Identification of the Commercial Dyestuffs: being vol Hi of a Method for the Identification of Pure Organic Compounds by a Systematic Analytical Procedure based on Physical Properties and Chemical Reactions

Abstract

THE identification of natural or artificial dyestuffs either as such or in association with textile fibres, colour lakes, paper, food, or other articles, is a problem which at the present day presents many difficulties. Twenty or thirty years ago the number of dyestuffs was so small that their identification by an expert was a simple enough matter, but the enormously greater number of artificial dyestuffs now in use and the rapid rate at which this number is daily augmented, has not only greatly increased the difficulty, but also the need of trustworthy means of analysis. The dyer with many hundreds of dyestuffs now at his command is able to match any particular shade in a variety of different ways, but since the fastness for the purpose in view depends entirely upon a suitable choice of colouring matters, it becomes particularly important that in matching an approved pattern it should be possible not only to reproduce the shade, but also to select the same or similar dyestuffs. It is also a desideratum for the merchant or textile manufacturer to be able to ascertain whether the colour of the materials dyed for him is always obtained with the dye-stuffs specified, whether the shade dyed by one firm is or is not a chemical match for that dyed by another, and other similar questions. The analytical chemist is also frequently called upon to determine the actual dyestuff or dyestuffs employed, for example, in the composition of a lake pigment for wall-papers or lithographic printing, or to identify the material used for colouring certain food products. Identification of the Commercial Dyestuffs: being vol. Hi. of a Method for the Identification of Pure Organic Compounds by a Systematic Analytical Procedure based on Physical Properties and Chemical Reactions. By Prof. S. P. Mulliken. Pp. vi + 274. (New York: John Wiley and Sons; London: Chapman and Hall, Ltd., 1910.) Price 21s. net.