CONDITIONS OP SECRETION OF GASTRIC JUICE. 159 



precisely analogous to those described by Hunter as seen in the bodies of 

 men killed by accident during the digestion of a full meal. It must be re- 

 membered, also, that the pepsin present in the glands of the stomach is 

 inoperative till it has mingled with the acid secreted on the surface. It is 

 difficult to give even an approximative estimate of the quantity of fluid 

 poured forth from the walls of the stomach, since it is certain that it varies 

 considerably, according to the nature of the substances ingested. Corvisart, 

 from experiments on dogs, 1 estimates it at about ^th of the weight of the 

 animal per diem; Harley, 2 at y-g-th ; Lehmaun, at T Vth; whilst Gruenewaldt 

 obtained nearly f Ib. avoird. from a woman of 116 Ibs. weight, with a gas- 

 tric fistula, in fifteen minutes; 3 and Schmidt gives as the mean of experi- 

 ments on the same woman, about 9000 grains hourly during active digestion. 4 

 111. A very important series of observations on the conditions under 

 which the gastric juice is secreted, was made some years since by Dr. Beau- 

 mont, in the remarkable case of Alexis St. Martin, already several times 

 referred to. 5 "The inner coat of the stomach (as seen through the fistulous 

 orifice) in its natural and healthy state, is of a light or pale pink color, 

 varying iu its hues according to its full or empty state. It is of a soft or 

 velvet-like appearance, and is constantly covered with a very thin, trans- 

 parent, viscid mucus, lining the whole interior of the organ. By applying 

 aliment or other irritants to the internal coat of the stomach, and observing 

 the effect through a magnifying glass, innumerable lucid points, and very 

 fine [nervous or vascular] papillae can be seen arising from the villous mem- 

 brane, and protruding through the mucous coat, from which distils a pure, 

 limpid, colorless, slightly viscid fluid." (The papillae here described appear 

 to be the orifices of the gastric follicles, which are usually closed by their 

 epithelial cells during fasting, and which would seem to become prominent 

 when the vis a tergo of the secreted fluid first causes this plug of cells to be 

 cast forth.) " The fluid thus excited is invariably distinctly acid. The 

 mucus of the stomach is less fluid, more viscid or albuminous, semi-opaque, 

 sometimes a little saltish, and does not possess the slightest character of 

 acidity. The gastric fluid never appears to be accumulated in the cavity of 

 the stomach while fasting ; and is seldom, if ever, discharged from its proper 

 secerning vessels, except when excited by the natural stimulus of aliment, 

 mechanical irritation of tubes, or other excitants. When aliment is received, 

 the juice is given out in exact proportion to its requirements for solution, 

 except when more food has been taken than is necessary for the wants of the 

 system." The observations of Dr. Beaumont have been confirmed by those 

 of M. Blondlot 6 and of M. Cl. Bernard, 7 which were made upon dogs in 

 whose stomachs fistulous openings were maintained for a length of time. 

 They found that the flow of gastric fluid is more excited by pepper, salt, 

 and soluble stimulants, than it is by mechanical irritation; and that if me- 

 chanical irritation be carried beyond certain limits, so as to produce pain, 

 the secretion, instead of being more abundant, diminishes or ceases entirely ; 

 whilst a ropy mucus is poured out instead, and the movements of the stom- 

 ach are considerably increased. The animal at the same time appears ill at 

 ease, is agitated, has nausea, and, if the irritation be continued, actual vom- 

 iting; and bile has been observed to flow into the stomach, and escape by 



i Longet, Physiologic, 1861, p. 182, vol. i. J Med.-Chir. Review, 1860, p. 211. 

 3 Quoted by M. Edwards, Lesons, t. vii, 1862, p. 24 

 * Annal. der Cbemie, von Liebig und Wohler, vol. xcii, p. 42. 

 6 See Dr. Beaumont's Experiments and Observations on the Gastric Juice and the 

 Physiology of Digestion, reprinted with Notes by Dr. Andrew Combe, Edinb., 1838. 



6 Traite Analytique de la Digestion. 



7 Arehiv. d'A"nat. Gen. et de Physiol., Jan. 1846. 



