charcoal, was finally discovered at a level of 27 ft. below the present crest.
It was followed up for a distance of 32 ft., when the cutting became too
dangerous to continue. The absence of a ditch in this floor in a similar posi-
tion to that found in the S.W. cutting was noticeable. We next excavated
te reach this floor from the northern side of the rampart. Digging down below
Floor B, we came upon the core of a stone rampart, with several massive wall-
facing stones in situ in front of it, erected upon a demonstrable continuation of
Floor C. This rampart had been visibly thrown down almost to its founda-
tions and its stones filled an earth-cut ditch 10 ft. wide which was subsequently
discovered a few feet in front of it. We cleared out most of these stones, finding
animal bones, pot-boilers, and an antler among them, and measured the V-shaped
sides of the ditch as we proceeded. But the dangerous nature of the cutting
unfortunately prevented our reaching the bottom, 7 ft. deep, except by probing ;
a cracking side obliged us to wifhdraw—just before a fall of earth commenced.
There could be litfle doubt that this ruined rampart and ditch were portions of
the earliest defences erected upon the hill-side. Strange to say, however, the
rampart did not’here rest upon the original ground. Beneath it there was a
layer, 6 in. to 12 in. thick, composed of broken stones—at first sight much like
the metalling of a road. But inspection showed that they were fractured by
heat and were such as were usually recognised as pot-boilers. Upon and among
these stones numerous bones of domestic animals were found, many broken’ for
marrow, as well as much charcoal. Altogether this layer, which we uncovered
for some four square yards, had all the appearance of a ‘cooking hearth,’ except
for the absence of an adjacent water-supply. This ‘hearth’ must have existed
on the hili-side before rampart C was thrown up.

While the main rampart was being excavated, about 85 square yards of the
top Floor A were explored in ‘the interior of the stronghold and many relics
found which were unmistakably dated by coins found alongside. These relics,
when worked out, will afford valuable material for the classification of the
later Romano-British pottery, or at any rate of such common wares as were
spread among native hill tribes by traders at that time. Although marked
progress has been made and much hag been learned as the result of this year’s
work, the area uncovered of the deeper Floors B and C is as yet very limited.
It is most desirable that larger surfaces of both should be excavated. Then
only will it be possible to join up the layers of occupation found in the ram-
parts with the roadways and constructions discovered in former years in the
8.E. entrances. Many promising sites spread over the 5} acres of the hill-
fort are also ‘calling out’ for exploration. We look forward to continuing
work at Dinorben next year.

ON THE DISTRIBUTION OF BRONZE AGE IMPLEMENTS. 265

Exploration of the Paleolithic Site known as La Cotte de St. Brelade,
Jersey.—Report of the Committee (Dr. R. R. Marert, Chairman ;
Mr. G. F. B. pr Grucny, Secretary; Dr. C. ANprEws, Professor
A. Kerrn, Mr. H. Baurovur, and Colonel R. GarpNer Warton).

Dourine August and September 1919 and again in April 1920 excavation was
continued, mostly by the aid of amateur labour, as funds were low. A trench
was driven along the W. wall of the cave some 10 ft. below the bottom of the
paleolithic floor. Nothing, however, came to light here except a curious peaty
deposit in two layers, each about a foot thick, and separated by a stratum of
sandy clay; nor was bedrock anywhere reached. On the other hand, just out-
side the cave-entrance a sloping platform was discovered where flint-knapping
must once have been energetically carried on, as was proved by the presence of
nearly 1,000 flint fragments, including a few well-finished instruments. Here,
among other bone, a tooth of the cave bear (Ursus spelceus) was found.
Strangely enough, this species had not hitherto been reported from this site.
At a higher level in the ravine adjoining the cave-entrance is a rodent-bed,
differing slightly in its composition from the rodent-bed within the cave. This
year’s collection consists, according to Mr. Hinton’s analysis, of two species
only, viz., Dicrostonyx henseli 85.3 per cent., and Microtus anglicus 14.7 per
cent. Associated with this bed was a bone determined by Dr. Andrews as
undoubtedly belonging to the Great Auk (Alca impennis). This also is a new
record for the cave, and it is interesting to find this species so far South.

The Distribution of Bronze Age Implements.—Interim Report of the
Committee (Professor J. L. Myres, Chairman; Mr. Haroip
PEAKE, Secretary; Dr. G. A. AupEn, Mr, H. Baurour, Mr.
L. H. D. Buxron, Mr. 0. G. §. Crawrorp, Sir W. Boyp
Dawkins, Professor H. J. Frnurn, Mr. G. A. Garrirr, Dr. RB. R.
Marerv, Sir C. H. Reap, and Sir W. RipGEeway).

THE Committee was first appointed in 1913, and decided that before any con-
clusions could be drawn as to the Distribution of Bronze Age Implements
it was necessary to compile an illustrated card catalogue of all the metal objects
of the Bronze Age found in the British Isles. This task was begun in July
1914, but during the war it was not possible to progress rapidly with the work.

The Committee has had throughout the assistance of Dr. H. S. Harrison,
representing the Royal Anthropological Institute; Lord Abercromby, represent-
ing the Society of Antiquaries of Scotland; and Mr. E. C. R. Armstrong, repre-
senting the Royal Irish Academy.

The method employed is to make full-size drawings of the objects, with one
or two sections, on thin paper, and to note full particulars as to the discovery
and subsequent history of each object, references to published accounts, as well
as its dimensions, weight, condition, and associations; these particulars were
then transferred to cards, 10 in. by 7 in., by the secretary. During the years
of war a number of such drawings were made by voluntary helpers, and about
a thousand cards were completed.

It was decided in 1919 that if the work was to progress more rapidly the
Committee would require the assistance of paid workers. The Association made
a grant of 100/., with permission to raise additional funds in its name. No
agin appeal has yet been made for funds, but the money received to date

as been:

British Association . P : : £100 0 0
Robert Mond, Esq. . ; : . £30 0 0
G. A. Garfitt, Esq. . , ‘ - 1010 0
Mrs. Hookham ; P ; - on 0.0
Royal Irish Academy “s ..0),0. 0

— 50 10 0

£150 10 0

Tho thanks of the Committee are due to these helpers for their support.

966 REPORTS ON THE SCATE OF SCIENCE.—1920.

In May 1920 a draughtsman was engaged and trained, and some work was
put out at piece rates to another draughtsman, so that by the end of June the
cards completed numbered 1,649, while about 1,000 additional drawings still
remained to be copied.

Several Curators of Museums have kindly supplied the drawings of the
objects in their custody. and many more have undertaken to do this in the near
future, so that the work of the draughtsman will be mainly confined to filling
in the cards and visiting small museums and collections.

On June 30 the expenditure amounted to 727. 5s., and the balance available
will pay for the draughtsman until the end of Sentember. It is estimated that
about 2007. a year will be required to pay for the one draughtsman regularlv
employed, together with his travelling expenses, and the purchase of additional
material.

Electromotive Phenomena in Plants.—Report of Committee (Dr. A. D.
Water, Chairman; Mrs. Warr, Secretary; Dr. F. O’B.
Exutson, Prof. J. B. Farmer).

Durine the last year we have taken a considerable number of observations on
the growth of plants in the garden and of their amputated parts in the laboratory.

We have examined into the relative physiological activity of growing and
non-growing zones as shown by their electrical response to electrical excitation
(blaze-currents).1. The disposition of apparatus has been as described in
previous publications and is summarised in the diagram overleaf.

Observations have for the most part been carried out upon Iris germanica
during the months of April, May, and June. The following is a representative
experiment :—

Tris in its natural habitat in a flower bed with S.W. aspect. Leaf. 25 cm.
long, marked by Indian ink into 50 equal parts on April 24. The marked leaf
was examined from time to time and the markings remained apparently unaltered
in length, but raised en masse with the growth of the leaf which was
measured and shown at the Royal Society on May 13 the lowest mark was
raised 5 cm.—.e.. the growth had been exclusivelv basal.

A similar leaf, about 20 cm. long, was led off to the galvanometer from its
base close to the rhizome and from a point of the leaf 5 cm. higher up; it
exhibited a current of rest directed in the leaf from base towards apex.

In response to a strong break induction shock. B to A (7.e., ascendine\,
a, strong blaze-current was aroused in the same direction B to A (post-anndic
homodrome action current indicative of predominant change at B). A similar.
but less marked, response in the same direction, B to A, was aroused by a strong
induction shock passed through the leaf from A to B (post-kathodic antidrome
response).

Strong alternating induction currents were now passed through the A B
nortion of the leaf for a period of one minute in order to effect its electrocution.
The blaze test bv a single induction shock first in the ascending then in the
descending direction failed to aronse anv marked resnonse: in each case the onlv
visible effect was a small deflection antidrome to the exciting current—t.e.. in
the direction of nolarisation. The suppression of the blaze-current by electro-
cution can be definitive or temporarv, according to strength.

Conclusion.—I. The basal zone of the Tris leaf, in which alone active growth
is in nrogress. is electrically active (zincative) in relation to parts where active
growth has ceased.

II. The zone of active growth is aroused to greater physiological activity
(i.e., is more zincable) than are parts in which growth is not proceeding.

1 The rationale of ‘blaze-currents’ as a sign of life has heen set forth in
several nrevious communications and is summarised in the following : Lectures
on the Signs of Life from their Rlectrical Aspect (John Murrav, London. 1903) :
Physiology the Servant of Medicine (University of London Press, 1910).

British Association, 90th Report, Cardiff, 1920. | (Puate I.

4m MM

Diagram of the circuit required for the systematic observation of the blaze-
currents of plants. B A are the unpolarisable electrodes by which the plant
currents are led off to the galvanometer G. Any accidental current or
current of injury of the plant is neutralised by the compensator. The wires
from the compensator are connected with the two ends of the three-plug key.
A single induction shock of given strength and direction can be short-circuited
or not by a plug at the first plug-hole. The plant can be short-circuited or
not at the second plug-hole. The galvanometer can be short-circuited or not
at the third plug-hole.

Procedure.—Any accidental current or current of injury of the plant is
neutralised (and measured) by adjustments on the dials of the compensator.
The galvanometer is short-circuited at the third plug-hole. A break induction
shock of given strength and direction is sent through the plant by (closing
and) opening a contact-key in the primary circuit of the induction coik
(during closure of this key the secondary coil is short-circuited at the first
plug-hole to cut off the make shock from the plant). Immediately after the
break shock has passed through the plant, the galvanometer is unplugged at
the third hole; the blaze-current aroused by the previous break induction
shock now causes deflection of the galvanometer. the voltage of a deflection
is ascertained by comparison with the deflection given by 0.01 volt from the
compensator. The resistance in circuit is ascertained by comparison with the
deflection of 0.01 volt through 1,000,000 ohms.

Illustrating ‘ Electromotive Phenomena in Plants.’
{To face page 266.

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ON MUSEUMS IN RELATION TO EDUCATION. 267

Museums in Relation to Education.—Final Report of Committee (Pro-
fessor J. A. GREEN, Chairman; Mr. H. Bouton and Dr. J. A.
Cuuss, Secretaries; Dr. F. A. Barner, Rev. H. Browns, Mr.
C. A. Buckmaster, Professor E. J. Ganwoop, Dr. A. C. Happon,
Dr. H. §. Harrison, Mr. M. D. Huu, Dr. W. E. Hoyts, Sir H.
Miers, Professor P. Newserry, Mr. H. R. Ratuzons, Dr. W. M.
TATTERSALL, Sir Ricnarp Trempte, Mr. H. Hamsuaw Tuomas,
Professor F. E. Wetss, and Dr. JEss1z WHITE).

Tue Committee was formed at the Birmingham Meeting of the British
Association in 1913, with the following terms of reference: ‘To examine, inquire
into, and report on the character, work, and maintenance of Museums, with a
view to their organisation and development as institutions for Education and
Research; and especially to inquire into the requirements of schools.’

The work was carried on energetically for four years, and numerous subsidiary
reports drawn up by sub-committees were considered. The increasing gravity
of war conditions and the absence of members upon various war activities
suspended further work.

Recent Legislation. Museums and Advanced Students.
The Functions of Museums. Museums and Classical Education and
Museums in 1914. the Humanities.
Museums in Relation to the Genera] | Staffing of Museums.
Public. Overseas Museums.
Museums and Schools. Manchester Scheme.

Recent Legislation.

The Education Act passed in 1918. and the more recent Libraries Act of
1919, have profoundly modified the position of Museums in relation to Education.
and definite lines of development have been foreshadowed by the Reports of
the Committee on Adult Education of the Ministry of Reconstruction, and by
the issue of ‘Draft Suggestions for the Arrangement of Schemes under the
Education Act of 1918,’ by the Board of Education.

These changes have been taken into account in the present Report, and
pare rendered necessary a revision of some parts of the work previously

one.

1. The Education Act of 1918 made it possible for local Education Committees
to seek the assistance of Museums in the furtherance of local schemes of

educational development.

This was emphasised in 1919 by the ‘ Draft Suggestions for the Arrangement
of Schemes under the Education Act of 1918,’ issued by the Board of Education.
These Suggestions indicate the desirability of arrangements for ‘securing and
developing the educational uses of Museums and Libraries,’ and for ‘ developing
the educational activities of local Literary, Historical, Archeological, Scientific,
Musical. Artistic. and Dramatic Associations.’

In 1918 the Ministry of Reconstruction presented to Parliament an ‘ Interim
Report of the Committee on Adult Education upon the Industrial and Social
Conditions in Relation to Education.’ The questions raised in that Report
were more fully reported upon in a ‘Third Interim Report’ presented to
Parliament in 1919.

In a still later Report the © nmittee on Adult Education considered the
conditions and work of Museums, and advanced the suggestion that these

968 REPORTS ON THE STATE OF SCIENCE.—1920.

institutions should, together with Public Libraries, be definitely included in
any scheme of education for a local area in England and Wales, and that
these institutions should be taken into account in State grants allotted to the
local authorities. :

It was further suggested that, under the powers and duties of the Local
Government Board, Libraries and Museums should be transferred forthwith
to the Board of Education by an Order in Council.

The Committee on Adult Education did not seek the advice of this Committee,
or of the Museums Association, and unfortunately their recommendations for
the transference of Museums and Libraries to the local Education Authority
proved unacceptable to both the Museums Association and the Library Associa-
tion. The Public Libraries Act, which received the Royal Assent in December
1919, makes it possible for the change to be brought about locally at any time.
The same Act also abrogates the Museums and Gymnasiums Act of 1891. under
which a rate of 3d. in the £ might be levied by a local authority for the
maintenance of Museums. A County or Town Council may constitute itself
as the Library Authority, and bring all public Museums under its control,
though it is in the discretion of this authority to appoint a separate committee
for Museum management. The amount of the rate for maintenance for any
year is to be decided by the Library Authority, no limit being fixed. Further,
it is provided that a county which has adopted the Libraries Acts may borrow
for the purpose of these Acts, as for the purpose of the Local Governments
Acts, 1888; sixty years is the time period laid down for repayment of loans.

The Libraries Act. 1919, thus provides for the adequate maintenance of
Museums, if local authorities choose to exercise their powers. It also enables
the raising of capital sums for buildings and fittings.

Furthermore, official recognition has now been given to the Museum as an
auxiliary factor in public education, but we desire at once to point out that
the recommendations of the Committee on Adult Education for the transference
of Museums by an Order in Council to the control of the Board of Education
may, if pressed too far, seriously prejudice the functions of Museums as
conservators of material and centres of research.

The Functions of Museums.

Before considering the questions specially raised in the terms of reference
to the Cemmittee, and in order to clarify the subject, it seems advantageous
to state what seem to the Committee to be the proper functions of a Museum.

Museums are of many kinds. There are institutions which rank as Museums
in one sense, yet have no collections; such is the Whitechapel Art Gallery,
which educates through loan exhibitions. There is at least one Museum in
the United States which has only a director’s office, since all its possessions
are always out on loan. The Circulating Department of the Victoria and Albert
Museum carries out the same idea on a larger scale; but by its historical
development, and in the general acceptation of the term, a Museum is a place
where objects appealing by their form, not by the written word, are preserved
for reference and study.

The aims and functions of this last kind of Museum are :—

1. Collection of works of Nature and of man. Collecting may be through
work in the field, through purchase, and through donations. The first of
these is the most valuable as assuring accurate data of provenance. Obviously,
the function of collecting must precede all others.

2. Preservation of material thus collected. Much of this is the irreplaceable
groundwork of human knowledge, and ought to be safeguarded at all costs.
This is the necessary second function.

3. Study of the collected objects. This is the research side of Museum
work, and, whether carried out by the staff (as in large measure it should
and must be) or by specialists under the direction of the staff, it must be
prosecuted if Museums are to fulfil their highest function, which is the
advancement of Science. Art, and Industry.

4. Classification of Museum material, so that each specimen is readily
accessible to future students,

ON MUSEUMS IN RELATION TO EDUCATION. 269

Functions 3 and 4 are the necessary preliminary to those which follow.
5. Publication of the results achieved and of guides to the contents of the
Museum.

(a) By printed memoirs, catalogues, summary lists, and guide-books.

(b) By the exhibition of specially selected series of specimens in an arrange-
ment designed to bring out some definite information, and provided
with labels written for the same end.

(d) By lectures in or outside the Museum, in the galleries or in a lecture-
room, on the ordinary exhibited series, or on specimens selected
ad hoc.

Whereas (a) is largely connected with the function of research (3), this in
part, and sections (b), (c), (d) entirely, constitute the educational side ot
Museum work, The greater the weight attached to this function, the greater
the need to realise that it must be based on those which precede, ;

Though implicit in the above statement, certain points require emphasis
for our present purpose.

The exhibition of all material is undesirable.

Special material liable to loss or damage (e.g., from light) should be withheld
from exhibition.

Access to exhibition cases by scholars is undesirable; if specimens are to
be handied they must form part of a special teaching series.

pen collections for scholastic purposes should consist of easily replaceable
material.

Museums in 1914.

A. Lstablishment.—A fair idea of the general character of Museums as
they existed in 1914 was obtained by the issue of a lengthy questionnaire, to
which the authorities of one hundred and thirty-four Museums replied. Two of
these Museums were privately owned, twenty were the property of Institutions
or Societies, and nineteen belonged to Universities, Colleges, and the large
Public Schools. Ninety-two were municipally owned. The governing authori-
ties were even more diverse than the ownership, and it seems probable that
many Museums, though more or less public in character, will remain unaffected
by recent legislation.

The replies to the questionnaire showed that Museums had arisen in various
fashion ; possessed widely diverse governing bodies; and were supported in a
great variety of ways. Purpose was as diverse as origin and control. Those
owned by municipalities had, however, gradually moved towards a common
type and common standard, owing largely to the work of the Museums
Association.

Governing authorities consist of elected Councils, Museum Committees,
Scientific Societies, Library Committees, Members of Town and Corporation
Councils, Boards of Directors, Subscribers, University Senates, &c. Sixty-four
were supported by Borough and District funds or by a Library rate, thirteen
had voluntary contributions, twenty-one had subscribers, eleven had invested
funds and donations, ten received admission fees, and two were supported by
Societies. Fourteen received funds from a University chest, a College, or a
School fund.

Annual income varied from 6/. to 11,000/., the greater number having an
income of less than 2,0007. Notwithstanding lack of income, most Museums
opened every day, and forty opened on Sundays. The value of the collections
in public Museums is probably beyond calculation, and the buildings themselves
represent a very large capital value. The following figures are indicative of
the actual position: Three Museums have buildings of a capital value of from
200,0007. to 300,0007. each, two from 100,000/. to 200,0007., nine from
50,0007. to 100,000/., and twelve from 10,0007. to 50,000/. The collections of
oe ae are valued at 320,000/.; another, 250,000/.; four at 100,000/. to

,000/.

The most widely represented sections of Museum work are: Zoology,
80 Museums; Geoloov. 75; Archeology and Antiquities, 60; Fine Arts, 40;

270 REPORTS ON THE STATE OF SCIENCE.—1920.

Botany, 35; Painting and Engraving, 30; Engineering, Geography, Commerce,
Chemistry, Physiology, Physics, and Astronomy are slightly represented im
existing collections.

It may also be pointed out that many towns of considerable size are not
provided with Museums. Possibly recent legislation may find its best fruits
in the filling up of these gaps.

B. Museums and Schools.—The Committee’s inquiries show that Museums
collectively have, on their own initiative, anticipated in a striking way many
of the requirements considered necessary for the needs of schools, a fact which
illustrates their readiness to co-operate with the educational developments fore-
shadowed by the Education Act of 1918. It shows also that educational work
on the side of Museums is possible without injury to their other functions.
Given an adequate staff and an increased maintenance income, Museum curators,
in conjunction with the teachers, will be able to work out suitable methods for
the educational use of their collections. The experience so far gained goes
far to show that the training and opportunities of teachers do not enable
them to realise for themselves the possibilities of Museum collections as aids
to education.

Many British Museums have for years encouraged visits from schools and
classes, either under the leadership of their teachers or the guidance of a
member of the Museum staff. In some cases these visits have been systematised
by arrangement with the educational authorities, and the Museum collections
have been studied according to a pre-arranged plan. A great development of
this system was tried with success in Salford and Manchester under special
conditions arising in connection with the late war. (See page 279 et seq.)

Other Museums have established systematic courses of lessons to school
classes upon a plan jointly agreed upon by the Education and Museum
authorities.

Sheffield has for years maintained circulating collections of special groups
of objects for schools.

Replies to the Committee’s questionnaire showed that for many years similar
work of a less systematic kind had been carried on in many centres. They
showed that :—

1. Instruction was given by the teachers alone in twenty-eight Museums.

2. Instruction was given mainly by teachers, the curators sometimes assisting,
in twenty-four Museums.

3. Instruction was given by the Museum staff in sixteen Museums.

4, Sketching parties, classes, and individual students from Schools of Art
were regular visitors in most Museums.

The experience gained by the use of Museums in education in the United
States is so extensive, and has been so thoroughly tested, that it is desirable
in any educational plans for the use of British Museums that this experience,
the methods adopted, and the nature and extent of the work, should be carefully
considered. (See page 277 et seq.)

C. Museum Guides.—From returns supplied to the Committee, only two
Museums, other than National, had established official guides; one was a rate-
supported Museum, the other owned by a Society.

That the need was recognised, and met as far as possible, is shown by the
fact that seventy-four Museums stated that arrangements exist whereby the
curator and his staff give demonstrations to special parties.

Financial stringency and inadequate staffs alone had prevented this work
from becoming a well-developed branch of Museum work. It is eminently
desirable that means should be available either for the employment of special
officers for this duty, or for enlarged staffs, if the time of curators is not to
be unduly taken up by work which is not the most important of their duties.

Museums in Relation to the General Public,

The special work of this Committee concerns the Museum as a factor in
education. The words ‘General Public’ are used in the widest sense. We
propose, therefore, to consider first the educational work the Museum may do
for the general public. The term covers a wide range of needs. It represents
the vast majority of visitors to the public Museums; we may safely regard them

ON MUSEUMS IN RELATION TO EDUCATION, 271

as having little or no special knowledge, and a very large proportion of them
enter the Museum without any specific purpose. They are just ‘looking round.’

For such people the Museum may do great service, if it sets about it in the
right way. By some means or other it should strive to put them en rapport
with the purpose of the Museum. This purpose, for them at least, is to reveal
one aspect or other of an ordered universe to people largely uninstructed.
These casual visitors are easily overwhelmed by multiplicity of specimens and
of words. The first essential is a definite scheme, carried out with simplicity,
boldness, and clearness. Elaborate labels, completely logical series, and involved
argument do not assist them.

What the scheme is to be, and its detailed carrying out, must vary with the
locality and circumstances. We may, however, suggest that every Museum
should illustrate fully in its exhibition cases the local fauna and flora, geology,
archeology, history, industries, and art. ‘The local natural history should be
treated from an ecological point of view, so that the visitor may not only realise
what is to be found locally, but will learn under what conditions it is found,
the associations of which it forms a part, why certain animals and plants are
found locally, and why others are not, and the relations of the fauna and flora.
to the local geology.

It is also important that the general public should realise the changes im
the local fauna and flora which have been brought about by the growth of
civilised communities and the activities of the human race. Every locality will
provide instances of this tact, and every Museum should make a point of
illustrating it for the locality which it serves.

Where towns or localities in which Museums are situated possess special
industries, such industries should be illustrated in the local Museum, both
historically, by showing the growth and development of the industry in the
town, and the products of that industry at various periods; and technically, by
illustrating the various processes of manufacture and technique. The Museum
should possess a representative collection of present-day industrial products
of the locality, and, by keeping that up to date, the industrial history of the
district will always remain clear. Similarly, the Public Health work of the
district should be adequately illustrated in the Museum. The general public
should look to the local Museum for information on all the various activities
going on around them. If they are sure of that, their powers of observation
will be stimulated. ‘They will go to the Museum to learn what ought to be
seen, its why and its wherefore. If they see anything new, they will go to
the Museum for information. Both Museum and public will thus be mutually
benefited.

It follows that in Museums reference collections of everything local should
be as complete as possible, not necessarily exhibited, but so housed as to be
readily available for the use of those who desire to consult them. By this
means it is possible to turn the general public into real students, which is the
ultimate aim of this branch of Museum work.

The Reference Library attached to the Museum should be accessible to
visitors, who should be encouraged to use it. The library might also make a
special feature of local publications and all books dealing with the locality from
any point of view. Reports of local societies and organisations should be made
a strong feature.

A Museum which remains entirely local misses something of high educative
importance. To interpret the local fauna and flora rightly means an acquaintance
with a wider range of facts, and the Museum should try to provide that wider
setting which will give meaning to local phenomena. in providing this wider
range of specimens, the well-conducted Museum will in its total form resemble
an iceberg of which only one-tenth appears above the water-line. The cases
will be suggestive and directive, not complete and confusing. Everybody should

ow, however, that there is much more material in the recesses of the Museum
than is shown in the public galleries, and that this is quite accessible to alk
who have an intellectual need which it can satisfy. Reference collections should
be as complete as possible within the range they cover. Better a narrow range
completely represented than a wide one with many gaps. Index collections
are necessary in all large Museums, and smaller Museums might well arrange
their cases on the principle of the Index collection.

272 REPORTS ON THE STATE OF SCIENCE.—1920.

Temporary exhibitions are a means of attracting the attention of the general
public. They offer an opportunity of driving home a particular lesson, and
suggest a wide field of activity for the living direction of a Museum. Similarly,
the frequent changing of exhibits in the cases will add to the attraction,
though aimlessness must be avoided here as everywhere in Museum work.
Crowded cases of birds, which are not merely inartistic and ugly, but are also
wholly ineffective, are characteristic features of many Museums. Their contents
ought to be re-arranged on some definite principle. In many cases, no doubt,
this overcrowding is due to the absence of store-rooms in the building.

é The general public may be helped by the Museum authorities in a variety
of ways :—

1. For general use a Guide, simply written and dealing with the collections
in the order in which they should be viewed, is best. Handbooks to special
sections are also useful, and often command a ready sale. Publications should
be as cheap as possible, and, if sold at some loss, the sale is merely carrying
a step further the provision of free specimens, free labels, and free lectures.

2. The part played by an official guide in a small Museum will probably
differ considerably from that of his colleague in a large Museum. It may be
found that the ‘conducted party’ is not easily got together in a small Museum,
and that the services of the guide will not be greatly in request. For societies
and other special parties he will be useful, and also for informal demonstrations.
Schools will make use of him, but this is not always necessary, as the teachers
themselves may be competent.

3. Lectures play an important part in attracting visitors, in developing
interest in the control of the Museum, and in stimulating further study. A
lecture-room should be provided in every Museum.

Museums and Schools.

The services of the Museum to the school must vary greatly according to
local circumstances. A Museum can never take the place of field work in
Nature Study, or Geography, nor can the exhibition of historical relics, models
and the like be more than a pale substitute for visits to historical sites, buildings,
&c., when these are accessible, though an enterprising curator may gather within
walls significant fragments from the past, and by careful arrangement do much to
help the young to build up pictures of the old times which will make history
something more than a mere matter of words. The success of the Museum as
an educative agency depends very much upon the skill with which it suggests
a world of reality outside the Museum itself. The difficulty of managing this
varies according to the experience of the visitor. The aimless wanderer whose
curiosity may be awakened and directed by good Museum. arrangement is not,
howeyer, here in question. The schoolboy is, ex hypothesi, under personal
guidance or under the guidance of ideas and problems which the schoolmaster
has inspired. How can the Museum encourage and assist him?

We have already noted activities in this direction actually in existence in
1914, and the Manchester experiment is a later development. Much may also
be learned from the practice of the Overseas Museums. The Committee's
inquiries have led to the following conclusions :—

There are, broadly speaking, two types of use to which the Museum lends
itself.

1. Its collections may be used to illustrate a particular course of instruction
and reading which is part of the school curriculum. A class which is studying
Australia may visit the Museum to see specimens of its fauna and its minerals,
and to study the ethnographical collection. Here the Museum renders ancillary
service of the highest value. A close acquaintance with the school curricula in
the locality seems desirable, and temporary exhibitions might be arranged if
co-operation between school and Museum eervices could be secured.

2. On the other hand, the Museum collection as such may be an object of study.
The work will be very different in character. It centres in the Museum which
is, as it were, a textbook in material form, and the instruction aims at making
_ this material intelligible. It is clear that for work of this kind the ordinary
logical arrangement of the Museum cases will in many ways need revision.
Teaching must take its start from the pupils’ own minds, and select its material

ON MUSEUMS IN RELATION TO EDUCATION. 273

from the point of view of its relation to the world they know. It is the
psychological order that must be followed, and the logical arrangement will
determine the end, not the beginning, of the course,

lt is precisely through the difficulties which this involves that the trained
teacher is more likely to be successful in this type of work than the curator or
his assistant, but the average teacher has neither the knowledge of the subject
ner the command of the Museum’s resources which are essential. The Manchester
device has much to teach us in this regard.

Whether or not a particular Museum is suited to this kind of work will
depend partly upon its contents and its buildings. A lecture-room equipped
with lantern, with various devices for showing specimens at the lecture table,
and with tables rather than sloping desks, in order that specimens may be
handled by the class, seems absolutely essential.

System and purpose must govern the use of the Museum by schools. The
aimless wanderings of groups of children about the galleries is sheer dissipation,
a nuisance to the staff and to the public. Enough has been said to indicate the
lines, which may be followed. A keen teacher will find something helpful even
in a dead Museum, and a living Museum will lay itself out to seek the advice
and help of teachers in the attempt to play its part in the educational service
of the locality.

We may especially note the possibilities, which have so far been only
slightly developed, in the provision of circulating sets of illustrative objects
designed for school use. It is essential, however, that such sets should avoid the
error of over-systematisation, especially for use in primary: schools. The contents
of the cases should be determined by the point of view of those for whom they
are designed, and not by a specialist who knows his subject ag a systematised
body of krowledge, but has no conception of what his specimens will mean to
a person who is both young and uninstructed.

Museums in Relation to the Advanced Student.

This question has to be considered from two distinct, and at times conflicting,
“points of view—viz., the needs of the particular class of student; and the needs
of the Museum and its staff in relation to other calls. These students for the

present purpose may be divided into :—

1. Research Students. | 3. Private Students.
2. University Students. / 4. Collectors.

The number of Museums which can render material aid to the advanced
student is limited, although it must not be forgotten that even the smallest
Museum usually, possesses one or more objects of scientific or artistic value.

The Redlands made upon the Museum staff by the advanced student are
serious. Not only is a great amount of time consumed in providing material,
but almost invariably calls are made for enlightenment upon points which arise
in the course of his inquiry; he needs frequently to discuss his conclusions with

a specialist member of the staff.
ut advanced students vary in type, and their needs are best considered
‘Separately.
_ The Research Student.—This student is frequently a man of established
scientific reputation. He requires only original material, and this must be
furnished with full data of provenance, evidence of its type distinction or other
points of interest, and full references to literature. Probably all other specimens
of similar type possessed by the Museum will be required for comparative study,
and all these should be supplemented by information similar to that of the study
‘Specimen or specimens.

When the material cannot be brought together in a room suitable for study,
provision for the accessibility of the series is necessary, the Index catalogue
will be required, and cases and cabinets must be open. When required specimens
are on exhibition, as they needs must be in m>«y, cases, it will be necessary
‘to dismount them, or if this is impossible, work must proceed at the open case,

@ most undesirable method. For the satisfactory work of a researcher, a well-
lighted work-room is essential.
., , Access to a good library is also essential, and very little good work is done
if books are only available for short periods on Joan.

1920 ui)

974 REPORTS ON THE STATE OF SCIENCE.—1920.

Instruments ot research will be required, such as microscope, preparatory
and developing tools, photographic appliances, &c. Everything which the
researcher requires for the thorough prosecution of his studies ought to be at
hand.

The needs of the researcher at a distance entail less calls upon the staff, and
are usually restricted to the loan of specimens, plaster casts, and tull details
of provenance, &c.

Uhe University Student.——Under this head we include the students of all
advanced training institutions, whether University or not. Where calls are
many, and on similar lines, it may be possible to form special ‘ Students’ Series,’
from which the student can gain a practical knowledge of his subject. Hither
lack or excess of material beyond what is absolutely required is a disadvantage.
The material will be chosen for its instructive value, not for its attractiveness.
A special Student Series can be kept on exhibition, from which it is not
removable, or in cabinets, so that its use throws no additional work upon the
curator, Special Student Series should be available for use by the lecturers
to advanced students, as well as by the students themselves. If required in
the lecture-room, the collection should be kept in drawers, and not exhibited,
unless special rooms, not open to the general public, are provided. Exhibited
series, which have been specially selected, arranged, and labelled in the public
exhibition cases, at times fall under the head of Special Students’ Series. ‘These
collections should have references to the literature dealing with the subject.
The arrangements should allow students to use note-books, or a small table.
Most, if not all, of the specimens in the series will have to be handled by the
student, and numbers corresponding to a catalogue list should be painted or
otherwise’ fixed upon each.

University students frequently work in pairs, or small numbers, and need
to have several specimens before them at atime. Suitable rooms must, therefore,
be provided for their special use.

There remains the larger question of co-operation between the University
and the Museum. The public Museums in most of the University towns are
large and well provided with collections, in which there is a considerable store
of material suitable for research. The staffs usually include one or more trained
scientific men, and more such are being attracted to permanent Museum work.
We believe that, with good will and intelligent co-operation between the
University and the Museum, difficulties will disappear, to the great gain of
both institutions. For University professors to restrict themselves to a Museum
of their own is to restrict themselves and their students to a limited field of
observation and research, as the public Museum is always likely to contain
and receive more material in any subject than the University is normally
likely to acquire. The curator, on the other hand, must conserve, suitably
labelled, and keep in good order, extensive collections which are of primary
value both for teaching and research. Mutual aid cannot fail to bring in good
results. The professorial staff of the University can help by furnishing scientific
or artistic knowledge, and by supplying dissections, prepared in the laboratories.

They can assist the curator in the preparation of exhibition groups of current —
scientific importance, and can in turn profit by a first-hand acquaintance with —

material in sections of their own science, which may not fall within the range
of their ordinary professorial teaching. F
Such a co-operation is merely extending to independent Museums what is

already done in those directly connected with a University, as at Oxford, :
Cambridge, Liverpool, and Manchester. It is, however, in the United States

that the best examples of co-operation are seen. (See Appendix I.)

The advantages of this intercourse are many. Expense is shared instead —

of duplicated, and through the intermediary of the Museum the public is
brought into close contact with the higher seats of learning. The Museum
comes into its rightful place in the fighting-line of science, and the student
comes face to face with actual problems and gets a close grip of connected
facts; he in fact does work under more real conditions than in the forcing

house, or laboratory. But the student, too, may fairly be asked to help by

doing some curatorial work. Instead of disarranging and damaging Museum
specimens, let the post-graduate prepare, determine, label, and arrange a limited

ae eee eS

ON MUSEUMS IN RELATION TO EDUCATION. 275

group under the joint direction of professor and curator. The Museum will
profit by the improved arrangement of the objects, and the student will learn
how to utilise specimens, and how to discover and use the relevant scientific,
or other, literature. Such work will also give him a solid foundation of syste-
matic knowledge too often wanting even in the best products of modern
education.

The Private Student.—This student is usually either working for an examina-
tion or to perfect himself in a subject which appeals to him. If of the former
type, he may find all he wants in the exhibition series, with a little guidance
from the curator, or it may be necessary to give him access to the series used
by the University student. The needs of the second type of student will
generally be amply supplied by the explanatory labels, and occasional access
to books.

The Collector Student.—This student usually visits the Museum in order to
identify specimens in his own collection, and therefore requires access to
systematically arranged and stored collections. As the exhibited series will
not, or ought not to,. contain the long series of specimens he desires to see,
these students will be best served and helped if Museums used by them provide
one or more well-lighted work-rooms, with large tables, adjacent to the reserve
series, which should be kept in strict systematic order, and fully labelled. The
rooms containing the reserve stores can frequently be used as work-rooms for
the advanced students also, and with great advantage, as specimens. can be
returned to place at once when done with, before others are taken out.

Museums in Relation to Classical Education and the Humanities.

Much of what might be written upon this branch of Museum work has
already been published in book form by a member of the Committee, and need
not be repeated again here (‘Our Renaissance: Essays on the Reform and
Revival of Classical Studies,’ by Professor Henry Browne, 8.J. Longmans,
Green and Co., no date of publication).

Professor Browne rightly urges that, whilst the subjects of Natural Science
may claim priority, Museums which neglect the promotion of the love of culture
and art among all classes will be incomplete and one-sided.

Teachers of Ancient History may reasonably expect to find, in Museums,
collections having a bearing upon the subjects they teach, and in some of the
large provincial Museums this is already the case. No Museum, however, need
consider itself too poor or remote to be able to do something towards illustrating
ancient life.

The objects required for the purpose can be so chosen as to appeal to the
public as well as to the student, and success will depend upon the exhibition
of such material as ought to interest persons of average intelligence and educa-
tion. The bringing together of local or other evidence of the Roman occupation
of England, for example, will attract. every one. Much can be done by the
provision of reproductions (including casts and electrotypes, as well as photo-
graphs and slides) of objects not otherwise obtainable. Many of these being
replaceable, could be loaned to schools and colleges.

From a special questionnaire much information was obtained, and can be
found set out in full in Professor Browne’s book. It will suffice if a summary
only is given here.

Practical evidence of the value to all grades of education by such collections
in Museums was supplied by the authorities of the British Museum, and of
the Museums of Oxford, Cambridge, Liverpool, and the Universities.

In this instance, again, American Schools of Learning and Museums are far
in advance of the British Isles. The greatest development has been reached
by the Museum of the University of Pennsylvania, Philadelphia, which is a
University and Public Museum combined. The classical and art collections
are remarkably good, and fully used by the University professors, who find
that the interests of students are stimulated and encouraged, whilst their
studies take on a more real character than from bookwork alone. The Boston
Museum of Fine Arts is doing much useful work, and teaching is carried on
upon a large scale. The collections are used by the students of Harvard, and

T 2

276 REPORTS ON THE STATE OF SCIENCE.—1920.

by Public Schools. In one year lectures were delivered to nearly 12,000 people
by ‘ Docents’ of Academic aistinction. The Museums of most of the American
Uniyersities possess a strong ciassical section, and all are used for instruction
purposes by the professors. i ; y

"he Archxological Institute of America is steadily encouraging the extension
of classical teaching, and specially promotes a knowledge of ancient cultures.
It also gives support to, and derives material from, the Archzological Schools of
Athens, Rome, Jerusalem, and Santa Fé (New Mexico), and publishes journals
which have a large circulation, Forty-five local branches, arranged in four
geographical sections, are in operation, and from 200 to 250 lectures are arranged
tor yearly. The study of classical history will probably increase in the near
future by reason of the renaissance which Eastern countries will experience as
the result of the recent war, and collections which illustrate, even fragmentarily,
some features of their ancient history, will be of great service, but any extensive
development of such collections will necessarily be restricted to the large cities
and University towns.

Principles of Museum Administration, Maintenance, and Staffing.

The determination of any general principles of government and administra-
tion does not appear to have been formulated or applied to British Museums.
Neither are British Museums, or their governing bodies, referable to a common
standard, even when they exist mainly for the benefit of the general public.
The Libraries Act, 1919, may eventually secure uniformity of government for
county and town Museums, although it is optional for a county or town to
place its Museum under the control of the Library Committee, or under a
distinct Museum Committee. The many public, or semi-public, Museums,
owned by societies and private bodies, are not recognised by the Act, and no
inducement or provision is made for their transference to the constituted public
authority. These will, therefore, remain under their present diverse methods
of administration, and be governed more in the interests of the societies, than
in that of the general public.

This is to be deplored, as many of these Museums contain the nucleus. of a
good public Museum, and many national] treasures, yet cannot develop sufiici-
ently for want of funds, whilst they are large and important enough locally
to hinder the formation of a wholly free public Museum. No fixed rate per %
can be devised applicable to ali Museums, as the differential rateable values,
population, and requirements of towns cannot be brought to a common stan-
dard, It is possible, however, to fix a minimum income based upon the cost
of maintaining a trained curator at an adequate salary, one attendant, and
cleaners. (No curator of average ability ought to receive less than 300/. per
annum, and this amount, added to the wages of attendant and cleaners, will,
with the fixed charges, and at least 150/. for purchases, printing, &c., entail a
minimum cost of 800/. per annum.)

It is essential that each department of a Museum should have a definite
sum allocated for purchases, mounting, labelling, &c., otherwise the balance of
sections is likely to be destroyed by the enthusiasts of one or more sections.
This is a prime fault in provincial Museums.

The principles and cost of maintenance of a Museum are questions not
always capable of settlement by the local governing body, and these would
profit considerably if it were possible to seek the advice of some recognised
national or central authority fully conversant with the cost, maintenance, and
development of the various departments suitable for a Museum in a given ‘town
or district. The help of such a body of experts would also assist local Museum
Committees in securing a suitable balance of departments and an economic
expenditure.

In order that the Museums may fulfil their proper mission in the community
it is obvious that the question of staff is of the first importance. The old
practice of uniting the functions of librarian and Museum curator is vigorously
and unanimously condemned by, the Committee. Progress of Museum work
depends upon the formation of an adequately paid corps of specialist workers.
At present all Museums are understaffed. Even in small Museums, a single
tnrator cannot be sufficiently well informed to arrange and label all his material,

ON MUSEUMS IN RELATION TO EDUCATION. 277

Large Museums will require two or more members of staff, each of whom
should have extended his general preparatory training by special study of those
groups with which he is called upon to deal.

The National Museums have for long specialised the work of their members
of staff. They require of them a high standard of attainment. A few of the
provincial Museums have secured directors and curators with recognised qualifi-
cations in science or in art, but the greater number of curators are either self-
trained or have acquired their special knowledge on other than systematic lines
of study. Notwithstanding the lack of preliminary systematic training, most
curators have acquired qualifications which fit them adequately to perform their
present duties. It is evident, however, that future Museum work will be best
served if Museum assistants and curators have previously passed through a
systematic course of instruction in those sciences and arts likely to be needed in
their subsequent work. A sound University training in letters or in science
must soon be a sine gud non. It is also desirable that the elements of Museum
technique should be taught whenever means can be devised. A reading know-
ledge of French and German is almost indispensable.

It is generally admitted that Museum officials are badly paid—that is, their
stipends are less than similar attainments and powers of mind would earn in
other walks of life. Considerable improvement has taken place in this matter
during recent years, but adequate progress in this direction ‘can only: be
effectively made when the curatorship of a Museum is looked upon as an honour-
able and desirable profession for men of high intellectual attainments’ (Sir W. H.
Flower).

Some General Conclusions.

Many of the recommendations of the Committee-are embodied in the Report,
but there are one or two general questions which may be briefly referred to here.

1. In the view of the Committee, Museums can and should be developed
into centres of research. This may be done partly in co-operation with
Universities. Much unworked material lies in many Museums, and a wide field
of useful research lies open, if suitable facilities for the work are provided.

2. It would assist research if an official list of the principal contents of all
provincial Museums could be published by the Board of Education. This list
would also doubtless indirectly increase local pride in the collections and so add
to the steps taken to secure safe custody.

3. All Museums suffer greatly from want of funds. If educational work
and research are to be developed. grants-in-aid on a liberal scale are absolutely
essential. There is some fear that Museum funds may be seriously diverted from
what all authorities agree to be their first aim—viz.. the advance of knowledge.
for the more popular ventures in connection with the schools. Research must
be regarded as the first function, at any rate, of all the greater Museums. Some
principle of grading of Museums for purposes of grant might be adopted, based
upon the work they are doing or planning.

4. Curatorial functions demand a high degree of special knowledge and
training. The Universities and the National Museums have a duty to the nation
in this respect.

5. In reference to the work Museums may do for schools, the Committee
helieves that the system of enecial circulating loan collections for schools. so
highly elaborated in the United States. deserves wider extension in this countrv :
and it recommends that, to pav far the necessary material and the svecial staff
required, annropriations should be made from the Education grant to _those
Museums which are prepared to carry out the system.

APPENDIX T.

Sub-Committee’s Report upon Overseas Museums.

(a). Australia.—The Committee’s delegates visited the Australian Museums at.
Perth, Adelaide, Melbourne. Sydnev. and Brisbane. and found that the general
work of each was carried out on similar lines to that in British Mvseums. The
fundamental purpose of Museums is well maintained, all material bearing upon

278 REPORTS ON THE STATE OF SCIENCE.—1920.

the aborigines, native plants and animals, and the mineral resources of Australia
is carefully conserved. The Art Gallery attached to the Melbourne Museum
takes special cognisance of examples of Australian Art. Public lectures are
given at all the Museums, and schools and classes encouraged to visit them,
the Museum staffs giving demonstrations and lectures whenever possible.
Special student collections are being made at Perth, Adelaide, and Brisbane.
The Technological Museum, Sydney, loans collections to illustrate lectures
given at the Technical Colleges and Nature Study in schools. Timber, minerals,
building and ornamental stones, &c., are in process of collection in order to
constitute an exposition of the mineral wealth of the country. It also sends
out collections of native material to distant towns and schools.

The educational work of the Queensland Museum, Brisbane, is on a more
extensive scale than elsewhere. Carefully graded lectures are given by the
Museum staff to classes from elementary and secondary schools, and special
time is allotted to classes for definite studies. Higher education and research
receive special attention, research being specially encouraged.

(6) Lhe United States.—Adequately to describe the educational activities
of the American Museums would require a large volume. The Committee’s
delegates visited those at Chicago, Pittsburgh, Washington, Philadelphia,
Harvard, Boston, Brooklyn, and New York. Time did not allow of more
extended visits, but information was readily obtained from all to which applica-
tion was made.

The Museum of Natural History and the Metropolitan Museum of Art,
New York, the Museum of the Academy of Sciences, and the Field Museum,
Chicago, the Carnegie Museum, Pittsburgh, and the Museum in Philadelphia
were pre-eminent amongst those visited for their extensive schemes of educational
work in connection with the Public Schools. They are also actively associated
with higher education and University work, as are the Museums of Washington,
Harvard, and Boston. The work of the Natural History Museum, New York,
may be outlined as an example of what most American Museums are doing
-to aid education, as it has probably done more work of this character than
any other Museum in the world. Large circulation sets of Nature Study
collections have been prepared, and in 1913 were sent out to 501 schools by
means of special motor vans. These collections were used by one and a quarter
million of pupils. The study collections number about 600, and have been
much increased since. Special teaching collections are set up in the Museum,
and class-rooms and lecture theatre are available for use at any time.

Members of the staff frequently lecture to the children and to the teachers,
whilst a special guide service is maintained. Special provision has been made
for blind students, who are permitted to handle specimens. It is said that
they gain in this way quite a remarkable knowledge of the form and adaptations
of animals.

A Lantern-slide Department has been organised for some years, and now
possesses over 30,000 slides, which are loaned in series to schools for teaching

purposes. At the time of the delegates’ visit the formation of. branch teaching
Museums was under consideration, and the establishment of ten Lecture Centres
in various parts of New York.

The needs of higher education and research have been met by an arrangement
with the Columbia University; the professors lecture to their students at the
Museum, and hold the position of curators in the Museum in their several
subiects.

.The Metropolitan Museum of Art, New York, retains expert guides to assist
its members, teachers, and schools when visiting the collections. The service
is free to teachers and schools. The city maintains one paid lecturer. Regular
visits are paid from schools for instruction in the History of Art. The University
and Museum are in close co-operation, especially on the classical and historical
sides. It has been suggested that a Faculty of Arts should be established in
the Museum, with lectures for snecial collections. The Boston Museum of Fine
Arts and the Art Institute of Chicago are doing similar work; in the latter
case. a School of Art is maintained in connection with the Museum.

_ The Field Museum of Chicago has entered upon an ambitious scheme whereby
a specially prepared series of Circulation Collections will be available for
schools..in the city area, A quarter of a million of dollars was given for this

ON MUSEUMS IN RELATION TO EDUCATION. 279

purpose, and has since been increased. The work of the Academy of Sciences,
Chicago, and of the Children’s Museum at Brooklyn, is remarkable in that the
children are encouraged to take part in the Museum work, by the maintenance
of aquaria, the loan of specimens to be taken home, and the preparation of
costumes, &c., to illustrate the clothing of various periods and nations. Classes
in the natural and physical sciences are taught in the Brooklyn Children’s
Museum by the staff, and many children have become expert in wireless tele-
graphy, blow-pipe analysis, and in the use of other scientific instruments,

The Public Museum, Milwaukee, possesses a full lecture system reaching
all sections of the public from the elementary schools upwards, and has
established a Science Club for High School Students. Arrangements are made
for all Public-school children of certain grades to visit the Museum twice yearly.

The American Museums make free use of Museum and Art ‘Docents’ for
the delivery of lectures and demonstrations. These ladies and gentlemen are
chosen for their special knowledge, and are maintained either by the Museum
or the city, or partly by both, or in some cases, as at the Brooklyn Institute
of Arts and Sciences, by an Art League. The two ‘Docents’ of this Museum
lectured to 114,000 pupils in one year.

The American Museums are in a position to undertake this valuable educa-
tional work owing to—

1. Large gifts of money from wealthy persons.

2. Large staffs of enthusiastic workers.

8. The association with every Museum of a large body of rich and cultured
people, who are themselves interested in the collection and study of Museum
objects; they frequently give large sums of money for general maintenance,
or earmarked for special purposes, and also present private collections.

As educational work extends, the popularity and usefulness of the Museums
increase, and their purpose and utility become more highly valued. The attain-
ments of the staff are recognised, and opportunity given for the prosecution of
their own line of research.

An essentially American feature in the formation of new Museums is the
preparation and publication, long in advance, of full plans of intended new
buildings, and their free display in journals and public places. Reduced models
to scale are also prepared of the suggested buildings, and these are exhibited
to the public. These people do not hesitate to embark upon schemes’ which
will take years of work to accomplish. Definite steps forward are taken as
opportunity arises. but the whole scheme is kept prominently before the public
as an earnest of the future and a stimulant to gift.

APPENDIX II.

Manchester Scheme.

Ar the beginning of the war several of the elementary schools in Manchester
were taken over for military hospitals, and the scholars, therefore, temporarily
dispossessed of accommodation. The Education Authorities thereupon instituted
a half-time system in certain of the remaining schools, in order that the dis-
possessed scholars should receive, at least, some instruction. It was decided

in these half-time schools to fill up part of the remaining half of the scholars’

time by visits of educational value to various Manchester institutions and other
places of local interest. In this connection the Keeper of the Museum, in con-
sultation with the Education Authorities, organised a scheme whereby the
scholars attended at the Manchester Museum for courses of lessons in Natural
History and Egyptology. The main points of the scheme are as follows :—

1. The classes are limited to twenty in number.

2. The classes are, as far as is possible with existing accommodation at the
Museum, provided with separate class-rooms, seating accommodation, desks, &c.,
so that the lessons are given as nearly as possible under school conditions.

3. The teachers are trained teachers on the staff of the Manchester Education
Committee. who have also a special knowledge of the subjects illustrated in the
Museum. They have heen specially appointed to this work by the Education

_ Committee.

280 REPORTS ON THE STATE OF SCIENCE.—1920.

4. The classes do not come for detached lessons, but regularly once a week
for organised courses of six to nine lessons on one subject.

5. The Museum authorities provide duplicate specimens for the use of the
classes, and the staff of the Museum render as much assistance and help in this
way as possible.

6. A lesson, broadly, consists of about forty minutes’ tuition in the class-
room, after which the class is taken into the Museum and shown the cases
illustrating the subject of the lesson.

At first eight classes in Zoology and Geology were held daily, and from
900 to 1000 children per week shared in the lessons. The scheme proved remark-
ably: successful, and two additional teachers for Botany were added the following
year. Class-room accommodation was a difficulty, and a part of the Museum
had to be shut off for'the purpose. It became clear, however, that work of this
character requires a Museum lecture-room and class-rooms to obtain the best
results. The increased demands upon the time of the Museum staff in providing
material were considerable.

By 1916-17 the scheme had so far proved its value that four teachers were
specially appointed by the Education Committee to conduct Museum classes
throughout the year in Geology, Zoology, and Botany. Towards the end of the
session a fifth teacher was appointed, whilst the assistant in charge of the
Egyptological collections also conducted classes. The attendance of scholars
increased to 2000 per week. In 1919-20 the number of special teachers was
increased to six, and the number of scholars attending the courses to 2500 per
week.

Classes from the secondary «chools also visited the Museum, and were taught
by their own teachers. The development of this valuable educational work
reacted upon the Museum in increased public interest, whilst a considerable
addition of adult visitors was brought by the scholars in their spare time.

The total attendance for the period of four years was as follows :—

1915-16 . . . 45,000 | 1917-18 <9." . 100,000
1916-17 ©. . . 70,000 «| «1918-19 ©. ~—. |. 1805000

It must be borne in mind that these were not discontinuous attendances, but
represent the total visits at complete courses of six to nine lessons for each
scholar. Some scholars attended more than one course per year.

The Manchester scheme was adopted after a close study of the educational
work conducted in other Museums in this country, and especially in America.
Compared with other schemes and methods, it is claimed that the Manchester
scheme shows considerable advantages in the following ways :—

1. The limitation of the classes to small numbers. It was felt that to attempt
to instruct large classes resulted in ‘ entertainment’ and not ‘ instruction.’

ps atmosphere of the school class-room is approached as nearly as
possible. ‘

This is valuable from a disciplinary point of view, and also avoids physical
fatigue so usually attendant on visits from school children to Museums and
such places.

3. The classes are taught by trained teachers and not by the Museum staff.

The advantages of this from an educational point of view are obvious. The
staff of a Museum is appointed primarily, for quite other work than teaching.
and Museum curators do not pretend to understand the psychology of the child
mind or to be trained in the art of teaching.

4. A proper balance is maintained between this branch of Museum work
and the many other functions and duties which a Museum is called upon to
fulfil, and the educational work can be carried on without the absorption of an
undue amount of time, to the detriment of the other work of the institution.

ee ee a

ON TRAINING IN CITIZENSHIP. 281

Training in Citizenship.—Interim Report of the Committee, Right Rey.
Bishop Weuupon, D.D. (Chairman), Lady Saw (Secretary),
Lieut.-Gen. Sir Ropert Bapren-Powetu, Mr. C. H. Buaxtston,
Mr. G. D. Dungertey, Mr. W. D. Eaaar, Principal Maxwei
Garnett, C.B.E., Sir RicHarp Grecory, Mr. Spurnry Hey,
Miss E. P. Hueues, LL.D., Sir THroporre Mortson.

Introduction.

TRAINING in Citizenship consists of two parts, subjective and objective. The
former may be described as character-training and is concerned with the develop-
ment in the individual of those qualities which fit him to take his place in a
community with full appreciation of such privileges and duties as are the birth-
right of every good citizen.

The second part is concerned with the education of the individual in the
history of civilisation and the laws appertaining to communal life which assure
to every member freedom for full personal development cf mind and body.

With this two-fold purpose in view it was decided to take, as far as possible
in the limited time and with the limited facilities at the disposal of a small
Committee of busy persons, a survey of the educational organisation of this and
of other countries from which information could be acquired for practical train-
ing of the young in citizenship, and, further, to draw up a syllabus of theoretical
instruction which would be capable of expansion into an authorised text-book
on civics.

A letter contributed by the Chairman appeared in The Times Supplement
for December 25, 1919, asking for help in compiling the items of the survey.
From the answers to this appeal it was evident that the pressing need was for
the syllabus. It did not, however, appear that one syllabus could be prepared
to meet all cases. A request came from Bootham School, York, for ‘ short courses
on the training of citizenship as well as long courses,’ ‘ to help in a practical way
schools that uphold the idea of citizenship throughout the school career, and are
unable to find the time for more than a short intensive course of lessons.’ Similar
requests came from other schools, but the greater number of correspondents asked
for an authoritative handbook of civics, and it was decided to take up this work
and to meet the other varying needs by appending a selection from the specimen
syllabuses and suggestions for lessons that were sent to the Committee by schools
and associations interested in the work.

The Preparation of the Syllabus.

The Chairman, at the request of the Committee, drew up and circulated a
detailed syllabus of civics which after criticism by the Committee was expanded
by Mr. Dunkerley from reports sent in by school teachers and from suggestions
made by members of the Committee and others and from his own. experience.
The syllabus thus expanded was again considered by the Committee and adopted
by them. It is included as Appendix I. in this Report.

The Committee learned that Mr. Blakiston had in hand a Text- book of Civics
designed for use in the senior classes of the Public Boarding Schools. This book
has been completed on the lines of the syllabus, and the Chairman has contri-
buted 1a foreword to it.

‘So important is it, however, that children of both sexes in all schools,
and not least in elementary schools, should be systematically taught to recognise
their duty to the Nation and the Empire that the Committee feel the time
is opportune for issuing an official handbook upon Civic Duty; and, if the
syllabus now printed should receive the approval of the Educational Section,
they desire that a handbook on the lines of the syllabus should, if possible,
be issued with the authority of the British Aggociation. They would invite

982 REPORTS ON THE STATE OF SCIENCE.—1920.

Mr. Dunkerley, with the assistance of the Chairman, Bishop Welldon, and the
Secretary, Lady Shaw, to undertake the task of drawing up such a book. The
Committee entertain the strong opinion that the handbook, while supplying
information upon various aspects of municipal and political life, should aim
especially at inculcating the unselfish patriotic spirit which would. as they
believe, go far towards preventing, or at least mitigating, the industrial contro-
versies now threatening to undermine the basis of society.

The Selected Syllabuses.

In response to their inquiry into the work now carried on in various educa-
tional institutions, the Committee received a number of syllabuses and notes of
lessons which may be of use and which will certainly interest the members of
Section L. soi :

The difficulty has been to decide which to reproduce when so many were
of equal value. Those appended have been selected because they include special
points not common to all.

Examples of Courses in Citizenship.

Sir Robert Baden-Powell’s scheme needs no comment by the Committee.
Its practical value has been thoroughly tested and proved. It is reproduced as
Appendix II.

Appendix IIT. contains the following :—

A. The Devon County Education Committee’s Report, 1911. Suggestions as to
moral instruction and training in citizenship.

B. The Hammersmith syllabus supplies an example of the short. intensive
courses for which many schools made inquiry.

C. That from Blackley. Manchester, is admirable as showing how the schoolboy
may be trained to be a good citizen and patriot in the widest sense of the
word.

D. Caerau Mixed School. Bridgend. gives its syllabus of lessons, and the school
self-government scheme by girls and boys working together.

E. The Roath Park Boys’ School. Cardiff. sets out (1) a Citizenship scheme
taken as part of history, (2) the Prefect system, which includes self-
government, and (3) an experiment in Scoutcraft as a school subiect.

F. The syllabus from First Derry (Ireland) Boys’ School is a specimen of courses
in Civics followed in certain Irish National Schools.

G. That from Stobswel] School is a specimen from Scotland.

Schemes of School Management.

Appendix IV. contains the following :—

Skerton Council School. Lancashire; the statement is long, but has great value
as that of a school having a ‘ constitution.’

Cowley pace, St. Helens, Lancashire. This account is written by a boy at
school.

Penarth County School, Wales. This is written by a girl at school.

Roath Park Boys’ School : Section on the Prefect system.

Roath Park Boys’ School : Section on Scoutcraft.

High School, Glasgow, describes a system of Prefects.

Appendix V. gives Lord Lytton’s Suggestions for Organising Regional Study
and Maintaining a Permanent Regional Record.

Appendix VI.—Mr. Valentine Bell : Notes of Lessons in Regional Survey.

A circular letter was sent on December 12, 1919, to the Secretaries of the
Head-masters’ Conference and to the Associations of Head Masters. Head Mis-
tresses, Assistant Masters, Assistant Mistresses, Private-school Masters, Private
Schools, Science Masters. and Training Colleges, asking them to bring the
matter to the notice of their members. It was also sent to Newnham and
Girton Colleges.

Of these the Committee of the Head-masters’ Conference agreed ‘to print
the statement contained in the Jetter in their termina} Bulletin’ in February

ON TRAINING IN CITIZENSHIP. 283

bf this year. The Private Schools Association inserted a notice, supplied
on the invitation of the President, in their paper ‘ Secondary Education’ on
February 1. Newnham College, Cambridge, inserted the letter in their journal,
the ‘Newnham College Roll.’ The Association of Science Masters put the
Committee in touch with the Catholic Social League.

All the Secretaries promised to bring the subject to the notice of. their
Committees.

Tue Epucationat SuRVEY.

The Committee decided not to confine their survey to the United Kingdom,
but to include as far as possible notes of educational methods throughout the
British Empire; and, for the sake of comparison, to ascertain the latest
developments in other countries. For this last purpose they have asked the
help of the Education Section of the International Council of Women, which
is engaged in a similar investigation. The response to the inquiry instituted
by the International Council is not due in this country before the meeting of
the British Association in August; and replies to the Committee’s letters
addressed to Japan and China have not yet been received. It is therefore not
possible to present a report of the survey to the meeting in August 1920, and this
must be postponed to 1921. The Section should, however, be in possession of
some account, of the action taken by the Committee to ensure complete informa-
tion for the final report.

In Canada in 1917 a movement was started at Winnipeg ‘ for a National
Conference to consider the bearing of Canadian Education on Character
and ‘Citizenship.’ After a considerable amount of preparatory work, money
was raised and the Conference was fixed for October 1919. This
Conference was attended by about 1,500 accredited delegates of public
offices, the aim being to gather business men and educators in one great
assemhly to secure the creation of a permanent body for study of the question.
The Committee have received a verbatim report of this Conference, the
attendance at each session of which was never less than 2,000 persons, and on
one evening rose to 5,000. The report says ‘the distinctive features of the
gathering were its diversified representative character, the combination of
citizens as such and professional educators. and the spirit of lofty ideality in
the interests of the nation that animated all.’ The outcome was the creation
of a National Council of fifty members, thirty-six to be elected from the various
provinces by the Conference itself, and fourteen to be elected by the Council
as so far constituted. This Council met in February of this year, and the
report of their proceedings has been supplied to this Committee. Inquiry has
now been made of four nrominent men whose names were supplied by Professor
Macallum, of Toronto University, asking what effect, if any, has been pro-
duced in the schools or in any way, and also asking for information as to the
training given in the schools. The Committee hope some similar action may
be taken in the Mother Country.

A list of voluntary agencies for dealing with Civic Education in the United
Kingdom is being compiled. Meanwhile the Committee have obtained varticulars
of methods of work from the National Federation of Teachers. the Schools
Personal Service Association, the Citizenship Studies Association, the Union of
Educational Institutions. the Union of Lancashire and Cheshire Institutes. the
Workers’ Educational Union, the Catholic Social League, the Civic and Moral
Education League. the Federation of Women’s Institutes. and the Cavendish
Association. A circular letter has been sent to thirty-six head-masters and
sixteen head-mistresses of public schools, to two mixed schools and to two private
schools. The answers received will be considered in next year’s report.

Application was made some years ago by a Committee of Section L to the
Roard of Education for lists of private and of charitable schools, and County
Directors have now been asked for lists of such schools in their respective areas,
but neither the Board of Education nor the local education authorities keep
such records. Further efforts will be made to obtain the necessary data to
complete this part of the survey.

From the Roard of Edveation the Committee have received conies of ‘Suc-
gestions for the consideration of Teachers and others concerned in the work of

284 REPORTS ON THE STATE OF SCIENCE.—1920.

Public Elementary Schools’ and of the ‘ Syllabus of the Board’s Final Examina-
tion of Students in Training Colleges, 1922.’

There are sixty-eight County Directors of Education in England and Wales.
A questionnaire was prepared for these, and Miss E. P. Hughes undertook its
circulation to the twenty-nine County Directors in Wales. In addition to the
thirty-nine questionnaires distributed in England, personal letters were written
to eight other Directors of Education. The response was not complete, but a
mass of valuable information is in the hands of the Committee to be dealt with
later.

Much time has not elapsed since the appeal was sent to Scotland and Ireland,
but some returns have already been received. A considerable amount of work
remains to be done before the survey can be considered to be complete.

Since this report was drafted the Committee have received from Mr. Shyam
Shankar, Pandit and Secretary to H.H. the Maharajah of Jhalawar, the terms
of a proposal for a Students’ League or League of Empire for Native Students in
India, which has practically the same objects as the schemes which ‘are heréin
referred to. The draft will be considered in connection with similar proposals
for other parts of the Empire in a future report.

The Committee desire to record their thanks to all who have given assistance
so far, and, since ‘ gratitude is the sense of favours to come,’ they look forward
to additional help in pursuing the research and preparing a final report.

ON TRAINING IN CITIZENSHIP. 985

TABLE OF APPENDICES.

I. Syllabus of Instruction in Civics prepared by the Committee.

1I. Analysis of the Scout Scheme of Training towards Citizenship, by Lieut.-
Gen. Sir R. Baden-Powell.

III. Examples of Courses in Citizenship selected from other sources :—

. The Devon County Education Committee.

. The Ellerslie Road School, Hammersmith.
. Blackley School, near Manchester.

. Caerau Mixed School, Bridgend, Glamorgan.
. The Roath Park Boys’ School, Cardiff.

. Ireland : First Derry Boys’ School.
Scotland : Stobswell School.

QAO pS

IV. Schemes of School Management :—

Skerton Council School, Lancaster.

Cowley School, St. Helens: Boy’s Essay, ‘ Civic Government by Boys,’

Penarth County School for Girls, Wales: Girl’s Essay, ‘ Self-Govern-
ment.’

Roath Park, Boys’ School, Cardiff.

The High School of Glasgow.

V. Suggestions for Organising Regional Study, by the Earl of Lytton.
VI. Notes of Lessons in Regional Survey (Lambeth), by Mr. Valentine Bell.

APPENDIX I.—SYLLABUS PREPARED BY THE COMMITTEE.

1. The Origin of the State.

Man a social animal.
Impossibility of his living a solitary life.
The family the birthplace of the State.
Plato and Aristotle upon the origin of the State.
Augustine upon the Christian State.
Society implies interdependence; interdependence implies division of labour or
specialisation.
Social unity of groups—Family—Guilds—Trade Unions,

286 REPORTS ON THE STATE OF SCIENCE.—1920.

Two objects of the State :—

(1) To produce worthy and contented citizens. Common interests of all who
are members of one Society, e.g. in obtaining the necessities of life, in
securing the safety of person and property, easy communication, and
opportunities of leisure and recreation.

(2) ‘Lo promote progress. The State can do for individual citizens something
which they cannot do for themselves. It can afford them means of know-
ledge and culture. It can encourage education, temperance, and civic and
patriotic devotion. It can offer opportunities for development and ele-
vation. True freedom lies not in self-assertion but in subordination to
the public good. Civilised man more truly free than a savage.

The State, therefore, essential to human welfare. But as every organism in
its development becomes more complex, so a modern State with interests, it may
be, in all parts of the world is far more complex than the ancient State, even
when the ancient State had become an Empire.

2. The History of Civilisation.

Process of civilisation from East to West.

Influence of Greece and Rome.

Life and death of States.

Characteristics or tests of civilisation.

Man’s command of Nature.

Influence of discoveries and invention, such as printing press, steam engine,
aeroplane, gunpowder.

Advance of civilisation, development of,

Science and its applications and inventions.

The great epochs of human progress marked by discoveries or inventions.

Comfort. Standard of living. Comparison of modes of living during the Roman
Conquest, English Conquest, Medieval Period (the Barons, Monks, &c.),
Elizabethan and Victorian Periods.

Interdependence of nations and countries—supply of wheat, wool, flax to
England—coal, iron and manufactured goods from England.

Growth of corporate life—association in

(a) The Feudal Structure.
(6) Craft Guilds.

(d) Co-operative Societies.
(e) Friendly Societies.

Knowledge. Education: its opportunity and responsibility.

Growth of Humanity, as in abolition of slavery, torture, &c.
Treatment of women and children.

The greatest happiness of the greatest number.

International relations : interdependence.

True end of civilisation :—The welfare of humanity as a whole.

3. Citizenship.

Citizenship begins at home.
Home life and surroundings.
Type case in poor district, 60 houses on each side in a typical slum.
Type family, father, mother, seven children (eldest 15).
Type house, two bedrooms, small kitchen, parlour, only water supply.a tap in
a yard.
Importance of the individual; poverty no bar to success.
Importance of knowledge of individual capacity; loss of much splendid talent
owing to wrong occupations being taken up.
Importance of individual joining some organisation with a definite object.
Good health a necessity for good citizenship.
Relation of the citizen to the State. Whether the individual citizen exists for
the State, or the State for the individual citizen.

ON TRAINING IN CITIZENSHIP. 987

Civic pride—a citizen of a great community with a glorious heritage in men
and books.

Interest in local history, natural history, and local industry, regional surveys.
Historical records; public memorials, historical pageants.

Civic ideals and duties.
Unselfishness (good turns) and self-sacrifice.

Individual service.

Home.

School. Care of buildings, &c.

Outside. Public property (Parks).

Proper use of conveyances and streets.
Use of proper language.
Community service. Country—Fire brigade, special constables, accident corps.
Humanity—Hospital service.
Religion—Mission work.
Development of self-control. Consider gambling—smoking.
Common Prejudices to be guarded against—
At School—ridicule of dull and physically weak boys.
Religion—bigotry ; sectarian jealousy.
National—depreciation of members of other nations and races.

Man is essentially and before all else a member of the State and must live up to
that membership.

Differences between the ancient and the modern world.

Compulsory military service; if a citizen can claim security he must be prepared
to fight for 1t if necessary, and the State has a right to call upon him
to do so.

Tendency of democracy to get as much as possible out of the State; to look upon
the State as a dispenser of charities. A citizen’s right—a fair wage; a
citizen’s duty—a fair day’s work.

Universal franchise of adult men and women based upon equal interest of both
sexes and of all classes in good government.

Danger of party spirit; each party only a section, and not justified in seeking
its own with little or no reference to the good of the State.

The spirit of true citizenship evoked and evinced by the War.

So great the debt of the citizen to the State that he may be justly expected to
make large sacrifices for the good of the State.

The daily life of a citizen.

Great citizens :—discoverers, inventors, philanthropists, writers, musicians,
artists.

Desire of all classes to have a more permanent share in the Government, hence
importance of all having a good conception of civic responsibilities :
Franchise implies a duty as well as a right.

Citizenship inculcated by practice, dramatisation, self-government (school
commonwealths, trials, debates). ;

4. Monarchy and Democracy.

Necessity for government.

Forms of government : absolute monarchy, limited monarchy, oligarchy, republic.

History proceeds as from East to West, so from the power of the few to the
power of the many.

Monarchy the only possible government in primitive society.

Few good Kings and Queens.

The divine right of Kings an exploded doctrine.

Sir Robert Filmer’s Patriarch.

The King the chief servant of the State.

Constitutional monarchy still useful as ensuring the unity of State and Empire.

The King to be recognised and to recognise himself as being what he really is.

oy the healthiest government, as resting upon the widest and strongest

asis.

Democracy the only possible government in the modern world. Autocratic
monarchy discredited.

Object of the Great War to make the world safe for democracy,

288 REPORTS ON THE STATE OF SCIENCE.—1920.

Drawbacks thought to be inherent in democracy :

(1) that it may resist progress—Sir H. Maine and Mr. Lecky.

(2) that it may fail to govern.

(3) that mob-rule may prevail. Cf. Greek historians.
No form of government without possible defects, e.g. ‘ vote-catching’ policy.
Failure in Ireland.
The need of strengthening democracy by constitutional safeguards, as in U.S.A.
Burke’s criticism of democracy. Democracy indeed above other forms of

government requires high character in its citizens.

Modern tendencies: anti-centralisation. Bolshevist theory of the State.

5. Central Government.

The State being one whole, a certain uniformity is necessary in its administration.
Such variety of laws and customs as might prevail in the Heptarchy im-
possible in the United Kingdom, Thus in U.S.A. authority tends to pass
from separate States to the Central Government, in such matters as: the
railway service, divorce, and temperance.

In general, as a State grows larger, the province of the Central Government
becomes restricted.

Home Rule.

Control of such matters as properly belong to the Central Government: Army
and Navy and Air Services, Customs and Excise, Post. Office, Telegraphsi
and Telephones, Taxation, Education, Foreign Affairs, including peace
and war, marriage and divorce, and the liquor trade.

Definitions of the functions attaching in the British Constitution to the
Sovereign, the Prime Minister, the Cabinet, and Parliament. Lords and
Commons. Election of Parliament. Exchequer. Direct and _ indirect
taxation.

Passing of Bills into Acis.
The franchise and the ballot.
Devolution now inevitable within the Cabinet itself.

Sir Robert Peel probably the last Prime Minister who, tried to keep his hand
upon all departments of administration.

Danger of allowing the Government to be upset by a chance vote in the House
of Commons.

Disadvantage attaching to the American system of associating offices which
ought to be permanent with the fortunes of a political party.

Amount of agreement necessary among members of the same Cabinet.

Value of permanent officials in a democracy.

6. Local Government.

Danger of a Central Government being overburdened by a multitude of tasks.

The British Parliament a signal example of the difficulty arising from excessive
centralisation,

Examples of local questions with which Parliament is obliged to deal.

Devolution possesses the advantage of an appeal to local knowledge, local interest,
and local patriotism.

Scotland and Ireland respectively instances of success and failure in combining
local with general sentiment.

Value of Municipal life. Unity of all large cities except London.

The Central Government to enunciate principles; the municipalities to execute

; them in detail.

Good work already done by local Boards of Guardians, local Education Authori-
ties, &c.

Difference between rates and taxes.

Money collected locally to be as far as possible expended locally; revenue from
dog licences, &c., expended in county in which licence is taken out.

Lord Mayors and Mayors. ;

County Councils.

Councils of County Boroughs, other Boroughs, other Urban districts, Rural
districts. Parish Councils, Boards of Guardians.

ON TRAINING IN CITIZENSHIP. 989

Functions and duties of statutory and other Committees.
(a) Municipal levies and expenditure—e.g. provision of Municipal baths
parks, trams, libraries, &c. ;
(6) Education.
(c) Provision for Public Health, including the care of the insane, and
Housing.
(d) ae for the destitute poor. Poor Law, almshouses, workhouses, casual
wards.
(e) Maintenance of roads, streets, buildings, and land.
(f) Police and justice. Licensing.
Gas, electricity, and water supplies.
The danger that the best citizens will stand aloof from local administration.
All honour due to the men and women who often spend their lives without
remuneration in the service of their cities and towns.
Municipal life as a training ground for political life.
Importance of dissociating municipal life as far as possible from political
partisanship.
Use of local history.
Description of the way in which a city or borough is governed.
Tendency to extend governmental power and interference.

7, The Administration of Justice.

The supremacy of law one main feature in civilisation; justice said to be a
reflection of the Divine Nature.

The law of a country to be (1) clearly defined; (2) popularly known; (3) equally
administered.

Distinction between civil and criminal law.

The presumption of innocence in an accused person.

Jurors—how appointed ; their powers and duties.

Classes of persons exempted from service on juries.

Defects of trial by jury.

Rights of individual citizens as guaranteed by laws; above all, the Habeas Corpus
Act and the Bill of Rights.

Equality of all citizens before the law.

Rights of women as well as of men.

Incorruptibility of judges not established without difficulty, but now an assured
fact of public life in Great Britain.

How laws are enacted and how law is gradually developed so as to become
applicable to changing conditions.

Sir H. Maine on law.

Value of assizes.

Law to be made cheap and easy, but not so as to facilitate vexatious litigation.

Tendency to substitute judicial arbitration for trials by law.

8. The Police and Public Safety.

Civilised society differs from barbarous society by the maintenance of law
and order.

All citizens entitled to perform their daily avocations in peace and safety.

Dangerous state of the roads, even so late as the beginning of the nineteenth
century. Highwaymen on the outskirts of London. Numerous robberies
and robberies with violence. Popular sympathy often on the side of the
highwaymen as being supposed to be friends of the poor and enemies of
the rich.

Inefficiency of the police down to 1829.

The police force as then instituted by Sir Robert Peel.

Difference between it and its predecessors (among these were the watchmen
known as ‘ Charlies’).

Occasions of appointing special constables.

The Riot Act. Power belonging to local authorities in grave emergency. The
Peterloo massacre:

Training of the police. Their functions and powers. Women police.

Relation between the police and other citizens.

1920 U

290 REPORTS ON THE STATE OF SCIENCE.—1920.

Friendly attitude of all classes except the criminal class to the police.

Juvenile offenders. Prevention better than cure.

Schools rather than prisons. The Borstal system. Reformatories.

Police-court Missions and Discharged Prisoners’ Aid Societies.

Perils attaching to misuse of cinematograph shows.

The young of both sexes to be instructed in the laws which they are called to
obey, and to be taught that the law is the only safeguard of liberty, as
civilised men, although subject to more control, enjoy far more liberty
than uncontrolled savages.

9. Public Health.

Health of the nation a chief concern of the country or city.

The Prime Minister’s statement that a million more men would have been
available for military service had the conditions of physical welfare been
observed.

Impossibility of making an A1 nation out of C 3 men.

Every child to have the chance of a healthy physical and moral life.

The State slowly waking up to its duty in respect of public health.

Reports of Medical Officers of Health.

Health Insurance Act.

Royal Commissions.

Provision of hospitals, clinics, and nurses.

Legislation affecting mines and factories.

Laws of Health.

Habits making for good health—

(1) Exercise—sports—swimming—outdoor life.
(2) Cleanliness—body and mind.

(3) Temperance in every way.

(4) Insistence on good ventilation.

Many diseases shown by experience to be wholly or nearly preventable, e.g.
small-pox, diphtheria, and, above all, hydrophobia. Leprosy and Black
Death long since extinct in Great Britain. Ravages of venereal disease.
Report of Royal Commission. Immediate measures to be taken for check-
ing and curing the disease.

Sanitation itself—a recent study. Effort and achievement of Sir E. Chadwick,
Importance of good sanitary conditions in schools. Neglect of conditions
even in public schools.

Statistics of infantile mortality. Need of instruction upon maternity. Peril
of drunkenness to health and life.

Clinics. Care of crippled and defective children.

Treatment of defective eyesight.

Crusade against dangerous employment. White lead. ‘ Phossy jaw.’

Warm clothing as a preventive of chills and consequent maladies. Injury
that women may do to themselves by following fashions in dress,

Provision of nurses for the poor in their homes during sickness.

Cleanliness. Free public baths.

Free medical attendance.

Hospitals at present inadequate to number of patients.

Quests ate hospitals voluntarily supported as against hospitals dependent on

e rates.

Welfare work.

A healthy and skilful body of workers, upright in character and self-reliant—
a source of strength to the country.

10. Life Assurance and Pensions.

Democratic conception of government—that it is the duty of the Government
to take at the public expense such measures as will give every citizen a
chance of working while his strength lasts, and of living in peace when

_ work is no longer possible.

In time past the poor have heen haunted by the dread of old age, without the
power of working, without resources, and without children or friends
who might be willing and able to support them. The life of the poor to
be set free from this anxiety.

ON TRAINING IN CITIZENSHIP. 991

The minimum rate of wages to be such that the wage-earner can live and
bring up a family in decent comfort. : ;

Life Assurance to be made compulsory when the workman is capable of paying
a part of the premium, the State to pay the other part.

The duty of advocating and practising thrift. Savings Banks before the War.

Causes of pauperism and how to diminish it.

Importance of self-dependence and habits of prudence.

Honourable dislike of charitable relief among the poor.

Dread of the workhouse. Almshouses wholly insufficient in number and not
ideal homes for old age.

Habit of casting upon Providence blame due to improvidence.

Valuable work done by Provident Societies.

Irresistible claim of mutilated soldiers and sailors.

National Insurance the affair of the Nation.

Apart from assurance, the equity of a pension payable to every man or woman
who after 70 (or an earlier age) can no longer make provision for himself
or herself.

Pensions give old people independence, or, if they live with their children, make
them no longer unwelcome guests.

‘he pensionable age to be reconsidered in view of the statistics of life.

The Government to avoid ill-considered charity.

11. Education.

Kducation acknowledged to be the right of every citizen.

The Educational Highway. The State not to subvert or impair responsibility
for children. ‘La carriére ouverte aux talents’ the true educational
object.

* Kntire object of true education is to make people not only do the right things
but enjoy the right things.’ (Ruskin.)

‘The value of education—influence on character—intelligence—observational
power—broad-mindedness—power of self-expression—decision in action—
self-reliance—capacity for responsibility.

Influence of Public Schools’ games in character training—not confined to Public
Schools.

Education inefficient if it ends too soon. Mr. Fisher’s Act. Age of compulsory
education prolonged.

Continuation Schools.

Vocational and non-vocational education.

‘Technical education—value to the workers.

Higher Education—Secondary Schools—The University.

Adult education—School and college only the beginning of the education of
the citizen—Study Clubs, Workers’ Educational Association.

‘he Educational curriculum not to be too wide.

peers, Risin, Spelling, and Speaking to be taught thoroughly in primary
schools.

Need of acquaintance with English History and Literature and the possessions
and resources of the British Empire.

Ancient and Modern Universities.

A common educational basis necessary. Evil of premature specialisation.

A teacher’s duty to discover and encourage special aptitudes in his pupils.

Mitigation in the severity of treatment of children.

Discipline—its value—obedience to just rules and orders.

“ Nelson’s signal.’
“Loss of the Birkenhead.’

Every oe to feel that his or her success lies in the treatment of difficult
pupils.

Study of writers upon education—e.g. Pestalozzi, Froebel, Spencer, Montessori.

Training and testing of teachers. Character of teacher even more important
than advanced literary attainments. Teachers not to look for results

_ _ too early.

Religious teaching. Advantage of non-sectarian teaching for children in day

schools. The co-ordination of different Christian Churches.

992 REPORTS ON THE STATE OF SCIENCE.—1920.

12. National Defence.

‘he experience of the Great Wav.

No nation safe against unscrupulous aggression unless it is able to defend
itself.

So great is the debt of every citizen to the State that every citizen may be
justly called on in time of need to defend the State.

‘he object of statesmen to be that all citizens should defend the State not
compulsorily but voluntarily.

Loyalty of Colonies in War.

Sea-power not in the future as in the past the determining factor of national
life. Submarine vessels and torpedoes.

Great Britain no longer an Island. All its past history infiuenced by its
isolation.

Recent and rapid development of aviation. Command of the air even more
important than command of the sea.

No nation secure so long as the nations of the world watch each other with
jealous, unscrupulous eyes.

The League of Nations. Attempt to introduce into public affairs the moral
standard of private life and to bring the general sentiment of humanity
into play against any one aggressive Power.

Information respecting the armed forces of the Crown.

No Monarch or Government to make war without the consent of the people.

Balance of power to yield place to the law of right, as defined by the majority
(presupposing general broad-mindedness and reasoning power).

The process of general disarmament. The nation to be strong, but solely for
defensive purposes.

Problems of national defence to be regularly considered by a committee on
Public Safety.

13. The British Empire.

The history of the Empire, its creation, the work of the Elizabethan mariners,
their names and exploits.
Stages in growth of the Empire.

(a) Foundation—American colonies in Stuart period. East India Company,
1600.

(6) The great quarrel—Loss of American colonies in eighteenth century ;
acquisition of Canada, India, and Australia; end of eighteenth century—
acquisition of South Africa.

(c) Modification in relation of colonies to home country; at first valued
mainly as contributing to welfare of home country, and governed from
home; gradual grant of self-government (Durham report, 1840, &c.);
federation of colonies (Canada, 1867, &c.).

(d) Twentieth-century development in organic connection between colonies
and home country, or, in a simpler way,

(1) That of Elizabeth.

(2) That of Cromwell.

(3) That of George the Third (really Chatham’s).

(4) That of Victoria.

The Crown in relation to the Empire.

History of the Indian Empire.

Present extent of the Empire. Its varieties of peoples and national resources.

Value of travelling over the Empire.

Children in the schools to learn the dignity of the Empire by the study of ©
the Union Jack, by the observance of Empire Day, and by the biographies
of the men who founded and extended the Empire. z

The British Empire is the greatest human institution under Heaven, the greatest
secular organisation for good. 5

Principles of the Empire which must never be forgotten or abandoned : ~
(a) Justice, respect of native races for British judicial integrity. (6b) Good i
faith, honesty in trade; Honesty the best policy, but honesty not to be =
practised because it is the best policy. The word of an Englishman. :

ON TRAINING IN CITIZENSHIP. 993

4 (c) Freedom of speech, of public meeting, of political sentiment, of
religious worship. (d) Progress.

Government of subject peoples to be always directed to their advancement and
improvement—instances of failure, New Zealand in the thirties and South
Africa subsequently.

14. National Unity.

Citizens in time of peace apt to make too much of divisions and dissensions.
Consciousness of unity inspired by the crisis of the Great War.

Great Britain, and England itself, a witness to the possibility of fusing different
elements, Anglo-Saxon and Norman characteristics. ‘ We are a people
et.’

How and why Scotland accepted union with England and made the most of it.
Why Anglo-Ivish Parliamentary Union has not been successful.

National unity involves the subordination of the party spirit to the good of
the whole.

All in danger of prosecuting sectional and not national ends.

Foreign affairs. Taken, by mutual consent among parties, out of the range of
party warfare.

The Crown as the centre of national unity. Benefit of a supreme authority
which is independent of the vicissitudes of political fortune.

Lessons of the War not to be lost in peace.

The ideal of national unity to be taught in schools and advocated from pulpits.

No hindrance to unity greater than social or political privilege which cannot
be overcome; caste a bar to all progress.

Glory of Great Britain that the humblest citizen may rise to the highest places.

Presidents of the United States, e.g. Lincoln.

National unity to be regarded as a means of upholding right.

15. Patriotism.

The sentiment natural to civilised humanity.

Pride in nationality and national life. Each citizen a member of the Nation

and Empire.

Spirit of service, sacrifice and sympathy—traditions of achievements in appli-
cation of ideals—atmosphere.

Children to learn at school patriotic poetry, e.g. Shakespeare and Scott. Value
of learning poetry by heart as inspiring noble ideas.

Patriotism either false or true. Chauvinism and Jingoism, forms of false
patriotism.

_ German patriotism before the War both aggressive and immoral, as taking no
account of the rights or claims of other nations than Germany. Evil
tradition of military power descending from Frederick the Great in
Germany. Influence of modern historians, e.g. Treitschke.

Issue of the War.

_ The collapse of false patrictism.

True patriotism recognises an ascending scale of duties from family to city,
from city to country, from country to humanity; as the interest of
family at times must give way to that of city or country, so must the
interest of city or country give way to that of humanity.

No patriotism justifiable unless it is such as can be inculcated in all countries
without injury to any one country. ‘True patriotism independent of
politics.

Patriotism and Imperialism—not the same, but often confused. Patriotism,
however, not complete without including something of the Imperial
spirit.

The League of Nations the supreme instrument for moralising international life.

ee a be all instructed in the obligation of service to the State. Example
of Japan.

The Public School spirit which has so signally vindicated itself in the War
to be encouraged in all secondary and elementary schools.

294 REPORTS ON THE STATE OF SCIENCE.—1920.

16. Industry and Commerce.

Industry the life-blood of a nation, Upon it depend the interest and influence
of national life—its value in development of character. But neither
industry nor commerce free from danger.

The plea ‘Business is business,’ like the plea ‘ War is war,’ may be used to
justify evil means and evil ends.

No nation secure without trade, yet trade by itself may lower the national
standard of duty. Free Trade expresses the natural relation between
countries, each country supplying what other countries need and getting
in return from them what it needs itself.

The world would be happiest if all the world were pacific and all Free Trading.
Speeches of Cobden and Bright. But so long as there is danger of one
nation attacking another, Free Trade qualified by the necessity of a
country being, or so far as possible being made to be, self-supporting.

Thus the decay of agriculture might imperil the national safety, as the War
has shown. It may be worth while to support agriculture even if the
support somewhat raises the price of bread.

Value of coal-fields.

Change in the character of great industries.

Personal relations between employers and employed greatly impaired.

Origin of ‘ combines.’

Necessity for restoring a friendly feeling and confidence among all persons
engaged in the same industry.

Co-partnership and profit-sharing.

Arguments for and against the Nationalisation of main industries.

Nationalisation not a question of right or wrong, but of expediency; will it
tend to the efficiency of the industries nationalised? To be considered
from point of view of national, not sectional, interests.

True conception of wealth. Adam Smith.

Exports and imports. Invisible exports.

Increased production the remedy for high prices.

Creation of new industries, application of science—electric, gas, dye industries.
Without progressive science, labour and capital cannot play their part
in modern life.

Discouragement of fraud in all relations of life and business.

Importance to nation of effective, honest, and intelligent working of all forms
of business or industry.

Disasters resulting from mismanagement or fraud.

The credit attaching to British honesty and thoroughness the chief asset in
the British trade.

Industrial and social reconstruction.

Development of various resources.

Co-operation and co-operative societies.

Crafts and Industrial Unionism. Arbitration. Wage Boards. Factors deter-
mining rates of wages. The living wage. The duty of every member
of a Union to abide by its agreements.

Industrial Councils. Employers’ Liability, Workmen’s Compensation, Factory
Acts. Welfare work. Strikes. Direct action.

Guild Socialism. Syndicalism.

Duty of community to sympathise with every effort of the workers to improve
their conditions and develop their intelligence.

17. International Relations.

Nations have historically regarded each other as enemies, but they are really
friends. Their interests are reciprocal, if not identical.

Different origins of wars between nations, racial, territorial, religious, com-
mercial, but all proceeding from the same spirit.

The comity of nations an ideal newly acquired or newly realised.

The word ‘international’ not found earlier than in Bentham’s writings.

‘International law ’ a misleading phrase, as it implies a sanction which does not
exist.

ON TRAINING IN CITIZENSHIP. 995

History of the Alabama Case.

Mr. Gladstone’s attempt to substitute arbitration for war.

Geneva Convention. Hague Conferences. Behaviour of the Powers, especially
Germany.

Diplomacy. Sir H. Wotton’s definition of an Ambassador.

President Wilson’s plea for open diplomacy.

The Balance of Power a rude attempt to stave off war by equalising the forces
of combatant or rival nations.

The League of Nations an attempt to bring the moral senses of civilised humanity
to bear upon one offending nation.

Appeal of Chili and Argentina to Queen Victoria for arbitration.

Statue in memory of the arbitration.

Owing to facility of intercommunication the world becoming one family.

18. The Press.

History of the Press. Its importance in the present day.

Nations no longer hearing but reading nations; hence the decay of the pulpit,
and even the platform, in point of influence, but increase in the power
of the Press.

The Press most powerful in a society in which men and women have learnt
to read but not to set a just value upon the news which they read.
Newspapers play the most distinctive réle in the enlargement of human nature—
a potent weapon in the creating of public opinion, replacing chatter and

gossip of earlier periods.

Advertisements as a means of success.

False credit given to vendors of patent medicines or tipsters in respect of
horse-racing.

Remedy lies in better education.

Responsibility of the Press. Possible misuses of its influence. One danger
lies in the control of an individual over many newspapers.

Importance of the law against slander or libel. The question whether the
publication of false news should not be punishable.

Danger of sensationalism.

Incorruptibility an honourable feature of the Press in Great Britain.

Contrast subsidised newspapers in foreign countries, most of all in Germany.

Purity and decency another honourable feature.

Freedom of the Press essential to constitutional liberty. Prynne and Cobbett

Help given by the Press in the detection of crime.

Check to be imposed on reports of divorce and murder cases, as of certain other
cases.

- Training for a journalistic career.

19. Housing.

The homes of the people the sources and centres of virtue.

Difficulty of the housing problem. Value of space in slums of great cities.
Statistics relating to occupants of single rooms. Morality almost impos-
sible where persons of all ages and both sexes are herded together.

Cellar dwellings nearly extinct. Need of houses never greater than to-day.

The question of housing both physical and moral.

Importance of light, space, and sanitation.

Municipal authorities now invested with requisite powers. Duty of voters to
see that these powers are exercised.

Sanitary inspection essential. Owners of insanitary property not to escape
responsibility.

Rivalry of the home and the public-house.

The best counter-attraction to the public-house lies in good private houses.

Infantile mortality the result of drinking and of bad housing.

Good lighting efficient as a means of lessening crime.

Advantage of Garden Cities constructed on scientific principles, e.g. Bourn.
ville, Port Sunlight.

296 REPORTS ON THE STATE OF SCIENCE.—1920.

Love of home one of the most potent forces in human nature, but impossible
unless there are comfortable homes.

Need of provision, especially in those parts of Great Britain which are rapidly
becoming vast cities.

Difficulty of constructing houses for which it is possible to charge a remunera-
tive rent.

The whole strength of a municipality to be employed under Parliamentary
sanction in improving the houses of the poor.

20. Temperance.

Drink the greatest national evil. The source of three-fourths of the crime and
misery in the nation. Physiological effect of alcohol.

Amount of the national bill for drink even during the War.

Waste of foodstuffs.

No private interest to be allowed to stand in the way of reform.

The nation cannot afford to be a drunken nation.

Question of the drink trade not local but national. Local option to be the out-
come of national control.

Local trade and politics. Tied houses. Relation of brewers to publicans.
Clubs to be treated like public-houses and beer-houses.

Effect of prohibition of vodka in Russia.

Prohibition in U.S.A. Not so much a social as an industrial measure. A
guarantee for industrial efficiency. Estimated to increase efficiency by
10 per cent.

Two influences making for temperance: (1) Women’s votes, (2) Education in
elementary schools.

Work of the Central Liquor Control Board during the War.

Similar, if not the same, control necessary in peace.

Nationalisation or State purchase of the liquor trade.

Argument for nationalisation. So jong as private interest in the sale of
liquor exists, the State is exposed to inevitable danger. Take away
motive of self-interest and improvement will become possible.

The late Earl Grey’s project of disinterested management.

Owners of public-houses to be made responsible for’drunkenness occurring in
them.

Duty of State to remove temptation as far as possible from citizens.

Gain of excluding children from public-houses.

In the present rivalries of the nations, Great Britain must become sober, or it
will lose its pride of place.

Temperance societies and their campaign for national sobriety.

21. Leisure and Recreation.

Daily life and its division into working, leisure, and sleeping periods.

Necessity for useful and strenuous work as opposed to slothfulness, idleness,
and luxury.

Pres of idleness and luxury. Gossiping. Street-corner and public-house
idlers.

The danger of morbid introspection.

The influence of habit upon development.

Many persons ruined through inability to employ non-working periods proper!y.

Importance of proper amount and kind of recreation.

Change from, and foil to, work.

Suitable recreation for manual workers, sedentary workers, and brain-workers.

Demand for more leisure-time from physical work.

Leisure-time not to be wasted in idleness but to be profitably occupied in neces-
sary rest, home duties, civic duties, amusements, and self-development.

Due proportion of leisure-time to be given to self-improvement or self-develop-
ment.

Self-development—hobbies—literature—music—art, &c.

Adequate provision of facilities—libraries, &c.

xz
ad

a ete

ON TRAINING IN CITIZENSHIP. 297 |

Amusements of the people: (1) Old-time : Morality plays, mummers, strolling
players, revels, fairs, morris dancers, May Day. (2) Present time: Pro-
cessions, sports, regattas, racing, picture palaces, theatres and music-halls,
athletics, &c.

The habit of looking at, as opposed to taking part in, sports.

Provision of open spaces in towns.

Enjoyment of open air and interest in natural history.

Games and their value in the development of esprit de corps, co-operation,
responsibility, perseverance, emulation, fair play, leadership, discipline.

Team-games for children. Importance of organisation and supervision of
games at school.

The evil of gambling—its effects upon sports.

Provision of play-grounds and playing-fields.

Boy Scouts. Girl Guides.

The proper use of holidays.

Summer camps and schools.

Co-operative holidays and tours.

Juvenile organisations, Committees. School clubs.

REPORTS ON THE STATE OF SCIENCE.—1920.

298

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299

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300 REPORTS ON THE STATE OF SCIENCE.—1920.

APPENDIX III.—SELECTED EXAMPLES OF COURSES ON
CITIZENSHIP.

A.—Devon County Education Committee.

Suggestions as to Moral Instruction and Training in Citizenship.
Infants (under 7 years).

1. Cleanliness. _ 4, Fairness. — ;
(a) Clean hands, faces, and | (a) Mine and thine.
clothes. | (5) Fairness towards others.
(b) Clean habits—e.g. the pro- | 5, Kindness.
per use of the lavatory. | (a) Love to parents.
) (6) Kindness to each other in
the home, school, and street.

2. Tidiness. |

(2) In the home, school, and | (c) Kindness to animals.
street. ; | 6. Truthfulness.
(6) Personal tidiness. | (a) Telling the truth.
(c) Care of furniture, books, | (b) Confidence in parents and
toys, and other property. teachers to be encouraged.
(c) ‘Dramatic’ untruths to be
3. Manners. discouraged.
(a) Greetings at home and at | 7. Courage.
school. (a) When alone.
(6) Behaviour at meals. (b) Darkness, shadows, and
(c) Punctuality and promptness. | strange noises.

Lower Standards (7 to 11 years).

1. Cleanliness. | (b) In. bearing: orderliness in
(i) (2) Use and care of parts of | the streets, behaviour in
the body—e.g. hair, eyes, | public places.
ears, nose, lips, teeth, hands, (c) How to perform a simple
and feet. service—e.g. how to carry
b) Care of clothing. a message.

BG oe ag ee (iii) (a) Unselfishness.
i) In the school, playground, (6) Respectfulness towards the
and street—e.g. to desist aged. ;
from scattering paper and (c) Cheerfulness : evil of
orange peel. grumbling and fault-find-
= F : ing.
(c) mee in person and in (d) Modesty.

(ii)

—_~~

(e) Self-respect.
4. Obedience.
(2) Immediate and hearty obe-
dience to parents and

2. Order.
(a) The valae of system—e.g.
a place for everything and

everything in its place. teachers.
(b) The value of punctuality. (6) Respect for rules and regu-
(c) The value of promptness. lations.
5. Kindness.
3. Manners. (2) To companions at play.
(i) (2) In eating and drinking : (6) To pet animals.
modpentian. (c) ze flies, worms, and other
b) In question and answer: armless creatures.
(2) politencee, (d) To birds: their nests.
(c) In bearing: quietness, un- | 6. Gratitude.
obtrusiveness, patience in To parents and teachers.
memine, 7. Yairness.

d) Punctuali i : E _
(d) a3 ere hee the home Ungrudging disposition, espe-
r! cially when favours are dis-
(ii) (2) In speech: courtesy and tributed, or when the suc-
clearness; refinement of cess of others is under
language. notice.

OO en

Pw ee

ON TRAINING IN CITIZENSHIP. 301

Lower Standards (7 to 11 years).—(Cont.)

8. Honesty.

(a) Respect for the property of
others.

(b) Restoration of lost property.

(d) In work.

9, Truthfulness.

(i) (a) In speech: the importance
of exactness; the avoidance
of exaggeration.

(b) In manner: the importance
of simplicity; the avoidance
of affectation.

. (c) Promises.

(ii) (2) In reporting: correctness ;

avoidance of slander and

gossip.

(b) In action: candour; not to
act a lie.

(d) Not to shirk a difficulty by

a pretence of understanding.
(iii) (a) All the truth and nothing
but the truth.

(b) Avoidance of prevarication
and withholding part of the
truth.

(d) The importance of frank-
ness.

10. Honour.
(a) In the eyes of others : trust-
worthiness.
(b) In the eyes of self: self-
respect.
(c) Avoidance of false pride.

11. Courage.

(i) (a) Cheerful endurance of little
pains and discomforts ; man-
liness and womanliness.

On behalf of the weak or
innocent.

(ii) (a) To follow good example and
to resist bad example.

(b) To confess faults or acci-
dents.

(d) In bad weather—e.g. not
to fear thunder and light-
ning.

difficulties: self-

(iii) (a) The importance of courage,
avoidance of bravado.
(b) Presence of mind, avoidance
of panic.

12. Temperance.
See Syllabus issued by the Board
of Education.

13. Self-Control.

(a) In bearing : the avoidance of
wilfulness, peevishness, ob-
stinacy, sulkiness, violent
temper, and quarrelling.

(v) In speech: the avoidance of
rudeness and hastiness.

14. Work.
(i) (a) Helping in the home.
(b) The value of industry in the
school.
(ii) (a) Pride in thorough work.
(6) Use of leisure time; value of
hobbies.

15. Perseverance.
(a) In work: hard or distasteful
tasks.
(0) In play, fighting out a losing
game.
(c) In self-improvement.

16. Humanity.

(i) (2) Personal help to those in
need.

(6) Making other people happy.

(ii) As shown by public institutions—

e.g. the fire brigade, life-

boat, lighthouses, hospitals,

asylums, Red Cross Society.

17. Justice.
(i) (a2) To companions, in the school,
playground, and home.

(5) To the less fortunate—e.g.
the weak, imbeciles, stam-
merers, deformed.

(ii) (2) To others—e.g. not to
spread infection.

(6) Avoidance of cruelty to
animals in pursuit of amuse-
ment or sport.

(iii) (a) In thought, word, and act.

(b) Forbearance.

remembering

302

REPORTS ON THE STATE OF SCIENCE.—1920.

Upper Standards (11 to 14 years).

1. Habits.
(a) How acquired.
6) How cultivated and avoided.
c) Harmfulness of juvenile
smoking.
2. Manners.
(i) (a) Courtes
ye) wards a.
(6) Self-restraint.
(ii) (a) As shown by dress.
(o) By choice of friends, litera-
ture, and amusements.
(c) By kindness to younger chil-
dren.
(d) In boys: by special courtesy
to all women and girls.

3. Truthfulness.
(i) (4) Respect for differences of
opinion.
(6) Living for truth: readiness
to receive new truths.
(c) What men have sacrificed for

and respect to-

truth.
(ii) (2) Conquest of science over
ignorance and superstition.
(6) Progress of truth.
(c) Love of truth.

4. Temperance.

See Syllabus issued by the Board

of Education.
5. Courage.

(a) Heroic deeds done in the ser-
vice of man : self-sacrifice.

(6) Everyday heroism.

(d) Moral courage.

6. Justice.

(i) (a) To all human beings, irre-
spective of sex, age, creed,
social position, nationality or
race; and to animals, tame
and wild.

(6) Charitableness in thought.

(ii) (a) Love of justice.

(0) Just and unjust relations be-
tween employers and em-
ployed.

(ili) (a) The development of the idea
of justice from the earliest
times.

(5) The development of the
humane spirit in laws.

7. Zeal.
(a) The value of zeal and energy
in overcoming difficulties.
(6) The dangers of misdirected
zeal—e.g. bigotry, fanati-
cism.

8. Work.
(a) The necessity for and dig-
nity of labour. ea
(6) The earning of a living:
different pursuits—their re-
sponsibilities and _ social
value.

9. Patriotism.

(i) (a) Pride in one’s school and
loyalty to it.

(6) Duty of local patriotism :
how to serve one’s town or
village. :

(ii) (2) What our forefathers have
earned for us—e.g. liberty,
social and political institu-
tions.

(b) How each may serve his
country and posterity.

(iii) (2) The vote: its nature and
responsibilities.

(6) Local government.

(d) Society as an organism : its
development through the
family, tribe, and nation.

(e) Universal brotherhood.

10. Peace and War.
(i) (a) The value of peace and her
victories.
(6) The duty of citizens in time
of war.
(c) The evils of war.
(ii) (a) International relations : how
nations can help each other.
(6) Value of arbitration.

11. Thrift.

(i) (2) Money : its uses and abuses.
(6) Economy in little things.
(c) Wise spending : avoidance of
extravagance and wasteful-
ness.
(ii) (2) How and why to save:
; Savings Banks.
(5) The cost of drink to the
nation.
(ii () shoe and insurance.
iii) (a) Simplicity of living.
(6) The evils of debt. :

ON TRAINING IN CITIZENSHIP.

803

Upper Standards (11 to 14 years).—(Cont.)

12. Co-operation,

(a) Between citizens.

(6) Between nations: in com-
merce, art, and thought.

13. Ownership.
(i) Talents and opportunities :
responsibility for their use.
(ii) (a) Individual and _ collective
ownership.
(6) Responsibilities of owner-

ship.
(c) Care of borrowed books,
tools, &e.
14. Self-knowledge.

(a) The need to know ourselves
and to test our moral pro-
gress.

(6) The claims of conscience, in-
dividual and social.

15. The Will.

(a) The training of the will.

(0) The right to be done in-
telligently, unhesitatingly,
thoroughly, cheerfully, and
zealously.

16. Self-Respect.
(a) Self-respect and self-restraint
in thought, word, and act.
(4) Avoidance of impure litera-
ture.

17. Ideals.

The value and beauty of an ideal
for life.

B.—Outlines of a Scheme of History (Six Months’ Course) at Ellerslie Road,
Hammersmith, London.

Past and present.

St. II. A. Stories of primitive men.
na B. Fifteen notable warriors in the world’s history.
St. III. A. Fifteen famous women in history.
ss B. Fifteen pioneers in English history.
St. IV. A. The making and welding of the British Race.
Bs B. England under Absolute Monarchs.
St. V. A. King v. Parliament.
+ B. Reaction—Kings again—Limited Monarchy.
St. VI. A. Industrial revolution and growth of democracy.
Ns B. Growth of British Empire.
St. VII. A. How England is governed.

appended.)
a . History of other countries.
Necessity for Government.

ie0]

(The syllabus for this course is

Forms of Government.

Absolute Monarchy, Republic, Limited Monarchy.

Hammersmith Borough Council.
Mayor, Alderman, Councillors’ Duties.
L.C.C. Chairman, Committees’ Duties.
Parliament : House of Commons.
Cabinet. Passing of Bills.
The King and Lords : Their Functions.

How elected. Parties.

Lords v. Commons.

Colonies and Great Britain—An Imperial Parliament.

The Exchequer.
Free Trade and tariffs.
Policeman. Soldier. Sailor.

Model election.

Direct and indirect taxation,

Civil Service.
Crime and its Punishment (model trial).

304 REPORTS ON THE STATE OF SCIENCE.—1920.

C.—lrom Blackley, Manchester.

Plans adopted to make men and good citizens.

1. Institution of Arbor Day in 1907.

2. Colonial and American Correspondence.

3. A system of class government throughout the school based upon the

Patrol system and Scouting.

4. Exchange of flags between the school and a school in Adelaide, South
Australia, and also with the Rhode Island Normal Schovl, Providence,
U.S.A.

. The provision of a sledge and forty pairs of clog-soles to the Trans-
Antarctic Expedition (Sir E. Shackleton).

6. Special lessons and ceremonies on Empire Day, St. George’s Day,
Nelson Day, Armistice Day, and other special occasions.

7. Telegrams to H.M, The King on each Empire Day, to Admiral Beatty,
Sir Douglas Haig during the War, to M. Deschanel on the occasion
of the first celebration of Empire Day in Paris.

8. Establishment of a link between the school and a unit of the Fleet—
a cruiser upon which an old boy was serving. The children pre-
sented a mirror and other accessories, and wrote Christmas letters
to the men. They responded by presenting a Union Jack and a White
Ensign (15 ft. by 74 ft.) to the school. Interesting ceremony.

9. The publication of The Torch containing a record of the activities
of the school and honourable service.

10. Christmas letter from the Headmaster to each child.

11. School Gardens, Flower and Bulb Shows, Exhibitions of Work.

12. Old Scholars’ Association. Reunion of Old Boys. Reunion of Old
Scholars (boys and girls) under the age of nineteen.

13. Blackley War Memorial. Special eight weeks’ effort to raise 101. by
personal gifts and work. Total sum realised, 12/. 12s.

14. Old Boys’ War Memorial. Combined effort—Old Boys and present
scholars to raise 2001. for a School Memorial.

15. The planting of a tree in the school grounds by a George and a Mary,
which, by permission of The King, was called ‘A Coronation Tree.’
His Majesty accepted a photograph of the ceremony, and ‘sent his
thanks to the children.

16. Evening Classes for Boy Scouts (each winter since 1911).

17. A troop of Boy Scouts in connection with the Day School,

D.—Caerau Mixed School, Caerau, Bridgend.

Scheme for Training of Citizenship.

1. Our School.—How we are governed; Education Committee and Local
Managers ; Attendance Officer and his duties; Why we attend school.

2. Our Town.—How our town is governed; The Urban District Council; Wards;
Elections; Duties of Urban District Council.

3. The County Council.—Its work—roads, bridges, &c.; Education, &c.

4. Our Country.—(az) How governed ; Parliament—its Houses and its origin,
(6) How order is kept—Police, Law Courts, Justice.
(c) Our duties as Electors—Seriousness of elections ; Why thought is neces-

sary rather than mere following of leader.

(d) Our duties as Burghers—in the street, the park, and on enclosed
(

property.
e) Our duties as Citizens of the Empire—‘ What we are in the days to
come, that will Britain be’; Our future work, &c.
Temperance Instruction and Thrift (War Savings Association at School), as

per C.C. scheme.

ee ee ee ee

SS BRS i

,
. 4
+
:

ON TRAINING IN CITIZENSHIP. 305

Civic Practice (Self-Government).
Class Committees.
1, General Committee.—Look after general welfare of school; appoint Sub-

Committees, monitors for corridors, cloak-rooms, &c.

2. Sub-Committees.—(a) Sports Committee,

(6) Debating Committee.—To arrange Debates. Typical subjects—Party
Government—Advantages and Disadvantages; Use and abuse of letter-
writing to papers; Is the working-man better off to-day than fifty
years ago? Up to what age should children attend schvol? &c.

3. Scholars’ Committee (each class).—Three girls and four boys elected by
class. Each responsible for class-room generally. Laziness, bad work,

&c., reported to Committee, who report their decision to Class Teacher.

Committee also appoint Class-room Monitors.

E.—foath Park Boys’ School, Cardiff.
Citizenship.
The scheme for History [St. V.-VII.] is framed with the definite object of
rousing interest in—
(a) The growth of liberty.
(6) England’s position among the nations.
(c) Value of sea-power.
(d) Growth of the Empire.
(e) Citizenship.
Part (e) includes :
(i) The Rights of a Citizen.
(ii) The Duties of a Citizen.
(iii) How an Act of Parliament is made.
(i) Rights of a Citizen.

1. The right to vote. Representative Government.

2. The right to protection.

3. The right to justice. The Courts of Justice and the administration
of justice.

(ii) Duties of a Citizen,

1. Municipal government. How a city like Cardiff governs itself.

2. Obedience to laws.

3. Service to the community. The best service to the community is
to be honest and industrious in the sphere in which we are
placed.

4. The protection of public property.

5. Ignorance a bar to progress and good citizenship. Every person
should take an intelligent interest in the affairs of city and
State.

IRELAND.
F.—first Derry Boys’ School.
1. Society—what ‘ society’ implies.
(a) Necessity of ‘Social System’ of living.
(6) Duties arising from ‘Social System’ of living.
These classified as A, B C, &c., as follows:

2. A. Liberty.
B. The Consequent Renunciation.
C. Duties must be discharged, rather than rights sought for.
D. Obedience to Law: loyalty to King and Constitution, issuing in.
KE. Development of a ‘ Spirit of Law.’
F. Personal duty in regard to thought, speech, act.
G. Limits to exercise of these.
H. Public duty of each in regard to these.
I. Spirit of carefulness, neatness, and cleanliness in person and ‘in environ-
ment.
J. Personal and Public; hence strive to abolish ugliness.
K. Reaction on character—public and privaté—if we observe these rules, &c.,
1920

806 REPORTS ON THE STATE OF SCIENCE.—1920.

SCOTLAND.

G.—Stobswell School.
A. A series of lessons on (1) the Rights and Privileges, (2) the Responsibilities
and Obligations, and (3) the Organisation, Finance, and Management of
(a) The Home,
(6) The School,
(c) The Municipality,
(d) The State, and
(e) The Empire.

B. Incidental instruction in Local and Central Government arising out of
History Course and passing events, including miniature elections con-
curring with Municipal and Parliamentary Elections.

C. Training in habits of punctuality, regularity, cleanliness, orderliness, thrift,
self-respect, consideration for others, mutual responsibility, and regular
assembly and dismission devotions.

D. Placing the discipline of the School as far as possible on the honour of the
pupils and their supervision outwith teaching periods in charge of Monitors,
nominated and elected by the pupils themselves at the beginning of each
session.

APPENDIX IV.—SCHEMES OF SCHOOL MANAGEMENT.
Skerton Council School, Lancaster—RBoys’ Side.
‘Order is Heaven’s First Law.’

Our Constitution.
First comes H.M. The King and his Government.
Next comes the Board of Education.
Next comes the L.E.A.
Next come the School Managers.
And... next... we! Now, who are we?
We are:

(1) The Headmaster and the Staff of Teachers.

(2) The School Prefects: viz. Captain, Sub-Captain, Secretary, Sergeant-
Major, Football Captain, Football Sub-Captain, Cloak-room Curators. Sani-
tary Inspectors (Outdoors), Assembly Sergeants, Corporals, Lance-Corporals,
Bugler(-Sergeant), Drummer(-Sergeant).

(3) The Senior School (Standard V. upwards) who are on the Roll of
Voters, and these only are eligible for Prefectship (Nota Bene: Only mem-
Pee of the Top Class zre eligible for Captaincy and Sub-Captaincy): Full

itizens.

(4) Disfranchised Members of the Senior School: Not Full Citizens.

(5) The Junior School—none of whose members are entitled to vote in
School Elections.

The Prefects.
Appointed by Election :

Captain, Sub-Captain, Secretary; each of whom retires at the end of the
last school day of each month (except December and August), but is eligible
for re-election.

Appointed, immediately after his election, by the Captain :

Sanitary Inspectors (outdoors), Cloak-room Curators.

Selected by Class Teachers from a list of Qualified Instructors in Drill:

Sergeant-Major, Sergeants and Corporals.

Appointed by Captain :

Corporal and Lance-Corporal- for tardy scholars; two supernumerary Lance-
Corporals. :

Appointed by the Master: in charge Football Team :

Football Captain, Football Sub-Captain,
Qualifications for admission to full Citizenship :

(1) To be in Standard V. or upwards.

(2) To have undertaken, and signed, the Citizens’ obligation, vide Girls’
Constitution.

ON TRAINING IN CITIZENSHIP. 307

Disfranchisement : Persistent idleness or misbehaviour, or a serious act of
insubordination or meanness, renders a boy liable to disfranchisement by his
class teacher until after the monthly election next ensuing.

The Prefects—their Privileges, &c. :

(1) They are, whilst holding office and wearing the badge of their rank,
immune from any corporal punishment, detention, or public reprimand ;

(2) They may be either suspended, degraded, or dismissed from office by
their class master or the Headmaster, if, by neglect of duty or other serious ~
misconduct, they have merited such punishment; in such cases, the badge of
rank will not be worn and the privileges of prefectship will be withdrawn
for the time being;

(3) No Prefect may assume the badge of rank and benefit by the privileges
of prefectship until he has

(a) been constitutionally appointed ;

(6) publicly undertaken and signed an obligation to bear in mind the

Prefects’ motto, Noblesse oblige.

This Constitution, so far as it concerns the Prefects and the Citizens, may
be modified—or withdrawn entirely—by the Headmaster, at any time he thinks
such modification or withdrawal necessary.

Skerton Council School, Lancaster—Guirls’ Side.
‘Order is Heaven’s First Law.’

First comes H.M. The King and his Government.
Next comes the Board of Education,

Next comes the L.E.A.

Next come the School Managers.

And... next ...we! Now, who are we?

We are:

(1) The Headmaster and the Staff of Teachers.

(2) The School Prefects: viz. Captain, Sub-Captain, Secretary, Games Cap-
tain and Sub-Captain, Superintendent of Playground Mothers, Sanitary. Inspec-
tors (Outdoors and Indoors), Sergeants, Corporals, and Lance-Corporals, Cloak-
room Curators.

(3) The Senior School (Standard V. upwards) who are on the Roll of Voters,
and these only are eligible for prefectship.

(4) Disfranchised members of the Senior School.

(5) The Junior School—none of whose members are entitled to vote in
school elections.

The Prefects.
Appointed by Election :

Captain, Sub-Captain, Secretary; each of whom retires at the end of the
last school day of each month except December and August, but is eligible
for re-election.

Appointed, immediately after her election, by the Captain :

Sanitary Inspectors (outdoors), Sanitary Inspectors (indoors), Cloak-room
Curators.

Selected by Class Teachers from a List of Candidates duly qualified (by
examination) as N.C.O.s:

Sergeants, Corporals.

Appointed by Captain :
Corporal and Lance-Corporals for tardy scholars; two supernumerary Lance-
Corporals.
Appointed by Playground Mothers each month end :
Superintendent of Playground Mothers.
Appointed by Headmaster each month:
_ Games Captain and Sub-Captain, two Lance-Corporals as time-keepers.
Qualifications necessary for inclusion on Roll of Voters :
1. To be in Standard V. or upwards;
2. To have undertaken, and signed, the Citizens’ Obligation; viz.
(a2) To be courteous and considerate to all;
(6) To speak and vote without meanness, spite, fear, or favour g
(c) To try to be a good citizen. x 2

808 REPORTS ON THE STATE OF SCIENCE.—1920.

Disfranchisement : Persistent idleness or misbehaviour, or a serious act of in-
subordination, renders a girl liable to disfranchisement by her Class
Teacher until the Monthly Election next ensuing.

Prefects: "

1. They are, whilst holding office and wearing the badge of their rank,

immune from any corporal punishment, detention, or public reprimand ; r

2, They may be either suspended, degraded, or dismissed from office, if

- the Headmaster considers that by neglect of duty or other serious misconduct

they have merited such punishment; in cases of suspension from office, the

badges of. rank will not be worn, and the girls suspended will no longer be
immune under the conditions stated above.

3. No Prefect may wear the badge of office or assume the privileges or
immunities of prefectship until she has

(1) been constitutionally appointed ;

(2) publicly undertaken to bear in mind the Prefects’ motto, Noblesse

oblige.

The conditions relating to the Senior School, the Junior School, the Prefects,
and the Roll of Voters may be modified by the Headmaster, or withdrawn’
entirely, if he considers such modification or withdrawal necessary.

Badges of Office: Boys’ Side.

Captain . : . : 5 : : . red plush: letter ‘C.’
Sub-Captain . ‘ ; 5 a : bs Aen a letter ‘s.’

Secretary F ; , : A 5 bs ,: letter ‘S.’
Sergeant-Major : 3 : : 5 . blue plush: letters ‘S.M.’
Cloak-room Curators : : : i . blue disc, yellow centre.

Sanitary Inspectors (outdoors) : : . blue disc, red centre.

Football Captain . A . : fy . black shield, yellow letters ‘ F.C.’
Football Sub-Captain . : is . black shield, yellow letters ‘F.C.’
Assembly Sergeants ; : . ° . red disc, blue centre.

Assembly Corporals ¢ : . : . yellow disc, black centre.
Assembly Lance-Corporals : < : . green disc, red centre.

‘Crack’ Sergeant and Corporal red ribbon.

Passed Qualifying’ Examination for Assembly
N.C.0.s . : : 5 - ; . green ribbon.

The Girls’ Secretary is responsible for collection of the badges and their
redistribution at the proper times, and must in particular see that the badges
of Prefects who are absent do not get lost. Prefects are not entitled to any
of the privileges or immunities attaching to prefectship unless they are wearing
their badge of rank.

Badges of Office: Girls’ Side.
Captain ; : 5 : : . . red plush: letter ‘ C.’

