472 ACANTHAOEiE. 



possessing active medicinal properties. It may be obtained by the 

 following process : — 



The leaves, previously exhausted by water, are extracted by means 

 of alcoliol, sp. gr. 'ySO. The tincture is concentrated until its weight is 

 equal to that of the leaves used, and then diluted by adding thrice its 

 weight of water. A pitch-like deposit is then formed ; digitale'in and 

 other substances remaining in solution. The deposit dried on blotting 

 paper is boiled with double its weight of alcohol, sp. gr. '907; on cooling, 

 crystals are slowly deposited during some days. They should be washed 

 with a little diluted alcohol ('9.58) and dried: to purify them, they should 

 be first re crystallized from chloroform, and subsequently from boiling 

 alcohol sp. gr. "828, some charcoal being used at the same time. Digi- 

 talin is thus obtained in colourless iieedle-slaiped crystals. It assumes 

 an intense emerald green colour when moistened with hydrochloric 

 acid, and has an extremely bitter taste. On the animal economy, it 

 displays all the peculiar effects of digitalis, the dose of a milligramme 

 taken by an adult person once or twice a day occasioning somewhat 

 alarming symptoms, but smaller doses exhibiting the sedative power of 

 the hei"b. 



Another body occurring in foxglove is the crystallizable sugar 

 called Inosite, which was detected by Marmd in the leaves, as well as 

 in those of dandelion (p. 894). Pectic matters are also present in fox- 

 glove leaves. 



Uses — Foxglove is a very potent drug, having the effect of reducing 

 the frequency and force of the heart's action, and hence is given in 

 special cases as a sedative ; it is also employed as a diuretic. 



Adulteration — The dried leaves of some other plants have occa- 

 sionally been supplied for those of foxglove. Such are the leaves 

 of Verhascum, which are easily recognized by their thick coat of 

 branched stellate hairs; of Inula Conyza DC. and /. Helen'min L., 

 which have the margin almost entire, and in the latter plant the veins 

 diverging nearly at a right angle from the midrib; in both plants the 

 under side of the leaf is less strongly reticulated than in foxglove. But 

 to avoid all chance of mistake, it is desirable that druggists should 

 purchase the fresh Jioiveriiig ])lant, which cannot be confounded with 

 any otlier, and strip and dry the leaves for themselves. 



ACANTHACE^. 



HERBA ANDROGRAPHIDIS. 



Kariydt or Creyat. 



Botanical Origin — J.'^itZi'o^/^'ctj^/i/is'^xwt'iciiZaftfc Nees ab E. (Justicia 

 Burm.j, an annual herb, 1 to 2 feet high, common throughout India, 

 growing under the shade of trees. It is found likewise in Ceylon and 

 Java, and has been introduced into the West Indies. In some districts 

 of India it is cultivated. 



^ Andrographia from &i/np and ytiaflAi, filament. — Fig. in Bentley and Trimen's 

 in allusion to the bnish-like anther and Med. Plants, part 23 (1877). 



