88 
VARIETIES. 
To obtain finer and more regular designs, the ivory is to be covered with 
the common ground, and by means of the point the designs are engraved 
upon it. They are then eaten in by a solntion formed as follows : — 
Fine silver 6 grms. 
Nitric acid - - - 30 " 
Distilled water - - 125 " 
At the end of about a half-hour according to the depth to be given, it is to 
be washed with distilled water and dried with bibulous paper. The design 
is then exposed for an hour to the solar light, and the layer of wax is removed 
by essence of turpentine. 
The design has then a black color or a dark brown, which blackens entirely 
at the end of one or two days. Other colors may be produced, by replacing 
the solution of nitrate or silver by a solution of gold or platina in aqua regia, 
or of copper in nitric acid. — Chem. Gaz. July \, from Revue Scientifqiie'xxxv. 
p. 433. 
Show Colors for Druggists 1 Shop Windows. 
BLUE. 
No. 1. — Sulphate of copper £], sulphuric acid ^ss, water ^x. 
No. 2. — Ammonio-sulphate of copper, ammonio-nitrate of nickel (see No. 
5) and water. 
No. 3. — Prussian blue gr. x., oxalic acid gr. xx., water §xvj. 
No. 4. — Dissolve nickel in diluted sulphuric acid, add ammonia in excess, 
and dilute with water. 
No. 5. — Dissolve nickel in diluted nitric acid, add ammonia in excess and 
dilute with water. 
GREEN. 
No. 1. — Sulphate of copper chloride of sodium giv. water ^xx. 
No. 2. — Dissolve of nickel in ^vj of nitric acid, and add Ov of water. 
No. 3. — Dissolve nickel in dilute sulphuric acid, and dilute with water. 
No. 4. — Dissolve sulphate of copper in water and add bichromate of pot- 
ash until the required color is produced. 
No. 5. — Dissolve ammonio-sulphate of copper in water, and add bichromate 
of potash until the required color is produced. 
No. 6. — Dissolve sulphate of copper in water, and add nitric acid until the 
required color is produced. 
No. 7. — .Dissolve distilled verdigris with acetic acid, and dilute with 
water. 
LILAC. 
No. t. — Dissolve zaffre (impure oxide of cobalt) in hydrochloric acid, filter, 
and add carbonate of ammonia in excess;, to this add ammonio-snlphate of 
copper until the required color is produced. 
No. 2. — Dissolve zaffre in hydrochloric acid, filter, and add carbonate of 
ammonia in excess; to this add ammonio-nitrate of nickel (see Blue, No. 5) 
until the required tint is produced. 
