92 report — 1859. 



it is difficult to believe that sikua and cucurbitula refer chiefly to the form of the 

 ancient cupping instrument. It seems more probable that the words in question are 

 memorials of the fact that a hollow gourd was itself the earliest flame-cup employed 

 by primitive races, from whom the civilized nations of antiquity inherited the name and 

 practice. The curious fact may be added, that both the African negroes and the 

 South American Indians are in the occasional habit of employing the neck of a bottle 

 gourd, or the body of a small oval one, with a wide aperture below and a narrow 

 one above, as a suction-tube, just as nations in possession of cattle use the suction- 

 horn. If this practice prevailed in ancient times and in classical regions, then the 

 words siJcua and cucurbitula were equally applicable to a suction-horn and a flame- 

 cup, and the shape of either goes for almost nothing. 



This, however, is an episode ; the only point of special interest to the present question 

 is the antiquity of the flame-cup, and of this there is no doubt. It was so well known 

 to the Greeks of all ranks, that Aristophanes refers to it in one of his plays, using the 

 term nvadoi (cyathoi), or cups. Cupping must have been as familiar to his audience 

 as leeching to modern play-goers, and the word cup excludes the idea of a suction 

 instrument. In round numbers we may date this allusion 500 b.c, and the practice 

 alluded to was then a very ancient one. It is impossible, however, to identify a cup 

 used for blood-letting, in the way we can identify so unique an instrument as a cupping 

 horn. Among the vessels found in Pharaonic Egyptian tombs, and in the ruins of 

 ancient cities, are many resembling cupping vessels, and some of which may have been 

 such. However, that learned archaeologist, Mr. Birch of the British Museum, could 

 not refer the author to any evidence derived from instruments, inscriptions, or draw- 

 ings illustrating the use of the flame-cup among theancient Egyptians or other civil- 

 ized nations of antiquity. It is enough nevertheless to know that for centuries before 

 Hippocrates, Socrates, and Aristophanes flourished, a method of applying heat to 

 produce a vacuum in a vessel previously full of air, was widely known and practised 

 in the ancient world, and that it now prevails among barbaric nations, who can give 

 no account of its origin. 



Between this flame-cup and the steam-vacuum it is impossible not to see a close 

 analogy. In both we rarefy an elastic fluid by heat, and then condense it by cold ; 

 the great difference being that in the one case we employ a gas which cannot be 

 liquefied, and in the other a vapour easily condensable into a liquid. In the cupping 

 vessel, however, we have always liquefiable water-vapour and carbonic acid produced, 

 and from the steam-vacuum we cannot exclude incondensable air. There is thus 

 rather a difference in degree than in kind between the two instruments. Nevertheless 

 historically the one is not the other grown perfect, or the descendant of the other. 

 Just as the barometer comes between the suction-horn and the air-pump, and interprets 

 the former into the latter, so the thermometer comes after the flame-cup and translates 

 it into the steam-vacuum. 



We find a barren interval till we reach the 16th century, and the progress in ap- 

 plying a thermic vacuum to the production of motion through the steam-engine is 

 exceedingly slow, till the thermometer has been graduated andrendered a trustworthy 

 measurer of the intensity and quantity of heat. The discovery of the laws of latent 

 heat, and of much else, soon leads to the construction of the condensing steam-engine, 

 and by and by to that of the vacuum-pan and vacuum-still. Neither of them recalls 

 its prototype the flame-cup, yet the crashing in of the sides of a collapsing boiler is 

 but a repetition on a large scale of the phenomenon exhibited by the sucking in of the 

 skin by a cupping glass as it cools. 



The cupping instrument is thus in a twofold way the precursor of the modern 

 vacuum-producer : as the cupping horn, it leads through the barometer to the air- 

 pump; as the cupping gourd, it leads through the thermometer to the vacuum-still. 

 The beginnings of both instruments are lost in prehistoric times, and in the present 

 state of our knowledge we are safest to regard them as equally ancient. 



The chemical vacuum produced by filling a vessel with a gas which can afterwards 

 be reduced to a solid form by chemical combination with another substance, is one of 

 the most perfect attainable vacua, but its consideration is postponed till a future op- 

 portunity. 



