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NATURE 



343 



HIGH EXPLOSIVES. 



High Explosives : 1 Practical Treatise. By Capt. 

 \V. S. Colver. Pp. xxix+830. (London: 

 Crosby Lockwood and Sim, 191S.) Price ; 

 guineas net. 



CAPT. COLVER has written this large volume 

 with the object oi Riling "a marked gap in 

 English technical literature, which is sadly de- 

 ficient in receni information on the subject of high 

 explosives." Though one may not entirely agree 

 with his statement that there is "very little col- 

 lected information regarding the manufacture, 



proper! ies, and use of modern high explosives," 



there is no such complete account as the author 

 - in this very comprehensive treatise, espe- 

 cially Oil the manufacture of these important com- 

 pound 



In dealing with this subject the author verj 

 naturally directs attention to the present diffi- 

 culties which must be encountered by a writer 

 owing to the impossibility of publishing- certain 

 information, so that it became necessary to 

 restrict the work in many important particulars. 

 Similar restrictions must also apply to criticism 

 of the work for fear of transgression. 



In the interesting introductory chapter the old 

 controversy over the use of picric acid as an 

 explosive crops up, and the author's statements 

 are contradictory, for on one page it is stated 

 that its detonating properties were discovered by 

 Turpin in 1885, whilst two pages later Sprengel's 

 address before the Chemical Society in 1S73, in 

 which he stated that "it is an extremely powerful 

 1 xplosive provided that it is ignited by a powerful 

 ," is quoted. Again, later, Capt. Colver 

 writes thai it was Turpin \s discovery which had 

 given the explosive industry a particularly valu- 

 "■w explosive. 



I he following section deals with raw materials 

 and outlines the separation of the primary pro- 

 duns. Although petroleum as raw material is 

 not of great importance, more recent records of 

 production than those for 191 1 might have been 

 given. No reference is made to the presence of 

 aromatic hydrocarbons in certain petroleums, 

 although for Russian petroleum "benzene" is 

 twice mentioned as the first distillate, when it 

 should obviously have been "benzine" (the 

 specific gravity being 0725). 



In dealing with synthetic phenol, a raw material 

 that has been made on a large scale, only one 

 process of manufacture is referred to, the 

 benzenc-sulphonic acid method. 



Very complete chapters deal with the nitro-com- 

 pounds of the aromatic hydrocarbons and of the 

 phenols and naphthols. Trinitrobenzene is stated 

 to be the most suitable of the highly nitrated 

 aromatic hydrocarbons lor use as a detonating 

 isive, the proportion of oxygen giving it 

 advantage over trinitrotoluene, as also does the 

 maximum density attainable, 107 ;is against r62 

 for the toluene derivative. Although slightly 

 more sensitive than T.N.T., it is less so than 

 picric acid. Trinitrobenzene is not at present ex- 

 XO. 2566. VOL. I02] 



tensivel) Used, probabl) owing to the difficulty and 

 expense of manufacture. Attempts to nitrate 

 T.N.T. more highly are shown to result in the 

 formation of trinitrobenzoic acid, or even rupture 

 of the benzene ring with the formation of tetra- 

 nitromethane, the intense odour of which has been 

 perceptible where decompositions have occurred 

 during manufacture. 



Less extensively employed nitro-dcrivatives, 

 including hexanitrodiphenylamine and the poly- 

 nitroanilines, and others which have scarcely 

 reached the stage of practical application, are 

 described. Tetranitroaniline is stated to have 

 proved by practical tests the most powerful of all 

 tin- explosives hitherto used. Several explosives of 

 this (lass have been employed for aircraft bombs; 

 thus mixtures of two parts of T.N.T. with one 

 part of tetranitroaniline, or of hexanitrodiphenyl- 

 amine (dipicrylamine), are stated to have been 

 used by the Germans. 



Search for suitable raw materials outside the 

 pure chemical compounds has naturally engaged 

 attention, principally in the directions of utilising 

 tar products boiling over a wide range, and 

 petroleum hydrocarbons. Naturally the nitro- 

 products are complex in character; thus from 

 coal-tar naphthas mixtures of solid and liquid 

 nitro-products are obtainable, those from fractions 

 boiling above 200° C. containing many nitro- 

 derivatives of the naphthalene series. The nitro- 

 products from petroleums are stated to consist 

 generally of uncrystallisable masses of reddish- 

 brown colour suitable only for certain plastic 

 explosives. The possibility of obtaining generally 

 useful materials by direct nitration does not 

 appear promising. A sounder procedure would 

 appear to lie in "cracking" the oils for the pro- 

 duction of aromatic hydrocarbons which can be 

 separated and then nitrated. 



Indirectly prepared nitro-deriyatives of paraffin 

 hydro-carbons are of considerable interest, and the 

 author considers that here is a profitable field of 

 research. The remarkable substance tetranitro- 

 methane [C(N0 2 ) 4 ] has been patented as an 

 oxidiser for other organic compounds, as in the 

 Sprengel type of explosives. This compound is 

 comparatively non-volatile, has no acid properties, 

 is completely stable, insoluble in water, and 

 not affected by it. Hexanitroethane [C 2 (N0 2 ) 6 ] 

 forms colourless crystals, which are extremely 

 insensitive to percussion and friction. 



Considerable space is given to the German rules 

 and regulations governing the manufacture, etc., 

 of explosives, the author considering that the ripe 

 experience of the Germans justifies this. British 

 regulations are not dealt with. There is a useful 

 section on the toxic effect of raw materials and 

 products. Some contradiction is evident over the 

 relative liability of more or less highly nitrated 

 products to produce ill-effects, for the general 

 statement is made that the toxic effect of the 

 lower grades of T.N.T. is greater than that of 

 tin' pure substance, whilst in a previous passage 

 the statement occurs that in general with the 

 various nitrobenzenes (and nitrotoluenes), "as the 



