888 SPECIAL PHYSIOLOGY. 



when the creature is roused from this condition, by any irritation, by heat, or 

 by^great cold, distinct respiratory movements take place, the heart's beats are 

 quickened, and it manifests increased activity. If the animal be aroused by 

 extreme cold, it soon becomes still more torpid, and may even die if the low 

 temperature be long continued. If excited too completely by warmth, it is 

 also apt to die, unless provided with suitable food, and carefully maintained 

 at a moderate temperature. The suspension of animation in Reptiles and 

 Amphibia, is still more complete ; but probably even here some vital action 

 goes on. In many instances, in the lower Non-vertebrate animals, it is prob- 

 able that all the organic processes are, for a time, completely suspended, as, 

 e. <?., when they are almost frozen, or first dried and then frozen. 



In the Animal Kingdom, considered generally, we observe that a high tem- 

 perature of the body not only increases the activity of the various functions, 

 but that this very activity produces, in its turn, a demand for increased res- 

 piration, and so engenders an increased amount of animal heat. In the case 

 of Cold-blooded animals, also, an elevation of the temperature of their bodies, 

 by external heat, increases their activity and their demand for increased res- 

 piration ; and, accordingly, it is found that in Reptiles more carbonic acid is 

 given off in high temperatures, a result opposite to that which takes place in 

 Warm-blooded animals, and in Man. The respiration of Warm-blooded and 

 Cold-blooded animals is said also to differ, if not absolutely, at least relatively, 

 in this particular : that it is only in the AV arm-blooded creatures, that some 

 portion of the food, when absorbed into the blood, is devoted at once to respi- 

 ratory purposes, forming, as it were, fuel immediately destined for the pro- 

 duction of heat by oxidation, without having previously entered into the tis- 

 sues ; whereas, in the Cold-blooded animals, the tissues only, and not the 

 food merely assimilated into the blood, except perhaps in exceptional cases, 

 and then in a far lower degree, are oxidated, and so produce a small amount 

 of animal heat. In the Warm-blooded animals the blood-corpuscles are much 

 more numerous, and the quantity of carbonic acid excreted is much greater, 

 than in the Cold-blooded species. 



Spontaneous Combustion. 



The highest natural temperature attained, in the healthy state, by 

 any animal, is that noticed in the swallow, about 111; the highest 

 temperature observed in the healthy human body, is 102 ; and in dis- 

 ease, 111. Moreover, experiments have shown that an increase of 

 13 in the temperature of the body of one of the Mammalia, is fatal. 

 It is obvious that the highest of these temperatures is entirely inade- 

 quate to set on fire the animal tissues; it is even insufficient to inflame 

 the vapor of alcohol. It is therefore, impossible to believe that the 

 body of a drunkard, whose blood and tissues may even be supposed to 

 be saturated with alcohol, or with some of the products of its decom- 

 position, could spontaneously burn; for the temperature of ignition of 

 the tissues, or of such compounds, is much higher. 



Of the so-called cases of spontaneous combustion, not one has actu- 

 ally been seen to happen. Naturally, no eye-witness is present, but 

 the more or less consumed body is found ; and such occurrences usually 

 take place in persons addicted, during their life, to habits of intoxica- 

 tion. The event is rendered marvellous by the supposition of a spon- 

 taneous process of combustion. Of the possibility of burning the dead 

 body with a due amount of heat, or even parts of the body before life 

 in the remainder of it is entirely extinct, there is no doubt, the sensi- 

 bility being supposed to be deadened by excessive alcoholism. But 

 the heat, necessary for this combustion, is far greater than is gener 



