[ ^73 3 



tHefe he buried up to the furface in a garden, fowed in each 

 fome grains of wheat, and then abandoned them to nature. 



Fertile Mixtures-. 



I. The firft mixture he found fertile confifted of |- of the 



potters clay of Gentilly = 0,375 i ^^ the parings of lime- 



ftone and f of river fand = 0,25. In this the corn grew very 

 well for three years, that is, as long as the experiment lafted. 



As potters clay is not pure argill, and as Mr. Tillet does not 

 mention the proportion the mere argillaceous part bore to the 

 filiceous, I muft fupply this defed, by fuppofing this clay to 

 contain near ^ its weight of pure argill, as it is clay of this 

 fort that potters generally chufe, and that of Gentilly is efteemed 

 one of the beft. Both the clay and limeftone, he tells us, were 

 pulverized, that they might more exuOly incorporate when 

 mixed. Then the centefimal proportions will Aand thus : 



Coarfe Silex - - 2'5 



Finer — - - 21^ 



46 



Argill — - - i6,s 



Galx — 



37.5 



100 



The 



