On Plaister of Paris >> 33 



Query 9. What is the greatest product per acre of 

 grass, &c. you have known by the means of plaister ? 



Answer, I cannot answer this query with certainty, 

 having never weighed any. But by computation from 

 land that has been manured before it was plaistered, I 

 have had from two crops of clover about four and a half 

 tuns per acre ; and from poor unmanured land, that I 

 should not suppose would have produced, half a tun, I 

 have had frequently one and an half, and perhaps two tuns. 

 I propose trying the experiment, by weighing a small 

 proportion of a piece I have plaistered, and another 

 sowed with clover at the same time, along side, and 

 treated every way in the same manner, except the plais- 

 tering. The plaistered, I think, will produce at the rate 

 of two tuns ; and the other I do not believe will produce 

 at the rate of five hundred weight per acre. 



Query 10. Have you ever used it with other manure, 

 and what ? — and the effect if any superior to the plais- 

 ter alone ? 



Answer, I have never found any kind of manure to 

 be of any advantage to strengthen the plaister. I have 

 put it on after lime and dung frequently, and have al- 

 ways found the greatest difference in the effect, where 

 it has been put on entirely alone, both on clover and In- 

 dian corn. Where the manure has been put- the crop has 

 been the greatest^ but their operations I believe to be 

 entirely independent of each other.* 



* Whether my idea of the sulphuric fici^ being the active 

 agent, in the gyps was original, or adopted, I cannot tell ; nor do 

 Iclaim merit on such accidental thoughts. But since my conjee- 



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