Water, 98 parts; _lactic acid_, muriate of ammonia, chloride of sodium, animal matter soluble in water, mucus, and phosphate of lime, 2 parts. Total, 100. Dr. PROUT and Mr. CHILDREN have announced the gastric acid, of which so much has been said, to be the muriatic, while M. CHEVREUIL had stated it to be the lactic. MM. LEURET and LASSAIGNE confirm the results of CHEVREUIL, and that with great confidence in their own accuracy. They found the contents of all the four stomachs of ruminating animals acid. MM. PREVOST and LEROYER had stated those of the three first to be alkaline. The observations of LEURET and LASSAIGNE agree with those of MONTEGRE, (vide Dict. des Sci. Med.) who believes digestion to produce acidity as a result of the regular process. The _faeces_ become alkaline. _Substances which contain no azote, from whatever class they are obtained, cannot serve for nutrition._ We cannot understand this, especially when compared with what follows. "If, on the contrary, they are soluble, one part is absorbed and another is expelled, either by urine or by the anus; such are sugar, gum, &c." This seems to us like a contradiction. It is impossible, in the present state of science, to determine the chemical change which aliments undergo in the digestive organs; both on account of their mixture and the insufficiency of our means of analysis. "The absorption of chyle takes place by the villi." "These communicate directly with the lacteals and the vena portae." "The transference of the chyle takes place by the lacteals; nevertheless, if they are obliterated, _this may be done through the vena portae_." _The section of the pneumo-gastric nerves does not stop the dilution of aliments in the stomach, or chylification._ The juices secreted by the liver and pancreas, are poured into the intestines in greater quantity during digestion than at any other period; in consequence of the contact of the acid chyme with the biliary and pancreatic orifices. The pancreatic juice is analogous to the saliva. The spleen is an appendage to the liver; it swells during the absorption of liquids by the vena portae. Liquid aliments are digested, just as much as solid; but they do not require so great a quantity of gastric and intestinal juices. Watery drinks are absorbed in the stomach and intestines, by the radicles of the vena portae. Spirituous drinks occasion an afflux of the gastric juices, become acid, and are absorbed. Excrements owe their colour and odour to the bile, and their consistence to the absorption of a portion of the water they contain. They carry off a large amount of the nutriment. Great obscurity still remains as to the cause of hunger. Thirst is thought to be produced by the drying which the pharynx undergoes, from the passage through it of the air used in respiration, and at a time when the supply of mucous fluid is scanty.