Sub-Captain F c : Fee ts ler 3 letter ‘s.’
Secretary . i 5 3 3 5 Most Bi letter ‘8.’
Superintendent of Playground Mothers . . plush, letters ‘S8.0.M.’ inmonogram.
Note.—Playground Mothers are not Prefects, but are entitled to wear a blue
badge.
Cloak-room Curators . . 5 . blue disc, yellow centre.
Sanitary Inspectors :
Outdoors = P E A . blue disc, red centre.
Indoors . > . : 3 if . blue disc, pale-blue centre.
Games Captain . . : t : . green rosette, red centre and edging.
Games Sub-Captain . . Ha Hag . red rosette, green centre and edging.
Assembly Sergeants. c ‘ d . red disc, blue centre. |
Assembly Corporals F : i s . yellow disc, black centre.
Assembly Lance-Corporals . t ; . green disc, red centre.

‘Crack’ Sergeant and Corporal . 3 . ved ribbon.

ON TRAINING IN CITIZENSHIP. 809

Qualified by examination as N.C.O.s.—These are entitled to wear a
green ribbon.

The Secretary is responsible for collection of the badges and their redistribu-
tion at the proper times, and must in particular see that the badges of
Prefects who are absent do not get lost. Prefects are not entitled to any of
the privileges or immunities attached to prefectship unless they are wearing
their badges of rank.

CowLey ScuHoots, Sr. HELens.
Civic Government by Boys.

(Written by a Boy at School.)

There is at Cowley a system of self-government by the boys, whereby
every boy of average intellect is given a chance of commanding his smaller

school-fellows.
Description of System.

School of 300 divided into 8 houses, and forms as usual.

Each house has a captain, a vice-captain, and a house-master, in addition
to house-prefects.

Inter-house competitions take place between houses in Rugby, cricket, box-
ing, swimming, and work. To each of the champion houses there are cups
awarded.

The school itself has about eight prefects and eight sub-prefects, who have
a private room of their own. These are led by a head-prefect.

The games in the school are compulsory, and take place after 4.15 on
Monday, Tuesday, Thursday, and Friday, and also on Wednesday afternoon.

On Monday, Tuesday, Thursday, and Friday, for twenty minutes after
12 o’clock, the school does ‘drill,’ not physical (takes place under tutorship of
master) but military. It is an actual fact in this school that the ‘boys’ do
self-govern and masters are in the school only to teach in certain periods.
Why are the boys able to do this?’ For the following reasons :—

Spirit of Command is fostered.

(a) Captains of Forms are responsible for their forms, and as form
matches take place between forms the captain has ample scope of the
exercising of his authority.

(6) The games are run in sets. Every set has two or three captains,
and almost every boy in the school has a chance of captaining a side
in Rugby or some other game at some time or other.

(c) As a boy grows older, having had practice as a form or set captain,
he becomes, perhaps, if he shows energy, vice-captain and the captain
of a house. This means work and plenty of it. When a boy becomes
a house-captain he begins to understand the spirit of responsibility.

(d) Minor and then chief commanding position in drill.—This point
cannot be too greatly emphasised. It is a well-known fact that chaps
in this school hate military drill until they obtain a minor command.
This enlivens their interest, and the worst grouser after a year of
commanding realises the value of the drill—not for its military value,
but for the effect it has on one’s personality. A boy afraid to enter
a room containing a master may come out so much in a year by
commanding a squad in the drill that a whole squad of masters would
not and do not frighten him.

(e) After these preliminary steps to the top a boy becomes first a sub-
prefect and then a prefect, a captain of games (either Rugby or
cricket) or a chief commander in the drill.

In this way the spirit of command is fostered and a boy leaves Cowley fit to
tule a kingdom (as well as the Coalition do England). A prefect may give a
boy lines, he may, in special cases, whack a boy, but what backing does the
prefect get from the powers that be?

(a) The Head supports him.
(6) The masters tolerate him.
_ (¢) The governors don’t know what he is and will not admit his rights.

810 REPORTS ON THE STATE OF SCIENCE.—1920.

Still the Head’s power goes a long way, and it is very few foolish parents who
seriously object to the prefect system. (In one or two cases only each year is
a boy beyond the control of prefects.)

The pretect’s chief weapon at Cowley is public opinion :

This shows out most clearly in the houses.

A boy transgresses (fumbles a ball in a house match or some other terrible
thing). The house-captain appeals to the house. Is the boy worthy of a
whacking? The house decides—the boy is whacked. All the parent can say
against this system is that the house are bullies, but can forty boys be all
bullies? The house whackings are, therefore, in most cases fair, and become,
as has already been said, the prefect’s chief weapon.

Public opinion :

Some prefects are liked very much—others are tolerated. Some are disliked.

It is safe to say that most prefects are not disliked, and if a prefect is not
disliked then public opinion helps him.

Duties of a prefect :

With these weapons a Cowley prefect sallies forth. No master challenges
his right. Masters teach and disappear. The prefects go in lessons and then
appear for duty in keeping the school in order, in arranging games, &c. But
no master interferes. Not even a house-master has much power in his own
house. A Cowley prefect has no masters to rival his authority. He can give
lines and whack (Only me! T.B.) (when backed by public opinion or in
special cases). A boy, with the help of set captains, through the school,
manages the games. The prefects manage the drill (alone). Do not the prefects
then rule the school, and, as public opinion either supports or does not support
a prefect, then is not the school self-governed by the boys?

PrenaRgtH County ScHoot ror Griris, WALES.

(Written by a Girl at School.)

The aim of self-government in school is an attempt to train the child as a.
responsible citizen without taking away his delight in childish things. It is an
attempt to train him to be that type of child who will later on in life be a.
self-respecting, responsible citizen, and, as such, it includes the true purpose:
of education.

It is impossible for any man or woman to be capable of controlling even a
local committee if he has not been trained to think for himself and act as a.
responsible member of society. If children are not made to think for them-
selves, if teachers and parents insist on doing all the directing and thinking
for them, they cannot expect that the child, when he grows up, will be capable
of looking after himself and his fellow-men.

It is difficult in an ordinary county school to carry on self-government to a
great extent, because external examinations demand so much time, and there
is a certain amount of work to be got through in a limited time. And the space
and means at the disposal of the Head-mistress are so limited that it needs clever
organising to be able to stray from the beaten track, but there is a certain
amount of experimenting possible even in the busiest school.

Practically all that we have done originated in our English Composition
lessons, but to give a definite account of the gradual growth of self-government
in school is impossible.

In IV.¢ and IV.8 there is a Form Committee which is elected by the form
to manage all matters connected with the form.

The III., V.8, and V.4 have themselves arranged a programme of English
Composition lessons for this term, and every form has a chairman who is pre-
pared to take the class and direct affairs at any moment. The lessons are
varied and are all such as will increase the pupils’ knowledge of and command
over the English language and literature, and will give them confidence to act
on their own initiative. It is significant that the younger girls soon got over
their shyness of facing a class and being called upon to give an ‘Oral Com-
position,’ but that older girls, who when working for examinations had little

ON TRAINING IN CITIZENSHIP. 311

time to spare, afterwards when they tried took far longer to get used to the
idea, and their attempts were often feeble. ;

It gradually became felt that something ought to be done to bring the
scattered committees together, and with the guiding help of the staff the idea
of a Girls’ Representative Council was thought of.

It was decided that the Council should be formed consisting of the secre-
taries of the different committees and a form representative from every form,
except the two lowest forms.

The voting for Secretaries and Representatives was done by ballot by the
whole school, with the head girl, chosen by Miss Lloyd, as President.

The Council sat for the first time in September 1919 and meets on an average
once amonth. As the Girls’ Representatives they carry out as far as possible all
new ideas and desires of the girls which have received the Head-mistress’s sanc-
tion, They act entirely on their own responsibility and as a rule are successful.
The last Prize-giving was practically all the work of the girls.

One of the most important features is the General Knowledge Club. Any
girl from IV.c upwards may belong, and it is held weekly. At the beginning
papers were read by courageous individuals on varying subjects. Lately whole
forms have combined to give a form entertainment.

At the end of last term Miss Lloyd asked the Council if they felt prepared
to take the responsibility of looking after a blind girl in school. The whole
Council agreed that it would be good for the girls to look after somebody who
lacked something they all enjoyed, and they appointed a Committee to arrange
her lessons, &c.

The girls have been, if anything, too kind, but now they seem to be realising
that it will be kinder to show her how to get about school on her own, rather
than that they should take her. This training is excellent for the girls, for no
one can be a good citizen unless he is gentle and courteous to those older or
weaker than himself.

Roatu ParK Boys’ ScHoot.
Prefect System.

The Prefect system has been in use for seven years and has passed altogether
out of the experimental stage. It has proved its great value :—

1. In developing a sense of responsibility.

2. In training boys to lead and manage others.

3. In improving the tone of the school.
Duties of prefects :

1. The head-prefect has a general supervision over the work of the other
prefects.
2. The other prefects take entire charge of
(a) Bell-ringing.
(6) Letters for staff.
(c) The lavatories, towels, soap.
(d) Latrines (regularly inspected).
(e) The stairs during entrance and dismissal.
(f) Lost and found articles.
(g) Late comers (lateness nearly stamped out by the system).

3. On rainy days, during interval, the prefects take charge of classes.
Self-government :

Prefects, with help of teacher, elect to vacancies, and also elect their own
head-prefect.

Offences committed by boys are reported to head-prefect, who investigates,
and reports, if necessary, to teacher of offender. If case is serious, to Head-
master.

Inattention to duties on the part of, or offences committed by, prefects, are,
first of all, investigated by a ‘tribunal’ of prefects. If case is proved, the
offender is admonished by the head-prefect. Serious cases are reported to the
Head-master.

812 REPORTS ON THE STATE OF SCIENCE.—1920.

Scout-craft.

For two years, 1916-18, one hour per week of the school time-table was
devoted to scout-craft. Boys were trained and drafted into regular troops.
The advantages of working as a preparatory organisation for feeding other
troops instead of running a regular school troop are :—

1. Boys over 14 years of age could continue as members of the troops they
join, and so avoid the ‘break’ when leaving school.

2. Most of the better boys of the school leave for secondary schools, and could
continue scout-training only as members of regular troops.

3. A troop run as part of school-work would always be associated with ‘com-
pulsion.’

Objects of system :

1. To develop character, work, self-training.

2. To counteract ‘ cinemas,’ discourage idleness and thriftlessness.

3. To interest boys in Boy Scout and Boys’ Brigade organisations.

4. To draft boys into local troops.

Membership :

1. Any boy in Standard V. and upwards may be a candidate.

2. He is admitted after one month’s home-work as a ‘test.’

Method :

I. Weekly meeting of one hour for instruction, including :

1. Talks on lines of Scout yarns.

2. Preliminary tests for Tenderfoot badge.

3. Talks on troops in Cardiff.

4. Practical work, such as

(a) Knot-making ;

(b) Flag-sketching ;

(d) Map-reading ;

(e) Use of the compass.

5. In most cases the leader of each patrol was responsible for training the

boys in his section.
II. Patrols.
. There were six patrols—A, B, C, D, EK, F.
. Each patrol had its leader, second, third, &c.
. Leaders and seconds acted as school prefects.
. Each boy had a note-book (ordinary exercise book) in which he kept a
record of work done at home.
. The books were marked by the leaders.
. In addition to ordinary school-work the following were accepted as

-satisfactory ‘home’ work :

(a) Model-making ;

(b) Sketching ;

(ad) Choir-practice ;

(e) Music lessons ;

(f) Attendances at churches;

(g) Attendances at Scout or other organisations.

oO or ee

Tur Hicu ScHoon or Guascow.

Extract from Prospectus for 1914-15.
Prefects.

Prefects are divided into two classes—Form and School. 1

Each Form ‘has two prefects, one chosen by the master, the other by the —
Form, subject to the veto of the master. These should be boys who have most
distinguished themselves for public spirit. In consultation with the master
they are responsible for—

1. The efficient government of the Form in the master’s absence.
2 The general welfare of the Form.
They will be under the command of the school prefects for police duty.

Se 4 ae

ON TRAINING IN CITIZENSHIP. 813

School prefects are appointed by the Rector. They are divided as follows :
The Captain; the Lieutenant; four Buildings Sergeants; four Privates.

The captain of the school is ex officio head of the games. Disobedience to
a prefect’s order is an offence against school discipline. ‘ wh

The duty of a prefect is to see that the welfare of the school is maintained.

The purpose of this class is the gaining of an intelligent acquaintance with
the facts connected with our system of government, both local and imperial,
and with the rights and duties devolving on a citizen. It is intended primarily
for those just leaving school, and it forms a valuable introduction to the study
of economics and industrial history :—

Methods of election of various governing bodies; powers and duties of
Parish, County, and Town Councils; Local Government; Education, Poor Law,
Public Health, Licensing, and Harbour Authorities; judicial and financial
systems, local and national; election of a member of Parliament; the Party
system; the Cabinet and the Departments of the Executive Government;
Governments within the British Empire; relations with Foreign States.

APPENDIX V.

Suggestions for Organising Regional Study and Maintaining a Permanent
Regional Record in a Parish,

(By the Karl of Lytton.)
I. Objects to be aimed at.

1. To prepare and keep up to date a complete historical survey and history of
the area.

2. To establish a local Regional Museum illustrative of the survey.

3. To secure the maximum educational advantages from the work.

4. To enlist the services of the children in the work, thus helping to train their
observation, stimulate their interest in their surroundings, and develop
their faculties.

5. To make the school and its work a centre of interest to all who live in the
neighbourhood.

6. To secure co-operation between the teachers, the children, and the adult
population.

II. Steps should be taken to :

. Hold a meeting for the discussion of the subject.

. Form a Regional Association for the study of the parish.

. The school to be recognised as the Regional Museum of the parish.

. Enlist the interest and co-operation of the teachers and children of the school.

. The survey and record to be kept at the school; the teachers and older
children to become the first members.

. Secure the interest and co-operation of the local Boy Scouts or any other local
organisation.

. All members of the Association will be expected to keep notes of any observa-
tions they may make and give them to the school to be incorporated in
the central record.

8. Members will also be expected to present to the school museum any articles

of interest they may find, such as flint implements, pottery, coins, fossils,
&c., also contemporary objects of local historical interest.

9. Members will also be expected to assist in the preparation of historical records
of any old buildings in the parish and in supplying information about the
houses which they occupy, as well as in keeping the annual record up to
date.

10. It is further hoped that members will help to provide in the school books

of reference on natural history or archeological matters, materials for

exhibit cases, &c., to be made by the children, illustrations in the form
of photographs or pictures of matters of local interest. They can also
elp by giving facilities to the children to make observations on their
property by assisting them to pay periodical visits to local museums and
by lending books or objects for any special branch of study.

“I for] of WN

814 REPORTS ON THE STATE OF SCIENCE.—1920.

III. Things which in course of time the school should contain.

1. A map of the parish, or area to be surveyed, on which every field, hedgerow,
road, lane, wood, river, pond, or house should be given a distinctive
number, and its separate name, where these can be ascertained.

2. A permanent register or record of the past history of every place in the area,
and of every fact which can be observed concerning the life of these
places year by year, under their distinctive names and numbers, &c.—e.g.
changes of property, rotation of crops, habits of animals, arrivals and
departures of migrants, striking weather conditions, &c.

3. A series of traced maps showing separately—

(a) The geology.
(6) The vegetation.
(c) The water supply.

4. A summarised history of all ancient buildings and monuments, and a biblio-
graphy of books referring to them.

5. A brief description of every modern building, containing the date of its con-
struction, alterations, and the names of the families occupying it.

6. A classified list of all animals, birds, butterflies, moths, insects, trees, shrubs,
plants, and wild flowers found in the area.

7. Specimens of any articles of historical interest, whether ancient or con-
temporary, found in the area.

8. Illustrations of local plant and animal life, or, if desired, actual specimens
of birds, nests, eggs, butterflies, moths, &c. If such specimens are
collected they must be properly preserved, mounted, and catalogued.

9. A list as complete as possible of Lords of the Manor, Rectors of the parish,
Ministers of other denominations, Head Teachers of the school, Parish
Councillors, distinguished natives of the parish, &c.

10. The record of the activities of the parish in the Great War 1914-1918, or
in any other period of special interest.

APPENDIX VI.
Suggestions for Local Survey for Town Schools.
(By Valentine Bell.)

The environment of the child plays such an important part in its education
that it is of the utmost importance that the school should be brought into
closer touch with the school district. The school should not be a cloister. One
of the first points to be driven home in the training of teachers should be that
a teacher cannot become a really successful influence unless he or she is
thoroughly acquainted with the school district. Local surveys are the best
practical means of teaching live citizenship. Other advantages of survey work
are palpable to any teacher.

Teachers should take advantage of the stores of information at the Town
Hall, Public Library, local museum, and local Societies (Archeological, Botanical,
Photographic, &c.). In most towns valuable information, e.g. old prints,
plans, maps, &c., is stored away in local libraries and museums, and is rarely
ever asked for. Local surveys can well be taken if the locality is made the
means of approach to the education of the child.

The Geography Lesson.—Physical features, means of communication, indus-
tries, population, &c.

The History Lesson.—The old manors; the old views and maps of the
district ; the pastimes; the evolution of the means of travelling; old toll-gates;
old buildings (manor-house, church, castle, abbey, gates, inns, &c.); the punish-
ment of crime (police-stations, old watch-house) ; public-house and street names ;
old industries, &c. 5

The Drawing Lesson.—Sketches of objects connected with locality (indus-
tries, &c.); details of old church, castle, &. (Norman, Gothic, and Tudor
arches, tiles, &c.); pictures from history books; flowers in locality, &c.

The Writing and Composition Lesson.—Examples of local interest,

ON TRAINING IN CITIZENSHIP. 815

The Literature Lesson.—Interest should be aroused in the work of celebrities
-connected with the district by birth or residence. Local memorials, as statues
or tablets, are frequently unknown by the inhabitants.

The Arithmetic Lesson.—This lesson can be made most practical when
approached locally. Exercises on the park (areas) ; local shopping centres (com-
pound rates); the river; the industries; Report of M.O. of Health (practical
percentages, decimals, and graphs), &c.

The Science and Nature Study Lesson.—In elementary schools children
should have the phenomena that surround them explained (vide Board cf
Education latest circular). Lessons.—Why doesn’t a factory chimney fall?
Why are water-tanks often above the roofs? How does a motor-bus go? Why
do we get gravel here, chalk there, &c.? The dispersal of seeds of local
plants, &c.

Lollard Street L.C.C. School, N. Lambeth.
Class Work (in most cases taken after Outdoor Work).

. The Ordnance Map of the district (explanation of conventional signs, &c.).
. The district as viewed from some ‘outdoor tower’ (top floor of school,
summit of local hill, &c.), and directions driven home with use of the
map. Important buildings noted, e.g. churches, factories, gasometers, &c.
. The Physical Features of the district. (In crowded areas, the district
before the houses. Map to be made.)
. The Simple Geology of the district. (Digging operations for sewers, &c.’;
sections of local borings for wells.)
. The Botany of the district. (In crowded areas, the vegetation in local
parks and other open spaces is of great interest.)
. The Growth of the district as traced from old maps. (The manors; the
old houses marked on modern map. The influence of railway, trams,
or new "bus route can be seen.)
7. A chat on old views of the district. (Often of value in discussing No. 3.)
8. The Parish Registers and what they teach us.
9. The Streets. (Street names. Style of house; when built.)
10. The Public-houses. (Value of names. The Breweries.)
11. The Amusements of the district. (Cricket, football, &. Comparison with
Amusements of our forefathers. The revival of old dances.)

12. The Good and Bad Influences at work in the district. (Picture Palaces,
Public-houses, Recreation-grounds, Home-gardening, Churches, Scouts,
Bands of Hope, Polytechnics, &c.)

13. The Means of Communication in the district. (Railways, "buses, tubes,

trams, canals, &c. Suggestions for improvement.)

14. The Open Spaces and Recreation-grounds. (Various features compared, &c.)

15. The Local Industries. (Decayed, decaying, and modern. Causes of growth

and decay.
16. The Important Buildings. (Town Hall, Library, Public Baths, Churches, &c.)
17. The Local Authorities (work of Borough Council, Board of Guardians, Police
Authority, &c.).

18, The Feeding of the locality. (Markets, Milk Supply, &c.)

19. The Health of the district. (Report of M.O.H., Graphs of Birth and Death
Rates, &c.)

Architectural Development :

Lambeth Palace. Lambeth Church. Eighteenth and early nineteenth cen-
tury houses.

The Amusements of the People :

Survey of Local Amusements. Sports. Kennington Oval. Open spaces.
Picture Palaces; Music Halls; Public-houses; the Old Pleasure Gardens;
Vauxhall Gardens; Duck-shooting in Lambeth Marsh; the last London
Maypole; the Regatta—old University Course from Westminster to Putney.

The Fight against Disease :

Report of Medical Officer of Health. Old Parish Registers. Survey of
Hospitals, Dispensaries, and Medical Missions.

_ Local Government :

Survey of Lambeth’s Local Authorities. The Old Church Vestry—Old

Vestry Hall—Old and New Town Halls.

a oOo - Ww

316 REPORTS ON THE STATE OF SCIENCE.—1920.

History for Four Upper Classes.

The classes will make a survey of the school district and by means of this
approach an elementary knowledge of the social and industrial history of
England will be attempted.

Introductory Lessons :

(a) The Scroll of History.

(6) The Centuries.

The Britons :

Local Items.—Lambeth before the Houses. Boadicea’s statue.
The Romans :

The Old Kent Road. The Roman Boat found when digging the County Hall

foundations. Stangate. The Roman Bath in the Strand.
The Land :

Local notice-boards advertising sites for sale. Local examples of Freehold,
Copyhold, and Leasehold. Local entries in Domesday Book. The
increased value of Pedlar’s Acre (site of County Hall). Notice summon-
ing General Court Baron for the Manor of Kennington. Enclosure of
Lambeth Green.

The Growth of Towns :

The 1593, 1750, 1797, 1820, and 1870 maps of Lambeth. Old views of
Lambeth.

The Growth of Industries :

The present and past industries of Lambeth. Survey of local trade unions
and friendly societies.

What we owe to Foreigners :

The introduction of glass- and pottery-making into Lambeth (Venetians
and Dutch).

The Evolution of the Means of Travelling :

Survey of Lambeth’s means of communication. The railways, tubes,
trams, ’buses, taxi-cabs, motors, &c. The Brighton Road via Kennington
Gate. The old inns.

The Punishment of Crime:

The police-station. Lambeth Police Court. The Old Watch-house in High

Street. The old Surrey Gallows at Kennington.

The Religious Life of the People :

Survey of the various local churches and chapels, &c. Lambeth Palace.
Bunyan’s Hall.

The Growth of Education :

Survey of local schools, evening institutes, polytechnics, colleges, &c.
Lambeth parochial school (Archbishop Temple’s). The Tradescants and
Elias Ashmole.

ON TRAINING IN CITIZENSHIP. 317

British qe CLERKENWELL
Museum Smithfield

De) ONIEYHD
>
2
“a>

>
“

2)
A

RTINS L

i)
2
o

gw Lollard St
School

SHOREDITCH

Places for Educational Visits.

Lambeth Palace. The Temple.

Tate Gallery. Westminster Abbey.
National Gallery. St. Margaret’s Church.
National Portrait Gallery. St. Paul’s Cathedral.
British Museum. Southwark Cathedral.

Find the nearest and cheapest way of reaching the above.

St. Bartholomew the Great.
The Guildhall.

The Tower.

Houses of Parliament.

Study the tram map.

318 REPORTS ON THE STATE OF SCIENCE.—1920.

VISIT TO WESTMINSTER ABBEY.

Lollard S*
School

Write down the Route we shall follow.

Points of interest to be noted.

Georgian Houses in Pratt Street.

View of Lambeth Palace from Archbishop’s Park.

Old Village Houses in Park Place.

Names of Public-houses in and near Paris Street.

The views up and down the river from Westminster Bridge.
The statues in Parliament Square.

The dwarfing of St. Margaret’s by the Abbey.

The link-extinguishers in Dean’s Yard.

The view of Lambeth from Millbank,

The Toll-house on Lambeth Bridge.

Kinds of Questions to ask Yourselves :—
Why is Juxon Street so named? Who controls the Archbishop’s Park?
Who built Lambeth Palace ? When were the Embankments constructed ?
Who is responsible for the upkeep of Westminster Bridge?

ON TRAINING IN CITIZENSHIP. 819

ROUGH PLAN OF WESTMINSTER ABBEY.

WESTERN
OOOoR

JERUSALEM
CHAMBER

COLLEGE

DEANERY
EAST CLOISTER

Dimensions.
Length, with Henry VII.’s Chapel, 513 ft. Length of transepts: 200 ft.
Height of towers: 225 ft. Height of Church: 102 ft.
Find in dictionary the meanings of the following :—

Aisle, nave, sanctuary, ambulatory, cloister, transept, vestibule, deanery,
chapter, pyx.

Find out any other terms used in architecture.

Draw a simple sketch illustrating a Norman and a Gothic arch.

320°: REPORTS ON THE STATE OF SOIENCE.—1920.

VISIT TO THE TOWER OF LONDON.

1. Name our route and the buildings marked.
2. What tram services run through the Obelisk and the Elephant and Castle?

3. What bridges can be seen from London Bridge? In what ways are the banks
of the Thames at London Bridge different from those at Lambeth Bridge?

4. What steamships did you notice? What flags were flying? What evidences
existed in the Pool of the war being on?

5. Where was the Fishmongers’ Hall? What is it? How do you account for
its site?

6. What particularly struck you in Lower Thames Street? Name some of the
public-houses. What type of shop was open?

7. Describe the dress of a Billingsgate fish-porter.

8. Draw a rough plan of the Tower of London, marking the Moat, Inner and
Outer Bailey, and the Keep.

9. What are the following: The arquebus, matchlock, flintlock, mace, lance,
stink-pot, rack, scavenger’s daughter, visor, pike, chain-shot, grape-shot,
halberd ?

10. Describe briefly the historical growth of the Tower.

11. Name any notable folk connected with the Tower.

12. In what Tower are the Crown Jewels guarded? Explain K.G., K.T., K.P.,
V.C., D.8.0., G.C.B., K.C.M.G., G.C.S.1I., C.V.O.

13. What regiments were stationed at the Tower? Describe the dress of a
‘ Beefeater.’

ON HARMONIC PREDICTION OF TIDES. 321

Tidal Institute at Liverpool.—Report of Committee (Prof. H. Lamp,
Chairman, Dr. A. T. Doopson, Secretary, Sir 8. G. Burrarp,
Sir C. F. Cross, Dr. P. H. Cowstn, Sir H. Darwin, Dr. G. H.
Fow.uer, Admiral F. C. Learmonts, Sir J. E. Peraven, Prof. J.
ProupMaN, Major G. I. Taytor, Prof. D’Arcy W. THompson,
Sir J. J. Toomson, Prof. H. H. Turner).

1. Report on Harmonic Prediction of Tides. By A. T. Doopson, D.Sc.

THE present state of harmonic prediction of tides cannot be regarded as very satis-
factory, and this report has been written with the object of calling attention to
the matter. For some of the information the writer is indebted to the Hydrographic
Department of the Admiralty.

While real accuracy in the prediction of tides is not obtainable at present, owing
to inability to predict effects of meteorological variations, yet one would expect that
the normal, or undisturbed, or periodic tide could be accurately given. That such
is not the case is well known to those who have compared observations with pre-
dictions ; there are periodic or systematic differences in height and time of high
water which are sufficiently serious in many cases to cause distrust. This is
especially the case with harbours in river estuaries or in comparatively shallow seas,
and, in fact, the distrust has led in many cases to the complete abandonment of the
method of harmonic prediction. Thus the Hydrographic Department of the
Admiralty report that the German and Netherlands tidal authorities have found
the methods of harmonic prediction so seriously in error that they have abandoned
them, and the experience of the Hydrographic Department for the North Sea has
also been very unfavourable to the continuance of this method. For many ports
situated in estuaries, and catered for by British authorities, it is customary to apply
non-harmonic corrections to the results of harmonic prediction.

It is generally admitted, however, that harmonic predictions for oceanic ports
(i.e., ports open to the free influence of the deep water oceanic tide wave) reach a
high degree of accuracy. The general continuance of the harmonic method of
prediction, therefore, will depend very largely upon the solution of the ‘shallow-
water problem.’ This calls for scientific research, and, concerning it, reference may
be made to future reports of the Committee.

That the method of harmonic prediction for river ports should be in danger of
discontinuance could be taken as sufficient evidence regarding the unsatisfactory
state of harmonic prediction, but a few figures may serve to show what degree of inac-
curacy is considered by authorities to be unsatisfactory. For instance, at Quebec
the average error, regardless of sign, is as high as 16 minutes for high water, and
_ 28 minutes for low water predictions, though the harmonic constants for Quebec are

based on over 19 years’ continuous observation. Again, a comparison of observa-
tions with predictions of high water at Liverpool shows a very marked oscillation
in the differences, of which the following is an example :—

10, 6, 11, 3, 9, 4, 18, —1, 8, —7, 8, 2, 8, 2, inches ;

thus successive high waters are alternately predicted too low or too high by as much
as seven inches. (The predictions are taken from the tables of 1918, It should be
stated, however, that these are not purely harmenic predictions, but are corrected
by non-harmonic methods.) This is probably due to incomplete or faulty analysis,
and, concerning this, reference may be made to Prof. Proudman’s Report on
Harmonic Analysis, where comparisons between observation and prediction of hourly
heights are recorded for Liverpool, 1869; it has been shown that this represents
also the present day state.

If, however, the above evidence were not available an estimate of the value of

1920 Y

822 REPORTS ON THE STATE OF SCIENCE.—1920.

harmonic prediction could be obtained from comparisons of the predictions made
independently for the Admiralty and by the United States Coast and Geodetic
Survey. One would naturally expect that predictions ostensibly obtained from the
same harmonic constants would be fairly concordant, even if slightly different mean
values were used, and that the lengthier the series of observations and analyses the
better would be the correspondence in prediction. But an examination of the
independent predictions shows that this is not so. The following table was prepared
by taking one month’s predictions from the Admiralty tables and comparing
with the corresponding predictions published in the United States tables. The
maximum difference and average difference, taken without regard to sign, are given.
for the heights and times of high and low waters.

Number Mean a8 Times

Port of years | range of | Greatest

Liverpool. . . | 7orover) 28 11 5 21 10
St. John, N.B. . |15 ,, ,, 23 12 3 16 4
Bombays «= i \1 (soe 15 if 14 32 4
Adeninoasrq 44 old leiaida,; 7 5 16 30 8
Wellington . . | 2 4 7 2°5 34 16
Balboa. .oos >. | -1 16 3 1:2 34 10

In the case of Aden, the range of tides on certain days is small, so that the time.
of high and low water is uncertain ; these days have been ignored.

The above table in itself bears testimony to the unsatisfactory state of harmonic
prediction, even if we had no further evidence. We are not at the moment con-
cerned with the cause of any discrepancy between the two independent predictions
so much as with the general results. Where, as in the case of Liverpool, we may
have two different predictions, each supposed to be authoritative, which differ
occasionally by nearly a foot and on an average by five inches in height, then one’s
confidence in the accuracy of prediction is badly shaken. The differences in times.
are also serious and are considered so by all authorities ; these provide the best test
of the accuracy of prediction in all cases, since the height differences are naturally
small when the mean range of spring tides is small,

While the maximum and average differences are conclusive, there is also much
interest in a fuller examination of the differences that do occur. It is found that
there are periodic differences of some magnitude in practically all cases. For
Liverpool, on certain days both high waters have a positive difference and both low
waters a negative difference; that is, there is a semi-diurnal oscillation (in the
differences), of which the amplitude is about seven inches; moreover, there are
diurnal oscillations also present in the differences, as is shown by one set of high-
water differences being consistently lower than the alternate set, e.g.

4, 8,0, 4, —4, -1, —7, —3 inches.

Similar results are found in the differences in times of high and low water. As
another example, in the case of St. John, N.B., there is a semi-diurnal oscillation of
nearly a foot on certain days, as is shown by the following series of differences in
heights for successive high and low waters :—

—7, 12, —12,11, —8, 12, —11, 12 inches.

The effects vary with different machines, but, generally speaking, for all the ports
there are systematic differences which should not be allowable.

Enough evidence has now been given to show why it is considered that harmonic
predictions are not at present satisfactory ; two independent methods of judging
them have been considered, the first being based upon the experience of tidal
authorities in comparing predictions with observation, and the second being based
upon the disagreements that exist between two sets of predictions calculated inde-
pendently of one another.

ON HARMONIC PREDICTION OF TIDES. 323

It is quite certain that the chief cause for the failure of harmonic methods for
shallow-water ports has been the incompleteness of analysis, and the absence of a
reliable method of dealing with the shallow-water constituents. This is under

investigation. ,
Regarding the differences in predictions, it is necessary to consider four possible

causes:

(1) differences in the values of harmonic constants used by the two authorities
furnishing the predictions,

(2) differences in the number of harmonic constituents that can be taken into
account on the machines used for the calculation,

(8) application of corrections, as at Liverpool,

(4) uncertainty in the behaviour of machines.

It will be admitted that the choice of harmonic ‘ constants’ that can be made ought
not to bea serious matter, especially where there are lengthy series of observations,
as in the first four examples quoted.

In the case of Balboa, it is believed that the harmonic constants used are identi-
cal, and that no corrections have been made to the machine results, so that one
seems driven to assign the fourth cause. There is evidence from other sources
which tends in some cases to throw a certain amount of doubt on the behaviour of
predicting machines, but this also is under investigation by the Committee.

The machines used for the purpose of predicting tides differ considerably in the
number of constituents that can be taken into account, but it is not much palliation
even to know that a machine is as accurate as it can possibly be, when important
constituents have necessarily to be treated as non-existent. Investigations at the
Tidal Institute point to the conclusion that the number of constituents required to
deal adequately with the shallow-water problem is considerably greater than that
allowed for in the building of tide-predicting machines: It is partly for this reason
that corrections by non-harmonic methods are sometimes applied, though their
success is very doubtful.

The whole problem of the harmonic prediction of tides is being investigated by
the Committee, in collaboration with the Liverpool Tidal Institute and other
bodies interested in tidal work, and further information concerning progress will
be presented in their reports to the Association,

2. Report on Harmonic Analysis of Tidal Observations in the British
Empire. By J. PRouDMAN.

1. The following report was undertaken for the Association through Prof. Lamb,
who has collected information from all the authorities concerned, and has been in
consultation with the author during the whole time of its preparation.

It is based on information very kindly supplied by the Admiralty, the National
Physical Laboratory, Messrs. Roberts, Prof. D’Arcy Thompson, the Survey of India,
the Tidal Survey of Canada, Prof. R. W. Chapman of Adelaide, the Government
Astronomer of Western Australia, and the Tidal Survey of New Zealand, as well as
on the published literature of the subject.

In the first place an indication is given of the origin of the various harmonic
constituents, which aims at explaining more than the customary popular accounts,
while avoiding the heavy mathematical formulz required for the analysis itself.

In the second place a table is given of the results of analysis, the inconsistencies
in which show that the subject is in an unsatisfactory state.

In the next place an account is given of the various methods of analysis that
have been used hitherto, with the object of making prominent their essential
features, and providing the basis of a critical examination of them. To complete
this critical examination requires a large amount of computative labour.

Finally, a complete historical account is given, with bibliographies and lists of
analyses made.

It is to be remarked that the principle of the harmonic analysis is part of the
theory of the gmall oscillations of a dynamical system, and its application becomes
less accurate as the range of tide becomes a larger fraction of the depth of the
water, or as the tidal currents become greater. It yet remains to be found to what

Y¥2

824 REPORTS ON THE STATE OF SCIENCE.-—1920.

precise extent the purely astronomical tide at any station may be expressed as a
series of a reasonable number of harmonic constituents. When this has been done
and the methods of analysis and prediction refined so as to give predictions correct
to this extent, a hopeful investigation may be made into the residual astronomical
tide and the whole of the meteorological disturbance.

In a preliminary report * presented to the Geophysical Discussion of June 1918,
it was stated that tide tables as at present produced appear to be adequate for
practical needs. ‘This was based on the facts that the practically important
constituents can be determined fairly accurately, and that harmonic prediction
presents no theoretical difficulties like those of harmonic analysis. The investiga-
tions of Dr. A. T. Doodson show, however, that the published tables of harmonic
predictions are also very unsatisfactory.

Harmonic Tidal Constituents.

2. The gravitational forces generating the tides are derivable from a potential
which is everywhere proportional to what the height of the tide would be if water
covered the whole earth and had lost its inertia without losing its gravitational
properties.

Such a tide—the equilibrium tide—may be calculated by adding the amounts by
which a certain pair of nearly spherical surfaces of revolution project. above the
mean water-level. Each of these surfaces encloses a volume equal to that of the
earth, and is slightly variable in shape. They move so that their axes, while always
passing through the centre of the earth, pass also always through the centres of
the sun and moon respectively.

The tides due to either of these spheroids may be expressed as a series of
constituents, each of which varies harmonically in a period determined by
astronomical data. From dynamical principles it follows that to each of these
constituents there will correspond a similar constituent in the actual tides, that is,
a constituent varying harmonically in the same period.

To find, in the actual tides at any station, the amplitude of each of these
constituents, together with the lag of its phase behind that of the corresponding
constituent of the generating potential, is the object of the harmonic analysis of
tidal observations.

Let us consider the speeds of the constituents of lunar origin; we have to
examine the motion, relative to any point on the earth’s surface, of the spheroid
whose axis passes always through the moon.

The pole of this spheroid which is nearer the moon is a little further from the
earth’s centre than is the opposite pole, while the whole departure from sphericity
depends on the distance of the moon.

Let y denote the angular speed of the earth’s rotation and o the mean motion of
the moon,

If the moon moved with constant angular speed in the plane of the equator and
at a constant distance from the earth, we should have, at any station, high water
occurring regularly at intervals of «/(y — oc), with a maximum range of tide at the
equator. The rise and fall of the water would not quite be simply harmonic, hut
could be resolved, with sufficient accuracy, into a harmonic constituent of speed

27 — ¢),

of amplitude inversely proportional to the cube of the moon’s distance, and two
much smaller constituents uf speeds

¥-% 3-2)

and of amplitudes inversely proportional to the fourth power of the moon’s distance.
The fact that the moon does not move as here supposed causes many modifications,
but it is only on the constituent of speed 2(y—o) that their effect need be
considered. ;

Let us still suppose the moon to move in the equator, but take into account the

* Brit. Assoc. Report for 1918, pp. 15, 16.

. Prwde

ON HARMONIC ANALYSIS OF TIDAL OBSERVATIONS. 825

elliptic, evectional and variational inequalities in her distance and motion, These
inequalities have speeds

7— «a, 2(0 — w), o¢—2n+ @, 2(0 — n),

where w denotes the mean motion of the lunar perigee and 7 that of the sun. The
effect of each is to make the moon’s sidereal motion increase and decrease with the
reciprocal of her distance, and thus to make the period of the tides increase and
decrease with their range.

The effect of the first order elliptic inequality and the evectional inequality is
the introduction of new harmonic constituents of speeds

24y-—97) + (o—-), 2y— oc) + (© —2n + w)

of which, for the reason just given, the greater are those of speeds

2(y-—9) —(o-w), Wy - 9) —(o — 2n + @).

The effect of the second order elliptic and variational inequalities is sufficiently
represented by the introduction of new harmonic constituents of speeds

{y—9)-Ao-—w), 2Ay--a)— 20 —7).

The daily mean level of the water depends slightly on the departure from spheri-
city of the spheroid, so that we have long-period elliptic, evectional, and variational
constituents of speeds,

o—@, o—2n+2, 2(o — n),
respectively.

3. If the moon moved with constant angular speed in a parallel of latitude other
than the equator, consecutive high tides would be unequal except at the equator,
and we should require the introduction of a new constituent of speed

Y=";
with an amplitude vanishing at the equator. Also, the amplitude of the constituent
of speed 2(7—«) would be less than when the moon was in the equator.

But since the declination of the moon changes, the diurnal constituent requires
modification. If its ampiitude could be regarded as changing harmonically with
speed o, it would be replaced by two harmonic constituents of equal amplitudes and
speeds

y-cuo.
Owing to the fact that this is not quite so, the amplitude of the constituent of
speed y — 2c is a little greater than that of speed y, and there is another smaller
constituent of speed
¥ + 20.

Again, introducing the first order elliptic inequality we get new harmonic con-

stituents of speeds
(y—20)+(¢-w), yt (o—w),
of which those of speeds
y-ciwW
are regarded as forming a single constituent of speed
on

and slowly varying amplitude. The second order elliptic, the evectional and varia-
tional inequalities give rise to new constituents of speeds

(y — 2c) —2(¢ — a), (vy — 20) — (o — 2 + w), (y — 20) — 2(¢ — 9).

_ Also, the changing declination of the moon causes the amplitudes of the semi-
diurnal constituents to vary, but it is sufficiently accurate to take mean values in
all cases except that of speed 2(y—). As the effect is to make the speed and
range of tide increase or decrease together, we get a new constituent of speed

2(y — o) + 20.

326 REPORTS ON THE STATE OF SCIENCE.—1920.

Again, the changing declination of the moon introduces the principal variation in
daily mean level, in the form of a constituent of speed

20,
which with the first order elliptic inequality gives two more of speeds
20 + (o — w).

The amplitudes of all the constituents depending on the inclination of the moon's
orbit to the equator vary with the position of the node on the ecliptic. As the
monthly mean level also depends on the inclination of the moon’s orbit to the
equator, we have a small constituent with a speed N equal to that of revolution of
the moon’s nodes.

The speeds of the constituents of solar origin may be similarly determined, but
only the declinational and first order elliptic effects on the primary constituent need
be considered.

4. On collecting the results we have the following tables. The constituents of
the same species have similar geographical distributions of generating potential ;
they are arranged in decreasing order of magnitude. The symbols are the same as
those in general use, with the exception of 0, which is now introduced for the first
time. The corresponding amplitude in the generating potential is larger than that
of some constituents given in the other species. All the constituents given in the
tables have, according to Darwin, larger amplitudes in the generating potential than
any omitted.

Semi-diurnal Species.

Symbol Name Speed
M, 5 4 Principal lunar . = . ‘ : 2(y- 0)
8, : - Principal solar . ; é g J 2(7-— 7)
N, : 3 Larger lunar elliptic ; : . 24y-30+0
K, - : Luni-solar . : : : : 27
Vy : : Larger lunar evectional ‘ ; } 2y —30 + 2n-—aw
L, Smaller lunar elliptic ; : - 24y-c0-a
Te : . Solar elliptic . ; : 2y — 38n
2Np mie ; Second order lunar elliptic : : 2y-—4o0 +20
My Lunar variational . ; ; 2y — 40 + 2n
A Smaller lunar evectional . : : 2y-—c0-I@Qn +a

Principal Diurnal Species.

Symbol Name Speed
K, b : Luni-solar . Y
O, . . Larger lunar 7 — 20
P, $ : Larger solar. 5 — 2n
Q, c : Lunar elliptic ; : : y-3c°+0
1 5 : Supplementary lunar elliptic 1 5 yto-—@
OXOH ae ; Second order lunar . - : ¥ + 20
P; . 5 Lunar evectional y—30+2n-—w
22, ~~. 4 Second order lunar elliptic y -4¢ + 2a
o; Z ‘ Lunar variational : y — 40 + 2n

Long Period Species.

Symbol Name Speed
Mf ; ; Lunar fortnightly . ; ; : 20
Mm. : Lunar monthly : f é . c-@
Ssa f : Solar semi-annual . . : : 2n
— , A Nineteen yearly ; d : A N
— : : Ter-mensual . 3 - 2 30 —w
— - , Monthly evectional . is C o-—Wn+w
MSf . : Fortnightly variational . : c 2(¢ — n)
Sa X 5 Solar annual . : 3 : 5 n

ees

ON HARMONIC ANALYSIS OF TIDAL OBSERVATIONS, 327

Besides the above there is the constituent M, of speed y — o which consists
partly of that of variable amplitude of the principal diurnal species and partly of
that of amplitude inversely proportional to the fourth power of the moon’s distance.
There is also the ter-diurnal constituent M, of speed 3(y — o) and amplitude
inversely proportional to the fourth power of the moon’s distance.

Shallow Water Constituents.

In shallow water a harmonic constituent is accompanied by others having for
their phases multiples of the phase of the primary constituent. Also, two harmonic
constituents are accompanied by two others, having for their phases the sum and
difference of the phases of the primary constituents. Some of these shallow water
constituents have speeds the same as those of certain primary constituents. In the
following tables only those shallow water constituents are mentioned which it has
been the custom to consider hitherto.

Primary Constituents affected by Shallow Water Constituents.

Primary Constituents of

Symbol Shallow Water Effect Speed
M, K,, O y+y7— 20
2 N,, M, d(y — ¢) — (2y — 30 + w)
Mo, 2MS8,, Ss, M, 4(y — ¢) — 2(y — n)
K, M, O, 2(y — ¢) — (y — 20)
0, M, K, 2G 6) ay
P, K, 8, 2y — 1) -- 7
Q K, N, (2y — 30 + w)—
Mf K,, 0, y —(y — 2c)
Mm M,, N, Wy — co) — (27 — 30 + Ww)
MSf M,, 8, 2(y — n) — Ay — 0)
M, Oo Ne (2y -— 30 + w)— (y — 20)
Other Shallow Water Constituents.
Primary Constituents of
Symbol Shallow Water Effect Speed
M, M, 4(y — oc)
Mw M, 6(y — «)
M, M, 8(v — «)
S, 8, aCe)
S, s, 6(y — 2)
MS, M,, S, 4y — 20 — 2n
MK, Me Ks M, O, 37 — 20
2MK, Mee Ons M, XK, By — 40
SK, 8, K, By — 2n
MN, M,, N, 4y —bo +o
28M, 8, M, 2y + 20—4n

Meteorological Constituents.

The observed values of Ssa and Sa are largely of meteorological origin, as also
those of S, of speed y — 7.

Results of Analysis.

5. In order to show how far the results of harmonic analysis of hourly heights
represent harmonic constants we give some figures relating to ten different analyses
for Bombay. The tidal observatory chosen is regarded as one of the most satisfac-
tory, and the results of the analyses of the records taken there are about the most
consistent from year to year.

Hach entry in the tables refers to ten different determinations of what ought to
be the same constant; by ‘standard deviation’ is meant the square root of the mean
of the squares of the differences from the mean.

It will be noticed that apart from

M, 8, N, K, K, O, P,

328 REPORTS ON THE STATE OF SCIENCE. — 1920.

the deviations from year to year are so great as to prohibit any reliance being placed
on the results of the customary analysing processes applied to a single year’s record.
In fact, instead of the results from all analyses for the same constant being equal,
the apparent amplitude for one year is sometimes more than ten times that for
another year, while the apparent lags are sometimes distributed through more
than three quadrants.

We also give some figures relating to three different analyses of tidal currents at
Smith’s Knoll (Lightship off Norfolk). In 1911 six weeks’ observations were
analysed, but in 1912 and 1913 only two weeks’ observations were analysed.

Tidal Heights at Bombay (Apollo Bandar) 1906-1915.

wd
Clare | Greatest Least ; Mean ptanvand Maximum Standard
rae Ampli- Ampli- |Difference) Ampli- | 5, Ampli- Difference| Deviation
tude tude tude eiades in Lags | in Lags
Feet Feet Feet Feet Feet Degrees | Degrees
Me 4-017 3°934 “083 3°970 “021 1-51 “49
Sp 1-569 1-548 021 1:560 007 2°94 “78
No 1-011 "943 “068 -976 023 4-67 1:69
Kg “448 “374 “074 “404 “019 9-60 2°98
V2 *318 033 +285 -200 093 134:55 56°3
Ly “139 “019 120 “079 033 197-09 —
T. “240 -022 "218 “151 “066 93°28 29-2
2Ne "213 “056 “157 136 “049 43°33 12°50
Pe 257 ‘177 -080 -208 026 22°87 7°68
Ay —- — — — os —_ —
Ky 1:394 1:376 “018 1:386 “006 1:19 34
O; 664 “643 021 *653 007 1:31 “40
Py “431 “403 028 *412 -008 3°07 1:00
Qi 174 “125 049 “154 “014 18-98 5-77
J 148 “052 “096 "096 ‘031 48°13 14-45
00, — -— — — —- —_ —
Ps =f = = Dre giv _ —
2Q1 te Sea 2 eS — —
a; —_— = —_ ae — | = —
Mf 057 O11 046 032 013 91-71 25°2
Mm 127 ‘010 117 058 030 237-91 —
Ssa 196 "106 090 142 024 69°94 20°71
Sa 163 "024 139 109 043 252-71 —
MSf 075 “014 061 032 019 287-58 _—
M, — — — | — — — —
M, == se Ss <7 — <a ra J
M, 109 “085 024 097 007 33°93 10°36
M, 019 ‘013 006 017 002 61:99 21-1
Mg ne — — — — —
Sa — _ =a an — — — —
Ss asi bs) ua — - — — —
MS, 116 064 052 090 “015 30°60 9-42
MK, 083 007 076 "054 025 281-23 —
Be, 068 040 028 "053 010 25°56 10°62
Ke —_ — — — —_— — —_—
MN, 022 002 020 “014 006 136-00 45°3
25M, 045 030 015 7037 004 32°65 10-71
Ss, 097 062 035 ‘079 011 11-78 3°35

ke ee

ON HARMONIC ANALYSIS OF TIDAL OBSERVATIONS. 329

M, Constituent of Tidal Currents at Smith’s Knoll.

Phase of

Direction of Maximum Current}; Minimum Current .
ag Maximum Current in cms. per sec. in cms. per sec. Be locttaas Le

métres |
1911 | 1912 | 1913 || 1911} 1912 | 1913 | 1911 | 1912 | 1913 | 1911 1912/1913

| |
2-5 |S 32°R|S 4°E|S 3°E|| 74:0) 98-0} 85:3 4 8-5 | — 7-4 |—11-6 1/2519 |247 °| 255°
5 Febh os «| 95.09, ponliast chase | 90°3|105:2| 91-6), ,, 7°4 | ,, 8°6 | ,,12°3|/253 |247 |254
10 Bees \as 1. ssuliags A soll Oe 8s Gp BEA [aay OP Lalonde bos 11°8 ||255 246 |254
15 s327 95 15,10 5, | 99 455 || 84:6) 94°77) 89-3] 557-5 | ., 8'4)|,, 10:9 ||255 |248 |255
20 24 5, | 5,11 ,, | 5, 455 || 80°4| 888) 84:0) ,, 771 | ,, 89 |,, 9-9 |/255 |249 |255
25 5523 95 | o5l2 55 | o> 455 | 70'8| SO'S| 78°S|| 4, 4-1 | ,,. 7:4] ,, 10°4 1258 |249 |257
30 92D 95 | 145,15, 5 >, || 65°6| 80°7| 73°3 | 3» D3 |5,9°7 |,, 9°$1|260 |248 258

The negative sign prefixed to the minimum current indicates that the current
turns in the clockwise direction.

Harmonic Analysis of Hourly Heights.

6. We assume that the height of the water at any station may be expressed as
the sum of a number of Fourier’s series in time. In each of these series only a few
terms are important; for instance, in the largest (M) series, the important terms
are the constituents

M,, M,, Mg, M,, M,, M,,
while in others (e.g. N or O) there is only one important term (N, or O,).

A typical short period series will have speeds

O,, 26,, 30, A B

where o;, is that of the diurnal constituent. We shall take r = 0 for the principal
solar series, so that 27/0) is a mean solar day.

The data for analysis consist in a number of heights at intervals of time equal
to one mean solar hour.

Noy, »

The Isolation of the Principal Solar Series.

Arithmetic means are taken of the heights at the times

h 2a h\ 2r h\ 2n h\ 29
— 1+ —) =, (2+ —)— Nie dot Sie bie.
e. ( +34) a,’ ( + 7) ee sah +) ne @)
for each of the values0,1,.2, . . - - 230fh.
For any value of h this process will leave unchanged the term
Ros (mot —«) . : : - : : (2)

and consequently the whole § series.
From the term

R cos (mo,t —) . : : : 5 : (3)
however, it will give

* > cos fan(« + AL nl, @ weds binosde aff)

which is equal to

a B cos an] » (=~ 1)+ i ale-¢. Phe opaili oF 1O1Qgy

830 REPORTS ON THE STATE OF SCIENCE.—1920.

and to

1 sin{Nn(o,/o, — 1)t} p 3 A te ya 7h be eater
N_ sin{n(o,/c, — 1)r} doa. dus o, Y) + Satetlnnle (6)
on summation.
If o,/o, is sufficiently near to unity, (6) may be replaced by

sin{Nn(o,/o, — 1)7} N—-1/or _ hoy| _.
Na(o,/c, — 1) ee {onl 2 (« 1) +94 | } ae?

which is exactly what we should have obtained if we had replaced (5) by the integral

0 I
Cy (Sens
= we feos 1) +f 2 lr — elas Hep se the NS)

It is the general practice to choose N so as to make as small as possible the
residue (6) from some one large term of the type (3).

When a year’s record is to be analysed the value of N chosen is 369, and it is
then generally assumed that all the residues (6) may be neglected; in other words,
that the isolation of the S series is complete.

With a month’s record Darwin’s plan is to use for N both 30 and 27, and with a
fortnight’s record both 15 and 14. It is assumed that the amplitudes of K, and P,
bear to those of 8, and K, respectively the equilibrium ratios, and that the lags of
K, and P, are equal respectively to those of 8, and K,, while T, is supposed simply
proportional to 8,. The residues from all other constituents are neglected.

For N = 369 and the constituents

M,, Noy K,, K,, O,, E

the coefficient -
1 sin { Nx(a;] 09 = 1)r } : ‘ y (9)
N sin { 2(0,/0) — 1)r } ; .
in (6) takes the values
000, -008, -010, ‘010, ‘000, 010
respectively, and the corresponding coefficient in (7) takes the same values.
For N = 15 and the constituents
M, N,, K,
(9) takes the values
7016, -204, 989,

respectively, and the only effect of replacing (6) by (7) is to give ‘200 instead of
“204.

For N = 14 and the constituents

K,, O,, P,,
(9) takes the values
998, -014, -998

respectively, which are not affected by replacing (6) by (7).

The Isolation of the other Series.

7. We shall now consider the isolation of the series which has o for the speed
of its diurnal constituent, and shall refer to 2m/o as a ‘special day.’ For the
isolation to be carried out exactly like that of the S series we should require the
heights at intervals of time equal to a ‘special hour.’ The method of summation
we should then have is made the basis of the actual methods now under considera-
tion. With each place in the summations is associated a definite time, and this in
general is necessarily different from that of the height which is assigned to the

lace.
: There are two ways in general practice of making the assignment, and we shall
refer to these as the B.A. and the Abacus assignments. The first is used by Roberts
and the Survey of India, while the second is that of Darwin’s tidal abacus.

igh

ON HARMONIC ANALYSIS OF TIDAL OBSERVATIONS. 881

In the B.A. assignment all the given heights are used and the maximum
difference between the time of a place in the summations and that of the height
assigned to it is 7/240 or half a special hour. When the times of two of the given
heights are nearer to that of a place than this interval, both are assigned to it, while
when no height has a time as near as this interval, none is assigned to the place.
The former case occurs regularly when o <4, the latter when o>a,. In both cases
the mean is formed by dividing by the total number of heights used in the
summation.

In Darwin’s tidal abacus the height at each mean solar noon is assigned to that
place in the summation whose time differs from this noon by less than half a special
hour, while any two consecutive heights belonging to the same mean solar day are
assigned to consecutive places in the summation. As in the B.A. assignment all the
given heights are used so that two heights are assigned to certain single places

when o<c, and no heights are assigned to certain places
when o> oy.

Let us now examine the effects of these averaging processes on the various
constituents.

Taking firstly the term

R cos (mat — €), A : : : f (10)
the summation for the special hour / will give
N-1
= 20 (3 + MoT, — ‘) B . : (11)
=

where 7, denotes the excess of the time of the (s + 1)th height in the summation
over that of the place to which it is assigned, and N the number of terms in the

summation.
Now, for given values of o, m, and N, the sums
1 N-1 : - N-1
N > cos (mors), XN > sin (mors) é - (12)
s=0 3s=0
may be determined accurately by direct addition. This would be laborious and the
sums are replaced by integrals. For the B.A. assignment they are replaced by

T T

= | cos (mor)dr, mn sin(mort)dt, . 4 . (13)
—T —T
respectively, where T is half a special hour. The effect is to replace (11) by
sin moT mhar
sin mer B cos (Tanas) ce Bae eS

For the abacus assignment (11) is replaced by

sin mm/24 sin { m(a]o9 — 1)r} m 7
mm|24 Ree 1)r R cos { “I 3 (a = “4 + a] m—€ S . (15)

Taking next the term

Ricos. (not6)scucuin GBlo (rte tashe an ee

the summation for the special hour h will give

N-1 :
= >> cos no;| (8+ 3a) o* |-¢. fet: Ges)

which we shall refer to as the residue from (16).
Again, for given values of o, o;, m and N, the series

N-1 N-1

x Bomar (2 +n) E Bin | ne 2 a “I, . (18)

s=0

832 REPORTS ON THE STATE OF SOIENCE.—1920.

may be calculated accurately by direct addition, and although this would be very
laborious it could be done once for all.

Again, it is the general practice to try to choose N so as to make as small as
possible the residue due to some one large constituent, and then to neglect all the
residues. For example, when a year’s record is available the B.A. plan is to take
N = 357 for the M series and N = 343 for the O series. Darwin's plan for a month’s
record is to replace these numbers by 29 and 25 respectively, and for a fortnight’s
record by 14 and 13 respectively. These values are taken on the basis of the formula
(17) with 7, omitted.

Analysis of the Separate Series.

8. From the isolation process for each series we have 24 values

G ’ Gq ? - - . Gus Hl 2 ~ os

associated with times which differ by intervals of one special hour. Certain fractions
of these values are residues from other series.

The usual method of analysing the Fourier’s series into its separate terms is by
what we may call the ‘least square rule.’ If the series is expressed by

(= A, + BR, cos (ot — €,) + R, cos (Qot—€,) . . + Rm cos (mat —€m) . (19)
the rule is given by

Ay = 24 ee Gu.
h=0
Fe y/
le mir
Rin COS Em = ia > G, cos iy : : ° (20)
h=0
1 ee y/
: 5 = mh
Rn sin Em = B= qG sin i=

and its application to the cases in question would be quite accurate if the isolation
were perfect.
We must therefore consider the effect on the results of imperfect isolation.
Taking the § series, the effect of a term of the type

h 2no,30
R — Le : 5 5
cos 8 tated .) - ‘ (21)
on A, is
1 sin (no;/a)) Rp 23 now
fi an GaP, Go nee, a ce

so that the effect of the term (3) on A, is

1_ sin (Nno;t/%) pp’ 23)\ no,
24N sin (no,1/240,) ae { a El se) ae ¢}. ae

The effect of (21) on Ry» cos €m is

Rf sin{(no,/oo + m)r} (23 (ney
sal anlenectos + m)n]24} °°S fia + m)\r = ¢

ei CLE Teme? cos te, — m)s - |]. : (24)

+ sin{(no;|/o) — m)n/24}

When 2 = m and a;/ao is near unity the second part of this is much larger than
the first, and it reduces to

23 Or
R cos {5am (% -1)*-«} (25)

ON HARMONIC ANALYSIS OF TIDAL OBSERVATIONS. 8338

approximately ; similarly the effect of (21) on R,, sine, reduces to
. {23 o
- Rsin {54m (-1)*-«} (26)
approximately.
On combining (7) with (25) and (26) we obtain as the corrections to

R,», cos €, and Ry», sin €,
required by (3)

— FReos(k—e), F Rsin (« — 6), (27)
respectively, where
~1)9 :
ge «= n(n ~ 54) (2 1) (28)
If these corrections are small compared with R,», they give
5 Rn = — F Roos (k + €» — ©), .
5 en = F Rsin (« + €m — ©); } i)

which we notice involve only the relative phase em — «.

Darwin's Method for Solar Constituents.

9. This method consists in applying the S series isolation process and the least
square rule to different sets of 30 consecutive days’ record and then analysing the
resulting sets of values for yearly and half-yearly harmonic variations.

When a year’s record is available, 12 sets of 30 days are used, and from the
results values of

ars eas) este ny SEs) Sate ANON ee \oeet oe

are immediately taken. Residues from M, are allowed for. When less than a
year’s but as much as half a year’s record is available, Ssa is neglected.

Analysis of Hourly Heights for Long Period Constituents.

10. There are two methods in general use, and we shall refer to them as the B.A.
method and Darwin’s short method. The B.A. method is used by the Survey
of India.

The principle of the B.A. method is the least square rule applied to daily mean
heights, using one decimal place for the multiplying sines and cosines, The residues
from all primary astronomical constituents are allowed for.

Darwin’s short method uses the principle of isolation and proceeds on a plan
similar to the assignments, the daily means taking the place of the given hourly
heights. Residues from M, are allowed for, but no great accuracy is claimed for the
method ; Darwin gave it as a much Jess laborious process than the B.A, method.

Darwin's Method for Harmonic Analysis of High and Low
Water Observations.

11. If ¢ denote the height of the water at time ¢, it will be given by an equation
of the type
¢ = R, cos (o,t—€,) + = R, cos (a;t—«,), : : . (80)
r
where o, is no longer the speed of S,, but that of any constituent conveniently chosen

to play a special part in the analysis.
At the time of high or low water we have

0 = R, sin (o,¢ — ¢,) + DR, mune €or. CL)
0
and if we let :

ieiabberdc! ovis: cure Seater oe ET Wena

834 REPORTS ON THE STATE OF SCIENCE. —1920.

denote respectively the times and heights of consecutive high and low tides, we
deduce from (30) and (31)
N
a S (s COS Outs — R, COS €y

s=1
N
1 1 oy es
= NS > By [a(i+ = ) cos (a; —o5)ts cs}
ry s=l1
C,. (
+4 ( - =) cos port Oy)ts — €r |
a) . (83)
N
2 Dd G sin ots — Ry sin €
s=1

N
ake >» | 4 (: + 3) sin Ca «}

r s=1
-3 ( 1 n) sin { (Gr | Oy)ts — € |
%

1, . cos | (0) -- oy)ts — € sf Dseoot eteoe a aod MSE)
N

s=1

If in the terms

we may approximate by substituting
t=tt+(-1)%, Se eee ae

cos {(« = *) (« gil = ir) — or} STSGe. OCG)

This vanishes when N is an exact multiple of 20/(¢,—o,), or when the tides taken
cover an exact number of synodic periods of the constituents of speeds o, and a;,,
while if N has the value of o/(c, — o,), or the tides taken cover exactly half a
synodic period of the constituents of speeds ¢, and o,, and (o; — 9,)/¢ be small, (36)

is equal to

2 N --1

x 008 {Cer — 9) (« CT *) = cf : : 7 (37)
approximately.

These are the equations and relations on which the method is based.

When analysing for M,, R, cos (o,¢ — ¢,) is taken as this constituent, and N is
chosen so that the tides considered cover an exact number of semi-lunations. ° It is
then assumed that the summations on the right of (33) may be neglected, so that

we get

N
R, cos € = = D ( cos apts,
s=1
P - - : (38)
Ry sin €, = S ¢ sin agts,
e=1 >

When analysing for N, and L,, R, cos (ot — €,) is again taken as M,, but N is
chosen so that the tides considered exactly cover a semi-lunar-anomalistic period.
Two series of 13 such sets of tides are taken, the tides in each series being

mals

ON HARMONIC ANALYSIS OF TIDAL OBSERVATIONS. 335

consecutive, and one series beginning a quarter-lunar-anomalistic period after the
other. By subtracting the equations (33) for consecutive sets in each series, M, is
eliminated from each series, and the results are then combined so as to eliminate
first N, and then L,. In these final equations it is assumed that all other
constituents may be neglected, and even for N, and L, that the terms involving
(1 — a,/o,) may be neglected, while those of the type (86) may be replaced by terms
of the type (37).

To find §8,, R, cos («,¢ — «,) is taken as S, and N is chosen so that the tides
considered cover an exact number of semi-lunations, All constituents except K,
and T, are then neglected in the summations. It is assumed that the amplitude
of K, bears to that of S, the equilibrium ratio, and that their lags are equal, while
T, is supposed simply proportional to §,, In the summations involving K,, the
terms containing (1 — o,/c,) are neglected.

To find K,, R, cos (o,¢ — ¢,) is again taken as §, and two sets of the same number of
tides are taken so that one begins 3 months after the other. Again T, is taken
proportional to §,, the factor of proportionality changing a little from one set to the
other. By subtracting corresponding equations (33) for the two sets, the terms
involving 8, become small, and when the value of §, already found is used, we have
two equations for the amplitude and lag of K,. All other constituents are again
neglected in the summations.

In finding K, and 0, the procedure is analogous to that for finding N, and L,,
M, taking the place of M, and a semi-lunar period taking the place of a semi-lunar
anomalistic period. This time, however, the contributions of M, and §, to the
summations are accurately computed with the values of these constituents already
found, while K, and P, are supposed to have their amplitudes in the equilibrium
ratio and their lags equal.

The finding of P, is analogous to that of K,, the process for K, and O, taking the
place of that for §,.

Only the constituents M,, S,, N., K,, L, and K,, O,, P, are considered.

Correlation with Generating Potential.

12. The amplitudes of some of the harmonic constituents of the generating
potential are really variable, though the variations are very slow. Also, some of
their speeds have not quite the values scheduled, though again the deviations are
small. In both cases the effects take a long time to accumulate and the changes
may be neglected over a year, while a longer record is not subjected to a single
analysing process.

When the amplitude and phase of a constituent observed at any particular time
are connected with the generating potential, the deviations mentioned have to be
taken into account. There is one type of case, however, in which this does not
appear to have been adequately done. It is the case in which shallow water
constituents have speeds equal to those of constituents of other origin. When the
ratio of the amplitudes and the difference of the phases of two constituents are
slowly changing, it is clear that true tidal coustants cannot be obtained until the
constituents have been separated in some way. Such separation has never been
made, and this fact may possibly account for some of the irregularities in the results
from year to year, especially for some of the long period constituents.*

Historical Account.

13. In 1866 Prof. Thomson (afterwards Sir William Thomson and Lord Kelvin)
applied to the Admiralty for a year’s record of any trustworthy tide-gauge, and
received that of Ramsgate for 1864. This he began to analyse harmonically with the
aid of Messrs. E. Maclean, J. Smith and W. Ross of the University of Glasgow, at
first using three-hourly heights but afterwards hourly heights. Approximate values
for M, and 8, were found and the existence of Ssa and Sa detected.

* In the preliminary report it was stated that the inconsistencies in the results
_ for long period constituents are not due to defects in the method of analysis. This

_ Was based on the fact that residues are allowed for; the subject of the present
section was not there considered.

336 REPORTS ON THE STATE OF SCIENCE.—1920.

At the Meeting of the British Association in 1867 Thomson obtained the appoint-
ment of a committee which, during the following nine years, carried out harmonic
analyses. The grants from the Association to the Committee amounted to £1,000,
and the work was done, under the superintendence of Thomson, by Mr. KE. Roberts,
of the Nautical Almanac Office, and assistant computers working under his imme-
diate direction.

To the members of this committee, in December 1867, Thomson issued a circular,
containing, among other things, the speeds of the constituents

M, K, Mf M, 8,
8, 0, Mm M,

N, P, Ssa

K, Q, Sa

L, J,

T, ‘y — 3m’

iS)

We have explained the nature of all these except R, and ‘y — 3n,’ which are solar
constituents analogous respectively to the lunar constituents L, and Q,. In the
development of the generating potential their amplitudes are less than those of
constituents which have always been neglected. Thomson gave S, as an astronomical
constituent analogous to M,, and the speed of Mm asco instead of o — w, as was
afterwards pointed out by Roberts. He thought that while all the above constituents
would be sensible on our shores, the effects of evection and variation would be
negligible. He also stated the ‘ equilibrium principle’ of allowing for the changing
inclination of the moon’s orbit to the earth’s equator.

From the Ramsgate 1864 record the terms of the

M, K, 8, O, N, L

series were first found. Special hourly means for the year were formed using the
B.A. assignment, and then analysed by the least square rule using the tabular forms
given by Archibald Smith for the deviation of the ship’s compass.

This analysis revealed the shallow water constituents

My, M,, M,, Sy

and this then suggested the possible presence of MS, and MSf.

By means of these first approximations a complete calculation of residues was
made, but it was afterwards concluded that first-approximations were sufficient for
short-period constituents, and no other residues for such constituents were calculated
by the Committee.

From the same record numbers for

Mf, Mn, Ssa, Sa, MSf,

were found, by using daily means for the year purified of lunar short-period
influence before analysis.

As a test, an hourly tide-table for one day in 1864 was made and compared with
the original record. The errors reached a foot at half-tide (mean spring amplitude
=8 ft.).

A series of records taker at Liverpool were supplied by the Board of the Mersey
Dock Estates, and from that for 1857-8, values for the

M, K, 8S, O, N, L
series were found.
A set of personal observations taken at Bombay were supplied by Mr. W. Parkes,
a member of the Committee, and special quarter-hourly means for 127 days were
formed and analysed for the
M, K, §, O, N, L
series.

14. From the Liverpool 1857-8 record the constituent P, was found, and then
the 1858-9 and 1859-60 records were analysed similarly. The constituents T, and
R, were also treated, each from two two-yearly records.

Now that records taken in different years at the same station were considered,
correlation with the generating potential was made, and a Liverpool hourly tide

ON HARMONIC ANALYSIS OF TIDAL OBSERVATIONS. 337

table for 13 specially chosen days in 1869 was constructed and compared with the
corresponding record,

To examine the variation of certain constituents with the inclination of the
moon’s orbit, the record for 1866-7 was analysed. It was decided that the variation
was not quite according to the equilibrium principle, but was afterwards always
treated as if it were so.

The new results of analysis were incorporated in the tide-table and then the
determination of y,, w, and A, was suggested and carried out for each of the
four years taken.

The tide-table was again emended and compared with the record: the
discrepancies over two typical days are shown in Fig. I. The determination of
MS, was suggested and the analysing process applied to each of the four yearly
records. The tide-table was emended accordingly and the results again compared
with the record. The final discrepancies over the two typical days are shown in

FEET +

rx)

Figs. I. AND II. —Difference between Predictions and Record for Liverpool,
April 26 and 27, 1869.

Fig. II. It should be stated that the tide-table contained a number of constituents
of amplitudes less than 0°1 ft.
Numbers for
Mf, Mm, Ssa, Sa, Msf

were also obtained from each of the four yearly records, but were inconsistent from
year to year.

The Ramsgate 1864 record was next further analysed for

Dior ep PAM MSy

A set of quarter-hourly observations taken during several periods within four
days in the Fiji Islands, and supplied by Lieut. Hope, R.N., were partially analysed.
The difficulties presented by the shortness of the periods led Thomson to apply to
the U.S. Coast and Geodetic Survey for a trustworthy record of Pacific tides. He
received that of Fort Point, California, for 1858-9, and it was analysed for all the
constituents considered at Ramsgate. As a test an hourly tide-table for 14 days
was made without p,, A,, the long-period constituents and MS,, but including several

1920 Z

338 REPORTS ON THE STATE OF SCIENCE.— 1920.

constituents of amplitudes less than 0:1ft. The discrepancies over two typical days
are shown in Fig. III.

A Karachi record for 1868-71 was supplied by Mr. Parkes and analysed for all
the constituents considered at Liverpool, together with

Q, J).

An hourly tide-table for 29 days in 1868 was made without T,, Q,, J,, the long-period
constituents and M§,, but including several constituents of amplitudes less than
0:1 ft. The discrepancies over two typical days are shown in Fig. IV.

Fia. IlI.—Difference between Predictions and Record for Fort Point,
March 16 and 17, 1859.

Fie. [1V.—Difference between Predictions and Record for Karachi,
November 11 and 12, 1868.

Next, three further yearly records of Liverpool tides were analysed for the same
constituents as before, with the exception of those of long period.

Also, two further yearly records from Fort Point were analysed, the constituents
Q, and J, being added.

A thirteen months’ record from Cat Island, in the Gulf of Mexico, was obtained
from the U.S. Survey, and analysed for the

M, K, 8, 0, N, L, P, Q J

series, as well as the long-period constituents.

From the Ramsgate 1864 record the constituents 28M, and 3MS5, were found, the
latter being a shallow-water constituent of speed 4y — 60 + 2n, derived from S,
and M,.

Another yearly record from Karachi was analysed for all the constituents yet
considered.

Four yearly records from Portland were analysed for the same constituents as at
Ramsgate, with the exception of those of long period.

In the British Association Report for 1872, Roberts gave a harmonic development
of the semi-diurnal tide generating potential.

15. In 1874 Lieut. (afterwards Col.) A. W. Baird, of the Survey of India, set up
tidal observatories at Hanstal, Navanar, and Okha Point. He was afterwards
deputed to Europe to study the practical details of tidal registration and harmonic
analysis. With the help of Roberts in England, he analysed the records from the
observatories he had set up.

The British Association Committee further analysed records for Hilbre Island,

eine

ON HARMONIC ANALYSIS OF TIDAL OBSERVATIONS. 339

Karachi, San Diego and Fort Clinch. When its funds were exhausted Thomson tried
to obtain £150 from the Government but was unsuccessful. The amount was provided
by the Royal Society out of their Government Grant Fund, and with it records from
West Hartlepool, Port Leopold, Beechy Island, Brest and Toulon were analysed.

For the 1876 British Association Meeting Thomson drew up a final report and
gave an investigation into the generating potential, tabulating speeds, arguments
and amplitudes.

A record taken at Freemantle by the Admiralty provided the first case of
harmonic analysis for a station in the Southern Hemisphere. Under the influence
of Thomson the Hydrographic Office was searched for other Southern Hemisphere
records, but the only ones found were from Port Louis, Mauritius and Port Louis,
Berkely Sound. Harmonic constants from these as well as from records taken at
Toulon, Marseilles, and Malta, were published by Thomson and Capt. Evans, R.N.

On Buird’s return to India in 1877 the systematic observation and analysis of
tides was there begun, he training the original staff of observers and computers.

Thomson next constructed the first mechanical harmonic analyser with the aid
of grants from the British Association and the Royal Society. It was designed to
determine the constituents

M, 8, K, O, M,
but has never been used for this purpose. It is deposited in the Museum at South
Kensington.

At the 1882 British Association Meeting Prof. Darwin (afterwards Sir George
Darwin) communicated a paper in which he pointed out that the methods of
analysis which had been used for the long-period constituents might be seriously
in error. A committee consisting of Profs. Darwin and Adams was appointed
to examine the whole subject of harmonic analysis.

In 1883 and 1885 Darwin presented reports which have ever since formed the
standard manual on the subject. They contain an elaborate analysis of the
generating potential (several errors in the report of 1876 being indicated) and a
complete treatment of the methods of analysing hourly heights. These methods,
except for T., R, and the long-period constituents, do not differ essentialiy from
those which had been used by Thomson’s Committee ; they complete the evolution
of what we have called the B.A. methods.

In 1885 Baird and Darwin published an up-to-date collection of results of
analysis; the number of stations considered was 43.

16. In 1885-6 the Canadian Expedition to Hudson Bay under Lieut. Gordon, R.N.,
was made and short series of observations taken at five stations in Hudson Straits
were afterwards harmonically analysed by Gordon with the aid of Prof, Carpmael
of Toronto.

In a final report (1886) of the British Association Committee Darwin gave his
methods of analysing short records.

In 1886 Baird left the Tidal Department of the Survey of India and published
his ‘ Manual of Tidal Observations.’ The methods of observation and analysis which
he had established have been continued without modification up to the present time;
they consist precisely of the B.A. methods, Baird constructing auxiliary tables.

In 1889 Darwin published a second up-to-date collection of results from all
‘sources, showing an increase of 27 stations since 1885.

Tn 1890 Darwin gave his method of harmonically analysing observations of high
and low water, and in 1892 his new method for solar constituents and his short
method for long-period constituents. In the same year he published his design of
the ‘tidal abacus,’ an apparatus for facilitating the computations in the analysis of
‘hourly heights. This apparatus has since been much vsed.

In 1891 the Australasian Association appointed a committee to report on the
tides of South Australia. Two of the members of this committee, Prof. R. W.
Chapman and Capt. A. Inglis, afterwards analysed records from Port Adelaide and
Port Darwin.

In 1894 the Survey of Tides and Currents in Canadian Waters was instituted by
the Canadian Government, and this organisation has worked continuously up to the
present time under the direction of Dr. W. Bell Dawson. The harmonic analyses
have keen made for the Survey by Messrs. Roberts, a firm of computers founded by
Mr. E. Roberts of Thomson’s British Association Committee, but only a few of the
tesults have been published.

340 REPORTS ON THE STATE OF SCIENCE.—1920,

Mr. T. Wright, of the Nautical Almanac Office, has analysed records by Darwin’s
methods with aid from the Royal Society Government Grant Fund.

Darwin and Messrs. Selby and Hunter have analysed with the abacus records for
Antarctic expeditions, and Selby has similarly analysed records for the National
Physical Laboratory.

Roberts has made new analyses for Liverpool and Dover, the former for a British
Association Committee, the latter with the aid of a small grant from the Royal
Society Fund.

In New Zealand tidal work began in 1909 and has been entirely under the charge
of Mr. C. E. Adams, the Government Astronomer. Records have been analysed by
the use of Darwin’s abacus and computation forms, and the results checked by
Mader’s mechanical analyser. This appears to be the only use that has been made
of mechanical analysers, in spite of the number of different machines that have
been invented.

In Western Australia records have been taken and analysed by the Government,
under the direction of Messrs. Cooke and Curlewis, Government Astronomers.

Prof. D’Arcy Thompson has studied averages of consecutive high and low waters at
Aberdeen, Dundee and Milford Haven, giving values for Ssa and Sa at these Stations.
He has also published lists of Ssa and Sa constants obtained from various sources.

The Admiralty has announced that for the North Sea the customary methods of
harmonic analysis lead to predictions which are entirely in error.

In 1911 the British Government, in connection with the ‘Conseil Permanent
International Pour l’Exploration de la Mer,’ began the taking and harmonic analysis
of continuous observations of tidal currents in the North Sea.

British Work on Harmonic Analysis of Tidal Heights.

BIBLIOGRAPHY.

1868.* Sir W. THomson, Report of ‘Committee for the purpose of promoting the
extension, improvement, and harmonic analysis of tidal observations.’
Brit. Assoc. Report, pp. 489-505. [Thomson’s Circular is reprinted in Pop.
Lect. and Add., pp. 209-223].
E. RoBERTS, Report supplementary to Thomson’s, Brit. Assoc. Report, pp.
505-510.
1870. Sir W. THomson, Report of same Committee for 1869, Brit, Assoc. Report,
pp. 120-123.
Sir W. THOMSON, Report of same Committee for 1870, ibid. pp. 123-125 ; 148-151.
KE. ROBERTS, ‘ Statement of work performed by him,’ ibid. pp. 125-148.
1871. E. RoBERTS, Report of same Committee, Brit. Assoc. Report, pp. 201-207.
1872. E. RoBeRts, Report of same Committee, Brit. Assoc. Report, pp. 355-395.
1876. Sir W. THomson, Report of same Committee, Brit. Assoc. Report, pp. 275-307.
1878. Capr. EVANS and Sir W. THomsoN, ‘On the Tides of the Southern Hemi-
sphere and of the Mediterranean,’ Brit. Assoc. Report, pp. 477-481. [Nature,
v. 18, pp. 670-672. ]
Sir W. THomMsoN, ‘ Harmonic Analyser,’ Proc. Ray. Soc., v. 27, pp. 371-373.
1881. Sik W. TnHomson, ‘The Tide Gauge, Tidal Harmonic Analyser and Tide
Predicter,’ Proc. Inst. Civil Eng1's., v. 65, pp. 2-25.
1882. G. H. Darwin, ‘On the Method of Harmonic Analysis used in deducing the
numerical values of the Tides of Long Period... , Brit. Assoc. Report,
pp. 319-327.
183. G. H. DARWIN, ‘Report of a Committee for the Harmonic Analysis of Tidal
Observations,’ Brit. Assoc. Report, pp. 49-118. [Sci. Papers, v. 1, pp. 1-68. ]
1884. G. H. Darwin, Second Report of same Committee, Brit. Assoe. Report,
pp. 33-35.

1885. G. H. Darwin, Third Report of same Committee, Brit. Assoc. Report, pp. 35-60.
[ Sei. Papers, v. 1, pp. 70-96. ]
A. W. Barrp and G. H. Darwin, ‘Results of the Harmonic Analysis of Tidal
Observations,’ Proc. Roy. Soc., v. 39, pp. 135-207.

1886. G. H. DAgwin, ‘Fourth Report of Committee for Harmonic Analysis . . ,’
Brit. Assoc, Report, pp. 41-56. [Sei. Papers, v. 1, pp. 98-116.]

*For Brit. Assoc. Reports, the dates are those of the meetings to which the
volumes refer ; in other cases the dates are those of publication.

ON HARMONIC ANALYSIS OF TIDAL OBSERVATIONS. 341

1886. G. H. DARWIN, ‘Instructions for the Reduction of Hourly Tidal Observations
. . . Admiralty Scientific Manual, ‘ Tides.’ [Sci. Papers, v. 1, pp. 122-139. ]

1889. G. H. DARwIn, ‘Second Series of Results of the Harmonic Analysis of Tidal
Observations,’ Proc. Roy. Sec., v. 45, pp. 556-611.

1890. G. H. DARWIN, ‘ On the Harmonic Analysis of Tidal Observations of High and
Low Water,’ Proc. Roy. Soc., v. 48, pp. 278-340. [Sci. Papers, v. 1, pp. 157-215.]

1892. G. H. DARWIN, ‘On an Apparatus for Facilitating the Reduction of Tidal
Observations, Proc. Roy. Soc., v. 52, pp. 345-389. [Sei. Papers, v. 1,
pp. 216-257. ]

1902. T. WRIGHT, ‘ Harmonic Tidal Constants for certain Australian and Chinese
Ports,’ Proc. Roy. Soc. (A), v. 71, pp. 91-96.

1904, J. N. SHOOLBRED, ‘ The Tidal Régime of the River Mersey,’ Rrit. Assoc. Report.

1906. J. N. SHOOLBRED, ‘The Tidal Régime of the River Mersey . . ,’ Proc. Roy.
Soc. (A), v. 78, pp. 161-166.

1907. Siz G. H. DaRwi1y, ‘ On the Antarctic Tidal Observations of the “ Discovery,” ’
Sct. Papers, v. 1, pp. 372-588. [Wat. Antarctic Hxp. 1901-1904, Phys. Obs.,

. 3-12.

1908" F. J. ee and J. DE G. HUNTER, ‘ Tidal Observations of the ‘‘ Scotia,” 1902-
1904,’ Nat. Antarctic Hxp., 1901-1904, Phys. Obs., pp. 13-14.

1909. T. WricgHt, ‘Harmonic Tidal Constants for certain Chinese and New
Zealand Ports,’ Proc. Roy. Soc. (A), v. 83, pp. 127-130.

1910. Sir G. H. DARWIN, ‘The Tidal Observations of the British Antarctic Expedition
1907,’ Proc. Roy. Soc. (A), v. 84, pp. 403-422.

1911. F. J. Sevpy, ‘ Analysis of Tidal Records for Brisbane for the year 1908,’ Proc.
Roy. Soc. (A), v. 86, pp. 64-66.

1913. E. ROBERTS, ‘ Re-reduction of Dover Tidal Observations for 1883-4, &c.,’ Proc.
Roy. Soc. (A), v. 88, pp. 230-233.

1914. D’ARcy W. THomMpPson, ‘On Mean Sea Level and its Fluctuations,’ Fishery Bd.
Scotland, Sci. Invest. iv.

British Work on Harmonic Analysis of Tidal Currents.

The work has all been done in connection with the ‘ Conseil Permanent Inter-
national pour 1l’Exploration de la Mer,’ and the results published in the Bulletin
Hydrographique for 1911, 1912, 1913.

Harmonic constants are given for the northerly and easterly components of the
current and also for the current-ellipses, at various depths at each station.

The English observations have been made on steamships and lightships under
instructions from the Board of Agriculture and Fisheries. The Scottish observations
were taken on board the ‘ Goldseeker’ by the ‘ North Sea Investigation Committee,’
under instructions from Prof. D’Arcy Thompson.

Indian Work on Harmonic Analysis of Tidal Heights.

The work has all been done by the ‘ Survey of India,’ a Government institution.
The results are published in the annual volumes of the ‘ Records of the Survey of
India’; prior to 1908 these volumes were called ‘ Extracts from Narrative Reports
of the Survey of India.’

Tn 1901, vol. 16 of the ‘Great Trigonometrical Survey of India’ was published,
being written by Mr. J. Eccles. It deals exclusively with tidal work and gives full
accounts of methods used, work done and results obtained up to 1892.

Canadian Work on Harmonic Analysis of Tidal Heights.

A few results are published in the annual ‘ Reports of Progress’ of the ‘Survey
of Tides and Currents in Canadian Waters.’

Australian Work on Harmonic Analysis of Tidal Heights.

BIBLIOGRAPHY.
1892. R. W. CHAPMAN and A. INGLIS, ‘The Tides of the Coast of South Australia,
Aust. Assoc. Report, iv., pp. 230-232.
1894. R. W. CHAPMAN and A. IN@uIs, ‘The Tides of Port Adelaide,’ Aust. Assoc.
Report, v.

342 REPORTS ON THE STATE OF SCIENCE.—1920.

1898. R. W. CHAPMAN and A. INGLIS, ‘The Tides of South Australia,’ Aust. Assoc.
Report, vii., pp. 241-244.

1902. R. W. CHAPMAN and A. IN@LIS, ‘The Tides of Port Darwin,’ Ast. Assoc.
Report, ix., pp. 67-68.

1903. R. W. CHAPMAN, ‘ The Tides of Port Darwin,’ Nature, v. 68, p. 295.

1914. H. B. CURLEWIS, ‘The Tides, with special reference to those of Freemantle
and Port Hedland,’ Journ. R.S. West Aust., v. 1.

1916, H. B. CuRLEWIS, ‘ Tide Tables for Port Hedland, 1917’ (Perth, W.A.).

Work done in New Zealand on Harmonic Analysis of Tidal Heights.

This work is done by the Government Department of Lands and Survey. The
results are published in the annual ‘ Reports of Survey Operations’ and in papers
by C. E. Adams.

Papers by C. H. Adams.

1909. ‘The Wellington Tide Gauge,’ Trans. N.Z. Inst., v. 41, pp. 406-410.

1912. ‘ Harmonic Tidal Constants of New Zealand Ports—Wellington and Auckland,’
Aust. Assoc. Report, v. 14.

1913. ‘ Harmonic Tidal Constants of New Zealand Ports—Wellington and Auckland,’
Trans. N.Z. Inst., v. 45, pp. 20-21.

1914. ‘Harmonic Tidal Constants of New Zealand Ports—Dunedin and Port
Chalmers,’ 7vans. V.Z. Inst., v. 46, pp. 316-318.

British Work on Harmonic Analysis of Tidal Heights.

Analyses Made.

Date e :

Porte Station Dates of Record Analysed a gi ie for

cation <

1868 | Ramsgate 1864 1 | Admiralty.
Liverpool 1857-8 2 | Mersey Dock Ba
Bombay ... 1867 2 | Parkes.

1871 | Liverpool 1866-7, 1867-8, 1868-9, 1869-70) 2 Mersey Dk. Bd.
Fort Point 1859-60, 1860-61 2 | U.S. Survey.
Cat Island 1848 2 bs

1872 | Ramsgate 1864 2 | Admiralty.
Karachi ... 1870-1 2 | Parkes.
Portland 1851, 1857, 1866, 1870 2 Sir J. Coode.

1876 | Hilbre Island 1858, 1859, 1860, 1861, 1862,

1863, 1864, 1865, 1866, 1867 2 Mersey Dk. Bd.
Karachi ... 1871-2, 1872-3 2 Parkes.
San Diego 1860, 1861 2 U.S. Survey.
Fort Clinch 1860-1 2 7
W. Hartlepool . 1858-9, 1859-60, 1860-1 2 —
Port Leopold 1848-9 2 | Clark Ross.
Beechy Is. 1858-9 2 | Capt. Pullen.
Brest 1875 2 | French Marine,
‘ Toulon 1853 2 a

1878 | Freemantle 1873-4 2 | Admiralty.

Port Louis 1838-9 = Sy
(Mauritius) "
Port Louis 1842 - pas
(Berkely Sd.)

Toulon ... He 1847, 1848 French Marine.
Marseilles 1850-1 = Pr
Malta 1871-2 — | Ad: Cooper Key

British Work on Harmonic Analysis of Tidal Heights—(cont.).

ON HARMONIC ANALYSIS OF TIDAL OBSERVATIONS. 343

Date
f

o
Publi-
cation

1889

1902

Unpublished

Station Dates of Record Analysed S pee Ror
a
Dover 1883, 1884, 1885 3 | Bd. of Trade.
Ostend 1883, 1884, 1885 3 | Belgian Minis-
| try of Public
| Works.
Singapore 1882 2 ==
Hong Kong 1883 2 —-
Princess Royal Har. | 1876-7 4 | Admiralty.
Neweastle (N.S.W. a) 1900 4 ae
Ballina 1898 4 9
Hong Kong 1889 4 | Chinese Customs
Swatow . 1897-8 4 b3
Wampoa 1894-5 4 -
Brisbane 1865-6 4 | Admiralty.
Sydney ees 1888 4 ”
Cooktown 1890 4 ef
Cairns Harbour 1892-3 4 99
Liverpool 1902 2 | Mersey Dk. Bd.
Liverpool 1902 2
Ross Island 1902-3 5. | ‘ Discovery’
Exp.
8. Orkneys 4 1903 6 | ‘Scotia ’ Exp.
Port Chalmers,N. re 1901 4 | Admiralty.
Port Lyttleton,N.Z. 1901-2 4 or
Wellington, N.Z. 1901 4 A
Auckland, N.Z.... 1900-1 4 5
Wei-Hai-Wei 1898-9 4 res
Woosung... 1902 4 | Shanghai
Customs.
Ross Island 1908 5 | ‘ Nimrod’ Exp.
Ross Island 1902-3 5 | ‘ Discovery ’
Exp.
Brisbane 1908 6 | Local.
Dover 1910-11 2 | Admiralty.
Cuxhaven 1841-2 2 | Admiralty.
Gibraltar... — 2 Si
Oban... 1910-11 2 >
Shatt-el- Arab — 2 35
Stromness 1910-11 2 BA
Georgetown 1915-16 2 | Colonial Office. |,
(Brit. Guiana)
London Bridge ... 1911, 1912 2 | Port of London.
Tilbury Dock ... _ 2 a
Royal Albert Dk. — 2 Pe
Southend — 2 7
Immingham 1911-12 2 | G.E. Railway.
Avonmouth 1910-11, 1911-12 2 | Bristol Harbour
Penang ... 1906-7 2 | Local.
Hong Kong 1887, 1888, 1889 2 ‘5
Port Swettenham — 2 3
Authorities for Analysis.
1. Thomson and Roberts. 3. E. Connor, 5. Darwin.
4, Wright. 6. Selby and Hunter.

* 2. Roberts.
The number of stations considered is 57; the aggregate record analysed amounts

to about 90 years.

344

REPORTS ON THE STATE OF SCITENCE.—1920.

British Work on Harmonic Analysis of Tidal Currents.

Sc, off Caithness.

E,, off Northumberland.
Smith’s Knoll, Lightship off Norfolk.

Varne, ”
Outer Dowsing, 5,
Swarte Bank, as

K, further out than E,.

E52, further out than KH.

in Straits of Dover.

off Lincoln.

Date Station Analyses made
1911 Se M, at 3 depths.
E, Mp, So 2” 3 ”
Smith’s Knoll IMG! “Fao! .,
Varne Mal ,f26f 3,
1912 E Mie ss-mele eas
Smith’s Knoll Mz at same depths as in 1911.
Varne Mp ” ” ” ”
1913 H52 Mz at 2 depths.
Outer Dowsing 1S a Sa
Swarte Bank M.,6 «4,
Smith’s Knoll M, xt 7 of depths taken in 1911, 1912.
Varne Mz, at same depths as in 1911, 1912.

about midway between Grimsby and Texel.

The number of stations considered is 8 ; the aggregate duration of the observa-
tions analysed amounts to about 34 weeks.

Indian Work on Harmonic Analysis of Tidal Heights.
Gauge Records Analysed.

Station Dates of Record Station
Hanstal ... 1874 to 1875 Galle
Navanar... ae oe Libis Colombo...
Okha Point wee >, », 1875, 1905 to 1906 Cochin
Bombay (A.B.)... | 1878 ,, present Cocanada
Karwar ... Ae sh 93 LSS Chittagong
Beypore ... 3s 95 1884 Akyab ... aoe
Pamban Pass 3. «9 1882 Bombay (P.D.)...
Aden 1879 ,, present
Vizagapatam >> »» 1885 Tuticorin
Madras 1880 to 1890, 1895 to present|| Bhaunagar
Rangoon +> 9) present Mergui
Amherst... a ot LSSO Trincomalee
Moulmein » os 9 1909topresent|| Minicoy ...
Port Blair ss 95 present Bushire ...
Karachi ... UES ay 2 5 Muscat
Negapatam +» », 1882, 1886 to 1888 || Diamond Is.
False Point >> >», 1885 Suez
Duoplat ag >» » 1886 Perim
Diamond Har. ... 56, ule taueates Porbandar bes
Kidderp ore ss 3, present Port Albert Victor
Elephant Pt. 1884 ,, 1888 Bassein ... a
Goa 1884 ,, 1889

Personal Observations Analysed.
Port Albert Victor, 1881 to 1882; Porbandar, 1893 to 1894.

Dates of Record
1884 to 1890
” 29 9
1886 ,, 1892

a3 1, 1891
9 9? ”
1887 ,, 1892

1888 ,,
present
990099 1893
1889 ,, 1894
99 ” 9
1890 ,, 1896
1891 ,, 55
1892 ,, 1901
1893 ,, 1898
1895 ,, 1899
1897 ,, 1903
1898 ,, 1902
” 9 9
1900 ,, 1903
1902 ,, 1903

Besides the above a record for Basrah was analysed in 1916-17 and the
published with those for the Indian stations.

results

ON HARMONIC ANALYSIS OF TIDAL OBSERVATIONS. 845

The number of stations considered is 43. The aggregate amount of record
analysed up to the present amounts to about 480 years.

Canadian Work on Harmonic Analysis of Tidal Heights.
Gordon’s Analyses.
The results were published in 1887.

Date and Length Date and Length

Station of Record Station of Record
Port Burwell ... | 1885, 2 weeks Stupart’s Bay ... | 1886, 2 weeks
Ash Inlet Sca f 1SS0R 4s se Port Laperriére ... el eg at
Nottingham Is. ... a an

Analyses made for Survey.
The results are mostly unpublished.
5 Date of beginning and - Date of beginning and

Station Length of Record Station Length of Record
Halifax ... ... | 1851, 13 years Forteau Bay... | 1898, 5 years
Quebec ... ... | 1894,18 ,, Vancouver oder 902d pos,;
St. John, N.B. ... spt DORs Port Simson ... sped Ohenrsys
St. Paul Is. dx. ShokS98,iN7- sass Clayoquet ... | 1905, 9 ,,
Sand Heads ans Pes elineti ce Prince Rupert ... | 1906, 8 ,,
Victoria, B.C. ... gu Abiniss Wadhams oi woah Ong S
Father Point ... | 1897,15 ,, Charlottetown ... | 1907, 8 ,,

Point Atkinson... | 1912, 5 ,,

The number of different stations considered is 19, Point Atkinson being prac-
tically identical with Sand Heads, which it has replaced; the aggregate length of
record analysed amounts to about 160 years.

Australian Work on Harmonic Analysis of Tidal Heights.
Analyses Made.

Date of
Publi- Station Date of Record Authority
cation
1892 | Port Adelaide ok 1889-90 Chapman & Inglis.
1894 ” oe ”? ” ”
1898 af oa 1889-90, 1893 “t bP
1902 Port Darwin vee 1896 by is
1914 | Freemantle nec 1908-9, 1909-10 Cooke.
“th °3 ae 1911, 1912 Curlewis.
+ Port Hedland 300 1913 Hp

The aggregate length of record analysed amounts to about eight years.

Work done in New Zealand on Harmonic Analysis of Tidal Heights.

Analyses made by the Survey.
The prefixed dates are those of publication, the others those of the records.

1911 Wellington. 1912 Auckland, 1914 Dunedin,
1909 1908-9 1911-12

346 REPORTS ON THE STATE OF SCIENCE.—1920.

The Urgent Need for the Creation within the Empire of a Central
Institution for Training and Research in the Sciences of Surveying,
Hydrography, and Geodesy.

By Dr. E. H. Grirriras and Major E. O. Henrict.

(Paper opening joint discussion in Sections A and E, August 27. Ordered by
the General Committee to be printed in extenso.)

Good maps are necessary for the development of a country, for such pur-
poses as defining property boundaries, limits of mining and other concessions,
and so on, as well as for such engineering purposes as railway, road, and canal
schemes, hydro-electric schemes, water supply, irrigation, &c. The importance
of good charts, as well as reliable information as to tides and currents, hardly
needs emphasising. An incorrect or out-of-date chart will cause losses due
to delays to shipping, even if it does not lead to more direct loss. Anything
that will assist in the production of up-to-date and accurate charts is of great
and direct benefit to the shipping industry, and through it to the nation. Even
when such work has once been completed there is no finality, as both maps and
charts require periodical revision at more or less frequent intervals, according
to circumstances.

The economical and speedy production of such maps and charts necessitates
a thorough knowledge of the principles on which all survey work is based,
and of the best means of applying such principles under varying conditions.
Apart from revision work, there is still a very great deal of survey work waiting
to be carried out. Enormous areas still exist in the Empire which are surveyed
very inadequately or not at all.

Very large sums have been misapplied in the past owing to a. lack of appre-
ciation of the. principles which should underlie all survey work. The following
quotation from the official account of the ‘Cadastral Survey of Egypt,’ by
Captain H. G. Lyons (Cairo, 1908), is an example of this:

‘Surveying has been carried on in Egypt to a considerable extent during
the last ninety years, and the work of Muallim Ghali and M. Masi, 1813-1822,
of Mahmud Pashael Falaki, 1861-1874, of the cadastre of 1878-1888, of the
Hydrographic Survey of 1889-1898, amounting to a total of some forty years’ work
on the geographical measurement of the country, had been accomplished before the
cadastral survey, which has just been completed, commenced. That more perma-
nent results were not obtained from them is mainly due to want of scientifically
organised control and supervision, so that inferior work was not detected, and the
standard of accuracy was allowed to fall below that which was necessary in
so densely populated a country. The circumstances of the time have usually
been responsible for this, and want of funds, urgent demands for maps to be
prepared within a minimum length of time, and other similar causes led to
much repetition of work without producing reliable maps of the country.

‘During the time that the present Survey Department has been engaged in
measuring the cultivatable lands in Egypt, much inconvenience has been
experienced from the want of any complete account of these earlier surveys.
. . . When the formation of the Survey Department was undertaken in, 1898,
no complete account existed of the work of this kind which had been previously
undertaken. References to it existed in various reports, but the detailed
information concerning the methods employed, their cost, the recruiting and
training of staff, and relative values of different ways of executing the work
was not available. There was no time then to undertake its compilation, but
had such a work existed, subsequent work would have been greatly expedited
and facilitated, and a considerable economy would have resulted.’

The Egyptian Survey of 1878-1888, mentioned above, cost some £360,000,
and produced incomplete maps of some 2,000 square miles. Almost the whole

4
7

ON SCIENCES OF SURVEYING, HYDROGRAPHY, AND GEODESY. 347

of the work had to be repeated in 1892-1907, when, owing to the adoption of
proper methods, and in spite of many difficulties, some 13,000 square miles
were satisfactorily mapped at a cost of under £450,000.

The methods to be adopted depend upon circumstances, the nature of the
country, and the objects of the survey. The difficulties to be overcome vary
in different parts of the world. The experiences of the various surveyors have
been published in their records and reports, but these are not in an easily
accessible form, nor is there any general index or summary to be found. The
originals are circulated to a limited number of persons and institutions, and
are buried in libraries, even if their existence is not forgotten. When a new
difficulty arises in any survey it has to be tackled de novo, though it is quite
likely that similar circumstances have arisen before. In such a case it is
probable that the surveyor in question does not know of it, and even if the
reports are accessible to him (which they frequently are not) the actual
information he wants is most etfectually buried. This leads to much waste of
effort, as there is no central body to which he can refer.

As regards existing Departments and Institutions, the Dominion, Indian,
and Colonial Surveys are all independent, and, broadly speaking, train their
own staff. There are, however, good survey schools in some of the Dominions.
The Ordnance Survey produce their well-known maps, which are revised

eriodically, and they are so complete that no extensive survey work is required
by outsiders in this country. This accounts for the lack of attention paid to
the subject outside Government Departments, but the result has been that the
development of the science of surveying has largely stagnated in this country,
the centre of the Empire.

There is, therefore, a distinct need for a school and institution where
students can be trained in the principles of survey work, and where the subject
is studied as a whole. This school would also serve as a central information
bureau, enabling the scattered’ surveyors of the Empire to keep in touch with
developments, and to which they could apply for information and assistance.

It might seem at first sight that this could and should be undertaken by a
Government Department, but this is hardly possible for various reasons. There
is no central authority which deals with the Government Surveys of the
Empire, though a link is kept between the Colonial (as distinct from the
Dominion) Surveys by the Colonial Survey Committee. The various Surveys
and Departments naturally have to consider their own immediate needs first;
they are usually short of funds, and consequently are not in a position to
carry out the work now being discussed. Even if a central authority were
formed for this purpose it could deal only with Government Surveys, and could
not train surveyors and engineers for private work.

There seems little doubt that most of the Government Surveys would wel-
come a school from which they could recruit their staff, and an institution to
which they could apply for information, and which could keep them in touch
with the activities and progress in other parts of the world.

The existence of such an establishment would also encourage the production
of improved designs of instruments, and the invention of new time-saving
devices; there have been many such improvements of late years, but mostly
from abroad—e.g., Invar tapes and wires for base measurement (France),
improved levelling instrument (Germany). There are also many developments
in view which require working out—e.g., the use of wireless time signals for
the determination of longitude in the field, survey from aircraft, &c. At
present makers have little inducement to bring out new and improved patterns
of instruments; their largest customers are engineers, who as a rule have had
a very elementary training as surveyors, and are shy of adopting a new
instrument or method.

The above remarks apply particularly to land surveying, but are largely true
also of hydrographic work. India and Canada have their own Hydrographic
Services, but apart from this the Hydrographic Department of the Admiralty
has to deal with all the seas and coasts of the Empire, and also with such others
as are not dealt with by their own Governments. The task is a large one, and
the resources available are all too small for the work. There is much work
waiting to be done, and anything that assists in getting this work done quicker

348 REPORTS ON THE STATE OF SCIENCE.—1920.

and better will be of great value to the shipping industry and the country as a
whole. Even in home waters there ismuch to be done, if only due to the changes
continually taking place in all estuaries. The Thames, the Humber, Portsmouth,
Plymouth, and Liverpool have to be resurveyed annually. The Bristol Channel
is badly in need of resurvey, which it is hoped will be carried out shortly (it
was last done about 1890). The approaches to Liverpool, the Solway Firth, and
the Clyde badly need revision. Most of the East Coast of England and the
North Sea has not been surveyed for fifty years, and some of the work is as
old as 1830. Apart from the shifting of sandbanks, &c., much of the earlier
work is not up to the standard of modern requirements.

As regards the rest of the world, the coast of Brazil has not been surveyed
since about 1852, and that survey suffered from the poor facilities available at
the time, and is very out of date. The approaches to Monte Video have not
been done since 1849, and the charts are bad. The Falkland Islands are partly
unsurveyed, and South Georgia and the South Shetlands almost entirely so.
The Straits of Magellan, other than the main routes, are largely unknown. The
coasts of China are yet imperfectly charted ; even the approaches to Hong Kong
are incomplete. Siam and the Straits Settlements require resurvey ; the charts
are not up to modern requirements and are out of date. The Red Sea coasts
are at present almost entirely charted from the original sketch surveys. The
Grecian Archipelago, the Dardanelles, and the Black Sea all require resurveying.

There is no school where hydrographic surveyors can receive instruction in
the principles and theory of their work, and no staff available for studying
methods and instruments and bringing them up to date. The Hydrographic
staff of the Admiralty is recruited from volunteers amongst the younger officers
of the Executive Branch of the Royal Navy who have passed in navigation.
They learn their surveying in the surveying ships while work is in progress,
and the staff of trained surveyors is at present so limited that they can give
little instruction to the beginners. Many officers, after serving in a surveying
ship for two or more years, return to ordinary duties afloat, or specialise in
other branches where their knowledge of survey work is of great benefit to
them. The remainder are advanced in rank with the officers of H.M. fleet.
The existence of a school where the theoretical side of the question could be
studied would be of great benefit to all.

The principles involved in survey are the same, whether applied by land or
sea, and the instruments are largely the same. One establishment could usefully
study and give instruction in both sides of survey work.

Survey cannot be carried out over large tracts of country without considera-
tion of the science generally known as geodesy, which is really only survey as
applied to the earth as a whole. The problems inyolved in this require not
only world-wide data but high mathematical skill. Problems interconnected
with these are those concerning the tides and terrestrial magnetism, both of
great importance to navigation. These, again, connect with the study of the
earth’s structure in its wider sense, and so connect with seismology and geology.
These problems may all be summed up in the word geophysics.

While a knowledge of geophysics is not necessary for every surveyor, no
survey authority can function satisfactorily without it. At the same time few
such authorities have the staff available for its proper study. A central institu-
tion, which could be referred to for information, would add greatly to the
efficiency of the Survey authorities.

The need for a British Geodetic Institute is admitted by all who are
acquainted with the nature and importance of the pressing Imperial and gcientific
problems which depend on the great surveys. The study of such problems has
hitherto been left, in characteristic British fashion, to the initiative of enthu-
siastic individuals or neglected altogether. Take, for example, the case of the
tides, so vital a matter to our sailors. While the late Sir George Darwin still
lived it could at least be said that one master-mind was devoted, with some
approach to continuity, to the study of the great problems which must be
attacked and solved if tidal prediction is to advance beyond its present elementary
and scrappy state, but since his lamented death in 1912 the subject-has lacked
attention.

At the request of the B.A., Prof. Horace Lamb recently reviewed the whole

ON SCIENCES OF SURVEYING, HYDROGRAPHY, AND GEODESY. 349

situation with regard to tides, and in a masterly report indicated the number
and importance of the problems awaiting solution. Problems comparable in
insistence are connected with the land surveys of our Empire, and a similar
review of the general situation, also initiated by the B.A. under the stimulus
of war, drew attention to the pressing need of some determined effort to
attack them. The report opened with this cogent sentence : ‘ There is no institu-
tion, association, or department whose business it is to deal with the higher
Geodesy.’ Consideration of the report by a special committee, subsequently
enlarged, developed in the direction of urging the establishment of a Geophysical
Institute. The need for such an Institute has been formally recognised as
urgent by the Conjoint Board of Scientific Societies (formed during the war
for the study of urgent questions), who appointed a small executive com-
mittee (which included the President and Secretary of the Royal Society) to
press for the immediate establishment of such an Institute.

A committee promoted by the ex-Vice-Chancellor of Cambridge was subse-
quently formed, and issued an appeal calling attention to the national import-
ance of the matter. Amongst its members are to be found the Astronomer-
Royal, the President of the Royal Society, Sir Charles Parsons, Col. Lyons
(formerly Director-General of the Survey of Egypt), Prof. Turner, Sir Charles
Close (Director-General of the Ordnance Survey), Sir Napier Shaw, Sir Joseph
Larmor, and other authorities on scientific matters.

In an appeal issued by that committee it is stated that ‘It is the widespread
British territories which are most closely concerned in the great international
surveys of the future, and indeed of the past; and the consolidation and exten-
sion of their special surveys is most necessary to the solution of the Geophysical
problems of the world. . . . It would be a matter for regret if, from omission
of the relevant scientific development at home, British official surveyors were
again compelled to rely on the Prussian Geodetic Institute at Potsdam for
information with regard to international work in the higher Geodesy.’

The following are extracts from letters received by this committee :—

Admiral Parry (then Hydrographer to the Admiralty)—‘ Such an Institution
would be warmly welcomed by the Hydrographic Department, and it is sug-
gested that courses of instruction should be available, not only for geodesists
and land surveyors, but also for the cognate Naval Service, so that these
services would be able to collaborate more closely than at present as regards
geodetic problems, and as regards tidal problems would assist in bridging the
gap between the practical and theoretical sides which at present exists. I
am convinced that the establishment of such an Institute would be of the
greatest benefit to the Empire at large, more especially as the latter is so widely
distributed, and it seems most essential that there should be such an Institute
where surveyors, geodesists. etc., of the Empire could not only receive instruc-
tion but to which they could also refer any practical and theoretical problems
which may arise.’

A letter from the Army Council states that—‘ The war which is now drawing
to a conclusion has shown the great value to the Army of trained surveyors
from the skilled geodesist to the topogranher and draughtsman. I am to say,
therefore, that the Council would view with great satisfaction the establishment
of an Institute which would encourage the study of Geodesy and Survey in
all its branches, and that such an Institute would undoubtedly be of immense
assistance to that study of survey work which it is the wish of the Council
to promote in the Army.’

It will be seen from the above that both the Navy and Army authorities
are anxious to see a combined Survey and Geodetic School and Institute
established.

Sir Charles Close (Director-General of the Ordnance Survey) writes—‘ I
have no doubt that it is in the national interest that a Geodetic Institute should
be created. and I think it would be a very satisfactory arrangement if it were
estahlished at Cambridge. and. in connection with it, a Professorship of Geodesy.’

We think it would be difficult to find, in any scientific matter. greater
unanimity amongst all the authorities concerned therein. We trust that suffi-
cient evidence has been given both as to the national importance of the subject
and the urgency of the need for action. We await the advent of the ‘ Vivus
Benefactor,’ for—as already indicated—there is a consensus of opinion that

350 ‘REPORTS ON THE STATE OF SCIENCE.—1920.

such an Institution should be established within a University by private bene-
factions, although assistance might, as a consequence, be forthcoming from
national funds. The wide ramifications of Survey, Geodesy, and Geodynamics
into mathematical, physical, and engineering sciences call for their study in a
University, rather than in a Departmental, atmosphere. ‘ Undue withdrawal
from the Universities to official special Institutes of the men who show promise
of ‘power would hamper their own development by removal from their proper
environment; moreover, it would weaken the efficiency of the Universities as
the national nurseries of scientific ability and genius at a time when, by more
intimate relations with the Dominions and increased contact with other nations,
they ought to be preparing for the discharge of imperial functions.’ 1

We trust that this conference of the Physical and Geographical Sections
will forward to the Council of the B.A. a resolution calling attention to the
urgency of this matter.

1 Sir Joseph Larmor.

SECTIONAL TRANSACTIONS.—A. 351

SECTIONAL TRANSACTIONS.

SECTION A.—MATHEMATICAL & PHYSICAL

SCIENCE.

(For references to the publication elsewhere of communications entered in

9.
10.

11.

12.
13.

the following list of transactions, see p. 380.)

Tuesday, August 24.

Presidential Address by Prof. A. S. Eppinaton, F.R.S.
See p. 34.

Mr. J. Eversuep, F.R.S.—Measures of the Shifts of the
Fraunhofer Lines and their Interpretation, particularly
with relation to the Einstein Theory.

Major P. A. MacManon, F.R.S.—A New Binomial
Theorem and its Arithmetic Interpretation.

Prof. H. Hiuvron.—Plane Algebraic Curves of Degree n
with a Multiple Point of Order n—-1, and a Conic of
2n-point Contact.

Prof. G. H. Bryan, F.R.S.—The Graphical Solution of
Spherical Triangles.

Mr. T. C. Lewis.—lIs there in Space of three Dimensions
an Analogue to Feuerbach’s Theorem? Is there any-
thing corresponding to the Hart System?

Wednesday, August 25.
Dr. F. W. Aston.—Mass Spectra and the Constitution of
Chemical Elements.
Sir E. Rurwerrorp, F.R.S.—The Building up of Atoms.
Prof. R. Wuippineton.—The Ultra-Micrometer.
Lieut.-Col. F. J. M. Srrarron.—Spectra of Nova
Aquile III.
Rev. Father A. L. Contin, 8.J.—Comparison of Drawings
of Solar Facule and Photographs of Calcium Floccult.

Thursday, August 26.
Discussion on The Origin of Spectra, opened by Prof. A.
Fowter, F.R.S., and Prof. J. W. Nicuouson, F.R.S.
Report of Seismology Committee. Prof. H. H. Turner,
F.R.S., and Mr. J. J, SHaw. See p. 210.

352 SECTIONAL TRANSACTIONS.—A.

14. Sir Outver Lopas, F.R.S.—Controversial Note on
Popular Relativity.

This note concerns the assumed necessary constancy of the
observed velocity of light in free space, as contrasted with
the universally admitted constancy of its true velocity. The
author contends that there is no experimental evidence for
the dogma that wave-fronts are concentric with a travelling
observer initially situated at the source. The Michelson-
Morley experiment is consistent with such concentricity, but
does not necessitate it. The FitzGerald-Lorentz contraction
of matter is a perfectly valid alternative explanation.
Einstein’s equations exercise no physical discrimination and
are consistent with either mode of expression. In interpretin
them verbally it is safer for a physicist to postulate a special
property of matter than to attempt to foist complications
upon time and space,

15. Prof. F. Horton and Miss A. C. Davies.—The Tonisa-
tion of Atmospheric Neon.

It has been found? that the following are critical electron
velocities for atmospheric neon :—11'8 volts and 17°8 volts
for the production of radiation, and 16-7 volts, 20-0 volts,
and 22:8 volts for the production of ionisation. The condi-
tions under which the different critical points were indicated
showed that the radiation velocity, 11°8 volts, is associated
with the ionisation velocity, 16°7 volts, and that the radiation
velocity, 17°8 volts, is associated with the ionisation velocity,
22:8 volts. No third critical velocity for radiation, corre-
sponding to the ionisation velocity, 20°0 volts, was detected,
but it is possible that such a critical velocity occurs too
close to one of the other radiation velocities to be distinguished
separately.

The conditions under which the various points were
obtained also showed that none of the critical velocities
mentioned can be attributed to the displacement of a second
electron from an already ionised atom. Neon is the only
gas so far investigated which has shown more than one
critical velocity for the removal of a first electron from the
atom.

Further information as to the ionisation of neon was
sought by observing the spectrum of the luminosity produced
in the gas as the electron velocity was gradually increased ;
for on the generally accepted view the line spectrum of a
gas results from the recombination wHich occurs when
ionisation has taken place. It was found that the lines
of the first and second subordinate series types never appeared
Below 22°8 volts, but that under certain conditions the lines
of the Principal series type came in at 20°0 volts. No lines
in the visible spectrum were ever observed below 20°0 volts,
although the earlier experiments show that considerable
ionisation must have been occurring.

The results of the ionisation experiments might be inter-
preted as indicating that atmospheric neon is a mixture of
different elements, since isotopes would be expected to have
the same critical velocities for electrons. Such a supposition
is, however, not borne out by the investigation of the spectrum
of the luminosity produced in atmospheric neon, for if there
were more than one element present it would be expected
that the complete spectrum of the element of lower ionising
velocity (including some lines in the visible spectrum) would

1 Proc. Roy. Soc. A, 1920.

16.

17.
18.
19.
20.
21.

22.
23.

SECTIONAL TRANSACTIONS.—-A, B. 358

be obtained for lower electron velocities than the spectrum
of the other element, and this was not found to be the case.
We therefore conclude that the different critical velocities
found for neon correspond to the displacement of differently
situated electrons within the atom, or, in other words, that
the external electrons in neon are not all symmetrically
situated about the nucleus.

Report of Committee on Gravity at Sea.
Friday, August 27.

Prof. S. CHapman, F.R.S.—Terrestrial Magnetism,
Aurore, Solar Disturbance, and the Upper Atmosphere.
Dr. A. EK. Oxtey.—Magnetism and the Structure of the
Atom.
Mr. J. H. SuHaxsy.—Vapour Pressures.
Reports of Committee on Tides. See p. 321.
(1) Prof. ProupMan.—Harmonic Analysis.
(2) Mr. A. T. Doopson.—Prediction.
Dr. P. V. Weuus.—The Thickness of Stratified Soap
Films.
Mr. H. P. Waran.—A New Type of Interferometer.
Joint discussion with Section E on Geodesy. See p. 346.

SECTION B.—CHEMISTRY.

(For references to the publication elsewhere of communications entered in

1920.

the following list of transactions, see p. 380.)

Tuesday, August 24.
Presidential Address by Mr. C. T. Heycocx, F.R.S.
See p. 50.
Capt. A. DessoroucH.—Industrial Alcohol.

Wednesday, August 25.
Joint Meeting with Section A for the discussion of papers
7 and 8 in the programme of that Section (which see).
Discussion on Lubrication.—Mr. A. E. Dunstan, Mr.
H. M. Weuus, Mr. J. KE. Sourncomse, Mr. H. T.
Tizarp, Prof. W. C. McC. Lewis.

Thursday, August 26.

Papers on the Metallurgy of Tungsten—Mr. J. L. F.
Voge, Prof. C. H. Descu. Electrolytic Zinc.—Mr. 8.
FIELD.

Dr. R. V. Stanrorp.—(a) New Method for the Estima-
tion of Carbon by Combustion in Organic Compounds,
using very small quantities of substance. (b) Hstima-
tion of Amino-acids, using very small quantities of
substance.

304 SECTIONAL TRANSACTIONS.—B, C.

7. Report of Committee on Fuel Economy (Prof. W. A.
Bone, F.R.S.), and Discussion thereon. See p. 248.

Friday, August 27.

8s. Dr. J. 8S. OwEens.—Researches on Atmospheric Pollution
and its Measurement.

9. Prof. F. M. Jancer.—Research Work at High Tempera-
tures, and the Determination of Surface Tension and
Electrical Conductivity between —100° and +1650° C.

The following excursions were arranged for members of the
Section: Melingriffith Tinplate Co.; South Wales Indiarubber
Co.; Cardiff Gas Co.; Cardiff Dowlais Works; exhibits, etc., in
Chemical Laboratories, Mental Hospital, Radyr; Powell Duffryn
Co. ; Tharsis Sulphur and Copper Co.

SECTION C.—GEOLOGY.

(For references to the publication elsewhere of communications entered in
the following list of transactions, see p. 380.)

Tuesday, August 24.
1. Presidential Address by Dr. F. A. Barusr, F.R.S.
See p. 61.
2. Prof. A. Huperr Cox.—Address on the Geology of he
Cardiff District.

3 Dr. J. W. Evans, F.R.S.—The Origin of the Alkali
Igneous Rocks.

These rocks, distinguished by unusually high proportion
of alkalies, relatively to alumina and lime, occur mainly
where the Crust of the earth is thick, the heat-gradient low,
and there has been no folding since remote times. Magmas
appear to have reached the sut face by fault fissures from great,
depths where high pressures are associated with compara-
tively low temperatures. Crystallisation proceeding under
such circumstances, there would be an early formation of
minerals with small molecular volumes, garnets, kyanite,
epidote, and zoisite, minerals rich in lime and alumina.
Zoisite may be regarded as the high-pressure representative of
anorthite, but there is no corresponding representative of
albite or orthoclase. Consequently we should expect a
residual magma exceptionally rich in alkalies which would
furnish the material necessary for formation of alkali rocks.

4. Reports of Research Committees. See p. 261.

Wednesday, August 25.

5. Joint Meeting with Sections D and K. Discussion.—
Mendelism and Paleontology: The Factorial Inter-
pretation of Gradual Changes, especially when New
Characters appear late in the Individual Life-cycle.

