PROCEEDINGS 



OF THE 



ROYAL SOCIETY OF EDINBURGH. 



1841-1842. No. 19.* 



Monday, Qth December 1841. 



Sir T. M. BRISBANE, Bart., President, in the Chair. 



The following communications were read : — 

 1. On the Circulation of the Blood, and the Difference of the 

 Laws of Fluids moving in Living and Dead Tubes. Part 

 Second. By Sir Charles Bell. 



He recommenced with the statement of the difference with which 

 water flowed from a reservoir through tubes of equal calibre, but 

 unequal lengths; and of the effect of pressure on elastic tubes, shew- 

 ing that the impediment to the transmission of fluid through them 

 was proportioned to their length. He stated that the obstruction 

 at the turn of a tube, was proportioned to the acuteness of the 

 angle. He then inferred that the arteries were in circumstances 

 to render the delivery of blood unequal, unless there was a living' 

 property additional to the hydraulic laws. 



Then, referring to the effect of capillary attraction, he argued, 

 that if the law prevailed in the animal body as in dead tubes, 

 then, on estimating the length of vessels of capillary size, and the 

 .attraction existing between solid and fluid, the circulation could 

 not go on. 



He then stated the surprising living qualities in the animal sur- 



