he 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.

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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?

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CHAPTER IV.

THE BONES.

64. The bones are firm and hard, and of a dull white color. In all the
higher orders of animals, among which is man, they are in the interior
of the body, while in lobsters, crabs, &c., they are on the outside,
forming a case which protects the more delicate parts from injury.

65. In the mechanism of man, the variety of movements he is called to
perform requires a correspondent variety of component parts, and the
different bones of the system are so admirably adapted to each other,
that they admit of numerous and varied motions.

66. When the bones composing the skeleton are united by natural
ligaments, they form what is called a _natural skeleton_, when united
by wires, what is termed an _artificial skeleton_.

67. The elevations, or protuberances, of the bones are called
_proc'es-ses_, and are, generally, the points of attachment for the
muscles and ligaments.

ANATOMY OF THE BONES.

68. The BONES are composed of both animal and earthy matter. The
earthy portion of the bones gives them solidity and strength, while
the animal part endows them with vitality.

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64. What is said of the bones? 65. Is there an adaptation of the bones
of the