130 FOURTH REPORT — 1834. 



fissures, G. F. WolfF first traced the gradual formation of the 

 walls of the vessels, and the conversion of the fluid into blood 

 by the included masses. The formation of the heart is effected 

 similarly from the granular mass. 



When, therefore, the junction between the vascular area and 

 heart has been effected, and the blood moves onwards by means 

 of the heart's contractions, the direction which it takes is not in- 

 determinate as it would be if left to the influence of that power 

 alone. On the contrarj^, its course is determinate ; it seeks the 

 different organs whose lineaments are perceptible, being soli- 

 cited thereto by the vital attraction which is now established be- 

 tween ihem. The streams which reach them vary in size, and sub- 

 divide through their masses in a way so peculiar for each organ, 

 that even in the adult and perfect form, each of them preserves 

 a mode of branching for its main vessels, and a figure for its 

 capillaries, which are found in no other. What, therefore, is es- 

 sential in the circulation of the blood, is an attraction subsisting 

 between the particles of each organ and the particles of the 

 blood, and a subsequent repulsion between the same, that which 

 is repelled by one set of organs being attracted by another. What 

 are the physical conditions of the organs and of the blood under 

 which thephEenomena are effected, has not been determined. 

 Some have supposed that the particles of the organs and of the 

 arterial blood are in different states of electric polarity. Accord- 

 ing to them, the organ, as the more fixed, attracts the blood; 

 communicates to it its ownelectric state, and then repels it. It fol- 

 lows, therefore, that arterial and venous blood are in opposite elec- 

 tric states. J. Midler, however, could discover no electric cur- 

 rent by the galvanometer, M'hen one of its wires was placed in 

 an artery, the other in a vein of a living animal. 



Though a negative experiment of this kind is not conclusive, — 

 for the electric organ of the Silurus does not affect the galvano- 

 meter, — yet Dutrochet's opinion that the red particles in the blood 

 perform the olfice of galvanic plates, and his belief that he had 

 effected the formation of muscular fibre by galvanizing a drop of 

 serum, cannot be supported. His ingenious experiments are de- 

 tailed in l\\eAnnales des Sciences NatureUes,\Sd\, p. 400. They 

 have been repeated by Miiller, who has shown that the supposed 

 muscular fibre is merely a collection of granules of albumen, with- 

 out consistence, coagulated by the acid of the decomposed salts 

 of the serum ; and that there is no sufficient reason for conclud- 

 ing that colouring matter and fibrin (the nuclei of the red par- 

 ticles according to Dutrochet,) are in opposite electric states*. 

 It is on this principle, however, of vital attraction, as I conceive, 

 * Miiller, Physiohgle, p. 132. 



