MOXA-WEED.
395
lead, and separating Iho excess of lead by sulphuretted hydrogen. The liquor was then evapo-rated to dryness, and Ihe extraet digested in alcohol mixed with ether; and the Solution aban-doned to spontaneons evaporation. The product was a very bitter matter, in brown ratnifications.By heat no crystalline Sublimate eould be obtained.
3. Absinthic acid. —May be precipitated, according to Braconnot, from the walcry infusionof worrnwood by acetate oflead. It is very acid, uncrystallizable, and delinquescent. It doesnot precipitate the Solutions of the nitrates of lead, mercury, and silver; but causes floeculentprecipitates when dropped into barytes or lime-water. Absinthate of ammonia crystallizes inquadrilateral prisms, insoluble in alcohol.
4. Salt of Wormwood (Sal Absinthii). —This is impure carbonate of potash obtained byincinerating wormwood.
Physiologicai, Effects. — In moderate doses it produces the ordinary effectsof the aromatic bitter tonics (see vol. i. p. 189). Its bitter principle becomesabsorbed : hence the fiesh and milk of animals fed with it are rendered bitter.Borrich (Act. Hafn. vol. ii. p. 165,) says that the milk, rendered bitter by itproves noxious to the Infant.
Large doses irritate the stomach and excite the vascular System. A specificinfluence over the nervous system, characterized by headache, giddiness, &c.has been ascribed to it. (See Lindestolpe, in Murray, App. Med. ; and Kraus,Heilmittell. p. 422.) This has usually been supposed to depend on the volatileoil; but a similar power has been assigned to the bitter principle.
Uses. —Wormwood is but little employed in medicine. It is adapted for dys-pepsia occurring in debilitated and torpid constitutions. It was at one timocelebrated for the eure of intermittents; but it has been superseded by other andmore powerful febrifuges. It is said to be efncacious as an anthelmintic, but isvery rarely employed as such.
Administration. —Dose of the poivder, 9j. to 3j.; of the infusion (preparedby macerating 3j. of the dried herb in Oj. of boiling water), fjj. to fgij.
EXTMCTUM ARTEMISIA ABSINTHII, D. Extraet of Common Wormwood.—(Prepared in the usual way from the tops of worrnwood, by water.)—It possessesthe bitterness of the plant, but is devoid of the odour, flavour, and aromaticqualities dependent on the volatile oil. It is stomachic and tonic.—Dose, gr. x.to 9j.
7. ARTEMI'SIA MOX'A, De CW.-MOXA.WEED.
Sex. Syst. Syngenesia, Polygamia superflua.(Folia; Moxa).
Histoky. —The moza is a small mass (usually cylindrical or pyramidal) ofcombustible vegetable matter, employed for effecting cauterization (mozybus-tion of Percy) (Dia. Sc. Med. xxxiv. 474). It has long been known that theChinese and Japanese prepared it from a species of Artemisia. (Loureiro, Fl.Cochinchinenis, ii. 492 ; Thunberg, Voyages au Japon, &c. iv. 74.) TheDublin College has adopted A. chinensis and A. indica as yiclding it. But Dr.Lindley (Fl. Med. 463) says it is from the A. Moza, De Cand:, and not fromA. chinensis, that it is prepared ; and Dr. Roxburgh 'Fl. Ind. in. 420) ob-serves, that the A. indica has none of the soft white down on the under side ofits leaves, of which moxa is rnade in Japan and China.
Botany." Gen. Char.—See Artemisia Absinlhium.
s P . cuar.—Shrubby. Leaves hoary, becoming naked, bipinnatisect; seg.ments linear-lanceolate, obtuse. Heads middle-sized, globose, drooping, race-mose-paniculate. Scales of the mvolucre membranaeeo-scariose at the apex.Corollas smooth. (De Cand.)—An under-shrub.
Hai>.—China.
P«epakation.— The Chinese and Japanese moxa is said by some to be pre-pared from the cottony or woolly covering of the leaves of the Artemisia.Thunberg, (op. cit.) however, states, that in Japan the dried tops and leaves arebeat tili they become like tow : this substance is then rubbed betwixt the hands