SUBSTANCE ANALOGOUS TO GUN COTTON. 
245 
mixture of 2 vols, of sulphuric acid of 1.83 and 1 vol. of 
nitric acid of 1.43 is poured into syrupy glycerine, a very 
lively oxidation ensues, the product of which I have not 
ascertained ; if, on the contrary, the above mixture of the 
two acids is placed in a freezing mixture, and glycerine 
poured into it, agitating to avoid all elevation of tempera- 
ture, the glycerine quickly dissolves without any percepti- 
ble reaction ; if the mixture be now poured into water, an 
oily substance heavier than water subsides to the bottom of 
the vessel ; when it is washed with a considerable quantity 
of water, to free it entirely from acids, without any loss, as 
it is quite insoluble in that menstruum. When well washed, 
it is wholly dissolved in alcohol-, and precipitated again by 
water, or dissolved in ether, and the solution left to spon- 
taneous evaporation, when it is obtained in a state of per- 
fect purity. It is readily freed from water by keeping it for 
a few days in vacuo over sulphuric acid. 
" In this state the body has the appearance of olive oil 
colored slightly yellow; it has no odor; its taste is sweet, 
pungent, and aromatic ; but in making this experiment 
great precaution should be used, for a very minute quantity 
held upon the tongue produces a violent headache for 
several hours. The effect upon the human body was expe- 
rienced by several persons in my laboratory, and I have 
frequently felt its effect myself." 
As far as my experience goes, it is not necessary that the 
acids shall be of the specific gravities given above, for in my 
experiments I used the Nordhausen sulphuric acid of 1.86 
and nitric acid of 1.48, and succeeded perfectly. Iam well 
satisfied that it matters little what the strength of the acid 
may be, provided that it is strong enough. The greatest 
difficulty which I met with was from the glycerine. In my 
first experiments I failed in every instance, in consequence 
(as I think) of the oxide of lead which had not been preci- 
pitated, and of the large amount of water which was com- 
bined with the glycerine. After having got rid of the lead 
21* 
