fact has been confirmed by Ernst of Caracas, near which place the plant abounds. Mr. Prestoe of the Botanical Garden, Trinidad, informs us (1874) that in that island a convolvulaceous plant, Ipomoea dissecta Willd., contains a juice with a strong prussic acid odour. According to Lösecke, a common mushroom, Agaricus oreades Bolt., emits hydrocyanic acid.2 This acid is consequently widely diffused throughout the vegetable kingdom. Yet amygdalin has thus far only been isolated from a few plants belonging to the genus Prunus or its near allies. In all other plants in which hydrocyanic acid has been met with, we know nothing as to its origin. Ritthausen and Kreusler (1871) have proved the absence of amygdalin in the seeds of a Vicia, which yield bitter almond oil and hydrocyanic acid. These chemists followed the process which in the case of bitter almonds easily affords amygdalin. Commerce-See preceding article. Uses Bitter almonds are used almost exclusively for the manufacture of Almond Oil, while from the residual cake is distilled Bitter Almond Oil. An emulsion of bitter almonds is sometimes prescribed as a lotion. Adulteration-The adulteration of bitter almonds with sweet is a frequent source of loss and annoyance to the pressers of almond oil, whose profit largely depends on the amount of volatile oil they are able to extract from the residual cake. FRUCTUS PRUNL Prunes; F. Pruneaux à médecine. Botanical Origin-Prunus domestica L., var. §. Juliana DC.-It is from this tree, which is known as Prunier de St. Julien, that the true Medicinal Prunes of English pharmacy are derived. The tree is largely cultivated in the valley of the Loire in France, especially about Bourgueil, a small town lying between Tours and Angers. History The plum-tree (P. domestica L.) from which it is supposed the numerous cultivated varieties have descended, is believed to occur in a truly wild state in Greece, the south-eastern shores of the Black Sea (Lazistan), the Caucasus, and the Elburz range in Northern Persia, from some of which countries it was introduced into Europe long before the Christian era. In the days of Pliny, numerous species of plum were already in cultivation, one of which afforded a fruit having laxative properties. Dried prunes, especially those taking their name from Damascus (Pruna Damascena), are frequently mentioned in the writings of the Greek physicians, by whom as well as at a later period by the practitioners of the Schola Salernitana, they were much employed. In the older London pharmacopoeias, many sorts of plum are 1 Archiv der Pharmacie, 181 (1867) 222. Jahresbericht of Wiggers and Husemann for 1871. 11. 3 Gmelin, Chemistry, vii. 389; xv. 422. 4 Loiseleur-Deslongchamps et Michel, Nouveau Duhamel, ou Traité des arbres et arbustes que l'on cultive en France, v. (1812) 189. pl. 54. fig. 2, pl. 56. fig. 9. enumerated, but in the reformed editions of 1746, 1788, and 1809, the French Prune (Prunum Gallicum) is specially ordered, its chief use being as an ingredient of the well-known Lenitive Electuary; and this fruit is still held by the grocers to be the legitimate prune. The same variety is regarded in France as the prune of medicine. Description The prune in its fresh state is an ovoid drupe of a deep purple hue, not depressed at the insertion of the stalk, and with a scarcely visible suture, and no furrow. The pulp is greenish and rather austere, unless the fruit is very ripe; it does not adhere to the stone. The stone is short ( too of an inch long, to broad), broadly rounded at the upper end and slightly mucronulate, narrowed somewhat stalk-like at the lower, and truncate; the ventral suture is broader and thicker than the dorsal. The fruit is dried partly by solar and partly by fire heat,-that is to say, it is exposed alternately to the heat of an oven and to the open air. Thus prepared, it is about 11 inches long, black and shrivelled, but recovers its original size and form by digestion in warm water. The dried pulp or sarcocarp is brown and tough, with an acidulous, saccharine, fruity taste. Microscopic Structure-The skin of the prune is formed of small, densely packed cells, loaded with a dark solid substance; the pulp consists of larger shrunken cells, containing a brownish amorphous mass which is probably rich in sugar. This latter tissue is traversed by a few thin fibro-vascular bundles, and exhibits here and there crystals of oxalate of calcium. By perchloride of iron, the cell walls, as well as the contents of the cells, acquire a dingy greenish hue. Chemical Composition-We are not aware of any analysis having been made of the particular sort of plum under notice, nor that any attempt has been made to discover the source of the medicinal property it is reputed to possess. Some nearly allied varieties have been submitted to analysis in the laboratory of Fresenius, and shown to contain saccharine matters to the extent of 17 to 35 per cent., besides malic acid, and albuminoid and pectic substances.' Uses The only