112 Dr. A. P. W. Philip o« M« 



To these analogies, Mr. Hunter might have added, that, as 

 the living muscular fibre is capable of repeated contraction 

 and relaxation, the blood, while it retains the vital principle, 

 is capable of repeated coagulation and liquefaction. It is found 

 in part coagulated in animals which have lain long in a torpid 

 state. " Mr. Cornish," Mr. Hunter observes, " found that in 

 bats, in the torpid state, the blood was, in a certain degree, 

 coagulated, but soon recovered its fluidity on motion and heat." 

 In the effects of galvanism we see other striking analogies 

 between the contraction of tlie muscular fibre and the coagula- 

 tion of the blood. It produces both more readily than any 

 other artificial means, and when applied in excess equally 

 destroys the powers on which both depend. We may add that 

 the labours of the chemist have shewn that it is chiefly from 

 that part of the blood in which the coagulating power in 

 question exists that the muscular fibre is formed. 



The close analogy between the coagulation of the blood and 

 that of other coagulable fluids cannot be overlooked ; so that 

 it seems a necessary inference that the contraction of the 

 muscular fibre is the effect of a power similar to that by 

 which certain fluids coagulate. But both the contraction of the 

 muscular fibre and what is called the spontaneous coagulation 

 of the blood belong to those results which are peculiar to matter 

 endowed with the vital principle. Although both may be pro- 

 duced by chemical agents, it is only while the vital principle 

 survives that any cause can produce them. 



The eflTects of inanimate agents acting on living matter, I 

 cannot help thinking, will, if duly investigated, throw consi- 

 derable light on some parts of the animal economy. It will, 

 as far as I am capable of judging, appear in the prosecution of 

 this subject that the vital functions of animals may be divided 

 into those in which an inanimate agent affects a vital part, and 

 those in which vital parts affect each other. The results in both 

 cases are of course equally vital actions. It is equally im- 

 possible to obtain them after the extinction of the vital prin- 

 ciple ; but in the former, as might, d priori, be expected, we 



