628 . NOVUM ORGAN UM [iJCOK H. 



be drawn out into so many letters ; that silver merely gilt on its 

 surface should be stretche'ii to such a length of gilt wire ; that n 

 little worm, such as you may find on the skin, should possess 

 both a spirit and a varied conformation of its parts ; that a little 

 saffron should imbue a whole tub or water with its colour ; that 

 a little musk or aroma should imbue a much greater extent of 

 air with its perfume ; that «. cloud of smoke should be raised by 

 a little incense ; that such accurate differences ot sounds as 

 articulate words should be conveyed in all directions through the 

 air, and even penetrate the pores of wood and water (though 

 they become much weakened), that they should be, moreover, 

 reflected, and that with such distinctness and velocity ; that 

 light and colour should for such an extent and so rapidly pass 

 through solid bodies, such as glass and water, with so great and 

 so exquisite a variety of images, and should be refracted and 

 reflected ; that the magnet should attract through every descrip- 

 tion of body, even the most compact ; but (what is still more 

 wonderful) that in all these cases the action of one should not 

 impede that of another in a common medium, such as air ; and 

 that there should be borne through the air, at the same time, so 

 many images of visible objects, so many impulses of articulation, 

 so many different perfumes, as of the violet, rose, &c., besides 

 cold and heat, and magnetic attractions ; all of them, I say, at 

 once, without any impediment from each other, as if each had 

 its paths and peculiar passage set apart for it, without infringing, 

 against or meeting each other. 



To these lancing instances, however, we are wont, not without 

 some advantage, to add those which we call the limits of such 

 instances. Thus, in the cases we have pointed out, one action 

 does not disturb or impede another of a different nature, yet 

 those of a similar nature subdue and extinguish each other ; as 

 the light of the sun does that of the candle, the sound of a 

 cannon that of the voice, a strong perfume a more delicate one, 

 a powerful heat a more gentle one, a plate of iron between the 

 magnet and other iron the effect of the magnet. But the proper 

 place for mentioning these will be also amongst the supports of 

 induction. 



XLIV. We have now spoken of the instances which assist the 

 senses, and which are principally of service as regards informa- 

 tion ; for information begins from the senses. But our whole 

 labour terminates in practice, and as the former is the beginning, 

 so is the latter the end of our subject. The following instances, 

 therefore, will be those which are chiefly useful in practice. 

 They are comprehended in two classes, and are seven in number. 

 Wo call them all by the general name of practical instances. 

 Now there are two defects in practicre, and as many divisions ol 



