556 
are discussed. A new species of pipe-fish, and one of 
Mastacembelus, are described and also.a new colour 
form of M. arvmatus.—B. Prashad: Revision of 
Kobelt’s nomenclature of the Indian Ampullariide. 


Official Publications Received. 
South Australia: Department of Mines. 
Year ended 80th June 1922. 
(Adeluide.) 
South Australia. Annual Report of the Director of Mines and 
Government Geologist for 1921. Pp. 10+2 maps. (Adelaide.) 
The Carnegie United Kingdom Trust. Ninth Annual Report (for the 
Year ending 3lst December 1922) submitted by the Executive Committee 
to the Trustees on Friday, 9th March 1923. Pp. xii+63. (Edinburgh.) 
The Journal of the Royal Anthropological Institute of Great Britain and 
Treland. Vol. 52, July to December 1922, Pp. vi.+151-324+12. (London : 
Royal Anthropological Institute.) 15s. net. 
Ministry of Public Works, Egypt. Report on the Work of the Physical 
Department for the Year ending 31st March 1922. By Dr. H. E. Hurst. 
Mining Review for the Half- 
Compiled by Lionel C. E. Gee. Pp. 64, 
Pp. 22. (Cairo: Government Printing Office.) P.T. 5. 
Regenwaarnemingen in Nederlandsch-Indié. Twee en Veertigste 
Jaargang, 1920. Pp. vi+123. Drie en Veertigste Jaargang, 1921. 
Pp. iii+123. (Weltevreden, Java: Landsdrukkerij.) 
Annual Reports: The Academy of Natural Sciences of Philadelphia for 
the Year ending 30th November 1921. Pp. 74. (Philadelphia.) 
Proceedings of the Academy of Natural Sciences of Philadelphia. 
Vol. 74, 1922, Pp. iii+318+22 plates. (Philadelphia.) 
Annals of the Missouri Botanical Garden, Vol. 9, No, 8, September. 
Pp. 233-332. (St. Louis, Mo.) 1 dollar. 
Library of Congress. Report of the Librarian of Congress and Report of 
the Superintendent of the Library Building and Grounds for the Fiscal 
Year ending 30th June 1922, Pp. 209. (Washington: Government 
Printing Office.) 50 cents. 

Diary of Societies. 
MONDAY, Apri 23. 
VictortA InstTiTUTE (at Central Buildings, Westminster), at 4.30.—Dr. D. 
Anderson-Berry : Occultism ; at the Bar of Philosophy and Religion. 
Royat Society of Mepicine (General Meeting), at 5.—Sir Archibald 
Garrod, Dr. F. J. Poynton, Dr. M, Cassidy, and Dr. A. F. Hurst: 
Discussion on The tiology and Treatment of Osteo-arthritis and 
Rheumatoid Arthritis. 
Royat CoLtLece or SurGcEons oF ENGLAND, at 5.—Prof. Shattock: 
Syphilis. 
InsTITUTION OF MECHANICAL EnoIneers (London Graduates’ Section), at 
tere H. G. Warne: Recent Steam-Wagon Progress, and a Suggested 
Jesign. 
INSTITUTION OF ELECTRICAL EncineERS (Informal Meeting), at 7.—E. H. 
Shaughnessy and others: Discussion on Practical Broadcasting. 
Roya Instirute oF British ARcHITECTsS, at 8.—W. G. Newton: The 
Literature of Architecture. 
Roya Socrery or Arts, at 8.—E. Kilburn Scott: Nitrates from Air (3). 
(Cantor Lectures.) 
Farapay Society (at Chemical Society), at 8.—J. H. Shaxby and J. C. 
Evans: The Properties of Powders—The Variation of Pressure with 
Depth in Columns of Powders.—E. E. Walker: The Properties of 
Powders. Part VI. The Compressility of Powders. Part VII. The 
Distribution of Densities in Columns of Compressed Powder.—E. K. 
Rideal: The Rate of Hydrogenation of Cinnamic and Phenylpropiolic 
Acids.—A. Taffel: The Temperature of Maximum Density of Aqueous 
Solutions.—L. Anderson: Note on the Coagulation of Milk by Acid. 
Roya Socirty oF Mepicine (Odontology Section), at 8.—Dr. C. F. 
