60. Gelatin is found in nearly all the solids, but it is not known to exist in any of the fluids. It forms the basis of the cellular tissue, and exists largely in the skin, bones, ligaments, and cartilages.
57. What are proximate elements? Do they exist already formed in organized bodies? Name the most important compounds. 58. What is said of albumen? Give observation relative to this element. 59. Of fibrin? How does albumen differ from fibrin? How can fibrin be obtained? 60. What is said of gelatin?
Observation. Gelatin is known from other organic principles by its dissolving in warm water, and forming “jelly.” When dry, it forms the hard, brittle substance, called glue. Isinglass, which is used in the various mechanical arts, is obtained from the sounds of the sturgeon.
61. Mucus is a viscid fluid secreted by the gland-cells, or epithelia. Various substances are included under the name of mucus. It is generally alkaline, but its true chemical character is imperfectly understood. It serves to moisten and defend the mucous membrane. It is found in the cuticle, brain, and nails; and is scarcely soluble in water, especially when dry. ([Appendix C.])
62. Osmazome is a substance of an aromatic flavor. It is of a yellowish-brown color, and is soluble both in water and alcohol, but does not form a jelly by concentration. It is found in all the fluids, and in some of the solids; as the brain.
Observation. The characteristic odor and taste of soup are owing to osmazome.
63. There are several acids found in the human system; as the A-ce´tic, Ben-zo´ic, Ox-al´ic, U´ric, and some other substances, but not of sufficient importance to require a particular description.
How is it known from other organic principles? 61. What is said of mucus? 62. Of osmazome? To what are the taste and odor of soup owing? 63. What acids are found in the system?