388 Proceedings of Learned Societies. 



impurity. The conditions under which the new gas was formed 

 still remained obscure, although Wbhler had done much to clear 

 them up : quite lately, however, Dr. Martius had discovered a way 

 of making silicuretted hydrogen in abundance. A mixture is made of 



80 parts of chloride of magnesium. 



20 parts of chlorides of potassium and sodium mixed in equi- 

 valents. 



40 parts of sodium. 



70 parts of silicofluoride of potassium. 

 The various salts, perfectly dry, are first intimately mixed together 

 and then introduced into a wide-mouthed bottle ; the sodium, cut 

 into pieces the size of a small pea, is then added, and the whole 

 contents of the bottle well agitated. A tall Hessian crucible having 

 been heated to bright redness, the mixture is suddenly projected 

 into it, and the cover placed upon the crucible. When the mass is 

 fused the crucible is withdrawn from the furnace, broken, and the 

 slag removed. This slag serves, by reason of the silicide of mag- 

 nesium which it contains, for the preparation of the desired gas. It 

 is necessary to break up the slag into fragments, and act upon them 

 under water with strong hydrochloric acid. The gas, the com- 

 position of which seems to be Si,, H4, is at once liberated, and 

 may be collected over water or mercury. If a bubble of the gas be 

 allowed to escape into the air, it bursts into flame with explosive 

 violence, a white, hollow, cylindrical ring of smoke ascends, rotating, 

 •undulating, and widening as it goes up, and distributing, when it 

 breaks, a multitude of fine flakes of dry silica. All the appearances 

 noticed remind the spectator forcibly of the phosphuretted hydrogen, 

 but there is no offensive smell produced. When the gas is left long 

 in contact with water, the curious hydrated oxide is formed, to 

 which we have already alluded. This substance is white, and when 

 dried and heated in a tube, scintillates just like the analogous sub- 

 stance obtained by the oxidation of graphite. This oxide of silicon 

 has the formula Si 2 H, 0.. 



EOYAL SOCIETY, November 20. 



On the Fossil Bird from Solenhofen. — Professor Owen read 

 an elaborate paper descriptive of the remarkable fossil bird, from the 

 lithographic stone of Solenhofen, which is described in the article 

 by Mr. Woodward. In the discussion that ensued, the Duke of 

 Argyle and Mr. Gould expressed their belief, founded on the small 

 size and peculiar character of the quill feathers of the wings, that 

 the bird could not have possessed the power of flight. Professor 

 Owen thought that the size of the furcula, or merry-thought, and 

 the development of the ridges on the humerus, which served for 

 the attachment of the pectoral muscles, proved the bird to have 

 been capable of flight. 



