2 3 8 



NATURE 



[May S, 1913 



cause is certainly confused by other ambiguous 

 statements. 



Some interesting results of experiments on the 

 liability of metals to erosion may be quoted. They 

 were carried out in an American steel works by 

 firing a heavy charge in a shell, the base of which 

 was formed of the metal under test with a 4 mm. 

 hole bored through. Martin, tungsten, and nickel 

 steels offered about the same resistance to erosion, 

 20 per cent, nickel steel was much more easily 

 attacked, whilst manganese bronze failed to stand 

 the action of the highly heated gases. 



There are several points of interest in relation to 

 the safety of explosives deserving of mention. In 

 view of the extensive investigations and introduc- 

 tion of new methods of testing the liability of 

 mining explosives to cause ignition of methane- 

 air and coal dust-air mixtures, Mallard and 

 le Chatelier's early observation that a methane-air 

 mixture requires ten seconds to ignite when con- 

 ducted through a porcelain tube at 650-660 C. 

 is worthy of being recalled. The influence of the 

 duration of the flame, on which Bichel has laid 

 great emphasis, is in such circumstances 

 apparent. 



With propellant explosives the unexplained 

 effect which gelatinisation of nitrocelluloses has in 

 decreasing the stability of the finished product, as 

 compared with the ungelatinised parent substance, 

 affords opportunity for speculation and research. 

 Here an apparently simple physical change, lead- 

 ing to consolidation, seemingly unconnected with 

 any chemical change, induces a marked increase in 

 the liability to spontaneous chemical decomposi- 

 tion. 



The disaster on the French battleship Una is 

 but an instance of such decomposition leading to 

 grave consequences. The B smokeless powder, 

 which was credited with being the initial cause, 

 consisted of two parts of insoluble nitrocellulose 

 and one part of soluble, gelatinised by an ether- 

 alcohol mixture. The temperature of the magazine 

 where the 10 cm. cartridges were stored which firs* 

 fired was extraordinarily high with the refrigera- 

 ting appliances out of action — estimated between 

 50 and 6o° C. The marked acceleration of de- 

 composition of such powders with rise of tempera- 

 ture is one of their striking features. 



The book should be generally welcome as an 

 addition to the already extensive literature on 

 explosives, for, in those parts outside the purely 

 practical, the subject is viewed from an unaccus- 

 tomed point of view, and different aspects from the 

 orthodox are always valuable. Further, the excel- 

 lent references and index of authors add appreci- 

 ably to its value. J. S. S. B. 

 NO. 22~ I. VOL. 91 J 



NEW BOOKS ON PHYSIOLOGY. 



(1) Human Physiology. By Prof. Luigi Luciani. 

 Translated by Frances A. Welby. Edited by 

 Dr. M. Camis. With a preface by Prof. J. N. 

 Langley, F.R.S. In four volumes. Vol. ii. : 

 Internal Secretion — Digestion — Excretion — The 

 Skin. Pp. viii + ssS. (London: Macmillan and 

 Co., Ltd., 1913O Price iSs. net. 



(2) Le Probleme Physiologiqite du Sommeil. By 

 Henri Pieron. Pp. xv + 520. (Paris: Masson 

 et Cie.. 1913.) Price 10 francs. 



(3) The Chemical Constitution of the Proteins. 

 By Dr. R. H. A. Plimmer. Part ii. : Syn- 

 thesis, &c. Second edition. Pp. .xii+107. 

 (London: Longmans, Green and Co., 1913.) 

 Price 2 s - 6d. net. 



(1) ^HE important character of Prof. 

 i_ Luciani 's text-book was well recog- 

 nised by English readers when the translation of 

 the first volume made its appearance. The second 

 volume, which has just been issued, confirms this 

 impression. The subject-matter is treated, as a 

 rule, in an interesting way, pros and cons on dis- 

 puted points are discussed intelligently, and the 

 work of past researchers, though in the main 

 chiefly interesting to the historian, is presented 

 with great fulness and lucidity. The book will 

 prove a valuable asset to the professed physiologist 

 and to the advanced student. 



For the average or junior student one may say 

 at once that the work is scarcely likely to benefit 

 him much. It assumes he already knows almost 

 as much as its veteran author, and the multiplicity 

 of the authorities quoted and the divergent views 

 expressed by them will only lead him into a quag- 

 mire of confusion. 



The book will be especially welcome, as it brings 

 to the knowledge of English-speaking workers 

 some idea of the energy and fertility of their Italian 

 colleagues. It is naturally these who are most 

 largely quoted. At the same time the preponder- 

 ance given to Italian work and thought has its 

 disadvantages, especially as one so often notices 

 the omission of important investigations carried 

 out in other countries. This leads in many cases 

 to a very imperfect presentment of certain prob- 

 lems, and in such instances the subject-matter is 

 consequently not complete or up to date. This is 

 especially noticeable in cases where chemistry has 

 played a part in the elucidation of physiological 

 mysteries. Prof. Luciani is a man of great erudi- 

 tion and boundless industry, but the chemical side 

 of physiology is evidently not his strong point. 



His account of the physiology of the suprarenal 

 body could not have been written in a more 

 interesting manner, but beyond the mere mention 



