40 Rev. P. Keith on Ihe Conditions of Life. 



mass*. It is a presumption in favour of the globulous struc- 

 ture of ultimate, living tissue. 



Do the vital powers reside in the fluids, or in the solids, or 

 in both ? Some ph3'siologists would confine them to the solids. 

 But if the solids originate in the fluids, how can the fluids 

 themselves be destitute of vital powers? They would thus 

 present the singular anomaly of communicating that which 

 they do not possess. Mr. J. Hunter believed in the vitality 

 of fluids ; or, at the least, in the vitality of the blood. But 

 Blumenbach can see no ground for adopting this opinion. 

 If you grant vitality to the blood because it is the material 

 out of which the living solids are formed, as well, says he, may 

 you grant it to water because the Nymphese and many other 

 remarkable plants are nourished by it f. We do not think 

 that the case is fairly put. Blood is an elaborated fluid fit for 

 immediate assimilation, and the vegetable fluid corresponding 

 to it is not water, but proper juice. 



Bichat is also of opinion that fluids do not possess vitality, 

 because they are incapable of contraction and of sensibility. 

 Fluids he regards as merely passive, and solids only as active \, 

 But fluids are stimulants, or exciters at least, and thus they 

 act upon solids. The blood stimulates the heart to action, 

 and ardent spirits stimulate the brain. After all, Bichat admits 

 that the fluids begin to acquire animalization and vital proper- 

 ties in the course of their elaboration in the system. The chyle 

 is more animalized than the alimentary mass ; the blood than 

 the chyle. This is granting enough to sanction the vitality of 

 some fluids ; and the vitality of all fluids is not contended for. 

 But why should we doubt the possibility of endowing a fluid 

 with vitality; or in what respect is it more easy to conceive a 

 solid endowed with it than a fluid? The rudiments of the 

 solids exist already in the fluids, that is, in the fluids elaborated 

 for nutrition ; so that the former can be nothing else than a 

 more compact aggregation of the minute and semi-organized 

 globules of the latter, effected by the agency of the living powers 

 of the plant or animal in some specific and determinate man- 

 ner. The fluids of the human body are represented by Bichc^t 

 as being to the solids in the ratio of 9 to 1 ; and the fluids of 

 vegetables as being to the solids in a greater ratio still. Many 

 of them contain globules of a regular figure and magnitude, 

 particularly the blood, lymph, and chyle ; and the spermatic 

 fluid contains millions of animalcules. The fluids yield by 

 chemical analysis the same principles as the solids §. 

 [To be continued.] 



* Edwards De Xlnfinexice dex Ageus physiques sur la Fie. 



\ Blumenbach's Physiology, by Elliotson. 21. 



t Anat. Gcner. 24. § Magendie, by Milligan. 14, 



V. Proceed- 



