Miscellanies. 199 



not the gastric fluid, and all his experiments and reasonings are in- 

 applicable to that as an agent in digestion. 



As this fluid is poured out so readily and in such considerable 

 quantities, Dr. Beaumont infers, that it has been already separated 

 from the blood, and is retained in the minute secreting vessels; and 

 in accordance with this opinion, he considers the sensation of hunger to 

 be occasioned M by a distention of the gastric vessels, or that apparatus, 

 whether vascular or glandular, which secretes the gastric juice ; and 

 it is believed to be the effect of repletion by this fluid.' 5 This opin- 

 ion he defends at some length, and with much ingenuity, and places 

 it upon as fair a ground of probability as any other explanation of 

 this sensation which has been advanced. 



3. The principal, if not the sole effect of the gastric juice, is the 

 conversion of alimentary matters into chyme, by a chemical agency. 

 Dr. Beaumont agrees with most preceding physiologists in the ac- 

 count which he gives of the chyme. 



" The resulting compound of digestion in the stomach, or chyme, 

 has been described as u a homogeneous, pultaceous, greyish substance, 

 of a sweetish, insipid taste, slightly acid," &c. In its homogeneous 

 appearance, it is invariable ; but not in its color; that partakes very 

 slightly of the color of the food eaten. It is always of a lightish or 

 greyish color ; varying in its shades and appearance, from that of 

 cream, to a greyish, or dark colored gruel. It is, also, more consis- 



■ 



tent at one time than at another; modified, in this respect, by the 

 kind of diet used. This circumstance, however, does not affect its 

 homogeneous character. A rich and consistent quantity is all alike, 

 and of the same quality. A poorer and thinner portion is equally 

 uniform in its appearance. Chyme from butter, fat meats, oil, fee. 

 resembles rich cream. That from farinaceous and vegetable diet, 

 has more the appearance of gruel. It is invariably distinctly acid." 

 The manner in which chyme is formed, has been examined by 

 Dr. B. with a great deal of care, and his experiments upon this sub- 

 ject are the most numerous and important which he has related. It 

 is well known, that however nearly, different observers have agreed 

 as to the appearance of the contents of the stomach at different 

 periods after the reception of food, their explanation of the causes 

 of these appearances has been widely diverse. The majority of 

 physiologists, since the days of Spallanzani, have agreed with that 

 distinguished and most accurate experimentalist, in considering these 

 changes as produced by chemical action, and the chyme as the solu- 

 tion of aliment in the gastric juice. 



