Sandal Red

: ON THE PRIMARY, RED.

We have kept this separate from other reds derived from woods, because

it is said (by Professor H. Dussance) to be obtainable not only equal in

beauty and brightness to carmine, but of greater permanence. The process

of preparation is as follows:--The powdered root exhausted by alcohol

gives a solution to which hydrated oxide of lead is added in excess. The

combination of colouring matter and lead oxide is then collected on a

filter, washed with alcohol, dried, dissolved in acetic acid, and mixed

with a quantity of water. The red being insoluble therein is

precipitated, while the acetate of lead remains dissolved. After being

washed, the colour is dried at a low temperature. The Professor affirms

that the red so produced is unaffected by sulphuretted hydrogen, or by

light and air; and it is stated that the colour which was used to paint

the carriages of the Emperor Napoleon, remained as bright at the end of

nine years as when it was put on. Possessing such properties, it is

curious that the red has never been--in this country at

least--introduced as an artistic pigment, the more especially as

seventeen years have elapsed since its discovery.



More

;