CHYMIFICATION. 579 



tion. To the nature of the gastric juice and its effects in the process 

 of digestion, we shall have occasion to recur presently. 



It is probably owing to the quantity of fluid secreted by the stomach, 

 that it is so largely supplied with bloodvessels; and that the mucous 

 membrane is more injected, during the presence of food in the organ. 

 Experiments, by Sir Benjamin Brodie 1 and others, would seem to show, 

 that the secretion is under the influence of the eighth pair of nerves. 

 Having administered arsenic to different animals on some of which he 

 had divided these nerves, he found, that, whilst the stomachs of those, 

 in which the nerves w r ere entire, contained a large quantity of a thin, 

 mucous fluid ; in those, whose nerves were divided, the organ was in- 

 flamed and dry. Leuret and Lassaigne, 2 however, affirm, that divi- 

 sion of the nerves had no influence on the secretion. But more of this 

 presently. 



Before entering into the views of different physiologists on chymifi- 

 cation, in other words, into the theories of digestion, it will be well 

 to refer to the physical and chemical properties of the chyme. Whether 

 the changes in the food be simply physical or chemical, or whether the 

 first stage of animalization be effected within the stomach, will be a 

 topic for future inquiry. Chyme is a soft, homogeneous substance, of 

 grayish colour and acid taste. Such are its most common characters: 

 it varies, however, according to the food taken, as may be observed, 

 by feeding animals on different simple alimentary substances, and 

 killing them during digestion. This difference in its properties accounts 

 for the discrepancy observable in the accounts of writers. The change 

 wrought on the aliments is, doubtless, of a chemical nature; but the 

 new play of affinities is controlled by circumstances inappreciable to 

 us. In the case of a female patient at the hospital La Charite, of 

 Paris, who had been gored by a bull, and had a fistulous opening in 

 the stomach, the food, during its conversion into chyme, appeared to 

 have acquired an increase of its gelatin; a greater proportion of chlo- 

 ride of sodium; phosphate of soda and phosphate of lime; and a sub- 

 stance, in appearance, fibrinous. 3 



It has been said, again, that the food becomes decarbonized and 

 more nitrogenized ; that the carbon which disappears is removed by 

 the oxygen of the air swallowed with the food, or by that contained in 

 the food itself; and that the nitrogen proceeds from the secretions of 

 the stomach, or predominates simply because the food is decarbonized. 

 M. Adelon 4 has properly remarked, that the fact and the explana- 

 tion are here equally hypothetical. Generally, the chyme possesses 

 acid properties. MM. de Montegre, 5 Magendie, 6 and Tiedemann and 

 Gmelin, 7 always observed it to be so. Haller 8 and Marcet found it to 

 be neither acid nor alkaline. In the chyme examined by the latter 

 gentleman, he detected albumen, an animal matter, and some salts, 



1 Philos. Trans, for 1814. 2 Op. citat. 



3 Richerand's Nouveaux Elemens de Physiologic, edit. ISeme, par Berard, aine, p. 72, 

 Bruxelles, 1837. 



4 Physiol. de 1'Homme, &c., edit, cit., torn. ii. 



5 Experiences sur la Digestion, Paris, 1824. 6 Op. citat., ii. p. 87. 



' Op. cit. 8 Element. Physiol., xix. 1. 



