Water of iron (per cent.) . . . . . 1.93
Silica and sand . . . . . . . . . .18.17
Lime, magnesia (in small quantity), alumina,
carbonic acid, sulphuric acid (traces) .11.81
______
100.00
The peroxide of iron contains 47.66 of metallic iron.

No. 24. "D." Lump of white quartz said to contain visible gold. I did not
observe any, but found a few minute specks of pyrites, and partially
resembling mica.

No. 25. Lump of quartz associated with red-brown oxide of iron. It
yielded no results.

No. 26. Lump of rock in which the "turquoise" occurs. There was a thin
layer of greenish blue turquoise mineral on one surface, and minute seams
of a similar substance throughout the specimen.

a. The layer of turquoise mineral, from which the rock or vein-stuff had
been detached as far as practicable, was found to contain phosphoric
acid, alumina, oxide of copper, oxide of iron, and water; which occur in
turquoise.

b. After the layer a had been separated, a fair average sample of the
rock was found to contain 1.69 per cent. of metallic copper. It was also
assayed and found to be free from silver[EN#7] and gold.

No. 27. "G." A variety of jasper, having a somewhat polished, and
irregular and deeply indented surface, the result of sand-action. The