86 THE POPULAR SCIENCE MONTHLY. 



that is, produces a shining flame. Pliny says, still more decid- 

 edly, that the Falernian wine, the product of the Faustian field, is 

 the only wine that can be ignited " on contact with a flame " ; a 

 thing that happens with some wines very rich in alcohol. These 

 are common phenomena, accidental observations made in the 

 course of sacrifices and festivals which served as the beginning of 

 the discovery. But there had to be many intermediate steps. 

 Among them was this experiment, an amusing trick in physics, 

 doubtless devised by some prestidigitator, which is explained in 

 a Latin manuscript in the Royal Library of Munich : " Wine can 

 be burned in a pot, as follows : Put white or red wine in a pot, 

 the top of the pot being raised and having a cover with a hole in 

 the middle. Having heated the wine till it begins to boil and the 

 vapor comes out through the hole, put a light to it. The vapor 

 will at once take fire and the flame will last as long as it comes 

 out." But alcohol was not isolated by the ancients. 



Distillation, or a method of separating the inflammable prin- 

 ciple from wine, had to be discovered before a further knowledge 

 of alcohol could be gained. This process passed through several 

 stages. It also started from common observations. When water 

 is heated in a vessel, its vapor condenses on the walls of surround- 

 ing objects, and especially on the cover of the vessel ; this can be 

 observed by every one, in domestic economy, on the covers of soup 

 dishes, of kettles, and of tea and coffee pots. Aristotle mentions 

 the fact in his Meteorologica. " Vapor," he says, " condenses under 

 the form of water, if we take pains to collect it." He speaks in 

 another place of a less usual observation, which was probably 

 likewise accidental, and which has been extensively applied in 

 our own time. " Experiment has taught us that sea- water when 

 converted into vapor becomes potable, and the vaporized product, 

 when condensed, 110 longer resembles sea-water. . . . Wine and all 

 liquids, when vaporized, turn into water." It appeared, then, 

 according to Aristotle, as if evaporation changed the nature of 

 the vaporized liquids and reduced them all to an identical condi- 

 tion that of water. This change was conformable to the philo- 

 sophical ideas of the author, wine and sea-water being reduced to 

 the same condition of water, the principle of liquidity, which was 

 regarded by the ancient philosophers as one of the four funda- 

 mental elements of things. 



Aristotle's remarks on sea-water soon gave the suggestion of a 

 practical process mentioned by Alexander of Aphrodisias, one of 

 his earliest commentators, about the second or third century A. D. 

 According to that author, sea- water was heated in brass kettles, 

 and the water that condensed on the covers was collected for 

 drinking. This was the germ of the industry of the distillation of 

 sea-water, which is practiced now on a large scale on board of ves- 



