AND OTHER URINARY DEPOSITS 153 



disappear from the urine. This may be demonstrated 

 by adding methylated spirit and allowing to stand, 

 when any oxalate present in solution is precipitated 

 in characteristic octahedra. On a milk diet, no such 

 crystals will be obtained. 



None of the ordinary derangements of metabohsm 

 causes the appearance of oxalates in the urine if 

 they are withheld from the food. Thus there is no 

 cxaluria in fever, in leukaemia (illustrating the 

 katabolism of nucleoproteins) , or in diabetes. In a 

 case of oxalic acid poisoning under my care, the 

 excretion was enormous, and there was a heavy 

 deposit of calcium oxalate crystals. 



It is not, however, correct to say that oxaluria 

 never occurs on an oxalate-free diet, though such a 

 condition is rare. As is well known, the usual 

 products of bacterial fermentation of carbohydrates 

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

 acetic, and butyric acids, and alcohol. Miss Helen 

 Baldwin has pointed out that in certain abnormal 

 circumstances oxahc 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 with such cases in man. I have not chanced to 

 observe such a case personally, and beUeve 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 



