261 



Report of the London Sub- Committee of the British Associa- 

 tion Medical Section, on the Motions and Sounds of the 

 Heart. 



The Committee of Members of the British Association resident 

 in London who have been charged with the investigation of the 

 motions and causes of the sounds of the heart, have held nu- 

 merous meetings, and performed a considerable variety of expe- 

 riments, on living and on dead subjects, with a view to the ends 

 of their appointment. They have also taken pains to inform 

 themselves of the facts and reasonings published by preceding 

 inquirers, and have now the honour to submit to the Section 

 the results at which they have hitherto arrived, together with 

 such particulars of their experiments as they consider necessary 

 to substantiate their conclusions. 



Before entering, however, upon the statement of their experi- 

 ments or of the conclusions to which they lead, they beg leave 

 to say a few words with regard to the scope and plan of their 

 inquiries, and the spirit in which they have entered on them. 

 The Committee would first remark, that though in their in- 

 quiries they did not neglect to take note of any phaenomena 

 which might illustrate the action of the diseased heart, yet 

 they have felt it their especial duty to investigate the physiolo- 

 gical branch of the subject, and have principally occupied them- 

 selves with that part which includes the normal sounds of the 

 heart. In thus limiting the field of research, it will be sufficient 

 perhaps to remind the Section that they have pretty closely fol - 

 lowed the example of the Dublin Committee of last year. 



With regard to the spirit and general views by which they 

 have been guided they wish to observe, that in entering upon the 

 investigation it seemed to them possible d, priori that each sound 

 of the heart might have a single peculiar cause, or several co-ope- 

 rating causes ; and if several co-operating causes should be found 

 more probable, that then some of such causes might be only con- 

 tingent or occasional, and others constant and invariably present; 

 also, upon the supposition of a plurality of causes of one or both 

 sounds, that some causes might be common to both sounds, or 

 that each sound might have its own set of causes exclusively. 

 Keeping in view those several possible d, priori positions, the 

 Committee made an enumeration of the circumstances attending 

 the heart's action that had been, or might be, supposed capable 

 of producing sound, and endeavoured so to vary their experiments 

 as to exclude in turn each of those circumstances, with a view 



