178 NOVUM ORGANUM. 



than sound. We perceive, also, that visible images are 

 received by the sight with greater rapidity than they are 

 dismissed, and for this reason, a violin string touched with 

 the finger appears double or triple, because the new image 

 is received before the former one is dismissed. Hence, also, 

 rings when spinning appear globular, and a lighted torch, 

 borne rapidly along at night, appears to have a tail. Upon 

 the principle of the inequality of motion, also, Galileo 

 attempted an explanation of the flood and ebb of the sea, 

 supposing the earth to move rapidly, and the water slowly, 

 by which means the water, after accumulating, would at 

 intervals fall back, as is shown in a vessel of water made to 

 move rapidly. He has, however, imagined this on data 

 which cannot be granted (namely the earth s motion), and 

 besides does not satisfactorily account for the tide taking 

 place every six hours. 



An example of our present point (the relative measure of 

 motion), and, at the same time, of its remarkable use of 

 which we have spoken, is conspicuous in mines filled with 

 gunpowder, where immense weights of earth, buildings, 

 and the like, are overthrown and prostrated by a small quan 

 tity of powder; the reason of which is decidedly this, that 

 the motion of the expansion of the gunpowder is much 

 more rapid than that of gravity, which would resist it, so 

 that the former has terminated before the latter has com 

 menced. Hence, also, in missiles, a strong blow will not 

 carry them so far as a sharp and rapid one. Nor could a 

 small portion of animal spirit in animals, especially in such 

 vast bodies as those of the whale and elephant, have ever 

 bent or directed such a mass of body, were it not owing to 

 the velocity of the former, and the slowness of the latter in 

 resisting its motion. 



In short, this point is one of the principal foundations of 

 the magic experiments (of which we shall presently speak), 

 where a small mass of matter overcomes and regulates a 

 much larger, if there be but an anticipation of motion, by 

 the velocity of one before the other is prepared to act. 



Finally, the point of the first and last should be observed 

 in all natural actions. Thus in an infusion of rhubarb the 

 purgative property is first extracted, and then the astrin 

 gent ; we have experienced something of the same kind in 

 steeping violets in vinegar, which first extracts the sweet 

 and delicate odour of the flower, and then the more earthy 

 part, which disturbs the perfume ; so that if the violets be 

 steeped a whole day, a much fainter perfume is extracted 



