ON VAniOUS CHEMICAL ACTIONS. 241- 



stances, but they further acquire the property of decompo- 

 sing acetate of lead, as well as other metallic acetates, and 

 of combining readily with their oxides, the acetic acid of 

 which is given out. These oils thus separated would produce 

 the same effect perhaps on other metallic salts. In general This common 

 all fats, resins, and turpentines, combine better with ^.^.^^^^5 

 other substances, after they have been reduced to soap and 

 separated by an acid, than in their natural state. Wax 

 comports itself in the same manner. A knowledge of this This oil exposed 



effect induced me to subject to the action of the process ^? ^^^ ^^*i°" ^ 

 - - . ,. . - •' ,, . ^ ., nitric acxd. 



for forming oxalic acid a small portion of oil separated 



from Marseilles soap, which I mixed with sugar previously 

 powdered. At the end of the operation I found, that the 

 oil had acquired the consistence of suet, and that it had 

 assumed a yellowish colour and a rancid smell, retaining 

 the property of swimming on water. This grease, having 

 been exposed to the same process a second time, had its 

 rancidity increased, contracting at the same time a little of 

 the smell of wax; and its specific gravity became so great, 

 that, after it had been well washed and perfectly freed from 

 acidity, it sank to the bottom of water, Mithout having 

 lost its property of being soluble in alcohol. 



My memoir on indigo shows, that I had long ago built Indigo- 

 great hopes on the action of nitric acid with respect to 

 other substances, and it is with great pleasure I perceive, 

 that Messrs. Fourcroy and Vauquelin have pursued my re- 

 searches on indigo exposed to the action of nitric acid 

 with more success than I obtained- I could only have 

 wished, that Mr. A. Laugier had passed me over in silence 

 in his abstract of the paper of those learned chemists, for 

 my way of thinking in cliemistry is totally difi'erent now 

 from what it was eighteen years ago. "When Mr. Laugier 

 quoted me, he should not have forgotten that passage in my 

 paper, which mentions the results of treating indigo with 

 nitric acid, results that struck me so forcibly, as to induce 

 me to recommend them to the attention of chemists. 

 Neither had I omitted to mention the phenomena of the 

 deflagration of the mixture, with the throwing of the glas« 

 rod out of the evaporating vessel. As a little time before 

 I undertook these experiments I had extracted the benzoic 



acid 



