GORGED LEECHES.

A pamphlet lately published by M. Chevalier, Professor of the School of Pharmacy, in Paris, contains an account of a fraud which has recently been practised by leech-merchants. The ponds which formerly furnished France with leeches have been for some time exhausted by the cupidity of the collectors who sold the whole stock, young and old, and thus left no chance of reproduction. France has for the last eighteen years been supplied from Egypt, Turkey, Wallachia, Hungary, and Prussia. Between 1827 and 1844 no less than 500,000,000 leeches were imported into France, and the price has increased from fifteen cents to forty cents each. Wholesale dealers buy and sell them by the weight, and in order to increase their profit gorge them with the blood of sheep and other animals, thus making 1,000 small leeches, weight two pounds and a half, value seventy-five francs, equivalent, by the addition of two pounds of blood, to four pounds and a half, and obtaining for them 180 or 200 francs. Several members of the Academy of Medicine have investigated the subject, and confirm M. Chevalier's statement, deprecating the fraud, and warning the public against such an imposition, alike injurious to commerce and to health.

ON THE RESIN OF CERADIA FURCATA.

AT a meeting of the Literary and Philosophical Society of Liverpool, held on the 24th of March, 1845, Dr. Watson presented two specimens of an African shrub, called by the sailors "the coral plant;" he also presented separate portions of its resinous secretion. Mr. Guthrie, who brought the plants to Liverpool, stated that the resin exists in great abundance. The following is the more detailed account, as given by Dr. Watson :

The natural history of this plant is not much known. The present specimens were gathered by the mate of an Ichaboe ship, Mr. Guthrie, not from off the island of Ichaboe itself, but from the corresponding western coast of Africa, in the most accessible part of the shore, marked down in the Admiralty chart of the spot as "Sandy Beach," from which landing-place a road has been found to the interior, over a desert tract, and the natives have been visited. The habitat of the shrub is among the rocks of the beach, down among the crevices of which the plant sends its serpent-roots in search of nourishment. When seen and gathered it resembles a coral very much in shape and appearance, only having green tufts of spathulose leaves surmounting each horn-like branch. The leathery aspect of the plant is singular, and the tout ensemble of it bespeaks it the melancholy denizen of a solitary beach; yet it is, nevertheless, profitable in its hermit-like life, yielding in grateful return for the scanty nutriment it obtains from the rock, a most bounteous and fragrant gum-resin. This may be readily gathered, as it is exuded in the usual nodules of large size, and lies under the shrub, ready to the hand of industrious commercial enterprise. A leading peculiarity of this plant is that the whole tree, bark, wood, and pith, is highly charged with this aromatic juice; to an extent, perhaps, unprecedented in the gum-yielding tribes, or in any resiniferous or balsamiferous tree. Not only is it present in the usual place, between the layers of new and old wood (alburnum and liber), but also everywhere else. In one of the dried specimens, Dr. W. showed that in the wounded parts of the plant, wherever the apex of a branch or bark had been broken, the fracture was sealed up by the exudation, as if it had

been thickly coated with varnish. A small specimen of the gum was produced, of a beautiful transparency and bright conchoidal fracture. The whole plant burns rapidly, yielding a fragrant perfume from its loaded frame. It at first appeared to belong to a natural class or family of plants-the turpentine or balsam-bearing-but as there was no flower to examine, and only the anatomy of the vegetable skeleton and the resinoid secretion to furnish data, the true nature could not be ascertained, nor the consequent description given. In the Glasgow Herald an account of a coral plant was mentioned, which had been shown to the Philosophical Society there, by Dr. Maclagan, of Edinburgh. Dr. Watson wrote to Dr. Maclagan a few days ago, and received a very polite note by return of post, stating some interesting particulars respecting the plant, which, therefore, had been previously known to the scientific world.

Dr. M. remarks, “when the plant was first shown to me, it was suggested as the probable source of the drug known as African olibanum, now Occasionally seen in continental commerce, but quite superseded in British trade by the Indian olibanum of the Boswellia; the source of the African olibanum is unknown. The gum-resin of the ceradia is much softer and more aromatic than the African olibanum--at least than the specimen in my museum-but it is somewhat remarkable, that, on looking at my sample of the drug, I found in it pieces of a bark quite undistinguishable from that of the ceradia, and I know that my African olibanum is a very old specimen, and may have lost by keeping. I should rather say that the gum-resin resembles some of the kinds of elemi, and might be substituted for it."

