TECHNO-CHEMICAL RECEIPT BOOK.
ADULTERATIONS, IMITATIONS, ETC. by a diaphragm. A sufficient quantity of bisulphide of carbon, to thoroughly
Olive Oil. The following process of testing olive oil for cotton-seed oil has been authorized by the Italian Government: Mix 1 part of pure nitric acid with 2 parts of the oil to be tested. Place a clean copper wire in the mixture, and stir thoroughly with a glass rod. The oil, if it contains cotton-seed oil, will turn red in the course of half an hour.
Animal Charcoal. To detect adulterations of animal charcoal used in the manufacture of sugar, place a weighed quantity of the suspected charcoal, previously finely powdered and dried, in a porcelain crucible, and heat until all organic substances have been incinerated. Not more than one-tenth of the weight should be lost by this operation. To determine whether the charcoal has been used before, boil the sample several times with pure water, dry, add a small quantity of potassium hydrate and bring again to the boiling point. After a few minutes, filter. If the filtrate appears colored, the charcoal has already been used, and not thoroughly revivified.
Determination of Percentage of Oil in Seeds. The apparatus, Fig. 1, consists of the vessel a, the cylindrical vessel b, and a small air pump c on the side of the vessel a. Further, of a small copper still, d (Fig. 2), and a boiler ef, a tinned copper saucer g, and the water-bath h. The lower half of this is perforated, and connected with the still by a rubber hose.
A convenient quantity, say 4 oz., of the seed to be tested is ground as fine as possible. One-half of it is placed in the cylindrical vessel b, a diaphragm placed upon it, and on the top of this, the second half of the seed, also covered