



Action of Nitric Acid on Sebacic Acid. 423 



with basic acetate of lead a thick curdy precipitate, cohering 



after some hours, easily soluble as well in acids as in an excess 



of basic acetate of lead- Nitrate of silver is precipitated by 



the ammonia salt in white floes very like fresh precipitated 

 alumina. 



All these qualities mentioned, agree so perfectly with those of 

 pyrotartaric acid as described by Pelouze, that, considering the 

 similarity of the composition of both acids, I do not hesitate in 

 the least to proclaim the identity of pyrotartaric acid with the 

 acid obtained by oxydation of sebacic acid with nitric acid. 



From the statements of Weniselos my own differ, only in re- 

 gard to the ammonia salt, which the first pretends to have obtain- 

 ed in fine crystals ; and in regard to the neutral lead salt, which 

 ought to deposit itself after a certain time in fine needles, 

 whereas Pelouze, as well as myself, obtained only granulated 

 precipitates, under the same conditions. 



For further analysis I selected the silver salt, which was pre- 

 pared by precipitating the nitrate of silver with the ammonia salt of 

 the acid ; but I am sorry to say, that I did not succeed in obtain- 

 ing it of a constant composition, which is very remarkable in a 

 silver salt. I procured from salts of two different preparations 2-3 

 per cents, of oxyd of silver less than the formula AgO, PT re- 

 quired, though the acid combined with it, calculated by itself, 

 after deduction of the mean amount of oxyd of silver, corres- 

 ponded exactly to the formula of the anhydrous acid. 



The silver salt is very sensible to light, dries slowly and forms 

 semi-transparent hard pieces, very like the dried hydrate of alu- 

 mina; which become brownish white when powdered. The 

 analysis gave the following results: 



I. Preparation. — (1.) 0-3358 grm. silver salt gave 02005 grm. 

 silver = 0-2 153 grm. oxyd of silver. 



(2.) 0-4038 grm. silver ^0'2415 grm. silver^ 0-2585 grm. oxyd 

 of silver. 



(3.) 0-6715 grm. silver gave by combustion with chromate of 

 lead, 0-465 grm. carbonic acid, and 0*1245 grm. water. 



IL Preparation.— (I.) 03355 grm. silver salt gave 02027 Ag 



021777 oxyd of silver. 



(2.) 1-0034 grm. silver salt, burnt with chromate of lead, gave 

 0-675 grm. carbonic acid and 0-178 grm. water. 



This calculated in per cent, gives, 



I. Preparation. II Preparation. 



•v~ 



I. II. I. **• 



A?0 64-11 6101 . . 64-88 . . 



C . • 18-88 . . 18-34 



H 



2-06 . . 1-97 



