CONCERNING LIGHT. 87 



are struck under water. But light is not at all visible in 

 a solid opaque body which is close on all sides. 



Light penetrates deeper than sound, as at the bottom of 

 waters. Every sound is produced in the motion and mani 

 fest collision of bodies : not so light. 



But hostilities of light, or privations, if any like the term 

 better, occur not. However, as is exceedingly probable, 

 the torpor of bodies, in their parts, is very inimical to light. 

 For almost nothing gives light that is not in its own nature 

 remarkably mobile, or excited by heat, or motion, or vital 

 spirit. 



Yet I always mean, that not only other instances remain 

 to be investigated (for these few we have adduced only by 

 way of example), but also that new topical articles, as the 

 nature of things requires, may be added. 



FRANCIS BACON S APHORISMS 



AND ADVICES CONCERNING THE HELPS OF THE MIND AND 

 THE KINDLING OF NATURAL LIGHT. 



MAN, the servant and interpreter of nature, does and un 

 derstands as much as he has actually or mentally observed 

 of the N order of nature : he neither knows nor can do more. 



The naked hand of man, however strong and constant, 

 suffices for but few operations, and those easy ; the same, 

 by help of instruments, performs many and obstinate ope 

 rations: so is it also with the mfhd. 



The instruments of the hand excite or direct motion : 

 and the instruments of the mind prompt or caution the in 

 tellect. 



On a given basis of matter to impose any nature, within 

 the limits of possibility, is the intention of human power. 

 In like manner, to know the causes of a given effect, in 

 whatever subject, is the intention of human knowledge: 

 which intentions coincide. For that which is in contem 

 plation as a cause, is in operation as a medium. 



The knowledge of him who knows the cause of any na 

 ture, as of whiteness or of heat, in certain subjects only, is 

 imperfect. And the power of him, who can induce an 

 effect upon certain substances only of such as are suscep 

 tible, is likewise imperfect. 



