All delicate trees, as fig, laurel, &c. must be set to the south, and great care taken to cover them; it is only requisite to remark that dry dung is preferable for this purpose to straw, because the latter not only does not so exactly cover them, but also from its always retaining some grain which attracts moles and rats, who sometimes eat the bark of trees to quench their thirst in frosty weather, when they can meet with no water to drink, nor herb to feed upon; and however singular this may appear, it is a circumstance which has happened to us several times; but when dung is made use of it must be dry, without which it will heat and make the young branches grow mouldy. All these precautions are, nevertheless, very inferior to the espaliers in niches, as in that manner plants are sheltered from all winds, except the south, which cannot hurt them; the sun, which warms these places during the day, prevents the cold from being so violent during the night; and over these defended places we may put a slight covering with great facility, which will hold the plants there in a state of dryness, infinitely proper to prevent all the accidents which the spring frosts and ice might produce; and most plants will not suffer from being deprived of their external humidity, because they scarcely transpire in the winter, or in the beginning of spring, so that the humidity of the air is sufficient for their supply. But since the dew renders plants so susceptible of the spring frost, might we not hope, that from the researches of Messrs. Musschenbroeck and Fay, some inferences may be deduced which may turn to the advantage of agriculture? for since there are some bodies which seem to attract dew, while others evidently repel it, if we could paint, plaster, or wash the walls with some matter which would have the latter effect, it is certain we should have room to expect a more fortunate success than from the precaution taken to place a plank in form of a roof over the espaliers, which cannot prevent the abundance of dew from resting on trees, since Fay has proved that it very often does not fall perpendicularly like rain, but floats in the air, and attaches itself to those bodies it encounters; so that frequently as much dew is amassed under a roof as in places entirely open. It would be easy for us to recapitulate all our observations, and continue to deduce useful consequences, but what we have said must be sufficient to shew the necessity of rooting up all trees which prevent the wind from dissipating mists. Since by cultivating the earth we cause more exhalations to issue, great attention should be paid not to cultivate them in critical times. We must expressly declare against sowing kitchen-plants on vine-furrows, as by their transpiration they hurt the vine.