UEIC ACID. 177 



4. Dissolve uric acid in boiling water, and observe 

 that a deposit ensues on cooling. Dissolve it in alka- 

 lies, and observe that the salts with excess of alkali 

 are much more soluble than the salts with excess of 

 acid. 



5. Dissolve one part of uric acid in four parts of 

 nitric acid of 1*42 sp. gr. The acid will dissolve under 

 evolution of carbonic acid, nitrogen and nitrous acid, 

 and on cooling alloxan (see p. 67) will be deposited. 



6. Evaporate the solution of uric in nitric acid to 

 dryness on the water bath, and allow the vapour of 

 ammonia to touch the residue. A purple colour of 

 murexide will be produced. 



7. To uric acid made into a pap with water add 

 gradually lead peroxide, and keep the mixture near the 

 boiling point. The lead is transformed into oxalate, 

 carbonic acid is evolved with effervescence, the filtered 

 fluid deposits crystals of allantoine on cooling, and the 

 mother liquid contains urea. 



8. Heat uric acid in closed tubes with concentrated 

 hydrochloric or hydriodic acid, and obtain glykoltoll by 

 decomposition of the resulting salt as described under 

 that substance. 



9. Examine the urates spontaneously deposited on 

 cooling from healthy or morbid urine ; collect them on 

 a filter, and observe that when washed with water 

 crystals of uric acid gradually form in them, but that 

 this formation does not take place when the washing is 

 effected with spirit. Determine the quantity of bases 

 contained in them, which are mostly a mixture of potash, 

 soda, and ammonia, and notice that their collective 



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