224 NOVUM ORGANUM 



to some scents) to that of the dog, and with regard to light 

 existing imperceptibly in the air, when not illuminated from 

 any extraneous source, to the sense of the cat, the owl, and 

 other animals which see by night. For Telesius has well 

 observed, that there appears to be an original portion of 

 light even in the air itself, 70 although but slight and meagre, 

 and of no use for the most part to the eyes of men, and 

 those of the generality of animals; because those animals 

 to whose senses this light is proportioned can see by night, 

 which does not, in all probability, proceed from their see 

 ing either without light or by any internal light. 



Here, too, we would observe, that we at present discuss 

 only the wants of the senses, and their remedies; for their 

 deceptions must be referred to the inquiries appropriated 

 to the senses, and sensible objects; except that important 

 deception, which makes them define objects in their rela 

 tion to man, and not in their relation to the universe, and 

 which is only corrected by universal reasoning and phi 

 losophy. 71 



XLI. In the eighteenth rank of prerogative instances we 

 will class the instances of the road, which we are also wont 

 to call itinerant and jointed instances. They are such as 

 indicate the gradually continued motions of nature. This 



70 Riccati, and all modern physicists, discover some portion of light in 

 every body, which seems to confirm the passage in Genesis that assigns to this 

 substance priority in creation. - -Ed. 



71 As instances of this kind, which the progress of science since the time 

 of Bacon affords, we may cite the air-pump and the barometer, for manifesting 

 the weight and elasticity of air: the measurement of the velocity of light, by 

 means of the occultation of Jupiter s satellites and the aberration of the fixed 

 stars: the experiments in electricity and galvanism, and in the greater part 

 of pneumatic chemistry. In all these cases scientific facts are elicited, which 

 sense could never have revealed to us. Ed. 



