argillaceous earth

Although the beaks and feet of birds are generally quite clean, I can show that earth sometimes adheres to them: in one instance I removed twenty-two grains of dry argillaceous earth from one foot of a partridge, and in this earth there was a pebble quite as large as the seed of a vetch.

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.