SOS Experhnenls with the Oxi-hydrogen Blow-pipe, 



EXPERIMENTS WITH THE OXI-HYDROGEN BLOW-PIPE. 



A letter just received from our valued correspondent M. Van 

 Mons of Brussels communicates the following information : 



" The Marquis Ridolphi of Florence has reduced earths with 

 much ease by means of the gaseous mixture of Clarke. Brugna- 

 telli had already made use of the same contrivance. He writes 

 nie, that he has constructed for this purpose a small apparatus, 

 very simple, which is composed of two bladders, the one filled 

 with phlogogene gas and the other with therm-oxygen. The 

 tube which conducts the latter gas is of a diameter the double 

 of that which conducts the former ; and the bladders are com- 

 pressed by a bar of iron. The effect is prodigious. 



" M. Ridolphi has not only procured the metals from earths, but 

 he has combined them to platinum and gold. These combina- 

 tions are always white, have a metallic brilliancy, and are mallea- 

 ble. Being introduced into oxygenated muriatic gas or into 

 oxygen gas, they enter immediately into a state of combustion, 

 and form in the first case muriates, and in the second case re- 

 generations of the earth, oxidations taking place at the same 

 time of the metal in union. One circumstance very remarkable 

 is, that during that oxidation it always forms itself with water, 

 the drops of which condense upon the sides of the recipient ; and 

 this has constantly happened in spite of every care being taken 

 to dry completely not only the apparatus but the mixture. : 



'* The metals of earths thrown into nitric acid or oxygenated 

 muriatic acid dissolve quickly, occasioning a hissing noise simi- 

 lar to that of a hot iron plunged into water. 



*' The oxides of cobalt, of platinum, and of gold, are reduced 

 in an instant under the flame of the gaseous mixture; but after 

 tlieir reduction they inflame and are oxidized anew. 



" The metals of earths decompose, in oxidizing, carbonic acid 

 gas and water, but more slowly than the metals of alkalies. 



" Of all the metals of earths, zircon is that which allies itself 

 in the greatest proportion with platinum and gold. 



" Alumine, silex, lime, and the carbonates of lime and of 

 barytes, have been fused, but in no experiment have they yet been 

 metallized or reduced. 



" Strontian and magnesia are reduced easily, provided they 

 are formed into paste with charcoal and oil, the paste being di- 

 vided into pills and left to harden by heat. Without this pre- 

 paration these earths do not fuse equally, but are fused and vitri- 

 fied. 



*' Zircon alone deoxidizes without the aid of reducing media, 

 and in less than fifteen minutes it appears in a metallic form. 



'^ In these reductions the greatest effect is obtained, when in- 

 stead of simple hydrogen gas, sub-carbonated hydrogen gas is em- 

 ployed 



