in the Materia Medica, the dried root of a species of orchis. See Orchis, Botany Index.

Several methods of preparing salep have been proposed and practised. Geoffroy has delivered a very judicious process for this purpose in the Histoire de l'Academie Royale des Sciences, 1740; and Retmus, in the Swedish Transactions, 1764, has improved Geoffroy's method. But Mr Moult of Rochdale has lately favoured the public with a new manner of curing the orchis root; by which salep is prepared, at least equal, if not superior, to any brought from the Levant. The new root is to be washed in water; and the fine brown skin which covers it is to be separated by means of a small brush, or by dipping the root in hot water, and rubbing it with a coarse linen cloth. When a sufficient number of roots have been thus cleaned, they are to be spread on a tin-plate, and placed in an oven heated to the usual degree, where they are to remain five or ten minutes, in which time they will have lost their milky whiteness, and acquired a transparency like horn, without any diminution of bulk. Being arrived at this state, they are to be removed, in order to dry and harden in the air, which will require several days to effect; or by using a very gentle heat, they may be finished in a few hours.

Salep thus prepared, may be afforded in those parts of England where labour bears a high value, at about eightpence or tenpence per pound; and it might be sold still cheaper, if the orchis were to be cured, without separating from it the brown skin which covers it; a troublesome part of the process, and which does not contribute to render the root either more palatable or salutary. Whereas the foreign salep is now sold at five or six shillings per pound.

Salep is said to contain the greatest quantity of vegetable nourishment in the smallest bulk. Hence a very judicious writer, to prevent the dreadful calamity of famine at sea, has lately proposed that the powder of it should constitute part of the provisions of every ship's company. company. This powder and portable soup, dissolved in boiling water, form a rich thick jelly, capable of supporting life for a considerable length of time. An ounce of each of these articles, with two quarts of boiling water, will be sufficient subsistence for a man a day; and as being a mixture of animal and vegetable food, must prove more nourishing than double the quantity of rice-cake, made by boiling rice in water: which last, however, sailors are often obliged solely to subsist upon for several months; especially in voyages to Guinea, when the bread and flour are exhausted, and the beef and pork, having been salted in hot countries, are become unfit for use.

"But as a wholesome nourishment (says Dr Percival*), rice is much inferior to salep. I digested several alimentary mixtures prepared of mutton and water, beat up with bread, tea-biscuit, salep, rice-flower, fag-powder, potato, old cheese, &c. in a heat equal to that of the human body. In 48 hours they had all acquired a vinous smell, and were in brisk fermentation, except the mixture with rice, which did not emit many air-bubbles, and was but little changed. The third day several of the mixtures were sweet, and continued to ferment; others had lost their intestine motion, and were sour; but the one which contained the rice was become putrid. From this experiment it appears, that rice as an aliment is slow of fermentation, and a very weak corrector of putrefaction. It is therefore an improper diet for hospital-patients; but more particularly for sailors in long voyages; because it is incapable of preventing, and will not contribute much to check, the progress of that fatal disease, the sea-scurvy. Under certain circumstances, rice seems disposed of itself, without mixture, to become putrid; for by long keeping it sometimes acquires an offensive flavor. Nor can it be considered as a very nutritive kind of food, on account of its difficult solubility in the stomach. Experience confirms the truth of this conclusion; for it is observed by the planters in the West Indies, that the negroes grow thin, and are less able to work, whilst they subsist upon rice.

"Salap has the singular property of concealing the taste of salt water; a circumstance of the highest importance at sea, when there is a scarcity of fresh water. I dissolved a dram and a half of common salt in a pint of the mucilage of salap, so liquid as to be potable, and the same quantity in a pint of spring water. The salap was by no means disagreeable to the taste, but the water was rendered extremely unpalatable. This experiment suggested to me the trial of the orchis root as a corrector of acidity, a property which would render it a very useful diet for children. But the solution of it, when mixed with vinegar, seemed only to dilute like an equal proportion of water, and not to cover its sharpness. Salap, however, appears by my experiments to retard the acetous fermentation of milk; and consequently would be a good lathing for milk-pottage, especially in large towns, where the cattle being fed upon four draft must yield acidulent milk.

"Salap in a certain proportion, which I have not yet been able to ascertain, would be a very useful and profitable addition to bread. I directed one ounce of the powder to be dissolved in a quart of water, and the mucilage to be mixed with a sufficient quantity of flour, salt, and yeast. The flour amounted to two pounds, the yeast to two ounces, and the salt to 80 grains. The loaf when baked was remarkably well fermented, and weighed three pounds two ounces. Another loaf, made with the same quantity of flour, &c. weighed two pounds and 12 ounces; from which it appears that the salap, though used in so small a proportion, increased the gravity of the loaf six ounces, by absorbing and retaining more water than the flour alone was capable of. Half a pound of flour and an ounce of salap were mixed together, and the water added according to the usual method of preparing bread. The loaf when baked weighed 13 ounces and a half; and would probably have been heavier if the salap had been previously dissolved in about a pint of water. But it should be remarked, that the quantity of flour used in this trial was not sufficient to conceal the peculiar taste of the salap.

"The restorative, mucilaginous, and demulcent qualities of the orchis root, render it of considerable use in various diseases. In the sea-scurvy it powerfully obtunds the acrimony of the fluids, and at the same time is easily assimilated into a mild and nutritious chyle. In diarrhoeas and the dysentery it is highly serviceable, by soothing the internal coat of the intestines, by abating irritation, and gently correcting putrefaction. In the symptomatic fever, which arises from the absorption of pus from ulcers in the lungs, from wounds, or from amputation, salap used plentifully is an admirable demulcent, and well adapted to refresh the dissolution of the clogs of the blood, which is so evident in these cases. And by the same mucilaginous quality, it is equally efficacious in the strangury and dysuria; especially in the latter, when arising from a venereal cause, because the discharge of urine is then attended with the most exquisite pain, from the ulceration about the neck of the bladder and through the course of the urethra. I have found it also an useful aliment for patients who labour under the stone or gravel." The ancient chemists appear to have entertained a very high opinion of the orchis root, as appears from the Secreta secretorum of Raymund Lully, a work dated 1565.