176 



granaries, or others, tlierefore, can be contrived beloW 

 that temperature, the evil will be cured by cold. A de- 

 gree of heat beyond that which hatches the egg we 

 know will kill it. But in aiming at this we easily run 

 into that which produces jjutrefaction. To produce 

 putrefaction, however, three agents are requisite, heat, 

 moisture, and the external air. If the absence of any 

 one of tliese he secured, the other two may safely be 

 admitted. Heat is the one we want. IMoisiure then, 

 or externa] air, must be excluded. — The former has 

 been done by exposing the grain in kilns to the action 

 of fire, which ])roduces heat, and extracts moisture at 

 the same titne: the latter, by putting the grain into 

 hogsheads covering it with a coat of lime, and heading 

 it up. In this situation its bulk produced a heat suffi- 

 cient to kill the egg ; the moi^ture is suffered to remain 

 indeed, but the external air is excluded. A nicer ope- 

 ration yet has been attempted ; that is, to j)roduce an 

 intermediate temperature of heat between that which 

 kills the egg, and that which produces putrefaction. 

 The t!ireshing the grain as soon as it is cut, and laying 

 it in its chaff" in large heaps, has been found very near- 

 ly to hit this temperature, though not [)erfectly, nor al- 

 ways. The heap generates heat sufficient to kill most 

 of the es:gs, whilst the chaff" commonlv restrains it from 

 rising into putrefaction. But all these methods abridge 

 too much the quantity which the farmer can manage^ 

 and enable other countries to undersell him which are 

 not infested with this insect. — There is still a desidera- 

 tum then to give with us decisive trium})h tothisbranch 

 of agriculture over that of tobacco. The culture of 

 wheat, by enlarging our pasture, will render the Ara- 

 bian horse an article of very considerable profit. Ex- 

 perience has shown that ours is the [)articular climate 

 of America where he may be raised without degenera- 

 cy. Southwardly the heat of the sun occasions a defi-* 

 ciency of pasture, and northwardly the winters are too 

 cold for the short and fine hair, tlie particular sensibili- 

 ty and constitution of that race. Animals transplanted 

 into unfriendly climates, either change their nature and 



