ALLANTOINE. 67 



0. should be O8095; at 14 0., 07982. It should 

 boil at 78 0. under a pressure of 760 millimetres of 

 the barometer. 



Allantoine, C 4 H 6 N0 3 . 1. Glassy, tasteless prisms. 

 Obtain from the allantoic liquid of cows by evaporating 

 to one fourth of its bulk. The crystals of allantoine 

 deposited on cooling redissolve in hot water, and boil 

 with a little good animal charcoal. 



2. From the urine of calves. Obtain the urine by 

 tying of bladder during killing process. Evaporate it 

 till syrupy, and allow to stand for several days ; dilute 

 with water, collect the deposit and wash it with a 

 little water. Boil the crystalline residue with water 

 and animal charcoal and filter hot. The allantoine will 

 be deposited in crystals on cooling. 



3. Prepare allantoine from uric acid as follows : 

 Take 20 grm. of uric acid, stir up in 300 to 400 c. c. of 

 water, add a small quantity of acetic acid, gradually 

 introduce 100 grm. of lead peroxyde, and expose to 

 sunlight for some time. Boil, filter, and evaporate the 

 nitrate until on cooling the allantoine crystallises out. 



4. Observe that it is slightly more soluble in alcohol 

 than in water. 



5. Boil with baryum hydrate, and notice evolution 

 of ammonia. 



6. Corrosive sublimate will produce no precipitate in 

 its solution, but mercuric nitrate precipitates it in the 

 cold even from dilute solutions. 



Alloxan. C 4 H 2 N 3 4 . 1. Add to strong nitric 

 acid, contained in a beaker placed in cold water, an 



