170 BLOOD — COMPARATIVE STRUCTURE. [BOOK I. 



opinion, as to the seat of perspirable matter residing 

 in the lacteal part of the system. 



Finally, as it is the blood which by its deposite 

 forms all those parts, so by means of the blood 

 must we endeavour to correct any derangement of 

 the system of animal life, whether of quadrupede 

 or bipede ; for the working of the system in the 

 making of new blood and cleansing the old is the 

 same in all, though differing in degree, whilst 

 mainly agreeing in the process. Would any one 

 demand how it comes to pass, that quadrupeds draw 

 so much substantial nourishment from herbaceous 

 vegetables, whilst man can only extract a watery 

 juice from such materials, devoid of all nutritious 

 qualities ? let him be answered, that all depends 

 on the digestive powers, these being greater in the 

 brute than in man. It even appears plainly to us, 

 that the animal food taken by man is the same 

 originally as the herbaceous food taken by qua- 

 drupeds, only that it has mean time undergone 

 the process of digestion, sanguification, and depo- 

 sition in the solids, &c. and hence arises the 

 difference in the practice of medicine, we de- 

 lusively term the curative art, as applied to the one 

 animal and the other. Every disease is in fact a 

 compound, varying in different constitutions, and 

 the composition of the remedy should be adapted to 

 every variation thereof, even of the same attack in 

 its several stages. 