SECTIONAL TRANSACTIONS.—C. 355

Dr. F. A. Baruer, F.R.S. :—

The question posed. Can characters be regarded as
independent, i.e. as manifestations of independent factors in
the germ? Does evolution take place solely by addition or
loss of such factors? Is there not also a gradual modification
of the body, resulting in a continuous transition? Palzonto-
logists find such transition to be the rule in those cases where
the geological record is sufficiently complete. (See President’s
Address, Section C, heading ‘ Continuity in Development.’)
Paleontologists support the theory of Recapitulation, and
believe that, in many cases, gradual modification of the
adult and senile body is, in the course of race-history, pushed
back to earlier growth-stages. (See President’s Address,
Section C, heading ‘ Recapitulation.’) Can such cases be
explained by independent factors in the germ? Does not
that hypothesis involve, first, an alteration of the germ
through change in the body; secondly, the determination of
that germinal change in a direction harmonious with bodily
change?

Dr. R. Ruaates Gatss :—

According to mutationist hypothesis, germinal characters
arise as alterations of single elements of the germ plasm.
This conception avoids the difficulties involved in considering
the change as due to the loss or addition of a factor. It
recognises on the one hand the solidarity of the germ plasm as
a whole, and on the other the independent origin of variations
in its several parts. Such variations are termed karyogenetic,
since they apparently arise in the nuclei and are perpetuated
by mitotic division. Mutations of this nature are almost
universal amongst wild plants and animals, and some of
them are so small that for general purposes they are practi-
cally continuous. They differ from the Darwinian conception
of continuous variation, however, in that (i.) they do not
arise in any regular order, (ii.) they are inherited as separate
units. But Recapitulation is an almost equally widespread
phenomenon in animals, and to a less extent in plants. The
recapitulation in animal embryos, and in such fossil groups
as the Ammonites, implies the addition of terminal stages to
the development of the organism. From the standpoint of
organic structure this process is clearly different from a
mutation by which the nuclear unit is modified throughout
the organism. Recapitulatory characters thus fall into two
groups : (i.) embryonic, which appear always to imply adap-
tation of the organism to different conditions, and are best
explained by the neo-Lamarckian principle; (ii.) orthogenetic,
which appear late in the life-cycle but are germinal in origin
and non-adaptational.

Prof. J. HE. Durrpen.—Mendelism; Paleontology ;
Evolution.

Recent investigations in genetics in general give support
to the factorial hypothesis, namely, that the characteristics
of the body are represented in the germ plasm, in all proba-
bility in association with the chromosomes. Supporting
evidence is forthcoming from sex, crossing-over and localisa-
tion. Any hereditary change in an organism must therefore
be associated with factorial change in the germ plasm.
Casual mutations readily admit of Mendelian interpretation,
but evolution in general does not take place by changes of
this kind. Evolution of species often seems to call for a
sintilar change in the whole assemblage of individuals within
an area, while paleontology and the study of numbers of

AA2

356

SECTIONAL TRANSACTIONS.—C.

related forms calls for gradual successional changes in the
same direction as regards any particular structure (ortho-
genesis). Mendelian experiments do not yet afford any great
support for either of these demands. Observed mutational
changes do not call for environmental influence, and are
wholly apart from any adaptive considerations; natural
selection plays no part in the origin or preservation of
variations, but may be eliminative. It is highly questionable
whether somatic or environmental influences can modify the
germinal factors in definite directions, but disruptive changes
and gradual loss of factorial vigour, or perhaps senility, may
be contemplated, continued over long ages. As the common
germ plasm of a race may at any one time be presumed to be
in somewhat the same condition, evolutionary changes on
somewhat similar lines may be expected.

Prof. A. Drenpy, F.R.S.

Thursday, August 26.

Dr. T. Frangurn Sisty.—The Old Red Sandstone of the

Mitcheldean District, Gloucestershire.

Mitcheldean lies on the Gloucestershire-Herefordshire
border ten miles west of Gloucester, and in the latitude of
the Breconshire Beacons. In this neighbourhood persistent
westerly dips determine an outcrop of the whole of the
Old Red Sandstone, with a thickness of some 7,500 feet, in a
band scarcely two miles wide, bounded on the east by the
Silurian strata of the May Hill anticline and on the west by
the Carboniferous of the Forest of Dean coal-basin. The
sequence of strata determined in this locality offers a possible
key to the wilderness of Old Red Sandstone in Herefordshire.

Prof. W. M. Furypers Perriz, F.R.S.—The Continuance
of Life on the Earth.

If by any process of aggregation the earth has been at a
ved heat, all the lime and soda would be combined with the
silica (now sandstone) and all the carbonic and hydrochloric
acids would be in the atmosphere (now locked up in limestone
and salt). The changes from that condition would consist in
the acids gradually decomposing the silicates; at present
there is only a minute fraction of the original carbonic acid
left in the atmosphere. The decomposition of a few more
inches of silicates over the globe would exhaust the carbonic
acid, and life could not exist. This may take place in a
few hundred thousand years, and such is the limit to
vegetable and therefore to animal life, irrespective of solar
cooling. The amount of carbon in the strata is probably
enough to combine with all the oxygen of the air; hence land-
breathing animals were impossible until after the carbon
had become separated and left oxygen free. This agrees
with the appearance of air breathers after the Carboniferous

age.

Dr. A. E. Trueman.—The Liassic Rocks of Somerset- |

shire and their Correlation.

The Liassic iocks of Somerset are thin but richly fossili-
fercus, yielding many large Ammonites. When followed
towards the Mendips there is. considerable reduction in
thickness and marked lithological change. At several
localities a white limestone resembling the Sutton Stone of
Glamorgan is seen to rest on the Carboniferous Limestone ;

nts eran»

SECTIONAL TRANSACTIONS.—C. 357

it is developed at various horizons and usually contains no
Ammonites, but correlation can be made by means of species
of Ostrea and Gryphea. In the numerous exposures near
Radstock many non-sequences can be located, and maps
showing the movement of intra-Liassic folds have been
prepared,

9. Dr. J. K. Cuarteswortu.—The Glaciation of the North-

West of Ireland.

The major part of the region investigated, including the
Donegal Highlands and the Sperrin Mountains, was never
invaded by the Scottish ice as currently supposed, but the
Donegal mountains, in particular the Barnesmore Hills,
formed a most powerful centre of radiation, whence ice
streamed westwards to the Atlantic and eastwards over the
Sperrin Mountains to Cookstown and beyond. In a south-
easterly direction the ice passed obliquely across the Clogher
Valley in Slieve Beagh to the Central Plain of Ireland, where
was located the ‘central axis’ of Hull and Kilroe. This
axis of dispersal existed at no period of the glaciation.

10. Mr. L. Dupury Stamp.—On Cycles of Sedimentation in
the Hocene Strata of the Anglo-F'ranco-Belgian Basin.
The Eocene deposits of the great Anglo-Franco-Belgian
Basin can be grouped naturally into a series of cycles of
sedimentation—the Montian, Landenian, Ypresian, Luetetian,
Ledian, and Bartonian. Each cycle commences with a marine
invasion and passes from marine to estuarine and continental
conditions. In England the changes are closely connected
with the gentle, intermittent wprise of the Weald.

Friday, August 27.

11. Dr. J. W. Evans, F.R.S.—The Geological Structure of
North Devon.

In early Permian times the Devonian and Carboniferous
were thrown by pressure from the south into overfolds, with
overthrust faults. A subsequent relaxation of pressure
resulted in a slip back on the same fault-planes. There were
also oblique tear-faults striking between north and west.
A mountain region then sloped southward from the Welsh
Coast to Mid-Devon and much material was transported in
that direction. In the ‘Triassic period, however, the
Palzozoic had, as a whole, its present contours, including
the great Glastonbury and Bristol Channel depression
descending to the west, and its subsidiary valleys still partly
filled with Mesozoic deposits. In Tertiary times there was
renewed pressure from. the south. This met with less
resistance in the west, and there was consequently a relatively
forward and downward movement on that side along the old
tear-faults and possibly new fractures with the same general
direction. In Pliocene times the land was more submerged
than now and the subsequent emergence seems to have con-
tinued in most places till a comparatively recent date.

12. Prof. W. L. Braaa.—Crystal Structure.

The investigation into crystal structure, which has been
made feasible by the discovery of the diffraction of X-rays
by crystals, has led to a determination of the precise positions
of the atoms in a number of the simpler crystalline forms.
Recent theories of atomic structure, such ag those put
forward by Bom and Landé, Debye, Lewis, and Langmuir,

358

SECTIONAL TRANSACTIONS.—C, D.

are largely based on the arrangement of the atoms in crystal-
line solids, since this arrangement affords an insight into the
nature of the forces acting between the atoms. In such
compounds as sodium chloride, it is probable that the atoms
exist as ions of sodium and chlorine, and that the crystal is
held together by the electrostatic attractions of these ions,
thus accounting for the fact that there is no grouping of the
atoms into molecules in the solid. In other compounds, such
as those of two electronegative elements, the molecular
arrangement persists in the solid state and the chemical com-
bination appears to be of a different type from that of sodium
chloride. A consideration of the distances between the
atomic centres in crystals supports the conception of the
two types of chemical combination.

13. Mr. D. C. Evans.—The Ordoviceo-Valentian Succession

in North-east Pembrokeshire and North Carmarthen-
shire.

14. Mr. Davi Davies.—Paleontology of the Westphalian

and lower part of the Staffordian Series of the Coal

Measures as found at Clydach Vale and Gilfach Goch,
East Glamorgan.

Recorded : 45,000 plants; 1000 shells; 2 insects and
one fish scale. Plants yielded 154 species, shells 6 species,
insects 2 species, fish scale one; 45 of these are new
to South Wales and 7 new to Britain. Ecology of ten
horizons : Equisetales predominate in four; Filicales and
Pteridosperms in three; Lycopods in two, and Cordaitales in
one horizon. When Lycopods predominate, Fern and Fern-
like plants are weak, and vice versa. 37 per cent. plants are
common to both series; 31 per cent. distinctly Staffordian ;
32 per cent. distinctly Westphalian. The Pennant Sandstone
produced smooth round coal pebbles, giving evidence of a
geological break. A significant feature is the appearance of
new species at this period.

SECTION D.—ZOOLOGY.

(For references to the publication elsewhere of communications entered in

the following list of transactions, see p. 381.)

Tuesday, August 24.

Presidential Address by Prof. J. SrannEy GaRDINER,
F.R.S. (see p. 87). Followed by a Discussion.

Afternoon.

2. Prof. J. SrepuHenson.—The Polyphyletic Origin of Genera

in the Oligocheta, and its bearings.
Prof. P. Fauven.—The Affinities of the Annelidan Fauna

of the Abrolhos Islands.

5.
6.

10.
11.
12.

13.
14.

SECTIONAL TRANSACTIONS.—D. 359

Wednesday, August 25.

Joint Meeting with Sections C and K. Discussion on
Mendelism and Paleontology: the Mendelian Inter-
pretation of gradual changes, especially when new
Characters appear late in the individual Life-cycle.
For speakers see Programme of Section C, p. 354.

Afternoon.
Reports of Committees.
Prof. J. E. Dusrpen.—A Caudal Vesicle and Reissner’s
Fibre in the Ostrich.
Mr. J. H. Luovp.—The Early Development of the Pro-
nephros in Scyllium.

Thursday, August 26.

Discussion on the Need for the Scientific Investigation of
the Ocean. Opened by Prof. W. A. Herpman, C.B.E.,
F.R.S. Other speakers: Prof. J. Sranuey GARDINER,
BRS. Drews. Aten,” ERtS., Mr. C. Tam
ReGcan, F-R.S., Prof. C. A.-Kororw, Prof. J. E.
Durrpen, Sit Francis Ocitviz, Mr. F. E. Smits,
Dr. EK. C. Juz.

Section E (p. 361) took part in this discussion.

Afternoon.

Discussion on the Need for the Scientific Investigation of
Fisheries. Opened by Mr. H. G. Mauvricr, C.B.
Other speakers: Prof. A. Mrrx, Prof. James Joun-
stone, Mr. Crawrorp Heron, Prof. G. GurLson,
Dr. E. J. Auten, F.R.S., Prof. W. Garsrana, Mr. C.
Tate Recan, F.R.S., Mr. Neate, Prof. J. SranLey
GARDINER, F'.R.S.

Friday, August 27.

Prof. J. E. Durrpen.—The Pineal Eye in the Ostrich.

Prof. A. Murx.—The Physiology of Migration.

Prof. C. A. Kororn.—The Neuro-motor System of Cilate
and Flagellate Protozoa, and its Relation to the process
of Mitosis and to the Origin of Bilateral Symmetry in
certain Flagellates.

Dr. Cresswetut Sunarer, F.R.S.—The Influence of Salts
on Growth.

Mr. E. Hrron-Auten, F.R.S., and Mr. A. Karuanp.—
Protoplasm and Pseudopodia.

360 SECTIONAL TRANSACTIONS.—--D, E.

Afternoon.

15. Prof. C. A. Korom.—Hookworm and Human Efficiency.

16. Prof. R. W. Heaner.—The Relations between Nucleus,
Cytoplasm, and External Heritable Characters in the
genus Arcella.

17. Prof. E. B. Poutron, F.R.S.—A Preliminary Account of
the Hereditary Transmission of a minute, extremely
variable, generally asymmetrical marking in the fore-
wing of the Currant Moth (Abraxas grossulariata).

Saturday, August 28.
Excursion to Southerndown and Merthyr Mawr.

Exhibits.
There were on exhibition throughout the meeting :—
(a) A series of plates for ‘A Monograph of the Unarmoured
Dinoflagellates,’ by Prof. C. A. Korom.
(b) Living specimens of Amphidinium, by Miss C. Herpmay.

SECTION E.—GEOGRAPHY.

(For references to the publication elsewhere of communications entered in
the following list of transactions, see p. 381.)

Tuesday, August 24.
1. Presidential address by Mr. J. McFaruane. See p. 98.
2. Mr. D. Lievurer Toomas.—Some Geographical Aspects
of the Distribution of Population on the South Wales
Coalfield.

The narrow valleys of the plateau provoke feelings of
imprisonment and isolation—originally the coal attracted the
raw material of industry, e.g. copper, iron—after 1850 coal
was worked in the interior valleys—the Rhondda valley
became populous after 1871 and caused the growth of Cardiff
and Barry,

Discussion opened by Dr. A. E. Trueman. Other
speakers: Prof. H. J. Fururn, Mr. H. J. Ranpatu,
Mr. A. E. L. Hupson, &c.

3. Dr. A. E. Trusman.—The Iron Industry of South Wales.
Iron ore either hematite or ironstone nodules—the iron-
stone worked all over the coalfield, but especially the east—
the growth of Merthyr Tydfil—phosphatic nature caused a
decline in mining—ore brought from Spain, despite transport
costs the iron industry persists in its original location.

Wednesday, August 25.

A. Lieut.-Col. W. J. Jounsron, C.B.E., R.E.—Small-scale
Maps of the United Kingdom.

The demand for coloured maps is increasing. Engraving

on copper for map reproduction is moribund. Of three

methods in use at the Ordnance Survey that dependent on
photo-zincography is probably best.

SECTIONAL TRANSACTIONS.—E. 361

‘Ss. Mr. A. E. L. Hupson.—Some Methods of Using Ordnance
Maps in School Teaching.

6. Capt. H. Autan Liovp.—The Pictorial Factor in Aérial
Map Design.

7. Joint Meeting with Section L (see p. 377) in the rooms of
Section L. Prof. J. L. Myres.—The Place of

Geography in a Reformed Classical Course. Discussion
by Mr. G. C. Cutsuoum, Mr. H. O. Bscxit, &c.

Afternoon.

8. Dr. Vaucuan Cornisu.—Imperial Capitals.

Paris, like other capitals, occupies a position between the
centre of the country and the middle of the most important
frontier—such a situation compromises between the best site
for civil (pout) administration and the best site for military
defence (foreign).

Hacursion.

Vale of Glamorgan, visiting Barry, Llantwit Major, and
Cowbridge.

Thursday, August 26,
9. Rev. W. J. Barton.—The Oases and Shotts of Southern
Tunis.

10. Joint Meeting with Section D in the rooms of Section D
(p. 359).

Dr. E. C. Jez.—The Movements of the Sea.

Afternoon.
11. Prof. E. H. L. Scuwarz.—The Kalahari and the Possi-
bilities of its Irrigation.
The Kalahari, The changed course of the Cunene river.

The three great depressions. Weirs on the Cunene and
Chobe and their utility for irrigation,

Excursion.
The Upland of Glamorgan and the Taff and Rhondda Valleys.

Friday, August 27.

12. Dr. T. Asuspy.—The Water Supply of Ancient Rome.

The four chief aqueducts of Ancient Rome. The Anio
valley, its river and springs. Recent exploration along the
course of the aqueducts—geographical considerations.

13. Joint Meeting with Section A in the rooms of Section E.

Dr. E. H. Grirritus and Major Henrici.—The urgent

need for the creation within the Empire of a Central

Institution for Training and Research in the Sciences of
Surveying, Hydrography, and Geodesy. See p. 346.

362

SECTIONAL TRANSACTIONS.—, F.

Exhibit.

A collection of maps illustrating various aspects of the
geography of South Wales, arranged by the Cardiff branch of the
Geographical Association, was exhibited in the City Hall through-
out the meeting.

SECTION F.—ECONOMIC SCIENCE AND

STATISTICS.

(For references to the publication elsewhere of communications entered in

the following list of transactions, see p. 381.)

Tuesday, August 24.

Mr. H. Auucocx.—A Criticism of the Majority Report of
the Royal Commission on Decimal Coinage.
Discussion,

Mr. L. Surry Gorpon.—Agriculture as a Business.

Suggestions as to the possibility of reconciling the psycho-
logical and economic demands of agriculture with modern
conditions by treating it as an industry to be organised upon
a scientific basis.

Mr. J. Lassen.—Danish Credit Corporations.

Details concerning a system of co-operative borrowing of
money on first-class mortgage security. The interest of the
system lies in the fact that whereas all financing is usually
performed through the medium of Lenders (bankers, trust
companies, &c.), the scheme under review is directly reversed
and relates to a ‘ Corporation of Borrowers.’

Discussion, introduced by Mr. C. R. Fay.

Wednesday, August 25.

Presidential Address by Dr. J. H. Cuapnam, C.B.E.
(See p. 114.)

Mr. J. O. CureTHam.—The present Supply of Coal and
its effects on the Shipping Interests of Cardiff.

Mr. R. F. Apats.—The Conduct of the Mining Industry.

An examination of some of its economic and psychological
aspects, with regard to the bearing on the socialisation of
ownership and control.

Discussion.

Thursday, August 26.

Mr. A. H. Grsson.—Credit : Inflation and Prices.

A short review of the early beginnings of bank credit, its
growth and elasticity in modern times, its relation to
commodity prices; and the abuse of bank credit during the
recent war.

‘SECTIONAL TRANSACTIONS.—F, G. 363

8. Mr. A. J. Beamtse.—Deflation and the National Balance
Sheet.

A consideration of the alternatives before the Chancellor
of the Exchequer.

Discussion.

9. Mr. R. Trovron.—The Liquidation of International Debts.

The fact that it was advantageous during the war for
some countries to furnish mainly finance and others mainly
men is not a reason for making the latter pay a tribute to the
former.

Discussion.

Friday, August 27.
10. Communications from Research Committees of Section F.
—Sir E. Brasrooxr, C.B.
11. Mrs. Woorron.—The Future of Earning.

An examination of the principles on which payment for
labour is now based and their probable future development ;
with special reference to the relations of wages and prices
and the influence of Government expenditure (by way of
subsidies, &c.) on real income.

Discussion, introduced by Prof. W. J. Roprrrs.

SECTION G.—ENGINEERING.

(For references to the publication elsewhere of communications entered in
the following list of transactions, see p. 381.)

Tuesday, August 24.
1. Presidential Address by Prof. C. F. Jenkin, C.B.E.

(See p. 125.)

2. Prof. F. C. Lea.—Testing Materials al High Tempera-
tures.

3. Col. R. E. Crompron, C.B.—The Cutting Edges of Tools.

Excursion.
In the afternoon a visit took place to the Bute Docks of the
Cardiff Railway Co.

Wednesday, August 25.

4. Mr. S. F. Evet.—Farm Tractors—Regarded from the
Viewpoint of the User and Potential User.

The writer traces the earliest appearances of the British
farm tractor, explains its failure to earn the encouragement
it deserved, and relates his experience of excellent work,
to-day, from a ten-year-old machine built by pioneers of
twenty years ago. He explains his preference, at present,
for a certain type of machine, touches upon the psychological
effect of the use of the tractor on the labour question, and
then discusses the various main classifications of tractors

364

SECTIONAL TRANSACTIONS.—G.

now in common use. Giving reasons for the greater success
of one generic type, he confesses his inability to name any
one machine which will do all sorts of work equally efficiently,
mentions the poor quality of knowledge often possessed by
those who actually operate tractors, but proceeds to encourage
designers and manufacturers to give us better and better
tractors, especially of better material, despite the temptation
to turn out less serviceable machines at low prices. Road-
haulage is a phase of tractor-work he asks designers to bear
in mind, but he admits that ‘one machine for one job’ is a
principle that designers and users may have, for some years,
to respect. Tracing the history of the British industry, he
sympathises with tractor-manutacturers in the past, he holds
out hope of a fine future, if they will strive to give the
farmer the best machines, in design, material, and workman-
ship alike. He expresses his belief in the future of the
tractor industry.

Mr. H. R. Ricarpo.—A High-speed Internal-combustion

Engine for Research.

6. Prof. W. H. Warxinson.—A Dynamical Method of Rais-

ing Gases to High Temperatures.

7. Dr. C. Batuo.—The Partition of the Load in Riveted

11.

Joints.

Hecursion.

In the afternoon a visit took place to the Melingriffith Tinplate
Works.

Thursday, August 26.

Prof. J. T. Macerecor-Morris.—A Portable, Direct-

reading Anemometer for Measuring Ventilation in Coal-
mines.

Mr. H. T. Tizarp and Mr. D. R. Pys.—Specific Heat

and Dissociation in Internal-combustion Engines.

Sir J. B. Henperson and Prof. H. R. Hasst.—The

Indicator Diagram of a Gun.

Prof. A. L. Meuuansy and Mr. W. Kerr.—Steam Action

in Simple Nozzles. A Short Study of the Variants in
Nozzle Expansion.

This paper gives an exposition of a simple method of
dealing with the latter in ‘straight’ nozzle expansion. It
is intended as an introduction to a more detailed considera-
tion, from the experimental point of view, of the same
problems. The general methods of investigating steam flow
are analysed, and it is shown that the somewhat neglected
search-tube experiments are the most promising. The
paucity of information regarding internal effects of steam
expansion is noticed, and it is contended that the ordinary
experiments on steam flow cannot give much further informa-
tion upon interior happenings. A series of equations are
derived from which the pressure ratio curve along a nozzle
can be calculated, and experimental evidence is brought
forward to show that the underlying theory is, at least,

SECTIONAL TRANSACTIONS.—-G, H. 365

approximately correct. Arising from a desire to study
jet conditions, the necessity of dealing with any type of
expansion is postulated, and some discussion is given on the
general influences of certain arbitrary laws of expansion on
throat and flow conditions,

Excursion.
In the afternoon a visit took place to the Dowlais (Cardiff)
works of Messrs. Guest, Keen & Nettlefolds, Ltd., at East Moors.

Friday, August 27.
12. Prof. W. Cramp.—The Pneumatic Conveying of
Materials.

13. Wing-Commander T. R. Cavu-Browne-Cave.—Airships
for Slow-speed Heavy Transport and their Application
to Civil Engineering.

The use of airships as a means of transporting considerable
loads over impassable country is developed from the opera-
tions actually carried out up to the present. The application
to Civil Engineering, Surveying, and Transport is discussed,
and a review is made of the uses of airships for purposes
other than those of the Mail and First-class Passenger
Services, which have been fully dealt with by Air Commodore
Maitland before the Royal Society of Arts.

14. Prof. G. W. O. Howrt.—The Efficiency of Transmitting
Aérials and the Power required for long-distance Radio-
Telegraphy.

15. Dr. J. S. Owens.—The Removal of Reefs in the Rio
Guadiana.

. This paper describes the removal by drilling and blasting
of about 11,000 tons of rock reefs from the bed of the Rio
Guadiana at Pomaron, the port of the San Domingos Mines.
There is at this point a rise of tide of 11 ft. springs,
maximum normal current up to about three knots, and a
maximum depth over the reefs of 30 ft. Drilling was done
from a floating drill barge using a 5-in. steam drill. Charging
was done without divers and by means of specially prepared
‘sausages’ of dynamite dropped through a pipe and fired
electrically in groups of about eight holes.

Excursion.
In the afternoon a visit took place to the surface plant of the
Great Western Colliery Co., near Pontypridd, including large
electric winder.

SECTION H.—ANTHROPOLOGY.

(For references to the publication elsewhere of communications entered in
the following list of transactions, see p. 381.)

Tuesday, August 24.

1. Presidential Address, by Prof. Karn Parson, F.R.S.
(See p. 135.)

366 SECTIONAL TRANSACTIONS.—H.

2. Prof. H. J. Fururzt.—The Welsh People: Physical Types.

Nine distinct physical types are found in Wales. Speaking generally the
Welsh show more longheadedness, more dark pigment, and shorter statures
than the English, but both are complex minglings of different breeds which in
some cases can be correlated with migrations of prehistoric and historic times.

3. Miss M. L. Tiupestny.—Preliminary Notes on the Bur-
mese skull.

4. Prof. F. G. Parsons.—The Modern Londoner and the
Long Barrow Man.

Afternoon.
5. Dr. Tuomas Asusy.—The Roman Site at Caerwent.

6. Mr. WitiovcHsy GarpNer.—Roman Site at Abergele.
(See p. 262.)

Wednesday, August 25.

7. Dr. W. H. RB. Rivers, F.R.S.—The Statues of Easter
Island.
In San Cristoval stone images represent the dead chief buried in the pyra-

midal structures with which the images are associated. It is suggested that the
statues of Easter Island represent a hypertrophy of one element of a similar

association.

8. Captain L. W. G. Matcoum.—The Anthropogeography of
the Cameroons, W. Africa.

9. Prof. E. H. L. Schwarz.—The Ovambo.

10. Signor Bacgnani.—Recent Archeological Discoveries in
Rome.

11. Dr. T. Asusy.—Further Observations on the Roman
Roads of Central and Southern Italy.

The roads now described are the Via Valeria, and its prolongation the Via
Claudia Valeria, which, with the Via Tiburtina, formed a continuous highway
from Rome to the Adriatic, and the Via Latina. An attempt to discover the
course of the Via Herculia from Venusia to Potentia was unsuccessful. One
of the finest stretches of Roman pavement in Italy was discovered on the Via
Cassia, which leads north from Rome through Etruria.

12. Prof. A. M. Woopwarp.—Note on Hacavations on a Hill
Fort at Ilkley.

Afternoon.

Excursion to Caerwent.

SECTIONAL TRANSACTIONS,—H, 367

Thursday, August 26.

13. Mr. L. H. Dupiry Buxton.—The Physical Anthropology
of Ancient Greece and Greek Lands.

The present essay is a continuation of a report rendered to the British
Association at Bournemouth in 1919, on the ethnology of Cyprus,

In classical times a clear distinction was made between ‘ Greeks’ and ‘ Bar-
barians,’ and this distinction was believed to have a physical basis. Modern
anthropologists are generally in agreement that at least two races are repre-
sented in Greek lands, ‘Mediterranean’ and ‘Alpine.’ The aboriginal popula-
tion remains at present uncertain, and in the absence of early material it
became necessary to reverse the time process and to study the ancient popula-
tion in the light of the modern. In order to make the matter clearer, the
material has been divided into classes. First, head form is considered ; secondly,
facial form; and thirdly, stature; a fourth class, pigmentation, has been added
for the living. Evidence which can be treated statistically is available from
Albania, Leukas, Messenia (Meligala), Peloponnese (Mani), Crete, Lycia, and
Cyprus.

The mean Cephalic Index varies from 79°20 in Crete to 87°51 among the
Bektash of Lycia. None of the measurements are in agreement with the pure
Mediterranean type as represented, for instance, in Corsica. Among the people
who claim to be Greeks we have three classes—the Cretans, Maniotes, and
Lycians have a cephalic index under 81, the Messenians and Cypriots a
cephalic of 82, and the Leukadians and Albanians an index over 84, This
classification does not appear to be of any real significance when we come to
examine the standard deviations, as these are sufficiently great to suggest
considerable admixture, especially in Lycia. Cranial~ evidence, such as it is,
confirms this theory. The ancient crania which have survived form too small
a series for statistical treatment. It appears as a general rule that the modern
Greeks are slightly more brachycephalic than the ancient inhabitants of the
same places—possibly sufficient correction has not been made for the difference
between crania and living heads. From such scanty evidence as we have it
appears that there is a general closer approximation between the earliest cranial
indices and the modern ones than between either of the former and those of
intermediate date. In Crete it would appear as though there was an immigration
or an extension of the longheads in early times, who were later supplanted by
a mixed round- and long-headed population.

The following tentative conclusions have been drawn: First, the cranial
indices of the Greeks exhibit great variety, sufficient to suggest ethnic admix-
ture. Secondly, this admixture has not been evenly distributed, and local and
distinct sub-races have been formed, so distinct that where crania over a long
period have been obtained the cephalic index of one modern village more
closely resembles that of their Bronze Age predecessors than that of a neighbour-
ing area. As a corollary to this, any sweeping statements about the cephalic
index of a modern administrative area, based on measurements made on sixty
individuals, as has been done by Clon Stephanos, is unjustifiable. Thirdly,
the mixture of race is early, possibly Neolithic in Leukas, certainly Bronze Age
{or before) in Cyprus or Crete.

The living stature is available, in large numbers, from Crete and Cyprus
only, and in both cases the stature is practically identical. Three other small
Series are available, all of which fall into a single shorter group—Leukas, Mount
Parnon, and Lycian gypsies. The modern stature appears to be slightly greater
than the ancient. The conditions, whatever they may be, which make for
heterogeneity in cephalic index, appear also to make for a similar condition in
stature. The small numbers represented, combined with the large degree of
variation, suggest that great caution is needed in ascribing high or low stature
to any race in our area.

Considerable evidence has been brought forward to suggest that the Upper
Facial Index is unreliable. If we accept it provisionally we find that it is
a factor which, while agreeing to a large extent in showing the same
degree of ‘ethnic stability’ as the cephalic index, in some cases shows wide
divergencies; for instance, the cephalic index of the Cretans is most allied to

368 SECTIONAL TRANSACTIONS.—H.

that of the modern Egyptians, whereas the index of Cyprus is the upper facial
index which most closely approximates to that of the modern Egyptian. The
standard deviations again suggest that there may be a mixture of race.

In dealing with pigmentation there are two points of special importance.
First, in Albania and Cyprus about one man in ten has blue eyes, and even
in dark Crete one man in twenty; and secondly, there is evidence to
show that pigmentation distinguishes the Western Alpines from their Hastern
congeners the Armenoids. Pigmentation does not appear to bear a definite
correlation to cephalic index.

Summing up the evidence, we may say that at both boundaries of the Greek
world there are two racial types of comparative homogeneity, and that those
intermediate peoples who present local divergencies are very variable.

As far as our present evidence goes, the division into numerous local types
would appear to serve no useful purpose. We have not at present sufficient
information to discuss the physical anthropology of Greece proper; such as we
have would appear to justify the assertion that the numerous small communities
of the ancient Mediterranean differed physically; that is to say, that there was a
physical background to the struggles between Amathus and Salamis, Athens
and Sparta. To suppose that it is possible to establish a Greek type and to
distinguish. between Hellene and Barbarian does not appear justifiable.

It has been suggested that the Nordic race has contributed to the popula-
tion of Greek lands, but the presence of fair Alpines would account for the
blue-eyed people of ancient Greece.

In conclusion, then, while admitting the presence of numerous minor differ-
ences sufficiently great to make it necessary to know the exact provenance of
any anthropological data we may wish to examine, it would not seem possible
at present to assign any definite racial position to the Greeks, but rather to
class them as representing a combination, probably early in date, of Alpines
and Mediterranean stocks, both of which are found sporadically in a compara-
tively unmixed state in some parts of the Greek world.

14. Mr. 5S. C. Casson.—Ezacavations of the British School at
Athens at Mycenae, 1920.

In the area known as the Grave Circle on the Acropolis traces of early
Bronze Age and Neolithic cultures were discovered. It seems certain that
there was a continuous mainland civilisation stretching back to the beginning
of the second millennium z.c. It has been possible to classify chronologically
the works of the different generations of dynasts, and it seems that all the
greater and’ more impressive monuments of Mycenae belong to the latest phase
of Mycenaean culture.

15. Mr. J. Wurraxer.—Ezcavations at Motya, N.-W. Sicily.
16. Mr. P. E. Newserry.—Some early connections between
Egypt, Syria, and Babylonia.
Afternoon.
17. Prof. W. M. Furnpers Perriz, F.R.S.—Recent Work
in Egypt.

18. Mr. BR. Campsett THompson.—The Earliest Inhabitants
of Babylonia.

Friday, August 27.

19. Prof. H. J. Freure.—The Scheme of the Welsh Depart-
ment of the Board of Education for the collection of
Rural Lore through the agency of Schools.

20. Mr. H. Kipner.—Round Barrows in the New Forest that
do not conform to either of the three generally recognised
types.

aes

SECTIONAL TRANSACTIONS.—H, I. 369

21. Mr. G. A. Garrirt.—Rock Sculptures from Eyam Moor
Stone Circle, Derbyshire.

22. Mr. D. MacRitcum.—Greenland in Europe.

Afternoon.
23. Dr. Lioyvp Wiu1aMs.—Welsh Traditional Music.
24. Dr. H. Watrorp Daviss.—Huphony and Folk Music.

SECTION I.—PHYSIOLOGY.

(For references to the publication elsewhere of communications entered in
the following list of transactions, see p. 382.)

Tuesday, August 24.
1. Presidential Address by Mr. J. Barcrorr, C.B.E.,
F.R.S. (See p. 152.)
Joint Meeting with Subsection I.
2. Dr. C. S. Myers, F.R.S.—The Independence of
Psychology.

3. Miss May Surry and Dr. W. McDovucatu, F.R.S.—The
Mental Effects of Alcohol and other Drugs.

Afternoon.

4. Dr. W. H.R. Rivers, F.R.S.—An Independent Section
of Psychology (Discussion).

Wednesday, August 25.
5. Visit to the New Laboratory of Physiology, Newport Road.
6. Dr. T. Lewis, F.R.S.—Auricular Flutter
7. Prof. A. D. Water, F.R.S.—Plant Electricity.

8. Prof. A. D. Watrer, F.R.S.—Emotive Response of the
Human Subject (Lantern Demonstration).

Thursday, August 26.

9. Dr. T. Lewis, F.R.S.—The Relation of Physiology to
Medicine.
10. Prof. P. T. Herrinc.—The Effect of Pregnancy on the
Organs of the White Rat.

11. Miss E. Bepate (in collaboration with others).—Report
on Caloric Value of the Ordinary School Meals and on
the Energy Output of the School Day for Ages 10 to
18 Years.

12. Miss Hips Watxer, Prof. A. R. Lina, and Mr. E. A.
Coorrr.—On the Estimation of Sugar in Blood (pre-

. liminary communication),
1920 BB

370 SECTIONAL TRANSACTIONS.—I.

The authors have investigated methods of estimating sugar in blood, and
consider that of Maclean to be convenient and accurate. They have improved
its technique somewhat. As regards the nature of the cupric-reducing sub-
stance present in normal blood, they show that it is neither creatinine nor
uric acid; that it is insoluble in ether; that its reducing power is destroyed
by boiling with ammonia; that it is completely dialysable, and when dialysed
against aqueous glucose solutions, equilibrium is adjusted as it should be with
glucose; it forms a crystalline osazone morphologically similar to glucosazone.
The authors conclude, therefore, that the reducing substance is glucose.

13. Dr. F. W. Eprince Green.—The Prevention of Myopia.

The direct exciting cause of myopia appears to be increase of intra-ocular
tension through back pressure on the eye, therefore lengthening its antero-
posterior diameter. There is no satisfactory evidence that the use of the eyes
for near work either increases or causes myopia.

In the prevention of myopia any cause which will increase the intra-ocular
tension by obstructing the outflow should be avoided. All exercises in children
which involve strain with the eyes pointing downwards should be avoided.
A typical example of this is the exercise in which a child moves itself up
and down from the floor with the eyes pointing downwards.

Physical training is of great importance, and it will be noticed that the
ordinary forms of exercise—cricket, football, golf, &c.—do not cause myopia,
whereas lifting heavy weights, dumbbells, wrestling, boxing, or riding a bicycle
uphill in a stooping position, do. It is particularly in those who have sedentary
occupations, and who are not in a fit physical condition, and have an hereditary
tendency to myopia, that these forms of exercise should be avoided. Exercises
which after inquiry are found to cause a feeling of pain or tension in the
eyes or distension of the veins of the neck should be strictly forbidden to
myopes. Reading in a recumbent or stooping position with the eyes pointing
downwards is not advisable.

Afternoon.
14. Visit to Cardiff City Mental Hospital at Whitchurch.
Dr. R. V. Sranrorp demonstrated various Biochemical
Methods.

Friday, August 27.

15. Prof. A. D. Wauuer, F.R.S.—The Energy of the Human
Machine as Measured by the Output of Carbon Dioxide.

16. Demonstration by Prof. J. B. Haycrarr.—d New
Electrokymograph.

17. Joint Discussion with Section K on Biochemistry and
Systematic Relationship. (See p. 374.)

SUBSECTION I.—PSYCHOLOGY.

(For references to the publication elsewhere of communications entered in
the following list of transactions, see p. 382.)

Tuesday, August 24.
Joint Meeting with Section I. (See p. 369.)

Wednesday, August 25.

1. Miss L. C. Frrpes.—Word-blindness in the Mentally
Defective,

SECTIONAL TRANSACTIONS.——I, K. 871

Miss V. Hazuitt.—Conditions of Learning compared in
Man and Rats.

Prof. C. Luoyp Morean, F.R.S.—The Territory Instinct
in Birds.

Mr. F. B. Kirxman.—The Experimental Study of Animals
in the Wild State.
Afternoon.

Dr. E. Pripraux.—A Psychologist’s Attitude towards
Telepathy.

Prof. AcNes Roaers.—Mental Tests in American Univer-
sities.

Thursday, August 26.
Joint Meeting with Section L. (See p. 378.)
Afternoon.
Dr. W. H. R. Rivers, F.R.S.—The Complex and the

Sentiment.
Discussion, opened by Miss Saxsy.
Mr. F. C. Barrierr.—The Function of Images.

Friday, August 27.

Mr. F. Warts.—Some Problems of Vocational Selection.
Mr. 8S. Wyarr.—The Psychology of Industrial Life:
Observations on Operatives in the Cotton Industry.
Prof. EK. L. Connis.—The Psychology of Industrial Con-

valescence.
Afternoon.
Mr. Henry Binns.—Psychological Skill in the Wool
Industry.
Prof. F. 8. Lzz.—Some Phenomena of Industrial Fatigue.
Dr. G. H. Mirzs.—Aims and Work of a National Institute
of Applied Psychology.

Dr. H. M. Vrernon.—The Influence of Adaptation after
Altered Hours of Work.

SECTION K.—BOTANY.

For references to the publication elsewhere of communications entered in

the following list of transactions, see p. 382.)
Tuesday, August 24.
Presidential Address by Miss E. R. Saunpgrs. (See
p. 169.)

BB2

372

10.

11.

SECTIONAL TRANSACTIONS.—-K.

Professor Luoyp Wriuu1ams.—Alternation of Generations
in the Laminariacee.

Mrs. Evranor M. Rew.—The History of the West Euro-
pean Pliocene Flora as Deciphered by the Study of
Fossil Seeds.

Afternoon.

Prof. R. Cuopat.—Some Aspects of Plant Ecology and
Biology in Paraguay.

Prof. F. J. Lewis and Miss Gwynnetu M. Torrie.
On the Phenomena attending Seasonal Conversion of
Reserve Food Materials in the Leaves of Picea
canadensis.

Miss Gwynnetu M. Turttr.—On the Nature of Reserve
Food Materials in the Tissues of some Plants of
Northern Alberta.

Wednesday, August 25.

Joint Discussion with Sections C and D on Mendelism and
Palaontology: The Factorial Interpretation of Gradual
Changes, especially when New Characters appear late
in the Individual Life-cycle.

(See programme of Section C, p. 354.)

Dr. E. A. Newent Arper.—The Leaves of the Irids and
the Phyllode Theory.

Afternoon.

Dr. Harorp Wacer. Geotropism of Foliage Leaves;
Geotropie and Nastic Growth; Localisation and
Differentiation of Geotropic Stimulus. Are Leaves
dia-geotropic ?

Prof. J. Smaun and Miss W. Rea.—Further Evidence for
the Differentiation in Hydrion Concentration in stem
and root as the explanation of Positive and Negative
Geotropism, with evidence for Carbon-Dioxide Balance
as the cause of that Differentiation.

Miss K. B. Buacksurn.—Anomalies in Mucrospore
Formation in ‘ Rosa’ and its possible connection with
Hypbridity in the Genus, including a description of
normal. meiosis in three species for comparison with
abnormal features found in ten forms, including two
hybrids.

Excursion.

A short Botanical Expedition took place to visit local plants
of considerable interest.

SECTIONAL TRANSACTIONS.—K. 373

Thursday, August 26.
Joint Discussion with Section M on Soil and Plant Survey Work.

Botanical part of the discussion centred round :

(i.) Types of grassland in view of importance in Wales
and in general in agriculture—the possibility of recognising
a number of types in different parts of the country. Ee

(ii.) Possibility of fixing on Some standard symbols or
colours for ecological mapping.

(ili.) Relation of ecological data to geological data.

(iv.) Study and representation of arable.

12. Mr. G. W. Rosinson.—Soil Types of North Wales.

It is suggested that while uniformity in sampling and
analytical methods should be secured, the classification of
soils must depend on the local conditions. In extreme humid
conditions it would appear that differences due to geological
factors tend to be obliterated. Large numbers of soil samples
should be collected and the types should be worked out from
actual observations, correlation with geology may follow
afterwards. The soil survey gives information as to one of
the factors affecting plant growth and, ultimately, agricul-
ture in a particular area. The survey in its widest sense
should take cognisance of all the other factors, including
climate and soil-water conditions. The vegetation survey
gives the results of the operation of all these factors.

13. Mr. E. A. Fisuer.—Soil Acidity.

14, Prof. R. G. SrarLepon.—Surveys of Grassland Districts.

Re (i.) A method of obtaining quantitative data; ~sub-
division of grassland; Fescue Agrostis pastures in detail.
Effect of grazing animals.

Re (ii.) Colour scheme must allow for transitions; sub-
types by ink symbols on a ground colour.

Re (iv.) Use of weed flora in representation of arable.

Importance of primary survey.

15. Miss W. H. Wortnam.—The Vegetation of Anglesey and

N. Carnarvonshire, with special reference to the Grass-
lands.

Until about 700 years ago the vegetation of Anglesey
and N. Carnarvonshire comprised :

(1) an area of moorland stretching up from the 1000-1700
contours over the Carnarvonshire mountains, interrupted only
by the associations of the summits, rock-ledges and screes ;

(2) A zone of woodland extending from the edge of the
moorland to sea-level, interrupted by marshes and by lowland
moors. The plant formations are closely related to the
geological structure of the district. The greater part of the
uncultivated area is now grassland and may be summarised
thus: (i) the sub-alpine grassland which has been derived
from upland moor. (ii) The siliceous, schistose, and cal-
careous grasslands which have been derived from the corre-
sponding woodlands. (iii) Molinia grassland formed (a) as
a product of the degeneration of woodland, or (b) as a
primary association developed on wet rocks ;

(3) Grassland, siliceous, schistose, or calcareous, according
to the nature of the soil, has also been formed by the
degeneration of lowland moor, the draining of the marshes,
the colonisation of screes, and the colonisation of sand-dunes

374
16.

17.

SECTIONAL TRANSACTIONS.—K.

Discussion.—Sir A. D. Hatt, K.C.B., F.R.S., Dr. E. J,
Russevu, F.R.S., Mr. C. G. T. Morison, Mr. T. J.
JENKIN, Mr. C. T. Gimmincuam, Mr. R. Auun RoBerts,
Dr. EK. N. Tuomas, Prof. Luoyp Wriuuiams, Mr. T. W.
FaGan.

In the Section Room.

Mr. D. Parron.—The Vegetation of Beinn Laoigh situated
on the West of the Breadalbane Mountains. Its Con-
figuration, Geological Formation, Climatic Conditions,
&c., and the Relation of these to the Conditions of
Plant Life, with special reference to the Associations.

Hacursion.

Botanical expedition to Mynydd y Glew and Wenyoe, vid Cow-

bridge.

Lunch was provided by the kind invitation of Mr. and

Mrs. T. Mansel Franklen, and tea at Duffryn by Mr. and
Miss Cory.

18.

19.

20.

21.

Friday, August 27.

Prof. F. J. Lewis.—Distribution of Vegetation types in
the Hastern Canadian Rocky Mountains (Lantern
Demonstration).

Mr. P. E. Marvingau.—Records of Growth of Pit Mound
Plantations.

Joint Discussion with Sections I and B on Biochemistry
and Systematic Relationship, opened by

The Hon. Mrs. Onstow.—Introductory paper on Buo-
chemistry and systematic relationship in the plant
kingdom.

Brief consideration of systematic relationship.—Bio-
chemical aspect of the plant.—Possibility of expression of
reproductive and vegetative characters in chemical terms.—
Lines of plant metabolism.—Aromatics.—Catechol and pyro-
gallol plants.—Oxidase and peroxidase plants. Suggestions
as to connection with relationships of other substances—e.g.,
anthocyan pigments, flavones, &c.

Dr. F. F. Buackman, F.R.S.—Photosynthesis and carbo-
hydrate metabolism from the point of view of systematic
relationship in plants.

The pigments of chloroplasts: their uniformity in
phanerogams and their diversity in certain phyla of alge.

The primary products of photo-reduction of CO,: the
balance of hexoses and pentoses in different groups : pentoses
as the basis of the succulent habit.

Diversity of condensation-products: saccharose, starch,
and inulin, their occurrence in relation to species and
families.

Riechert’s work on the individuality of the starch grains
of every species of plant: its bearing on the chemical speci-
ficity of protoplasms.

ee a

ee, Se a ee

tal NE hl ne eee See ste ™

Dh dee pes

;

SECTIONAL TRANSACTIONS.—K, L. 375

22. Prof. G. H. Nurrauy, F.R.S. — Precipitive Reactions
as a means of determining Systematic Relationships in
Animals and Plants.

23. Mr. J. Barcrort, F.R.S.—Correlation of properties of the
oxygen-carrying power of blood (essentially the proper-
ties of hemoglobin) with the functions and habits of the
animal in question rather than with its phylogeny.

Afternoon.

24. Prof. C. J. CHampBeruain.—Semi-popular lecture on The
Origin and Relationships of the Cycads.

25. Mr. Kiyapon Warp.—On the Distribution of Floras in
S.-H. Asia as affected by the Burma-Yunnan Ranges.

26. Sir J.C. Bosz, F.R.S.—Plant Autographs and their reve-
lation, with demonstration of growth by means of the
Magnetic Crescograph.

Exhibition.
There was an exhibition during the Meeting of microscope
preparations, drawings, specimens, maps, &c. (many illustrative
of the papers).

SECTION L.—EDUCATION.

(For references to the publication elsewhere of communications entered in
the following list of transactions, see p. 383.)

Tuesday, August 24.

1. Presidential Address by Sir Roperr Buam. (See p. 191.)

2. Report of the Committee upon Training in Citizenship.
(See p. 281.) Speakers: Bishop Weruipon, Mr. J.
Cuarke, Mr. A. Parrerson.

Afternoon.
3. Mr. Spurtey Hey.—The Supply of Teachers.

There is a serious shortage in the supply of teachers.
The actual supply is insufficient to repair wastage, makes
little contribution towards increase in quality of staff, and
makes no increase whatever towards reduction of classes
and other necessary reforms, or towards additional require-
ments arising under the Education Act, 1918. Boards of
Education policy has led to a decrease in supply; some
L.E.A.’s have done nothing, whilst most L.E.A.’s have failed
to supply their own wastage; the teaching profession has for
some years been often indifferent, sometimes hostile, to the
creation of an adequate supply. The Board of Education
should provide adequate money and should penalise default-
ing L.E.A.’s. L.E.A.’s must provide good scales of salaries
and better school conditions, and must utilise the wider
avenues now allowed by the Board of Education. Teachers

376 SECTIONAL TRANSACTIONS.—-L.

should actively co-operate in creating an adequate supply.
Rural areas must be more thoroughly tapped for young
recruits, educated manhood and womanhood for adult recruits.

Wednesday, August 25.

(4-7). Papers on The Relation of Schools to Life, as follow-
Ingest
4. Mr. A. Linecar.

Schools should induce capacity for life as well as, or
before inducing, ability to earn a livelihood. A general
governing principle guiding all the school work is wanted,
as ‘Induce into pupils the power of concentration of mind.’
Then multiplicity of subjects disappears; we have instead
various postures of one endeavour. The broader the curri-
culum the broader the culture. We shall find we can vary
our postures so as to cultivate capacity to appreciate art,
literature, beauty, nature, nobility; we shall no longer find
ourselves struggling to attain sectional high efficiency. We
shall give power to be happy, the greatest gift; we shall give
possibility of broad, tolerant, healthy and full mental life:
we shall find that unusual efficiency has come, unsought, so
that while giving a splendid chance of real life we have also
provided an added probability of livelihood.

5. Mr. J. M. McTavisa.

(1) Primary function of schools to assist in cultivating
such practical emotional and intellectual habits, systemati-
cally organised as will fit man to his social and physical
world. (2) Necessity of re-interpreting in terms of man’s
widening social relations individualistic conceptions of edu-
cation which hinder us from understanding. the importance
of their social function. (3) Education as being the develop-
ment of the physical and mental capacity too limited. It
dissociates education from social change. (4) Each historic
epoch carries with it corresponding changes in educational
motives and methods. (5) During periods of social stability
this creates no problems, but man’s social world is to-day in
a condition of rapid flux. (6) The world’s problems due to
conscious social conduct being primarily determined by
sentiments which determine the behaviour of the conscious
stream and their influence upon consciousness may be
regarded as the psychological analogue of the conception of
force in physics. (7) The disintegrating sentiments in civili-
sation are egoism, patriotism, and class sentiment. (8) The
need for cultivating a human sentiment powerful enough
to hold these in check. (9) The relation of the above con-
siderations to secondary education. (10) Schools most closely
related to life through adolescent education.

6. Mr. RB. O. Bray.

Paper concerned with industrial aspect of life. Need for
industry to regard the entrants as persons in training. Ten-
dency of industry to regard them as adults. No adequate
provision made for trade teaching, for physical welfare, or
for general training. Figures justifying statement. Work-
shop training neglected both-by employers’ associations and
trade unions. Tendency to regard the schools as offering a
substitute for training in workshop. The workshop, the
stronger influence, undermines the training in the schools.
The most urgent educational problem lies not inside the

Pie:

SECTIONAL TRANSACTIONS.—L. 377

schools. but in industrial life outside. The solution must be
found by industry, trade unions, and employers, regarding
the juvenile worker as a person in training. The double duty
of the schools: first to educate industry itself by securing a
change of attitude towards its method of regarding the
juvenile worker. Secondly to assist industry in the selection
and training of its entrants. The first the most important
and the most neglected of the tasks. The schools must pre-
pare industry for the child before it can prepare the child
for industry.

Miss StRUDWICE.
General Discussion,

Joint Meeting with Section E. (See p. 361.)

Prof. J. L. Myres.—The place of Geography in a Reformed
Classical Course.

Recent decisions about ‘compulsory Greek’ compel
drastic revision of classical teaching. With language courses
restricted and postponed, the aim must be earlier acquaint-
ance with ancient conduct and thought, through closer co-
ordination between history, literature, and geography.
The Mediterranean region being exceptionally suited to
supplement, by contrast, Homeland notions of geography, and
being also the physical cradle of those ancient cultures,
Hebrew and Greco-Roman, which have most influenced our
own: reformed ‘classical’ education would begin by
illustrating, through ancient narrative and description, in
translations, man’s behaviour under these conditions, both
normally and in great crises; and his solutions of social and
moral problems in ancient times compared with ours. Later,
these episodes would be linked, chronologically and topo-
graphicaily, to illustrate historical growth and_ interaction
between local types. But study of ‘special periods’ would
be reserved till these outlines were familiar, and ancient
languages until required for appreciation of literature.

Afternoon.

Dr. Vincent Naser.—The International Intellectual

Relations.

Wealth of a nation, a function of its directing energies.
All students to organise locally, creating committees at each
University representing both undergraduates and _post-
graduates, and having complete modern office equipment at
their disposition. These committees to take the initiative
of establishing local bureaux of information under the super-
vision of University authorities, and acting as local branches
to central State-authorised bureau of all the nation’s Univer-
sities. Local committees to elect National Council of
Students. Necessity of caring for undergraduates travelling
abroad by established bureaux of information, and creating
facilities for introduction to families, etc. Tendency at
modern Universities to specialise in certain post-graduate
specialities to be encouraged to avoid overlapping. Idea of
World’s University to be realised locally by the inter-
nationalisation of post-graduate education with lectures in
English and French being prepared by the teaching of Eng-
lish and French in all schools. Introduction of official
students, international identity cards with photo of bearer

373

10.

11.
12.

13.

14.
15.
16.

SECTIONAL TRANSACTIONS.—tL.

affixed, etc. Railroad and shipping companies to provide
special rates, after being shown the necessity for the keeping
up of the standard of instruction and life generally of
intellectual classes.

Thursday, August 26.
Joint Meeting with Subsection of Psychology.

Prof. T. P. Nunn.—The Tendency towards Individual
Education.

Education must effect a modus vivendi between two prin-
ciples : (i.) the principle of ‘mental discipline,’ and (ii.) the
principle of spontaneity which requires the pupil to be his
own educator. The second implies that the individual pupil,
not the class, is the proper unit for instruction, and that he
should be free to go his own way at his own speed. The
former demands expert control of his studies and at least a
minimum prescribed curriculum, The problem of reconciling
the two principles in the case of young children is relatively
simple, and has been solved (e.g.) by Dr. Montessori. For
older pupils it seems to require (a) the reduction of formal
class-teaching to a minimum, and (6) setting free a large part
of the school week for ‘elective’ work under tutorial
supervision. Cautious experiments in this direction are
immediately practicable, and should be encouraged.

Prof. G. H. Tsomson.—Do the Binet-Simon Tests
measure General A bility ?

Dr. C. W. Kimuins.—The Dreams of Children who are
Physically Abnormal.
General Discussion upon the above Papers.

Afternoon.

Report of Committee upon the Educational Value of
Museums. (See p. 267.)

Friday, August 27.

Right Hon. H. A. L, Fisner.—The Universities m a
National System of Education.

Mr. Frank Furrcuser.—The Public Schools in a
National System of Education.

Miss H. M. Woprnovusse.—The Training Colleges in a
National System of Education.

Do we aim at requiring that all teachers, including all
those teaching ages 2-11, shall be graduates? (Estimate
of numbers.) Jf not, training colleges other than university
departments ought still to exist: (i.) To take non-matri-
culated students, (ii.) to take students who, even though
qualified for matriculation, do not wish to take a full-length
university course. From staff, from learning, and from
social life, these students gain more in a college of their own
than in a university. Most desirable that training colleges
should be widened by amalgamating the training of teachers
with other work. Z.g., physical training, arts, crafts, agri-
culture, engineering, preparation for business or secretarial

17.

SECTIONAL TRANSACTIONS.—L, M. 379

work, for social service, &c., &c. Question of connection
with universities (absorption in universities being rejected).
(a) Advantage to staff; (b) should improve some governing
bodies. The university should not act as external examiner
to the college. Services apart from official connection.

Mr. J. C. Maxweut Garnert, C.B.E.—Higher Tech-
nical Schools in a National System of Education.

The paper included a description of his diagram of a
national] system of education. The diagram illustrated cer-
tain recommendations recently published by the Federal
Council of Lancashire and Cheshire Teachers’ Associations.
The diagram represented sixteen different types of education ;
nine different types of school or college; a system of scholar-
ships and maintenance allowances sufficient to secure that
every kind of education is brought within the reach of all
young people of sufficient educational promise; and the num-
bers of young people who should be attending any particular
type of school or receiving any particular type of education
at any given age. As indicated by its title, the paper was
especially concerned with the provision of the highest
technological education in the national system of education
represented in the diagram.

A General Discussion followed.

Afternoon.
Excursion to Barry Summer School.

SECTION M.—AGRICULTURE.

(For references to the publication elsewhere of communications entered in

the following list of transactions, see p. 383.)

Tuesday, August 24.

Presidential Address by Prof. F. Kursus, C.B.E., F.R.S.,
on Intensive Cultivation. (See p. 200.)

Mr. H. V. Taytor (Ministry of Agriculture).—The Distri-
bution of Wart Disease in Potatoes; (b) Some Results
of the Ormskirk Potato Trials.

Mr. F. J. Currrenpen.—EHzperimental Error in Potato
Trials.

Mr. T. Wurrenpap.—A Preliminary Repori on the Para-
sitic Fungi of North Wales.

Mr. C. L. Watton.—Agricultural Zoology of North Wales.
Wednesday, August 25.

Captain R. Wettweaton (Ministry of Agriculture).—
Orchard Survey of West of England.

Mr. R. G. Hartron.—f ruil Tree Stocks:

Mr. §. P. Wiursurre.—Methods of Infection of Apple
Trees by Nectria ditissima, Tul. 2 .

380 SECTIONAL TRANSACTIONS.—M.

9. Prof. T. WispertEy.—LHzperiments in Intensive Corn-
growing.
10. Prof. A. Henry.—The Artificial Production of Vigorous
Trees.
Afternoon.
Excursion to St. Fagans.

Thursday, August 26.
11. Joint Discussion with Section K (see p. 373) on Plant and
Soil Survey Work.

Friday, August 27.
12. Mr. Georce S. Ropertson.—Result of Experiments with
Rock Phosphates.

13. Captain H. J. Pace, M.B.E.—EHzperimenis on Green
Manuring of Light Soils.

14, Mr. 8. Hoare Cotuins.—Sugar Content of Straw.
15. Mr. C. B. V. Marquanp.—The Varieties of Oats.

REFERENCES TO PUBLICATION OF COMMUNICATIONS
TO THE SECTIONS.
AND OTHER REFERENCES SUPPLIED By AUTHORS.
Under each section, the index-numbers correspond with those of the papers in the
sectional programmes (pp. 351-380).
References indicated by ‘cf.’ are to appropriate works quoted by the anthors
of papers, not to the papers themselves.

Srecrion A.
2. Cf. Bulletins Kodaikanal Observatory, 1913-18 ; also Observatory, Apr. 1920.
4. To be published in Proc. London Math. Soc.
6. To be published in Messenger of Mathematics ; cf. recent papers, ibid., on
Pentaspherical Co-ordinates.
7. Cf. Phil. Mag., 39, p. 707, Dec. 1919 ; 40, p. 451, Apr. 1920; p. 611, May 1920.
9. Expected to he published in Phil. Mag., Nov. 1920.
10. Cf. J. H. Moore, ‘ Recent Spectrographic Observations of Noya Aquile III.,’
Asirorom. Soc. of Pacific, 32, p. 232.
11. Observutory, 43, No. 558, Nov. 192€.

14, To be publishedin Nature.
17. Cf. Proc. Roy. Soc.,95A ; Camb. Phil. Trans., Oct. 1919; also forthcoming

Encyclopedia of Physics, ed. Sir R. T. Glazebrook (Macmillan), s.v. Terrestrial Mag-
netism.

18. To be published in Proc. Roy. Soc. ; cf. Phil. Trans., 214A, p. 109 (1914) ;
215A, p. 79 (1915) ; 220A, p. 247 (1920) ; Proc. Roy. Soc., 95A, p. 58 (1918) ; Sctence
Progress, Mar. 1920.

Srcrion B.
2. Journ. Soc. Chem. Ind., Sept. 15, 1920.
8. Results to be published in 6th Rep. Advisory Committee on Atmospheric
Pollution. t
Section C.
2. See Handbook to Cardiff (B.A. Meeting, 1920); also Proc. Geol. Assoc., 31,

p. 45 (1920).
8. Expected to be published in Mineralogical Magazine.

REFERENCES TO PUBLICATIONS, ETO. 381

10. To be published (abbreviated) in Geol. Mag.
12. Cf. ‘The Arrangement of Atoms in Crystals,’ Phil. Mag., 40, Aug. 1920 ;
* Crystal Structure,’ Royal Inst., May 28, 1920.

Srorion D.
8, For summary of discussion, see Nature, 106, p. 30.
10. Nature, 105, p. 516.
11. Nature, 105, p. 197
16. Journ. Exp. Zool., 30, p. 1.

Section E.
2. To be published in Yearbook Welsh Housing and Development Assoc., 1921.
3. Cf. Geog. Journ., 1919, p. 410.
8. Volume, The Sites of Imperial Cities, in preparation.

10. Cf. Fishery Investigations Reports (new series), III. Hydrography, 1; Hydro-
graphy of the English Channel, pt. 1 (Start Point to Channel Is.), 1904-17; pt. 2
(Isle of Wight to Cape de la Hague), 1904-18 ; pt. 3 (Isle of Wight to Havre), 1904-18 ;
pt. 4 (Newhaven to Caen), 1903-12 ; pt. 5 (Plymouth to Brest), 1907-11. 2. Hydro-
graphical Observations at English Lightships, pt. 1 (Seven Stones Lightship). 3.
Hydrography of the Atlantic Ocean, pt. 1 (Area centred on 50°N., 20° W.) 4. Hydro-
graphy of the North Sea, pt. 1 (Section from R. Tyne towards Naze of Norway).

11. Cf. The Kalahari, by E. H. L. Schwarz (Blackwell, Oxford, and Miller, Cape
Town), 1920.

12. Cf. Builder, 94, (1908, i.), pp. 37, 64, 89, 111, 121, 142, 153, 174, 184, 203, 234;
Neue Jahrbiicher fiir das Klassische Altertum, 23 (1909), pp. 246-260; Public Works,
2, iii. (Jan. 15, 1904), pp. 193-201; also ‘ Livellazione degli Antichi Acquedotti
Romani, memoria del Prof. V. Reina, degli Ing. G. Corbellini e G. Ducci,’ in-Memorie
Soc. Ital. d. Scienze detta dei XL., series 3a, 20.

Section F.

1. Waysand Means, Oct. 16, 1920, p. 62.

2. Better Business (Co-op. Ref. Library), Noy. 1920. Cf. Rural Reconstruction
in Treland (P. 8. King & Son), Co-operation for Farmers (Williams & Norgate).

5. Cardiff Journal of Commerce, Aug. 26,1920; Colliery Guardian, Aug. 27, 1920.

7. Bankers’ Magazine, Oct. 1920.

9. Economic Journ., Dec. 1920.

Section G.
2. Engineering, Aug. 27, 1920, p. 293.
3. Aug. 27, 1920, p- 292.
4. Farm Life, Sept. 4, 1920.

5. Engineering, Sept. 3, 10, 1920, pp. 325, 361.

6. As Aug. 27, 1920, p- 276.

7. rf Sept. 3, 1920, p. 314.

8. fs Aug. 27, 1920, p. 279; The Hlectrician, Aug. 27, 1920.
9. a Sept. 3, 1920, p. 325. d

11. Ss Sept. 3, 1920, p. 310.

12. # Sept. 3, 1920, p. 330.

13. Sept. 3, 1920, p. 381.

14, Radio Review, Aug., Sept., Nov. 1920.
15. The Engineer, Aug. 27, 1920, p. 201.

Srotioy H.
2. Cf. Journ. Roy. Anthrop. Inst., 46 (1916), 48 (1918), 50 (1920).
3. Cf. (forthcoming) Biometrika, 13 (1921).

5. Cf. Arch@ologia, 57, pp. 295-316 (1901); 58, pp. 119-152 (1902), 391-406 Sees a
59, pp. 87-124 (1904), 289-310 (1905) ; 60, pp. 111-130 (1906), 451-464 (1907): 61,
pp. 565-582 (1909) ; 62, pp. 1-20 (1910), 405-448 (1911) ; 63, pp. 487-452 (gis).

7. Expected to be published i in Folk Lore.

11. Cf. (forthcoming) R. Gardner, ‘ The Via Valeria,’ in Papers Brit. School a
Rome, 10, and future articles by T. Ashby and R. Gardner, also (forthcoming) T.
Ashby on an ancient Lucanian hill-fort in Journ. Roman Studies.

18. To be published in Biometrika; also forthcoming article in Nature.

382, SECTIONAL TRANSACTIONS.

14, To be published in Annual of the British School of Archaeology at Athens,
XXIV. ; see also Times Literary Supplement, June 24, 1920 (A. J. B. Wace), and
July 15, 1920 (Sir Arthur Evans).

15. Man, Dec. 1920.

17. Results to be published in Lahun IJ., Brit. Sch. in Egypt.

18. Cf. (forthcoming) Semitic Mythology (series, Mythology of all Races, Marshall
Jones, Boston, U.S.A.) ; also ‘ The British Museum Excavations at Abu Shahrain,’ in
Arch@ologia.

20. Proc. Hampshire Field Club and Archeological Soc., 1920.

21. To be published in Man.

22. Expected to be published (abbreviated) in Discovery. Cf. ‘The Lapps in
Scotland.’ The Link, Sept. 1917 (Bellows, Gloucester) ; ‘ Kayaks of the North Sea.’
Scott. Gecg. Mag., Mar. 1912; ‘ The Kayak in North-Western Europe.’ Journ. Roy.
Anthrop. Ins., 42, 1912 ; * The Abudeen Kayak and its Congeners.’ Proc. Soc. Antigq.
Scot., 1912; ‘ Les Kayaks dans le Nord de l'Europe,’ Compte Rendu XIVe Session
(Genéve, 1912) Cong. Internat. d’ Anthrop. et d’ Archéol. Préhist., 2, 1914; ‘ Der Kajak
im nérdlichen Europa,’ Petermanns Mitt., 1911; ‘Notes on a Finnish Boat pre-
served in Edinburgh,’ Proc. Soc. Antig. Scot., 1890; ‘The Testimony of Tradition ’
(Kegan Paul, 1890).

24, Cf. Musical Times, Oct. and Nov. 1920.

Secrion I.

2. To be published in Discovery.

3. To be published in special reports, Medical Research Council. Cf. communi-
cations to Brit. Assoc., 1913 and 1915, published as ‘ A Contribution to the Study of
Fatigue,’ in Brit. Journ. Psycholugy, 8.

9. Brit. Med. Journ. 2, pp. 439-462 (1920).

10. Brit. Med. Journ., Dec. 11 (1920), p. 886.

Sussecrion I (Psychology).

8. Cf. ‘ Instinctive Dispositions,’ Sctentia, Oct. 1920.
4. Cf. (forthcoming) The Intimate Life oj a Seagull (T. C. & E. C. Jack, 1921) ;
paper to be published probably in Brit. Journ. Psychology.

6. To be published in Brit. Journ. Psychology.

10. To be published in Brit. Journ. Psychology, 11, pt. ii. (Jan., 1921).

11. Cf. forthcoming Reports of Industrial Fatigue Board.

12. To be published in Hngineering and Industrial Management.

13. Wool Record and Fextile World, Aug. 26 and Sept. 2, 1920; Cf. ‘ The Human
Factor in the Judgment of Yarn and Cloth,’ to be published in Journ. Bradford
Textile Soc. and Wool Record.

14, Cf. ‘Studies in Industrial Physiology: I. Comparison of an Eight-Hour
Plant and a Ten-Hour Plant : Report by Josephine Goldmark and Mary D. Hopkins
on an Investigation by P. S. Florence and Associates under the general direction of
Frederic 8. Lee,’ Public Health Bulletin, No. 106, U.S. Public Health Service,
Washington.

16. Report No. 6, Industrial Fatigue Research Board, 1920.

Section K.

3. Cf. Paper to be published by Geological Soc.

4. Cf. R. Chodat and W. Vischer, ‘ Végétation du Paraguay,’ in Bull. Soc. Botan.
Genéve (1916-20).

8. Abstract to be published in Journ. Indian Botany, and it is hoped that the
full paper will appear in Annals of Botany.

10. Summary in New Phytologist, 19, p. 208 (1920) ; cf. ‘ A Theory of Geotropism,’
ibid. 19, p. 49 (1920).

11. Results to be published (with Dr. J. W. H. Harrison) in Annals of Botany.

12. Cf. ‘ A Survey of the Soils ana Agriculture of Shropshire,’ published by Salop
County Council, 1913; ‘Studies on the Paleozoic Soils of N. Wales’ in Journ.
Agric. Science, 8, 3; ‘ Further Studies on the Soils of N. Wales’ (in collaboration
with O. F. Hill), 2bid., 9,3; Dr. Edward Greenly in Geol. Survey Memoir on Anglesey,
pp- 877-881.

13. To be published in Journ. Agric. Science.

Ce a

Zz : REFERENCES TO PUBLICATIONS, ETC. 383

19. Cf. Communication to Brit. Assoc., Newcastle, 1916; also annual Reports
Midland Reafforesting Assoc., 1905-19.

20. Cf. (forthcoming) Biochemical Journ. ; also ‘ Nature of the Peroxide naturally
associated with certain direct oxidising Systems in Plants,’ in Biochemical Journ., 18,
p. 1 (1919).

21. To be published in New Phytologist, Jan. 1921.

24. Cf. C. J. Chamberlain, The Living Cycads (Univ. of Chicago Press) ; Botanical
Gazette, passim.

Srerion L.
4, Education, Sept. 24, 1920. ;
5. Highway, Oct. and Noy., 1920; Education, Oct. 1, 1920.
6. Cf. R. O. Bray, Boy Labour and Apprenticeship (Constable).
7. Journ. of Education, Oct. 1920.

11. Cf. ‘ General versus Group Factors in Mental Activities,’ in Psychological
Review, 1920.

14, Education, Sept. 3, 1920; Tie Times Educational Supp., Sept. 2, 1920.

15. Journ. of Education, Oct. 1920.

16. To be published in Education. Cf. Atheneum, July 1917.

17. Cf. An International System of Education (Manchester University Press).

Srction M.

2. Journ. Ministry of Agriculture and Fisheries, Nov.—Dec. 1920.

5. Cf. (for Mid-Wales). ‘The Liver Rot of Sheep, and Bionomics of Limnza
truncatula in the Aberystwyth Area,’ and ‘ Some Results of a Survey of the Agricul-
tural Zoology of the Aberystwyth Area’ (both in) Parasitology, 10, 2 (1917) ; ‘Farm
Insects Observed in the Aberystwyth Area, 1913-16,’ and ‘ A Note on Agricultural
Decology in Mid-Wales,’ in Annals of Applied Biology, 4, 1 and 2 (1917).

7. Journ. of Pomology, 5, Nov. 1920; Gardeners’ Chronicle, Oct. 16, 1920; cf.
Journ. R.H.S., 42, p. 261 (1917), 44, p. 89 (1919), 45, pp. 267, 269 (1920) ; Bulletin,
By. ie G. Hutton, ‘Summary of the Results in selecting and propagating Paradise
Stocks.’

9. Farm Life, Oct. 2, 1920.

10. Quarterly Journ. Forestry, 14, pp. 253-257 (Oct. 1920).

12. Cf. ‘Solubility of Mineral Phosphates in Citric Acid,’ pt. ii., Journ. Sec.
Chem. Industry 35 (1916); Notes on the Nature of the Phosphates contained in
Mineral Phosphates,’ in Journ. Agric. Science, 8; ‘ Trials on Grass Land with Open-
hearth, Basic Slag and Rock Phosphates,’ in Journ. Boord of Agriculture, 24 (1918).

18. Summary in Gardeners’ Chronicle, Sept. 18, 1920, p. 189. Results expected
to be published in Journ. Roy. Horticultural Soc.

EVENING DISCOURSES.

ile
Tuurspay, August 26.

Some Requirements of Modern Aircraft.
By Sir R. T. Guazeprook, K.C.B., F.R.S.

The differences between the requirements of military and of commercial
flying are not merely due to the fact that the military flying machine has
developed into a formidable weapon, whilst commercial aircraft must be a means
of rapid transit and transport.

The lecturer quoted from a paper, recently communicated by Squadron Leader
R. M. Hill, to characterise these differences : ‘If commercial aeroplanes are to
compete successfully with other forms of transport, they must compete on grounds
of economy, speed, and reliability, but such achievement will not be of the
slightest value until a standard of safety nearer to that reached by railways
and shipping is attained. The most pressing difficulties seem to be those of
flying to a place and landing when there is a mist down to the ground, of the
comparative unreliability of the light aero-engine, of the space which any
aeroplane requires to land in, and of the imperfect control of small aeroplanes
at low speeds and of large ones at any speeds.’

The lift, the upward force on an aeroplane, is greatest for an approximately
rectangular wing when the long side is horizontal and at right angles to the
direction of flight, when the lift W=/, p & v?, where p is the air density, s the
area, v the speed of the machine, and k, the lift coefficient, depending both
upon the section of the wing and on the angle between the bottom chord of the

Fig./. POSSIBLE LOADING OF WINGS & BODY OF

HIGH SPEED AEROPLANE IN FLIGHT. a
BE2 Type Machine with 150HE Engi ucts 1

Max. Speed trom Horizontal Fight -110MPH.
Tailp tora asinBE2c. ||| fir
Weight of Machine -1930Lbs. in er
ing out trom a vertical nase dive | 254 T=-18
b stgier beenreached. kutial Speed=157 MPH. ar=0-4°
i : 018 Secs pee 160
ToadFactor on Wings mw gn = A= BZ
Load,on Tail in Lbs per'S +¥e)= joerg
Angle of Incidence of =a U=165
Forward Speed in Miles per Hour =U
am 200
T=4
a-4
U-148 3
Aat etd =
6560.4.) 300 200 100 oo

wing and the flight direction, 7.c., the angle of attack. As the angle of attack
increases, and the wing is held more and more obliquely, the lift coefficient
increases until the angle is about 15 deg.; at this, known as the stalling angle, k,
suddenly drops, and the wing ceases to support the weight it has borne. The
actual values reached by i; before stalling differ appreciably ; 0°6 or 0°7 is about

EVENING DISCOURSES. 385

the usual maximum, but 0°9 has been exceeded by Messrs. Handley Page and by
the Blackburn Company.

The stalling speed, the minimum speed at which the machine can fly, is
inversely proportional to the square root of the maximum lift coefficient, and
since W=k,psv*, W/s=k,pv’, this quotient expressing the ‘loading,’ i.¢.,
the weight carried per unit wing area; the loading varies between 5 lb. and
10 lb. per sq. ft. The drag or resistance to the motion of the wing is equal to
k,psv’, the drag coefficient £, also depending upon the shape of the wing
section and the angle of attack. As that angle increases, k, decreases at first,
then increases more and more as the angle grows steeper. But kz is always
smaller than k,, and the force D required to move the wing is given’ by
D=W &,/k,. The resistance of the rest of the machine is about the same in
amount as that of the wing. The resistance is entirely due to the friction

1g... POSSIBLE LOADING OF WINGS & BODY
Fgd OF HIGH SPEED AEROPLANE IN FLIGHT.

fo 7 - 260
CC ae ee TT
To ad oie oes

4. vay
‘ - L208
A |
3se HN a6 3
PTT 00 s
7-0 re
AA tat-3
a \e-iae
Ke
psa pe Bs
AZYMPN, ee
Load.Factor ow a9 ts \ {z 3-85
Load mTail-T ths, . * tars 2
ei ig (act e 6 peppy males/ro:
B.E.2. MAGHINE WITH 450 HP ENGINE.
Weight - 1930 Ubs.

Resistance in normal flying altitude -340 lbs. at 100 fs.
Mac. hordctttad flight Bmp

1290 trol leverages as uy B.E. 2c.
Sipe ane aaa ae opole
: aUNL LL LEE ECET ECE
must rol
loop.
a Oe In 4 Oo. 6 7a, 8
(6560.8) Seconds.

between the moving body and the air, and to the viscosity of the air, the
friction itself is due rather to the eddies, which owe their origin to the viscosity,
than to the direct motion of the machine through the air.

As regards the engines, the weight per horse-power is smaller for radial
air-cooled engines than for water-cooled motors ; 3 lb. per horse-power is perhaps
a reasonable figure. According to Bairstow, a light aeroplane capable of
travelling at 125 miles p.h. would be able to carry a useful load of 270 lb. out
of a total weight (machine, engine, and pilot) of 2,100 lb. The modern Bristol
Pullman triplane for fourteen passengers, capable of a best speed of 130 m.p.h.,
weighs empty 11,000 lb., and fully loaded 18,000 Ib., 4,375 lb. of that total
being available for cargo or passengers. The engines are not yet reliable in the
sense that marine engines are reliable. The useful load can be increased by
making the structure light. A light md¢hine can be flown at a lower angle of
attack, but the structure must remain sufficiently strong, and the calculation of
the stresses is not an easy matter, except when the machine is moving horizon-
tally. In steep diving, at twice normal speed, the stresses might rise to sixteen
times their magnitude for normal] flight, if the pilot were able to change his con-
trols instantaneously, and although that is impossible, the controls can be changed
within one-fifth of a second. For these calculations the ‘load factor’ is

1920 co

386 EVENING DISCOURSES.

important, this factor indicates the ratio of the stress in any part of the
structure under given conditions of flight to the stress under normal conditions
of horizontal flight. The load factor during recovery from a dive can be
determined in two ways. Starting with an aeroplane diving at a given speed
we could calculate the initial stresses on the parts, and if we knew the
aerodynamic forces, the values of k; and the resistances of the various parts,
and were able to make some assumption as to the rapidity at which the
pilot altered his controls, we could determine mathematically the rest of the
path and the stresses on the machine at any point of that path. Fig. 1 shows the
results of that calculation for a machine flattening out from a dive, and Fig. 2
the results from a machine doing a loop. In both cases the machines were
moving at high speeds, and high load factors were required for safety. In the
former case the pull on the control levers was 160 Ib., reached after 0-18 second ;
in the latter case it was 100 lb., attained in about the same period.

The other method of determination relies upon the experimental measure-
ment of the forces on the machine as a whole by the aid of accelerometers. On
aeroplanes pendulums of heavy weights or springs of high inertia, which would
go on swinging, would be useless. The accelerometer used took the form
illustrated in Fig. 3. It consisted of a quartz fibre, 1/2,000th in. in diameter,

Fig.3. ACCELEROMETER

bent to an arc A B C, and held, normally, in a horizontal position. The fibre
would be slightly deflected downwards by its weight, and would be still more
deflected by a vertical acceleration, and this additional deflection of the point C
to positions C, or C, was recorded photographically. The accelerometer camera
and the lamp were contained in a small box strapped to the observer’s knee.
The curves thus obtained indicates only the accelerations of the centre of
gravity, without taking account of the twists and turns about this centre. The
kinematograph has also been utilised at the Royal Aircraft Establishment for
the determination of the stresses. A kinematograph was fitted on to the tail
of one machine rising steadily, while the second machine following close behind
performed the loop spin, or other evolution, it was desired to analyse. Series
of these photographs were exhibited. \
A- commercial machine should be stable, as it would be impossible, without
a great expenditure of the pilot’s energy, to fly through a continuous cloud.
Yet stability pushed too far gave the machine a will of its own and made it
sluggish, and military pilots, to whom rapid contro] meant life or death, differed
as to the desirability of stability. On the other hand, the stable machine would
fly on, if the pilot lost control, and, if the engine stopped, the machine glided
down, while the unstable machine got into a spin and crashed down to earth.
Stability may be automatic or inherent. Automatic stability, secured by con-
trivances which came into play when a deviation from the steady course
occurred, is unsatisfactory because the device necessarily takes some time to
operate, overshoots the mark, and hunts. An inherently stable machine would
be brought back to the steady state by the disturbing wind forces. The lecturer
indicated how, thanks mainly to the labours of Bryan and Bairstow, longitudinal
stability, at any rate, had been successfully secured; our knowledge of the
conditions for lateral stability is unfortunately far less complete. Longitudinal
stability is important in connection with looping. It is known that an unstable
aeroplane has a stable flying position on its back. If it got into that position

BVENING DISCOURSES: 387

by some accident, it could only be righted again with the greatest difficulty, if
at all. od
The lecturer finally referred to the difficulties which the aviator, as distinct
from the sailor, had with his navigational instruments. The aviator does not
know whether or not he is moving uniformly. A bubble level indicator will only
tell him that the acceleration, if any, is at right angles to the surface of the
bubble. The compass is disturbed by the vibrations of the engine, to damp the
effect of these the whole compass is encased in a closed vessel usually filled with
alcohol. In the ordinary compass, the card carrying the magnets is fitted with a
cup resting on a pivot. The vibrations make the card rotate and set the liquid in
motion; to reduce these movements the vessel is made spherical, the pivot and
cup are interchanged, the cup being attached to the support, and the card itself is
replaced by a short length of a cylinder having the cup on its axis. Even thus
improved the R.A.F. spherical compass, of which Fig. 4 gives a diagrammatic
section, will, on an initially northern course, move to the east or west, only, say,
10 deg., when a turn of 15 deg. has been made, because, in describing the curve,
the aeroplane is banked inwards so that the axis of the magnet card does not
remain vertical, and the directive force on the magnet is no longer the full
horizontal component of the earth’s field. Moreover, the compass cannot take
up its position instantaneously. When the compass turns more quickly than

Fig 4.
RAF SPHERICAL COMPASS. DASHBOARD MOUNTING.
DIAGRAMMATIC SEC. Bezel.
Filling Screw. Rubber Jointing Strip
Glass wilh Spherical
LubberLinel $ server SHER gr.
Outer Case, | Brass Bowl
Cylindrical Card
Eapansion gsi P
em Carrying Sapplure Cup.
(65600) Holder for Adjusting Magnets.

the aeroplane, the observer would at first imagine that he was steering towards
the west when he was really turning eastward. This trouble could be remedied
by making the time of swing of the needles long compared with the time taken
by the machine to complete its turn. On a northerly course the turn would
then appear in the right direction, though too small in amount; on a southerly
course the turn would also appear in the right direction, but too large in amount.

The aviator’s trouble with the sextant is that he is rarely able to take a
horizon reading, and even if he can that reading would have to be corrected for
the dip of the real horizon below the level of his machine. In the bubble sex-
tant, illustrated in the diagram Fig. 5, the image of the bubble is visible at the
same time as the distant object. The observer has to bring the object to appear
in the centre of the bubble and to bring the two on the axis of his observing
telescope. But, as in the case of the compass, the observer should be sure that,
at the moment of reading, he is flying uniformly without acceleration. His
speedometer gives him his rate of motion through the air, and, with a steady
wind, he would know that he was flying at constant speed. His altimeter
aneroid, or his climbmeter, would enable him to keep on a horizontal path, but
he still needs something to tell him whether he is flying straight or on some
curve. The turn indicator gives him this information. When he banks on a
curve, the extremity of the outer wing is higher up and moving faster than
the inner-wing extremity, and there is a difference of pressure at these two
points; a small difference, of course, yet measurable by Sir Horace Darwin’:

388 EVENING DISCOURSES.

turn indicator, which marks zero when the aeroplane is travelling straight.
In the gyro-turn indicator, developed at Farnborough, the principle of which is
explained by the diagram Fig. 6, the gyro-wheel is placed outside the machine

Stlvered Face 4
(6560.4)

so as to rotate in a vertical plane at right angles to the direction of flight,
the rotation being maintained by the wind playing upon suitable holes in the
wheel. If the machine when moving straight horizontally begins to turn about
a vertical axis, a pointer attached to the gyrostat indicates that motion or, if
controlled by a spring, shows the force tending to make the gyrostat move.
There remains the dangers from mists and fogs, which are more formidable
to the aviator than to the sailor. The sailor has fog signals, leader cables,

buoys, and harbour lights to guide him; the aviator frequently has little warning
that he is within a few feet of the ground. Captive balloons, if feasible, are
themselves sources of danger; sound signals would not be appreciated by the
neighbours of aerodromes; signal beams do not penetrate far through mists ;
radio-telegraphy and radio-telephony promise best. But the landing troubles
and means of control at low speeds, as well as the construction of reliable aero-
engines, remain urgent problems of modern aircraft.

EVENING DISCOURSES, 389

II.
Fripay, August 27.

A Grain of Wheat from the Field to the Table.
By Sir Danten Hat, K.C.B., F.R.S.

In the history of mankind there are no processes older, more essential, or
more universal than the growing, grinding, and baking of wheat and its kindred
food grains.

What, then, has the British Association to do with so fundamental a busi-
ness, brought to something like perfection long before anything we can call
science existed ?

That is precisely what I want to tell you to-night.

Countless years have elapsed since primitive man took the momentous step
of sowing a little of the wild grain he had hitherto been content to gather,
in the hope of saving himself some trouble in collecting the next year’s crop.
Millions of men have spent their lives in growing wheat. All sorts of rewards—
nay, the very life of the community—have attended on improvements in the
crop. What can there be to learn about it now?

Yet at every stage in the story of the grain of wheat from the seed-bed
to the breakfast table we find that we do not know what we need to know in
order to get on with the business of making two grains grow where one grew
before. I want to show you that, however old, however fundamental the
industry, science comes in at every turn, and research, calling for all our
imagination, skill, and determination, is required if progress is to continue.

All biologists would agree that development demands an abundant food
supply, just as fine flowers want a fat soil. Now, the population of the
world is rapidly growing up to, if it has not for a time exceeded, its available
food supply, and only by research and the utilisation of the fruits of that
research are we going to obtain more food. If I had to name one remedy
for the present discontents it would be more wheat, and as we are nearing
the limits of the potential wheat land we must therefore set about the other
problem of getting more from what land we have. Beginning with the grain
of wheat, we find it consists of a tiny embryo, that part that possesses life,
and the endosperm or food store, which is to nourish it until it can push a
green leaf above the ground and begin to feed upon the air and the soil.
The embryo’s food store is our food supply; flour is only the powdered
endosperm.

In its dry state, when it cannot draw upon the endosperm, the embryo
soon dies, and with it the whole grain; some in one year, more in two; few
can survive for ten years. Mummy wheat is a myth. Can you excite the seed
before sowing by electricity or other means to grow better and give a bigger
crop? Experiments are being made, but the results are dubious. Probably
not, because the seed only starts the plant in life; its growth and yield depend
on development after the start, on the soil, the manure, the weather.

Tt is usual in England to sow two and a-half bushels of seed wheat to
the acre; properly managed, half a bushel or less would cover the field with
the necessary plants for a maximum crop. Experiments are on foot to get a
machine that will sow economically. Even if we can save a bushel an acre of
seed the country would gain 3 per cent. of its output of wheat, worth well
over a million pounds a year.

There are hundreds of kinds of wheat—early and late, tall and short, close-
packed or open in the ear, varying in colour and size and in other ways. Each
sort breeds true because the flower is self-fertilised. If we pick out each year
the longest ears in the field, or the plumpest berries, and grow only from them,
no improvement results. Selection of this kind has been tried for fifty years
without result. Change, and with it improvement, only comes when varieties
are crossed; then we get new varieties. The scientific breeder working on
Mendel’s principles can in a few years raise and fix a new wheat, combining
the sood points of both parents. New English wheats have been bred in the

390 EVENING DISCOURSES:

last few years which raise the produce per acre of Hastern County farms by
at least 10 per cent.

For all its vigour, wheat cannot stand the competition of weeds. At Rotham-
sted a crop was left unharvested to sow itself without cultivation. In three
years the wheat had entirely disappeared in the wilderness that grew up.

Nevertheless, wheat has, more than any other cultivated plant, the capacity
of growing upon all sorts of soils, even the poorest. At Rothamsted, on one
of the plots, wheat has now been grown for seventy-seven successive years
without any manure, and it still yields about twelve bushels to the acre, pretty
much the average crop of all the wheat lands of the world. Wheat is the
crop for breaking in the wilderness. In the new countries the settler always
begins with a succession of wheat crops before he resorts to mixed farming.

Experiments haye long since settled what manures wheat wants. The real
trouble now is to get the big crops grown with plenty of manure to stand up,
and this is a problem now being attacked in various fashions—stiffer-strawed
varieties, special cultivation, and corrective manures, etc.

The wheat plant practically finishes growing a month or five weeks before
it is harvested. In the last period the valuable material is being moved from
stem and leaves to the seed. The migration is incomplete; half or less of
the stuff manufactured by the plant gets into the seed, and here are great
possibilities of improvement.

The object of the modern flour miller is not to grind wheat into a meal
and then sift out the flour, but to crack the berry without breaking the husk
(bran) and let the endosperm fall out. The best white flour is pure endosperm.
It is the most digestible part of the grain, and weight for weight yields the
most food. In peace times only two-thirds of the grain is recovered as flour,
but under war conditions it was necessary to use the less digestible portions
as well, and the extraction was raised from 68 to well over 90 per cent. Though
imperfectly digested and not suited to all constitutions, the higher extraction
was equivalent to an extra two months’ supply of wheat.

Flour from most English wheats produces small dense loaves; certain Canadian
and other foreign wheats give big spongy loaves, which the public prefer. A
wheat was found that retains this property of strength in the English climate.
This wheat crops badly, but the wheat-breedez is at work combining the strength
of this (Fife wheat with the cropping power of English wheats. Professor
Biffen’s ‘ Yeoman’ wheat, on suitable soils, is now the biggest cropper known,
and gives flour as strong as Canadian wheat

Before the war we only grew one-fifth of the wheat we ate; the rest came
from North and South America, Russia, India, and Australia. Some of these
foreign supplies have been cut off, and the world’s supply of wheat will be short
for years to come. As a national insurance we must grow more at home,
and this can only ibe done by better skill and more knowledge, because we cannot
expand our land indefinitely. We must not grudge expenditure on knowledge;
our food supply in the future depends upon the advancement of science, which
is the purpose of the British Association.

CORRESPONDING SOCIETIES COMMITTEE.

Corresponding Socielies Committee. Report of the Committee con-
sisting of Mr. Winit1am Wuiraxer, F'.R.S. (Chairman), Myr.
Witrrep Mark Wess (Secretary), Mr. P. J. Asuton, Dr. F. A.
Baruer, F'.R.S., the Rev. J. O. Brvan, Sir Epwarp BrapBroox,
C.B., Sir H. G. Forpuam, Mr. T. Surpparp, the Rey. T. R. R.
Sreppinec, /'.R.S., Mr. Marx Sykes, and the PRresmIpENT and
GENERAL Orrrcers of the Association. (Drawn up by the Secre-
tary.)

Tur Committee reports that the following are the officers of the Conference of

Delegates to be held at Cardiff: President, Mr. T. Sheppard, M.Sc., F.G.S. ;

Vice-President, Mr. F. W. Sowerbutts; Secretary, Mr. Wilfred Mark Webb,

F.L.S. ; and that the programme is as follows :—

Wednesday, August 25, at 2 p.M.—(1) Presidential Address by Thomas Sheppard,
M.S8c., F.G.S., on ‘ The Evolution of Topographical and Geological Maps.’
(2) Paper on ‘ Railways and their Obligations to the Community,’ by A. H.
Garstang, Secretary of the Railway Facilities Sub-Committee of Section F.

Friday, August 27, at 2 p.m.—Discussion on ‘ The Status of Local Societies: the
means of developing their objects, of getting new members, of publishing
papers and making announcements,’ which will be opened by William
Whitaker, B.A., F.R.S.

After the meeting the Delegates will be entertained to tea by Principal A. H.
Trow, D.Se., F.L.8., President of the Cardiff Naturalists’ Association, and
will have an opportunity of seeing the Exhibition, illustrating the Presidential
Address and the work otf local Societies.

The Committee recommends that the Offa Field Club, Oswestry, be admitted
as an Affiliated Society, and the Scottish Natural History Society, the Darlington
and Teesdale Naturalists’ Field Club, and the Greenock Philosophical Society
as Associated Societies.

The Committee asks to be reappointed, with a grant of 40.

ray

At the first meeting of the Conference of Delegates on Wednesday, August 25,
the President, Mr. T. Sheppard, delivered the following address :—

The Evolution of Topographical and Geological Maps.

One of the secrets of successful collecting—and every scientific man is a col-

lector in some form or other—is to secure series of certain specimens or objects
for which few people, if any, are in search. In this way it is possible to
contribute something tangible towards the advancement of science.
_ On a previous occasion I had the privilege of bringing before your notice
information relating to the past difficulties in connection with the exchange
of currency, clearly demonstrating the necessity for the decimal system of
weights and measures. (See ‘ Rep. Brit. Assoc. for 1917,’ pp. 228-235.) That
paper was made possible by collecting old boxes of money scales and weights,
a few years’ work resulting in the finest series of English examples in existence
being gathered together.

In the same way, and for somewhat similar reasons, collecting old topo-
graphical and geological atlases and maps was indulged in, and by methods
familiar to experienced collectors, examples of old road-books, charts, and

geological plans, diagrams, and maps began to accumulate to an extent which
was positively alarming !

392 CORRESPONDING SOCIETIES.

On the topographical side, a predecessor of mine in this chair, Sir George
Fordham, exhibited before the British Association at the Dublin and Dundee
meetings in 1908 and 1912 respectively, a fine series of old road-books. With
regard to geological maps, however, which naturally follow the topographical
series, nothing systematic seems yet to have been accomplished, and it is extra-
ordinary how this most valuable source of information has been neglected—
even by our special geological societies. A few years ago the Geological Society
of London asked me to prepare a Catalogue of British Geological Maps, and
the work has occupied nearly all my ‘spare time’ ever since, as will be under-
stood when I say that the Catalogue, as yet in manuscript, contains details
of thousands of such maps. The preparation of this, and the collecting of old
maps and charts, has resulted in the accumulation of facts which will, I think,
be of interest to the delegates of the Corresponding Societies, and, it is hoped,
will give them an idea of the method of obtaining, from sources which are
usually neglected, information relating to the physical geography and geology
of their respective areas.

I possess ‘ Edward, Duke of Norfolk, Earle Marshall of England’s’ copy of
Moll’s ‘ New Description of England and Wales,’ dated 1724. It consists of
fifty maps, measuring 10 by 74 inches. Each map is folded, and mounted in
the middle on guards, so that no information is lost or distorted in the binding.
The volume measures 73 by 8} inches. Bound up with it is a map of ‘The
Roads of ye South Part of Great Britain Called England and Wales,’ by Herman
Moll, Geographer. It is dedicated to Frederick Prince of Wales (and therefore
must be after 1729), and contains the following engraved upon it: ‘ Note:
This map has been copied four times very confused and Scandalously’! Pre-
sumably by other ‘ enterprising’ publishers.

On the margins of each of the county maps various ‘curios’ are engraved,
usually ‘bearing upon the district. For example, the first map, Bedford Shire,
is decorated by representations of obverses and reverses of six Roman coins,
in the execution of which—as in other illustrations—the artist has had very
fair licence.

Besides giving evidence of changes due to coast erosion, alterations in
estuaries and river channels and lakes; these old maps yield much interesting
geological information, albeit the ‘Geographer, Moll,’ knew not the science of
geology. On the map of Cornwall, for instance, not only are the mines indi-
cated, and their names and depths given, but details occur of the various metals
obtained—tin, copper, and lead; there are ‘ lead mines producing much silver,’
and even ‘ ancient lead mines.’ On the margin is engraved ‘ The Wring Cheese
‘Stones near Rillington,’ the ‘ Hurlers’ Stones,’ etc. Thus this map not only
indicates the extent to which mining for metals was practised precisely two
centuries ago, but gives evidence of mining in still earlier times.

Black-lead_ mines, copper mines, and lead works are shown on the Cumber-
land map. That of Derbyshire is dotted over, ‘to a surprising extent, with
triangular marks indicating lead mines: the margins being devoted to repre-
sentations of geological ‘curios,’ as well as engravings of ‘Poole’s Hole’ and
another cave named after a portion of the anatomy of the devil. These illus-
trate the characteristic weathering of the local Carboniferous Limestone. The
fossils are better engraved than described. An obvious Huomphalis is ‘A
Petrify’d Cockle’; a Productus is ‘A Petrify’d Oyster’; a piece of encrinital
limestone is ‘A Terrene course Fluor or Spar found in the Lead Mines’; a
Silurian Brain-Coral has somehow crept in, and is ‘ Bufonites or Brain-stone,
viz. from ye Representations; it Bears to a Toad.’ A chalk echinoderm—
which has also strayed—is ‘One of the Echini Petrify’d with the Representa-
tions of Trees,’ the ‘Trees’ being the lines between the plates forming the
test. Two sharks’ teeth, suspiciously Tertiary, are ‘A Glossopetra or Crow-
bill found in ye Lead Mines,’ and ‘A Glossopetra found in the like Mines both
in this County and Wales,’ respectively.

The Devonshire map indicates lead, tin, and copper mines, ancient lead mine,
and ‘Z'he Most Ancient Copper Mine.’ Lead mines and ‘Ooal Pitts’ occur
on the Durham map, as well as ‘Hell Kettles’ and other natural features.
On the Essex map are two engravings labelled ‘Near Tilbury are several Arti-
ficial spacious Caverns built with Stone in a Chalky cliff to ye height of 10

PRESIDENTIAL ADDRESS. 393

Fathom. as nere represented,’ but the artist had not quite understood the
structure of the dene-holes (as now named); his plans are all right, but the
shafts are drawn above ground like factory chimneys. The Lincolnshire map
indicates the former appearance and extent of the Fens and the Wash, and
with it is ‘A Perpetual Tide Table for Foss-Dyke and Cross-Keys Washes in
the county, showing from the Moon’s Age the exact time of Full Sea of ye
beginning and ending of the Wash, or when Travellers may safely pass over.’

The Northamptonshire plate shows a pear-shaped mass of Serpule labelled
“A Vertebra or single Joint of the Back-Bone of a large fish. “Tis two inches
and a half in length, and near as much in breadth. Digged up at Peakirk
almost 4 foot deep in the Earth.’ A well-known Oolitic coral is ‘ Astroites, or
Star Stone, with round radiated holes in its surface found at Cartenhall ’; two
Kimmeridge Clay Ammonites are ‘‘A Five wreath’d double straited (sic)
Ammonia found in Oxenden’ and ‘ The Studded Ammonites Modiolaris found
near Towcester.’ Another is ‘A Four wreath’d Ammonites found at Marston
russel.’ ‘Lead Mines and Coal Pitts’ are indicated on the Northumberland
map. On that of Shropshire it is amusing to read that ‘or want of antiquities,
&e., in the county we have inserted some out of ye Neighbouring County of
Staffordshire.’ Five ‘Form’d Stones partly Cylindrical’ are clearly encrinite-
stems, and four organ-pipe and similar corals are labelled ‘ Minerall Coral,’
‘Museus Pyreidatus found near Stansop,’ ‘ Honey Comb Stone,’ and ‘A Form’d
Stone like a Stool of Reeds’ respectively. For the same reason the Worcester
map is decorated by specimens alleged to have been found in Staffordshire,
though in this case minerals as well as fossils are given. In addition to ‘Lead
Mines and Coal Pitts,’ ‘Allom Works’ are indicated on the ‘North Riding
of York Shire’ map, the last referring to a one-time flourishing industry in
‘the Whitby area. On the East Riding of the same county ‘Sunk Island’ is
shown as an island in the middle of the Humber—an area now joined to the
mainland—as a result of which one-time seaport towns are now far inland;
similarly, on the sea-coast, towns are shown which have since been entirely
washed away by the sea.

On the South Wales map a frond of Neuropteris and a fragment of Sigil-
laria are given as ‘Mock Plants out of a Cole Pit near Neath in Glamorgan-
shire,’ and presumably examples of

‘The sport of Nature, aided by blind chance,
Rudely to mock the works of toiling man.’

I have mentioned only a few contents of this old atlas, but I trust it has
been demonstrated that, two centuries ago, information now of great value,
both geographically and geologically, was being placed upon these maps. Mboll’s
work is only one of scores which were issued, some earlier, some later. What
I wish to emphasise is the necessity for preserving these maps and atlases
before it is too late. Each county society should collect, store; and eventually
catalogue and describe the maps relating to its area.

During the past few weeks three different booksellers have sent me books
wrapped up in county maps, or, more annoying still, parts of maps. In one
ease I asked if any others were available similar to those used for packing.
1 secured those I required, but at a price which clearly indicated that the
“packing * was about as valuable as the books!

I am sorry to say that the systematic compilation of lists of county maps
has only as yet been accomplished for a very few areas, and we thus have many
more ‘imperfections in the geological record’ than are really necessary. <A
few have been published, and as they contain a fair proportion taken from
atlases which contain charts of all the counties, a careful examination of these—
or the latest one issued—will give a good basis for a catalogue, to which the
locally-published archeological, geological, and topographical maps should be
added. Mr. T. Chubb, of the Map Room, British Museum, would, I feel sure,
give every assistance to anyone seriously taking the matter up.

Sir George Fordham appears to have led the way, his admirable papers on
Hertfordshire maps being published by the Hertfordshire Natural History
Society and Field Club (1901-1914) ; he followed with ‘Cambridgeshire Maps’
(‘Communications Cambridge Antiquarian Society,’ 1905-1908).

394 CORRESPONDING SOCIETIES.

Mr. William Harrison was early in the field with his ‘ Early Maps ot
Lancashire and their Makers’ (1908), published in the ‘Transactions’ of the
Lancashire and Cheshire Antiquarian Society, and in the same year this society
published his ‘ Early Maps of Cheshire.’

Mr. T. Chubb prepared a catalogue of Wiltshire maps, published by the
Wiltshire Archeological and Natural History Society in 1911, a more sub-
stantial catalogue of Gloucestershire maps issued by the Bristol and Gloucester-
shire Archeological Society in 1913, and in 1916 the Somersetshire Archzo-
logical Society printed his catalogue of Somersetshive maps, which, having the
advantages of all the lists previously published, is remarkably complete. In
1918 the Cumberland and Westmorland Antiquarian and Archeological Society’s
‘ Transactions ’ contained a list of the maps of those two counties by Mr. J. F.
Curwen. This brief list exhausts our record of county catalogues, though
Miss Ethel Gerard has dealt with early Sussex maps (Library, 1915), Miss M.
Frost with early Sussex Geological maps (in manuscript), and the present
writer with East Riding maps (‘ Transactions’ East Riding Antiquarian
Society, 1912), but in these instances complete catalogues were not attempted.

A careful perusal of these various compilations shows that the history
of British cartography can be divided roughly into three periods, perhaps best
classified by Fordham as—

1. 1579-1673 (Saxton to Blome). The early and archaic maps: Period of the
Dutch School, and of the meridian of the Azores or Canaries.

2. 1673-1794 (Seller to Cary). The modern and detailed maps with roads :
Period of the English School, and of the meridian of London.

3. 1794-1900. Period of the Ordnance Survey, and of the meridian of Greenwich.

With vegard to the earliest maps of the British Islands: these are usually
on vellum and preserved in one or other of our great libraries. Useful repro-
ductions of some of these are given in Richard Gough’s ‘ British Topography,
or, An historical account of what has been done for illustrating the Topographical
Antiquities of Great Britain and Ireland,’ 1780, two valuable volumes which are
not used by students so much as they deserve to be. Gough’s illustrations are
especially serviceable, as the originals of some of his plates have since faded
to such an extent that portions are entirely useless. These maps of the thirteenth,
fourteenth, and fifteenth centuries, however, wre principally remarkable for
their quaintness, and are historically of service from the place-names they
record and the rough sketches of ecclesiastical buildings, castles, and fortifica-
tions. But, as for illustrating any geographical or geological features, their
scale is too small and the conditions under which they were prepared were too
primitive. But they were the stepping-stones to greater cartographical
achievements.

The first engraved map of England and Wales (1573) was by Humphrey
Lloyd, a Welshman; the first county maps were produced by a Yorkshireman,
Christopher Saxton, who had special facilities for surveying granted to him
by Queen Elizabeth. The work was carried out between 1574 and 1579. Various
maps were engraved during this period, the whole being brought together and
issued as an atlas, with title page, etc. in 1579.

Between 1584 and 1593 John Norden surveyed seven counties and issued
maps thereof.

The next important series was by John Speed, said to have been a native
of Cheshire. He issued a ‘ History of Great Britaine’ for which fifty-four
county maps were prepared between 1608 and 1610. The maps alone were pub-
lished in 1610 in an atlas entitled ‘ The Theatre of the Empire of Great Britain.’

Speed’s maps were based upon Saxton’s and Norden’s. Copies of these were
issued by W. Kip and W. Holl, in the various editions of Camden’s ‘ Britannia,’
and still further copies appeared in numerous other works. Also, the remark-
able maps of English counties, printed in Holland, and often gorgeously
coloured, made their appearance. This was due to the anxiety of two pub-
lishers, Blaeu and Jansson, in Amsterdam, vieing with each other in the repro-
duction of an enormous atlas of the world.

But in all these various maps the geographical details were essentially the
same, the same errors of spelling and of positions of townships were faithfully

| . PRESIDENTIAL ADDRESS. 395

{

copied one after another; and additional misspellings and other mistakes crept
in as fresh ‘ editions’ appeared. True, the shipping, the scroll-work, borders,
decorations, and dates were altered from time to time; a map dedicated to
Queen Elizabeth bears a date long after that lady became an angel; and even
the positions and attitudes of the various grotesque sea-monsters besporting
themselves in the ocean were altered, but no advance was made in scientific
cartography as a result of these various ‘ new editions.’

During the succeeding century the production of atlases and maps was
tremendous : partly owing to the increased interest being taken in travel and
exploration generally ; partly, no doubt, from improved methods of engraving
and printing. In this period occur maps by Seller, Lea, Morden, Moll, Blome,
Overton, Kitchen, Bowen, Jeffery, Ellis, Carington, Bowles, Cary, and others,
whose names are familiar to map collectors. Some were beautiful pieces of
work, decorated by views or plans of the principal towns, cathedrals, or other
items of interest. Many of the later maps had been specially surveyed, the
roads were carefully portrayed, and even the smallest hamlet was indicated.
Of these, the work of John Cary stands out with prominence. Between 1787 and
1832 he produced an extraordinarily large series of maps and atlases, all excel-
lently ‘ performed.’ His work consisted of various county and road atlases,
while his large maps, on the scale of two miles to an inch, compare well with
the Ordnance Survey map of the same scale.

Facilities for travelling betwceu one point and another, in the way of stage
coaches and improved roads, resulted in the appearance of ‘road-books’ of
various descriptions. Among the first of these was John Ogilby’s ‘ Britannia.’
This consisted of details of all the items likely to be of interest to the traveller
being represented on scrolls, engraved parallel to each other, particulars of a
definite road being shown on cne plate. At first these books were large and
unwieldy, but improved as time went on, and eventually were issued small
enough to fit the pocket.

Road-books alone provide a wealth of information relating to the former
appearance of the country, and should be carefully examined by those interested
in the past history or geography of any particular area. Streams, bridges, hills,
good roads, moors, and commons, woods, and other details are given with
wonderful precision. Beacons, gibbets, and similar by-gones are indicated ; in
those days the approach to the gibbet meant whipping up the horses in order
to pass the ghastly spectacles hung in chains, with their accompanying stench,
as quickly as possible. In Yorkshire these books have provided minute details
of roads which have long since been swallowed up by the sea. Their perusal
therefore yields valuable facts relating to the appearance of the country before
it was changed by the Enclosures Acts, and all interested in coast changes,
the reclamation of fen and bog land, the former extent of forests, moors, and
commons will do well to consult them.

The period of really reliable and accurate mapping may be said to have
started by the formation of the Board of Ordnance, the surveying and triangu-
Jations in connection therewith commencing in 1784, though nothing was actually
published until 1801, seventeen years later. This Government work prac-
tically stopped all private enterprise in the way of surveying and publishing
maps, a remarkable exception being the beautiful productions of the Greenwoods,
who published several fine maps, and a county atlas in 1831. About the same
time (between 1823 and 1835) A. Bryant surveyed and published maps of about a
dozen counties. These were very well done and are eagerly sought by collectors.

From the early topographical maps illustrating coast changes and alterations
in the physical features of the country, and recording the occurrence of various
fossils and minerals, it becomes an easy process to imagine the evolution of the
map upon which rocks and soils are indicated by signs or colours. Yet, although
all the steps leading up to geological maps had been laid down, it was not
until early in the nineteenth century that William Smith produced the first
map upon which were definitely indicated the different rocks forming the
earth’s surface. From his primitive hand-coloured maps, upon which he
“plotted ’ what he personally investigated in the field, to the colour-printed
geological and mineralogical maps now being issued in enormous numbers by
every civilised State in the world, is a line of scientific progress rarely followed.
Yet in few directions has the pet hobby of a scientific crank, as ‘ Strata Smith’

396 CORRESPONDING SOCIETIES.

was then considered to he, become so necessary and so economically essential in
every part of the world.

The early history of geological mapping shows that the foundations of this
particular work are essentially British, and as usual these foundations were
laid by amateurs, often at great pecuniary sacrifice to themselves, and without
proper aprreciation at the time.

That geological observations were made, long before maps recorded them,
is obvious from various early writings. Even so long ago as 1595 George Owen
of Henllys in Pembrokeshire, in a ‘ History of Pembrokeshire,’ has a chapter
on ‘natural helpes which in this countrey to better the lande [‘‘lyme’’ being
the ‘‘chiefest ”’].’ In this he states ‘Tirst you shall understand, that the
lymestone is a vayne of stones running his course, for the most part right east
and west, although sometimes the same is found to approach to the north and
south. Of this lymestone there is found of ancient, two veynes, the one small
and of no great account, and not of breadth above a butt length, or stones
cast ; and therefore whosoever seeketh southward or northward over the bredth
misseth it.’

The course of this ‘ veyne’ is then traced for a considerable distance; and
a third ‘veyne of lymestone’ is referred to. We then read that ‘ For the
veyne of coales which is found between these two vaynes of lymestone, as a
benefit of Nature, without which the profit of the lymestone were neare lost ;
betweene the sayd two vaynes from the beginning to the ending, there is a
vayne (if not several vaynes) of coles, that followeth those of lymestone. This
vayne of coal in some partes joineth close to the first lymestone vayne, as in
Pembrokeshire, and Carmarthenshire; and in some partes it is found close by
the other vayne of lymestone, as in Glamorgan, Monmouth, and Somersetshire.
Therefore whether I shall say that there are two vaynes of coles to be found
between these two vaynes of lymestone, or to imagine that the cole should
wreathe or turne itself in some places to one, in other places to the other; or
to think that all the land betweene these two vaynes should be stored with
coles, I leave to the judgement of the skilfull miners, or to those which with
deep knowledge have entered into these hidden secrettes.’

A comparison between these observations and a recent geological map will
show that Owen’s observations were quite reliable, although made over three
centuries ago.

Later, but still long ago, Dr. Martin Lister in March 1683-1684 read a paper to
the Royal Society entitled ‘An Ingenious proposal for a new sort of Maps of
Countrys, together with Tables of Sands and Clays, such chiefly as are found
in the north of England.’ The author commences : ‘ We shall be better able to
judge of the make of the earth, and of many phenomena belonging thereto,
when we have wel] and duly examined it, as far as human art can possibly
reach, beginning from the outside downwards. As for the most inward and
central parts thereof, I think we shall never be able to confute Gilbert’s opinion,
who will, not without reason, have it altogether iron.’

‘And for this purpose it were advisable that a soile or mineral map, as I
may call it, were devised. The same map of England may, for want of a
better at present serve the turn. It might be distinguished into countries, with
the rivers and some of the noted towns put in. The soils might either be
coloured, or otherwise distinguished by variety of lines or etchings; but the
great care must be, very exactly, to note on the map, where such and such soiles
are bounded. As for example, in Yorkshire, (1) Zhe Woolds: chaulk, flint
and pyrites, &c. (2) Blackmoor: moores, sandstone, &c. (3) Holderness :
boggy, turf, clay, sand, &c. (4) Western Mountains : moores, sandstone, coal,
ironstone, lead-ore, sand, clay, &c. Nottinghamshire : mostly gravel pebbles,
clay, sandstone, hall-playster or gypsum, &c. Now if it were noted how far
these [soils] extended, and the limits of each soil appeared upon a map, some-
thing more might be comprehended from the whole and from every part than
7 can possibly foresee, which would make such a labour well worth the pains.
For, I am of opinion, such upper soils, if natural. infallibly produce such under
minerals, and for the most part, in such order. But TI leave this to the industry
of future times.’

Thus we get the first idea of preparing a map of England showing the

PRESIDENTIAL ADDRESS. 397

various soils and their boundaries by colours. Unfortunately the scheme was
apparently not carried out until long after Lister’s death.

A paper on ‘The Somersetshire Coal District’ was contributed to the
‘Philosophical Transactions’ in 1719, and was republished ten years later as
‘Observations on the Different Strata of Earth and Minerals, more particularly.
such as are found in the Coal Mines of Great Britain.’ This is accompanied
by a carefully prepared section of some coal seams ten miles south-west of Bath.
Though two centuries old, it clearly indicates the order and composition of
the beds, their interruption by ridges [faults]; and the occurrence above the coal-
seams of freestone [Oolite] lias, and red marl, lying unconformably upon the
older beds. The author has some weird and wonderful theories to account for
his facts, but he gives a section showing the proper relative order of the various
beds between the Chalk and the Carboniferous Rocks.

‘A new Philosophico-chorographical Chart of East Kent’ was ‘ invented and
delineated’ by Christopher Packe in 1743. It is now very: scarce, but there
is a copy in the library of the Geological Society of London. In this the valleys
and other physical features were shown, with the chalk districts, stone hills,
clay hills, ete. here is, however, no reference to stratification. Dr. Packe
was proud of his work. It was ‘no dream or devise, the offspring of a
sportive or enthusiastical imagination, conceived and produced for want of
something else to do, at my leisure in my study, but it is a real’ scheme, taken
upon the spot with patience and diligence, by frequent or rather continued
observations, in the course of my journeys of business through almost every
the minutest parcel of the country; digested at home with much consideration,
and composed with as much accuracy, as the observer was capable of.’

John Woodward, in his ‘ Natural History of the Earth’ (1723); Nicholas
Desmarest, in the ‘ Encyclopédie Méthodique’; John Michel (1760), whose
work has recently: been described by Sir Archibald Geikie; John Whitehurst, in
his ‘Inquiry into the origina] State and Formation of the Earth’; John
Smeaton, the engineer, in 1788; Prof. Jamieson (‘ Memoirs,’ Wernerian Society),
1811; James Parkinson (‘ Transactions,’ Geological Society), 1811, and other
early investigators have left evidence that they were familiar with the various
beds of the earth’s surface, their relative positions, thicknesses, and economic
contents. ‘l'hey were also aware of the various parts of the country in which
the different beds occurred. But none of them recorded that information on a
map or chart, although Prof. Jamieson got very near it; his paper being ‘On
Colouring Geognostical Maps,’ but the enormous number of complicated signs
and symbols he suggested proved unsuitable for practical purposes, though there
were many good features in his colour-scheme.

In the library of the Board of Agriculture and Fisheries, Whitehall, is a
very fine but incomplete series of the old county Agricultural Reports. These
were prepared upon a definite plan, for most, but not all, of the counties in
Great Britain, and principally date between 1790 and 1820. Occasionally two
or more editions were issued. In most of them is a coloured or shaded map of
the soils of the county. While these maps are usually but briefly, described.
and sometimes not described at all, their great bearing upon the geological
features of the counties dealt with, together with their early date, make their
consideration of some importance. They are also of value as it is obvious that
they were seen by William Smith, and considerably influenced him in his work
on his geological maps. The words used, e.g., brash, dunstone. freestone, etc.,
were also used by Smith. We know that he regularly attended the various meet-
ings of the Agricultural Societies, exhibited his draft geological maps there.
and, apparently, often bored his hearers by his talk on ‘strata’ and ‘ organised
fossils.’ ‘Strata Smith’ was a man to be avoided at these sheep-shearing
meetings, and we learn that on one occasion he was made aware that no one
was paying any heed to his remarks, so he folded up his maps and brought his
discourse to an abrupt termination. Most of the maps in the Agricultural
Reports were doubtless familiar to Smith; his intimate knowledge of rocks and
their methods of disintegration into soils enabled him to extract much geological
information from the soil maps, and there can be little doubt that they consider-
ably assisted him in the preparation of his great geological map of England and
Wales of 1815. T have carefully compared the soil maps of the areas which

398 CORRESPONDING SOCIETIES.

we know were unfamiliar to Smith, and it is apparent that he depended upon
them for the extent of the outcrops of the different beds, his masterly geological
mind enabling him to translate ‘ limestone soil,’ ‘marl,’ and other terms to
their proper horizons. :

In these circumstances it seems desirable briefly to refer to these old soil
surveys. : ; ‘

In the ‘ Journal of the Royal Agricultural Society ’ for 1898 Sir Ernest Clarke
prints an account of ‘The Board of Agriculture, 1793-1822,’ in which he gives
some information of value as to the dates of the appearance of the county
surveys. He states that ‘Sinclair commenced on too ambitious a scale with the
comparatively small funds at his disposal.’ Sir John’s original estimate of the
funds necessary for the Board’s support had been 10,000 guineas per annum,
which was reduced by degrees to 3,000/7., the actual sum annually voted by
Parliament. But to a man of Sinclair’s temperament it was impossible to
‘hasten slowly,’ and therefore the initial efforts of the Board were directed
with an impetuosity for which an annual income of 10,5007. would not have
been excessive. By the middle of the ensuing year, 1794. the whole of the
kingdom had been divided into districts and assigned to different ‘Surveyors,
and by July 1795 nearly all their reports had been received. They were then
issued as what Sinclair called ‘ printed manuscripts,’ in quarto size, with large
margins for the corrections and additions of practical agriculturists. The plan
was not a bad one, but it did not answer the expectations formed of it. This
is not surprising when we consider the undue haste and bad judgment displayed
by the President in the choice of the men employed. ‘The result was the
production of a huge mass of ill-digested articles of the most varying degrees
of merit, from valuable and exhaustive monographs in a few isolated instances
to scrappy Memoranda of but a few pages in others, according to the writers’
ability and thoroughness, or lack of these qualities. Though ostensibly drawn
up for private circulation, the reports were entered at Stationers’ Hall. and
may be regarded as practically published documents. The issue of such un-
reliable literature brought the Board at once into bad repute, and this unpopu-
larity was accentuated by a belief, groundless it is true. that the inquiries of
the surveyors were intended to lead to increased taxation. Another circum-
stance which added to the Board’s difficulties was the hostility of the Church,
provoked by an attempt to obtain information on the subject of tithes. Sinclair
had derived much help from the Scottish clergy in the preparation of his
“Statistical Account’’ of Scotland, and he now hoped similarly to enlist the
co-operation of the English clergy. But the mention of the vexed question of
tithes excited their suspicion, and even led to an intimation by the Archbishop
of Canterbury to Pitt, that any interference with this matter would alienate
the support of the Church from tle Government.’

‘In view of the fact that every now and then appear in booksellers’ cata-
logues what are described as “large paper” copies of the reports to the Board
of Agriculture on particular counties, it appears necessary to point out that
these are the origina] imperfect drafts on quarto paper. circulated for correction
amongst agriculturists of the district in the manner above described, and that
the final reports were all printed (in most cases years after the original drafts
and by different authors) in octavo size.’

Sir Ernest then supplies the following particulars of the publication of the
Asricultural Reports, which I give here for the use of the delegates ; though

this list is not quite correct, my own collection containing a number of editions
not here recorded :

— PRESIDENTIAL ADDRESS. 399

‘ABLE SHOWING AuTHORS AND Dares or Pusiication or (A) THE Drarr (QuaRTO) REPoRTS,
AnD (B) THE Finat (Octavo) Reports, ON THE SEVERAL CouNTIES or ENGLAND
AND WALES.

