On well' rotted Diing^ Stercoraries^ SsV. 229 

 Vol. 11. Plaster of Paris, page 44. No material yields 



flattering to first impressions ; which is not singular. But I do not 

 stand alone in believing ; and actual results of frequent experi- 

 ments, give me strong grounds to support such belief; that sw/- 

 Jihur in its crude state, and its offspring the sulfihuric-acid, are, of 

 themselves, operative in promoting vigorous and healthy vegeta- 

 tion. See Vol. II. page 206. Same; On plaster of Paris, 92,94, 95. 

 Whether they act merely as seplics, or stimulants, or both ; or in 

 what way they operate, I do dot presume, peremptorily to ducide ; 

 though I have strongly urged an opinion. But it is of indispensable 

 importance to know, what are the component parts essentially re- 

 quired, to constitute good plaster. The fallacy of experiments, too, 

 I am practically convinced of ; having myself failed in so many. 

 Yet I never presume, that my success, or failure, is the test of 

 truth. Times, seasons, state of atmosphere, quality and situation 

 of land, differ so materially, that experiments may fail at one time, 

 and at one place, which would succeed at others. In the year 

 1772 (more than forty years ago) I began the career of plas- 

 ter. In this long course of time, I have never ceased applying it. 

 I have experienced numberless failures and disappointments, from 

 the htst gyfisum, on the most suitable soils. This season, with me, 

 has been so remarkably unfavourable ; that, had I exclusively to 

 decide on its efiicacy, on the results of this year, I should really 

 pronounce the plaster worthless and inefficient. Yet I know the 

 quality of that I used, to be perfect ; and the soil exactly suitable. 

 On some other farms, it has succeeded as well as is common. I 

 therefore conclude, that no decisive opinion ought to be formed, 

 from the experiments of any one person (including myself in this 

 remark) or those tried at one place, or in one, or two seasons. It is 

 fortunate, however, that we have a cloud of witnesses to practical 

 results. If causes remain hidden, ingenuity and science may conti- 

 nue their speculations. But farmers (among whom alone I class 

 myself) have long experience in practical proofs, to animate them, 

 in their unhesitating reliance on this invaluable substance. 



R. P. 