Sonntag : Some Points in the Comparative Anatomy of the Mouth and 
Tongue.—G. J. Harborow: A Case of Unerupted Incisors and Canines 
in a Male aged 59.—K. Sprawson: The Vascular Supply of the Enamel 
Organ of Felis domesticas. : 
Royat GeoorapuicaL Society (at Holian Hall), at 8.30.—L. M. D. 
Buxton: Inner Mongolia. 
TUESDAY, Aprit 24, 
Roya Institution or Great Britain, at 3.—Sir Arthur Keith: The 
Machinery of Human Evolution (3). How New Features are Gained. 
Royal Society or Mepicine (Medicine Section), at 5.80.—Dr, C. Gouldes- 
brough : Osteo-arthritis of the Spine.—Dr. H. L. Tidy ; Glandular Fever 
and Infective Mononucleosis. 
Zooroaica Society oF Lonpon, at 5.30.—R. B. Murray: Exhibition of a 
Giant Centipede from Trinidad, and Mounted Skins of Oil-birds.—Lt.- 
Col. 8. Monckton Copeman and Major E. E. Austen: Exhibition (with 
photographs) of a unique British Dipteron, taken on Primrose Hill.— 
Baron F. Nopesa: The Origin of Flight in Birds.—E. C. Stuart Baker : 
Cuckoos’ Eggs and Evolution. 
InsTiTuTION OF CIvIl. ENGINEERS, at 6.—Annual General Meeting. 
RoyaL Pxroroarapnic Society or Great Briratn (Scientific and 
Technical Group), at 7.—Capt. J. W. Bampfylde: Photomicrography as 
applied to the Lron-Carbon. 
WEDNESDAY, Aprit 25. 
Roya Society or Arts, at 4.30.—Conference on the Milk Question.— 
Papers: Prof. R. 8. Williams: The Arguments for maintaining an Open 
NO. 2700, VOL. Enq] 
NATURE 
[APRIL 21, 1923 

Market for Fresh Milk.—Prof. J. C. Drummond: Changes in the 
Digestibility and Nutritive Value of Milk induced by Heating.—Dr. 8. 8. 
Zilva: The Effect of Heat on some Physiological Principles in Milk,— 
Capt. J. Golding and Mrs. A. T. R. Mattick: A Demonstration of some 
of the Chemical Changes in Milk on Heating to various Temperatures. 
Roya Microscoricay Sociery (Industrial Applications. Section), at 7.— 
C. Baker: Junior Engineer Metallurgical Microscope and the Wee 
Binocular Microscope.—R. and J. Beck, Ltd. : New Research Outfit for 
Metallurgical Work, including Microscope, Gamera, Optical Bench, ete.— 
Edison Swan Electric Co., Ltd.; Projector and Fullolite Lamps.— 
M. P. Swift: Use of Dichroiscopes for the Identification of certain Gem 
Stones.—W. Watson and Sons, Ltd. : Petrological Microscopes.—At 8.-— 
J. E. Barnard: The Manipulation of the Microscope in Industvial 
Laboratories. PartI. Uluminants and Illumination.—Dr. M. C. Stopes : 
The Microscopical Examination of Coal in relation to Fuel Economy 
and Efficiency. 
British PsycnonocicaL Socrety (Medical and Education Sections) 
(at London Day Training College), at 8.—Drs. East, Burt, Shrubsall, 
and Stoddart: Symposium on Delinquency and Mental Defect, to be 
followed by a discussion. 
THURSDAY, Apri 26. 
Roya InstrruTion or GREAT BRITAIN, at 3.—Prof. J. T. MacGregor- 
Boni ; Modern Electric Lamps (1). Glowing Solids in vacuo (Tungsten 
amps). 
Royat Socrery, at 4.30.—Prof. T. R. Merton and R. C. Johnson: Spectra 
associated with Carbon.—R. A. Watson Watt and Dr. E. V. Appleton : The 
Nature of Atmospherics.—Prof. W. A. Bone, D, M. Newitt, and D. T. A. 
