This following paper discusses a method for determining the total mass of dust contained in the coma of a comet. On assumption of a certain frequency distribution of particle dimensions, and based on photometrical data, it arrives at the conclusion that the maximum total quantity of dust in the atmosphere of comets at the time of observation, amounts to 8 x 10^11 g. This value appears as the result from photometric parameters of the comets, which show strong continuous spectra and are therefore by the author supposed to yield a 1 : 1 relation between the brightnesses of the dust and gas components of the coma. The photometrical measurements of Comet Arend-Roland 1956h result in a maximum value of 1.4 x 10^11 g. The photometric measurement of the anomalous tail of Comet Arend-Roland arrives at 10^13 g as the maximum value of its mass.