[ ■?■■ ] 



two of calcareous earth, and one of magnefia (in all ten parts), 

 but the laft not being of abfolute neceffity, may be annexed to 

 the calcareous. 



The compofition of the clay he does not exprefsly mention, 

 but we may fuppofe it fuch as moft frequently occurs, contain- 

 ing 66 per cwt. of fine filiceous fand and 34 of of mere argill, 

 confequently 0,40 of it contain nearly 14 of mere argill, and 0,26 

 of fine filiceous fand. 



The filiceous fand, mentioned by Mr. Bergman, is what wc 

 call gravel (confifting of ftone from the fize of a pea, or lefs, 

 to that of a nut) and thus he himfelf explains it*; this amounts 

 to 30 per cwt. 



Hence we may ftate the proportions thus : 



Coarfe Silex - - 30 



Finer — - - 26 



— — 56 parts 



Argill — - - 14 



Calx — - - 30 



loo 



The ufe of the gravel is to keep the foil open and loofe, 

 a circumflance abfolutely necefifary, as I have before obferved. 



Y 2 . The 



* 5 Bergman, 102, 103. 



