ANIMAL OXIDES WITH AZOTE NOT OILY. 



porous brick or upon bloating-paper. In twenty-four hours the 

 liquid portion is removed, and there remains a dry white powder, 

 easily purified by repeated crystallizations. It is mixed with its 

 own weight of water in a porcelain capsule, and heated till com- 

 plete solution takes place. The solution being filtered and left 

 in a warm place, colourless transparent crystals, having the dia- 

 mond lustre and considerable bulk, are gradually deposited. 

 These crystals constitute alloxane in a state of purity. 



Alloxane crystallizes in water under different forms. On al- 

 lowing a hot saturated solution to cool, very bulky crystals are 

 formed, very deliquescent, and containing a great deal of water 

 of crystallization. The crystals deposited in a hot solution are 

 always anhydrous, and do not effloresce. The form of the crystal 

 is a right prism with a rectangular base, and its primary form is 

 a rhomboid. They have a pearly lustre, especially after having 

 been kept for some time, and may be easily obtained an inch in 

 length. The anhydrous crystals have the form of pyroxen ; the 

 primitive form being an oblique prism with a rhomboidal base. 

 The crystals have usually the form of rhomboidal octahedrons 

 truncated on the angles. They have a vitreous lustre, are trans- 

 parent and much smaller than the hydrous crystals. 



Alloxane is soluble in alcohol, and very soluble in water. Its 

 solution communicates a red stain to the skin, and a peculiar 

 disagreeable smell. It reddens litmus-paper ; but loses that 

 property when a base is present, although it does not form a salt. 

 Its solution does not decompose the carbonates of lime or barytes. 

 Oxide of lead may be boiled with it, without oocasioning any al- 

 teration. From these facts, it is obviously not entitled to the 

 name of acid. 



After the addition of an excess of barytes water, the liquid so- 

 lution of alloxane remains for some time clear and colourless, 

 but after some hours, it deposites white brilliant crystals, which 

 are soluble in hot water, and again deposited when the solution 

 cools. An excess of lime-water occasions an immediate white 

 crystalline precipitate, soluble in a great quantity of water. 



When alloxane is mixed with the salts of protoxide of iron, it 

 occasions at first no precipitate ; but the liquid assumes an intense 

 indigo blue colour. 



Alloxane, heated with sulphuric acid and metallic copper, does 

 not give out a trace of oxide of azote or of nitrous acid. When 



