( 114 ) 



tlie extremity of the top would bo sliifted a little to the left and 

 upwards. Tlie necessary correction is small however and its amount 

 maA' be approximately estimated at less than 0.2 mm. for Ihe shifting 

 to the left and less than one mm. for the shifting upwards. 



Photogram 8 represents the electrocardiogram of the same person 

 whose capillary-electrometric curve is shown in the text. When the 

 registered curve of fig. 8 plate II is compared with the formerly 

 plotted curve of fig. 2 in the text, it is evident that both cnrves 

 have gi-eat similarity. The toj)S P, Q, R, S, and T are not only 

 present in both cui-ves, but have also the same relative height in both. 



In the plotted curve 1 millivolt of ordinate has been made equal 

 to 0.1 sec. of absciss, wiiile in the galvanometer curve 1 millivolt 

 of ordinate corres])onds to 0.4 sec. of absciss. Hence the galvano- 

 meter curve is compressed in the direction of the abscissae, as a 

 superficial inspection will reveal. Besides the galvanometer curve, 

 on account of the gradual transitions of one top to another, gives 

 the imj)ression of being in its minor details a more faithful represent- 

 ation of nature than the plotted curve. It is obvious that of this 

 latter curve only a limited number of points could be accurately 

 calculated, while for the rest the calculated points had to be joined 

 by the curve that fitted them best. But these small differences are 

 immaterial. 



It may give some satisfaction that the results formerly obtained 

 by means of the capillary electrometer and more or less laborious 

 calculation and plotting have been fully confirnied in a dilferent and 

 simple manner by means of the new instrument. For this affords us a 

 twofold proof, first of the validity of the theory and of the practical 

 usefulness of the formerly followed methods and secondly of the 

 accuracy of the new" instrument itself. 



The six electrocardiograms of plate II were selected among a 

 greater number and arranged after the dimensions of the down\\ ard 

 top S (see the figure in the text). In 6 and 7 the curxe remains, 

 at the spot wliere *S' ought to be, above the zero-line of the diastole, 

 in 8 and 9 ^S is only small, in 10 and 11 great. The numbers 

 6 and 11 mark in this respect the extremes which occur in our 

 collection of electrocardiograms, whereas N". 8, that of Mr. v. d. W. 

 represents a sort of norm with which the other numbers may 

 all be easily compared. 



The constancy of shape of the curve for a certain person is 

 remarkable. This shape seems even to change so little in course of 

 time, that with some practice one may recognize many an indi\'idual 

 by his electrocardiogram. We conclude this essay with a remark on the 



