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rice flour, sometimes to the extent of 50 per cent. There is not so much adulteration as has often been supposed, if the articles are purchased of the large firms and of reliable dealers. Alum is not infrequently found in powders sold in bulk. The following simple tests may be of use to those who have had a little practice in chemistry.
Good cream of tartar is soluble in eighteen parts of boiling water. Good baking powder is also soluble; a small quantity of starch present will give a certain opacity to the solution, but if in excess a paste may be formed stiff enough for laundry use. If there is in either case much residue insoluble in water which dissolves in hydrochloric acid, phosphate or sulphate of calcium is to be suspected.
A few drops of barium chloride added to the hydrochloric acid solution will cause a white precipitate if sulphates are present in the substance under examination. If the phosphates are to be tested for, the acid to be used for a solution is nitric, and to the solution a few cubic centimeters of molybdate of ammonia are added. A fine yellow color or precipitate indicates phosphates. Ammonia is sometimes found in baking powders. If present, a small lump of potassium hydrate added to the strong aqueous solution will, on heating, cause the ammonia to be given off in the steam, which will then turn red litmus paper blue.
To test for alum prepare a fresh decoction of logwood; add a few drops to the solution or substance, and render it acid by acetic acid. A yellow color proves the absence of alum ; a purplish red or a bluish color, more or less decided, means more or less alum. If the substance were not acidified the test might be vitiated by the presence of an alkali, as in the case of a baking powder. Caution: Use a new solution, or a new portion of an old one, for each test.
To judge of the quantity of any of the substances it is necessary to have a standard article with which to compare the suspected one. If the same quantity of each is taken, and it is subjected to the same tests, a very correct judgment of its quality may be formed. Acids should be used in glass or china vessels only. CHAPTER XIII
~OOD FOOD FOR LITTLE MONEY means those ma
terials which may be sown, gathered, and prepared largely by machinery, or those which, growing abundantly in distant lands, are dry and hard, and may be transported without serious loss and kept in ordinary storage. All such materials are too abundant and of too low cost by the pound to be subjected to substitution or adulteration. Wise providers make these the chief articles of diet.
Good Foods Costing MORE MONEY are such as are perishable because of high water content, making a satisfactory food for the ever present micro-organisms of decay. The transportation of so much water (80 to 90 per cent in fruits, 75 per cent in meats) and the need of cold storage add to the original cost, also to the inevitable waste, because of the soft character and frequent accidents in transportation causing delay and the risks of storage. Such foods grown out of season are those of which the supply for the market of the world is limited, of which there are “not enough to go around." There is a temptation to use preservatives with this class of foods. All these should be scrutinized carefully and used sparingly if the pennies must be counted in the week's accounts.
EXPENSIVE Foods, reckoned by the pound, are those valued for some special reason; imported from the tropics; or without competition in the market. Certain of these lend themselves to adulteration or sophistication or to both, as mustard, cinnamon, vanilla, and lemon extracts, etc. The ready manufacture of artificial flavors and colors adds to the probability of this practice. The remedy is a knowledge of the pure article; then the others will have no attractions.
NUTRITIOUS Foods are those that contain considerable amounts of either or all of the three chief constituents of human food :
Carbohydrates (starch, sugar, gums, etc.).
found in meat, eggs, cheese, peas, peanuts). Foods VALUABLE FOR QUALITY RATHER THAN QUANTITY OF CONSTITUENTS :
Fruits for acids and potassium.
Such gastronomic qualities are widely imitated and frauds are to be looked for.
FOODS THAT MAY BECOME DANGEROUS :
toxins (meats and milk).
vegetables exposed to street dust, hence to some disease-giving organisms).
Liable to carry animal or vegetable organisms, be
cause of mode of cultivation (as lettuce fertilized
Over-ripe fruits harboring worms.
Too salt, too sweet, too dry.
Contaminated by dirt. Foods SAFE AND WHOLESOME BY THEMSELVES, but liable to superficial contamination by exposure and handling: