130 CONTENTS OF THE INTESTINAL CANAL. 



Chevillot* found from 25'2 to 27'8g- (by volume) of carbonic 

 acid, from 8'2 to 13'Of of oxygen, and from 66'8 to 59'2^ of 

 nitrogen, with mere traces of hydrogen, in gas taken from the 

 stomach twenty-four hours after death. 



In the small intestine we usually find far less gas than in the 

 large intestine : in the small intestines of three persons who had 

 been executed, Magendie and Chevreul found no oxygen, but an 

 extraordinary abundance of hydrogen and carbonic acid (in the 

 first case 24'39 CO 2 , 20'08 N, and 55'53 H ; in the second 

 case, 40-00^ CO 2 , 8'85-- N, and 5M5 H ; and in the third case, 

 25*0 CO 2 , 66-6^ N, and 8'4 H.) ; Chevillot,t on the other hand, 

 always found 2 or 3^- of oxygen in the air discharged from the 

 small intestines of the bodies of aged persons. We can easily 

 understand how in cases of disease, and even in healthy persons, 

 after the use of flatulent food or drink, these accumulations of gas 

 occur more frequently than in the stomach ; for on the one hand, 

 the flatus is not so readily discharged from hence by eructation as 

 from the stomach, and on the other, the fermentation and decom- 

 position of the above named substances proceed here with a 

 rapidity proportional to the length of time they have already 

 remained in the stomach and small intestine. Constrictions of 

 individual portions of the small intestine, and other diseases of the 

 intestinal tube, contribute also essentially to the augmentation of 

 these accumulations of gas. 



On comparing the composition of the air from the small 

 intestine with that of the gas obtained from the stomach, we 

 observe in the one case a perfectly opposite relation to that which 

 holds good in the other ; we have here to deal with mere residual 

 traces of atmospheric air, the greater portion of the gas having its 

 source in the decomposition of nitrogenous and non-nitrogenous 

 substances. We must, however, always bear in mind that these 

 gases are only separated from those of the blood by permeable moist 

 membranes, and that, for this reason, the analysis of the air never 

 correctly expresses the gaseous products arising from the decom- 

 position of the food. Hence it is more than probable that the 

 symptoms of meteorism, which in children and hysterical women 

 occasionally supervene to a dangerous extent, are not merely 

 dependent on the mechanical contraction of the thoracic cavity (by 



* Journ. de Chim. med. 1 S^r. T. 5, p. 596-650, and Arch. ge'n. de He'd. 

 2 Sr. T. 5, p. 285-292. 



t [On referring to the Journ. de Chim. meU, we find that oxygen was only 

 found in the small intestines once in fifty-four cases ; in that case the proportion 

 was from 2 to 3g. e. E. D.] 



