Ladanum Pharm. Lond. Labdanum: a refinous juice, exuding upon the leaves of a small shrub, ciflus ladanisera cretica slore purpureo Town. Ciftus creticus Linn. which grows plentifully in Candy and some of the other islands of the Archipelago, and bears the winters of our own climate. The juice is said to be collected, by lightly brushing the shrub, in the summer heats, with a kind of rake having several straps or thongs of leather fixed to it instead of teeth (a): the unctuous juice adheres to the thongs, and is afterwards scraped off with knives. The shrub is said to be very plentiful also in Spain (b), but it does not appear that any labdanum is brought from thence.

Tincturae Kino Ph. Ed.

Two sorts of labdanum are met with in the shops. The best, which is very rare, is in dark-coloured black masses, of the consistence of a soft platter, growing still softer on being handled: the other is in long rolls coiled up, much harder than the preceding, and not so dark. The first has commonly a small, and the last a very large admixture of fine fand, which, in the labdanum examined by the French academy, amounted to three fourths of the mass. It is scarcely indeed to be collected pure, independently of designed abuses; the dust, blown on the plant by winds from the loose sands among, which it grows, being retained by the tenacious juice.

Labdanum has been sometimes exhibited as a resinous corroborant and restringent, but principally employed in external applications and persumes: the soft kind makes an useful ingredient in the cephalic and stomachic plasters of the shops. This sort has an agreeable smell, and a lightly pungent bitterish taste; the hard is much weaker, and the common means of purifying these kinds of fubftances, though they feparate separate the sandy matter mixed with it, render it weaker stil. Rectified spirit of wine dissolves nearly the whole of the pure labdanum into a gold-coloured liquor: on infpiffating the siltered solution, the finer part of the labdanum rises with the spirit, and the remaining resin proves both weaker and less agreeable than the juice at first. On infusing the labdanum in water, it impregnates the liquor considerably with its smell and taste: in distillation with water, there comes over a fragrant essential oil; and there remains in the still a brittle almost insipid resin, with a pale coloured liquor, which, inspissated, yields a weakly bitterish extract. The specific flavour of this juice seems to be sooner dissi-pated by heat than that of almost any of the other officinal resins or gummy resins.

(a) Belon, (Bellonhis) obfervations des choses memorables trouvees en Grece, etc. I. i. c. vii.

(b) Clufius, Rarierum stirpium per Hispanias obfervatariim hifloria, l. i. c. v.

Lac; lac asininum, caprinum, muliebre, ovil-Ium, vaccinum. Milk: asses, goats, human, sheeps, and cows milk: a fluid prepared and secreted in the bodies of animals, but not completely elaborated into an animal nature. On a chemical analysis, it yields the same general principles with substances of the vegetable kingdom.

Milk. is a mild nutritious balsamic fluids when taken freely, an excellent obtunder of acrid and deleterious substances, and of over-doses of the stronger cathartics and emetics; one of the best restoratives in emaciated habits; a palliative, whilst its use is continued for the only aliment, in gouty cases not inveterate, and in some rheumatic pains; the medicine principally depended on in hectics and consumptions;

- prejudicial in acute diseases, bilious fluxes and dysenteries, swellings of the praecordia, and obstructions of the abdominal viscera.

It sometimes happens, that when the body stands most in need of this medicinal nutriment, the intestines are too slippery to retain it. In such cases it may be advantageously boiled with gentle astringents, as granate peel, balaustines, red roses; about an equal quantity of water being added, by a little at a time as the milk boils up, so as that all the water may be wafted in the boiling (a).

It may be presumed that milk thickens in a found stomach, before its digestion, nearly in the same manner as it is thickened by the run-net or infusion of the stomach of a calf; and that, where the gastric juices are too inert to produce this change, or so acid as to produce it in too great a degree and to separate a firm curd from the serous part; the milk will be difficult of digestion. Debilities of the stomach are endeavoured to be corrected by the medication above-mentioned, or by the interposition of proper stomachics; acidities by the absorbent earths. The absorbent earths, however, are in this intention commonly insufficient, unless assifted by stomachics; for as they absorb only the acid already generated, and have no power of remedying the weakness or indisposition which tends to produce more, they afford only a temporary and palliative relief: and indeed it may be questioned, whether they are capable of so far destroying the force, even of the acid they are mixed with, as to prevent its curdling milk in the stomach.

