connected with the Boiling of Liquids. 433 



of the distinguished Genevese sufficiently comprehensive to in- 

 clude all the phenomena, while he may regard it as a merit in 

 himself to endeavour to confirm and support it. Nevertheless 

 I beg to remind him that when the theory was started in 1772 

 it met with no favour, nor when it was restated in 1786; but 

 when again brought forward in 1803 it was violently opposed in 

 the very journal* in which M. Gernez now advocates it. 

 Nor was it until M. Donny published in 1846, in the same 

 journal t, his remarkable researches that the theory rose at all 

 into favour ; but at that time, and even long after, the merit 

 was given to Donny and not to De Luc. The details given in 

 my "Historical Notes " established, I believe for the first time, 

 the claim of De Luc, and the identity of Donny's results with 

 his. 



It is remarkable that although De Luc published his theory 

 several times with very full experimental details, it attracted no 

 attention, although many researches were being made about the 

 same period, and the Committee of the Royal Society were con- 

 sidering their Report on Thermometers. De Luc was much in 

 England and on intimate terms with many of the Fellows of the 

 Royal Society, was admitted a Fellow himself in 1773, and as 

 Reader to Queen Charlotte resided at Windsor and published 

 several of his works, including the theory in question, in London. 

 And yet his theory attracted no attention, and researches on the 

 phenomena of boiling were made during upwards of half a 

 century entirely without reference to this theory. Thus in 

 1784-85 AchardJ studied the subject of boiling with reference 

 to the material of the vessel and the influence of solid substances 

 on the boiling-point. In 1812, and again in 1817, Gay-Lussac 

 worked in the same direction as Achard, and also attached im- 

 portance to the cohesion of the liquid, its adhesion to the sides 

 of the vessel, as well as to pressure in influencing the boiling- 

 point. In J 825 Bostock published his experiments on the boil- 

 ing of ether and the influence of solids thereon ; and still no 

 reference is made to De Luc. Bostock suggests that the pre- 

 sence of air may have something to do with the results, but he 

 has difficulty in explaining them on this ground. In 1835 Le 

 Grand published some experiments on boiling, and endeavoured 

 to show that the process becomes difficult in proportion as the 

 air dissolved in the liquid is expelled. But I do not remember 

 that he makes any reference to De Luc, any more than Magnus, 

 who in 1836 recurred to the old idea of cohesion, or Schonbein, 



* Ann. de Chim. et de Phys. Ser. 1. vol. xlix. p. 235. 

 *t* Ibid. S. 3. vol. vi. p. 167. 



X The references to the authorities here briefly enumerated are given in 

 my " Historical Notes." 



Phil. Mac/. S. 4. Vol. 49. No. 327. June 1875. 2 H 



