BOOK II.] CITING INSTANCES. 519 



in sufficient quantity to strike the senses, or because there j not 

 ^sufficient time for their acting upon the senses, or because the 

 impression is too violent, or because the senses are previously 

 filled and possessed by the object, so as to leave no room for any 

 new motion. These remarks apply principally to sight, and next 

 to touch, which two senses act extensively in giving information, 

 and that too upon general objects, whilst the remaining three 

 inform us only, as it were, by their immediate action, and as to 

 specific objects. 



There can be no reduction to the sphere of the senses in the 

 first case, unless in the place of the object, which cannot be per 

 ceived on account of the distance, there be added or substituted 

 ome other object, which can excite and strike the sense from a 

 greater distance, as in the communication of intelligence by fires, 

 bells, and the like. 



In the second case we effect this reduction by rendering those 

 things which are concealed by the interposition of 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, &c. 



The third and fourth cases apply 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 delicate, can neither be 

 Been nor touched a reduction, therefore, Ij the senses becomes 

 necessary in every investigation relating to such bodies. 



Let the required nature, therefore, be the action and motion 

 of the spirit enclosed in tangible bodies ; for every tangible body 

 with which we are acquainted, contains an invisible and intan 

 gible 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 j 

 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 mani 

 fest effects. 



For in every tangible and inanimate body the enclosed spirit 

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

 wuicli are most open and prepared for it; and when it haf 

 digested and modified them, and turned them into spirit, it 

 escapes with them. This formation and increase of spirit is ren 

 dered sensible by the diminution of weight ; for in every desic 

 cation something is lost in quantity, not only of the spirit pre 

 viously existing in the body, but of the body itself, which was 

 previously tangible, and has been recently changed, for the spirit 

 itself has no wtiglit. The departure or emission of spirit is ren- 