(a) Mead, monita & praecepta medica, p. 49.

Milk is curdled by all acids; by most, perhaps by all, of the combinations of acids with earthy and metallic bodies; by alkaline salts both fixt and volatile; by some vegetables that have no acidity or alkaline quality, as mustard seed; and by strong vinous spirits. The concentrated acids produce a strong curd immediately on mixture: most of the other substances scarcely have their full effect without a boiling heat. The coagulum made by acids falls to the bottom of the serum: that made with alkalies swims on the surface, forming, especially if the alkali is of the volatile kind, a thick coriaceous skin. The serum, with alkalies, proves of a greenish hue: that made with the other substances is nearly of the same appearance with the whey which separates spontaneously.

The perfect neutral salts, or those compounded of an acid and an alkali, produce no coagulation, either with or without heat: some of them, particularly nitre and sal ammoniac, make the milk less coagulable, and, if added to the boiling mixture when already curdled by vegetable acids, render nearly the whole fluid again (a). Sugar retards the spontaneous coagulation, and impedes likewise the separation of the cream from milk, and of the butyraceous part from cream. Lime-water and animal gall redissolve the coagula.

Milk, distilled with a gentle warmth, gives over a colourless and tasteless liquor, which seems to be mere water, but is found to differ from the simple element in growing four upon keeping. The residuum is a grumous, undtuous, yellowish or brownish mass; which, on being boiled in water, partially dissolves. This solution contains the sweet substance of the milk, freed from the grosser unctuous caseous matter; and proves an elegant whey, more agreeable in taste, and which keeps better, than those prepared in the common manner. These sorts of liquors are very useful, cooling, diluent, aperients and detergents; in hypochondriacal complaints, impurities of the humours, acute diseases, etc. They promote the natural excretions in general, and remarkably increase the action of the purgative sweets, casia and manna The saline matter of these liquors may be obtained in a pure solid crystalline state, by clarifying the whey with whites of eggs, and, after due evaporation, setting it to shoot, in the same manner as other saline solutions.

(a) Willis, Pharmactuiice rationalis, parsi. fect. iv. cap, i. & 8.

Thus milk is resolved into a watery sluid; a gross substance indiffoluble in water, which appears to contain the directly nutrimental part; and a sweet aperient salt. The milks of different animals differ remarkably in the proportions of these ingredients, and in the quality of the salt.

Breast milk and asses milk are very nearly alike: twelve ounces leave on evaporation, according to Hoffman's experiments, eight drams of folid matter, of which boiling water dissolves six drams: the solution, inspissated or. crystal-lized, yields a salt of a rich honey-like or sac-charine sweetnefs. The same quantity of cows milk leaves thirteen drams of solid matter, from which water extracts only about a dram and a half: the salt obtained from this solution is much less sweet, when purified is almost insipid, dissolves very difficultly, and seems to have little claim to the pectoral and antiphthisical virtues vulgarly ascribed to it. All the other milks that have been examined are of an intermediate nature between the two first and the last: goats milk approaches more to that of the ass than sheeps milk does, though both of them come nearer to that of the cow than of the ass.

Accharum lactis Ph. Paris.

There are considerable differences in the milk of one and the same animal according to its different aliment. Dioscorides relates, that the milk of goats, which fed on the scammony plant and spurges, proved cathartic; and instances are given, in the Acta Hasniensia, of bitter milk from the animal having eaten wormwood. It is a common observation, that cathartics, spiri-tuous liquors, etc. taken by a nurse, affect the child; that the milk of animals, seeding on green herbs, is more dilute than when they are fed on dry ones; and that many of the common plants, which are eaten by cattle, give a particular taste to their milk. Hoffman is of opinion, that, on this principle, milk may be use-fully impregnated with the virtues of different medicinal substances.