» (A) Draft (Quarto Renee, | (B) Final (Octavo) Report
in | | No. | | No.
County | Author Date | of | Author Date | of
| Pages Pages
Fat. tail i ee * AL a} uns eM thal
Bedford . | Thomas Stone 1794 | 70 || Thomas Batchelor . | 1808 | 651
Berkshire - | Wm. Pearce . . | 1794 | 74 || Wm. Mavor . 1808 | 559
Buckingham .| Wm. James and/| 1794 63 || Rev. St. J. Priest . | 1810) 420
| Jacob Malcolm = |
Cambridge | Chas. Vancouver | 1794 219 || Rev. W. Gooch 1813 | 312
Cheshire . | Thos. Wedge 1794 88 || Henry Holland 1808 | 387
Cornwall >) Robt. Fraser 1794 | 70 || G. BY Worgan 1811 | 208
Cumberland . | John Bailey and | 1794| 51 John Bailey and | 1797 69 |
é George Culley George Culley
Derby | Thos. Brown . 1794 | 72 John Farey (3 vols.)/1811-7| 1901
Devon | Robt. Fraser . | 1794 | 75 Chas. Vancouver 1808 | 491
Dorset | John Claridge 1793 49 Wm. Stevenson 1812 | 498
Durham | Joseph Granger 1794 | 74 || John Bailey . 1810 | 426
sex Messrs. Griggs 1794 | 26 | 7
laChiceserintad beater 1795 | 213 i Arthur Young (2 vols.) 1807 | 873
loucester . George Turner . | 1794 | 57 Thos. Rudge . 1807 | 416
mpshire _ Abr. and Wm. Driver} 1794 | 78 Chas. Vancouver 1810 | 528
tereford John Clark 1794 | 79 John Duncumb 1805 | 181
tertford | D. Walker 1795 | 86 || Arthur Young 1804 | 255
Tuntingdon . Thos. Stone . 1793 | 47 || R. Parkinson 1813 | 358
y . John Boys 1794 | 107 || John Boys 1796 | 222
' ae ih—sil | le—svalfisnt sil) Gh ee eobt gos! 306
sancashire John Holt | 1794 | 114 | John Holt and) | 1795 253
R. W. Dickinson J 1814 | 668
eicester John Monk . | 1794) 75 Wm. Pitt : 1809 | 420
incoln Thos. Stone . | 1794 | 108 Arthur Young 1799 | 462 |
liddlesex Thos. Baird . 1793 | 31 || J. Middleton 1798 | 614
+ | Peter Foot. 1794 | 92 os 1807 | 720
onmouth _ John Fox 1794} 43 Chas. Hassall 1812 | 154
| || Nathaniel Kent 1796 | 252
\orfollk Nathaniel Kent | 1794 | 56 Arthur Young 1804 | 552
orthampton . | Jas. Donaldson 1794} 87 || W. Pitt t - | 1809 | 332
orthumberland. John Bailey and | 1794) 7 John Bailey and | 1797 | 168 |
George Culley | George Culley
Rs ‘2 (al = FF » (8rded.) | 1805 | 213
fottingham Robert Lowe | 1794 | 128 || Robert Lowe - | 1798 | 204
xford : Richard Davis | 1794) 39 | Arthur Young 1809 | 374
wutland= | John Crutchley | 1794 | 34 | R. Parkinson 1808 | 194
aropshire . J. Bishton | 1794 | 38 | Joseph Plymley 1803 | 390
omerset . J. Billingsley | 1794 192 J. Billingsley 1797 | 336
afford . W. Pitt . | 1794 | 168 || W. Pitt 1796 | 264
. — ea ee 1813 | 347
folk Arthur Young (1794) 92 || Arthur Young 1797 | 329
a | eT he x » (3rded. )) 1804 | 447
ey / Wm. James and / 1794; 95 || Wm. PPh 1809 | 624
Jacob Malcolm
issex - | Rev. A. Young. | 1793 | 97 || Rev. A. Young 1808 | 479
Jarwick . | John Wedge . | 1794) 60 | Adam Murray 1813 | 204
estmorland Andrew Pringle . | 1794) 55 || Andrew Pringle . | 1797 7
pe a2 — — » (8rd ed.) | 1813 87
iltshire Thos. Davis, Sen. 1794 | 163 Thos. Davis, Jun. . | 1811 287
orcester _W. T. Pomeroy 1794 | 94 W. Pitt 3 1810 | 448

400 CORRESPONDING SOCIETIES.

TABLE SHOWING AUTHORS AND DarTsEs OF PUBLICATION, ETC.—continued.

(A) Draft (Quarto) Report | (B) Final (Octavo) Report
| | No. | No.
County Author | Date, of | Author Date
| Pages Pages
| Yorks, N. Riding | Mr. J. Tuke, Jun.. | 1794 | 123 | John Tuke . . | 1800
Tah ence 83M Isaac Leatham . 1794) 68 | H. E. Strickland . | 1812
4 A vie Rennie, Brown, and | 1794 | 140 | Robert Brown . | 1799
! Shirreft | i |
North Wales . | Geo. Kay . . | 1794 | 119 | Walter Davies . | 1813
Brecknock . . | John Clark . . | 1794) 55. ||
| Cardigan . . | T. Lloyd and Turnor | 1794 37 |
| Carmarthen . | Chas. Hassall. . | 1794 | 52 ||| “South Wales ”
| Glamorgan . . | John Fox. . | 1796) 71 | Walter Davies . | 1814 | 1170
Pembroke . . | Chas. Hassall. . | 1794 | 68
| Radnor. . | John Clark . . | 1794] 41 | |
| Isle of Man . | Basil Quayle . - | 1794 | 40 | Thomas Quayle . pes
| | 2? 29 2 |

a correct idea as to the nature of his discourse. It was probably some such
trait in his character which caused the men who formed the Geological Society
to give Smith a wide berth, otherwise it seems difficult to account for the way
in which he was at first ignored. However, Smith lived to see his work recog-
nised by the Society, and the words uttered by the President, when the first
Wollaston Medal was awarded to him in 1831, made amends,

I have dealt fully with Smith’s work elsewhere (‘ William Smith : His Maps
and Memoirs,’ ‘ Proceedings,’ Yorkshire Geological Society, 1917, reprinted
1920), but the great part he played in connection with the evolution of geological
maps demands a brief reference here.

On the walls of the library of the Geological Society, Burlington House, in
a circle fifteen inches in diameter, is ‘A map of Five Miles round the City of
Bath. . . . Presented to the Geological Society, February 18th, 1831. Wm.
Smith, Coloured geologically in 1799.’ This is the first geological map ever
prepared, and is one of the greatest cartographical treasures we possess. By
collecting old Bath Guides I was able to find that its basis was a plan appear-
ing in ‘The Historic and Local New Bath Guide,’ published in that year.
There are only three colours, but they illustrate Smith’s well-known method of
colouring the base of a formation with a deep tint, and shading this upwards
towards the outcrop of the next overlying stratum. It also demonstrates how
carefully he mapped all the geological lines around Bath.

A year later (1800) he coloured a geological map connecting the structure of ~
the north of England with that of the south-west, recording the Oolitic series —
throughout England with remarkable accuracy. This map is lost, but we hope
it may yet be found. In 1831 it was in the possession of John Phillips, the
curator of the York Museum. : ps

In 1801 a copy of Cary’s ‘Index Map of England’ (11 in. by 9 in.) was
coloured by Smith and labelled ‘General Map of the Strata found in England ~
and Wales.’ This was also given to the Geological Society in 1831. It is —
coloured after the manner of Smith’s later maps, the eight tints representing
Chalk, Sand of Portland Rock, Oxford Clay, Oolite, Lias, Trias and Permian,

PRESIDENTIAL ADDRESS. 401

Carboniferous [and Magnesian] Limestone, Old Red Sandstone. It is the
first geological map of England and Wales.

In 1805 Smith finished a large and detailed map of Somersetshire, which
was publicly exhibited and described at meetings of the Agricultural Societies.
In an incomplete state it had been shown at a meeting of the Bath Agricultural
‘Society (of which he was a member) so early as 1799. This map is lost, but
we hope search in old Somersetshire libraries may bring it to light.

Smith’s great work was his wonderful map of England and Wales, measuring
6 ft. by 84 ft., on the scale of five miles to an inch. It was projected in 1801
and published in 1815. Twenty different colours were used, and opposite the
Humber Mouth is a ‘Sketch of the Succession of Strata and their relative
Altitudes,’ often being accompanied by Smith’s autograph, and the number of
the map. In addition to the strata, collieries, various lead, copper, and tin
mines, salt and alum works were indicated. The map, as might be expected,
has defects, and these were pointed out by Judd (‘Geological Magazine,’ 1898,
page 101), but they do not minimise the credit due to ‘The Father of English
Geology’ for his masterpiece.

From a copy of the original prospectus it appears that the map was dedicated
to Sir Joseph Banks, sanctioned by the Board of Agriculture, and was sold at
prices varying from 5/. 5s. to 12/., according to the method of mounting. At
least 96 numbered copies were published. Some idea of the amount of work
‘eonnected with them may be gathered from the following extract from Smith’s
diary :—

‘May 14, 1815.—Began at nine in the morning with an artist to colour
for me the first printed copy of the ‘‘ Map of the Strata ’’ on canvas.

‘May 22, 1815.—Finished colouring the first ‘‘ Map of the Strata’’ on
canvas.

‘May 23, 1815.--Attended a meeting of the Board of Agriculture with
the first finished copy on canvas of my ‘‘ Map of the Strata.’’’

This was the map for which the Society of Arts awarded Smith the premium
of 50.

Between 1819 and 1824 Smith published six parts of a ‘ New Geological
Atlas of England and Wales’ twenty-one counties being represented in this work,
which evidently did not receive adequate support, and was unfinished. The
maps, which are very rarely met with, show much more detail than was possible
on the large sheet of 1815. Yorkshire, in this series, is exceptionally accurate
and complete, due to Smith’s residence in the county from 1820, the map being
issued in 1821.

In 1820 a reduced copy of Smith’s large map of England and Wales was
published by Cary. It measures 24 in. by 30 in. and is on the scale of 15 miles
to an inch. It was entitled ‘A New Geological Map of England and Wales,
with the Inland Navigations, exhibiting the districts of Coal and other sites of
Mineral Tonnage.’ Information as to the economic products of the strata is
here given. A second edition wag contemplated, and I have a copy, engraved
_ from the same plate as the 1820 issue, but with the date altered to 1824. The
_ colours, however, have not been filled in. My copy, with another, was found
in Scarborough a short time ago. So far I have not traced a copy of the
1824 edition coloured : it may never have appeared.

From 1828 to 1834 Smith was land steward to Sir John V. B. Johnstone,
and resided at Hackness, near Scarborough. While there he prepared a
geological map of the Hackness area, briefly referred to by his nephew Phillips.
This map had not been seen, and neither the Geological Society nor any other
society seemed to possess one or know anything about it. Through inquiries
made in the Scarborough district, where Smith spent his last years, I was success-
ful in securing two copies. A comparison between these and those of the
Geological Survey shows a remarkable similarity, and the way in which Smith was
able to map the intricate series of beds in the Scarborough area—nearly a cen-
tury ago—is most creditable to him. It was lithographed by Day, London, hand-
coloured by Smith, measures 23 in. by 36 in., scale 12 chains to 1 inch. Smith
prepared a memoir describing the rocks represented upon it, which has recently
been published. “

1920 DD

402 CORRESPONDING SOCIETIES.

in the Fourth Report of the Scarborough Philosophical Society, for 1833,
there is a note ‘that Mr. W. Smith has been kind enough to colour for the
Society Knox’s excellent map of the Vicinity of Scarborough.’ This map
could not be found at Scarborough, but on examining the maps in the possession
of the Geological Society at Burlington House recently, I found it there, signed
“W. Smith, 1831.’ How long it had been there, and how it got there at all,
no one knows. I should imagine that Phillips, once curator of the Museum
at Scarborough, later President of the Geological Society, had borrowed it!
At the same time I found a copy of each of two second editions of Smith’s
county maps of Northumberland and Durham. These originally appeared in
his Geological atlas in 1824, but the second issues are dated 1831, and were
not previously known.

In addition to his maps Smith published a remarkable set of cross-country
sections, the first being on his large map of 1815, eight others on a larger
scale being published separately between 1817 and 1819. Geological sections
hardly come within the scope of the present address, but as they form such
an important feature on many maps subsequently published, it is as well to
bear in mind the fact that Smith was the first to embellish a map in this way.

Improvements in engraving and in colour printing resulted in geological
maps being issued which showed more detail and were less’ liable to error than
the hand-coloured maps. Close upon Smith’s heels came G. B. Greenough,
President of the Geological Society, whose ‘Geological Map of England and °
Wales’ (63 in. by 75 in., scale 1 in.=5 miles) was published ‘under the
direction of the Geological Society’ and was accompanied by a memoir. Thirty-
eight different strata were indicated, as well as various signs representing
mines, etc. The first edition, though ready in 1814 and dated November
1819, appeared in May 1820. A second edition, with the colouring much
improved, appeared in 1839, and a third in 1865, after Greenough’s death.
On this last edition appeared, for the first time, the words ‘On the basis of
the original Map of William Smith, 1815.’

As an indication of the enthusiasm displayed in connection with the issue
of geological maps a century ago, the cost of the preparation of this map
was 1,3007., most of which was guaranteed before publication. I have recently
had occasion to examine many reports of Philosophical Societies and Mechanics’
Institutes of that time, and have been astonished at the number of items,
varying from six to twenty pounds, shown in the accounts for the purchase
of geological maps. Entries of this sort are very rare in these reports nowadays.

From the great wealth of Greenough’s manuscript material in the possession
of the Geological Society we can form some idea of the way in which he
prepared his large maps, and of the great variety of sources from which
he obtained information relating to the geological structure of our islands—
even casual references in the daily papers supplied him with particulars. In
his collection are some of the soil maps from the reports of the Board of
Agriculture, clearly indicating, as with Smith, that Greenough could put these
to good use.

Of a somewhat similar type, and certainly to be included as classics, are
MacCulloch’s map of Scotland (1834) and Griffith’s map of Ireland (1839
and 1853). Of especial historical value is a manuscript map of ‘Scotland
coloured according to the Rock formations, presented to the Geological Society by
Mr. A. L. Necker, Nov. 4th, 1808’ (21 in. by 26 in., scale 1 in.=125 miles).
There are seven different colours used to define the various rocks, these being
placed upon a copy of Kitchin’s map of 1778. The chart is far in advance
of the soil-maps, is twenty-six years earlier than MacCulloch’s map of Scotland,
and even anticipates Smith’s large map of England and Wales by seven years.
Following these, the middle of the nineteenth century witnessed a veritable
epidemic of geological maps of England and Wales, including those of Arrow-
smith, Murchison, Walker, Ramsay, Ravenstein, Knipe, Phillips, Johnston, and
others, many of which were reprinted and revised on numerous occasions. In
addition to the geology, these maps vied with each other in the matter of the
quantity of information of all sorts which was crowded upon every available
sprees the number of cross-country sections shown on some of them being extra-
ordinary.

PRESIDENTIAL ADDRESS. 403

in addition were issued Paleontological maps, Mineralogical maps, and
many others, specialising more and more as additional students came into the
field. ‘Then followed the maps of Geikie and his contemporaries, and finally
those issued by the Geological Survey—at first hand-coloured, but now colour-
printed, and as nearly perfect as it is possible to be, in this country.

Besides these separately published maps, mention should be made of the
beautiful examples of mapping occurring in various valuable monographs issued
in the early part of last century, MacCulloch’s ‘ Western Isles of Scotland,’
Phillips’ ‘Geology of Yorkshire,’ and Mantell and Dixon’s monographs on Sussex
Geology being representative of their kind.

Privately-printed maps of the geology of portions of our country exist, the
three most noteworthy perhaps being Sanders’ map of the Bristol Coalfield,
Jordan’s ‘London District, and Elias ‘Hall’s ‘ Lancashire Coalfield.’

That of William Sanders was the most elaborate and complete geological
map ever privately published in Great Britain. It was in nineteen sheets,
each 30 in. by 24 in., on the scale of 4 in.=1 mile, and was issued to subscribers
at 37. 19s. plain, 47. 19s. coloured. It was published by Lavars, of Bristol,
from whom I obtained my copy, said to be a ‘second edition,’ though I cannot
find that it differs in any way from the original issue. Two hundred and
twenty parishes around Bristol are included; every line is the result of Sanders’
own work, which occupied the summer months for twelve years. Hach of the
nineteen sheets covers about 45 square miles. So reliable was his work that
the Geological Survey practically adopted it, or at any rate included the informa-
tion it contained, for the Government maps, as was fully acknowledged by
De la Beche in vol. i. of the ‘Survey Memoirs,’ 1864, page 126, as follows :
“We are here anxious to acknowledge the great assistance the Geological Society
| Survey] has derived from the labours of Mr. William Sanders, of Bristol, who
most handsomely placed at the disposal of the Survey his beautiful maps of
the country bounded by the Severn and Bristol Channel from Purton Passage
to Clifden, and thence inland by Chipping Sodbury, in one direction, and by
Keynsham and Newton on fhe other, to the Week rocks, a large area, and
containing very complicated ground.’

Jordan’s map first appeared as ‘Stanford’s Geological Map of London
showing superficia! Deposits, compiled by J. B. Jordan’ (225 in. by 244 in.,
scale 1 in.=1 mile). This was followed by ‘ Stanford’s Library Map of London
geologically coloured by James B. Jordan,’ in 24 sheets, each 16 in. by 13 in.,
and on the scale of 6 in.=1 mile. Nine different beds between the Alluvium
and the Chalk are defined on this fine map. In the following year, 1878, ‘ Stan-
ford’s Geological Map of London and its Suburbs’ was also in 24 sheets, and
on the scale of 6 in.=1 mile. It includes the country between Wimbledon on
the south-west and Hampstead on the north-west, Leyton on the north-east, and
Beckenham on the south-east.

Contrasting with these two reliable and careful pieces of work is ‘A
Mineralogical and Geological Map of the Coal Field of Lancashire, with parts
of Yorkshire, Cheshire, and Derbyshire, by Elias Hall [1832].’ It measures
51 in. by 38 in., and is on the scale of 1 in.=1 mile. The representations of

_ the strata are more peculiar than reliable, and the author’s knowledge of the

—————————— -—

fossil contents of the beds. as shown by the ‘ Verticle [sic] Section,’ is both

“extensive and peculiar.’ Elias Hall copies Smith and Greenough by publishing
sections of the rocks covered by the map, and in 1836 he issued a 32 pp.
pamphlet as an ‘ Introduction to his Map.’

A handy modern volume is ‘Stanford’s Geological Atlas of Great Britain
and Ireland,’ edited by the late H. B. Woodward, which contains coloured
maps of the counties, upon which are indicated the various collecting grounds
for fossils, in addition to which is a general introduction to the geology of the
country. But this atlas has ‘evolved.’ William Smith’s incomplete Geological
atlas of the counties was the start. In its present form the work began as
‘Reynolds’ Geological Atlas of Great Britain,’ published in 1860, twenty-eight
colours being used. But the plates, before being geologically coloured, were
engraved by John Emslie and originally appeared in Reynolds’ County Atlas
in 1849. A ‘New’ [second] edition of this work, entirely re-set throughout,
was issued by Reynolds in 1864. In 1889 another edition was described as the
“second’ edition, but was really the third. In 1904 appeared ‘Stanford’s

DDdD2

404. CORRESPONDING SOCIETIES.

Geological Atlas,’ based on Reynolds’ atlas, with plates of characteristic fossils,
etc. In this Emslie’s plates were still being used. Stanfords issued a ‘second ’
edition of their atlas in 1907, and a ‘third’ (actually the sixth) edition in
1914. In 1913 was issued a ‘Photographic Supplement’ to the atlas. These
different editions with their varying county maps are occasionally to be picked
up at a reasonable figure, and the maps of any particular county might be
exhibited in order to show the additions made to geological knowledge from
time to time.

In urging the delegate, therefore, to collect, vigorously, while there is still
an opportunity, I do so with every confidence that future students will be
grateful for the efforts made. Few people yet realise the valuable information
to be derived from an examination of a series of maps of any particular area.

It is quite possible at times that maps may be obtained which do not bear
any date. In many cases the only clue to the date of the publication is in a
review, or in the advertisements on the cover of the ‘ Geological Magazine’ or
other publications, though unfortunately the almost general practice of destroying
the covers when binding the volumes results in much useful information being
lost.

Except in a few rare cases even the publishers do not keep any particulars
of the dates of the appearance of the various editions of maps they issue, nor
can they supply lists of their own maps.

I trust in the preceding remarks the scientific value of the collection and
study of maps has been demonstrated. In recent years there has been occa-
sional evidence of their proper appreciation, but it should be more systematic
and continuous. Certain districts have received careful and proper attention,
others and far greater tracts of our islands do not seem to have received any.
Without attempting to give a complete list of recent publications on the subject
I may mention, as admirable examples of work: the Reigate sheet of the
one-inch Ordnance Survey; ‘A Study in the Geography of the Surrey Hills,”
by Ellen Smith, published by A. & C. Black, London, in 1910, which is accom-
panied by six large maps; and a similar work issued by the same house in
1911, entitled ‘Highlands of South-west Surrey : a Geographical Study in Sand
and Clay,’ by E. C. Matthews, with seven maps. In addition, there are the
regional surveys such as those carried out by Mr. C. E. Fagg, of the Croydon
Society, and a ‘ Regional Study of North-east England,’ by C. B. Fawcett, in the
‘ Geographical Teacher ’ issued a few weeks ago. Of a more specialised character.
but still indicating progress in the evolution of mapping, are the Botanical
Survey sheets of Yorkshire by Drs. Smith and Woodhead, and similar publi-
cations relating to different areas in Scotland.

That more attention should be paid to maps is shown by the volumes which
have recently appeared dealing entirely with the question of reading them.
Probably at no period in the world’s history have the advantages of accurate
cartography been so vital as during the past few sad years, when it might
safely be said that the future of the world’s history largely depended upon
the care expended in the preparation of the maps of North-west Europe.

Two centuries ago it was stated ‘Most Students in Geographie take more
delight to contemplate the remotest and most barbarous Countries of the earth,
than lightly to examine the Descriptions of their owne.’ I am afraid that
the same remarks applied to the years which have since passed, but we now
seem to be reaching the time when in our schools, in our Scientific Societies.
and in the country generally, more attention is being paid to the geographical
problems at home, and these can probably best be solved by an examination of
our country’s maps: this examination being facilitated if collections are made
at convenient centres in various parts of the British Isles.

PRESIDENTIAL ADDRESS. 405

After a brief discussion Mr. A. H. Garstang, Secretary of the Railway
Facilities Sub-Committee of Section F, read a paper on ‘ Railways and their
Obligations to the Community.’

At the second meeting on Friday, August 27, a discussion on ‘ The Status of
Local Societies : the means of developing their objects, of getting new members,
of publishing papers and making announcements,’ was opened by Mr. William
Whitaker, and the following resolution was passed :—

Status of Societies.

‘That this Conference suggests to the Council that a further meeting be held
in London to which the Officers as well as the Delegates of the Corresponding
Societies be invited.’

A further resolution arising out of Mr. Garstang’s paper (read. at the previous
meeting) was proposed by Sir Edward Brabrook as follows, and carried :—

Railway Facilities.

‘Having regard to the many important questions at issue with regard to
Railway management this Conference recommends that the Association should
urge upon the Government the reappointment of a Royal Commission such as

that which was appointed in 1913, but in consequence of the War broke up
without reporting.’

406 CORRESPONDING SOCIETIES.

LIST OF PAPERS

BEARING UPON THE ZOOLOGY, BOTANY, AND PREHISTORIC ARCHAOLOGY
OF THE British ISLES, ISSUED DURING JUNE-DECEMBER, 1919.*
ComPILED By T. SHEPPARD, M.Sc., F.G.S., Toe Muszum, Hutt.

At a recent meeting of the Corresponding Societies’ Committee held at Burlington
House, London, at which some of the General Officers of the British Association were
present, the question of the continuance of the annual lists of publications received
was discussed, and the present writer was asked to prepare a report on the subject,
and to continue the preparation of the lists in a modified form. Subsequently the
following report was submitted :—

‘In the past the bibliography issued by the British Association has been limited
to papers appearing in those publications forwarded by the Corresponding Societies,
it has embraced practically all the sciences, related to any part of the earth (or the
heavens), and it has ended each year on May 31. In this way the lists were incomplete,
and contained much that was useless. For instance, of the fifty-eight papers relating
to Mathematical and Physical Science, in the bibliography issued in our last report,
thirty-three were published by the Royal Astronomical Society of Canada, five by
the Royal Society of South Africa, leaving twenty titles to represent a year’s work
of British mathematicians and physicists. Similarly, in Chemistry, there are eight
entries, five of which relate to South Africa, thus leaving three to represent the work
of the British chemists—two of these papers being printed by the Mining Engineers,
and one by the Cotteswold Club.

‘ True, as a catalogue of the publications sent to our library, the list is complete,
but in its present scrappy form it is of little use scientifically, as indicated by the fact
that the publications in the rooms of the British Association are seldom consulted.

‘I would suggest that in future the bibliography be confined to papers and
memoirs bearing upon the fauna, flora and prehistoric archeology of the British
Isles, and include all published, whether sent to the Association or not, and that the
lists close each year on December 31. This can be accomplished by printing the
items June 1 to December 31, 1919, in our Report for 1920, each subsequent volume
to contain the complete bibliography for the preceding year.

‘It is not desirable to duplicate work already being accomplished by special
societies. For example, Astronomy, Chemistry, Geography, Statistics, Electricity,
Physiology, Agriculture and Engineering are already well catered for by the journals
or other official organs issued by the supporters of those sciences. The lists of
geological literature issued by the Geological Society of London, which have been
in abeyance during the war, are, I understand, to be continued and completed, and
if, in future, that Society could be prevailed upon to include all papers on British
Geology, whether in its library or not (very few additional entries would enable this
to be accomplished), the necessity for publishing geological items in the British
Association’s bibliography would be dispensed with.

‘This would practically leave the Sciences of Zoology, Botany, and Prehistoric
Archeology, in their various ramifications, to be dealt with in our lists.

‘In addition to the papers on these subjects appearing in the publications of the
various societies in the British Isles, and those relating to these islands which are
published abroad, the contents of the weekly, monthly, and quarterly scientific
magazines dealing with specific portions of the British Isles should be included.
Similarly, suitable papers bearing upon the three sciences mentioned, appearing in
any of the engineering, agricultural, geological or other publications, would, of course,
be noted.

‘With these suggested alterations, omissions and additions, the bibliography
might be kept within reasonable limits and be of distinct value to British science.

‘TI may add that I have the list for June 1 to December 31, 1919, well in hand,
and I do not anticipate any serious difficulty in the compilation of the lists for
future years. 3

‘T. SHEPPARD.”

* The last list compiled by the late H. C. Stewardson included the months January
to May 1919, but, as was stated, included only titles of papers in publications actually
sent to the Corresponding Societies’ Committee.

LIST OF PAPERS, JUNE-DECEMBER, 1919. 407

Some correspondence with the Geological Society ensued, resulting in receipt
of the following letter, which enables us to leave papers bearing upon Geology to the
Geological Society.

Geological Bibliography of the British Isles.

Dear Mr. Surprarp,—In reply to your letter of the 8th inst., I hasten to thank
you for your kind offer to supply particulars of such British geologica] serials and papers
as we do not receive here, and have no hesitation in undertaking to have them included
in our future lists of geological literature, so that these may include everything
published in this country relating to the British Isles.

Yours very truly,
L. L. Betmyrantr, Permanent Secretary.

The preparation of the list here printed, as well as that.for 1920, which is in
progress, prompts the following observations :—

Titles of Papers.

I should like to appeal to contributors to journals, and particularly to editors,
to insist on seeing, as far as possible, that the title of a paper gives some indication
of the nature of its contents; for if a bibliography is to be of service at all, it must,
in addition to giving the titles of papers, indicate to what they refer. Thus, when
Natural History and Archeological articles are headed, ‘A Find’; ‘A Puzzle’ ;
“A Combat’; ‘Battle Royal’; or ‘A Curious Find’; ‘Dorset’; ‘ Vanessa
io’; these headings have necessarily to be quoted, in addition to which the biblio-
grapher has to insert what should have been the correct title to the paper, in this
way considerably adding to the amount of work and to the cost of printing. Authors,
and especially young ones, may be pardoned for making errors of this sort, but editors
should be able to put them right.

There is a further difficulty to be contended with, which should be corrected,
as the habit is growing more prevalent in our scientific journals. As far as possible
the title should be brief and clearly convey the subject of the articles. For instance,
a student searching for records, say, of the marten in Shropshire, could easily search
through the lists for a heading, ‘Marten in Shropshire.’ Judging, however, from
titles examined during the past few weeks, the record might easily occur under ‘ On,’
‘Notes on,’ ‘Stray Notes on,’ or even ‘Memorandum of,’ ‘The Occurrence of,’
or ‘Record of ’ a Marten in Shropshire, or many other varieties. It seems un-
necessary to head a record, ‘ Notes on ’ or * Record of,’ as this is obvious.

Another means of causing extra work and expense is the way in which authors
appear under various names. In one journal with which we are familiar, during the
last few months notes have appeared by a welcome contributor, as by, say, ‘C. T. J.,’
*C.T. Jones,’ ‘ Chris. T. Jones,’ or ‘Chris. Thomas Jones.’ Had they all appeared
under ‘ C. T, Jones,’ or ‘ Chris. T. Jones,’ one entry of the name would suffice, and
the various contributions could be placed in alphabetical or datal order.

A further means of causing unnecessary confusion and search is when two authors
who write conjointly change the names about, and one month a paper is by ‘ Smith
and Jones,’ and the next by ‘Jones and Smith.’ It is obvious there should be
consistency, for when, as happens in one well-known journal, each joint author has
three long names, which are given in different forms, and sometimes one set is placed
first and sometimes another, the numbers of references and cross-references become
irksome.

Another source of inconvenience in quoting references is the growing habit of
issuing what are described as ‘double numbers,’ which are consequently double
the usual price, presumably because they appear bi-monthly instead of monthly.
There is not much objection to the words ‘double number’ appearing on the cover
for the benefit of the publisher and for the enlightenment of the subscriber, but when
both months are named and both parts to the volume are indicated, and when every
issue is a so-called ‘ double number,’ the question of giving proper reference becomes
exceedingly complicated, quite apart from the time and space occupied. One
publication recently received is for July and October, but was ‘ published August 24.’
It is also ‘ Nos. 7 and 8’ of the volume, and a ‘ double number,’ although it con-
tains only twenty-four pages. It is difficult to say what objection there can be to
numbering each part separately, and adding the month of publication. If, as in the

408 CORRESPONDING SOCIETIES.

case of some societies’ publications, a journal is behind-hand in its issues, there is no
difficulty in adding that it is issued ‘for ’ such a month of sucha year. This need
not interfere with the actual number of the volume or part, or date.

To save expense and for convenience of reference, all varieties of an author’s
name will, in the following list, be included under the most complete form given
(thus, C. T. J., C. T. Jones, Chris. T. Jones and Chris. Thomas Jones will all appear
under the last named). Similarly, in the case of double numbers, the date of the first
month and the number of the first part only will be given ; thus a journal Vol. 66,
Parts 1 and 2, for July and October, issued in August, will be quoted as ‘ Vol. 66,
Part 1, July.’

As the following list has heen prepared at short notice, it may not be absolutely
complete, but it includes references to all the papers relating to the British Isles
occurring in the journals devoted to general natural history, entomology, botany,
conchology, archzolegy, etc., as well as in the proceedings of the various London
and Provincial scientific societies. Next year it is hoped to print a list of the
publications which have been examined.

In the past the list of papers published by the Corresponding Societies’ Committee
has been classified according to the different sciences. Now that the number is much
smaller, Zoology, Botany and Prehistoric Archeology only being dealt with, and
that quite a large proportion of the titles refer to two or sometimes three of these
subjects, it seems desirable to avoid repetition hy making one alphabetical] list, and
indicating the subject dealt with at the front by the letters Z, B, and P respectively.

The references to journals, etc., are given in the usual abbreviated forms; thus,
Ent.=The Entomologist; New Phy.=The New Phytologist ; Geol. Mag.=The
Geological Magazine ; Scr. Progr. =Science Progress, and so on..

BZ Anon. Proceedings, Summer Session [Reports of Excursions]. Ann. Rep.
Proc. Belfast Nat. F. Club, 1918-19, pp. 10-15.

BZ —-- Winter Session, loc. cit., pp. 16-26.

Z —-—- Report of the Council. Ann. Rep. Yorks. Phil. Soc. for 1918, pp.
vi.-xXiv.

Zz —— Additions and Corrections to the Hand-List of British Birds (Third
List). Brit. Birds. June, pp. 2-4.

Z —— Spring Immigration ot Jackdaws on the Hampshire Coast, loc. cit. Aug.,

. 80.

Zz —-— eco of Marked Birds, loc. cit. Oct., pp. 125-128.

v4 —— Short Notes, Joc. cit. June, p. 32; July, pp. 63-64; Aug., p. 87;
Sept., pp. 111-112; Dec., p. 198.

Zz --— (olosoma sycophanta L. at Exmouth. Hnt. Mo. Mag. Aug., p. 180.

BZ —— Insects and Fungi on Grass Land, loc. cit., pp. 181-182.

Z —— The Dollman Collection, loc. cit. June, pp. 135-136.

z —— Current Notes and Short Notices. Hnt. Rec. June, pp. 113-115; July,
pp. 184-136; Aug., pp. 173-175; Oct., pp. 188-191; Nov., pp.
210-211; Dec., pp. 226-229.

Zz —— The South London Entomological and Natural History Society [Report], —
loc. cit. June, pp. 118-120; July, pp. 137-139; Ang., p. 176;
Oct., pp. 191 -192 ; Nov., pp. 211-212.

Zz —— Lancashire and Cheshire Entomological Society [Report}, loc. cit. June, —
p- 120; July, p. 140.

Z —-— The Entomological Society of Londen [Report], Joc. cit. June, pp,
115-118.

BZ —— Hssex Field Club : Reports of Meetings [May 11, 1918, to March 29, 1919].
Essex Nat. Vol. xix., pt. 1, pp. 31-47.

BZ --— Proceedings of the [Glasgow Naturalists’] Society. Glasgow Nat. Sept.,
p- 82. Excursions [Aug. 21, 1915, to May 23, 1916], Joc. cit., pp.
93-111.

B —— Pctamogeton panormitanus in Ireland [Note of record by Arthur Bennett,
which see]. Jrish Nat. Sept., p. 106. a

B —— Tolypella glomerata var. erythrocurpa [Note of record by J. Groves —
and G. R. Bullock- Webster, which see], foc. cit., p. 106.

BZ —— Dublin Microscopical Club [Report], Joc. cat. June, p.79; Nov., p.133.

B —-— Watson Botanical Exchange Club Report [Notice of]. Journ. Bot.

Nov., pp. 314-318.

70 7 Ww BASEN BD ON No
N

wo UNO NN N® © N NNN © N NNN

BZ
BZ

LIST OF PAPERS, JUNE~DECEMBER, 1919. 409

Anon. Coslett Herbert Waddell {Obituary ], Joc. cit. Dec., pp. 358-359.

Proceedings of the Conchologica! Society of Great Britain and Ireland
[Oct. 8, 1919, to June 9, 1920; including reports by F. Booth, J. E
Cooper, B. Bryan]. Journ. Conch. Aug., pp. 117-124.

Editorial Notes, loc. cit., pp. 125-127.

Botanical Section [Report]. Journ. Northants Nat. Hist. Soc. & F
Club. No. 158, p. 60.

Proceedings of the Quekett Microscopical Club. Jowrn. Quekelt Micro.
Club. No. 84, pp. 41-54. _ No. 85, pp. 92-102.

The Report of the Departmental Committee on the Protection of Wild
Birds. Journ. Wild Bird Inves. Scc. No.1, pp. 12-13.

Notes & News [Ornithological], loc. cit., pp. 15-17.

The Late Dr. J. Wiglesworth. Lanc. 4: C. Nat. Sept., pp. 67-68.

The Late Samuel Lister Perry [should he Lister Petty], loc. cit., pp.
68-69.

Liverpool Botanical Society [Reports]. Lane. & C. Nat. July, pp.
27-29; Nov., pp. 136-140.

United Field Naturalists’ Society [Reports], Joc. cit. Sept., p. 87;
Nov., pp. 134-135.

A Piece of Carved Chalk from Suffolk. Man. June, pp. 95-96.

Fossil Skulls, and Compression, Brachy- and Dolicho-cephalic. The
Galley Hill Skull [Notice of paper by 8. Hansen]. Nat. Sept., pp.
283-284.

Early record of Cypripedium calceolus, loc. cit. Sept., pp. 282-283.

Thomas Boynton, I.S.A. [Obituary], doc. cit. Dec., p. 404.

List of Seeds collected in the Royal Botanical Garden, Edinburgh,
during the year 1919. Noles Roy. Bot. Garden, Edin. YDec., pp.
elxvii.—cccii,

Birds and the Agriculturalist. Animal World. Aug., pp. 93-94.

Farmers’ Folly, loc. cit. Oct., pp. 117-118.

The Protection of Wild Birds—Report of the Departmental Committee,
loc. cit. Dec., pp. 139-140.

Alfred Merle Norman, 1831-1915 [Obituary]. Proc. Malacol. Soc. Oct.,
pp. 116-117.

List of Seeds of Hardy Herbaceous Plants and of Trees and Shrubs.
Bull. Misc. Information, Kew. Appendix I., pp. 1-39.

Reconstruction. Bird Notes & News. Summer, pp. 41-42.

Kconomic Ornithology, loc. cit., pp. 42-438. Autumn, p. 51.

The Bird Protection Laws. Report of the Departmental Committee,
loc. cit. Suplt., 6 pp.

Notes, Joc. cit. Summer, pp. 46-47. Autumn, pp. 50-51. Winter,
p. 59.

Wood, Abnormai Growth. Archives Cambr. Forestry Assoc. 1919,
pp. 5-10.

The History of the London Plane. Nature. June 26, pp. 333-336.

Sex, Reproduction, and Hetedity in Pigeons and Fowls. Nature.
July 31, pp. 436-437

The Protection of Wild Birds, loc. cit. Sept. 4, pp. 7-8.

The Reconstruction of the Wishing Industry, loc. cit. Oct. 16, pp.
133-135.

British Botanic Gardens and Stations, loc. cif. Nov. 6, p. 263.

Lord Walsingham [Obituary }, Joc. cit. Dec. 11, p. 376.

Summary of Proceedings [March 11 to May 24, 1919]. Proc. Prehist.
Soc. E. Angha. Vol. 111., pt. 1, pp. 162-164.

The Committee’s Report on the work of the Club during 1912-1913,
1917-18. Trans. Hull Sci. & F. N. Club. Voi. IV., pt. vi., pp.
321-340.

Natural History Society of Northumberland and Durham, Field Meet-
ings, 1918. Vasculum. July, pp. 185-139.

Notes of the Summer Term’s Work. Sedgwick Soc, Rep. [Sedbergh].

No. 1, pp. 4-6.
Finds and Captures, loc. cit., p. 9.
Botanical [First Finds], loc. cit., p. 10.

CORRESPONDING SOCIETIES.

Anon. Entomological [First Finds], loc. cit.
—— The.Common Partridge (Perdix cinera), loc. cit., pp. 10-11.

bourne Nat. Hist. etc. Soc. Aug., pp. 91-92.
—— The Gardener's Friends and Foes, loc. czt., pp. 96-97. .

BPZ-— Excursion to Hellingly, The Caburn Earthworks. Trans., etc., Hast-
Zz

on N BB NNNN @B DUN N
N

NN NN N NN © NNN N NNNNNN

—— Onion Mildew (Peronospora Schleideni Ung.). Ministry of Ag. &
Fisheries. Leaflet No. 178, 4 pp.

—— Instructions for Collectors. Brit. Mus. (Nat. Hist.) No. 6, Mosquitoes
(Culicide). 4th ed., 8 pp., No. 10. Plants, 5th ed., 10 pp.

—— Sectional Meetings and Field Work in 1918. Proc. Ashmolean N. Hist.
Soc. for 1918, pp. 17-18.

George ABBEY. Variations in the Diet of Wild Birds. Journ. Wild Bird
Inves. Soc. No. 1, pp. 10-11.

W. J. Lewis Asrotrr. Implements from Cromer Forest Bed and the
Admiralty Section. Proc. Prehist. Soc. 2. Anglia. Vol. IIl., pt. i.,
pp. 110-114.

W. M. Assporr. Large Flock of Ring Doves in Spring. Jrish Nat. July,

. 94.

B. G. ed Bupithecia albipunctata var. angelicala in Surrey. Ent.
June, pp. 138-139.

8S. O. Appy. House-Burial, with Examples in Derbyshire. Jowrn. Derby
Arch. ete. Soc. Vol. XLI., pp. 86-161.

Rosert ApKin. Devastation of Oak Trees by Spring Larve. Hnt. Aug.,
pp. 187-188.

—— The Sydney Webb Collection, Joc. cit. Dec., pp. 275-276.

—— The Mitford Collection, loc. cit., p. 276.

H. E. Anpripcr. Luminous Worms. Nature. Oct. 30, p. 174.

H. G. ALExANDER. Winter Immigration of Goldcrests and Firecrests in Kent.
Brit. Birds, July, p. 56.

EK. J. Atten. A Contribution to the Quantitative Study of Plankton. Journ.
Marine Biol. Assoc. Juiy, pp. 1-8.

J. W. Aten. Epuraea distincta Grimmer, A Beetle New to Britain. nt.
Mo. Mag. Sune, pp. 128-129.

J. C. Atsor. Botanical Section [Report]. Rep. Marlborough Coll. Nat. Hist.
Soc. No. 67, pp. 21-28.

—— Malacological Report, loc. cit., p. 34

Ornithological List, loc. cit., pp. 36-38.

Josep ANDERSON. Saint Mark’s Fly {Bibio marc). Ent. Kec. Nov., p. 207.

—— Sirex gigas at Chichester, loc. cit., pp. 206-207.

—-— Colias edusa at Chichester. Hunt. Nov., p. 259.

—— Notes from Chichester [Entomology], /oc. cit. Dec., p. 279.

PeTeER ANDERSON. White Snipe and Ruffin Tiree. Scot. Nat. Sept., p. 156.

W. H. N. Anprews. Rough-legged Buzzards in Norfolk. Brit. Birds. June,

p. 31.

E. T. Anquetin. Opisthograptis luteolata feeding on Laurel. Ent. Nov..
p. 257.

W. J. ArRKELL. Polygonia c-aibum in Wiltshire, Jee. cit. Nov., p. 261.

—— Pocota apiformis in Berkshire., loc. cit.

ArtHuR ARNOLD. Green Woodpecker in the Isle of Wight. Brit Birds.
Sept., pp. 109-110.

S. Arnotr. The Colchicum, or Meadow Saffron. Trans. Dumfries. 4: Gall.
Nat. Hist. & Ant. Soc. Vol. 6, pp. 27-390:

W. J. Asopown. Agrilus lunatus in Surrey. Hnt. Rec. Aug., p. 170.

G. H. Asur. Platypus cylindrus in Worcestershire. nt. Mo. Mag. Nov.,
pp. 260-261.

A. Asttey. Status of the Yellow Wagtail in Westmorland. Brit. Birds.
Oct., pp. 134-135. :

--— Crossbill in Westmorland, Joc. cit. Dec., p. 194

Howarp Arxkins. Young Garden-Warbler fed on Moths, loc. cit. Sept.,
p. 108.

JASPAR ATKINSON. White Grouse Chick. Nat. Sept., p. 294.

—— Accident to a Skylark, Joc. cit.

NN N NN@® GBOORDDON N NN N @ NN NN ON NN N BD BB NND N N ON NN

LIST, OF PAPERS, JUNE—DECEMBER, 1919. 41)

A. Bacoy and L. Linzitt. The Incubation Period of the Eggs of Haema-
topinus asini, Parasitology. Oct., pp. 388-392.

Ricnarp 8. Bagnaty. On the Discovery of two species of Brachychateumide,
a Minor Group of Millepedes peculiar to the British Isles. Anr. &
Mag. Nat. Host. Aug., pp. 79-84.

—— Brief Description of new T'hysanoptera, loc. cit. Oct., pp. 253-277.

—— A Curious Coccid-like Midge (Rhabdophuga pseudococcus). Vasculum.
Dec., pp. 175-177.

—— See J. W. H. Harrison.

—— and J. W. H. Harrison. Talks about Piant Galls. \V1I.—The Wasp
Galls of the British Oak. Vasculum. July, pp. 127-134.

R. H. Batti. Grey Wagtail Nesting in Warwickshire. rit. Birds. June,

27.

(Cpa Oe pis, E. Rem. Ornithology. Lepidoptera [Records}. Proc.
Inverpool Nat. F. Club for 1918, p. 39.

—-- See H. J. Hotme.

C. L. E. Batcome. Colias edusa in Hampshire. nt. Oct., p. 235.

R. C. Banks. Pomatorhine Skua in Monmouthshire. Brit. Birds. Dee.,

. 197.

W. Bagels Report on Summer Excursions, 1918. Yrans. & Rep. Perth.
Soc. N. Sci. Vol. VII., pt. 1, pp. vii-x.

—— [Presidential Address]. rans. Perth. Soc. Nat. Sct. Vol. VI., pt. v.,
pp. exci-ce.

W. H. Barrow. Status of the Little Owl in Leicestershire. Brit. Birds.
June, p. 30.

—— See I. C. R. Jourparw.

James BartruoLtomew. ‘Tree-sparrows nesting near Glasgow. Scot. Nat.
Sept., p. 166.

-—— Number of Young in Stoat’s Family, loc. cit. Nov., p. 181.

W. C. Barton. Report of the Distributor for 1918. Rep. Bot. Soc. Vol. V.,
pt. iv., pp. 483-535.

W. Barrson. The Progress of Mendelism. Nature. Nov. 5, pp. 214-216.

Lucy JANE Bawrreer. Birds feeding upon Winged Ants. Brit. Birds. Nov.,
p- 160.

Evetyn V. Baxter. See Leonora JEFFREY RINTOUL.

—— and Leonora Jerrrey Rivtouu. Behaviour of Birds under Abnormal
Conditions. Scot. Nat. Nov., p. 182

Perer Baxter. A Perthshire Nataralist—James Stewart McGregor of
Glenisla. Trans. Perth. Soc. Nat. Sci. Vol. VI., pt.v., pp. 183-187.

H. A. Bayurs. Ona curious Malformation in Tenia saginaico. Ann. & Mag.
Nat. Hist. Sept., pp. 114-118.

M. Beprorp. Hobby in Bedfordshire. Brit. Birds. July, p. 58.

H. Brrston. The Non-Marine Mollusca ot Llandudno and District. [Journ.
Conch. Aug., pp. 128-132.

Atrrep Bett. Fossil Shells from Wexford and Manxland. Jrish Nat. Oct.,
pp. 109-114.

H. Benporr. See Annie Dixon.

ArtHuR BEnNE?rT. Utricularia [size of}. Journ. Bot., Sept., p. 260.

—— Aelosciadium mnundatum L.‘ (Koch), {. fluitans (Fr.). Prahl., doc. cit.

—— Vaccinium intermecium Ruthe, luc. cit. Oct., pp. 284-285.

—— Potamogeton dualus Hagstrém, loc. cit., p. 285.

—— Carex montana L., loc. cit., p. 322.

—— Calamagrostis stricta Timm., forma pilosior Norman, loc. cit., pp. 322--
323.

—— Cypripedium Calceolus L, Nat. Nov., p. 372.

Ernest H. Bennis. Carabus clathratus in Co. Clare. Jrish Nat. July, p. 91.

Howaro BrentHam. Large Flock of Hawfinches in Surrey and Kent. Brit.
Birds. June, p. 26.

H. Dovatas Bussemer. Larva: of Papilio machaon in Sussex. nt. Aug..
p. 189.

Mary G. 8. Best. Smews off Aberdeenshire. Brit. Birds. June, p. 32

Ferep. 8. Bevrripge. The Status of the Redshank in the Outer Hebrides.
Scot. Nat. Novy., pp. 185-186.

412

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ae |

N N N BD BN NNNN N

CORRESPONDING SOCIETIES.

Frep. S. Beveripee. Golden Eagle in North Uist., loc. cit., pp. 195-196.
J. Binrner. Silver Leaf Disease. Ball. Misc. Information, Kew. No. 6,
pp. 241-263.
A. HenprErson Bisuor. Note ona Burial after Cremation. Trans. Dumfries.
& Gall. Nal. Hist. & Ant. Soc. Vol. 6, pp. 44-48.
James. E. Buack. Coleoptera at Dunster, Somerset. Hnt. Mo. Mag. Oct.,
p- 231.
Joun E. Buackis. Variation in Chrysophanus phleas, Arica medon, and
Nisoniades tuges. Ent. Oct., p. 234.
—— Altacus prometheus in England, loc. cit.
F. M. Buapon. Oak Apples. Sedgwick Soc. Rep [Sedbergh]. No. 1,
pp. 12-14.
K.G. Bram. Some Notes on Catonia aurata. Ent. Mo. Mag. ept., pp. 200-
203.
Lytta vesicatoric L. in Norfolk and in the Isle uf Wight, due. cit., p. 207.
F. L. Brarnwayt. Vertebrata [Report]. Trans. Lincs Nat. Union fer 1918,
pp. 114-115.
—— The Birds of Lincolnshire, Past, Present and Future, loc. cit,
pp. 121-133.
—— The Late Dr. J. Wiglesworth [Obituary]. Brit. Birds. July, pp. 52-55.
Arruur Briss. Note on Stauropus fagi and Smerinthus ocellatus. Ent. Nov.,
p. 262.
Grorce Boutam. Bank Vole (Evotomys glareolus Schr.) nesting above ground.
Lance. & C. Nat. Aug., pp. 51-54.
Some Winter Wildfowl. Vasculum. Dec., pp. 145-152.
Hersert Botton. The British Museum and Art Gallery. Reportfor ....
1919. 16 pp.
C. J. Bonn. On Certain Factors concerned in the production of eye colour
in birds. Journ. Genetics. Dec., pp. 69-81.
F. Boon. See Anon.
H. A. Boorn. A Wood-Pigeon Ruse. Brit. Birds. Nov., p. 165.
Harry B. Boota. H. A. Paynter, 1846-1919 [Obituary]. Nat. Aug.,
pp. 275-276.
—— Blackbirds using the same nest twice, loc. cit., p. 302.
—— Common Seals in Morecambe Bay, loc. cit., p. 370.
G. S. Bouncer. The Cryptogams of Andrews’s Herbarium. Jowrn. Lot.
Dec., pp. 337-340.
Morgis BouRNE. Agrolis simuians in Oxfordshire. Ent. Nov., p. 262.
F. O. Blowrr]. Prof. J. W. H. Trail, F.R.S. [Obituary!. Nature. Sept. 25,
pp. 76-77.
W. Brapsrook. Newton Longville Parish Books [wild cats, polecat, etc.].
Records of Bucks. Vol. XI. No. 1, pp. 1-10.
Hinpa K. Brape-Birks and S. Granam Brave-Birks. Notes on
Myriopoda, xviii. Report on Chilopoda and Diplopoda for the
latter part of 1918. Lance. & C. Nat. Oct., pp. 101-106.
S. GranAm BrapE-Birks. Dragon-fly in the Darwen District [Correction].
Lance. & C. Nat. Aug., p. 61.
—— Luminous Worms. Nature. Sept. 11, p. 23; Oct. 2, pp. 93-94.
—— See Hizpa K. Brapve-Brmks.
F.G. 8. Bramwett. The Larva of Jno globularie. Ent. Sept., pp. 214-215.
—— Aberrations of Argynnis aglaia, Brenthis euphrosyne and Bb. selene at
Brighton, loc. cit. Oct., p. 236.
—— TLimenitis sibylla at Brighton, loc. cit. Nov., p. 257.
Winrrrep E. BReNcHLEY. The Uses of Weeds and Wild Plants. Sci. Progr.
July, pp. 121-133.
Witt1am B. Bariertey. Some Concepts in Mycology—an attempt at
Synthesis. Trans. Brit. Mycol. Soc. Sept., pp. 204 et seq.
H. Beirten. Hemiptera, Heteroptera and Homoptera in Lancashire and
Cheshire in 1918. Lanc. & C. Nat. July, pp. 15-19.
—— Hymenoptera. Caraphractus cinctus Hal. in. Manchester in 1918,
loc. cit. Aug., pp. 47-51.
—— Coleoptera. Interesting Records by Local Collectors in Lancashire and
Cheshire during 1917 and 1918, Joc. cit. Nov., pp. 126-130, and
Dec., pp. 163-167.

NN N &®NN N N NNNNNN NN N N NUD NN NOON NNNNND TND DVNN N BNNBON N

LIST OF PAPERS, JUNE—-DECEMBER, 1919. 413

H. Brrrren. Parasitic Worms in Sticklebacks from Whitworth Park, Man-
chester, Joc. cit. Dec., p. 170.
—— Reputed Nest of Vespa crabo IL. in Lancashire, loc. cit., p. 175.
[James Brirren]. Mimulus moschatus L. Journ. Bot. Oct., p. 285.
C. E. Brirron. Note on Centaurea, loc. cit. Dec., pp. 340-342.
Artuur Brook. The Merlin. Animal World. July, pp. 75-76.
—— The Dipper, loc. cit. Oct., pp. 115-116.
F. T. Brooks. An Account of Some Field Observations on the Development
of Potato Blight. New. Phy. May, pp. 187-200.
Epmunp R. Brown. Teratological Variations in the Wings of Lepidoptera.
Lane. & C. Nat. Sept., pp. 70-72.
James Mrerxtv Brown. Sirex gigas in Sheffield. Nat. Sept., p. 292.
—— Some Derbyshire Plant Galls, loc. cit. Oct., pp. 330-332.
G. BrowNnen. Hedenesbury or Hengisthury of Prehistoric Time. [Abs.].
Man. Oct., p. 158.
J. P. Brunxer. Plants of Co. Louth. Jrish Nat. July, p. 95.
B. Bryan. See Anon.
Cnartes Butta. The Bronze Age infUlster[Abs.]. Ann. Rep. Proc. Belfast
Nat. F. Club, 1918-19, pp. 20-21.
G. R. Bunnock-WesstrErR. See J. GRovEs.
P. F. Bunyarp. Weights of Cuckoos’ Eggs. Brit. Birds. Oct., p. 144.
—— Observations on the Cuckoo, loc. cit. Nov., pp. 166-167.
J. P. Burxirr. The Wren. Jrish Nat. July, pp. 85-89.
—— Relation of Song to the Nesting of Birds, Joc. cit. _Sept., pp. 97-104.
A. I. Burntry. Marine Biology at Scarborough. Nat. Nov., pp. 363-
364.
A. E. Burras. Sciapteron tabaniformis. Ent. Dec., pp. 276-277.
W. H. Burrett. See W. E. L. WatramM. —
—— See T. SHEPPARD.
Cc. R. N. Burrows. Catalogue of Palearctic Psychides. Hnt. Rec. Aug.,
pp. 165-167. j
—— Records from Mucking, loc. cit., pp. 168-169.
—— The Larve of Hydroecia crinanensis and that of Apamena leucostigma
(fibrosa), loc. cit., pp. 177-178.
Henry Bury. Some Paleolithic Problems. Sci. Progr. July, pp. 81-97.
Hersert Bury. Diptera. Supplementary List for 1918. Lanc. & C. Nat.
Oct, pp. 107-110.
E. A. Buttrr. Hemiptera in Jersey. Ent. Mr. Mag. June, pp. 137-
138.
--— Lasiacantha capucina Germ. <A Tingid Bug new to the British List,
loc. cit. Sept., pp. 203-204.
E. P. Borrerrieny. | Cucullia verbasci near Bingley. Nat. Aug., p. 278.
—— (Cause of Melanism in Phigaha pilosaria [with note by G. T. Porritt},
loc. cit., pp. 279-280 ; Oct., pp. 339-340 ; Nov., pp. 373-374.
—— More Plusia moneta, loc. cit. Oct., p. 337.
—— Blackbirds using the same nest twice, loc. cit., p. 373.
——- See W. GYNGRLL.
—— See W. E. L. Wattam.
R. Burrerrierp. See W. E. L. Wartaw.
W. R. Blurrerrteip]. Note on Protura and how to collect them. Mus.
Journ. June, pp. 196-197.
W. T. Carman. Marine Boring Animals Injurious to Submerged Structures.
Brit. Mus. (Nat. Hist.). Econ. Ser. No. 10, 34 pp.
M. Campron. Aleuonota egregio Rye and Ocypus cyaneus Payk. in Nortolk.
Ent. Mo. Maa. Aug., p. 178.
Bruce CAMPBELL. Quail in Midlothian. Scot. Nut. Sept., p. 166.
D. C. Campsett. Hoopoe in Innishowen. Jrish Nat. July, p. 93.
¥. Campseri-Bayarp. Report of the Botanical Section for 1918. Proc
Croydon N. & Sci. Soc. Vol. VIII., pt. v., p. elxvi.
Herpert Cameron. Limenitis sibylla Linn. at Burnham Beeches, nt.
Oct., pp. 236-237.
A. E. J. Garter. Colias edusa in Forfarshire. Scot. Nat. Nov., p. 199.
—— Diptera in Perthshire. Ent. Mo. Mag. Oct., p. 233.

414

BON BDRWONDNNNNN N NNN N N N DB W@W NN WN
NNN

75> DN N DB ND BeW waaeHeW eS UD

CORRESPONDING SOCIETIES.

A. E. J. Carrer. [Diptera at Aberfoyle], loc. cit. Oct., p. 233. Also
noticed in Scot. Nat. Nov., p. 202.

B. A. Carter. Greenshank in Warwickshire. Brit. Birds. July, p. 61.

J. W. Carter. Symvetrum sanguineum Mull., a Dragon-fly new to Yorkshire.
Nat. Dec., p. 299.

Newuire Carrer. On the Cytology of two Species of Characiopsis. New
Phy. May, pp. 177-186.

—--- Studies on the Chloroplasts of Desmids. Ann. Bot. July, pp. 295-
304.

H. E. Gastens Black-necked Grebe on Kent and Sussex Border. Prit.
Birds. July, p. 60.

G. C. Cuampron. Note on a dark form of Liopus nebulosus Lion. Ent. Mo.
Mag. July, p. 158.

—— Another note on the habits of Melanophila acuminata De Geer, loc. cit.
Aug., pp. 177-178.

—— Hemiptera, etc., in the New Forest, loc. cit. Sept., p. 209.

Epaar Caance. Observationson the Cuckoo. Brit. Birds. Sept., pp. 90-95.

Aprn Crapman. Bird-Notes on the Borders, 1918-19. Vasculum. Dec.,
pp. 152-155.

T. A. Caapmay. Note on Hoplocampa testudinea Klug. Ent. Mo. Mag.
June, p. 138.

—— Trichiosoma tibiale and Acampsia pseudospretella, loc. cit., pp. 1388-129.

S. A. Crartrers. D. nerit at Eastbourne. Ent. Rec. Oct., p. 188.

——- Late appearance of Agriades coridon, loc. cit., p. 226.

Curtis. A. CoerrHam. Yorkshire Diptera Notes. Not. July, p. 244.

—-- Xiphura atrata L. in Yorkshire, loc. cit. Dee., p. 380.

—— Yorkshire Naturalists’ Union, Rotanical Section, Joc. cit., p. 389.

—— Additions to Yorkshire Diptera, loc. cit., pp. 394-395.

--— See T. SHEPPARD.

—-— See W. EF. L. Warram.

Mictvrk Curisty. Hornets, Wasps, and Flies sucking the sap of Trees.
Essex Nat. Vol. XIX., pt. 1, pp. 10-14.

—— Qn the Arboreal Habits of Field Mice, Joc. cit., pp. 18-21.

—— Fungus on Stem of Oak Tree, loc. cit., p. 48.

—— Samuel Dale (1659 ?-1739) of Braintree, Botanist, and the Dale family :
some genealogy and some portraits, loc. cit., pp. 49-64 [continued
in 1920).

A. H. Cuurcu. The Plankton-phase and Plankton-rate. Journ. Bot. June
Supplt., pp. J-8.

—— The Building of an Autotrophic Flagellate. Bot. Memoirs. No. J,
pp. 1-27.

—— Thalassiophyta and the Subzrial Transmigration. No. 3, pp. 1-95.

-_—. Elementary Notes on Structural Botany, Joc. cit. No. 4, pp. 1-27.

—— Elementary Notes on Reproduction of Angiosperms, loc. cit. No. 4,
pp. 1-24.

—— Brunfelsand Fuchs. Journ. Bot. Sept., p. 233.

——- Historical Review of the Pheophycee, loc. cit. Oct., pp. 265-273.

—— Historical Review of the Floridex.—I., loc. cit. Novy., pp. 297-304 ;
II., Dec., pp. 329-334.

—— The Ionic Phase of the Sea. New Phy. Oct., pp. 239-247.

Ricwarp Crarnam. Footprints of the Wild. Animal World. Dec., pp.
137-138.

J. Eomunp Crarx. Garden Phenology, Asgarth, Riddlesdown Road, Purley.
Proc. Croydon N. H. & Sci. Soe. Vol. VIIL., pt. v., pp. elxvii-clxviii.

Wm. Faatr Crarke. The Starlings of Shetland, Fair Isle, and St. Kilda.
Scot. Nat. Nov., pp. 183-185.

—— Wild Swans observed on the Western Islands in Summer, Joc. cit.,
pp. 196-197.

W. G. Guarke. Three Old Essex Herbaria. Hssex Nat. Vol. XIX., pt. 1,
pp. 23-25.

—-— Some Essex Plant Records, Joc. cit., pp. 47-48.

——- W. Allen Sturge, M.V.O., M.D., F.R.C.P. [Obituary]. Proc. Prehist.
Soc. E. Anglia. Vol. III., pt. 1, pp. 12-13. :

NN N NN NNNN® &@ N N N NNNNN NNN OQ @O NNNNNNN &@ NNN N DV N NNN WV

LIST OF PAPERS, JUNE—DECEMBER, 1919. 415

W. G. Cuarke. The Distribution of Flint and Bronze Implements in Nor-
folk, loc. cit., pp. 147-148.
W. J. CuarKke. Large Yorkshire Trout. Nat. July, p. 245.
W. G. CnuTtren. Colour Variation of Odezia atrata. Ent. Nov., p. 256.
C. GRaNVILLE ChuTTEeRBUCK. Pselnophorus brachydactylus in Gloucester-
shire, loc. cit. Dec., p. 275.
E. A. Cockayng. Inheritance of Colour in Diaphora mendica Cl. and var.
rustica Hb. Ent. Rec. June, pp. 101-104,
C. V. Cotnizr. Thomas Boynton, F.S.A. [Obituary]. Yorks. Arch. Journ.
Pt. 98., pp. 271-272.
Watrer E. Cottiser. Some Remarks on the Food of the Barn-owl (Strix
flammea Linn.). Journ. Wild Bird Inves. Soc. No. 1, pp. 9-10.
—— Two interesting cases of Melanism, loc. cit., p. 15.
—— Strange accident to a heron, loc. cit.
—— Wild Birds and Distasteful Insect Larve. Nature. July 24, p. 404;
Aug. 21, p. 483.
E. J. Coutins. Sex Segregation in the Bryophyta. Journ. Genetics. June,
pp. 139-146.
A. H. Cookr. ‘Ground’ Clausilias. Journ. Conch. Aug., p. 102.
J. E. Cooper. See Anon.
A. Strven Corsut. Argynnids in Wiltshire. Ent. Dec., p. 278.
H. H. Corserr. Woodcock near Doncaster. Nat. Oct., p. 336.
—— Cormorant at Doncaster, loc. cit. Novy., p. 371.
—— See W. E. L. Warram.
Ernest CornELL. Some Notes on the Butterflies of the South Coast of the
Isle of Wight, 1919. Ent. Dec., pp. 279-280.
A. D. Corton. The Occurrence of Oak Mildew on Beech in Britain. Trans.
Brit. Mycol. Soc. Sept., pp. 198-200.
—— Entomogenous Fungi new to Britain, loc. cit., pp. 200-203.
—— and E. M. Waxkerietp. A Revision of the British Clavariae, loc. cit.,
pp. 164-198.
T. A. Cowsrp. Night-Heron in Anglesey. Brit. Birds. July, pp. 58-59.
—— One pair of Meadow-pipits feeding two young Cuckoos, loc. cit., p. 139.
—— Notes on the Vertebrate Fauna of Lancashire and Cheshire. Lanc. &
C. Nat. Oct., pp. 89-100; Dec., pp. 159-162.
E. Crise. Papilio machaon in Sussex. Ent. Oct., p. 236.
—— AHyloicus pinastri in Suffolk, loc. cit. Nov., pp. 257-258.
5. G. Commines. Unusual site for Chiffchaff’snest. Brit. Birds. June, p. 27.
—— Breeding Habits of the Nightjar, loc. cit., pp. 2° -28.
Joun Currie. Common Scoter on Duddingston Loch in May. Scot. Nat.
Noy.. p. 197.
J. W. Curmorr. Some Notes on the Rats of the Port of Liverpool. Proc.
and Trans. Liverp. Biol. Soc. Vol. XXXIII., pp. 68, 69.
+. G. D. Hereward Chune Dollman, F.E.S. [Obituary]. Ent. Mo. Mag.
June, pp. 139-140.
Cuarues A. Dantas. Woodecocks perching on Trees. Brit. Birds. Oct.,

pp. 142-143.
A. A. Datiman. Galiwm erectum Huds. in Cheshire. Lance. & C. Nat. Sept.,
p. 73.

—— Geranium versicolor L. in North Wales, loc. cit. Oct., pall

J. rrottiotr Dariinc. Pollan in Lough Ree. Jrish Nat. July, p. 93.

—— Incubation of Birds, loc. cit., p. 93.

Francis Darwin. A Phenological Study. New. Phy. Nov., pp. 287-298.

G. MacDonatp Davies. Excursion to Norbury, Mitcham Common and
Beddington. Proc. Geol. Assoc. Vol. XXX., pt. 1, pp. 75-81.

W. Davigs. Pied Flycatcher in Staffordshire. Brit. Birds. Sept., pp. 107-108.

J. T. Dawson. Art Gallery and Museum. [Additions.] 48th Ann. Rep.
Rochdale Public Lib. ete. Committee, pp. 11-13.

Frank H. Day. Carlisle Natural History Society. [Report.] Ent. June,
p. 148.

—— Westmorland Coleoptera. Nat. July, pp. 239-242 ; Oct., pp. 327-328.

J. Davy Dean. Occurrence of Physa gyrina Say in Great Britain. Jowrn.
Conch. Aug., p. 127.

416

N on N N NN BD BO WN

ON DB weB WD

NN N N N N NN NBO N N

CORRESPONDING SOCIETIES.

L. S. DEAR. Long-eared Owl laying twice in same nest. Brit. Birds. June,
p. 30.

Antuony W. N. Disnny. Lycena arion in North Cornwall. Ent. Sept.,
p. 216.

Annie Dixon. Protozoa. Report on Gatherings from a Pond at Lawnhurst,
Didsbury, from 14th March to 12th Sept., 1918. Lane. & C. Nat.
Sept., pp. 74-81.

—— W. Leacu, H. Benporr, and J. G. Kitcuen. Manchester Microsco-
pical Society [Report], Joc. cit. Aug., pp. 61-63.

H. N. Drxon. Mosses collected on Deception Island, South Shetlands, by
Mr. James C. Robins [Abs.]. Journ Bot. July, p. 200.

Lronarp Dorstn. On the presence of Formic Acid in the Stinging Hairs of
the Nettle. Proc. Roy. Soc. Edinb. Vol. XXXIX., pt. 1., pp. 137-142.

Horace DonistHoRPE. Wasps attacking Flies. Irish Nat. Sept., p. 107.

—— A New County Record for Zeugophora flavicollis Marsh. Ent. Rec.
Oct., pp. 185-186.

—— The Myrmecophilous Lady-bird, Coccinella distincta Fold., its Lifé
History and Association with Ants, loc. cit. Dec., pp. 214-222.

—— Further localities for Platypus cylindrus F. Ent. Mo. Mag. Sept.,
p. 232.

H. Downes. Juncus pygmeus Rich. Journ. Bot. Sept., p. 260.

G. Cuartpce Drucr. The Botanical Society and Exchange Club of the
British Isles. Report for 1918. Rep. Bot. Soc. Vol. V., pt. 11.,

p- 267-271.

— Plant. ‘Notes, etc., for 1918 (mostly New ‘Plants to the British Isles),
loc. cit., pp. 272-318.

—— Noteson Publications, New Books, etc., 1917-18, ioc. cit., pp. 319-349.

—— Obituaries. [J. E. Bagnall, Wilham Brack Boyd, Edward Fry, Joseph
John Geoke, Reginald Philip Gregory, Edward Walter Hunnybun,
Ernest David Marquand, T. W. ae William Frederick Millar,
Bishop John Mitchinson], loc. cit., pp. 349-365.

—— New County and Other Records, Joc. “Cit, pp- 365-412.

—— The Dates of Publication of Curtis’s “Flora Londinensis,’’ loc. cit.,
pp. 412-414.

—— Additions to the Berkshire Flora, loc. cit., pp. 443-480.

—— Additions to the Berkshire Flora. Proc. ‘Ashmolean N. Hist. Soc. for
1918, pp. 21-58.

Martin C. Ducnesne. Afforestation: Its Practice and Science. Rep. Brit.
Assoc. for 1918, pp. 68-75.

James Duncan. COolias edusa near Aberdeen. Hnt. Oct., p. 235.

T. A. Dymes. Notes on the Life-history of the Yellow Flag (/ris Pseudacorus
Linn.), with special reference to the seeds and seedlings during their
first year. [Abs.]. Journ. Bot. Aug., pp. 231-232.

F. W. Epwarps. Gnophomyia tripudians Bergroth: A New British Fly.
Ent. Mo. Mag. Aug., pp- 176-177.

L. A. Curtis Epwarps. Continental Jays in Oxfordshire and Sussex. Brit.
Birds. Sept., p. 107.

Rosr Eazrton. See W. 8S. LAvVEROcK.

J. Sree Exniotr. Grey Wagtails nesting at a distance from water. Brit.
Birds. Aug., p. 81. <

—-—— Hobby in Shropshire and Worcestershire, loc. cit., p. 84.

—— Large Numbers of Bramblings in Worcestershire, Ice. cit. Dec.,
pp. 194-195.

GrorcE Exzison. The Nest of the Bank Vole. Proc. and Trans. Liverpcol
Biol. Soc. Vol. XXXIII., pp. 65-66.

—— Note on a White Orkney Vole, Microtus orcadensis, v.;«lba., loc. cit.,
p. 67.

G. W. Exurson. Bank Vole (Evotomys glareolus, Schr.) nesting above ground.
Lance. & C. Nat. Nov., pp. 124-125.

Ricuarp Etmutrst. Orthocladius Spp. breeding in the sea. Scot. Nat.
Noy., pp. 193-194.

L. G. Esson. Zygena achillee in Argyllshire. Ent. Aug.,.p. 189.
j i it. Nov.; p. 259.

DWNNNUNN NNNN N N N NNNN NNNNNNN NNN DU N NNN NN NNNNOONN

LIST OF PAPERS, JUNE—DECEMBER, 1919. 417

Wiu1AmM Evans. Boarmia gemmaria in the Forth Area. Scot. Nat. Noy.,
pp. 199-200.

J. Cosson Ewart. Telegony. Nature. Nov 6, pp. 216-217.

R. W. THomas Ewart. Capercaillie in Montrose. Scot. Nat. Sept., p. 156.

Wm. Fatconer. The Spiders of Yorkshire. Nat. July, pp. 235-238 ;
Aug., pp. 267-270; Oct., pp. 323-326; Nov., pp. 365-368; Dec.,
pp. 400-403.

—— New and Rare British Spiders, loc. cit. Sept., pp. 295-302.

—— Additions to the ‘ Spiders of Wicken,’ loc. cit. Nov., p. 356.

——- Plant Galls from the Searborough District, loc. cit. Dec., pp. 392-393.

—— See W. E. L. Warram.

H. H. Farwie. Late Nesting of Linnetsin Surrey. Brit. Birds. Dec., p. 195.

—-— Grey Wagtails breeding in Kent and Sussex, doc. cit., p. 196.

—— Greenshanks in Surrey, loc. cit., p. 198.

ANDERSON Frrausson. Aspidiphorus orbiculatus Gyll., in Scotland. Scot.
Nat. Nov., p. 200.

—— Staphylinus cesareus, Ceder. in Main Argyll, loc. cit.

—-- Halyzia 16-guttata, L., and Coccinella conglobata, L., in Main Argyl,
loc. cit., p. 201.

—— Additions to the List of Scottish Coleoptera, loc. cit. Sept., pp. 167-169.

J. Dicey Firty. See W. E. L. Wartam.

Epexram Fisier. Ornithology [Report]. Ann. Rep. Huddersfield Nat. etc.
Soc., 1918-1919, pp. 13-15.

N. H. FrrzHersert. Ornithological Record of Derbyshire, 1918. Journ.
Derby. Arch. etc. Soc. Vol. XLI., pp. 170-178.

H. J. Furore. Correspondence [Dolmen in Guernsey: quotes letter from
Col. Guérin}]. Man. Sept., pp. 130-132.

H. D. Forp. Aspilates ochrearia in Cumberland. Ent. July, pp. 167-168.

—— Zephyrus quercus, var. bellus, loc. cit. Oct., p. 236.

W. J. Forpusm. William Ernest Sharp, 1856-1919 [Obituary]. Nat. Aug.,
pp. 274-275.

—— See W. E. L. Wartam.

H, E. Forrest. Nightingales in Shropshire. Nat. Aug., pp. 277-278.

—— Hoopoe in Shropshire. Brit. Birds. July, p. 57.

—-— Shifting of Rreeding-grounds by Terns, loc. cit., pp. 61-62.

—— Bar-tailed Godwits in Shropshire, loc. cit., p. 165.

--— Little Owl in Montgomeryshire, loc. cit., p. 196.

—— |[N. E. Forrest, error.} Little Owl Breeding in Shropshire and Radnor-
shire, loc. cit. June, p. 30.

R. Forrunr. Herons nesting in Nidderdale. Nat. Nov., p. 371.

—— Black-necked Grebe in Washburn Dale, loc. cit.

—— See E. A. Wooprurre-PEacock.

Nevin H. Foster. Early Arrival of Redwings and Fieldfares. Jrish Nat.
Sept., p. 107.

—— A List of the Myriapoda of Ulster. Ann. & Mag. Nat. Hist. Dec.,
pp. 395-407.

W. W. Flower]. [William E. Sharp, Obituary]. nt. Mo. Mag. Nov.,

263

Hitperic Frrenp. Sparganophilus: A British Oligochet. Nature. July 31,
p- 426.

—— Luminous Worms, loc. cit. Aug. 7, p. 446; Nov. 27, pp. 334-335.

—— British Well-worms, loc. cit. Sept. 4, p. 5.

—— A New British Enchytreid Worm, loc. cit. Oct. 30, p. 174.

F. W. Fronawxk. Nisoniades tages Imbibing its Excretion. Ent. Sept.,
pp. 212-213.

—— Variation of Limenitis sibylla in the New Forest, loc. cit., p. 213.

—— Variation of Dryas paphia, loc. cit., pp. 235-236.

Martan Frost. Guide to the Worthing Museum and Art Gallery. pp. 1-16.

GREEVZ FysHer. See W. E. L. Warram.

—— See T. SHepparp.

J. GARDNER. Plusia moneta, F. at Hart, Co. Durham. Ent. June, p. 138.

L. V. Lester Gartanp. New County Records [Botanical] for Argyle. Jowrn.
Bot. Nov., p. 322.

1920 ; EE

418

N BD N NNN NN

NN NN N NN NN

UN NN @©@ DB DW NN 3B BW VUDVUD UVNNN

CORRESPONDING SOCIETIES.

D. G. Garnett. Agrotis precor in Westmorland. Ent. Nov., p. 257.

Margory GARNETT. Coloration of the Soft Parts of some Birds. Brit. Birds.
July, p. 62-63.

Watter GArstanc. Songs of the Birds. Nat. June, pp. 195-198.

—— More Songs of the Birds, loc. cit. July, pp. 231-234. Sept., p. 281.

—— Sea-fishery Investigations and the Balance of Life. Nature. Sept.,
18, pp. 48-49,

L. R. A. GAtEHousE. American Blue-winged Teal in Anglesey. Brit. Birds.
Aug., p. 85.

J. Bronth Gsatensy. The Identification of Intracellular Structures. Jewrn.
Roy. Micro. Soc. June, pp. 93-118.

—— Notes on the Bionomics, Embryology, and Anatomy of Certain Hymen-
optera Parasitica, especially of Microgaster connerus (Nees). Journ.
Linn. Soc. (Zool.). No. 224, pp. 387-416.

A. GrepetEer. Jno globularie. Ent. Dec., p. 278.

E. Lronarp Git. Crows, Rooks and Starlings versus Kestrels and Peregrine
Falcons. Brit. Birds. June, pp. 23-25.

—— Bird Notes from the Hancock Museum. Vasculum. Dec., pp. 156-157.

FREDERICK GILLETT. Luproctis chrysorrhea on Hippophaé rhamnoides. Ent.
Sept., pp. 215-216.

C. T. GrmincHam. Some Coleoptera taken in Hertfordshire in 1918. Ent.
Mo. Mag. July, pp. 157-158.

—— Platyrrhinus latirostris, F. at Long Ashton, Somerset, loc. cit., p. 158.

—— Some Coleoptera taken in Somersetshire, loc. cit. Aug., pp. 179-180—a
correction, Sept., pp. 207—208.

Huan 8. Guapsrone. Kite in Kent in 1822. Brit. Birds. Aug., p. 84.

—— A Naturalist’s Calendar, kept by Sir William Jardine, Bart., LL.D.,
F.RB.S., F.R.S.E., ete., at Jardine Hall, Dumfriesshire, from January 1
to May 31, 1829. Trans, Dumfries. & Gall. Nat. Hist. & Ant. Soc.
Vol. VI., pp. 88-124.

—— Observations on Carrion-crows. Scot. Nat. Sept., p. 166.

—— Hawfinch nesting in Dumfriesshire, loc. cit., p. 171.

—— Albino Spotted Flycatcher, loc. cit. Nov., p. 195.

E. H. Gopparp. Plans of Wiltshire Earthworks. Wilts. Arch. & Nat.
Hist. Mag. No. CXXX. p. 352.

—— Romano-British Interments at Broad Town, loc. cit., pp. 353-354.

—— Sarsens at Avebury, broken up, 1799, loc. cit., p. 354.

—— Identification of Wiltshire Barrows, loc. cit.

—— Aldbourne, Flint Celts, loc. cit., p. 355.

—— Bronze Implements found in Wiltshire not previously recorded, loc. cit.,
pp. 359-360.

—— Lydiard Millicent Natural History Notes. Kentish Plover in Wilts ?
Little Owl at Netherstreet. Rare plants, loc. cit., pp. 364-365.

M. J. Goprery. The Problem of the British Marsh Orchids. Journ. Bot.
June, pp. 137-142.

W. Goprrey. Spilosoma urtice in the Isle of Wight. Ent. June, p. 138.

J. G. M. Gorpon. The Lepidoptera of Wigtownshire. Trans, Dumfries,
é& Gall. Nat. Hist. & Ant. Soc. Vol. VI., pp. 156-167.

W. Batrour Gourbay. Vaccinium intermedium Ruthe, Journ. Bot. Nov.,

p. 322.

—— George Stephen West, M.A., D.Sc., F.L.8. (1876-1919), [Obituary],
loc. cit. Oct., pp. 283-284.

—— and G. M. Vevers. Vaccinium intermedium Ruthe, loc. cit. Sept.,
pp. 259-260.

JANE Gowan. The Kentish Glory Moth on Deeside. Scot. Nat. Nov., p. 200.

Gro. GracE. Protection Coloration of Birds and Eggs. Nature. Aug. 7.,

—— Calosoma inquisitor at Coniston. Nat. Sept., p. 292.

G. 8. Grauam-Smity. Anvil Stones: with Special Reference to those from
Skelmuir, Aberdeenshire. Proc. Prehist. Soc. E. Anglia. Vol. IIL,
pt. L, pp. 33.

—— Further Observations on the Habits and Parasites of Common Flies,
Parasitology. Oct., pp. 347-384,

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LIST OF PAPERS, JUNE-DECEMBER, 1919. 419

CG. Greatorex. Some Ornithological Notes from Shetland, Brit. Birds.
Noy., pp. 158-159.
Wm. Harry Greenaway. ‘The Fulmar Petrel at Foula Isle during Winter.
Scot. Nat. Sept., p. 170.
W. D. W. GreenHAM and C. B. Lown. Entomological Section [Report].
Rep. Marlborough Coll. Nat. Hist. Soc..No. 67, pp. 28-34.
T. Greenters and T. K. Hotprn, The Flora of Bolton. Lanc. & C. Nat.
Dec., pp. 153-158.
Tuomas GREER. Variation in Diaphora mendica in Ireland. Ent. Rec. Aug.,

-—— Lepidoptera from East Tyrone. Jrish Nat. Oct., pp. 118-119.
H. G. Grecory. Polygonia c-album near Salisbury. nt. Rec. Dec.,
226.

Percy H. Grimsuaw. The Collection and Preservation of Diptera. Scot.
Nat. Sept., pp. 151-156.

Ernest GrinpEY. Gannets in Derbyshire. Brit. Birds. July, p. 59.

A. J. Grove. The anatomy of the head and mouth parts of Psylla mali,
the Apple-sucker, with some remarks on the function of the labium.
Parasitology. Oct., pp. 456-488.

W. B. Grove. Mycological Notes IV. Journ. Bot. Aug., pp. 206-210.

James Groves. Tolypella glomerata Leonh. in the Isle of Wight. Journ.
Bot. July, p. 197.

—— and G. B. Butuock-WesstEeR. New Variety of Zolypella glomerata,
loc. cit. Aug., pp. 224-225.

G. F. B. pr Grucuy [Secretary]. Exploration of the Paleolithic Site
known as La Cotte de St. Brelade, Jersey. Report of the Com-
mittee. Rep. Brit. Assoc. for 1918, p. 42.

T. W. M. Gutrim. Notes on the Discovery of a Human Figure Sculptured
on a Capstone of the Dolmen of Déhus, Guernsey [Abs.]. Man.
Oct., p. 157.

See also under H. J. FLEURE.

H. B. Gurry. Plant-Distribution from the Standpoint of an Idealist. Journ.
Linn. Soc. (Bot.). No. 299, pp. 439-472.

Donaup GutTuRie. Some Bird Notes from South Uist. Scot. Nat. Sept.,
pp. 145-150, and Nov., pp. 187-192.

W. Gyne@EtL. Common Wild Birds of the Scarborough District. Nat. Aug.,
pp. 263-266 ; Oct., pp. 333-336.

—— Sounds that resemble the Songs and Calls of Birds, loc. cit. Sept.,
pp. 311-312.

—— fand] E. P. Burrerrietp. Former status of the Starling, loc. cit.
June, p. 215.

F. H. Hames. Argynnids in Dorsetshire. Ent. Oct., p. 237.

—— Orthoptera in Derbyshire, loc. cit., pp. 238-239.

J. N. Hatsertr. Planorbis corneus in Co, Dublin, Jrish Nat. Novy., pp.
135-136.

—— See W. F. Jonnson.

H. O. Hatrorp. Notes from Godalming. Hnt. Dec., p. 278.

Aupert Ernest Hatt. Harmful and Useful Birds. Nat. July, p. 246.

—— [Note on Martyn’s ‘ Figures of Non Descript. Shells ’], loc. cit. Aug.,
p. 279.

H. M. Hatterr. Aculeate Hymenoptera in the Channel Islands. Znt. Mo.
Mag. Nov., p. 262.

W. Harimay. Naturein the Isle of Lewis. Animal World. Aug., pp. 91-92.

S. H. Hamer (Secretary). The National Trust for Places of Historic Interest
or Natural Beauty. Report, 1918-1919, 52 pp.

A. H. Hamm. Observations on the Horse Bot-Fly, Gastrophilus equi, F.
Ent. Mo. Mag. Oct., pp. 229-230.

Soren Hansen. On Posthumous Deformation of Fossil Human Skulls.
Man. Aug., pp. 121-124. See notice in Nat. Sept., pp. 283-
284.

J. Rup@p Harprye. Willow-tit in Ross-shire. Brit. Birds. Dec., p. 195.

—— Spotted Crake in Ross-shire, loc. cit., pp. 197-198.

J. A. Harereaves. See W. E. L. Warram.

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CORRESPONDING SOCIETIES.

S. F. Harmer. Progress of the Natural History Museum. Nature. Dec. 4
p. 353.
H. S. Harrison. The Ascent of Man: A Handbook to the Cases illustrating
the Structure of Man and the Great Apes. Horniman Museum
Handbook No. 13. 74 pp.
JAmes M. Harrison. Iceland Gulls in the Orkneys. Brit. Birds. July,
p. 62.
—— Long-tailed Duck feeding on Grain [with note by F. C. R. Jourdain],
loc. cit. Aug., pp. 85-86.
J. W. H. Harrison. Stray Noteson Plants. Vasculum. . July, pp. 115-117.
—— The Moth and the Candle, loc. cit. Dec., pp. 172-175.
—— Studies in the Hybrid Bistoninae. III. The Stimulus of Heterozygosis.
Journ. Genetics. Sept., pp. 259-265. IV. Concerning the Sex and
related problems. Dec., pp. 1-38.

—— A Preliminary Study of the effects of administering ethy] alcohol to the
Lepidopterous insect Selenia bilunaria, with particular reference to
the offspring, loc. cit., pp. 39-52.

—— See R. S. BaGnatt.

—— R.S. Bacnatn and J. E. Hunt. Notes and Records. Vasculwm.
July, pp. 140-142.

EB. Hartert. Serins in Sussex. Brit. Birds. June, p. 26.

—— See W. J. WILLrAMs.

Ernst Harrert. See H. F. WiIrHErRBy.

J. Hartsuorn. See W. E. L. Warram.

B. S. Harwoop. Sarothrus areolatus Htg. bred. Hnt. Mo. Mag. Dec.,

. 280.

Pi Hangin. Chaetocnema sahlbergi Gyll. in Sussex, loc. cit.

Mavup D. Havmanp and Frances Prrr. The Selection of Helix nemoralis by
the Song-thrush (T'urdus musicus), Ann. & Mag. Nat. Hist. June,
pp. 525-531.

F. N. Hawarp. The Origin of the “ Rostro-carinate implements ”’ and other
chipped flints from the Basement Beds of East Anglia. Proc.
Prehist. Soc. E. Anglia. Vol. III. pt. 1, pp. 118-146.

H. C. Hayvwarp. Hesperia malve in Derbyshire. Hnt. July, p. 168.
—— Sesia asiliformis feeding in the Wood of Birch in Company with S.
culiciformis, loc. cit., p. 190.

—— Some Notes on Collecting Lepidoptera or Repton, 1918, with some
records from other parts of the County. Journ. Derby. Arch. ete.
Soc. Vol. XLI., pp. 179-182.

F. W. Heapiey. Great Tit laying in an open nest. Brit. Birds. July,

. 56-57.
—— Adult Cuckoo killing nestling birds [with note by F. C. R. Jourdain},
loc. cit., p. 57.
E. W. Henpy. Field Notes on Nesting Kingfishers. Brit. Birds. June,
pp. 28-29.

W. A. Herpman. The Marine Biological Station at Port Erin, being the
Thirty-second Annual Report of the Liverpool Marine Biology
Committee. Proc. and Trans. Liverp. Biol. Soc. Vol. XXXIII.
pp. 25-38.

—— An Address on Some Periodic Changes in Nature. Appendix A [to
above Report], Joc. cit., pp. 39-50.

—— Report on the Investigations carried on during 1918 in connection
with the Lancashire Sea Fisheries Laboratory at the University of
Liverpool, and the Sea-fish Hatchery at Piel, near Barrow, Joc. cit.,
pp. 71-84.

—— Anprew Scorr and H. Mazen Lewis. An Intensive Study of the Marine
Plankton around the South end of the Isle of Man. Part x1. oe. cit.
pp. 95-105.

T. F. Hewer. Odonata in Bristol District. Hrt. Aug., p. 191.

H. Dixon Hewirr. Notes on Some Flint-chipping Sites at Risby, Suffolk.
Proc. Prehist. Soc. E. Anglia. Vol. TII., pt. 1, pp. 67-72.

A. Hrepert-Ware. Food of Little Owl. Essex Nat. Vol. XIX., pt. L,
p. 26. 3

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LIST OF PAPERS, JUNE-DECEMBER, 1919. 421

W. P. Hiern. Eleventh Report of the Botany Committee. Rep. and Trans.
Devon. Assoc. Vol. LI., pp. 114-129.

—— Clavis to Devonian Sedges. Rep. Bot. Soc. Vol. V., pt. UL, pp.
414-416.

lan G. W. Hitt. Colias edusa and its var. helice in the Edinburgh District.
Scot. Nat. Nov., p. 199.

T. G. Hitt. The Water Economy of Maritime Plants. Sci. Progr. July,

. 60-80.

H. E. ital Observations on Capillitia of Mycetozoa. Journ. Quekett.
Micro. Club. No. 84, pp. 5-12.

Frank Hiyp. Birds of Skegness and District. Trans. Lincs. Nat. Union for
1918. pp. 134-142.

Epwarp Hrnpie. Sex Inheritance in Pediculus humanus var. corporis.
Journ. Genetics. Sept., pp. 267-277.

Martin A. C. Hinton. The Field Mouse of Foula. Scot. Nat. Nov.,
pp. 177-181.

Stantey Hirst. On Two new Parasitic Mites (Myocoptes hintoni [from
Exeter] and Psoroptes natalensis, Ann. & Mag. Nat. Hist. June,

. 524,

HaroLp oeee Colias edusa, etc., in West Cornwall. Ent. Nov., p. 260.

T. V. Hopeson. Memorandum of Flint Implements found on Dartmoor.
Rep. and Trans. Devon. Assoc. Vol. LI., pp. 175-176.

H. 8. Hotpryx. A Suggested Scheme for the Investigation of Marine Bacteria.
Journ. Marine Biol. Assoc. July, pp. 136-140.

T. K. Hotprn. See T. GREENLEES.

H. J. Houmer, G. E. Baxer, E. M. Woop. Botany [Records]. Proc. Liverpcol
Nat. F. Club for 1918, p. 38.

Artuur T. Hopwoop. On Some Spurious Records of Southport Non-Marine
Mollusca. Lane. & C. Nat. Dec., pp. 168-169.

—— Intergrowth of Oak and Sycamore, loc. cit., pp. 169-170.

M. A. Horsratt, Osprey in Yorkshire. Brit. Birds. Dec., pp. 196-197.

A. R. Horwoop. Fourth Report of the Flora Committee, 1916-19. Trans.
Leicester Lit. & Phit. Soc. Vol. XX., pp. 76-78.

T. B. Hoven [late]. Notes Regarding Bird Life in the Stewartry. Trans.
Dumfries. d: Gall. Nat. Hist. & Ant. Soc. Vol. VI., pp. 48-66.

H. Extot Howarp. Behaviour of a Cuckoo. Nature. July 31, p. 426.

W. O. Howartu. Festuca rubra near Cardiff: a Taxonomic, morphological
and anatomical study of three sub-varieties of Festuca rubra, L.
subsp. eu-rubra Hack., var. genwina Hack., growing near Cardiff,
S. Wales. New. Phy. Nov., pp. 263-286.

Henry Hoyite Howorrtu. Presidential Address [to Museums Association].
Mus. Journ. Aug., pp. 17-30.

H. C. Huaeins. Notes on Kentish Mollusca. Journ. Conch. Aug., pp. 104-
105.

J. E, Hutz. Demodex and Follicular Mange. Vasculim. July, pp. 125-
127.

—— The Wolf [Wolf-spider] of the Shingle, Joc. cit. Dec., pp. 178-181.

—— See J. W. Harrison.

Gro. R. Humenreys. Dotterel in Co. Dublin. Brit. Birds. July, p. 61.

Dovetas G. Hunter. Black-tailed Godwit in Forfarshire. Scot. Nat.

Nov., p. 198.

G. E. Hutcuryson. Notonecta halophila, Edw. in Cornwall. Ent. Mo. Mag.
Nov., p. 261.

J. S. Huxtry. Note on the Drumming of Woodpeckers. Brit. Birds. July,
pp. 40-41.

—— Some points in the Sexual Habits of the Little Grebe, with a note on
the occurrence of vocal duets in birds, loc. cit. Oct., pp. 155-158.

A. D. Imms. Grain Pests and their Investigation. Nature. June 26, pp.
325-326.

W. Ineuam. See W. E. L. Warram.

CoLtiyawoop Ineram. Incubation during the laying period. Brit. Birds
July, p. 64.

—— Down Tracts in Nestling Birds, loc. cit., pp. 78-79.

i
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CORRESPONDING SOCIETIES.

Grorrrey C. 8. Ingram. On the Breeding of the Lesser Redpole in Gla-
morganshire. Brit. Birds. Oct., p. 136.

J. J. The Fisheries and Scientific Research. Nature. July 17, pp. 385-386.

A. B. Jackson and A. J. Witmorr. SBarbarea rivularis in Britain. Journ.
Bot. Nov., pp. 304-306.

Anniz C. Jackson. See H. F. WiruErsy.

Dorotuy J. Jackson. Further Notes on Aphides collected principally in
the Scottish Islands. Scot. Nat. Sept., pp. 157-165.

J. Witrrip Jackson. The Bristly Millipede at Saltwick Bay, near Whitby.
Nat. July, pp. 243-244.

—— ‘Shell-Pockets’ on Sand-Dunes on the Wirral Coast, Cheshire ; and
Notes on Ancient Land Surfaces. Lanc. & C. Nat. July, pp. 9-14,
and Aug., pp. 39-44.

—— andJ.G.Kircnen. Planorbis dilatatus and Physa heterostropha in the
River Tame, at Dukinfield, Cheshire, loc. cit. Nov., pp. 131-132.

A. W. Jamieson. Some Sussex implements. Proc. Prehist. Soc. E. Anglia.
Vol. IIIL., pt. 1, pp. 108-110.

T. A. Jerreries. Natural Transformations in the Vegetation of Blackstone
Edge. Trans. Rochdale Lit. & Sci. Soc. Vol. XIII. pp. 18-24.

GERTRUDE JEKYLL. Pollination of Viscum album. Journ. Bot. Oct., p. 286.

H. C. Jippren-Fisuer. The Insects of East Grinstead District. Ent. Nov.,

. 256.

T. J. J nie Swallows. Rep. and Trans. Devon Assoc. Vol. Ll., p. 63.

J. W. HaicH Jonnson. Fungi [Report]. Ann. Rep.. Huddersfield. Nat.
etc. Soc. 1918-1919, p. 19.

—— See W. E. L. Warram.

W. F. Jounson. Athous hirtus, Herbst, a correction. Jrish Nat. June,
p. 80.

—— Ploiariaculiciformisin Co. Armagh [with note by J. N. Halbert], loc. cit.
July, p. 91.

—— Rhyssa persuasoria in the counties of Down and Fermanagh, loc. cit.
Oct., pp. 115-118.

—— Entomological Notes for 1919, loc. cit. Nov., pp. 127-129.

—— Irish Hymenoptera Aculeata in 1919, loc. cit. Nov., pp. 132-133.

Water Jounson. The Jew’s Ear Fungus (Hirneola auricula-jude, Fr.).
Nat. July, pp. 225-230; Aug., pp. 255-258; Sept., pp. 287-290 ;
Oct., pp. 319-322.

Jas. JoHNsTONE. The Dietetic Value of Sprats and other Clupeoid Fishes.
Proc. and Trans. Liverp. Biol. Soc. Vol. XXXIII., pp. 106-133.

—— The Probable Error of a Bacteriological Analysis, loc. cit., pp. 134-155.

—— Pearl-like Concretions in Tripe, loc. cit., pp. 156-158.

K. H. Jones and A. 8. Kennarp. Notes on the non-Marine Mollusca
observed in East Ross and the Orkney and Shetland Islands. Proc.
Malac. Soc. Oct., pp. 146-152.

R. Jones. See W. KE. L. WArraAm.

Ricuarp W. Jones. Velvet-Scoters in Summer off Carnarvonshire. Brit.
Birds. Sept., p. 111.

T. A. Jones. Liverpool Geological Society [Report]. Lanc. & C. Nat.
Dec., p. 174.

Francois C. R. Jourpary. Ornithological Report, 1918. Proc. Ashmolean
N. Hist. Soc. for 1918, pp. 11-18.

—— Red-throated Divers in Derbyshire and Leicestershire [with note by
W. H. Barrow]. Brit. Birds. July, p. 60.

—— Large Clutch of Eggs of Little Grebe, loc. cit. Oct., p. 142.

—— See James M. Harrison.

—— See F. W. Heaptey.

—— See A. Mayatt.

—— See W. H. Mutuens.

—— See J. H. Owen.

—— See B. VAN DE WEYER.

— See H. F. Wiruzrsy.

Norman H. Joy. Fierce Attack on a Cuckoo by a Meadow-Pipit. Brit.
Birds. Oct., pp. 138-139.

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LIST OF PAPERS, JUNE—DECEMBER, 1919. 493

D. Kemiy. On the life-history and larval anatomy of Melinda cognata
Meigen (Diptera Calliphorinae) parasitic in the snail Helicella (Helio-
manes) virgata da Costa, with an account of the other Diptera living
upon Molluses. Parasitology. Oct., pp. 480-455.

—— and G. H. F. Nurratyt. Hermaphroditism and other Abnormalities
in Pediculus humanus, loc. cit., pp. 279-328.

H. G. O. Kenpatn. Windmill Hill, Avebury, and Grime’s Graves, Cores and
Choppers. Proc. Prehist. Soc. H. Anglia. Vol. IlI., pt. 1, pp.
104-108.

A. 8. Kmnnarp. See K. H. Jonzs.

—— and B. B. Woopwarp. Report on the Mollusca [Grime’s Graves],
loc. cit., pp. 91-92.

—— —— On Helix revelata, Britt. auctt. (non Férussac nec Michaud), and
the validity of Bellamy’s name of Helix subvirescens in lieu of it for
the British Molluse. Proc. Malac. Soc. Oct., pp. 133-136.

—— —— On the Generic Names for the two British Ellobiide [Olim auri-
culide|, Myosotis, Drapenaud (= Denticulatus, Montagu) and biden-
tata, Montagu) loc. cit., pp. 136-139.

Bart Kennepy. Insects Ihave met. Animal World. July, p. 79.

—— My Window Sill [Birds], loc. cit. Dec., pp. 135-136.

James H. Knys. Coleoptera at the Lizard, Cornwall. Ent. Mo. Mag. Nov.,
pp. 259-260.

H. Kipner. Recent Discovery of an Unrecorded Type of Circular Earth-
work in the New Forest [Abs.]. Man. Oct., p. 158.

E. Botron Kine. EHuvanessa antiopa in Warwickshire. Ent. Nov., pp.
260-261.

CHARLES Kirk. Great Spotted Woodpecker in Argyll. Scot. Nat. Nov.,
p- 185.

—— Hawfinch in Dumbartonshire, Joc. cit., p. 194.

D. J. Batrour Kirke. Nesting of the Pied Flycatcher and Garden Warbler
in Ross-shire, loc. cit. :

Mavup Krirxwoop. Black-tailed Godwits in Co. Mayo. Jrish Nat. Sept.,

. 108.

J. G. Krrconen. See Annie Drxon.

—— SeeJ. Witrrip Jackson.

F. Lame. A Note on Four British Coccids. Ent. Mo. Mag. Oct., pp. 233-
234

—— Two species of British Aphides, loc. cit., Dec., pp. 272-274.

—— Insects damaging lead, loc. cit., pp. 278-279.

W. D. Lana. Old Age and Extinction in Fossils. Proc. Geol. Assoc. Vol.
XXX., pt. 01, pp. 102-113.

KE. Ray Lanxester. The Foundation of Biological Sciences. Nature.
Nov. 6, pp. 198-201.

J. Larprr. Size of specimens of Acer campestre. Nat. Nov., p. 372.

C. E. Larter. Hypericum humifusum. Journ. Bot. Oct., p. 287.

Wm. S. Lavzrock. Presidential Address. [‘ The Collecting of Flowering
Plants and Ferns and the Making of a Herbarium.’] Proc. Liverp.
Nat. F. Club. for 1918, pp. 10-19.

—— KE. Rem, Rosr Earrtron. The Field Meetings of 1918 [Report],
loc. cit., pp. 20-37.

A. K. Lawson. Vitrea and Pyramidula Destroyed by Ants. Jowrn. Conch.
Aug., p. 127.

Nina F. Layarp, The Mundford Pebble Industry. Proc. Prehist. Soc. E.
Anglia. Vol. TIL, pt. 1, pp. 150-157.

—— Flint Tools showing well-defined finger-grips. Proc. Suffolk Inst. Arch.
& Nat Hist. Vol. XVII. pt. 1, pp. 1-12.

—— Remains of a Fossil Lion at Ipswich. Nature. Dec. 25, p. 413.

W. Luacn. Manchester Microscopical Society [Reports]. Lanc. & C. Nat.
Nov., p. 133.

—— See Anniz Drxon.

Marie V. Lesour. Feeding Habits of Some Young Fish. Journ. Marine
Biol. Assoc. July, pp. 9-21.

—— The Food of Post-Larval Fish, loc. cit., pp. 22-47

424

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CORRESPONDING SOCIETIES.

Marie V. Lrzour. The Young of the Gobiide from the Neighbourhood of |

Plymouth, doc. cit., pp. 48-80.

—— Further Notes on the Young] Gobiide from the Neighbourhood of
Plymouth, loc. cit., pp. 146-148.

A. Luz. See E. Warnurst.

Joun R. Ler. Some Clydesdale Sphagna. Glasgow Nat. Sept., pp. 71-72.

F. Arnotp Less. The Nightmare of Names in the bed of Roses. Nat.
June, pp. 211-213.

—— Cypripedium Calceolus: Earliest Record, loc. cit. Oct., p. 341;
also Dec., p. 399.

—— The Distribution of Gentiana verna, loc. cit: Dec., pp. 390-391.

H. Maxwewt Lerroy. See K. M. Smiru.

W. Haroip Leicu-Suarrr, The Genus Lernaeopoda. Including a description
of L. mustelicola n.sp., remarks on L. galei and further observations
on L. scyllicola. Parasitology. Oct., pp. 256-266.

G. B.C. Lemon. Silpha atrata L., with Abnormal Antenne. Ent. Rec. Oct.,

; p: 185.

—— Notes on Coccinellidae, loc. cit., pp 213-214.

H. Masen Lewis. See W. A. HerpMan.

Srantey Lewis. Introduction of Red Grouse into Somerset. Brit. Birds.
Aug., p. 86.

—— Rock-Dove absent from Cheddar Cliffs, Joc. eit., p. 111.

T. Lewis. Young Buzzard takes a Shower-bath. Brit, Birds. Oct., pp. 140-
141.

L. Linzetu. See A. Bacor.

GutietmMa Listrr. A Three-spurred form of the Larger Butterfly Orchis
(Habenaria chlorantha Bab. var. tricalcarata Helmsley). Essex Nat.
Vol. XIX., pt. 1, p. 22.

—— Mycetozoa found during the Selby Foray. Trans. Brit. Mycol. Soc.
Sept., pp. 88-91. .

J.E.Lirtie. Notes on Bedfordshire Plants. Journ. Bot. Nov.,pp. 306-312.

S. H. Lone. Osprey in the Norfolk Broads. Brit. Birds. July, p. 58.

W. ArtHuR Lona. Catocala nupia ob. Ent. Nov., p. 261.

C. B. Lown. See W. D. W. GrEeEnHAm.

Lewis R. W. Loyp. Little Owl in South Devon. Brit. Birds. Nov., p. 164.

W.J.Lucas. Noteson British Orthoptera in1918.. Hnt. Aug., pp. 171-174.

—— Agriades corydon in the New Forest, loc. cit. Oct., p. 237.

—— Pararge megera, Linn., loc. cit.

—— Vespa crabro, loc. cit., p. 239.

—— Orthoptera in Captivity, loc. cit. Nov., pp. 249-250.

—— Preserving Orthoptera, Joc. cit., pp. 250-252.

—— Dorset Orthoptera, loc. cit. Dec., p. 280.

—— The Odonata of the Lancashire and Cheshire District, Lanc. & C.
Nat. Aug., pp. 55-60.

G. T. Lyte. Contributions to our knowledge of the British Braconide. Ent.
June, pp. 134-136; July, pp. 149-155; Aug., pp. 178-181.

D. Macponaup. Wigeon nesting in Ross-shire. Scot. Nat. Sept., p. 171.

—— The Whooper Swan in Ross-shire in June, loc. cit., Nov., p. 196.

—— Whooper in Ross-shire in June. Brit. Birds. Oct., p. 141.

CaarteEs McIntosx. Note on a Stone Cist found at Dalguise. Zrans. Perth
Soc. Nat. Sci. Vol. VI., pt. v., p. 206.

[W. C.] M‘Intosu. The Fisheries and the International Council. Nature.
July 3, pp. 355-358 ; July 10, pp. 376-378.

—— Sea-Fishery Investigations and the Balanceof Life, loc. cit., Sept. 18, p. 49.

T. ToHornton Mackeitu. The Nightjar in Renfrewshire. Scot. Nat. Sept.,
p. 166.

THomas McLaren. Note on a Stone Cist found at Kildinny, near Forteviot,
November, 1917.. Trans.- Perth. Soc. Nat. Sci. Vol, VI., pt. v.;
pp. 201-203.

—— Bronze Age Burial Urns and other Remains found at Sheriffton, near
Scone, December, 1917, loc. cit., pp. 203-205.

M. C. McLeop. Catocala fraxini [near Eastcote]. Ent. Aug., p. 189.

-—--- Colias edusa in Surrey., loc. cit., Oct., p. 235.

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LIST OF PAPERS, JUNE—DECEMBER, 1919. 425

A. Honre Macrnerson. Wild Hybrid between House-sparrow and Tree-
sparrow. Brit. Birds. Dec., p. 199.
Wm. Percy Mam. Haunts of the Black-headed Gull. Vasculum. July,

pp. 97-101.
G. W. Mazcorm. Unusual Nesting-place of Grey Wagtail. Scot. Nat. Nov.,
p. 195.

M. Matone. See W. E. L. Watram.

Wm. Manssriver. Lancashire and Cheshire Entomological Society |Report].
Ent., June, p. 144; Lanes. & Ches. Nat. July, pp. 26-27.

—— Lepidoptera. Report of the Recorder for 1918. Lanc. & C. Nat. Aug.,

p. 44-47,

R. R. pi es Recent Archeological Discoveries in the Channel Islands.—
(1) La Cotte de St. Brelade [Abs.]. Man. Oct., p. 157.

A. W. Marriage. Multiple Nests of Blackbird. Brit. Birds. Sept., pp. 108-
109,

J. G. Marspren. Cone Cultures at the Land’s End. Proc. Prehist. Soc. £.
Anglia, Vol. IIL, pt. 1., pp. 59-66.

E. 8. Marswarni. Notes on Somerset Plants for 1918. Journ. Bot. June,
pp. 147-154; July, pp. 175-181.

—— Barbarea rivularis in England, loc. cit., Aug., pp. 211-212.

—— Verbascum thapsiforme as a British Plant, loc. cit., Sept., pp. 257-258.

James M‘L, Marswaun. Woodcock and Young, Scot. Nat. Nov., p. 198.

F. A. Mason. See W. E. L. Wartram.

G. W. Mason. Entomology. [Report.] Zvans. Lincs. Nat. Union for 1918,
p. 113.

W. W. Mason. Jackdaw’s Unusual Nesting Site. Nat. Oct., p. 318.

Hersert Massey. J. J. Lister on Hodgkinson’s Record of P. egon in Tutt’s
** british Butterflies.” Hnt. June, p. 137.

—— Late Third Brood of Swallows. Brit. Birds. Nov., p. 161.

—— Weights of Cuckoos’ Eggs, loc. cit., Dec., p. 198.

GERVASE F. Matnew. Notes on Butterflies. Hnt. Oct., pp. 227-228.

—— Cherocampa nervi at Dovercourt, loc. cit., p. 237.

—— Issoria (Argynnis) lathonia and Colias edusa at Folkestone and Dover,
loc. cit. Nov., pp. 259-260.

J. L. Maxim. Discovery of a Bloomery at Birches, Healey. Trans. Rochdale
Lit. & Sci. Soc. Vol. XIII, pp. 94-99.

—— Querns and other Corn-grinding Stones recently found in the Rochdale
District, loc. cit., pp. 100-102.

E. Ketty Maxweitt. The Amateur Microscopist during Wartime. Journ.
Quekztt Micro. Club. No. 85, pp. 63-72.

Hersert Maxwetu. Antlers. Trans. Dumfries. & Gall. Nat. Hist. & Ant.
Soc. Vol. VI., pp. 12-21.

A. Mayatt. Abnormal Clutches of Chaffinch’s Eggs. With note by F. C. RB.
Jourdain. Brit. Birds. Aug., pp. 80-81.

C. M. Mayor. Colias edusa var. pallida (helice). Ent. Nov., p. 260.

—— _ Enugonia polychloros in Devon, loc. cit., p. 261.

D. H. Mrargs. Great Crested Grebes nesting in Kent. Brit. Birds. July,
pp- 5 and 60.

W.S. Mepricorr. Wood-Lark in North Lincolnshire, loc. cit. June, p. 26.

—— _ Goshawk in Lincolnshire, loc. cit. Nov., p. 164.

R. MrmNertTzHAGEN. <A Preliminary Study of the Relation between Geo-
graphical Distribution and Migration, with special reference to the
Palearctic Region. Ibis. July, pp. 379-392.

C. Mettows. Agriades corydon in the New Forest. Ent. Noy., p. 262.

—— Vespa crabro, loc. cit., pp. 262-263.

J. Cosmo Mertvitn. Teratology in Papaver orientale. Journ. Bot. Aug.,
p. 226.

James Menzies. Note on a Rare Myxomycete. Linbladia effusa Rost.
Trans. and Proc. Perth Soc. N. Sci. Vol. VIL., pt. 1., p. 1.

—— A List of the Discomycetes of Perthshire, loc. cit., pp. 2-27.

Epwarp Meyrick. Habits of Pancalia leuwenhoekella. Ent. Mo. Mag.
July, p. 160.

F, E. Mmsom. See W. E. L. Warram.

wow N N N NNN ONNNNNN NNN N N N BB VUUN N N

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CORRESPONDING SOCIETIES.

R. 8. Mirrorp. Hylotrwpes bajulus near Weybridge. Ent. Ree. Dec.,
pp. 222-223.

C. B. Morrat. The Rey. Charles William Benson, M.A., LL.D. [Obituary].
Irish Nat. June, pp. 73-78.

—— Leucophasia sinapis in Co. Wexford, loc. cit. Sept., p. 106.

J. Reto Morr. The Antiquity of Man. Nature. Nov. 27, p. 335.

—— A Piece of Carved Chalk from Suffolk. Man. Dec., pp. 183-186.

—— A few notes on the sub-crag flint implements. Proc. Prehist. Soc. E.
Anglia. Vol. IIL, pt. 1, pp. 158-161.

Horace W. Monexton. The Flora of the Bagshot District. Jown. Bot.
Sept., pp. 251-257.

H. J. Moon. Turtle-Dove breeding in North Lancashire. Brit. Birds. Aug.,
p. 86.

F. D. Morice. Tenthredella flavicornis F. at Lichfield. Ent. Mo. Mag. June,
pp. 133-135.

—— Lygaeonematus wesmaeli Tischb., a hitherto unrecorded British Sawfly
(from Yorkshire), Joc. cit. Sept., pp. 204-206.

B. Morury. Yorkshire Entomology [in 1919]. Nat Dec., pp. 407-408.

—— See W. E. L. Wartam.

CLauDE Mortry. Ocypus cyaneus Payk. in Suffolk. Hnt. Mo. Mag. July,
p. 159.

—— A few insects in the New Forest, loc. cit. Sept., pp. 208-209.

—— Caratomus megacephaius, Fab. Ent. Aug., pp. 186-187.

—— Historical Note: Nicholas Gwyn, loc. cit. Oct., p. 233.

—— Stilpnid Ichneumons, loc. cit., pp. 233-234.

—— Dragonfly at Light, loc. cit. Nov., p. 255.

GORDON Morrison. Manduca atropos in Co. Durham, loc. cit. Aug., p. 189.

Cartes Mostey. Natural History Report. Ann. Rep. Huddersfield Nat.
etc. Soc., 1918-1919, pp. 4-7.

—— Mammalia [Report], loc. cit., p. 13.

—— _ Entomology [Report], loc. cit., pp. 15-18.

W. H. Moutens. The Ruff—an early record. Brit. Birds. June, pp.
13-23.

—— H. Kirke Swann and F.C. R. Jourpam. <A Geographical Biblio-
graphy of British Ornithology. Part 1, Nov. 7, pp. 1-96.

J. F. Musuam, Conchology [Report]. Trans. Lines. Nat. Union for 1918,
pp. 112-113.

—— Wim Denison Rorsucs, M.Sce., F.L.S. [Obituary], loc. cit., pp.
116-117.

L. F. NewMan and G. Watwortn. A Preliminary Note on the Ecology of
Part of the South Lincolnshire Coast. Journ. Ecology. Nov.,
pp. 204-216.

ALFRED NrwsTEeAp. Curator and Librarian’s Report. Chester Soc. Nat.
Set., ete. 48th Rep., pp. 13--15.

—— New Varieties of British Lepidoptera from Cheshire. Znt. Oct., pp.
226-227.

R. NewstEAp. Some Scale-insects (Coccide) found in the Isle of Man. Proc.
and Trans. Liverp. Biol. Soc. Vol. XXXIII., pp. 63-64.

A. H. Newton. Notes on Odonata collected in North Wales in June and
July, 1918. Hnt. July, pp. 155-157.

J. B. Nicnots. Wild Hybrid between House Sparrow and Tree Sparrow.
Brit. Birds. Oct., p. 130.

C. Nicnonson. Pararge megera, and Vespa crabro in Essex. nt. Nov.,
p. 262.

—— Is Aretia caja habitually a day-flier ? Ent. Rec. June, p. 111.

—— Hibernia defoliaria in January and February, loc. cit.

—— Pararge megera in Essex and Gloucestershire, loc. cit. Nov., p. 206.

G. W. Nichorson. Ozytelus insecatus Gr. in ants’ nests. Ent. Mo. Mag.
July, p. 136.

--— Note on the occurrence of Lumprinus saginatus Gr. with ants, loc. cit.,
pp. 136-137.

—— Melanophila acuminata de G. at a fire in June, loc, cit. July, pp.
156-157. '

NOW

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LIST OF PAPERS, JUNE-DECEMBER, 1919. 427

G. W. Nicuotson. Atheta inhabilis Kr. and A. valida Kr. in Berkshire, Joc.
cit. Sept., p. 207.

James Noonan. Vaccinium Myrtillus on Raths. Irish Nat. Sept., p. 105.

Georce H. F. Nurratz. The Systematic Position, Synonymy and Icono-
graphy of Pediculus humanus and Phthirus pubis. Parasitology.
Oct., pp. 329-346.

—— Observations on the Biology of the Ixodidae. Part m1. Dealing with
the behaviour of the sexes in Amblyomma hebraewm, Hyalomma
aegyptium and Rhipicephalus bursa when upon the host, loc. cit.,
pp. 393-404.

—— See D. Kemi.

Cuas. OrpHAm. Lesser Shrew (Sorex minutus) in Cumberland. Nat. Sept.,
p. 292.

—— Palmated Newt (Molge palmata) in the Lake District, loc. cit. Oct.,
p. 337.

—— Diving Powers of Shoveler, Joc. cit., p. 110.

—— See H. F. Wirurrsy.

H. Onstow. Wild Birds and Distasteful Insect Larve. Nature. Aug. 14,
p. 464.

—— The Inheritance of Wing Colourin Lepidoptera. I. Abraxas grossulariata
var. lutea (Cockerell). Journ. Genetics. Sept., pp. 209-258. II.
Melanism in Tephrosia consonaria (var. nigra Bankes). Dec., pp. 53-60.

Artuur J. CAMPBELL OrDE. Fulmars nesting at Haskier. Scot. Nat. Sept.,
p. 166.

J. H. Orvron. Sex-Phenomena in the Common Limpet (Patella vulgata).
Nature. Dec. 11, pp. 373-374.

J. H. Owen. Birds covering their eggs at night during the laying period.
Brit. Birds. June, | p. 23.

—— On the procuring of food by the male for the female among birds of
prey, loc. cit., p. 29.

—— Large Clutch of Wren’s Eggs (with note by F. C. R. Jourdain), loc. e7t.,
p. 82.

—— Cuckoo’s Eggs and Nestlings in 1919, loc. cit. Sept., p. 109.

—— Some Habits of the Sparrow-hawk, loc. cit. Oct., pp. 114-124

M. Nast Owen. The Skin Spot Disease of Potato Tubers. Bull. Misc.
Information. Kew. No. 8, pp. 289-301.

A. H. P. Obituary. The Late Frank Norgate. Brit. Birds. June, pp.
21-22.

Vy. C. Parye. An Aerial Combat [Sparrow-hawk and Rook]. Rep. and Trane.
Devon Assoc. Vol. LI., pp. 63-64

C. K. Parker. Lesser Black- backed Guli (Larus fuscus affinis) perching on
wire. Lance. & C. Nat. Nov., p. 125.

W. H. Parxty. Tree Creeper (Certhia familiaris). Nat. Oct., p. 336.

—— See W. BE. L. Wartam.

Davin Pavu. Presidential Address. On the Earlier Study of Fungi in Britain.
Trans. Brit. Mycol. Soc. Sept., pp. 91-104.

Rogsert Pautson and Percy G. Tuompson. Supplemental Report on the
Lichens of Epping Forest. Essex Nat. Vol. XIX., Pt. 1, pp. 27-30.

Donaup Payer. Dwellers Underground. Animal World. Aug., pp. 89-91.

J. H. Payne. Undocked Dogs. Nat. Sept., p. 311.

A. E, Peake. Excavations at Grime’s Graves during 1917. Proc. Prehist.
Soc. BE. Anglia. Vol. Ifl., Pt. 1, pp. 73-92.

E. J.. Pearce. Adimonia oelandica Boh. in Dorset. Ent. Mo. Mag. Sept.,
p. 207.

—— Some Coleoptera taken on Dartmoor, Joc. cit. Nov., p. 261.

Wittiam Harrison Prarsatt. The British Batrachia. Rep. Bot. Soc.
Vol. V., Pt. m1, pp. 428-441.

A.A. Prarson. ANewMycena. Trans. Brit. Mycol. Soc. Sept., pp. 135-136.

—— See KE. M. WakEFIELD.

Dovuctas = Prarson. Dorset [Entomology of]. nt. Rec. Nov., pp.

-209.

Wittiam Henry Pearson. Notes on Radnorshire Hepatics. Journ. Bot.

July, pp. 193-195.

—~
bo
io 2)

ONNNON © @ N N N ON DOWD ON NNN NNNNN NNN 7 ON NOOO
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CORRESPONDING SOCIETIES.

A. E. Peck. Fungus Foray at Helmsley (1919). Nat. Dec., pp. 396-399.

—— Thomas Hey [Obituary], loc. cit., pp. 404-405.

R. C. L. Perkins. Note on a peculiarity in the burrows of Halictus maculatus
Sm. L£xrt. Mo. Mag. July, pp. 160-161.

—— Andrenadorsata K. and A, similis [Sm.]stylopised, loc. cit. Aug., p. 181.

T. Percu. Further Notes on Colus Gardneri (Berk.) Fischer. Trans. Brit.
Mycol. Soc. Sept., pp. 121-132.

G. H. PeTnysripce. Notes on some Saprophytic species of Fungi, associated :
with diseased Potato Plants and Tubers. Trans. Brit. Mycol. Soc. —
Sept., pp. 104 ef seq.

Watrer Pierce. Limenits sibylla in Bucks. Ent. Oct., p. 237. |

—— Polygona c-album, loc. cit. |

O. G. Pike. Probable Long-tailed Skua in Hertfordshire. Brit. Birds. Oct.,
pp- 143-144.

—— The Black-necked Grebe, loc. cit., pp. 146-154.

Frances Pirt. The Little Owl. Nat. Nov., pp. 370-371.

—— Little Owl breeding in Shropshire. Brit. Birds. Nov., p. 163.

—— See Maup D. Havmanp.

Gro. T. Porritt. Choerocampa nerii at Huddersfield. Ent. Mo. Mug. Oct., ©
p. 232.

