PROCEEDINGS 



OF 



THE ROYAL SOCIETY. 



1834-1835. No. 21. 



June 4, 1835. 



The Rev. GEORGE PEACOCK, M.A., Vice-President, in the Chair. 



Edward Blackett Beaumont, Esq. j William Borrer, Esq. ; John 

 Davidson, Esq. ; Sir Richard Dobson, Knt. ; Thomas Jones, Esq. ; 

 Thomas Mayo, M.D. ; Benjamin Oliveira, Esq. $ and Captain Wil- 

 liam Symonds, R.N., were elected Fellows of the Society. 



M. Elie de Beaumont $ M. Frederick Cuvier 5 M. Flourens 5 Pro- 

 essor Hanson 3 and Dr. Rosenberger, were elected Foreign Mem- 

 bers of the Society. 



The reading of a paper, entitled, " On the Influence of the Tricus- 

 pid Valve of the Heart on the Circulation of the Blood." By T. W. 

 King, Esq., M.R.C.S. Communicated by Thomas Bell, Esq., F.R.S., 

 — was resumed and concluded. 



The purport of this paper is to prove experimentally that the tri- 

 cuspid valve of the human heart does not, in the ordinary state of the 

 circulation, completely prevent the reflux of blood from the ventricle 

 into the auricle on the right side, and that the amount of regurgita- 

 tion is continually varying according to the different degrees of disten- 

 tion of the ventricle. The author points out the anatomical differences 

 between the auriculo-ventricular valves on the right and left sides of 

 the heart; from the consideration of which it might have been inferred, 

 independently of direct experiment, that while the structure of the 

 mitral valve is adapted to close accurately all communication between 

 the left auricle and ventricle during the contraction of the latter, that 

 of the tricuspid valve is designedly calculated to allow, when closed, 

 of the flow of a certain quantity of blood from the right ventricle back 

 again into the auricle. The comparatively imperfect valvular func- 

 tion of these latter membranes is shown by various experiments on 

 recent hearts, in which it was found that fluids injected, through the 

 aorta, into the left ventricle, were perfectly retained in that cavity, by 

 the closing of the mitral valve; but that when the right ventricle was 

 similarly injected through the pulmonary artery, the tricuspid valves 

 generally allowed of the escape of the fluid in streams, more or less 

 copious, in consequence of the incomplete apposition of their margins. 

 On repeating these experiments on different animals the author ob- 

 tained similar results ; but found that the imperfection of the valvu- 



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