Zoonomia/II.I.III.III

ORDO III.

Retrograde Irritative Motions.

GENUS III.

Of the Sanguiferous System.

SPECIES.

1. Capillarium motus retrogressus. In microscopic experiments it is usual to see globules of blood regurgitate from the capillary vessels again and again, before they pass through them; and not only the mouths of the veins, which arise from these capillaries, are frequently seen by microscopes to regurgitate some particles of blood during the struggles of the animal; but a retrograde motion of the blood in the veins of these animals, from the very heart to the extremities of the limbs, is observable by intervals during the distresses of the dying creature. Haller, Elem. Phys. T. i. p. 216. See Section XXIX. 3. 8.

2. Palpitatio cordis. May not the ineffectual and weak unequal motions of the heart in hysteric cases be ascribed to the retrograde motions of it, which continue for a short time, or terminate in syncope? See Class IV. 3. 1. 6.

3. Anhelatio spasmodica. In some asthmas may not the difficulty of respiration arise from the inverted action of the finer branches of the bronchia, or of the pulmonary artery or vein, like those of the capillaries above described in No. 1. of this genus?