Miscellaneous Intelligence. 195 



modeled in principle after the Welsbach goniometer lamp of 

 Goldschmidt (Zeitschr. Kryst. xxiii, 149-151, 1894), and consists 

 essentially of a tee with side outlet (tig. 1, A, l*5-in. diameter) with 

 iron pipe fittings, B and C, of proper length, together with a 

 base plate, D. This device fits over the acetylene burner L, and 

 can be removed at any time and the aeetylene burner used for 

 other purposes. The mirror, F, serves to reflect the light from 

 the burner to the verniers of the goniometer, and, like the Gold- 

 schmidt lamp mirror, furnishes all light requisite for goniometric 

 work. By means of the brass shield plate at E, the side outlet of 

 A can be opened and closed at will, and with it the light from 

 the burner to the mirror. The materials of which this lamp is 

 made are all on the market and can be readily procured from any 

 pipe-fitting establishment and assembled at moderate cost by a 

 mechanic. The acetylene burner is of the usual one-half foot 

 type and the generator No. 102 of the firm of J. B. Colt, New 

 York. 



2. A Containing Device for Salts Used as /Sources for Mono- 

 chromatic Light ; by Fred. Eugene Wright. (Communicated 

 from the Geophysical Laboratory.) — For many years sodium, 

 lithium and thallium compounds have been employed to produce 

 fairly monochromatic light, — yellow, red and green respectively — 





Fig. 1. 





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and a number of different devices for holding such salts in the 

 Bunsen flame have been suggested which answer the purpose 

 more or less satisfactorily. The following simple arrangement 

 (fig. 1), which is apparently novel, has been found useful and 

 effective by the writer in this connection and merits a brief word 

 of description. The salt is placed in a small thin-walled platinum 

 crucible about 1-5 to 2 cm long and 10 mm in diameter (P of fig. 1) ; 

 a bundle of fine platinum wires (fig. 1, D, 4-5 cm in length serves 

 as a wick and is held in proper place by pinching together one 

 side of the platinum crucible, as indicated in the figure. The 

 crucible is supported by a thick platinum wire L, which in turn 

 is attached to the tube B of the Bunsen burner by the clamp A. 

 The platinum crucible is purposely inclined at an angle as indi- 

 cated in the figure, in order that its side may be reached by the 

 flame and heated so hot that the salt it contains melts and is 

 gradually fed into the flame by the wick of platinum wires. A 

 single charge of sodium carbonate thus introduced has-been 



