NOVUM ORGANUM 223 



mon, should be referred to this division; for they bring that 

 which is not the object of the senses within their sphere. 

 They are therefore to be everywhere diligently sought after. 



With regard to the fifth cause of objects escaping our 

 senses, it is clear that the action of the sense takes place by 

 motion, and this motion is time. If, therefore, the motion 

 of any body be either so slow or so swift as not to be pro* 

 portioned to the necessary momentum which operates on the 

 senses, the object is not perceived at all; as in the motion of 

 the hour hand, and that, again, of a musket-ball. The mo 

 tion which is imperceptible by the senses from its slowness, 

 is readily and usually rendered sensible by the accumula 

 tion of motion; that which is imperceptible from its veloc 

 ity, has not as yet been well measured; it is necessary, how 

 ever, that this should be done in some cases, with a view to 

 a proper investigation of nature. 



The sixth case, where the sense is impeded by the power 

 of the object, admits of a reduction to the sensible sphere, 

 either by removing the object to a greater distance, or by 

 deadening its effects by the interposition of a medium, 

 which may weaken and not destroy the object; or by the 

 admission of its reflection where the direct impression is too 

 strong, as that of the sun in a basin of water. 



The seventh case, where the senses are so overcharged 

 with the object as to leave no further room, scarcely occurs 

 except in the smell or taste, and is not of much consequence 

 as regards our present subject. Let what we have said, 

 therefore, suffice with regard to the reduction to the sensi 

 ble sphere of objects not naturally within its compass. 



Sometimes, however, this reduction is not extended to 

 the senses of man, but to those of some other animal, whose 

 senses, in some points, exceed those of man; as (with regard 



