C 55 ] ^ 



^Letter on the Ufe of Plaijler of FariSy as a Manure, From 

 George. Logan, Efq. to the Philadelphia County Society for the 

 Promotion of Agriculture and Domeflic ManufaBures. From 

 the American Mufeum — Vol. VI. Page 399. 



Gentlemen, 

 T TAVING for four years paft, made ufe of Plaiftcr of Paris, 

 or Gypfiim, as a manure upon variety of foils, and under 

 different circumftances — I beg leave to lay before you the refult 

 of my experiments, together with fome obfervations refpefting 

 the nature of this foffil. I am the more anxious to comply 

 with my duty to the fociety in this refpeft, becaufe many of 

 our fellow-citizens are lofing the great advantage to be derived 

 from the ufe of this manure ; entertaining an opinion, that it 

 does not, in itfelf, contain any nutriment to plants, but that it 

 afts merely as aftimulus to the foil, by which, although vegeta- 

 tion is for a fliort time rapidly .promoted, yet the ground 

 becomes exhaufted, and is left a dead inert mafs. 



ift. In the year 1785. I fowed three acres of alight ifinglafs 

 foil, containing a little clay, with barley and clover. In the 

 month of April, the following year, I divided the field into 



* Note — Tho' this letter of Mr. Logan lias been publifhed, yet as it 

 contains much nfefiil information, and Pnews the ability of Gypfum in aiding 

 the fertility of ground in the produdion of wheat and rye, to which in the 

 firft inftance it appears to be of little ufe, it is thought that u would ferve 

 as an jllullration of Mr. Livingllon's theory. 