pharmaceutical preparation of which the pulp of prunes is an ingredient, is Confectio Senna, the Electuarium lenitivum of the old pharmacopoeias. The fruit stewed and sweetened is often used as a domestic laxative. Substitute-When French prunes are scarce, a very similar fruit, known in Germany as Zwetschen or Quetschen, is imported as a substitute. It is the produce of a tree which most botanists regard as a form of Prunus domestica L., termed by De Candolle var. Pruneauliana. K. Koch, however, is decidedly of opinion that it is a distinct species, and as such he has revived for it Borkhausen's name of Prunus œconomica. The tree is widely cultivated in Germany for the sake of its fruit, which is used in the dried state as an article of food, but is not grown in England. The dried fruit differs slightly from the ordinary prune in being 1 Liebig's Ann. der Chemie, ci. (1857) 228. 2 This was especially the case in the winter of 1873-74. 3 Dendrologie, part i. (1869) 94. rather larger and more elongated, and having a thicker skin; also in the stone being flatter, narrower, pointed at either end, with the ventral suture much more strongly curved than the dorsal. The fruits seem rather more prone to become covered with a saccharine efflorescence. CORTEX PRUNI SEROTINE. Cortex Pruni Virginiana; Wild Black Cherry Bark. Botanical Origin-Prunus serotina Ehrhart (P. virginiana Miller non Linn., Cerasus serotina DC.)—A shrub or tree, in favourable situations growing to a height of 60 feet, distributed over an immense extent of North America. It is found throughout Canada as far as 62° N. lat., and from Newfoundland and Hudson's Bay in the east, to the valleys west of the Rocky Mountains. It is also common in the United States. The tree is often confounded with P. virginiana L., from which, indeed, it seems to be separated by no fixed character, though American botanists hold the two plants as distinct. It is also nearly allied to the well-known P. Padus L. of Europe, the bark of which had formerly a place in the Materia Medica. History-Experiments on the medicinal value of Wild Cherry Bark were made in America about the end of the last century, at which time the drug was supposed to be useful in intermittent fevers.2 The bark was introduced into the United States Pharmacopoeia in 1820. elaborate article by Bentley published in 1863 contributed to bring it into notice in this country, but it is still much more employed in America than with us. Description-The inner bark of the root or branches is said to be the most suitable for medicinal use. That which we have seen is evidently from the latter; it is in flattish or channelled pieces, to 20 of an inch in thickness, an inch to 2 inches broad, and seldom exceeding 5 inches in length. From many of the pieces, the outer suberous coat has been shaved off, in which case the whole bark is of a deep cinnamon brown; in others the corky layer remains, exhibiting a polished satiny surface, marked with long transverse scars. The inner surface is finely striated, or minutely fissured and reticulated. The bark breaks easily with a short granular fracture; it is nearly without smell, but if reduced to coarse powder and wetted with water it evolves a pleasant odour of bitter almonds. It has a decided but transient bitter taste. The bark freshly cut from the stem is quite white, and has a strong odour of bitter almonds and hydrocyanic acid. of Microscopic Structure-The chief mass of the tissue is made up hard, thick-walled, white cells, the groups of which are separated by a 'Hooker, Flora Boreali-Americana, i. (1833) 169. 2Schöpf, Materia Medica Americana, Erlanga 1787; 77.-Also Barton, Collec - tions for Mat. Med. of U.S., Philad. 1798. 11. brown fibrous prosenchyme. The liber is crossed in a radial direction by numerous broad medullary rays of the usual structure. The parenchymatous portion is loaded both with very large single crystals, and crystalline tufts of calcium oxalate. There is also an abundance of small starch granules, and brown particles of tannic matters. Thin slices of the bark moistened with perchloride of iron, assume a blackish coloration. Chemical Composition- The bitterness and odour of the fresh bark depend no doubt on the presence of a substance analogous to amygdalin, which has not yet been examined. Hydrocyanic acid and essential oil are produced when the bark is distilled with water, and must be due to the mutual action of that substance alluded to, and some principle of the nature of emulsin. From the fact that an extract of the bark remained bitter although the whole of the essential oil and hydrocyanic acid had been removed, Proctor inferred the existence of another substance to which the tonic properties of the bark are perhaps due. The fresh bark was found by Perot' to yield per mille of hydrocyanic acid in April, 1 per mille in June, and 14 in October. The best time for collecting the bark is therefore the autumn. Uses In America, wild cherry bark is held in high