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ber) 17 degrees less than it was in the months of August and September.

108. I hope this paradox will be explained, and that the principles which may clear it up will draw useful consequences along with them. Those philosphers who look upon evaporation as a dissolution of water by air in the manner of menstrua, that is, by affinity, will easily apply their principle to the solution of part of these phaenomena The dissolution is greater when the menstruum is warmer, and consequently the air must keep a greater quantity of water in dissolution, and suffere a less part of it to be precipitated, in summer than in winter. I can- not but allow that this system is extremely specious, and that many phznomena are very happily explained by means of it. This is what Mr le Roy has shewn us in the memoir I have already quoted ; in which, without contending that ai r really acts as a menstruum with respect to water, he demonstrates, by a parallel very well kept up, that all the chemical expressions concerning dissolutions may with propriety be applied to describe the several phaenomena be examines, relative to the elevation and suspension of water in air, as well as to its precipitation under different forms

109. If it was not too common a practice, to conclude things from words, I should in fact think these chemical expressions very conveniently adapted to explain a number of these phaenomena. But I have rejected them here, on account of this consideration; that when I took in a greater number of phaenomena, I found them no longer accurate, any more than the general idea of the dissolu-

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