128 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



but it expands in breadth at the same time, thus resembling 

 the so-called contraction of muscular fibre. 12 A, IX., 502. 



plateau's researches ox the phenomena of liquid 



FILMS. 



The great investigations of Professor Plateau, of Ghent, 

 both experimental and theoretical, on the statics of liquids 

 which are exposed only to molecular forces, and are freed from 

 the influence of gravity, have been recently published in two 

 volumes, with much new material. These investigations 

 have occupied Plateau's attention for over thirty years past, 

 and many of his results have become familiar to American 

 readers through the admirable translations published from 

 year to year in the annual reports of the Secretary of the 

 Smithsonian Institution. In the volumes before us, Plateau 

 begins with some preliminary and general notions, and pro- 

 ceeds to the verification of the more important principles of 

 the theory of capillary action. In the second chapter he in- 

 vestigates the questions relative to figures of equilibrium in 

 general; the simpler surfaces of revolution are passed over 

 somewhat cursorily, although with sufficient fullness; and 

 especial attention is paid to the new figures of revolution, 

 which he denominates the unduloid, catenoid, and nodiod, 

 which he has himself been so fortunate as to discover and very 

 successfully investigate. The research upon the superior limit 

 of the very small distance of sensible molecular attraction leads 

 him to the result that in the glyceric liquid which he employs 

 the radius of sensible attraction is less than the 0.0017 part of 

 a millimeter. The subject of the tension of the surface of a 

 liquid film is one of the most important matters in the inves- 

 tigations of Plateau, and has received from him, as it has in- 

 deed from very many investigators, the full attention that it 

 deserves. The theoretical investigations of Thomson, as well 

 as the experimental studies of Quincke, Dupre,Van der Mens- 

 brugghe, and many other observers, come in to supplement 

 his own exhaustive researches. The curious question of the 

 relations between the superficial viscoscity of a liquid and the 

 interior viscoscity is investigated, for pure water, for glycer- 

 ine, for alcohol, for sulphuric ether, and for several other typ- 

 ical chemical substances. Among the causes influencing the 

 duration of thin liquid films, Plateau enumerates: 



