sessed the faculty of vomiting at pleasure." In this way, he obtained from his stomach, in the morning, about three ounces of fluid, which was analyzed by M. Thénard, who found it composed of a considerable quantity of water, a little mucus, and salts with a base of soda and lime; but it was not sensibly acid, either to the tongue or to reagents. On another occasion, M. Pinel obtained two ounces of fluid in the same manner. This was analyzed by M. Chevreul, and found to contain much water, a considerable quantity of mucus, lactic acid-united to an animal matter, soluble in water, and insoluble in alcohol,—a little muriate of ammonia, chloride of potassium, and some chloride of sodium. Messrs. Tiedemann and Gmelin' procured the gastric fluid by making animals, that had fasted, swallow indigestible substances, as flints. It always appeared to them to be produced in greater quantity, and to have a more acid character, in proportion as the alimentary matter was less digestible and less soluble; and they assign it, as constituents,chlorohydric acid; acetic acid; mucus; no, or very little, albumen; salivary matter; osmazome; chloride of sodium, and sulphate of soda. In the ashes, remaining after incineration, were, carbonate, phosphate, and sulphate of lime, and chloride of calcium. MM. Leuret and Lassaigne assign its composition, in one hundred parts, to be,-water, ninety-eight; lactic acid; muriate of ammonia; chloride of sodium; animal matter soluble in water; mucus; and phosphate of lime, two parts. M. Braconnot3 examined the gastric juice of a dog, and found it to contain-free chlorohydric acid in great abundance; muriate of ammonia; chloride of sodium in very great quantity; chloride of calcium; a trace of chloride of potassium; chloride of iron; chloride of magnesium; colourless oil of an acid taste; animal matter soluble in water and alcohol, in very considerable quantity; animal matter soluble in weak acids; animal matter soluble in water, and insoluble in alcohol (salivary matter of Gmelin); mucus; and phosphate of lime. In the winter of 1832-3, the author was favoured by Dr. Beaumont, with a quantity of the gastric secretion obtained from the individual with the fistulous opening into the stomach, which was examined by himself, and his friend, the late Professor Emmet, of the University of Virginia, and found to contain free chlorohydric and acetic acids, phosphates, and chlorides, with bases of potassa, soda, magnesia, and lime, and an animal matter-probably pepsin--soluble in cold water, but insoluble in hot. The quantity of free chlorohydric acid was surprising on distilling the fluid, the acids passed over, the salts and animal matter remaining in the retort: the amount of chloride of silver thrown down on the addition of the nitrate of silver to the distilled fluid, was astonishing. The author had many opportunities for examining the gastric secretion obtained from the case in question. At all times, when pure or unmixed except with a portion of the mucus of the lining membrane of the digestive tube, it was a transparent fluid, having a marked smell of chlorohydric acid; and of a slightly

1 Op. cit.

2 Recherches, &c., Paris, 1825.

Journal de Chimie Médicale, tom. ii., ser. 2, 1836, and Records of General Science, Jan., 1836.

See a letter from the author to Dr. Beaumont, in Beaumont's Experiments, &c., on the Gastric Juice, p. 77; and the author's Elements of Hygiene, p. 216, Philad., 1835.

salt, and very perceptibly acid, taste. It matters not, therefore, that M. Blondlot, in his experiments on the gastric secretions of dogs and other animals, obtained by artificial fistulous openings made into the stomach, did not find, when distilled, that they exhibited any acid reaction, whilst the residue in the retort was always strongly acid. The results referred to by the author as regards the gastric juice of man were positive and uniform; and established, that it always contains a large quantity of chlorohydric acid.

