Читать книгу The Practical Ostrich Feather Dyer - Alexander Bartlett Paul - Страница 16

Sulphuric acid, commonly called oil of vitriol, a common, yet very important, acid. Although not used to any great extent in ostrich feather dyeing, it occurs in commerce in various states and degrees of purity. It was at one time prepared by distilling dried copperas at a high temperature. It is now obtained in greater purity from the alkaline bisulphates. It is a clear colorless oily fluid, weighing about eighteen pounds to the gallon. If mixed with cold water, a great increase of temperature takes place. It rapidly destroys organic bodies, depriving them of their oxygen and hydrogen, and leaving the carbon behind, as a blackish mass. If any particle of organic matter falls into a carboy of acid, it is decomposed, and imparts a dark color to the liquid. It takes up water from the air rapidly, if left uncorked, and thus dilutes itself. Its use in feather dyeing is principally to extract colors that are too dark.