Most writers have said that it is the dew, scorched by a burning sun, that is the cause of mildew[554] in corn, and of coal blight in the vine; this, however, seems to me in a great measure incorrect, and it is my opinion that all blights result entirely from cold, and that the sun is productive of no injurious effects whatever. This, in fact, will be quite evident, if only a little attention is paid to the subject; for we find that the blight makes its appearance at first in the night time only, and before the sun has shone with any vigour. The natural inference is, that it depends entirely upon the moon, and more particularly as such a calamity as this is never known to happen except at the moon’s conjunction, or else at the full moon, periods at which the influence of that heavenly body is at its greatest height. For at both of these periods, as already[555] stated by us more than once, the moon is in reality at the full; though during her conjunction she throws back to the heavens all the light which she has received from the sun. The difference in the effects produced by the moon at these two periods is very great, though at the same time equally apparent; for at the conjunction, that body is extremely hot in summer, but cold in winter; while, on the other hand, at the full moon, the nights are cold in summer, but warm in winter. The reason of this, although Fabianus and the Greek writers adopt another method of explaining it, is quite evident. During the moon’s conjunction in summer, she must of necessity move along with the sun in an orbit nearer to the earth, and so become warmed by the heat which she receives by reason of her closer vicinity to the sun. In winter, again, at the time of the conjunction, she is farther off from us, the sun being also removed to a greater distance. On the other hand, again, when the moon is at the full in summer, she is more remote from the earth, and in opposition with the sun; while, in winter, she approaches nearer to us at that period, by adopting the same orbit as at her conjunction in summer. Naturally humid herself, as often as from her position she is cold, she congeals to an unlimited extent the dews which fall at that period of the year. CHAP. 69.—CAUSES OF STERILITY. But we ought always to bear in mind, more particularly, that there are two varieties of evils that are inflicted upon the earth by the heavens. The first of these, known by us under the name of “tempests,” comprehends hail-storms, hurricanes and other calamities of a similar nature; when these take place at the full moon, they come upon us with additional intensity. These tempests take their rise in certain noxious constellations, as already stated by us on several occasions, Arcturus, for instance, Orion, and the Kids.