58 Translation of Key's Essays. 



mogeneous bodies. But let us see if it be more consibtent with 

 truth when applied to simple bodies. 



Ess AT XIII. 



Fire can thicken Water, 



Water, unquestionably, is a simple body, and it is equally 

 certain, that fire acting on it, dilates some of its parts, and 

 thickens others ; albeit, as I have said already, the first action 

 is proper and natural to it, and the second accidental. Pour a 

 barrel of water into an alembic, heat it according to the rules of 

 art, and draw off first a gallon (pot*) of it. It is certain that the 

 •water of this gallon will be more subtile than that which you 

 put into the alembic. If any one stimulated by the desire of 

 contradiction deny it, let him be refuted by the chemists ; who 

 not being able to make their extracts conveniently with common 

 water, are accustomed to use distilled water or dew, (which is 

 nothing else than water passed through the great alembic of 

 nature,) for such water being more subtle, better penetrates 

 the substance of the simples, and more readily draws out their 

 virtues and tinctures. Moreover, its greater diuretic effects, 

 and its less weight, (the inseparable companion of a less degree 

 of thickness), give ample proof of the truth of my assertion. 

 But if the water of this gallon be more subtle than the water 

 put into the alembic, that which remains must be thicker, 

 inasmuch as a thickening is a necessary consequence of the 

 separation of the subtle part. This will be more evident if 

 you continue the distillation ; for, drawing off gallon after 

 gallon, till no more remains, the last will be sensibly heavier 

 and thicker than the first ; and this sensible difference will 

 ensue by small, but imperceptible, degrees, from the first to the 

 second, from the second to the third, and so on consecutively 

 to the last. Nor will this difference be only from gallon to 

 gallon, but from glass to glass, indeed, from drop to drop ; 

 for since the two extreme drops must manifestly differ in thick- 



• A measure nearly equal to a gallon. 



