2 
tallises in small primrose-yellow needles. It is very little 
soluble in cold water, but soluble in boiling water, and still 
more soluble in alcohol. It dissolves easily in caustic alka- 
lies forming solutions of a deep yellow colour, from which it 
is again deposited in crystalline needles on adding an excess 
of acid. Muriatic and sulphuric acid change its colour to a 
deep orange, the colour disappearing on the addition of a 
large quantity of water. It is not decomposed when exposed 
for a length of time to the action of boiling dilute sulphuric acid, 
and is therefore not a copulated compound, like so many of 
the other colouring matters. Boiling nitric acid converts it into 
oxalic acid. It is also decomposed when its solution in alkali 
is exposed for some time to the. air, being converted into an 
amorphous substance easily soluble in water, which resembles 
gum in appearance. The compound with oxide of lead has 
a bright yellow colour similar to that of chromate of lead- 
The watery solution imparts to printed calico, colours, some 
of which exhibit considerable liveliness. The composition of 
the substance is expressed by the formula C3 Hg Oj. The 
true formala is probably C30 Hgo Ogo* It appears to be iden- 
tical with Rutine, the yellow colouring matter contained in 
the Ruta graveolens, or common rue, and in capers and 
with Ilixanthine, a substance derived from the leaves of the 
common holly. The author obtained from 1000 parts of 
fresh buckwheat leaves a little more than 1 part of crystal- 
lised rutine. As the seed of the plant is the only part at 
present employed, it might be of advantage to collect and 
dry the leaves to be used as a dyeing material. 
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