argillaceous earth

During its winter sojourn on the pampas the flock always selects as a feeding-ground a patch of whitish argillaceous earth, with a scanty withered vegetation; and here when the birds crouch motionless on the ground, to which their grey plumage so closely assimilates in colour, it is most difficult to detect them.

Some were partially painted with a white argillaceous earth; others were blackened with charcoal; one of the men was daubed all over with a white pigment.

Argillaceous earth is found in clay, schistus, or slate, and in mica; but the purest is that which is precipitated from a solution of alum by alkalies; for alum consists of the union of vitriolic acid and argillaceous earth.

The fields in this part of the country are excellent, being extensive and level, the soil consisting of sandy and argillaceous earth.

The ascent of one yard in ten gives that gentle fall to the road, which, in a smaller degree, ought to be conferred artificially on all roads, in order that they might drain lengthways, and that the argillaceous earth might be carried off in solution, and only the hard bed of silex remain behind.