Lead. 
257 
water for twelve or fourteen hours ; washing away the 
soda ; and drying and fusing the white muriat, I have al- 
ready mentioned under the head of white lead a few 
pages back ; I shall therefore say no more about it. 
Turner’s patent was taken out February 26, 1780. It 
was set aside in 1787. See Turner v. Winter, 1 Durn. 
and East, 602. 
But as the method of making it in this country, appears 
to me to be an improvement, I shall give it. I am oblig- 
ed for the process to Dr. Hunter. 
Take 66 lbs. litharge, and one bushel of salt : (by the 
way I would remark, that one bushel of Lake or Genesee 
salt, of Liverpool fme, and of Norwich fine, will weigh 
but 56 lbs. : a bushel of Liverpool salt, second fine, light- 
ly put into the measure and not pressed down, will weigh 
61 lbs. : a bushel of St. Ubes’ salt in like manner, will 
weigh 76 lbs. : of Turk’s island salt from 83 to 81 lbs. : 
All this I have tried myself, T. C.) Dissolve the salt in 
a pan. When dissolved, strain it and pour back the 
liquor into the pan : then add the litharge, keep a strong 
fire under the pan for three hours, until the mixture be 
perfectly white. The liquor then is caustic mineral al- 
kali, which must be poured off and preserved. Then 
wash off the alkali that remains in the sediment by repeat- 
ed waters, adding it to the liquor poured off. Take the 
sediment, which is a muriat of lead ; dry it on chalk 
stones ; when dry, put if in crucibles half filled, and melt 
the substance in an air furnace. The crucible should be 
covered, for any carbonaceous matter will reduce the mu- 
riat into metallic lead. It should remain in the furnace 
till cold, to preserve its crystallized form. 
Sheet Lead Boxes . These are convenient in many 
respects for the keeping of substances, that require to be 
preserved from air and moisture. But as it does not seem 
Vol. TIL K k 
