CHEMISTRY OP THE LEUCOMAINES. 295 



as stellate needles and plates when a mixture of hot solu- 

 tions of adenine and mercuric cyanide are allowed to cool. 



An adenine bismuth iodide, C5H5TSr5.HI.2Bil3 + 2H2O, 

 is obtained when an aqueous adenine solution is treated 

 with potassium bismuth iodide containing free hydriodic 

 acid. The heavy precipitate, which in color resembles 

 carbon monoxide hsemoglobin, consists of microscopic glit- 

 tering red needles. On contact with miich water it partly 

 decomposes, forming light reddish-yellow amorphous floc- 

 cules, which become darkish-brown at 100°. 



Adenine bromide. By treating well-dried adenine with 

 excess of dried bromine a dark-red body is obtained which 

 appears to contain six atoms of bromine. On mere ex- 

 posure to the air, more rapidly on heating at 100°-120°, 

 it decomposes, yielding bromine and a brom-adenine, 

 CjH^BrJSTj. This compound is white, difficultly soluble in 

 cold water (1 : 10,000), more readily in hot water, very 

 easily in ammonia. It crystallizes from water or dilute 

 ammonia in stellate needles. It is a rather strong base and 

 forms well-characterized salts from which it is thrown 

 down as a white micro-crystalline precipitate by addition 

 of ammonia. It is also formed from adenine- bromide by 

 treatment with sodium bisulphite. The picrate resembles 

 that of adenine but is more voluminous ; silver compounds 

 are also formed resembling those of adenine. The silver 

 nitrate compound decomposes on boiling with nitric acid 

 with separation of silver bromide. It is only difficultly 

 attacked by boiling alcoholic potash. 



When adenine is treated with zinc and hydrochloric acid, 

 in the cold, it forms a difficultly soluble crystalline double 

 salt which has not been obtained in the pure state. This 

 double salt is not obtained by direct treatment of adenine 

 hydrochloride with zinc chloride. 



One of the hydrogen atoms of adenine is capable of re- 

 placement by organic radicals. Thus it forms crystalline 

 methyl and ethyl compounds. 



Acetyl-adenine, CjH^iN's.CO.CIIj, can be obtained by 

 lieating the anhydrous base with an excess of acetic anhy- 

 dride for some time, in an oil-bath, at 130°. It crystallizes 



