46o 



NATURE 



[August 7, 19 19 



91 grams the velocity can be expressed by the formula 



V= Tp.'^ , where V is velocity in metres per 



minute, P is the weight of the balloon, and F the 

 initial ascensional force. — R. Rignier : The bacterial 

 nodule of the poplar {Micrococcus populi). Observa- 

 tions on the development of the disease on the tree, 

 and suggested means of preventing its spread. — P. 

 .Carnot and P. Gerard : Mechanism of the toxic action 

 of urease. The injection of urease into the blood 

 causes death by ammonia poisoning; the urea in the 

 blood completely disappears and is replaced by am- 

 monia. — R. Fosse : The formation of cyanic acid by 

 the oxidation of organic substances. Its identification 

 based on quantitative analysis. Aqueous solutions of 

 glucose, glycerin, or glycocoll, oxidised by potassium 

 permanganate in presence of ammonia, give cyanic 

 acid as one of the oxidation products. This was 

 identified by precipitating as the silver salt. The 

 silver in this salt was determined by addition of am- 

 monium chloride, and the urea formed from the 

 ammonium cyanate separately estimated. — P. Woog : 

 The variable persistence of luminous impressions on 

 the various regions of the retina. Reply to an objec- 

 tion. — P. Girard : Relation between the electrical state 

 of the cell-wall and its permeability to a given ion. — 

 R. de la Vaulx : Intersexuality in Daphne atkinsoni. — 

 J. Pellegrin : The Eleotris of the fresh-waters of 

 Madagascar. — M. Lienhart : The possibility of chicken- 

 breeders obtaining at pleasure male or female 

 chickens. For a given strain of bird, the heavier 

 eggs produce a higher proportion of males. — J. 

 Danysz : The life of a micro-organism, individual and 

 species. — P. Delbet : Researches on the toxicity of 

 crushed muscles from the point of view of the patho- 

 geny of shock. 



Cape Town. 



Royal Society of South Africa, May 21. — Dr. J. D. F. 



Gilchrist, president, in the chair. — B. de St. J. v. d. 

 Riet : Note on coloration produced in clay by injured 

 roots of Pinus pinea. Instances were described in 

 which vapours from injured roots of the stone pine 

 produced, in warm sunshine, blue, green, and occa- 

 sionally purple stains on soil and subsoil on occasions 

 when excavations were made close to the tree. The 

 author ascribed the phenomenon to (i) oxidation of 

 volatile matter given off by roots of Pinus pinea; 

 (2) the resulting oxidation products, or product, under 

 favourable conditions reacting with iron salts in the 

 clay (the well-known reaction between many phenolic 

 carbon compounds and ferric salts) ; and (3) the pro- 

 duction of a kind of lake with aluminium compounds 

 in the clay.— Dr. J. D. F. Gilchrist : Note on the shells of 

 Schizoderma spengleri. Shells of the bivalve Schizo- 

 derma are found in abundance on the Muizenberg 

 sands, and present the peculiarity that they are either 

 whole or broken up into small fragments. This seems 

 to be due to the fact that, when the living animal is 

 cast up on the beach, it is seized by the gull {Larus 

 dominicanus) and dropped from a height of 20-30 ft. 

 on the wet sand. This has the effect of causing both 

 shells to open without injury, or one shell only is 

 broken, rarely both. It was shown by experiment 

 that this depends on how the shells fall.- — Dr. 

 Dru-Drury : An extreme case of microcephalv. The 

 author describes the skull of a Basuto woman aged 

 thirty-two which is preserved in the Port Alfred 

 Mental Hospital. The tvpe of skull is long-headed 

 and. narrow, with ape-like protrusion of the jaws 

 (thick-lipped in life). The nose was of niclium 

 breadth and the orbits were unusually high. The 

 cranial capacity is 340 c.c, which is much smaller 

 than an average case of microcephaly. 



NO. 2597, VOL. IO3I 



BOOKS RECEIVED. 



The British - Freshwater Rhizopoda and Heliozoa. 

 By J. Cash and G. H. Wailes, assisted by J. Hopkin- 

 son. Vol. iv. : Supplement to the Rhizopoda. By 

 G. H. Wailes. Bibliography by John Hopkinson. 

 Pp. xii+130 + plates Iviii.-lxiii. (London: The Ray 

 Society, 1919.) 



Camping Out for All. A Complete Handbook for 

 All who Love the Out-of-Doors. By J. Gibson. 

 Pp. x+81, (London : Gale and Polden. Ltd., 1919.) 

 25. net. 



Training for Young England. By F. G. Cooke. 

 Pp. xiv + 98. (London : Gale and Polden, Ltd., 1919.) 

 2S. net. 



The Boys' Own Book of Great Inventions. By 

 Floyd L. Darrow. Pp. ix+385' (New York: The 

 Macmillan Co.; London: Macmillan and Co., Ltd., 

 1918.) I2S. 6d. net. 



Education for the Needs of Life : A Text-book in 

 the Principles of Education. By Dr. I. E. Miller. 

 Pp. vii+353. (New York : The Macmillan Co. ; 

 London : Macmillan and Co., Ltd., 1919.) 7*- "et. 



The Sugar-Beet in America. By Prof. F. S. Harris. 

 (The Rural Science Series.) Pp. xviii-l-342 + xxxii. 

 plates. (New York : The Macmillan Co. ; London : 

 Macmillan and Co., Ltd., 1919-) 2.25; dollars. 



British Science Guild : British Scientific Products 

 Exhibition, Central Hall, Westminster, July 3 to 

 August 5, 19 iq. Descriptive Catalogue. Edited by 

 Sir Richard Gregory. Pp. xxiii+358. (London : 

 British Science Guild, 1919.) 2S. 6d. 



CONTENTS. PAGE 



The Forestry Bill 441 



Hydrogen in War and Industry '. . . . 442 



Organic Readjustments 444 



Our Bookshelf 444 



Letters to the Editor: — 



Wild Birds and Distasteful Insect Larvae.— Edward 

 R. Speyer . . . 44"= 



Luminous Worms.— Rev. Hilderic Friend . . . 446 



Protective Coloration of Birds and Eggs.— Geo. 

 Grace . 44^ 



Teeth of Sea-Otter.— M. D. Hill 44^ 



The Late Sir Edward Stirling.— L. M. Harwood . 446 

 Labour and the Higher Values. By Prof. F. Soddy, 



F.R.S 



Australian Rainfall. By J. S. D. . . 



Gustav Magnus Retzius. By Prof. A. Keith, F. R.S. 



Notes 



Our Astronomical Column : — 



The August Perseids 



Kopff's Periodic Comet 



MiraCetl 



Royal Observatory, Edinburgh 



Patent's in Relation to Industry 



The Lister Institute of Preventive Medicine . . 

 Colloids and Chemical Industry. By Prof. W. C. 



McC. Lewis .... 



The British Pharmaceutical Conference . . . 



A Model of the Volcano Kilauea, Hawaii, {///us- 



trated.) By Robert W. Sayles 



University and Educational Intelligence . ... 



Societies and Academies 



Books Received .... 



447 

 447 

 44S 

 449 



453 

 453 

 453 

 453 



453 

 454 



454 

 455 



456 

 458 

 459 

 460 



ST. 



Editorial and Publishing Offices: 

 MACMILLAN AND CO., Ltd., 

 MARTIN'S STREET, LONDON, W.C.2. 



Advertisements and business letters to be addressed to tht 

 Publishers. 



Editorial Communications to the Editor. 

 Telegraphic Address : Phusis, London. 

 Telephone Number : Gehr.ird 8810. 



