94 W. G. Mixter—Estimation of Sulphur in:Coal. 
of aleohol and of sugar-charcoal made by the method here de- 
seribed, yielded with barium chloride, a precipitate apparently 
no ereater than that obtained from the oxygen alone, an 
slight to influence headed results. This shows that with suit- 
able care rma stoppers are not objectionable. 
The following results, obtained in the order they are given, 
show the applicability of the method, while some of the details 
mentioned may help to explain the use of the apparatus. 
Weight taken. Per cent. found. 
0°0658 51°20 
ti Iron pyrites (mixed with car roi cee 
2. Cust Sei. | OORT 51°26 
3. Sulphur, cis ay ye Be eens caer we ey cre eon 0°2070 99°76 
4 : ere els 0°2807 99°92 
6. sf Wane cis OAOD 99°93 
6. M ghiki Gees Meliliew MOG te a omie - 0°5882 100°02 
7, Carbon disulphide, .. .- 6c ds aes 0°7725 84°12 
8. Deieiad se pistol Mine ymin 0°4598 84°16 
Me SOUNONE OR 0°6640 2°97 
1] eae pence Sr 0°7860 2°99 
11. Wool, 5 goes OOO 3°44 
a DEA AS hes ate fe 0°4675 3°46 
13 Tobacco, eiv en cues lca een mene on 2°0720 
iota 2°1370 
. 0°36 
Nine liters of oxygen were used in Nos. 1, 2, 13 and 14, and 
four liters in each of the other analyses. 
o. 1 the iron pyrites was mixed wei 13 gr., and in No. 
aqua regia, after evaporation. honing ni dryness to “aap the 
excess of acid, gave no turbidity with barium chloride. The 
sulphur in this pyrites was estimated by another method by 
way of control.* This mixture of pyrites with charcoal was 
* The analyses of pyrites were mostly made by a modification of the method 
of sprig and Pearson ee Journal, xviii, 190). The pulverized | dron pyrites 
he - was mix ate, about 
26 ec. nee acid, Sp. gr. T -40 were then added to ie mixed powders, a my whole 
was heated cautiously but not to boiling, for fear of melting the sulphur which 
separated. complete solution was obtained in five n minutes. It was 
evaporated to dryness and the evaporation twice repeated with the addition, of 
water, was then dige with three separate portions of Asem acetate, a 
the washing was continued with water till sulphuric acid gave no turbidity in ‘the 
washings. These precipitates after ignition yielded no ah. ralhgpan to hot dilute 
chlorhydric acid; they were slightly reddish in color, and the sulphur 
from their weight amounted to 51°69 and ~ Deg cent. rg ae vely 
In two other — tions, potassium ure tartaric acid 
being at hand) and chlorhydric acid were added “A the sao Betore precipita- 
ting, with the . of retaining the iron in solution more perfectly; the barium- 
