to the Rearing and Feeding of Cattle. 
221 
ents of common air ; and its affinity for the elements of organic 
matter is so great, that it constantly endeavours to destroy it. 
The whole life of an animal consists in a conflict of tliese rival 
powers — in the endeavour of vitality to sustain and increase — in 
that of chemical affinity to waste and destroy. In health, vitality 
possesses the ascendancy, and modifies the destructive efl'orts of 
the chemical powers. Disease, on the other hand, is a temporary 
conquest of the chemical over the vital forces ; while death is the 
victory of the former, and annihilation of the latter. 
When the chemical power oxygen succeeds in effecting a waste 
of the body, it converts it into the elements from whence it sprung — 
into carbonic acid, water, and ammonia. There are indeed inter- 
mediate compounds formed, but these are the final ])i'oducts of the 
decay of the body or of its parts ; and they are the very substances 
upon which plants live : so that decay and death thus become 
the source of life. It is known that the vital forces decrease when 
the body is exposed to a certain degree of cold ; and when this is 
sufficiently intense, that they are either suspended or are alto- 
gether annihilated. But the chemical force oxygen is condensed 
or increased in its power by such agencies, and it therefore now 
reigns triumphant. Vitality (the cause of increase and of sus- 
tenance) being removed, chemical affinity (the cause of waste) 
acts upon those tissues which have been freed from the dominion 
of vitality, and effects their destruction. Hence it is that cattle do 
not fatten so well in cold weather as in hot. The chemical 
powers being now in the ascendant prevent the increase of mass. 
We know, also, that the intervention of cold weather in summer 
either wholly arrests, or greatly retards, the fattening of our cattle. 
But as the decrease of vitality has been occasioned by a diminution 
of the temperature of the body, it is obvious that by an elevation 
of the temperature vitality would be again enabled to resume its 
proper functions. It has been shown that the food of various 
countries is more or less combustible, according to the tempera- 
ture of the climate ; and proofs were adduced that the amount of 
the food consumed varied also according to the temperature. 
The animal body is a furnace which must be kept up to a certain 
heat in all climates.* This furnace must, therefore, be supplied 
with more or less fuel according to the temperature of the 
external air. If then in winter we wish to retain the vital func- 
tions of our cattle in a proper degree of activity, we must keep up 
the heat of their bodies. This we may do in two ways. We 
may either add more fuel (food) to the furnace, or we may protect 
* This is a homely and trite comparison, but a very perfect one. The 
body is the furnace — the food is the fuel — the excrements are the ashes — 
and the gases expired from the mouth are of the same composition as 
those winch fly up the chimney of the furnace. 
