WHOLESOMENESS OF FOOD. 73 



This apparent anomaly is explained by the fact that the 

 wholesomeness of a food for horses is largely dependent 

 on the respective percentages of fibre (p. 65) and nitrogenous 

 matter (p. 63) contained in it. Oats are rich in fibre, which, 

 though practically indigestible, greatly aids the digestion of 

 the nutritive part of that grain, and prevents digestive disturb- 

 ance. Also, oats do not contain, like beans, too high a per- 

 centage of nitrogenous matter, which, when consumed in 

 excess, has a poisonous effect on the system (p. 122). Thus 

 we find that when the quantity is not limited, a horse can 

 obtain a larger amount of nutritious material from oats, 

 without his digestion becoming upset, than from either barley 

 or beans. We may therefore see that digestibility and whole- 

 someness, as applied to foods, are not convertible terms ; and 

 that a comparatively indigestible food may be an eminently 

 wholesome one. What a horse, like every other animal, re- 

 quires, is a wholesome food which contains a sufficiency, but 

 not an excess, of easily digestible nutritive matter, the respec- 

 tive constituents of which are in proportions suitable to his 

 requirements. 



As the wholesomeness of a food cannot be exactly measured, 

 we have in estimating it to rely more on practical observation, 

 than on chemical experiment. In this respect, the state of the 

 dung is a valuable guide. In ordinary conditions of health, 

 the dung, without being hard, will be fairly formed, brittle, 

 though moderately damp and free from foul odour and 

 adherent slime, the presence of which will indicate irritation 

 of the intestines. A loose and unformed state of the dung 

 will show either that the mechanical nature of the food is 

 unsuitable (being irritating or too watery), or that the absorp- 

 tion of some of its constituents had produced a purgative 

 effect. During constipation, the dung of a horse becomes 

 hard and dry from its being kept too long in the lower 

 part of the large intestine, and it assumes a consistency 