—— Crocallis elinguaria, form signatipennis. Ent. Nov., p. 258.

—-— See E. P. Burrerrie.p.

M. Portat. Abnormal Late Hatching of Partridges. Brit. Birds. Nov.,
p- 166.

J. Porter. See T. SHEPPARD.

R. Lioyp PraEGcer. Clavaria argillacea fin Co. Carlow]. Irish Nat. June,

p. 79.

naan Ree Cosslett Herbert Waddell, B.D. [Obituary], loc. cit. Sept., p. 108.

—— Nathaniel Colgan. [Obituary], loc. cit. Nov., pp. 121-126.

—— See W. B. Srezte. k

D. Praw. J. W. H. Trail, M.D., F.R.S. [Obituary]. Journ. Bot. Nov.
pp. 318-320. 3;

H. Preston. Fossil Mammalia. Trans. Lincs. Nat. Union for 1918, p. 116.

H. W. Puastey. Notes on British Euphrasias. {. Journ. Bot. July, pp. 169-

175.

W. Ramspen. Presidential Address on Surface Films. Proc. and Trans.
Liverp. Biol. Soc. Vol. XXXTII., pp. 3-24.

GILBERT H. Raynor. Colias edusa and C. hyalenear Maldon. Ent. Oct.,

p- 235.

—— Abraxas grossulariata ab. exquisita and ab. pulchra. Ent. Rec. Nov.,
pp. 205-206.

CARLETON Rea. Llatine Hydropiper in Worcestershire. Journ. Bot. Nov.,
p. 323.

—— Amphlett, John, M.A., S.C.L., J.P. [Obituary]. Rep. Bot. Soc.
Vol. V., pt. M1, p. 349,

R. A. S. RepMAyneE. Nyssia lapponaria in Inverness. Ent. June, p. 141.

E. Rem. See W. 8. Laverock.

—— See G. E. Baker.

Percy C, Rem. <A Hunt for Zygena achillee. Ent. Aug. pp. 188-189.

—— Colias edusa in Essex, loc. cit. Oct., p. 235.

A. B. Rennie. The President’s Address. Some Cases of Adaptation amon
Plants. Journ. Quekett Micro. Club. No. 84, pp. 23-28.

—— John Hopkinson, F.L.8., F.Z.S., F.G.8., F.R.M.S., Secretary of th
Ray Society (1844-1919) [Obituary], loc. cit. No. 85, pp. 103-104.

—— George Stephen West, M.A., D.Sc., F.L.S. (1876-1919) [Obituary],
loc. cit., pp. 104-105.

L. P. W. Renovur. The Deceptiveness of Adult External Features as Guides —
to Relationship, as illustrated by Decapod Crustacea. Glasgow Nat.
Sept., pp. 72-77.

Joun Renwick. David Gregorson—a Memorial Notice, Joc. cit., pp. 77-80.

—— Robert J. Bennett—a Memorial Notice, loc. cit., p. 81.

T. W. Ricuarps. Notes on Lepidoptera from Wales and Hereford. Ent.
Aug., p. 190. ;

LIST OF PAPERS, JUNE--DECEMBER, 1919. 429

H. J. Ripperspexy. Simethis planifolia Gren. & Godr. Journ. Bot. Oct.,
. 285,
a Glonbedtershite [Botanical] Notes, loc. cit., pp. 350-353.
Witi1amM Riperway. An Irish Decorated, Socketed Bronze Axe. Man. Nov.,
pp. 161-164.
Leonora JEFFREY Rintoun and Evetyn Y. Baxter. Report on Scottish
Ornithology in 1918. Scot. Nat. July, pp. 99-144.
—— See Evetyn V. Baxter.
B. B. Riviere. Continéntal Jays in Norfolk. Brit. Birds. June, pp. 25-26.
Hueu G. Riviere. Daphnis nerit at Studland, Dorset. Hnt. Rec. Nov.,
= 207.

Joun laeaisivecin: The Whinchat as Imitator. Scot. Nat. Novy., p. 195.

Frep Rostnson Jsoetes Hystrix Durien in Cornwall. Journ. Bot. Nov.,
. 322.

H. W. Tcuncow. The Great Crested Grebe in Scotland. Scot. Nat. Nov.,
p LOT

— Shenker ict Tern bred on Farne Islands recovered in Cumberland. Brit.
Birds. Sept., p. 111.

—— Numbers of Swallow Broods in 1919, loc. cit. Nov., pp. 161-162.

—— Black-headed Gulls returning to their parent colony, loc. cit., pp. 165-
166.

W. D. Rorsucx [late]. Census Authentications [Conchology]. Journ.
Conch. Aug., pp. 101-102.

I. M. Roper. Green, Charles Baylis [Obituary]. Rep. Bot. Soc. Vol. V.
pt. I., p. 355.

H. Rowranp-Brown. Hibernation of Aglais urtice. Ent. June, p. 137.

—— Spring Emergencies in South Devon, Joc. cit., p. 139.

—— The Cotteswold Arion, loc. cit. Aug., pp. 174-178; a correction,
Sept., p. 212.

—— Anthrocera achillew, Esper, in Scotland. Notes on its distribution and
Variation, loc. cit. Oct., pp. 217-226.

—— A plea for Pioneer Work [in Entomology], loc. cit., pp. 229-231.

—— Erebia ethiops at Arnside, loc. cit. Dec., pp. 265-267.

—— Hippotion celerio and other Lepidoptera in the Maidstone Museum,
loc. cit., p. 277.

—— Scarcity of Aglais urtice, loc. cit., pp. 277-278.

Grorce Russet. Caterpillars of the Pale Mottled Willow Moth in Flax.
Scot. Nat. Nov., p. 200.

Gzorce B. Ryxe. Coleoptera of the Brighton District. Ent. Mo. Mag.

4 Aug., pp. 178-179 ; a correction, Sept., p. 232.

—— Odontaeus mobilicornis Fab. in Wiltshire, loc. cit., pp. 231-232.

E. J. Sautspury. Botany. Sci. Progr. July, pp. 43-48 ; Oct., pp. 224-227.

C. E. Satmon. Norfolk Notes [Botanical]. Journ. Bot. July, pp. 190-192.

—— Argyle Records, loc. cit. Dec., p. 354.

—— See AntHony WALLIs.

E. U. Savaet. Grey Wagtails nesting at a distance from water. Brit. Birds.
July, p. 56.

R. F. Scuarrr. William Spotswood Green, C.B., M.A. [Obituary]. Irish
Nat. July, pp. 81-84.

—— A New Irish Whale [Mesoplodon mirus], loc. cit., pp. 130-131.

Atex M. Scotr. The Caledonian Camp, the Haer Cairns, and the Steed
Stalls, in the Stormont. J'rans. and Proc. Perth Soc. N. Sci. Vol. VII.,
pt. 1, pp. 28-36. ’

AnpReEw Scorr. On the Monthly Occurrence of Pelagic Fish Eggs in Port
Erin Bay in 1918. Proc. and Trans. Liverp. Biol. Soc. Vol. XX XIII.
pp- 85-94.

—— See W. A. HerpMman.

[D. J.] Scourrrenp. Pond Life Exhibition [Remarks on]. Journ. Roy.
Micro. Soc. June, pp. 195-196.

Reamatp W. Scutty. Some Stray Botanical Notes. Jrish Nat. June,
p. 80.

—— Eriophorum latifolium in County Dublin, with some notes on the rarer
County species, Joc. cit. July, pp. 89-90.

430

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CORRESPONDING SOCIETIES.

Epmunp Senovus. Ornithological Observations and Reflections in Shetland.
Nat. Aug., pp. 259-262; Nov., pp. 357-360; Dec., pp. 381-385.
D. G. Srvastoruto. An Experiment on Andrena fulva. Ent. June, p. 138.
FE. P. and P. A. Suarp. Sphinx pinastriin Sussex. Ent. Rec. Aug., p. 168.
W. G. Suenpon. The Variation of Sarrothripus revayana, Scopoli. Ent.
June, p. 122-129.
—— The Re-discovery of Anthrocera achillew in Scotland, Joc. cit. Sept.,
pp- 213-214.
-_— The Earlier Stages of Peronea maccana, Tr., P. lipsiana, Schiff, P.
rufana, Schiff, and P. schalleriana, loc. cit. Nov., pp. 252-255 ;
Dec., pp. 271-274.
W. F. J. SuHeruearp. Zoological Section [Report]. Chester Soc. Nat. Sci. etc.
48th Rep. pp. 18-21.
C. E. SuerHerp. On Otoliths. Trans. Dumfries. & Gall. Nat. Hist. & Ant.
Soc. Vol. VI., pp. 21-27.
T. Suepparp. The Hull Whaling Trade. Mariner's Mirror. Dec., pp. 162-
178.
—— Dane’s Dyke [British Earthwork]. Trans. East R. Antig. Soc. Vol.
XXII, pp. 33-42.
—— Whaling Relics [Carved Tusks, ete. |, loc. cit., pp. 43-54.
—— Spring-gun enclosed in Oak Tree. Naf. June, p. 214.
—— Bones of Bear from York, loc. cit. Sept., pp. 293-294.
—— Yorkshire Naturalists at Spurn [with contributions by E. W. Wade,
J. Porter, C. A. Cheetham, Greevz Fysher, W. H. Burrell], loc. cit.
Dec., pp. 386-389.
Atrrep Sion. Notes on Coleophora vibicella, Hb. Ent. Rec. Aug., pp. 169-
170.
—— Notes on Cemiostoma wailesella and other Lepidoptera in Sussex in 1919,
loc. cit. Nov., pp. 201-204.
[W. W. Sippaxu.] Botanical Section [Report]. Chester Soc. Nat. Sci. ete.
48th Rep., p. 18.
H. M. Srrxar. Hylowcus pinastri in Suffolk. Hnt. Nov., p. 258.
G. H. Smureson-Haywarp. An Unusual Form of Aplecta nebulosa, loc. cit.
Aug., pp. 189-190.
James Smarty. The Origin and Development of the Composite. New Phy.
May, pp. 129-176; July, pp. 201-234.
F. W. Smatiey. Mallard, Wigeon, and Lesser Black-backed Gull in North
Vist. Scot. Nat. Sept., pp. 169-170.
G. W. Smatuwoop. Potters’ Tools of Slate. Proc. Prehist. Soc. E. Anglia.
Vol. III., pt.1., pp. 115-118.
H. Dovatas Smarr. Crocallis elinguaria signatipennis. Ent. Dec., p. 278. |
Artuur Smiru. The General Secretary’s Report. Trans. Lincs. Nat. Union
for 1918, pp. 101-104. 4
A. Lorrarn SuitH. New or Rare Microfungi. Trans. Brit. Mycol. Soc.
Sept., pp. 149-158. :
[Extiot Smir]. The Significance of the Cerebral Cortex. Nature. July 17,”
pp. 396-397.
K. M. Surrn. A Comparative Study of Certain Sense-organs in the An-"
tenne and Palpi of Diptera. [Appendix by H. Maxwell Lefroy.] |
Proc. Zool. Soc. Sept., pp. 31-69. ‘a
Reainstp A. SmitH. Foreign Relations in the Neolithic Period. Proc.
Prehist. Soc. E. Anglia. Vol. III., pt. 1., pp. 14-32. J
Tuomas Surrg. Diaphora mendica in North Staffordshire. nt. Sept., p.
216

Cuas. D. Soar. British Hydracarina. Vasculum. July, pp. 107-112.

—— Hydracarina. The Genus Oxus Kramer. Journ. Quekett Micro. Club, —
No. 84. pp. 29-34. .

W. Somervite. Ear Cockles in Wheat. Journ. Board Agric. Dec., pp.”
907-909. :

Ricwarp Sours. Colour Variation of Cacecia crategana, Hb., in the New”
Forest. Ent. Aug., pp. 190-191.

—— Sphinx convolvuli at Putney, loc. cit. Oct., p. 237. &

F, W. Sowersy. Zuoris occulata in Lincolnshire. Hnt. June, p. 138.

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LIST OF PAPERS, JUNE-DECEMBER, 1919. 431

Epwarp R. Sprryrr. Wild Birds and Distasteful Insect Larvee. Nature.
Aug. 7, pp. 445-446.

Henry Speyer. Papilio machaon in Surrey. Ent. Rec. July, p. 130.

T. Staryrorts. The Thomas Stather Collection of Lepidoptera. Trans.
Hull Sci. & F. N. Club, Vol. TV., pt. vi., pp. 281-298.

—— The Bristly Millipede in North Lines. Nat. July, p. 234.

—— Some Yorkshire Arthropods, loc. cit. Nov., pp. 361-362.

R. Stanpen. Armadillidium pulchellum, Zenker, near Whalley. Lanc. &
CO. Nat. Oct., p. 106.

—— The Hairworm (Gordius aquaticus, L.), Joc. cit., p. 111.

—— Entomological Notes from Dovedale, Derbyshire, loc. cit., pp. 112-118,
and Nov., pp. 121-123.

J. K. Stanrorp. Pied Flycatcher in Suffolk in Spring. Brit. Birds. Aug.,

. 81-82.

a Seimedbtes on the Wryneck, loc. cit., pp. 82-83.

—— Pied Flycatchers on Migration in London, loc. cit., p. 160.

—— Ornithological Notes from Suffolk, loc. cit., pp. 170-172.

T. R. R. Stessinc. Alfred Merle Norman. 1831-1918 [Obituary]. Proc.
Roy. Soc. B. 634, pp. xlvi-l.

W. B. Streeter. Vicla stagnina in Fermanagh. [With Note by R. Lloyd
Praeger.] Jrish Nat. July, p. 95.

A. W. Stetrox. Pisidiwm parvulum in Co, Antrim, loc. cit., pp. 92-93.

F. Stevens. Skeleton found at Fargo, Wilts. Arch. & Nat, Hist. Mag. No.
CXXX., p. 359.

PZ [H. C. Srewarpson]. Catalogue of the more important Papers, especially

those referring to Local Scientific Investigations, published by the
Corresponding Societies during the year ending May 31, 1918.
Rep. Brit. Assoc, for 1918, pp. 90-1038.
Annot L. Stone and Cuas. F. THoRNEWILL. Report of the Committee for
1918. Proc. Ashmolean N. Hist. Soc. for 1918, pp. 9-10.
H. F. Stonzenam. Meadow-pipits fiercely attacking Cuckoo, Brit. Birds.
Nov., pp. 162-163.
E. A. C. Stowers. Notes on Lepidoptera around. Alton, Hants. Znt.
Noy., pp. 258-259.
Frep J. Stusss. Climbing of the Water Shrew. Hssex Nat. Vol. XIX.,
t. 1, p. 21.
—— @idumencs of Trout in the River Roding, loc. cit., pp. 25-26.
H. Kirke Swann. Peregrine Falcon attacking a boy. Brit. Birds. June,
p. 31.
—— Probable Montagu’s Harrier breeding near Sussex, J2c. cit. Oct., p. 141.
— A Synoptical List of the Occipitres (Diurnal Birds of Prey). Part I.,
July, pp. 1-38; Part II, Nov., pp. 39-74.
—— See W. H. Muttens.
C. F. M. Swynnerton. Experiments and Observations bearing on the
Explanation of Form and Colouring, 1908-1913. Journ. Linn.
Soc. (Zool.). No. 224, pp. 203-385.
JosrrH H. Symes. Number of Eggs laid by a Marsh-Warbler. Brit. Birds.
Nov., p. 160.
W. M. TarrrrsaLy.. Crustacea. Notes on Lancashire and Cheshire Specimens.
Lance. & C. Nat. July, pp. 20-26.
—— Lancashire and Cheshire Mosquitoes, loc. cit. Sept., p. 69.
—— Rotifera, loc. cit., p. 73.
—w— Rare Lancashire and Cheshire Spiders, loc. cit. Oct., p. 120.
—— Erysimum orientale, Mill., at Prestwich, loc. cit. Dec., p. 170.
Beatrice Tayror. Sargant, Ethel, F.L.S. [Obituary]. Rep. Bot. Soc. Vol. V.,
pt. 1., pp. 365-366.
R. H. 8. Tess. Leucophasia sinapis in Co. Wicklow. Irish Nat. July,
02:
Gurorce W. Temprertry. Fulmar Petrels in Yorkshire in Summer. Brit.
Birds. July, p. 59.
A. G. Tuackrer. Anthropology. Sci. Progr. Oct., pp. 235-240.
Frep. V. Tuzosatp. New and Little Known British Aphides. Ent. July,
pp. 157-161.

432

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CORRESPONDING SOCIETIES.

Frep. V. Turosaup. Insects on the Sea Buckthorn, loc. cil. Aug., pp. 169-171.

ALFRED Tuomas. Number of Eggs laid by Marsh-Warbler. rit. Birds.
Oct., p. 137.

E. N. Tomas [Secretary]. Plant Pathology. Report of the Committee.
Rep. Brit. Assoc. for 1918, pp. 56-58.

J. F. Toomas. Unusual Nesting Site of a Kestrel. «Brit. Birds. Aug., p. 84.

A. H. Tuoompson. Hesperia malve in Cheshire. Ent. Aug., p. 189.

—— Larval Food-plants of Xanthecia flavago, loc. cit., p. 256.

H. Stuart THomeson. Habitats of Hypericum humifusum. Journ. Bot.
July, pp. 195-196.

—— Yew on Oak, loc. cit., p. 197.

—— [Hypericum humifuswm), loc. cit., pp. 226-227.

—— Carex montana L., loc. cit. Oct., pp. 274-275.

—— Galium erectum in Somerset, Joc. cit. Oct., pp. 286-287.

—— The Genus Huphrasia and HL. minima, loc. cit. Dec., pp. 335-337.

M. L. THomrson. See W. E. L. Warram.

Percy THomeson. New Essex Lichen. Hssex Nat. Vol. X1X., pt. 1, p. 15.

—— Rare Essex Bryophytes, Joc. cit., p. 17.

Percy G. THompson. See Ropert Pautson.

A. LanpssporoucH THomson. Pied Flycatcher in Aberdeenshire. Scot. Nat.
Nov., p. 195.

J. A. Tinomson], 8.G., E.8.G., A.G., A.LS., J.E. B. B. Wloopwarp], H.F.W.,
J. E. B., H[sron]-A[tnen] and E[arnanp], A. B. R[ENDLE].
Summary of Current Researches relating to Zoology and Botany
(principally invertebrata and Cryptogamia), Microscopy, ete. Journ.
Roy. Micro. Soc. June, pp. 127-186; Sept., pp. 229-299 ; Dec., pp.
329-386.

H. J. Tuontess. Leptura rubra L. in Norfolk. Ent. Mo. Mag. Aug., ppe
174-175.

Cuas. F. THoRNEWILL. See Annot L, STONE.

N. F. Ticrnurst. The Birds of Bardsey Island. Brit. Birds. July, pp.
42-51. Aug., pp. $6-75. Sept., pp. 101-106. Oct., pp. 129-134.
Dec., pp. 182-193.

—— Some Notes on the Wryneck, loc. cit., pp. 82-83.

—— Are Cuckoos ever reared by Greenfinches ? loc. cit. Oct., pp. 137-138.

—— See H. F. Wirnersy.

J. R. up B. Tomnry. New localities for Hydrovatus clypealis Sharp. Ent. Mo.
Mag. July, p. 159.

—— Colpodes splendens Morawitz, a Japanese Carabid in Berkshire, loc. cit.

—— Bagous lutulosus in Glamorgan and Berks, loc. cit. Nov., p. 260.

—— [J. R. U. B. Tomlin, in error]. William Ernest Sharp. An apprecia-
tion. Lanc. & C. Nat. Sept., pp. 65-67.

A. BE. Tonagz. C. polyodon [at Worthing]. Hnt. Rec. June, p. 110.

Guapys M. Towsry. Birds near London. Journ. Wild Birds Inves. Soe.
No. 1, pp. 7-8.

N. Tracy. The Drumming of Woodpeckers. Brit. Birds. Aug., p. 88.

CHARLES TAYLOR TRECHMANN. On a Bed of Interglacial Loess and some Pre-
glacial Fresh-water Clays on the Durham Coast [Abs.]. Abs. Proc.
Geol. Soc., pp. 22-25. Ann. & Mag. Nat. Hist. June, pp. 50-52;
and Phil. Mag. Sept., pp. 425-426.

Tuomas H. C. TrousripGE [Thomas H. H. Troubridge, in error]. Spoonbill
in Hants. Brit. Birds. Aug., p. 85. Nov., p. 165.

J. G. Tuck. The late Frank Norgate, loc. cit. July, p. 64.

Emma L. Turner. The Bittern in the Norfolk Broads. ‘“‘ A Great Entail,”
loc. cit. June, pp. 5-12.

—— Further Notes on the Bittern in the Norfolk Broads, loc. cit. July,
pp. 34-36.

Hy. J. Turner. The South London Entomological and Natural History
Society [Reports]. Hnt. June, pp. 141-143. July, p. 168.
Aug., pp. 191-192. Nov., pp. 263-264; and nt. Mo. Mag.
June, pp. 141-143. July, pp. 162-163. Aug., pp. 182-183.
Sept., pp. 209-210. Oct., pp. 235-236. Dec., p. 280.

—— Tortriz viridana and others. Hnt. Rec. June, p. 111.

N N @ N N NW OOD DB DN BON N DBD BD N WN

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LIST OF PAPERS, JUNE-DECEMBER, 1919. 433

Hy. J. Turner. Acalla reticulata, Str6m.=contaminana, Hiib.—Ilts History
and its Variation, Joc. cit. Aug., pp. 158-164.
R. E. Turner. Xiphydria prolongata Geoftr. (= dromedarius Fabr.), bred
from an artificial leg. Hnt. Mo. Mag. July, p. 161.
W. B. Turrmt. Female Flowers of Plantago lanceolata. Journ. Bot. July,
p- 196.
— Observations on the Perianth in Ranunculus auricomus and Anemone
coronaria, New Phy. Oct., pp. 253-256,
B. VAN pE Weyer. Pheasant breeding in Sparrow-Hawk’s nest, with note
by F. C. R. Jourdain. Brit. Birds. Aug., p. 87.
H. J. Vaueuan. Pied Flycatcher in South Wales, Joc. cit. June, p. 27.
G. M. Vevers. See W. Balfour Gourlay.
ArtHuR E, Wapr. The Flora of Aylestone and Narborough Bogs. Trans.
Leicester Lit. & Phil. Soc. Vol. XX., pp. 20-46.
E. W. Wave. See T. Sheppard.
Harotp Waacer. A Fluorescent Colouring Matter from Leptonia incana, Gill.
Trans. Brit. Mycol. Soc. Sept., pp. 158-164.
E. M. WAKEFIELD. The Selby Foray [and] Complete List of Fungi gathered
during the Foray. Trans. Brit. Mycol. Soc. Sept., pp. 77-87.
—— New British Fungi, loc. cit., pp. 132-134.
—— Charles Ogilvie Farquharson [Obituary], loc. cit., pp. 236-237.
—— and A. A. Pearson. Additional Resupinate Hymenomycetes from the
Weybridge District, loc. cit., pp. 136-143.
—— See A. D. Corton.
J. J. WatKer. Interim Report on Coleoptera. Proc. Ashmolean N. Hist.
Soc. for 1918, p. 16.
A. H. Watt. Hawk and Canaries. Rep. Marlborough Coll. Nat. Hist. Soc.
No. 67, p. 39.
W. Wauuacr. Anopheline Mosquitoes of Lincolnshire. Trans. Lincs. Nat.
Union for 1918, pp. 118-119.
Antuony Watts. [&] C. E. SAntmon. Pembrokeshire and Carmarthenshire
Plants. Journ. Bot. Dec., pp. 347-350.
E. ArnoLtp Wats. One Meadow-pipit feeding two young Cuckoos. Brit.
Birds. Nov., p. 163.
H. H. Wats. On the Aquatic Coleoptera, etc., of the Trent Valley in the
Neighbourhood of Long Eaton. Hnt. Mo, Mag. ‘June, pp.
127-128.
Gro. B. Watse. Notes and Records of Coleoptera. Vasculum. July, pp.
142-144. Dec., pp. 182-184.
G. Watworts. See L. F. Newman.
Eruet Waruurst. Liverpool Botanic Gardens. Lancs. & C. Nat. Dec.,
pp: 171-173.
—— and A. Lex. Liverpool Botanical Society [Reports], loc. cit. Sept.,
pp. 83-87.
G. W. Warner. Colias hyale in Leicester. Ent. Nov., p. 260.
S. Hazztepine Warren. The Dating of Surface Flint Implements and the
Evidences of the Submerged Peat Surface. Proc. Prehist. Soc. °
E. Anglia. Vol. IIL, pt. 1, pp. 94-104.
—— A Stone-axe Factory at Graig-Lwyd, Penmaenmawr. Journ. Anthrop.
Inst. July, pp. 342-365.
A. Joycr Warson. Occurrence of Chirocephalus diaphanus- in Seavernake
Forest. Wilts. Arch. & Nat. Hist. Mag. No. CXXX., p. 368.
Huau Watson. Notes on Hygromia limbata (Drap.). Proc. Malacol. Soc.
Oct., pp. 120-132.
W. Watson. Habitats of Hypericum humifusum. Jowrn. Bot. Dec., pp.
353-354.
A. 8S. Warr. On the Causes of Failure of Natural Regeneration in British
Oakwoods. Journ. Heology. Nov., pp. 173-203.
Lawrence Wart. Notes on Plants from Banff and from Old Kilpatrick
and on the Oaks in Erskine Policies. Glasgow Nat. Sept., pp. 65-10.

Z W. E. L. Warram. Yorkshire Naturalists at Coxwold [With Contributions

by Greevz Fysher, F. A. Mason, W. Ingham, M. L. Thompson,
[W. J.] Fordham]. Nat. June, pp. 206-210.

1920 FE

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CORRESPONDING SOCIETIES.

W. E. L. Warram. Yorkshire Naturalists at Ryhill [With Contributions by
W. H. Parkin, J. Digby Firth, J. A. Hargreaves, H. H. Corbett,
W. Falconer, B. Morley, [W. J.} Fordham and J. W. H. Johnson],
loc. cit. Aug., pp. 271-273.
—— Yorkshire Naturalists at Hawes [With Contributions by R. Jones,
Cc. A. Cheetham, [W.] Falconer, M. L. Thompson, J. Hartshorn,
k. E. Milsom, F. A. Mason], loc. cit., pp. 303-308.
—— Yorkshire Naturalists at Pateley Bridge [With Contributions by W. H.
Burrell, M. Malone, E. P. Butterfield, C. A. Cheetham, R. Butterfield],
loc. cit., pp. 308-310.
—— Phanerogamic Botany [Report]. Ann. Rep. Huddersfield Nat.
ete. Soc. 1918-1919, pp. 19-20.
Guapys E. Wess. The Development of the Species of Upogebia from Plymouth
Sound. Journ. Marine Biol. Assoc. July, pp. 81-135.
F. D. Wetcr. Starling. Nat. Oct., p. 341.
—— Combat between Hedge-Sparrow and House-Sparrow. Brit. Birds.
Nov., p. 161.
Grorce West. Amphora infleza, a rare British Diatom. Journ. Quekett
Micro. Club. No. 84, pp. 35-40.
W.S. D. Westropp. Colias edusain Co. Cork. Irish Nat. Oct., p. 120.
Harotp J. WHELDON. Observations on the Fungi of the Lancashire and
Cheshire Sand-Dunes. Trans. Brit. Mycol. Soc. Sept., pp. 143-148.
J. A. WHetpon. Notes on Braithwaite’s Spagnacee Hxsiccate. Journ,
Bot. June, pp. 142-147.
E. Wuirtry. Dugonia polychloros in Devon. Ent. Sept., p. 216.
Aberrations of Coccinella 7-punctula, loc. cit. Oct., p. 238.
Oscar WuirraKker. A Rare Fairy Fly [Mymar regalias] in Cheshire. Lane.
& C. Nat. Nov., p. 144.
Henry J. Wiixrnson. Cypripedium Calceolus L. Nat. Nov., p. 373.
J. W. Wrtutams. Anthidium manicatum, Linn., in Worcestershire. nt.
Dec., p. 278.
W. J. Wiitrams. American Goshawk in Ireland [With Note by E. Hartert
and H. F. Witherby]. Brit. Birds. June, p. 31.
H. C. WimxramMson. The Common Tern and its Enemies. Journ. Wild
Bird Inves. Soc. No. 1, pp. 3-6.
[E. Witimott]. Pied Blackbird from Worley Place. Essex Nat. Vol.
XIX., pt. 1, pp. 14-15.
A. J. Wiimor. See A. B. Jackson. ;
A. Witson. West Yorkshire Botanical Notes. Nat. Nov., p. 369.
Matcotm Witson. Some British Rust Fungi. Journ. Bot. June, pp. 161-

163.

R. Winckwortu. Loligo vulgaris, Lam. in British Waters. Journ. Conch.,
Aug., p. 127.

H. F. Wirnersy. The Pied and White Wagtails. Brit. Birds. July,
pp., 37-39.

—— The ‘British Birds’ Working Scheme. Progress for 1918, loc. cit.
Sept., pp. 96-100.

—— Swallow ringed in Yorkshire found in South Africa, loc. cit. Dec.,
p- 196.

—— Ernst Hartert, AnniE C. Jackson, F. C. R. Jourpatn, C. OLDHAM,
Norman F. Ticrnurst. A Practical Handbook of British Birds.
Part 3, June, pp. 129-208 ; Part 4, Sept., pp. 209-272; Part 5,
Nov., pp. 273-336.

—— See W. J. WILLIAMS.

E. M. Woop. See H. J. Hotme.

T. W. WoopuEAp. Geology [Peat, etc.]. Ann. Rep. Huddersfield Nat. etc.
Soc. 1918-1919, pp. 20-21.

E. ApriAn Wooprurre-Pracock. Miss 8. Catherine Stow. Trans. Lincs.
Nat. Union for 1918, pp. 99-101.

—— Botanical Report, Joc. cit., pp. 104-111.

—— Cytcuspora chrysosperma, loc. cit., p. 120.

—— The Grey Dagger Moth, loc. cit., p. 142.

—— Undocked Dogs the Quicker. Nat. July, p. 246.

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LIST OF PAPERS, JUNE-DECEMBER, 1919. 435

FE. ApriAn WoopruFFE-PEAcocK. Do Leaves want Watering ? loc. cit., p. 246.

Tom

The Greenfinch’s Nest, loc. cit., p. 277.

Two Phytophagous Chalcids, loc. cit. Oct., pp. 329-3309.

Large Pike and Herons [With Note by R. Fortune], loc. cit., pp. 340-341 ;
also Dec., pp. 405-406.

The Witchery of Gilbert White. Nat. June, pp. 199-205.

Cocoons of the Horse Leech, loc. cit. Aug., p. 278.

Whitethorn Seed Notes, loc. czt., pp., 353-355.

Pond Frequenting Birds as Seed Carriers. Journ. Wild Bird Inves.
Soc. No. 1, pp. 1-2.

Hypericum humifusum. Journ. Bot. Aug., p. 225.

W. Wooprvurrr-PEacock. Vertigo pygymea, Drap. Nat. July, p. 245.
Freshwater Sponge, loc.. cit., p. 245.

A. Smita Woopwarp. The Antiquity of Man. Nature. Nov. 6, pp. 212-

213; Nov. 27, p. 335.

B. B. Woopwarp. See A. 8. Kennarp.
H. Wormotp. The ‘Brown Rot’ Diseases of Fruit Trees, with Special

7 oR

Reference to Two Biologic Forms of Monihia cinerea, Bon. Ann.
Bot. July, pp. 361-404.

Hansrortu Wortu. Thirty-Highth Report of the Barrow Committee,

Kistvaens in the Erme Valley. Rep. and Trans. Devon. Assoc.
Vol. LI, p. 79.

H. Bonaparte Wyse. Leucophasia sinapis in Co. Cork. Irish Nat,

July, p. 92.

H. Yarr. The Fenland of East Anglia [Abs.]. Ann. Rep. Proc. Belfast

Nat. F. Club. 1918-19, pp. 21-22.

J. W. Yersury. Seashore Diptera. Journ. Marine Biol. Assoc. July,

pp. 141-145.
List of Diptera Hitherto Recorded from the County of Devon. Rep.
and Trans. Devon, Assoc. Vol. LI., pp. 222-252.

INDEX.

R2Jerences to addresses, reports, and papers printed in extenso are given in italics.
* Indicates that the title only of a communication is given.
+ Indicates reference to publication of a paper, or to the subject thereof, elsewhere.

Absorption Spectra of Organic Com-
pounds, Report of Committee 02, 222.
Adaptation after altered hours of work,
influence of, by Dr. H. M. Vernon,

*371, T382.

Address by the President, Prof. W. A.
Herdman, 1.

Apaie (R. F.), Conduct of the mining
industry, 362.

Agricultural Section :
F. Keeble, 200.

—— zoology of N. Wales, by C. L.
Walton, *379, +383.

Agriculture as a business, by L. Smith
Gordon, 362, +381.

Aircraft, some requirements of modern,
by Sir R. T. Glazebrook, 384.

Airships for slow-speed heavy transport,
by Wing-Commr. T. R. Cave-Browne-
Cave, 365, 7381.

Alberta, on the nature of reserve food
materialsin tissues of plants of northern,
by Miss G. M. Tuttle, *372.

Alcohol and other drugs, mental effect
of, by Miss M. Smith and Dr. W.
MacDougall, *369, +382.

—— industrial, by Capt. A. Desborough,
*353, 7380.

Alkali igneous rocks, origin of, by Dr.
J. W. Evans, *354, 7380.

Autcock (H.), Criticism of majority
report of Roya] Commission on decimal
coinage, *362, 7381.

Aen (Dr. E. J.), in discussion on need
for scientific investigation of fisheries,
#359.

—w— in discussion on need for scientific
investigation of the ocean, *359, +381.

Amino-acids, estimation of, ..., by
Dr. R. V. Stanford, *353.

Amphidinium, exhibition of, by Miss
C. Herdman, *360.

Anemometer for measuring ventilation
in coal-mines, a portable, direct-
reading, by Prof. L. T. Macgregor-
Morris, *364, {381.

Address by Prof.

Anglesey and N. Carnarvonshire, vege-
tation of, by Miss W. H. Wortham, 373.

Animals in the wild state, experimental
studies of, by F. B. Kirkman, *371,
7382.

Annelidan fauna of the Abrolhos Islands,

Affinities of, by Prof. P. Fauvel,
*358.
Anthropological Section: Address by

Prof. K. Pearson, 135.

Apple trees, infection by Nectria ditissima,
Tul., by 8S. P. Wiltshire, *379.

ArsBeEr (Dr. Agnes), Leaves of Irids and
phyllode theory, *372, +382.

Arcella, relations between nucleus, cyto-
plasm, and external heritable charac-
ters in genus, by Prof. R. W. Hegner,
*360, 7381.

Asupy (Dr. T.), Further observations on
Roman roads of central and southern
Italy, 366, 7381.

—— Roman site at Caerwent, *366, 381.

—— Water supply of ancient Rome, 361,
7381.

Aston (Dr. F. W.), Mass spectra and
constitution of ._ chemical elements,
*351, +380.

Atoms, Building-up of, by Sir E. Ruther-
ford, *351.

Auricular flutter, by Dr. T. Lewis, *369.

Babylonia, earliest inhabitants of, by R.
Campbell Thompson, *368, +382.

Baenanit (Sr.), Recent archeological
discoveries in Rome, *366.

Bary (Prof. E. E. C.), on absorption
spectra of organic compounds, 222.

Barcrort (J.), Address to Physiological
Section, 152.

Correlation of properties of
oxygen-carrying power of blood .. .,
#3705.

Bartiett (F. C.), Function of images,
*371.

INDEX.

Barton (Rev. W. J.), Oases_and shotts
of southern Tunis, *361.

Bareson (Prof. W.), on inheritance of
colour in Lepidoptera, 261.

Barner (Dr. F. A.), Address to Geological
Section, 61.

in discussion on Mendelism and
paleontology, 355.

Batuo (Dr. C.), Partition of load in
riveted joints, *364, +381.

Beamisu (A. J.), Deflation and national
balance sheet, 363.

Bepate (Miss E.), Caloric value of
ordinary school meals . . ., *369.

Beinn Laoigh, Vegetation of .. ., by
D. Patton, *374.

Binet-Simon tests, do [they] measure
general ability? by Prof. G. H.
Thomson, *378, +383.

Bruns (H.), Psychological skill in the
wool industry, *371, +382.

Binomial theorem and its interpretation,
‘a new, by Major P. A. MacMahon, *351.

Biochemistry and systematic relation-
ship in the plant kingdom, by Hon.
Mrs. Onslow, 374, +382.

Birds, territory instinct in, by Prof.
C. Lloyd Morgan, *371, +382.

BLacksurn (Miss K. B.), Anomalies in

microspore formation in ‘ Rosa’
. . «, *372, $382.
Brackman (Dr. F. F.), Photosyn-

thesis and carbohydrate metabolism
from point of view of systematic
relationship in plants, 374.

Bratr (Sir R.), Address to Hducation
Section, 191.

Braxiston (C. H.), on training in citizen-
ship, 281.

Blood, correlation
oxygen-carrying power of, . .
J. Bareroft, *375.

Botton (H.), on museums in relation to
education, 267.

Bone (Prof. W. A.), on fuel economy,
248.

Boss (Sir J. C.), Plant autographs. . .,
*375.

Botanical Section: Address by Miss
BE. R. Saunders, 169.

Braae (Prof. W. L.), Crystal structure,
357, +380.

Bray (R. O.), Relation of schools to life,
376, +383.

Bronze Age Implements, Report of Com-
mittee on distribution of, 265.

Bryan (Prof. G. H.), Graphical solution
of spherical triangles, *351.

Burmese skull, preliminary notes on,
by Miss M. L. Tildesley, *366, +381.
Buxton (L. H. D.), Physical anthropo-
logy of ancient Greece and Greek lands,

367, +381.

of properties of
. by

437

Caerwent, Roman site at, by Dr. T.
Ashby, *366, 7381.

Caloric value of ordinary school meals
. . ., by Miss E. Bedale, *369.

Cameroons, Anthropogeograpby of the,
by Capt. L. W. G. Malcolm, *366.

Carbon by combustion in organic com-
pounds . . ., new method for estima-
tion of, by Dr. R. V. Stanford, *353.

Cardiff District, Geology of, by Prof.
A. H. Cox, *354, 7380.

Casson. (8S. C.), Excavations
at Mycenez, 1920, 368, +382.

Cavr - BRowNE-Cave_ (Wing - Commr.
T. R.), Airships for slow-speed heavy
transport, 365, 7381.

CHAMBERLAIN (Prof. C. J.), Origin and
relationship of Cycads, *375, +382.

CuapMan (Prof. 8%.), Terrestrial mag-
netism, aurore, solar disturbance, and
upper atmosphere, *353, +380.

CHARLESWoRTH (Dr. J. K.), Glaciation
of north-west of Ireland, 357.

Curetuam (J. O.), Present supply of
coal and its effects on shipping interests
of Cardiff, *362, +381.

Chemical Section: Address by C. T.
Heycock, 50.

Currrenden (F. J.), Experimental error
in potato trials, *379.

CuopaT (Prof. R.), ... Plant ecology
and biology in Paraguay, *372, +382.
CiapHam (Dr. J, H.), Address to Econo-

mics Section, 114.

CuaRKE (J.), on training in citizenship,
#375.

Cuvee (Dr. J. A.), on museums in relation
to education, 267.

Coal measures ..., paleontology of
Westphalian and lower part of Staf-
fordian series of, by D. Davies, 358.

——, present supply of, and its effects
on shipping interests of Cardiff, by
J. O. Cheetham, *362, +381.

Cotius (8S. H.), Sugar content of straw,
*380.

Cots (Prof. E. L.), Psychology of in-
dustrial convalescence, *371, +382.

Complex and the sentiment, by Dr.
W. H. R. Rivers, *371.

Corn-growing, experiments in intensive,
by Prof. T. Wibberley, *380, +383.

Cornisu (Dr. V.), Imperial capitals, 361,
*381.

Corresponding Societies Committee and
Conference Report, 391.

Cortig (Rey. A. L.), Comparison of
drawings of solar facule and photo-
graphs of calcium flocculi, *351, +380.

Cox (Prof. A. H.), Geology of Cardiff
district, *354, +380.

Cramp (Prof. W.), Pneumatic conveying
of materials, *365, 381.

438

Credit: inflation and prices, by A. H.
Gibson, 362, +381.

Crompton (Col. R. E.), Cutting edges of
tools, #363, +381.

Crystal structure, by Prof. W. L. Bragg,
357, 7380.

Currant moth, preliminary account of
hereditary transmission of a
marking in forewing of, by Prof. E. B.
Poulton, *360.

Cycads, origin and relationship of, by
Prof. C. J. Chamberlain, *375, 382.

Danish credit corporations, by J. Lassen,
362.

Davigs (D.), Paleontology of Westpha-
lian and lower part of Staffordian
series of coal measures. . ., 358.

Davies (Dr. H. Walford), Euphony and
folk music, *369, +382.

Decimal coinage, criticism of majority
report of Royal Commission on, by
H. Allcock, *362, +381.

Deflation and national balance sheet, by
A. J. Beamish, 363.

Denpy (Prof. A.), in discussion on
Mendelism and paleontology, *356.
DesporoucH (Capt. <A.), Industrial
alcohol, *353, +380.
Descu (Prof. C. H.),

tungsten, *353.

Devon, geological structure of north, by
Dr. J. W. Evans, 357.

Dinorben, Willoughby Gardner on excava-
tions in, 262.

Dossts (Sir J. J.), on absorption spectra
of organic compounds, 222.

Doopson (Dr. A. T.), on harmonic pre-
diction of tides, 321.

Dreams of children who are physically
abnormal, by Dr. C. W. Kimmins, *378.

DourrpEN (Prof. J. E.), A caudal vesicle
and Reissner’s fibre in the ostrich, *359.

—— in discussion on Mendelism and
palzontology, 355.

in discussion on need for scientific

investigation of the ocean, *359, 381.

The pineal eye in the ostrich,
*359, T3811.

DunkrrRLEyY (G. D.), on
citizenship, 281.

Dunstan (A. E.), in discussion on lubri-
cation, *353.

Dynamical method of raising gases to
high temperatures, by Prof. W. H.
Watkinson, *364, +381.

Metallurgy of

training in

Earuanp (A.) and E. Herron-Atien,
Protoplasm and pseudopodia, *359.
Earning, future of, by Mrs. Wootton,

363.

INDEX.

Easter Island, Statues of, by Dr. W. H. R.
Rivers, 366, $381.

Economics Section :
J. H. Clapham, 114.

Eppryeton (Prof. A. S.), Address to
Mathematical and Physical Section, 34.

Epaz (8. F.), Farm tractors, 363, {381.

EpRIDGE-GREEN (Dr. F. W.), Prevention
of myopia, 370.

Education, higher technical schools in
national system of, by J. C. Maxwell
Garnett, 379, +383.

public schools in national system

of, ky F. Fletcher, *378, 7383.

Section: Address by

Blair, 191.

tendency towards individual, by

Prof, T. P. Nunn, 378.

training colleges in national

system of, by Miss H. M. Wodehouse,

378, $383.

universities in national system
of, by Rt. Hon. H. A. L. Fisher,
*378, $383.

Egypt, recent work in, by Prof. W. M.
Flinders Petrie, *368, +382.

Syria, and Babylonia, early con-
nections between, by P. E. Newberry,
*368.

Electrokymograph, a new, by Prof. J. B.
Haycraft, *370.

Electromotive Phenomena in Plants, Re-
port of Committee on, 266.

Emotive response of the human subject,
by Prof. A. D. Waller, *369.

Energy of human machine as measured
by output of carbon dioxide, by Prof.
A. D. Waller, *370.

Engineering Section :
C. F. Jenkin, 125.

Eocene strata of Anglo-Franco-Belgian
basin, Cycles of sedimentation in, by
L. Dudley Stamp, 357, +380.

Euphony and folk music, by Dr. H.
Walford Davies, *369, 7382.

Evans (D. C.), Ordoviceo-Valentian
succession in north-east Pembroke-
shire and north Carmarthenshire, *358.

Evans (Dr. J. W.), Geological structure
of north Devon, 357.

Origin of alkali igneous rocks,
*354, 7380.

EversHeD (J.), Measures of shifts of
Fraunhofer lines and their interpreta-
tion, *351, 7380.

Address by Dr.

Sir R.

Address by Prof.

Faaan (T. W.), in discussion on soil and
plant survey work, *374.

Farm tractors, by 8. F. Edge, 363, +381.

Fauvet (Prof. P.), Affinities af the
Annelidan fauna of the Abrolhos
Islands, *358.

INDEX.

Feuerbach’s theorem, ls there in space

of three dimensions an analogue to
?. .., by T. C. Lewis, *851, 380.

Firtp (8.), Electrolytic zine, *353.

Finpes (Miss L. C.), Word-blindness in
the mentally defective, *370.

Fisuer (E. A.), Soil acidity, *373, +382.

FisHer (Rt. Hon. H. A. L.), Universities
in national system of education, *378,
+383.

Fisheries, discussion on need for scientific

- investigation of, *359.

FLEetTcHER (F.), Public schools in national
system of education, *378, +383.

Firvure (Prof. H. J.), Scheme of Welsh
department of Board of Education for
collection of rural lore through agency
of schools, *368.

The Welsh people : physical types,
366, +381.

Floras in 8.E. Asia, distribution of, . .
by Kingdon Ward, *375.

Fow.er (Prof. A.), in discussion on
origin of spectra, *351.

Fraunhofer lines, measurements of shifts
of, and their interpretation, by J.
Evershed, *351, +370.

Fruit tree stocks, by R. G. Hatton, *379,
7383.

Fuel Economy, Report of Committee on,

Function of images, by F. C. Bartlett,
*371.

Fungi of N. Wales, parasitic,
Whitehead, *379.

by T.

Garpiner (Prof. J. Stanley), Address to
Zoological Section, 87.

— in discussion on need for scientific
investigation of fisheries, *359.

— in discussion on need for scientific
investigation of the ocean, *359, 381.

GARDNER (Willoughby), on excavations
in Dinorben, 262.

Garrirt (G. A.), Rock sculptures from
Eyam Moor. . ., *369, +382.

GarnetT (J. C. Maxwell), Higher tech-
nical schools in national system of
education, 379, +383.

Garstane (A. H.), Railways and their
obligations to the community, *404.

Garstane (Prof. W.), in discussion on
need for scientific investigation of
fisheries, *359.

Gates (Dr. R. R.), in discussion on
Mendelism and paleontology, 355.

Geographical Section: Address by J.
McFarlane, 98.

Geography in a reformed classical course,
place of, by Prof. J. L. Myres, 377.

Geological ‘Section : Address by Dr. F. A.
Bather, 61.

439

Geotropism of foliage leaves . .
Dr. H. Wager, *372.
Gipson (A. H.), Credit:

prices, 362, +381.

Giuson (Prof. G.), in discussion on need
for scientific investigation of fisheries,
#359.

GimmineHam (C. T.), in discussion on
soil and plant survey work, *374.

Glaciation of north-west of Ireland, by
Dr. J. K. Charlesworth, 357.

GLAZEBROOK, Sir R. T., Some require-
ments of modern aircraft 384.

Gorpon (L. Smith), Agriculture as a
business, 362, +381.

Graphical solution of spherical triangles,
by Prof. G. H. Bryan, *351.

Greece, ancient, and Greek lands, physi-
cal anthropology of, by L. H. D.
Buxton, 367, 7381.

GREEN (Prof. J. A.), on museums in
relation to education, 267.

Greenland in Europe, by D. MacRitchie,
#369, 1382.

Grirritus (Dr. E. H.), and Major E. O
Henrict, Need for central institution
for training and research in , . . sur-
veying, hydrography, and geodesy,
346.

Grucuy (G. B. de), on paleolithic site in
Jersey, 265.

Guadiana, removal of reefs in Rio, by
Dr. J. S. Owens, 365, $381.

Gun, indicator diagram of a, by Sir
J. B. Henderson and Prof. H. R.
Hassé, *364.

+ by

inflation and

Hatt (Sir A. D.), A grain of wheat from
the tield to the table, 388.

—— in discussion on soil and plant
survey work, *374.

Hass& (Prof. H. R.), and Sir J. B.
HENDERSON, Indicator diagram of a

gun, *364.
Harton (R. G.), Fruit tree stocks, *379,
$383.

Haycrart (Prof. J. B.), A new electro-
kymograph, *370.

Hazuirr (Miss V.), Conditions of learning
compared in men and rats, *371.

HeaGner (Prof. R. W.), Relations between
nucleus, cytoplasm, and external heri-
table characters in genus Arcella,
*360, {381.

Henperson (Sir J. B.), and _ Prof.
H. R. Hassk, Indicator diagram of a
gun, *364.

Henrict (Major BE. O.), and Dr. E. H.
Grirritus, Need for central institution
for training and research in... sur-
veying, hydrography, and geodesy,
346,

440

Henry (Prof. A.), Artificial production
of vigorous trees, *380, {383.

Herrpman (Miss C.), exhibition of Amphi-
dinium, *360.

Herpman (Prof. W. A.), Presidential
Address, 1.

in discussion on need for scientific
investigation of the ocean, *359, 7381.

Heron (C.), in discussion on need for
scientificinvestigation of fisheries,*359.

Heron-AtLen (E.), and A. EARLAND,
Protoplasm and Pseudopodia, *359.

Herring (Prof. P. T.), Effect of preg-
nancy on organs of the white rat, *369,
7382.

Hey (S.), Supply of teachers, 375.

Heycockx (C. T.), Address to Chemical
Section, 50.

Hill-fort at Ilkley, excavations on a,
by Prof. A. M. Woodward, *366.

Hinton (Prof. H.), Plane algebraic curves
of degree » with multiple point of
order n-l]. . ., *351.

Horne (Dr. J.), on Old Red Sandstone
rocks at Rhynie, 261.
Horton (Prof. F.) and Miss A. C. Davtss,
Jonisation of atmospheric neon, 352.
Howe (Prof. G. W. O.), Efficiency of
transmitting aérials. . ., *365, 381.
Hupson (A. E. L.), Methods of using
ordnance maps in school teaching, *361.

Hydrion concentration in stem and root,
further evidence for differentiation
in, . .. by Prof. J. Small and Miss
W. Rea, *372, 7382.

Imperial capitals, by Dr. V. Cornish, 361,
7381.

Industrial fatigue, phenomena of, by
Prof. F. S. Lee, *371, +382.

Interferometer, new type of, by H. P.
Waran, *353.

Internal-combustion engine, high-speed,
for research, by H. R. Ricardo, *364,
7381.

Internal-combustion engines, specific
heat and dissociation in, by H. T.
Tizard and D. R. Pye, *364, 7381.

International intellectual relations, by
Dr. V. Naser, 377.

Irids and phyllode theory, leaves of, by
Dr. Agnes Arber, *372, $382.

Jer (Dr. E. C.), Movement of the sea,
*361, 7381.

JENKIN (Prof. C. F.), Address to Engineer-
ing Section, 125.

JENKN (T. J.), in discussion on soil and
plant survey work, *374.

INDEX.

Jersey, Report of Committee on excava-
tion of paleolithic site in, 265.

Jounston (Lt.-Col. W. J.), Small-scale
maps of United Kingdom, 360.

JOHNSTONE (Prof. J.), in discussion on
need for scientific investigation of
fisheries, *359.

Kalahari and possibilities of its irrigation,
by Prof. E. H. L. Schwarz, 361, 7381.

Kees.e (Prof. F.), Address to Agricul-
tural Section, 200.

Kerr (W.), and Prof. A. L. MeLtiansy,
Steam action in simple nozzles, 364,
7381.

Kipner (H.), Round barrows in New
Forest... . ., *368, +382.

Kiwis (Dr. C. W.), Dreams of children
who are physically abnormal, *378.
Kireman (IF. B.), Experimental study

of animals in the wild state, *371, $382.

Kororn (Prof. C. A.), Exhibition of plates
for monograph of the unarmoured
Dinoflagellates, *360.

Hookworm and human efficiency,

+360.

in discussion on need for scienti-

fic investigation of the ocean, *359,

7381.

Neuro-motor system of ciliate and

flagellate protozoa . . ., *359.

Lams (Prof. H.), on tidal institute at
Liverpool, 321.

Laminariacez, alternation of generations
in, by Prof. J. Lloyd Williams, *372.
Larsen (J.), Danish credit corporations,

362.

Lea (Prof. F. C.), Testing materials at
high temperatures, *363, 7381.

Learning compared in men and rats,
conditions of, by Miss V. Hazlitt, *371.

Lee (Prof. F. S.), Phenomena of indus-
trial fatigue, *371, 7382.

Lepidoptera, Report of Committee on
experiments in inheritance of colour
in, 261.

Lewis (Prof. F. J.), Distribution of
vegetation types in eastern Canadian
Rocky Mountains, *374.

Lewis (Dr. T.), Auricular flutter, *369.

Relation of physiology to medi-
cine, *369, 382.

Lewis (T. C.), Is there in space of three
dimensions an analogue to Feuer-
bach’s theorem. . . ? *351, 7380.

Lewis (Prof. W. C. McC.), in discussion
on lubrication, *353.

Liassic rocks of Somersetshire, by Dr.
A. E. Trueman, 356. i

INDEX.

Life on the earth, continuance of, by
Prof. W. M. Flinders Petrie, 356.

Linecar (A.), Relation of schools to life,
376, +383.

Lioyp (Capt. H. A.), Pictorial factor in
aérial map design, *361.

Luioyp (J. H.), Early development of the
pronephros in Scyllium, *359.

Lopge (Sir O.), Controversial note on
popular relativity, 352, +380.

‘Louts (Prof. H.), on fuel economy, 248.

Lubrication, discussion on, *353.

Macpovucatt (Dr. W.), and Miss M.
Smiry, Mental effect of aleohol and
other drugs, *369, +382.

McFaruane (J.), Address to Geographical
Section, 98.

Macerrcor-Morris (Prof. J. T.), Por-
table, direct-reading anemometer for
measuring ventilation in coal-mines,
*364, 7381.

Mackie (Dr. W.), on Old Red Sandstone
rocks at Rhynie, 261.

MacManon (Major P. A.), New bino-
mial theorem and its arithmetical
interpretation, *351.

MacRirtcnte (D.), Greenland in Europe,
*369, 1382.

McTavisu (J. M.), Relation of schools to
life, 376, 7383.

Magnetism and structure of the atom, by
Dr. A. E. Oxley, *353, 7380.

Matcotm (Capt. L. W. G.), Anthropo-
geography of the Cameroons, *366.
Manuring of light soils, green, by Capt.

H. J. Page, *380, 7383.

Map design, pictorial factor in aérial, by
Capt. H. A. Lloyd, *361.

Maps of the United Kingdom, small-
scale, by Lt.-Col. W. J. Johnston, 360.

, ordnance, methods of using, in
school teaching, by A. E. L. Hudson,
*361.

Marett (Dr. R. B.), on paleolithic site
in Jersey, 265.

Marquanp (C. B. V.), Varieties of oats,
*380.

Martineau (P. E.), Records of growth
of pit-mound plantations, *374, +382.

Mass spectra and constitution of chemical
elements, by Dr. F. W. Aston, *351,
*380.

Mathematical and Physical Section :
Address by Prof. A. S. Eddington, 34.

Maorice (H. G.), in discussion on need
for scientific investigation of fisheries,
*359.

Meek (Prof. A.), in discussion on need
Sy scientific investigation of fisheries,

359.

441

Meek (Prof. A.), Physiology of migra-
tion, *359, 7381.

Mexuansy (Prof. A. L.), and W. Kerr,
Steam action in simple nozzles, 364,
7381.

Mendelism and paleontology, discussion
on, 354,

Mental tests in American universities,
by Prof. Agnes Rogers, *371, 7382.

Microspore formation in * Roas 0RGt
Anomalies in, by Miss K. B. Black-
burn, *372, 7382.

Migration, Physiology of, by Prof. A.
Meek, *359, 7381.

Mines (Dr. G. H.),. . . National institute
of applied psychology, *371.

Mining industry, conduct of, by R. F.
Adgie, 362.

Modern Londoner and the long barrow
man, by Prof. F. G. Parsons, *366.

Monp (R.), on fuel economy, 248.

Morean (Prof. C. Lloyd), Territory
instinct in birds, *371, 7382.

Morison (C. G. T.), in discussion on soil
and plant survey work, *374.

Motya, N.-W. Sicily, excavations at, by
J. Whitaker, *368, 7382.

Museums in Relation to Education,
Report of Committee on, 267.

Mycene, excavations of the British
school at Athens at, 1920, by 8. C.
Casson, 368, +382.

Myers (Dr. C. S.), Independence of
psychology, *369, 7382.

Myopia, prevention of, by Dr.
Edridge-Green, 370.

Myres (Prof. J. L.), on distribution of
Bronze Age implements, 265.

Place of geography in a reformed

classical course, 377.

F. W.

Naser (Dr. V.), International intellec-
tual relations, 377.

Negae (Mr.), in discussion on need for
scientific investigation of fisheries,
#359.

Neon, Tonisation of atmospheric, by Prof.
F. Horton and Miss A. C. Davies,
352.

Neuro-motor system of ciliate and
flagellate protozoa . . ., by Prof. C. A.
Kofoid, *359.

Newserry (P. E.), Early connections
between Egypt, Syria, and Babylonia,
*368.

New Forest, round barrows in,. .
H. Kidner, *368, 7382.

Nicuonson (Prof. J. W.), in discussion
on origin of spectra, *351.

Nova Aquile III., Spectra of, by Lt.-Ccl.
F. J. M. Stratton, *351, 7380.

suby.

442

Nunn (Prof. T. P.), Tendency towards
individual education, 378.

Nourratt (Prof. G. H.), Precipitive
reactions as means of determining
systematic relationships in animals and
plants, *375.

Oats, varieties of, by C. B. V. Marquand,
#380.

Ocean, discussion on need for scientific
investigation of the, *359, 381.

Oaitvis (Sir F.), in discussion on need
for scientific investigation of the ocean,
*359, 7381.

Old Red Sandstone of Mitcheldean district,
Gloucestershire, by Dr. T. F. Sibly, 356.

Oligocheta, Polyphyletic origin of genera
in,. . ., by Prof. J. Stephenson, *358.

Onstow (Hon. H.), on. inheritance of
colour in Lepidoptera, 261.

Onstow (Hon. Mrs.), Biochemistry and
systematic relationship in the plant
kingdom, 374, +382.

Orchard survey of west of England, by
Capt. R. Wellington, *379.

Ordoviceo-Valentian succession in north-
east Pembrokeshire and north Car-
marthenshire, by D. C. Evans, *358.

Ostrich, a caudal vesicle and Reissner’s
fibre in the, by Prof. J. E. Duerden,
#359.

Pineal eye in, by Prof. J. E.
Duerden, *359, +381.

Ovambo, The, by Prof. E. H. L. Schwarz,
*366.

Owens (Dr. J. 8.), Removal of reefs in
Rio Guadiana, 365, +381.

Oxuny (Dr. A. E.), Magnetism and struc-
ture of the atom, *353, +380.

Pace (Capt. H. J.), Green manuring of
light soils, *380, +383.

Paraguay,. . . plant ecology and biology
in, by Prof. R. Chodat, *372, +382.

Parsons (Prof. F. G.), Modern Londoner
and the long barrow man, *366.

Partition of load in riveted joints, by
Dr. C. Batho, *364, +381.

Parrerson (A.), on training in citizen-
ship, *375.

Parton (D.), Vegetation of Beinn Laoigh
RitrntO7 4:

Praxe (H. J. E.), on distribution of
Bronze Age implements, 265.

on Roman sites in Britain, 262.

PEARSON (Prof. K.), Address to Anthropo-
logical Section, 135.

Perris (Prof. W. M. Flinders), Continu-
ance of life on the earth, 356.

Recent work in Egypt, *368, +382.

INDEX.

Phosphates, experiments with rock, by
G. 8. Robertson, *380, +383.

Photosynthesis and carbohydrate meta-
bolism from point of view of systematic
relationship in plants, 374.

Physiological Section: Address by J.
Barcroft, 152.

Physiology to medicine, relation of, by
Dr. T. Lewis, *369, +382.

Pit-mound plantations, records of growth
of, by P. E. Martineau, *374, +382.

Plane algebraic curves of degree n with
multiple point of order n-l ..., by
Prof. H. Hilton, *351.

Plant autographs. . ., by Sir J. C. Bose,
*375.

electricity, by Prof. A. D. Waller,
*369.

Pliocene flora, history of west European,
..., by Mrs. E. M. Reid, *372, +382.
Pneumatic conveying of materials, by

Prof. W. Cramp, *365, 7381.

Potatoes, wart. disease in, by H.. V.
Taylor, *379, +383.

Potato trials, experimental error in, by
F. J. Chittenden, *379.

Poutton (Prof. E. B.), Preliminary
account of hereditary transmission of
a... marking in forewing of currant

moth, *360.

Precipitive reactions as means of deter-
mining systematic relationships in
animals and plants, *375.

PripEAux (Dr. E.), A psychologist’s
attitude towards telepathy, *371.

Protoplasm and Pseudopodia, by E.
Heron-Allen and A. Earland, *359.

ProupmMan (Prof. J.), on harmonic
analysis of tidal observations in the
British Empire, 323.

Psychologist’s attitude towards tele-
pathy, by Dr. E. Prideaux, *371. f

Psychology, . . . a national institute of
applied, by Dr. G. H. Miles, *371.

—— an independent section of, by
Dr. W. H. R. Rivers, *369.

—— independence of, by Dr. C. S.
Myers, *369, +382.

—— of industrial convalescence, by
Prof. E. L. Collis, *371, +382.

of industrial. life aeibys is.
Wyatt, * 371, 7382.

Pye (D. R.), and H. TT. Tizarp,
Specific heat and dissociationininternal-
combustion engines, *364, 381.

Radio-telegraphy, efficiency of trans-
mitting aérials,and powe rrequired for
long-distance, by Prof. G. W. O.
Howe, *365, +381.

Railways and their obligations to th
community, by A. H. Garstang, *404

INDEX.

Rat, effect of pregnancy on organs of
white, by Prof. P. T. Herring,*369,+382.

Rea (Miss W.), and Prof. J. SMstt,. . .
Differentiation in hydrion concentra-
tion in stem and root. . ., *372, +382.

Reagan’ (C. Tate), in discussion on need
for scientific investigation of fisheries,
*359.

in discussion on need for scien-
tific investigation of the ocean, *359,
7381.

Rerp (Mrs. E. M.), History of west Euro-
pean Pliocene flora . . ., *372, +382.
Relativity, Controversial note on popular,

by Sir O. Lodge, 352, +380.

Rhynie, Report of Committee on Old Red
Sandstone Rocks at, 261.

Ricarpo (H. R.), High-speed internal
combustion engine for research, *364,
7381.

Rivceway (Sir W.), on Roman sites in
Britain, 262.

Rivers (Dr. W. H. R.), An independent
section of Psychology, *369.

Statues of Easter Island, 366, +381.

The complex and the sentiment,

Roserts (R. Alun), in discussion on soil
and plant survey work, *374.

Rosertson (G. 8.), Experiments with
rock phosphates, *380, 383.

Rosson (G. W.), Soil types of north
Wales, 373, 382.

Rock sculptures from Eyam Moor.. .,
by G. A. Garfitt, *369, 7382.

Rocky Mountains, Distribution of vegeta-
tion types in eastern Canadian, by
Prof. F. J. Lewis, *374.

Rogers (Prof. Agnes), Mental tests in
American universities, *371, 1382.

Roman roads of central and southern
Italy, further observations on, by Dr.
T. Ashby, 366, +381.

Roman Sites in Britain, Report of Com-
mittee on, 262.

Rome, recent archzxological discoveries
in, by Sr. Bagnani, *366.

Rural lore through agency of schools,
scheme of Welsh department of Board
of Education for collection of, by
Prof. H. J. Fleure, *368.

Russett (Dr. E. J.) in discussion on
soil and plant survey work, *374.

Routuerrorp (Sir E.), Building-up of
atoms, *351.

Salts on growth, influence of, by Dr. C.
Shearer, *359.

Saunpers (Miss E. R.),
Botanical Section, 169.

Schools to life, papers on relation of, 376,
$383.

Address to

443

Scuwarz (Prof. E. H. L.), The Kalahari
and. .. its irrigation, 361, {381.

The Ovambo, *366.

Scyllium, early development of the pro-
nephros in, by J. H. Lloyd, *359.

Sea, movement of the, by Dr. E. C. Jee,
*361, 381.

Seismological Investigations,
Committee on, 215.

Suaw (J. J.) on seismological investiga-
tions, 217, 218.

SHaw (Lady) on training in citizenship,
281.

Suaxsy (J. H.), Vapour pressures, *353.

SHEARER (Dr. C.), Influence of salts on
growth, *359.

SHEPPARD (T.), Address
of Delegates, 391.

List of papers on zoology. botany,
and prehistoric archeology of the British
Isles, 406.

Srpty (Dr. T. F.), Old Red Sandstone of
Mitcheldean district, 356.

SMALL (Prof. J.), and Miss W. RBA,. ..
Differentiation in hydrion concentra-
tion in stem and root. . ., *372, +382.

Smit (F. E.), in discussion on need for
scientific investigation of the ocean,
*359, 7381.

Situ (Miss M.), and Dr. W. McDouGatL,
Mental effect of alcohol and other
drugs, *369, 7382.

Soap films, thickness of stratified, by
Dr. P. V. Wells, *353.

Soil acidity, by E. A. Fisher, *373, +382.

and plant survey work, discussion

on, 373, *374, $382.

types of north Wales, by G. W.
Robinson, 373, +382.

Solar facule and photographs of calcium
floceuli, Comparison of drawings of, by
Rev. A. L. Cortie, *351, +380.

SoutHcomve (J. E.), in discussion on
lubrication, *353.

South Wales. coalfields, geographical
aspects of distribution of population
on, by D. Lleufer Thomas, 360, +381.

iron industry of, by Dr. A. E.
Trueman, 360, 7381.

Spectra, Discussion on origin of, *351.

Stamp (L. Dudley), Cycles of sedimenta-
tion in Eocene strata of Anglo-Franco-
Belgian basin, 357, +380.

StanForp (Dr. R. V.), Estimation of
amino-acids . . ., *353.

New method for estimation of
carbon by combustion in organic com-
pounds. . ., *353.

SrarLepon (Prof. R. G.), Surveys of
grassland districts, 373.

Steam action in simple nozzles, by Prof.
A. L. Mellanby and W. Kerr, 364,
7381.

Report of

to Conference

444 INDEX.

SrepHEeNnson (Prof. J.), Polyphyletic | Tunis, oases and shotts of southern, by
origin of genera in the Oligocheta. . ., Rev. W. J. Barton, *361.
*358. Turner (Prof. H. H.), on seismological

Strarron (Lt.-Col. F. J. M.), Spectra of
Nova Aquile III., *351, +380.

Straw, sugar content of, by 8. H. Collins,
*380.

STRUDWICK (Miss), Relation of schools to
life, *377, +383.

Sugar in blood, estimation of, by Miss
H. Walker and others, 369, 370.

Surveying, hydrography and geodesy, The
urgent need for the creation within the
empire of a central institution for train-
ing and research in the sciences of, by
Dr. E. H. Griffiths and Major E. O.
Henrici, 346.

Surveys of grassland districts, by Prof.
R. G, Stapledon, 373.

Taytor (H. V.), Distribution of wart
disease in potatoes, *379, +383.

Teachers, supply of, by 8. Hey, 375.

Terrestrial magnetism, aurore, solar dis-
turbance, and upper atmosphere, by
Prof. S. Chapman, *353.

Testing materials at high temperatures,
by Prof. F. C. Lea, *363, +381.

Tuomas (D. Lleufer), Geographical aspect
of distribution of population on §&.
Wales coalfield, 360, +381.

Tuomas (Dr. Ethel), in discussion on soil
and plant survey work, *374.

THompson (R. Campbell), Earliest in-
habitants of Babylonia, *368, +382.

Txomson (Prof. G. H.), Do the Binet-
Simon tests measure general ability ?
*378, $383.

Tidal Institute at Liverpool, Report of
Committee on, 321.
Titprestey (Miss M. L.), Preliminary
notes on Burmese skull, *366, +381.
Tizarp (H. T.) and D. R. Pysx, Specific
heat and dissociation in internal-com-
bustion engines, *364, 7381.

Tizarp (H. T.), in discussion on lubrica-
tion, *353.

Tools, cutting edges of, by Col. R. EK.
Crompton, *363, +381.

Training in Citizenship, Report of Com-
mittee on, 281; discussion, *375.

Trees, artificial production of vigorous,
by Prof. A. Henry, *380, 7383.

Trouton (R.), Liquidation of inter-
national debts, 363, +381.

Trueman (Dr. A. E.), Tron industry of
S. Wales, 360, 7381.

—— Liassic rocks of Somersetshire,
356.

Tungsten, Metallurgy of, by J. L. F.
Vogel and Prof. C. H. Desch, *353.

investigations, 215.

TuttLe (Miss G. M.), On the nature of
reserve food materials in tissues of
plants of northern Alberta, *372.

Ultra-micrometer, the, by Prof. R.
Whiddington, *351, +380.

Vapour pressures, by J. H. Shaxby, *353.

Vernon (Dr. H. M.), Influence of adapta-
tion after altered hours of work, *371,
$382.

Vocational selection, problems of, by
F. Watts, *371, 7382.

VogeEn (J. L. F.), Metallurgy of tungsten,
*353.

Wacer (Dr. H.), Geotropism of foliage
leaves... ., *372.

WALKER (Miss H., &c.), Estimation of
sugar in blood, *369.
Waturr (Prof. A. D.), Electromotive

phenomena in plants, 266.

—— Emotive response of the human
subject, *369.

—— Energy of human machine as
measured by output of carbon dioxide,
*370.

—— Plant electricity, *369.

Warton (C. L.), Agricultural zoology of
N. Wales, *379, +383.

Waran (H. P.), New type of interfero-
meter, *353.

Warp (K.), Distribution of floras in
S. EB.) Asia. aciiss: F375! :

Warxinson (Prof. W. H.), Dynamical
method of raising gases to high tem-
peratures, *364, 7381.

Warts (F.), Problems of vocational selec-
tion, *371, +382.

WELLDON (Rt. Rev. Bishop), on training
in citizenship, 281; in discussion, *375.

WELLINGTON (Capt. R.), Orchard. survey
of west of England, *379.

WEeLLs (H. M.), in discussion on lubrica-
tion, *353.

WELLts (Dr. P. V.), Thickness of stratified
soap films, *353.

Welsh people: physical types, by Prof.
H. J. Fleure, 366, 7381.

—— traditional music,
Lloyd Williams, *369.

Wheat from the field to the table, a

grain of, by Sir A. D. Hall, 388.

Wuipprineton (Prof. R.), The ultra-
micrometer, *351, 380.

by Prof. J.

EE ————E——=- Se

=o =

> __ an

bine

INDEX.

Wnuitaker (J.), Excavations at Motya,
N.-W. Sicily, *368, +382.

WuHiItTakER (W.), Status of local societies,
*404.

Wuirrnnap (T.), Parasitic fungi of N.
Wales, *379.

WisBERLEY (Prof. T.), Experiments in
intensive corn-growing, *380, +383.

Wuu1aMs (Prof. J. Lloyd), Alternation
of generations in Laminariacez, *372.

in discussion on soil and plant

survey work, *374.

Welsh traditional music, *369.
Wutsurre (8. P.), Infection of apple
trees by Nectria ditissima, Tul., *379.
Wopeuouse (Miss H. M.), Training col-
leges in national system of education,

378, $383.

NP nee,

1920

AL HisT®

445

Woopwarp (Prof. A. M.), Excavations
on a hill fort at Ilkley, *366.

Wool industry, psychological skill in, by
H. Binns, *371, 382.

Woorton (Mrs.), Future of earning,
363.

Word-blindness in the mentally defective,
by Miss L. C. Fildes, *370.

Wortnam (Miss W. H.), Vegetation of
Anglesey and N. Carnarvonshire . .
373.

Wvyarrt (8.), Psychology of industrial life
«ina POUL, F382.

=3,

Zine, electrolytic, by S. Field, *353.
Zoological Section: Address by Prof. J.
Stanley Gardiner, 87.

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Testing ~materials at sh

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Colloid Chemistry and its General and Industrial Applications.—-
Third Report of the Committee consisting of Professor F. G.
Donnan (Chairman), Professor W. C. McC. Lewis (Secretary),
Dr. E. ArpErRN,* Dr. E. F. Armstrone, Professor W. M.
Bayttss and the late Professor A. J. Brown, Mr. W. Ciayton,*
Dr. C. H. Descu, Mr.W. Harrison, Mr. E. Hatscuex, Professors
H. R. Proctor and W. RamspeEn, Dr. E. J. RussEexyu, Mr.
A. B. Searzte,* Dr. S. A. SHortER, Dr. H. P. STEVENs, and
Mr. H. B. Srocks.

INTRODUCTION.

Tue plan already adopted in the two previous Reports of arranging
the subject matter under two heads, viz.: (1) classification according
to scientific subject; and (2) classification according to industrial
process, has been employed in the present Report.

The subjects dealt with under the first head in the accompanying
Report are :—

2.
3.

4.
5.

CoLtLoip CHEMISTRY OF Soap, Parr I.—SoxvutTions. By
Professor J. W. McBain.

Uurramicroscopy. By G. King, M.Sc., F.L.C.

SOLUBILITY OF GASES IN CoLLorDAL SoLuTions. By G. King,
M.S8c., F.I.C.

ELECTRICAL CHARGE ON CoLuoIps. By J. A. Wilson.
Imprpition oF Gets, PartI. By J. A. Wilson.

The subjects dealt with under the second head are :—

IMBIBITION OF GELS, Part IJ.—INDUSTRIAL APPLICATIONS.
By J. A. Wilson.

. Cottotp PROBLEMS IN Breap-Maxkine. By R. Whymper.

. COLLOID CHEMISTRY IN PHoToGcRAPHY. By Dr. R. E. Slade.
. COLLODION IN PHoToGRAPHY. By H. W. Greenwood.

. CELLULOSE EstEerRS. By Foster Sproxton, B.Sc., F.I.C.

. CoLLoID CHEMISTRY OF PETROLEUM. By Dr. A. E. Dunstan.
. AspHALT. By Clifford Richardson, M.Am.Soc., C.E., F.C.S.

. VARNISHES, PaInts, AND Piaments. By Dr. R. 8S. Morrell.

. Cuays AND Cray Propucts. By A. B. Searle.

The Committee has again to express its sense of obligation to the
authors of the sections enumerated above.

A number of subjects yet remain to be considered. It is hoped
that these will be dealt with in the Fourth Report.

W. C. McC. Lewis.

* Names so marked are those of Assessors or Consultative Members, not
being Members of the Association.

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COLLOIDAL CHEMISTRY OF SOAP.
PART I.—SOLUTIONS.

By J. W. McBatn, Leverhulme, Professor of Physical Chemistry,
University of Bristol.
I.— Brief Résumé.

Recent investigations of aqueous soap solutions culminating in
1914, have revealed soaps as a prototype of a great class of colloids
remarkable alike for their theoretical interest and their industrial
importance. The substances belonging to this class have been defined
by McBain and Salmon?‘ as “ colloidal electrolytes.”

Colloidal electrolytes are salts in which one of the ions has been
replaced by a heavily charged, heavily hydrated ionic micelle which
exhibits equivalent conductivity that is not only comparable with
that of a true ion but may even amount to several times that of the
simple ions from which it has been derived. In other words, this
ionic micelle is a typical but very highly charged colloidal particle
of very great conductivity.

The conductivity of such a colloidal electrolyte is quite comparable
with that of an ordinary electrolyte. On the other hand since the
ionic micelle exhibits only the osmotic effect characteristic of an
ordinary colloid, the total osmotic activity of the colloidal electrolyte
is correspondingly deficient and may be distinctly less than that of
a non-electrolyte. Thus high conductivity goes hand in hand with
only moderate osmotic effects.

Some of the very numerous substances which must be recognised
as belonging to this group are the protein and gelatine salts
(T. Brailsford Robertson’s well-known alternative hypothesis, which
is to the effect that there are no ordinary ions present, but that the
protein salts ionise into two colloidal ions resembling ordinary slow
complex ions, appears to have been built up upon early E.M.F. data
which Pauli, Manabe, and Matuli have since shown to be erroneous),
dyes, such as Congo-red, indicators, the higher sulphonic acids and
hydrochlorides, tellurates and many inorganic substances; in fact,
most substances of high molecular weight or containing long carbon
chains which are capable of splitting off an ordinary ion.

The soaps are a particularly interesting case for investigation
in that their chemical formule are well ascertained, tautomerism
does not occur, true reversible reproducible equilibrium is established
in all solutions, and finally the definite transition from typical simple
electrolyte through colloidal electrolyte to neutral colloid may be
observed in all its stages. This transition from crystalloid to colloid
is exhibited not only in passing from salts of the lower to those of
the higher fatty acids, but may be demonstrated in any one of the
higher members merely upon change of temperature and concentration.

This striking and wholly unexpected combination of properties
on the part of the ionic micelle, was plausibly explained in 1913 by
the writer, on mechanical grounds. This conception is based upon
the consideration of the application of the principle contained in

Stokes’ Law, that the frictional resistance to motion of a definite
amount of substance depends directly upon its degree of subdivision.
Thus, if say ten simple palmitate ions unite to form one single particle
carrying ten electrical charges, the resistance to movement under the
action of the electric current is considerably diminished and therefore
one should expect greatly enhanced conductivity. This is, indeed,
observed to a very appreciable extent in some cases, but it is partly
off-set by the action of this enormous aggregation of electrical charges
in condensing upon the particle large amounts of water and, indeed,
any other constituent available in the solution such, for example, as
undissociated colloidal soap. This also obviated the difficulties
advanced by Bayliss’® in proposing his tentative assumption of a mere
ageregation of the anions of Congo-red.

This heavy hydration is held by many authorities to be a plausible
explanation of the high viscosity frequently exhibited by substances
of this class as well as the effect of varying conditions upon this
viscosity, and it also accounts for the effects of temperature, for
example, the high temperature coefficient of the conductivity.

The recognition of this class of colloid in spite of the assistance of
isolated data for particular cases, was long delayed owing to the
supposed irreconcilability of these properties and to their being.
ascribed to the presence of impurities and hydrolysis, &c. It will
be seen that the results have now been experimentally established
beyond reasonable doubt.

It is worth while noting that a colloidal electrolyte differs wholly
in its behaviour from the class of substances represented by the
dextrines which may be termed “ semi-colloids.”” The semi-colloids
are non-electrolytes exhibiting various degrees of osmotic activity,
ranging from that of a typical crystalloid such as dextrose down to
that of a colloid such as starch.

It is also worth while mentioning that cataphoresis has often

_ been confused with conductivity. Most ions and charged colloidal

particles and even coarse suspensions exhibit a velocity of cataphoresis
of the same order of magnitude, but it is only in the case of the ions
and a few selected cases of colloids that this has been regarded as
being identical with conductivity. In dealing with colloids, in no
case was a conductivity predicated greater than might be expected
for a very slow-moving complex ion, whereas the theory of the ionic
micelle predicts enhanced conductivity, and in the case of soap
experiment shows that ionic micelle has to be recognised as being
several times more mobile than the ions from which it is derived.

The writer incidentally considers that it has not yet been proven
that there is any difference in kind between cataphoresis and ionic
migration, except that in an ion the number of electrical charges is
equal to the number of equivalents of substance in the ion. If so,
electrical endosmosis would be a result of solvation. Quantitative
data are being sought in order to test this point.

I1.—Constitution in Alcohol.

__In alcohol soaps exhibit a wholly different and much simpler
behaviour. The soap here exists in the form of a simple unpolymerised

A 2

electrolyte in true solution, whereas in most aqueous solutions it is
of course a colloidal electrolyte. The conductivity is only moderate,
and the ebullioscopic measurement indicates that it is a rather weak
electrolyte. ;

The great dissimilarity in the constitution of soaps in alcohol
and aqueous solution is brought out strikingly in an observation
of the writer. When alcohol is added to a clear aqueous solution of
sodium oleate the oleate is immediately salted out as a transparent
gel, although this readily dissolves again after a few minutes shaking.

There are, however, colloidal properties in alcoholic soaps which
require further investigation. Thus, although Miss Laing!” has proven
that in solutions of potassium oleate in dry alcohol at boiling point
there is no appreciable proportion of colloid present, yet sodium oleate
solutions, which have not yet been carefully studied in anhydrous
alcohol, are said to solidify to a gel on cooling; and this would appear
to prove the presence of a large amount of colloid. Potassium oleate
on the other hand solidifies to a white curd on cooling. Oleic acid
itself in all concentrations of alcohol is a simple electrolyte only very
slightly dissociated.

Ill.—Hydrolysis, Hydrolysis- Alkalinity and Products of Hydrolysis.

(a) Hydrolysis- Alkalinity.

Until quite recently, the extent of the degree of hydrolysis and
the hydrolysis-alkalinity of soap solutions has been a moot point,
the estimates ranging practically from neutrality up to nearly complete
hydrolysis. This was due to the difficulty of finding a satisfactory
method of investigation, one which should not destroy the soap
solutions that were being subjected to measurement.

The two methods introduced by McBain and Martin™* and McBain
and Bolam?*, that of E.M.F. and rate of catalysis have sufficed to
establish that the alkalinity of soap solutions is very small, being of
the order of magnitude of 0-001 N free OH’ for most concentrations
of soap. The E.M.F. method is of doubtful application where
unsaturated compounds are present, as in the case of all commercial
soaps, and the catalytic method is only applicable in dilute solutions
at high temperatures.

The hydrolysis-alkalinity of soap solutions depends upon the
concentration, the temperatures, the nature of the soap, and upon
its state of aggregation.

Taking first the effect of concentration; in extreme dilution
hydrolysis is very appreciable, but once the concentration of soap
approaches decinormal, the hydroxyl ion increases but slowly with
future increase of concentration and passes through a flat maximum
shortly before normal concentration is obtained.

The results obtained by E.M.F. in sodium and potassium soaps at 90°
are given in the following table in which all concentrations are
expressed in weight normality. Diffusion potential was not taken
into account; a recalculation in which diffusion potential is allowed

for gives appreciably lower values for the alkalinity of the more
concentrated solutions :-—

Soap. Sodium Palmitate. Potassium Palmitate.

OH’ Y% Hydrolysis. OH’. % Hydrolysis.
0-20

1:0N_ - 0-0020 0-0008 0:

0:75 N - 00-0023 0-30 0.0024 0-31
0-5N - 0-0019 0:37 0-0032 0-65
O-1N - 0-0013 1-28 0:0013 1-25
0-05N - 00-0011 2-22 0-0010 2-02
0:02N - — — 0-0011 5-6
0-01 - 00-0007 6-6 0: 0007 6:8

The hydrolysis of soap solutions above decinormal (3 per cent.
soap solution) is only a fraction of 1 per cent., and it is not very
different for sodium and potassium salts. The falling off in alkalinity
in concentrated solution is probably quite real, the chief experimental
error is in the opposite direction and the diminishing alkalinity is readily
accounted for by the disappearance of the hydrolysable palmitate
ion to form ionic micelle. The addition of sodium chloride also
diminished the alkalinity, which in this case, however, passes through
a minimum, since whenever a soap solution becomes heterogeneous,
its alkalinity becomes distinctly increased. Further measurments

‘show that the soap solution persists in being distinctly alkaline, even

in presence of large excess of palmitic acid. Thus an excess of 10 per
cent. palmitic acid reduces the alkalinity to two-fifths of that given
in the table, and even in presence of 100 per cent. excess of palmitic
acid the OH’ is still 0-00004 N. It is very important to note that
even this slight degree of alkalinity precludes the existence of more
than minute traces of free fatty acid in any soap solution, so that
any solid product of hydrolysis can never be free fatty acid, but must
always be an acid soap, intermediate in composition between neutral
soap and NaHP.,, where P represents the fatty acid radical.

It is equally important to note that when the excess of alkali is
added, it is not appreciably taken up by the soap present but remains
almost entirely in the free condition, in other words, basic salts
are not formed.

If various fatty acids are compared it is found that degree of
hydrolysis increases rapidly as the homologous series is ascended.

Influence of temperature again is important. The hydrolysis-
alkalinity decreases with lowering of temperature as, indeed, would
have been expected.

Very few measurements of the hydrolysis-alkalinity of commercial
soaps have been made, but the OH’ concentrations of solutions made’
from soaps which were finished neutral, are usually less than that of
sodium palmitate.

(b) Degree of Hydrolysis.
Whilst the experimentally determined values of the hydrolysis

alkalinity, that is, the concentration of hydroxyl ions, seems to be
well established, it is a matter of opinion how to interpret these in

terms of hydrolysis. The writer regards the extent of hydrolysis
as being identical with observed alkalinity, in this particular case,
asin most cases. Bancroft, however, in the Second Report (1919,
p- 15) has expressed his opinion that soaps are really greatly hydro-
lysed, but that the hydroxyl ion is almost completely adsorbed by
undissociated sodium palmitate. Not to mention the difficulty in
accounting for the disposal of the equivalent quantities of palmitic
acid set free, this interpretation is diametrically opposed to experi-
mental data, which show that any excess of hydroxyl ion added
to a soap solution, remains free in the solution as such and is not
adsorbed.

Since all soap solutions are slightly alkaline, they must contain
at least small amounts of products of hydrolysis. This has been
observed from the time of Chevreul, who found that most soap
solutions exhibit fine suspensions of acid soap of varying composition,
varying between nearly neutral soap and a soap in which the alkali
is deficient by any value up to one-third of the theoretical value for
a neutral soap. The more dilute the solution, as Krafft and Stern}?
have found, the more nearly the composition of the suspensions
approaches that of a sodium hydrogen soap (NaHP,). McBain,
Laing and Taylor find that acid soap formed in palmitate solutions
at 90° has the composition HP.2NaP. -

Whereas in aqueous solution even the presence of one complete
equivalent excess of palmitic acid still leaves free OH’ present, a
concentration 40 times as great as that required for coloration
of phenol phthalein, the alkali is so rapidly diminished by the
addition of alcohol that titration can be carried out in 40 per cent.
ethyl alcohol, although 60 or 80 per cent. solution is distinctly
preferable.

(d) Effect of Carbon Dioxide.

Although the dissociation constants of the fatty acids are perhaps
40 times greater than that of carbonic acid, yet the comparative
insolubility of the fatty acids and of the acid soaps often results in
extensive decomposition of the soap by excess of carbon dioxide.
Even alcoholic solutions are decomposed. As a rule, the result of
the interaction is the visible separation of acid soaps, as Krafft,!? Stern,’
and Wiglow”’, and Fendler®*, and Kuhn? showed. In the case of soaps
from such oils as olive oil, however, the solution remains clear. Repeated
treatment with carbon dioxide removed progressively less of the
fatty acid, although ultimately nearly all may be removed. The
equilibria involved have not as yet received quantitative study.

The solubility of the fatty acids is slight, nevertheless they are
sufficiently strong to make it impossible for them to exist even in
such concentrations in the presence of more than the merest traces
of alkali hydroxide. The theoretical necessity for the existence of
minute traces of free acid in all soap solutions is substantiated by the
observation of Krafft and Wiglow, that soap solutions yield appreciable
concentrations of fatty acid when shaken out with toluene or petroleum

ether, solvents in which the concentration of a fully saturated solution
would be very great. The fact that such extracts are far from
saturation—concentration is further proof that the fatty acid in the
aqueous layer cannot have reached its minute saturation value either.

IV.—ELvidence for, and Properties of, the Ionic Micelle.

(a) Conductivity.

Soaps particularly in concentrated solutions all exhibit a high
conductivity quite comparable with that of, say, sodium acetate.
This conductivity must be a property of the soap, since as we have
seen, there is very little free alkali present, and there is nothing else
to which the conductivity can be ascribed. These points are well
brought out in the following table from McBain and Martin’s paper,
which comprises the conductivity of sodium and potassium palmitate
solutions divided in each case into their two components; that due
to free hydroxide as indicated above and the remainder of the observed
conductivity which has to be ascribed to the soap itself. The raties
of the conductivity of the soap to that of the corresponding acetate
solutions are also given for comparison :—

Cone. Sodium Palmitate. Potassium Palmitate.

le ene yw NaP. NaP/NaAc.» KOH. KP. KP/KAc.

1-0N Nei 83-6 0-644 0-46 123-7 0-699
ia N -. 1°65 85°8 0-619 1-87 126-0 0-685
0-5 N 2-1 87-4 0-568 3°8 123-2 0-627
0-3.N - 2:7 84-3 0-499 — ~~ —
0-2N - 3:0 79-4 0-444 3°8 107-2 0-492
0-1N - 7:0 759°5 0-387 fits) Bos 0-421
m0a N. .- 12-2 76-4 0-368 12-1 98-7 0-396
0-02N - — = — 33°5 99-7 0-380
0-01N_ - 36-0 101-7 0-446 40-6 131-0 0-435

The form of the conductivity curve is remarkable, and is such
as has hitherto been observed only for certain anomalous non-aqueous
solutions. Both relatively and absolutely, the conductivity is at a
minimum between 0:05 N and 0:1 N solution. Thereafter, instead
of decreasing steadily with increasing concentration, the conductivity
rises to a pronounced maximum in 0-75 N solution. The relative
conductivity as compared with the corresponding acetate, has nearly
doubled with this same increase of concentration. These unique
relationships clearly establish that when such soap solutions increase
in concentration, the palmitate ion is being replaced by some other,
much better conductor of electricity, namely, the ionic micelle already
referred to.

The experimental evidence for the reliability of these results rests
upon a very painstaking study carried out during several years by
McBain and Taylor,* in which all possible sources of error were
carefully studied and eliminated in the special case of sodium palmitate,

8
This was necessary in order to place beyond controversy the fact
that colloids could exhibit a proper conductivity that could not be
explained away as being due to unknown impurities in accordance
with universal custom hitherto. There has since accumulated a mass
of corroborative evidence in the measurements carried out by Taylor,?
Cornish,? Bowden,* Bunbury,‘ Martin,’ and Laing!* in collaboration
with the writer; as also the measurements carried out by F. Goldsmidt
and his co-workers,* Weissman’ and Kurzman,’ and by Reychler,® and
by Arndt and Schiff.1° (See the classified list of references appended.)

When the results for the potassium and sodium salts of all
saturated fatty acids from acetic to behenic acid and likewise the
oleates, are reviewed, the utmost regularity is observed in the gradual
and regular transition from a typical curve of an electrolyte presented
by sodium acetate through the appreciable deviations of the lower
fatty acids (hexoates and caprate) to the laurate, in which a step
out or maximum and minimum is first observed (in the case of sodium
and potassium laurate respectively).

’ It must be borne in mind that some of these solutions are extremely
viscous whilst others are quite fluid. This enormous alteration in
viscosity appears to exert no effect upon the conductivity. Work
at present being carried out by Miss Laing in collaboration with the
writer shows that when the soap solution has been converted into
a solid gel, its conductivity. vapour pressure and concentration of
sodium ions are identical with that of the same solution in a state
of fluid sol at the same temperature and concentration. This
revolutionary observation appears to us to be of great importance
for the theory of gels since here the constituent out of which the
mechanical structure of the gel is built up has to be recognised as
constituting one of the best conductors present or the colloidal ionic
micelle has to move as freely through the stiff colloidal gel (where
structural constituent must then be neutral soap) as through the fluid
sol itself. This work and the conclusions to which it leads will be
reported upon elsewhere.

The independence between conductivity and viscosity is further
exemplified by the temperature coefficient of conductivity. In some
cases the viscosity is diminished several hundred fold by rise of |
temperature and yet the temperature coefficient of conductivity is
no greater than in others where the viscosity is not so markedly
affected. The fact that the temperature coefficient is rather higher
than that of an ordinary typical electrolyte is ascribed to hydration
and hence increased mobility of the ionic micelle with rise of
temperature.

Finally it should be noted that although potassium and sodium
soaps exhibit a surprisingly close general resemblance, the typical
relationships which have been described are rather more markedly
exhibited by the solutions of potassium soaps which evidently
contain rather greater quantities of ionic micelle.

(b) Osmotic Pressure.

It is, perhaps, hardly realised how difficult it is to obtain really
reliable and unambiguous determinations of the osmotic activities

of colloids. The well-known osmometer method in which the
membrane is not always strictly semipermeable involves a further
very serious and not completely evaluated complication described
in Donnan’s approximate theory of membrane equilibria. Results
of such measurements therefore are almost always subject to a certain
ambiguity of interpretations. The classical methods of boiling
point, lowering of vapour pressure, and freezing point lead to results
which are beyond question, only provided that the essential conditions
for the application of these methods are fulfilled.

The classical experiments of Krafft and of Smits using boiling
point and vapour pressuré respectively were completely vitiated by
the unsuspectedly large amounts of dissolved air from which soap
solutions cannot readily be freed and which develop a partial pressure
quite comparable with the lowering of the vapour pressure of an
ordinary crystalloid or electrolyte. To carry out a single vapour
pressure measurement really requires several weeks of effort. The
result then obtained is in agreement with those by the dew point
method, to be described below. The osnometer data of Moore and
Parker,1® in the case of soaps were wholly erroneous on account of the
effects of carbon dioxide.

The effect of dissolved air can be completely eliminated and
accurate measuzements of the vapour pressure made, by a modification
of the dew-point method described by McBain and Salmon,

The freezing point method is applicable where solutions remain
in sol condition at the freezing point and where ice separates out in
erystals free from colloid. In the case of soap solutions the latter
condition was attainable by inoculation, but very few soap solutions
are liquid at 0° C. Determinations of all these have been published
by McBain, Laing, and Titley.

Thus the bulk of the available data for soap solutions are those
obtained by the dew-point method which possesses an additional
advantage in that it can be utilised at any temperature.

The results of the lowering of dew-point and freezing point agree
in establishing the fact that soap solutions have a very real osmotic
pressure of the same order of magnitude as that of a non-electrolyte
such as sucrose. A continuous series of values for the osmotic
activity is obtained, depending upon the concentration and position
in the homologous series, which range from a fraction of that for
non-dissociated crystalloid to that of a moderately dissociated
electrolyte. ~

In discussing osmotic data, it is almost always essential to keep
clearly in view the very important effect which hydration exerts in
magnifying the apparent osmotic pressure more especially in con-
centrated solution. For instance, the apparent dissociation of
electrolytes frequently exceeds 100 per cent. according to osmotic
methods.

It is generally agreed that hydration is greatest at lower tempera-
tures. In the case of the potassium salts of the lower fatty acids this
enhanced osmotic effect is clearly visible at 0° as compared with the
more normal results at 90°, but in spite of the magnification of osmotic
data at lower temperatures the osmotic activity exhibited by soap

is very decidedly less at 0° than at 90°. Soap solutions are very
much more colloidal at lower temperatures than at the boiling point,
and the presence of colloid extends into comparatively dilute solutions
at 0°.

In case of the higher sbaps the relative osmotic activity is practically
independent of the concentrations above 0-4 N at 0°, showing how
complete the formation of colloid has been. Again, potassium
octoate is distinctive in its behavoiur at 0° in that in lower concentra-
tions it is a typical electrolyte whereas in extreme concentrations
the relative osmotic activity rapidly diminishes.

‘The evidence for the existence of the ionic micelle is based primarily
upon comparison of conductivity and osmotic data. Briefly it
amounts to this, that in concentrated solution of the higher soaps,
the osmotic activity is often only about one half that required to
explain the conductivity. The conductivity is, say, 2/3 of that of a
salt like the acetate, whereas the osmotic pressure is, say, half that
of a non-electrolyte such as sucrose, and yet both sets of data are
fully trustworthy. The osmotic activity, therefore, corresponds with
that of one ion only, and the other half of the current must be carried
by an ion that is colloidal so as not to exhibit appreciable osmotic
activity, and that nevertheless retains the sum total of the electrical
charges of the ions from which it was derived. This is the ionic
micelle.

The osmotic activity measures the total concentration of crystalloidal
matter of all kinds. The conductivity measures the K- or Na~ in
addition to the carrier of the equivalent negative charges. To
reconcile the experimental data, say in normal solution of potassium
laurate at 0°, it is necessary to ascribe the whole of the observed
osmotic activity to the potassium ion, and even when this is done,
about half of the conductivity is still to be accounted for and must
then necessarily be ascribed to colloid. It is notable that the
equivalent conductivity thus ascribed to the ionic micelle of potassium
laurate is about three times greater than the sum total of the
conductivity which the separate laurate ions that are grouped in the
micelle, would have exhibited if they had retained an independent
existence. This, however, as the writer has indicated above, is only
what would have been predicted from Stokes’ Law, since the resist-
ance offered to a particle increases directly with its diameter. When
a number of small particles coalesce to form larger particles, the
diameter of the larger particle does not increase by any means in
the same ratio, whereas the electrical driving force will be directly
proportional to the number of aggregated laurate ions if these latter
have retained their equivalent electrical charges. Therefore for
electrical forces the mobility of such a large particle is very great,
whereas its diffusibility is only that of a colloid.

It is necessary to make some sort of assumption as to the mobility
of the ionic micelle for a particular case in order to be able to evaluate
the conductivity observed. A safe provisional rule is to ascribe to
the ionic micelle, the minimum conductance which will serve to

reconcile the conductivity and osmotic effects. Of course, when it is
possible to take hydration into account as it is hoped to do when
certain measurements have been completed, the equivalent conduc-
tivity of the ionic micelle will then be ascertained.

On reviewing the results for all concentrations and temperatures,
it is found necessary in concentrated solutions to ascribe to the ionic
micelle a conductance which is equal to that of the potassium ion.
This is by no means identical with the well-known and striking fact
that the mobility of many mechanical suspensions as well as of colloids
in the electric field is as great as that of an ordinary ion, since in the
case of the ionic micelle of soap it is not merely the mobility but the
equivalent conductivity that is so great.

There is a good deal of evidence for the conception that the
mobility of the ionic micelle increases with concentration owing to
diminishing hydration due to increasing amount of neutral colloid
in the micelle. The most important considerations is, that other-
wise it would follow from the principle of mass action that within
a very narrow range of concentration the colloidal electrolyte would
pass completely into undissociated form and no longer conduct.

The small but unmistakable difference between a potassium and
a sodium palmitate solution is not readily accounted for if the ionic
micelle is considered to be merely an aggregate of palmitate ions, and,
therefore, necessarily identical in the two cases. There are a number
of reasons for considering that the ionic micelle contains some of
the colloidal undissociated sodium and potassium palmitates respec-
tively, which would thus account for the difference in behaviour,
since thus the micelles are no longer identical.

For these reasons the formula ascribed to the ionic micelle in a
soap such as sodium palmitate is—

(NaP)x: (P’)n -(H,O)m.

According to this formula, the composition of the micelle must
alter continuously with change in concentration or temperature or
-upon the addition of salts. Thus in very concentrated solution or in
presence of large amounts of another electrolyte such as sodium
hydroxide or chloride, the soap must be nearly all colloid of approxi-
mately the composition—

(NaP)x: (P’)n- (H,O)m.

Again this formula accounts for the real difference, namely, in
conductivity and osmotic behaviour, between solutions of potassium
and sodium soaps, as was pointed out above.

With regard to the value of n, the number of negative charges on
the micelle, it must be at least 10, and probably is very much greater.
Thus the “ molecular weight” of the ionic micelle must be at least
of the order of magnitude of 3,000, although the true molecular weight
of palmitate is only 255. In a similar way the enormous molecular
weights ascribed to various substances which occur only in the
colloidal form may well be derived from the aggregation of compara-
tively small molecules.

One solution may be cited to illustrate typical values of the
concentrations arrived at for the respective constituents 0:6 N KOl
at 0° — 18°, is found to contain 0-17 N potassium ion, not more“than
9-01 of other crystalloidal matter, the remainder being entirely
colloid, probably largely included in the ionic micelle and comprising
0:16—0-17 N aggregated oleate ion, with a total of 0-41—0-43 N
aggregated neutral potassium oleate.

In many other cases, however, the limits of concentration of the
constituents have not yet been so narrowly defined.

V.—Physical Properties of Soap Solutions.

Having discussed the general constitution of soap solutions, we
shall now discuss in turn a number of their chief physical properties.

(a) Viscosity. (For references, see classified bibliography appended.)

As in the case of so many colloids the viscosity constitutes a
prominent characteristic responding in typical fashion to alteration
in experimental conditions. Whilst very readily measured and
reproducible, the data do not lend themselves to quantitative inter-
pretation and explanation. Nearly all our exact knowledge of this
subject is due to the numerous and careful measurements of F. Gold-
schmidt® 7 and his collaborators, although Farrow carried out a series
of exact measurements at 70° in Donnan’s laboratory.

The viscosity increases with rise in concentration of the soap,
at first gradually, then enormously. For instance, potassium oleate
at 20° exhibits a viscosity of 1-19 for N/20, 1-87 for N/5, 8-02 for
0-4 N, and no less than 1573 for 0-6N, taking water as unity.

The effect of temperature in the case of less viscous soap solutions
is practically that of the alteration of the fluidity of water.

Addition of hydroxide, chloride or carbonate at first lowers the
viscosity, which passes through a minimum, and _ thereafter rises
enormously. This was observed by Mayer, Schaeffer and Terroine,*é
Botazzi and Victorov?? and Leimdorfer, Farrow,?® Goldschmidt and
Weissmann, and most carefully studied by Kurzmann.? The more
concentrated the soap solutions, the more pronounced is the minimum,
and the less the salt required to produce it.

The following data present typical cases of such minima produced
by the addition of potassium hydroxide at 20° and at 90° to solution
of 0-375 N, potassium laurate and 0-6 N potassium oleate respectively,
the viscosity of water at 20° being taken as unity :—

At 20° the viscosity of the laurate is decreased from 1-96 to 1-57,
that is, by 20 per cent. At 90° the decrease is from 0-604 to 0-522,
being 14 per cent. At 20° the values for the oleate are 1573 to 728,
by 54percent. At90°,3-80 to 3-01 by 21 per cent. These remarkable
changes are produced by the addition of 0-5 N KOH to the laurate,
but only 0-02N KOH to the oleate. -

It is at once apparent that the lowering of the viscosity is dependent
upon the presence of ionic micelle. There must be at least three
primary effects at work in all these cases. The first, lowering is

dehydration through lowering of the reactivity (vapour pressure)
of the water upon addition of the salt and its ions; for as
McBain and Salmon have indicated, the heavily hydrated micelle
must be extraordinarily responsive to such slight changes in the
availability of the water. The second factor is formation of ionic
micelle through the influence of the added potassium ion. The
third, like the second, raises the viscosity, and consists in that
unexplained change which, upon further addition of salt, tends to
produce a jelly perhaps ten thousand times as viscous in the original
soap. This last effect may well be due to the formation of neutral
undissociated colloid and its subsequent linking up as explained in
Section VI below. It is interesting to note that in accordance with
all these views such high viscosities are more quickly obtained by
adding further quantities of the soap itself, rather than by adding
equivalent amounts of salt or alkali.

However, it must be concluded that the foregoing is merely a
programme or working hypothesis for further experiment (a colloidal
explanation used as a term of reproach), and quantitative work is
called for in order to test whether or not the first two effects are due
solely to the value of the total osmotic pressure and to the actual
concentration of potassium ion respectively. Colloidal chemistry at
present abounds in such problems and “ explanations’ which need
to be replaced by precise and quantitative conceptions and measure-
ments, otherwise such explanations do more harm than good.

In the case of concentrated soap solutions or those to which large
amounts of electrolyte have been added, the temperature coefficient
of viscosity becomes extremely great, so that the viscosity at 20°
may be several hundred or thousand fold greater than at the boiling
point.. Of course, the addition of these electrolytes tends to induce
gelatinisation or, in the case of higher sodium soaps, salting out.
Since salts effect the viscosity to different extents, depending upon
the nature of the salt, the effect is ascribed to the anion. Obviously this

requires further and quantitative elucidation.

The effect of position in the homologeous series is very marked.
Even in rather dilute solution the sodium behenate (C,.) is highly
viscous, whereas in the case of the laurate (C,.) only the most
concentrated solution containing large amounts of electrolyte can
really be termed viscous. A normal solution of potassium laurate

at 20° and at 90° exhibits 8-4 and 2-8 times the viscosity of water,

whereas a normal solution of potassium oleate is 1573 and 3-80 times
as viscous as water at the same temperatures.
Potassium or sodium oleate (C,,) at room temperature is very
uch more viscous than say potassium myristate (C,,). It is
probably much like the stearate (C,s) except that the effect of the
double bonds is to render it liquid even at the freezing point. The
effects of additions of an electrolyte is much more pronounced in
the case of the oleate than the laurate, and again in concentrated
soap solution as compared with dilute soap solution. In other words,
it is evident that the typical effects of added electrolytes are to be
attributed to their effect upon{the ionic micelle and its development,
concentration and composition.

Electrolytes with the common alkali ion must exert three chief
effects upon a colloidal electrolyte. First the furthering of formation
of ionic micelle if large quantities of simple ions are still present;
secondly, driving back the dissociation with its corresponding altera-
tion in the composition of the ionic micelle; and third, diminishing
hydration of the ionic micelle.

The only mixtures which have been properly investigated are
those of potassium laurate and potassium oleate. Addition of small
quantities of potassium laurate to potassium oleate slightly increase
the viscosity at 90°, whilst at 20°, the viscosity is greatly diminished,
thus very much lowering the temperature coefficient. Such an addition
must have partly the same effect of that of an electrolyte with the
added complication of the possible formation of mixed ionic micelle.
A mixture of equal quantities of potassium laurate and potassium
oleate fairly closely resembles the pure laurate. A mixture of even
relatively small amounts of laurate with the oleate causes the solution
to respond to the addition of salts in a manner much more closely
resembling the laurate than the original oleate.

An addition of equivalent quantities of various electrolytes the
hydroxide has the greatest effect, followed by the chloride, and then
the carbonate. Although if equimolar concentrations of carbonate
and hydroxide are taken, the order of magnitude of the effects are
the same.

It should be emphasised that other colloidal electrolytes exhibit
the same typical behaviour in the addition of electrolytes as has
been observed, for example, by Woudstra in the case of ferric
hydroxide (chloride). According to Pauli this also is a case of a
colloidal electrolyte.

An excellent example of an industrial application of this behaviour
in the closely analogous case of sodium silicate is to be found in the
use by Malcolmson (Jour. Ind. and Eng. Chem., 1920, 12, 174) of
brine for diluting water glass whilst retaining its adhesive power.
In this way a given volume of water glass could be increased by
25 per cent. without reducing its viscosity.

(b) Density.

Soap solutions are remarkable for their bulkiness. All soap
solutions have approximately the same density as water of the tempera-
ture, and this even in extreme concentration. For example, the
volume of a normal solution of sodium stearate is 31 per cent. greater
than that of a solution of sodium acetate containing the same amount
of water. Not only so, but we have here the almost unique case.
of the solution being in some cases less dense than either constituent.*
For instance, a normal solution of sodium palmitate has a density
equal to 0-997 of that of water of the same temperature (at 90°).

The potassium soap solutions are slightly denser than those of
sodium. The ammonium soaps are somewhat lighter than the
sodium soaps. The highest homologues of the fatty acids produce
soap solutions of the least density. There is a steady increase as

* Compare the case of p. nitrotoluene in earbon bisulphide; Hyde, Journ.
Amer. Chem. Soc., 1912, 84, 1507.

the homologous series is descended, with a definite break in the curve
between the hexoate and the acetate, once again indicating the
relatedness of the hexoate to the higher soaps. The appearance,
washing power, density, and conductivity curve of potassium hexoate
distinctly mark the beginning of that deviation from the behaviour
of the acetate, which rapidly and regularly increases through the
other members of the homologous series until it attains the typical
character of the higher soaps.

It is worthy of note that the density of soap solutions does not
by any means conform with the conception of electro-striction, although
in these solutions there are almost as many ions and opposed electrical
charges as in the case of a typical electrolyte.

(ec) Surface Tension.

Some of the matter which might have been discussed under this
heading will be referred to in paragraph 8 below, which deals with
detergent action, and further, the rather extensive subject of soap
films and bubbles will not be considered. Several years of further
investigation would be required to answer all the questions which any
chemist would at once ask with regard to the surface tension of soap
solutions. The existing data are so isolated that it is still impossible

-to give a satisfactory broad survey of the subject, They refer, in

a few instances to surface tension against air, but most of the experi-
ments refer to surface tension at the interface with fatty or petroleum

- oils. In many cases the results are affected to an unknown extent

— = —- ~

sea +" *

by the carbon dioxide of the air, and frequently the composition of the
soap is extremely ill defined, and in the experiments, for example,
of Botazzi, the soap was rendered still more undefined by being
‘submitted to a process of dialysis. Another factor which can interfere
with the results is the rather ready oxidation of the unsaturated
substance like the oleate. It is well worth while determining not

merely the surface tension, but the actual amounts of adsorbed

substance, and still further the actual composition of the “‘ soap ”’

in the meniscus; that is, the amounts of alkali, fatty acid, and hydrate
water in the surface film. Lastly, an experimental difficulty which
should be taken into account is the insolubility of the saturated fatty

acids and of the acid soaps which separate out unless the solutions

are kept hot.
Soap Solution—Air I nterface.

Sodium oleate solutions in contact with the atmosphere constitute
the only case in which the interfacial tension of the boundary between

soap solution and a gaseous phase, has received any serious considera-

tion. Plateau, Quinke, Marangoni, Lord Rayleigh, Milner, Hall,
Harkins, Perrin, and Hillyer may be referred to in this connection,
although some of the results refer to the chemical decomposition
of the soap by carbon dioxide, oxidation, and hydrolysis. By far
_the most careful work is that of Harkins, Davies and Clark (Jour. Am.
‘Chem. Soc., 1917, 89, 586), who, like Hillyer (Ibid, 913, 25, 515), used
the drop weight or drop number method. These authors found that
when pure sodium oleate was added in increasing quantities to water

of surface tension 2-8 dynes per cm. at 20°, the surface tension falls
at first with extreme rapidity to 24:29 dynes when 0-002 N sodium
oleate has been added, but that further addition of sodium oleate
causes only a slight and gradual increase of the surface tension to
the value 27-20 dynes for decinormal solution. A 0-0001 N sodium
oleate has a surface tension as low as 60-46 dynes and,even when,
to diminish hydrolysis, 0:0002 N NaOH had been added, the surface
tension was still only 61-32 dynes. Similarly, a 0-008 N sodium
oleate solution of surface tension 25-30 dynes still exhibits a surface
tension of 31:79 dynes in presence of the comparatively large amount
of sodium hydroxide 0-008 N. Harkin’s conclusion is that the
surface film consists largely of a single layer of sodium oleate molecules,
with possibly singly and multiply charged oleate ions (ionic micelle),
and hydroxyl and hydrogen ions, the film is thus entirely saturated
even at low concentration of solution.

According to Hillyer the drop number of a decinormal rosin soap
is the same of that of sodium oleate.

There is no recorded analysis of the composition of the substance
actually adsorbed. Perrin’s work in 1918 in this connection is again
vitiated by the possibility that the observed effects were due to carbon
dioxide.

It is worth while remembering that the power of foaming, like
emulsification, is not always or entirely due to low surface tension ;
for instance, saponin solutions whose surface tensions are only slightly
less than that of water, have a very great power of foaming on account
of the formation of a solid or highly viscous film of adsorbed material
in the surface.

Soap Solution—Oil Interface.

Here again the stalagometer or drop method has been almost —
invariably employed. An excellent and luminous investigation was —
published by Hillyer in 1903, and it was very unfortunate for this
subject that his researches were not continued since his elucidations
of the phenomena of surface tension and detergent action are, still
as convincing as ever. His papers are published in the Journal of the |
American Chemical Society which, as the writer knows from personal
experience, has been inaccessible in many of the European Universities
in spite of its present enormous circulation in America.

Hillyer found that in contradistinction to the behaviour of their
surface tensions against air, the surface tension of sodium oleate
solutions against paraffin oil (kerosene) continues to diminish rapidly
and steadily with increasing concentration up to decinormal.
Decinormal rosin soap like decinormal sodium oleate exhibits a
surface tension which is only 5 or 6 per cent. of that of water.
Decinormal sodium hydroxide has almost as great a surface tension
against paraffin oil as pure water. Sodium oleate solution at 100°
exhibited no marked difference in the form of curve connecting surface
tension and concentration. ‘

Hillyer also investigated the effect of excess of alkali and of acid,
the former had but little effect upon any concentration of sodium
oleate, whereas excess of oleic acid gradually and steadily removed

the lowering of surface tension, although even the acid oleate NaOl,
HOI, causes a marked lowering of surface tension.

Finally Hillyer invéstigated solutions of sodium palmitate and
stearate at 70° and 100°. The first traces of soap do not greatly lower
the surface tension of the water but as the concentration passes through
N/1000, the surface tension falls very rapidly at first and then above
N/80 more gradually up to N/20 solution. This anomaly in very
dilute solution was not further investigated, but was ascribed to
hydrolysis. Rosin soap, whether at 100° or in the cold, does not
differ markedly from sodium oleate, and is not very much affected
by temperature. Both, however, exhibit a slightly developed
inflexion in dilute solution like that of the stearate or palmitate.

* Donnan and Potts (Kolloid Zeitsch, 1910, 7, 208) measured the
drop numbers of a nearly neutral paraffin oil against various
concentrations of the sodium salts of the saturated fatty acids from
the acetate up to the myristate (C,,). They found that the surface
tension was lowered roughly in proportion to the concentration of
the salts up to and including the heptoate (C,). Decinormal solutions
have a surface tension between 87 and 78 per cent. that of water.
The octoate which appears as the lowest soap, has a much more
marked effect, N/400 solution causing a lowering of 4 per cent.
A N/400 myristate has a surface tension only 58 per cent. of that of
water, and the curve connecting surface tension and concentration
is only slightly curved. Donnan’s earlier work (Z. physikal Chem.,
1899, 81, 427), in which various fatty acids were dissolved in oils
and their drop numbers determined against dilute alkali is explained
by those results owing to the formation of soapin these experiments.
This is invariably the case when commercial fatty oils come in contact
wtih alkaline solutions, since they all contain more or less of free
fatty acid, and it is only under these conditions that emulsification
occurs.

Soap Solution—Benzene Interface.

Harkins, Davies, and Clark have further made exact measurements
of the surface tension of sodium oleate against benzene. It falls
extremely rapidly at first from the value for pure water, 35-03 dynes,
through 9-00 dynes for 0-005 N, and 2-22 dynes for 0-014 N to
1-78 dynes for 0-1 N soap. It may be noticed this behaviour differs
from both of those in the two interfaces already discussed. Briggs
(Jour. Phys. Chem., 1915, 19, 210) has done experiments in which
he measured instead the apparent amounts of sodium oleate removed
from the aqueous layer, using a somewhat unsatisfactory and very
incomplete method of analysis. He found a similar behaviour in
that the amount removed increased only slightly in higher concentra-
tions. Absolute results were not obtained. Briggs and Schmidt
(Jbid., 1915, 19, 479) found that the optimum amount of soap for
emulsification of the benzene is 1 per cent.; that is, three times the
value given by Harkins, 0:01 N. Addition of 0-1 per cent. alkali
favoured emulsification, but larger amounts interfered.

Shorter (Jour. Soc. Dyer-Colourists, 31, 1915, 64; ibid, 32 (1916)
92), Shorter and Ellingworth (Proc. Roy. Soc., 1916, A, 92, 231),

@ 11454 B

showed first that potassium hydroxide has practically no effect upon
the surface tension against benzene. Then he found that though
the addition of oleic acid to benzene lowered the tension against
water, it had no effect on the tension against soap solution, and he
concluded that the surface activity of the hydrolysis alkali was only
about one-fifth to one-fourth that of the undecomposed soap.

In all these cases again there is still the greatest uncertainty as
to what it is that is adsorbed in the interface. In Spring’s work,
referred to in the section of “‘ Detergent Action,’ he concluded that
it was acid soap that was sorbed by lamp black, whereas filter paper
sorbed alkali leaving acid soap in the solution.

Woodmansey (Jour. Soc. Dyers Colourists, 385, 1901, 169) found
that the amount of base sorbed from a solution of soap was greater
than that of fatty acid, an acid soap remaining in the water.

(d) The Optical Properties of Soap Solutions.

Soap solutions constitute clear transparent solutions disturbed
only by the suspended insoluble particles of acid soap resulting from
hydrolysis, and exhibited in varying degrees by all soaps from caproate
upwards. Here investigation (Darke and Salmon) shows that the
clear liquid is not resolvable under the ultramicroscope, and that
the ionic micelle is invisible in the cardioid ultramicroscope. The
suspended particles of course exhibit Brownian movement, the purple
ones being exceptionally active, the smallest green ones coming next.
This Brownian movement serves as an excellent index to the viscosity
of the liquid; it is scarcely detectable when the soap is highly viscous,
and it is highly developed when most of the soap has been removed
from solution as by the formation of curd. It is probable that with
higher resolving power innumerable white particles would be visible,
and that these constitute the particles of neutral colloid. We
have detected them only when conditions of illumination, &c., were
exceptionally good, just upon the limits of possible observation and
they exhibited a degree of Brownian movement which corresponded
to the fluidity of the medium.

Earlier investigations of the optical appearance of soap solutions
whether microscopic or ultramicroscopic, have thus all had reference
to the suspensions of insoluble acid soap produced in smaller or greater
amounts by hydrolysis. The frequent turbidity of soap solutions
has thus been an illusory proof of their colloidal nature. The
insoluble acid soap may sediment out almost completely upon standing,
leaving the bulk of the soap in prefectly clear transparent solution,
or it may remain partly or wholly suspended in particles whose
dimensions range all the way from coarse suspensions down to the
smallest resolvable in the ultramicroscope. Every change of tempera-
ture or of concentration or of additions which affects hydrolysis will
affect the amount of this product of hydrolysis. The acid soaps in
suspension constitute an ordinary colloid.

It is now clear why Mayer, Schaeffer, and Terroine observed
progressively more colloidal particles in any one soap by passing
from alkaline to acid solution. Further it becomes plain why the
viscosity of solutions of salts of the lower fatty acids up to the

valerianate is not markedly altered upon the addition of strong acid
which liberates the soluble liquid fatty acid, although excess of
base raises the viscosity. In the higher members of the homologous
series, where insoluble acids and acid soaps are in question, addition
of strong acids increases the viscosity appreciably through formation
of colloidal acid soap; alkali does so also, although through formation
of ionic micelle and neutral colloid. In accordance with this the
higher soap solutions{require a slight excess of alkali to clarify them
completely by driving back hydrolysis. The authors named thought
to identify the point of complete clarification with the point of
minimum viscosity without carrying out the quantitative work and
without a knowledge of the constitution of these solutions.

Lifschitz and Brandt have recently studied refractive index at
70°. They find that the refractive index varies linearly with the
* concentration; this held good also in the alcoholic true solutions.
This undoubtedly shows that the molecular refraction is independent’
of whether the soap is present as crystalloid or colloid, and in the
latter case is independent also of the actual constitution and of the
degree of dispersion of such colloid. This conclusion was directly
confirmed by the agreement of the values observed with those
calculated from the atomic refractivities which, of course, have been
obtained in the study of crystalloids.

(f) Ulirafiltration and Dialysis.

The behaviour to be expected in the ultra-filtration or dialysis of
soap solutions is now clear on the basis of the theory which we have
established. In the case of ultrafiltration the effect will depend
largely upcn which fatty acid is taken and the concentration of the
soap. In dilute solution or solutions of the salts of the lower fatty
acids, they will tend to pass through the filter unchanged. In more
concentrated solutions of the higher soaps which contain very little
crystalloid other than the alkali ions accompanying the ionic micelle,
- the membrane will retain practically all the soap. Intermediate cases
will be particularly interesting as they will afford a direct quantitative .
measurement of the crystalloid matter present in such solutions.

The only published investigation is the brief note of Mayer,
Schaeffer, and Terrione, already referred to, whose results were
apparently in quantitative agreement with that here outlined.
A systematic investigation is now in progress whose results likewise
agree with prediction. Further it is readily shown that this may be
made a general method for the study of hydration of colloids. It is
only necessary to include in the solution to be filtered some readily
analysed material which is not sorbed by the colloid and then to
determine the increase in concentration of this reference substance
which the filtrate exhibits. The amount of this increase affords a
quantitative measurement of the total amount of water which was
abstracted by the' colloid from solution whether as adsorbed, or
chemically combined water.

