zoology. See Cancer.

Crab's claws, in the materia medica, are the tips of the claws of the common crab broken off at the verge of the black part, so much of the extremity of the claws only being allowed to be used in medicine as is tinged with this colour. The blackness, however, is only superficial; they are of a greyish white within, and when levigated furnish a tolerable white powder.

Crab's claws are of the number of the alkaline absorbents, but they are superior to the generality of them in some degree, as they are found on a chemical analysis to contain a volatile urinous salt.

Crab's eyes, in pharmacy, are a strong concretion in the head of the cray-fish. They are rounded on one side, and depressed and sinuated on the other, considerably heavy, moderately hard, and without smell. We have them from Holland, Mucovia, Poland, Denmark, Sweden, and many other places.

Crab's eyes are much used both in the shop-medicines and extemporaneous prescriptions, being accounted not only absorbent and drying, but also diuretic and diuretic.

engine of wood, with three claws, placed on the ground like a capstan, and used at launching or heaving ships into the dock.