This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
Sprinkling borax is not only cheaper, but also dissolves less in soldering than pure borax.
The borax is heated in a metal vessel until it has lost its water of crystallization and mixed with calcined cooking salt and potash—borax, 8 parts; cooking salt, 3 parts; potash, 3 parts. Next i; is pounded in a mortar into a fine powder, constituting the sprinkling borax.
Another kind of sprinkling borax is prepared by substituting glass-gall for the potash. Glass-gall is the froth floating on the melted glass, which can be skimmed off.
The borax is either dusted on in powder form from a sprinkling box or stirred with water before use into a thin paste.
For the detection of sawdust in bran use a solution of 1 part of phloroglucin in 15 parts of alcohol, 15 parts of water, and 10 parts of syrupy phosphoric acid. Place 2 parts of the solution in a small porcelain dish, add a knifepointful of the bran and heat moderately. Sawdust is dyed red while bran parts only seldom acquire a faint red color. By a microscopic examination of the reddish parts, sawdust will be readily recognized.
 
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