Prince Rupert’s Drop

Prince Rupert's Drops. Lacrymæ Vitreæ

It is more than probable that these drops, and the singular property which they possess, have been known at the glass-houses since time immemorial. All glass, when suddenly cooled, becomes brittle, and breaks on the least scratch. On this account, as far back as the history of the art can be traced, a cooling furnace was always constructed close to the fusing furnace. A drop of fused glass falling into water 573  might easily have given rise to the invention of these drops; at any rate this might have been the case in rubbing off what is called the navel 574. It is however certain that they were not known to experimental philosophers till the middle of the seventeenth century. Their withstanding great force applied at the thick end, and even blows; and on the other hand, bursting into the finest dust when the smallest fragment is broken off from the thin end, are properties so peculiar that they must excite the curiosity of philosophers, and induce them to examine these effects, especially at a time when mankind in general exert themselves with the greatest zeal to become better acquainted with the phænomena of natural bodies. On this account they have been noticed in almost every introduction to experimental philosophy. To determine the time then in which they were first made known, seems to be attended with little difficulty; but it still remains doubtful by whom and in what country.

It appears certain that the first experiments were made by philosophers with these drops in the year 1656.Monconys 575 , who travelled at that period, was present when such experiments were made at Paris, before a learned society, which assembled at the house of Mommor, the well-known patron of Gassendi; and the same year he saw similar experiments made by several scientific persons at London. He tells us expressly that Chanut, the Swedish resident, procured glass drops for the first Parisian experiments, and that these drops were brought from Holland.

It appears, therefore, that the first glass drops were made in Holland; yet Montanari, who was professor of mathematics at Bologna, says that the first were not made by the Dutch, but by the Swedes. The grounds, however, on which he rests his assertion are exceedingly weak. Because a Swedish resident procured those used for the first experiments, it does not follow that they were made at Swedish glass-houses, especially as it is positively said that they were brought from Holland. It was indeed stated so early as 1661, by Henry Regius or Van Roy, professor at Utrecht, that these glass drops came from Sweden; but may not this have been a lapse of memory, occasioned by the circumstance that the first drops used by the natural philosophers of Paris were procured by a Swedish resident.

Monconys, whose relation indeed bears evident marks of great haste as well as credulity, calls Chanut Résident de Suède, and seems to have considered him as a Swedish resident at the French court; an opinion in which he has been followed by many literary men. But Pierre Chanut was French resident at Stockholm, and at that time so well-known that Monconys could hardly be unacquainted with his quality. He was resident from the year 1645 to 1649; and he was afterwards envoy for adjusting the disputes between Sweden and Poland, which were to be settled at Lubec. He is often mentioned in Puffendorf's book De Rebus Suecicis, and the printed account of his missions and negociations contain important materials towards a history of queen Christina, with whom he was a great favourite. He superintended the funeral of Descartes, who was interred with great honour. He was born in 1601; but with the time of his death I am unacquainted. He was celebrated as a man of great learning, and particularly an able mathematician; and it is neither improbable nor even impossible that he may have sent the first glass drops to Paris from Sweden; but why does Monconys add that they were brought from Holland?

It deserves to be mentioned, that about fifteen years before, that is in 1641, the first glass-houses were established in Sweden, and in all probability by Germans. It is possible that when the blowing of glass was first seen, glass drops may have excited an attention which they had not met with in Germany, where no one expected anything new in glass-houses, which were there common and had long been established. It can nevertheless be proved that they were known to our glass-blowers at a much earlier period.

In 1695, John Christian Schulenburg, subrector of the cathedral school of Bremen, published there a German Dissertation on glass drops and their properties, in which he says that he was informed by glass-makers worthy of credit, that these drops had been made more than seventy years before at the Mecklenburg glass-houses, that is to say, about the year 1625.

Samuel Reyher, professor at Kiel, says that Henry Sievers, teacher of mathematics in the gymnasium of Hamburg, had assured him that such glass drops were given to his father by a glass-maker so early as the year 1637; and that his father had exhibited them in a company of friends, who were much astonished at their effects. Reyher adds, that he himself had seen at Leyden, in 1656, the first of these glass drops, which had been made at Amsterdam, where he afterwards purchased some of the same kind; but in 1666 he procured for a very small sum a great many of them from the glass-houses in the neighbourhood of Kiel. It is worthy of remark, that Huet 576 , who paid considerable attention to the history of inventions, says that the first glass drops, which he had seen also in the society held at the house of Mommor, were brought to France from Germany. According to Anthony Le Grand they came from Prussia 577.

The first glass drops were brought to England by the well-known Prince Rupert, third son of the elector Palatine, Frederic V., and the princess Elizabeth, daughter of James I.; and experiments, described by Rupert Moray, were made with them in 1661 by command of his majesty. This is expressly stated by Merret 578 ; and therefore what some English writers have supposed, that Prince Rupert himself was the inventor, is entirely erroneous 579. The services which he rendered to the useful arts were too great and too numerous to be either lessened or increased by such trifles.

I shall take this opportunity of remarking, that those small glasses hermetically sealed and containing a drop of water, which when placed on hot coals burst with a loud report, and therefore are called in German knallgläser, fulminating glasses, were known before 1665. Hooke speaks of them in his Micrographia 580  printed in that year, and they were mentioned by Reyher in 1669, in his Dissertation already quoted. In Germany they are made chiefly by Nuremberg artists; one of the most celebrated of whom was Michael Sigismund Hack. He learnt the art of glass-blowing in England, and in 1672 returned to Nuremberg, where he was born in 1643 581.


573  It is not always necessary that the water should be cold; these drops will be formed also in warm water, as well as in every other fluid, and even in melted wax. See Redi's experiments in Miscellan. Naturæ Curios. anni secundi, 1671, p. 426. They succeed best with green glass, yet I have in my possession some of white glass, which in friability are not inferior to those of green.

574  The navel, in German nabel, is that piece of glass which remains adhering to the pipe when any article has been blown, and which the workman must rub off. These navels, however, are seldom in so fluid a state as to form drops.

575  Journal des Voyages de M. Monconys, Lyon, 1666, 4to, ii. p. 162.

576  Commentarius de rebus ad eum pertinentibus, Lips. 1719.

577  Historia Naturalis. Edit. secunda, Londini 1680, 4to, p. 37.

578  In his Observations on Neri Ars Vitraria, Amstel. 1668, 12mo.

579  This is said, for example, by Grainger in his Biographical History of England. London, 1769, vol. ii. part 2, p. 407.

580  This book was only once printed, but the title-page has the date 1667. See Biographia Britannica, iv. p. 2654.

581  Doppelmayer, p. 276.