PHYSIOLOGY. 177 



CCVII. The proper alimentary matters are animal or vege- 

 table only. " What are the proper aliments of the human 

 species ? In answer to this, we know in general from experi- 

 ence, that the human aliments are taken entirely either from 

 other animals or from vegetables, and that no part of them, 

 excepting water, is taken from the fossil kingdom. The sub- 

 stances employed are seemingly various ; and in order to know 

 the greater or less fitness of the individuals, it is necessary to 

 consider in general how animal and vegetable matters are suited 

 to give nourishment to the human body." M. M. 



CCVIII. The animal aliments seem to be so nearly of the 

 same nature with the matter of the body itself, that, to be ren- 

 dered fit for the purposes of the economy, they seem to require 

 no other change but that of being rendered fluid. " The most 

 part of the matter taken from animals is so nearly of the same 

 qualities with the matter of the human body, that there is little 

 difficulty in supposing that the animal matters taken into the 

 human body, as aliments, are perfectly well suited to this pur- 

 pose, and require only the means of solution and mixture, 

 with very little change of their qualities. It is true, indeed, 

 that in many of the animal substances we take in, the likeness 

 of qualities to those of the human body is not always exact and 

 complete : but, in the mean while, all of them agree so much in 

 the qualities which chiefly characterize the human fluids, that we 

 may presume on their being a matter so nearly the same, that 

 the former may be very well suited to supply the latter." M. M. 



CCIX. But the vegetable aliment is very different from the 

 matter of the animal fluids or solids, and must therefore be 

 changed into the nature of these by the powers (CXCIX.) ; 

 and as many animals are nourished by vegetable aliment alone, 

 and as, perhaps, all animal matters may be ultimately traced to 

 a vegetable origin, it will appear, that, to account for the pro- 

 duction of animal matters, it is especially, and in the first place, 

 necessary to show how vegetable matter may be converted into 

 animal. " We may remark it to be highly probable^ that all 

 animal matter is originally formed of vegetable ; because all ani- 

 mals either feed directly and entirely on vegetables, or upon 

 other animals that do so. From hence it is probable, that all 

 animal substances maybe traced to a vegetable origin; and 

 VOL. i. K 