Townend: Gaseous Combustion at High Pressures. Part III. The 
Energy-absorbing Function and Activation of Nitrogen in the Combus- 
tion of Carbon Monoxide.—Dr. I. Masson and L. G. F. Dolley: The 
Pressures of Gaseous Mixtures.—W. R. Bousfield and C. Elspeth 
Boustield ; Vapour Pressure and Density of Sodium Chloride Solutions.— 
Prof. F. A. Lindemann and G. M. B. Dobson: A Note on the 
Temperature of the Air at Great Heights.—Prof. G. H. Hardy and J. E. 
para Lindelif's Hypothesis concerning the Riemann Zeta- 
unction. ‘ 
Lonpon MATHEMATICAL Society (at Royal Astronomical Society), at 5.— 
Grace Chisholm Young: The Solution of a Pair of Diophantine Equations 
connected with the Nuptial Number of Plato.—H. W. Richmond : (1 
The Electrostatic Field ofa Plane Grating with Thick Rounded Bars ; (2) 
Notes on the use of the Schwarz-Christoffel Transformation in Electro- 
statics.—E. G. C. Poole: The Discontinuous Motion produced in an 
Intinite Stream by Two Plane Obstacles.—A. E. Ingham: Two Mean 
Value Theorems concerning Riemann’s Zeta-function.—A. E. Jolliffe : The 
Inflexions of the Non-singular Plane Quartic.—R. Vaidynathaswami : 
Transversal Problems in Hyperspace.—T. Stuart: Certain Diophantine 
Equations.—M. Riesz: Sur l’équivalence des certaines méthodes de 
sommation.—K. Basu: The Perturbations of the Orbit of the Valency- 
electron in the Generalised Hydrogen-unlike Atom.—Pandit Oudh 
Upadhyaya: Cyclotomic Heptasection. 
Cuitp-Stupy Society (at Royal Sanitary Institute), at 5.30.—Annual 
General Meeting.— At 6.—Dr. W. G. Sleight: Children’s Taste in 
Pictures. 
UystiTuTIoNn OF ELECTRICAL ENGINEERS, at 6.—L. Breach and H. Midgley: 
The Drive of Power Station Auxiliaries. 
Society or DyERs AND CoLourists (London Section) (at Dyers’ Hall, 
Dowgate Hill), at 7.—L. G. Lawrie: Fur Dyeing. 
Roya Society or Mepicive (Urology Section), at 8.30—Clinical and 
Pathological Evening. 
FRIDAY, Apri 27. 
Association OF Economic Brotoaists (in Botany Theatre, Im 1 
College of Science and Technology), at 2.30.—Dr. C. M. Wenyon ; Some 
Recent Observations on Pathogenic Protozoa of Plants and Animals.— 
(To be followed by a discussion.) 
RoyaL Society oF Mepicine (Study of Disease in Children Section), 
at 5.—(Epidemiology and State Medicine Section), at 8—Dr. T. F, 
Dewar: The Incidence of Venereal Disease in Scotland. 
PuysicaL Sociery oF Lonpon (at Imperial College of Science and 
Technology), at 5.—The Research Staff, General Electric Co., Ltd. : 
The Analysis of Bubbles in Glass.—Dr. H. P. Waran: A Simple 
Regenerative Vacuum Device, and some of its Applications.—Capt. 
H. Shaw and E, Lancaster. Jones: Application of the Eétvés Torsion 
Balance to the Investigation of Local Gravitational Fields.—L, F. 
Richardson: Demonstration of an Electromagnetic Inductor. — Dr. 
F. Ll. Hopwood : Demonstration of Experiment Illustrating Time-Lag 
in Vision. 
Royat CoLLEGE or SurGEONS OF ENGLAND, at 5.—Sir Arthur Keith: 
Surgical Anatomy of the Foot. 
InstiTUTION OF MECHANICAL ENGINEERS (Informal Meeting), at 7.— 
Adjourned Discussion on paper by A. B. L. Chorlton: The Use of Light 
Alloys in place of Iron and Steel. 
JuNtoR [NSTITUTION OF ENGINEERS, at 7.30.—J. Fearn : Stock Control. 
Royat PuoroarapHic Society oF GREAT Britain, at 8.—A. Watkins: 
Early British Trackways. 
Roya. InstiruTIon OF GREAT BRITAIN, at 9.—Prof. C. V. Boys: Measure- 
ment of the Heating Value of Gas. 
SATURDAY, Aprit 28. 
Royat Insvirurion oF GREAT Britain, at 8.—Dr. L. L. B. Williams: 
The Physical and Physiological Foundations of Character (1). 
PUBLIC LECTURE. 
WEDNESDAY, Apri 25. 
Krxo's Coteae, at 5.30.—The late Prof. E. Troeltsch (by Dr. E. Barker) : ° 
Ethics and the Philosophy of History. (Succeeding lectures on May 
2 and 9.) 