Moreover, free chlorohydric acid was found in the gastric juice of animals by Enderlin, Hübbenet,3 and Bidder and Schmidt. Funkes is of opinion that their researches leave no doubt on the subject of its presence; and Dr. Brinton, after an inquiry into the whole matter, thinks "there seems little doubt that we ought to regard the balance of evidence as inclining decisively towards a single gastric acid," and that acid the chlorohydric. Schmidt is of opinion, that the essential gastric acid is the chlorohydric, and believes it to be a conjugated acid in union with pepsin--chloro-pepso-hydric acid-chlorpepsinwasserstoffsäure; the existence of which is hypothetical.7 More recently, Grünewaldt has had an opportunity of instituting a variety of experiments in a case of fistulous opening into the stomach of a woman. Three analyses of the fluid obtained were made by Schmidt, who found the mean to be as follows:

From this analysis it is manifest, that the proportion of water is very great. It would seem, indeed, that an enormous amount of fluid is secreted from the stomach in the twenty-four hours. It has been attempted to estimate the amount by that of the albuminous matter known to be dissolved by it; but all calculations thus made must be vague and uncertain. Certain aliments are known to occasion a more copious secretion of the gastric solvent than others; and those nitrogenized substances which remain longest in the stomach will require

Traité Analytique de la Digestion, Paris, 1844. An abstract of his views is given by Mr. Paget, Brit. and For. Med. Rev., Jan., 1845, p. 270; see, also, Gazette Médicale de Paris, 1851, No. 33, p. 526.

Canstatt, Jahresbericht, 1843, i. 149.

Disquisitiones de Succo Gastrico, Dorp. Liv. 1850: and Canstatt, op. cit., 1851, s. 97, and 1852, s. 109.

Die Verdauungsäfte und der Stoffwechsel, s. 46, Mitau und Leipzig, 1852.

5 Rudolph Wagner's Lehrbuch der Speciellen Physiologie, von D. Otto Funke, s. 163, Leipz., 1854.

Art. Stomach and Intestines in Cyclop. of Anat. and Physiol., Pt. 46, p. 332, June, 1855.

7 Moleschott, Physiologie des Stoffwechsels, u. s. w., s. 428, Erlangen, 1851; and Lehmann, Lehrbuch der Physiologisch. Chemie, iii. 330, Leipz., 1852.

8 Succi Gastrici Humani Indoles, &c., Dorpat, 1853; Vierordt's Archiv. für Physiol. Heilkund. xiii. 459; and Canstatt, 1854, i. 145, Würzburg, 1855. Grünewaldt found free chlorohydric acid in smaller proportion in man than in animals.

a greater amount of fluid. Lehmann' estimates the daily quantity in man to be about four pounds; whilst Bidder and Schmidt, founding their deductions on experiments on dogs with gastric fistula, infer that in that animal as much as one-tenth of its weight is daily secreted; and Grünewaldt,3 from his experiments on the woman with the gastric fistula, was led to infer that the secretion amounts to the enormous quantity of from one-fifth to one-quarter of the weight of the body daily! Of course, a large amount of this fluid passes again into the circulation along with the products of digestion that are dissolved in it. Still, the amount is so vast, it is difficult to imagine that there is not some error in the observation, or fallacy in the deductions.

After this it seems unnecessary to examine into the statement of M. Blondlot, that the true and almost only source of the acidity of healthy gastric fluid is the presence of acid phosphate salts. If, at least, we admit this to be the case in animals, it is assuredly not so in man. The remark applies equally to the experiments of Dr. R. D. Thomp. son on the gastric secretions of the sheep and pig. By these observers, the results obtained from the examination of the gastric secretions in man, seem to have been passed over, and they have deduced their inferences from those of animals, which may, in part--but in part only--account for the great discrepancy in their statements."

The source of the chlorine or chlorohydric acid in the gastric juice, as Dr. Prout' suggests, must be the common salt existing in the blood, which, he conceives, is decomposed by galvanic action; the soda, set free, remaining in the blood, a portion being "requisite to preserve the weak alkaline condition essential to the fluidity of the blood;" but the larger part being directed to the liver to unite with the bile. This is plausible; but, it need scarcely be added, not the less hypothetical. Drs. Purkinje and Pappenheims are of a similar opinion in regard to the source of the chlorohydric acid. From their galvanic experiments they think it follows, that the juices mixed with the food in the natural way, saliva, mucus, the portions of chloride of sodium present therein, and still more the gastric mucous membrane itself, develope as much as is required: and that if the nervous action in the stomach be either identical with, or analogous to, galvanism, it would be sufficient to account for the secretion of the quantity of chlorohydric acid requisite for digestion, without the assumption of a special organ of secretion."

