EXAMINATION OF JALAP RESIN. 31 
water-bath, formed when pulverized a nearly white powder, 
which dissolved entirely in alcohol and aether to a transparent 
clear liquid. It is entirely dissolved by warm aqueous solu- 
tions of potash, soda, and the carbonate alkalies, and is sepa- 
rated by muriatic acid from these solutions in white flakes. 
Concentrated sulphuric acid dissolves it in the course of five 
to ten minutes with a beautiful purple-red color ; after some 
time a brown smeary resin separates. It melts when heated 
on platinum foil, and burns when ignited with a bright, some- 
what smoky flame, leaving a porous coal, which can be en- 
tirely consumed. It possesses neither smell nor taste, is very 
brittle and easily pulverized. The resin obtained by evapo- 
rating the alcoholic solution in the water-bath, and dried at 
212°, gave on combustion with chromate of lead the following 
result : — 
Carbon, 58.58 58.64 42 = 3185.9 58.88 
Hydrogen, 8.01 8.13 34 424.3 7.84 
Oxygen, 33.41 33.23 18 1800.0 33.28 
According to Johnston, the resin of Scammony = C 4 <> H 33 O 20 . 
The resins of the Convolvulacece abound, therefore, most in 
oxygen, and form by the soluble hydrorhodeoretine the transi- 
tion from salicine and phloridzine. 7 equivalents starch 
(C 84 H 70 O 70 ) = 2 equiv. rhodeoretine + 30 O. 
Chem. Gaz. from Liebig's Annalen. 
