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residues would have given one some idea what credit to give it, 
for chemistry like other sciences has much advanced of late years, 
and the method of working out an estimation of CO’ or Fe some 
30 years ago would hardly be considered a correct process at the 
present time. 
For the reasons just mentioned I shall submit to your notice 
the circumstances under which the different determinations in this 
analysis were arrived at. 
A Qualitative Analysis having been first made, a Quantitative 
was proceeded with in much about the following order :— 
Ist. For the Solid Residue :—A Platinum basin was cleaned, 
heated to redness, allowed to cool, and weighed; 100 C.C. of 
the water poured into it and evaporated to dryness on a water 
bath ; then transferred to an air bath and kept at a temperature 
of 130° Centigrade for a few minutes; taken out, allowed to 
cool and weighed, the difference between this weighing and the 
former one = 311 Milligrams, or 3110 parts per million, 
For the Silica. :—A litre of the water was placed in a large 
porcelain basin, and Hydrochloric acid in excess added and 
digested at a gentle heat with constant stirring until the residue 
was dry; again moistened with Hydrocloric Acid, warmed, 
diluted, the residue washed on the filter, dryed, and finally ignited, 
the result giving 13 Milligrams, or the same number of parts per 
million. I should mention that this residue was examined by the 
spectroscope for Barium, which was found to be absent. 
For the Sulphuric Acid:—The turbidity produced on the 
addition of Chloride of Barium being very great, only a } of a 
litre was taken for this determination ; some Hydrochloric Acid 
added, then heated to boiling, and Chloride of Barium added, 
washed by decantation with hot water, collected on a filter, and 
the washing continued as long as the filtrate gave a precipitate 
with Sulphuric Acid, then dried and ignited, the residue weighed 
as Sulphate of Barium, and the amount of Sulphuric Acid 
estimated therefrom, 
