540 EVOLUTION OF HEAT, LIGHT, AND ELECTRICITY. 



blooded animals upon the Heat of their bodies, and of the dependence of 

 their calorifying power upon the due supply of material for the combustive 

 process, has received some remarkable additions from the experiments of 

 M. Chossat upon Starvation. 1 He found that Birds, when totally deprived 

 of food and drink, suffered a progressive, though slight, daily diminution of 

 temperature. This diminution was not so much shown by a fall of their 

 maximum heat, as by an increase in the diurnal variation, which he ascer- 

 tained to occur even in the normal state ( 425, n). The average variation 

 in the inanitiated state, was about 6 (instead of 1^) gradually increasing as 

 the animal became weaker ; moreover, the gradual" rise of temperature, which 

 should have taken place between midnight and noon, was retarded ; whilst 

 the fall subsequently to noon commenced much earlier than in the healthy 

 state; so that the average of the whole day was lowered by about 4i, be- 

 tween the first and the penultimate days of this condition. On the last day, 

 the production of heat diminished very rapidly, and the thermometer fell from 

 hour to hour until death supervened ; the whole loss on that day being about 

 25 Fahr., making the total depression about 295. This depression appears, 

 from the considerations to be presently stated, to be the immediate cause of 

 Death. On examining the amount of loss sustained by the different organs 

 of the body, it was found that 93 per cent, of the Fat had disappeared ; being 

 all, in fact, which could be removed ; whilst the nervous centres scarcely ex- 

 hibited any diminution in weight ( 78). From the constant coincidence 

 between the entire consumption of the fat, and the depression of temper- 

 ature, joined to the fact that the duration of life under the inauitiating 

 process evidently varied (other things being equal) with the amount of fat 

 previously accumulated in the body, the inference seems irresistible, that 

 the calorifying process depended chiefly on the materials supplied by this 

 substance. Whenever, therefore, the store of combustible matter in the 

 system was exhausted, the inanitiated animals died, by the cooling of their 

 bodies consequent upon the loss of calorifying power. 



432. That this is the real explanation of the fact, was shown by the results 

 of a series of very remarkable experiments performed by M. Chossat, with 

 the purpose of testing the correctness of this view. When inanitiated animals 

 whose death seemed impending (death having actually taken place in several 

 instances, whilst the preliminary processes of weighing, the application of the 

 thermometer, etc., were being performed), were subjected to artificial heat, 

 they were almost uniformly restored from a state of iuseusibility and want of 

 muscular power to a condition of comparative activity; their temperature 

 rose, their muscular power returned, they flew about the room, and took 

 food when it was presented to them ; and if the artificial assistance was suffi- 

 ciently prolonged, and they were not again subjected to the starving process, 

 most of them recovered. If they were left to themselves too early, however, 

 the digestive process was not performed, and they ultimately died. Up to the 

 time when they began to take food, their weight continued to diminish ; the 

 secretions being renewed, under the influence of artificial heat, sometimes to 

 a considerable amount. It was not until digestion had actually taken place 

 (which, owing to the weakened functional power, was commonly many hours 

 subsequently to the ingestion of the food), that the animal regained any power 

 of generating heat : so that, if the external source of heat was withdrawn, the 

 body at once cooled ; and it was not until the quantity of food actually digested 

 was sufficient to support the wants of the body, that its independent power of 



1 Kecherches Experimentales sur 1'Inanition, Paris, 1843; an analysis of this work 

 will bo found in the Brit, and For. Mi-d. Rev., April, 1844. See also H. Senator, in 

 Reichert and Du Bois-llcymond's Archiv., 1872, p. 1. 



