1887.] The Sinuses of Valsalva and Auricular Appendices. 469 



occurs, possibly owing to the presence in the solution of such reducing 

 agents as nascent hydrogen, &c. 



In the present incomplete stage of the enquiry these remarks are 

 only offered tentatively. 



The effects could not be expected to be large ; I anticipate, however, 

 generally more marked results in a more powerful magnetic field, 

 exerting its influence, perhaps, for longer periods ; but I think the 

 experiments now submitted appear sufficient at least to afford an 

 indication that, under the conditions recorded, magnetisation exerts 

 on iron, in some solutions, an appreciable effect. The results 

 already obtained in this direction are so far interesting as to 

 encourage further research into the nature of this novel and subtle 

 phenomenon. 



XXVII. "Note on the Functions of the Sinuses of Valsalva and 

 Auricular Appendices, with some Remarks on the Mechanism 

 of the Heart and Pulse." By M. Collier. Communicated 

 by Victor Horsley, F.R.S., Professor Superintendent of 

 the Brown Institution. Received June 9, 1887. 



(Abstract.) 



The object of the paper is to disprove the present apparently 

 accepted idea, that the sinuses of Valsalva are mere bulgings of the 

 arterial walls, formed by a reflex current induced by the sudden 

 closure of the semilunar valves. 



The existence of a reflex current is shown to be impossible, and the 

 theory of the sudden opening and closure of the semilunar valves is 

 strongly opposed. 



The presence of the sinuses of Valsalva is urged as an absolute 

 essential to the mechanism of the heart's action. The paper then 

 treats of the action of the auricle and the part played by the auricular 

 appendix, the latter being considered as the only part of the auricle 

 that sensibly and vigorously contracts. 



The causes of the first sound of the heart are next alluded to, and 

 the theory that the closure and vibration of the tricuspid and mitral 

 valves assist in its production is refuted. The action of the ventricle 

 and the mode of the injection of its contents into the aorta is dwelt 

 upon at some length. 



The latter part of the paper is devoted to the mechanism of the 

 pulse, and an explanation is given of the so-called dicrotism. 



The paper terminates with a summary of the chief points of the 

 conclusions arrived at. 



