ADVANCEMENT OF LEARNING 145 



loadstone attracts iron urge, therefore, the iron, or urge the 

 loadstone, till they attract no longer ; for example, if the load- 

 stone were burnt, or steeped in aqua-fortis, would it entirely, or 

 only in part, lose its virtue ? So if iron were reduced to a cro- 

 cus, or made into prepared steel, as they call it, or dissolved in 

 aqua-fortis, would the loadstone still attract it? The magnet 

 draws iron through all known mediums gold, silver, glass, 

 etc. Urge the medium, therefore, and, if possible, find out one 

 that intercepts the virtue. Thus make trial of quicksilver, oil, 

 gums, ignited gold, and such things as have not yet been tried. 

 Again, microscopes have been lately introduced which strange- 

 ly magnify minute objects ; urge the use of them, either by ap- 

 plying them to objects so small that their power is lost, or so 

 large till it is confounded. Thus, for example, can microscopes 

 clearly discover those things in urine which are not otherwise 

 perceptible ? Can they discover any specks or clouds in gems 

 that are perfectly clear and bright to appearance ? Can they 

 magnify the motes of the sun, which Democritus mistook for 

 atoms and the principles of things ?w Will they show a mixed 

 powder of vermilion and ceruse in distinct grains of red and 

 white? Will they magnify larger objects as the face, the 

 eye, etc. as much as they do a gnat or a mite, or represent a 

 piece of fine linen open as a net ? But we need not insist 

 longer on compulsory experiments, as they do not justly come 

 within the limits of literate experience, but are rather referred 

 to axioms, causes, and the New Organum. 



The application of an experiment is no more than an ingen- 

 ious translation of it to some other experiment of use ; for ex- 

 ample, all bodies have their own dimensions and gravities. 

 Gold has more gravity and less bulk than silver, and water than 

 wine hence a useful experiment is derived for discovering 

 what proportion of silver is mixed with gold, or of water with 

 wine, from a knowledge of their measure and weight, which 

 was the grand discovery of Archimedes. Again, as flesh pu- 

 trefies sooner in some cellars than in others, it were useful to 

 transfer this experiment to the examination of airs, as to their 

 being more or less wholesome to live in, by finding those 

 wherein flesh remains longest unputrefied; and the same ex- 

 periment is applicable to discover the more wholesome or pes- 

 tilential seasons of the year. But examples of this kind are 

 endless, and require that men should have their eyes contin- 

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