M. Blondlot" denies-and Liebig" formerly did likewise-that in

1 Lehrbuch der Physiologischen Chemie, ii. 49, and iii. 330, 342, Leipz., 1852, or Translation by Dr. Day, Amer. edit. by Dr. R. E. Rogers, i. 448 and ii. 520, Philad., 1855.

Op. cit., s. 36.

3 Op. cit.

4 See on the Gastric Juice and its office in Digestion, Dalton, Amer. Journ. of the Med. Sciences, Oct., 1854, p. 317.

Ranking's Abstract, vol. i., Pt. 2, Amer. edit., p. 271, New York, 1846.

6 Carpenter, Principles of Physiology, 4th Amer. edit., p. 494, Philad., 1850; and Kirkes and Paget, Manual of Physiology, 2d Amer. edit., p. 170, Philadelphia, 1853. 7 Bridgewater Treatise, Amer. edit., p. 268, Philad., 1834.

Müller's Archiv. für Anatomie, u. s. w. Heft 1, 1838, noticed in Brit. and For. Med. Rev., Oct., 1838, p. 529.

9 See also Dr. Brinton, loc. cit.

10 Op. cit.

"Animal Chemistry, Gregory's and Webster's edit., p. 107, Cambridge, 1842.

health lactic acid exists in the stomach. In certain diseases, according to the latter, both it and mucilage are formed from the starch, and sugar of the food; and he affirms, that the property possessed by these substances of passing, by contact with animal substances, in a state of decomposition, into lactic acid, has induced physiologists without farther inquiry, to assume that lactic acid is produced during digestion. He now, however, admits its existence in health,' and with Dr. R. D. Thompson, MM. Bernard and Barreswil, Frerichs, J. Béclard,' and others, consider it to be an important agent in the digestive process. With some other chemists, he denies the existence of free chlorohydric acid in the stomach, and believes, that when it is obtained by the simple distillation of the gastric juice it is formed by the reaction of the lactic and phosphoric acids, which are present in the fluid, on the chlorides; and Lehmann found, when he experimented on the stomachs of dogs placed in vacuo in such a manner as to cause the vapours from the gastric juice to pass through a tube containing a solution of nitrate of silver, that there was no indication of free chlorohydric acid until the fluid had become so concentrated as to permit the action of the lactic acid on the earthy chlorides. His results would tend to confirm the later conclusions of Liebig, as well as those of MM. Bernard and Barreswil, and others, as to the nature of the acid of the gastric juice of certain animals at least. It is proper to remark, however, that neither Prout nor Braconnot could detect lactic acid in the gastric juice; and, moreover, it does not appear to be formed in artificial digestion."

The diversity of results obtained by chemical analysis; the difficulty of comprehending how the same fluid can digest substances of such opposite character; and the uncertainty we are in, regarding the organs concerned in its production, had led some physiologists to doubt the existence of any such gastric juice or solvent as that described by Spallanzani. M. Montègre, for example, in the year 1812, presented to the French Institute a series of experiments, from which he concluded, that the gastric juice of Spallanzani is nothing more than saliva, either in a pure state, or changed by the chymifying action of the stomach and become acid. As M. Montègre was able to vomit at pleasure, he obtained the gastric juice, as it had been done by previous experi menters, in this manner, whilst fasting. He found it frothy, slightly viscid, and turbid; depositing, when at rest, some mucous flakes; and commonly acid; so much so, indeed, as to irritate the throat, and render the teeth rough. He was desirous of proving, whether this fluid was in any manner inservient to chymification. For this purpose, he began

Chemistry of Food, London, 1847.

