Part 65

II. Forms of the Broad Muscles.

Where they are situated.—Thickness.—Peculiar forms of the broad pectoral muscles. 330

III. Forms of the Short Muscles.

Where they are found.—Their arrangement.—Remarks upon the three species of muscles. 331

ARTICLE SECOND.

ORGANIZATION OF THE MUSCULAR SYSTEM OF ANIMAL LIFE.

I. Texture peculiar to this Organization.

Arrangement of this texture into fasciculi.—Its division into fibres.—Length of the fleshy fibres compared with that of the muscle.—Their direction.—Their figure.—Their softness.—Ease of their rupture in the dead body.—Difficulty in the living. 332

Composition of the muscular texture.—Action of the air in desiccation and putrefaction.—Action of cold water.—Maceration and its products.—Ease with which the colouring substance is removed.—Analogy of the remaining texture with the fibrin of the blood.—Relation of the forces with this texture.—Action of boiling water.—Some peculiar phenomena of common boiled flesh.—Roasting of the fleshy texture.—Singular affinity of the digestive juices to this sort of texture.—General observations.—Influence of sex and the genital organs upon the fleshy texture. 336

II. Parts common to the Organization of this System.

Cellular texture.—Manner in which it envelops the fibres.—Its uses for muscular motion.—Experiment.—Fatty muscles. 343

Blood vessels.—Arteries.—Of the blood of the muscles.—Of their colour.—Free and combined state of the colouring substance.—Veins.—Remarks upon the injection of them. 346

Nerves.—There are hardly any but those of animal life.—Their difference in the extensors and the flexors.—Manner in which the nerves penetrate the muscles. 348

ARTICLE THIRD.

PROPERTIES OF THE MUSCULAR SYSTEM OF ANIMAL LIFE.

I. Properties of Texture. Extensibility.

This property is continually in action.—It is in proportion to the length of the fibres.—Its exercise in diseases. 350

Contractility of texture.—Phenomena of the antagonists.—Distinction in these phenomena of that which belongs to the vital properties from that which belongs to those of texture.—Of the contractility of texture in diseases.—Extent and quickness of the contractions.—They continue after death.—Essential differences between the contractility of texture and horny hardening. Their parallel. 352

II. Vital Properties.

Properties of animal life.—Sensibility.—Most of the ordinary agents do not develop it.—It is put into action by repeated contractions.—Of the sensation of lassitude.—Sensibility of the muscles in their affections. 359

Animal Contractility.—It should be considered in three relations. 361

Animal contractility considered in the brain.—The principle of this property exists in this organ.—Proofs drawn from observation.—Proofs derived from diseases.—Proofs borrowed from experiments upon animals.—Cases in which the brain is foreign to the muscles. 362

Animal contractility considered in the nerves.—Influence of the spinal marrow upon this property.—Observations and experiments.—Influence of the nerves.—Observations and experiments.—All the nerves do not transmit equally the different irradiations of the brain.—Direction of the propagation of the nervous influence. 367

Animal contractility considered in the muscles.—Necessary conditions in the muscle for it to contract.—Obstacles to contraction.—Various experiments. 374

Causes which bring into action animal contractility.—Division of these causes.—Of the will.—Of the involuntary causes.—Direct excitement.—Sympathetic excitement.—Influence of the passions.—Remarks upon the motion of the fœtus. 374

Duration of the animal contractility after death.—Various experiments.—Consequences relative to respiration.—Variety of the duration of this property.—How it is extinguished. 379

Organic Properties.—Organic sensibility and insensible organic contractility.—Sensible organic contractility.—Various experiments upon this last property.—Phenomena of irritations.—In order to study this contractility the animal contractility must be destroyed.—How this is done.—Various modes of contraction. 382

Sympathies.—The animal sensibility is the property especially brought into action by them.—General Remarks.—Sympathies of animal sensibility.—The organic properties are rarely brought into action. 386