1047 



sound. EiNTFiovKN ') foiiiid tluit third sound in Ins records ;is a faint 

 vibration, at a distance of 0,13 sec. from the commencement of the 

 second sound. In our subject, who has a slow heart (from 60 to 70 

 per minute) I, very often, but not always, noted this third sound 

 as a faint diastolic murmur, which got more diMinct when the tube 

 }Das slipped as far down as 38 cm. In fact the \enous pulse of 

 this person often, though not always, yielded a beautiful Gibson 

 '7/'-peak in the diastolic portion of the cardiac cycle. 



It is evident, therefor:', that it is of ventricidar origin. If we return 

 again to Fig. 5, the esophagogram of the same subject, and look 

 at wave IV in the diastole at 0,135 sec. after line 4, the place of 

 the closure of the semilunar valves, we shall observe that this place 

 corresponds to the site of Einthoven's third sound. 



Frédéricq *) also sometimes found a similar diastolic wave in the 

 anriculcxr-pressnre tracings. 



When putting these facts together, viz. 1 ventricular origin ; 2 

 inconstancy; 3 wave in the auricular-pressure tracings; 4 wave in 

 the ssophagogram ; 5 wave in the venous pulse curve; Gibson's 

 explanation seems to me the most plausible. He ascribes the origin 

 of this third sound to the fact that, at a high pressure or at a 

 copious onflow of blood into the veins, the atrio-ventricular valves 

 will close for some moments just before the diastole, on account of 

 the blood rushing into the ventricle during the diastole, in conse- 

 quence of which the membranes are swung up by the eddies. Thsy 

 produce a short sound and slightly check the blood in its passage 

 to the ventricles. 



The evidence presented in this article will, I hope, support the 

 view that, together with the esophageal cardiography, the auscul- 

 tation and the recording of heart sounds through the esophagus 

 yields results not obtainable through the chestwall. 



Physics. — '^1 new relation betioeen the critical quantities, and on 

 the unity of all the substances in their diermie behaviour.'' 

 (Continued.) By J. J. vam La.\r. (Communicated by Prof. 



H. A. LORENTZ.) 



(Communicated in the meeling of March 28, 1914). 



13. If in the found ') expression h = f{v), viz. 



1) W. EiNTHOVEN. A third heart sound. Ned. Tijdschrift voor Geneesk. 1907 Vol. 2 

 p. 470. 



^) L. Frédéricq. La seconde ondulation positive (première ondulation syslolique) 

 du pouls veineux physiologique cbez le chien. Arch, intern, de Physiol. 1907. 



3) These Proc. XVi, p. 924 to be cited as II. 



