ErrECT or mode of feeding on the manure. 616 



apply to animal food, since we may have a kind of animal food, such as 

 gelt^ine, which would greatly promote tlie growth of muscle, but which, 

 from its composition, is capable of ministering so little to the wants of 

 the other parts of the body'that it wUl not even support life for any length 

 of time. 



§ 16. Effect of different modes of feeding on the manure and on the soil. 



There remains still one practical point in connection with the feeding 

 of stock, to which I think you will feel some interest in attending. 



The production of manure is an object with the European farmer of 

 almost equal importance with the production of milk or the fattening of 

 stock. What influence has the mode of feeding or the purpose for 

 which the animal is fed, upon the quantity and quality of the manure 

 obtained ? 



1°. The quantity of the manure depends upon the quantity of food 

 which is necessary to sustain the animal. With the exception of the 

 carbon, which escapes from the lungs in the form of carbonic acid, and 

 a comparatively small quantity of matter which forms the perspiration, 

 the whole of the food which sustains the body is rejected again in the 

 form of dung. 



Now the sustaining food increases with the size of the animal, with 

 the coldness of the teriiperature in which it is kept, and with the quantity 

 of exen^ise it is compelled to take. Large, hardly worked, much driven, 

 and coldly housed animals, therefore, if ample food is given them, will 

 produce the largest Quantity of manure. It might be possible, indeed, tc 

 keep large animals for no other purpose but to manufacture manure — by 

 giving them an unlimited supply of food, using means to persuade them 

 to eat it, and causing them at the same time to take so much exercise as 

 to prevent them from ever increasing in weight. 



2°. Quality of the manure. — The quality of the manure depends al- 

 most entirely upon the kind of food given to an animal, and upon the 

 purpose for which it is fed. 



a. ^he full- grown animal, which does not increase in weight, returns 

 in its excretions all that it eats. The manure that it forms is richer in 

 saline matter and in nitrogen than the food, because, as I have already 

 explained to you in detail (p. 472), a portion of the carbon of the latter 

 is sifted out as it were by the lungs, and diffused through the air during 

 respiration. In other respects, whatever be the nature of the food — the 

 quantity of saline matter or of gluten it contains — the dung will contain 

 nearly the same quantities of both or of their elements. 



h. The case of the fattening animal again is different. Besides the 

 sustaining food, there is given to the animal some other fodder which 

 will supply an additional quantity of fat If this additional food be only 

 oil, then the dung will be little afiected by it. It will be little richer than 

 the dung of the full-grown animal to which the same sustaining food is 

 given. 



But if the additional food contain other substances besides fat — saline 

 substances, namely, and gluten — then these will all pass into the dung 

 and make it richer in precise proportion to the quantity of this addition^ 

 food which is given. Thus if oil-cake be given for the purpose of laying 

 on fat — the usual sustaining food at the same'time being supplied — the 



