CHAP. II.] THE MODES OF KXPERIMENT. 191 



An experiment is produced two ways; viz., by repetition 

 and extension, the experiment being either repeated or 

 urged to a more subtile thing. It may serve for an example 

 of repetition, that spirit of wine is made of wine by one dis- 

 tillation, and thus becomes much stronger and more acrid 

 than the wine itself, — will likewise spirit of wine propor- 

 tionally exceed itself in strength by another distillation? 

 But the repetition also of experiments may deceive ; thus 

 here the second exaltation does not equal the excess of the 

 first; and frequently, by repeating an experiment after a 

 certain pitch is obtained, nature is so far from going farther, 

 that she rather falls back. Judgment, therefore, must be 

 used in this affttir. So quicksilver put into melted lead, 

 when it iDCgins to grow cold, will be arrested, and remain no 

 longer fluid; but will the same quicksilver, often served so, 

 become fixed and malleable ? 



For an example of extension, water made pendulous 

 above, by means of a long glass stem, and dipped into a 

 mixture of wine and water, will separate the Avater fi'om 

 the wine, the wine gently rising to the top, and the water 

 descending a-nd settling at the bottom. Now, as wine and 

 water, being two different bodies, are separable by this con- 

 trivance, may likewise the more subtile parts of wine, which 

 is an entire body, be separated from the more gross by this 

 kind of distillation, performed as it were by gravity, so as to 

 have floating a-top a liquor like spirit of wine, or perhaps 

 more subtile ? Again, the loadstone draws iron in substance, 

 but will loadstone jDlunged into a solution of iron attract the 

 iron and cover itself with it ? So the magnetic needle applies 

 to the poles of the world; but does it do this after the same 

 course and order that the celestial bodies move ? Suppose 

 the needle held at the south point, and then let go, would 

 it now turn to the north by the west or east?? Thus gold 

 imbibes quicksilver contiguous to it; but does the gold do this 

 without increasing its own bulk, so as to become a mass spe- 

 cifically heavier than gold 1 Thus men help their memories 

 by setting up pictures of persons in certain places; but wo":ild 



P This question is impossible to decide, as we are never certain at 

 the moment of the experiment that the needle has not been deflected 

 fi*ora the south point, and the slightest imperceptible degree, toe fine 

 for human instrument to discover, would render the trial nugatory £aU 



