C 44 ] 
Experiment III. 
I mixed three parts white wax, and one part 
white refin, hoping the tenacity of the refin might 
preferve the picture. This was laid on a board 
heated, with a brufh, as in the former; and the 
ground was chalk, prepared as before. This was 
placed horizontally on an ironing box, charged with 
an hot heater, fhifting it from time to time, that the 
wax and refin might penetrate the chalk ; and hoping 
from this pofition, that the ground, bloated by melt- 
ing the wax, would fubfide into its proper place : 
but this, like the other, came from the board, and 
would not at all adhere. 
Experiment IV. 
Prepared chalk four drams, white wax, white 
refin, of each a dram, burnt alabafler half a dram, 
were all powdered together and fifted, mixed with 
fpirit of moloffes inftead of water, and put for a 
ground on a board fmeared with wax and refin, as 
in Exp. 3. This was alfo placed horizontally on a 
box-iron, as the former : the pidture biift'ered, and 
was cracked all over ; and tho’ removed from the 
box-iron to an oven moderately heated (in the fame 
horizontal pofition), it would not fubfide, nor be- 
come fmooth. When it was cold, I took an iron 
fpatula made warm, and moved it gently over the 
furface of the picture, as if I were to fpread a plaifter. 
(This thought occurred, from the board being pre- 
pared with wax and refin, and the ground having the 
fame materials in its compofition, the force of the 
fpatula 
