Many workers following certain occupations show pigmented scars due to the penetration of carbon and other pigments from superficial wounds caused by gunpowder, explosions, &c.
These men seldom use vitrifiable enamels, pigments being much more tractable and less costly.
Haematogenous pigments are derived from the haemoglobin of the red blood corpuscles.
Other minerals whose production may be found stated in detail in the annual volume on Mineral Resources of the United States Geological Survey are: natural pigments, felspar, white mica, graphite, fluorspar, arsenic, quartz, barytes, bromine.
By careful selection and preparation of pate, glaze and pigments, Dr Wagener proved not only that the manufacture was reasonably feasible, but also that decoration thus applied to pottery possesses unique delicacy and softness.