[97] 



SECT. I. 



effetfs of different fubftances with regard 

 to vegetation. 



1 



E manures which I have 

 examined, are fuch as chance di- 

 covered to be ufeful in vegeta- 

 tion, and practice has continued, becaufe 

 they can be eaiily and cheaply got. But, 

 for what we know, there may be others, 

 which, though not in fuch plenty as to be 

 of ufe to the farmer, may have effects on 

 vegetation, that may be ufeful to thofe who 

 inquire into the nature of the vegetable 

 food. The more they know of the effects 

 of different bodies on plants, the greater 

 chance they have to difcover the nourifh- 

 ment of plants -, at leaft this is the only 

 road. I made the following experiment 

 with this defign. 



H Exp. 



