WATER DOCK. 391 



the characters of the various British species of Dock, we must 

 refer to Sir W. Hooker's Flora, and other works. Of the 

 foreign kinds the Patience Dock (R. patientia) has been cele- 

 brated for its medicinal qualities, but is inferior to some of our 

 British species, such as R. crispus, obtusifolius, acutus, and 

 sanguineus. The Alpine Dock or Monk's Rhubarb, (R. alpinus,) 

 the root of which was formerly used as a succedaneum for 

 common rhubarb, has been found wild in the Scottish High- 

 lands. 



The foliage of most of the Docks is slightly laxative, and 

 that of R. patientia and sanguineus, is still used on the continent 

 as spinach. Horace speaks of this property, — 



" Aut herba lapathi prata amantis, et gravi 

 Malvae salubres corpori." 



Epod. lib. Od. ii. v. 57, 



" Si dura morabitur alvus, 



Mitulus et viles pellent obstacula conchae, 

 Et lapathi brevis herba. " 



Satir. lib. ii. v. 27« 



Qualities. — The fresh root has a slightly fragrant odour ; 

 and is at first of a reddish colour internally, but soon changes 

 to a yellowish or yellowish brown hue by exposure to the air. 

 It has a very astringent, austere, and bitter taste. The leaves 

 are acescent and somewhat styptic. Water takes up the active 

 matter of the root, and the aqueous infusion, which is of a yel- 

 lowish or reddish brown colour, speedily assumes a black hue 

 with sulphate of iron, and deposits a copious precipitate on the 

 addition of solution of isinglass. Proof spirit also extracts 

 much of its virtue. We have no analysis of this root, but it 

 most probably contains tannin and gallic acid, oxalate of lime, 

 sulphur, colouring matter, and extractive, with other less import- 

 ant constituents. 



Medicinal Properties and Uses. — Muritingius *, a pro- 

 fessor of botany and medicine at Groningen, wrote a treatise 

 in which he endeavours to prove this plant to be the true 

 Herba Britannica of the ancients ; and in addition to the re- 

 semblance in their external characters, he adduces instances of 

 the efficacy of the Water-Dock in stomacace, scelotyrbe, and 



* De vera antiquorum Herba Britannica. Amstelodami^lG8l. 



