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FLAME-HEAT IN THE CHEMICAL LABORATORY. 



The principle, however, of the above burner is introduced in 

 constructing a more simple form, and the flattened orifice is 

 now used in the construction of what I conceive to be the best 

 form of furnace for heating glass tubes for organic analyses and 

 other purposes. Such furnaces are made by Weisnig, of Paris, 

 and Desaga, of Heidelberg. 



The use of the flattened burner is not fully appreciated ; its 

 advantages are, that there is no cold point in the flame, and the 

 burner can be brought much nearer to the object to be heated — 

 within twenty to twenty -five millimetres for the small-sized 

 burners. In this burner, as usually made, the opening is too 

 broad, experience having convinced me that a slit two milli- 

 metres across and about forty millimetres in length is the most 

 effective one for a small-size burner, consuming about five and 

 a half cubic feet per hour. This burner is repre- 

 sented in fig. 2, which can be used with the ordi- 

 nary tube by detaching the tube with the flattened 

 orifice. 



By taking a burner of this description and 

 putting two pieces on each side of the center, as 

 represented in fig. 3, a very efficient burner is 

 made for heating platinum crucibles in silica 

 fusions, etc., and with such a burner, consuming 

 five and a half to six cubic feet of gas per hour, 

 Fi s- 2 - I conduct most effectually all silica fusions in 



one hour or less, taking care to protect the 

 crucible from the current of the air by a 

 properly-constructed short conical chimney. 

 As was stated in the commencement of 

 this article, it was not intended to describe 

 the methods of burning gas in furnaces and 

 by means of a blast, but to confine the re- 

 marks to the simpler forms in every-day 

 use, which can be made to accomplish all 

 the ordinary requirements of the laboratory, 

 and when a higher heat is required the 

 furnace must be our recourse, whether burning gas, charcoal, 

 or coke. The burner represented in figure 2 is the one I now 

 employ in heating the crucible in my method of alkali determi- 

 nation with carbonate of lime and sal ammoniac. 



Fig. 3. 



