Some medico-legal cases under state and national laws / by B. Joy Jeffries.

  • Jeffries, B. Joy (Benjamin Joy), 1833-1915.
Date:
1886
Catalogue details

Licence: Public Domain Mark

Credit: Some medico-legal cases under state and national laws / by B. Joy Jeffries. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    other cases,” continues Skoda, “ the pause between the first and second sound is almost as long, or exactly as long as the pause between the second and the ensuing first sound.” The words printed in italics would lead us to believe, that he is here speaking of a and therefore also of A, if all the rest had not evidently reference to the pauses alone. With Friedreich® I found the same confusion, even including the brief state ment of Volkmann’s results, which nevertheless referred only to « and A. From all this it appears, that little trouble has been taken with respect to the rhythm of the sounds of the heart. And yet this rhythm is un- mistakeably of great physiological importance. In a subsequent article I shall show more precisely, that « represents the active period of the heart, consequently the duration of the process, the ground of which is to be sought in the heart itself, while the period P is determined rather by the regulatin nervous svstem external to the heart. In modification of the heart’s action, under this or that influence, the altei'ed frequency of the strokes is thus only one side of the question; and if our principal object be also to determine the modification of the active process, this can be known from the rhythm of the cardiac sounds. For this the simple state- ment of the existence of this or that rhythm is not sufficient; it must be measured. II. Method.—In order to measure the rhythm, the cardiac sounds must be registered : that is, the times must be reduced to long measure. If with the slight force of the cardiac sounds it was scarcely to be con- ceived that they could be recorded by means of a body brought into a state of corresponding vibration, this might be effected in an indirect method. Now the latter was found in the registration of movements of the hand, practised in unison with the rhythm observed by the ear: during auscultation we follow the rhythm of the cardiac sounds by striking on the arm of a marker, and this registers the times on a revolving cylinder. In order in each experiment to ascertain also the frequency of the pulsations, the seconds of a clock are, by means of electro- magnetism, registered on the same cylinder. We thus obtain figures, as the following: Fig. 1. R is the tracing of the rhythm, S that of the seconds, the distance from 0 to 2 being equal to two seconds. In the tracing R the distance 111=0, and II I=A, so that 11' as well as II IT=P. At « the marker * Hanrlh. cler bijzondere pathologie en therapie, onder redactie van Virchow. D. V. Afd. 2. bl. 199. Q 2