in 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 urinary 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 situated on the other, considerably heavy, moderately hard, and without smell. We have them from Holland, Mafcovy, 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.

Crab-Lice, a troublesome kind of vermin, which stick Crab stick so fast with their claws to the skin as to render it difficult to dislodge them. Being viewed with a glass they nearly resemble the small crab-fish; whence they obtained their popular name. They are also called *pudicula*, *morpiones*, *petoles*, and *pelletaria*: they usually infect the arm-pits and pudenda. They will be quickly destroyed, and drop off dead, upon the application of a rag wet with the milk of sublimate. This sort of vermin is reckoned to prognosticate speedy mortality to those whom they abandon without being removed by medicine.

sort of wooden pillar, whose lower end, being let down through a ship's decks, rests upon a socket like the capstan; and having in its upper end three or four holes, at different heights, through the middle of it, one above another, into which long bars are thrust, whose length is nearly equal to the breadth of the deck. It is employed to wind in the cable, or to purchase any other weighty matter which requires a great mechanical power. This differs from a capstan, as not being furnished with a drum-head, and by having the bars to go entirely through it, reaching from one side of the deck to the other; whereas those of the capstan, which are superior in number, reach only about eight inches or a foot into the drum-head, according to the size thereof. This machine is represented in Plate CXXVII. n° 4. See also Capstan.

*Crab-Town*, a name in Jamaica for a kind of ulcer on the soles of the feet, with hard callous lips, so hard that it is difficult to cut them. The ung. curul. fort. is their cure.