A brief history of the measurement of diffusion of gases (excluding “effusion,” “transpiration,” and other processes from which data for the calculation of the diffusion coefficient may be obtained) is given.
A visual method of following the diffusion of a strongly coloured vapour (bromine) into colourless gases is described.
The diffusion coefficients calculated from the observed data are in good accordance with those obtained theoretically.
The authors desire to thank Miss Netta Macnaughton for valuable assistance in the experimental work.