COMMENTARY. Hippocrates declares in one of his Aphorisms, that the sudden evacuation of the matter in empyema, or of the water in dropsy, proves fatal. He speaks of evacuating the fluid with an instrument called τρυπαντρωγλητήριον, which Camper thinks must have been a kind of trochar. Galen, in his Commentary on the Aphorisms of Hippocrates, (vi, 7) remarks, that in his time the operation of paracentesis was in general use, instead of burning. He states, however, that he had seldom seen recovery take place after the operation. (See in particular Meth. Med. xiv.) Aristotle alludes to paracentesis near the conclusion of his work on the ‘Generation of Animals.’ Cælius Aurelianus mentions that Erasistratus, Evenor, and Thessalus were advocates for paracentesis, but that Asclepiades, Themison, and Soranus disapproved of it. He himself approves very much of the operation, and answers all the objections which had been made to it. He says, it relieves the fulness and difficulty of breathing, and prepares the parts for the action of the remedies. He agrees, however, with the other authorities, that a sudden evacuation of the water is attended with danger. (Pass. Tard. iii, 8.) Celsus gives a good description of the operation. Some, he says, perform it at a spot four fingers’ breadth below the navel in the left side; some do it at the navel; and some burn the skin and then perforate the abdominal parietes. He directs the operator to be careful not to wound a vessel. The size of the point of the perforator, he says, should be the third part of a finger’s breadth. After the perforation has been made, a tube (canula) of lead or copper is to be introduced and the water drawn off gradually. The whole is not to be removed at one time, but a tent is to be introduced into the opening, unless it was made with fire, to prevent it from healing too soon. He speaks favorably of the operation, unless the patient be much debilitated. (vii, 15; also ii, 10.) Aëtius and most of the medical authors subsequent to Galen, mention the operation of paracentesis, and approve of it. Vegetius, the veterinary surgeon, recommends paracentesis for the dropsy of cattle, when the swelling is not removed by purging. (Mulom. iii, 25.) Avicenna expresses himself rather unfavorably of paracentesis. He says, it ought never to be attempted until every other remedy has proved ineffectual, and unless the strength of the patient be good, and he can endure exercise, abstinence from drink, and restricted diet. His description of the operation is taken from Paulus. (iii, 14; iv, 13.) Serapion mentions the operation in very brief terms. (iv, 7.)