466 Royal Society: — « 



immediately to oxidize, throwing out excrescences of white 

 and yellow oxide. On removal from the flame it still con- 

 tinues in ignition, and pushes out further excrescences. The 

 unoxidized internal portion (if any remain) is malleable. 



28. Lead and Bismuth unite readily : the molten globule 

 acquires a thin dark coating of oxide on the surface only, and 

 admits of being flattened out, more or less, upon the anvil. 



29. Lead and Thallium form a malleable globule. 



30. Bismuth and Tin unite readily ; but the fused mass 

 immediately throws out excrescences, and becomes covered 

 with a dense crust of oxides. The reaction, however, is not 

 so striking as with lead and tin. 



31. Thallium and Tin exhibit the same reaction as lead and 

 tin ; but the cauliflower-like excrescences are brownish black. 



LYIII. Proceedings of Learned Societies, 



ROYAL SOCIETY. 



[Continued from p. 394.] 



April 6, 1876.— Dr. J. Dalton Hooker, C.B., President, in the 



Chair. 



JT^HE following paper was read : — 



•*- " Experiments on the Eriction between Water and Air." By 

 Br. Bitter von Lang. 



The method adopted for estimating the mutual friction of water 

 and air consisted in connecting a glass tube of 8 centims. length 

 and 0*72 internal diameter with the pipes which supply Vienna 

 with water at a pressure of four atmospheres. Arrangements 

 for securing a vertical position for the tube ensure a perfectly 

 continuous jet, devoid of any broken surface ; and a glass tube 

 surrounding this jet, with its axis coinciding with that of the jet, 

 acts as an aspirator, into and along which air is drawn through a 

 lateral feeding-tube. The amount of this indrawn air correspond- 

 ing to the fall of a given amount of water was determined by 

 observing the rate at which a film of soap was borne along the 

 feeding-tube ; and the velocity of the water causing the indraught 

 was calculated from the diameter of the water column and the 

 quantity of water discharged along it in a given time ; but after 

 having once determined the form of the slightly conical water 

 column, the amount of water discharged was the only datum re- 

 quired for the calculation. 



The influence of a greater or less section of the air- feeding- 

 tube on the volume of the aspirated air was carefully determined, 

 while also the absence of any appreciable retardation due to the 

 soap film was established. 



