i So 'The Principles of Part IY 



out nitre. The creffes in the nitred pot, 

 when diftilled, gave no acid felt, though fed 

 on a fait which contained an acid. The 

 fennel fed in the wa/hed earth gave an acid,, 

 though there was none in the earth. This 

 experiment mows, that the veffels of plants 

 have a power of changing the falts taken in 

 from the earth, into their own particular 

 natural one, probably by combining them 

 with different proportions of water, oil, 

 earth, air, and the particles of light which 

 iflue from the fun, 



BUT how fhall we account for die diffe- 

 rent external forms of plants ? Shall we fly 

 to the immediate hand of the Supreme 

 Being ? or, as this ought to be the laft ftep 

 in philofophy, can we find no chymical 

 agents capable of this effect ? From many 

 experiments, which mow the natural inhe- 

 rent power in falts, efpecially the nitrous 

 kind, to run into vegetations, as they are 

 called, and to take the figure of plants, with 

 branches, leaves, nay even an appearance 



of 



