A manual of organic materia medica : being a guide to materia medica of the vegetable and animal kingdoms for the use of students, druggists, pharmacists, and physicians / by John M. Maisch.

  • John Michael Maisch
Date:
1882
Catalogue details

Licence: Public Domain Mark

Credit: A manual of organic materia medica : being a guide to materia medica of the vegetable and animal kingdoms for the use of students, druggists, pharmacists, and physicians / by John M. Maisch. Source: Wellcome Collection.

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    8Ci8H35°2; palmitin, C3HS.3C16H3102; myristin, C3H5. 3C]4H2702; laurin, C3II5.3C12H2302; and olein, C3II5. 3C18H3302. The drying oils which gradually harden on exposure to the air, contain linolein, the acid hav- ing the formula ClfiH2Q04. Fats become rancid through the generation of volatile fatty acids and perhaps of other compounds. On saponification most of the liquid and solid fats yield glycerin, C3Hg03. Soaps made with potassa are softer than soda soaps, and the soaps of drying oils are softer than those prepared from non-drying oils. Fats having a high fusing point, are often called waxes; but this name is more properly applied to the compounds of the fatty acids with the radicals of monatomic alcohols, such as cetyl, C16H33 (in sperma- ceti), ceryl, C27II55 (in Chinese wax), and myricyl, C30IT61 (in beeswax). Adulterations.—The detection is difficult. The spe- cific gravity, the melting point, and the congealing point should be observed. Drying and non-drying oils are distinguished by the effect of nitrous acid, which causes the latter to congeal in the course of two or three hours to one or two days, through the conversion of liquid olein into solid elaidin; linolein and allied oils are not affected by this agent. The test is applied by mixing 2 parts of nitric acid, spec. grav. 1.42, 3 parts of water, and 5 parts of the oil, and adding 1 part of copper. Maumend's sulphuric acid test is applied by stirring together 50 grams of the oil and 10 cubic centimeters of sulphuric acid, and noting the rise of temperature. Heydenreich's test consists in adding to 10 or 12 drops of the oil 2 or 3 drops of sulphuric acid, noting the color, then stirring and again noting 36*