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3rd, that the life residing in a minute sphere is related even to a 

 limited or circumstantial dependence with that of adjoining spheres, 

 is also proved by the circumstance that although the mechanic ar- 

 rangement of the textures might be preserved, and its chymical 

 qualities also either preserved or conferred by imitation, yet the life 

 of this piece of structure will immediately become extinct on its 

 being removed from its connexions. Indeed that the properties of 

 life existing in any seat are perfected by and related variously with 

 the vital properties of other seats, is perfectly allowed, and the 

 modes of the relation will be hereafter considered. 



22. This truth being established, viz. that the relation between 

 vital properties is according to their states in respective spheres, it 

 follows that the spheres of properties cannot undergo a change 

 without a corresponding derangement of the phenomena which 

 result from their natural relation. 



23. As these phenomena, in the natural condition of the 

 structures and their alliances, constitute the state of health, so 

 those which result from an unnatural condition, whether primitively 

 of the mechanical, of the chymical, or of the spiritual agents, com- 

 prise the state of disease. 



24. But although the relation just mentioned should be freely 

 conceded, it will be inquired whether the influence of external 

 mechanical agents upon the spirit may not be of the direct kind? 

 To this question it can only be replied, that it disagrees with our 

 nearest analogies to suppose that mechanical bodies can affect 

 spiritual properties in the way of constitution, that is, by imparting 

 constituents, or in any other way than by producing indirectly new 

 relations, or destroying those which are established. 



25. The examples of our nearest analogies may be drawn from 

 among invisible flqids (or those even of a grosser kind). Thus, a 

 solid body placed in air or water has no quality to change the fluid 

 which surrounds it : it is only an interposition which interrupts the 

 continuity of the medium it exists in. The same thing happens 

 with any of the gases, the nature of which is not changed by any 

 mechanical agency, though it may be possible that it should be 

 changed by the chymical properties existing in the mechanical agent, 

 provided there is a relation subsisting between them. 



26. But the case is different where the relation of mechanical 

 agents is with others of the same kind, with which latter, properties 

 reside whose natural identity is dependent upon a state of continuity 

 and a free communication with related properties. In this case 

 (which is the case we are considering) an external mechanical agent 

 operates in the following order : the foreign mechanical, related with 

 its resemblance in the textures, produces a corresponding effect, 

 which is comprised in change of place, either simply affecting the 

 line, or the existence, of continuity ; the particles of the textures, 

 thus Displaced, containing chymical properties ; , these following the 

 fate of the substances in which they are embodied; the chymical 

 properties having in alliance with them spiritual ones, these latte? 



