The acid used in this table was prepared from Baker and Adamson's c.p. sulphuric acid 95 per cent, which was strengthened to 100 per cent by the addition of fuming sulphuric acid made by distilling fuming acid (70 per cent free SO3) into a portion of the 95 per cent c.p. acid. The final acid was tested for impurities: residue upon evaporation, chlorine, niter and sulphur dioxide. The only impurity found was a trace of sulphur dioxide (0.001 per cent) which was less than the sensitiveness of the determination.

The analytical and specific gravity determinations, and the allowance for temperature were made in the same manner, and with the same accuracy as in the sulphuric acid table adopted in 1904, the specific gravity 1.8354 and 93.19 per cent H2SO4 being taken as a standard.

The actual determinations were made within a few hundredths of a per cent of the points given in the table, the even percentages being calculated by interpolation.

(WEIGHT AT STANDARD CONDITIONS, o° C. AND 760 MM.)

One cubic foot of water at 60° F. weighs 62.37 pounds.

1.2929 grams 1.9654 grams

0.09004 grams

1.2515 grams

1.4292 grams

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