25f) Ni'w inflammuUe and detonating SuhsfanceJ 



of inflammation and detonation, of course its intimate and 

 peculiar nature, has altogether escaped him. 



The substance tcrn)cd by Wekher the bitter principle, 

 in which he discovered a power of detonating, seems to be 

 the san)e matter: but he has attributed this peculiarity to 

 the presence of a portion of nitrate of potash. 



The most convenient mode of procuring the substance 

 in question, is to boil four parts of nitric acid, of IS or 20 

 degrees strength, upon one part of powdered indigo of 

 Guatinala, until its colour is destroyed, while the acid be- 

 comes yellow, and till there remains on the surface only a 

 thin layer of resinous matter, which becomes firm by cool- 

 ing. This is to be removed, the solution evaporated to the 

 consistence of honey, and the residuum dissolved in hot 

 water, and filtered, A solution of the potash of commerce 

 is now to be poured into the liquor, when a number of r-malF 

 yellow crvstals of a circular shape will appear, forming the 

 inflauMTiable substance. 



The re?'.ri v.liich has been separated may, bv the addition 

 of a new p )rt;o;i oF acid, be also converted into the same 

 yellow detouaiino substance. 



If the process be stopped before the point mentioned, 

 we obtain, instead of the detonating substance, a matter of 

 a yellow colour and crvstallized, but more soluble in water, 

 and subliming in the form of white needles. 



This substance exhibits all the characters of benzoic acid, 

 altered bv a portion of the resin. In all probability the 

 continuance of the process decomposes or volatilizes this 

 acid. 



The orange colour of the detonating matter; its bitter 

 taste; its solubility in boiling water, iti alcohol, and, above 

 all, in nitric acid ; the verv deep blood-red colour which it 

 acquires on iJie application of alkalis, and which it com- 

 municates to the precipitate from the suiohate of iron; the 

 tenacity with which it adheres to the benzoic acid which is 

 formed along with it by the action of the nitric acid upon 

 indigo; and lazily, its property of detonating strongly with 

 a clear purple light when wrapped up in a bit of paper and 

 struck with a hammer, are characters which sufficiently 

 distinguish this substance from every other with which we 

 are acquainted. 



The celebrated authors of this memoir have ascertained 

 that the detonating property of the new substance depends 

 neither on the presence of nitric acid nor on that of ammo- 

 nia 3 for concentrated sulphuric acid disengaged from it no 



acid 



