OXALATE OF LIME IN THE URINE OF THE HORSE. 249 
methodical manner on horses in hospital for slight troubles 
not affecting their general health, such as rope-cuts, over- 
reaches, trivial lamenesses, &c. An individual employed for 
the purpose of catching the first urine passed by the horse 
in the morning, before water had been given him, has been 
overlooked by the farrier on duty, and the vessel brought to 
me at the same hour daily, namely, 9 a.m. 
By these examinations, I find that the average specific 
gravity of healthy urine is 1*030 and a fraction. With the 
exception of five cases, the reaction on litmus paper has been 
alkaline, and one neutral. In no case have I found the dumb- 
bell crystal of oxalate, although that form of carbonate is 
almost constant, for whenever the octohedral crystal of oxalate 
has been in abundance, accompanied by dumb-bells, these 
latter have invariably vanished on the application of acetic 
acid, leaving the former intact. The form of oxalate, too, is 
in some instances (and that not infrequently) compound, 
being double, triple, and even quadruple, as if two, three, or 
four crystals were superposed upon each other ; while the 
fact of this not being the case, is easily demonstrated by a 
gentle sliding motion being given to the thin glass cover, by 
w hich the crystals may be made to roll over, and thus show 
their solidity. 
The variation of the daily specific gravity is singular, and 
forms, I fear, one of the greatest obstacles to any benefit that 
might be otherwise looked for as assistance in diagnosis of 
disease ; for w ithout any change in food, watering, or exercise, 
I find the urine of the same horse one day giving a specific 
gravity of 1*015, also show ing oxalate of lime, and the triple 
phosphates to be present, as w^ell as the usual carbonates, 
and the next day, under exactly the same circumstances, it 
has been 1*050, w r ith the same salts in equal abundance, and 
no other, and the same reaction on litmus paper. 
Since the 4th of January, I have continued these observa- 
tions on tw’o horses daijy, and this being the 15th of the 
month, I can record, of course, twenty-two more cases, in all 
of w 7 hich, except one, oxalate of lime has been present, and 
in that one the urine had an acid reaction, and carbonate of 
lime only. 
I see no reason why, if others will but put similar exami- 
nations to the test, that the fact, as I consider it, of oxalate 
of lime being a normal constituent of healthy horses’ urine, 
should not be either established or refuted. If the former, 
which I do not doubt, what becomes of the confidence hitherto 
placed in the other authors so abundantly quoted by Mr . Gamc/ee ? 
Professor Fraas, in the same paper, is said to assert; 
xxx. 34 
