26 



THE FARMER'S MAGAZINE, 



In respiration, or the act of breathinir, the animal 

 inhales and exhales the atmospheric air. The air 

 drawn in, or inhaled, if dry, consists nearly of 



Nitrogen 79.16 



Oxygen 20.80 



Carbonic acid 0.04 



100. 



After the air has passed through the lungs, it then 



consists of 



Nitrogen 79-16 



Oxygen 16.84 to 12 



Carbonic acid 4.00 to 8 



100. 



The amount of carbonic acid, therefore, is much 

 greater after the air has passed through the lungs 

 than what it was when first inhaled. "On an 

 average, the natural proportion of carbonic acid in 

 the air is found to be increased one hundred times 

 after it is expelled by breathing from the lungs." — 

 (Johnston.) Whence, then, is this excess of car- 

 bon derived ? It must evidently be from some 

 other source than the atmospheric air. 



Carbonic acid is formed by the union of carbon 

 and oxygen, m the proportion of one part of the 

 former with two parts of the latter. Water is a 

 compound of eight parts of oxygen and one part of 

 hydrogen. Starch, gum, and sugar, therefore, con- 

 sist almost wholly of carbon and water. The 

 oxygen of the air inhaled, combining with the car- 

 bon contained in the starch and sugar existing in 

 the food of the animal, produces carbonic acid, 

 which is expelled from the lungs in breathing ; and 

 the union of the oxygen with the hydrogen of the 

 food, in hke manner, produces water, the excess of 

 which passes off in the urine, in a vapour exhaled 

 in respiration, which is visible at a low temperature, 

 and in the perspiration. The reason is evident, 

 therefore, why the amount of carbonic acid in the 

 air is so much greater after it has passed through 

 the lungs than what it was previous to being inhaled. 



But this consumption of carbon in the process of 

 respiration is precisely similar to what takes ])]ace 

 in combustion. A union takes place of the carbon 

 and oxygen of the substance which is being burnt> 

 and their dispersion is accompanied by the pro- 

 duction of heat. From the consumption of carbon, 

 therefore, which takes place in respiration, heat is 

 evolved and diffused throughout the body, and 

 thus the starch, gum, and sugar of the food pro- 

 duces that degree of temperature which is necessary 

 for the life of the animal. When, therefore, the 

 animal is exposed to a lower temperature than the 

 natural heat of the body, a larger quantity of the 

 elements of respiration are required to maintain 

 the necessary degree of heat ; and hence, animals 

 which are exposed consume more food with less 

 profitable results in the production of fat than thos^ 



which are kept in a temperature at least not less 

 than the natural heat of the body. In the former 

 case, owing to the deficient supply of the elements 

 of respiration, caused by an insufficiency of suitable 

 food, or their more rapid consumption or dispersion 

 in consequence of the coldness or low temperature 

 of the suri'ounding atmosphere, there is no excess 

 of these elements — nothing to spare towards the 

 production of fat, and if the substance of the animal 

 does not actually waste from the strong combustion 

 which is going on in the system, it at least remains 

 stationary. Warmth, therefore, is equivalent to an 

 increase of food, inasmuch as it prevents unneces- 

 sary waste of the elements of respiration and fat. 



To those who have always been accustomed to 

 the sleek, fine coats of carefully-tended cattle, the 

 shaggy winter covering of the Kyloe appears gro- 

 tesque, and more ornamental than useful ; but they 

 overlook the fact that this shaggy covering is an 

 economiser of food, and that by means of the addi- 

 tional warmth which it affords, the scanty food 

 which the Kyloe procures during winter in its 

 natural state, and which would be insufficient of 

 itself to sustain the animal — that is, to evolve a 

 sufficient amount of heat to enable the animal to 

 imdergo the rigour of the winter — becomes equal 

 to the purpose, in consequence of this covering. 

 There is a less demand on the combustible materials 

 stored up in the food, and thus the shaggy covering 

 becomes essential to the existence of the animal. 



Insufficient house accommodation is a serious 

 loss to the owner of cattle, entailing as it does an 

 extra expenditure of food without an equivalent 

 return ; but how much greater is the loss in the 

 case of those whose cattle are exposed during the 

 entire winter without any shelter beyond that which 

 is afforded by a hedge ! When we see cattle on a 

 cold winter's day 



" Mouru in corners where the fence 

 Screens them, and seem half petrified to sleep 

 lu unrecumbent sadness," 



we see a waste of material going on, which is 

 nearly as absurd as if the owner would wilfully 

 undertake the office of the incendiary, and set fire 

 to his hay-ricks. All cattle ought to be put, on the 

 approach of winter, either into properly-constructed 

 houses or covered yards, where their food will be 

 expended in promoting their growth and develop- 

 ment, and not wasted in meeting the extra demand 

 for animal-heat-producing material which exposure 

 creates. 



But there is in the construction of cattle accom- 

 modation one important essential to be attended 

 to, namely, perfect ventilation, combined with an 

 entire absence of cold currents of air. 



We have alluded to the change which takes place 

 after the air has passed through the lungs, by which 

 the amount of carbonic acid becomes greater than 



