34 ON THE INFLUENCE 



not have been the same alteration in the specific 

 heat of this fluid, as it flowed from the arteries 

 into the veins. But on this supposition, if the 

 theory of Dr. Crawford be admitted as correct, 

 there must have been a gradual but enormous 

 accumulation of latent heat in the blood, which 

 we cannot suppose to have taken place without 

 its nature having been entirely altered. If the 

 blood undergoes the usual change in the capil- 

 lary system of the pulmonary, it is probable that 

 it must undergo the usual change in the capillary 

 system of the greater circulation also, since these 

 changes are obviously dependent on and connected 

 with each other. The blood in the aorta and pul- 

 monary veins was not more florid, and that in 

 the vena cava and pulmonary artery was not 

 less dark- coloured, than under ordinary circum- 

 stances. We may moreover remark, that the 

 most copious secretions in the whole body are 

 those of the insensible perspiration from the 

 skin, and of the watery vapour from the mouth 

 and fauces, and the effect of these must, be not 

 to raise, but to lower the animal temperature. 

 Under other circumstances also, the diminution 

 of the secretions is not observed to be attended 

 with a diminution of heat. On the contrary, in 

 the hot fit of a fever, when the scanty dark- 

 coloured urine, dry skin, and parched mouth, 

 indicate that scarcely any secretions are taking 

 place, the temperature of the body is raised above 

 the natural standard, to which it falls when the 



