52 VOELCKER on the Chemistry of Food. 



into fat. It is for this reason that grain crops, more especially 

 oats, when harvested before the plants have become dead-ripe, 

 produce straw which is greatly more nutritious than the straw of 

 dead-ripe grain crops. In some parts of Scotland the custom 

 prevails to cut the oat when the top of the haulm is still some- 

 what green ; and it is upon straw of that description that store 

 cattle are kept during the winter almost entirely. 



3. On the amount of Flesh-forming Substances. Food too rich 

 in these constituents is not readily digested by cattle, whilst 

 working horses are greatly benefited by food of that description. 

 Thus, bean-meal or peas ought to be given sparingly to cattle, 

 because beans and peas contain a very large amount of flesh- 

 forming substances, which renders them indigestible when given 

 to cattle. 



4. On the Bulk of the Food. The normal functions of the 

 digestive organs not only depend on the composition of the food, 

 but also on the volume. ' The volume or bulk of food contributes 

 to the healthy activity of the digestive organs, by exercising a 

 stimulating effect on the nerves which govern them. The whole 

 organization of ruminating animals necessitates the supply of 

 bulky food to keep the animal in good condition. Experience 

 shows that horses require a less bulky and more concentrated 

 food than cattle ; but if we reverse the case, and feed cattle with 

 too concentrated a food and horses with too bulky a feeding sub- 

 stance, much of the food will remain undigested. 



5. On the form in which Food is presented to the Animal. It 

 sometimes happens that an article of food is said to possess 

 little value, which, properly prepared, may be given to cattle with 

 much advantage. Thus, straw cut into chaff and, better still, 

 steamed afterwards when mixed with sliced roots constitutes a 

 very acceptable food for cattle. The bruising of oats, barley, 

 cake, &c., the making of linseed into jelly, the steaming of hay 

 and cooking of food, are illustrations, showing how, by an altera- 

 tion in the form of a feeding material, its digestibility, and with 

 it its nutritive value, becomes enhanced. 



The benefit of steaming or cooking of food is principally due 

 to this circumstance. It does not add anything new to the food ; 

 it does not call into existence any fresh nutritious matter ; but 

 brings the nourishment present in the food in an unfit condition 

 into a state in which it is more readily assimilated by the animal. 

 Steaming, moreover, reduces the bulk of the food, and masticates, 

 so to speak, the food for the animal. The animal, therefore, is 

 enabled to consume in a given time a larger quantity of food, 

 and so saved to some extent the work of mastication, which, like 

 every movement of the muscle, is attended with a certain loss of 

 the substance of the beast. The quieter and warmer we keep 



