[OBSERVATIONS AND EXPERIMENTS ON TREES AND OTHER VEGETABLES.]
THE physical study of Vegetables is one of those sciences which require a multiplicity of observations and experiments beyond the capacity of one man, and must consequently be a work of time; even the observations themselves are seldom of much value till they have been repeatedly made, and compared in different places and seasons, and by different persons of similar ideas. It was for this purpose that Buffon united with M. Du Hamel, to labour, in concert for the illustration of a number of phenomena, which appeared difficult to explain, in the vegetable kingdom, and from the knowledge of which may result an infinity of useful matters in the practice of agriculture.
The frost is sometimes so intense during winter, that it destroys almost all vegetables, and the scarcity in the year 1709 was a melancholy proof of its cruel effects. Seeds, and some kinds of trees, entirely perished, while others, as olives, and almost all fruit-trees, shared a milder fate, shooting forth their leaves, their roots not having been hurt; and many large trees, which were more vigorous, shot forth every branch in spring, and did not appear to have suffered any material injury. We shall, nevertheless, remark on the real and irreparable damage this winter occasioned them.
Frost, which can deprive us of the most necessary articles of life, destroys many kinds of useful trees, and which scarcely ever leaves one insensible of its rigour, is certainly one of the most formidable misfortunes of human nature; we have therefore every reason to dread intense frosts, which might reduce us to the last extremities if their severities were frequent; but fortunately we can quote only two or three winters which have produced so great and general a calamity as that in 1709.
The greatest spring frosts, although they damage the grain, and principally barley, when it is but just eared, never occasion great scarcities. They do not affect the trunks or branches of trees, but they totally destroy their productions, deprive us of the harvest of the vines and orchards, and by the suppression of new buds cause a considerable damage to forests.
Although there are some examples of winter frosts having reduced us to a scarcity of bread, and deprived us of vegetables, the damage which spring frosts occasion becomes still more important, because they afflict us more frequently, and their effects are felt almost every year.