184 



If a sufficient quantity of sulphate of lime exist in the soil, the appli- 

 cation of gypsura becomes perfectly useless, and on this account, its 

 value as a manure has been doubteil by some persons, who did not un- 

 derstand the cause of its failure. Many interesting experiments have 

 been tried, in order to prove the value of gypsum as a manure; some 

 of them are worth recording. Mr. Smith, of Turnstall, near Setting- 

 bourn, having a field of red clover which had been manured with gyp- 

 sum, and had produced a Very fine crop, he repeated his trial, on two 

 square perches — one carefully spread, about the middle of April, with 

 powdered gypsum, at the rate of five bushels per acre — the other with- 

 out any ; the crops when mown, and afterwards cut for seed, produced 

 as follows : 



pet acre. cut for seed. 



Gypsumed part, 60 cwt. 3.2 1 



No manure, _ 20 cwt. .20 



Mr. Smith says his cattle showed a remarkable predilection for the 

 gypsumed clover. 



The following experiments on different perches of clover, illustrate 

 the value of gypsum: 



No. 1. No manure, - 38.6 



No. 2. 4 quarts sifted coal ashes, 50.0 



No. 3. 1 quart gypsum, — 54.8 



The above experiments also show that coal ashes are a good manure. 



An experiment is recorded in the " Library of Useful Knowledge," 

 in which five bushels of gypsum per acre, were applied to part of a 

 large field of clover. Its eflect in promoting the weight and luxuriance 

 of the crop was remarkable. In November the entire field was sown 

 with wheat, and the dark color and luxuriant growth of that part which 

 had been gypsumed, became apparent in the spring. When the wheat 

 was threshed, ttie produce was as follows: 



qrs. bush. ^ «• 



Gypsumed part produced per acre,4. 72 IV 2 



No manure,... - 2. 4 do 9 



Three quarters per acre was the largest amount that had been grown 

 in the same field during a period of twenty eight years, that it had been 

 occupied by the same tenant. The good eftiect of plaster on wheat, 



