4-2 Experiments and Obfervations 



with its heat, probably in the form of inflammable air. As all 

 plants poffefs this, they muft have fome means of feizing upon 

 it when brought within their reach. They will therefore either 

 abforb it by their leaves, or it will attach itfelf to the water that 

 it finds in the air or on the earth, and thus be imbibed by the 

 plant. Chymifts fuppofe that this air which becomes fixed in 

 plants, caufes the produftion of oils, tho' by what combination 

 they are not yet fatisfied. (Fourcroy's Chymiflry, 55, fecond 

 edition. 



This then is one mode in which Calcarious earth may fupply 

 the oils and inflammable principle found in vegetables ; fince 

 plants imbibe inflammable air and emit it pure, retaining the 

 phlogifton or inflammable part, which is known to be a prin- 

 cipal ingredient in tliem ; the acid and alkali will alfo be 

 furnifiied, when the moifl.ure of the air, dews or rain 

 diflblve the neutral falls they have formed, and by rendering 

 them liquid difpofe them to enter the abforbent veflels of plants. 

 In this folution, the water which had lofl; its heat where it 

 chryfl;alized, will again refume it with great rapidity from 

 the air in contaQ; with it. As the repulfive power or elafl.icity 

 of the air depends like that of all other fluids upon heat, it is 

 not unreafonable to fuppofe that the fudden aflumption of heat 

 from the inflammable air which compofes a great proportion 

 of the atmofphcric air, will decompound it, and compel it to 



