THE HAKVEIAN ORATION. 745 



to continue itself into the other. There is then a pause, which 

 seems comparatively of considerable duration, and which. is suc- 

 ceeded by a recommencement of the heart's action, beginning with 

 the ventricular contraction.' 



Dr. Pavy has very kindly gone to the trouble of repeating the 

 experiment upon which these statements are based; and from a 

 letter with which he has favoured me, I gather that the auricular 

 contraction detectable by the cardiographic tracing, as immediately 

 preceding the ventricular contraction, is also detectable, of course 

 during the pause just mentioned, by the eye, unassisted by the 

 cardiograph, and turned simply upon the exposed heart, in which 

 the auricular appendix is seen to become redder or more flesh- 

 coloured at the moment in question. And he further remarks that 

 this auricular contraction, difficult^ though it be to be observed 

 under physiological conditions, may be exaggerated into consider- 

 able prominence in disease entailing contraction of the auriculo- 

 ventricular orifices, and may then make itself known by a pre- 

 systolic murmur. 



I should now be glad to draw attention shortly to a few memoirs 

 which have appeared comparatively recently, and which treat of 

 matters of considerable interest, not merely as scientific problems, 

 but also as practical questions. First among these I would name 

 the paper which appears in the third volume of Professor Ludwig's 

 'Arbeiten,' 1868 (having previously appeared in vol. xx. of 'Bericht 

 Math.rPhys.-Klass. K. S. Gesellsch. Wissensch.,' Leipzig), by Pro- 

 fessor Ludwig himself and Dr. Dogiel. In this paper we have a 

 number of experiments recorded as performed with the hearts of 

 dogs removed from the body, and as nearly as possible emptied of 

 blood ; and the conclusion which the authors come to is that the 

 heart of the dog, when removed from the body and emptied of 

 blood, still produces a sound during the systole of the ventricles 

 which is not essentially different from that which is recognised as 

 the normal iirst sound of the heart. The authors add, however 

 (p. 85), that they do not think these experiments entirely exclude 

 the possibility of the tension of the auriculo-ventricular valves 



1 I apprehend that Dr. Walshe's account of the auscultatory phenomena as occur- 

 ring under normal conditions will be accepted as correct. It runs thus ('Diseases of 

 the Heart and Great Vessels,' 3rd ed. 1862, p. 65): 'In the normal state the blood 

 enters the ventricles from the auricles with a current so calm as to prevent audible 

 sound from being thereby produced in the former cavities,' 



