570 PHYSIOLOGY AT THE FARM. 



namely, 20.48 to 260, or nearly 1 to 12. In the diet of man 

 at rest or under moderate exercise, this ratio is no more than 

 1 to 5 in round numbers ; and in that of men under bodily 

 exertion, as that of soldiers during war, it is, on an average, 1 

 to 435. In the normal diet of the horse at rest, the ratio be- 

 tween the amount of flesh-formers and that of heat and fat 

 givers is 28.9 to 150, or nearly 1 to 4.4 ; and the ratio be- 

 tween the same when the horse is under exertion is 59.1 to 

 251, or nearly 1 to 4.2. In the diet of the ox when intended 

 for the market, the ratio of flesh-formers to heat and fat givers 

 is 56.3 to 253, or as 1 to 4.5 nearly. 



This difference in the ratio of the flesh-formers to the 

 heat and fat givers in the pig is exactly what might be 

 anticipated, since in our piggeries the life of the animal is 

 reduced almost to vegetation, so that there is little waste 

 of muscular tissue, and a rapid accumulation of fat. The 

 small quantity of salt directed to be used in the formula of 

 diet on which we are commenting is not to be forgotten. 

 Salt that is, chloride of sodium is essential to the digestion 

 of mammals in general. It is, indeed, contained in the ordin- 

 ary articles of food ; nevertheless, when nutrition is forced, as 

 in the case of animals fed for the market, it may be required 

 to be added separately, to insure complete digestion, by sup- 

 plying freely the hydrochloric acid on which stomach-digestion 

 is believed to be dependent. Nevertheless it is held to be 

 possible to retard the fattening of an animal by the use of an 

 excess of salt, for which statement we have the authority of 

 Liebig. Here, then, is a point for inquiry. Chloride of 

 sodium is uniformly present in the urine of mammals. If the 

 normal proportion can be ascertained, under a given mode of 

 management, without the direct use of salt, any failure in that 

 normal quantity will be an indication for the addition of salt 

 to the food. 



