1889.] The Chemistry of the Urine of the Horse. "600 



were obtained I failed to keep any of them long enough under obser- 

 vation to find ont this point of variability. 



Again, diet influences the production, as proved by the work of 

 Tereg, Munk, and others, who have shown that on a hay diet more 

 nitrogen is excreted than on one containing oats as well as hay ; this 

 seems so opposed to what one would expect that I overlooked the 

 point entirely. 



Tereg and Munk put down the amount of urea as 120 grams ex- 

 creted daily in a horse weighing 400 kilos., the diet being oats (4*5 

 kilos.) and hay (2*5 kilos.). The mean of my own observations is 

 111 grams; but urea varies much, even on a fixed diet, iu different 

 horses ; in Tereg and Munk's experiments it varied from 81*5 to 

 149 - 5 grams in twenty-four hours. 



I experimented on a pony weighing 5 cwt. 21 lbs. ; the experi- 

 ments lasted from 2nd February to 29th March, and were divided 

 into periods of rest and work ; the diet throughout remained the 

 same, viz., hay 7 lbs., oats 5 lbs. 



In the first series of rest and work I found that the animal 

 excreted, on an average, for the resting days 63*63 grams urea, and 

 for the working days 72*913 grams. 



In the second series of rest and work, all conditions remaining the 

 Same, I found more urea daring the resting than- during the working 

 •period, viz., for rest 65*125 grams, and for work 43*33 grams. 



Urine of Rest. 



Total nitrogen. Urea. 



2nd February 28 "56 grams. 60 *0 grams. 



4th „ 35*20 „ 62*5 „ 



6th „ 32*00 „ 68-4 „ 



The animal was now worked from the 7th until the 15th February, 

 and again worked on the 17th and also on the 19th. 



Urine of Work. 



Total nitrogen. Urea. 



16th February 32 *48 grams. 63 *0 grams. 



18th „ " 47*71 „ 81*37 „ 



20th „ 42*63 „ 74-37 „ 



Complete rest was now given until the 23rd February, when the 

 experiments were repeated. 



Urine of Rest. 



Total nitrogen. Urea. 



23rd February 44 *60 grams. 84 '0 grams. 



26th „ 57*10 „ 80-0 „ 



1st March 31 '36 „ 56 '0 „ 



13th „ 19-00 „ 40 -5 „ 



