Thebaine crystallises in colourless square plates of silvery lustre and acrid, styptic taste. It is insoluble in alkalies and in water, but readily so in alcohol or ether. It melts at 257° Fahr., and at a higher tem perature is decomposed; is coloured red by sulphuric acid • rapidly attacked by nitric acid ; with acids forms salts that crystallise with difficulty, or not at all; and, finally, is very poisonous.
4. Paparcrine (C„H„NO.). This base was discovered by Dr. Merck in 1848. It is separated from the lead compound already mentioned, by digesting in alcohol, filtering, distilling off the alcohol, treating the residue with hydrochloric acid, again filtering, evaporating, and setting aside, when hydrochlorate of papaverine gradually crystal lises out.
Papaverine occurs in confused aggregated, acicular, white crystals. It is tolerably soluble in hot alcohol or ether, but insoluble in water. In contact with great excess of hydrochloric acid it separates in oily drops, and collects as a layer at the bottom of the vessel, but this layer gradually solidifies into a mass of crystals. Papaverine differs from the other opium alkaloids in giving a blue colour with strong sulphuric acid. The salts that it forms with acids are mostly difficultly soluble in water, and do not appear to be very poisonous.
5. Opianine (C„,H,„N,0„). This alkaloid seems to exist only in Egyptian opium, and occurs along with the morphine prepared from that variety of the drug. It is less soluble in alcohol than morphine and may therefore be separated by crystallisation. It forms long, colourless, transparent, brilliant needles ; is precipitated from its solutions by ammonia as a white impalpable powder ; is insoluble in water and cold alcohol, and not very soluble in boiling alcohol, the solution possessing a marked alkaline reaction, powerfully bitter taste, and is apparently as poisonous as an equally strong solution of mor phine. The hydrochlorate forms double salts with the chlorides of platinum and mercury. Opianine is unaltered by strong sulphuric acid ; is turned yellow by nitric acid ; and blood-red changing to yellow by sulphuric acid containing nitric acid. It much resembles nar cotise.
6. Narcolinc 2 Aq.) derives its name from the Greek
vapuorriubs, narcotic ; its narcotic properties are, however, far inferior to those of morphine. It is extracted from that part of the opium that remains insoluble after exhaustion with water, by treating with dilute acetic or hydrochloric acid, and precipitating the filtrate with ammonia ; the precipitate digested in boiling alcohol, filtered and allowed to cool, deposits the narcotine in crystals.
Narcotine occurs in opium to the extent of six to eight per cent. It crystallises in colourless right rhombic prisms, inodereus, but of bitter taste. It is insoluble in cold water ; only soluble in seven thousand parte of boiling water ; insoluble in caustic alkalies, but soluble in ether, alcohol, and tho fixed and essential oils. Its alcoholic solution exerts lwvo-rotation on polarised light, but dextro-rotatiou if excess of an acid is present. It is coloured blood-red by sulphuric acid containing nitric acid. By heat it fuses and gives off water, and at a higher temperature than 340° Fehr. is decomposed.
Narcotino combines with some of the acids, but the resulting salts are somewhat unstable and crystallise with difficulty. The chloro platinate contains (C„H„NO,,, HC1, PtCI,). The sulphate is decom posed, when boiled with dilute sulphuric acid, into a dark green amorphous powder termed sulphonarcolide (C„H„N,S.0„), that is to say, the elements of neutral sulphate of narcotine less four atoms of water : if sonic binoxide of lead is also present a brown amorphous alkaloid termed narcctine results.
Narcotic acid is produced as an oleaginous potash salt, on boiling narcotine for some time with strong caustic potash.
Ilumopic acid is a dark brown amorphous body formed on heating narcotino in an oil bath to a few degrees above its fusing point.
Calamine (C„H„NO,+ 2 Aq.) is produced when narcotine is acted upon by oxidising agents. forms starry groups of colourless needles, slightly soluble in cold water, more so hi hot water, insoluble in potash, but soluble in alcohol, ether, and ammonia. It readily combines with acids to form salts. The hydrorhlorate contains (C„ H„NO,, }JCL+ 5Aq.), and crystallises in long silky needles.