1045 



Here 1 have been forlmiute eiioii^li lo rec'ür<i the short iind I'liiiit 

 second auricular sound. 



At the auscultation this subject often exhibited clearly Gibson- 

 Einthovkn's third sound. In accordance with this 1 notice at I a 

 faint vibration of the string, which for the rest is perfectly quiet. 

 However the tracing' is not clear enough to convince others. 



1 have also endeavoured to record the heart murmurs by taking 

 a superimposed curve, as suggested by Geuhartz. If, for instance, 

 we leave the im[)idses to themselves, the recording apparatus will 

 take a cardiogram in which the more rapid vibrations of the heart 

 sounds are represented. 



The esophagus tube being directly in circuit with the microphone, 

 with a side opening though, yielded the cardiogram (Fig. 4), taken 

 from subject P In it we discern all the features of the so-called 

 complex esophagogram as instanced in Fig. 5 for comparison. 



The apex of the auricle is indicated by As; Vs is the ventriculai- 

 apex; D the diastolic portion of the third elevation. 



The systolic apices I, H, and HI, which are so prominent in both 

 curves, I shall not discuss any further in tiiis communication. The 

 points 1 to 5 are to be found in both tracings. A wave IV in tiie 

 diastole, visible only in Fig. 5, I shall revert to later. 



Though, for the rest, the string is rather quiet, we observe, especially 

 witii the aid of a magnifying glass, at tlie site of the lirst and the 

 second auricular sound, vibrations which have been siq)erinq)osed in 

 the curve. Moreover at the auricle apex a good many fine oscillations 

 are discernable together with some bolder am[)litudes. 7%'.se are the. 

 vibrations of the first auricular sound, which run up to the comnience- 

 inent of the ventricular contraction. Though less prominent, some 

 vibrations, originating from the second auricular sound, are notice- 

 able in the descending limb of peak I. 



Now, how are these auricular sounds produced? 



It has been generally admitted now, that heart sounds result from 

 muscle murmurs, from vibrations of membranes (valves or cell-walls) 

 and from eddies. An explanation for the tirst auricular sound is 

 soon found. Most likely it is chiefly due to muscular contraction, 

 but then the auricular contraction must last till tJie ventricular systole, 

 more particularly till the closure of the atrio-ventricular valves. The 

 continuance of the auricular systole in the isoelectric portion of the 

 electrocardiogram, between P and Q, is moreover demonstrated by 

 the fact that the largest vibrations of the auricular sound fall in this 

 portion, nay the systole is even prolonged for some time while the 

 i^-peak is being formed (Fig. 3). 



