i66 The Conchjion. 



and foils, fuch as will afford them their due 

 proportion of nourifhment ; which foils, as 

 they are exhaufted, muft, as 'tis well known, 

 from time to time, be replenifhed with frefh 

 compoft, fuch as is full of faline, fulphu- 

 reous and aereal particles, with which com- 

 mon dung, lime, afhes, fvvord, or burn- 

 bated turf abound ; as alfo fuch manures, 

 as have nitrous and other falts in them : for 

 tho' neither nitre nor common fait be found 

 in Vegetables, yet fince they are obferved to 

 promote fertility, it is reafonable to con- 

 clude, that their texture is greatly altered 

 in Vegetation, by having their acid volatile 

 falts feparated from the attracting central 

 air and earthy particles, and thereby make- 

 ing new combinations with the nutritive 

 juice; and the probability of this is further 

 confirmed, from the great plenty of air and 

 volatile fait, which is found in another com- 

 bination of them, vfa in the Tartar of 

 fermenting liquors : For it is the opinion of 

 Chymifts, that there is but one volatile Salt 

 in nature, out of which all other kinds of 

 falts are formed by very different combina- 

 tions; all which nutritive principles do, by 

 various combinations of the cultivated earth, 

 compofe that nutritive ductile matter, out 



of 



