(i() ANIMAL ACIDS CONTAINING AZOTE. 



Cholesteric acid, . 26-32 or 5 or 17-875 



Oxide of lead, . 73-68 or 14 or 50 - 3^ atoms. 



It was probably a mixture of tetrakis-cholesterate of lead and 



cholesterate of lead. 



12. Cholesterate of mercury. When cholesterate of potash is 

 poured into proto-nitrate of mercury a black precipitate falls. 

 The colour of the precipitate is deep-red when the mercurial 

 salt is the per-nitrate. 



13. Cholesterate of copper. When cholesterate of potash is 

 poured into any salt of copper an olive-coloured precipitate falls, 

 without taste or smell, and quite insoluble. According to the 

 analysis of this salt by Pelletier and Caventou it is composed of 



Cholesteric acid, . 5 or 15 1 atom 



Oxide of copper, . 15 or 45 9 atoms. 



It is very unlikely that this analysis can have been made upon 

 any thing else than a mixture. At least no analogous compound 

 has hitherto been observed. 



14. Cholesterate of iron. When cholesterate of potash is 

 poured into sulphate of iron a deep-brown precipitate falls, which 

 is slightly soluble in water. On exposure to the air it becomes 

 yellow by absorbing oxygen. This salt was analyzed by Pelle- 

 tier and Caventou, and found composed of 



Cholesteric acid, . 11-1 or 16*65 1 atom 



Oxide of iron, . . 4*5 or 6-75 = 1^ atom. 



From this analysis it would appear that the salt was a subsesqui- 



cholesterate of iron. 



15. Cholesterate of Zinc is obtained by double decomposition. 

 It has a fine red colour, and is slightly soluble in cold water, and 

 still more soluble in boiling water. 



1 6. Cholesterate of cobalt is obtained by double decomposition, 

 and has a yellow colour similar to that of plain Spanish snuff. 



17. Cholesterate of tin is also yellow, but lighter, and having 

 a tint of orange. 



18. Cholesterates of nickel and manganese have a bistre colour. 



SECTION XIV. OF HYDROMELONIC ACID. 



This acid was discovered by M. L. Gmelin in 1835, and nam- 

 ed hydrojnelonic, because it is composed of one atom of melon 

 and one atom of hydrogen.* 



* Annalen der Pharmaeie, xyi. 252. 



