270 ANNUAL KEPORT SMITHSONIAlSr INSTITUTION, 1908. 



shells, giving special protection to the primers, and generally taking 

 the utmost precaution to prevent access of foreign bodies while the 

 acid is in the molten state. Picric acid has an intensely bitter taste 

 (which is still more pronounced in the inky black smoke of burning 

 picric acid), and therefore its manipulation is not very pleasant. It 

 also imparts a fairly fast yellow coloration to the skin, which in some 

 parts has procured the nickname of " canary birds " to the workers 

 in picric acid. (I have found that in one factory common salt was 

 used for removing the yellow coloration from the skin, but why it 

 should do so is not quite clear.) "WHien used together with other ma- 

 terials it must be remembered that, being an acid, it is liable to dis- 

 place other acids; for instance, it sets free nitric acid from nitrates, 

 and therefore while picric acid might be useful for increasing the 

 power of certain explosives it would actually decompose them. 



In order to obviate these drawbacks Hauff had proposed the use of 

 trinitroresorcine " and the Chemische Fabrik Griesheim that of trini- 

 trobenzine^ and trinitrobenzoic acid.*^ These substances were not 

 favorably received, but trinitrotoluene has within the last few years 

 come very much to the fore, and also possesses a great many good 

 qualities. Its melting point varies between 72° and 82° C. It may 

 be handled with almost perfect safety if pure, does not give off nox- 

 ious fumes on melting, is quite stable, does not combine with metals, 

 and generally has no acid properties. Like picric acid it is only 

 slightly soluble in cold water. It is slightly less powerful than picric 

 acid, which is rather an advantage, since the latter frequently pul- 

 verises a shell, instead of bursting it into a number of fragments 

 sufficiently large to have destructive effect. Trinitrotoluene is very 

 easily detonated. I have been able to explode it in the form of pow- 

 der, with a No. 3 detonator only (0.540 gram of fulminate compo- 

 sition). 



Trinitrotoluene has been introduced into the French service under 

 the name of tolite. The Spanish Government call it trilit. The 

 carbonite works of Schlebusch are introducing it into other services 

 under the name of trotyl, and Messrs. A. and W. Allendorf, of 

 Schoenebeck, under the name of trinol, whilst other factories retain 

 the name of trinitrotoluol. 



The manufacture of trinitrotoluene is carried out in stages, like 

 that of most aromatic nitro compounds. Great care has to be taken 

 to purify the toluene, since that usually found in commerce contains 

 benzine and other compounds. Nitration is effected in enameled 

 iron vessels, and purification of the higher nitrates, which cake to- 

 gether during nitration, has to be performed with some care. Wash- 



« British patent No. 9798, of 1894. 

 6 German patent No. 79477, of 1893. 

 c Id., No. 79314, of 1893. 



