DIGITALIS GROUP. 
§§ 555, 556.] 
449 
toxin, from Urechitis suberecta ; and the alkaloid erythrophlein from 
the Erythrophlceum judiciale (see p. 458 et seq.). This list is yearly 
increasing. 
§ 555. Local Action. —The digitalins have an exciting or stimulating 
action if applied to mucous membranes— e.g. if laid upon the nasal 
mucous surface, sneezing is excited ; if applied to the eye, there is red¬ 
ness of the conjunctive with smarting ; if to the tongue, there is much 
irritation and a bitter taste. The leaves, the extract, and the tincture 
all have this directly irritating action, for they all redden and inflame 
mucous membranes. 
§ 556. Action on the Heart. —The earlier experimenters on the 
influence of digitalis on the heart were Stannius and Traube. Stannius 1 
experimented on cats, and found strong irregularity, and, lastly, cessation 
in diastole, in which state the heart responded no longer to stimuli. 
Babbits and birds—especially those birds which lived on plants—were 
not so susceptible, nor were frogs. 
Traube 2 made his researches on dogs, using an extract, and adminis¬ 
tering doses which corresponded to from 0-5 to 4-0 grms. He divided 
the symptoms witnessed into four stages :— 
ls£ Stage. —The pulse frequently diminishes, while the pressure of 
the blood rises. 
2nd Stage. —Not seen when large doses are employed ; pulse fre¬ 
quency, as well as blood pressure, abnormally low. 
3rd Stage. —Pressure low, pulse beats above the normal frequency. 
The curves in accompanying figure illustrate one of Traube’s experi¬ 
ments on blood pressure and pulse frequency in a dog treated by intra¬ 
venous injections of digitalis infusion, and illustrate the three stages 
just described. 
The slowing of the heart 3 is attributed to the stimulus of the inhibi¬ 
tory nerves, but the later condition of frequency to their paralysis. 
After the section of the vagi the slow pulse frequently remains, and this 
is explained by the inhibitory action of the cardiac centre. The vagus, 
in point of time, is paralysed earlier than the muscular substance of 
the heart. 
The increased blood pressure Traube attributed to increased energy 
of the heart’s contraction, through the motor centre being stimulated 
later ; the commencing paralysis explains the abnormally low pressure. 
■ 
There is, however, also an influence on vaso-motor nerves. What 
1 Arch. f. Physiol., 1852. 
2 Ann. d. Charite-Krankenhauses, ii. 785. 
3 Slowing of the pulse was mentioned first by Withering {An Account of the Fox¬ 
glove, Lond., 1785). Beddoes afterwards observed that digitalis increased the force 
of the circulation, the slowing of the pulse not being always observed ; according to 
Ackermann, if the inhibitory apparatus is affected by atropine, or if the patient is 
under deep narcosis, the slowing is absent. 
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