I 



45 



altliou"h the observations on which it rests can be satisfactorily made 

 on those only which contain opaque globules. 



II. The second set of facts are those connected with the visible 

 currents, which take place in water, in contact with many living 

 bodies ; as ascertained, >>*/, By the observations of Dutrochet and of 

 Dr Grant on living sponges ; secondly, By those of Dr Sharpey, M. 

 Quillot, and M. Raspail, on many aquatic animals, chiefly mollusca 

 and the larvic of reptiles ; and, laslhj, By those of M. Raspail, and 

 of many others, on certain animalcules, chiefly of the genus Vorti- 

 cella. In all these instances, facts seem to be established, which are 

 altogether inconsistent with the supposition of the movements de- 

 pending merely on contractions or vibrations of any living solid tex- 

 tures. 



III. The third class of facts adduced on this subject consists of 

 those which show, that, in the foetal state of animals, diflferent parts 

 are successively developed from the semi fluid matter of the ovum ; 

 and the particles of that matter must therefore have been much and 

 variously moved before the heart acts, or any contractile vessels have 

 been formed; and farther, that the human ovum itself, during the 

 time when it is surrounded on all sides by the shaggy chorion, must 

 draw its nourishment from the semi-fluid matter contained in the 

 uterus, through the filaments of the chorion, without the aid of any 

 contracting vessels in these filaments. These points appear esta- 

 blished by the observations of Prevost and Dumas, Breschet, Vel- 

 paeu, Raspail, and others. 



IV. The author considers the existence of attractions and repul- 

 sions, peculiar to the living state, among certain of the particles of 

 the blood of animals, to be established by due consideration of the fol- 

 lowing facts : 



1. By the phenomena of the coagulation of healthy blood, and the 

 utter absence of any contemporaneous mechanical or chemical change, 

 adequate to explain the change of aggregation of the particles of the 

 fibrin, on which that process depends. 



2. By the great retardation of that process, when blood (although 

 its circulation is arrested) is confined within a healthy living texture. 



3. By the great acceleration of that process, when the living tex- 

 ture, in which blood is contained, is severely injured. 



4.' By the total suspension of that process, when death is produced 

 by a sudden and violent cause, especially by a cause which at the 

 same time destroys the power of contraction after death in muscular 



fibres. n 



A 2 



