Johann Beckmann - A History of Inventions, Discoveries, and Origins, Volume II (of 2)

In the Mineralogy of Aldrovandi, first printed in 1648, this process is described after Villafranca; but where the editor, Bartholomæus Ambrosianus, speaks of common salt, he relates that it was usual in countries where fresh water was scarce to make deep pits in the earth; to throw rock-salt into them; and to place in them vessels filled with water, in order that it might be cooled. This remark proves that the latter salt was then employed for the same purpose; but it has led the editor into a very gross error. He thinks he can conclude from it, that the intention of potters, when they mix common salt with their clay, is not only to render the vessel more compact, but also to make it more cooling for liquors. But the former only is true. The addition of salt produces in clay, otherwise difficult to be fused, the faintest commencement of vitrification; a cohesion by which the vessel becomes so solid that it can contain fluids, even when unglazed; but for this very reason it would be most improper for cooling, which is promoted by the evaporation of the water that oozes through.

The Jesuit Cabeus, who wrote a voluminous commentary on the Meteorologica of Aristotle, which were printed at Rome in 1646, assures us that with thirty-five pounds of saltpetre one can not only cool a hundred pounds of water, by quickly stirring it, but convert it also into solid ice; and for the truth of this assertion he refers to an experiment which he made. Bartholin says that for the above account he can give him full credit 402 402 De Nive, p. 38. ; but the truth of it is denied by Duhamel, who suspects that this Jesuit took the shooting crystals of the salt to be ice 403 403 J. B. Du Hamel, Opera Philosophica, Norimb. 1681, 4to. .

Who first conceived the idea of mixing snow or ice with saltpetre and other salts, which increases the cold so much, that a vessel filled with water, placed in that mixture, is congealed into a solid mass of ice that may be used on the table, I cannot with certainty determine; but I shall mention the earliest account of it that I have been able to find. Latinus Tancredus, a physician and professor at Naples, whose book De Fame et Siti was published in 1607, speaks of this experiment; and assures us that the cold was so much strengthened by saltpetre, that a glass filled with water, when quickly moved in the above mixture, became solid ice 404 404 L. Tancredi de Fame et Siti libri tres. Ven. 1607, 4to, lib. iii. .

In the year 1626, the well-known commentary on the works of Avicenna, by Sanct. Sanctorius, was published at Venice. The author in this work relates, that in the presence of many spectators, he had converted wine into ice, not by a mixture of snow and saltpetre, but of snow and common salt 405 405 When snow or ice is mixed with salt, both begin to be liquid. This process is employed in Russia to clean windows covered with frost. They are rubbed with a sponge dipped in salt, and by these means they become immediately transparent. [The rationale of this appears to consist in the salt absorbing water and deliquescing, and in this fluid the snow subsequently dissolves, the mixture requiring a much lower temperature for its assuming the solid state.] . When the salt was equal to a third part of the snow, the cold was three times as strong as when snow was used alone.

Lord Bacon, who died in 1626, says that a new method had been found out of bringing snow and ice to such a degree of cold, by means of saltpetre, as to make water freeze. This, he tells us, can be done also with common salt; by which it is probable he meant unpurified rock-salt; and, he adds, that in warm countries, where snow was not to be found, people made ice with saltpetre alone; but that he himself had never tried the experiment 406 406 Historia Vitæ et Mortis, § 44. – De Augmentis Scient. v. 2. – Silva Silvarum, cent. i. . Boyle, who died in 1691, made experiments with various kinds of salts; and he describes how, by means of salt, a piece of ice may be frozen to another solid body 407 407 History of Cold, title i. 17; title v. 3; title xv. 7. [The method of making one or two freezing or cooling mixtures will not perhaps be without interest here. Where snow is not at hand, a mixture of 5 parts of powdered nitre and 5 of powdered sal-ammoniac may be mixed with 16 parts of water. This reduces the thermometer from +50° to about +10° F., or, 9 parts of phosphate of soda, 6 of nitrate of ammonia, and 4 of dilute nitric acid, reduce the thermometer from +50° to -21°; 5 parts of common salt, 5 of nitrate of ammonia and 12 of snow, reduce it from the ordinary temperature to -28°. The most intense degree of cold, probably known, has been produced by Dr. Faraday in his experiments upon the liquefaction of gases. This was effected by placing solid carbonic acid mixed with æther, under the air-pump, and exhausting.] . Descartes says that in his time this was a well-known phænomenon, but highly worthy of attention 408 408 Des Cartes Specimina Philosophiæ. Amst. 1650, 4to, p. 216. .

Since that period the art of making ice has been spoken of in the writings of all philosophers where they treated on heat and cold, and with many other experiments has been introduced into various books of receipts. It was then employed merely for amusement 409 409 Von Hohberg says, in his Adliches Landleben, “The following, which serves more for amusement than use, is well-known to children. If one put snow and saltpetre into a jug, and place it on a table, over which water has been poured, and stir the snow and salt well round in the jug with a stick, the jug will be soon frozen to the table.” This baron, therefore, who, after he had sold his property in Austria on account of the persecution against the Protestants, wrote at Regensburg (Ratisbon), where he died in 1688, at the age of seventy-six, was not acquainted with iced delicacies. Had they been known to him, he would have certainly mentioned them where, in his Book of Cookery, he gives ample directions for laying out a table of the first rank. ; and no one suspected that it would ever form an important item of luxury. In the like manner Fugger’s first bills of exchange were said to be useful only for gambling, and gunpowder was called a trifling discovery.

In the beginning of the seventeenth century, drinking-cups made of ice and iced fruit were first brought to the table; but towards the end of that century it appears that the French began to congeal in this manner all kinds of well-tasted juices, which were served up as refreshments at the tables of the great and wealthy 410 410 [The application of ice to the purposes of confectionary, has, within the last few years, become much more extensive; encouraged, no doubt, by the facility with which it is now procurable at all seasons of the year, and in any quantity. Imitations of peaches, nectarines, apricots, and other fruits, are now produced in ice paste in such perfection, as at first sight to deceive the most practised eye; and such elegances are no longer confined to the tables of the wealthy.] . This was a grand invention for the art of cookery; which became common among the German cooks, both male and female, about the middle of the last century; and since that time our confectioners sell single glasses of iced articles at balls and in the theatres.

I am acquainted with no older information respecting this invention than what is contained in Barclay’s Argenis, which is, indeed, a romance; but the author’s account makes the possibility of its being used so clear, that we may certainly conclude it was then employed; especially as he mentions it several times. Arsidas finds in the middle of summer, at the table of Juba, fresh apples, one-half of which was encrusted with transparent ice. A basin, made also of ice and filled with wine, was handed to him; and he was informed that to prepare all these things in summer was a new art. Snow was preserved throughout the whole year in pits lined with straw. Two cups made of copper were placed the one within the other, so as to leave a small space between them, which was filled with water; the cups were then put into a pail, amidst a mixture of snow and unpurified salt coarsely pounded, and the water in three hours was converted into a cup of solid ice, as well-formed as if it had come from the hands of a pewterer. In the like manner apples just pulled from the tree were covered with a coat of ice.