TRANSACTIONS OP THE SECTIONS. 91 



ricke's first modern air-pump (1054), or Boyle and Hooke's first English one (1G59), 

 we seem to see a copy In all essentials of the suction horn : the horn is replaced by 

 a glass vessel, the mouth by a metal cylinder and piston directly communicating with 

 the glass. But history does not confirm this supposition. Had it been well-founded, 

 we should not have had to wait for much more than a thousand years before we had 

 an air-pump; neither should we find that instrument totally unknown to the great 

 majority of those nations who were quite familiar with the cupping horn. 



It appears from the writings of Guericke, Boyle and their contemporaries, that it 

 was the Torricellian tube that led them to construct their air-pumps. We must in 

 truth intercalate the barometer between the suction-horn and the air-pump ; for al- 

 though the last seems but a copy in glass and metal of the second, it was not in reality 

 so. Galileo in 1600 explained the action of a water-pump and suggested the Torri- 

 cellian experiment. Torricelli tried it in 1644; and men at length believed in the 

 possibility of producing a vacuum, a truth which the cupping horn had not taught 

 them. 



At length, after ten years' endeavour, not without success, to make a large bulbed 

 barometer serve the purposes which the air-pump now fulfils, Guericke took courage 

 to attempt a pump. But he did not at first endeavour to pump out air, as he certainly 

 would have done, had he modeled his instrument on the suction-horn. On the other 

 hand, he filled a barrel or globe with water, and pumped out that. In short, his first 

 air-pump was a Torricellian tube, from which the liquid, instead of being withdrawn 

 by its weight, compared with that of the air, was exhausted by a syringe. By and by, 

 struck with the elasticity of the air and its continual expansion under diminished 

 pressure, he dismissed liquids, and acted with his pump directly on the air in a shut 

 vessel. Till, however, the Torricellian experiment taught him two truths — the one 

 that a vacuum is possible, the other that air is elastic — the air-pump remained an un- 

 realized possibility. The barometer, accordingly, and not the cupping horn, was the 

 genetic precursor of the modem air-pump, a fact which has not apparently received 

 from the historians of science the attention it deserves. The later stages in the air- 

 pump — involving the introduction by Hooke and Boyle (1667) of the separate "plate " 

 on which bell-jars could stand, the employment of two barrels by Papin (1676), with 

 a stirrup or treddle arrangement for working the pistons by the feet, and the replace- 

 ment of this curious device by the familiar rack and pinion to move the two pistons, 

 by Hauksbee (1704) — was not enlarged upon, as it had been treated by the author 

 elsewhere. 



Thermic Vacuum. — The condensing chamber of a Watt's steam-engine, or the vacuum 

 pan of a sugar refiner, are generally regarded as very modern inventions. These 

 powerful pneumatic evacuators, however, stand in the same relation of descent to the 

 cupping glass, in which a vacuum is produced by the action of a flame, as the scien- 

 tific air-pump does to the suction cupping horn. The former, which may be called the 

 flame-cup, was as familiar to Hippocrates as the suction horn, and is equally referred 

 to, as in his day an ancient instrument. Later Greek and Roman medical writers, 

 such as Oribasius, Paulus iEgineta and Celsus, describe the flame-cups as made chiefly 

 of bronze, sometimes of glass, and occasionally of earthenware. In the ruins of Her- 

 culaneum and Pompeii examples have been found, which are now in the Museo Bor- 

 bonico at Naples, and have been figured by Vulpes. Of whatever material these in- 

 struments were anciently constructed, they were similarly named, the Greek term 

 for a cupping glass being o-Uva (sikua), and the Latin cucurbitula, each alike signi- 

 fying a small gourd. Lexicographers refer this unexpected title, solely to the resem- 

 blance in form of the cupping glass to a gourd. The author believes this to be a 

 mistake, in consequence, mainly, of finding that an actual gourd has been used as a 

 flame-cup by the natives of Africa on the Old Calabar river, as well as by negroes 

 from other African districts, from time immemorial. In illustration he showed three 

 cupping gourds brought from Old Calabar by A. Hewan, Esq., Surgeon to the United 

 Presbyterian Mission there. This gentleman has frequently seen the gourd employed 

 to let blood by the native women, who scarify the skin with a razor, and then burn a 

 piece of cotton within the gourd till the air is sufficiently rarefied, when the light is 

 withdrawn and the vegetable cup applied. When it is further remembered that the 

 ancient cupping vessels were of very various shapes and sizes, and that the terms 

 under notice were applied to the horn-cone as well as to the bronze egg-shaped cyathus, 