As regards dialysis, there are two points to be emphasized, the
one theoretical, the other practical. In the first place the crystalloid
present will be able to pass through the membrane so that in no case

B 2

will the membrane be quite impermeable to soap, and further, since
dilute solutions in particular are appreciably hydrolysed, hydrolysis
will be developed by the continued removal of the alkaline products
of hydrolysis, leaving behind the insoluble or colloidal acid soap,
the whole forming an instance of membrane hydrolysis. In the
second place, however, one practical consideration vitiates the niceties
of theoretical interpretation, that is that quite exceptional opportunities
are afforded for decomposition of the soap by the carbonic acid from
the air or from the large quantities of water employed. For instance,
as we have seen Moore and Parker1* obtained an osmotic pressure
50 times too small, and were unable to detect any alkali coming
through ordinary parchment. Various other investigators, Rotondi,
Botazzi, and Victoroff?? found that acid soaps or possibly even free
fatty acid remained behind on dialysis under such conditions. How-
ever, they, like Mayer, Schaeffer, and Terroine®’ found that as long as
the solution was kept alkaline some of the soap did pass through the
membrane.

V1.—Solidification and Gelatinisation of Soap Solutions.

The solidification and gelatinisation and salting out of soap solutions
afford penomena of extraordinary interest which have not received
adequate interpretation in the literature.

Upon cooling, or upon the addition of various substances white
opaque curd may be formed, or again, there may be obtained typical
gels, clear and transparent or ranging through various degrees of
cloudiness. These two very distinct forms, white curd and clear
gel have always hitherto been confused with each other and referred
to indiscriminately. Hence there has been controversy as to whether
they were colloidal at all.

Sodium oleate solutions as studied by Miss Laing present a
particularly interesting case since here it is possible to obtain one and
the same solution at any one temperature in the form of transparent
sol, clear jelly, or white opaque curd. The conductivity of a given
soap solution is independent of whether it is studied as sol or clear
gel. Again the concentration of sodium ions present is also indentical
in the two cases.

We are tending towards the opinion that in a gel there exist well-
developed strings of long molecules forming an exceedingly fine
filamentous structure which accounts for the elasticity of gels and
also for the fact that they exhibit more or less clearly oriented
properties, such, for instance, as the lenticular, fairly definitely
oriented, form of bubbles generated within gels. This assumed
structure is, however, not resolvable under the ultramicroscope, as
is only to be expected. If we are able to obtain sufficiently definite
evidence for this, it would appear that the same forces are in play
here as account for the phenomena of crystalline liquids and liquid
crystals. There is a great deal of circumstantial evidence for this.
It would serve also to explain the incipient structure which most sols
develop on standing and which is such as prevents for example,
definite measurements of viscosity from being taken independent

21
of age and rate of shear. An illustration of this general and well-
known behaviour is the case of sodium behenate, where occasionally
a perfectly clear and apparently homogeneous solution can be divided
by pouring into two test tubes, one of which will then be found to
contain practically all of the behenate, the other containing almost
only water.

Freundlich in his study of certain vanadium pentoxide sols which
had been aged during many years, found that at boundaries or
throughout the sol, whenever the sol was set in movement, it was
anisotropic and exhibited all the behaviour of a crystalline liquid,
a behaviour which is likewise now attributed to the presence of long
molecules, both on physical and chemical grounds. This explanation
therefore links up with Bose’s theory of swarms of long molecules
and with Vorlinders’ observations that long molecules are required
for the formation of liquid crystals. Sandquist’s bromophenanthrene-
sulphonic acid is obviously a colloidal electrolyte, analogous to soap;
and solutions can be obtained under certain conditions as crystalline
liquids.

These strings of molecules which we contemplate may be microns
or millimetres long, in other words, they consist of innumerable
molecules placed length-wise and their formation would, of course,
be ascribed to residual affinity. The very strong tendency of soaps
to form such structures is proven by the manner in which they form
filamentous and fibrous curds (see below). We investigated several
sulphonates containing up to 10 carbon atoms, but as these are ring
compounds, the development of ionic micelle was only very slight,
and the solutions crystallised without tendency to form fibres.

The ultramicroscopic investigation of soap gels presents some
difficulty, since it is difficult to know when it is a real gel that is being
observed. Probably all of Zsigmondy and Bachmann’s® work (like
our own) refers to curds. A gel is probably optically clear apart
from the particles which result from hydrolysis and which are, of.
course, devoid of motion on account of the high viscosity of the
soap solution. Nevertheless in one undoubted instance, we observed
and photographed a cloudy gel of sodium oleate which, in addition
to curd fibres, contained an exceedingly fine and delicate filamentous
network. The quartz surfaces in contact with these sodium oleate
gels often exhibit indefinitely long and exceedingly fine filaments
just on the limits of visibility and just capable of being photo-
graphed with long exposures. Their regularity of form and texture
is astounding. They simulate living matter in their appearance;
they may take the form of a simple sine wave, or of regular waves
with higher harmonic series superimposed on them. Any one part
of such a filament is identical in form and structure with any other
part. They are probably derived from originally straight just
resolvable translucent tubes containing very regularly spaced whitish
dots or lengths.

The beautiful pioneer observations of Zsigmondy and Bachmann
on soap curds and our own studies, in which the cinematograph was
combined with the ultramicroscope in order to follow the genesis

and life histroy of the various structural elements, have shown that
soap curds consist invariably of fine fibres.

In the case of all sodium soaps these may be many centimetres in
length, and may be straight or characteristically curled but they are
never of greater thickness than about 1 micron. Most of them are of
ultramicroscopic diameter, and the thicker ones may be always or
usually merely parallel bundles of finer ones These fibres are often
so fine that shorter or unattached fibres exhibit Brownian movement
when the medium is not too viscous. These curd fibres constitute
the only mechanical structural element of sodium soap curds and
represent the stable condition of such curds even after the lapse of
years.

The potassium soaps are somewhat more complicated and the
phenomena require more time for development. Upon slow cooling,
minute V-shaped twin fibres appear of about a few tenths of a micron
in diameter, but never more than a few hundredths of a millimetre
in length as compared with the inch-long fibres of sodium soaps. These
twin fibres hotvever, do not constitute the stable solid phase in
potassium soap solutions for, on standing for a few days, they gradually
become replaced by thin irregular leaflets or crystals less than 1 micron
in thickness.

The curd fibres of sodium soaps may scarcely be called crystals,
nevertheless they constitute a sufficiently definite phase to exhibit
some of the properties of crystals. For instance, they appear to
exhibit a definite solubility at each temperature. A curd of sodium
soap therefore in general consists of a felt of curd fibres in which
is enmeshed an aqueous liquid containing, according to the tem-
perature, traces of soap and alkali, the product of hydrolysis, or
perhaps large amounts of soap sol or gel depending upon age,
previous history and, of course, temperature.

At the temperature of initial solidification only a few fibres are
formed, the bulk of the soap remains in the solution which therefore
exhibits a practically undiminished vapour pressure and conductivity.
As the temperature is lowered, the solubility of the curd fibres rapidly
diminishes until the enmeshed liquid consists chiefly of water and its
vapour pressure and conductivity behave accordingly. Throughout
this range of temperature the stable condition of the soap solution
is the formation of the appropriate amount of curd fibres with
enmeshed gel. The definite solubility of the curd fibres at any one
temperature is evinced by the fact that the conductivity of a well-aged
curd is approximately independent of the concentration of the original
soap.

It follows from the above conception based upon direct measure-
ments that different concentrations of any one soap cannot solidify
at the same temperature, but this depends upon the temperature-
conductivity curve of the curd fibres. The lower the concentration
of the soap, the lower the temperature of initial solidification.

It is a remarkable fact to which Krafft and Wigelow?’ called
attention, that there is a certain parallelism between the initial
solidification temperature of a sodium soap solution and the melting
point of the pure anhydrous fatty acid from which the soap is derived.

This is strictly true for only one concentration. Rather concentrated
soap solutions have an initial solidification temperature which is very
near the melting point of the fatty acid, dilute solutions of course fall
much below it, whilst, as we have found, highly concentrated soap
solutions come distinctly above it. No tenable explanation of this
behaviour has been put forward. It is probable that the soap fibres
consist of hydrated neutral colloid and that the slight alkalinity of
the mother liquor is due to the particles of acid soaps resulting from
hydrolysis and which we have so often referred to. There are
particles in fact still visible under the ultramicroscope leading an
independent existence in the wet curd, and it is amusing to watch
a small particle performing violent Brownian movement up and down
the length of a curd fibre from whose neighbourhood it often has
difficulty in escaping. This form of Brownian movement has not
previously been described. The coincidence with regard to melting
points refers of course, only to sodium soaps.

It is worth while emphasizing that neither gelatinisation nor
formation of curd is identical in kind with the process of attainment
of equilibrium within the liquid sol. A true reversible equilibrium
is attained from both sides within the sol whilst it is supersaturated
with respect both to gelatinisation and formation of curd.

Several authors have observed that formation of curd is accom-
panied by the evolution of heat.

VII.—The Effects of Additions.

(a) Hucess of Fatty Acid.

In the case at least of the saturated fatty acids, the addition of
excess of acid results in the formation of acid sodium or potassium
salts which are insoluble. These acid soaps probably do not correspond
to any very definite chemical formula and as yet no complete chemical
analysis of such a specimen has been obtained from which, for example,
the amount of water in it could be deduced. As regards amount of
alkali, their composition lies between that of the acid salt exemplified
by the acid sodium acetate, NaH Ac,, and that of neutral soap. These
acid soaps do not lie within the region investigated from the stand-
point of the phase rule by Donnan and White,’® who showed incidentally
that possibly no pure acid sodium palmitate NaHP, exists.

In the case of sodium palmitate, we have found that addition of
palmitic acid to the solution causes a change in the conductivity
and also in the vapour pressure. Both conductivity and lowering
of vapour pressure when plotted against the amount of acid added,
are seen to diminish linearly to a small value at a point corresponding
roughly to HP:2NaP. At this point the magnitude of the conductivity
and lowering of vapour pressure although small is definite and
independent of the original concentration of the sodium palmitate.
This behaviour clearly points to the formation of the insoluble acid
soap HP:2NaP, in equilibrium with its saturated solution. Further —
addition of palmitic acid causes both the lowering of vapour pressure
and conductivity of the aqueous fluid tojbecome still’smaller, showing

that the acid soap becomes more and more insoluble as the amount
of acid in it increases beyond the composition mentioned. These
“ solutions ”’ appear as translucent pastes or jellies at 90°. On cooling
silky fibrous crystals of acid soaps may separate. More dilute solutions
froth very readily.

(b) Excess of Sodium Hydroxide.

Most of the phenomena occurring upon the addition of caustic soda
or other electrolytes, which ultimately result in the quantitative
salting out of the soap from the solution, will be discussed in Part II.,
which- deals with the technical colloidal chemistry of soaps, their
solutions, gels, and curds.

Rarely are homogenous solutions of soap to be met with during
the process of manufacture, since these would be of prohibitively
great viscosity. Usually, as has been found in this laboratory, the
soap is in the form of an emulsion of two soap solutions, whether~
sol-sol, sol-gel, or sol-curded gel. The experimental evidence will be
published elsewhere.

A number of theoretical points also must be reserved for forth-
coming publications. However, it should be mentioned here that
for the greater part these additions do not actually combine with .
the soap, but drive back its dissociation or displace the numerous
equilibria involved.

VIII.—Detergent Action of Soaps.

The brilliant work of a number of such investigators as Hillyer
(1903) and Spring (1908) has shown conclusively that the detergent
power of soaps is due to their colloidal nature, and it is only influenced
by their chemical constitution in so far as this affects their behaviour
as colloids.

In commerce soaps are usually bought and sold upon their
appearance and texture after assurances have been given with regard to
their classification as curd soaps, tallow rosin soaps, cleanser soaps, &c.
There are no universally accepted quantitative standards to which
soaps are referred with regard to their washing power. It is convenient
to give a list of all the cognate experimental methods hitherto
published as having more or less bearing upon this question :—

(1) Measurement of surface tension against air by capillary tubes
or by drop members or by bubbling or by measuring the
amount of froth produced under definite conditions.

(2) The measurement of surface tension against oil or paraffin oil
or benzene by drop numbers or measurement of emulsifica-
tion.

(3) Measurement against carbon or other powders by measuring
rate of sedimentation or protective action in filtration.

(4) Protective action as measured by gold numbers.

(5) Direct washing experiments with specially soiled clothes under
controlled conditions of true temperature and concentra-
tion. (Zhukov and Shestakov, Chem. Ztg., 1911, 35, 1027.)

It is, of course, impossible to give here a summary of the mass of
information, chiefly of a technical character, with regard to the
detergent action of various soaps and soap substitutes and their effect
upon various textiles, but the chief theoretical results will be referred
to.

Krafft has quite rightly insisted that the soaps must be in solution
in order that such solutions should exhibit appreciable detergent
action. Thus in cold water sodium palmitate and stearate are nearly
insoluble, whilst the soluble oleate is an ideal detergent, and even
the only moderately soluble laurate and rosinate wash fairly well.
Hot water is necessary for the use of tallow soaps, which consist
largely of palmitate and stearate; as Jackson (Cantor Lecturer) has
pointed out, potassium soaps are more soluble in the cold than sodium
soaps. We would add here the deduction from our measurements of
the amount of ionic micelle present in various pure soap solutions, that
the washing power which the oleates exhibit par excellence is connected
with the fact that their colloidal nature persists well into dilute
solutions; whilst the laurate in dilute solutions and more especially
at higher temperatures is largely broken down to simple electrolyte.
For this reason, stearate is suitable for washing at the boiling point,
since at this temperature it is soluble and it contains much more
colloid than the lower soaps. Such considerations are of importance,
for example in the choice of a suitable soap for the washing of woollen
goods in the cold.

Earlier theoretical writers, such as Chevreul, Berzelius, Persoz,
von Bussy, Waren-Delarne, Knapp, Stiepel and Moride emphasized
the emulsifying powers of soap solutions and of soap foam towards
fats and fatty materials. The capacity of soap solutions to wet
oily matter was also emphasized whilst the unknown amount of
hydrolysis alkali was credited with powers of saponification.

Hirsch, in 1898, showed experimentally that fatty oils were not
more readily emulsified than were various other organic liquids,
and he demonstrated also that the large amount of oil emulsified
was quite out of proportion to the small amount of soap present.
This showed that the effects produced were ascribable to the soap
itself and not to any alkali present.

Donnnan (Zeitsch physical Chem., 1899, 31, 42) showed experi-
mentally that emulsification and lowering of surface tension went
hand in hand in the case of solutions of different soaps. Plateau had
pointed out that in general formation of solid surface films might be
quite as effective as low surface tension in emulsification.

Hillyer (Jour. Amer. Chem. Soc., 1903, 25, 511, 524, and 1256)
showed experimentally that the emulsifying properties of soap could
not be attributed to hydrolysis alkali hydroxyl ions, nor did alkali
possess the power of wetting oily matter that soap did. Hence both
these factors in detergent action must be due to the soap itself. Of
course, as Donnan had pointed out, the free fatty acid contained in all
natural fats and fatty oils could be neutralised with formation of soap
this would be quite different from saponification of glycerides which is
anextremely slow reaction. Hillyer demonstrated again the parallelism

of low-surface tension and emulsification in the case of soaps, and
incidentally showed that saponin emulsified through formation of solid
surface film instead of through low surface tension. Hillyer also
demonstrated the power of penetration into capillary interstices which
is conferred upon soap solutions by their very low surface tension.

We have then experimental proof of the operation of two of the
previously assumed factors of detergent action, emulsification (parallel
to low surface tension), and wetting power, both ascribable to the
undecomposed soap itself. The third suggested factor, the action
of soap in making tissue and impurities less adhesive to one another
was also put forward again by Hillyer, but the experimental evidence is
entirely due to Spring (Kolloid, Zeitsch, 1909, 4, 161; 1909, 6, 11,
109, 164; Arch. Sci. phys. nat., 28, 569; 29, 41, 36, 80; Rec. trav.
chem., 29, 1; Bull. acad. Roy. Belg., 1909, 187, 949; 1911, 24, 17).
Goldschmidt has already postulated a protective action of the
colloidal soap upon dirt particles, since Zsigmondy had shown that
the gold number of sodium stearate (the minimum quantity to protect
10 c.c. of red gold sol from colour change upon addition of 1 c.c. of
10 per cent. sodium chloride solution) was 10 mg. at 60° and 0-01 mg.
at 100°. The value for sodium oleate was 0-6 to 1 mg.

Spring pointed out that all previous workers had been imbued
with the conception of dirt as being of a fatty or oily nature, or
covered with a coating of such nature. In his experiments, therefore,
he carefully eliminated all fatty matter, which leaves the detergent
action of soap quite unimpaired. His striking and original experi-
ments dealt with purified lamp black, silica, alumina, and iron oxide.

Spring’s conception is that carbon promotes the hydrolysis of a
soap solution and forms a stable non-adhesive sorption compound
with the acid soap produced. Dirt upon a fabric he regards as being
combined with the fabric in an analogous way. Cleansing by soap
is simply the formation of a sorption compound dirt and soap in
place of the sorption compound dirt and fabric by direct substitution.
A more logical alternative is that of double decomposition in
which two sorption compounds are formed, fabric + soap and dirt
+ soap. As a matter of fact it is often extremely difficult to
remove soap from a fabric after the operation of washing. Spring
points out that alcoholic solutions possess poor detergent power
because hydrolysis is not so great, this is not true if the alcoholic
soap is used in water. However, he found that whilst lamp black
took up acid soap, ferric oxide, silicic acid, and cellulose take up soap
containing an excess of alkali, so that his results in some cases might
be more logically attributed to soap itself. The basic soaps of which
he speaks do not in fact exist. The poor detergent action of alcoholic
soaps on this view would simply be ascribable to the fact that in
alcohol the soap contains only traces of colloid.

Spring’s two chief experimental results, are that lamp black is
carried through filter paper which, in the absence of soap, would
retain it completely, and, secondly, that the rate of sedimentation
is a function of the concentration of soap or, indeed, of alkali present.
Lamp black sedimented as fast in 2 per cent. soap solution as in
water, whereas in 1 per cent. solution it remains suspended for

months, and in 4 per cent. solution for days. In the case of ferric
oxide, the optimum concentration was } per cent. soap, and in the
case of potters’ clay, 1/32 per cent. soap. Alumina showed remarkable
periodic optima in 1/4, 1/8, and 1/16 per cent. soap, with a similar
numerical periodicity of coagulation. Zhuknov and Shestakov found
that in laundry practice the best results were obtained with 0-2 to
0-4 per cent. soap solution.

Donnan and Potts found a similar optimum concentration in the
emulsification of paraffin oil by soap solutions in a concentration
of N/300. They emphasize that the excess of soap in the interface
which is a necessary corollary of the lowered surface tension and
the viscous nature of the surface film must both contribute to the
stability of the emulsions. Pickering (Jour. Chem. Soc., IfI., 86)
agrees both with Donnan and Spring, but considers also that oil
and other substances are soluble in the presence of soap.

Jackson (Jour. Soc. Aris, 55, 1101 and 1122 (1908), Cantor
Lectures) called attention to the influence which soap exerts upon
the state of subdivision of the dirt, and he observed under the micro-
scope dirt particles and fibres of linen being brought first into oscilla-
tion and then completely loosened by a soap. This spontaneous
action was best exhibited by an alkaline oleate. He also, pointed
out that the presénce of glycerine in soaps had only an unimportant
influence upon their detergent action.

Shorter (loc. cit) adduces experiments from which he concluded
that acid soaps exhibit no surface activity and that detergent action
is due mainly to undecomposed soap. Excess of alkali enhances
the detergent action. Developing the consideration of the electrical
effects introduced by Donnan and Potts (loc. cit), he points out that the
effect of the alkali is to increase the negative charge both on the
particles of oil and dirt and on the surface to be cleansed, which tends
to prevent coagulation and redeposition of those particles.

It emerges from all this discussion that there are a number of
definite factors in detergent action; first, the necessity of having
the soap in solution; second, power of emulsification which goes
parallel with low surface tension and the formation of surface films ;
third, wetting power which like the last, is ascribable to the unde-
composed soap itself; fourth, the action of soap in forming non-
adhesive colloidal sorption compounds with tissue and impurities
due sometimes to acid soap, but more often to soap itself and capable
of remaining in stable suspension; fifth and lastly, it is an essential
in all cases that the soap should be in colloidal form.

It is evident that comprehensive quantitative work is necessary
to complete and co-ordinate the existing fragmentary work in any
one case. Each of these factors are perfectly capable of simultaneous
determination and quantitative evaluation.

IX.—Retrospect.

We have seen that all the phenomena of soap solutions point to
the existence of a highly conducting heavily hydrated ionic micelle
of the general formula (NaP), * (P’), * (H.O),; and that from

the scattered indications in the literature it is evident that many
colloidal substances of great industrial importance must exhibit
similar behaviour and be classed together with soaps as colloidal
electrolytes.

This conception leads then to the following complete circle of
continuous transitions between types of solutions and sols through
each of the well-recognised intermediate types. For convenience,
the circle is given as a table. The + signs indicate the relative extent
to which osmotic pressure and conductivity are exhibited by the
various standard types. The table is intended to represent the
natural sequence of transition in which consecutive pairs are much
closer than non-consecutive pairs. Thus there is evidently a gradual
transition from neutral colloid through semi-colloid (not through
charged colloid or colloidal electrolyte) to ordinary crystalloid, that
is, non-electrolyte. Some of these transitions may be realised in
the case of soap solutions by merely altering the concentration or
temperature or by passing from one member of the homologous series
to another.

TABLE [.

Circle of Continuous Transition between Types of Solutions and Sols.

Group. Examples. Osmotic Conductivity.
Activity.
Crystalloid, non-electrolyte | Sucrose - - ++ 4+
Semi colloid - - - | Dextrines - +
Neutral colloid- - Pauli’s egg alburnin 0
tb
i]

Charged colloid - - | Gold sol - -
Colloidal electrolyte - | Soap, dyestuffs - +4

++
++

Crystalloidal Prete - | KCl -- - - teak ak

Electrolyte = - - | HgCl, = - Jak 6

Crystalloidal non- Piece Sucrose - : ++ 4
lyte.

The conception here presented of the constitution of soaps and
their solutions, gels, curds, and sediments is only a preliminary sketch
but its main outlines would appear to be authenticated by experiment.

SELECTED REFERENCES.

Free use has been made in the text of the various investigations carried
out in this laboratory, a number of which have not yet appeared, and a few of
which are not yet completed.

‘ I.— Conductivity.
1, KAHLENBERG and ScHREINER. (Zeitschr. physikal. Chem. 1898, 27, 552.)

Conductivity of dilute solutions of sodium oleate, potassium stearate
and potassium palmitate. Freezing points of N/8 and N/16 sodium oleate.
Boiling point experiments showing that the method was unreliable,

2, J. W. McBarn and M. Taytor. (Zeitschr. physikal Chem. 1911, '76, 179 )

Very painstaking measurements of the conductivity of sodium
palmitate in all concentrations, sodium, acetate, sodium hydroxide, sodium
palmitate with excess of hydroxide and of palmitate acid; boiling point
determinations showing that the method was inapplicable, to a vapour
pressure measurement in which the vitiating influence of dissolved air
was largely eliminated; salting out experiments and analyses of sediments.

3. J. W. McBain, E. C. V. Cornisu, and R. C. Bowpren. (* Trans. Chem, Soe.’
1912, 101, 2042.)
Conductivity and densities, solidification, temperatures and appearance
of sodium laurate and myristate at various temperatures.

4, R. C. Bowpren. (‘ Trans. Chem. Soe.’ 1911, 99, 191.)
Conductivity of sodium stearate at 90°.

5. A, Reycuter. (‘ Kolloid Zeitschr.’ 1913, 12, 277; 16th ‘ Viaamsch Nat
Gen. Congres, Leuven,’ 1912, 69; * 8th Intern. Congress App. Chem.’ 1912,
92, 221; * Bull. Soc. chim. Belg.’ 1913, 87, 300; 27, 217; 26, 193, 485; 27,
110, 113.)

Conductivity of sodium palmitate, cetyl sulphonic acid, sodium cetyl
sulphonate, cetyl sulphonate of tri-ethyl cetyl ammonium, hydrochloride
of di-ethyl cetyl amine, tri-ethyl cetyl ammonium iodide, sodium oleate.
Boiling points of the frothing solutions of many of the above, unreliable.
Sediments in sodium palmitate solutions, extractability of sodium oleate
solutions by toluene.

6. F. Gorpscummpt and L. Weissmann. (‘ Kolloid Zeitschr,’ 1913, 12, 18;
*Seifensieder Zeitung,’ 1914, 41, 337.)
Conductivity and viscosity of the ammonium soaps of the fatty acids
of palm kernel oil at various temperatures and concentrations, with and
without additions of ammonia and ammonium chloride.

7. F. Gorpscumipt and L. Weissmann. (‘ Zeitschr. Elektrochem,’ 1912, 18,
380.)
Conductivity and viscosity of the potassium soaps of the fatty acids
of palm kernel oil with and without additions of potassium hydroxide and
potassium chloride.

8. H. M. Bunsury and H. BE. Marin. (‘ Trans. Chem. Soc.’ 1914, 105, 417.)

Conductivity, density and appearance of potassium salts of the fatty
from the acetate to the stearate at 90°.

9. J. Kurzmann. (‘ Kolloidchem. Beiheft.,’ 1914, 5, 427; Dissert. Karlsruhe.
1914.)
Conductivity and viscosity of potassium myristate, laurate and oleate
and their mixtures with each other and with potassium hydroxide and
potassium carbonate at various concentrations and temperatures.

10. K. Arnpt and P. Scuirr. (Kolloidchem. Beihefte. 1914, 6, 201.)

Conductivity, viscosity sediments and solidification of sodium and
potassium palmitates with and without added chloride.

1l. H. Pick. (Seifenfabr. 1915, 85, 255-7, 279-81, 301-5, 323-5.)
Probably a review of work chiefly from this laboratory.

12. M. E. Late. (‘ Trans. Chem. Soc.’ 1918, 118, 435.)

Conductivity and boiling point measurements of dry alcoholic solutions
of potassium oleate and of oleic acid.

13. McBarn, M. E, Laine and Titty. ((‘ Trans. Chem. Soc.’ 1919, 115, 1279.)

Conductivity, density, and freezing points of potassium, laurate, oleate,
octoate, acetate and decoate and of sodium oleate and acetate. Formu-
lation, concentration and mobility of the ionic micelle. Dew point
measurements of ammonium laurate and palmitate and of potassium
chloride, laurate, octoate, and oleate at 20°. *

14, J. W. McBarn and C. 8. Satmon. (‘ Proc. Roy. Soc.’ and ‘ Journ. Amer.
Chem. Soc.,’ March 1920.)

Dew point measurements of most of the sodium and potassium soaps
down to the acetate at 90°. Formulation, concentration and mobility
of the ionic micelle.

15. J. W. McBarn, M. E, Larye and M. Taytor. (Not yet appeared.)

Conductivity, dew point and density of sodium palmitate solutions
containing various additions of sodium hydroxide and of palmitic acid.

II.—Molecular weight and Osmotic activity.
1, 2, 5, 12, 13, 14, 15 above.
16. B. Moorr and W. H. Parker. (‘ Amer. Journ. Physiol.’, 1902, 7, 261.)

B. Moore and H. E. Roar. (‘ Kolloid Zeitschr.’, 1913, 18, 133.)
Osmometer experiments with soaps giving unreliable and erroneous
results, in some cases of the wrong order of magnitude.

17, F. Krarrr and A, Stern, H. Wictow, A. Srrutz. (‘ Ber.’, 1894, 27, 1747,
1755; 1895, 28, 2,566; 1896, 29, 1,328; 1899, 32, 1584.)

Ebullioscopic measurements of the sodium and potassium salts of
most of the fatty acids in water and in alcohol, in most cases vitiated by
the partial pressure of air in the soap bubbles. Salting out. Extract-
ability with toluene. Appearance and sediments Effect of carbon
dioxide, :

18. A. Smrrs. (‘ Zeitschr. physikal. Chem.’, 1902, 39, 385; 1903, 45, 608.)

Tensimetrie determinations of sodium palmitate vitiated by partial

pressure of air present.

19. W. M. Bavyuiss. (‘ Proc. Roy. Soc.’, 1910, B, 81, 269.)

F. G. Donnan and A. B. Harris. (‘ Trans. Chem. Soc.’, 1912, 99, 1,554.)
Conductivity and osmometer measurements with Congo-red.

TIL.—Hydrolysis,
20. J. Lewxowitscu. (‘ Zeitschr. Angew Chem.’, 1907, 20, 951.)
The hydrolysis of soap solutions could never be complete since it was
impossible to extract all the fatty acid by shaking with another solvent.
21. D. Horpe. (‘ Zeitschr. Elektrochem.’, 1910, 16, 436.)
Extraction of ‘aqueous alcoholic soap solutions by petroleum ether
See 2 above.
22, G. Fenpier and O. Kuun. (‘ Zeitsher. angew. Chem.’, 1907, 22, 107.)
Effect of carbon dioxide upon various soaps. See 17 above.

23. F. Gorpscumipr. (‘Chemiker, Zeitung.’, 1904, 302.)
Hydrolysis in aqueous alcoholic solutions of soap

' 31

24, J. W. MoBarn and H. E. Martin. (‘ Trans. Chem. Soc.’, 1914, 105, 957.)

Determinations of hydrolysis alkali by hydrogen electrode in sodium
hydroxide, sodium and potassium palmitates, potassium myristate to
acetate, with and without excess of palmitie acid or alkali or sodium
chloride at various temperatures and concentrations and some commercial
soaps at 90°.

25. J. W. McBarn and T. R. Botam. (‘ Trans. Chem. Soc.’, 1918, 118, 825.)

Determination of hydrolysis-alkali by rate of catalysis of nitrosotriace-
tonamine in sodium acetate and palmitate with and without added sodium
hydroxide and of potassium palmitate at various temperatures and
concentrations.

IV.— Viscosity.
6, 7, 9, 10, above.
26. A. Mayer, G. ScHArFFER and E. F, Terroine. (‘ Compt. rend.’, 1908,
146, 484.)

Viscosity, appearance, sediments, dialysis of sodium oleate, from the
caproate to the stearate and oleate, with excess and deficiency of allcali.
Ultramicroscopic particles.

27, F. Borazzt and Vicrororr. (‘ Atti. R. Accad. Lincei.’, 1910, 19, i., 659.)

Surface tension, viscosity and appearance of a dialysed Marseilles
soap of unknown composition, with and without addition of alkali.
28. F. D. Farrow. (‘ Trans. Chem. Soe.’, 1912, 101, 347.)

Viscosity of sodium palmitate solutions at 70° in various concentrations
with and without additions of palmitic acid, sodium hydroxide, sodium
chloride or potassium chloride.

V.— Optical.
29. R. Zstemonpy and W. Bacumann. (‘ Kolloid. Zeitschr. , 1913, 11, 145.)

Ultramicroscopic observations of the formation of curd in aqueous and
alcoholic solutions of sodium and potassium oleate, stearate and palmitate,
also solubilities and sediments and solidification temperatures.

30. J. Lirsourrz and J. Branpt. (‘ Kolloid-Zeitsch.’, 1918, 22, 133.)

Refractive index of sodium stearate, palmitate and oleate solutions
and of potassium palmitate in various concentrations at 70°.

_ [Nore.—The subject of soap manufacture will be dealt with by Prof. J. W.
McBain and Mr. Ernest Walls in the 4th Report of the Committee.—W. C. McC.L.]

ULTRA-MICROSCOPY : DEGREE OF DISPERSION—
MEASUREMENT WITH THE ULTRA MICROSCOPE.

By Grorce Kine, M.Sc., FLTC.

The physical and chemical phenomena observed in colloidal
solutions, depend upon four factors: the concentration of the disperse
phase, its size, shape, and internal structwre. A knowledge of these
factors is desirable in order that the phenomena observed in any
particular investigation may be interpreted in terms of the energy
distribution in the system.

(a) Concentration of Disperse Phase.

The concentration is often determined by the evaporation of the
dispersion medium—this method is satisfactory only in the absence

32
*

of non-volatile substances of molecular dimensions. The concentration
of the disperse phase in hydrosols is most conveniently determined
by ultra-filtration through collodion membranes. The method used
by Zsigmondy*? gives very accurate results and is less complicated
than the Bechold? method. By suitably varying the composition
of the collodion (Schoep**), a rough grading of a non-uniform disperse
phase is rendered possible, those colloidal particles above a definite
size only, remaining on the filter. Certain physico-chemical methods,
such as colorimetric determinations have been successfully used to
determine concentration and Marc** has developed the interferometer
for technical use, whilst Mecklenburg®*, and more recently, Tolman’’,
have used the intensity of the light scattered by a colloidal solution
(Tyndall Beam*1),

(b) Size, Shape, and Internal Structure.

The size of the particle more than any other property determines
.the behaviour of a particular solution, and its estimation is therefore
of considerable importance.

According to Ostwald the dimension is best expressed as the
degree of dispersion, or, the ratio of the absolute surface of an
individual particle of the disperse phase, to the volume of that particle.
von Weimarn®, however, has pointed out that this ratio alone does
not sufficiently determine the properties of the system, on account
of the difference in the internal structure of two otherwise similar
particles. Moreover the shape and hence the value of the ratio,
depends upon the method used for the preparation of the colloid
(Svedberg, Gans'*). Since nothing definite is known of the internal
structure and shape of the particle under particular experimental
conditions, it is more usual to express the size in terms of the linear
dimensions of the particle. The method used for this determination
depends upon (1) the physical condition of the continuous phase and
the size of the particle, (a) microscopic, (6) sub-microscopic. Sus-
pensions containing particles as large as 10 w= -01 mm. exhibit
colloidal properties—e.g., Brownian movement, cataphoresis—and
for the purpose of classification, such particles are called microns®s,
The lower limit for the micron is conventionally fixed at -2 yw and
corresponds with the limit of microscopic visibility as determined by
Johnston Stoney’. Sub-microns are detected by means of the ultra-
microscope, and range from -2 yu, to the lower limit 3 yz = -000003 mm.
observed by King” using the Zsigmondy* immersion ultra-microscope.

I.—Continuous Phase Solid.
(a) Microns.

Owing to the absence of Brownian movement, direct microscopic
measurements can be made. Tinker‘? using an oil immersion fluorite
objective, and improved illumination, was able to measure the
particles in a semi-permeable membrane up to the theoretical limit
of microscopic visibility.

(b) Sub-Microns.

Two methods each depending upon the application of the Tyndall
effect are available, but they cannot be applied to the non-transparent
solid solutions encountered in metallurgical practice.

1. Rayleigh’s Formula—It is well known that an incident beam
of light falling upon particles, small compared with the wave length
of light, is not reflected but scattered and polarized. The intensity
of the scattered light varies according to the Rayleigh? formula
I, = Anr */\* where A is a factor which depends upon the experi-
mental conditions, ‘‘n” is the number of particles of radius “r”
scattering light of wave length “A” With a particular solution
where “n” is constant and the intensity of the scattered light may
be measured by means of a spectrograph and “r ”’ found by substitution
in the Rayleigh formula. The method is considered by Henri to
be very sensitive and to give exact results with hydrosols. But it is
neither so convenient nor so rapid as the method elaborated by
Zsigmondy* in his investigation of gold ruby glass and for which,
in collaboration with Siedentopf** the first ultra-microscope was
designed.

2. Ultra-Microscopy—Zsigmondy observed the scattered light in
a microscope set orthogonally to the illuminating beam. The particle
then looks like a planet, self-luminous in a dark field. The light
observed is sometimes coloured® and appears as diffraction rings,
the size and colour of which is independent of the size of the particle,
but depends upon the numerical aperture of the objective and con-
denser, and the intensity of the illuminating beam. The light used must
be of high specific intensity, and the illumination system such that
in the solid under examination, a layer of known thickness, and less
than the depth of vision in the microscope, is illuminated, by a beam
of known width. Suitable apparatus made by Zeiss** and Reichert*
is known as the Zsigmondy “ slit” ultra-microscope, and the method
of manipulation has been well described by Heimstadt.14

The solid solution to be examined is cut so as to form at parallelo-
piped some 3 mm. thick, with two carefully polished faces at right
angles. This is placed on a special microscope stage so’ that the
illuminated layer can be observed at any point in the parallelopiped.
By direct counting it is then possible to determine the number of
particles ““N ” in unit volume of the solid, containing a mass “M”

of the disperse phase of density D. By substitution in the formula
—

L= = the linear dimension of the particle, considered as a

cube,is calculated (c.f. Wiegner®4), Errors may be introduced in the
determination of density and mass. It is usual to assume that the
density is constant and independent of the size of the particle, and
accordingly the ordinary density of the substance in microscopic
condition is used. For metal sols in solid solution the error, if any,
is negligible (Cholodny’), but for oxides, hydroxides, and emulsions
this assumption may introduce an error making he estimated size
too large (Wintgen®*, Biichner*). The determination of mass per

w% 11454 Cc

unit volume in solid solutions gives the total mass of submicrons
and also amicrons* present. Since the amicrons are not included
in the number of particles counted, their mass should be subtrated
in order to obtain the true concentration of the submicrons. For
solid solutions there is no satisfactory method of correcting for this
error, but with hydrosols it is possible to separate the amicrons by
ultra-filtration, and it is found that the error they introduce does
not affect the order of the magnitude, and is seldom more than 50 per
cent. The more recent ultra-microscopes cannot be used for the
examination of solid substances.

II.—Continuous Phase Liquid.
(a) Mucrons. ;

1. Filtration —For the rapid grading of microns filtration through
special earthenware filters is convenient, this was the method of
Linder and Picton? (1892). Bechold? extended the method by
preparing a series of graduated filter papers which are standardised
for known solutions, and used under pressure in a special apparatus.

2. Stokes’ Law.—The viscous resistance of spheres of radius “r”
density “p”’ moving with uniform velocity “v’”’ in a medium of
density p! and viscosity 7 is given by Stokes’ Law F = 6zyrv. This.
Law was first applied to colloidal solutions by Barus and Schneider
(1891) to measure the radius of particles precipitated by electrolytes.
Since the force acting is gravity ‘‘g”’ the equation becomes—

r= & ny
2 p—p';
It was shown by Perrin®® that Brownian Movement does not
interfere with the mean velocity of the particle in colloidal suspensions
and solutions so that, assuming they are spheres, we have a ready

means of determining accurately their size from diameters of 1 mm.
to and beyond the microscopic limit.

(b) Sub-Microns.

Methods may be classified as (1) ultra-filtration; (2) ultra-
microscopy; application of single reflecting condensers, using
(3) Stokes’ Law; and (4) density of distribution; (5) double reflecting
condensers for direct measurement; (6) improved ultra-microscopy ;
application of (7) light absorption; (8) Rayleigh Formula; (9)
diffusion constant.

1. Ultra-Filtration—Bechold’s method (referred to under Microns)
may be used but the prepared papers, owing to the negative charge

in the capillaries, cause adsorption and precipitation of the positive
colloid.

2. Ultra - Microscopy. — The Zsigmondy - Siedentopf apparatus
(described above) was adapted for the examination of liquids and
gases by introducing an observation cell. This cell—improved by

* The term amicron is used for particles which cannot be detected in the
ultra-microscope.

—

Thomae**—is provided with quartz windows at right angles and
held in a special clip so that the condenser and water immersion
objective are directly opposite the windows. On account of the
Brownian Movement it is more difficult with liquids than with
solids to count the particles in a known illuminated volume. The
solution should be so diluted, that at the same time, about four
particles only are visible and ten momentary counts are made. The
solution in the cell is changed ten times, counted each time, and the
mean of the 100 counts is found. A control observation should be
made with a different dilution. With experience the total time
required for a determination is about 30 minutes, and it is recom-
mended by King”, that for rapid work, momentary illumination by
means of a pendulum be used, and the momentary observations
recorded on a typewriter. With this apparatus hydrosol submicrons
of 2u to 5up can be measured, provided the refractive index* of the
particle is sufficiently different from that of the water—a proviso
which applies to all ultra-microscopic observations.

Shortly: after the introduction of the “slit”? ultra-microscope
other systems of dark ground illumination, well known to earlier
English microscopists, were used for the examination of colloidal
solutions. These systems differ from the Zsigmondy arrangement
in that the illuminating beam is coaxial with the microscope, and is
brought to a focus in the colloidal solution by means of a special
substage condenser, provided with a central stop, so that the solution
is illuminated from all sides by rays comprised within the apertural
zone of 1-0 to 1-3 NA. It is evident that the value of the apertural
zone need not be greater than the refractive index of the medium,
e.g., for hydrosols 1-33. The earlier condensers of this type are of
historical interest only, as also are the Cotton and Mouton’, Scarpa*4,
and modified Abbe condensers used with centre stop objectives of

high numerical aperture. Reference should be made to the useful

summary by Burton’.

The substage ultra-condensers suitable for colloidal solutions or
the observation of living and unstained bacteria may be classified
as (1) single reflecting, Reichert and the Zeiss Paraboloid®?; (2) double
reflecting, Leitz®®-Jentzsch1*; and Zeiss Cardioid*s.

1. Single Reflecting Condensers—The Reichert and _ so-called
paraboloid} although different in principle have both the same uses
and limitations. They are suitable only for comparatively coarse
hydrosols, and cannot be used for direct quantitative estimations,
since both show spherical aberration and in the paraboloid the images
produced by the different zones vary in size. Consequently the
intensity of illumination decreases from the centre of the field. Owing

* The intensity of scattered light

7 2
noe [ME |
u2

where vp is the refractive index of medium, and p, of the submicron,

{ Siedentopf modified the shape of the true Paraboloid of Wenham (1584)
and so made the technical reproduction of the condenser cheaper and less
tedious;

to the fact that both of these condensers do not focus at a sharp point,
but rather build up a patch or fleck of light, no difficulty is experienced
in the centering of the condenser, and although the thickness of the
microscope slide or observation chamber may be varied slightly
(0-3 mm.) this does not seriously interfere with the observation.
The illumination used is either an inverted incandescent gas mantle
or a Nernst lamp. For the rapid examination of.a series of solutions
the paraboloid is not so convenient as the Zsigmondy arrangement
since the microscope setting must be distrubed after each reading
and the slide and cover glass most carefully cleaned. For use with
the Reichert instrument a small observation cell has been constructed
through which a series of solutions may be passed.

3. Stokes’ Law.—Although useless for direct quantitative work,
Reichert and Paraboloid ultra-microscope when arranged horizontally,
are well suited for the purpose of determining the radius of sub.
microns from their speed of settlement by the application of Stokes’
Law (see above under Microns). The method cannot conveniently be
used for submicrons of less than 20up diameter since calculation
shows that gold particles of this size take seven hours to fall 0-1 mm.
By super-imposing on gravity an electrical field, the speed of settle-
ment is increased and Burton® by this means has applied the Law
to the “ weighing of the particles ” (c.f. also Westgren*®).

4. Density of Distribution—These instruments may also be used
to count the number of particles n and n° of radius r density p in
equilibrium at heights o and h. The radius is then calculated from
Perrins®! equation (c.f. also Oden**)—

1 n° h r? 1027
Bae int (Okt Pll etajien.A

2. Double Reflecting Condensers—The Siedentopf Cardioid*®* and
Jentzsch!8 are practically free from spherical aberration and are
almost aplanatic. By means of a micrometer eye-piece the area of
an illuminated layer of fixed depth—slightly moe than the depth of
vision—is determined and the volume calculated. This volume
cannot be varied as in the slit or immersion ultra-microscope (see
later), and the determintions are not so reliable. On the other hand
owing to the increased intensity of the illumination it is possible to
measure particles which are too small for counting in the slit ultra-
microscope, but which can be counted in the new Zsigmondy™
immersion apparatus. The Jentzsch or Cardioid are particularly
suitable for the examination of thread-like bacteria of microscopic
length but ultra-microscopic breadth. Such bodies in the slit or
immersion ultra-microscope appear as points of light. Siedentopf*?
showed that this was due to illumination from one side only, and that
the appearance of such bodies depends on the azimuth of the incident
light. Owing to the fact that the illumination in all reflecting
condensers is concentric, the complete structure of such bodies is
revealed. Since the rays are brought to a sharp focus it is essential
that double reflecting condensers should be accurately centred and
that the special slide, cell, and cover be “ ultra-microscopically clean.”

The need for the careful adjustment of these parts after each observa-
tion renders the cardioid instrument troublesome for the rapid
quantitative examination of a series of sols. This has been recognised
by Siedentopi*® who describes an accessory objective for preliminary
qualitative investigations. Jentzsch* has designed an ultra-condenser
specially suitable for the purpose, the cell of which is provided with
inlet and outlet for hydrosols, and if desired with electrical and other
fittings. Mention should also be made of the Leitz-Ignatowski**
Universal condenser, which may be used for both ordinary and dark
ground illumination, but the dark field is not so perfect as in the
Jentzsch condenser.

The determination of the size of metal hydrosols less than
5up diameter is best made by the “nuclei”? method. It was found
that very small particles, 5uy or less (amicrons), which cannot be
counted in the slit ultra-microscope, but which give to the field a
uniform illumination, can be seen by means of the cardioid condenser.
For the determination of their size an indirect method due to
Zsigmondy® is reeommended. It is known that a gold sol prepared
under standard conditions by reduction with phosphorus, gives a
colloidal solution which contains amicrons only—so small as to be
beyond the range of the “slit” ultra-microscope. If some of this
solution (containing 5 mgs. of gold per 100 c.c.) be added to a
colloidal gold solution which is being prepared by other methods,
e.g., formaldehyde or hydrazin) the small amicrons function as
nuclei around which the gold present in the second solution builds
up, forming a larger particle. Doerinckel and Menz?* observed that
the size of the particles in the resulting solutions depend upon the
number of “ nuclei’? added. Thus, knowing the amount of gold in
the nuclear solution it is possible to calculate the size of the amicron
nuclei. Good agreement was found within the range of the slit
ultra-microscope and the method has been frequently used by
Svedberg and Zsigmondy to determine the size of amicrons. Recently
Zsigmondy has succeeded in increasing the intensity of the orthogonal
illumination in a system similar to the “ slit’ ultra-microscope so
that particles between 5uyz and 344 may now be counted as sub-
microns. The diameters of such particles as calculated by the “ nuclei”
method, from observations in the slit ultra-microscope, and as directly
observed in the new immersion ultra-microscope agree.

6. Improved Ultra-Microscopy.—Other conditions being equal
the brightness of the particles seen in the ultra-microscope depends
upon the product of the square of the numerical aperture of the
condenser and objective. In the slit ultra-microscope it was found
necessary** to use a condenser of small aperture (-30) and objective
of -75 NA. By using a condenser and objective of high numerical
aperture, 1:05 N.A. set orthogonally, Zsigmondy® has very con-
siderably increased the intensity of the illumination and the corres-
ponding intensity of the scattered light, so that smaller particles can
be detected and measured. Since the focal distance of such a lens
system is only 6 mm., it was found necessary to cut away a portion
of the front lens and mounting, in order to be able to bring both

objective and condenser near enough to enable the point of focus of
the condenser to be observed through the objective set at right angles.
The hydrosol to be examined is introduced into the small space
between the front lens of condenser and objective, in fact a drop
will remain suspended in this position, so that the path of the beam
through the solution can be seen. For convenience a small ebonite
cup is used to hold the drop in position and this cup is so arranged
that fresh hydrosol or water can be rapidly brought into the field by
opening a spring clip. The instrument is thus an immersion ultra-
microscope with a dark field superior to any other. The illumination
is by sunlight or are lamp and the dimensions of the beam are
accurately defined by a special micrometer slit and eye-piece so that
particles of gold of 3up are countable and smaller particles are visible.
This apparatus is by far the best for the examination of hydrosols*
and no difficulty is experienced when using viscous or jelly-like
hydrosols. It has the disadvantage that, unlike the Cardioid or
Jentzsch thread-like structures and bacteria are observed as points of
light. Observations with this instrument have been reported by
Zsigmondy®*?; Zsigmondy and Bachmann*, and King”.

7. Application of Light Absorption.—The investigations of Garnett®
and Mie?’ should be referred to but so far insufficient is known of the
fundamental relationship to enable the size of the particle to be
determined by this means (c.f. however Voigt*®, Svedberg, Kruyt*4.

8. Rayleigh’s Formula—See under Solid Continuous Phase, (b) 1.

9. Diffusion Constant—The Sutherland*? Einstein“ equation will
be discussed later under gas as continuous phase. The equation has
been applied to measurements obtained in highly disperse liquid
systems c.f. Dabrowski, Svedberg, but the method is too tedious
to be of practical value.

IIl.—Continuous Phase-Gas (Smokes).
(a) Microns.

On account of the rapid Brownian Movement direct microscopic
observation is impossible, unless the particles are collected on a
microscope slide. Stokes’ Law may be applied to gases up to the
microscopic limit.

(b) Sub-Microns.

The methods are classified as (1) Rayleigh’s Law (see above, (b) 1);
(2) Stokes’ Law; (3) Diffusion constant; (4) Ultra-microscopy ;
(5) Oscillation in alternating field.

2. Stokes’ Law.—The formula may be used for particles greater
than 10-4 cms. diameter, granules below this size are comparable
with the mean free path of the molecules of the gas and Cunningham’s®
correction factor must be applied. For particles 10-4 cms. the rate

* Tn 1914, when the author was associated with Zsigmondy in the development
of this instrument, only aqueous solutions could be used, since the cement used
for fastening the front lens was not chemically resistant. The instrument is
now made by R. Winkel, Gottingen.

of fall in air, due to gravity is about 11 cms. per hour, but
convection currents interfere with the observation in highly disperse
smokes. :

3. Diffusion Constant—The value of the diffusion constant D in

N saya "Bere IR, (= 8 - SG Soc pt
N = 606 x 10%) may be substituted in the Einstein equation
x = /2Dt for the displacement x due to Brownian Movement.
This gives a simplified equation d = 4-7 x 10-1 t/x? for calculating
the diameter d of a particle in air as continuous phase at room
temperature (20° C.) when the mean displacement x in time t is
measured. This displacement was recorded photographically by
De Broglie*, but such records are reliable only if a photographic plate
moving at a known rate be used: Owing to the impossibility of
excluding convection effects this method is not recommended for
measuring the size of granules in highly disperse gaseous systems.

Sutherland’s#2 formula D =

4, Ultra-Microscopy—Smokes are conveniently observed in the
Jentzsch or “ slit” ultra-microscope, but not in any of the others.
Precaution should be taken to prevent disturbance due to convection
and heating by using a heat filter (ferrous-ammonium sulphate
solution 1 : 5) in the path of the beam.

5. Oscillation in an Alternating Electric Field —If the particles are
charged, they will move in an electric field, according to Stokes’ Law,
with a uniform mean velocity.

¥ Xe’.

y sand

where X is the field in volts per centimetre and e the electronic charge
(c.f. Hevesy"®). By measuring the velocity and the field the diameter
of any individual particle is determined. This method has recently
been applied by Wells and Gerke®? to the examination of smokes.
By means of a rotating commutator the particles were caused to
oscillate, and their motion was observed, either photographically or by
means of a micrometer eye-piece, in a modified Zsigmondy ultra-
microscope constructed for this purpose. Since the motion due to
convection was perpendicular to the oscillation a zig-zag line was
obtained. It was thus possible to measure the oscillation amplitude
which, multiplied by the frequency of the field reversal gave the
velocity. By varying the field and determining the corresponding
velocities good agreement was obtained for the diameter of a tobacco
smoke particle (2-73 X 10-5 cms.). The method can be used for the
measurement of the size of individual particles in a non-uniform
disperse phase. This represents a distinct step forward. von
Weimarn proposes to construct an ultra-microscope with quartz or
fluorite lens and to use ultra-violet light, which by reason of its short
wave length will increase the intensity of scattered light. With such
an instrument, using the photographic plate method of Wells and
Gerke*, it should be possible to make still further progress into the
realms bordering on the molecular,

BIBLIOGRAPHY.

1 Barus and Schneider, Zeit. f. Phys. Chem., 8, 278 (1891).

2 Bechold, Zeit. f. Phys. Chem., 60, 257 (1907).

3 de Broglie, Le Radium, 6, 203 (1909).

4 Biichner, Proc. Akad Wetenschap, 18, 170; J. C. S., 108 II., 749 (1915).

5 Burton, Phys. Properties of Coll. Solutions, Longman, p. 45 (1916).

6 Burton, Proc. Roy. Soc., 95, 480 (1919).

7 Cholodny, Koll. Zeit., 340 (1907).

8 Cotton and Mouton, Jour. Chim. Phys., 4, 365 (1908) and Compt. Rend.,
186, 1,657 (1903).

8 Cunningham, Proc. Roy. Soc., 834, 357 (1910).

10 Dabrowski, Acad. of Cracow (vide Henri) (1912).

11 Kinstein, Arn der Phys., 21, 756 (1906).

12 Gans, Phys. Zeit., 18, 1,185 (1912).

18 Garnett, Phil. Trans., 208, 385 (1904); 205, 237 (1906).

14 Heimstadt, Handbuch der Mikroskop Technik V. Mikrokosmos, p. 24 (1915).

15 Henri, Trans. Farad. Soc., p. 52 (1913).

16 Hevesy, Koll. Zeit., 21, 129 (1917).

17 Tonatowski, Zeit. f. Wiss. Mik., Technik, XXV., 1.

18 Jentzsch, Phys. Zeitsch, XI., 993 (1910).

19 Johnston Stoney, Jour. Roy. Mic. Soc., p. 564 (1903).

20 King, Jour. Soc. Chem. Ind., 88, Trans. 4, (1919).

21 Kruyt, J. Chem. Soc., II., 452 (1917)

22 Linder and Picton, Jour. Chem. Soc., 61, 137 (1892).

23 Leitz, Wetzlar, 44D., p. 12.

24 Mare, Zeit. f. Chem. Ind. Koll., 14, 181.

25 Mecklenburg, Koll. Chem. Beiheft, 5, 375 and Chem. Abs., 2,974 (1914).

26 Menz, Zeit. Phys. Chem., 66, 132 (1909).

27 Mie, Ann der Phys., 25, 337 (1908).

28 Odén, Koll. Zeit., 18, 33, Chem. Abs., 10, 2,429 (1916).

29 Ostwald-Fischer, Handbook of Coll. Chem., Churchill, p. 27 (1915).

30 Perrin-Hammick, ‘‘ Atoms,” Constable, p. 99 (1916).

31 Perrin, Bull Soc. Fr. Phys., 3, 155 (1909).

32 Rayleigh, Phil. Mag., 375 (1871) and (1889).

83 C, Reichert, Optical Works, Vienna.

34 Scarpa, Ann. Chim. Applicata, 3, 295, Chem. Abs., 3, 395 (1915).

35 Schoep, Bull. Soc. Ch. Belg., 24, 354 (1910).

36 Siedentopf and Zsigmondy, Drudes Ann der Phys. (4), 10, p. 1 (1903).

37 Siedentopf, Zeit. Wiss. Miks., 24, 13 (1907).

38 Siedentopf, Verhd. Deut. Phys. Ges., 12, 6 (1910).

39 Siedentopf, Jour. Roy. Micr. Soc., 573 (1903).

40 Siedentopf, Zeit. Chem. In Koll., 12, 68, Chem. Abs., 7, 2,872.

41 Strutt, Proc. Roy. Soc., 95a, 155 (1918).

42 Sutherland, Phil. Mag., 9, 781 (1905).

48 Svedberg, Zeit. Chem. Ind. Koll., 9, 418 (1915).

44 Svedberg, Zeit. Chem. Ind. Koll., 6, 318 (1909).

49 Svedberg, Zeit. Phys. Chem., 76, 145.

‘6 Thomae, Jour. Pract. Chemie., 80, 390.

47 Tinker, Proc. Roy. Soc., 92a, 359 (1916).

48 Tolman, Jour. A. Chem. Soc., p. 297 (1919).

49 Voigt, Koll. Zeit., 15, 1914, Chem. Abs., 406 (1915).

50 yon Weimarn, J. Russ. Phy. Ch. Soc., 46, 96, Chem. Abs., 9, 2,832 (1905).

51 Weimarn, Zeit. Chem. Ind. Koll., 2, 175.

52 Wells and Gerke, Jour. Am. Ch. Soc., 41, 312 (1919).

53 Westgren, Zeit. Anorg. Allg. Chem., 93, 231, Chem. Abs., 10, 551 (1918).

54 Wiegner, Koll. Chem. Beihefte, 213 (1911).

55 Wintgen, Jour. Chem. Soc., Abs. II., 251 (1915).

56 Zeiss, Jena. Mikro, 308 and 306.

5? Zsigmondy, Ber. 45, 579 (1912).

*8 Zsigmondy, Zur. Erkenntnis der Koll, p. 87 (1905):

59 Zsigmondy, Physik Zeits., 14, 975 (1913.

60 Zsigmondy-Spear, Chemistry of Coll., Wiley, p. 117 (1917).

61 Zsigmondy, Kolloid Zeits., 14, 281 (1914).

6° Zsiomondy, Zeit f. Phys. Chem.. 56, 65 (1906).

THE SOLUBILITY, RATE OF ABSORPTION AND OF
EVOLUTION OF GASES, AS INFLUENCED BY COLLOIDS,
WITH SPECIAL REFERENCE TO PHYSIOLOGY AND
BREWING.

By Groret Kine, M.Sc., F.I.C.

Although the conditions governing the equilibrium in the simple
gas-liquid and gas-solid systems, have received a considerable amount
of attention both theoretically?’ and experimentally** no satisfactory
explanation has yet been given of the mechanism of the process**.
It is not surprising, therefore, to find that comparatively little
systematic work has been done on the more intricate problem of gas
distribution in colloidal solutions, although it is with such solutions
that many of the problems of biology, brewing, botany, sanitation,
and agriculture are chiefly concerned. For the purpose of this report
the experimental investigation will be considered under :—(1) gas
solubility in colloidal solutions; (2) rate of evolution (effervescence) ;
(3) rate of solution (aeration).

I.—Solubility.

The well:known Ostwald* co-efficient of solubility gives the ratio
of the concentration of the gas in the liquid and gaseous phase
C,/C, = A (solubility) and is an alternative expression of Henry’s Law.
This law, as Findlay", 1°, 17, has shown, is valid for solution of the
common gases in water and aqueous solutions of salts and non-
electrolytes, at 25° C., and over a pressure range of 250 mm. to
1,400 mm. of mercury. Cassuto!, working between one and ten
atmospheres, and, more recently, Sander*®, at pressures up to 160
atmospheres observed that, at high pressures, the solubility (A)
decreased slightly with increasing pressure.

At such pressures (2,500 lbs. per square inch) the gas concentration
in the liquid phase is high, and the observed departure from Henry’s
Law is presumably closely connected with the compressibility of the
concentrated gas solution (c.f. Ritzel‘*): Biologists often express
solubility in terms of Bunsen’s coefficient of absorption—the quantity
of gas in cubic centimetres at N.T.P. which is absorbed by unit volume
of the liquid at 760 mm. pressure. This coefficient has not proved so
satisfactory as the solubility coefficient of Ostwald, and Sackur and
Stern®® propose to refer the gas absorbed to unit mass of the liquid.
Stern has recently determined the solubility and absorption co-
efficients for solutions of carbon-dioxide in aliphatic alcohols, and
found that Henry’s Law held good to within one per cent., and that
the solubility coefficient was constant over a much wider range of
pressures than the modified Bunsen coefficient (c.f. also Drucker’).

(a) Physiological Aspect.
The difficulties which physiologists have encountered in explaining
the transport of oxygen and carbon-dioxide by blood have been

_ * Ina paper published in 1877 (Hufner Wied Ann, 1633) it is suggested that
instead of employing Bunsen’s coefficient, solubility should be expressed as “ das
Verhaltnis des adsorbierenden Fliissigkeits volumens zim absorbierten gas
Volumen ” (Drucker).

discussed by Professor W. M. Bayliss in the Second Report of Colloidal
Chemistry, 1918, p. 151. The study of colloidal chemistry has thrown
new light upon the problem of the abnormal solubility of these gases
in blood. Findlay and Harby** (1908) suggested that the effect
is due, partly to absorption on the surface of the disperse phase, and
partly to ordinary chemical combination. The accepted view was
that absorption of oxygen by blood was due to the formation of a
compound of oxygen with the hemoglobin; and this view has recently
received the support of Barcroft‘. According to Peters4*—on the
basis of the iron content of hemoglobin—one molecule of hemoglobin
combines with one molecule of oxygen, but the total quantity of
oxygen absorbed, for one gram of iron, varies according to the nature
of the blood, being 280 c.c. to 401 ¢.c. for pig’s blood and 320 c.c. to
468 c.c. for dog’s *plood. This considerable variation must be due
to the difference in the chemical or physical nature of the hemoglobin
and not to any great extent to variation in the plasma, for the total
amount absorbed by centrifuged plasma of dog’s blood is only
12-6 c.c., whereas the variation in total gas absorbed is 40 c.c. to
70 c.c. In order to investigate the influence of colloidal hemoglobin
on the solubility, Findlay! and co-workers carried out a series
of systematic investigations on the influence of colloids and fine
suspensions on the gas solubility. The specific effect due to the
colloid was investigated by studying the influence of concentration
and pressure on the solubility coefficient. ‘The following are typical
of the 17 colloids used :—ferric hydroxide, gelatin, starch, ox blood,
hemoglobin, peptone. Carbon-dioxide and nitrous oxide were used,
and it was found that, for both gases, at pressures below atmospheric,
the solubility (A) is sometimes less, sometimes more, than in water,
it always falls with increasing pressure, and passing through a
minimum, rises again slightly.

The pressure at which the minimum occurs is practically constant
for all concentrations of a particular sol, but varies for different
solutions. It has been tentatively suggested by Findlay and Creighton*®
that this unique behaviour is due to gas solubility in the disperse
vhase and since the solubility then no longer follows Henry’s Law, it
nust be assumed that gas polymerises in this phase. For the upward
trend of the curve the increased solubility can ey satisfactorily
interpreted in terms of the absorption law. C*,/C, = constant
(e.g., serum albumen, charcoal, suspensions).

It is well known that the solubility of gases in salt solutions decreases
with increasing salt concentration*—provided there is no chemical
reaction. About 20 aqueous solutions of non-electrolytes have been
studied, and in three only, Quinol, Resorcinol®, and Aniline’ is the
solubility of carbon-dioxide greater than in water. These exceptions
are no doubt due to chemical combination of the solute with the gas.

In considering the influence of the concentration of colloids on
solubility, distinction must be drawn between suspensoids and
emulsoids. In physiological and technical chemistry, suspensoids
occur but seldom. Geffcken™ and Findlay*® have both found that

the solubility (A) of carbon-dioxide in arsenious sulphide sols, is less —

than in water, and the latter has observed that_it is constant for

all pressures, furthermore the hydrogen” solubility in silver hydrosol
was indistinguishable from that in water. Very different is the
influence of emulsion colloids on the gas solubility, which is often
considerably influenced by the concentration of the disperse phase,
and especially is this so with serum albumen, egg albumen, starch,
and dextrin, in which the solubility of carbon-dioxide™, nitrous
oxide*, and hydrogen?’ is less than in water. Thus the behaviour
is comparable with that of the non-electrolytes and salt solutions,
and in fact provided adsorption and chemical combination do not
interfere, collodidal solutions in general diminish the gas solubility.
Thus gelatine, glycogen, ferric hydroxide, ox blood and serum diminish
the solubility of nitrous oxide!® at atmospheric pressure, so also
hydrogen in gelatine, nitrogen in blood and serum, and carbon monoxide
in serum‘ have a lower solubility than the corresponding gas”in
water.

For each system at and above a definite pressure there is evidence
of adsorption, this adsorption effect being greatest for egg and serum
albumen and least for gelatine and starch. Very different, however, is
the behaviour of a gas which is known to act chemically with the
disperse phase in solution. In such systems as carbon-dioxide in
methyl orange!’?, hemoglobin, ox blood, and serum, and carbon-
monoxide and oxygen in ox blood and serum! the gas solubility (A)
is very considerably increased, and within the range of the pressure
investigated (to 1500 mm. of mercury) the solubility decreases with
the pressure and the curves show no evidence of adsorption. Judging

from solubility pressure measurements gelatine’, ferric hydroxide’,

peptone’’, and propeptone!’, react chemically with carbon-dioxide
and evidence from other sources confirms this view (c.f. Stocks®,
Luther®*), These observations, therefore, support the chemical
theory of oxygen and carbonmonoxide absorption by blood and
clearly indicate that the absorption of carbon-dioxide must also be
considered as in part due to chemical combination. This view of
the carbon-dioxide solubility is supported by Harnack**, Tissot®*, and
more recently by Buckmaster® (c.f. also Boycott’). Mention should
be made here, however, of the paper by Christiansen! and co-workers
on the reciprocal solubility of these gases in blood in which the authors
support the adsorption theory.

(b) Botanical Aspect. :
The question of the assimilation of carbon-dioxide by plants has

_ been shown by Willstiitter®* to depend upon the nature of the colloidal
chlorophyll, and some experiments have shown that, whereas

chlorophyll ,in organic solvents behaves as an electrolyte (c.f.
Kremann*®) and does not increase the gas solubility, the same
chlorophyll in aqueous solution produces an hydrosol which absorbs
much more gas “ than other colloidal solutions.”

(ce) General Application.

(1) Wolman and Emslow® :—Chlorination of turbid river water.
(2) D. Berthelot’ and R. Trannoy :—Absorbent’power of dry and

moist earth with respect to chlorine gas. (3) Swanson*? and Hulett :—
Estimation of gases in efflueuts by partition between vacuum and
liquid—assumption that Henry’s Law holds true for such solutions.

(d) Application to Brewing.

In the brewing industry it has long been recognised that a know-
ledge of the carbon-dioxide equilibrium is of the first importance in
connection with the sprakling quality, persistency of head and
palatability of beer. After Langer** and Schultze’s experiments it
was for a long time thought that the solubility of carbon-dioxide in
beer was greater than the solubility in a corresponding water-alcohol
solution. Prior**, modifying the method of investigation, considered
that increased absorption was due to presence of phosphates. The
mean phosphate content of beer, however, is about -07 per cent. ;
insufficient to explain any considerable increase in carbon-dioxide
solubility. The assumption that an ester of carbon-dioxide and
alcohol is formed, has been shown by Mohr*? to be without foundation
as also was the suggested combination with proteids. Mohr concluded
that the gas was merely held in suspension to an extent determined
by the viscosity. On the basis of Langer’s experimental data,
Emslander* and Freundlich, considered that the increased solubility
was due to adsorption of the gas by the colloids—chiefly dextrin and
albuminoids. These colloids have each been found to lower the
solubility of carbon-dioxide in water; and alcohol also lowers the
solubility (Miller*’). It is not surprising therefore that Findlay and
Shen!* found for wort and different grades of beer that, contrary to
the usually accepted view, the carbon-dioxide solubility was con-
siderably less than for water, and independent of pressure. Increase
in alcohol content, with corresponding increase in total colloids,*
was shown, also, to decrease the solubility, and that even allowing for
the alcohol, the solubility was much less than in water. It is evident
that the method used by the earlier investigators gave the total
amount of carbon-dioxide in a beer which was supersaturated to an
unknown degree. Distinction must therefore be drawn between true
solubility, and degree of supersaturation, and to understand the
problem better the second aspect of gas equilibrium must be
considered, namely :—

Il.—Rate of Evolution of Gas.

It is well known, although not always sufficiently well recognised,
that gas supersaturation readily occurs in aqueous salt solutions
(Lamplough*?), and in ordinary brewing practice during fermentation
in cask, the beer becomes supersaturated. It was shown by Findlay
and King? that certain colloidal solutions supersaturated*with carbon-
dioxide remain quiescent, sometimes over a period of 20 minutes.
In this condition of metastability the solution is exceedingly sensitive,
a very slight mechancial shock being sufficient to cause gas evolution
(c.f. Young*). Such quiescence only occurs if scrupulous care is
taken in the cleaning of the apparatus and filtration of the solutions

* According to Mare colloids are proportional to total solids present in
beers.

used (Veley®), The period of quiescence is followed by periodic
evolution of gas, and the duration of the period is, perhaps, a measure
of the rate of growth and number of gaseous nuclei formed in the
liquid. No quiescence was observed with solutions of peptone and
ferric hydroxide, but after an initial rapid effervescence the process
went on as in the case of the other solutions. An important contri-
bution to our knowledge of the law governing the rate of escape of
gases from solution was made by Carlson® (1911), who passed an
indifferent gas over a well-stirred solution of oxygen in water. This
method of investigation (Bohr*) enables the results obtained, as
Meyer** pointed out, to be interpreted in the light of the Nernst*?
diffusion theory. Perman*® and later Steele** showed that the rate
of removal of carbon-dioxide by a stream of air, was proportional
to the concentration of the gas in solution. Both the apparatus
employed and the method of interpreting results are well suited for
the investigation of colloidal solutions. In the only investigation of
this nature which has been reported, Findlay and King” used
mechanical shaking and supersaturated solutions of carbon dioxide
(saturated at two atmospheres and reduced to one). Experimental
conditions so obtained are more in accordance with those encountered
in brewing, and it was shown that the gas effervescence is considerably
influenced by both the quantity and nature of the disperse phase.

Using water as a standard of reference the degree of supersaturation
was proportional to the rate of evolution* and inversely proportional
to the coefficient k in the equation—

Velocity = k x (degree of supersaturation).

By plotting the values of velocity coefficient against degree of
supersaturation a means of representing distinctly the characteristic
behaviour of colloids is obtained. Hugo Muller*t observed that
freshly carbonated water loses its gas more readily than a solution
which has stood. This was not confirmed, for all observations on
water k is almost constant and directly proportional to degree of
supersaturation. ;

There is a much more rapid evolution of gas initially from solutions
of gelatine, peptone, ferric hydroxide, and agar, than from water
solutions of potassium chloride, dextrin, starch and platinum sol
(dilute), in fact, a -05 per cent. gelatine sol effervesces as rapidly
as a 3 per cent. dextrin or starch solution and a little more than half
as rapidly as a -7 per cent. peptone sol. Towards the end of the
effervescence, i.e., as the degree of supersaturation diminishes, in
the gelatine and agar solutions, the velocity coefficient increases
—the more so the greater the concentration. But there is a marked
falling off in the value of the coefficient for solutions of dextrin,
starch, peptone, ferric hydroxide and suspensions of charcoal. Such
decrease is attributed to the slow outward diffusion of the gas
dissolved in the disperse phase. With carbon the effect was observed
only when the suspension was kept in contact with the gas for a

* That the logarithmic law hoids true for rate of evolution from super-

saturated solutions is confirmed by calculations from the Pressure recovery
curves of Patten and Mains for carbonated water.

prolonged period. This slow outward diffusion from solid solution
is the counterpart of the phenomenon observed when the initial taking
up of the gas is followed by a period of very slow absorption. The
same behaviour was observed by Lefebure®® (1914) for the rate at
which gases are taken up by celluloid, and a similar explanation is
given. The comparatively slow saturation of beer containing high
proportion of solids is, without doubt, to be interpreted as evidence
of solution of the gas in the disperse phase, the rate of which is
directly proportional to the rate of diffusion.

Practically nothing is known of the mechanism of this solution
in the solid phase, and it is instructive to compare the phenomena
observed by Findlay and King®* with the results obtained by
Anderson who investigated the rate of elimination of water vapour
from silicic acid gels®.

Anderson showed that the rate depends upon the capillary structure
of the gel and towards the end of the dehydration the rate is influenced
by the same phenomena which is responsible for a section of the
Van Bemmelen* curve. Anderson’s results recalculated in terms of
the velocity coefficient used by Findlay and King yield a curve of
the same form as that obtained by the latter for starch, dextrin, and
suspensions of charcoal. The influence in the Van Bemmelen and
Anderson curve is considered to indicate solid solution of the gas
in the walls of the capillaries (Zsigmondy*). The slow evolution
of gas from solutions of starch, peptone, and dextrin is obviously of
considerable importance in connection with the palatability and
sparkling quality of beverages, and if, as it appears, this depends
upon the slow diffusion outward from the disperse phase, every
facility must be afforded, during carbonation, for the gas to dissolve
in that phase. In fact the beer should, as Langer®® has shown by
practical tests, contain a high proportion of residual extracts, and
be carbonated at low temperature. The assumption by Siegfried®?
of the formation of a carbamic acid which at the higher temperature
of the palate gives free carbon dioxide would seem to be unnecessary.
The formation of head is governed by the rate of effervescence, the
increase being greater, the greater the concentration of colloids, within
limits obviously determined by viscosity. More important, however,
is the absence of substances tending to reduce the surface tension
(Bau*), and according to Ihnen” under similar conditions those beers
rich in dextrins retain the foam best.

When the complicated phenomena of gas solubility in colloidal
solutions is better understood, it will no doubt be found that much
of the conflicting evidence as to the effect of colloids will be explained,
simply, as due to alteration in the physical condition of the particular
colloid. It has long been known that gelatine solutions if repeatedly
heated above 60° C. lose their power of jellying when cooled. The
experiments of Menz??, Ganett**, von Schroeder*!, and more recently,
Smith*?, have shown that both an irreversible change (decomposition ?)
and a reversible change gel sol takes place. At temperatures above
35° C. sol is stable, the gel form being stable below 15° C. When a
solution is cooled between these two temperatures the change sol
so gel does not take place at once but the equilibrium depends on

i el i le eee eee

temperature and time during which the solute is heated, and on the

rate of cooling of the solution. Such variations must be taken into
account and carefully controlled, since it has been shown that the
physical condition of*both gelatine and starch has a very considerable
effect on the rate of escape of gas from solution, in fact the determina-
tion of gas evolution provides a means of closely following the changes
indicated above, and of investigating the nature and history of a
particular gelatine. (For details, see Findlay and King’, Part IT.)

IlI.—Rate of Solution.

Except for incidental observations by Findlay and co-workers
and by Gefficken, no investigation on this question appears to have
been reported. A bibliography of work published on the rate of
solution in water will be found under Papers 2, 9, 34, 38, 43, 47, 64.

BIBLIOGRAPHY,

1 J. S. Anderson, Zeit. f. Physikal Chem., 58/-, 191-228 (1914).
2 Adeney & Becker, Sci. Proc. Roy. Dubl. Soc., 15/-, 385 (1918).
§ Bau, Woch. f. Brau., 382 (1904).

1 J. Bareroft (The respiratory function of blood) Cambridge, 320 Pp. (1914).
5 Berthelot & Trannay, Compt. Rend., 168, 121 (1919).

® Buckmaster J. Physiol., 51, 164 (1917).

* Boycott & Chisholm, Bio. Chem. Jour., 523 (1910).

8 Bohr, Wied. Ann., 68, 500 (1899).

-® Carlson, Jour. de Chem. Physique, 9/-, 235 (1911).

20 Cassuto, Nuovo Chem., 6, 5-20 (1903); J. C. S., abs. i., 161 (1904).
11 Christiansen, Douglass & Haldane, J. Physiol. 48, 244 (1914).
12 Drucker, J. C. S., abs. ii., 25 (1911).

18 Hmslander & Freundlich, Zeit Physikal Chem., 49, 317 (1904).
14 Findlay & Harby, Zeit. Chem. Ind. Koll., 3, 169 (1908).

1° Hindlay & Creighton, Bio. Chem. Jour., 5, 304 (1910).

16 Findlay, Ibid, J. C. S. Trano, 97, 536, 555, 560 (1910).

17 Findlay & Shen, ibid, 101, 1459 (1912).

18 Findlay & Shen, ibid 101, 1313 (1912).

19 Findlay & Willians, ibid, 103, 636 (1913).

20 Findlay & Howell, ibid, 105, 291 (1914).

21 Findlay, Ibid, ibtd, 107, 282 (1915).

22 Findlay & King, ibid, 103, 1170, 1175 (1913).

28 Findlay, Ibid, ibid, 105, 1297 (1914).

*4 Geficken Zeit. Physikal Chem., 49, 257 (1904).

*> Garett, Phil. Mag., 6, 374 (1903).

26 Harnack, Zeit. Physikal Chem., 26, 571 (1899).

27 Thnen, J. Soc. Ch. Ind., 504, (1905).

28 Jager, Chem. Abs., 10, 551 (1916).

29 Kremann, J. C. S. (i), 544 (1919).

30 Langer, Zeit. Brauwesen, 27, 307 (1904); J.uS.C.J. 555 (1904).
$1 Langer & Schultze, Zeit. Brams., 2, 369 (1879); 6, 329 (1883).
32 Lamplough, Rig Camb. Phil. Soc., 14, 591 (1908).

38 Lefebure, J. C. Trans. 332 (1914).

34 Luther & Mdacoukall J. C.'S., ii., 361 (1908).

%> Luther & Kasnjavi, Zeit. Physikel Chem. 46, 170 (1905).

36 Mare, Zeit. F. Chem. Ind. Koll., 14, 181.

37 Menz., Zeit. Physikel Chem., 66, 129 (1909).

shold Meyer, Zeit f. Elektroch., 241 (1909)

89 Mohr, Woch f. Brau., 363 (1904).

40 Muller, Wied Ann, 87, 24 (1889).

41H, Miller, J. C. S., 23, 37 (1870).

42 Nernst, Zeil. Physikal Chem., 52 (1904).

43 Patten & Mains, J. Ind. Eng. Chem., 10, 279 (1918)

44 Peters, Jour. Physiol. 44, 131 (1912).

45 Perman, J. C. S., 67, 868, (1895); 73, 511 (1898).

46 Prior, J. Soc. C. Ind., 288 (1899). .

47 Roth, Zeit. Hlektroch. (15), 328 (1909).

48 Ritzell, Zeit Physikal Chem., 60, 319 (1907).

49 Sander, Zeit. Physikal Chem (1912).

50 Sackur & Stern, Zeit. Hlektroch., 18, 641 (1912).

51 yon Schroeder, Zeit. Physikal Chem., 45, 75 (19038).

52 Siegfried, Zeit. Physiol. Chem., 44, 451 (1905).

53 Smith, J. Am. Ch. Soc., 41, 145 (1919).

54 Steele, J. C. S., 88, 1470 (1903).

55 Stern, Zeit. Physikal Chem., 71, 468 (1912).

56 Stocks, First Report on Coll. Chemy. Brit. Assn., 73 (1917).
*7 Swanson & Hulett, J. Am. Chem. Soc., 37, 2490 (1915).
°8 Trautz, Zeit. Anor. Chem., 106, 149 (1919); J. C. S., 137 (1919).
°9 Tissot, Compt. Rend., 158, 1923 (1914).

60 Usher, J. C. S. Trans , 97, 73 (1916).

61 Van Bemmelen, Zeit. f. Anor. Chem., 18, 233 (1897).

62 Veley, Phil. Trans., 275 (1888); Phil. Mag., 209 (1903).
638 Wellstattér & Stoll, Ber., 50, 1791 (1917).

64 Wolman & Emslow, Ind. Eng. Chem., 209 (1919).

65 Young, J. Am. Chem. Soc., 38, 48-1375 (1911).

66 Zseigmondy & Spear, Chemistry of Colloids, p. 147 (1917).

THE ELECTRICAL CHARGE ON COLLOIDS.

By Joun Antuur Witson, Chief Chemist, A. FP. Gallun & Sons Co.,
Milwaukee.

The origin of the electrical charge on colloids is still a matter of
uncertainty, although it is possible that the charges may not always
arise from the same cause. It has been common practice for writers
to shelve the question by assuming that a sufficiently satisfactory
answer is given by Coehn’s empirical law that ‘‘ a substance of higher
dielectric constant charges itself positively when it comes in contact
with a substance of smaller dielectric constant.” Even if the state-
ment of this law were true, it would not constitute an explanation
since it tells nothing regarding the manner of bringing about the
charging.

Taylor has suggested the possibility of the charge arising from
the colloid surface being more impermeable to certain ions than to
others. He found that a membrane of aluminum hydroxide is formed
by the interaction of aluminum salts and ammonia which is permeable
to hydrion, but impermeable to hydroxidion, even a large E.M.F.
failing to drive hydroxide ions across such a film. Thus, when
alumina is suspended in water, the hydrion dissolves in or diffuses
into it, leaving the hydroxidion at the surface, and the particles
become positively charged. This will also explain the alteration of
the charge on albumen by acids and alkalis, if it may be assumed
that hydrogen and hydroxide ions are equally soluble (or diffusible)
in albumen. In such.a case the concentration of either ion in the
albumen would vary directly as its concentration in the solution
This explains why albumen possesses no charge in neutral solution

and why the positive charge increases with increasing acidity and
the negative charge with increasing alkalinity, However, Taylor
admits that these explanations are not necessarily correct, because
they fit the facts and even suggests that adsorption, rather than
differential diffusion, is responsible for the charge.

The great majority of opinion regarding the origin of the charge
seems to be included in the following possibilities; that the charge
results from the selective adsorption of ions at the surface of the
colloid; that it is due to the ionization of foreign substances incor-
porated in the surface of the particles; or to the ionization of the
colloid itself.

In his recent book, Burton gives an interesting discussion of the
subject. In hydrosols of the oxidizable metals, the particles are
positively charged, while in hydrosols of the non-oxidizable metals,
the particles are negatively charged. Hardy explained this on the
assumption that the charge is due to a reaction between the metal
and water at the moment of formation of the hydrosol. In the case
of the oxidizable metals, ionizable hydroxides are formed; in the
case of the non-oxidizable metals, ionizable hydrides. The particles,
however, are so comparatively large that the greater portion of the
metal compound has the properties of matter in mass and ionization
takes place only at the surface of the particles. Burton has confirmed
this view by experiments with methyl and ethyl alcohols, which
have easily replaceable OH groups. He was unsuccessful in repeated
attempts to prepare alcosols of platinum, silver, and gold, but
succeeded in preparing alcosols of the oxidizable metals. On the
other hand, when platinum, gold, and silver wires were sparked under
ethyl malonate, which has a replaceable hydrogen, very stable sols
were obtained, in which the particles were negatively charged; but
sols of the oxidizable metals could not be obtained with ethyl malonate.
Burton’s own view is that the charges on the particles are due, in the
case of the Bredig metal sols, to the ionization of a layer of hydroxide
or hydride on the surface of the particles. Duclaux believes that
the charge always arises from the dissociation of a portion of extraneous
substance retained by the particles from the reacting media and he
has shown that there is always a trace of FeCl, in Fe(OH)? sols.

Zsigmondy admits that in special cases the charge is due to the
ionization of the colloid itself, for example, where an ionizable
substance has molecules so large as to give it the properties of a
colloid. He objects to the idea of the formation of chemical compounds
in all cases on the ground that it would entail “ the inclusion in the
category of chemical compounds of a large number of badly defined
bodies, and load chemistry with much useless ballast.”’ He prefers
explaining such reactions on the basis of adsorption of ions. The
acceptance of Langmuir’s explanation of adsorption as a chemical
phenomenon would reduce Zsigmondy’s objection to one of terminology.

Among the more recent papers dealing with colloidal metallic
hydroxides may be mentioned that of Pauli and Matula, who confirm
Duclaux’s belief concerning colloidal Fe(OH);. Kimura regards the
charge as due to simple ionization of the hydroxide, the extent of
which is determined by a balancing of the forces causing ionization

a 11454 D

and the attractive forces acting between the positively charged
particles and the hydroxide ions. But Powis produced negatively
charged colloidal ferric hydroxide by adding a sol of the common
type to a dilute solution of sodium hydroxide. He considered the
change in sign of the charge to be due to the adsorption of hydroxidion.

No reliable method has yet been devised for determining the
absolute value of the electrical charge on a colloidal particle. From
Burton’s data, Lewis made an extremely rough calculation of
8 x 10° electrostatic units for a platinum particle. Powis calculated
a value of about 2 x 10~ for a coarse silver particle. Upon the
assumption of the existence of the Helmholtz double-layer at the
surface of colloidal particles, the difference of potential between the
disperse phase and the medium has been calculated. The voltages
found lie almost entirely between — 0-07 and + 0-07. The results
of Ellis and of Powis for oil emulsions indicate that for a stable
emulsion the absolute value of this voltage must be greater than
0-03. Between the values — 0-03 and + 0-03, complete coagulation
occurs, but at a velocity apparently independent of the voltage.

Wilson has shown that the electrical charge on the surface of
colloidal particle must cause an unequal distribution of ions between
the surface layer of solution surrounding the particles and the bulk
of solution, which would, in turn, result in a difference of potential
between the two phases. A very important conclusion of this work
is that the addition of an electrolyte to a sol, provided no chemical
changes follow, must result in a lowering of the absolute value for
the potential difference between the two phases, even though there
may be no change in the magnitude of the electrical charge on the
colloid itself. This is considered to be the explanation of the
precipitation of suspensoids by addition of salt.

This subject is so closely allied to that of electrical endosmose
that the report compiled by Briggs (Second Report, p. 26) should be
consulted.

BIBLIOGRAPHY.

Erans, H. T., and Easriack, H. E. ‘The Electrical Synthesis of Colloids
‘J. Am. Chem. Soc.,’ 87, 2667 (1915).

Burton, E. F. ‘The Physical Properties of Colloidal Solutions’ (Longmans,
Green & Co.).

Exuis, R. ‘Properties of Oil Emulsions’: I Electric Charge; ‘Z. Physik.
Chem.’ 78, 321. II. Stability and Size of the Globules, ibid., 80, 597.
III. Coagulation by Means of Colloidal Solutions, ibid., 89, 145 (1914).

FRENKEL, J. ‘The Surface Electric Double-Layer of Solid and Liquid Bodies.’
‘Phil. Mag.’ 38, 297 (1917).

GurxE.ut, 8. ‘ The Electrical Transference of Gels.’ ‘ Kolloid-Z.’ 18, 194.

Harpy, W. B., and Harvey, H. W. ‘Surface Electric Charge of Living Cells.’
Proc. Royal Soc.’ London, 84, 217,

Harpy, W. B. ‘ Differences in Electrical Potential within the Living Cell.’
‘J. Physiol.’ 47, 108,

von Hrvesy, G. ‘The Charge and Dimensions of Ions and Dispersoids,’
* Kolloid-Z.’ 21, 129 (1917). :

Kimura, M. ‘ Nature of the Double Layer in Colloidal Particles,’

I * Memoirs
Coll. Science,’ and ‘ Eng. Kyoto Imp. Univ.’, 5, 201.

Krouyt, H. R. ‘Current-Potential of Electrolytic Solutions.’ ‘ Verslag. Akad,

Wetenschappen,’ 238, 252 (1914).

‘ Electrical Charges and the Limiting Values for Colloids,’ ibid., 28, 260
1914). :

‘Current Potentials and Colloid Stability.’ ‘ Kolloid-Z.’, 22, 81 (1918).
Lewis, W.C.McC. ‘ A System of Physical Chemistry.’ (Longmans, Green & Co.)
Pavui, W., and Maruna, J. ‘A Physicochemical Analysis of Colloidal Ferric

Hydroxide.’ ‘ Kolloid-Z.’ 21, 49 (1917).

Powis, F. ‘The Relation between the Stability of an Oil Emulsion and the

Potential Difference at the Oil-Water Surface Boundary and the Coagulation

of Colloidal Suspensions.’ ‘ Z. physik. Chem.’ 89, 186 (1914).

‘The Influence of Time on the Potential Difference at the Surface of Oil
Particles Suspended in Water,’ Jbid., 89, 179 (1914).

‘ Negative Colloidal Ferric Hydroxide.’ ‘ J. Chem. Soe.’ 107, 818 (1915).

* Transference of Electricity by Colloidal Particles.’ ‘ Trans. Faraday Soe.’,
(1915).

‘The Coagulation of Colloidal Arsenious Sulfide by Electrolytes and its
Relation to the Potential Difference at the Surface of the Particles.’ ‘J.
Chem. Soe,’. 109, 734 (1916).

Snorter, S. A. ‘The Capillary Layer as the Seat of Chemical Reactions.’

‘J. Soe. Dyers & Colourists,’ 84, 136 (1918).

Taytor, W. W. ‘The Chemistry of Colloids’ (Longmans, Green & Co.).
Tuomas, A. W., and Gararp, I. D. ‘The Fallacy of Determining Electrical
Charge of Colloids by Capillarity.’ ‘J. Am. Chem. Soc.’ 40, 101 (1918).

Witson, J. A. ‘Theory of Colloids.’ ‘J. Am. Chem. Soc.’ 38, 1982 (1916).
ZstemonDy, R. ‘ Theoretical and Applied Colloid Chemistry.’ (John Wiley &
Sons. 1917 )

IMBIBITION OF GELS—PART I.

By Joun Artuur Witson, Chief Chemist, A. F. Gallun & Sons Co.,
Milwaukee.

One of the commonest methods of demonstrating what is meant
by imbibition is to immerse a thin sheet of ordinary gelatin in water.
In less than an hour the gelatin will be found to have become mutch
swollen by absorbing, or imbibing water. After the first hour, the
rate of swelling noticeably decreases, and the volume papers to
approach a definite limit. The amount of water taken up can be
determined by weighing the gelatin before and after swelling. The
absorbed water behaves much as though it were dissolved in the
gelatin, and it can be removed by washing the gelatin with absolute
alcohol. As the water is removed, the volume of the gelatin diminishes,
approaching its volume before swelling. During imbibition heat is
evolved, which has often been referred to as heat of swelling. Probably
this is responsible for the repeated statement that the application
of heat will repress the swelling of gels. On the contrary rise of
temperature causes greater swelling, which seems to indicate that
the liberation of heat is not due to swelling, but to some other cause,
which the writer believes to be chemical combination between the
gelatin and a small portion of the absorbed water. Procter has
shown that the degree of swelling is also dependent upon the previous
history ot the gelatin. He prepared three solutions containing
5 per cent., 10 per cent., and 20 per cent. respectively of gelatin and
allowed them to set. He then dried the jellies and, after weighing,
allowed them to soak in water for seven days. The sample with the

greatest volume at time of setting absorbed 14-6 times its weight
of water, the second sample, 7-7; and the sample with smallest setting
volume only 5:8 times its weight of water.

Gelatin swells to a much greater extent in dilute acid solutions
than in water. The parts of solution absorbed by one part of a
certain sample of gelatin, at 18°, were in pure water 8, in 0-006 N
HCl 42, in 0:05 N HCl 28, in 0-3 N HCl only 17. Stronger solutions
of the acid caused the gelatin to soften and finally dissolve. This
action appears to be independent of the swelling phenomenon, and
at higher temperatures becomes more marked, even with lesser
concentrations of acid. By plotting the amount of swelling against
the concentration of acid up to 0:3 N, a curve with a maximum is
obtained, the explanation of which has given rise to several theories,
which will be treated later.

The most extensive investigation of the hydrochloric acid gelatin
equilibrium seems to have been made by Procter, who showed that
the concentration of free acid is always less in the solution absorbed
by the gelatin than in the remaining external solution, and that the
sum of the amounts of free acid in both these solutions is less than
the amount in the solution before the introduction of the gelatin.
He attributes this difference to chemical combination between the
gelatin and some of the acid and regards the product as a hydrolyzable,
but highly ionizable chloride of gelatin. This agrees with the electro-
metric determinations of Manabe and Matula, who found that in
certain hydrochloric acid solutions of gelatin nearly all hydrogen ions
were bound by the protein and nearly all chloride ions were free.
They examined acid solutions of serum albumin similarly and regarded
the behaviour of both proteins as that of weak bases forming
hydrolyzable salts.

Gelatin swells likewise in solutions of other acids, but not to the
same extent as in HCl, nor does the point of maximum occur at
exactly the same concentration of either total acid or hydrogen ion.
With strong acids the maximum in the swelling curve is very
pronounced, becoming less so with weaker acids, With acetic acid
the maximum is hardly reached at concentrations so great as to cause
solution of the gelatin. Extremely weak acids like boric produe
very little swelling.

If sodium chloride, or other neutral salt, be added to acid- swollen
gelatin, the latter contracts and gives up the solution it had absorbed
to an extent depending upon the concentration of added salt. If
the solution be saturated with salt, the gelatin shrinks to a horny mass.
Fischer found that even non-electrolytes, such as sugars, produce
this repression of swelling, although not nearly to the same extent
as salts. Repression is produced by the acid itself when present
in concentrations greater than that required to produce maximum
swelling.

Experiments dealing with the swelling of gelatin in alkalis are
generally not so satisfactory as those with acids, because of the more
powerful solvent action of alkalis on the swollen gelatin. Nevertheless,
by using only very dilute solutions at low temperatures, sufficient
data have been collected to show that alkaline swelling is of the same

general nature as acid swelling. The swelling increases with increasing
concentration of alkali to a maximum and then falls until such
concentration is reached that the gelatin softens and dissolves.
Swelling is repressed, here too, by addition of neutral salts.

While neutral salts are capable of repressing the swelling of gelatin
in acids and alkalis, it must not be overlooked that they are also
capable of producing swelling. Procter found that, with increasing
concentrations of sodium chloride, gelatin swells to a maximum
and then contracts steadily until the solution is saturated. The
swelling was not so marked as in the case of acids, however, the
gelatin taking up a maximum of only about 17 times its weight of
water as compared to three times this amount with HCl. He also
noted that the gelatin removes some of the salt from solution,
suggesting combination, but that the addition of HCl again liberates
this salt and causes the salt to become more concentrated in the
external solution than in the solution absorbed.

Loeb has done some work on neutral salts that should be mentioned
_here. In each of aseries of experiments he placed two grams of finely
powdered gelatin into a cylindrical funnel, the powder being held
in the cylinder by a circular piece of filter paper. One sample was
perfused six times in succession with 25 cc. of distilled water and
the amount of swelling noted, which was taken as the height in
millimetres to which the gelatin rose in the cylinder; this sample was
taken as the standard. Another sample was perfused twice with
25 c.c. of M/8 NaCl, and then four times with 25 c.c. of distilled water ;
the swelling here was several hundred per cent. greater than that
of the standard. Still another sample was perfused six times in
succession with 25 c.c. of M/8 NaCl; it did not swell to any greater
extent than the standard. Loeb attributes these results to a chemical
combination between the gelatin and salt, a highly ionizable sodium
gelatinate being formed. In the third experiment, much swelling
_ was prevented by the excess of salt present; when this was washed
away, as in the second experiment, the gelatin swelled to a much
greater extent than in pure water. He confirmed this view by showing
that, when placed in an electric field, gelatin which has been treated
with NaCl migrates to the anode. A sample first perfused with
calcium chloride solution and then with distilled water showed very
little more swelling than the standard. He accounts for this by
saying that the calcium gelatinate formed is only very slightly
ionizable.

Collagen, fibrin, and other proteins behave much like gelatin when
immersed in solutions of acids, alkalis, or salts, and are probably
subject to the same general laws. Other examples of imbibition are
the swelling of agar-agar, gums, and cellulose in water and the swelling
of rubber in organic solvents. It would take volumes to mention
all of the work done on this subject.

Numerous attempts have been made to explain the molecular
mechanism of imbibition, particular attention being paid to the
explanation of the peculiar swelling curve. Most of these, however,
have been guilty of drawing largely upon the imagination for some-
thing that would agree qualitatively with the experimental data

without regard for lack of grounds for the assumptions involved,
Several of these still survive because, while they cannot be proved,
they are not of a nature to be easily disproved. It will probably be
sufficient to outline two of the more recent ones.

Perhaps it would be unfair to consider Fischer’s theory of imbibition
as attempting to give an explanation of the molecular mechanism
of the phenomenon. He regards gelatin as a substance capable of
existing in different degrees of association or polymerisation; in other
words, the particles of gelatin may vary greatly in size, dependent
upon conditions to which they are subjected. Thus rise of tempera-
ture or increase in concentration of acid or alkali, causes the particles
to become smaller in size, the change being reversible. The particles
are assumed to be capable of becoming most heavily hydrated, that
is, of absorbing most water, when they have a medium diameter.
The particles of neutral gelatin are large and capable of absorbing
comparatively little water. Increasing the concentration of acid
decreases the size of the particles, making them capable of absorbing

more water, and the gelatin swells until the size of particle most -

readily hydrated is reached. As the particles become still smaller,
the swelling becomes:less until finally the particles become so small
that the gelatin apparently goes into solution.

The theory of Tolman and Stearn assumes that, because of their
amphoteric nature, protein colloids have marked tendencies to
adsorb hydrion from acid solutions and hydroxidion from alkaline
ones. In a solution of a strong acid, the adsorbed hydrogen ions,
together with a corresponding number of anions, form a “ double
layer’ on the walls of the pockets or pores in the interior of the gel,
and this leads to swelling and imbibition of water by electrostatic
repulsion. The addition of neutral salt or excess of strong acid to
such a swollen colloid will furnish ions in the interior of the pockets
which will tend to arrange themselves so as to neutralise the electrical
fields of the adsorbed layer and thus being about a reduction of the
swelling. The addition of a neutral salt to the acid solution tends to
neutralise the electrical field of the adsorbed acid, making it easier
for more acid to get to the surface of the pockets, thus leading to
increased adsorption. Polyvalent ions are more effective than
univalent ions in reducing swelling because, while taking up no more
room than univalent ions, they are twice as eleeeve in neutralising
an. existing electrical field.

In contrast to these stands the theory saat by Procter and
developed by him in collaboration with his pupils. By very extensive
investigations with gelatin and aqueous solutions of acids and salts,
he succeeded in finding quantitative relationships between several of
the variable factors involved. Once a foothold was gained in the form
of an equation, it was found possible to make big advances merely
by an application of mathematics. Procter built up his theory from
experimental data; more recently J. A. and W. H. Wilson worked
in the opposite direction by purely mathematical reasoning from the
assumption of the existence of a certain hypothetical substance and
calculated what results Procter should have found experimentally.

terete,

All of their calculated curves coincided completely with Proctor’s
experimental ones, and for this reason the writer considers the essential
part of the theory as proved. The importance of the subject warrants
our giving a review of the mathematical deductions, which include an
adequate explanation of Procter’s theory.

Consider the purely hypothetical substance G which is a colloid
jelly completely permeable to water and all dissolved electrolytes,
is elastic and under all conditions under consideration follows Hooke’s
law, and which combines chemically with the positive, but not the
negative ion of the electrolyte MN, according to the equation—

[@] x [M+] = K[GM*] (1)
In other words, the compound GMN is completely ionized into
GM~*+ and N-. The brackets indicate that concentration is meant

and all concentrations are in moles per litré. The electrolyte MN is
also considered totally ionized.

Now take one millimole of G and immerse it in an aqueous solution
of MN. The solution penetrates G, which thereupon combines with
some of the positive ions, removing them from solution, and conse-
quently the solution within the jelly will have a greater concentration
of N- than of M+, while in the external solution [+] is necessarily
equalto[N~]. The solution thus becomes separated into two phases,
that within and that surrounding the jelly, and the ions of one phase
must finally reach equilibrium with those of the other phase.

At equilibrium,+in the external solution, let—
MF iL]
and in the jelly phase let-—

y= [M*]
and—
e=— (Gs |
whence—
[N-]=y+z.

The relation existing between the concentrations of diffusible ions
of the two phases at equilibrium can be derived from the consideration
of the transfer of an infinitesimally small amount, dn moles, of Mt
and N~ from the outer solution to the jelly phase, in which case,
since no work is done—

dnRT log x/y + dnRT log x/(y + z) = 0,
whence—
a? = yy + 2). (2)
But in this equation, the product of equals is equated to the product
of wnequals, from which it follows that the sum of those unequals is
greater than the sum of the equals, or—

2y + 2 > 2a.
This is a mathematical proof that the concentration of diffusible

ions of the jelly phase is greater than that of the external solution,
and makes possible the derivation of a second equation involving e,

which is defined as the excess of concentration of diffusible ions of
the jelly phase over that of the external solution—

2e + e= 2y+z. (3)
Since [V~-] is greater in the jelly than in the surrounding solution,
the negative ions of the colloid compound will tend to diffuse outward
into the external solution, but this they cannot do without dragging
their colloid cations with them. On the other hand, the cohesive
forces of the elastic jelly will resist this outward pull, the quantitative
measure of which is e, and according to Hooke’s law—

e— CV. (4)
where C is a constant and V the increase in volume in cubic centi-

meters of one millimole of the colloid.
Now, since we have taken unit quantity of the substance G—

[G] + [4M +] = 1/(V+ a)
[G] = 1/(V +4) —z (5)

where a is, not the initial volume of the colloid, but the free space
within the jelly before swelling through which the ions may pass.
For our hypothetical substance, we may consider the limiting case
where the value of a is zero, in which case, from (1) and (5) we get—

. (1/V —z)y = Kz (6)
and from (2) and (3)—
z2=e-+ 2Vey
or—
z= CV +2V/CVy (7)
From (6) and (7)—
VK + y)(CV + 2vVCVy) —y=0 (8)

where the only variables are V and y. Now we have only to know
the values for the two constants, K and C, to plot the curve for any
variable in terms of any other value. For example, by giving y a
definite value, we can calculate V from (8). Knowing y and V, we
can calculate z from (7) and with y and z, we can calculate x from (2),
while e is obtained directly from (4).

If any values for K and C be substituted, the resulting relations
will be found to be of the same general nature as are obtained with
any proteins in acid solutions, but values of K and C for gelatin have
been determined. By means of the hydrogen electrode, Procter and
Wilson found the value K = 1-5 x 10~-‘ for gelatin and HCl, while
their experimental value for C at 18° was 3 x 10-4. The whole
series of curves for these values of the gelatin constants has been
plotted, and appears in the Journal of the American Leather Chemists’
Association for 1918, pages 184 and 185, which should be consulted.
Procter’s experimental determinations are included in the same figures,
and it will be seen that better agreement could not be obtained if the
curves were drawn from his data.

Since, theoretically, the calculated curves should not coincide
absolutely with the experimental ones for gelatin and HCl, it is
interesting to note why no appreciable discrepancies were found.

———————— << er

6. %¢@

That the quantity a, defined as the free space within the unswollen
jelly, has a measurable value for gelatin is suggested by the fact that
the volume of the swollen jelly is slightly less than the sum of the
volumes of the gelatin and absorbed water before swelling. But the
values for V are generally so much greater than the total volume of
the gelatin before swelling that any error due to neglecting a would
be insignificant. Appreciable errors might have resulted from the
assumption of total ionization of the electrolyte, were it not for the
fact that the rates of change of the slopes of the curves are greatest
for concentrations of HCl less than 0-01 N.

In order to apply the theory to weak acids, it is necessary to
include the equation which defines the ionization constant of the
acid. Procter and Wilson have derived equations which explain
the action of salt in repressing the swelling of gelatin in acid solutions ;
for these and others dealing with polybasic acids, reference should
be made to the original papers. At the moment of writing no evidence
incompatible with the theory has been discovered. EH. A. and H. T.
Graham stated that the theory would not account for the repression
of swelling by sugars, but Wilson pointed out that the difference in
molal fugacity of the sugar in the two phases due to the differences
in ion concentrations is sufficient to account for the repressing action
of sugar.

The possibilities of gain to pure science fully justify the undertaking
of the enormous amount of work still to be done on the theoretical
side of imbibition and the problem appears to lie as much in the
field of the mathematician as in that of the chemist.

Recent Publications on Imbibition of Gels,
(See also bibliography at end of Part IT.)

Arisz, L. ‘The Sol and Gel State of Gelatin Solutions.’ I. Gelatinising.
II. Swelling. ‘Koll. Beihefte,’ 7, 1 (1915). Size of gelatin particles and
attractions between them probably decrease during swelling. Swelling
and solution are considered two stages of the same process, indefinite swelling
amounting to solution.

Bennett, H. G. ‘ The Swelling of Gelatin.’ ‘J. Soc. Leather Trades Chem.’,
2, 40 (1918). Polemical.

FiscHer, Martin H. Epema and Nepureiris. (J. Wiley & Sons, 1915.) On
Hydration and “Solution” in Gelatin. ‘Science,’ 42, 223 (1915). A
warning against the general adoption of the view that the “ solution” of a
protein represents but the extreme of that which in a lesser degree is called
swelling. Hydration or swelling is to be regarded as a change through which
the protein enters into physicochemical combination with water; ‘‘ solution’”’
as one which can be most easily understood as the expression of an increase
in the degree of dispersion of the colloid.

Fiscner, M. H. and Sykes, A. ‘The influence of Non-electrolytes on the
Swelling of Protein.’ ‘ Kolloid-Z.’ 14, 215. Non-electrolytes decrease the
degree of swelling of protein the more so the greater the concentration. The
conclusion is drawn that the phenomenon is one of adsorption rather than
osmosis.

“The Non-acid and Non-alkaline Hydration of Proteins.’ ‘ Kolloid-Z.’
16, 129 (1915). In the swelling of gelatin by urea, there are two changes,
one towards increasing hydration, the other towards increasing degree. of
dispersion.

Fiscner, M. H. and Hooxer, M.O. ‘On the Swelling of Gelatin in Polybasic
Acids and their Salts.’ ‘J. Am. Chem. Soc.’ 40, 272 (1918).

Fiscuer, M. H., and Benzrincer, M. ‘On the Swelling of Fibrin in Polybasic
Acids and their Salts.’ ‘J. Am, Chem. Soc.’ 40, 292 (1918).

FiscHer, M. H., and Corrman, W. D. ‘On the Liquefaction or “ Solution” of
Gelatin in Polybasic Acids and their Salts.’ ‘J. Am. Chem. Soe.’ 40, 303
(1918).

Granam, E. A., and Granam, H. T. ‘ Retardation by Sugars of Diffusion of
Acids in Gels.’ ‘J. Am. Chem. Soc.’ 40, 1900 (1918).

HatscHer, Emin. ‘ Viscosity and Hydration of Colloidal Solutions.’ ‘ Biochem.
J.’ 10, 336 (1916).
‘An Analysis of the Theory of Gels as Systems of Two Liquid Phases.’
‘Chem. News,’ 116, 167 (1917).

Karz, J. R. ‘ Micella are not necessary for the Explanation of Uncomplicated
Swelling.’ ‘ Z. Physiol. Chem.’ 96, 255 (1916). The facts are fully covered
“by the theory of a solid solution of water in the swellling substance, and in
Nagelli’s theory micella can be replaced by molecules.

“The Laws of Swelling. The Swelling in Water without Complications.’
“Kolloidchem, Beihefte,’ 9, 1 (1917).

Lenk, Emm. ‘Importance of Electrolytes for Swelling Processes”: A. The
Action of the Individual Electrolytes. B. Combinations of Electrolytes.’
‘Biochem. Z.’ 78, 15 and 58 (1916). The conclusion is drawn that the
antagonistic actions of ions must be due to colloidal phenomena and not to
osmotic pressures,

Lors, Jacques. ‘Ionization of Proteins and Antagonistic Salt Action.’
“J. Biological Chem.’ 338, 531 (1918).

“The Stoichiometrical Character of the Action of Neutral Salts upon the
Swelling of Gelatin.’ Jbid. 34, 77 (1918).

Manazse, K., and Maruna, J. ‘ Physical Changes in the States of Colloids.’
XV. Electrochemical Investigations of Acid Albumin. ‘ Biochem. Z.’ 52,
369 (1913). The work involved the electrometric determinations of the
hydrion and chloridion concentrations of hydrochloric acid solutions of serum
albumen and of gelatin.

OstwaLtp, Woxireane. ‘Importance of Electrolytes for Swelling Processes.’
‘Biochem. Z.’ 77, 329 (1916).

Pavuri, W., and Hrrscuretp, M. ‘ Alteration in the Physical Conditions of
Colloids.’ XVIII. Protein Salts of Different Acids. ‘Biochem. Z.’ 62,
245. Equal concentrations of protein bind less of a weak than of a stronger
acid.

Procter, H. R. ‘On the Action of Dilute Acids and Salt Solutions upon
Gelatin. ‘ Kolloidchem. Beihefte, 1911; ‘J. Am. Leather Chem. Assn.’
6, 270 (1911. This paper contains a great deal of valuable experimental
data.

‘The Equilibrium of Dilute Hydrochloric Acid and Gelatin.’ ‘J. Chem.
Soc.’ 105, 313 (1914).

‘The Combination of Acids and Hide Substance.’ London ‘ Collegium,’
1915. A paper dealing with the subject in a more popular style.

“The Swelling of Gelatin.’ ‘J. Soc. Leather Trades Chem.’ 2, 73 (1918).
A reply to Bennett’s paper of the same title.

Procter, H. R., and Witson, J. A. ‘ The Acid-Gelatin Equilibrium.’ ‘J. Chem.
Soe.’ 109, 307 (1916).
‘The Swelling of Colloid Jellies.’ ‘J. Am. Leather Chem, Assn.’ 11, 399
(1916).

Rincer, W. E. ‘Further Studies on Pekelharing’s Pepsin.’ ‘Z. Physiol.
Chem.’ 95, 195 (1915). The action of pepsin and swelling of protein are closely
related. 3

‘Further researches upon Pure Pepsin.’ ‘ Proc. Akad. Wetenschappen,’
18, 738 (1915). The point of maximum swelling of protein does not occur
at the same hydrion concentration with different acids.

‘The Importance of the Condition of the Substrate in the Action of
Pepsin.’ ‘ Kolloid-Z.’ 19, 253 (1916).

}

Rosertson, T. B. ‘The Physical Chemistry of the Proteins.’ (Longmans.
Green & Co., 1918.)

Rosensoum, E. ‘ The Heat of Swelling of Colloids.’ ‘ Kolloidchem. Beihefte,’
6, 177 (1914). The swelling of gelatin appears to be divided into two phases,
the first where a small amount of water is taken up and all the heat of
swelling is evident, and the second Where a large amount of water is taken
up and no heat evolved.

Totman, R.C., and Stearn, A.E . ‘ The Molecular Mechanism of Colloidal
Behaviour.’ I. The swelling of Fibrin in Acids. ‘J. Am. Chem. Soc, 40,
264 (1918).

Witson, J. A. ‘ Retardation by Sugars of Diffusion of Acids in Gels.’ ‘J. Ams
Chem. Soe.’ 41, 358 (1919). A reply to the statement by E. A. and H. T.
Graham (see above) that Procter’s theory cannot account for the repression
of the swelling of acid-swollen gelatin by sugar.

Witson, J. A., and Witson, W. H. ‘ Colloidal’ Phenomena and the Adsorption
Formula.’ ‘J. Am. Chem. Soc.’ 40, 886 (1918). A further mathematical
development of Procter’s theory of the swelling of colloid jellies and its
relation to other branches of colloid chemistry.

Wo rrr, L. K., and Bicuner, E. H. ‘ The Behaviour of Jellies towards Liquid,
and their Vapours.’ ‘ Verslag. K. Akad. Wetenschappen,’ 21, 988 (1912)
and 22, 1323 (1914). It is contended that von Schroeder’s observation
that the amount of water in gelatin swollen in liquid water decreases when
the gelatin is placed in water vapour rests upon a defective method of

experimentation.
IMBIBITION OF GELS. PART II.—_INDUSTRIAL
APPLICATIONS.
By Joun Artuur Witson, Chief Chemist, A. F. Gallun & Sons Co.,
Milwaukee.

Imbibition plays a most important role in the manufacture of
leather, paper, textiles, and many other colloidal products, but few
cases are generally known of applications of theory to manufacturing
conditions. In view of the fact that Procter’s theory grew from
an investigation of the process of pickling hides, it is not surprising
that what applications of it have so far been published have been
connected with the leather industry, especially since many of the
formulas are of recent derivation. A general survey of applications,
to the leather industry has been given by Procter in the First Report
pp. 5-20, and need not be repeated here. Wilson and Kern used
the theory to explain causes for certain discrepancies in tannin
analyses made by the hide-powder method, which is widely employed
both in Europe and America. One direct outcome of the theory of:
imbibition is the Procter-Wilson theory of vegetable tanning, which
like its parent theory is largely mathematical in character. The
equations forming part of the theory enable one to regulate the
astringency of the tannins, their rate of diffusion into the hide, and
the degree of plumping of the hide fibres, by simple alterations of the
concentrations of electrolytes in the tan liquors.

Bovard, in pointing out the importance of imbibition to the

- manufacture of paper, claims that the character of the sheet is largely

determined by the degree of hydration and length of the fibres. He
noted that cellulose swells more rapidly in alkaline than in neutral
or acid solutions, and since the rosin size used in paper manufacture
is alkaline, he reasoned that the hydration of the stock would be

promoted if the size were added to the beater before the alum. In
an actual test, working in this order, the paper tested 14 points higher
than that made by putting the alum into the beater first.

Photographic workers sometimes experience a most annoying
reticulation of the surfaces of negatives, particularly when fixing or
washing during hot weather. The wet gelatin layer becomes finely
wrinkled or corrugated, the network of puckers forming a pattern.
Sheppard and Elliott have found two causes for this difficulty.
When sheets of gelatin swell or contract slowly, they undergo a
change in volume but not in shape. On the other hand, the gelatine
on a negative must undergo a change in shape, since one face of
it is held to the plate. So long as the amount and rate of swelling
are not great, no trouble is experienced, but when the swelling is
excessive, due to higher temperatures or chemicals in the fixing bath,
the upper surface of the gelatin will have an area so much greater
than the lower surface as to cause puckering. The second cause is
the presence in the solution with which the plate is treated of both
swelling and contracting agents. Reticulation is readily produced by
immersing the plate in a solution containing acetic and tannic acids,
the former tending to swell or soften the gelatin, the latter to
contract or harden it. Their rates of diffusion are determined by
their effects upon the gelatin, and the result is a mosaic-like alternation
of hardening and softening effects, the ridges being more swollen and
the valleys contracted by tanning.

Judging from the literature available, the most extensive
applications of imbibition have been in the field of biology. Almost
without exception, this has been done by analogy, rather than by
application of theory. Fischer’s book, “Edema and Nephritis”’ is
replete with analogies between inbibition of such proteins as gelatin,
fibrin, and gluten, and that of things so widely different as muscles,
eyes, nervous tissues, catgut, and living frogs. Loeb showed that
the behaviour of dried pig’s bladder in solutions of various salts very
closely resembles that of powdered gelatin in the same solutions.
Reference should also be made to Loeb’s work on the fundulus egg,
to Arnold’s studies of the swelling of human muscle, and Traube’s
work on the swelling and germination of plant seeds.

Recent Publications Dealing with the Application, or Suggesting an Application?
of the Subject of Imbibition of Gels.

(See also Bibliography at end of Part I.)

Arnotp, R. ‘The Swelling Capacity of Different Kinds of Muscle in Acid
Solutions.’ ‘ Kolloidchem. Beihefte,’ 5, 511 (1914). The structure of human
muscle is not a criterion of its relative swelling capacity.

Bovarp, W. M. ‘Colloidal Chemistry in Papermaking.’ ‘Paper’ 22, 11 (1918).
Shows the importance of controlling hydration of the stock in making paper.

Fiscuer, M.H. ‘:Relation between Chloride Retention, Edema, and ‘‘ Acidosis.”
‘J. Am. Med. Assn.’ 64, 325 (1915).

‘The Classification and Treatment of the Nephritides.’ ‘The Journal-
Lancet,’ July 1, 1916.

FiscHer, M. H., and Hooxrer, M. O. ‘Trench Nephritis.’ ‘The Int. Assn. of
Med. Museums,’ Bulletin No. VII., May, 1918.

‘Ternary Systems and the Behaviour of Protoplasm. ‘Science, 48, 143
(1918). Many of the laws governing the hydration and dehydration of soaps

are identical with those governing the hydration and dehydration of certain
proteins, which in turn show analogies to living cells.

Harrison, W. ‘Investigations on the Physical and Chemical “Properties of
Cotton. Report of ‘The Nat. Assn. of Cotton Mfrs.’, 1916.

Lors, Jacgurs. ‘The Mechanism of the Diffusion of Electrolytes through the
Membranes of Living Cells.’ I. The Necessity of a General Salt Effect upor
the Membrane as a Prerequisite for this Diffusion.’ ‘J. Biol. Chem,’ 27,
339 (1916). II. The Diffusion of Potassium Chloride out of the Egg of the
Fundulus and the Relative Efficiency of Different Ions for the Salt Effect.
Ibid., 353. III. The Analogy of the Mechanism of the Diffusion for Acids
and Potassium Salts. Ibid., 363.

‘The Similarity of the Action of Salts upon the Swelling of Animal Mem-
branes and of Powdered Colloids. Ibid., 31, 343 (19177).

Procter, H. R. ‘Recent Developments in Leather Chemistry. ‘J. Royal
Soe. Arts,’ 1918.

‘Colloid Chemistry of Tanning. ‘First Report,’ p. 5.

Procter, H. R., and Burton, D. ‘The Swelling of Gelatinous Tissues.’ J.
Soc. Chem. Ind,’ 35, 404 (1916). Treats the subject from the viewpoint of
the leather chemist. ;

Prootrer, H. R. and Witson, J. A. Theory of Vegetable Tanning. J. Chem.
Soe,’ 109, 1327 (1916).

SHEPPARD, S. E., and Exxiorr, F. A. ‘The Reticulation of Gelatin.’ J. Ind.
and Eng. Chem.’ 10, 727 (1918). An application to photography.

TRAUBE, I., and Kéuter, F. ‘The Velocity of Formation and Solution and of
Swelling of Gels.’ ‘ Intern. Z. Biol.’ 2, 42 (1915). A discussion is given of the
relation between experimental results and the following biological problems :
narcosis, plasmolysis of cells, chemotaxis, muscular work, edema, and
inflammations.

TrRAUBE, I., and Marusawa, T. ‘Swelling and Germination of Plant Seeds.’
“Intern. Z. Physik. Chem. Biol.’ 2, 370 (1915).

Upson, F. W., and Catvin, J. W. On the Colloidal Swelling of Wheat Gluten,’
“J. Am, Chem. Soe.’ 37, 1295 (1915),

Wuson, J, A. ‘Theories of Leather Chemistry.2 ‘J. Am. Leather Chem.

Assn.” 12, 108 (1917).
‘Theory of Tanning,’ 2bid., 18, 177 (1918).
‘Theory and Practice of Leather Chemistry,’ ibid., 14, 93 (1919).

Wuson, J. A., and Kern, E. J. ‘The Non-Tannin Enigma.’ ‘J. Am. Leather
Chem. Assn.’ 18, 429 (1918).

COLLOID PROBLEMS IN BREAD-MAKING.

By R. Wuymesr, Chief Chemist to Messrs. Peek, Frean & Co., Lid.,
Biscuit Manufacturers, London, and late Assistant Inspector of Bakeries,
B.E.F., France.

There is no manufacturer less aware of the chemical problems
underlying his trade than the master baker. In spite of his ignorance,
however, he is one of the most efficient members of society, in that
he produces an excellent article with great regularity. This is,
perhaps, less a matter of wonder when it is realised that the art of
bread-making of a high order can be traced through the Chinese to
about 2,000 years B.c., and is of course older than that, and that
ot to this day the majority of people can make a very passable
oaf.

Such scientific work as has been done, in or for the bakery, has
usually been undertaken for some specific material object, for advantage
to the large manufacturer (yields, moisture retainers, effect of machinery)
or for the protection of the consumer (sanitary conditions of manu-
facture, effect of alum, bleaching agents, &c.). There is comparatively

little published work available to show that the problems have been
tackled for,a scientific purpose, or for improvement of the process.
_ Indeed, there has been no stimulus for the chemist, since, in the bakery
the ability of a master baker to feel, taste and smell the ingredients
is a more sure guide in the production of good bread than the know-
ledge obtained by use of test tubes and balance.

It will be observed that the two points of view, that of the producer
and that of the consumer, are largely but not entirely sympathetic.
The former, whether the small hand-baker or large manufacturer,
demands the greatest yield from hisingredients, and the most attractive-
looking product, but really is not greatly concerned about the flavour,
provided he can sell his bread. The result is the exhibition loaf
of perfect proportion, if somewhat insipid, or the water-laden and
profitable loaf, both the outcome of scientific treatment. All the
consumer asks to-day is that his bread shall be palatable, and be
made in a cleanly manner and cheap, whilst he is not greatly interested
in the amount of water present in his loaf. Such a loaf, to suit the
consumer, can generally be assured by the hand-baker. It is therefore
rather in the economic direction that any considerable amount of
work has been done by the bakery chemist, who himself is only just
beginning to realise the variety and complexity of the problems
underlying the art. That he will, at a near date, assume supreme
importance in the bakery, especially in the large machine or automatic
bakery, is certain, but the time is not yet, for he does not know enough
and, above all, the master baker is well aware of the fact. It is easy
to analyse all the ingredients in use in the bakery, but it is less easy
to determine how a combination of these ingredients will turn out
as bread, since the mutual influence of one complex upon another
is not known with any degree of certainty.

