262 AMERICAN AGRICULTURE. 



has observed, that this is fully shown in the pig, the sheep, 

 the ox and the horse, whose aptitude to fatten and smallness 

 of lungs, are in the order enumerated. This position is fur- 

 ther illustrated, by the different breeds of the same classes of 

 animals. The Leicester sheep have smaller lungs than the 

 South Down ; and it was found in an experiment made on 

 Lord Ducie's example farm, that a number of the former, 

 on a given quantity of food, and in the same time, reached 

 28 Ibs. a quarter, while the South Downs with a greater 

 consumption of food, attained in the same period, only 

 18 Ibs. The Chinese pigs have much smaller lungs than 

 the Irish, and the former will fatten to a given weight on a 

 much less quantity of food than the latter. (Playfair.) The 

 principle would seem to be corroborated by the fact, that 

 animals generally fatten faster in proportion to the quantity 

 of food they consume, as they advance towards a certain 

 stage of maturity ; during all which time, the secretion of 

 internal fat is gradually compressing the size, by reducing 

 the room for the action of the lungs. Hence the advantage 

 of carrying the fattening beast to an advanced point, by 

 which not only the quality of carcass is improved, but the 

 quantity is relatively greater for the amount of food con- 

 sumed. These views are intimately connected and fully 

 correspond, with the principles of 



RESPIRATION IN ANIMALS. 



From careful experiments, it has been found, that all ani. 

 mals daily consume a much larger quantity of food than the 

 aggregate of what may have been retained in the system, 

 added to what has been expelled in the fceces and urine, and 

 what has escaped by perspiration. Boussingault, who com- 

 bines the characteristics of an ingenious chemist, a vigilant 

 observer and a practical agriculturist, made an experiment 

 with a " milch-cow and a full-grown horse, which were pla- 

 ced in stalls so contrived that the droppings and the urine 

 could be collected without loss. Before being made the sub- 

 jects of experiment, the animals were ballasted or fed for a 

 month with the same ration that was furnished to them, during 

 the three days and three nights which they passed in the ex- 

 perimental stalls. During the month, the weight of the ani- 

 mals did not vary sensibly, a circumstance which happily 

 enables us to assume that neither did the weight vary during 

 the seventy-two hours when they were under especial obser- 

 vation. 



