is occasioned by any humour flowing from another part; for in pituitous constitutions acid eructations are apt to occur; but in the bilious, fetid airs and other disagreeable qualities are apt to prevail. The common symptom of them all is nausea. If the depraved humours swim within the cavity of the stomach, they float on the surface, and are discharged by vomiting; but if they are contained in the substance of it within its coats, they annoy it with vain attempts to vomit. * * * * * COMMENTARY. We shall now state briefly the opinions of the ancients with regard to the functional office of the stomach. Actuarius says, “I am of opinion, that there are four species of concoction which are performed in different parts of the body: the first in the stomach; the second in the vena ramalis (vena portæ?), meseraic veins, and concave part of the liver; the third in the convex part of the liver and veins proceeding from it; and the fourth, consisting of fabrication or assimilation, which takes place in the extreme parts of the body.” (De Urinis.) The various modes of change or concoction which the food undergoes in the body, are minutely described by Macrobius. (Saturnal. vii.) In another place, Actuarius says, “Digestion is performed by moderate heat and moisture.” (De Spiritu Animali, p. ii, s. 1.) Alsaharavius in like manner states, that the digestive faculty depends partly on the heat, and partly on the humidity of the stomach. (Pract. tr. xvi, c. 1.) It is impossible not to see that the gastric juice is alluded to in these passages. It is particularly stated of Asclepiades, that he held digestion to be the solution of the food. See C. Aurelianus. (Morb. Acut. i, 14.) And that the ancients were aware that the stomach secretes a fluid possessed of solvent properties, is put beyond a doubt, by the following extract from the works of Haly Abbas. Speaking of the changes which the food undergoes in the mouth and stomach, he says: “Immutantur cibi in ore, retinenturque, et flegmati admiscetur quod digestum est, calorque ei datur. Quod autem flegma hoc hujusmodi sit, signum nobis est quod impetigines et sarpedones curat, quædam maturat ulcera, scorpiones necat. Hac ergo de causa et in ore cibus immutatur. Sic et stomachus ipsum immutat: ejus etenim circum amplectitur substantia, quasque habet imprimit qualitates, immutaturque ipsius naturali calore cibus: _Sed et quoniam cibus ipse in eo flegmati admiscetur humido._” (Theor. iv, 3.) The whole bearing of this passage, but more especially the last clause, puts it beyond a doubt that the process of digestion was supposed to be performed, in a certain measure, by the solvent powers of a fluid secreted in the stomach. And the ingenious Alexander Aphrodisiensis, in like manner, treating of the digestion of mustard, pepper, and other acrid substances, says decidedly, that their acrimony is dissolved in the copious fluid of the stomach. (Probl. i, 30.) See also Macrobius (Saturnal.