It is unfortunate also that so many technologists, having acquired
a smattering of chemistry, pose as scientific experts, with the result
that conflicting opinions, arising from the interpretation of inaccurate
results, have injured the prestige of the chemist. On the other hand,
the chemists have not been free from the fault of supplying, from a
laboratory, advice which clearly indicates that they do not know the
elements of bread-making.

Briefly put (for it must be assumed that the elementary principles
of bread making are understood by the reader), bread is made from
flour, yeast, water and salt, with occasionally milk, fat, malt extract,
yeast salts, wheat germ, aerating chemicals, &c., according to the
quality of bread required, English bread, farmhouse bread, milk
bread, germ bread, malt bread, tin loaves, Viennese rolls, French
rolls, &c.

With the addition of any new ingredient over the first four
mentioned, fresh complications in the chemical changes during bread-
making are introduced. Added to these must be considered the
changes involved during fermentation and baking, and, one of the
largest problems of all, during the change from freshness to staleness
which the loaf undergoes with the passage of time. With the use
of flour, yeast, water and salt alone, a mixing of dough, and the
subsequent loaf, are of sufficient complexity, involving the saturation

and swelling of the starch granules (for future gelatinisation by heat),
the production of hydrated forms of gluten, itself a complex proteid,
biological changes during the growth of yeast, the occlusion of gas ,
evolved during that growth, the action of the yeast enzymes on the
carbo-hydrates, the working of the dough to secure suitable elasticity,
proteolytic enzyme action on the gluten, the hardening action of
salt on the gluten, gelatinisation and saturation of the starch-water
system on baking, and the gradual changes, physical and chemical,
during cooling and ageing which bring about eventual staleness.
This is but a broad outline of the problems to be attacked when the
barest necessities for the production of bread are used, and it is
evident that the addition of milk or fat must increase the complication
of the bread system.
I.—Flour.

The flour components of greatest importance are starch, gluten,
mineral salts and enzymes.

(a) Starch.

Some space has already been devoted in Report I. (p. 46 et seq.)
to the consideration of wheat starch and its behaviour in the presence
of water at a temperature to cause gelatinisation. It is not intended
to cover this ground again.

Wheat starch in the presence of a sufficiency of water will commence
gelatinisation about 60° C., and every granule will be completely
burst at about 65° C. Since the baking temperature of a bread oven
is usually between 200° and 240° C., and the amount of water present
in a normal dough is about 41 per cent., the baking lasting for one
hour, it might be imagined that, all other factors removed, a great
proportion of the starch granules to be found in bread-crumb would be
gelatinised. Yet, as a rule, the starch granules inside a loaf show
a mixture of those untouched by the damp heat and of those only
slightly swollen, whilst a few only have undergone complete gelatinisa-
tion. The reason for this divergence from theory may be found in
the fact that a temperature seldom higher than 95° C. is reached
within the loaf, and then only for a very short period, during the
baking hour, though temperatures as high as 99-5° C. have been
recorded. It is probable that the time factor is of some importance
here. Further, the saturation of starch by water is reached when
a mixture shows 41 per cent. of the latter, hence, after allowing for
the absorption of water by gluten (which is not inconsiderable, being
as much as 200 per cent. of the dry gluten of a strong flour and slightly
less for weaker flour), there is an insufficiency of water present to
allow complete gelatinisation of all the starch granules at the
temperature of baking. The complexity of the colloid systems in
a baked loaf is, therefore, considerable.

Were there no component other than starch to consider, such
problems as the change in physical consistency from freshness to
staleness of a loaf would be comparatively easy of solution. But
there are so many underlying difficulties connected with dissolution
by enzymic action on the one hand, and coagulation by electrolytes
on the other, that the behaviour of the colloids in the loaf after

baking is less easy to interpret. It must not be forgotten, moreover,
that gluten, so far as can be ascertained, hinders the deposition of
_ starch from its jelly. At any rate, by the addition of extra gluten

to flour-dough the resulting bread possesses better keeping qualities,
which, from our recent researches (Whymper, R., “ Z'he Conditions
that Govern Staleness in Bread,” Maclaren and Sons, Ltd., 1919) in
the Army, have been shown to depend chiefly upon the: rate of
deposition of starch from its solutions with the passage of time. In
other words, gluten acts as a protective colloid to starch in solution.
Exception may be taken to such a generalisation as this, on the
ground that it is the quality of the gluten that determines whether
bread will keep well or quickly become stale. Snyder (U.S. Dept.
Agric., Bull., 101, 56, 1901) found that the addition of starch or the
addition of gluten, the former up to 20 per cent. of the flour, was
without material effect upon the size of the loaf, though the water-
absorbing capacity of the starchy flour was reduced. We are of
the opinion, however, that the conclusion reached by that worker
and by Jago (“ The Technology of Bread-Making,’”’ 1911, p. 305), that
“the character rather than the quantity of the gluten content ”
governs the quality of bread, is too far-reaching, since they omitted
to consider the keeping qualities of the loaf. Jago’s figures for the
viscometer readings of a similar experiment are not without interest
(Table I.), for, though of a rough order, they give some indication
of a previously observed fact, that, in the case of flours of high water-
absorbing capacity, this power is retained but little diminished on
being reduced to a uniform wet gluten-percentage level by the addition
of wheat starch.

TABLE I. °

Viscometer Determinations on Mixtures of Flour and Starch. (Jago.)

Patent. | Patent. | Bakers. | Patent.

Original percentage
of wet gluten - 39.2 28.2 32.0 35.0 27.75 31.9 38.4
Water - absorbing ;
power by visco-
meter - - | 68.6 54.8 69.0 76.0 61.0 60.5 64.0
Viscometer readings
on gluten being
reduced by ad-
mixture of starch
to—

35 per cent. - 65.0 — — = a = =
3 » - 62.7 — = 71.3 — 60.0 63.0
25 t - 62.0 55.5 66.0 70.7 59.5 = =
20 »” : 61.4 55.4 62.0 66.0 57.5 57.5 58.5
Weight of starch
added to 100 parts

of flour to reduce
gluten to 20 per
cent. - -

96.0 41.0 60.0 75.0 38.75 59.5 92.0

EO =

With regard to starch solutions and starch pastes, some viscosities
have already been given. (Report I., p. 47. See especially Samec,
1911, Koll. Chem. Bethefte, 3, 123-160; 1912, idem, 4, 132-174;
1913, idem, 5,,141-210.) Elsewhere (“‘ The Conditions that Govern
Staleness in Bread,” 1919) the present writer has observed that “ the
change in viscosity, with time, of starch paste follows a general rule
in that, at first thinly viscous when first prepared (hot), it sets to a
jelly, and later becomes thinly viscous again.” Pure supsensoids
change their viscosities (usually a decrease) in days, the more typical
emulsoids showing an increase in viscosity much more quickly. It is
assumed that, in starch paste, the latter changes are masked by the
slower changes of the former. As a matter of fact, the curve (viscosity
plotted against time) is of a distinct S shape, the changes being more
marked the more concentrated the solution. The solutions worked
with were prepared by digesting 8 grams of wheat starch (containing
10-8 per cent. water) in 180 c.cs. of water, and boiling till the clearest
paste was obtained. Other figures of interest obtained with such
a solution are shown in Table II., but should be compared with those
in Table III. showing the same methods applied to Doughs and
Bread-crumb, since, in every case, it is clear that the principle under-
lying changes in starch paste need not necessarily be reproduced in
bread-crumb, in which the phases are so differently distributed.

TABLE II.
Starch Paste.

Soluble Colorimetric
Apparent Extract* on Value of
= == Moisture, | Bone-dry Solids | Extract with
per cent. per cent. standard lodine
solution.
I | After 30 minutes cooling 95-90 [19-15] 1-31 blue
II ap 6 hours 35 95-95 [12-74] POS sy
Iil JD ZA 193) _ 95-92 [7-62] fo. ays
" a) ‘ sak O- O7 ”
IV iy Lo uass as 935-97 | [19-5] 0-104. red
- ‘ Lee 0-04 blve
Vv cys A aaee ups 96-84 [16-55] 0-05 red
: 0-08 blue
95 2
VI Bee ROO 5 a 95-95 [17-26] 0-2] red
mtrt | 5, 14a, e 95-99 [33-91]+ 0434 blue

0-20 red

* These values are unreliable, owing to magnification of experimental error
by calculation.
+ After 150 hours a still higher figure was obtained,

w 11454 E

66
TaBxe III.
Doughs and Bread-Crumb.

Soluble Colorimetric
Apparent | Extract Value of
— Loaf weights Moisture | on Bone- | Extract with
in grams. per cent. | dry Solids |standard Iodine
per cent. solution.
ae _f 0-21 red
Dough after mixing _ 41-21 10-07 0-05 yellow
Dough after proving a 41-10 9-76 Nil.
Original 997 ait : 1-10 blue.
Bread 6 hours old - 6 hours 973 41-42 12-84 2-50 red
Original 995 }
6 hours 972 1& blue
Bread 70 hours old- 24 hours 964 41-35 15:31 0:25 red

48 hours 952
70 hours 945

Among other conclusions reached by this research were :—

1. The loss of water during cooling and drying-out of a loaf is not
responsible for staleness.

2. During the process of becoming stale, there is a fall in soluble
extract obtained from the crumb, followed, after a time, apparently
independent of staleness, by a rise. The soluble starch in bread-
crumb (as shown by the iodine colouration) drops rapidly between
6 hours’ and 24 hours’ cooling.

3. Investigation shows that a similar fall and rise of soluble
extract is to be seen in starch pastes, whilst the iodine colouration
follows the same rule observed in bread-crumb.

4, Staleness may be attributed to—

(i) Deposition of solid starch in the crumb of bread, starting
between 6 hours and 24 hours’ cooling period—
(a) By change of temperature ;
(b) Accelerated by the presence of solid starch particles
already existing in the crumb.
(ii) Partial polymerisation of starch, independent of the
deposition already stated, which tends to crumble the
gelatinous nature of the bread-crumb when fresh.

The statement in 4 (i) (b) is open to dispute, for we have no actual
proof that the deposition of solid starch from solution is accelerated
by the presence of other solid particles. This work is even now in
progress. On the other hand, the statement made in para. 4 (i1) is,
we believe, substantially correct, for the following reasons, which
must be taken in conjunction with the figures given in Table II
showing the soluble extracts from starch paste decreasing with time,
(especially as indicated by the iodine colouration) :—

If we take the suspension of starch granules in water as the starting
point of our consideration, it is seen to be a coarsely disperse system, .

or a crude suspension of colloid matter in a dispersion medium,
increasing in uniformity of distribution as the subdivision of the
suspended particles is increased. Such a system allows almost
complete separation of the dispersion means by filtration through
an ordinary filter paper. The ordinary filter paper will hold back
particles having a diameter greater than about 5u, though, according
to the method of preparation, filters can be obtained which will stop
the passage of particles down to an approximate diameter of 2 wp.
According to E. F. Armstrong (Brit. Assocn., 1909), the smallest
wheat starch granules vary from 3 to 5 y, and the largest from 30 to
35 yz, so that the filtration of the water from the granules should be
almost complete. This, in practice, has been observed to be the
case.

The simplest form of starch has been given (Brown, H. T., and
Morris, G. H., Jour. Chem. Soc., 58, 610, 1888) a molecular formula
[(CysH001)20];- Lobry de Bruyn and Wolff (Rec. Trav. Chim. des
Pays. Bas., 23, 155, 1904) estimated the size of the starch molecule
to be approximately 5 yu, as compared with hydrogen gas 0-067—
0-159 pu, and water vapour 0-113 py. Soluble starch prepared by
the action of ozone on common starch was examined by Friedenthal
(Physiol. Zentralbl., 12, 849, 1899). who obtained a molecular
weight of 9,450 as against 32,400 in the formula above. The product
obtained in this way was clearly more highly dispersed than ordinary
starch, a fact borne out by the definite depression of the freezing point
of water containing it in contrast to a suspension of ordinary starch
or to a starch paste.

Depression of Freezing Point of Soluble Starch.

Concentration per cent. Depression of the Freezing Point.
2-5 0-005 ,
5-0 0-01
10-0 0-02

On the figures of Lobry de Bruyn and Wolff, “‘ if a cubic centimeter
of dry starch could be subdivided into its molecules or dissolved in
the ordinary sense of the word, the starch would present a total surface
of several thousand square metres towards the solvent,” and, in doing
so, would pass from an average size of its individual particles of 20 wu
through the value 0-1 yu, which represents the limit of microscopic
visibility, to a value of 1 yy, a figure somewhat smaller than that
of a particle hitherto observed with an ultra-microscope.

It is between the last two values that colloid chemistry has to deal,
according to Zsigmondy’s system of classification. (Zsigmondy, R.,
Zur Erkenntnis der Kolloide, X XII., Jena, 1905.)

With regard to filtration of colloids through various papers and
diaphragms, a considerable amount of work has been done, the
most interesting for the immediate purpose being that by Bechold
(Zeitsch. physik. Chem., 64, 328, 1908). Bechold’s results, from
his experiments with the pores of filter papers, cannot be taken
as absolutely accurate during prolonged filtration of colloid solutions,

E 2

since absorption effects are often observed, due to the action of the
paper on the dispersed phase, and often lead to clogging of the pores
of the filter. The results are, however, interesting, since they show
that typical colloids, with particles having a diameter less than 0-1 p,
are easily able to pass through all the filters tested.

Size of Pores in Filters.
Average Size of Pores

Filter. (Permeability to Water).
Ordinary thick filter paper - - - 3°3 ps
Filter paper, No. 556. (Schleicher and
Schill) - - . - - - - Lay
Filter paper, No. 602. (Extra hard,
Schleicher and Schill) - - - - 0-89-1-3 yu

The degree of solubility is also of importance in this question of
filtration, chiefly because the solubility of a substance is dependent
upon its specific surface, or, in other words, the solubility rises greatly
with the extreme subdivision. The jelly concentration of silicic acid
was found by Graham (Jour. Chem. Soc., 1864), in the very early days of
colloid chemistry, to influence the maximum molecular solubility
in excess of water. Thus he found that only two parts of | per cent.
silicie acid jelly formed a molecular disperse solution in 10,000 parts
of water, one part of a 5 per cent. jelly, and less of greater concentra-
tions of jelly in the same amount of water. Concentrated jellies,
therefore, are less disperse than the more dilute, and so have a lower
molecular solubility. The low solubility of gelatinised starch will be
appreciated when the figures shown in Tables IT. and III. are compared.

The viscosity, of starch solutions and separation of starch paste
into two phases has already been pointed out in the First Report
(p. 49), but, before passing to other points, it is as well to consider
another aspect of true soluble starch. Some description’ of soluble
starch has already been given in a previous Report (No. IL. p. 51),
but there is little doubt that confusion has arisen owing to its variable
nature according to the method of its preparation.

Soluble Starch.—Soluble starch paper, prepared by the action of
diastase or acids on starch paste or by heating dry starch in a suitable
manner (Zalkowski, Chem. Zeit., 1888, 1060), is soluble only to a
very small extent—about 2-3 per cent.—in cold water, yet itis
possible to obtain a preparation, by the action of sodium peroxide
(Syniewski, Ber., 1897, XXX., 2415) on starch suspended in water,
that is soluble to the extent of some 12 per cent. in the cold. The
latter seems quite a different compound to that prepared by Lintner’s
method with diastase.

The varied descriptions of the behaviour of soluble starch when
placed in water, dissolved and subsequently cooled, would add weight
to the conclusion that it was not always the same kind of soluble
starch that was under consideration. It may, and usually does, form
a thin opalescent paste, remaining fluid on cooling, however prepared,
but it does not always revert to the insoluble form in time. Fouard
(Compt. Rend., 1908, 97, 931-3) used a soluble starch that reverted

Co ry ae ae

apparently in a comparatively short time, whilst the writer, in
Table IV., has shown that, if there were any reversion at all after
144 hours, in the soluble starch that he employed, it was quite
insignificant. There is undoubtedly a small quantity of true soluble
starch formed in bread-making.

Tassie IV.
Soluble Starch. (From Messrs. Baird and Tatlock.)

Soluble
Apparent Extract* on Colorimetric
— —— Moisture Bone-dry Solids Value.
per cent. per cent.
I | After 30 minutes’ cooling 95-97 [82-38] 1:78 blue
II - 6 hours’ a 96-05 [84-05] 100 ees
iit SM ee as 13 95-93 [77-64] U:68s 5,
TV eel Sh we 96-04 [77-52] LO De iss
Vv = NE of 95-94 [72-66] SOR:
VI BAe OGit ss ‘3 96-06 [89-34] 1-43 ,,
VII apg nds sa 96-69 [83-38] Oey ce

* These figures are open to less error than those for starch paste, owing io
the greater amount of soluble matter actually present.

(b) Gluten. :

Wheat gluten has been briefly referred to in Report I. (p. 72),
from which it may be gathered that the proteid is itself a mixture of
coagulable albumin, glutin, and gliadin. These more or less distin-
guishable proteids have been again subdivided by Osborne and Voorhees
(Amer. Chem. Jour., 1893, “The Proteids of the Wheat Kernel’)
into glutenin, gliadin, globulin, albumin, coagulum, proteose, and
certain nitrogen compounds soluble inwater in the following proportions,
for flour milled from specified wheat :—

TABLE V.
Composition of Wheat Gluten. (Osborne and Voorhees.)

Spring Wheat. Winter Wheat.

— Nitrogen x 5:68 = Proteid. | Nitrogen x 5-68 = Proteid.
Glutenin - - 0: 8245 = 4-683 0: 7346 = 4-173
Gliadin - - 0: 6977 a 3° 963 0: 6884 = 3-910
Globulin” - “ 0: 1148 = 0-624 0-1148 = 0-625
Albumin - = 0: 0657 = 0-391 0- 0603 = 0-359
Coagulum - - 0- 0453 = 0-269 0: 0379 = 0-223
Proteose - - 0: 0341 = 0-213 0: 0791 = 0-432
From water- 0: 2239 = 1-272 0- 1552 = 0-881

washings of Glu-
ten.
Total - 2- 0050 = 11-415 1-8703 == 10-603
In meal - - 2-10 — 11-93 1-94 = 10-96

Gluten of wheat flour is therefore a variable colloid when met
with in the bakery. It is upon the proportion of glutenin to gliadin
and upon the amount and quality of salts present that the nature of
the gluten of wheat flour depends. Unless these proportions are
known (obtainable only by laborious effort in the laboratory), it is
not possible for the chemist to predetermine the quality of the
_ resulting bread. “Washing out” accompanied by baking trials
are the speedier tests for the quality of a flour.

Glutenin is insoluble in water, saline solutions and dilute alcohol,
soluble in dilute acids and alkalis, and reprecipitated from such
solutions by neutralisation.

Gliadin is insoluble in absolute alcohol; soluble in dilute alcohol,
(slightly in 90 per cent. and very soluble in 70-80 per cent. alcohol), from
which it is precipitated by adding a large quantity of water or strong
alcohol, especially in the presence of much salts. It is soluble in
distilled water, forming an opalescent solution from which it is
precipitated by addition of sodium chloride.

Globulin is soluble in sodium chloride solutions, precipitated
therefrom by dilution or saturation with magnesium sulphate or
ammonium sulphate, but not with sodium chloride. Partly pre-
cipitated by boiling, but not coagulated at temperatures below 100° C.

Albumin is precipitated from its solution by saturating with
sodium chloride or magnesium sulphate. Coagulated at 52° C.

Coagulum and proteose are both probably formed during the
extraction of the gluten with water. The former is precipitated by
saturating its solution with sodium chloride, or by adding 20 per cent.
of sodium chloride and acidulating with acetic acid. On concen-
trating this solution, the proteose is coagulated, leaving behind a
proteid called coagulum, which has not been separated in a pure state.

The behaviour of wheat gluten under the influence of salts is,
therefore, clearly the result of complex and mutual action among
the various colloid components and electrolytes. Very little more
can be said definitely.

Ostwald and Liiers [Koll-Zeits. 25, 26-45, 82-90, 116-136,
177-196, 230-240 (1919); 26, 66-67, (1920)] were evidently
working on the colloid chemistry of bread at the same time as the
present writer who, unfortunately, has not had an opportunity of
seeing the complete papers. The general results obtained seem,
however, to bear ont the conclusions reached by us in 1918, and
published in the British Baker in the following year. Ostwald and
Liters have found that the chief differences between flour, dough, and
new and stale breads, are of a physical rather than of a chemical
nature, and these workers have studied each material separately as
a colloid, in much the same way as we have done. The viscosity of
various mixtures of flour and water, containing as much as 20 per
cent of flour, were made, and mixtures of wheat “flour and water were
compared against rye mixtures. It was found that rye mixtures
became more viscous, whilst wheat mixtures became thinner, on
standing, and that traces of acids greatly increased the viscosity of
the wheat mixtures, whilst sodium chloride appeared to reduce it.
One point of great importance was established, viz., that a flour of

poor baking quality invariably gave viscosity figures considerably
below those of good flours.

The action of gliadin in gluten was also studied, and the viscosity
of gliadin solutions was found to be increased by traces of acids and
alkalis, and diminished by neutral salts. Further, the viscosity of
gliadin solutions was greatly affected by change of temperature, and
it is interesting to observe that the temperature at which the
maximum viscosity was reached was also the temperature at which
the best doughs and breads are produced.

The more recent work of Wood, on the action of acids and salts
on gluten, has already been briefly outlined in the First Report, but
his subsequent comments (Wood and Hardy, Proc. Roy. Soc., 1909,
B. 81, 38), made to bring the phenomena of the solubility of gluten
into harmony with the ionisation theory, cause rather a strain upon
the imagination. We may well believe that “the variations in
coherence, elasticity and water content, observed in gluten extracted
from different flours, are due rather to varying concentrations of
acid and soluble salts in the natural surroundings of the gluten than
to any intrinsic differences in the composition of the glutens them-
selves,” but it is less easy to understand that the formation of aqueous
solutions of gluten “is due to the development of electric charges
round the particles of the proteid owing to chemical interaction
between proteid, acid, or alkali, and water,” and that the converse,
“the tenacity, ductility and water-content of a solid mass of moist
gluten depends upon the total or partial disappearance of these
electric double layers (supposed to surround each particle of solute),
and the reappearance of what is otherwise obscured by them, namely,
the adhesion, or ‘ idio attraction’ as Graham called it, of the colloid
particles for each other, which makes them cohere when they come
together.” This may be the explanation, but it does not help us
largely in predetermining the quality of the bread from any particular
flour, especially as the glutens were treated after washing out and
not in their normal surroundings.

Weyl and Bischoff (Jago, “The Technology of Bread-making ’’)
showed that a flour moistened with a 15 per cent. sodium chloride
solution gave a dough that had lost its tenacity. Flour baked for
several hours at 60° C. can also not be doughed. Both experiments
have given rise to the theory that a ferment “ myosin” is largely
responsible for the ultimate production of gluten during doughing.

Distilled water dissolves a certain amount of gluten from flour,
and leaves the dough sticky rather than springy. Soft alkaline
water destroys the springiness of gluten by disintegration of the
gluten, and by prevention of the coherence of its particles. Hard
waters, especially those containing much sulphates, harden the gluten
considerably. Chlorides generally are more gentle in their action and,
up to a point, assist the water-absorbing and retaining power of gluten.

For other information concerning gluten and its components,
see also :—

Jour. Amer. Chem. Soc., 263, Guess (1900); 1068, Snyder, and 1657, Cham-
ae a 8, Norton (1906); 74, Matthewson (1908); 1295, Upson & Calvin

Jour. Soc.Chem. Ind., 1417 Arpin (abs.) (1902); 368, Baker & Hulton (1908).
Canadian Dept. Agric., [57], 37, Shutt (1907).

Jour. Board Agric. Supp. 4, 29, Saunders (1910); 52, Hardy (1910).
Agric. Gaz., N.S. Wales, Guthrie (1896).

Compt. Rend., 128, 755, Fleurent (1896); 182, 1421, Fleurent (1901).

Agric. Expt. Stn., Arkansas, Bull 53, Teller (1898).

U.S. Dept. Agric., Bull 101, 56, Snyder (1901).

Zeit. anal. Chem., 44, 516, Osborne & Harris (1903).

Jour. Agric. Soc., 2, 1, Humphries & Biffen (1907).

The character of bread and, incidentally, the character of gluten
are so intimately connected with the action of mineral salts (or other
electrolytes) upon colloids, that reference should first be made to the
collection of information to be found in the two previous Reports.
The works of Wood and Hardy have already been referred to, and
scattered through the literature on colloids may be found many other
‘references to the influence of various salts upon wheat gluten, the
chemical composition and original nature of which is seldom specified.

The “ maturing of gluten” is often mentioned in technical works,
and means little else than modifying a “ short ”’ gluten to a condition
by which it is capable of retaining the gas generated by the yeast.
Kohman and Hofiman (Jour. Ind. Eng. Chem., 1916, 8, 781-9;
1917, 9, 148-59) have made special claims for potassium bromate
in this connection, and have employed it in a special yeast food which
was used in the U.S.A. Army with great success. It should be noticed
that the action of potassium bromate is more effective the higher
the grade of flour used, both in modifying the gluten and in improving
the colour and texture of the bread (Rep. Conn. Agric. Expt. Stn.,
Bull, 200, 1917). The addition of alum was but another attempt
to modify a bad gluten, the hardening or coagulating effect of that
chemical upon many colloids being well known (Odling, Jour. Soc.
Arts, 1858). As a rule, alum was only employed on old or damp
flour, in which the gluten had deteriorated due to the action of acetic
or lactic acids. [See also the ancient use of sulphate of copper for
improving flour. (Liebig, “ Letters on Chemistry ’’).]

Deterioration with age of the physical qualities of gluten for
bread-making is also well known (Whymper, R., ‘“ Knowledge,”
386, 85, 1913), whilst the maturing effect on flour gluten of time and
bleaching materials should be considered. (Rep. Local Govt. Board,
1911, I. and IL., N.S. 49, Food Report 12, by Hamill and Monier-
Williams respectively.)

The nature of the water used in bread-making is of as much
importance in securing quality as in brewing. It is, of course, the
quality of the contained mineral salts in the water that determines
the suitability or otherwise of any given source. The action of the
salts is not only upon the starch and gluten colloid systems but also
upon the degree and speed of development of yeast cells. The effect
of soft and hard waters upon gluten has already been mentioned ;
that upon yeast nd fermentation can be found in any text-book
(Reynolds Green, ‘‘ The Soluble Ferments and Fermentation,’ &c.). |
It is not without interest in the latter connection that Miiller

(Ber. d. deus. chem. Gesell., 8, 679, 1875) has found that diastase in
the presence of CO, can act upon unboiled starch.

(d) Enzymes.

The colloid problems of enzymes have been reviewed in Report IL.,
and but little can be added to this information so far as bread-making
isconcerned. Those enzymes that have to be considered are principally
maltase, diastase, invertase, zymase, and certain proteolytic enzymes
that are not easy to identify.

Of considerable interest to us is the future development of the
work of Panzer (Zeitsch. physiol. Chem., 98, 316, 339, 1914) on the
activation of carbohydrates. This worker found that dry lactose
treated with dry hydrogen chloride and subsequently with ammonia
acquires feeble amylolytic power. The same, he states, to be true of
starches, dextrins, gum arabic, maltose, dextrose, levulose, and
galactose. (See also Jour. Soc. Chem. Ind., 1908, 389, Ford and
Guthrie.)

I1.— Yeast.

The work of Professor Bayliss in Report IT. (p. 117), surveying the
existing knowledge of protoplasm, its nature and properties, and of
enzymes that regulate the chemical reaction of the living organism,
fully covers the experience of the bakery chemist so far as yeast is
concerned. The problems are by no means simple, and involve the
biological history of Saccharomyces cerevisiz (see Lafar, “‘ Technical
Mycology ’’) in a variety of media (see Jago, “The Technology of
Bread-making,’’ Chap. X1.), and the action of the enzymes contained
in and produced by the yeast, as well as certain bacteria, such as
the lactic, butyric, and acetic ferments. The auto-digestion of yeast
is particularly interesting and important to the baker, who to-day
uses, so largely, compressed yeast containing 70-75 per cent. of water
In the Army in France the deterioration of yeast during the hot
weather was studied, recourse to barms being frequent there in the
summer months. Barms were in constant use in Gallipoli and
Mesopotamia during the war.

The growth of “rope” (B mesentericus) and moulds should also
be mentioned, since their presence must indicate that the bread had
become a suitable medium for their propagation from internal changes,
and by reason of suitable environmental conditions.

IIL. and IV.—Water and Salt.

As already indicated, the nature of the water is important in
considering the quality of bread produced, and the action of various

_ salts commonly found in water, and of sodium chloride in particular,
_ upon the strength or quality of wheat gluten has already been outlined.

V. et seq.—Fai, Milk, kc.

The colloid nature of these ingredients has also been considered
in previous reports. When used in conjunction with flour, water,

salt and yeast, in quite small quantities, their influence, both on the
physical nature and on the keeping qualities of the bread (so far as
staleness is concerned), is out of all apparent proportion, however,
to the amount present. The present writer has already remarked
elsewhere that :—

“ The effect of freshness can be enormously increased and sustained
for many days by the addition of small quantities of fat. With
added fats, up to 3 lbs. to the sack of flour, to doughs made by the
short, straight process, the colour is but little impaired, whereas
the crust is shorter, the crumb sweeter and more palatable, and the
effect of staleness is not appreciated for a much longer time than is
the ‘case with bread from the simple standard mixing. The use of
half milk and half water, instead of all water, as liquor has a some-
what similar effect, and the bread produced from this mixing recalls
the home-made farm loaf, which does not appear to change from
the original state of freshness for a week or more, if kept in a cool,
dry place.”

The reason is not so far to seek, yet, up to the present, no figures
have been obtained to demonstrate the protective influence of the
colloid existence of these added ingredients upon starch solutions.
There is little doubt, however, that they prevent the deposition of
starch in much the same way as they oppose the setting of cements.

COLLOID CHEMISTRY IN PHOTOGRAPHY.

By R. E. Stave, M.C., D.Sc., F.1.C., Director of Research, British
Photographic Research Association.

Introduction.

Most photographic processes fall into one of the two following
classes :-—

(1) The substance sensitive to the light is eventually turned
into the pigment.

(2) The substance sensitive to light is the support of a
pigment already present.

In both classes of process the support of the sensitive substance
or pigment is usually a dried gel, e.g., collodion, gelatin, gum.

As an example of class (1) we will consider the ordinary commercial
dry plate. The sensitive film consists of very small crystals of silver —
bromide, sometimes containing some iodide, supported in a dried —
gelatin gel. On exposure to light some of the grains become develop-
able. On development—treating with a reducing agent, e.g., alkaline
hydroquinone—the gelatin swells and the developer diffuses into the —
gelatin, reaches the grains of silver bromide and reduces to metallic
silver those previously made developable by light.

As an example of class 2 we will consider the carbon process.
A gelatin solution containing a pigment such as finely divided carbon
is coated on to a suitable support, dried, sensitised by immersion
in a solution of ammonium bichromate and dried again. The print

-_—_

——— es eee eS

is exposed behind a negative and is then developed by washing in
warm water. Where the bichromated gelatin film has been exposed
to light it has become insoluble, where it has not been exposed to
light it dissolves in warm water and the pigment is washed away.
Since the bottom of the film will have been protected from light by the
pigment it will dissolve in water and all the gelatin film will come
away from its support. It is therefore necessary to transfer the
gelatin layer on to another support and to develop the image by
washing away the pigment that was the bottom of the film.

Photographic Emulsions.

If, to a solution of potassium bromide we add an equivalent amount
of a solution of silver nitrate, we obtain a precipitate of silver bromide
which quickly collects in the form of large flocks and settles to the
bottom of the vessel. If the precipitate in this state or after washing,
is shaken up with a solution of gelatin containing a trace of potassium
bromide, a colloidal solution of silver bromide is obtained®. Such
solutions are usually termed emulsions, though, strictly speaking,
this is a misnomer they are suspensions, in which gelatin acts as a
protective colloid. If the silver bromide is allowed to stand for
two or three days before treatment with the gelatin and bromide, it
will not form the emulsion. The usual method of preparing emulsions
is to precipitate the silver bromide in the presence of gelatin. .The
particles in the emulsion as soon as they are prepared, are very fine
indeed, and such emulsions are sometimes called grainless. If the
emulsion is washed free from dissolved salts at any time and kept
at ordinary temperatures it becomes fairly stable, that is to say it
changes fairly slowly or not at all. If there are dissolved salts present,
which have a slight solvent action on the silver bromide, an increase
in the size of grain takes place. The change is favoured by rise of
temperature. The grains become more sensitive to light as they
grow. This growing of the grains is called ‘“ripening.’”’ Under
suitable conditions the grains grow by capilliary forces until they are
2u to 10u diameter!*. The smaller grains being more soluble than
the larger, dissolve and make the solution supersaturated with respect
to the larger ones which therefore grow. Usually crystals will only
grow in this way until their diameter is about 2u, because above this
size the solubility no longer diminishes as the size increases. The
erystals of silver bromide can certainly grow to 10u diameter during
ripening, and this may be due to the fact that such crystals are in
the form of very thin plates (less than lu thick), or it may be caused
by unequal heating and the presence of convection currents in the
solution during ripening.

The chloride and bromide of silver crystallise in the cubic systems
at all temperatures used in the preparation of photographic emulsions.
The iodide crystallises in the hexagonal system below 146° C., and

above that temperature in the cubic system. The three halides
_ form solid solutions with each other, so that in an emulsion containing
more than one halide, we have only one kind of mixed crystals present.

Although in many plates several per cent. of silver iodide is present

with the silver bromide we only get crystals of the cubic system.
A microscopic examination of ripened emulsion shows that the
particles vary in size from 0-4 to about 10u, but emulsions used in
practice do not often contain crystals larger than from 2-3y. It is
difficult or almost impossible, to determine the shape of particles
smaller than 0-84 in diameter, but all particles of this size and
larger are found to be forms of the cubic system, principally
hexagonal and triangular plate and tetrahedra. Since there is no
sharp break in the properties of an emulsion at any particlar size
of particle, it is probable that even the smallest particles are crystalline.
There is no evidence of the existence of amorphous silver bromide.
When crystals of silver chloride are grown from an ammoniacal
solution, cubes are formed, if gelatin is present there seems to be a
tendency for the 1.1.1 faces of the crystal to develop. The simple
cube does not seem to be formed in the presence of gelatin.

When light shines on the silver halide a red coloration is produced.
Luther showed that the halogen was liberated, and that the reaction
did not take place if the pressure of halogen present exceeded a certain
equilibrium value depending on the intensity of the light. These.
coloured halides are often called photohalides, they may also be
prepared by subjecting a mixture of finely divided silver and silver
halide to a high pressure. It was formerly considered that these
photohalides consisted of silver subhalides. The work of Sichling,
Lorenz und EHitel, and Lorenz und Hiege has, however, conclusively
proved that these photohalides are colloidal solutions of silver in the
halide. Sichling showed by E.M.F. measurements that if silver sub-
bromide existed at all in the halides, it was only to a very small extent,
and was only stable over a very short range of concentration. The
existence of colloidal silver in the photobromide of whatever composi-
tion was definitely established. Lorenz and his co-workers showed
that optically clear silver halides may be prepared by treating the
fused salt with the halogen. When these optically clear crystals are
exposed to light they darken, but remain at first optically clear, later
the surface at which the beam enters becomes brown and the particles
become visible in the ultra-microscope. The particles grow rapidly
in the light, and will continue to grow if they are removed from the
light and heated to 350° C. Heating without previous exposure to
light does not produce these particles. The growth of these particles
is accompanied by a diminution of coloration in the immediate neigh- |
bourhood. The effect is evidently due to the separation of colloidal |
silver in the metallic form. The analogy between these fogs and
the metallic fogs formed in fused salts seems to be complete. It is
probable that the latent image in the photographic plate consists of
a colloidal solution of silver in the halide, and is the first stage of ©
the formation of the photohalide. Many theories of the latent image
have been put forward, among which may be mentioned that of
H. 8. Allen, who has suggested that the latent image is due to the
loss of an electron by a molecule of the silver’ halide and the electron
remains embedded in the gelatin. Under certain circumstances the
electron may get back and the latent image may be destroyed. This,
and many other theories have never been put to the proof. Some- —

—_—™

; 77

times it is difficult to devise experiments which will decide between
various theories, all of which have been made as wide and indefinite
as possible and consequently of little practical use. A deeper know-
ledge of the latent image can only be obtained by further experiments
to test the various theories.

When silver bromide is precipitated by the addition of a soluble
silver salt to potassium bromide in the presence of gelatin a colloidal
solution is obtained. If the concentration of the silver salt added to
the gelatin solution of potassium bromide is strong, the resulting
colloidal solution appears blue by transmitted light®, *%, 7. Such
emulsions are sensitive to red and even infra-red light. In the
ordinary way emulsions are prepared from a dilute solution of silver
nitrate, the emulsion thus obtained appears red by transmitted lights
On ripening the colour changes to green. We do not know the size
of the particles in the blite emulsion, they are probably very small.
The red emulsion contains particles up te about 0-1 in diameter,
the green emulsion contains particles from +54 upwards. In the
blue and red emulsions the colours are quite well accounted for by
the Rayleigh theory of the scattering of light by small particles, but
as yet there is no explanation of the cutting off of the red end of the

*spectrum by the emulsions with particles of about the diameter of
a wave-length of light. Keen and Porter have shown that a similar
colour change takes place in a suspension of sulphur when the size
of particle becomes a little greater than the wave-length of light.

BIBLIOGRAPHY.

Preparation of Emulsions.

; -
1 Abney, Sir William (Piper & Carter, London, 1883). ‘ Photography with
Emulsions.’
. 2 Eder, Handbuch der Photographie, Vol. III.
3 British Journal of Photography, 275, 286, 300 (1917).
4 Liesegang, R. E., Zeit. Phys. Chem., 75, 374 (1910). ‘ Uber die Reifung
von Silberhaloidemulsionen..’
; > Bancroft, Wilder D., Jowr. Phys. Chem., 14, 12, 96, 201, 620 (1910). ‘ The
Photographic Plate.” The Emulsion, Pt. I., II., III., IV.
These papers give an excellent summary and extracts from the
literature of the subject up to 1910.
6 Luppo-Cramer, Phot. Korr., 44, 572 (1905).

Theories of Ripening and the Latent Image.

? * Photohalides of Silver.’ Carey Lea, Sill. Am. Jour., 8, 33, 349, 476 (1887) ;
Sill. Am. Jour., 3, 38, 129, 237, 248 (1889).

8 W. Ostwald, Eder’s Jahrbuch fur Photographie (1897), 402.
__ *R. Luther, Zeit. Phys. Chem., 30, 628 (1899). * Studien uber umkehrbare
chemische Prozesse.’

10 R. Luther, Die Chemische Vorgange in der Photographie (1899).

11 Thiel, Zeit. Anorg. Chem., 24, 32 (1900). ‘* Formation of Mixed Crystals of
_ the Halides of Silver.’
a 12 Monkemeyer, Jahr. Min. Beil., 22, 1 (1906).
4 18 Bellach, Wilhelm Knapp, Halle (1903). ‘Struktur der Photographischen
_ Negative.’
f M Quincke, Hder’s Jahrbuch fur Photographie (1903), 3.

15 W. D. Bancroft, Jowr. Phys. Chem., 12, 209, 318, 417 (1908); 18, 1, 181,
269, 499, 538 (1909); 14, 292 (1910), * The Electrochemistry of Light.’

4
7
"

16 Luppo-Cramer, (Theodor Steinkopf), Dresden (1908). § Koloid-Chemie
und Photographie.’
Several papers are published each year on this subject by Luppo-Cramer
in the Kolloid Zeitschrift.

17 Sheppard & Mees, Zeit. f. wiss. Phot., '7, 27 (1909). ‘ Theorie der Photo-
graphischen Prozesse: Reifen und der Photoelektrische Effekt.’ ;

18 A, P. H. Trivelli, Zeit. f. wiss. Phot., 8, 17 (1910). ‘ Beitrag zu einer
Theorie des Reifungsprozesses der Silberhaloide.’

19 Sichling, Zeit. Phys. Chem., 77, 1 (1911). ‘Uber die Natur der Photo-
chloride des Silbers und deren Lichtpotentiale.’

20 W. D. Bancroft, Jour. Phys. Chem., 15, 313, 551 (1911); 16, 27, 89 (1912).
‘The Photographic Plate’: The Latent Image, Pt. L, U., I1., IV.

A summary of the literature up to that date.

21 Allen, The Photographic Journal, 54, 175. ‘The Formation of the Latent
Image.’

22 Lorenz und Eitel, Zeit. Anorg. Chem., 91, 57 (1915). ‘ Uber Silbernebel
in Silberchlorid und Silberbromid.’

23 Lorenz und Hiege, Zeit. Anorg. Chem., 92, 27 (1915). ‘Uber den
Belichtungsvorgang in festen Silberchlorid und Silberbromid.’

24 Krohn, Phot. Jour., 58, 179 (1918). ‘The Mechanism of Development of
the Image in a Dry Plate Negative.’

25 Ritz, Oewvres de Ritz, 4, 80. ;

26 Abney, Phil. Trans., 171, II., 653 (1880). ‘The Photographic Method
of Mapping the least Refrangible end of the Solar Spectrum.’

27 Ritz, Comptes Rendus, 148, 167 (1903). ‘ Sur la Photographie des Rayons*
infrarouge.’

References to the papers on optical properties of colloidal solutions
are given under the next section.

Colloidal Silver and the Colour of Silver Deposits. :

Colloidal solutions of silver in the finest state of division are
yellowish brown in colour and as the size of the particles is increased
the colour changes to ruby red, lilac, and blue. When these solu-
tions are precipitated by the addition of an electrolyte a dark
grey precipitate of silver is obtained. If a soluble silver salt is reduced
by a powerful reducing agent such as alkaline pyrogallic acid, silver
is precipitated in the black form, if a less powerful reducer such as
pyrogallic acid alone, is used, a grey precipitate is obtained’.

Any circumstance which tends to prevent the coalescence of
the reduced silver such as the reduction of an insoluble salt, or the -
enclosure of the salt in gelatin, yields the dark modification. Collodion
does not hinder the coalescence of the silver particles to nearly the
same extent as gelatin?.

The colour of the image obtained varies to some extent with the
developer used. If gaslight paper is developed with an excess of
bromide in the developer the first image becomes red, but appears
black as the develpoment proceeds. The products of oxidation of
some developers stain the gelatin yellow or brown as these oxidation
products are present in the greatest concentration at those parts of
the plate which have been most exposed, the silver deposit in the
negative appears to be stained through, though this is not the case.

1 Luppo-Cramer, Zeit. f. Chemie und Ind. der Kolloide, 3, 33, 130, 170 (1908).
‘Uber das Silbergel in den photographischen Schichten.’

‘ 719

* Rayleigh, Proc. Roy. Soc., 84, 25 (1910). ‘The Incidence of Light upon a
Transparent Sphere of Dimensions comparable with the Wave-length.’

* Chapman Jones, Phot. Jour., 51, 159 (1911); 57, 158 (1917). ‘On the
relationship between the size of particles and the colour of the image.’

4 Nils Philbad, Zeit. f. Chemie und Industrie der Kolloide, 9,156 (1911). ‘ Zur
Kenntnis der Lichtabsorption in Silberhydrosolen.’

®°Swen Oden, Zeit. Phys. Chem., 78, 682 (1912). ‘ Beziehung zwischen
Teilchengrésse und Stabilitaét disperser Systeme.’

6 Keen and Porter, Proc. Roy. Soc., 89, 370 (1914). ‘ Diffraction of Light
by Particles comparable with the Wave-length.’

? Paris, Phil. Mag., 80, 459 (1915). ‘On the Polarisation of Light scattered
by spherical metal particles of Dimensions comparable with the Wave-length.’

§ Gans, Ann. d. Physik, 47, 270 (1915). ‘ Uber die Form ultramikroskopischer
Teilchen.’

® Liesegang, R. E., Zeit. wiss. Phot., 14, 343 (1915). ‘ Uber die Polychromie
des Silbers.’

10H. F. Burton (Longmans, Green & Co., London) (1916). ‘The Physical
Properties of Colloidal Solutions.’

1 Rayleigh, Phil. Mag., 35, 378 (1918). ‘Scattering of Light.’

2 W. D. Bancroft, Jour. Phys. Chem., 22, 601 (1918). ‘ Colour of Colloids.’

13 Haas, Ann. d. Physik., 57, 7, 568 (1918). ‘ Die Beziehungserscheinungen,
welche an einer grossen Anzahl unregelmissig verstreuter Offniingen oder
undurchlassigen Teilchen auftreten.’

: Gelatin.

In the dry plate the gelatin is not only a protective colloid for
the preparation of the emulsion, an adhesive substance for attaching
the sensitive substance to the glass and a photochemical sensitiser

_ of the silver halide, but it plays a most important part in development.

_ Unless gelatin, or some other colloid, is present, strong reducing agents
such as alkaline developers will reduce silver halides without previous
exposure to light. In presence of gelatin, however, this reaction is
extremely slow!.

The oxidation products of developers usually tan the gelatin—

make it less soluble so that an ordinary negative shows the pictures
in relief. The parts containing most silver being lowest, and the
clear gelatin projecting to the greatest height’.
Sheppard and Elliot have given an explanation of the reticulation
of the surface of photographic negatives. Their explanation is based
on Procters’ work on the effects of acids and alkalis on the swelling of
gelatin??.
The colloid chemistry of gelatin is discussed in detail by Procter
in the First Report. The most important later work on the subject
is that of C. R. Smith, who has studied the mutarotation of gelatin.
He showed that gelatin in solution may be in a sol form A, stable
above 35° C., or a gel form B, stable below 15° C. Between these
_ two temperatures the two forms eventually come into equilibrium
and this causes mutarotation. Form B is much more viscous than
form A, and a certain definite concentration of B is necessary to
_ produce gelatinisation. The authors’ experiments show that probably
two molecules of the A form combine to form one molecule of the
-B form.

1W. Reinders & J. van Niewenburg. Koll. Zeit., 10, 36 (1912). ‘ Gelatine
und andere Kolloide als Verzogerer bei der Reduktion von Chlorsilber.’

‘ * Lumiere & Seyewitz, Bull. Soc. Chim., iii., 85, 14 (1906). * Sur la composi-
tion de la gélatine insolubilisée spontanément dans 1’ obscurité.’

3 Lumiere & Seyewitz, Bull. Soc. Chim., iii., 88, 1032 (1905). ‘Sur la
composition de la gélatine impregnée de bichromate de potassium insolubilisée
par la lumiére et sur la théorie de cette insolubilisation.’

4 Lumiere & Seyewitz, Bull. Soc. Chim., iii., 85, 676 (1906). ‘ Action des
alums et des sels d’alumines sur la gélatine.’

® Lumiere & Seyewitz, Bull. Soc. Chim., iii., 85, 377 (1906). ‘Sur le
phénoméne de Vinsolubilisation de la gélatine dans le développement et en
particulier dans l'emploi des révélateurs a lacide pyrogallique.’

6 Lumiere & Seyewitz, Bull. Soc. Chim., iv., 1, 428 (1907) ‘Sur Vinsolu-
bilisation de la gélatine par la quinoine.’

7 Lumiere & Seyewitz, Bull. Soc. Chim., iv., 8, 743 (1908). ‘Sur les phénoménes
de la précipitation et de Vinsolubilisation de la gélatine.’

8 Procter, Transactions of the Chemical Society, 105, 313 (1914). ‘ Equilibrium
of dilute hydrochlorie acid and gelatin.’ :

9 Procter, British Association, First Report on Colloid Chemistry and its
Industrial Application, 24 (1917). ‘ Colloid Chemistry of Tanning.’

10 Sheppard & Elliot, Brit. Jour. Phot., 65, 480 (1918). ‘ The Reticulation

of Gelatin.’
110, R. Smith, Jour. Am. Chem. Soc., 41, 149 (1919). ‘ Mutarotation in

gelatin and its significance in gelatinisation.’

Gum.

Gum is used in the gum bichromate process as the base of a pigment
process just as gelatin is used in the carbon process, but a very thin
layer of the colloid is used so no transfer is necessary. The gum is
made insoluble by exposure to light after sensitisation with a
bichromate. Gum arabic is generally used in this process. Starnes
states that better results are obtained by the use of gum senegal.

Starnes has made some experiments from which he concludes
that when bichromate is added to the gum it is at once rendered
less soluble. On exposure to light it first becomes quite soluble and
then, on further exposure more and more insoluble. Thus in the
early stages, of printing there is a reversal of the image. The
phenomenon has, however, not been investigated quantatively.

Starnes, The Photographic Journal, 42, 287 (1918). ‘The gum-bichromate
process with a new colloid.’

COLLODION IN PHOTOGRAPHY.

By H. W. Greenwoop, Research Chemist to The Leto Photo Materials
Co. (1905), Ltd.

The use of collodion has been coincident with the rise and progress
of photography—by collodion is here meant a solution of pyroxylin
in ether alcohol.

Any discussion of the colloid chemistry of collodion apart from
other forms of nitro-cellulose is almost an impossibility, for although —
a great volume of work has been done, only a very small part of this —
may be claimed as appertaining solely to collodion.

The role of collodion in photography is similar to that of gelatine.
It acts as a protective colloid, as a support, and also at times plays
a part in the actual reactions. The greatest difference between
collodion and gelatine is that collodion, except to a negligible degree,
does not act as a sensitiser. Its insolubility in water, comparative

1 =

indifference to temperature, and its chemical inertia, are in marked
contrast to gelatine, and are the main characters which render it of
such importance as a support. Any discussion of the photo-chemical
reactions involved in the preparation or utilisation of collodion plates
or papers would be redundant, as they are of the same general character
as occur in all photographic processes, and are dealt with elsewhere.

A very full account of the history and preparation of collodion
and its application to photography will be found in Vol. 2 of Worden’s
* Nitro-cellulose Industry,” 1911, pages 827 to 897, where copious
references are given to both patents and literature.

Very little exact information exists as to the specific characteristics
of photographic collodion. It is obvious that the character of any
solution will depend upon the nature of the nitro-cellulose used, the
solvents being under comparatively perfect control. The exact
nature of the nitro-cellulose depends upon two factors, namely, the
raw material used for nitration, and the constitution of the resultant
nitro-cellulose, which latter naturally depends upon conditions and
details of the nitration process. The permissible nitrogen content
for the production of a photographic collodion lies somewhere between
11 per cent. and 12 per cent., and generally about 11-5 per cent. It
is found that quite small variations of nitrogen content may involve
large variations in physical character, such as, refractive index,
viscosity, water compatibility, &c. Hence the mere nitrogen content,
within the limits mentioned, does not in any way constitute a guide
as to the suitability, or otherwise, of a nitro-cotton. Many attempts
have been made to devise methods which would yield more positive
results, but with comparatively small success; the behaviour of the
nitrated fibre towards polarised light has been investigated by several
workers, and a rough indication of the degree of nitration of the
cotton can be obtained in this manner. The greatest value of the
method so far is that it clearly differentiates, first, unnitrated fibres;
and second, fibres of varying degrees of nitration. It is now realised
that the usefulness of polarised light will be greatly extended when
the results obtained by its use are correlated, not only with the nitrogen
content, but with the physical properties, such as viscosity, refractive
index, &c., which are of much greater significance than the nitrogen
content in determining the properties of the collodion as far as its
photographic utility is concerned.

The lack of knowledge as to the constitution of the nitro-cellulose
molecule is a bar to more exact information regarding the behaviour
of nitro-cellulose solutions, as collodion, in the various processes for
for which it is used in photography. Results of an anomalous
character are frequent in all investigations, and although there is now

-available a large volume of observations, they cannot yet be exactly

correlated, nor is the information available which explains their
occurrence. The effect of drying the cotton before nitration, and
especially the temperature and treatment to which it is subjected
before the actual nitration takes place, has a profound influence on
the physical properties of the resultant nitro-cellulose. Further,
both time and temperature modify the nitrated cotton. It would
appear that all nitro-cottons undergo a process of denitration to a
a 11454 F

greater or lesser degree, and that this denitration explains the anomalies
that are so frequently met with in connection with the viscosity of
collodions, and also with the behaviour of different films from one
and the same solution. This decomposition is capable of acceleration
not only by temperature but by many chemical agents; and also,
probably takes place spontaneously at ordinary temperatures. The
action of bromides in causing denitration is well known. One aspect
of this phenomena is its importance in relation to the question of
the keeping properties of collodion plates and papers, and of the
permanence of the photographic image, whether negative or positive
after the usual processes of development, fixation, &c., and in this
direction much further investigation is called for.

CELLULOSE ESTERS.

By Foster Sproxton, B.Sc., F.L.C., Chief Chemist to the British
Xylonite Co., Ltd.

The technical problems which arise in any colloid industry naturally
depend on the uses to which the finished material is put, and in view
of the varied nature of the applications of such products as leather,
glue, starch, explosives, and colloidal metals, it is not surprising
that each industry is concerned with a somewhat different aspect of
the chemistry and physics of highly disperse matter.

The industry of the cellulose esters has for its principal object
the manufacture of a material of valuable mechanical properties.
Its colour, transparency, surface, &c., though of great importance,
would be of little moment if the material did not possess elasticity,
tensile strength, and toughness at ordinary temperatures, and plasticity
at higher temperatures. The object of the industry is the provision
of a material combining these properties without prejudice to its
adaptability for artistic and imitative effects.

It must be admitted that in the case of celluloid a high standard
of technical excellence has been reached without the assistance of
theories of the nature of the plastic material. The reproduction of
material possessing the desired properties is accomplished only by
strict control of the raw and semi-manufactured material, and close
adherence to the conditions ascertained by experience.

A brief account of the manufacture of celluloid will be found in
Thorpe’s “ Dictionary of Applied Chemistry,’! to which the reader
is referred. The manufacture of plastic materials from acetyl cellulose
is described by Worden.? The colloidal problems encountered in
the two manufactures are very similar except in the case of the
preparation of the starting materials, nitro-cellulose and acetyl
cellulose. These will be considered separately.

Nitro-cellulose is made, as is well known, by the action of a mixture
of sulphuric and nitric acids on eellulose, usually in the form either
of cotton or paper. The two phases, solid cellulose and liquid acid
mixture, persist throughout. It has been shown by Cross, Bevan,
and Jenks, and by Hake and Lewis, that there is an intermediate
formation of sulphuric esters of cellulose, which are gradually converted

almost entirely into nitric esters. Leaving this complication out of
account, however, it is evident that the reaction must proceed by the
diffusion of the acid mixture through the fibre. The final degree of
nitration reached depends principally on the composition of the acid
mixture, and nitrocelluloses of all percentages of nitrogen from
10 to 13 occur in commerce. From what has been said it is evident
that the nitration process is very complicated, and it is not to be
wondered at that it has not been brought to mathematical expression,
although a vast amount of data has been accumulated’. However,
by the accurate control of the composition of the bath, the purity
and humidity of the cellulose, the temperature and time of nitration,
very uniform products are obtained, and, to take only one instance,
that of the manufacture of guncotton, the accuracy of modern
musketry and artillery practice proves how uniformly a two-phase
reaction can be controlled, although involving diffusion through a
membrance which itself alters during the reaction’.

Acetyl-cellulose is prepared by the prolonged action of acetic
anhydride, acetic acid and sulphuric acid on cellulose, but the process
differs from nitration in that the product is soluble in the reaction
mixture. In this case, therefore, the acids reach the cellulose by
diffusion through a gel of acetyl cellulose in acetic acid. The final
product of the reaction is homogeneous, at any rate down to ultra-
microscopic limits, and the acetyl-cellulose is recovered in the solid
state by precipitation with water. The acetylation of cellulose takes
much longer than nitration, and up to the present the uniformity of the
product is inferior to that of nitrocellulose. This is probably due
partly to the difficulty of temperature control, and partly to the
complications introduced by modifications designed to produce material
soluble in special solvents®.

The central point in the manufacture of celluloid and acetyl-
cellulose plastic materials is undoubtedly the gelatinisation of the
base. Nitrocellulose retains the form of the original cellulose,
although harsher to the touch. When it is kneaded with camphor
and alcohol it is converted into a transparent gel, and the remaining
processes of the manufacture merely consist in manipulating the
gel while it is slowly hardening through loss of aleohol and part of
the camphor. It is rolled out into sheets, pressed into blocks, sliced
on a planing machine, and finally polished if required. The treatment
of acetyl-cellulose is similar in principle, although different solvents are
employed. .

During the evaporation of the volatile solvents from celluloid in
its seasoning or drying stage, there is a gradual loss in weight, diminu-
tion in volume, and increase in specific gravity. It may be noted in
passing that the specific gravity of celluloid is of particular interest
to the manufacturer of celluloid articles, since he buys the material by
weight, and, in effect, sells it by volume. The relation of the loss of
weight to the loss of volume was investigated by the writer in relation
to another technical problem. The extreme cases would be that of :
(1) a sponge-like structure which could lose weight without (apparent)
loss of volume in which case loss of weight/loss of volume = © ;
(2) a structure which could shrink in volume without loss of weight,

; F2

in which case loss of weight/loss of volume = 0. On a priori grounds,
therefore, any value for this ratio (which is the apparent specific gravity
of the alcohol and camphor lost) might be expected. It was found
in some careful experiments on a certain variety of celluloid in the
final stages of drying that the ratio varied only from 0-82 to 0-91,
the mean value for 28 samples being 0:87. This is the specific gravity
of a solution of camphor in alcohol containing 42 per cent. of camphor
by weight. Although these experiments do not prove that the
shrinkage in volume of celluloid while seasoning is exactly equal to
the volume of camphor and alcohol lost, they show that the difference,
if any, must be small.

There is no more fascinating branch of the technology of cellulose
esters than the study of solvents. Hundreds of substances and mixtures
of substances are known which have more or less marked solvent
action on nitrocellulose or acetylcellulose, but the question of how to
make a fair comparison between one solvent and another has never
been completely worked out. The work was begun for nitrocellulose
by the late F. Baker’. He came to the conclusion that the best
solvent of a particular sample of nitrocellulose was the solvent which
yielded the solution of lowest viscosity, and this is in agreement with
manufacturing experience. It may be pointed out, however, that
another method might be chosen, and that is to find the solvent
yielding solutions which will bear the greatest dilution with an
indifferent, miscible non-solvent, such as petroleum ether, before the
cellulose ester is precipitated. This method is also in line with the
technical valuation of solvents. and a rigorous comparison between
the two methods would be most interesting. Petroleum ether has been
suggested here as the indifferent liquid, because of the unexpected results
sometimes obtained when mixtures of liquids-act on cellulose esters.
It has been long known that ethyl alcohol and ether are, separately,
non-solvents of soluble nitro-cotton, but form a solvent when mixed.
This mixture was investigated by Baker*, and he concluded that the
solvent power was exerted by a complex formed by the combination
of ether and alcohol. This is a reasonable explanation of this par-
ticular case, but it does not explain the extraordinary effect sometimes
‘produced on solvent power by the additions of quite small amounts
of foreign substance. One instance which has long been known is
the solvent power imparted to methyl alcohol by the presence of
traces of acetone. A recent example of the technical application of
the principle is Eng., Pats. 14,655 and 14,656, in which the addition
of small quantities of substances such as nitro-toluenes, formanilide,
&c., is employed to facilitate the solution of nitrocellulose in nitro-
glycerine.

But, returning to the consideration of mixtures such as ether-
alcohol where each constituent is present in bulk, it would be of
interest to extend Baker’s viscosity work on solvent power to such
mixtures, and find what proportions of the constituents produced the
best solvent mixture. Probably the records of such experiments exist,
but they do not appear to have been published.—Index 9a. The results
would be of value in a field somewhat remote from that of colloid
chemistry, in view of the recent work of Bramley and others on binary

mixtures’. The viscosity/concentration curves of such mixtures
usually show maxima, the positions of which vary with the temperature,
and Bramley concludes that the viscosity of liquid mixtures as an inde-
pendent test of compound formation in liquid mixtures is unsatis-
factory. The writer suggests that the viscosity/concentration curves
of mixtures of liquids containing a constant weight of a viscous colloid
in solution might give more useful results. The viscosity of the
solvent would be masked by the viscosity due to the colloid, dissolved,
presumably, in a complex of the two liquids. It is certain that in
many cases minima would be found, and it would be interesting to
see whether these minima also shifted with change of temperature,
and whether their position corresponded with molecular addition
compounds. The method could be applied to all mixtures possessing
solvent power for a viscous colloid, whether the constituents separately
were solvents or not. For instance, mixtures of aliphatic alcohols
and benzene hydrocarbons should be examined with nitrocellulose
in solution, and mixtures of aliphatic alcohols and chlorinated paraffins
with acetylcellulose in solution, and so on. Although the results
obtained would be chiefly valuable as a contribution to the study
of binary mixtures, they would also be useful data in the chemistry
of emulsoid solutions’.

The same question was encountered in a different form some years
ago by the writer in a purely technical investigation. It is well known
that ethyl alcohol and toluene together form a solvent for nitro-
cellulose of low nitration. To find the composition of the best solvent,
constant weights of nitrocellulose of imperfect solubility were treated
with a constant volume of toluene and alcohol in different proportions
and the amount of nitrocellulose dissolved by each mixture was
estimated. The results showed that the optimum mixture corresponded
closely with a mixture of three molecules of alcohol to one of toluene
thus suggesting the existence of a complex C,;H;, 3C,H;OH. Regarded
from the purely colloid point of view, perhaps, the development of
solvent power by relatively small additions of other substances to
partial or non-solvents is the more interesting owing to its analogy
to organised processes such as nutrition.

The nature of the solid camphor-nitrocellulose complex is still
unknown. Schiipphaus"™ believes that there is some kind of chemical
combination between camphor and nitrocellulose, chiefly on the
ground that the heat of combustion of celluloid is less than that of its
constituents. But this is only the complement of the fact that
camphor and nitro-cellulose evolve heat when mixed, which cannot
be regarded as evidence of chemical combination. The large changes
in surface energy which must accompany gelatinisation would be
sufficient to explain the thermal phenomena.

The optical rotation of an acetone solution of camphor and
nitrocellulose is equal to the sum of the separate rotations of the
camphor and the nitrocellulose, within the limits of experimental
error??.

Dubosc1* expresses the following views on the constitution of
celluloid. Celluloid is a “ camphrogel’’ of nitrocellulose, camphor
being the dispersion medium. In the process of gelatinisation

solid nitrocellulose absorbs camphor present in the liquid phase
(camphor and alcohol), forming a mass of gel cells enclosing a pseudo-
solution of nitrocellulose in camphor and alcohol. The subsequent
rupture of the cells during kneading and loss of alcohol by evaporation,
leads to an enormous increase in viscosity. There is, however, in the
case of camphor celluloid, no separation of suspensoid or solid phase,
such as may happen with some of the substitutes of camphor. This
is shown by milkiness or opacity in the celluloid, by brittleness and
lack of plasticity in the working. The plasticity of camphor
celluloid on heating to about 80° C. is attributed to the formation of
a liquid phase by fusion, diminishing internal friction.

, Dubosc admits that experimental evidence in support of these
views is meagre, but on the whole they appear reasonable. Exception
might be taken to regarding camphor as the dispersion medium when
it occupies only about one third of the bulk of the celluloid.

Speculations on the structure of cellulose esters and the plastic
materials made from them inevitably lead to a consideration of the
structure of cellulose itself. Cellulose has already been treated by
other writers in these Reports'*, and a much-needed emphasis has
been placed on its colloidal character. There are still chemists who
write as if the elucidation of the structure of cellulose were a problem
analogous to the determination of the formula of, let us say, brucine
or dextrose. The underlying assumption appears to be that some
day the suffix n in the formula (C,H,,O;) n will be determined, and
then, given a sufficiently large sheet of paper, the complete formula
will be constructed. It must be admitted that this assumption has
led to much interesting research!.

It is only natural that chemists should attempt to assign definite
molecular weights to the materials they handle. The tendency
probably arises ultimately from the extraordinary developments of
theoretical chemistry on the basis of Avogadro’s hypothesis, culminating
in the work of Vant’ Hoff. It may not be out of place to point out
that of all the materials that we wear, handle and consume, those
to which the methods of Vant’ Hoff can be applied are in a vast
minority. Colloidal chemistry would be immensely simplified if it
could be brought under systematic mathematical treatment, but in
view of the vast differences in properties between the colloidal and
crystalline states, it is unreasonable to expect to force colloids into
the crystalline system. It is agreed on all hands that if cellulose and
similar colloids have a definite molecule, its weight must be extremely
large. But the larger the assembly of (C,H,,O;) units becomes, the
more difficult it is to imagine what forces would come into play to
put a sudden stop to the process of aggregation. In view of the
continuous nature of plant growth, it is not to be expected that there
should be a definite limit to the size of the cellulose aggregate, any
more than there is to the size of a honeycomb. The limit to the
aggregation of C, units is probably set, not by internal chemical forces,
but by external conditions such as atmospheric temperature and
humidity, and the vital activity of the plant—TIndex 14a. Wohler’s
synthesis of urea was hailed as breaking down the barrier between
organic and inorganic chemistry, but crystalline substances like urea

are not typical of vital processes. It is always in a colloid medium
that the phenomena of life are manifested'*. Fischer’s synthesis of
the polypeptides comes much nearer to an imitation of vital processes,
and there appears to be no chemical limit to the application of the
reactions he employed.

A distinction should be drawn between efforts to determine the
size of the cellulose molecule and experiments to determine the
configuration of the C,H,,O; units. It may be remarked in passing
that there is no reason to suppose that all the C,H,,0; units have
the same configuration, and a quantitative conversion of cellulose to
any particular sugar is unlikely’. Pictet and Sarasin’? by the dry
vacuum distillation of cellulose obtained levoglucosan, and Sarasin
has suggested that cellulose is built up from this unit?®. Owing to the
drastic nature of the decomposition involved, the suggestion must
be taken with some reserve, and Irvine has criticised it on other
grounds’. It is interesting, however, to build up 1|-glucosan with
the aid of tetrahedral carbon atom models, when it will be found that
the carbon atoms 1, 2, 3, 6 and the oxygen atom are approximately
in one plane, and the carbon atoms 6, 3, 4, 5 and the oxygen atoms 7
and 8 in another plane, approximately at right angles to the first plane
(see formula in bibliography). The complex would therefore grow
in three dimensions (an elementary detail which is sometimes over-
looked), and groups and atoms would be brought into proximity in
a way which would never be demonstrated by a diagram in two
dimensions. One is tempted to speculate whether the insolubility
of cellulose in water is due to this mechanical smothering of the
hydroxyl groups by the growing complex, or even whether the hydroxyl
groups really exist as such in solid cellulose?®. Certainly any reaction
which degrades the cellulose complex yields a product which will
take up more water than the original cellulose, and even long-continued
mechanical grinding will yield a sticky or pasty mass; from which
it appears that increasing the surface of cellulose increases its
solubility in water. On the other hand, the vulnerability of cellulose
to esterification without profound hydrolysis militates against this
view.

The chief contribution which the manufacture of celluloid makes
to colloidal theory at the present time is in its insistence on the
fundamental difference between emulsoids and suspensoids. There
is a close connection between the viscosity of dilute solutions of
cellulose esters, and the mechancial properties (or what is called in
the rubber industry the nerve) of the solid product®!. So far as
the writer is aware, neither suspensoid nor crystalloid solutions
possess any physical properties which can be correlated with the
properties of the solid derived from them by evaporation. In
crystalloid and suspensoid solutions we have free particles—ions,
molecules, or aggregates—moving independently of each other in
the dispersion medium. But in emulsoid solutions, as exemplified
by cellulose esters, we find a manifestation, in a reduced degree,
of the same forces that produce “ nerve ” in the solid form. Therefore
the disperse phase cannot consist, at any rate entirely, of particles
having independent existence in the dispersion medium. There

must be structure, and perhaps the most reasonable assumption
is a form of network in three dimensions, the interstices being filled
either with pure solvent or with solvent containing disperse phase
in a lower state of aggregation. There are admittedly difficulties in
such a hypothesis, e.g., in regard to the equilibrium between the
two concentrations co-existing?’. This view of the viscosity of °
nitrocellulose solutions draws a distinction between them and the
highly viscous solutions of such crystalline substances as cane sugar
in water, which may be regarded as owing their viscosity to the
presence of large aggregates consisting of molecules of sugar surrounded
by attracted water molecules. This suggests another contrast between
the two. The attraction of sugar molecule for water molecules is
regarded as being related to the high solvent power of water for
sugar and also to the high viscosity of the solution. In the case
of cellulose esters, as we have already seen, the best solvent is regarded
as the one which gives solutions of least viscosity.

In view of these considerations, a study of the transition from
emulsoid to suspensoid solutions would be of great interest. It is
well known that an alcoholic solution of mastic, if poured into water,
yields a suspensoid solution of mastic. In a similar way a dilute
acetone solution of nitrocellulose on dilution with water yields a
suspensoid solution of nitrocellulose. From some incomplete experi-
ments it appears that the gradual addition of water to the acetone
solution, keeping the concentration of nitrocellulose constant, produces
@ gradual rise in the viscosity of the solution, both absolutely and
relatively to the viscosity of the solvent, until a maximum is reached,
after which the viscosity falls until it almost coincides with that of
the solvent. The Tyndall effect becomes marked close to the position
of maximum viscosity. On the network view of the structure of
nitrocellulose solutions these changes would mean a stiffening and
probably a shrinkage of the network as the percentage of water in
the solvent increases, and finally rupture into free particles, possessing
a refractive index sufficiently different from that of the medium to
show the Tyndall effect.

Reference should be made to the analogy developed in text-books
of physics between viscous stress in liquids and shearing stress in
a strained elastic solid, according to which a viscous liquid is regarded
as able to exert a certain amount of shearing stress, but is continually
breaking down under the stress. The equation developed is 7 = n/A
in which 7 is the co-efficient of viscosity, n the co-efficient of rigidity,
and 1/A the time of relaxation of the medium, i.e., the time taken
for the shear to disappear from the substance when no fresh shear
s supplied to it. This is a much more illuminating way of regarding
the viscosity of liquids than the analogy with gases, since the viscosity
of liquids, unlike that of gases, diminishes with rise in temperature.?*
But it is particularly suggestive in the case of solutions of colloids
like nitrocellulose and rubber which depend for their value on their
mechanical properties***. In the case of celluloid, in particular, we
are dealing with what is at ordinary temperatures an elastic solid,
and it would be most instructive to follow up its properties from dilute
solution to the solid state, both with and without the addition of

camphor. The intermediate zone would offer considerable experi-
mental difficulties, but the ground has already been broken by Trouton
and Rankine”*.

A complete examination of celluloid from this point of view would
include the viscosity in dilute solution, gradually increasing the
concentration until determination of Trouton’s coefficient of viscous
traction became practicable, and finally the rigidity, bulk elasticity,
and tensile strength as the celluloid gradually lost its solvent. In
all cases temperature effects would have to be studied, and the
comparison of rigidity and viscous traction at various temperatures
would be of particular value in the case of finished celluloid, while
the data as a whole could hardly fail to throw light on the problem of
the structure of viscous colloids.

REFERENCES.

1Vol. 1, p. 705 (1912 edition). The account given here is written by
Schiipphaus.

2“ Technology of Cellulose Esters,’ Worden, Vol. VIII.

3 Cross, Bevan & Jenks, Ber., 34, 2496; Hake & Lewis, J.S.C.I., 24, 374
(1905).

4 See, for example, Lunge, J. Amer. Chem. Soc., 28, 527 (1901), and many
others.

5 Nathan, J.S.C.I., 28, 177 (1909). Note particularly (p. 185) the small
variation in nitrogen percentage (from 12-95 per cent. to 13-05 per cent. in a
year’s work).

® See Miles, Eng. Pat. 19,330 of 1905, on the solubility changes induced by
partial hydrolysis. An extensive list of patents is given by Worden, J.S.C.1.,
38, 370 T (1919).

? Baker, Trans. Chem. Soc., 108, 1653 (1913). The viscosity of nitrocellulose
in various solvents follows the empirical law 7=y, (1--ac)k, in which 7=
viscosity of solution, 70 = viscosity of solvent, c = concentration, a and k are

d logy. :
constants depending on solute and solvent. The value of - ros 7 is convenient

for comparing different solvents.

8 Baker, Trans. Chem. Soc., 101, 1409 (1912). From the viscosity concen-
tration curves given by mixtures of ethers and alcohols, it appears that dissociation
of the latter takes place in such mixtures, but this dissociation is probably

. associated with the formation of an ether-alcohol complex, and to this complex
the solvent power of these mixtures for nitrocellulose is due.

® Eng. Pats. 14,655 and 14,656 of 1915. (Rintoul, Cross, & Nobel’s Explosives
Co., Ltd.) The additions are of the order of 0.1 to 1 per cent., and enable the
mixture of nitrocellulose and nitroglycerine to be gelatinised without raising the
temperature.

% Since this report was written, an important paper on the subject has been
published by Gibson & McCall, J.S.C.I., 89, 172-176 T, (1920). They find that
the composition of the ether-alcohol mixture of optimum solvent power depends
on the nitrogen content of the nitrocellulose.

10 Bramley, Trans. Chem. Soc., 109, 469 (1916).

108 Price (Trans. Chem. Soc., 115, 1116 (1919)) has shown that the abnormality
of the volatility of cordite made with equal properties of acetone and ethyl
methyl ketone is not due to any abnormality of vapour pressure or density of
the mixed solvents. ; ?

1. Thorpe, Dictionary of Applied Chemistry, loc. cit.

12 Unpublished observation. Only dilute solutions have been examined.

18 Dubosc, Le Caoutchouc et la Gutta-Percha, 9803-9808 (1919).

14 Ist Report, King 20-38, Chrystall 82-84.

2nd Report, Harrison 54-61.
14 Gibson makes the same suggestion in a recent paper. Trans. Chem, Soe.
117, 482 (1920).

16 Cf. Boeseken, v. den Berg & Kerstjens, Rec. Trav. Chim. Pays Bas, 85,
320-345 (1916). Cellulose is regarded as (C;Hj,.Og)n—(n—1) H,O, and the
acetylation process is studied. As the molecule is hydrosed the acetyl number
increases from 62-5 for cellulose triacetate to 77 for dextrose pentacetate. The
molecule combines with 3n+2 mols of acetic acid, giving a triacetate of molecular

t 1,000 (3n+ 2)
weight (162n+18)+(3n+2)42. The acetyl number = 48m 17
n can be calculated. Values of n as high as 47-5 were found.

16 The viscous colloids are nearly all of vital origin. Cf. gelatin, rubber,
casein, the gums, etc.

16 See in this connection Miss Cunningham, Trans. Chem. Soc., 118, 173-181
(1918).

1” Pictet & Sarasin, Compt. rend., 166, 38-39, (1918).

18 Sarasin, Arch. Sci. Phys. Nat., IV., 46, 5-32 (1918). Starch and cellulose
are polymerides of 1-glucosan.

from which

HO—CH: CHOH
1 2
HC&— O’—°CH
|
HAC’ O& 4CHOH

Polymers are found by the opening of the oxygen atom marked 8. This explains
the presence of 2-5 dimethyl furane in the products of decomposition.

19 Irvine, Annual Reports (Chem. Soc.), 69 (1918). The glucosan-polymeride
formula is criticised on the ground that it does not account for the particular
trimethyl glucose obtained from methylated cellulose by hydrolysis. (See
Denham & Woodhouse, Trans. Chem. Soc., 111, 244 (1917)).

20 Compton (J. Franklin Inst., 185, 745-774 (1918)), concludes that in the
solid state, atoms are so intimately intermingled that particular molecules
cannot be said to have any real existence.

21 ng. Pat. 114, 304 (H. Dreyfus) states that the higher the viscosity of
cellulose acetates, the greater the amount of plastifying or softening agents
which can be incorporated, and the stronger the resulting material from every
point of view.

22 Tn this connection see Bayliss, 2nd Report of this Committee. ‘ Protoplasm
and Cell Contents,’ and ‘.The Nature and Permeability of the Cell Membrane.’

. 117-137.

PP* sa J. D. van der Waals, jnr. (K. Akad Amsterdam, Proc. 21, 5 pp., 743-755,
1919) points out this difference between gaseous and liquid friction. He attributes
liquid friction to the forces exerted by the molecules on each other, whereas in
gases it is due to the transfer of momentum from one layer to another.

3 The resistance to shearing stress gradually increases as solvent is removed,
until finally an elastic solid results.

*4 Trouton, Proc. Roy. Soc. 77, 426 (1906) and Trouton & Rankine, Phél.
Mag. [6], 8, 538(1904). In the stretching of rods of highly viscous material the
following relation is found :—

F /dv

A/ dx —*
Where F = stretching force.
A = cross section of rod.
v = velocity of given point of rod.
x = distance of moving point from point of suspension.
From a chemical point of view it is unfortunate that Trouton worked with
substances of so indeterminate a nature as pitch and shoemakers’ wax. The
use of a plastic material composed of a celluloid ester, a crystalline filler such as
camphor, and alcohol, in a similar series of researches, would to some extent
simplify the interpretation of the phenomena. We do not know yet why
camphor is par excellence the solid solvent for nitrocellulose. It evidently
possesses a somewhat unique combination of chemical and physical properties.
Substitutes for camphor can only be accurately compared with it by some system
of physical tests of the resulting material such as these. The explanation of its
colloidal behaviour is not likely to be found until these experiments are done.

COLLOID CHEMISTRY OF PETROLEUM.

By Dr. A. E. Dunstan,

A considerable body of evidence is available concerning the
colloidal nature of crude petroleum and some of its distillates. Crude
oil of the paraffin base type (i.e., oil which on distillation yields solid
paraffins in the high boiling fractions) usually contains colloidal
amorphous matter which only assumes the crystalline state after
distillation. It is probable that the effect of heat in this case is
physical, bringing about a change of state whereby the wax is no
longer in the dispersed condition characteristic of the original oil.
Such oils and their residues after the removal of benzine and kerosene
are frequently highly viscous, particularly at low temperatures,
owing to the “setting” of the paraffin sol. This phenomenon may
be demonstrated by immersion of a suitable residual oil in ice for
several hours when the mass appears to be quite solid. A sudden
jerk or violent shaking will destroy the quasi-solid mass and a thick
clotted semi-fluid material will be formed.

The black or dark coloured “asphaltic base” oils contain
bituminous matter which is to be regarded as being derived from
the petroleum hydrocarbons by oxidation (and sulphuration) and
condensation. .

These oils are optically heterogeneous, although in most cases
the degree of dispersion is very high (see Holde, Koll. Zcits., 1908, 8,
270; Schneider and Just, Zeit. f. Wiss. Mikrosk, 1905, 22, 561).

The colloidal asphalts may readily be coagulated by means of
strong sulphuric acid (Schultz, Petroleum, 5, 205, 446). The
chemistry. of the well known “ acid treatment ” has _ been
investigated by B. T. Brooks and I. Humphrey (Jour. Amer. Chem.
Soc., 1918, 40, 822). The usually accepted view that olefines are
polymerised to tar and removed as sludge is erroneous, for pure
olefines (up to the C,, member) do not give tars with acid up to
100 per cent. strength at 15° C. The formation of “acid tar” is
probably a dual phenomenon—firstly, the acid coagulates the colloidal
matter present in the oil; and, secondly, it brings about polymerisa-
tion of olefines and diolefines, sulphonation of aromatic derivatives,
together with oxidation of primary materials and products.

Pyhala (Zeits. Chem. Ind. Koll., 1911, 9, 209) considers that crude
oils are sols of which the disperse phases are solid gels such as asphalt,
together with liquid particles. Separation may be achieved by means
of centrifuging or the addition of electrolytes. When the disperse
phase exceeds 60 per cent. the phenomenon of gelatinisation makes
its appearance. ;

In the discussion on a paper by Glazebrook, Higgins and Pannell
(Jour. Inst. Petr. Techn., 1915, 2, 54 et seq) the writer brought forward
the peculiar hysteresis effect in the viscosity of fuel oils and showed
that by a suitable alteration in the previous history of a given oil,
wide variations in its viscosity may be effected. The corresponding
» behaviour in aqueous gelatine sols is well known and affords an
interesting parallel, :

The colloidal asphaltic matter in crude oil and the yellow colouring
matter in benzine, kerosene, and other distillates which is largely
caused by “ tar-fog’”’ mechanically carried over, may be removed
by coagulation (and solution) brought about by agitation with strong
sulphuric acid. Direct adsorption on specific surfaces however, is
equally effective. The writer has shown that floridin, Fuller’s earth,
and bauxite which, when freshly ignited, possess powerful adsorptive
action, follow the well-known exponential adsorption rule :—

Y/m = ac". For example, using a 0-25 per cent. solution of a crude
asphaltic base oil in benzine as a test liquid, constant values of n were
obtained and the Y/m — c curves were of the usual parabolic type.

The application of the adsorptive action of these substances in
the refining of various distillates is well known and much of the
theoretical side has been admirably expounded by Day and his
co-workers (Proc. Amer. Phil. Soc., 1897, 36, No. 154; Trans. Petr.
Congress, Paris, 365; Gilpin and Cram, U.S. Geol. Survey Bull., 365;
Washington, 1908; and Gilpin and Bransky, U.S. Geol. Survey Bull.,
475, Washington, 1911. See also Richardson and McKenzie, Amer.
Jour. Sci., May 1910; Richardson and Wallace, Jour. Soc. Chem. Ind.,
March 1912; Porter, Bull. 315 U.S. Geol. Survey, 1907).

In brief, the following conclusions were arrived at :—

(1) Fuller’s earth tends to retain the unsaturated hydro-
carbons and sulphur compounds in petroleum, thus exercising
a selective action on the oil.

(2) When crude petroleum diffuses upwards through a
column of Fuller’s earth a fractionation of the oil occurs. The
oil displaced by water from the earth at the top of the tube
is lower in density than that from the bottom of the tube.

(3) The aromatic hydrocarbon in a mixture of a paraffin
oil and benzene tends to collect in the lower end of the diffusion
column.

Gilpin and Schnerberger (Amer. Chem. Jour., 1913, 50, 59) consider
that the Fuller’s earth behaves as a dialysing septum which allows
paraffins and saturated hydrocarbons to pass freely but adsorbs
bitumen, aromatic hydrocarbons, sulphur, and nitrogen compounds.
The determining factor is surface. Similar views are propounded
by Gurwitsch (Peir., 1912, 8, 65) who ascribes Day’s results not to
capillarity but to specific surface adsorption. This author shows
that floridin will adsorb solid paraffin from solution in petroleum
spirit and benzol, but not from lubricating oil. An interesting
observation was made by Herr (Peér., 1909, 4, 1284), who filtered
Baku oil through fuller’s earth and discovered that all the formolite
forming compounds were removed, i.e., the unsaturated compounds
which react with formolin were adsorbed on the mineral gel.

It by no means follows that the compounds which are adsorbed
can be recovered unchanged. Being possessed almost invariably

of residual affinity the close contact afforded in the adsorbed layer .«

promotes condensation and polymerisation, and thus Gurwitsch

(Jour. Russ. Phys. Chem. Soc., 1915, 47, 827) was able to show that
floridin brings about active polymerisation when brought into contact
with amylene and pinene, resulting in considerable rise in temperature.
Curiously enough the same polymer, di-amylene, is produced both
by sulphuric acid and by fuller’s earth. Pinene, similarly, is converted
after adsorption into sesqui and polyterpenes.. Alumina behaves in
the same way towards amylene, but is apparently without effect
on pinene. The writer’s experience has been that freshly ignited
precipitated alumina is particularly effective as a decolourising agent
for petroleum and its distillates and a series of experiments using a
0-25 per cent. solution of crude asphaltic oil in benzene showed the
following order :—

c.c. of coloured solution

Material (1 gram). decolourised.

Alumina - : : : = f AGU
Fuller’s earth I. - - : ee ad 2) 836
Bauxite I. - = : e : aopaath
Bauxite II. - - . 2 E eS
Bauxite ITT. - = A - 3 pie 4)
Ignited peat B - E z 3 =e Ua)
Bone charcoal - : - é Z Sate
Bog iron ore - - eae ar : : Peis 16
Fuller’s earth II. - = “ é = Same
Ferric oxide - - E : _ i e FLO
Ball clay : : / m é 2 BR
Fuller’s earth III. - - 2 2 Lantg
Fuller’s earth IV. - - 4 . HM hig
China clay - 1 : u Z j spre
Kieselguhr_- ~ : : u u 47) 0g

The temperature at which the adsorbing surface exerts its specific
effect is of some importance. Gilpin and Schnerberger (Amer. Chem.
Jour., 1913, 50, 59) on passing Californian crude oil through fuller’s
earth found little fractionating effect at 20° C. but a satisfactory
result at 70° C.

A peculiar observation made by the writer is of interest in this
connection. Cold bauxite, which has been ignited and cooled in
a vacuum desiccator was found to have lost its power of adsorbing
sulphur derivatives from kerosene. When freshly heated (to 200° C.)
its activity in this direction was regained. Heat appears to be evolved
during active adsorption, thus a 20° C. rise in temperature was
observed during the passage of 100 c.c. of kerosene through 50 grams
of bauxite.

Amongst other effective materials may be mentioned Kambara
earth (Kobayashi, Jour. Ind Eng. Chem., 1912, 4, 891), a mineral
containing hydrated silica, which decolourises crude petroleum and
adsorbs unsaturated hydrocarbons therefrom. Fibrous alumina has
been recommended by Gawolowski (Allg. Oesterr. Chem., 1908, 26, 87),
whilst animal charcoal and prussiate residues have long been employed
for these purposes.

Naturally the degree of fineness of the adsorbent is. important.
The following case will illustrate this point :—

Bauxite Mesh. Activity.
40/60 —s- - - - - - - - 1-0
60/80 - | - - : c : 3 (eee

In point of fact the activity—all experimental conditions being the
same—is approximately directly proportional to the mesh. A con-
venient method of demonstrating this point consists in treating a
100 c.c. of coloured solution (as e.g., that already mentioned) with
varying weights of decolourant, matching the filtered resultant solution

with the standard solution in a Nessler jar (C. ¢.cs.) and plotting = =

ass
against C. Ordinates at C = 50 give directly the reciprocals of the
masses required to remove 50 per cent. of the colour. Thus with

floridin :—

Mesh. Mass.
Passing 180 - - - - - - - 50/320
Passing 80 and retained on 180 - - - - 60/170
Passing 20 and retained on 30 - 7 - - 50/44

and with Bauxite
Passing 80 - - - - - - 50/175
Passing 60 and retained. on 80: - - - - 50/80
Passing 20 and retained on 30 - - - - 50/30

Little can be said as to the relationship between the chemical
composition of the material and its adsorbent properties. Apparently
hydrated silica or alumina is effective after combined water is expelled,
but no general statement can be made. Substances giving the same
analytical figures may behave quite differently, and again, bodies of
dissimilar chemical composition may be equally effective as decolour-
ising agents.

The essential feature of all effective adsorption agents is develop-
ment of surface, hence mineral gels containing water of combination
which, on ignition, possess a characteristic structure are decidedly
likely to possess decolourising and desulphurising properties.

Very characteristic is the behaviour of bauxite (say, 40/60 mesh)
on being gently agitated with kerosene or benzene. Apparently a
process of peptisation goes on, for a considerable amount of very finely
divided material separates in suspension in the petroleum, and is
sufficiently fine to pass readily through filter paper (see W. Bancroft,
Vol. II. Report on Colloid Chemistry, 1918, page 2 et seq).

A highly important contribution to the application of colloid
chemistry to industry was made by Clifford Richardson (“‘ The Modern
Asphalt Pavement ”’ and reprint of a paper read before the St. Paul
Engineering Society, 1917). This investigator showed that the
durability of anasphalt pavement is directly connected with the fine-
ness of the mineral aggregate, 7.e., with the extent of the surface
developed. The capacity factor of the surface energy is measured by
the absolute surface displayed and the intensity factor by the particular
surface tension of the materials employed. As a case in point, a

—_—

particular pavement laid in 1895, the surface of the aggregate was 44
square feet per lb. of material, whereas in a later one the surface was
iucreased to 60 square feet per lb. The former pavement was
unsatisfactory, and the latter was excellent.

Naturally occurring colloidal suspensions are found in Trinidad,
where the asphalt contains 25 per cent. of finely divided mineral
matter, but artificial mixtures of bitumen and dispersed clays can be
made which may contain as much as 60 per cent. of mineral. The
various asphalts (natural and artificial) possess different powers of
retaining the disperse phase. Broadly speaking, asphaltic residues
from crude oils are inferior in this respect to the natural bitumens.

Miatures of 67 per cent. Bitumen and 33 per cent. Clay (introduced while
wet) and maintained at 325° F. for 24 hours.

Colloidal Matter.

Source of Bitumen eae lo ee
; Before After tion.

heating. heating.

per cent. per cent. per cent.
Trinidad residue : - - - 33-5 33-7 0-0
Badabin ,, - - - - 32-4 30-1 7:0
Mexican be - - - - 33°3 27-2 18-3
California ,, 2 - - - 31-8 23-8 25-2
Mid Continental residue - - — = —
Semi-paraffin A - - - 33-8 21-7 35°8

The temperature 325° F. is that at which is formed the film of
bitumen which covers the mineral aggregate of a sheet asphalt
pavement. It is striking that the Trinidad residual is so thoroughly
differentiated from all the others, confirming the opinion based upon
service tests in regard to the unique character of this material.

Although in actual refining operations the adsorptive properties
of the materials described above have mainly been directed towards
the removal of colour, yet considerable success has been achieved
in connection with the equal important problem of desulphurisation.

It by no means follows that an adsorbent is equally effective in

removing colouring matters and sulphur derivatives. Usually this
is not the case, and each material must be tested for its specific
purpose. So far as the writer’s experience goes, the sulphur compounds
present in the lighter distillates are more readily adsorbed than those
in the higher boiling fractions, although it is possible that in the
latter case there is preferential adsorption of other substances, e.g.,
unsaturated hydrocarbons. Whilst for example, floridin will desul-
phurise benzine quite readily, it has little effect on the sulphur
compounds which occur in the lubricating oils derived from the same
crude petroleum.

An interesting application of adsorption is to be seen in the method
patented by Hall Motor Fuel, Ltd., for the purification of cracked

spirit. This material, as is well known, contains a considerable
proportion of highly unsaturated hydrocarbons—olefines and diolefines
—to the presence of which it owes its characteristic odour and its
objectionable propensity towards resinification or “ gumming.”
Although the reactive hydrocarbons can be removed by the agency
of strong sulphuric acid, the operation is attended by serious loss,
but by utilising the adsorbent capacity of floridin, the diolefines present
are polymerised to high boiling products and a spirit free from
objection is produced. The refining operation is best carried out
with the spirit in the vapour state, under these conditions adsorption
is followed by condensation and/or polymerisation.

Incidentally the sulphur derivatives present in many , benzines
and kerosenes may be removed in a precisely similar manner,

The problem of the breaking of persistent emulsions in refining
operations is obviously one for treatment by the application of colloid
chemistry. The soda wash which is employed to remove the traces
of sulphuric acid in the refining of lubricating oils is a common source
of this trouble and in some cases a practically permanent emulsion
isformed. The sodium salts of naphthenic and sulphonated naphthenic
acids are notable emulsifying agents and it is possible that hereinlies
the cause of what is sometimes a serious difficulty. Itis interesting to
remember that sodium naphthenates are used very extensively as soap.

A recent patent by Southcombe and Wells brings out the novel
point that a small amount (1 per cent.) of free fatty acid added to a
mineral lubricating oil, not only replaces the usual blending fatty
oil, but according as its molecular weight is low or high, yields a
non-emulsifying or an emulsifying oil. It appears that the addition
of the free fatty acid appreciably lowers the interfacial tension
between the lubricating oil and the bearing.

Petroleum jelly or “ vaseline ” appears to be an emulsion of soft
paraffins dispersed in heavy oils. The viscosity increases gradually with
decreasing temperature until the gel state is attained, without, however,
any separation of crystalline wax, but on being distilled, wax appears
in the distillate. Various artificial jellies are on this market, being com-
pounded of soft wax and heavy oil, these, on the contrary, are incliried
to deposit crystalline matter on being cooled, and do not possess
the salve-like nature of the natural product.* An apt comparison
is in the different appearance of ice cream made with and without
the addition of gelatine and in both cases—vaseline and ice creaam—
the presence of a protective colloid may be the explanation.

A peculiar illustration of the coagulation of a colloidal solution
is seen in the action of flowers of sulphur on the yellow liquid which
is produced by treatment of sulphur-containing distillates with
sodium plumbite. There is a rapid flocculation and a dark brown
precipitate appears.

* By this is meant the material which is obtained from a suitable crude oil
by distilling off the lighter compounds and decolorising the residue (usually by
filtration through fuller’s earth).

The United States Navy Department and the Submarine Defense
Association have developed a “ colloidal fuel,” and a summary of
their report follows :—

* Pulverized coal can now be successfully held in suspension
so that the colloidal liquid flows freely through the pipes
pre-heaters, and burners of ships and power, heating and
industrial plants equipped to burn fuel oil. Months after
mixing, the composites show little or no deposits. A fixateur,
which comprises about 1 per cent. or 20 lbs. per ton, acts to
stabilise the particles of pulverised coal dispersed in the oil.
In colloidal fuel every solid particle has its film of liquid hydro-
carbon and a protective and peptizing colloid, itself combustible.
These particles are in three classes as to dimensions—coarse,
colloid, and molecular. By coarse is meant here the fineness
of fifty million particles per cubic inch. The fixateur and fixated
oil are readily made and may be shipped anywhere. The
manufacture or distribution of the new fuels incorporating
solid carbon in fixated oils involves no doubtful process or
industrial problem. On burning, the combustion is so complete
that with fair coal there is left no slag and very little ash, what
there is being light as pumice and granular as sand.

“Tt is the property of colloidal fuel that without loss of
efficiency per unit volume or change of oil storage or burning
equipment it makes possible the conservation of at least 25 per
cent. of the fuel oil now burned, or conversely with the oils
now available in increases by 50 per cent. the world supply of
fuel that is liquid. We may go further and state that a number
of new fuels have been realised, each with varying percentages
of oil and solid carbon. One useful composite, in the range of
ordinary temperatures, is composed of about half coal and half
oi!. Another unctuous semi-liquid is nearly three-fourths coal
and one-fourth oil. All the fuel pastes are mobile to sustained
and easily applied pressure, and may thus be pumped, fed,
and atomised in the combustion ehamber. These semi-fluid
composites will constitute the most compact and safest fuel
for domestic and industrial use, and they will largely eliminate
the smoke and ash nuisances of cities.

“For example, industrial colloidal fuel, grade No. 10,
devised to use up some poor coal holding 25-5 per cent. ash,
is composed of 614 per cent. of pressure still oil, wax tailings,
petroleum pitch and fixateur running 18,505 B.T.U. per lb.
and 38} per cent. of ‘anthracite rice’ running 10,900 B.T.U.
per lb. This grade contains 162,500 B.T.U. per gallon, and
has 10-2 per cent. of ash. The fixated oil itself had 151 5750
B.T.U. per gallon. In fuel value, therefore, the colloidal fuel
of grade No. 10 is worth 74 per cent. more per gallon than the oil
from which it is made.

“Tf instead of ‘ anthracite rice’ very high in ash, a crude
oil coke which is ashless had been employed, the colloidal fuel
gallon would have contained 182,154 B.T.U., or roundly,
20 per cent. more than the oil base, and only quarter of 1 per cent.
sulphur.”

@ 11454 @

According to Wo. Ostwald (‘‘ A Handbook of Colloid Chemistry ”
page 103), petroleum oil fractions of high boiling point are to be
classed as iso-colloids, i.e., a category in which disperse phase and
dispersion means possess the same (or analogous) chemical composition.

The ultra-microscopic examination of a number of mineral
lubricating oils (Dunstan and Thole, Jour. Inst. Petr. Tech., 1918,
4, 191) has demonstrated that optical heterogenity exists, although,
however, the degree of dispersion is exceedingly high. The same
behaviour obtains for the fatty oils and it is possible that lubricating
power is in some way connected with this iso-colloidal state.

Lubricating greases are examples of oil-water emulsions stabilised
by soap. Commonly sodium soaps are used for motor greases and
the proportions are lubricating oil (sp. gr. *900--910), 80 parts;
stearin acid, 15 parts; and caustic soda, 2 parts. Part of the oil is
mixed with the stearin acid and this is added to the soda in 40 per cent
aqueous solution, with constant agitation. The remainder of the
oil is then incorporated. Cheaper greases are compounded with
lime soaps.

Acheson’s oil-dag and aqua-dag are suspensoids of graphite in
oil or water containing a protective colloid (tannin). Aqua-dag is
made first, and the graphite is transferred from this to oil. The
oil-dag contains about 15 per cent. of “‘ deflocculated graphite ” and
is used in a dilute solution of lubricating oil (0-1 per cent. graphite)
with beneficial results to the bearings, which gradually become coated
with a “ graphitoid ”’ layer. ;

The colloidal graphite in oil-dag may be removed for analysis in
two ways. Freundlich (Chem. Zeit., 1916, 40, 358) throws out the
graphite by adding an electrolyte (acetic acid) to the benzol solution
of the oil-dag whilst Holde (Zeit. f. Hlektrochem, 1917, 28, 116)
adsorbs the graphite on recently ignited Fuller’s earth in a Gooch
crucible. A German proprietary material named ‘“ Kollag ” appears
to be similar to oil-dag.

The influence of colloidal bituminous matter which is mechanically
carried over during distillation is frequently sufficient to preyent the
easy separation of paraffin wax from that fraction known as “ heavy
oil and paraffin,” and recourse is made to a sulphuric acid treatment
before refrigeration. The paraffin scale is usually discoloured and
contains a greater or less amount of uncrystallisable material which is
removed by the process of “ sweating,” i.e., fractional fusion. This
operation serves to raise the melting point of the wax and also in part
to purify it. Final decolourisation is effected by filtering the melted
wax through Fuller’s earth, bauxite, or prussiate charcoal.

THE COLLOIDAL STATE OF MATTER IN ITS RELATION
TO THE ASPHALT INDUSTRY.

By Currrorp Ricnwarpson, M.Am.Soc. C.E., F.C.S. (Consulting
Engineer, New York).

The presence of mineral matter in a high state of sub-division
in a system solid-liquid, the latter phase consisting of asphalt, reveals
some interesting phenomena, connected with the relation of surfaces
of solids and films of liquids, particularly where the mineral matter
is sufficiently subdivided to exist in a colloidal state as regards the

bitumen. Owing to the viscosity of such a continuous phase the
particles of mineral matter with which it is associated may be
regarded as a colloidal state, although they may be of dimensions
which would prevent their existence in such a state with a more
mobile liquid, such as water. Clay and finely divided silica present
such a relation to a highly viscous liquid, asphalt for instance, which
may be regarded as a colloidal one. Attention was attracted to the
subject in the course of a study of the native asphalt found in the
Pitch Lake in the Island of Trinidad, British West Indies. This
deposit is unique from a geophysical standpoint. It exists in a crater
of an old mud spring on the West Coast of the island, and at a distance
of about half a mile from the Gulf of Paria. Its surface was originally
138 feet above sea level. Borings which have been recently made
show that the crude asphalt exists to a depth of more than 175 feet
at the centre of the deposit, which consists of a bowl-shaped mass
covering, originally, an area of 114 acres. Specimens taken at various
points on the surface and at different depths show that it originates
in an asphaltic petroleum, derived from oil sands occurring at con-
siderable depth below the lake, with which a paste of mineral matter
and water, originating in a mud spring, has become associated by
the churning action of the natural gas accompanying the petroleum,
on the release of the pressure to which it has been subjected as the
oil approaches the surface. The material formed in this way is of
highly uniform composition in all parts of the deposit, and consists
of an emulsion of bitumen with a paste of clay and fine sand, and
has the following composition :—

Per Cent.
Bitumen - - - - - . - - 39
Mineral matter - - - - 27
Water and gas, volatile at 100° Co - 4,29
Water of hydration of mineral matter = - - 5
100

The water, which on melting the asphalt under certain conditions
can be separated therefrom, in a somewhat concentrated condition,
has been found to contain in solution large amounts of sodium chloride
and sulphate with a considerable amount of ammonium and ferrous
sulphates, together with borates and a readily recognisable percentage
of iodides. It also contains smaller amounts of potassium, calcium,
and magnesia salts. It is plainly of thermal origin.

Refined Asphalt.

As it occurs in the deposit it is known as crude asphalt. As such
it is submitted to a process of so-called refining at a temperature of
325° F., which removes the water and results in a material known
as refined asphalt, which has the following composition :—

Per Cent.
Bitumen - - - - - - ef
Mineral matter - - - - - 39
Water of hydration of lay - - - - 4
100

100

In determining the percentage of bitumen in the refined material
by means of solvents it is found that some of the mineral matter
passes through the finest filters and is not removed from the solution
on prolonged centrifuging. On examination under the ultra-
microscope it is revealed that it consists of clay in a colloidal condition,
originating in the mineral matter of the mud spring in which it existed
in this state as regards the water with which it is associated, and
which is introduced into the bituminous phase on the removal of the
water on refining. The amount of mineral matter in the colloidal
state depends on the concentration of the solution, that is to say, upon
its viscosity, as shown by the following data :-—

Characterisation of Solutions of Trinidad Asphalt (T.R.A.).

Amd Ae anti
: gravity solute ee :
Per cent. concentration. Pp, ms ig increase for | Viscosity itis, ae: po
= y: 1 per cent. | of Solution. oe re ;
(T.R.A.). We eee
Solvent : Benzol - 0-876 _ 0: 00652 —
1 per cent. (T.R.A.)- 0-877 0- 0010 0- 00654 0- 00002
2 . he 0-879 0- 0020 0- 00687 0- 00033
5 0 2 0-883 0- 0013 0: 00759 0- 00024
10 “4 a 0-889 0- 0012 0- 00961 0- 00040
20 es a 0-911 0- 0022 0- 01629 0- 00067
30 ” paints 0-930 0-0019 0- 04198 0- 00257
40 ” bys 0-957 0- 0027 0: 09477 0- 00521
50 0 eth 1, 012 0- 0055 0-31800 0- 02240
100 ” Ping 1-400 0- 0076 — —

Characterisation of Solutions of Trinidad Asphalt.

Refined, amount
calculated per
1 per cent. (T.R.A.).

; Refined, per cent.
Per cent. Concentration. Gaicidal inte

Solvent : Benzol—

1 per cent. (T.R.A.) - - - 2:54 2-54
eis a - - - 2-01 1-00

DT 55 5 - - - 2-09 0-42
UO) Gee; Ss - - - 2-73 0; 27
vets a saivibisehe' toe? 3-13 0-16
30s, 2 - - - 4-19 0-14
LO iss “ - - - 6°51 0-16
50s, % - - - 10:69 0-21
100s, ” = - - 35-40 0-35

In dilute solution it appears that the amount of matter in a
colloidal state is comparatively small, but with increased concentration,
that is to say, with increased viscosity of the continuous phase, it

101

becomes progressively larger until in the refined asphalt itself all
of the mineral matter, at ordinary temperatures, may be regarded
as in a colloidal state. Trinidad asphalt appears, therefore, to be
a material the components of which are in a state of equilibrium.
and this accounts for its uniform composition. It is, therefore, a
unique material, and it is to the large amount of surface energy
developed by the highly divided mineral matter which it contains
that the demonstrated industrial value of the asphalt is to be
attributed.

The Introduction of Colloidal Clay into the purer forms of Bitumen.

In the light of the preceding facts the inference was drawn by
the writer that clay in a colloidal state might be introduced in a
similar manner, industrially, into the purer forms of asphalt, and
into the residual asphalts prepared from petroleum. For this purpose,
a paste of clay and water, in which the clay was in a colloidal state
as regards the water, was emulsified with residual asphalts from various
types of petroleum. The water was then driven off at high tempera-
tures and it was found that the relation of the clay to the bitumen
became a colloidal one. The proportions were so selected that the
resulting material, after the removal of the water, should consist of
67 per cent. bitumen and 33 per cent. of clay. These materials were
then maintained in a melted condition in tubes for 24 hours, at a
temperature of 325° F. The sedimentation which ensued, with the
reduction of the viscosity of the continuous phase at this high tempera-
ture, varied with the different residuals, and was as follows :—

Per cent.

Colloida' Matter. Per cent.
Source. Penetran: = Sedimenta-
vis Te pero Before | After tion.

Subsidation. | Subsidation.

Trinidad Residual - 50 33:5 33-7 0-0
Bababui = - 48 32-4 30-1 7-0
Mexican 4 : 50 33°3 27-2 18-3
California = : 50 31-8 23-8 25-2
Mid-Continental Semi- 51 33°8 21-7 35-8

Paraffin Residual.

It is apparent from the preceding data that the colloidal capacity,
if it may be so designated, of the different materials is characteristic
of the particular bitumen and of its viscosity at a definite temperature.
The various bitumens are, in this way, very plainly differentiated.

industrial Application.

Industrially these observations are of importance, especially in
the construction of asphalt pavements, such as that laid on the
Victoria Embankment in London. The mineral aggregate of this
surface consists of fine sand, a filler for the voids in the sand,

102

Portland cement, and the mineral matter afforded by that present
in the Trinidad lake asphalt cement which forms the cementing or
binding material of the surface. Experience has shown that the
stability of such a surface under heavy travel is dependent on the
amount of surface energy developed by the mineral aggregate, that
is to say, by the state of sub-division of the particles composing this
aggregate. While this will depend upon the size of the sand particles
and of those composing the filler, it is also contributed to by the
highly developed surface of the colloidal components of Trinidad
asphalt and to an extent which would be entirely lacking if the purer
forms of bitumen were used with the aggregate, a fact which has been
demonstrated by the difficulties which have been encountered in the
construction of asphalt surfaces with the residual pitches, free from
colloidal mineral matter, which have been met with in the past decade
in England, and which have necessitated the employment of various
expedients to overcome them.

The relation of surfaces of solids to films of liquids, especially
when the surface is developed to such an extent as occurs in material
in a colloidal state, has been demonstrated, therefore, to be a matter
of supreme importance in carrying out successfully the construction
of asphalt roadways to carry intense traffic.

[Norr.—A more detailed account of the colloid chemistry of asphalt is
given in the following paper: ‘ The Colloidal State of Matter in its Relation to

the Asphalt Paving Industry,’ C. Richardson, Minnesota Engineering Society,
May, 1917. W. C. McC. L.]

VARNISHES, PAINTS AND PIGMENTS.

By B. 8. Morrety, M.A.Ph.D., F.LC., Chief Chemist, Mander Bros,
Wolverhampton.

In spite of the importance of the problems of surface it is surprising
that the scientific study of the class of products comprising varnishes,
paints and pigments, has been so much neglected.

The primary components in some form or other, dissolved in a
suitable liquid or a finely ground pigment incorporated with a medium
as in a paint, introduce a field of investigation of great practical
importance and of absorbing interest. If the medium contains
water, as in water paints, the properties of ordinary emulsions are
prime factors of success. Problems of viscosity arise in varnishes,
paints, dopes, and coatings containing cellulose esters; moreover
polymerisation .of drying oils confers valuable properties on many
varnishes and paints. The conditions of spreading on a surface
depend on the physical properties of the components and of the
mixtures. The changes on “drying” are essentially superficial,
involving questions of adsorption, oxidation, and polymerisation,
causing increases in viscosity. The permeability to water and the
alteration in the appearance of films’ introduce the study of the
properties of gels.

The resins in their many forms are typically colloid bodies, and
their solutions show the properties of that class. The thickened oils

Ue et Bee

103

are considered by some to belong to the class of Isocolloids (Wo.
Ostwald).
Drying Oils.

The drying oils used in varnishes and in paints in contact with
- water ought to behave like other vegetable oils in their power to yield
emulsions, and the generalisations laid down in E. Hatschek’s Report
(B.A. Reports on Colloid Chemistry, 2, 16), may be considered to
apply.’ (See also ‘‘ Modern Conceptions of Emulsions,’ W. Clayton,
J.S.CI., 38, 113, 1919.)

The drying oils seem to differ among themselves in their emulsifying
power, although no drop number data are available. In the writer's
opinion soya bean and linseed oils are superior to China wood oil;
moreover, polymerised linseed oils emulsify better than raw linseed
oil, but the emulsions are less stable. The properties of the emulsions
with the soaps of the drying oils containing divalent metals are similar
to those of other vegetable oils.

When a drying oil is thickened by heat out of contact with the
air a marked increase in viscosity and modification of other physical
and chemical properties are manifested. (The Chemistry of Linseed
Oil, J.N. Friend, 1917, contains a full bibliography of the subject.)

Thickened linseed oil contains polymerised molecules, but
there is also evidence of the shifting of the unsaturated linkages
(Morrell, J.S.C.I., 84, 105, 1915). Such thickened oils are considered
by Wo. Ostwald to belong to the Isocolloid class which includes
petroleum, paraffin, liquid sulphur above 170° C.,and highly polymerised
liquids. (Wo. Ostwald, ‘‘ Handbook of Colloid Chemistry,’ 2nd Edit.,
p- 102.)

The Isocolloids are considered to be composed of one chemical
substance; in other words the disperse phase and the: continuous
medium contain the same substance in different states. Their
internal friction shows remarkably high temperature coefficients
varying greatly with changing temperature. Comparison with the
system styrol-metastyrol is, perhaps, the best in considering thickened
drying oils (Lemoine, Compt. Rend., 125, 530, 1897, and 129, 719,
1899). Seaton and Sawyer (Jour. Ind. Eng. Chem., 8, 490, 1916), in
an investigation on the molecular weights of drying oils and their
polymers have found that only in stearic acid as solvent were they
able to obtain values of the molecular weights which were independent
of the concentration of the solution or which showed absence of
combination of solvent and solute. ;

In view of the complexity of composition of linseed oil with its
varying amounts of mixed glycerides more reliable results may be
expected from China wood oil.

C. J. Schumann (Jour. Ind. Eng. Chem., 8, 5, 1916) has investigated
the changes which Tung oil undergoes on heating. The oil at first
forms a simple polymeride and on further heating it sets to a stiff gel.
Schapringer (Chem. Zent. Blatt, 2, 1469, 1905), considers that. the
gelatinisation proceeds in two stages, the first progressive, and the
latter instantaneous; a case of mesomorphic polymerisation. (Kron-
stein, Ber. 35, 4150, 1902, and 49, 722, 1916.)

104

Fahrion considers that the polymerisation of wood oil is not
analogous to that of styrol. Polymerised styrol, on further heating,
yields styrol, but not so in the case of wood oil (Farb. Zeit., 17, 25, 83,
1912, and Ber., 49, 11, 94, 1916). Schumann concludes that a
dipolymerised glyceride is first formed which has the power of forming
molecular complexes under favourable conditions, giving an insoluble
colloidal mass, not, however, accompanied by any further loss of
double linkages beyond those diappearing in the first stage of the
change. :

The presence of decomposition products from the oil prevents the
gelation; rosin has the same effect. The solid gel is stated to be
transformable into the dipolymer on heating with rosin or with the
decomposition products of the oil. It is stated that if the decomposi-
tion products of linseed oil are removed while the oil is heated linseed
oil will gel rapidly. Schumann concludes that the polymerisation
is mesomorphic.

The writer (Morrell, J.S.C.I., 87, 181, 1918) can confirm the
formation of the dipolymer with its subsequent gelation, but he
wishes to lay stress on intramolecular changes occurring during the
heating of other drying oils; thus Cyclolin or Polyolin (solid polymerised
linseed oil) is difficult to saponify, insoluble in amyl alcohol and is
considered by de Waele to be of a ring structure (Jour. Ind. Eng.
Chem., 19, 1, 1917).

Krumbhaar states that the speed of polymerisation of Tung oil
constitutes the greatest difference between it and linseed oil, and
agrees with Fahrion that the polymerisation product is partially
soluble in the unchanged oil. The viscosity increases with the amount
of the polymer until saturation is reached, when the polymer is thrown
out. (Chem. Zeit., 40, 937, 1916.)

This property of thickening is only markedly shown by the more
highly unsaturated oils of the open chain series. Union of molecule
with molecule undoubtedly occurs and the polymeride remains
dissolved in the liquid oil with increasing viscosity until the fluid
coagulates. In the writer’s experience half the oil has been poly-
merised short of the point of setting, beyond that point the mass
consists of a gel of the dipolymeride whose viscosity is influenced by
the presence of specific substances as in the case of gelatine in water.

The problems of polymerisation and of thickening of drying oils
are of the highest practical importance. Further investigation of
the Polyolin of China wood oil would throw light on the properties
of the thickened oils, especially in their emulsions in water and in other
media.

The formation and properties of linoxyn, the oxidation product
of linseed oil, are those of a gel, due to oxidation and not to heat, as
in the polyolins or cyclolins (Annual Reports of the Society of Chemical
Industry, 1916-18). In the manufacture of lmoleum (A. de Waele,
Jour. Ind. and Eng. Chem., 9,1, 1917,and M. W. Jones, J.S.C.I., 1919,
88, 26) four oxidation products result of which linoxyn is one. These
differ in degree of oxidation and linoxyn may be considered as solid
oxidised linseed oil. It must again be noted that the degree of
unsaturation plays an important part, because olein gives no linoxyn

105

substance, although it contains unsaturated groupings. In oil varnishes
the function of linoxyn is of paramount importance.

J.N. Friend (Chem. Soc. Trans, 111, 162, 1917) +has, studied the
effects of heat and of oxidation on linseed oil with reference to changes
of density, viscosity, and coefficient of expansion. The problem is
complicated by the decomposition of peroxides with the loss of water
carbon dioxide, and organic vapours. There is an increase in volume
up to the setting point of the oil, after which contraction ensues, and
the expansion is dependent on the increase in weight. The contrac-
tion suffered by the linoxyn explains the cracking of old paint. The
action of driers is bound up with the formation of peroxides. (Ingle,
J.S.0.I., 36, 319, 1917, and Morrell, Chem. Soc. Trans., 118, 111,
1918.)

From the writer’s experience the peroxides undergo polymerisation
passing from viscid oils to varnish films. On exposure to air the
peroxides undergo slow decomposition. (Ingle, J.S.C.J., 1913, 32,
and 38, 101, 1919, and Salway, Chem. Soc. Trans., 109, 138, 1916.)

The gelatinisation of drying oils and oxidation is a problem of
the greatest importance affecting the protective power of coatings
on wood and on metal. No doubt too much attention has been paid
to the interpretation by changes due to modifications in composition
or in orientation, but the distinctive and finer differences in the
qualities of the coatings often find no explanation on strictly chemical
grounds, and the investigator is driven to find some other cause.
Many observers have noted the importance of the presence of the
glyceryl radicle in the drying of an oil film although its presence has
no marked effect on rate or amount of oxygen absorbed.

Primarily surface phenomena have to be studied and as yet
no adequate help has been. rendered by experience of other colloid
systems. The writer has experienced this difficulty for many years,
and is of the opinion that much can be learnt by closer investigation
on the lines of study of the properties of gels. (Morrell, J.S.C.L., 1920,

89, 153.)

In the changes occurring during the drying of oils attention must
be paid to the surface action of the drier. Driers like lead and
manganese are in colloid solution, and according to Wenzel’s Law
the amount of chemical change in unit time is proportional to the
absolute surface. If it be granted that there is a large absolute
surface in colloids many reactions will occur more rapidly and the
phenomena of catalysis are especially marked in colloid systems.

Ostwald (‘‘ General Colloid Chemistry,” p. 95) states that surface

tension may be either raised or lowered by chemical action occurring
in the two phases. A lowering of the surface tension between two

phases would accelerate the reaction.
To the best of the writer’s knowledge no such measurements in
reference to linseed oil have been published. From his own experi-

ence from the measurement of the weights of drops in air by

Morgan’s method (Amer. Chem. Journ., 38, 1911), no change in

surface tension of China wood oil before and after exposure
could be observed. Possibly the linoxyn was insoluble because it

106

was necessary to filter the oil from an insoluble skin before the weight .
of the drops of the exposed oil could be determined.

The surface tension of lead drying oil against air is, however,
lower than that of linseed oil, from which it would follow that the
lead soap would tend to accumulate on the surface, whereby its
specific surface would be increased and consequently its chemical
activity.

The whole subject requires further investigation, and it is much
to be deplored that so little attention has been paid to it.

Varnishes.

In a paper on the viscosity of varnishes, Seaton, Probeck, and
Sawyer (Jour. Ind. Eng. Chem., 9, 35, 1917) state that varnishes show
two types of solutions, viz., true and colloidal; they may, under
certain conditions, show the Tyndall effect.

The suspensoid and emulsoid classes differ in viscosity character-
istics. The systems consist generally of three components, resin,
oil, and thinner, 7.e., resin incorporated by heat with oil and thinner
added. The variation in the viscosity of the emulsoid type with
change in concentration is very great. Seaton shows that the
viscosity temperature curves (determined by the Doolittle method)
of the true solution type, containing soluble gum and low in polymerised
oil, are curves whilst varnishes containing highly polymerised oils
give straight lines; moreover, determinations of the viscosity of —
varnishes at various temperatures will give information as to the ~
nature of the varnish solution.

Decrease in dispersion increases viscosity in emulsoid colloids and
addition of thinner, increasing the dispersion of the polymerised
components, will lower it.

If Seaton’s view is correct the viscosity temperature curve before
addition of the solvent would be a straight line, but after addition
of the thinner it would be a curve. The examples given by Seaton
are striking, but a number of variables define the viscosity of emulsoid
colloids besides concentration, temperature, and degree of dispersity
(Wo. Ostwald, J'rans. Faraday Soc., 1913, 9, 34); especially there
is to be considered solvate formation where the viscosity increases
with the amount of dispersion medium taken up by the disperse
phase. In view of the difficulty in deciding with accuracy the amount
and even presence of polymerised oils in varnishes such a relationship
as indicated by Seaton is of great value. Similar changes in viscosity
during ageing are of importance because unless. the viscosity approaches
a constant value in a month’s time the varnish may become unsuitable.

The importance of viscosity measurement in the standardisation
of aeroplane dope and aircraft varnishes has been fully recognised
as a determining factor for flow and freedom of working of these —
coatings. In view of the variety of composition of varnishes the —
volatility of the thinner as affecting the flow is of considerable practical
importance. }

Varnishes often contain a disperse phase associated with the —
continuous medium. ¢
f

107

The application of Hatschek’s formula :—

” = viscosity of the continuous phase.

7! = viscosity of the emulsion phase.

A = ration of total volume of the emulsoid to the volume of the
continuous phase.

* (Zeit. Chem. Ind. Kolloid, 11, 284, 1912) would throw light on the
relationship of resin, oil and thinner and also on the composition of
the disperse phase, although the formula is stated to be inapplicable
to organic solvents. Von Smoluchowski (Koll. Zeitsch., 18, 1910,
1916) does not consider the prospect of deducing such a formula likely
to be suecessful.

The drying of varnish films is chemically an oxidation process
accompanied by increase in weight, volume, and in viscosity during
the formation of the colloid lmoxyn. The rate of drying may at
first be rapid, followed by a period of sweating or syneresis. After
a time the sweating disappears; this is possibly a chemical process
connected with movements in the combined oxygen of the peroxides
primarily formed or to changes in the character of the preliminary
linoxyn coating. Wolff (Farben Zeit, 24, 1119, 1919) maintains that
oxidation and polymerisation proceed at rates depending on the wave
length of light to which a varnish is exposed. ~

It is to the linoxyn that the water-resisting power of varnishes is
due. Recently work has been done in connection with the protection
of metal and wood parts of aircraft under the auspices of the British
Engineering Standards Association, and for the Materials Section of
the Technical Department of the Air Ministry. Few resin or resin
oil coatings are impervious to water; possibly Japan lacquer is the
best.

From the writer’s unpublished investigations the whiteness of a
varnish layer when immersed in water is an emulsion of water in
the resin oil mixing as continuous medium.

An emulsion would be formed if the emulsifying agent in this
case, the resin or oil soap, forms a colloid solution in the non-aqueous
solvent (Bancroft, Jour. Phys. Chem., 17, 501, 1918).

