Zoonomia/II.II.III.I

ORDO III.

Retrograde Sensitive Motions.

GENUS I.

Of Excretory Ducts.

The retrograde action of the œsophagus in ruminating animals, when they bring up the food from their first stomach for the purpose of a second mastication of it, may probably be caused by agreeable sensation; similar to that which induces them to swallow it both before and after this second mastication; and then this retrograde action, properly belongs to this place, and is erroneously put at the head of the order of irritative retrograde motions. Class I. 3. 1. 1.

SPECIES.

1. Ureterum motus retrogressus. When a stone has advanced into the ureter from the pelvis of the kidney, it is sometimes liable to be returned by the retrograde motion of that canal, and the patient obtains fallacious ease, till the stone is again pushed into the ureter.

2. Urethræ motus retrogressus. There have been instances of bougies being carried up the urethra into the bladder most probably by an inverted motion of this canal; for which some have undergone an operation similar to that for the extraction of a stone. A case is related in some medical publication, in which a catgut bougie was carried into the bladder, and after remaining many weeks, was voided piece-meal in a semi-dissolved state. Another case is related of a French officer, who used a leaden bougie; which at length found its way into the bladder, and was, by injecting crude mercury, amalgamated and voided.

In the same manner the infection from a simple gonorrhœa is probably carried further along the course of the urethra; and small stones frequently descend some way into the urethra, and are again carried up into the bladder by the inverted action of this canal.

3. Ductus choledochi motus retrogressus. The concretions of bile, called gall-stones, frequently enter the bile-duct, and give violent pain for some hours; and return again into the gall-bladder, by the retrograde action of this duct. May not oil be carried up this duct, when a gall-stone gives great pain, by its retrograde spasmodic action? See Class I. 1. 3. 8.

M. M. Opium a grain and half.