LYTTELTON OCHRES.

Globe, Volume XXIII, Issue 2402, 16 December 1881, Page 3

LYTTELTON OCHRES.

The following report was laid upon the table at the meeting of the Harbor Board yesterday, respecting the samples of yellow oobre procured from the property of the Lyttelton Harbor Board at Naval Point: — In the examination of the samples o! yellow ochre received from the Board, it was thought that their value would be better indicated ii they were compared with the ochre imported into this country. For this purpose a sample of the best imported was obtained, and the samples received examined side by side witb it. The results of the analyses made were as follows:

The above analyses were made on the samples as received without any preparation other than grinding, whereas the purchased sample had probably been prepared by elntriatim. The effects produced by roasting the samples were not favorab'e. The dark sample yielded a red ochre, but not such as would compare with that imported, or with those of Canterbury already examined in this laboratory. The light sample did not yield a red ochre on roasting. The ochres as received possessed ph>aioal characteristics as follows The dark sample was of a dark yellow colour, soft with a resinous lustre, yielding a powder when ground of a darker colour than the imported sample. From experiments made as to the colouring properties of the two samples, the dark sample was fonnd superior, and the light sample inferior to the imported sample. The same conclusions are arrived at if the percentage of iron in the samples be taken as an index of the coloring matter. A valuable feature in conneotion with these ochres is, that by admixture cf the two almost any tint could ha produced, and I think, taking into consideration the mean valne of the two samples, and also the fact that they contain a higher percent ge of moisture, that after preparation these ochres will he found to compare very favorably with the imported article. A. F. Bickeeton, Public Analyst,

Dark Light Imsample. sample. ported Per cent. Percent. Percent Moisture 13.85 13 65 2.85 Loss on ignition 7.15 7 60 6.00 Silica and insoluble matter 57.80 68.25 76.70 Iron peroxide ... 14.40 8.00 10 60 Alumina 6.60 1.00 2.40 Loss and undetermined 0.23 1.50 1.45 Total . 100 ioa 100