320 Proceedings of Learned Societies. 



and great permanency. Dr. Frankland stated that he had succeeded, 

 by means of a blowpipe bellows, in obtaining a bubble nearly nine- 

 teen inches in diameter. When inflated with air these bubbles 

 often last more than twenty-four hours ; but, when the breath is 

 employed, the oleate of soda is slowly acted on by the carbonic 

 acid expired, and their duration is limited to three or four hours. 



A series of these bubbles, about six inches in diameter, were 

 placed on a number of glass rings situated in a line, and on a ray of 

 light from the electric lamp being transmitted through the series, 

 their beautiful irridescent colours were developed in the most magni- 

 cent manner. 



Other bubbles were inflated with a mixture of eight parts of 

 air and one part of coal gas, which, by overcoming the specific 

 gravity of the film, enabled the bubbles to float in the atmosphere 

 so as to be wafted by the slightest current. The tenacity of the 

 film was shown by allowing drops of water to fall through the bub- 

 bles which could be accomplished without breaking them. 



By dipping small wire cages forming the outlines of geometrical 

 solids, into the mixture of oleate of soda and glycerine, plane 

 films were produced intersecting each other in various directions 

 in the interior of the wire frames. Many of these offered very 

 remarkable geometrical combinations ; the wire outline of a tetra- 

 hedron, for example, on being withdrawn from the solution, was 

 shown to contain six triangular films, all meeting at the centre of 

 the figure. 



The films, formed in the cages which represented the outlines 

 of short rectangular prisms, were in several cases bounded by 

 curved lines, the mathematical properties of which have been closely 

 investigated by M. Plateau. 



SOCIETY OF ARTS.— April 2. 



Oxidized Oil as Substitute for the Elastic Gums. — Mr. F. 

 Walton described the manufacture of a new substitute for gutta 

 percha and india-rubber, consisting of oil oxidized by exposure to 

 the air in thin films, and subsequently either dissolved in a volatile 

 solvent, or worked up in a solid form. By these means an elastic 

 solid is obtained, possessing in a great degree the properties of 

 rubber in its various conditions, and applicable to similar purposes. 



LINNEAN SOCIETY.— April 3. 



On the Fertilization op Certain Orchids. — Mr. C. Darn in 

 described some remarkable peculiarities existing in certain orchids, 

 specimens of which were in the possession of the Linnean Society. 

 In the plants belonging to the genus Catasetum, it not unfrequently 

 happens that two, and sometimes three, supposed distinct genera 

 exist on the same spike. Thus the Catasetum tridentatum is inter- 

 mixed with the flowers of the Monocanthus viridis and those of the 

 Myanihus harbatus. 



