parts were made of gum elastic. The figure was made to say with 

 a peculiar intonation, but surprising distinctness, " Mr. Pat-ter-son, I 

 am glad to see you." It sang " God save Victoria," and " Hail, Co- 

 lumbia," the words and air combined. Dr. Patterson had deter- 

 mined to visit the maker of the machine, Mr. Faber, in private, in 

 order to obtain farther interesting information; but on the following 

 day Dr. P. was distressed to learn, that in a fit of excitement he had 

 destroyed every particle of a figure which had taken him seventeen 

 years to construct. 



Professor Henry made a second communication on the sub- 

 ject of cohesion. 



He had prosecuted his experiments on the soap bubble to a greater 

 extent, and had arrived at a number of results which appeared to him 

 of some interest in reference to capillarity, a subject which had given 

 rise to a greater diversity of opinion than any other part of natural 

 philosophy. As an evidence of its present unsettled state, he men- 

 tioned the fact, that the last edition of the Encyclopaedia Britannica 

 contained two articles on this subject, under different names; one by 

 Dr. Young, and the other by Mr. Ivory, which explain the phenome- 

 na on entirely different physical principles. 



According to the theory of Young and Poisson, many of the phe- 

 nomena of liquid cohesion, and all those of capillarity, are due to a 

 contractile force existing at the free surface of the liquid, and which 

 tends in all cases to urge the liquid in the direction of the radius of 

 curvature towards the centre, with a force inversely as this radius. 

 According to this theory the spherical form of a dew-drop is not the 

 effect of the attraction of each molecule of the water on every other, 

 as in the action of gravitation in producing the globular form of the 

 planets, (since the attraction of cohesion only extends to an unappre- 

 ciable distance) but it is due to the contractile force which tends con- 

 stantly to enclose the given quantity of water within the smallest sur- 

 face, namely, that of a sphere. Professor H. finds a contractile force 

 perfectly similar to that assumed by this theory in the surface of the 

 soap bubble; indeed, the bubble may be considered a drop of water 

 with the internal liquid removed, and its place supplied by air. The 

 spherical force in the two cases is produced by the operation of the 

 same cause. The contractile force in the surface of the bubble is 

 easily shown by blowing a large bubble on the end of a wide tube, 

 say an inch in diameter; as soon as the mouth is removed, the bubble 

 will be seen to diminish rapidly, and at the same time quite a forcible 



