varnish.


184. CHLORINE FOR SHELL-LAC VARNISH

This may be formed by mixing intimately eight parts of common salt,
and three parts of the black oxide of manganese in powder; put this
mixture into a retort, then pour four parts of sulphuric acid,
diluted with an equal weight of water, and afterwards allowed to
cool upon the salt and manganese; the gas will then be immediately
liberated, and the operation may be quickened by a moderate heat. A
tube leading from the mouth of the retort must be passed into the
resinous solution, where the gas will be absorbed, and the lac
precipitated.


185. SHELL-LAC VARNISHES OF VARIOUS COLOURS

These may be made by using ant colour in fine powder with the
varnish, in the following manner: rub up the colour with a little
alcohol or spirits of turpentine till it becomes perfectly smooth,
then put it into the cup with the varnish. Shell-lac varnish is the
best spirit varnish we have, and may be made any colour by the above
process.


186. GOLD OIL-COLOUR, OR SIZE

The English method of preparing the colour in size, which serves as
the ground on which the gold is laid, is, to grind together some red