GUANINE. 127 



8. Diabetic sugar is identical with dextro -glucose 

 above described. 



Guanine, C 5 H 6 N 5 0. 1. Boil 500 grm. of Peruvian 

 guano with milk of lime till the liquid has turned from 

 brown to greenish yellow, filter, neutralise with hydro- 

 chloric acid, and allow to stand some hours. Wash 

 the deposit, treat with boiling hydrochloric acid, decant 

 the clear liquid from the undissolved uric acid, set 

 aside to crystallise, and purify the crystals by re- 

 crystallising from HC1. Finally precipitate by ammonia, 

 wash with water and dry. 



2. Pure guanine is a white, neutral amorphous 

 powder, insoluble in water, soluble in strong acids and 

 alkalies. The hydrochlorate crystallises in thin, light 

 yellow needles, which lose water at 1 00 C., and acid at 

 200 0. 



3. Dissolve a little guanine in hot nitric acid. On 

 cooling, long, very fine, interlaced crystals of nitrate 

 will form. 



4. Treat solution of guanine hydrochlorate with 

 ammonia oxalate. Crystals of guanine oxalate will be 

 produced. 



5. Mix hot saturated solution of guanine in HC1 

 with excess of hot concentrated PtCl 4 , evaporate to 

 one half and allow to cool. Wash with alcohol and 

 ether the yellow needles formed, and dry in vacuo over 

 sulphuric acid. Weigh a small portion, ignite in a 

 weighed crucible, and weigh the residue of spongy 

 platinum. The salt should contain 35'17 of platinum. 

 Formula C 5 H 5 N 5 0, HCl+PtCl 4 +2H 2 O. 



