The colour and clarity of gelatin and glue solutions

A method is described for measuring the separate properties, colour and clarity, of gelatin and glue solutions. The optical densities of gelatin or glue solutions, before and after filtration by means of a bacterial filter, are measured either as a function of wavelength, with a spectrophotometer, or in terms of the light transmitted by standard colour filters, with a photoelectric absorptiometer. The limitations of the method and its usefulness in routine control are discussed.