522 MEDICAL BOTANY. 



peu laxative," and James (Pharm. Umversalis, 1747) states that it "is emetic 

 and vulnerary, and agrees in its virtues with the pilewort." Even Vogel 

 (Hist. Mat. Med. 1760) merely observes that "acris est, intus assumta vomi- 

 tum movet et purgat ; extus contusa ad strumas, podagram et rachitidem ab 

 Anglis praedicatur. De utroque vero dubitat." 



The parts employed are the leaves and seeds, the latter, however, but sel- 

 dom. The leaves should be collected about the time of the inflorescence ; 

 those from plants of the first year are very inferior. They should be dried 

 in the dark, and always kept protected from the light. Much of the digitalis 

 in our shops is derived from plants cultivated in this country, and although 

 in some cases of good appearance, is far from being as efficient as the foreign 

 article obtained from the wild plants. In general, however, it is almost worth- 

 less, being mouldy and changed in colour, which is always an indication of 

 deterioration. When good, the leaves should have a dull-green colour, a 

 feeble but somewhat narcotic odour, and a bitter, unpleasant taste. The 

 seeds, which are not employed in this country, but are recognised by the 

 Dublin College, are small, roundish, and of a grayish-brown colour. 



Numerous analyses have been made of the leaves, one of the latest of 

 which is that of Radig (Pereira, ii, 297) ; he found in it Picrin, Digitalin, 

 Scaptin, Acetic Acid, &c. The substance he calls picrin is the digitalin of 

 Le Royer (Bib. Univer. des Sci.), and appears to be one of the active prin- 

 ciples, though not the principal, which is the digitalin; this is a white, some- 

 what crystalline substance, of an intensely bitter taste, soluble in alcohol, but 

 scarcely so in water, not soluble in the acids, and possessing all the proper- 

 ties of the leaves in a very concentrated degree. Scaptin is a brown extrac- 

 tive, which leaves an acrid sensation in the mouth. The fullest account of 

 digitalin is that by M. Homolle (Am. Jour. Pharm. xi. 97). 



Medical Properties. — Digitalis acts in a different manner on the system 

 according to the dose and mode of administration, but is exceedingly variable 

 in its effects in whatever way it is given. In small quantities often repeated, 

 it usually affects the organic functions, either singly or collectively, the most 

 obvious and frequent results being an increased flow of urine, and a reduction 

 of the frequency and force of the pulse, but both these are very inconstant; 

 in some cases the diuretic effect of the medicine cannot be produced, whilst 

 in others it readily occurs, even from very small quantities ; but its influence 

 over the circulation is still more capricious, for though its more general re- 

 sult is to decrease the activity of the pulse, in some instances it operates in a 

 diametrically opposite manner, or it may cause an irregularity of it, whilst 

 on some individuals the medicine appears to exercise no power over the cir- 

 culation, even in large doses. 



This article is said to be one of those, which given in frequently repeated 

 doses, have a cumulative effect, or in other words, do not display their powers 

 for a certain time, and then produce effects equivalent to the whole amount 

 administered ; that this has happened there can be no doubt, but the experi- 

 ence of most practitioners shows that it is much less frequent than has been 

 supposed, though it should always be borne in mind that such an event is 

 possible, and is to be guarded against by suspending the use of the medicine 

 from time to time, and closely watching its effects. 



Where it is given in too large doses, or its employment too long continued, 

 it operates like the acro-narcotics, especially tobacco and lobelia, causing a 

 disordered condition of the digestive organs, the circulation and the cerebro- 

 spinal system. In still more increased quantities it induces vomiting, purging, 

 stupor, or delirium ; slow, feeble and irregular pulse, cold sweats, great pros- 

 tration of strength, disordered vision, followed, if the person be not relieved, 



