Natural History, 171 



the fourth stomach, which like the last is on the right of the 

 paunch. It is larger in size, and communicates at the lower part with 

 the duodenum, by an aperture corresponding to the pylorus of single 

 Btomachs ; a very delicate mucous membrane covers it internally, 

 presenting large valves, disposed in a longitudinal direction. 

 The liquids which come into it from the third stomach undergo a 

 remarkable change, from alkaline becoming acid, and a white 

 opalescent flocculent matter precipitates on the valves, to which it 

 adheres as a false membrane would do. This precipitate is the 

 chyme, it is nearly pure albumen, and contains globules ; it does 

 not dissolve either in cold or hot water, or in mineral acids or 

 alcohol, but is very soluble in alkalies. The chyme and the parts 

 of the food pressed in the third stomach are evacuated into the 

 duodenmn, and brought into contact with the alkaline secretions 

 of the liver and pancreas. The chyme becomes an emulsion con- 

 taining globules ; the albumen remaining in the vegetable matter, 

 is extracted during the passage through the intestines, whilst, by 

 a particular set of vessels commencing on the surface of the latter, 

 the nutritive portion called chyle is absorbed, conveyed to the 

 thoracic duct, and from thence into the sanguiferous system. The 

 chyle of the sheep and horse is white, opalescent, readily coagulating 

 when received into vessels, the clot swimming in the serum, which 

 ultimately separates : it becomes slightly reddened on exposure 

 to air. 



One ounce of chyle was obtained from a moderately large sheep : 

 the coagulated portion washed, compressed in a cloth and dried, 

 gave 0.424 graimnes; it was more soluble in alkalies than fibrin, 

 but composed like it of white globules, having the same general 

 properties. The serum, gradually evaporated, weighed, when dry, 

 2.332 grammes; hot water dissolved 0.106 grammes of jelly 

 from it. 



As to the manner in which these phenomena were produced, it 

 would appear that the soda contained in the fluids of the two first 

 stomachs extracts albumen from the vegetables, and changes a 

 portion of it into jelly : a view confirmed by the following experi- 

 ment. To pure white of e^g was added a solution of 2.424 

 grammes of soda, in 183 of water, the whole well mixed, and left 

 exposed to air ; as usual, it became a transparent yellow jelly. 

 In 24 hours the whole had become fluid ; carefully evaporated, it 

 became brown ; as it became more concentrated, some transparent 

 insoluble films formed, and when the production of these had 

 ceased, the whole was filtered through a cloth : further evapo- 

 ration produced pellicles, which dissolved when stirred in the so- 

 lution, and ultimately, when cold, the whole became a gelatinous 

 mass, like that obtained from the second stomach. 



The albumen in solution meets in the fourth stomach with free 

 acid, which Pr. Prout has shewn to be the muriatic acid. This 



