[190] Rep. Mass. Bd. Health, 1909, 41, 477.
[191] Pharm. Jour., 1912, 89, 610.
[192] Pharm. Jour., 1912, 89, 610.
[193] The time required to complete the process after the initial portion of lard has been added should be about twenty minutes.
[194] In order to facilitate the incorporation of the iodine with the fatty base the iodine was first powdered by trituration with alcohol and drying the powder in the air.
[195] Rep. Chem. Lab., A. M. A., 1916, 9, 118.
[196] Pharm. Jour., 1912, 89, 610.
[197] The resultant fatty residue was of a brownish-green color. It no longer had either the taste, color or odor of lard. It was noted that the fats, after removal by this method from the freshly prepared ointment, were nearly white. As the ointment aged the fat became successively darker in color.
[198] The method depends upon the conversion of all of the iodine compounds into iodate by fusion with sodium hydroxide and oxidation with potassium nitrate. The melt is dissolved in water, a little sodium bisulphite added, the solution cooled and neutralized with phosphoric acid, using methyl orange as indicator. An excess of bromine water is added, and the mixture boiled to expel carbon dioxid and bromine. A little sodium salicylate is added, the solution cooled, an excess of potassium iodid added, and the liberated iodine titrated with tenth-normal sodium thiosulphate in the usual way. One sixth of the iodine found is obtained from the material assayed, the balance being furnished by the potassium iodide added.—Jour. Biochem., 1914, 19, 251.
[199] In order to determine whether the iodine which is in combination with fat is absorbed through the skin, a few experiments were carried out. The dark-colored iodine-containing fat (obtained from the ointment and washed free from potassium iodide by the method described above) was rubbed thoroughly into the skin of the forearm. It was allowed to remain for four hours, after which the limb was scoured with soap suds. Beginning at the time of the application the urine was collected for forty-eight hours. This was evaporated to small bulk and the residue tested for iodine by Kendall’s method. Small amounts of iodine were found. These findings were taken to indicate that the iodine-containing fat is absorbed to some extent by the skin. It is generally believed that potassium iodide is not absorbed by the unbroken skin. Therefore it seems reasonable to suppose that the principal iodine effects obtainable from iodine ointment are those due to the free iodine contained in the preparation, supplemented to a slight extent by the iodine which is contained in the fatty ointment base.—Jour. Biochem., 1914, 19, 251.