A N D G R O W T H. 4^ 



they grow or are expended by abforblng thofe or- 

 ganic particles which correipond to their own na- 

 ture; and they propagate, becaiife they contain 

 foiiie organic particles fimilar to themfelves. It 

 only remains to examine whether thefe fimilar 

 organic particles are extradled from the food, or 

 have a primary and independent exiflence in the 

 bodies themfelves. If we fuppofe the latter, we 

 recur to the infinity of fimilar paris or germs 

 contained within each other, an hypothefis which 

 we have already fhown to be replete with diffi- 

 culties and abfurdities. We muft, therefore, 

 maintain, that the fimilar parts are extracted from 

 the food ; and, after what has been faid on the 

 fubjedl, we hope to be able to explain the man- 

 ner of their abforption, and how the more mi- 

 nute organi(l!*particlcs wnich coinpofe them are 

 united. 



We formerly remarked, that the organic parts 

 of food were feparated from tiiole which have 

 no analogy to tlie animal or vegetable, by tran- 

 fpiration and other excretions. The tirft re- 

 main, and ferve to expand and nourilh the body: 

 But thcfc organic parts muft be of very differ- 

 ent fpecies; and, as each part of the body re- 

 ceives only a proper number of thofe which corre- 

 fpond 10 it,' the furplus, it is natural to imagine, 

 will be returned from all parts of the body, and 

 be colledted in one or more refervoirs, where they 

 will unite and form Imall or^ianic bodies fimilar 

 to the firfi:, and which require nothing but pro- 

 per 



