174 Intelligence and Miscellanies. 
hibit after this operation. Some pigments present a chem- 
ical combination with the oil, while others can be suspended 
in it only by considerable labor, and soon separate when left 
at rest. These differences can be rendered of trifling impor- 
tance, by employing such a substance as will retain those com- 
pounds which possess no attraction for the oil, in a state of 
a small portion of alumina. The artist has it 
in his power thus, to increase or diminish the fluidity of his 
paints and to render them uniform. Some pigments becom 
valuable as glazing colors, as the Prussiate of copper, (Hatch- 
ette’s Brown.) Vermillion and Naples Yellow, acquire new 
properties. 
or printing from blocks, as in the manufacture of orna- 
mental floor-cloths, it is often desirable to increase the fluid- 
ity of the paint, so as to prevent the dropping of small 
thread-like parts on the work, without causing it to spread. 
i accomplished, by adding a small quantity of 
whiting to the pigment while grinding ; the artisan can then 
load his blocks with paint and consequently give a thick coat- 
ing to the print. 
A. A. Haves, Roxbury Laboratory. 
6. On a fine scarlet pigment for the pallet.—While prose- 
a some experiments on the pigments employed by art- 
ists, | prepared a quantity of the biiodide of mereury and 
gave it to Mr. R. Peale, requesting him to make some ex- — 
periments on its working properties and permanency. This 
distinguished artist, obligingly commenced them, but they 
were not finished, at the time he left thiscountry. He found 
at it readily mixed with oil; combined with other colors 
