-----------------------------+---------+---------+--------- | I. | II. | III. +---------+---------+--------- |per cent.|per cent.|per cent. Ferric oxide (Fe_{2}O_{3}). | 43.26 | 78.91 | 77.74 Ferrous oxide (FeO). | 37.86 | 3.46 | 1.44 +---------+---------+--------- Total. | 81.12 | 82.37 | 79.18 +---------+---------+--------- Calculated: | | | Ferric oxide (Fe_{2}O_{3}). | ... | 71.23 | 74.54 Magnetic oxide (Fe_{3}O_{4}).| 62.72 | 11.14 | 4.64 Ferrous oxide (FeO). | 18.40 | | +---------+---------+--------- Total. | 81.12 | 82.37 | 79.18 +---------+---------+--------- Percentage of total oxygen reduced. | 16.44 | 1.49 | 0.42 Metallic iron. | 59.73 | 57.93 | 55.54 -----------------------------+---------+---------+--------- NOTE.--The carbon monoxide (CO) had failed to remove from the ore the carbon dioxide existing as calcic carbonate. The summary of experiments in the following table appears to show that the water gas is a more powerful reducing agent than CO in proportion to the ratio of as 4.21 x 100 4.21 : 6.72, or ------------ = 52 per cent. 72 Mr. B.D. Healey, Assoc. M. Inst. C.E., and the author are just now constructing large experimental plant in which water gas will be used as the reducing agent. This plant would have been at work before this but for some defects in the valvular arrangements, which will be entirely removed in the new modifications of the plant. * * * * * ANTISEPTIC MOUTH WASH. Where an antiseptic mouth wash is needed, Mr. Sewill prescribes the use of perchloride of mercury in the following form: One grain of the perchloride and 1 grain of chloride of ammonium to be dissolved in 1 oz. of eau de Cologne or tincture of lemons, and a teaspoonful of the solution to be mixed with two-thirds of a wineglassful of water, making a proportion of about 1 of perchloride in 5,000 parts.--_Chemist and Druggist_. * * * * * ANNATTO. [Footnote: Read at an evening meeting of the North British Branch of the Pharmaceutical Society, January 21.] By WILLIAM LAWSON.