14 CORRELATION OF PHYSICAL FORCES. 



astronomy and mechanics ; Archimedes, for instance, seems 

 to have constantly had this end in view ; but, while pursuing 

 natural knowledge for the sake of knowledge and the power 

 which it brings with it, the greater number seemed to enter- 

 tain an expectation of arriving at some ultimate goal, some 

 point of knowledge, which would give them a mastery over 

 the mysteries of nature, and would enable them to ascertain 

 what was the most intimate structure of matter, and the 

 causes of the changes it exhibits. Where they could not dis- 

 cover, they speculated. Leucippus, Democritus, and others, 

 have given us their notions of the ultimate atoms of which 

 matter was formed, and of the modus agendi of nature in the 

 various transformations which matter undergoes. 



The expectation of arriving at ultimate causes or essences 

 continued long after the speculations of the ancients had been 

 abandoned, and continues even to the present day to be a very 

 general notion of the objects to be ultimately attained by 

 physical science. Francis Bacon, the great remodeller of 

 science, entertained this notion, and thought that, by experi- 

 mentally testing natural phenomena, we should be enabled to 

 trace them to certain primary essences or causes whence the 

 various phenomena flow. These he speaks of under the 

 scholastic name of ' forms ' a term derived from the ancient 

 philosophy, but differently applied. He appears to have un- 

 derstood by i form ' the essence of quality that in which, ab- 

 stracting everything extraneous, a given quality consists, or 

 that which, superinduced on any body, would give it its pe- 

 culiar quality: thus the form of transparency, is that 

 which constitutes transparency, or that by which, . when dis- 

 covered, transparency could be produced or superinduced. 

 To take a specific example of what I may term the syn- 

 thetic application of his philosophy : ' In gold there meet 

 together yellowness, gravity, malleability, fixedness in the fire, 

 a determinate way of solution, which are the simple natures 

 in gold ; for he who understands form, and the manner of 



