470 
dilute solution of tartaric acid. This acid was placed in a 
tall flint-glass bottle with narrow neck, the mouth of which 
was closed (but not air tight) by a cork which was perforated 
so to receive the vertical arm of the bent tube. Upon con- 
tact of the chlorine and ore considerable heat was developed. 
When, the current of gas being still maintained, this began 
to subside, a lighted spirit lamp with circular wick was 
placed beneath the ball, and its flame gradually augmented 
so as to expel the chlorides of sulphur and antimony, and 
finally to fuse the chloride of lead; and a smaller spirit 
flame was at the same time made to play on the tube beyond 
the ball, so as to cause the volatile chlorides to pass into the 
tartaric acid, or at least into the vertical portion of the tube 
whose further extremity was immersed in the acid solution. 
The tube was now nicked with a file, and broken across 
at its point of flexure; and the portion not connected 
with the ball was subjected to a stream of distilled water, 
so as to wash any chlorides which it might include into the 
bottle containing the tartaric acid. This portion of the 
tube was now heated to redness, so as to render it perfectly 
dry, and then weighed along with the remaining fragment on 
which the ball was blown, and which contained the chloride 
of lead. The weight of this chloride was thus obtained ; 
being obviously equal to the weight last obtained, diminished 
by the weight of the ball and tube. It was thus found to 
amount to 40°96 grains, equivalent to 30°52 of metallic lead. 
The remaining constituents of the ore were now in the tar- 
taric acid, the sulphur being partly in the free state, but 
chiefly in the form of sulphuric acid. The free sulphur was 
first separated, and found to weigh 0:1 grain. To the acid 
solution chloride of barium was added, which threw down 
the sulphuric acid in the form of sulphate ofbarytes. This, 
when well washed, dried, and ignited, weighed 51°87 grains, 
equivalent to 7°15 sulphur ; hence 7°15 + 0°10 = 7°25 is the 
total amount of the sulphur. 
