7 44 Proceedings of Royal Society of Edinburgh. [sess. 
I have not obtained evidence of any primary action on the brain, 
medulla oblongata, spinal cord, nor motor nerves. Sensibility, 
however, is slightly affected ; one of the most conspicuous evidences 
of which is the insensibility of the cornea following the application 
of dilute solutions to the eye-ball. 
In the preliminary communications I have stated that the chief 
action is that exerted upon the heart, produced when large toxic 
doses are given by a powerful action upon the heart-muscle. 
This action upon the heart-muscle is one which Strophanthus 
exerts upon all the other striped muscular fibres of the body. 
These muscles are affected by twitching movements, their tonicity 
is increased, and, finally, their contractility is destroyed. They 
are not then, however, flaccid, soft, and alkaline, but hard and acid 
in reaction. In fact, the condition of the muscles is one of rigor 
mortis , in which the alkaline reaction of the living muscle has given 
place to the acid reaction of rigor ; and, just as the acid reaction of 
ordinary rigor mortis continues until the muscle becomes flaccid in 
the process of putrefaction, so the acid and hard condition produced 
by the pharmacological action of Strophanthus remains until 
putridity causes the muscle again to become alkaline, soft, and 
flaccid. This prevention of the initial muscular flaccidity of death 
and precipitation, as it were, of rigor mortis , to which I drew 
attention so long ago as 1870,* has since been recognised by other 
observers as events in the pharmacological action of digitalis, and 
of several members of the digitalis group. 
The twitches produced in the muscles of the body have been 
further examined in detached muscles, immersed in normal saline 
solution to which Strophanthus had been added, and connected 
with a lever recording the movements on a revolving cylinder. The 
movements in the detached muscle are thus seen to be very re- 
markable. At first a faint twitch occurs in an individual muscular 
fibre, then simultaneous and independent contractions of different 
fibres rapidly succeed each other, until by and by a perfect tumult 
of contractions occurs in rapid succession in different muscular fibres, 
and the lever attached to the muscle is kept in almost constant 
motion, its excursions being altogether irregular both in time and in 
extent. [Tracings were shown.] While the muscle is so affected, 
* Pros. Roy. Soc. Edin., vol. vii., 1869-70, p. 102. 
