60 Translation o/'Rey's Essm/s. 



and efficacy. A pretty invention, certainly, to draw off brandy 

 without fire, if the fact be so, (*i la chose allait ainsi;) and the 

 difficulty of making the instrument did not prevent the use of 

 it. All these observations serve me as a bridge to pass to this 

 general assertion, that in all fluids, as well compound as simple 

 or elementary, the upper parts always differ in subtlety and 

 weight from the lower ; and that this difference is distinguished 

 by as many degrees as their matter is divisible by their height 

 into distinct parts : so that if we conceive a line drawn from the 

 lowest part of one of the fluid elements (as air) to its highest 

 surface, just so many degrees of weight and subtlety will there 

 be in that element, as the line can be divided into different 

 parts, (I mean materially to avoid sophistry,) and the upper 

 part of all will always be thinner and lighter than the second, the 

 second than the third, and so on to the end. For to attribute 

 to all the parts of each element the same body, (corpvlence) is to 

 belie our sense, which compels us to consider air (for instance) 

 more subtle at the summit of a mountain, than in the plain at 

 its foot. And, in like manner, when the heat of the sun, or of 

 our fire, subtilizes it here below, it mounts on high, unques- 

 tionably, till it meets with its like, according to the degree of 

 subtlety it has acquired. Besides, if this equality prevailed 

 through the whole elements, there would be no reason why one 

 portion of it should be below, and one above, when the air is 

 calm. For to commit that to chance and hazard, would be to 

 shock the incomparable wisdom of the Author of nature, who 

 has made nothing in it without number, weight, and measure ; 

 and has established such order throughout, that nothing happens 

 fortuitously and without cause. I conclude, therefore, that this 

 arrangement is derived from weight, and no otherwise. But to 

 conclude this essay, I say that every one may now see that fire 

 acting on the simple body, water, does not equally distend all 

 its parts, but by dilating some it separates them, whence follows 

 the thickening of others. Thus the maxim in dispute is not 

 true. But it will be said this must be shewn of air, on which 

 the pivot of the controversy turns. That is their last refuge, 

 and I proceed to deprive them of that. 



