APR III.] DIFFUSIBILITY OF ALBUMOSES AND PEPTONES. 489 



III. 



ON THE DIFFUSIBILITY OF ALBUMOSES AND PEPTONES. 

 (Supplementary to pages 135 and 141.) 



The experiments of Funke 1 led him to assert that peptones in 

 aqueous solution diffuse through animal membranes with much 

 greater facility than other proteids, and Wittich, as well as Maly, 

 Herth and others (refer to p. 141), repeating Funke's observations, 

 but employing parchment paper instead of animal membranes, 

 arrived at a very different conclusion. The matter has recently 

 again been investigated (though as yet not in a complete manner) by 

 Kiihne 2 . Under the name of peptones, Funke and succeeding 

 observers had worked with indefinite mixtures of albumoses and 

 amphopeptone. Kiihne, on the other hand, has experimented with 

 solutions of the separate albumoses and with ampho- and anti- 

 peptones, though these peptones were not quite free from albumoses. 

 He has shewn that hetero-albumose is practically indiffusible, but 

 that proto- and deutero-albumose possess tolerably high diffusive 

 powers. Curiously, deutero-albumose, which according to Neumeister 

 is a secondary albumose, appears to be less diffusible than proto- 

 albumose. 



The diffusibility of ampho-peptone and of anti-peptone is very 

 much greater than that of either of the diffusible albumoses. Kiihne 

 has estimated that the diffusibility of both peptones (which strangely 

 appear to possess the same diffusive power) is about one-fourth that 

 of grape-sugar. 



1 0. Funke, ' Das endosmotische Verhalten der Peptone, ' Virchow's Archiv, Vol. xin. 

 (1858), p. 449. 



a W. Kiihne, ' Erfahrungen iiber Albumosen und Peptone. II. Zur Diffusion der 

 Albumosen und Peptone,' ZeiUch.f. Biol. Vol. 29 (1893), p. 20. 



