436 M. G. Vander Mensbrugghe on some curious Effects 



necessary to do so, since the pretty experiment of M. Melsens*, 

 in which bubbles of mercury are produced by employing, it is 

 true, a very different method, has long been known. 



When a large quantity of liquid is operated upon, it may 

 easily be made to take the form of a sheet with determinate cur- 

 vature. To do so, it is merely necessary to propel it by a force- 

 pump through tubes provided with suitable terminations. To 

 apply this method I had two such terminations constructed ; 

 the form of one was a semicylindrical canal, and that of the 

 other a semiconical one. The length of the canal was about 

 50 millimetres, and the section of efflux was the space enclosed 

 between two concentric semicircles whose radii were 20 and 

 17 millimetres respectively. I used both well-water and soap- 

 water. The semicylindrical termination gave, with well-water, 

 a multitude of bubbles, from 3 to 4 centimetres in diameter, 

 which burst after a trajectory of some metres ; and with soap- 

 water, a great number of hollow bubbles which floated in the air. 

 The semiconical termination produced, with ordinary water, a 

 sheet which gradually became broader and thinner until it 

 resolved itself into a shower of hollow bubbles which burst a few 

 instants after their formation; with soap-water innumerable 

 spherules were thus formed, of which a great number had very 

 thin envelopes. 



I also employed terminations narrower than 3 millimetres, 

 but they yielded results much less developed than were the pre- 

 ceding ones. 



On the whole, these experiments appeared to me to prove that 

 the majority of liquids, if not all, after being spread out in sheets 

 of proper breadth and thickness, may assume the form of hollow 

 spheres. 



2. Floating globules of mercury. — Attractions and repulsions 

 exhibited by these globules. 



For some time past physicists have been frequently occupied 

 with the examination of the globular form assumed by a liquid, 

 even at ordinary temperatures, at the surface of the same or of a 

 different liquid. The communication of an experiment which I 

 believe to be new, and which, whilst showing in a remarkable 

 manner the effects of the molecular actions of liquids, also fur- 

 nishes the means of proving capillary attractions and repulsions, 

 will therefore be here not out of place. I operated thus : 



A broad capsule being filled with distilled water, a globule of 



mercury, of about 0*5 of a millimetre in diameter, was taken on 



the blade of a knife and brought into proximity with the liquid, 



the blade being inclined as little as possible. The latter was 



* See L'Institut for 1845, p. 207. 



