172 BASIC BODIES. 



Carbon 10 atoms .... 39'73 



Hydrogen .... 5 .... 3'31 



Nitrogen 5 .... 46'36 



Oxygen 2 .... 10'60 



100-00 



Its atomic weight=1887'5. The hydrate consists, according 

 to Unger, of 2 atoms of water and 3 atoms of guanine. On account 

 of its basic nature, Berzelius* regards it as ammonia with a nitro- 

 genous adjuncts H 3 N.C 10 H 2 N 4 O 2 . 



Combinations. Like caffeine and theobromine, and other weak 

 bases, guanine readily unites in several proportions with acids, but, 

 like the above-named substances, parts with them readily on the 

 addition of large quantities of water, so that the pure base, mostly 

 as a hydrate, is separated, while an acid salt remains in solution. 



Hydrochlorate of guanine: the neutral salt,3(C 10 H 5 N-O 2 .HCl) + 

 7 HO, crystallises in bright yellow needles, loses all its water under 

 100, and all its hydrochloric acid above that temperature: the acid 

 salt, C 10 H 5 N 5 O 2 4 2HC1, loses half its hydrochloric acid at a mode- 

 rate temperature : with bichloride of platinum it forms a crystal- 

 line compound, C 10 H 5 N 5 O 2 .HCl + PtCl 2 + 4HO, which is as inso- 

 luble in cold water as the ammonio-chloride of platinum, but 

 dissolves very freely in hot water. The following basic hydrochlo- 

 rate has also been obtained: 2C 10 H 5 N 5 O 2 +HC1. 



Sulphate of guanine, C 10 H 5 N 5 O 2 .HO.SO 3 + 2HO, crystallises in 

 yellow needles, often an inch in length. 



Nitrate of guanine was obtained by Unger in several proportions : 



3C 10 H 6 N 5 O 2 +3NO 5 +12HO. 

 3C 10 H 5 N 5 2 +4N0 5 +12HO. 

 3C 10 H 5 N 5 2 +5N0 5 +16HO. 

 3C 10 H 5 N 5 2 +6N0 5 +18HO. 



The phosphate, oxalate, and tartrate of guanine may also be 

 obtained. 



Guanine-soda, C 10 H 5 N 5 O 2 +2NaO + 6HO, is precipitated from 

 the soda-solution on the addition of alcohol: it is a foliaceous crys- 

 talline mass, which attracts carbonic acid from the air, and effloresces. 

 At 100 it loses all its water; on the addition of water one portion 

 of the guanine separates, and another portion remains in solution 

 with an excess of soda. Guanine also unites with certain salts, as, 

 for instance, with nitrate of silver, forming crystalline compounds. 



Products of its metamorphosis. Guanic acid, C 10 H 3 N 4 O 7 , (termed 



* Jahresber. Bd. 27, 8. 678. 



