620 



NATURE 



[February 4, 19 15 



TRINITROTOLUENE IN THE WAR. 



IN a recent article in Nature (December 24, 

 1914), brief reference was made to the high 

 explosives used as bursting- charges for shells, the 

 most important being the much-discussed trinitro- 

 toluene, used largely by the Germans- The 

 following summary of an able contribution on 

 the subject, published in the St. Thomas's Hos- 

 pital Gazette for December, will prove a useful 

 supplement to the previous article in our columns. 



Few people realise the exacting conditions 

 which a high explosive for shells must fulfil ; these 

 may be summarised as high bursting power, 

 stability in storage, insensitiveness to shock on 

 firing from the gun and on impact of the projec- 

 tile, where it is desired that penetration shall 

 precede bursting. Yet it must be possible to cause 

 the material which withstands such drastic treat- 

 ment to detonate when required with frightful 

 violence. It is a case of reconciling the irrecon- 

 cilable. Further points are safety in handling in 

 the shell factory and the suitability for producing 

 maximum density of loading, say by some such 

 method as melting and pouring into the shell. 



The brisance, or bursting power, is shown to 

 depend on the potential energy of the explosive, 

 the velocity of detonation, and the degree of con- 

 centration (density of loading). 



It will be realised that few substances will 

 fulfil such conditions, and the number will be still 

 further reduced by difficulties and cost of manu- 

 facture. The paper discusses the four most im- 

 portant explosives which have been tried for this 

 purpose, namely, picric acid (lyddite), trinitro- 

 toluene (TNT), tetranitromethylaniline (tetryl), 

 and tetranitraniline. 



The trinitrotoluene is the symmetrical isomer 

 (1:2:4:6) melting at 8o'6. It is manufactured 

 iDy dissolving orf/ionitrotoluene in concentrated 

 sulphuric a^id, nitrating first to the dinitro and 

 finally to the trinitro stage, the purification being 

 effected by recrystallisation from ethyl alcohol 

 containing a little benzene. 



Data are given of comparative trials of TNT 

 and picric acid, both in France and Germany. In 

 velocity of detonation and with the lead block 

 test (increase in size of cavity on firing a charge) 

 the advantage is with lyddite, as the following 

 figures demonstrate : — 



Lyddite TNT 



Velocity of detonation 7745 7140 metres per sec. 

 Lead block test 228 218 c.c. 



TNT caused, however, a greater displacement 

 of earth than lyddite when fired in a bore-hole 

 I metre deep. 



Except in the last instance, picric acid held a decided 

 advantage throughout, and the question at once 

 arises : Why, then, has trinitrotoluol been adopted by 

 Germany, Russia, Italy, and other countries in pre- 

 ference to the picric acid that is still mainly used by 

 us under the name of lyddite, and by France under 

 the name of melinite? The struggle between the two 

 explosives has been long and of doubtful issue, but it 

 has now probably ended in the victory of trinitro- 

 toluol. 



NO. 2362, VOL. 94] 



In furnishing the answer to this conundrum the 

 writer continues : — ■ 



We have seen it to be inferior in regard to power, 

 velocity of detonation, and density of concentration ; its 

 advantages lie in its greater insensitiveness to shock, 

 its freedom from poisonous dust and fumes, the much 

 lower temperature at which it can be poured into 

 shells, and its chemical indifference to substances like 

 lead and iron which are liable to form dangerous 

 picrates. When firing a shell against a ship's armour, 

 at certain limits of the thickness and toughness of 

 the armour-plate and of the velocity of the shell's 

 impact, picric acid would explode when trinitrotoluol 

 would perform its work efficiently, and the latter is 

 therefore better adapted to a high-velocity shell of 

 large calibre. 



Since TNT contains too small a percentage of 

 oxygen for complete combustion, attempts to use 

 it incorporated with bodies rich in oxygen, such 

 as potassium chlorate, have been tried. The 

 Belgian high explosive, "macarite," is stated to 

 consist of 30 parts of TNT and 70 parts of lead 

 nitrate. A very high density of loading is thus 

 attained, but the velocity of detonation of macarite 

 is given as only some 4600 metres a second. 



In concluding his article, the author says that 

 tetranitraniline or tetryl seem to be the only known 

 substances that may supersede trinitrotoluol. 



TYPHOID IN THE FIELD. 



T^HE anti-vivisectionists, by their raging attack 

 on the protective treatment against typhoid 

 fever, have shown us, once more, the dark and 

 ugly side of anti-vivisection. Kind people may 

 try, but may try in vain, to find any excuse for 

 such goings-on. The only possible sort of excuse 

 for them is, that the treatment is not perfect, not 

 faultless ; and that, among some hundreds of 

 thousands of men and women who have received 

 it, a few-^perhaps one in a thousand — have not 

 done well. One in a thousand is a fair guess, 

 founded on the experience of the 20,000 Valcartier 

 men of the Canadian forces : but Surgeon- 

 General Williams, Director of Medical Services, 

 Australian Imperial Force, says of the protective 

 treatment of 20,000 Australian troops, "Not one 

 single case showed any after-symptom which 

 could be considered worthy of consideration, 

 Not a man had to be taken off duty ; drills and 

 exercises proceeded as usual " (Times, January 

 30). Further, we may admit that the overwhelm- 

 ing rush of work, at the beginning of the war, 

 may have caused, here or there, some error of 

 judgment, or some neglect of this or that bit of 

 technique. The strain on the Army Medical De 

 partment, the incessant overwork, were well-nig 

 intolerable ; and it is more than likely that som 

 men got the treatment without any precise direc- 

 tions how to take care of themselves after 

 it. or even without much chance of taking care 

 of themselves. If a man, for a couple 

 of days after the treatment, will avoid over- 

 exertion, and alcohol, and exposure to the danger 

 of pneumonia, he may be confident that he will do. 



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