Paper and Printing Recipes / A Handy Volume of Practical Recipes, Concerning the Every-Day Business of Stationers, Printers, Binders, and the Kindred Trades

by John Sawtelle Ford

For Making Dextrine.

Five hundred parts of potato starch are mixed with 1,500 parts of cold distilled water and eight parts of pure oxalic acid. This mixture is placed in a suitable vessel on a water-bath, and heated until a small sample tested with iodine solution does not produce the reaction of starch. When this is found to be the case the vessel is immediately removed from the water-bath, and the liquid neutralized with pure carbonate of lime. After having been left standing for two days, the liquor is filtered, and the clear filtrate evaporated upon a water-bath until the mass has become quite a paste, which is removed by a spatula, and having been made into thin cakes is placed upon paper and further dried in a warm situation; 220 parts of pure dextrine are thus obtained. When needed for making mucilage, the solution has only to be evaporated to the proper thickness.