“Single value” soil constants: a study of the significance of certain soil constants VI. On the changes produced in a soil by exposure to high temperatures (With One text-figure.)

Abstract

1. Measurements on the loss of ignition of four soils of different physical type are not affected by changes in the temperature of furnace, provided that the temperature is above 600°. Errors in the determination of the loss on ignition are of the order of 1 per cent. of the true value.2. The loss in weight of the soils can be ascribed in the main to loss of free and interstitial water up to about 100°; to destruction of organic colloids between 100° and 250°; and to destruction of inorganic colloids at higher temperatures.Thanks are due to Miss T. Alper, M.A. (Cape Town) for assistance in making some of the preliminary measurements.