STARCHING 165 



and soap which has escaped rinsing does not react with it to 

 form spots and stains. For this reason ultramarine is one of 

 the most satisfactory blues which can be used. Indigo is also 

 a safe and satisfactory dye. Like ultramarine, it is not affected 

 by either alkalies or light and is widely used in laundry work. 



Prussian blue, a poor blue. This blue is a compound of iron, 

 carbon, and nitrogen. It is cheaper than ultramarine, but is 

 correspondingly inferior. It is an intense blue and is so strong 

 in color that 600 pounds of white lead can be tinged by one 

 pound of it. Prussian blue is objectionable in laundry work 

 largely because it is easily decomposed by washing soda and 

 soap. Many a laundress who does not hang her clothes on 

 rusty hooks, and who uses only clean rope clotheslines, is sur- 

 prised and annoyed by iron rust spots on her clothes, and by the 

 bad color of the wash in general. This is explained by the fact 

 that Prussian blue when decomposed liberates iron. 



Starching. Starch, as well as blue, is an important article in 

 laundry work. Without starch collars and cuffs would be soft 

 and would crumple easily ; pillow cases would not give the fine 

 appearance they do to the bed ; sash curtains would be flimsy 

 and would soil quickly, and table linen would lack its gloss. 

 Even articles which are usually thought of as unstarched, fre- 

 quently have a little starch in them ; for example, fine lace collars 

 are often dipped in thin starch for a mild stiffening, and ruchings, 

 edgings, and frills are usually treated in the same way. 



There are two ways of preparing starch for laundry work .- 

 the cold-water process and the hot-water process. Cold or raw 

 starch is made by stirring starch in cold water until the liquid 

 has a strong milky appearance. Starch does not dissolve in 

 cold water, but if it is stirred in the water its granules spread 

 through the liquid and become suspended in it, forming starch 

 water. Clothes placed in the water soak up enough starch to 

 become very stiff on drying. 



