376 



Professor Sir James Dewar 



[Jan. 11 



chain of film-enclosed cells. From the outermost facets of these 

 there radiated a film structure of pyramidal frustums bounded 

 externally by curved bubble films. Two forms of these faceted 

 " cells " are shown in Fig. 17 ; some have the regularity of a well- 

 cut gem, and exhibit great brilliance in a concentrated light. Some 

 forms frequently occurring have («) parallel regular hexagons top 

 and bottom with pentagonal facets ; others have {b) irregular 

 heptagons at the top and bottom : the facets being then either 



Fig. 14. 



Fig. 15. 



pentagons alone or alternate hexagons and quadrilaterals, or even 

 all three together. An interesting example occurred when the 

 qiiadi'uple column Avith alternate diamond-shaped planes distri- 

 buted along the axis (Fig. 11) was disengaged from its nozzle and 

 allowed to fall on the surface of the soap solution 15 cm. below. 

 The cluster had already drained to complete blackness, and was 

 therefore so light that at first it rel)ounded several cms., finally 

 floating on the surface for some time, delicately poised like a nautilus. 



