Article by Professor N. Wosnessensky on steam aniline black for calico printing. It argues that the aniline content of printing colours can be cut sharply because roughly half is lost by evaporation, and it reviews 20 published recipes in a comparative table. It calculates the potassium ferrocyanide and sodium chlorate needed, reports volatility tests on aniline chlorhydrate, tartrate and ferrocyanide, and gives a working recipe using 40 g aniline per kilo of colour, which was used in production at the Trechgornaia Manufaktur.