564 
ARTICLE XXIV. 
On the Action of the Molecular Forces in producing Capillary 
Phenomena*. By Prof. Mossorti. 
1. THE application of the theory of the molecular forces to the 
explanation of the effects of what is called capillary attraction, 
constitutes one of the most delicate branches of physical mecha- 
nics. The capillary phenomena set forth in the first instance 
by Hauksbee before the Royal Society in London, were theo- 
retically discussed by the said Hauksbee+, by Newton], by 
Jurin§, by Vietbreckt ||, by Segner§], by Clairaut** and others. 
Dr. Young, one of the most sagacious minds that modern times 
have produced, was the first to give a correct theory of these 
phenomena, though incomplete in some of the fundamental 
principles}++. Dr. Young’s theory was thrown into the shade 
by the more brilliant but less accurate theory of Laplace, which 
appeared a short time after{}. Finally, Poisson, in his Nouvelle 
Théorie de ? Action Capillaire, has remedied the defects which 
still remained in Laplace’s theory, by deducing the explanation 
of the capillary phenomena from an accurate investigation of 
the action of the molecular forces that produce them. Poisson’s 
theory, however, is founded on very abstruse analysis, which 
cannot well be translated into language suited to the compre- 
hension of more common understandings. I hope therefore 
that I shall not be doing an unacceptable thing, if, starting with 
* Translated from the Italian, and communicated, at the Author’s request, 
by E. H. J. Craufurd, B.A., Trin. Coll., Cambridge. This Article is one of a 
course of lectures on Natural Philosophy delivered by Mr. Mossotti when 
Professor in the University of Corfu. It was published first in the Biblioteca 
Italiana, and afterwards reprinted in the Nuovi Annali delle Scienze Naturali, 
together with a Note by the same author on a Capillary Phenomenon observed 
by Dr. Young, which forms the subject of Article XXIV. of this Journal. 
t+ Hauksbee. Sperienze fisico-meccaniche. Firenze, 1721. 
t Newitonis Optices. Questio 31. 
§ Lecons de Physique Expérimentale par Cotes, p. 410 et suiv. 
|| Lentamen Theorie qua ascensus aque in tubulis capillaribus explicatur. 
Comm. Acad. Petrop. tom. viii. et ix. 
q Commentarii Soc. Reg. Scientiar. Gottingensis. Tom. i. 
** Théorie de la Figure de la Terre, p. 105, et suiv. 
++ Young. An essay on the Cohesion of Fluids. Phil. Trans. Dec. 20, 1804. 
tt Supplement au deuxiéme livre de la Mécanique Céleste, et Supplément a 
la Théorie de l’ Action Capillaire, vol. iv. 
