EXAMINATION OF JALAP RESIN. 29 
oily liquid, acquiring a dark yellow color ; the remaining 
alcoholic solution continued of a dark yellow-red color. 
The sethereal solution was washed with water, to separate 
the hydrochloric acid, and then exposed to the air. A dark 
brownish-yellow, thick, oily fluid separated on evaporation 
of the asther, which possessed a strong and not disagreea- 
ble odour. The neutral liquid volatilized with difficulty, 
but entirely, on exposure to heat, and burnt with a red 
flame. Boiled with solution of caustic potash, no action 
resulted; cold concentrated sulphuric acid was likewise 
without any efTect upon it. The liquid was placed over 
sulphuric acid for some days, and then submitted to analy- 
sis, with the following results : — 
Carbon, 66.95 66.65 30 67.51 
Hydrogen, 10.67 23 8.53 
Oxygen, 22.38 8 23,96 
The author has given the name of Rhodeoretinol to this 
body, from its origin and consistence. 
The acid liquid separated from the rhodeoretinol was satu- 
rated with carbonate of lead, the filtered liquid evaporated to 
dryness in the water-bath, and extracted with absolute alcohol. 
A viscid transparent mass was obtained, which had a sweetish 
taste, dissolved in water and alcohol, burnt on platinum foil, 
giving off the well-known odour of burnt sugar; and when 
warmed with potash and sulphate of copper, exhibited the 
characteristic reaction of grape-sugar by the reduction of the 
oxide of copper, gave the characteristic crystals with common 
salt, and finally, on being dissolved in water and brought into 
contact with yeast, passed into vinous fermentation. It is 
evident from these reactions that this substance is identical 
with grape-sugar, &c. 
The author made the same experiment with a solution of 
hydro-rhodeoretine in absolute alcohol and hydrochloric acid 
gas, as with rhodeoretine. The solution acquired a dark yel- 
low color, and on mixing with water white flakes separated, 
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