FOOD 161 



harmful with hay than with oats. The degree to which it 

 may become affected varies from a faint mouldy smell to a 

 mass of decomposing and offensively smelling material. 



Hay and grains are not the only food substances which 

 undergo decomposition and produce disease. Boots and 

 potatoes are frequently given in an unsound state from 

 motives of economy, and produce symptoms either of 

 poisoning or extreme digestive irritation. 



Cleanliness is an important condition of quality, stomach 

 and intestinal trouble is very common as the result of 

 dirty feeding ; sand, gravel, and stones are found in bad 

 samples of corn. Gravel and sand frequently accumulate 

 in the large colon, the result of feeding on dirty grain, such 

 as the ' cooltee ' of Southern India ; colic, enteritis, and 

 impaction are in consequence very common. With army 

 horses and mules, sand and gravel in the intestines are 

 frequently met with among those living in the open ; it is 

 taken in with the food, and frequently licked up. 



A food may cause mechanical irritation without being 

 dirty, the awns of barley and of certain grasses, for 

 example, also undecorticated cotton cake, which is held 

 responsible for diarrhoea in cattle, and abortion in cows, 

 due to the irritation it is capable of producing when given 

 in large quantities. 



Intestinal calculi are the result of the accumulation of 

 the phosphates of lime and magnesia derived from the 

 food, particularly bran and oats; the salts of these accumu- 

 late in the bowel instead of passing away with the fseces, 

 and form a calculus around any foreign body such as a nail 

 or stone. 



Oat hair calculi are formed from the fine but indigestible 

 hairs which are to be found covering the grain inside the 

 external envelope ; in the bowel they are frequently mixed 

 with the salts of the food. 



Millers' horses had the reputation at one time of being 

 very prone to intestinal calculi, through being fed on 

 sweepings from the mill floor, with which were chips from 

 the grinding stones ; the chief cause of their trouble was 



11 



Digitized by Microsoft® 



