SALICYLIMIDE. 873 



and ammonia are described as soluble and possessing an alkaline 

 reaction, all the others as insoluble; most of them as yellow 

 and containing water of crystallization. The salts of lead and 

 copper are anhydrous. The neutral salt of soda contains 2 atoms 

 of water which it loses at 248, the salt of barytes contains 2 

 atoms of water. They are all decomposed by strong acids, and 

 salicylous acid set at liberty. Dr. Ettling describes an acid salt or 

 bisalicylite of potash having the same composition as the biben- 

 zoate of potash ; also a corresponding salt of soda, both of 

 which form colourless acicular crystals. 



SaKcyUmide, salhydramide C 42 H 18 O 6 N 2 . This body is pre- 

 pared by dissolving salicylous acid in three or four times its 

 volume of cold alcohol, and adding a quantity of aqueous solu- 

 tion of ammonia, equal to that of the salicylous acid employed. 

 Yellowish white needles are immediately produced, and the 

 liquid soon becomes a solid mass. By a gentle heat the whole 

 is re-dissolved and crystals of salicylimide are deposited on cool- 

 ing. This body is insoluble in water ; it is soluble in 50 parts 

 of boiling alcohol, but very slightly soluble in cold alcohol ; its 

 solution has a strong alkaline reaction. Solutions of alkalies 

 and acids act upon salicylimide, with the aid of heat, as they do 

 upon amides, reviving the ammonia and acid. 



In the formation of this compound 3 atoms of salicylous 

 acid unite with 2 atoms of ammonia, while 6 atoms of water 

 containing all the hydrogen of the ammonia are abandoned ; 

 2 atoms of nitrogen are thus substituted for 6 atoms of oxygen, 

 in the formation of salicylimide. It may be represented as 



42 H 15 3 or dividing by three: 



'2? 



Salhydramidide of copper, C 14 H 6 NO 2 Cu; or H,C 14 H 5 NO 



-fCuO. This remarkable compound is represented in the 

 last formula as a salicylous acid, in which 3 atoms of 

 oxygen of the salicyl are replaced by 1 atom of nitrogen, 

 and this is combined with 1 atom of oxide of copper. It 

 is obtained in a state of purity on mixing a solution of salhy- 

 dramide, the preceding compound, very dilute and slightly 

 cooled, with the ammoniacal acetate of copper. The liquid 



