NATURE 



[May 5, 1898 



The advance in knowledge since the fifth edition of the 

 " Gewebelehre " is nowhere so striking as in the case of 

 the central nervous system. The extended study of 

 degeneration following upon injury, and the histological 

 methods introduced by Erlich, Golgi, and others, have 

 led to a rapid increase in knowledge concerning the 

 distribution of nerve fibres both within the central 

 nervous system and outside its limits ; while an alto- 

 gether new conception of the anatomical relations of 

 ganglion cells has been established. Prof, von Kolliker 

 was one of the first to recognise the importance of 

 Golgi'swork ; and after visiting him in Padua in 1887, he 

 adopted the new method in a series of investigations, 

 some of which are described in seven papers published 

 between 1889 and 1891 (cf. especially Zeitschr. f. w. 

 Zoologie, vols. xlix. and li.), while the results of others 

 appear for the first time in the second volume of the 

 "Gewebelehre." This volume, of nearly 900 closely- 

 printed pages, illustrated by 840 figures, most of which 

 are as usual original, attempts nothing less than an 

 outline of the comparative histology of the central 

 nervous system in Vertebrata generally. The value of 

 this enormous work arises not only from the new state- 

 ments of fact which it contains, but from the systematic 

 treatment of the mass of detail, constituting almost a 

 new science, by a man who knows every fact referred 

 to from his own observation. 



This is not the place in which to speak of the 

 numerous and well-merited honours conferred upon 

 Prof, von Kolliker by the Government of his own country 

 and by scientific societies and academies in almost every 

 land. It is hoped that the foregoing imperfect outline of 

 his work may give some idea of his position as one of 

 the founders of modern systematic histology, and of 

 his valuable services to embryology and comparative 

 anatomy. Those who are best able to judge the im- 

 perfections of this sketch will be best able to understand 

 the magnitude of the attempted task. 



W. F. R. Weldon. 



NITRO-EXPL OS IVES. 

 Explosifs Nitres. By J. Daniel. Pp. viii -f 235. (Paris : 



Gauthier-Vniars et Fils.) 

 D Y far the greater portion of this book is a fairly 

 -L' literal translation of Mr. Sanford's work on 

 nitro-explosives, published in 1894. It suffers there- 

 fore, in many respects, from the same defects, though in 

 others it is a decided improvement. Like the original 

 it gives, for example, a description of all the gelatinised 

 nitroglycerine preparations before giving the manufacture 

 of the various nitro- cottons used in gelatinising them, 

 which is, in several respects, an inconvenient arrange- 

 ment. Like Sanford's work, it describes the manufacture 

 of nitroglycerine and nitrocellulose in greater detail than 

 IS necessary for the use of a general chemist, and yet 

 insufficiently so to serve as a com.plete guide to the 

 manufacturer. The description of nitroglycerine is, 

 however, a marked improvement on the original, and 

 does not, for example, leave the reader in doubt as to : 

 whether nitroglycerine should be regarded as a nitric i 

 ether or not. It is, therefore, all the more surprising to \ 

 find that M. Daniel, like Mr. Sanford, has apparently 

 NO. 1488, VOL. 58] 



failed to grasp the great importance, from a theoretical 

 as well as a practical point of view, of the fundamental' 

 difference between a nitric ether, on the one hand, and a 

 true nitro-compound on the other. The former, although, 

 when pure, perfectly stable at ordinary temperatures, 

 decompose readily at, comparatively speaking, low 

 temperature, and are one and all unstable at ordinary 

 temperature in the presence of even minute traces of 

 strong mineral acids as well as in the presence of many 

 organic acids. Hence, in order to ensure the stability 

 of a powder containing a nitric ether, it is absolutely 

 essential not only to exclude all free acids, but also all 

 compounds likely to become acid. Hence ammonium 

 salts, like nitrate of ammonium, for example, may be 

 used with perfect safety in admixture with a nitro- 

 compound, such as dinitrobenzole in the manufacture 

 of bellite, roburite, securite, &c., whereas the presence 

 of this salt would be fatal in an explosive containing a 

 nitric ether such as guncotton or nitroglycerine. 



The preparation of the various nitro- celluloses, soluble 

 and insoluble, is given very fully — too fully for the general 

 chemist ; but the author, in following too closely his 

 original, fails to point out that the question of solubility 

 or non-solubility of nitro-cotton is, in great measure, at 

 least, one of method of manufacture and not one of 

 degree of nitration, and also depends, in a measure, on 

 the temperature of the ether alcohol mixture. This is 

 very remarkable, seeing that the Cordite trial, during the 

 progress of which this question of soluble and insoluble 

 guncotton was very fully discussed, is several times 

 alluded to in the work. The statement, found in both 

 works, that the sulphuric acid in the manufacture of gun- 

 cotton does not take part in the reaction, is, at least, open 

 to doubt. The manufacture of celluloid, to which eight 

 pages are devoted, however interesting in itself, should 

 scarcely occupy so much space in a work of only 271 

 pages devoted to nitro-explosives. 



A very useful addition of M. Daniel consists in a de- 

 scription of the physiological effects of nitroglycerine 

 and dinitrobenzole. The baneful effects of this latter 

 compound on the health of the workpeople employed in 

 the manufacture of explosives containing it, was first 

 clearly established by a small Departmental Committee 

 of the Home Office, and it is curious to find it taken 

 up by a Frenchman and omitted from the work of an 

 Englishman. 



Most of the more commonly used explosives are 

 shortly, but sufficiently described ; but the mistakes found 

 in the original unfortunately reappear in the translation. 

 Thus roburite never was a mixture of ammonium nitrate 

 and chlorodinitrobenzole, but one of the former salt with 

 chlorinated dinitrobenzole containing, at most, 2 per cent, 

 of chlorine, a very different thing. This original roburite 

 is no longer manufactured in England. M. Daniel also, 

 like Mr. Sanford, gives what may be called the ideal 

 composition of dynamite (25 per cent, kieselguhr and 75 

 per cent, nitroglycerine) as the ordinary one, whereas, as 

 a matter of fact, commercial dynamite practically never 

 contains 75 per cent, nitroglycerine, and almost always 

 contains mineral matters besides kieselguhr. 



As a further interesting addition by the translator may 

 be mentioned the statement regarding the curious differ- 

 ence in the behaviour of frozen gelatine dynamite and 



