MANURE- -GYPSUM. 327 



A. and C were the surfaces which I proposed to myself to contrast ; 

 the intermediate zone, B, was a kind of neutral ground employed 

 merely to prevent the immediate contact of the g-ypsed with the un- 

 g^ypsed zone. I may here remark, that it would be well always to 

 take such a precaution in making experiments on the effects of dif- 

 ferent manures. 



In 1842 I tried the effect of gypsum upon w heat coming after three 

 different crops. 1st. After clover ploughed in. 2d. After beet- 

 root. 3d. At'ter potatoes. 



The gypsum was applied the 19th of May, at which time the 

 wheat looked extremely well. The crop was cut between the 21st 

 and 26th of July, and the following are the results obtained : 



P Weig-ht o^' grain, corn, and straw. 



P A. piece gypseil. B. not g-ypseJ. C not gypsed. 



Wheat after clover 319 lbs. 323 lbs. 327 lbs. 



Wheat after mangel-wurzel 195 " 17G " 158 " 



Wheat after potatoes 235 " 158 " 2C4 " 



Average of the three experiments 250 '* 248 " 250 " 



The year 1842 having been unfavorable to wheat in consequence 

 of the long drought, the experiment required to be repeated. This 

 was done in 1843 ; and it must be allowed, that an experiment could 

 scarcely be conducted under circumstances of weather more favora- 

 ble to the cultivation of grain ; the results here are given for equal 

 spaces of three French acres, equal to 385 square yards. The gyp- 

 sed zones had been treated with 70 lbs. of silphate of lime each : 



Year 1843. Sheaves. Grain. Straw, chaff, anil waste. 



lbs. lbs. lbs. 



Rye with eypsum 516 137 379 



Rye without 472 127 345 



Wheat with gypsum 462 147 315 



Wheat without 510 156 254 



Wheat without 453 143 310 



Oats with g^-psum 329 112 217 



Oats without 368 113 255 



From these numbers it is obvious that gyp&um produces no appreci- 

 able effect upon wheat, oats, and rye, conclusions that agree with 

 those come to in the previous year. 



EXPERIMENT WITH FIELD-BEET OR MANGEL-WURZEL, OPENING THE 

 ROTATION WITH MANURED SOiL, 1842. 



The plants were transplanted and waterel, and the gypsum was 

 applied at the time of earthing up ; a good deal of rain fell, and 

 Bhortly after having been laid on, he^ gypsum had become incorpo- 

 rated with the ground. The crop vas gathered on the 8th of Octo- 

 oer, three months after the gypsing, and from two equal surfaces, 

 each of 242 square yards in extent, weighed as follows : 



From the gypsed ground ^3 cwt. 2 qrs. 6 lbs. 



From the ungypsed i 2 " 2 " 3 " 



The gypsum would therefore appear to have had no beneficial 

 effect ; for the difference in favor of the gypsed piece is so trifling 



