216 NOVUM ORGANUM 



other bodies, and which cannot easily be laid open, evident 

 to the senses by means of that which lies at the surface, 

 or proceeds from the interior; thus the state of the body 

 is judged of by the pulse, urine, etc. 



The third and fourth cases rpply to many subjects, and 

 the reduction to the sphere of the senses must be obtained 

 from every quarter in the investigation of things. There 

 are many examples. It is obvious that air, and spirit, and 

 the like, whose whole substance is extremely rare and deli 

 cate, can neither be seen nor touched a reduction, there 

 fore, to the senses becomes necessary in every investigation 

 relating to such bodies. 



Let the required nature, therefore, be the action and 

 motion of the spirit inclosed in tangible bodies; for every 

 tangible body with which we are acquainted contains an 

 invisible and intangible spirit, over which it is drawn, and 

 which it seems to clothe. This spirit being emitted from 

 a tangible substance, leaves the body contracted and dry; 

 when retained, it softens and melts it; when neither wholly 

 emitted nor retained, it models it, endows it with limbs, 

 assimilates, manifests, organizes it, and the like. All these 

 points are reduced to the sphere of the senses by manifest 

 effects. 



For in every tangible and inanimate body the inclosed 

 spirit at first increases, and as it were feeds on the tangible 

 parts which are most open and prepared for it; and when 

 it has digested and modified them, and turned them into 

 spirit, it escapes with them. This formation and increase 

 of spirit is rendered sensible by the diminution of weight; 

 for in every desiccation something is lost in quantity, not 

 only of the spirit previously existing in the body, but of 

 the body itself, which was previously tangible, and has 



