[ '52 ] 



fore in each of the fix fummer months of the fucceeding year 

 it paffes X 3730=110 lb. of water, and receives a depofite of 

 310 grains, and at the end of the fecond year the depofite amounts 

 to 2220 grains. At the commencement of the third year the 

 tree gaining a farther acceffion of 32 lb. mufl weigh 691b. and pafs 

 in each of the fummer months 69x30=270 lb. of water, and 

 receive a depofite of 690 grains, which multiplied into 6=4140 

 grains. At the commencement of the fourth year the tree ftill 

 gaining 32 lb. muft weigh loilb. and if it paffes 101x30 in 

 each of the fummer months it muft gain a depofite in each of 

 1 010 grains of earth, and at the end of the year 6060, At the 

 commencement of the fifth year it weighs 1331b. and gains at 

 the end of the fix months 23940 grains of earth. The quanti- 

 ties of earth depofited each year exceed 5 lb. avoirdupoife, a 

 quantity equal to that which 1691b. of willow can be fuppofed 

 to contain ; for the commiffioners employed to infped the fabri- 

 cation of falt-petre in France, having examined the quantities of 

 afties aflibrded by trees of various kinds, found that 1000 lb. of 

 fally, a tree much refembling the willow, afforded 281b. of afhes, 

 and confequently 1691b. fiiould produce 4,7 :];. I do not give 

 this calculation however as rigoroufly exad ; it is certain that if 

 the depofite left at the end of every month were exadly taken 

 the total would exceed the quantity juft mentioned, but that 

 found even by this rude mode fufficiently proves that water 

 conveys a portion of earth into vegetables equal to any that the 

 experiments hitherto made can prove to exift in them. 



As 



if 3d Tranf. Royal Irifli Acad. 



