C. GENERAL PHYSICS. 129 



The small agitations of air. 



The evaporation of the liquid. 



The temperature. 



The action of gravity. 



The combination of the films into more complicated systems. 



The size of the films: the smaller films last longer than the 

 large ones. 



The nature of the solid to which the film adheres. 



The historical portion of the second volume is not the least 

 interesting part of the book. Beginning with the knowledge 

 which has come down to us from the ancients, and giving a 

 full summary of the remarks of Boyle, Hooke, Newton, Gray, 

 and Leidenfrost, he takes up, in succession, the works of all 

 those who have followed these early explorers in this field, 

 giving what appears to be an absolutely exhaustive review 

 of all published knowledge on this subject. After consider- 

 ing, in an experimental way, the question of the stability of 

 the figures of equilibrium, and showing that the experiments 

 afford a complete verification of theoretical notions in this 

 respect, Plateau concludes his work with the application of 

 the properties that he has discovered to the theory of the 

 formation of drops, the explosion of bubbles, and the consti- 

 tution of liquid veins flowing from circular orifices. The his- 

 torical treatment of the matter in connection with the last- 

 named subject is equally as full as the previously given nar- 

 ration of the literature on the subject of thin films. Plateau 

 concludes with a list of the works of all authors accessible to 

 him published previous to December, 1873. It has become 

 the custom of late years for well-known scientists to collect 

 together, in convenient form for reference, the essays contrib- 

 uted by them to various scientific bodies throughout the 

 world, a custom that certainly has very much to commend it; 

 but Plateau has departed from custom in one point namely, 

 that, instead of giving us the separate essays as they were 

 originally published, he has revised the entire series, and has 

 in the present work followed a more methodical order, and 

 rectified numerous passages, filling up many gaps, especially 

 in historical matters. lie has even added two entirely new 

 investigations relative to the superficial viscosity of liquids 

 and the constitution of liquid veins. Statique des Ziquides, 

 Bruxelles, 1874. 



F 2 



