December 16, 1922] 



NA TURE 



azide, and several other explosives were not detonated 

 by exposures to a-particles which would have caused 

 several thousand detonations of iodide of nitrogen. 

 Probably only a very sensitive body, such as the 

 iodide, can be detonated in this way, and the risk of 

 such an effect with detonators or explosives in common 

 use is negligible. — T. G. Mason : Note on the growth 

 and the transport of organic substances in bitter 

 cassava (Manihot utilissima). Weekly measurements 

 of 20 plants were made over a period of 27 weeks.; 

 alternate plants were ringed close to the ground. 

 The rate of growth of the stems of the ringed plants 

 was not affected by the operation for about 3 weeks ; 

 it then commenced to lag behind that of the unringed 

 plants. The weight of the tuberous roots formed by 

 the ringed plants was about one quarter of that 

 formed by the unringed ; the weight of the stem was 

 more than 1-2 times as much. Probably the activity 

 of the cells of the apical meristem is not controlled 

 by the available supply of organic substances, but is 

 determined by autogenous changes within the growing 

 point. No evidence was obtained of the presence of 

 a factor correlating the activity of the apical meristem 

 and the growth of the tuberous roots. The results 

 are in accord with the view that the rate of growth 

 of the stem is conditioned by the catalytic activity 

 of the cells of the apical meristem. 



Paris. 



Academy of Sciences, November 20. — M. Emile 

 Bertin in the chair. — The president announced the 

 death of M. G. Lemoine. — Marcel Brillouin : Einstein 

 and Newtonian gravitation. Remarks on a recent 

 note by M. Le Roux. The criticisms of M. Le Roux 

 are regarded as unfounded. — Pierre Termier : The 

 structure of the eastern Alps. — L. Joubin : The geo- 

 graphical distribution of some deep - sea corals in 

 western European seas. In consequence of the in- 

 crease in the size and power of steam trawlers, trawling 

 is now carried out at much greater depths than 

 formerly. As a result, the quantities of coral brought 

 up in the nets causes great inconvenience. As a 

 guide to fishermen, a chart is given showing the dis- 

 tribution of the most objectionable corals (Lophohelia, 

 Amphihelia, Dendrophyllia), so that the trawlers can 

 avoid these localities. — E. Mathias, C. A. Crommelin, 

 and H. Kamerlingh Onnes : The rectilinear diameter 

 of neon. The purification of the neon used in these 

 experiments is described in detail, and its purity was 

 confirmed of observations of the critical phenomena. 

 Neon obeys the law of the rectilinear diameter. Like 

 other gases, the diameter shows a deviation in the 

 neighbourhood of the critical point. In the case of 

 hydrogen the deviations are distributed irregularly, 

 but with neon they are systematic : at low tempera- 

 tures the diameter is slightly convex to the tempera- 

 ture axis, and at higher temperatures slightly concave. 

 Argon, nitrogen, and carbon dioxide behave similarly. 

 — M. Charles Camichel was elected Correspondant for 

 the section of mechanics. — S. Bays : Steiner's cyclic 

 systems of triplets. — A. Myller : Remarkable ruled 

 surfaces passing through a given curve. — Paul Mentre : 

 Complexes which present projective singularities of 

 the second infinitesimal order. — H. Roussilhe : Re- 

 sults obtained in 1921 and 1922 by the application of 

 aerial photography to precision plans on the large scale. 

 The mean errors of plans derived from aerial photo- 

 graphs are less than those of a topographical plan 

 taken with every precaution ; the area covered by a 

 given staff is also greater when the photographic 

 method is employed. — C. Raveau : Fresnel's law of 

 the entanglement of the aether. — Emmanuel Dubois : 

 The minimum potential of electric discharge in gases 



NO. 2772, VOL. I IO] 



at low pressures. Some anomalies described in an 

 earlier communication have been now shown to be 

 due to the presence of saline substances on the 

 electrodes. — L. Bouchet : An absolute plane-cylinder 

 electrometer. A cylinder is mounted on a balance 

 beam and the attraction between the cylinder and a 

 plane surface measured. The theory of the instru- 

 ment is developed. The limits between which the 

 formula holds have been determined by experiment. 

 — Georges Dejardin : The production of the spectrum 

 of mercury. The influence of helium. A study of 

 the spectrum emitted by mercury vapour traversed 

 by electrons of variable velocity. The lines are those 

 of the arc spectrum. For potentials below 20-4 volts 

 a mixture of helium and mercury vapour gives the 

 same arc spectrum as that observed in the absence 

 of helium. Above 20-4 volts the mercury spectrum 

 undergoesmodification, andat thesame time the helium 

 spectrum appears. — Pierre Lafon : Anomalies in the 

 expansion of glass. — A. Portevin : The reduction and 

 disappearance of internal strains in steels by reheating 

 followed by slow cooling. — Andre Kling and D. 

 Florentin : The spontaneous formation of sulphate on 

 limestone in urban centres. Chemical analyses of 

 various limestone structures, showing the serious 

 attack by the sulphuric acid in town atmospheres. — 

 MM. Tiffeneau and Orekhoff : The semipinacolic 

 transposition of the alkylhydrobenzoins : the influence 

 of the alkylradicles. — Raymond Delaby : The alkyl- 

 glycerols. The preparation of vinylalkylcarbinols. — 

 E. Grandmougin : The acyl-aminoanthraquinones as 

 vat dyes. — Paul Gaubert : The action of heat on 

 spherolites. — H. Joly : Preliminary note on the general 

 direction and age of the folds of the Celtiberic Chain 

 (Spain). — M. Teilhard : A fauna of mammals found 

 in northern China. — V. Van Straelen : The decapod 

 crustaceans of the Callovian of Voulte-sur-Rhone 

 (Ardeche). — Lucien Daniel : Hyperbioses of the sun- 

 flower and artichoke. — Maurice Lenoir : The nucle- 

 oles during the prophase of kinesis II. of the embryonic 

 sac of Fritillaria impevialis. — M. Mascre : The stamen 

 of the Boraginaceac. — Mile. Marie Braecke : The pres- 

 ence of aucubine and of melampyrite (dulcite) in 

 several species of Melampyrum. Aucubine was iso- 

 lated from Melampyrum pratense, M. nemorosum, and 

 M. cristatum : dulcite (Hiinefield's melampyrite) was 

 also extracted in the pure state from the two latter 

 species. — Pierre Lesage : The comparative action of 

 svlvinite and its components on the first development 

 of plants. Sylvinite proved more favourable to the 

 development of seedlings than its constituents 

 (chlorides of sodium, potassium, magnesium, and cal- 

 cium sulphate) taken separately, or even when mixed 

 in the proportions present in the mineral employed. 

 — J . Stoklasa : The respiration of the roots. Experi- 

 ments are described confirming the conclusion pub- 

 lished by the author in an earlier communication, that 

 no acid, organic or inorganic, other than carbonic acid 

 is secreted by growing roots. The respiration of the 

 roots is more intense in the presence of air containing 

 radium emanation. — A. Goris and P. Costy : Urease 

 and urea in fungi. — L. Leger and A. Ch. Hollande : 

 Coccidia of the intestine of the eel. — L. M. Betances : 

 Some refinements on the morphogenesis of the 

 haematic cell. 



Cape Town. 



Royal Society of South Africa, September 27. — Dr. 

 J. D. F. Gilchrist, president, in the chair. — II. B. 

 Fantham : Some Protozoa found in soils in South 

 Africa. Protozoa belonging to the Sarcodina, Masti- 

 gophora, and Ciliata have been found. As regards 

 actual numbers of organisms, flagellates are the 



