Vol. I, No. 4.] Colouring Principle of Nyctanthes Arbor-tristis. 103 
EN.S.] 
colour was produced at the junction of the two liquids. This soon 
darkened and disappeared. 
When the infusion was allowed to stand for a few days alone, 
a reddish-brown deposit settled. If a little hydrochloric acid was 
added to the infusion, a reddish flocculent precipitate settled after 
about twelve hours. A similar precipitate was obtained by 
heating the infusion with basic lead acetate, decomposing the 
washed yellow precipitate with sulphuretted hydrogen, and warm- 
ing the yellow solution obtained on filtering. The amount ob- 
tained was always very small, but attempts to get more from the 
solution by heating on the water-bath with dilute hydrochloric acid 
resulted in the deposition of a black amorphous substance. When 
dried, it was very light and. friable, and varied in colour from a 
very dark-brown to a jet black. On evaporating the solution after 
removal of this black substance, it was found to contain a sweet 
substance, which reduced Fehling’s solution on boiling. 
About two grains of the red colouring matter were collected, 
and washed with water. On boiling with alcohol a large quantity 
dissolved, and the residue appeared to consist of mineral matter, 
The alcoholic solution on evaporation gave a dark-red lustrous 
deposit. This was entirely soluble in alcohol. Thus obtained, the 
substance melted between 250° and 260°, dissolved in alcohol, ethyl 
acetate, and ether, but it could be made to crystallize from none 
of these. It also dissolved readily in alkalis and alkaline carbon- 
ates, and in a solution of borax. It was sparingly soluble in 
chloroform and carbon bisulphide, insoluble in benzene and cold 
ea very slightly soluble in hot water, and soluble in acetic 
acid. 
Alcoholic extract.—Owing to the apparent high solubility of the 
colonring matter in alcohol, some of the flowers were extracted in a 
Soxhlet apparatus with alcohol (sp. gr. ‘810) till they were colour- 
less, and the hot alcohol was then allowed to cool. On cooling, 
bunches of needle-like crystals had settled all over the flask. 
These were pale-yellow, but after several recrystallizations became 
white. They had a sweet taste, reduced a solution of ammonia- 
cal silver nitrate, but did not rotate polarized light. 
Analysis gave :— 
Carbon =389'62 
Hydrogen. = 7:96 
Mannitol ne C=39'57 
18 (Oh requires 4 4 _ 7.0 
The crystals melted at 166°; 
Mannitol melts at 168°. 
When the filtrate from the mannitol was slightly evaporated 
and cooled, no further precipitation occurred, but a small quantity 
of wax separated. The residue contained crude colouring matter 
with some resinous products. To obtain the colouring principle, 
