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XXVII. Note on the Production of Coloured Flames of High 

 Luminosity for Demonstration and Experimental Purposes. 

 By G. A. Hemsalech, Honorary Research Fellow in the 

 University of Manchester * . 



THE observation recorded in the preceding paper, § 4 — 

 namely, that the admixture of oxygen to the gases 

 feeding an air-coal gas flame greatly intensifies the flame 

 lines — provides a ready and convenient means of obtaining 

 very luminous coloured flames with either the electric or 

 Gouy sprayer. A suitable apparatus embodying this 

 principle and constructed for the purpose of a lecture- 

 experiment is described hereafter. It is so arranged as to 

 permit the sprays from six different salt solutions to be 

 alternately passed into the flame without disturbing the 

 stability of the latter. 



The arrangement comprises six small electric sprayers, a 

 collector, and the burner. The sprayers, of which only one 

 is shown in the accompanying sketch, are simplified forms 

 of the type already described in a previous communication |. 

 They are built up of ordinary household tumblers, into the 

 open and wider ends of which are waxed wooden lids. 

 Through these pass the in- and outlet tubes for the air, and 

 two capillary tubes which carry the electrode wires of alu- 

 minium or iron. The positive electrode of each sprayer is 

 further insulated by a wider glass tube. The air which 

 is to carry the spray into the flame arrives through a long 

 brass tube AB fixed parallel to the row of sprayers. Short 

 branch tubes placed opposite each sprayer are connected 

 with the inlet tubes by means of pieces of rubber tubing- 

 provided with the pinch-cocks P 1 . . . P 6 . The outlet tubes of 

 the sprayers are connected to three pairs of glass tubes 

 fitted into the flat wooden base of the collector, which is 

 merely an inverted glass funnel. Between the collector and 

 burner is inserted a four-branch tube, allowing of the influx 

 of coal-gas and oxygen. The gas mixture then passes into 

 the mixing chamber of the burner, which consists of a J-in. 

 by 6 in. brass tube, and thence through one or more orifices 

 into the flame. These orifices, which are drilled into a brass 

 disk 6 millimetres thick, are not more than 2 millimetres in 

 diameter. One hole will generally be found sufficient, but 

 a longer and more brilliant flame is obtained with four holes 

 arranged in a square and placed close together. The positive 



* Communicated by Sir E. Rutherford, F.R.S. 

 Mag. vol. xxxiii. p. 3 (1917). 



