ON MANURES. 117 



temperature, at least, arrests its effects, and seems even to 

 suppress them altog-ether if the gypsum has been calcined : 

 but it should be observed, that this only occurs if rain falls 

 soon after its application ; for if it happens previously, its mois- 

 ture upon the plants will be found useful. This employment 

 of the gypsum, either during the prevalence of rain, or imme- 

 diately before it has fallen, has given rise to many mistakes, 

 which have occasioned much of the prejudice which is enter- 

 tained against its use. Tims, in the Sussex Report it has 

 been stated that equal quantities of French and English gyp- 

 sum were laid, on the 14th of June, on six different fields of a 

 sandy loam, sown with beans, peas, potatoes, and barley, besides 

 natural grass, at the rate of 8 bushels to the acre. On the day 

 it was strew^ed it was showery, and on the 15th it rained from 

 10 in the morning till the evening ; yet neither in that, nor in 

 the following year, could any greater appearance of luxuriance 

 be perceived than on the surrounding ground. The experi- 

 ment was also repeated in March and the middle of April upon 

 some patches of red clover, wheat, and spring tares, with simi- 

 lar effect : on both occasions it rained heavily. Thus, not only, 

 as we- shall perceive, has it been applied to some crops to 

 which it is useless, but in seasons which were inappropriate, 

 and it has been washed off those plants, on the stems of which 

 had it been allowed to remain, it no doubt w^ould have been 

 attended with good effect. 



The crops to which it is the most appropriate are the arti- 

 ficial grasses and leguminous plants, though it has been also 

 known to materially improve the sward of moss-bound pasture. 

 It never appears to produce better effects than when it has 

 been laid on red clover, already so far grown as that the leaves 

 nearly cover the soil ; for there seems no doubt that it acts 

 with the greatest force when it adheres to them, and that the 

 longer it remains upon them the better. It should, therefore, 

 be used as a top-dressing, and applied in the latter end of April, 

 or the beginning of May. Besides the effect attributed to its 

 application to the leaves, it has not been found so advantageous 

 wdien laid on during the cold months of winter, while plants 

 are in a torpid state; though many people spread it in autumn 

 upon the young clover of the first year, and others, after the 

 first cut, which has thus been often known to produce a larger 

 crop than the former. Perhaps, however, these plans might 

 be beneficially combined were the quantity of gypsum divided; 

 one portion to be used as an early sprinkling when the first 



