137 



turbid on the addition of diluted acetic acid ; this reagent, however, 

 threw down a distinct precipitate from the saccharine solution. 



January 5, 1856 (from note-book). "The mucous membrane 

 infused in simple water is today looking disintegrated, in layers, the 

 solution opake and slimy ; slightly alkaline, just bitter. The mucous 

 membrane in sugar very bitter, perfectly transparent. I believe that 

 the difference of the mucous membrane, as infused in water and in 

 syrup, appears to be well established." 



January 9. "The sugar solution is perfectly transparent, very 

 litter, very slightly alkaline ; the membrane is much swelled out and 

 thickened ; fresh. The watery solution is becoming decomposed, 

 alkaline, has lost its bitter taste, very turbid ; the membrane is 

 shrivelled and separating into layers. Microscopic examination re- 

 ferred the turbidness to broken-down epithelium." 



The report of the above series of experiments has been thus 

 minutely transcribed, because it seems to place the active agency of 

 the mucous membrane beyond reasonable doubt, so far as the class 

 of bodies alluded to is concerned ; but principally because, as will be 

 seen in the sequel, Pettenkofer's method alone appears to fail in 

 some cases as a discriminating test of the bile. 



Action of the Mucous Membrane of the Gall-bladder upon Albumen. 



January 27. "At 3 P.M. took a portion of dry mucous mem- 

 brane and carefully washed it in several waters ; it was then plunged 

 into the white of an egg. 8 P.M. the glairy fluid is bitter." 



January 31. "The solution apparently increasing in bitterness; 

 a little water added to supply the loss by evaporation." 



February 18. "The albumen solution has from time to time 

 been diluted with water. Today I can barely detect bitterness, nor 

 is the colour changed. On applying Pettenkofer's test, the play of 

 colour, supposed to be characteristic of bile, was very distinct in the 

 fluid portion ; the albumen coagulated by the heat, retaining its 

 white colour." 



This result was perplexing ; on the 19th, therefore, an experiment 

 was made on the white of an egg, per se, to ascertain whether the 

 effect was due to the albumen. The white of an egg was first boiled 

 in water, to coagulate the albumen, and the filtered fluid, containing 

 soluble albumen and probably other organic matters, was examined 



