In recent years evidence has been produced that makes clearer certain points that have
been observed by clinicians during the administration
of digitalis for therapeutic purposes, that helps to
indicate with more certainty the effect that can be
expected in a particular case, and that enables the
drug to be administered with greater efficiency.
The author of this thesis has worked in
collaboration with others in producing some of this
evidence, and some of the results have already been
published as follows:-
1. Certain Effects of Digitalis on the Heart.
Cohn and Fraser.
International Congress of Medicine.
2. The Influence of Digitalis on the T wave of
the Human Electrocardiogram.
Cohn, Fraser and Jamieson.
Journal of Experimental Medicine.
The Author of this thesis had clinical
charge of the cases employed in the investigations.
The electrocardiographic records were made and analysed by him under the direction of Dr.A.E.Cohn,but
for the analysis and discussion here presented the
author is entirely responsible. The preparation of
this thesis was commenced in 1914 but was interrupted by the war.
In a field of this nature, where so
many observers have been engaged, it is necessary
to indicate the work of others, whether previous or
contemporary, to such an extent that the sequence
of thought may he maintained, hut it is impossible to
refer to much work of importance that has helped to
build up the present knowledge of the actions of the
The observations will be recorded in so
far as they apply to our knowledge of the action of
digitalis in human beings on :-
(I) the normal pace-maker of the heart;
(II) the auriculo-ventricular conducting mechanism;
(III) the ventricular muscle.