in the Materia Medica, CASTOR; Caistorum, the inguinal glands of the beaver. The ancients had a notion that it was lodged in the testicles; and that the animals, when hard pressed, would bite them off, and leave them to its pursuers, as if conscious of what they wanted to destroy him for. The best sort of castor is what comes from Russia. So much is Russian castor superior to the American, that two guineas per pound is paid for the former, and only 8s. 6d. for the latter. The Russian castor is in large hard round cobs, which appear, when cut, full of a brittle, red, liver-coloured substance, interspersed with membranes and fibres exquisitely interwoven. An inferior sort is brought from Dantzig, and is generally fat and moist. The American castor, which is the worst of all, is in longish thin cobs. Russian castor has a strong disagreeable smell; and an acrid, bitterish, and nauseous taste. Water extracts the nauseous part, with little of the finer bitter; rectified spirit extracts this last without much of the nauseous; proof-spirit both: water elevates the whole of its flavour in distillation; rectified spirit brings over nothing. Castor is looked upon as one of the capital nerve and antihysteric medicines: some celebrated practitioners, nevertheless, have doubted its virtues; and Newman and Stahl declare it insignificant. Experience, however, has shown that the virtues of castor are considerable, tho' less than they have been generally supposed.