271 Method of Obtaining Patents* 
wards wash the mixture, to separate the sand, and let 
the finer part gradually dry for use. 
lied Colour , equal to Indian-Red . Take some of the 
pyrites, usually found in coal-pits, calcine them, and they 
will produce a beautiful red. 
Grey Colour is made by calcining together blue-slate 
and bone-ashes powdered, grinding them together, after- 
wards washing them, and drying the mixture gradually. 
Blue-Black is made by burning vine-stalks in a close 
crucible in a slow fire, till a perfect charcoal is made of 
them, which must be well ground for use. 
Crayons are made of bone- ash powder mixed with 
spermaceti, adding thereto the colouring matters. The 
proper proportion is, three ounces of spermaceti to one 
pound of the powder. The spermaceti to be first diffused 
in a pint of boiling water, then the white bone-ash added, 
and the whole to be well ground together, with as much 
of the colouring matter as may be necessary for the shade 
of colour wanted. They are then to be rolled up in the 
proper form, and gradually dried upon a board. 
White Chalk , if required to work soft, is made by add- 
ing a quarter of a pound of whitening to one pound of 
the bone-ash powder will answer alone. The coloured 
chalks are made by grinding the colouring matter with 
bone-ashes. 
N 0. 56. 
Account of the Method of Obtaining Patents . My Ih\ 
William Thornton. 
HAYING been requested by several persons to point 
out, in the Emporium, the mode to be pursued in obtain- 
ing a patent right from the United States, I have thought 
