746 THE HARVEIAN ORATION. 



entering as a factor into the production of the first sound; and 

 hereby they would be guarded from coming into contradiction with 

 most English authorities — as for example, Dr. Walshe (' Diseases of 

 the Heart,' 3rd ed. 1862, p. 62). Dr. Guttmann, however, in a 

 paper of no great length, but of considerable merit, published sub- 

 sequently to the one just mentioned, and in Virehow's Archiv for 

 1869, points out with much acuteness what, when once pointed out, 

 is ever thereafter obvious — viz. that it is, in the nature of things, 

 impossible, with all possible precautions in the way of emptying 

 the heart of blood, to empty the complex phenomenon made up by 

 a systole of the heart of the condition of tension of the auriculo- 

 ventricular valves. Surely the musculi papillares will contract 

 with the rest of the ventricular walls, and, contracting, will they 

 not stretch the chordae tendineae and the valves ? For myself, I 

 would say that we are more likely to overrate the share taken by 

 the valves than to underrate that taken by the muscular walls. I 

 need not say to this audience that the fact with which we are all 

 familiar, of the alteration in the first sound produced by disease of 

 the auriculo-ventricular valves, does not absolutely prove that they 

 produce any part of it during health ; and, finally, to my own ear 

 at least, a modification of WoUaston's experiments, which anybody 

 can try for himself by making his temporal and masseter muscles 

 contract at any time of perfect stillness, appears to produce a sound 

 which is scarcely, if at all, different in quality from the first sound 

 of the heart. A judgment, however, upon the nature of a sound, 

 or, indeed, an aggregation of sounds, as in music, is one upon 

 which two observers may very well differ, as neither of them can 

 lay his proof of supposed identity or difference alongside of that 

 which the other may possess, or may suppose he does. 



It is with much pleasure that I refer to Dr. Rutherford's paper 

 on the Influence of the Vagus on the Vascular System, which 

 appears in the Edinburgh Royal Society Transactions for 1870, 

 vol. xxvi. In that year, having to deliver an address to the 

 Biological Section of the British Association at Liverpool, I 

 made bold to say that the results to which Dr. Rutherford had 

 come, and which were then only known to me in an abstract 

 in the 'Journal of Anatomy and Physiology' (May 1869, p. 402), 

 would prove to be of the highest value and importance. His 

 memoir now" published in extenso^ and extending over forty-two 