Dr. M. believes it to contain soluble oil, resin, and that peculiar substance allied to, but not identical with, gum, which elemi and similar drugs contain. Dr. Maclagan said that Professor Lindley had seen the plant in flower lately (first found in Chatsworth Conservatory), and that it was described in the February number of the Botanical Register as belonging to quite a different order-viz., the Compositæ. Professor Lindley mentions that Dr. Maclagan had sent him the first dead specimen in December last, covered with a peculiar red lichen-the Dufourea flammea-when he found it impossible to guess what manner of plant this curious production might be. Dr. Watson's specimens were also covered with a brownish lichen. Professor Lindley had since, from seeing it in flower at the Horticultural Society, been able to determine the natural order of it, which he found to be allied to those fleshy-stemmed shrubs from the Cape of Good Hope, now termed Kleinias (the old Cacalias). Bright veinless leaves, of rather a succulent character, grow in clusters at the end of the horns or branches; the pale yellow flower grows from between the footstalks of the leaves supported on shorter similar pedicles.

The Professor states that "the resin when burned was totally destitute of fragrance, and evidently had nothing to do with any of the drugs to which the name of Olibanum has been applied." The absence of fragrance in the resin, as above quoted from so high an authority, was remarkably at variance with the fact of the fragrant odour of the resin which Dr. Watson burned before the society. The article must vary: possibly the specimens may represent different species of the same genus.

The name of the shrub is Ceradia furcata, derived from the Greek and Latin terms for its horny shape. If the gum-resin proves, on further examination, to be what Dr. Dickinson seemed inclined, from his own observations, to consider it, as possibly one of those gum-resins mentioned so often in scripture under the general term of frankincense, then the general name being retained as characterising the plant, the specific name might, perhaps, be changed to one in accordance with the qualities of the exuded juice, instead of being, as it at present stands, scarcely more than a reiteration of the generic character. The forked horn plant may become the

Ceradia thurifera, or something of like meaning. Dr. Watson observed, that on going to the Botanic Garden here, he had been gratified at finding under the watchful care of the conservator, Mr. Shepherd, a young plant actually in leaf which he had received from Mr. Hadwen three months ago, with but the faintest hope of its being alive or rearable; however, it shot forth its green tufts, under glass, and now looks healthy and promising, and probably will send out its little yellow flower in the course of the ensuing summer. The horns are much stouter than the dried, and evidently much older plants of Dr. Watson's; their three-forked or trichotomous extremities, each with its crest of leaves, corresponded exactly with the new nomenclature of the exotic; the bark was also smooth and void of lichen. The old dry shrubs did not show the same undeviating partiality for the number three, some branches being content with a bifurcation, others running to the excess of four-prongs. Was it possible that the resin of the younger plant might be comparatively inodorous, whilst that from the mature tree was fully endowed with an aromatic essential oil.

Dr. Watson showed a green leaf of the plant, and also a diagram of the sections of the branch and root, as seen through a lens, together with a drawing of the shrub. He also stated the specific gravity of the resin to be 1.234, which is much higher than that of amber, which Liebig states at 1.065, to which fossil pseudo-balsam it bore some general resemblance, but which disappeared on analysis.

The chemical constitution of the resin was given, as ascertained upon examination of a small portion only, by the kindness of Dr. Brett, at the laboratory of the Royal Institution. Dr. Watson considered that the article might very likely prove of commercial value sufficient to remunerate any persons for gathering both the shrub and its resinoid, as it might be yet found useful in the healing, or social arts.

The President hoped the subject would be further pursued, as it was likely to prove an interesting field for research.

Mr. Guthrie was present, and, in reply to questions from members as to the probable quantity of the article, stated that he considered there was a good deal, and that he could have got bags full of it if he had then known its interest or value. He presented a specimen to the Society, for the museum of the Royal Institution, having a root attached, showing its rocky habitat, also a specimen of the resin.

Dr. Watson has subsequently obtained another of the pieces, and his friend, Dr. Brett, has analysed it; the results of the examination, as being verifications and extensions of the first essay, are now given as follow :

Physical Characters. It is translucent; of a pale yellowish colour when dry, resembling ordinary specimens of amber or gum arabic, but of a greenish tinge when taken from the stem of the living plant. Both the recent and that which has been kept, possess the fragrance already alluded to, and which adapts it so well for burning as a frankincense. Its fracture is bright and conchoidal, and it is remarkably brittle under the knife or file.

Chemical Properties.-It is only partially soluble in alcohol. Upon evaporating, the alcoholic solution-a yellow, oily-looking substance-remains, giving off whilst hot a vapour which has a peculiar aromatic odour. This substance, the residue insoluble in alcohol, appeared, however, to be a mixture of volatile oil and resin. The colour is associated with the oil and resin. The insoluble residue was treated by ether, which appeared to extract the same sort of substance as had been extracted by alcohol-viz., the oleoresinous matter. The white powder not soluble in alcohol or ether was not dissolved by boiling water, nor by a mixture of equal parts of rectified spirit and water. Iodine did not render it blue. When heated per se, it gave off a vapour which had an aromatic odour: it finally fused, burnt with fuliginous flame, and left a carbonaceous residue. The white powder insoluble in

alcohol and ether, became of a deep brick-red colour in cold nitric acid. When acted upon by hot nitric acid red fumes were given off, and an orange red-coloured residue was obtained by evaporating the acid. This residue bad no bitter taste. This residue, after being exhausted by alcohol and ether, yielded to water no gummy matter. A small quantity only having been acted upon by nitric acid, no evidence of oxalic acid could be detected When boiled in a solution of caustic alkali little or none appeared to be acted on; in which respect, therefore, it differs from the gum-resins. The essential oil of turpentine scarcely acts upon it.

