CONFIRMATION OF TILE GENERAL RESULTS. We have thus passed in review the principal phenomena of animal heat, reducing or proximating these at all times to the most simple conditions. These conditions them selves are, in the first place, assumed from comparisons of the organization of the two grand groups or series into which the animal kingdom is divided with reference to heat— the cold-blooded animals, and the warm blooded animals. In this review we have avoided all hypothesis, confining ourselves to the severe method of deduction, always starting from well-authenticated facts, and even con firming each step in advance by new data equally indisputable. The harmony which reigns in this comprehensive whole, which embraces the different classes of animals and man, not only in the various modifications of health, but even of disease, in their relation to external agents, and the therapeutic pro cesses of nature and of art, afford the surest confirmation of the reality of these relations. As the phenomena of animal heat are re ferable to two general conditions of the eco nomy,—the state of the blood and that of the nervous system; and as we have only in the first instance deduced these from the com parison of natural facts, although we have confirmed them by new observations and par ticular experiments, one may be desirous of seeing them confirmed by experiments of a more general bearing. To the reasonableness of this wish we yield assent the more willingly, as the results we have to quote are deductions from some of the most admirable researches that have been instituted by I allude to the enquiries of Legallois, Sir Benjamin Brodie, and Dr. Chossat.
The first of these experimenters, by the em ployment of various means for impeding re spiration, or limiting the consumption of air, found that the refrigeration of animals is in the compound ratio of the difficulty experienced in breathing and of the quantity of oxygen con sumed; so that when, in two experiments, the difficulty of breathing is the same, the greatest extent qf cooling occurs in that in which the smallest quantity of oxygen is vitiated, and the contrary. Now, the end of the process of respiration being to change the venous into arterial blood, this conclusion of Legallois con firms directly the one of the two principal conditions—Tit E STATE OF TUE BLOOD, which we have laid down as influencing the production of heat among animals, and to the knowledge of which we had attained by induction.
The results of the direct experiments which we have still to quote also come powerfully in aid of our inferences concerning the other principal condition, which we have assumed from induction, influencing the production of animal heat : this is THE STATE OR ACTION OF