Intelligence and Miscellaneous Articles. 231 



Properly to treat this subject, and to bring Thomson's investiga- 

 tions into connection with the older ones, we must no longer adopt 

 the ordinary mechanical treatment, but must have recourse to 

 general thermodynamical methods. The considerations arising 

 from this point of view form the contents of the present research. 



It is first of all shown, that for a system of bodies touching each 

 other we are not to seek the potential at a fixed temperature, but 

 the thermodynamical potential, which contains the changes of 

 energy for varying temperature. The only assumption made is 

 that the densities and the actions of the molecular forces of bodies 

 vary only in infinitely thin layers at the surfaces. 



It is seen that this supposition is sufficient to prove that the 

 thermodynamical potential consists of two parts, one of which is 

 a linear function of the content of the various bodies, the other a 

 linear function of the surface in contact. This easily furnishes a 

 proof of the admissibility of the older view. From the formulae 

 obtained, the laws of Grauss and Laplace for the shape of the sur- 

 faces are explicitly deduced ; the same formulae render it possible 

 to investigate the capillary changes which occur in thermal changes. 

 New results are thus not obtained, but the old ones are brought 

 into connection with each other. 



The general equations are then applied to the two special pro- 

 cesses of evaporation and super saturation. — Ann. Ecole Normale 

 [3] ii. p. 217 (1885) ; Beiblatter der Physik, vol. x. p. 330. 



of Peltier's phenomenon in liquids, 

 by e. naccari and a. battelli. 



Two glass cylinders, 16 centim. in width, were placed near each 

 other in a vessel of water, and a paper disk fastened in each half 

 way up. At the bottom of each cylinder was a copper disk 13 cen- 

 tim. in diameter, Solution of blue vitriol was poured in up to the 

 disk, and on this solution of zinc sulphate ; in each of these solu- 

 tions a zinc plate perforated in the centre was suspended. Both 

 zinc plates were connected by a copper wire and a current passed 

 through the apparatus, the intensity of which was determined by 

 a reflecting-galvanometer, one division of the scale of which repre- 

 sented an ampere. A very thin perforated glass plate was brought 

 in the centre of each of the paper disks. In this aperture was 

 accurately fitted the bulb of a thermometer, which was surrounded 

 by a caoutchouc tube as far as the part in the aperture. The cur- 

 rent of one or two Bunsen elements was sent through the apparatus 

 in either direction, and the course of the thermometer observed 

 every minute. If i and \ are the intensities of the current, y and y l 

 the corresponding thermal effects, the magnitude of the Peltier 

 phenomenon is given by the formula 



Only those experiments were taken into consideration in which i 

 and i x were not greatly different from each other. With the 



