90 THE PHYSIOLOGY OF URIC ACID 



given. Salts of lithium used to be preferred, since 

 lithium urate is the most soluble of the urates, but 

 potassium is cheaper and better. The uric acid 

 shower of crystals may often be prevented by Gee's 

 treatment, consisting of a large cupful of whey three 

 times a day. 



A simple apparatus for determining the amount 

 of total purin in the urine has been invented by 

 Walker Hall. It is readily used for clinical work. 

 The principle adopted is to precipitate the phos- 

 phates with magnesia mixture, then add ammoniacal 

 silver nitrate, leave standing for twenty-four hours, 

 and read the amount of the silver purin precipitate. 

 With regard to the treatment of gout, it becomes 

 evident at once that as it is impossible to repair the 

 damaged kidneys, all that can be done is to keep 

 the purins as low as possible by dieting, and by 

 avoiding the various causes of increase of those 

 purin bodies which are formed in the body. We 

 continue to give colchicum, but without any adequate 

 physiological explanation of its undoubted powers 

 over the disease. Abundance of fluid will help to 

 carry the urates through the kidneys, and potassium 

 salts will furnish the most soluble base with which 

 to combine them. 



CALCIUM OXALATE. 



It has been found very difficult to obtain reliable 

 estimates of oxalates in the urine. The method 

 commonly employed, introduced by Dunlop, is open 

 to serious objections from the chemical standpoint. 

 Wo rking with O. C. M. Davis, the writer has used a 



