114 0?i Plaister of Paris, 



countries, and used as a top dressing. But the quantity- 

 necessary is enormous, compared with that of the 

 plaister. 



5. There is no country where limestone lands are to 

 be found in greater proportion, than in this. I know 

 many farmers of limestone lands, who use plaister. 

 The results of their practice, much the same with those 

 on other soils. It depends on the texture and staple, of 

 the upper stratum of soil. Limestone is here found 

 under clay, loam, and sand. In our coal countries, ge- 

 nerally under clay. It is curious to observe the gene- 

 ral uniformity of the strata, in our western country, 

 beyond the mountains ; where in many parts, they 

 scarcely ever sink a well, without finding clay, coal, lime- 

 stone, 2ind Jreestone, or slate, in strata, each of from four 

 to six feet thick. The clay is generally on the surface, 

 but it frequendy happens otherwise. 



6. By a recurrence to the facts in the foregoing 

 collection, it will appear, that the idea of plaister not 

 being beneficial, where lands have been long under cul- 

 tivation, is unfounded. Mr. Robert's lands have been 

 cleared 90 or 100 years. Some of mine above 60, Mr. 

 Sellers's is an old farm, and so are those of Mr. Duf- 

 field and Mr. Price. 



I have lately been informed, in a letter from Robert 

 Barclay Esq. of London, a worthy member of our soci- 

 ety, that plaister succeeds in some parts of England; 

 where it has been used with various success ; and 

 often, in that kingdom, without any benefit. Mr. Bar- 

 clay writes, under date of 31st July, 1810. 



