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flame continues to burn as long as themixture is explosive. When the carbu-retted hydrogen is to the air as 1 to 12,the flame of the wick appears within theflame of the fire damp, when the propor-tion is as high as 1 to 7, the flame of thewick disappears.

“ When the thickest wires are used in thegauze it becomes strongly red hot, particu-larly at the top, but yet no explosion takesplace. The flame is brighter the larger theapertures of the gauze, and the cylinder of625 apertures to the square inch, gives abrilliant light in a mixture of 1 part ofgas from the distillation of coal and 7 partsof air. The lower part of the flame isgreen, the middle purple, and the upper partblue.

“ I have tried cylinders of 6400 aperturesto the square inch, in mixtures of oxygenand carburetted hydrogen, and even inmixtures of oxygen and hydrogen, andthough the wire became intensely red hot,yet explosions never took place; the com-bustion was entirely limited to the interiorof the lamp.

“ In all these experiments, there was a