PHYSIOLOGY. 189 



float near to the upper orifice of the stomach, and are therefore 

 most readily brought up. I have known several persons liable 

 to this rumination, and from them have learned, that certain 

 substances are more commonly brought up than others, and 

 some at a longer time after eating than others ; and both cir- 

 cumstances seem clearly to depend upon the different degrees 

 of solubility in these substances.' 1 M. M. 



CCXXXIV. However, from what happens in the stomachs 

 of certain animals, there is ground to presume that indeed in 

 every one there is a peculiar solvent. But whether this be a 

 menstruum dividing the solid into integrant parts, and thereby 

 reducing it to a fluid state, or if the solvent here be a peculiar 

 fermentative power, resolving matters more or less into constit- 

 uent parts, is not clearly perceived. 



CCXXXV. The latter is the most probable, as the circum- 

 stances of fermentation very constantly appear, and as the de- 

 viations which at any time appear in the course of digestion ap- 

 pear always to be an excess of fermentation, either acescent or 

 putrefactive. 



CCXXXVI. The business seems to us to proceed in this 

 manner : The fluids of the stomach have the power of suddenly 

 and powerfully loosening the fixed air of the alimentary mat- 

 ters, which is the first step towards putrefaction, and that which 

 most effectually breaks down the texture, and perhaps the mix- 

 ture of bodies. But we now know, that putrescent bodies are 

 very powerful in exciting an acescent fermentation in vegetable 

 substances, which the human stomach is hardly ever without ; 

 and that this acescency therefore, in the next place, very con- 

 stantly succeeds, and an acid is produced in the stomach. This 

 acidity makes the effects of the putrefaction disappear ; and the 

 acidity, in its turn, disappears also, probably by its being ab- 

 sorbed by, or united with the putrescent and oily matters here 

 present ; and it is in this manner that we suppose that the ani- 

 mal fluid is produced, and daily renewed by the combination of 

 a fresh portion of acid with putrescent fluids previously exist- 

 ing in the body. The daily production of acid in the human 

 stomach, and its readily disappearing again, without showing 

 any morbid effects, renders our doctrine sufficiently probable. 



CCXXXVII. This is the assimilation of vegetables that I 



