Vfgi- LITERARt iJTTiLLIGENCER. 299 



but how far he has publiflied the ufe of it in England* 

 I do not know ; as yet I have not been able to procure 

 a fight of his treatife. 



" This manure has produced a great revolution in 

 agriculture. The fine watered and banked meadows in 

 this country, are no longer held in the eftimation they 

 were ; our dry poor uplands, from the elFeft of this 

 valuable and cheap manure, are infinitely more produc- 

 tive, and more valuable, than the bell low lands, I 

 mean for grafs : in fliort, the value of farm-yard ma- 

 nure is alfo much lelTened ; ybr it is cheaper Jor the far- 

 mer to purchafe the plaller at two-thirds of a dollar per 

 bufhel, for his grafs land, than to draw out his dung 

 thereon. 



" This difcovery exceeds credibility ^ it puzzles the 

 philofopher, and allonifhes the farmer. Indeed, it tells 

 us all reafoning hitherto extended to the principles of 

 vegetation, was without foundation ; and that the hu- 

 man race are in a total ftate of ignorance refpecting it." 



Experitncnts on Gyp/um as a Manure. 

 "luanfwer ro your queries refpecling gypfum or plafter 

 of Paris, I fliall give you as full information as I can, 

 confident with my own and neighbour's experiments. 



" The beft kind is imported from hills in the vicinity 

 of Paris ; it is brought down the Seine by water, and 

 is exported from Havre de Grace. I am informed there 

 are large beds of it up the Bay of Fundy, fome of 

 which I have feen nearly as good as that from France ; 

 but feveral cargoes brought from thence to Philadelphia, 

 have been ufed without effect. It is probable this was 

 taken from the top of the ground, and was, by the in- 

 fluence of the fun and atmofphere, difpoirefi'ed of the 

 qualities necefTary for the purpofe of vegetation. The 

 lumps compofed of flat ^i\\\\x\gfpecularis, are preferred 

 to thofe wliicli are formed of round particles like fand ; 

 when pulverized, and put dry in an iron pot over the 

 lire, that which is good will foon boil, and great quan- 

 tities of the fixed air cfcape by ebulition. It is pulve- 



P P a 



