2. What becomes of the coloring matter?
Experiment 27—Bleaching by Bleaching Powder
Apparatus: Porcelain dish.
Material: Piece of calico.
Reference: Textiles, page [148].
Directions
Place a quarter of an ounce of bleaching powder in a quart bottle containing a pint of water.[27] Then place a piece of calico in the water containing the bleaching powder. What is the effect on the calico? Then remove cloth to another bottle filled with dilute hydrochloric or dilute sulphuric acid. What is the effect on the color? Then wash the whitened cloth thoroughly in water.
Why is it necessary in practice to pass cotton fabrics through two baths in bleaching? What is contained in the first bath? in the second bath?
Experiment 30—Determining Style of Weave
Apparatus: Pick glass.
Materials: Different fabrics.
References: Textiles, pages [56-58], etc.
Examine different samples of cloth and classify them according to the seven standards given on pages [56-58], etc.