From the foregoing chemical experiments, it may be concluded that the substance in question cannot be classed among the gum-resins, as shown by its indifference to certain menstrua which notoriously act upon the lastnamed bodies.

Nor does it appear to contain that description of vegetable mucilage somewhat allied to gums, and called Bassorine. The incomplete action of alcohol and alkalies upon it, clearly throw it out of the list of ordinary resins, such as colophony, guaiac resin, cobaina [?] resin, elemi resin, animi resin, and others.

The more decisive analysis, subsequently given by Dr. Brett, is the following:

The substance was burnt in the usual way with oxide of copper. The following is its composition in 100 parts :—

If the atomic constitution be deduced from this analysis we shall have the following formulæ :

C24 H19 Os

There is a resin noticed by Thomson in his Organic Chemistry, and also by Liebig, called Pasto-resin, which appears to have been analysed by Boussingault, the composition of which is identical with the Ceradian-resin. The per centage composition of the Pasto-resin :

This establishes an interesting example of Isomerism. We have not, however, as yet had an opportunity of studying the physical and general chemical character of the so-called Pasto-resin.

Dr. Watson thinks it highly probable, from a variety of facts, that this was the frankincense mentioned in scripture; but Dr. Maclagan, who corresponded with him on this point also, does not speak decisively.

There are two specimens of the living plant in town at present, to which those in the society who are intimate with the subject will look with considerable interest.-Proceedings of the Literary and Philosophical Society of Liverpool, 1845.

ON A VERY INFERIOR CINCHONA BARK FOUND IN COMMERCE. BY ST. GEORGE, APOTHECARY IN GIESSEN.

SINCE the discovery of quinine, ash cinchona (Ten or Jaen China) called also pseudo-loxa, has been entirely rejected on account of its being deficient in this alkaloid. It is however frequently met with in commerce. The outward appearance of this bark is remarkably fresh; and its colour is, on the whole, blackish slate gray, which is given to it principally by lichens which thickly coat it. Larger and more slightly adhering lichens are rarely to be found in it; whereas the genuine loxa is more frequently covered with them, by which it obtains a somewhat variegated appearance. The transverse cracks of the ash cinchona (Ten China) are very short and close together; those of the genuine bark more annular and farther apart. Ash cinchona is only about a quarter of a line thick, on account of the thinness both of the cortex and alburnum [Splint]; whereas the loxa is at least half a line thick. For this reason, we find less entire and closed quills than such as are broken lengthways and blistered; by which the inner, and for the most part, bright, rust-coloured, or sometimes pale yellowish surface is more exposed than in the quills of the other kind of cinchona. In this way, the ash cinchona acquires its peculiar fresh appearance. Thin splinters of wood, adherent to the internal surface, are also frequently met with.

When broken, the alburnum [Splint] generally appears much brighter, and when seen in opposition to the rust-coloured surface, is almost of a straw-colour, whilst genuine loxa on breaking presents uniformly a cinnamon brown colour; and externally is dusty, and therefore appears less fresh. The tranverse and oblique fracture of the ash cinchona gives no trace of resin; whereas the horn-like appearance of the cut surface of the loxa bark shows a considerable proportion of resin. A decoction of the ash cinchona does not become turbid on cooling; its taste is acidulous, very astringent, and not at all bitter; whilst the decoction of a very good cinchona becomes on cooling like coffee with milk, and has an acid, but less astringent, and very bitter taste. It is advisable to reject both sorts, to be the more sure of not obtaining the ash cinchona.-Jahrb f. Prakt. Pharm., x, pp. 103-4.

ON THE DISTILLED WATERS WHICH CONTAIN PRUSSIC ACID.

BY G. H. ZELLER.

ZELLER is of opinion, that the leaves of the cherry-laurel gathered in wet and cold weather, yield more hydrocyanic acid than those collected in dry and hot weather. He is doubtful whether, in a northern climate, more acid and less oil are produced than in a southern one, though the above observations respecting the effect of the weather would lead us to infer that such would be the case. The proportion of oil contained in the aqua lauro-cerasi is difficult to be determined. The reason why much of the commercial water brought from the south is rich in oil but poor in prussic acid, is perhaps referable to the circumstance that part of the acid has combined with the metal of the bottles in which it is usually preserved and exported, and in this way, cyanide of copper has been formed. With reference to the influence of time on the aqua lauro-cerasi, the author has made the following observations:

A certain quantity of the water which yielded soon after preparation 2.80 grains of cyanide of silver, yielded at the end of one year only 2.70 grains, and after four years only 2.40 grains. Another sample had lost only 0.33 grains in four years. Paton obtained almost the same proportion of cyanide