The best water-resisting coatings give an emulsion with difficulty,
and although the layer may take up as much as 5 per cent. water, the
varnish film will remain clear. The conditions are essentially dependent
on the nature and concentration of the linoxyn surface layer and on
the nature of the oil and rosin together with the electric charge on
the metallic components present in the mixing. It must be pointed
out that increased rate of drying of the oil is not sufficient to prevent
emulsification.

The surface layer of a varnish. is essentially semi-permeable to
water, but not to salts contained therein, e.g., NaCl, K,SO,, KCNS.

If plain wood be suitably varnished and placed in water absorption
will proceed at a rate which varies with the nature of the coating.
Professor Lang and the writer have found that for a high class article

108

the daily rate is 0-0003 grms. per sq. cm., and the rate appears to be
the same either in a water-saturated atmosphere or when immersed
in water. The absorption will continue without whiteness appearing
until the wood is impregnated and the emulsion can form.

Similarly, gelatine under shellac will pull water through the film.
If the film is in glass, cloudiness will appear at once in the absence
of the absorbing undercoat, or if the layer is applied on an impervious
surface. The milkiness disappears generally on drying the film. On
continued immersion swelling ensues with the formation of blisters
and detachment of the film.

Often the surface is ridged and shows numerous perforations as

if the surface had been scratched and punctured, so that the water
absorption on a glass plate becomes steady owing to complete
saturation. The swelling must be due to the osmotic pressure of the
colloid solution under the protecting layer of linoxyn compelling
the compensating migration of water which forms the disperse phase
of the emulsion.

It has been shown that normal solutions of NaCl, MgCl, and CaC,l
prevent the whiteness of an ordinary varnish film and reduce largely
but do not prevent the passage of water through the film.

N/2 solutions of the above salts have nearly the same effect, and
this is true for solutions of K,SO, and KCNS. There are slight
differences in behaviour due to the nature of the metal, so that although
sodium and potassium salts show the same behaviour yet magnesium
is slightly different to calcium, and that again different to aluminium
in the form of chlorides in normal and half normal solutions. In
the case of calcium there is an indication of surface adsorption with
the production of a surface bloom which can be rubbed off leaving a
clear film. From the figures given by the Earl of Berkeley and
Hartley (Roy. Soc. Proc. A, 92, 477, 1916), it would appear that an
osmotic pressure approaching 13-5 atmospheres is necessary to
prevent the passage of water into a high-class ordinary outside varnish.

With the solutions of N/20 and N/200 of the above salts the water
absorption increases largely, and attains its maximum in distilled
water. The concentration of the linoxyn surface film together with
polymerisation of the drying oil present appear to be factors deciding
the impermeability ; whereas the formation of the emulsion with the
absorbed water depends on the nature of the emulsifying pent in the
oil. (Morrell, Jour. Oil and Col. Chemists’ Assoc., 111, 36, 1920.)

Sufficient has been given to show that in varnish films similar
problems await solution as in ordinary emulsions, and the experience
gained in researches on colloids in a water medium are of great value
although the presence of non-aqueous solvents render many of the
generalisations inapplicable.

Reference may be made here to some instances of application of
knowledge gained by investigation of other colloid systems.

Bancroft (Jour. Phys. Chem., 19, 275, 1915) gives a number of
instances of emulsions involving the use of varnish materials, e.g.,
bronzing liquids in which the metal goes into the dineric surface.

Gelatine can be precipitated from a solution of glue by shaking

with benzole, and rosin dissolved in dilute caustic alkali can beremoved _

*
,

109
by benzene (Winkleblech, Z. Angew. Chem., 19, 1953, 1906). Kerosene

- benzol, carbon disulphide, chloroform act similarly, but ether has no
effect, and produces no emulsions. Such emulsions are noticeable
- in varnish analysis and are considered by Bancroft to be due to violent

shaking, causing drops of the second liquid, which have the power of
condensing colloid particles on the surface and coalescing to larger
complexes, to form a rigid emulsion with water.

Colophony in the form of resinates behaves similarly to the soaps

_ of fatty acids in forming emulsions. Among the more recent contri-

butions to the subject may be mentioned the work of L. Paul (Kolloid

Zeits, 21, 176-91, 1917), who states that solutions of alkali and resin
_ soaps behave like highly dispersed colloid systems. These colloidal
_ soaps combine with basic dyes to form coloured rosin lakes and are

characterised by the readiness with which they combine with
petroleum hydrocarbons (Z. angew. Chemie., 28, Ref. 41a 73875 lols
and Seifen Zeitwng., 42, 640, 659, 1915). The same author (Kolloid
Zeits., 21, 148 and 191) finds that certain fractions of the distillate
obtained by distilling a mixture of colophony with phenol or a and B
napthol yield dyes with diazo and tetrazo-compounds.

Just as in the case of fats, fatty acids, soaps, and tannic acid, the
surface tension of water is lowered by resins or resinates which may
be considered to assume emulsoid or suspensoid properties in different
dispersion media. J. Friedlander (Z. phys. Chem., 88, 430, 1901)

- showed in the solution of rosin in 1 perjcent. alcohol how very slight

are the changes in viscosity of a liquid when it takes up a suspensoid
phase, and again a solution of rosin in alcohol containing a little water
possesses a relatively high temperature coefficient (5-6 per cent. per
degree temperature) against that of water, 2 per cent. (Hardy,
Z. phys. Chem., 38, 328, 1900). Cohn (Chem. Zeit, 40, 791, 1916)
describes gel formation produced when colophony is treated with
aqueous ammonia.

A. P. Laurie and Clerk Ranken (Roy. Soc. Proc. A, 94, 53, 1917)
describe the imbibition exhibited by some shellac derivatives. The
solid which separates on cooling a solution of shellac in boiling sodium
carbonate when immersed in water expands rapidly and ultimately
disintegrates to a flocculent precipitate. At the maximum point of
expansion the solid on immersion in a solution of sodium carbonate
contracts, expanding again when transferred to water. It was found

_ that the expansion was inversely proportional to the concentration of

the salt solution. Since the shellac molecule is here considered to

be permeable to salt solutions the mechanism of the expansion may
be accounted for by the passage of the salt solution through the

diaphragm, the soluble nucleus dissolving in the presence of the salt

solution and the amount which can dissolve controlling the consequent

osmotic pressure.
Shellac films from spirit solutions do not absorb normal salts from
half normal solutions. The writer (loc. cit.) has found that the presence

_ of salts, e.g., N/2 K,SO, or N/2 KCNS reduces the water absorption

of the shellac film and no salt could be detected passing through it.

_ The water absorption by shellac is much less than in the case of

ordinary varnishes, but the effect is more permanent giving a cloudy

110

layer which does not clear on drying and becomes very granular
with eventual loss of cohesion. Like varnish films shellac gives a
semipermeable membrane and with half normal solutions of salts
the absorption of water is practically inhibited. _

In a varnish film such an equilibrium would leave the film clear,
but in shellac there is a persistent cloudiness indicating that the film
is becoming granular. The examination of the properties of shellac
films is of interest in comparison with oil rosin films. In some respects
there is much in common, but in the impregnated shellac film, water
is probably the continuous medium. As in the case of oil varnishes
a certain per cent. of water can be absorbed without opalescence
appearing.

Natanson (Z. phys. Chem., 38, 690, 1901) has followed up Poissan’s
researches of 1829 in which it was stated that when a liquid is subjected
to deformation a certain time is necessary for obtaining equilibrium,
different for different liquids. Liquids have a very small relaxation
value. For castor oil from G. de Metz’s results the relaxation time
is 0-0031 secs., and for solutions of tragacanth and collodion, values
of the same order.

Reiger (Physik Zeitschrift, 8, 537, 1907; and Annalen der Physik,
4, 31, 51, 1910) has shown that fluid mixtures of rosin and turpentine
have a possible elastic reaction by an oscillatory viscometric method
provided due allowance be made for surface forces.

De Metz (Comptes Rendus, 186, 604, 1903) has examined the very
slow relaxation in the double refraction of a copal varnish induced
by mechanical deformation caused by pressure or extension. The
phenomenon of relaxation in a varnish lasts long enough to be observed

1
in the fall in the double refraction. T= pia tc
log A — log at
to base e and »=nT (Maxwell, Phil. Mag., 4, 25, 129, 1868).
T = time of relaxation, A and A! the difference of path of two rays at
times t and t4; » = coefficient of internal friction of the varnish and
n = modulus of rigidity.

The modulus of rigidity of a liquid varnish calculated on the

ss at 22° C., and is of the same order as
f e

that of gelatine in water calculated by another method (c.f. Schwedoff,

Jour. d. phys., 8, 341, 1889, and 9, 34, 1890).

, where log is

above formula is n = 0:12

Paints and Pigments.

In the literature on oil paints the. application of the principles
of colloid chemistry is very scanty.
_ H. A. Gardner (Jour. Ind. Eng. Chem., 8, 794, 1916) discussing
the physical character of pigments and paints, points out that the
opacity of pigments generally increases with fineness of division.
As the refractive index of the vehicle approaches that of the pigment
the opacity diminishes. Hence, in turpentine and in linseed oil ©
the opacity will be less than in water as those media haye higher —
refractive indices,

111

A lead paint will be opaque since its refractive index is greater
than that of the oil, whilst a silica paint in turpentine or linseed oil
will be practically transparent owing to close equality in the refractive
indices of pigment and medium.

The opacity varies inversely with the amount of oil absorbed by
the pigment, but the durability is improved by the presence of more
oil.

The refractive indices of silica, barytes, zinc oxide, white lead, and
zine sulphide are 1-55, 1-6, 1-9, 2-0, and 2-37 respectively.

In lithopone a mixture of the components fails to give the same
opacity as when prepared in contact. Between the limits of 28 per
cent. and 38 per cent. zinc sulphide the covering power is best. It
is probable that surface adsorption of the zine sulphide by the barium
sulphate occurs.

Rapidity of precipitation, strength of solution and temperature
control, are factors which aid in the production of fine grained particles
giving the greatest opacity.

The phenomenon of surface adsorption shown by certain lake
bases in the presence of colouring matters is of interest and explains
why the highly colloid pigments are often preferred. A measure of
the degree of dispersion might be based on their colour.

Bingham and Green (Am. Soc. Testing Materials, 1919) distinguish
between the viscosity of true liquids and the rigidity of plastic solids.

The application of the generalisations drawn from the study of
other classes of colloid bodies to problems of the paint industry are
referred to by Bancroft (‘‘ Theory of Emulsification,” V., Jour. Phy.
Chem., 17, 501, 1913). The use of sodium silicate to give an emulsion
with linseed oil to prevent the paint from setting or hardening in the
package has been known from 1865. Generally 2 per cent. water is
the limit, although 4 per cent. may be employed to prevent settling,
provided the emulsification of oil with water is assured. Instead of
water as combining medium a rosin oil mixing may be employed.
An alkaline water fluid is not desirable, and the addition of zine oxide
be the lead white is useful in maintaining the suspension in the linseed
oil.

KE. E, Ware and Christman (Jour. Ind. Eng. Chem., 8, 879, 1916)
recommend that a non-aqueous protective colloid, eg., aluminium
palmitate or oleate should be added to mixed paints to which small
quantities of water have been added containing a protective colloid to
prevent settling of the pigment.

The same authors have investigated the skinning, puttying, and
livering of mixed paints. Livering is dependent on the acidity of
the pigment, and in the case of enamels must be connected with the
gelatinisation of the colloid resin due to reduction of its acidity, The
coagulation depends on many factors of composition and the presence
of foreigi substances. Such gels would absorb oil and thinner with
separation of the pigment. Skinning would seem to be caused by
the oi! acids acting on the pigment.

In an oil paint containing rosin the formation of resinates increases
the viscosity and the further formation of zinc soap separating from
the viscous solution of zinc resinates gives a gel occluding pr adsorbing

112

the remaining oil (livering). Under suspensoid pigments the adhesive
properties and cementing values of paint pigments apparently increase
with approach to colloidal form. All paint pigments have colloidal
properties. Gardner found in the clear oil upon the surface of
specially prepared pigments which had stood for a year, the presence
of pigment material showing Browman movement on thinning with
benzols. Experiments made with zine oxide and with silica ground
in linseed oil (thickened) gave even after thinning with four vols of
benzole a cloudy fluid which yielded no clarification on centrifuging,
but could be partially clarified by mixing the two fluids, a change
probably due to electric neutralisation.

Paranitraniline red in oil is clear and slightly coloured, becoming
bright red when benzole is added, a colour change common in the
case of many suspensoid sols.

Prussian blue shows strongly Brownian movement and many
particles of chrome green suspensoids are coloured crimson, orange,
green, and blue in the ultramicroscope.

Carbon black (containing 90 per cent. carbon) probably adsorbs
linseed oil as in the case of pigments. In the presence of strongly
oxidised or boiled oils precipitation may occur on addition of benzene,
which may be due to imbibition of the spirit comparable with the
swelling of rubber in benzene or of gelatine with water. Again, if
zine oxide or lithopone be ground in alcohol and linseed oil added,
the alcohol is displaced probably due to lowering of surface tension
by introduction of the®oil.

[An excellent summary of the properties and uses of carbon black
is given by Perrott and Thiessen (J. Ind. Eng. Chem. 12, 324, 1920,).]

Ayres (J.S.C.I., 35, 676, 1916) considers that “‘foots’’ from raw
linseed oil can be removed easily by heating to 100° ©. and
centrifuging.

The presence of the mucilaginous material containing salts is
considered by some to be highly detrimental not only in the manu-
facture but in the durability of many mixings and paint coatings.

Ware and Christman (loc. cit.) conclude that the use of emulsifying
agents in paint grinding to prevent hard setting has not been satis-
factorily explained. The emulsifying agent must exert no saponifying
action on the oil, but the presence of metallic soaps in certain quantity
retards the settling.

Hurst and Heaton state that the emulsification of the oil requires
to be assisted by metallic salts such as zinc sulphate, manganese
sulphate, and borax, &c.; moreover the addition of a minute
proportion of tannic acid incorporated with the pigment prior to
grinding with the oil causes the deflocculation of the pigment (Acheson,
J.S.C.I., 80, 1426, 1911).

Cellulose varnishes have already been dealt with in previous
reports under nitrocellulose, celluloid, and cellulose acetate.

A class of varnishes containing synthetic rosins on a phenolic
trioxymethylene basis is of growing importance.

[Annual Reports of the Society of Chemical Industry (Paints,
Pigments, Varnishes, and Resins, 1916, 17, and 18) and G. Matsumato,
Jour. Chem.WUnd., Tokyo, 18, 484, 1915; J.S.0.0., 1104, 1915.]

113

The synthetic rosins may be soluble or insolubie in alcohol depending
on the conditions of manufacture and show a great variety of chemical
and physical properties. Their composition is complex (Lebach,
J.S.C.1., 82, 559, 1913). The preliminary substance is a phenol
alcohol, C,H, (OH) CHOH.

Bakelite discovered by Baekeland, consists of soluble and insoluble
forms. On stoving alcohol-soluble Bakelite at 140°-170° it passes
to a hard insoluble layer or lacquer or to a solid of high chemical
and mechanical resistance (Bakelite C, Resite).

Resite has been considered to be. derived from polymerisation
products of CH, : <~ > = O (Wohl, Ber., 45, 2046, 1912).

The advantages of further study of such synthetic organic colloids
seem to invite inquiry. Viscosity, gelation, relaxation effects, and
dielectric properties are of importance, and, with the exception of the
latter, await investigation.

There remains one important class of varnishes, viz., the black
japans and black varnishes with carbon black as base.

In general, the pitch base blacks ought to show similar behaviour
to the resin mixings or to resin mixings containing no oil with
allowance for the nature of the pitch (asphaltum or resin or stearine).

The knowledge of their properties is in the hands of the craftsmen
and owing to the complexity of the mixings is of the nature of a trade
secret.

Those on a carbon black base involve the knowledge of the properties
of carbon black in non-aqueous media. The suspensoid black in
a high degree of fineness adsorbing the continuous medium is assisted
by an emulsifying colloid forming a membrane around the particle
of black.

The results obtained from attempts to produce liquid fuel from
petroleum and coal dust are industrially applicable in this case, but
the presence of resin and oil gives a more favourable medium for
holding the carbon black in suspension.

_ From the brief summary of a very scanty literature it will be
evident that although the main properties are conditioned by the
chemical composition of the components, nevertheless the properties
which decide between a high and low class of article or between
suitability or unfitness are rather to be looked for in a comparison
of relationship of phases and in changes of surface energy and
adsorption. ;

The author desires to express his thanks to Mr. P. J. Fay, M.A.

for help in the selection and arrangement of the material for this
report.

CLAYS AND CLAY PRODUCTS.

By A. B. SEARLE, Consulting Chemist, Sheffield.

The details of the structure 6f clays and clay products are to-a
large extent unknown. This is due to the variety of the materials
commonly known as clays, to the complexity of the reactions which
take place when the clays are moistened, dried, and heated, and to
the extreme difficulty in studying the products of the reactions.

@ 11454 H

114

There are numerous definitions of the term clay, but most of them
are incomplete. Some are so inclusive as to be applicable to any
plastic material, others involve an erroneous assumption as to the
manner in which the “ alumina’”’ and “ silica”’ are combined, and
no definition has yet been published which is entirely satisfactory.
Until a better one is forthcoming the following is convenient, though
hy no means free from objection :—

A clay is a naturally occurring earthy material, whose chief physica
characteristic is its plasticity, and whose essential constituents are reported
in an analysis of the substance to be “‘ alumina,” “‘ silica’’ and ‘‘ water.”

This definition does not exclude those highly siliceous and plastic
materials commonly known as “ brick clays”’ though some of these
are known to contain as much as 60 per cent. of materials of a non-
plastic, sandy nature, which is certainly not of the nature of elay.

When a commercial sample of clay is mixed with an equal weight
of water and allowed to stand for a few moments, and the liquid
decanted through a sieve having 200 holes per linear inch, this treat-
ment being repeated with fresh water until all the small particles
have been removed, the residue will usually be devoid of plasticity
and will not possess the properties of clay. Usually, it will resemble
sand or a mixture of gravel, sand, and rock flour. When some clayey
materials, such as some indurated clays, are subjected to this treat-
ment, the whole of the plastic material is not removed, but on
prolonged exposure to water, or better still, if the water is made
slightly alkaline and boiled in contact with the clay for several hours,
the material will be effectively separated into a coarser, sandy,
non-plastic matter, along with the smallest non-plastic particles.
By asuitable modification of the treatment just mentioned, a “ clay ”
may be divided into a number of fractions, of which all those
consisting of particles which will not pass through a No. 200 sieve
are obviously not clay. The finer particles are sometimes designated
‘clay substance,’ but, though they contain the whole of the plastic
material, they are not wholly “clay,” as by careful elutriation or
repeated sedimentation a further series of non-plastic and siliceous
materials may be separated. Seger! suggested that the particles
which were carried away by a stream of water flowing at the rate
of 0-18 mm. per second should be regarded as “ clay substance,”
but this fraction contains a considerable proportion of non-clayey
material unless it is derived from a particularly pure clay, so that
this use of the term “ clay substance ”’ should be abandoned.

The smallest particles which are obtained by elutriating the |
materials commonly known as clays are found to correspond more or
less closely, on analysis, to a composition which may be represented
by the formula H,Al,Si,0,. In some samples of Cornish clay and
some kaolins, the composition is remarkably constant, but many
highly plastic clays and most fireclays yield a product richer in silica
and deficient in the elements of water. The constancy of the
composition of the better qualities of white-burning clays has led
to the supposition that there is in all clays an essential substance—
true clay, clayite, or pelinite—on which all clayey mixtures depend
for their chief properties. The existence of this “true clay” has

115

been so often assumed that there is a widespread impression that it
really exists as a definite chemical compound, though it has never
been satisfactorily isolated. A further objection to this belief in
the existence of a single substance as the essential ingredient of all
clays, is the fact that the composition and properties—especially
the plasticity—of the elutriated product differs with the origin and
nature of the “ clay ” from which it is obtained. A further objection
is that all attempts to obtain a pure product by chemical means or
to produce a synthetic clay have failed.

It has also been suggested by W. and D. Asch? that the essential
ingredient of all clays is not to be expressed by a single substance,
but by a large number of substances, each of which have a general
similarity in composition, but differing from each other in the
arrangement of the atoms in highly complex molecules. Thus, all
clays possess properties corresponding to those of a series of insoluble
acids and may, therefore, be regarded as alumino-silicic acids.
W. and D. Asch? go still further and suggest that the essential
substances in all clays are alumino-silicic acids, the atoms of which
are arranged to form several ring-compounds united together, each
ring containing six atoms of either silicon or aluminum together
with the requisite number of oxygen and hydrogen atoms (the latter
being in the form of hydroxyl groups) to form a saturated compound.
In most cases, two or more hydrogen atoms are assumed to be replaced
by those of sodium, potassium, calcium, magnesium, or iron.

Asch’s theory has been worked out in great detail with regard to
the available evidence, but for ‘its ultimate proof it requires the
synthetic production of clays of various compositions and_ this
synthetical proof has not yet been accomplished. The synthesis of
silica in the form of a hexagonal ring compound, $i,0,., by G. Martin®
in 1913 lends some support to the suggested constitution of the purer
clays. It has also been suggested that plastic clays are compounds
of “alumina” and “ silica” with organic groups. This theory does
not appear to have been very fully investigated. It has the dis-
advantage of being largely inapplicable to the purer kaolins which
are almost devoid of organic matter.

It was, at one time, thought that the plasticity of clays is due to
the presence of bacteria and bacterial products, but this has not been
proved, and appears to be improbable.

Although there is a considerable amount of evidence of the existence
of one or more definite chemical compounds which are the essential
ingredients of clays and, therefore, to be regarded as “true clay,”
there are numerous properties of clays which cannot be explained
by any purely “‘ chemical” theory, and of these the most important
is the plasticity. There are also properties which are capable of other
explanations, particularly those based on the colloidal nature of
clays.

The existence of colloidal matter in clays was first established
by Th. Schloesing* in 1872, but the most systematic exposition on
the colloidal properties of clays is that of P. Rohland® in 1891, and
more recently the possession of colloidal properties of clays has been
generally recognised’,

H 2

116

At the present time, the most probable theories of the constitution
of clays are as follows :—

(a) Clays are a mixture of adventitious minerals (such as
sand) and one or more alumino-silicic acids, the latter being
the true clays.

(6) Clays are adventitious mixtures of an inorganic colloidal
compound, or of several analogous compounds, and of inert
minerals such as sand.

(c) Clays are mixtures of alumina and silica or other simple
mutually precipitated colloids with other non-colloidal minerals,
such as sand.

A little consideration will show that (a) is not necessarily incom-
patible with either (b) or (c), as the two latter do not give any indication
of the chemical composition of the colloidal matter. Moreover, (c) is
not applicable to all clays, though it may be to some, so that present-
day views of the constitution of clays may be reduced to regarding
them as mixtures of non-clayey material (sand, &c.), with either
(1) a complex compound possessing colloidal properties, or (2) a
mixture of colloidal silica and alumina.

There is evidence in support of both these theories and no
comprehensive combination of both of them has been published, yet
neither theory alone explains all the facts, unless it is sufficient to
regard the first theory as applying to some clays, whilst the second
is more applicable to others. -

It appears quite certain that commercially useful clays are not
wholly colloidal in character; they rather resemble a mass of mineral
particles, each covered with a film of colloidal matter. If the latter
could be wholly separated, it would not possess all the properties
which make a clay technically useful, and in this respect the application
of the term clay to mixtures of sand and colloidal matter would appear
to be justified. The laterite clays which are widely distributed in
the tropics, are characterised by a large proportion of alumina and
silica soluble in hydrochloric acid. The ratio of these two oxides is
very variable, and seldom reaches 1 : 2 which is a conspicuous feature
of the purer British clays. This great variation makes it more
probable that the laterite clays are merely mixtures of colloidal silica
and alumina; their other properties resemble those of such a mixture
rather than those of typical clays, and the conclusions based on the
results of elutriation may require to be received with caution.

The proportion of colloidal matter which can be definitely
separated from clays is extremely small, being less than 3 per cent.*
in the’ most highly plastic specimens.* Many investigators find it
difficult to believe that so small a proportion can account for such
great differences in the behaviour of lean and highly plastic clays,
and have urged this as an argument against the plasticity of clays
being due to the colloidal material present. On the other hand,

* Ashley’ has proposed to determine the relative amounts of colloids in clays
by observing the amount of each required to just decolourise a standard solution
of malachite green. This method, whilst useful for comparative purposes,
gives no idea of the absolute amount of colloidal matter present.

117

there is a close similarity between the behaviour of many clays and
that of a fine concrete composed of Portland cement and fine sand,
the freshly-made concrete possessing a considerable amount of
plasticity even when the total proportion of colloidal matter present
is extremely small. A careful comparison of the structure and
properties of such a concrete with those of a plastic clay gives a very
clear idea of the possible nature of clay and especially of that of its
most characteristic property—plasticity.

The properties of clays which are most closely allied to those of
colloids or mixtures of colloids and inert materials differ according
as the clays are respectively in the dry, pasty, or “slip” state. The
pasty condition is produced by reducing the clay to a powder by
grinding, and then mixing it mechanically with a suitable proportion
of water. Some highly plastic clays‘ occur naturally in the form of
a stiff paste which may be softened by crushing between rolls so as
to reduce to thin sheets and mixing this mechanically with water.
Clay is converted into a slip or slurry by grinding or crushing it and
then mixing with a sufficient quantity of water to keep the clay in
suspension. The amount of clay which can be suspended in a given
volume of water depends on the physical condition of the clay and
the presence or absence of very small amounts of alkali, acids, or
salts in the water.

The following properties of clay can be most satisfactorily eXplained
by assuming the presence of colloidal matter :—

Water is absorbed by any clay in fairly definite proportions which
appear to have some relation to its plasticity, the lean clays absorbing
much less water than the more plastic ones.

When clay is completely dried without being excessively heated,
it is highly hygroscopic and absorbs water readily—sometimes up to
15 per cent. of its weight—without becoming appreciably moist. It is,
therefore, difficult to keep clay perfectly dry, and most specimens
contain a considerable proportion of water which may, in some cases,
cause the clay to be tough and plastic.

The hygroscopic nature of clay distinguishes it from silt and sand.
When a piece of air-dried clay is placed in water, the latter enters
into the pores, drives out the air, and lifts up the smallest particles
of clay, disturbing the structure of the material so that a partial or
complete breakdown or slaking occurs. The disruptive action of the
water on the solid particles forming the clay mass may be attributed
to a molecular attraction between the water and the clay whereby
the water wets the surface of the latter and the resulting interposed
film of water reduces the cohesion of the clay grains so that they
separate easily. The absorption of water is accompanied by a slight
rise in temperature, which though scarcely noticeable is characteristic.
The amount of water absorbed varies greatly with different clays;
in some cases, it is equal to 80 per cent. of the weight of the clay.

Rohland® suggests that this power of imbibing a definite amount
of water is due to the colloids in the clay, and that as soon as the
clay has absorbed a sufficient amount of water to convert its colloids
into the form of a colloidal sol its ability to absorb water reaches a
saturation point and ceases; this is proportional tof[the colloids

118

present, and probably, roughly to the plasticity of the clay. It may,
however, be proportional to the capillary spaces between the clay
particles.

In the manufacture of articles from clay paste, it will be found
that each kind of clay requires a definite proportion of water for its
efficient manipulation. If more is added it will become too weak, if
less it will become too short. This water is known as “ water of
formation,” and its amount has a theoretical as well as a practical
importance, being closely related to plasticity. Unfortunately, there
is no certain method of ascertaining the consistency of the clay paste,
nor of ascertaining when the correct proportion of water has been
added to a clay. The ordinary method consists in adding such a
proportion of water that when the mixture is worked up into a paste
it readily receives the impression of finger-prints, but does not adhere
to the skin, the amount of water required being found by trial.
This procedure is too rough for scientific purposes.

If water is added to a moderately plastic, dry clay in increasing
quantities, the clay can at first be moulded with difficulty, then more
easily, and later it may be moulded with the greatest facility. If
the proportion of water is still further increased, the clay becomes
sticky, then fluid, and it is eventually impossible to form it into any
definite,shape.

If the same experiment is repeated with a more plastic clay, using
the same proportions of clay and water as before, it will be observed
that it will adhere to the fingers and will allow of no further shaping
unless its plasticity is diminished by adding non-plastic material or
altering the proportions of clay and water.

An excessively lean clay, on the contrary, only acquires the desired
plasticity when it has a very soft consistency, which does not allow
it toremain in any given form, and it must, therefore, be rendered more
plastic if it is desired that it should be shaped by hand. If the
formation is done by mechanical means, in which the clay is subjected
to much stronger pressure, less water must be added to the body in
order to give it the required plasticity, and it will be expedient to
make it of a stiffer consistency. Pressure, in this case, plays the
same part as water in the plastic qualities of clays; the one can be
partially replaced by the other, so that if the amount of pressure is
increased the proportion of water should be diminished and vice
versa.

If a sufficient quantity of water is added to a clay to form a slip
or slurry, the latter will have certain characteristics, according to
the proportion of water and clay, to the nature of the clay and the
purity of the water. If the proportion of water is very large and the
particles of clay difficult to separate, they may fall to the bottom
very soon after the mixing ceases, or the greater part of them may
so fall, leaving only the smallest particles suspended in the water for
many hours. With high grade clays, such slips have marked colloidal
properties (see Viscosity, Adsorption, &c.).

Slips containing about an equal weight of water and clay are
largely used in various branches of clay-working, for covering other
clays of inferior quality when burned, and for making objects by the

119

process of casting. In the former case, the articles to be covered
are immersed in the slip, and in the latter, the slip is poured into plaster
moulds and allowed to remain for a short time, after which any
superfluous slip is poured away. On allowing the mould to dry, the
water is absorbed by the plaster, and the clay article may be removed
in due course.

In both cases, it is necessary that the proportions of clay and
water should be carefully adjusted, in order to obtain the best results.
When a suitable mixture has been obtained, it will usually be sufficient
to weigh exactly one pint of it accurately, and to dilute other mixings
with a stronger slip or with water, until they reach the same weight
per pint. The specific gravity of the slip may be determined with
great exactness in a pycnometer, if desired, but this involves unneces-
sary trouble for most purposes.

Schwerin has found that water and alkalies in the clay slip may
be removed by electro-osmosis by connecting the bottom of the tank
containing the slip with the negative pole and the cover with the
positive pole of a battery when, on passing a suitable electric current,
the water and alkali will collect at the bottom, and the slip will become
very stiff and apparently—though not actually—dry.

The hygroscopicity of dried clay is very marked, up to 20 per cent.
of water being absorbed from a damp atmosphere by some clays. It
does not necessarily prove the presence of colloidal gels, but if they
were present such hygroscopicity would be anticipated.

Miscibility—It is a remarkable fact that highly plastic clays, in
addition to having a limited power of absorbing water, are incapable
of forming a uniform mixture with less plastic clays. According to
Rohland®, this is due to the fact that when colloids in clay are
coagulated they form gels which cannot be brought into solution by
the addition of more water, and resist the absorption of water. They
are also incapable of taking up anything from a second colloid. Hence,
if the colloids are coagulated, as in very plastic clays, they will not
absorb more than a certain amount of water, will not take up other
plastic clays, and will not mix homogeneously with them. Many
objectionable qualities of a highly plastic clay may be obviated by
saturating it with water and then adding a suitable amount of non-
plastic material. In this way, also, highly plastic clays gain the
power to be mixed thoroughly with other plastic clays and with
felspar, which forms coagulable colloid solutions.

Rohland has found that plastic clays in which there is only a small
proportion of colloids, and these not coagulated, may be uniformly
mixed with other similar clays.

Deflocculation —Clays usually exist in large masses which are not
readily affected by water, but smaller pieces may be broken down
or “ slaked,”’ as just described, in a manner which is very similar to
the deflocculation of colloidal gels. If a suitable electrolyte such
as sodium hydroxide, carbonate or silicate, or baryta is added, the
amount of suspended matter is increased, as with well-known colloids,
and, if an acid is added to the suspension, the clay particles are
rapidly precipitated like a coagulable gel. Clays are remarkably

120

sensitive to the action of electrolytes, a very small quantity of a
solution of soda being capable of converting a clay-paste into a viscous
fluid which, on the addition of just sufficient acid to neutralise the
alkali, will again become solid. This behaviour bears a remarkably
close resemblance to the action of electrolytes on the coagulation and
deflocculation of colloids. Rohland® has suggested that the formation
of a clay slip (sol) may be explained as due to the action of electrolytes
on the colloids present in the “ clay.”’ With a negative sol in colloidal
suspension, the most powerful factor in coagulation is the positive
ion of the electrolyte added, the negative ion having but little influence.
The power of different positive ions appears to be the same for those
of the same valency, but divalent and trivalent ions are more powerful
than monovalent ones. Thus, Foerster has shown that if a clay
contains just enough calcium ions to keep the colloidal matter in the
gel state, and sodium carbonate is added, the sodium will combine
with the colloid clay so as to form the sol, the plasticity being reduced
according to the completeness of the reaction, but if an excess of sodium
ions is added they will recoagulate the colloid. This has been confirmed
by experiments on the viscosity of clay slips by Mellor and others.

The addition of electrolytes to a clay body also affects some of the
materials present. Thus, Schurecht® has found that the working
properties of mixtures of graphite with sufficient plastic clay to act
as a binder, such as are used in the manufacture of plumbago crucibles,
are considerably inaproved by the addition of 0-3-0-4 per cent. of
sodium hydroxide or, in some cases, of hydrochloric acid, according
to the nature of the colloidal matter present.

Kosmann® attributes the disintegration action of alkaline solutions
on clays to the solution of a siliceous film on the particles which acts
as a binder. This explanation scarcely seems to account for the great
effect produced by so small a proportion of soda.

When clay is saturated with water and an electrolyte is then added,
the adhesion of the particles is reduced, partly as a result of the
osmotic pressure of the solution on the porous particles!® which then
act as a permeable diaphragm and force the water more strongly into
the interior of the particles than would be the case if plain water
were used. If the basicity or alkalinity of the solution is altered
by the addition of an acid, the particles tend to coagulate and adhere
to each other with the result that the mass becomes semi-solid.

When clay is suspended in a liquid having a higher coefficient of
capillarity than water (e.g., acids) the particles tend to precipitate,
but in a liquid with a lower coefficient than water (e.g., bases and
alkalies), they tend to remain in suspension. This behaviour is
attributed to the difference in the adhesion of the fluid particles of
the liquid to the particles, the surface of the smallest particles being
much greater in proportion to their weight than that of the larger.
ones.

Adolph Mayer has determined the limiting power of electrolytes
which permit a fine clay (freed from carbonates and soluble salts by
treatment with hydrochloric acid) still to be kept in suspension in
water (100 grammes clay, 500 grammes water). The limits are :—
ammonia, 2-5 per cent.; sulphuric, hydrochloric, and nitric acids

ae -sS-

121

and the alkali salts of these acids, 0-025 per cent. Although 2-5 per
cent. of ammonia caused precipitation in Mayer’s experiments, a less
amount favours deflocculation, or breaking up of the lump.

The “ fluidity ”’ of any clay slip depends chiefly on the proportion
of water added, but it is largely affected by the presence or absence
of very small proportions of electrolytes. According to Rohland’,
the addition of hydrochloric, nitric, sulphuric, acetic, or propionic
acid increases the plasticity of the clay slip, apparently by coagulating
the colloidal matter present. Solutions with an acid reaction such as
sal-ammoniac, aluminium chloride, ferric chloride, and potassium
bichromate behave similarly. Alkalies such as ammonia, caustic
soda, caustic potash, lime-water, baryta, and basic salts, make the
slip more fluid and reduce the plasticity of the material, but their
behaviour depends on their concentration. The action of alkalies
in reducing the viscosity, sometimes requires several days, and is
accompanied by coagulation. An excess of alkali may cause a
reversion of this action, the viscosity increasing again. The addition
of salts usually decreases the osmotic pressure and increases the
viscosity.

Acheson has patented the use of a solution of tannin and alkali
to make a clay “ fluid,”’ and, followed by the addition of an acid—
presumably by precipitating the colloid matter—to increase the
plasticity of the clay.

The viscosity of clay suspensions, before and after the addition
of various substances, can best be understood by assuming that it
varies according to the condition, and proportion of the colloidal
matter present. Mellor, Green, and Baugh" have arranged the
substances likely to be present in, or added to, clays into five groups
according to their action on the viscosity of the clay* :—

(1) Substances which first make the slip more fluid, while
further additions stiffen the slip. Examples: sodium and
potassium carbonates, fusion mixture, potassium sulphate,
potassium bisulphate, potassium hydroxide, potassium nitrate,
sodium sulphide, tannin and gallic acid.

(2) Small amounts thicken the slip; larger amounts make
the slip more fluid. Examples: copper sulphate, dilute
ammonia, and potassium aluminium sulphate.

(3) Substances which make the slip thinner: magnesium,
mercury and sodium sulphates, sodium sulphite, sodium acetate,
sodium chloride, sodium phosphate, ammonium gallate, hydro-
chloric acid, water-glass. It is just possible that some of these
substances may have to be transferred to the first (or second
group) if greater (or less) concentrations be tried than_ those
employed by Mellor, Green, and Baugh.

(4) Substances which only stiffen the slip: grape sugar,
humic acid, ammonium chloride, calcium chloride, calcium

* It should be noted that the slips used were not made trom a single clay,
but from a body mixture consisting of 16g. ball clay, 19g. China clay, 13g.
Cornish stone, 20g. flint and 100c.c. water, To this mixture, varying quantities
of acid, alkali and salt—ranging from 0-1 to 6g. or 0-1 to 35¢.c.—were added.

This may account for the difference between these results and those obtained
by some Continental investigators,

122

sulphate, ammonium urate, aniline, ethylamine, methylamine.
Here, again, some of these substances may have to be transferred
to the second (or first) group if greater (or less) amounts than
those mentioned are used.

(5) Substances which have no appreciable effect on the slip :
e.g., alcohol.

Rieke has stated that the most soluble substances increase the
viscosity of the slip, but their effect may be neutralised by the
addition of a solution of barium hydroxide. The most harmful
sulphates according to the same investigator are those of calcium,
aluminium, and the heavy metals. Alkali sulphates stiffen the slip
when only 0-1 per cent. is present; larger proportions render it thinner
until 1 per cent. is reached, after which they stiffen it again. Zinc
and copper sulphates exhibit this phenomenon of variableness to a
marked degree.

Bleininger found that the first addition of clay (up to 3 per cent.)
decreased the viscosity of water on account of the deflocculation
of the clay by dilution and the solution of the contained electrolytes.
When, however, the addition of clay became so great that no further
matter went into solution and the effect of the gel showed itself, the
viscosity increased with each addition of clay. This negative viscosity
is peculiarly characteristic of some clays.

The size of the particles of the purer clays is comparable with that
of colloidal particles, but most clays contain so large a proportion
of larger particles that it is almost impossible to isolate those which
are colloidal, in an entirely satisfactory manner.

The adsorptive power of clays bears a striking similarity to that
of colloids, or rather to that of a mass of inert material, the particles
of which are covered with a film of colloidal matter which also fills
some of the interstices. Thus, clays adsorb soluble dyestuffs, tannin,
humus, oil, grease, salts,* &c.; and Hirsch and others have found
that barium, lead, and aluminium salts are adsorbed more readily
than those of lime and magnesia. Chlorides and nitrates are adsorbed
more than sulphates, but alkali salts with the exception of the alkaline
carbonates are not adsorbed. The behaviour of the alkaline carbonates
may be explained by the almost invariable presence of calcium ions
in clays, which react with the carbonate forming a precipitate of
calcium carbonate, and so removing the carbonate ion from solution.
Rohland® states that some clays which are only moderately plastic
may, on the addition of alkali and certain salts, or through some
chemical change, be made more adsorptive. The adsorptive power
of clay is valuable in some industries, and it is on account of this
power that if clay is mixed with neutral or slightly acid muddy
solutions or emulsions, when the clay settles it will be found to leave
a clear liquid. The adsorption of a clay is usually determined by
noting the loss of colour of a dye solution such as malachite green,
and comparing it with another similar solution to which a standard
clay has been added.

* Many clays retain salts so tenaciously that it is impossible to wash them

clean with plain water, but they can be removed by washing with a solution of
a salt which is more readily absorbed by the clay.

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If Olschewsky’s suggestion that the particles of clay are porous
is correct, the phenomena ascribed to adsorption may really be due
to adsorption within the capillaries or pores.

The ‘ scum ”’ observable on some bricks is due to the salts adsorbed
by the clay and carried to the surface during the drying of the bricks.

The capillary phenomena shown by many clays and soils may also
be explained on the hypothesis that clays are colloidal in character.

The porosity of clays varies with the amount of water present,
some stiff plastic pastes being quite impervious, though the same
materials are porous when dry. This porosity appears to be associated .
with the capillary structure of many clays and whilst it is a property
possessed by non-colloidal substances, it is a characteristic property
of some colloids.

The semi-permeability of clays, like that of colloids, is a characteristic
property, and although its nature is by no means well understood,
it appears to confirm the presence of colloidal matter in clays.

When clays are made into semi-permeable “‘ membranes,” they
behave according to their plasticity. The plastic clays effect a perfect
separation between the colloid and crystalloid solutions and are truly
semi-permeable, but very lean clays such as china clay are very
irregular in their action. In some cases, the presence of a crystalloid
may cause a sol to pass through a membrane, as when silicic acid is
mixed with sodium chloride both will pass through. It is also stated
by W. Ostwald" that fresh colloids (particularly silica) will pass through
a membrane, but after keeping a few days they will not pass through.
* There is no connection between the rate of diffusion through the
membrane and the molecular weight.

According to Rohland®, plastic clays will allow ferric chloride and
sugar (crystalloids) to diffuse, but not tannin (colloid). In emulsions
of oil and water, plastic clays permit the (crystalloid) water to pass,
but not the (colloid) oil. In alcoholic solutions of fat, such clays
permit the alcohol to pass but not the fat. In aqueous rubber solutions,
plastic clays prevent the rubber from diffusing, and in albumen,
solutions the albumen is retained, both rubber and albumen being
typical colloids. The diffusibility or speed at which the substances
dialyse through the membrane depends upon their nature. Thus,
water* which is a crystalloid, and electrolytes, e.g., salts dissolved
in it, diffuse rapidly, but colloids, such as ferric hydrate, hydrated
silica, hydrated alumina, and most products of organic life such as
starch, vegetable oils, and gelatin are either indiffusible or pass
through with extreme slowness. Colours, on account of their complex
composition, play a special part; they are retained by plastic clays,
though these colours are crystalloid and not colloid. Berlin blue,
potassium ferricyanide, aniline blue, sulphated triphenyl rosaniline,
aniline red, carmine, malachite green, fluorescin, aurin, and other
animal, vegetable, and tar colours, cannot diffuse through clay, and
this, in spite of their crystalloid nature.

* Zschokke™ suggests that plasticity is possessed by all substances composed
of extremely minute particles with sufficient affinity for each other and with
a power for combining with water.

124

The explanation of semi-permeable membranes most widely

accepted at the present time is that of selective solubility, suggested
by L’Hermite®. The membrane is permeable to those substances
which dissolve in it but not to others.
_ As the semi-permeability of clays appears to be connected with the
plasticity, any treatment which will increase the latter should increase
the former. Rohland® has found this to be the case with some lean
clays he has examined. Some of the phenomena occur whenever
plastic clay is mixed with solutions, as the particles allow the
crystalloids in the latter to pass through them, but retain the colloids
on their surface. In this way, the adsorption of crystallised matter
as well as colloidal matter occurs; but as the particles of clay are so
minute the effects are scarcely distinguishable, and clays appear to
be capable of absorbing both colloidal and crystalloidal substances.

The permeability of raw clays has been studied by Spring, who
found that when such clays are confined so that they cannot expand,
they will only absorb enough water to fill the .pores. The amount
absorbed varies from 3 per cent. with some fireclays to 25 per cent.
with some sandy loams. When not confined in this manner, the
extent to which the water can permeate a clay is dependent on the
amount of non-plastic material it contains, and increases when sand
or grog is added. The permeability of a fired clay is an important
characteristic, and is described later.

The more permeable a clay, the more easily can it be dried and
heated without damage, large pores being prefereable to small ones.

Wet clay in the form of a stiff-plastic paste is generally considered
to be extremely impermeable, but, as already mentioned, this is only °
a relative property, as such a mass of clay, if left in water, will, in
time, fall to pieces. Clay which has been suspended in water and
allowed to settle is usually quite permeable, as are many natural
clay deposits. It is only when the material has been “ worked ” or
“ pugged ” that it becomes impermeable.

The plasticity! of clays is one of their most important properties.
Plasticity may be defined as that property of a material which enables
it to change its form without rupture, the new shape being retained
when the deformatory force is removed. In other words, a material
is said to be plastic when it can be kneaded or pressed into any desired
shape, and remains in that shape when the kneading ceases or the
pressure is removed; this alteration of shape being capable of being
repeated indefinitely. It is a characteristic of many substances
besides clays,* though clays possess it to the most marked degree.
Ashley? has pointed out that very few people agree exactly with the
conception of plasticity. Thus, a brickmaker terms a clay plastic
when it works well in his machine, and is capable of being kneaded
into a “‘good’”’ paste, but a potter usually places more emphasis on
the binding power of the clay, though he terms this its plasticity.

Although these definitions are sufficient for practical purposes,
they are not entirely satisfactory, nor is there any explanation of the

”

* The “‘ possible plasticity ” is that which can be developed under the best
known conditions. For many purposes, it is not necessary to develop the
plasticity of a clay to the utmost.

125

causes of plasticity which meets all the needs of the case. Plasticity
varies with different samples and on different occasions, though no
raw moist clays are entirely devoid of plasticity. Clays which are
quite dry are not plastic, but become so when mixed with a suitable
proportion of water so as to form a paste. Hence, the amount of
plasticity developed is dependent on the proportion of water present.

Liquids other than water may be added to the clay to produce
plasticity, but they must usually contain water, and even then,
sometimes produce quite different characteristics. Thus, glycerine
may be used, but it prevents the clay from drying, and Krupsay has
pointed out that if plastic masses made from clay and glycerine and
clay and water respectively be kneaded together the resulting mixture
is non-plastic. Fatty liquids, such as oils, seem to make a more
plastic body than with water, especially if the clay has been dried
so as to take away from it the hygroscopic water, but alcohol, etheg,
and turpentine produce bodies with little or no plasticity.

The nature of the plastic product formed when liquids other than
water are used is worth further study. In the case of an oil, the
plastic mass is quite different from that produced with a liquid such
as anhydrous nitric acid, anhydrous sulphuric acid, absolute alcohol
and glycerine. ach of these fluids is soluble in water, and is, therefore,
able to wet the hydrated clay grain with its attached water molecule
and to separate the grains sufficiently to produce a plastic mass.
In each case, the clay may be “ dried ” again and made plastic with
any of the other fluids. According to R. F. MacMichael** only those
liquids which “wet” the clay particles can produce plasticity.
Water and fatty oils do this, but ether, gasoline, kerosene, engine oil,
and ‘similar fluids which do not “wet” the clay grains are either
unable to penetrate between them and so do not develop plasticity
in the clay or they form a film of such a nature around the clay grain
as to prevent cohesion, so that the mass acts like sand and water,
but there is no gradation or balancing of the forces, as is necessary
in order to obtain true plasticity.

Plasticity also depends both on the nature of the fluid and that
of the solid. Thus, while both water and oil wet quartz sand, water
under suitable conditions will easily displace oil films from a mixture
of sand and oil. On the other hand, both oil and water wet zinc oxide,
but in this case the oil will readily displace the water films, forming
paint or putty. The resulting mass, in this case, may be said to be
oleated, in very much the same manner as clay is said to be hydrated.
The same principle is employed commercially on a very large scale
in the flotation of metal-bearing ores.

The possible plasticity? of clay or other substance cannot be
developed by commercial methods of grinding unless the material
is in a state which may be regarded as dormant plasticity. This has
been regarded as an objection to the view that plasticity is due to
the colloidal properties of clay, but the objection may be met by
the difficulty of reducing some clays to so fine a state as is required
to produce the requisite amount of colloidal matter.

Plasticity also varies with the presence of certain other substances ;
thus, the following soluble substances reduce the plasticity of clay :

126

ammonia, caustic soda, caustic potash, lime, sodium carbonate,
potassium carbonate, borax, and water glass. They appear to do this
by coagulating the colloidal portion of the clay, but their action
may be prevented by the addition of a sufficient quantity of weak
acid to neutralise the alkali in the clay.

The addition of certain organic acids as humus, or of gum, glue
and starch confers a pseudo-plasticity on clay which is, however,
quite different from true plasticity and makes the clay “sticky ”
rather than plastic.

The stickiness of certain clays (e.g., London clay) is very pronounced,
but must not be confused with true plasticity. Ashley’ has stated
that if the granular constituent is removed from a plastic body it loses
plasticity and becomes sticky until the granular constituent is restored.
This suggests that the practice of adding granular material of a non-

lastic nature, so common among the users of London clay is based
upon a sound principle. The stickiness of clay may be regarded as
due to colloidal material which is not properly distributed throughout
the inert granular mass.

Plasticity does not appear to be connected with the chemical
composition, as clays which yield the same results on analysis may
differ widely in plasticity, yet on heating above 415°-600° C. all
clays lose their plasticity, and it cannot be restored. It is also a curious
fact that the clays which are richest in “true clay” are seldom so
plastic as those which are not so pure, so that any peculiar structure
of the clay molecule can scarcely account for its plasticity, though
several eminent investigators have laid stress on this suggested cause.

Several investigators have attributed the plasticity to the shape
or size of the clay particles. Thus, Aron considered plasticity was
due to the particles being spherical, but Zschokke, Biedermann, and
Herzfeld dispute this, and attribute it to the presence of flat and
laminated crystals,* a view early put forward by Johnson and Blake,
and held later by Bourry*, who stated that plasticity becomes greater
in proportion as the grains diminish, and that all minerals if reduced

.to a sufficiently impalpable powder, will on the addition of a liquid
produce bodies having a certain amount of plasticity.

According to Le ‘Chatelier, the lamellar structure and the well- |
known capillary attraction are a sufficient cause of plasticity. He has”
shown that all plastic masses contain a large proportion of air by
comparing their density with that of clay and water, and that in each
plastic mass there are innumerable capillaries of not more than one
three-thousandth of an inch in diameter. He concludes that the
tension of the menisci between the water-surface and the air-surface
in these capillaries explains the toughness of the plastic mass, as the
capillary force prevents the mass from breaking up under pressure,
but allows the minute particles to slip over each other, and yet adhere
so strongly that the mass retains the new form when the pressure is
removed. In other words, clay is plastic when sufficient water is

* The particles are so extremely minute that it is exceedingly difficult to
ascertain their shape. Le Chatelier has noticed that if the material is disturbed
when under the microscope, the crystalline form may be observed for a fraction
of a second by polarised light if their symmetrical axis is perpendicular to the
microscope axis. As soon as they are fiat they are isotropic.

127

added to induce the cohesion to a point where it can readily be
overcome by the pressure of the worker’s hands, i.c., to 1-3 lb. per
square inch, so that it is a balancing of forces producing a peculiar
combination of fluidity and rigidity in the mass of wet clay; under
a light pressure it acts as a rigid body, under a heavier pressure, it
acts as an imperfect fluid. The rigidity is attributed to friction
between the clay grains, so that a mass of clay retains its form until
acted on by a force sufficient to overcome this friction and produce
distortion. The fluidity of the wet clay is due to the freedom of the
individual particles to move over each other, after cohesion has been
partially neutralised by the addition of water.

The theory that plasticity, instead of being a special property,
is’simply the result of molecular attraction, and that all bodies which
are made up of laminated particles must become plastic when they
are reduced to sufficiently impalpable powder has been confirmed by
Vogt as regards mica, which is highly laminated, being made up of
thin layers, and when reduced to an impalpable powder becomes
distinctly plastic if water is added. The insistence laid by Bourry*
on the laminated structure of the particles has been frequently over-
looked, and the suggestion that, because burned clay may be ground
equally fine and yet never become plastic his experiments are not
conclusive, is irrelevent.

Seger!, and independently Schumacher, consider plasticity to be
due to molecular differences in the clay particles, and Bischof agrees
with the latter in considering that clay has undergone great changes
in density during deposition, and a kind of “‘ felting ” of the particles
has resulted so that they adhere much more closely to each other than
the quartz and other particles in which this felting process has not
taken place.

Wolff has calculated the attraction of the particles of various
substances to each other on the assumption that they are spherical.
He finds that the mutual attraction of the clay particles is vety high
and that the ratio between their mutual attraction for each other
and for water is much higher than for any other substances examined.
He stated in confirmation of this theory that other substances can
be made plastic, if they can be made sufficiently small, as by
precipitation.* He also pointed out that the combined water in a
clay particle increases the ratio considerably and is accompanied by an
increase in plasticity not only in the clay, but in alumina and iron
oxides. Zschokke confirmed this theory, and has shown that clay
particles have a thicker film of water around them than particles of
non-plastic materials such as sand.

It is extremely difficult to find satisfactory reasons for attributing
the plasticity solely to the plate-like or lamellar structure of the
particles or to purely mechanical or chemical characteristics in the
atoms and molecules of the clay and water, though these are
undoubtedly important. Nor has the effort of Le Chatelier to find
the source of plasticity in the presence of small amounts of impurities
proved really helpful. The smallness and shape of the particles
appear to be important, as clay ground in a pan-mill is more plastic
than when a ball-mill is used, as the former flattens out the material,

128

but this does not really affect the cause of plasticity. Grinding is not a
cause of plasticity, though Johnson and Blake claim to have made a
non-plastic china clay plastic by fine grinding.

It has been suggested by Olschewsky, who based his experiments
on those of Daubée, that the water used has a chemical action, and
that plasticity is due to the formation of a system of capillaries in
the clay, a felt-like or spongy material being formed, and in this way,
the clay particles are able to come into closer contact, owing to the
production of a kind of gelatinous or colloidal film, but the presence
of an alkali appears to be essential for this alteration to take place.
Thus, Mellof found ground pottery, felspar, and Cornish stone become
plastic on heating with water under pressure to a temperature of
300° C. for several days, but china clay and flint are scarcely affected.
The finer a substance is ground the more complete is its reaction with
water, because a small particle has a greater surface in proportion
to the water than a coarse one. If the particles are sufficiently fine,
water may, indeed, act in a similar manner to a caustic alkali; thus,
very finely divided silica becomes colloidal when brought into contact
with boiling water, just as coarser particles do when brought into
contact with a boiling solution of caustic potash.

Koerner found that other substances (as alumina) become
sufficiently finely divided in water, but their power of cohesion is
lost on drying, and suggested that the plasticity may be brought
about in a similar manner. This would explain why it is impossible
to produce highly plastic clays from kaolin.

As many organic substances possess certain characteristics of
plasticity, several suggestions have been made that these may be the
cause of plasticity in clay. It is found, however, that there is no
definite relation between the plasticity and the proportion of carbon
in the clay, dark coloured clays, rich in carbonaceous matter, being _
no more plastic than lighter ones almost free from this material.

Several observers have suggested that bacteria produce plasticity,
but Hecht and Gosmann have not found sufficient data to warrant
this suggestion, especially as it has not been found possible to increase
the plasticity of clay by inoculation.

Whenever plastic clay is subjected to pressure it tends to obey the
laws of fluids, transmitting its pressure to all parts of its mass
and flowing through an orifice through which it can escape, though
it is far from being a perfect fluid. From this arises the modern
conception of clay as a very viscous liquid in which every particle
of solid matter is surrounded by a film of liquid, so that the particles
are virtually in a state of suspension, and hence, that a plastic clay is,
at any rate in part, in a colloidal condition.

As far back as 1872 Schloesing* suggested that the plasticity of
clay was due to its colloidal nature, and claimed to have found an
amorphous material of the same composition as kaolin which had
all the characteristics of a colloid, and was termed by him argile
colloidale. Very little notice was taken of this suggestion or of the

* This has more recently been confirmed by Cohn and Atterburg, who found

that precipitated barium sulphate and calcium fluoride are both plastic when
fresh.

129

allied work of other observers until 1896, when Rohland® investigated
the subject further, and found indications that the colloidal nature
of clay appeared likely to explain many of the facts noted in regard
to plasticity.

The nature of the colloid material apparently existing in many
clays has already been described. In attempting to explain plasticity
as being due to these colloids, it is assumed that some or all of the
pores of the clay are filled with a colloidal solution (gel) obtained
by the partial hydrolysis of the clay, and that the larger the
proportion of pores so filled, the fatter and more plastic will be
the clay, provided the proper ratio of granular material to colloid
gel is retained.

Rohland® and others have further shown that the addition of
trifling amounts of electrolytes often produces great changes in the
plasticity of a clay, and suggest that this characteristic of colloids is
a strong argument in favour of the connection between the colloidal
material in clay and plasticity. All electrolytes (such as acids) which
yield hydrogen-ions on dissociation, increase the plasticity of clay,
whilst those (such as alkalies) which yield hydroxyl-ions make a
clay more fluid.

Plasticity is not, however, entirely due to the presence of colloidal
matter in clays, though the effect of colloids in increasing plasticity
cannot, be denied. Hermann and others maintain that the presence
of inorganic colloids in clay has never been conclusively proved. It
should be noted that clay may be suspended in water and then
precipitated or deflocculated indefinitely without impairing its
plasticity. This is not usually the case with true mineral colloids,
which usually set irreversibly and do not return to the colloidal condi-
tion. Moreover, the whole of any individual clay grain is not softened
upon the addition of water. Repeated wetting and pugging does
not materially alter the size of the grains or change their general
outline or appearance. This would not be the case if the clay were
softened and reduced to a homogeneous mass, wetted, and subse-
quently broken up with the formation of new grains when it was
dried and ground. Whether wet or dry, under the microscope, the
grains retain the appearance of a sharply-defined body.

Another difficulty has been pointed out by J. M. van Bemmelen,
viz., the rapidity with which colloids lose their power of absorbing
water. This suggests that clays of great geological age cannot contain
active colloids produced when the clay was formed, though they may
contain colloidal substances derived from adventitious materials—
organic or otherwise—at a comparatively recent period, The fact
that many highly plastic clays appear to be free from such extraneous
colloids only increases the difficulty regarding the latter as the cause
of plasticity. Other objections of equal or greater weight may be
urged against any single theory yet published on the causes of
plasticity so that much further work requires to be done.

Summarising the results of the numerous theories and experiments
made, plasticity may be said to be due not to one, but to several
causes, the chief of which are :—

(i) The nature of the molecules of ‘“ true clay ” present.
a 11454 I

130

(ii) The extremely small size of the particles, their lamellar
shape, large surface (due to their porosity), and (possibly) their
fissile character. In such small particles, the phenomena of
cohesion are quite different from those in larger particles.

(iii) The hydrolysing action of water on the particles and the
probable production of inorganic colloid matter. If this is absent
or neutralized by hydrogen-ions added purposely or occurring
naturally or through fermentation of the organic matter in the
clay, the plasticity will continue to increase until an excess
of hydroxyl-ions is again produced; when the concentrations
of hydroxyl-ions is large, the negatively charged clay particles
will go into suspension. As the extent to which water can be
dissociated is very limited, the plasticity of the clay can only
be increased at so slow a rate that it is unlikely that slightly
plastic clays (kaolin) can ever be made highly plastic by artificial
means, though the increase in plasticity may be sufficient to
show the nature of the reactions which take place.

(iv) The presence of organic colloid matter due to impurities
in the clay, or added purposely, may still further increase the
plasticity.

(v) The presence of minute quantities of soluble salts may
exercise a pronounced effect on the plasticity. Their action has been
mentioned under Viscosity (p. 121). Plasticity appears to be a
resultant of several properties (see also Cohesion, Adsorption, Tensile
Strength, Binding Power, &c.).

To increase plasticity—The limits within which the plasticity of
clay may be increased by the addition of soluble salts are very small,
but there is such an abundance of naturally plastic clays that it is
only where materials of exceptional purity are required that an
increase in plasticity is desirable.

A small increase in plasticity may be obtained :—

(1) By increasing the hydrogen-ions in the material, by
allowing the organic matter in the clay to decompose (ferment)
and become acid, by adding weak acid, or by keeping the clay
in intimate contact with fresh water by stirrmg the two together.
‘This appears to hydrolyse the clay and forms colloid matter on
the particles. It is important to have the particles of clay
‘as small as possible in order to facilitate the hydrolysis. It
‘water alone is used for this purpose, the clay must be allowed
to stand until fermentation of the organic matter begins, and
the mass reacts faintly acid. In any case, the time required
for an appreciable increase in the plasticity may be several
years. No addition of any electrolytes or substance other than
plastic clay can increase the true plasticity of a paste chiefly
composed of non-plastic materials. Many of the so-called “ lean
clays” are of this nature; they are rich in inert matter, but
the proportion of colloidal matter in them is very small. Such
clays can only be made more plastic by removing a large
proportion of the inert matter naturally present in them or by

131

the addition of a highly plastic clay. The addition of electrolytes
to such clays is only of value when their low plasticity is due
to the clay gel present having become hardened or coagulated,
but is still capable of being revived or deflocculated by means of
an electrolytes or other simple treatment.

(2) By keeping the clay in a moist damp cellar. This is
termed “ ageing ”’ or “ souring.”’

(3) By the addition of colloids such as colloidal silica, alumina,
or iron hydrate, hot starch, dextrin, tannin, rubber, sumach,
inulin, caramel, gelatin, gum, glycogen, or various ferments and
enzymes, the plasticity of the clay may be increased, but care
must be taken to avoid confusion between true polasticity and
the pseudo-plasticity caused by the addition of materials of an
oily, gelatinous, or gummy nature.

Some very interesting experiments. by Acheson and Ries
on the effect of a 2 per cent. solution of tannin (gallotannic acid)
on clay show that the addition of this substance notably increases
the plasticity of clay, and at the same time apparently
deflocculates it and breaks it up into finer particles. The tensile
strength of the clay was nearly doubled.

In a later patent, Acheson first adds tannin and alkalies or
ammonia and stirs the clay into a fluid state, and then by the
addition of a suitable quantity of acid he coagulates the colloids
and forms a stiff paste.

(4) By reducing a sufficient number of particles to so minute
a state that they assume colloidal properties in the presence
of.water. Thus, by very prolonged grinding with water many
hard clays! become appreciably more plastic.

The softer materials become exceedingly smooth and plastic ;
the harder ones yield less readily to the treatment, but still
develop marked pasticity, very similar to that of normal clay
heavily overloaded with sand or grog.

By selecting the materials and method of grinding, many
degrees of plasticity may be obtained, from that of a very
smooth plastic clay to that of a very short sandy clay, indicating
that the difference is one of degree and not of kind, the essential
characteristics being that the clay or other materials shall occur
in a state of very fine subdivision, and that their surfaces are
readily wetted by water. The chief practical difficulty lies
in grinding sufficiently fine, as the smallest particle that can
be seen under the microscope does not by any means represent
the limit towards which the grinding should proceed. The
plasticity produced by artificial grinding depends on the size
and shape of the particles, and only indirectly on the materiak
of which the plastic mass is formed.

To reduce plasticity—(1) Hydroxyl-ions may be added and the
temperature raised (direct reduction). (2) Non-plastic material may
be added so as to spread the plasticity over a larger volume of material

1 Plastic material has been formed in this way from slate, plaster moulds,
iron ore, ashes, lava, limestone, sandstone, burned brick, silica, mica, felspar,
and even glass.

132

(indirect reduction or dilution). (3) The material may be heated to
200° C. or other suitable temperature.

For the first method, any basic material, either organic or inorganic,
may be used though lime water is the cheapest. If lime is too weak
in hydroxyl-ions, caustic soda may be used, as may any salt composed
of a strong base and a weak acid, such as sodium (or potassium)
phosphates or silicates, all of which readily hydrolyse and yield
hydroxyl-ions, though the cation constituent of the salt may exercise
a considerable effect. Thus, borax reduces the influence of the
hydroxyl-ions and potassium carbonate increases it, yet both are
salts composed of a strong base and a weak acid. The concentration
of the alkaline or basic material added is also of importance, and it
may be necessary to render sulphates and other soluble salts insoluble
by the addition of baryta, as suggested by Weber. Certain clays,
as Weber has shown, act in precisely the reverse manner. These are
free from sulphates, and appear to be rich in colloidal matter.

Certain clays containing organic acids of a fatty nature are saponified
on treatment with alkali, and the soap so produced increases, instead
of diminishing, the plasticity, owing to the coagulation effected.

The reduction of plasticity by raising the temperature considerably
is described later. A comparatively small rise in temperature produced
by the action of mechanical stirrers—will reduce the plasticity of
clay if free hydroxyl-ions are present.

The addition of non-plastic material, such as sand or grog, effects
a reduction of the plasticity in an entirely different manner, by
separating the clay particles from each other. It thus reduces the
strength of the material, but by diminishing the shrinkage, it enables
the clay to be used in a manner which would, otherwise, have been
impossible, and the strength is seldom reduced sufficiently to make
any notable difference to the user of the material. The proportion
of non-plastic material to be added depends on the size of its grains
and on the binding power of the clay. As the latter is closely connected
with its plasticity, it will usually be found that the more plastic the
clay, the larger the proportion of non-plastic material which may
be used.

Some sands are quite useless for this purpose, so that great care
is needed in their selection. For some clays, chalk, flints, or grog is
preferable to sand.

The measurement of plasticity is a problem which has not yet been
satisfactorily solved, probably for the reason that plasticity is the
result of the united action of several forces some of which may not,
as yet, have been recognised as important. Early attempts to measure
plasticity usually resulted in only measuring one or more of these
forces. Thus, Bischof added sand until the mixture was so soft that
it could be rubbed away between his finger and thumb. Bischof’s
figures are, however, a measure of the binding power of the clay, but
not of its plasticity. Measurements of tensile strength, viscosity, the
amount of water required to produce a mass of given consistency,
the consistency, or the depth to which a Vicat needle will penetrate,
Sokoloff’s slaking test and other single characteristics are all useful
ia their way, but they fail to include all the properties involved in the

133

use of the term “ plasticity.’”’ Zschokke, who has examined the
subject very fully, considers that the percentage of extensibility
multiplied by the tensile strength of a freshly moulded clay cylinder
of standard size (60 mm. high by 30 mm. diameter) is a coefficient of
the plasticity. Modifications of this method have given excellent results
in the hands of several experimenters in different countries and with
a very large variety of clays. Grout considers that plasticity is
proportional to the product of (a) the load required to sink a Vacat
needle to a definite depth in a mass of clay; and (b) the deformation of
the clay under stress, which he measures by the increase in area of
a clay cylinder produced by a load which just causes eracks to appear.
Both Zschokke and Grout?’ really consider plasticity to be measured
by the product of the deformability and force resisting deformation,
though they differ in the manner in which they measure these forces.
More recently, Ashley? has adopted the same general idea as to the
forces involved, but has assumed that the force-resisting deformation
is exerted by the colloids in the clay. He, therefore, regards the
plasticity of clay to be measured by the ratio :—

Relative colloids x the shrinkage of the clay
Jackson-Purdy surface factor.

The term ‘relative colloids”? is explained in the section on
Adsorption.

As the ratio of the surface factor to shrinkage is approximately
constant, Ashley concludes that the plasticity of the clay is directly
proportional to the colloids present. The objection to this conclusion
is that it appears unlikely, from other considerations, that the whole
of the plasticity is due to the colloidal matter.

Rohland’, also assuming that the colloidal matter in the clay is
the chief factor of the plasticity, has suggested that the ratio obtained
by dividing the coagulable colloids by the non-coagulable material
is a measure of the plasticity. He ascertains it is by measuring the
amount of water required to make the clay into the consistency of a
good modelling paste, and argues that this is a-measure of the colloids
because as soon as sufficient water is present to dissolve the coagulable
colloids, a saturation point is reached and no more water can be
absorbed without the clay iosing its stiffness. ,

Stormer has stated that plasticity may be judged by the following
characteristics :—

(1) The proportion of water (absorption) which must be
added to the clay to make a good modelling paste. This is not
always reliable.

(2) The “ feel ’ of the paste when rubbed between. the finger
and thumb (binding power).

(3) The behaviour of the paste when rolled up into a
““ sausage ”” (toughness).

(4) The adhesiveness of the clay (adhesion).

(5) Twisting a piece of clay into a spiral and noting its
behaviour (torsion). Metts a

134

(6) Noting the length of the threads, produced by expressing
the clay from a vertical pug mill, before they break off by their
own weight (tensile strength and extensibility).

(7) Forming balls of clay and pressing them until the edges
crack (crushing strength).

(8) Bending cylinders of clay into a ring (bending moment).

None of these characteristics taken alone can give a measure of
the plasticity of a clay, though several of them are closely related
to each other. The most reliable measure of plasticity appears to
be that devised -by Zschokke (p. 133) or by Rosenow, who multiplies
Zschokke’s figure by the percentage of water added to the dry clay
to make it into a workable paste, 7.¢., by Rohland’s figure (p. 133).

The binding power of a clay is the property it possesses of uniting
with non-plastic material and water to form a uniform plastic paste,
and is consequently closely related to the plasticity. This absorption
of non-plastic material with the spread of plasticity throughout the
whole mass has been attributed to the power of the saturated colloids
(gels) to retain the non-colloidal particles in a state of pseudo-solution.
Other colloids are known to possess ‘the property of preventing insoluble
matter from settling, and this is, in some senses, a parallel case. The
binding power of a clay may be determined by measuring the tensile
strength of mixtures of clay with varying amounts of sand, but a
skilled clayworker can tell by the “ feel” whether such mixtures are
strong enough to be useful. In order to determine how much lean
clay or non-plastic material can be added to a clay without unduly
destroying its value for moulding into shape, Bischof’s test may be
used. In this, the two materials are mixed in various proportions
and the same measured quantity of water is added to each. The
pastes are then rolled into small balls as equal in size as possible, and
allowed to dry. They are then rubbed gently between the finger and
thumb, or with a small “‘ camel hair”? brush. The mixture which
just resists the action of rubbing may be taken as the standard.
Some authorities make up balls of mixture in this way and then
notice to what length a cylinder can be rolled from each without
cracking.

Clays with a high binding power are known technically as “ fat ”
clays; ‘‘lean”’ clays are deficient in binding power.

Some writers appear to consider that binding power and plasticity
are synonymous; this is by no means the case, as a clay may be very
plastic and yet not be able to bind much non-plastic material into
a uniform plastic paste. At the same time, there is clearly some
relationship between these two properties of clays.

The dehydration of clays is accompanied by changes which are
remarkably similar to those which occur in the dehydration of colloidal
gels. The most important of these changes is the shrinkage or
contraction of the mass, the production of a hard material which—
if the dehydration is accomplished. by heat—may result in, the
production of a material comparable to an irreversible gel.

Plastic clays, like colloidal gels, shrink greatly when dehydrated
and possess both a drying-shrinkage and a kiln-shrinkage. By mixing

135

an inert substance, such as sand, with a true colloid the shrinkage
is lessened, and the cohesion of the dried colloid, including its
adhesion to inert substances, are the causes of the increased
mechanical strength of many such mixtures. This is another charac-
teristic common to colloids and to all plastic clays.

As there is no wholly reliable method of measuring plasticity
(see p. 124), it is not possible to state precisely what relationship
exists between the plasticity and the shrinkage of clays. Speaking
broadly, the most plastic clays shrink more than those which are
less plastic, but this is not invariably the case. For instance, the
Lias clays usually shrink less than would be expected from their
plasticity.

When articles made of plastic clay are dried under suitable condi-
tions, they contract equally in all directions, the contraction in volume
being almost three times the linear shrinkage. Excessively plastic clays
erack, or twist, when dried and many moderately plastic clays will do
so if dried irregularly or too rapidly.

When water is added to a dry clay, it is first absorbed by the pores,
but, when these are filled, any further supply of water appears to cause
a separation of the particles from each other so that the volume of clay
is increased, though not in proportion to the water added. The
amount of water which can be absorbed in this manner differs greatly
with different clays. The stage at which the clay contains the
maximum quantity of water without loss of shape is also the point
of maximum plasticity; it is said to be the “ point of saturation
of the coagulated colloids (gels) in the clay.’ If some of this water
is removed, the volume of the mass begins to diminish and contraction
occurs. This contraction or shrinkage is chiefly, but not entirely,
due to the removal of water from the clay by evaporation at the
ordinary temperature (air-shrinkage), at a somewhat higher tempera-
ture in the dryer (dryer-shrinkage), or during the burning (kiln-
shrinkage).

As all coagulated colloids (gels) which are saturated with water
shrink when the water is removed, some investigators consider that
the shrinkage of clay may be due in part to this cause.

The more general idea (which states facts rather than explains them)
is that, as the water is removed, any whith remains draws the clay
particles together into a smaller and denser mass.

The amount of shrinkage appears to depend partly upon the rate
‘at which the clay is dried, for if this operation is performed rapidly
the shrinkage will be less, the clay particles not having time to move
over each other so freely as when the drying is slower. When drying
a strong, porous clay, the water first evaporates from the surface
and is replaced by capillary action from the interior, the mass
contracting by the same amount as the water diminishes. All the pores
remain filled with water until the rate of evaporation exceeds the rate
at which the pores will transmit water. This point occurs, when
the clay particles move so much less freely on each other that the
rate of evaporation exceeds that of the contraction. After the first
stage of surface-drying, the exterior loses water more rapidly than
the interior; in the second stage the pores are no longer filled with

136

water at their outer ends and begin to form spaces in the clay, these
spaces being filled with air and water vapour. Contraction still
occurs throughout this second stage until the substance is so far
solidified that the individual particles can no longer slip over each
other at all. The third stage is then reached in which capillary action
and shrinkage cease entirely. Evaporation now takes place entirely
within the mass, and spaces are formed exactly corresponding to the
water lost. That shrinkage ceases before the clay is completely
deprived of water is shown by Aron and Brogniart to be characteristic
of many, but not of all, clays. Aron supposed that the clay shrinks
until the particles are practically in contact with each other, so that
any further water which may be driven off does not make any notable
difference in the volume of the clay; but supporters of the colloid
theory argue that the heat used in drying really cause the colloid
particles to shrivel, thus reducing their surface and increasing their
density. Aron has further shown that the “ pore space”’ is constant
for each kind of clay,:and is independent of the amount of water of
formation added to the clay, though this last statement is only true
of the purer clays.

If, now, the pastes made with varying amounts of water of
formation are subjected to exactly the same conditions of drying,
the rate is not proportional to the water added, but is slower in
proportion for those with less water. It takes, approximately, the
proportional time in the first two stages of drying, but the more solid
the mass the longer it takes to eliminate the last portions of the
water. It follows also from this, that want of uniformity in the
substance of a mass of clay, such as must exist in bricks made by
hand, and in a less degree in those made in a press or die, causes a
corresponding want of uniformity in the shrinkage and the rate of
drying in different parts of it. This is one cause of the warping or
twisting of bricks in drying.

In the second stage of drying, all clays lose water more rapidly on
the outside than on the inside, the angles and arrises in their turn
drying more rapidly than the faces. The consequence of the greater
shrinkage of the outer layer is a frequent cause of cracking, and it
is, therefore, necessary to pursue this stage with great caution and
to effect the drying with air already heavily charged with moisture.
It is also essential, for this reason, to avoid the excessive prominence
of any part of a complex-shaped article, and it is advisable to follow
any projections on the exterior with hollows on the interior, so as
to maintain an approximately regular thickness of material throughout.
The frogs or indents on both sides of a common brick are serviceable
in drying for the same reason. In a re-pressed brick, they serve the
additional purpose of rendering the consistency more even throughout.

For objects of reasonable size, the rate of drying is approximately
proportional to the ratio of surface to volume. Objects of large size,
however, take much longer to dry, and require the application of
considerable heat to complete the removal of all the water of manu-
facture from the interior. Many large goods made of fireclay and
stoneware clay require extremely careful treatment, and have to
be kept in a heated atmosphere for several days after the moisture

137

has apparently been completely removed. Disastrous results have
frequently been known to occur in the steaming operations in the
kiln for want of sufficient care in this particular. Manufacturers
frequently adopt a very wise precaution in having such goods
stamped with the date of making, and in holding their workmen
responsible if they are rendered unsound by being burned before
the lapse of a stated period of drying.

In order that the goods may not twist or warp when drying, it
is essential that they should shrink very little. This means that
only a limited proportion of plastic clay can be used in the material,
although some is necessary to bind the particles together and to
give it the general characteristics of “clay.” With a carefully
compounded mixture, the contraction of the paste prior to entering
the kiln should not exceed 1 inch in 16 (or ? inch per foot). If it
does so, more non-plastic material must be added. The lower the
contraction, the better the chance of the ware coming “ true” out
of the drying rooms; hence, as much non-shrinking material as
possible should be used in the clay mixtures, so as to keep the contrac-
tion at a minimum. The addition of a non-plastic material to a
clay enables less water of formation to be used, and so reduces the
shrinkage, but Aron has shown that if the amount of water is kept
the same as for the clay alone, the addition of non-plastic material
will increase the contraction which occurs on drying, until a certain
point (that of maximum density) is reached. After this, the more
“grog” added to the clay the less will it shrink, and the greater
will be the porosity. The nature of the non-plastic material added
will also affect the shrinkage to some extent, and will exercise a
considerable influence on the amount of water which must be mixed
with the clay. Thus, a porous, burned clay will absorb more water
than will sand. Provided the non-plastic material is of a nature
suitable to the clay (this must be determined by actual experiment),
it may be added in any desired proportion so long as it does not too
seriously reduce the strength of the mass, as it will do if more is added
than the binding power of the clay can accommodate.

The porosity of a dehydrated clay appears to be due to the
capillary structure of the material.

Other properties which clays in the plastic state possess in common
with colloids are :—

Unctuousness, or a smooth, almost greasy, “ feel,” is a characteristic
of some clays, a few being so oleaginous that they may be saponified
by treatment with caustic alkali, the plasticity being thereby increased.
In most cases, however, such treatment makes the clay more fluid.

Toughness, or cohesion, is closely allied with (1) extensibility, or
the ability of clay to stretch when pulled, which is measured by
ascertaining the fullest extent to which a clay test-piece of a given
size will stretch without breaking; (2) torsion, or the extent to which
a piece of clay can be twisted, which is measured by. clamping one
end of a bar of clay as rigidly as possible and rotating the other slowly
by means of a screw, counting the number of complete revolutions
which can be made before the bar breaks; (3) bending moment, or

1338

the angle through which a bar of clay can be bent without rupture;
(4) elasticity, or the extent to which a piece of clay can be stretched
and yet return to its original length when the tension is removed.
Many plastic clays show slight elasticity, though it is usually too
small to be measurable.

The tensile strength of a clay is its resistance to torsion or to being
pulled apart. The non-plastic materials influence its strength
inversely as the diameter of their grains, so that fine-grained clays
will usually be the strongest, though an excess of very fine or very
coarse grains will cause the clay to break prematurely. In support
of the theory that the grains of clay interlock to some extent, Ries
found that mixtures of two clays can be made which have a higher
tensile strength than either clay taken separately. This fact has
long been known by the makers of crucibles for steel-melting in this
country, as many as four different clays being sometimes used to
produce a sufficiently strong crucible. The tensile strength of the
clay has, in fact, an important bearing on its resistance to accidents
in the process of manufacture, particularly from the commencement
of drying to that of firing. It has sometimes been stated that the
tensile strength of a clay enables it to carry a large quantity of
non-plastic material, but this is rather confusing the effect with the
cause. It is the binding power of the clay which enables it to carry
such a large quantity of added material and still retain a sufficiently
high tensile strength. Olschewsky has proved that there is no direct
relationship between the binding power of a clay and its tensile
strength when dry. It was at one time thought that the tensile
strength of clays is proportional to the plasticity, but this is only
true, if at all, when the pieces are tested in the moist (plastic) state.
If air-dried, the definite relationship ceases.

The tensile strength of dried raw clays depends on the proportions
of the grains of different sizes. Equal-sized grains cannot be packed
into a dense mass. An excessive proportion of the finest clay particles
or a large percentage of sand grains (0-5-1:Omm.) weakens the
strength of an air-dried clay.

Fissility—or capability of being split up into thin slabs or flat
pieces, or even into flakes or foliations—is characteristic of many
indurated clays, especially of shales. If the splitting can be effected
sc as to form plates of extreme thinness, the material is said to be
laminated; if the tendency to split_is strongest in the direction of
bedding, the material is termed shaley; if this tendency is strongly
marked in any other direction it is said to be fissile, as are slates and
certain limestones and sandstones.

Sectility, or capability of being easily cut, is a characteristic of
clays which occur in a plastic condition, such as ball clays and many
surface clays. This property often serves as a means of distinguishing
“clays ” from other minerals, though the “ clays”? so found may be
too impure to be of any commercial value. Anyone constantly
engaged in examining clays soon learns to recognise some varieties
by their sectility and by the slightly glossy appearance of the freshly-
cut surfaces, though these cannot be clearly described.

139

The effects of age on a clay paste are similar to those on colloidal
gels, provided the conditions of storage (including the low temperature
and a sufficiently humid atmosphere) are favourable. The plasticity
of the clay is slightly increased and the colloidal properties are more
marked.

From the foregoing, there appears to be a close parallelism between
the more important properties of plastic clays and those of other
colloids, but the question still remains as to whether these colloidal
properties are due to the nature of an essential constituent of clays
(clay substance) or to other colloidal substances which may be present.

Other Colloids in Clay.

The most important colloidal substances which are known definitely
to exist in some clays are :—

Colloidal silica, which may exist in the form of a silica hydrogel,
with or without occluded silica hydrosol, the latter being confined
to any liquid portions of the clay paste, but distributed more or less
uniformly throughout the clay slip. Various mineral forms of silica
which are hydrogels are known; they possess the anticipated
properties of inorganic gels and their nature is fairly well known.
A small percentage of colloidal silica may be extracted by boiling
some clays with water, with or without the addition of a little sodium
carbonate, but in no clay of commercial importance is the amount
of silica obtainable so large as to account for the whole of the

_ plasticity of such clays, though it may partly do so.

Wolfgang Ostwald” holds the view that silicic acid sols are hydrated
emulsoids, i.e., the dispersed silicic acid is a liquid and not a solid.
Like other known emulsoids, its viscosity is high and rises very
rapidly after a given concentration whilst in suspensoid sols the
increase of viscosity is steady throughout and the viscosity is very

low. He also states that the silicic acid gel differs from the better
known organic emulsoids in possessing little elasticity.

Attempts to increase the plasticity of sand by mixing it with silica
_hydrosol, and coagulating the latter, do not produce a material at

all closely resembling plastic clay. Such a mixture, when dry, is
_ deficient in strength and even in its most plastic state it is inferior
_to clay for modelling purposes. <A’ still more striking difference
_between such a mixture and a clay is that when both are dried at
105° C. and afterwards mixed with water, the clay forms a plastic
paste with all its original modelling power restored, but the silica-
sand mixture is not “ workable ” or truly plastic.

Silica gels have a peculiar property of varying according to their
| age as well as according to the mode of formation. When a clay
_is soured, the proportion of silica gel tends to increase, but if soured
_too long the silica gels grow together forming larger particles and

cause a diminution in the plasticity of the mass, the vapour pressure
in the old gel being greater than in the new one. .
_ _A. Cushmann?* found that the addition of dried colloidal silica
gel to a dry clay, the mixture being afterwards made into a paste

140

with water, increased in binding power and shrinkage, but not in
plasticity, whilst colloidal alumina, when similarly treated, increased
in plasticity but not in binding power and shrinkage. A mixture of
colloidal silica and alumina, made by adding a solution of water-
glass to one of alum, increased both the binding power and the
plasticity of a clay. Grout repeated this experiment, but obtained
a negative result.

On drying the silica gel, the volume decreases to a characteristic
point (Van Bemmelen’s’® “ transition point ’’), after which it remains
constant. On further dehydration, the clear gel becomes turbid and
eventually chalk white, but becomes clear again when the water
content is reduced to less than one molecule. The addition of water
causes little change in volume. At low red heat the gel is completely
dehydrated and strong ignition prevents the gel from again taking
up water. Any salts present cause the gel to lose its power of taking
up water more rapidly. Salts are also favourable to local fusion and
destruction of the gel. These characteristics are equally characteristic
of plastic clays.

Colloidal alumina, of which a small and variable proportion occurs
in many clays, especially those known as laterites. Colloidal alumina
has a very curious and variable effect on the clay. In some cases,
it behaves as an acid easily combining with bases to form salts, whilst
under other conditions it acts as a base combing with acids. It is
soluble in both acids and alkalies forming different compounds in
each case. The gel has a particularly low water content, having only
about 24 per cent. more than is required to form the hydrate, a fact
which is very unusual, as most mineral gels have a very large proportion
of free water which can be removed on drying. In most of its
physical properties, such as shrinkage, swelling power, &c., it is
similar to silica.

Mixtures of sand and alumina hydrosol, treated so as to coagulate
the latter are somewhat plastic, but would not be acceptable to
clayworkers as a substitute for plastic clay.

Colloidal Ferric Hydroxide has been isolated in very small quantities
from some ferruginous clays, but clearly cannot be an important cause
of plasticity in clays which are almost free from iron compounds.
Like silica, ferric hydroxide sols increase in viscosity with the concen-
tration. The surface tension of ferric hydroxide sol is the same as that
of water and the electric conductivity was observed by Malfitano
to be 200 x 10~*.

Colloidal ferric hydroxide particles carry a positive charge, 7.e.,
that opposite to that of colloidal silica, so that the two substances
mutually precipitate each other. This accounts for some siliceous
minerals and clays having a thin coating of iron which also partially
fills the interstices. A very peculiar fact with regard to colloidal
ferric hydroxide is that it is entirely free from the inky taste which
is so characteristic of ordinary iron compounds, and it has no reaction
with potassium ferrocyanide (the Prussian blue test which is the most
characteristic test for iron), whereas yellowish china clays when
treated with ferrocyanide become whiter owing to the Prussian blue

141

colour being complementary to the yellow tinge caused by iron
compounds in the clay. The proportion of water present in colloidal
ferric hydroxide is very variable; it parts with water on drying in
a similar manner to silica though it is much more irregular. The
variable proportion of water probably explains the variable colour
to different clays containing iron compounds.

Various colloidal silicates have been found in small quantities in
some clays, though absent in many highly plastic clays. The only
exception to this is a possible “ silicate of alumina ” or more correctly
“ alumino-silicic acid” (or series of such acids), which appears to be an
essential constituent of clays and may be the origin of the colloidal
substance to which they are supposed to owe their value.

Colloidal organic matter, chiefly humus, may play an important part
in giving to clays their characteristic properties, but as some well-
known highly plastic clays are almost devoid of carbonaceous matter,
the latter cannot be the chief cause of their plasticity. Moreover,
the addition of certain organic colloids to feebly plastic clays does
not increase their true plasticity, though it may increase the cohesion
and stickiness of the particles.

From the foregoing it may be assumed that the characteristic
properties of clays are not due to colloidal silica, alumina, ferric
hydroxide or organic matter, or to colloidal silicates of the alkalies
or alkaline earth metals, though when any or all of these are present
they may slightly increase the plasticity, or otherwise modify the
properties of the clay.

To what Colloidal Matter do Clays owe their Character ?

It has been suggested in the foregoing pages that the more
important properties of clays may be due to the presence of colloidal
matter in them. It has been shown that colloidal matter does exist
in clays and that many of the characteristic properties of clays are
equally characteristic of colloidal gels, though none of the latter
possess all the properties of a valuable plastic clay. The question
therefore arises, as to whether the so-called colloidal properties of
clays are merely coincidental with the composition of clays, or
whether plastic clays contain some substance or substances not
hitherto identified as a colloidal gel.

There can be no doubt that most plastic clays contain a large
proportion of non-plastic and non-clayey material and may be
regarded as diluted clays. Some of the most highly plastic clays,
on the contrary, consist of such small particles that the non-clayey
matter cannot be satisfactorily separated. On the one hand, attempts
to separate an ideal ‘“‘ clay substance’ by chemical or mechanical
methods have resulted in a material which is almost devoid of plasticity,
and on the other, attempts to show that clays are essentially colloidal
have not satisfactorily produced any definite colloidal substance
which can be regarded as clay. We are, therefore, compelled to
realise that many of the more important properties of clays are due
to the colloidal nature of the material, though clays are not wholly

142

colloidal, and that this essential colloid has not been identified. In
so far as it does exist, it appears to be (a) a colloidal alumino-silicic
acid widely distributed through a mass of inert granular material of
the same chemical composition or even of an entirely different one,
such as sand, the whole being comparable to a freshly-made concrete,
but differing from the latter in requiring heat to “set” it. Alter-
natively, (b) the colloidal material may be a mixture of colloidal
silica and colloidal alumina precipitated simultaneously from the
sol state in such a manner as to appear to be a definite chemical
compound. This possibility can only be confirmed or disproved by
a large amount of experimental work which is not yet completed.
The chief difficulty in accepting the alternative hypothesis is that,
if it were correct, it should be possible to isolate relatively large
quantities of colloidal silica and alumina from such highly plastic
and relatively pure clays as the ball clays, but this has not been
accomplished. This may be rendered difficult or impossible by the
mutually coagulated silica and alumina gels behaving as a compound
in which the silica and alumina have so great an affinity for each
other that they cannot be separated by means applicable to the
isolation of the simpler gels. Finally, (c) as almost any material may,
by suitable treatment, be converted into the colloidal state, the
characteristic properties of plastic clays may be independent of the
chemical composition of the colloidal matter present in them. If this
were the case, any mineral substance which could be converted into
colloids by the natural agencies to which clays had been subject
would be possible sources of clay. This explanation has the great
advantage of explaining the small proportion of colloidal matter
present in even the most plastic clays, as if such colloidal matter
were the result of age-long grinding of minute rock particles under
water, it is only natural to suppose that the product of such action
would be grains of the original rock surrounded by a film of colloidal
material. If, on the contrary, clays are produced by mixing colloidal
matter (formed separately) with non-plastic grains, it is most likely
that considerable quantities of such wholly colloidal matter would
be found in small pockets or fissures in clay beds. This does not
appear to be’ the case.

If any or all of these three alternatives were correct they would
explain many of the known properties of clays. Both silica and
alumina gels readily become irreversible; even when prepared under
the most favourable conditions they are much less “ manageable ”
than many other colloids. Hence, it is only to be expected, that if
a complex gel containing both silica and alumina in intimate admixture
or even in a state of combination would be extremely difficult to
isolate in an approximately pure state.

The conditions, under which clays are formed from felspar and
other silicates, are so varied, that they do not throw much light on
the nature of clays. China clays in Cornwall appear to have been
formed by the action of water and acid vapours on granite at a high
temperature, the felspar present being decomposed into soluble
potassium silicate which has, presumably, been removed in solution,
insoluble quartz and clay, the clay being readily separated from other

143

detritus by a slowly moving stream of water. This explanation—
though widely accepted—is by no means satisfactory, and if it is
assumed to account sufficiently for the low degree of plasticity of
china clay it does not explain the high plasticity of Devonshire ball
clays not many miles away, unless the latter are presumed to
have no connection with the Cornish clays. Rohland®, on the
contrary, attributed the low plasticity of some kaolins to the colloidal
clay having been largely removed in the sol state.

So far as can be ascertained at present, the colloidal material to
which clays appear to owe their characteristic properties has been
produced by the very prolonged action of water on rocks, chiefly
those composed of one or more alumino-silicic acids, the precise
nature and origin of which is still uncertain, though represented
roughly by the formula H,Al,Si,O, in the case of Cornish china clays,
Dorset and Devonshire ball clays, and possibly of other less pure
clays. This colloidal constituent of clays appears to be a very finely
divided, solid cellular substance* which can absorb water like a sponge
and thereby form a kind of jelly which retains the water by capillary
attraction and only permits it-to evaporate very slowly at the ordinary
atmospheric temperature. Consequently, the proportion of water
present in a clay paste of given consistency is a rough measure of the
colloidal matter present and when precisely similar clays are compared,
it may also be a measure of the plasticity of the paste; the latter
property is partly due, however, to the size of the grains coated by
the colloidal material and by the thickness and other physical
characteristics of the colloidal coating and the extent to which it
penetrates any pores or interstices in the granular material. If such
a colloidal material were isolated, it would apparently be peptised by
a dilute solution of alkali, or by lime water, and recoagulated by strong
acids. On heating, it would first contract greatly and simultaneously
part with a considerable part of its absorbed water. On further
heating up to 500° C. or above, it would be decomposed with the
evolution of water and the formation of an irreversible material
largely colloidal in character, though different in many ways from
most well-known colloids. On further heating,it might undergo other
changes, the nature of which can only be summarised as including
polymerisation, but one product which under favourable conditions
may be expected to be formed is crystalline sillimanite, Al,O,Si Oy.
When heated with caustic alkalies, bases, and most metallic oxides,
the colloid would probably form mixtures of the corresponding silicates
and aluminates. The colloid alone would probably be highly resistant
to heat, but in the presence of a metallic oxide (other than alumina)
it would fuse more readily.

It is comparatively easy to obtain colloidal silica from calcined,
and therefore irreversible, or from the crystalline forms of silica,
but the process is so drastic (including the fusion of the material with
sodium carbonate) that it appears inapplicable to clay, as the latter
is completely decomposed during the heating with the flux and the
final colloidal product is merely a mixture of colloidal alumina and

* It need not, of course, consist cf any one chemical compound; even if it
consisted chiefly of one such compound, it would seldom, if ever, be pure.

144

silica which does not possess the properties of the original clay.
Various other attempts to synthezise “‘ true clay ” have been equally
unsuccessful.

It is generally considered that one of the most important sources
of clays is the mineral felspar which can be obtained in the form of
pure crystals, should form a good starting point. The felspar to
which certain clays are commonly attributed is orthoclase, which
has the formula K,Al,Si,O,,.. This is a minimum formula and may
be more correctly represented by K ,, Al,.Si,,3;0;,... Keeping the simple
form, the decomposition may be represented by

K,AlI,Si,O,,+ 3H,0 = 2K,0 + H,Al,Si,O, + 48i0,,
which assumes that the felspar is a potassium alumino-silicate with
china clay as the corresponding acid, but containing much less silica.
Fireclays, on the contrary, even after such limited purification as
can be effected, often contain more silica, and indicate a slightly
different equation and they appear to have an entirely different origin
both chemically as well as geologically. Unfortunately, this decom-
position of-felspar has never produced clay when carried out in the
laboratory. Water produces under great pressure a white body
which has little or no plasticity, which may be clay, but cannot be
identified as such.

Another attempted synthesis was that of Pukall,?° who decomposed
a pure china clay with sodium chloride and treated the product with
carbonic acid. It then yielded a salt deficient in silica and soda
and corresponding to 2Na,0 4H,O 6A1,0; 10SiO,. The same salt
when treated with a strong acid (HCl) dissolves and from the solution
ammonia precipitates a material which Pukall mistook for synthesized
clay, but which contains rather more hydrogen and oxygen and
dehydrates readily at 350° C. instead of 500° C. Apparently, an
isomer of clay had been formed.

At present, it seems quite impossible to be certain of the composition
of the substance or substances to which clays owe their chief character-
istics. The reporter favours the view (p. 125) that age-long grinding
has produced a film of colloidal matter on grains of non-plastic
material as probably accounting for most clays, but he also believes
that no single cause can account for the formation of all kinds of
clay, and that other explanations, such as those given on p. 126 seq.,
may be equally correct in some cases. The fact that the finer
particles of all plastic clays correspond more or less closely to the
formula H,AI,Si,J, does not necessarily invalidate the theory that
clays are simply a product of intensely ground rocks, as there are
many clays which do not correspond to the formula just mentioned
and some of these which correspond to it more closely are only feebly
plastic. The similarity in composition of materials regarded as
clays may, possibly, be merely a coincidence due to the predominating
proportion of alumino-silicious rocks in the material of which the
earth’s crust consists.

Whatever its nature and origin, it is now fairly well established
that many of the properties of clays are closely connected with the
colloidal matter present, such matter being in the form of a film of

145

colloidal gel surrounding particles which are of a non-plastic or
colloidally inert nature; in some cases, they may be rich both in
alumina and silica—as in china clays and ball clays—whilst in others
they may be almost wholly silicious, as in fireclays and many brick
earths.

The particular kind and amount of gelatinous matter present,
the size and shape of the grains of non-colloidal material, and the
relative proportions of large and small grains are important factors
in determining the various physical properties of clays, particularly
their binding power, compressive strength, tensile strength, and
air shrinkage.

Some Technical Uses of the Colloidal Properties of Clays.

Although the nature of the materials to which clays apparently
owe their colloidal properties is unknown, great use is made of the
properties in various industries, as will be seen from the following
notes :—

In purifying clays and similar substances, the suspension of the
material in water, followed by a process of elutriation or sedimentation,
whereby the coarser impurities are removed whilst the partially
purified clay is carried off in suspension, has been in use since ancient
times. More recently—especially in America—electrolytes, such as
sodium carbonate, caustic soda, &c., have been added to the water
employed, so as to ensure a maximum amount of clay being held in
suspension in a minimum quantity of water. The use of such
electrolytes also ensures a sharper separation of the inert sandy
material present. The suspension is run off into suitable vessels,
the added alkali neutralised by the addition of sulphuric acid; the
clay is allowed to deposit and afterwards removed and dried. The
separation of the impurities is due to the fact that whenever a charged
colloid particle in suspension meets another similarly charged particle
they mutually repel each other and so remain in suspension. When
two particles of opposite charge come into contact, the charge is
neutralised, and the two particles unite and are precipitated. The
electrolyte added must, therefore, be one which will increase the
negative charge of the material as a whole, so as to effect the precipita-
tion of the impurities, (which are chiefly electro-positive) and retain
in suspension the electro-negative particles of clay and, along with
them, some silica which is also electro-negative. The coarser particles
of silica, pyrite, felspar, mica, &c., do not hecome charged, but settle
on account of their size and weight. If the liquid is too viscous,
the impurities will not settle properly, and it must then be diluted
until the density and viscosity are such that sufficient separation
is effected without the loss of clay by sedimentation.

A similar process of purification is used as a preliminary stage
of the Schwerin electro-osmosis process*!, but instead of the clay
being allowed to settle it is caused to migrate to a rotating electrode
immersed in the liquid and is scraped off in the form of a stiff paste.
Schwerin found that all clays did not behave thus, and only migrated

so when they carried an electric charge. This charge is supplied,
a 11454 K

146
in some cases, by the addition of organic colloidal matter, such as
humic acid prior to the use of alkali.

The apparatus for treating clays consists of a wooden trough
with one electrode of wire gauze, and the other a metal drum rotating
in the trough containing the alkaline clay slip. The electric current
is then passed through the fluid, using the gauze and drum as poles.
In this apparatus, a further slight purification is effected owing to the
tendency of the impurities to travel to one electrode whilst the clay
(with some silica) travels to the other. The clay and finest silica
particles assume a negative charge, but that of the silica is so slight
that the silica remains almost stationary in the fluid, whilst the clay
travels to the anode. Pyrite, alumina and ferric oxides are positively
charged and travel with the water towards the cathode. The
dominant feature in the speed of migration is the valency of the
material attracted to the diaphragm.

The chief use of the electro-osmosis process is for producing a
clay paste sufficiently dry for commercial purposes, as the greater
part of the purification is effected before the current is applied.

The electro-osmose process whilst theoretically interesting, is not,
at present, regarded as of much practical importance, as the use of
electricity to separate clay and water is more costly than other equally
efficacious methods. Moreover, the finest particles of free silica
migrate simultaneously with the “true clay” so that only a very
limited purification by the electric current is possible, the greater
part having been done by the electrolyte added, which is not an
essential part of the osmosis process.

In East Germany, it has been used for some time on a commercial
scale, and about two years ago an English syndicate was formed to
exploit the Schwerin patents, and to supply certain requirements
of the Optical Department of the Ministry of Munitions. For further
information on the electro-osmose process for the treatment of clays
see “ The British Association Report on Colloids, I, 1918,” pp. 42-4,
47-52.

A possible method of purifying clay and separating the colloidal
silica is due to Billitzer (1905), who found that in N/2 to N/10
solutions of hydrochloric acid, the charge of colloidal silica is changed
from electro-positive to electro-negative so that the careful addition
of acid should enable a practical separation of colloidal silica from
colloidal clay to be made. The importance of this suggestion appears
to have been overlooked.

In separating clay and*water, as when it is desired to dry a clay
slip or suspension, use may he made of the electric and colloidal
properties of the clay. This is an essential feature of the Schwerin
electro-osmosis process! previously described. On passing a current
of electricity through the clay slip, the clay migrates to, and is retained
by the rotary electrode (anode) and the water tends to travel to the
cathode, so that the clay removed from the drum is drier than from
a filter press worked at a pressure of 150 lb. per sq. inch. Thus,
some ball clays may be obtained with only 17 or 18 per cent. of
water, and so dry that it cannot be pugged, whilst the same clay,

147

when removed from a filter press would not contain less than 30 per
cent. of water. The clay acts like a porous diaphragm made of
capillary tubes and this shows the well-known phenomena of
endosmosis.

In making articles of clay and allied materials by the casting
process, 7.e., by pouring a suspension of the materials, into a mould
and, after a suitable time, pouring off the surplus fluid, it is important
to have as concentrated a suspension as is reasonably possible. When
water is used, only moderate concentrations can be used, but by
adding a small percentage of a suitable electrolyte such as sodium
carbonate or water-glass, or both, the amount of clay in suspension
can be doubled and the casting process greatly facilitated. This
use of an electrolyte, is based solely on the assumed colloidal nature
of the clay. Care must be taken in choosing the electrolyte, as some
substances such as sodium carbonate if used alone will cause a very
high surface tension, with the result that the slip “balls up” and
may cause the inclusion of air bubbles, whilst sodium silicate used
alone causes the clay to flow in “strings” like a thick syrup. A
suitable mixture of the two, however, is excellent, and gives a smooth
flowing stream without any tendency to the defects just mentioned.
Slips containing a suitable electrolyte require far less time in the
mould than those slips in which plain water is used. This is necessary
in consequence of the smaller proportion of water present and is of
great practical importance as it reduces the number of moulds required.
With a good stoneware slip containing soda, a mould may be used
five or six times in succession without drying and with slips of leaner
clays, the moulds may be used still more frequently. On the other
hand, the salts absorbed by the plaster tend to make the moulds less
durable when soda is present in the slip.

A slip to which soda or other electrolyte has been added feels
more soapy and plastic than one with plain water; on passing it
through a sieve, it does not flow so readily and tends to form long
syrupy strings, and, on long standing, little or no separation occurs.
A soda-slip also flows more steadily and with less tendency to include
bubbles of air than one made without an electrolyte and the painting
of portions of a mould with slip, which is sometimes essential to
ensure the production of a good surface on the ware is entirely
unnecessary when a suitable electrolyte is used.

In increasing or reducing the plasticity of a clay or earth, so as to
make it suitable for the manufacture of various articles, the methods
most extensively used are based on the assumed colloidal properties
of the clay. Plasticity is increased by, methods (p. 130) which
increase the amount of colloidal gel in the material and it is reduced by
the methods (p. 131) which will lessen the amount of irreversible colloid
gel, or by converting it into a hydrosol. Thus, the processes of ageing
and souring the clay are dependent on an increase of colloidal matter
by the prolonged hydrolysing action of the water on the clay, followed
by a fermentation or acid-producing action which coagulates any
hydrosols previously formed.

% 11454 L

148

Weathering.—The reduction of large arid hard masses of clay and
shale is often greatly facilitated by exposure to weather, 7.e., to the
action of air, sunshine, frost and rain. When so exposed, many clay
materials disintegrate rapidly and may afterwards be made into a
plastic paste much more easily than by any mechanical process of
grinding and mixing with water. Different clays and shales are
affected differéntly by exposure; some disintegrate after a few hours’
exposure on a warm day, whilst others“appear to require a succession
of frosts and rainy periods. In most cases, the most feasible explana-
tion of the physical changes which occur is that the conditions of
exposure result in the partial peptisation of the colloidal cementing
material which binds the particles of clay together. It is well known
that sand grains soaked in concentrated glue and then suitably dried,
form a hard rocky material which, on exposure or soaking in water,
falls "to powder as the colloidal element absorbs water, swells, and is
no “longer able to hold the particles together. It is suggested—
though no definite proof is available—that *when natural clays are.
exposed to weather a similar absorption of water by the colloidal
matter occurs, and is followed by a corresponding disintegration of
the mass. In the case of some clays, a certain amount of chemical
change such as the fermentation of organic matter, or the oxidation
of the pyrite, &c., also occurs and may also facilitate the disintegration,
but the chief cause of the reduction of the material to a more or less
pulpy mass, bears a much closer resemblance to the softening of the
colloidal cementing mass than to any ordinary process of oxidation
or other obviously chemical reaction.

Commercially, the weathering of indurated clays is of great import-
ance, as it not only reduces the cost of grinding and mixing, but the
weathered product is much more homogeneous and the water present
is far more uniformly distributed than when the treatment of the clay
is purely mechanical.

According to W. Taylor, the colloids produced during the
weathering are not amorphous alumino-silicates, but mixtures of single
gels produced by the mutual precipitation of positive and negative
sols.

The ancient practice of storing clay in cellars for a long time, and
known as maturing or ageing, is now seldom practiced to anything
like the extent to which it was formerly thought necessary. Where
hollow goods of very fine quality are made there is an undoubted
advantage in thus storing the clay before it is made up into goods,
but the keeping of clay in air-tight boxes for several years, as practised
by the Chinese and more recently by Wedgwood and other famous
potters, is no longer considered essential, though its beneficial effect
on the clay cannot be denied. In Germany, the use of sumps, in
which the clay and water remains in contact’ with each other for a
considerable time, is still regarded as necessary.

In freshly pugged paste, there is only a limited amount of colloidal
matter in an active form. Its amount may be increased by subjecting
the paste to conditions under which any dry and horny colloidal gel
will absorb water, swell, and form a soft friable jelly, and the same

149

result is obtained when a clay paste is stored in a'cool place in a moist
atmosphere for a sufficiently long time; the requisite coagulation
oceurs when sufficient acid is added to the material. This acid may
be produced internally by the putrefaction of the organic matter,
or it may be added artificially.

The swollen gel produced on prolonged storage is very permeable
to water, and its structure may be compared to a series of solid grains
wholly surrounded by liquid films which are not sufficiently thick
to allow the particles to separate from each other or to flow appreciably.
Such a structure has a powerful capillary action and consequently,
it affects the distribution of water through the mass in a most thorough
and efficient manner. This uniform distribution of the water largely—
in conjunction with the coagulating and swelling of the colloidal
matter—accounts for the increased ease with which an old clay-paste
can be manipulated. The water in freshly pugged clay cannot’ be
so uniformly distributed as when such a paste has been allowed to
stand for several weeks, during which time the water is distributed
through the mass by capillary attraction.

A much shorter storage of the clay paste, frequently in open sheds
the material being covered with wet sacking, is known as souring.
Its effect is undoubtedly to increase the active, as distinct from the
dormant, plasticity of the clay, though there is a great variation in
the extent to which this takes place. There is a widespread impression
that souring is the result of bacteria or ferment-organisms, and some
potters added sugar or honey to the clay to assist the fermentation
but, whilst this may account for some of the observed effects, the
hydrolysing action of the water present in the mass on the clay, silica,
and iron hydroxide particles must not be overlooked. Rohland®
suggested that the fresh clay paste is slightly alkaline owing to the
felspar, &c., present in the clay being hydrolysed and converted
into the colloidal form. The acids produced by the decomposition
of any organic matter also present neutralise the cations; and the
excess of hydrogen-ions produced coagulates the colloid matter and
correspondingly increases the plasticity of the clay. This explains
why the old vinegar “ tip’ of bygone potters develops the plasticity.
Previous to this, Seger! had found that clays which remain alkaline
do not increase in plasticity on storage, but do so if they are acidulated
with acetic acid.

As heat is a disadvantage, souring must usually take place in a
cool, moist, shed or cellar, if it is to be really effective; though in
opposition to this, it may be noted that slips which are dried by heat
are often more plastic than those treated in a filter press. :

Some firms apply souring or storage to clays which are highly
plastic, not to develop more plasticity but to secure a better distribu-
tion of moisture through the mass, and, as they express it, “ to bring
it into a better and tougher condition.”

The weathering of crystalline minerals generally yields gels or
mixtures of gels; thus, tale is formed from the weathering of
Serpentine, and some forms of brown iron ore from yellow ochre,
but this is not invariably the case. It is, therefore, possible that

150

some clays may be mixtures of gels whilst others are mixtures of
colloidal and amorphous alumino-silicic acids.

The customary arrangement of the paste in the souring shed is
to fill a large clean floor with the paste to a height of about 5 feet,
cover it with wet sacking and keep the latter moist for the desired
duration of the souring. As fresh clay is added to one part of the
floor, the soured clay is removed from another. Where the output
is sufficiently large, it is convenient to use an annular building with
12-20 entrances as the addition of fresh paste and the removal of
the soured paste may then proceed continuously with a minimum
of trouble and space. In some works, the clay is stored in the form
of balls or blocks about 3 feet diameter. If the paste is allowed to
sour in wagons, each holding about 1 ton, a considerable amount of
labour is avoided, though the gain is largely counterbalanced by
the cost of the wagons.

During the souring period, the paste must be kept moist and special
care should be taken not to allow a dry crust to form on its surface.

Air as well as moisture is necessary for the effective souring of
some highly plastic clays, as the desired decomposition of the organic
matter cannot occur in the absence of air.

It is very important to cover the clay to be soured, with wet
sacking, as if this is not done the plasticity will be decreased instead
of increased. In time, the union of the particles and also the growth
of larger particles at the expense of the smaller ones may occur.
Both may lead to the enlargement of the interstices between the grains
and to the solidification of the gel residue, by which the total volume
of gel remains fairly constant under constant tension. Crystallisa-
tion and other processes which enlarge the interstices during ageing
also increase the vapour tension. During ageing the total surface
of the particles is reduced, but the interspaces grow larger. This
indicates that ultramicrons grow at the expense of the amicrons.

The duration of the souring period varies greatly in different cases.
In some cases, only a couple of days is allowed; six to eight weeks
is much more valuable when practicable, and the ancient makers of
some Chinese porcelains are understood to have kept their paste for
a hundred years! It is by no means unusual for the clay to be soured
as much as six months and in exceptional cases, several souring
periods are arranged. In making glass-house pots, for instance, the
clay, is allowed to sour after a preliminary treading; it is then
re-trodden, again allowed to sour and finally is re-pugged before it is
ready for use.

Increasing the Souring Effect—As the results which oceur when
the paste is allowed to sour are so beneficial, it is obviously advantageous
to develop them as much as possible. The chief methods of doing
this are :—

(i) To increase the amount of organic matter in the paste
and to secure a more intense souring action. For this purpose,
various putrefactive organic solutions such as wine, old vinegar,
sewage, peat extract and also solid organic substances such as
chopped vegetable matter, tannery waste, and even molasses

a a —

151

are sometimes used instead of plain water in pugging the clay.
Such additions do not usually increase the plasticity of the clay
to more than a small extent and they greatly increase the difficulty
of burning the ware satisfactorily.

(ii) The addition of weak acid such as acetic acid, oxalic
acid, or tannin (gallotannic acid) to neutralise the acid present
or to discharge any hydroxyl-ions formed by the dissociation
of salts present as impurities in the paste. One of the most
interesting proposals in this connection is that of Acheson and
Ries who have found that on the addition of a 2 per cent.
solution of tannin to certain clays the plasticity may be greatly
increased and the clay was apparently deflocculated and broken
up into smaller particles, whilst the tensile strength was greatly
increased. The use of a substance definitely known as an acid
is not necessary; any substance which acts as a corresponding
electrolyte of either organic or inorganic nature is advan-
tageous because it neutralises the charge on some other electro-
lyte present in the paste and so effects a definite increase in the
plasticity of the clay.

The great importance of souring is not appreciated as it should
be, because the phenomena which occur are largely misunderstood
and consequently, it is often omitted where it would be most useful.
In the manufacture of bricks, and coarse goods, omission may not
be serious, but it should never be omitted in the preparation of a
paste for the manufacture of tiles, glazed ware, earthenware, fine
pottery, and poreclain.

Ware made from a properly soured paste is less sensitive to sudden
changes of temperature, can have thinner walls, does not break so
easily, and is easier to produce as the souring increases the plasticity of
the paste.

It is usually necessary to pug the paste after it has been soured
so as to form it into a compact and homogeneous paste.

Certain clays have long been used as absorbents for grease and
similar materials especially in fulling cloth and for medicinal purposes.
Curiously enough, these clays are among the least plastic. Their
usefulness depends on their absorptive and adsorbent properties.

Conversely, the use of clay in the preparation of wltramarine
depends partly on its chemical composition, but chiefly on the colloidal
nature of the product.

It should be remembered that clays can only be used for removing
basic dyes and colours such as malachite green, as their removal from
solution depends on the negative electric charge carried by the
colloidal particles in the clays. Incidentally it may be noted that
elays containing much colloidal silica or colloidal alumina give
uncertain results when treated with malachite green.

Clays are also used in the preparation of several other colloidal
substances including Portland cement.

The clarifying power of clays, when mixed with’ turbid fluids, also
depends on ‘the colloidal nature of the finely suspended particles

152

coalescing with, or being entangled with, the coarser particles of clay
and being carried down by the latter. For this purpose, the clays
should not be too finely divided, nor should they be highly plastic,
as a somewhat coarser, porous material is more efficient and settles
more readily. It must, however, possess sufficient power of adsorption
to retain the finely suspended particles which cause the turbidity
in the fluid which it is desired to clarify.

The use of clays as clarifying agents is particularly successful in
the treatment of slightly oily effluents of spinning works, wool-
scouring plants, distilleries, tanneries, dye-works, glue-factories,
breweries, and other industries producing an effluent containing
organic matter in a very finely divided or colloidal state. The best
results are obtained when the colloidal matter in the effluent carries
a positive electric charge as it is dissipated by the added colloidal
matter bearing a negative charge. Domestic sewage, however, is not
of this character, and, therefore, cannot be clarified in this manner.
This fact confirms the essentially colloidal nature of the active
ingredient in clay used as a clarifying agent.

The separation of water from clay in filter presses may, according
to F. Ulzer®® be facilitated by inserting suitable electrodes in the
filter chambers, so as to coagulate the colloidal material and yet
keep it from blocking the cloth.

The extrusion of clay through dies is made more rapid by the
application of an electric charge, as described in “ British Association
Report on Colloids, II.,” 1918.

The binding power of clays, like that of dextrin, gelatin, and other
well-known colloids is used for uniting other particles into a compact
mass as in the manufacture of refractory materials from non-plastic
materials, “lead ’’ in lead pencils, &c. Conversely, use is made of the
colloidal property to reduce the excessive shrinkage of certain clays
by the addition of suitable non-plastic materials.

In agriculture, the colloidal properties of clays play,«,most important
part. It is now generally agreed that plants and »ther organisms
growing in the soil, derive their sustenance chiefly from a film of
colloidal matter surrounding the particles of inert material constituting
the bulk of the soil and occupying some of the interstices between
these particles. The soluble salts extracted from the mineral
material in the soil or subsoil, or added in the form of a fertiliser,
are adsorbed by this film of colloidal matter and transferred to the
plant-roots, &c. There are several different substances existing in
the colloidal state in soils, the more important being the colloidal
“clay,” silica, alumina, ferric hydroxide, and a mixture of partially
decomposed organic substances collectively known as “ humus.”
The last-named acts as a protective colloid for other substances, and
absorbs many soluble salts. In association with other colloids, it
determines the amount of water retained by the clay. Humus is
negatively charged and is, therefore, coagulated into a gel by basic
substances, such as lime.

The colouring matter in swamps is generally positively charged,
and is, therefore, precipitated by colloidal clay. Alkaline humates
are not colloids, but soluble substances. Being a negative colloid,

153

humus is precipitated by cations such as Ca, Fe, or Al which alter its
permeability, absorption, and the way in which a soil “works.”
Fertilisers convert the silica gels into sols which rise by capillary
action, and are again gelated nearer the surface of the ground or
in the cells of the plants which absorb them. For further details, see
** British Association Report on Colloids, IT.,” 1918, pp. 70-81.

In the manutacture of detergents, the use of clay has been
developed to some extent on account of its colloidal properties, apart
from its use as a filler.

It is well known that the amount of active colloidal material in
clays can be increased by the addition of a certain proportion of
alkali, which disperses the particles of clay, as shown on p. 119.
F. E. Weston”? made use of this fact in order to bring china clay
into a highly colloidal state, and claimed that the colloidal clay thus
formed could be used as a substitute for soap. His results are not,
however, conclusive, and the clay-soap can only be used in special
cases. It is of little value in toilet preparations, but as a substitute
for the coarse soaps used in wool scouring it has been used with
success, and several preparations are now on the market.

The chief advantages claimed for colloidal clay soap are that it
absorbs dirt and grease, and removes them without any deleterious
effect on the material, there being no injurious chemicals in the
preparation, and that it is capable of removing unsaponifiable oily
substances—a result which is not possible with the ordinary scouring
media. It is stated to have a greater detergent power than ordinary
soap and its antiseptic properties may be of considerable value.

It has been shown by Bancroft, the organic soaps depend partly
on their solubility and decomposition (hydrolysis) for their detergent
properties, and as such properties are not possessed by clay soap,
they have a disadvantage in this respect.

As yet, the colloidal properties of clay have not been widely
investigated ir this direction, and a very large field may be opened
out for the us of ls clays in pean manufacture, though the cost
of purifying brick, even though they are more
plastic and contain more colloidal ee Heme tg ia most cases, be
prohibitive.

REFERENCES.

1 Seger, Gesamm., Schriften., ed. Dr. H. Hecht and E. Cramer (Tonindustrie
Zeitung, Berlin, 1908).

* Asch, W. & D., The Silicates in Chemistry and Commerce (Constable & Co.,
London).

3 Martin, G., Chemical News.

- Schloesing, Compt. Rend., lxxix., 376-380, 473-477 (1874).

5 Rohland, P., Die Tone.

6 Searle, A. B.; An Introduction to British Clays (Griffin, London, 1911).

7 Ashley, Trans. Amer. Cer, Soc., xii., 768 (1910).

® Schurecht, Journ. Amer. Cer. Soc., 443-450 (1919).

® Kosmann, Tonindustrie Zeitung, 352 (1895).

10 Zebisch, Sprechsaal, 1028 (1894).

11 Mellor, Green & Baugh, Trans. Eng. Cer. Soc., vi., 16t-170, 1906,

12 Ostwald, W., Colloid Chemistry.

154

13 L, Hermite, Ann. Chim. Phys., (3), 43, 352 (1855).

14 Zschokke, Chem. Technologie der Neuzeit, Bd. 1, 775.

15 MacMichael, R. F., Brick and Clay Record, 690 (1919).

16 Bourry, Treatise on the Ceramic Industries (Scott, Greenwood & Son,
London, 1911).

17 Grout, W. Va. Geol. Survey, TIT. (1906). ;

18 Cushman, A. Trans. Amer. Cer. Soc., vi., 7 (1907).

19 Bemmelen, A. Van, z. anorg. Chem., v., 466; xiii, 233; xvili, 14; ete.

20 Pukall, W., Berichte d. Deutsch. d. Chem. Gesellsch., 43, 2107 (1910).

21 Brit. Assoc. Rept., I.

22 Ulzer, F., z. angow. Chem., 28, i., 308 (1915).

23 Weston, F. E., Chem. Age., Jan. 17, 1920, pp. 58-60; see also Chem. Age.,
Jan. 31, p. 115; Feb. 7, p. 146; Feb. 14, p. 170; Mar. 6, p. 247; April
3, p. 351.

-RECENT REFERENCES.

Not Included in this Report.

Weston, F. E., Colloidal Clay, China Clay Trade Review, p. 337, 1920.

Hay, J. Gordon, Colloidal Clay as a Catalyst in Oxidation and Hydrogenation
Chem. Age., Feb. 21, 1920, p. 194.

Ormondy, W.R., The Filtration of Colloids, Soc. Chem. Ind. Conference, July,
1920 (deals with the electro-osmosis of clays).

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