161 ENGLISH BOTANT. 



The whole of this plant, but especially the roots, abounds in a uiucilaginoiis 

 matter. It has long been used in medicine as a demulcent and emollient, and is 

 still retained in the British Pharmacopoeia. The root is the part of the plant 

 most useful in medicine, as it contains a large quantity of gum. It should be 

 gathered in the autumn from plants not less than two years old. It is extensively 

 used in France, where it is known by the name of " guimauve." A favourite lozenge 

 prepared from it is known in this country as pdte de guimauve, and is considered 

 efficacious in coughs, hoarseness, etc. A decoction of the leaves is sometimes used for 

 fomentations, and emollient cataplasms ai'e prepared from the pounded root ; an oint- 

 ment made from the same part was formerly applied to burns and the bites of animals. 

 It has a sweetish, pleasant taste. Cold water is rendered very ropy by it, but does not 

 indicate the presence of starch by turning blue with tincture of iodine ; boiling water, 

 however, removes starch from it, and yields the blue appearance. Dr. Christison gives 

 us the chemical composition of Althea root, which has of late been very carefully 

 examined. It contains a little starch, neai-ly twenty per cent, of gum or mucilage, some 

 uncrystallizable sugar, and a crystallizable pi-inciple, besides other unimportant consti- 

 tuents. The mucilage lies like the fecula in small cells in the form of minute grains, 

 which may be obtained pure by washing the chopjied root in rectified spirit, and allowing 

 them to subside. A yellowish-white powder is thus procured, consisting of micrcscopic 

 transparent grains, which seem intermediate between true gum and perfect starch. 

 The crystalline principle, which was discovered in 1827 by M. Bacon, and termed by 

 him "althsein," was afterwards found by Plisson to be identical with the asparagin of 

 asjiaragus, or what is now considered the aspartate of ammonia. Marsh Mallow root 

 is not only demulcent and soothing in itself, but it forms a most convenient vehicle for 

 other remedies. It was known to the ancients, and is mentioned by Pliny, Virgil, and 

 Dioscorides. The Marsh Mallow was then not only valued as a medicine, but was 

 used to decorate the graves of deceased friend.s ; and so indispensable was the plant 

 deemed to the welfare of the living, that the poet exclaims, — 



" Alas ! when Mallows in the garden die." 



The stems of the Marsh Mallow yield a good fibre, longer and stronger than that of 

 the true Mallow, but not so fine. The leaves may be eaten when boiled ; and wc are 

 told that they were formerly consumed in this way by the Romans. 



GENVS II.— li A V A T E R A. Zlun. 



Epicalyx of 3 (or more rarely 1 to 6) leaves, whieli are nearly 

 equal, and united at the base. Calyx 5-cleft. Pruit depressed- 

 orbicular, the carpels not equalling the dilated apex of the torus, 

 from which they separate Avlien ripe as 1-secded iudehiscent 

 cocca. 



Sub-glabrous or pubescent herbs, indistinguishable in habit 

 from the other British genera of Malvaceae. 



Tliis genus of jilants was named by Tournefort in honour of two Lavaters — neither 

 of them the celebrated physiognomist, but physicians and naturalists, of Zurich. 



