92 THE PHYSIOLOGY OF URIC ACID 



in the bowel are various gases (CH 4 , CO 2 ), lactic, 

 acetic, and butyric acids, and alcohol. Miss Helen 

 Baldwin has pointed out that in certain abnormal 

 circumstances oxalic acid also may be formed in this 

 way. Copious feeding on sugar will ruin a dog's 

 digestion, and then oxalates may appear in the urine 

 even on an oxalate-free diet. Occasionally she has 

 met w : ith such cases in man. I have not chanced to 

 observe such a case personally, and believe that they 

 are not common. 



Fermentation of carbohydrates in the stomach and 

 intestines to an excessive degree is common enough, 

 but it is only rarely that there is any formation of 

 oxalates. I have never been able to obtain the 

 crystals, either from the gastric contents or from the 

 urine, of patients with obstruction of the pylorus 

 and gastric dilatation, on an oxalate-free diet. 



When ammoniacal fermentation of urine takes 

 place, as on standing, any oxalate crystals present 

 are rapidly dissolved and disappear. 



The oxalate calculus is by far the most important 

 variety occurring in the kidney. B. Moore has 

 shown that a pure uric acid stone is found only in the 

 bladder, and that all renal calculi are composed for 

 the most part of calcium oxalate. This is fortunate 

 for the #-ray diagnosis of the condition, and as it is 

 comparatively easy to control the oxalate excretion, 

 it makes it possible for us to advise the patient how 

 to avoid a relapse after operation. To draw the 

 practical lessons from our study, it is evident that 

 any patient suffering from oxaluria should abjure 

 the use of green vegetables, and fruits should be 



