﻿Phenomena connected with the Boiling of Liquids. 165 



until more air got into the fine tube, when it was opened and the 

 air expelled. After continuing these operations of shaking and 

 heating the tube in order to get rid of the air, the tube was 

 raised to 212° ; and the point being broken so as to reestablish 

 atmospheric pressure, the water was further heated to 234^° F. 

 without boiling*. 



8. Proceeding in the order of time, we come to Gay-Lussacf. 

 While engaged in his experiments on solubility, he seems to 

 have rediscovered the two facts respecting the influence of the 

 vessel on the boiling-point, and also of the effect of an insoluble 

 body in lowering the boiling-point. But it is remarkable that 

 in both his papers Gay-Lussac refers to Achard's results, or 

 rather to his faulty conclusions, with a view to contradict them, 

 without giving him credit for those points that were true. It is 

 quite possible that Achard's fame was more injured by his friends 

 than his opponents, since an attempt had been made by Gmelin 

 and others, in answer to Gay-Lussac^s paper of 1812, to show 

 that in a number of vessels of different material, all sunk to the 

 same depth in a sand-bath, water boiled at the same temperature J; 

 while in 1817 Muncke stated§ that copper-filings appeared to 

 have no influence in lowering the boiling-point, and that sand did 

 so only to the extent of one-tenth of a degree. Gay-Lussac in 1817 

 noticed these papers, and reasserted the original facts with even 

 more decision than he had done in 1812. But even in this his 

 first notice of the subject, his language is not to be mistaken. 

 His paper is on Deliquescence, and he says : — " In determining 

 the boiling-point of saline and acid liquids I observed a very 

 singular phenomenon which deserves to be known. Water or 

 any other liquid boils later in a glass vessel than in a metallic 

 one, except when we put into the former some turnings of iron, 

 copper, or other metal, or carbon in powder, or pounded glass. 

 The difference in the case of water may amount to 1'3° C. and 

 upwards." In 1817 he states || that water boils later in glass 

 and earthenware [faience) than in metal vessels. He does not 

 give the measure of the difference, but believes it to vary with the 

 nature of each body, and, with the same substance, according to 

 the nature of its surface : " car il est probable quelle depend a 



* De Luc also dropped water into oil heated to 82° or 90°, and even 100° R.; 

 but he was by no means satisfied that the water ever attained this tempe- 

 rature. He says : — " Ces gouttes d'eau, renfermees dans l'huile, pouvoient 

 etre dans un etat particulier " (see paragraph 9.93 of the Recherches). That 

 is, they were probably in what would now be called the " spheroidal state," 

 which De Luc understood and accurately describes in § 1007- 



t Annales de Chimie, vol. lxxxii. p. 171. 



% Schweigger's Journal, vol. xxvii. p. 27. 



§ Gilbert's Annalen, vol. lvii. p. 215. 



II Ann. de Chim. et de Phys. vol. vii. p. 307. 



