APPENDIX V. 369 d. Silicic acid.

e. Phosphoric acid.

/. Arsenic, a trace.

The quantitative examination was carried on in the same manner as in the case of sample No. 1.

1. Estimation of the Water.

4-527 grm. of ore di'ied at 110° C. lost 0-065 water = 1-435 % Further heated to a red heat there was a further loss of weight of 0-465 grm 10-271 % 2. Estimation of the insoluble parts.

2-931 grm. of ore gave 0-5025 grm. insoluble matter 17-144 4-7435 grm. of ore gave 0-82108 grm. insoluble matter 17-309 % Mean .. .. 17-226 % From this 0-82108 grm. of residue, 0-16658 grm. was present as combined silicic acid, or 3-511 % of ore ; that is to say, silicic acid was present in the state of quartz 17-226 - 3-511 = 13-715 %.

3. Estimation of the Iron.

2-931 grm. of ore dissolved, the solution made up to 500"" ; 50""" of this solution (B) estimated with a solution of permanganate of potassium, as in No. 1. 21-0""" permanganate of potassium solution was used. This test was tried three times. The result = 0-206388 grm. of oxide of iron, Fe O3, or 70-412 % oxide of iron.

4. Estimation of Phosphoric Acid.

4-7435 grm. of ore gave 0-028765 gi-m. of phosphate of magnesium, Mgj 0„ corresponding to 0-0184 grm. Pj O5 = 0-39 % phosphoric acid.

VOL. II. 2 B