Ry ae erring: Pe 
Potassium as an Oxydiziny mixture. 193 
phur. Thus, the oxydation might perhaps be effected in a 
flask provided with a wide funnel tube for the addition of the 
chlorate and a delivery tube through which the carbonic acid 
formed could be led into baryta-water or some other substance 
fit to absorb that gas. Upon this point, however, I have as 
yet made no experiments, 
May, 1869. 
Assay of Sulphur in Iron Pyrites ; by A. H. Pearson. 
The proportion of sulphur in iron pyrites (“ Sulphur-ore ”) 
may be readily and accurately estimated as follows :—Weigh 
out a gram or less of the powdered ore, place the powder in a 
oxydized with chlorate of potassium and nitric acid, and the 
