Crops of Grain are liable. 55 



growth is thereby promoted ; but it seldom happens, that snow, to any 

 injurious extent, falls on the crops in harvest. The only instance, for 

 more than a century past, of snow hurting the crops, was on the 3d 

 October 1782, when it fell to the depth of eighteen inches, over the 

 greater part of Scotland, at a time when three-fourth parts of the 

 oats were unreapecl ; and as it was followed by severe frost, for more 

 than two weeks, the crop was in a great measure lost. 



7. Heat. Although crops suffer more in Britain, from cold and 

 excessive rains, than from any other cause, yet heat and drought have 

 sometimes injured them to a considerable extent, not only in summer, 

 but even when ripening. The extraordinary heat and drought in the 

 summer of 1826, was not injurious to the wheat crops, but it nearly 

 ruined\>ats, barley, beans and pease. In 1819, a course of hot sun- 

 shine, for three or four weeks, about the beginning of September, com- 

 pletely destroyed a considerable portion of the crop of oats, in some 

 parts of Scotland. Fortunately, much of the oat crops was nearly ripe, 

 before that drought, and uncommon heat set in, but where it overtook 

 the oats in a milky state, it was so powerful, as to wither the foliage, 

 dry up the juices of the plants, and thereby to render the straw so 

 shrivelled, that it could not bring the grain to perfection. The want 

 of moisture, rendered the stems of the oats so sickly and feeble, that 

 they ripened prematurely, with scarcely any meal or farina in the 

 grain. Even the straw became dry, brittle, and so useless, that no 

 cattle would eat it ; and when reaped or handled, it emitted a disagree- 

 able dust, and much of it was thrown to the dunghill. So long as 

 oats remain in a grassy state, they can draw some moisture from the 

 atmosphere by their leaves, but after the seeds begin to ripen, the foliage 

 becomes withered, and if there is no rain, the plant becomes too dry, 

 to be able to bring the grain to perfection. 



8. Lightning. Grain crops have often suffered by lightning, but 

 seldom to any great extent in Britain. Some have imputed the black- 

 ish spots on the stems and foliage, to lightning, but these are 

 evidently the effects of mildew, as shall afterwards be explained. 

 Lightning cannot fail however, to injure grain crops, wherever it 

 falls, and the disease or injury termed blight, is chiefly to be attributed 

 to it. 



9. Calms. A moderate current of air, is always favourable to the 

 health and life of plants, and its circulation is calculated to promote 

 their growth, and to bring them to perfection. Wind shakes off su- 

 perabundant moisture, and promotes the growth of every species of 

 plants, by carrying to them that portion of their food, that has been 

 reduced to the state of gas, and which they take in by their leaves and 

 foliage. On that account, some have complained of the interruption 

 given to the current of air by plantations, high hedges, &c. ; but it 

 ought to be remembered, that though moderate gales are beneficial, 

 yet high winds and cold blasts are injurious to the land, the crops, 

 and the cattle, and therefore shelter is required. We have occasion- 

 ally too many calms in Britain, but these are not nearly so injurious, 

 as our cold winds and stormy blasts. 



10. Variable Weather. Every excess of wetness, drought, cold 

 or heat, is injurious to the crops, and every sudden transition from 

 one to another of these, serves to increase that injury, by operating 



