The 14th, 15th, and 22d of May, it froze pretty sharply, accompanied by the north and north-west winds, and I then likewise observed that all those sheltered from the wind were very much injured, but that all those which were exposed thereto had suffered but very little. This experiment appeared decisive, and showed that although it froze most strong in parts exposed to the north wind, yet the frost in that situation did the least injury to vegetables. This circumstance is certainly opposed to common prejudice; but it is not less the fact, and is even easy to be explained; for this purpose, it is sufficient to pay attention to circumstances in which frost acts, and we shall discover that humidity is the principal cause of its effects, so that all which occasions humidify renders, at the same time, the frost dangerous to vegetables, and all that dissipates humidity, even if it should be done by increasing the cold (for every thing that dries diminishes the disasters of a frost) acts towards their preservation. We have often remarked, that in low places, where mists and fogs reign, frost is felt more sharply, and oftener than elsewhere. For instance, in autumn and spring we have seen delicate plants frozen in a kitchen-garden, in a low situation, while the like plants were preserved sound in another kitchen-garden situated on an eminence. So, likewise, in vallies and low forests the wood is never of a beautiful vein, nor of good quality, although the vallies are often by much the best soil. The coppice wood is never good in low places, although it shoots forth there later than upon high places, and which is occasioned by a freshness that is always concentered therein. When I walked at night in the wood I felt almost as much heat on eminences as in the open plains, but in the vallies I experienced a sharp and uncomfortable cold. Though the trees shoot out the latest in those parts, yet the shoots are still injured by the frost, which spoiling the principal buds obliges the trees to shoot forth lateral branches, and thus prevents their ever becoming straight and handsome trees fit for service. What we have just advanced must not be understood only of deep vallies, which are liable to those inconveniencies from northern expositions, or those inclosed on the southern side in the form of an alley, in which it often freezes the whole year, but also of the smallest vallies, so that by a little custom we can discover the bad figure of the shoots from the inclination of the earth; this I particularly observed on the 28th of April, 1734; on that day the buds of all the trees, from one year up to six or seven, were frozen in all the lower places; whereas in the high and uncovered places there were only the shoots near the earth which were so; the earth was then very dry, and the humidity of the air did not appear to have greatly contributed to this injury. Neither vines, nor the trees of the plain,