The extraction of blood by means of cups has been practised from remote antiquity. The Hindoo Vedas mention it, and it is interesting to note that one of the methods was to apply a gourd with fire in it, for both the Latin _cucurbitula_ and Greek σικύα signify a gourd. The usual theory as to its action was that in a diseased part there was a vicious πνεῦμα which required removal. Celsus (II. xi) thus describes the different kinds of cups: Cucurbitularum vero duo genera sunt; aeneum, et corneum. Aenea, altera parte patet, altera clausa, est; cornea, altera parte aeque patens, altera foramen habet exiguum. In aeneam linamentum ardens coniicitur, ac sic os eius corpori aptatur, imprimiturque donec inhaereat. Cornea per se corpori imponitur; deinde ubi ea parte qua exiguum foramen est ore spiritus adductus est, superque cera cavum id clausum est, aeque inhaerescit. Utraque non ex his tantum materiae generibus, sed etiam ex quolibet alio recte fit. Ac si cetera defecerunt, caliculus quoque, aut pultarius oris compressioris, ei rei commode aptatur. Ubi inhaesit, si concisa ante scalpello cutis est, sanguinem extrahit; si integra est, spiritum. 'There are two kinds of cups, bronze and horn. The bronze is open at one end and closed at the other, the horn, open at one end, as in the previous case, has at the other end a small foramen. Into the bronze kind burning lint is placed, and then the mouth is fitted on and pressed until it sticks. The horn one is placed empty on the body, and then by that part where the small foramen is, the air is exhausted by the mouth, and the cavity is closed off above with wax, and it adheres in the same way as before. Either may advantageously be constructed not only of these varieties of material but of any other substance. If other things are not to be had a small cup or a narrow mouthed jar will answer the purpose. When it has fastened on, if the skin has previously been cut with a scalpel it extracts blood; but if it be entire, air.' Paul says: 'When we are about to apply the empty instrument, having placed the limb in an erect position, we fasten it to the side, for if we apply the light above when lying down, the wick falling upon the skin with the flame burns in a painful manner, and for this there is no necessity. It is necessary that the size of the instrument be proportionate to the part to which it is applied, and on that account there is great difference of cupping-instruments with regard to the smallness and greatness of size. Moreover those which are made with longer necks and broader bellies are possessed of a strong power of attraction' (VI. xli).