Parti. 7>//;5^ Cre ATioK. 4^ 



lition, fufficiently confuted by our Harvey, m 

 his Book of Generation, 'that the Seed doth ma- 

 terially enter into the Compofition of the Egg ; fa 

 is it all along precarious and exceptionable : Nor 

 doth it extend at all to Differences that are in 

 feveral Animals, nor offer the leail Reafon why 

 an Animal of one Species might not be formed 

 out of the Seed of another. Thus far the Docior, 

 wich whom for the main I do confent. I fhall 

 only add, that Natural Philofophers, when they 

 endeavour to give an Account of any of the 

 Works of Nature, by preconceived Principles of 

 their own, are for the moil: Part grofly miftaken, 

 and confuted by Experience ; as Des Cartes in a 

 Matter that lay before him, obvious to Senfe, 

 and infinitely more eafy to find out the Caufe 

 of, than to give an Account of the Forma- 

 tion of the World ; that is, the Pulfe of the 

 Heart, which he attributes to an Ebullition and 

 iiidden Expanfion of the Blood, in its Ventri- 

 cles, after the Manner of the Milk, which 

 being heated to fuch a Degree, doth fuddenly, 

 and as it were all at once, flu ill uo and run 

 over the Veffel. Whether this Ebullition be 

 caus'd by a Nitro-Sulphureous Ferment lodg'd 

 efpecially in the left Ventricle of the Heart, 

 which mingling with the Blood, excites fuch 

 an Ebullition, as we fee made by the Mixture 

 of fome chymical Liquors, viz. Oil of Vi- 

 triol, and deliquated Salt of Tartar ; or, by the 

 vital Flame warming and boiling the Blood. 

 But this Conceit of his is contrary both to Rea- 

 fon and Experience : For, firfr, it is altogether 



unrea- 



