FOOTNOTES
[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.