198 
PIERRE A. FISH. 
can determine whether or not the disorder is active or quies¬ 
cent ; one may also more easily determine the seat of lameness 
according to such examination, whether due to spavin, etc., or 
to hip or to shoulder lameness, as the case may be, and arrange 
the treatment accordingly. In cases of fractures an enormous 
amount of phosphates are thrown out into the urine. The pro¬ 
gress of knitting together and healing of the parts may readily 
be followed by noting the gradually diminishing amount of 
phosphates in the urine. 
For purposes of diagnosis or prognosis a quantitative deter¬ 
mination of the phosphates is essential. This formerly was 
beyond the reach of the ordinary practitioner, because the skill, 
training, experience, time and the complicated methods were 
not available, but with the introduction of the centrifuge, an 
apparatus comparatively inexpensive, such quantitative deter¬ 
minations can be made in from three to ten minutes by any one 
who can prepare the proper chemical reagents and mix them in 
the proper proportions in the tubes. 
The urinary phosphates are divided into two general groups : 
the earthy and alakaline. 
The earthy consists of the phosphates of calcium (abundant) 
and magnesia (scanty). They are insoluble in an alkaline 
medium, but to a certain extent are held in solution in the 
urine by the presence of free CO2. 
The alkaline consist of the phosphates of sodium and 
potassium and are very soluble. They never form ordinary 
urinary deposits. They are more abundont than the earthy. 
The urine of the horse is always more or less turbid and 
this is due for the most part to the deposition of certain of the 
salts before the urine has been passed from the bladder. These 
salts consist mainly of the carbonates, but also, to a smaller 
extent, of the earthy phosphates. 
A frequent source of error in testing for phosphates in the 
urine of the horse is in not allowing time enough for the pre¬ 
cipitate to settle. On account of the density and viscidity of 
the urine the precipitate does not always form nor settle readily 