estimation for its mildly tonic and sedative properties. It is administered most appropriately in the form of cold infusion or syrup, the latter being a strong cold infusion, sweetened; a fluid extract and a dry resinoid extract are also in use. The bark is said to deteriorate by keeping, and should be preferred when recently dried. FOLIA LAURO-CERASI. Common Laurel or Cherry-laurel Leaves; F. Feuilles de Lauriercerise; G. Kirschlorbeerblätter. Botanical Origin-Prunus Lauro-cerasus L.,a handsome evergreen shrub, growing to the height of 18 or more feet, is a native of the Caucasian provinces of Russia (Mingrelia, Imeritia, Guriel), of the valleys of North-western Asia Minor, and Northern Persia. It has been introduced as a plant of ornament into all the more temperate regions of Europe, and flourishes well in England and other parts, where the winter is not severe and the summer not excessively hot and dry. History-Pierre Belon, the French naturalist, who travelled in the East between 1546 and 1550, is stated by Clusius to have discovered the cherry-laurel in the neighbourhood of Trebizond. Thirty years later, Clusius himself obtained the plant through the Imperial ambassador at Constantinople, and distributed it from Vienna to the gardens of Germany. Since it is mentioned by Gerarde3 as a choice garden shrub, it must have been cultivated in England prior to 1597. Ray, who like Gerarde calls the plant Cherry-bay, states that it is not known to possess medicinal properties. In 1731, Madden of Dublin drew the attention of the Royal Society 1 Pharm. Journ. xviii. (1852) 109. 2 Rariorum Plantarum Historia, 1601. 4. 3 Herball (1636) 1603. Hist. Plant. ii. (1693) 1549. of London' to some cases of poisoning that had occurred by the use of a distilled water of the leaves. This water he states had been for many years in frequent use in Ireland among cooks, for flavouring puddings and creams, and also much in vogue with dram drinkers as an addition to brandy, without any ill effects from it having been noticed. The fatal cases thus brought forward occasioned much investigation, but the true nature of the poison was not understood till pointed out by Schrader in 1803 (see art. Amygdala amaræ, p. 248, note 2). Cherrylaurel water, though long used on the Continent, has never been much prescribed in Great Britain, and had no place in any British Pharmacopoeia till 1839. Description-The leaves are alternate, simple, of leathery texture and shining upper surface, 5 to 6 inches long by 13 to 2 inches wide, oblong or slightly obovate, attenuated towards either end. The thick leafstalk, scarcely half an inch in length, is prolonged as a stout midrib to the recurved apex. The margin, which is also recurved, is provided with sharp but very short serratures, and glandular teeth, which become more distant towards the base. The under side, which is of a paler colour and dull surface, is marked by 8 or 10 lateral veins, anastomosing towards the edge. Below the lower of these and close to the midrib, are from two to four shallow depressions or glands, which in spring exude a saccharine matter, and soon assume a brownish colour. By the glands with which the teeth of the serratures are provided, a rather resinous substance is secreted.2 The fresh leaves are inodorous until they are bruised or torn, when they instantly emit the smell of bitter almond oil and hydrocyanic acid. When chewed they taste rough, aromatic and bitter. Microscopic Structure-The upper surface of the leaf is constituted of thin cuticle and the epidermis made up of large, nearly cubic cells. The middle layer of the interior tissue exhibits densely packed small cells, whereas the prevailing part of the whole tissue is formed of larger, loose cells. Most of them are loaded with chlorophyll; some enclose crystals of oxalate of calcium. Chemical Composition-The leaves when cut to pieces and submitted to distillation with water, yield Bitter Almond Oil and Hydrocyanic Acid, produced by the decomposition of Laurocerasin. This is an amorphous yellowish substance isolated by Lehmann (1874) in Dragendorff's laboratory. He extracted the leaves with boiling alcohol, and purified the liquid by gently warming it with hydroxide of lead. From the liquid, crude laurocerasin was precipitated on addition of ether; it was again dissolved repeatedly in alcohol and precipitated by ether. The yield of the leaves is about 13 per cent. Laurocerasin is readily soluble in water, the solution deviates the plan of polarization to the left, yet not to the same amount as amygdalin. The molecule of laurocerasin, CHNO, would appear to include those of amygdalin, CH"NO", amygdalic acid, CHO and 7 OH. The proportion of hydrocyanic acid in the distilled water of the leaves has been the subject of many researches. Among the later are those of Broeker (1867), who distilled a given weight of the leaves 1 Phil. Trans. xxxvii. (for 1731-32) 84. für wissenschaftliche Botanik, x. (1875) 2 Reinke, in Pringsheim's Jahrbücher 129. |