580 DIGESTION. 



differing, however, slightly, according as it proceeded from animal or 

 vegetable food. In the latter case, it afforded four times as much 

 carbon as in the former, but less saline matter; and this consisted of 

 lime and an alkaline chloride. MM. Leuret and Lassaigne 1 analyzed 

 the chyme from the stomach of an epileptic, who died suddenly in a 

 fit, five or six hours after having eaten. It was of a white, slightly- 

 yellowish colour ; and strong, disagreeable taste. On analysis, it 

 afforded a free acid, the lactic; a white, crystalline, slightly saccha- 

 rine matter, analogous to the sugar of milk ; albumen, soluble in 

 water; a yellowish, fatty, acid matter, analogous to rancid butter; an 

 animal matter, soluble in water, having all the properties of casein; 

 and a little chloride of sodium, phosphate of soda, and much phosphate 

 of lime. Dr. Prout 2 affirms, that a quantity of chlorohydric acid is 

 present in the stomach during the process of digestion. He detected 

 it in that of the rabbit, hare, horse, calf, and dog, and in the sour 

 matter ejected by persons labouring under indigestion: a fact which 

 has been confirmed by Mr. Children. MM. Tiedemann and Gmelin, 

 and Dr. Beaumont, 3 affirm, that the secretion of acid commences, as 

 soon as the stomach receives the stimulus of a foreign body, and that 

 it consists of chlorohydric and acetic acids. The experiments of these 

 gentlemen were not confined to the chymous mass obtained from digesti- 

 ble food. They examined the fluids, secreted by the mucous membrane 

 when indigestible substances were sent into the stomach, and the acid 

 character was equally manifested. These experiments, consequently, 

 remove an objection, made by Dr. Bostock, 4 regarding the detection 

 of the chlorohydric acid by Dr. Prout; that, as there did not appear 

 to be any evidence of the existence of this acid before the introduction 

 of food into the stomach, it might rather be inferred, that it is, in some 

 way or other, developed during the process of digestion. In all Dr. 

 Beaumont's experiments, the chyme was invariably and distinctly acid. 

 The principal theories on chymification have been the following: 

 1. Coetion, or elixation. This originated with Hippocrates, and was 

 vaguely used by him to signify the maceration, and maturation expe- 

 rienced by the food in the stomach. The doctrine was embraced by 

 Galen and others, who ascribed to the organ, an attracting, retaining, 

 concocting, and expelling quality effected by heat. 5 In proof of this, 

 they affirmed that the heat of the stomach is increased during chymi- 

 fication ; that the process is more rapid in the warm, than cold-blooded 

 animal; that it is aided by artificial heat, and continues even after 

 death, if care be taken to keep up the heat of the body; that in the ex- 

 periments on artificial digestion made by Spallanzani, heat was always 

 necessary, and the greater the degree of heat the more easy and com- 

 plete the digestion. 



It is hardly necessary to say that the heat of the stomach is totally 

 insufficient to excite any coction or ebullition in the physical sense of 



1 Rechercbes, &c., p. 1 14. 



2 Phi los. Trans, lor 1824; and Bridge water Treatise, on Chemistry, &c., Amer. edit., p. 

 26S, Philad., 1834. 



3 On the Gastric Juice, &c,, p. 105. 4 Physiology, 3d edit., p. 569, Lond., 1836. 

 5 Boerhaav. Preelectiones Academ. Not. Adv., 86, torn, i., Getting., 1740-1743. 