Canstatt, Jahresbericht, 1850, Bd. i. s. 134.

Traité Élémentaire de Physiologie, p. 86, Paris, 1855.

Lehrbuch der Physiologischen Chemie, ii. 42, Leipz., 1852, or Amer. edit. of Dr. Day's translation by Dr. Robt. E. Rogers, i. 441, Philad. 1855.

5 Archiv. der Pharmacie, cited in the British and Foreign Medico-Chirurgical Review, p. 261, Jan., 1849.

6 A full account of the various views in regard to the gastric acid is given by Frerichs, Art. Verdauung, Wagner's Handwörterbuch der Physiologie, 21ste Lieferung, s. 780, Braunschweig, 1849; and Bérard, Cours de Physiologie, 11e Livraison, p. 97, Paris,

7 Expér. sur la Digestion, p. 20, Paris, 1824.

by ejecting as much as possible by vomiting; and, afterwards, swallowed magnesia to neutralize what remained. On eating afterwards, the food did not appear less chymified, nor was it less acid; whence he concluded, that, instead of the fluid being the agent of chymification, it was nothing more than saliva and the mucous secretions of the stomach, changed by the chymifying action of that viscus. To confirm himself in this view, he repeated with it, Spallanzani's experiments on artificial digestion; making, at the same time, similar experiments with saliva: the results were the same in both cases. When gastric juice, not acid, was put into a tube, and placed in the axilla,--as in Spallanzani's experiments,-in twelve hours it was in a complete state of putrefaction. The same occurred to saliva placed in the axilla. Gastric juice, in an acid state, placed there, did not become putrid, but this seemed to be owing to its acidity; for the same thing happened to saliva, when rendered acid by the addition of a little vinegar; and even to the gastric juice,-used in the experiment just referred to,-when mixed with a little vinegar. Again:-he attempted artificial digestion with the gastric juice, acid and not acid; fresh and old; but they were unsuccessful. The food always became putrid; but sooner when the juice employed was not acid; and, if it sometimes liquefied before becoming putrid, this was attributed to the acidity of the juice, as the same effect took place, when saliva, mixed with a little vinegar, was employed. M. Montègre, moreover, observed, that the food rejected from the stomach was longer in becoming putrid, in proportion to the time it had been subjected to the chymifying action of the stomach; and he concluded, that the fluid, which is sometimes contained in the empty stomach, instead of being a menstruum kept in reserve for chymification, is nothing more than the saliva continually sent down into that viscus, and that its purity or acidity depends upon the chymifying action of the stomach.

As regards the fluid met with in the stomach of fasting animals, M. Montègre's remarks may be true in the main; but we have too many evidences in favour of the chemical action of some secretion from the stomach during digestion to permit us to doubt the fact for a moment. Besides, some of M. Montègre's experiments have been repeated with opposite results. MM. Leuret and Lassaigne, and Dr. Beaumont3 performed those relating to digestion after the manner of Spallanzani, and succeeded perfectly; whilst they failed altogether in producing chymification with saliva, either in its pure state, or when acidulated with vinegar.

By steeping the mucous membrane of an animal's stomach in an acid liquor, a solution is obtained, to which Eberle gave the name pepsin. This solution has the property of dissolving organic matter in a much higher degree than diluted acids. It dissolves coagulated albumen, muscular fibre, and animal matters in general. In an experiment, one grain of the digestive matter dissolved one hundred grains of coagulated white of egg. Eberle thought that all mucus has the

1 Chaussier and Adelon, in Dict. des Sci. Médicales, xx. 422.

2 Recherches sur la Digestion, Paris, 1825.

Op. citat., p. 139.

Physiologie der Verdauung nach Versuchen, u. s. w., Würzburg, 1834; Müller, Archiv., Heft 1, 1836, or London Lancet, p. 19, March 31, 1838.