ON THE SUBFRIC ACID, 



trescency, which necessarily precedes the formation of the 

 sinnt in ull cases, whether it depend on contagion or arise 

 spontaneously, attacks particularly the gluten; and pro- 

 cedes, indeed prevents, the formation of the starch : since 

 we know positively, that ttiis fecula, no traces of which are, 

 found in the smut of wheat, suffers no alteration from that 

 septic process, which so powerfully attacks the glutinous 

 substance. 



XV. 



Of the Action of Nitric Acid on Cork; by Mr. Chevreul*. 



1*9 



•RUGNATELLl having examined the action of nitric History ©f the 

 acid on cork, in 1787* found, that the cork was converted disc0 T ery ° f 

 into a peculiar acid. In 1797 Bouillon-Lag range resumed 

 the inquiry of the Italian chemist, and connrmed the ex- 

 istence of the suberic acid. In the two papers he pxibli shed 

 on thjs subject, he described the characters of this acid, 

 and its combinations with the salifiable. bases, which Brug- 

 natelli had not studied. Notwithstanding these labours, 

 several persons still entertained doubts of the existence of 

 this acid. They thought, that it was only one of the acida 

 previously known combined with some matter, by which its, 

 properties were concealed. Of the truth of this I was de- 

 sirous to satisfy myself by experiment. 



To form suberic acid, I followed the common process .;> preparation ©f 

 which I shall here recite, with the phenomena that occurred the suberic 

 in the operation, „* C1 * 



In a. retort, to wh'ich a receiver was adapted, I heated six 

 parts of nitric acid at 29* on one of rasped cork. The 

 matter grew yellow; nitrous gas mixed with carbonic acid 

 was evolved ; and a pretty large quantity of prussic acid 

 was formed, J returned the product from the receiver inta 

 the retort several times, that the cprk might be acted upuu 

 sufficiently. When the action of the acid appeared to 



* Annates 4c Cnimie, vol. LXn, p. 323. 



afcate t 



