26 
EXAMINATION OP JALAP RESIN. 
Salt of Ammonia. — Some ammonia was poured over a 
quantity of the resin, and digested with it until it was en- 
tirely dissolved. The liquid, which had a somewhat brown- 
ish color, was warmed until the excess of ammonia had 
been removed and the liquid had become perfectly neutral. 
On evaporation in the water-bath, the combination formed 
a brownish resinous mass, which was very readily soluble 
in alcohol and water ; it possessed no odour, a bitter taste, 
and on treating it with potash it liberated ammonia. 
Lead Salt. — A solution of the ammonia salt in water 
was mixed with some basic acetate of lead as long as any 
precipitate resulted, and the white rlocculent deposit ob- 
tained carefully washed with water. Dried and pulverized 
it forms a powder. 
Hydro-rhodeoretine. — To obtain the acid combined with 
the oxide of lead, the lead salt, carefully washed, was sus- 
pended in distilled water, and a current of sulphuretted 
hydrogen gas passed through it, frequently stirring, until it 
was entirely decomposed. The liquid filtered from the 
sulphuret of lead was transparent, and afforded on evapo- 
ration in the water-bath a slightly brownish resinous mass, 
possessing the following properties : — When dry it resem- 
bles externally the original resin, is quite as brittle and as 
easily pulverized ; it dissolves readily in water and in alco- 
hol, but is insoluble in aether, has no odour, but a tolerably 
strong, pure bitter taste. It melts on platinum foil, and 
then burns, giving off the same odour and the same bright, 
somewhat smoky flame, as rhodeoretine, leaving behind a 
porous cinder, which is consumed without residue. The 
aqueous solution has an acid reaction, and is neither ren- 
dered turbid by solutions of neutral metallic salts nor by 
those of the alkaline earths. The original lead salt is ob- 
tained only with basic acetate of lead, or with the neutral 
acetate and the addition of ammonia. It likewise dissolves, 
in alkalies and carbonate alkalies, and forms the same salts 
as those obtained by dissolving the original resin in alka- 
