182 



universally pass to another; or, in other words, that they do not 

 expire, as we must say, for want of a better word, in the' seat io 

 which they assimilate and live. Thus we have no reason to sup- 

 pose that the function of any seat is influenced by the properties 

 of that life which assimilates in the muscles of the foot, the skin 

 of the forehead, in the os calcis, the olecranon, or the alae of the 

 nose, &c. 



23. If then, as it appears from this view, it is not an universal 

 or even a general tendency in the properties of the organic spirit 

 to pass from one seat to another (under natural circumstances), it 

 is to be asked, why they do so in those few instances in which 

 such a communication has been reasonably supposed! We cannot 

 reply to this question: a real answer to it would comprise, 1st, a 

 specification of the properties which pass (for example) from the 

 brain to the stomach; and, 2nd, a citation of the properties with 

 which the latter are related, and by which their migration from 

 one seat to another is determined. This necessity is founded 

 upon principles of causation already sufficiently explained. 



24. Here then again we are brought to a recollection of that 

 which we want for a satisfactory information on subtilties which 

 we aspire to understand. The deficiency I allude to is an addi- 

 tional sense, which would enable us to /enow properties, whose 

 existence and laws we can now only infer, from particular analogies, 

 or in conformity with general principles. 



25. Hence we cannot pretend to say what causes sometimes 

 determine vital properties, to leave their native sphere, and some- 

 times not. We can merely remark, that the vital properties of 

 respective spheres are of various kinds; that various relations ob- 

 tain among them; and that the phenomenon in question is one 

 among the results of particular relations, which we must be con- 

 tent to enumerate, and that imperfectly. 



26. Concerning the mode of the union of properties which 

 do not assimilate, to understand this process requires that we 

 should be informed what becomes of the properties which do 

 assimilate; or what is meant by their being consumed. This con- 

 sideration we have said is to be deferred to the subject of death. 



27. But, in order to make our present question dependent 

 only upon the result of that inquiry, it is to be observed, 1st, that 

 the properties communicated modify only the life of the seat 

 which receives them; and, 



2nd, That they endure no longer than the communication with 

 their source is preserved ; and that therefore they, uniting with 

 the assimilating life (when their communication is unremitting) as 

 fast as it is formed, follow the fate of that life, or they expire; a 

 process which we shall hereafter consider. 



28. Although it is rendered probable that some part of the 

 organic function of the stomach is dependent upon the connection 

 of this seat with the brain, yet it has not been attempted to 

 Ascertain how much. The experiments before alluded to refer 



