ripen much earlier when he obtains his seed-corn from a very warm district and gravelly soil which lies a few miles distant, than when he employs the seeds of the vicinity. Barley, also, grown on sandy soils in the warmest parts of England, is always found by the Scotch farmer, when introduced into his country, to ripen on his cold hills earlier than crops of the same kind do when he uses the seeds of plants which have passed through Several successive generations in the colder climate of Scotland.
Farmers have certainly an indistinct and confused notion of some benefit to be derived from changing their seed: and accordingly, every three or four years, most of them do obtain from some neighbour a supply of seed-corn. Not knowing the principle, however, upon which the anticipated advantage is to be calculated, it is a matter of much uncertainty whether their expectations are gratified or disappointed. The general principle I think seems to be, a disposition in plants to retain under different circumstances their own former habits, and a disposition in seeds to acquire the habits of their parent plants. Thus, on rich luxuriant soils where the crops are much disposed to have great length of straw, and consequently are very liable to be laid during the summer, it seems desirable to select seed from a poor and naked soil where it has been the habit of the parent plants to bear deficient straw: on the contrary, upon those bare and barren heaths, where a meagre vegetation does not half conceal the parched-up ground, it is probably adviseable to obtain seed from the most luxuriant and fertile fields. The product of the hills should be spread upon the vallies, and that of the vallies on the hills. As the Scotch farmer has found advantage by obtaining seed-corn from the warmest districts of England, so the farmers of the northern and the eastern counties of England would probably reap similar benefit by having recourse to their brethren of the west and south. Whatever preserves corn in a healthy state, whether wheat, barley, oats, peas, or any thing else, arms it against the attack of those parasitic fungi which, when they have taken possession of the plant, we call the mildew, and which is rather to be considered as the consequence of previous unhealthiness than as a disease per se. Too great luxuriance and too little are alike injurious; a man may kill himself by eating too much as well as too little, and die of fat, instead of famine. The adaption of seed to soil and climate, by promoting the health may repel the mildew of the corn; and to protect the young crop as much as possible against excessive moisture is of the greatest consequence: no land that is not thoroughly drained should be entrusted with wheat.
In Mr. Egremont's pamphlet he endeavours to account for some effects upon vegetation, which atmospheric variations alone seem insufficient to explain.
