Prep. 1. From ASPARAGUS-SPROUTS:—The expressed juice, after being heated to the boiling-point (to coagulate albumen) and carefully skimmed and filtered, is evaporated, at a gentle heat, to a syrupy consistence, and then abandoned to spontaneous evaporation in a warm dry atmosphere for several days; the resulting crystals being purified by cautious washing with very cold water or very strong alcohol, re-solution, and re-crystallisation.
The following are cheaper and more convenient processes.
2. From MARSHMALLOW-ROOT:—a. The root (chopped small, or grated) is macerated for several days in milk of lime, in the cold; the filtered liquid precipitated with carbonate of ammonium, and the clear solution evaporated in a water-bath, and otherwise treated as before.
b. From the expressed juice, 2 parts; milk of lime, 1 part; agitated well together; the liquid portion, after some hours, being decanted, filtered, and evaporated, &c., as before.
3. From the ETIOLATED SHOOTS OF VETCHES:—The expressed juice of the young shoots when from 2 or 3 to even 12 or 15 inches long, is gently simmered for 8 or 10 minutes, to coagulate the albumen; and, after straining or clarification, the clear liquid is gently evaporated to the consistence of a thin syrup, and set aside to crystallise, as before. The resulting brown crystals are purified by washing with very cold water, re-solution in boiling water, and re-crystallisation, as in No. 1; or, and what is better, the hot liquid, before evaporation to a syrup, is digested for a short time with a little pure animal charcoal in coarse powder, and then filtered, when large and beautifully white crystals are obtained by the first operation.[91] An excellent and very economical process.
[91] This use of animal charcoal may also be advantageously extended to the other formulæ. Mr C. G. Williams, in Ure’s ‘Dict. of Arts, M., & M.,’ 4th ed., directs the shoots to be used when of “a length of 2 inches;” but some authorities recommend them to be of 9, 12, or even 15 inches. The selection must, however, in many cases, depend upon circumstances and convenience.
Prop., &c. Crystals brilliant, transparent, colourless, right rhombic prisms; neutral to test-paper; non-basic; having a faint, cooling, and scarcely nauseous taste; scarcely soluble in cold water; freely soluble in hot water; insoluble in strong alcohol and ether; solution unaffected by alkaline sulphurets, oxalate of ammonia, acetate of lead, or infusion of galls; triturated with quick-lime, ammonia is evolved; heated to 212° Fahr. the crystals lose two equiv. or 12% of water; heated with water under pressure in a closed vessel, or boiled along with an acid or an alkali, or dissolved in a saccharine liquid and then submitted to fermentation it is converted into ammonium and aspartic acid; aqueous solutions of asparagin and aspartic acid treated with a current of nitrous acid evolve pure nitrogen, with the formation of malic acid which remains in solution. It was called asparamide under the impression that it is aspartite of ammonia minus 1 atom of water; and malamide, for similar theoretical reasons.
Uses. It is sedative and diuretic.—Dose, 1 to 6 gr.; in dropsies, heart-affections, &c.
ASPAR′AGUS. [L., Eng.] In botany, a genus of low, spiny plants, with scale-like leaves, many of which are shrubs and climbers, of the nat. ord. Asparageæ (DC.).; Liliaceæ (Lindl.). The following species, which is that best known in England, is, however, an exception to this description, as it is neither climbing nor spinose.
Asparagus Officina′lis. [Linn.; L.] Syn. Aspar′agus, Comm′on a., Gard′en a.; Spar′agus§, Spar′row-grass§, Sper′age†§; Asperge, Fr.; Spargel, Ger. A well-known perennial plant, and one of the oldest and most delicate of our culinary vegetables.—Young shoots, from the underground eyes (TURIO′NES ASPAR′AGI, L.), the asparagus of our tables; diuretic; communicate a peculiar fœtid odour to the urine, and, when eaten in excess, occasion bloody urine and accelerate fits of gout; formerly esteemed emmenagogue and aphrodisiac.—Root (RA′DIX ASPAR′AGI, L.), properties resemble those of the young shoots, but stronger; one of the five ‘greater aperient roots’ (RAD′ICES APERIEN′TES QUIN′′QUE MAJO′′RES, L.) of old pharmacy. The tops and roots, though no longer officinal in the British Pharmacopœias, are both occasionally employed as popular remedies in dropsy and stone—the first being eaten in the usual way at table; and the second made into an infusion or decoction (1⁄2 oz. to the pint), taken ad libitum.