An interesting form of cup is described by Hero of Alexandria (B. C. 285-222). Hero's description is quite intelligible, although it would be difficult to give an accurate translation that would be readily understood. I shall content myself with summarising his account. The figure (Pl. XXXVII, fig. 2) shows a cup of ordinary flattened form, divided into two by a diaphragm. Two tubes pass through the fundus, one passing through the diaphragm, the other not. Each of these tubes is fitted with another which is open at its inner end, but closed at its outer end and provided with a small crossbar to rotate it. Each of these sets of tubes is perforated by small openings. In the case of the short tube these are outside the cup, in the case of the long tube they are inside the cup, in the chamber shut off by the diaphragm. By rotating the pistons these openings can be placed in apposition or not at will, thus forming valves. Open valve A by placing the holes in apposition. Close valve B by turning the holes away from each other. The inner chamber of the cup is now shut off except for the small hole A. Apply the mouth to the valve A and suck the air out of the chamber. Close valve A. Apply the cup to the affected part. Open valve B and the negative pressure draws on the affected part. The advantage of this arrangement is that the affected part is not directly sucked upon by the mouth, and the instrument is therefore more pleasant for the operator to use. Bleeding cups occur on the coins of Epidaurus (300 B. C.), Atrax (400 B. C.) and Aegale (200 B. C.). _Clysters._ The ancients made frequent use of injections into the various orifices of the body. The apparatus used was a bladder or skin of an animal fixed to a tube. This form of instrument remained in use till the beginning of the nineteenth century, although the elaborate enema syringe, on the principle of the force pump, had been in use since the fifteenth century at least. The following passage from Heister (anno 1739) is interesting as showing exactly the method of its manipulation: Pl. XXXVII, fig. 3 machinam clysteri iniiciendo adaptam designat, qua Germani ut et Batavi vulgo utuntur. Litt. AA vesicam denotant cum liquore contento; quae vero in adultis duplo vel triplo amplior quam hic indicatur esse solet, pro libra circiter, et quo D excedit, liquoris continenda; BB tubulum sive fistulam osseam ano immittendam, per quam liquor in intestina iniicitur; CC vinculum superius, quod, postquam fistula in ano est, solvitur ac removetur; DD vinculum inferius, quo vesica clauditur, ne liquor immissus elabi queat (vol. ii. p. 1117). The rectal apparatus is called by Galen κλυστήρ, the uterine μητρεγχύτης, and the bladder injector is called καθετήρ. In x. 328 we find all these three terms used in one paragraph: