BALANCE BETWEEN THE INGESTA AND FINAL PRODUCTS. 419 



vice to science, or furnish any fixed points of support for more 

 extended conclusions. As was naturally to be expected, the com- 

 prehensive experiments on animals, conducted by Valentin and 

 Boussingault, and more recently, and to a still greater extent, by 

 C. Schmidt and Bidder, possess far greater certainty, and afford us 

 a deeper insight into the combined relations of nutrition in the 

 animal organism. 



Valentin* prosecuted very careful investigations on the balance 

 of the metamorphosis of matter for three days consecutively on a 

 four-year-old mare. The results of these experiments may be thus 

 summed up. The quantity of the discharged faeces exceeded in 

 this case, by three or four-fold, the quantity of the urine that was 

 excreted ; half of all the excreted matters was always carried off 

 by the perspiration, and, consequently, half of the daily food was 

 again eliminated by the lungs and skin during the twenty-four 

 hours. A larger quantity of water was discharged with the faeces 

 than with the urine, and less water was given off by the perspira- 

 tion than through the urine and excrements. The quantity of 

 water which was daily introduced into the system amounted to one- 

 fourteenth of the mean weight of the body. A larger quantity of 

 organic matter was removed with the faeces than with the urine. 

 Upwards of twice, but considerably less than three times the 

 amount of the organic elements was eliminated by the perspiration. 

 The quantity of organic matter daily consumed amounted to from 

 l-42nd to 1 -4.3rd of the mean weight of the body; the organic 

 matters eliminated with the faeces ranged from l-139th to l-150th 

 of the w r eight of the body, and those excreted with the urine 

 from 1 -208th to l-209th ; and those through the perspiration on 

 an average to l-62nd of the weight of the body. By far the 

 greater part of the fixed salts was eliminated with the faeces. 

 About 3-10th of the fixed salts taken up with the food are carried 

 off by the perspiration. The sensible excretions consisted on an 

 average of 84'11-g- of water, 13'?6$ of organic constituents, and 2-13- 

 of ash ; and the perspiration contained 64' 28-8 of water, 34*67^ of 

 organic constituents, and 1*05^ of ash ; the food which was daily 

 consumed contained on the other hand 74*75 of water, 23'63 of 

 organic constituents, and 1'62^ of ash. The percentage numbers 

 obtained for the food stand between those yielded by the sensible 

 excretions and the perspiration. 



Boussingaultf made a similar series of experiments on a horse 



* Op. cit. 



t Ann. de Chim. et de Phys. T. 61, p. 128. 



2 E2 



