ASPAR′AGIN

(-ă-jĭn). C 4 H 8 N 2 O 3 . [Eng., Fr.] Syn. Althe′ine , Aspar′amide , Mal′amide *; Asparagi′na , Asparagi′num , L.; Agédoïle , Fr.; Spar gels toff , Ger. A peculiar azotised principle discovered by Vauquelin and Robiquet in asparagus, and since found in the potato, marsh-mallow, liquorice, climbing vetch, and several other plants. Many plants which do not naturally contain it may be made to yield it by growing them in dark damp cellars; whilst many which only normally contain it in very small quantities are found to yield much more when allowed to vegetate in the same manner. Prep. 1. From ASPARAGUS-SPROUTS :—The expre ed 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 proce es. 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 expre ed juice, 2 parts; milk of lime, 1 part; agitated well together; the liquid portion, after some hours, being decanted, filtered, and evaporated, ., as before. 3. From the ETIOLATED SHOOTS OF VETCHES :—The expre ed 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 proce . [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., . Crystals brilliant, transparent, colourle , 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 pre ure in a closed ve el, or boiled along with an acid or an alkali, or di olved 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 as par amide under the impre ion that it is as partite 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, .