30 
EXAMINATION OF JALAP RESIN. 
which on being magnified exhibited the appearance of minute 
coherent drops of oil, and dissolved in sether. The sethereal 
solution, freed by washing with water from acid, gave on 
evaporation in the air a brown waxy mass, which possessed a 
similar odour to the rhodeoretinol. The acid solution, from 
which the substance had been removed by aether, likewise 
yielded, with excess of potash and sulphate of copper, the re- 
action of grape-sugar. 
Resin soluble in JEther.- — The sethereal extract of the resin, 
which was of a dark yellow color, was evaporated by expo- 
sure to the air, when a clear brownish-yellow liquid mass 
separated, which on solution in alcohol was thrown down by 
water as a brownish oily mass, which also separated any 
remaining portions of rhodeoretine. The mass, purified by 
being again dissolved in alcohol and precipitated with water, 
possessed the following properties : — It was strongly acid to- 
wards blue litmus-paper, left a grease-spot on paper, possessed 
a very strong disagreeable smell, resembling that of the jalap- 
root, and an irritating taste, and was insoluble in hydrochloric, 
nitric and acetic acids even on warming. It dissolves in an 
aqueous solution of potash or soda, and is separated unaltered 
by muriatic acid. The alcoholic solution is precipitated by 
an alcoholic solution of acetate of lead with a yellow color ; it 
does not crystallize either from the sethereal or from the alco- 
holic solution, and remains, even after several months, still 
quite soft and smeary. Left in contact with water for some 
length of time, it is converted into a mass of prismatic acicular 
crystals, which adhere together, and even after several months 
form a smeary mass. 
Pararhodeoretine. — A quantity of the accurately-determined 
root of Ipomea orizabensis, Pellet., was exhausted with alcohol, 
the extract mixed with water, and the alcohol removed by 
distillation ; the resin so obtained was washed with hot water, 
again dissolved in alcohol and entirely decolorized by means 
of washed animal charcoal The resin obtained by distilling 
off the alcohol, and boiling in water after desiccation in the 
