RESPIRATION IN THE ALIMENTARY CANAL. 



729 



stances, as is shown by the following table, which gives the results 

 obtained by Euge 1 from the analysis of the gas obtained from the 

 rectum of the same man under different conditions : 



The distribution of these gases -in the different parts of the aliment- 

 ary canal was examined by Tappeiner, 2 in the body of a criminal, who 

 had been executed a short time before the examination was made. The 

 following are the results : 



Zuntz, Lehmann, and Hagemann 3 found in the gas drawn off from 

 the intestine of a living horse about 22 per cent, carbon dioxide, 59 per 

 cent, marsh-gas, and 2*5 per cent, hydrogen. 



These gases have several sources of origin. Oxygen and nitrogen 

 occur in the air swallowed ; hydrogen, marsh-gas, and carbon dioxide 

 are formed by the fermentations which take place in the contents of 

 the alimentary canal; nitrogen and carbon dioxide, under certain 

 conditions, diffuse from the tissues into the intestines, and carbon 

 dioxide arises from the neutralisation of the sodium carbonate of the 

 intestinal secretions. Further details on the origin of these gases will 

 be found elsewhere ; 4 here it is necessary only to consider the part 



1 Sitzungsb. d. k. Akad. d. Wissensch., Wien, 1862, Bd. xliv. S. 739. 



2 Arb. a. d. path. Inst. zu Miinchen. Stuttgart, 1886, Bd. i. S. 226. See also Planer, 

 Sitzungsb. d. k. Akad. d. Wissensch., Wien, 1860, Bd. xlii. S. 307 ; Hofmann, Wien. med. 

 Wchnschr., 1872 : Tappeiner, Ztschr. f. physiol. Chem., Strassburg, 1882, Bd. vi. S. 432 ; 

 Ztschr. f. RioL, Miinchen, 1883, Bd. xix. S. 228; 1884, Bd. xx. S. 52; Arb. a. d. path. 

 Inst. zu Miinchen, Stuttgart, 1886, Bd. i. S. 215. 



' A Arch.f. Physiol., Leipzig, 1894, S. 354. 



4 See " Chemistry of Digestion," this Text-book, vol. i. 



