1. The first variety, Crown or Loxa Bark, called also True Laza Bark, is obtained either exclusively from the C. Condansinca, or from it and C. acrobiculata. It occurs in pieces from six to fourteen inches long, the quills varying in diameter from the fourth or even smaller part of an inch to nearly half an inch ; the rolls are sometimes double, meeting at the centre : the diameter of the bark is from a quarter of a line to a line and a half. The colour of the exterior is marked dark gray, in some specimens verging to brown. A shining but peculiar appearance is observable upon it, owing to the thallua of the lichens spreading over it. This commonly alternates with the colours of other lichens, grayish-white, yellowish white, bluish-white, so that the bark acquires an appearance as if it were painted. Numerous transverse cracks, often extending from one aide of the bark to the other, with the edges a little raised, are seen, sometimes close to each other, sometimes more remote, especially in the larger pieces, in which also they rarely extend to the whole cir cumference of the piece. In the larger pieces longitudival cracks are observed, these warts or knots frequently arise, which give a very rough feel to such specimens. The Usnea and some foliaceous lichens, such as Parmelia perforata (Ach.), often remain attached to it. The inner surface is smooth, except some deli cate, irregularly-longitudinal fibres : the colour is a cinuamon or darker brown. The fracture of the smaller quills is even, or slightly fibrous ; that of the larger pieces more ao, the fibres firm, but neither oblique nor vitreous, as in the yellow bark (China regia); but the outer circle presents a resinous aspect. The odour resembles that of tan. The taste at first is slightly astringent, and faintly acid ; after wards very astringent, somewhat bitter, but not acrid.
In respect to its chemical composition, this variety is commonly supposed to contain Cinchonia (discovered in pale bark by Dr. Duncan, jun.) only; but this is a mistake, and it is most probable that the specimens which, when analysed, yielded no Quinia, were either very thin quills obtained from young branches or trees, or were specimens of Huauuco Bark. Bucholz analysed sixteen ouucca of the Lola Bark of commerce, yet found no Quinia, but some error is reasonably suspected ; the other constituents were found to be— Drachms. Grains.
Fatty matter, with Chlorophylls . . . 1 0 Bitter soft Resin (Geiger thinks this con . tained Quinia) . . . . . 2 0 Hard Resin (red insoluble colouring-matter) . 12 0 Tannin (with trace of Acetic Acid) . . . 3 0 Cinchonia 0 28 Kinic Acid 1 30 Hard Resin, with Phyteumacolla . . . 1 40 Tannin, with Chloride of Limo . . . 4 25 Gum 5 40 Kinato of Lime . . . . 1 40 Starch, a trace Woody Fibre . . . . . .
The Cinchonia exists in combination with the kinic acid, in the form of kinate of cinchonia. A prejudice exists in favour of the thin quilled pieces, but they are not so well adapted to form extracts, &c., nor to be employed as medicine. Mutis many years ago stated that
the thick pieces obtained from branches of middle-aged trees were the most efficacious; and the analysis of Von Santen (in Von Bergen's ' Versuch einer Vonographie der China ') confirms the correctness of this statement, as far as the relative amount of Quinia yielded by barks of different ages is concerned. From 100 lbs. of Lox& Bark, he obtained of Quinia Ounces.
Thin selected quills . .
:Moderately thick pieces . . . . . Selected thick pieces, with rough cracked bark 11.104 2. Thu second kind, Iluanuco Bark, termed also Silver or Gray Cinchona, has been known in European commerce only since 1799. Tho majority of writers on the origin of the barks refer it to the C. glandulifera. (Ruiz and Peron, ' FL Peruvl As it is sent from Huanuco to Lima for shipment, it is also called Lima bark, though some apply the term Lima to a bark supposed to come from the C. /naerfofia (Mutis). It is likewise called Havanna bark. We have the authority of Poppig, as stated above, for considering it one of the finest sorts of Cinchona. The variety of it termed Case. Provinciana Negrilla (the Quinquina Huanuco Noirittre of the French) is likewise stated by Reichel to be equal to the finest from Loxa, yet it is not known in Europe except in mixture with other kinds. Tho explana tion of which is two-fold : first, that though the trade in this bark was at first very brisk, owing to its excellent quality, the subsequent shipments of it being very inferior, it fell into disrepute ; and though it is now again pure and good, still it is necessary to introduce it as Crown Bark. Farther, as the French give the name Lima bark to another kind as above mentioned, probably the dark-ash bark, the dark Ten (China the false Loxa bark, confessedly a very bad bark, it has caused the genuine Lima bark to be little esteemed. Farther, as the Huanuco Bark is in quills which are larger and coarser than those of the Crown Bark, the prejudice in favour of thin quills operates to the disadvantage of this very excel lent sort.
The quilts are from three to fifteen inches, generally from four to ten inches long, with a diameter from a few lines to one or even two inches. They are in single rolls, or double and inclosed rolls ; the inclosed rolls exhibit spiral windings, and frequently traces of a sharp oblique incision of the knife. This incision is not observed iu the ease of any other kind, end it is probably made by the Casearilleros to facilitate the separation of the bark from the trunk of the tree. The diameter of the bark varies from one-fourth of a line to five lines. The epidermis is seldom absent, but now and then portions of it have been rubbed off, and then the rusty surface of the liber is seen. The epidermis is a whitish-gray, but often covered with numerous lichens, chiefly Glyphis eicatricosa, Graphic duplicate, Porina granulate, Pyrenula discolor, .1fastoidea, Pupulo, Lecanora puniceu, Parrnelia perforate, Sticta aurata, and Once florida.