Dilute to 1 litre, having previously added not
less than 50 c.c. of strong sulphuric acid: 1 c.c. will contain .01 gram
of TiO_{2}. For the assay take 10 c.c. of this, add 2 c.c. of peroxide
of hydrogen and dilute to 100 c.c. Run this from a burette into the
flask until the colour equals that of the assay. Each c.c. equals 1
milligram of TiO_{2}. Fluorides must be absent.
[116] C + O_{2} = CO_{2}
[117] For example, soluble organic acids formed by partial oxidation
with nitric acid.
[118] For coals, and other bodies containing sulphur, chromate of lead
should be used instead of oxide of copper; and the temperature should be
limited to dull redness.
[119] This may be prepared by dissolving 534 grams of ammonium chloride
and 854 grams of crystallized cupric chloride (CuCl_{2}.2H_{2}O) in hot
water and crystallizing.
[120] Soda-lime is made by dissolving 100 grams of "soda" in water, and
carefully slaking 200 grams of lime with it. Evaporate to dryness in an
iron dish and ignite at a low red heat in a crucible. Use the small
lumps.
[121] Made by diluting 1 part by measure of saturated lime-water up to
10 with recently boiled distilled water.
[122] See under _Gasometric Assays_.
[123] See "A Method for the Separation and Estimation of Boric Acid," by
F.A. Gooch, _Chemical News_, January 7, 1887.
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