§ 3 20 -] SUBLIMATION OF THE ALKALOIDS. 263 
Morphine, at 150°, clouds the upper disc with nebulse ; the nebulae 
are resolved by high magnifying powers into minute dots ; these dots 
gradually become coarser, and are generally converted into crystals at 
188° ; the alkaloid browns at or about 200°. 
Thebaine sublimes in theine-like crystals at 135° ; at higher tempera¬ 
tures (160° to 200°), needles, cubes, and prisms are observed. The 
residue on the lower disc, if examined before carbonisation, is fawn- 
coloured with non-characteristic spots. 
Narcotine gives no sublimate ; it melts at 155° into a yellow liquid, 
which, on raising the temperature, ever becomes browner to final black¬ 
ness. On examining the residue before carbonisation, it is a rich brown 
amorphous substance ; but if narcotine be heated two or three degrees 
above its melting-point, and then cooled slowly, the residue is crystalline 
—long, fine needles radiating from centres being common. 
Narceine gives no sublimate ; it melts at 134° into a colourless 
liquid, which undergoes at higher temperatures the usual transition of 
brown colours. The substance, heated a few degrees above its melting- 
point, and then allowed to cool slowly, shows a straw-coloured residue, 
divided into lobes or drops containing feathery crystals. 
Papaverine gives no sublimate ; it melts at 130°. The residue, heated 
a little above its melting-point, and then slowly cooled, is amorphous, 
of a light brown colour, and in no way characteristic. 
Hyoscyamine gives no crystalline sublimate ; it melts at 89°, and 
appears to volatilise in great part without decomposition. It melts into 
an almost colourless fluid, which, when solid, may exhibit a network 
not unlike vegetable parenchyma ; on moistening the network with 
water, interlacing crystals immediately appear. If, however, hyoscya¬ 
mine be kept at 94° to 95° for a few minutes, and then slowly cooled, 
the edges of the spots are arborescent, and the spots themselves 
crystalline. 
Atropine (daturine) melts at 97° ; at 123° a faint mist appears on 
the upper disc. Crystals cannot be obtained; the residue is not 
characteristic. 
Solanine. —The upper disc is dimmed with nebulae at 190°, which 
are coarser and more distinct at higher temperatures ; at 200° it begins 
to brown, and then melts ; the residue consists of amber-brown, non- 
characteristic drops. 
Strychnine gives a minute sublimate of fine needles, often disposed 
in lines, at 169° ; about 221° it melts ; the residue (at that temperature) 
is resinous. 
Brucine melts at 151° into a pale yellow liquid, at higher tempera¬ 
tures becoming deep brown. If the lower disc, after melting, be 
examined, no crystals are observed, the residue being quite transparent, 
with branching lines like the twigs of a leafless tree ; light mists, pro- 
