338 CHEMISTRY OF THE PROTEIDS CHAP. 



into alkali-albuminate on being heated for some hours to 40 in a 

 feebly alkaline solution. No other investigations into this question 

 have been made, but the statements of Bernert 1 regarding the 

 oxidation of albumin by means of permanganate and caustic alkalies, 

 as well as Hammarsteri's investigations into the acid- albumins : mucin, 

 globulin, fibrinogen, casein, which, as a rule, were dissolved in dilute 

 alkalies, in alkali -carbonates, or in ammonia, all show clearly that 

 albumin is denaturalised with great rapidity when it is brought intc 

 contact with alkalies. 



This denationalisation can readily be proved, for the alkali 

 albumi nates differ chemically from the albumins from which they are 

 derived. Nasse 2 and Schmiedeberg 3 found alkali-albuminates poorei 

 in nitrogen than the native albumins, and for this reason Schmiedeberg 

 introduced the term ' desamido-albuminic acid.' Nasse has found acid 

 albumins to be also poorer in nitrogen. The ultimate dissociation 

 products resulting from the action of acids and alkalies have beer 

 discussed on pp. 90-96. 



As already pointed out, the formation of acid-albumins and o: 

 alkali-albuminates in the absence of salts is accompanied by no visiblt 

 change, while in the presence of small amounts of salt a precipitate 

 is formed. Quite different is the behaviour of concentrated albumins 

 when they are brought into contact with very strong acids or alkalies 

 for more or less stiff jellies are formed, which may show all transition; 

 between glass-like transparency and milk-white opacity. To thes( 

 jellies were originally restricted the terms 'acid-albumins' anc 

 * alkali-albuminates.' 



The first to observe this jelly formation or gelation was Rose 

 in 1833, who prepared an albumin-ferric-chloride jelly. Magendie, 

 Lieberkuhn, Johnson 7 were other early observers ; while subsequent!} 

 this question was investigated by Rollet 8 and his pupil Zoth ; 9 b} 

 Kieseritsky 10 and Rosenberg n under the direction of Alexandei 

 Schmidt ; by Neumeister and the author. Whether a jelly is formet 



1 R. Bernert, Zeitschr. f. physiol. Chem. 26. 272 (1898). 



2 0. Nasse, Pfliigers Arch, fur die gesammte Phys. 7. 139 (1872). 



3 0. Schmiedeberg, Arch.f. experiment. Path.u. Pharmak. 39. 1 (1897). 



4 Ferdinand Rose, Poggendor/'s Ann. 28. 140 (1833). 



5 Magendie, Lemons sur le sang, Paris, 1836, p. 170 (according to Rollet). 



6 N. Lieberkiihn. Arch.f.Anat., Physiol. u. wissenschaftl. Med. 1884, pp. 285, 323 



7 Johnson, Journ. of the Chemical Soc. N.S. 12. 734 (according to Rollet). 



8 A. Rollet, Sitzungsber. d. Wien. Akad., Math.-naturw. KL, Abteil. III. 84 

 332 (1881). 



9 0. Zoth, ibid. 100. 140 (1891). 



10 W. Kieseritsky, Die Gerinnung des Faserstoffes, Alkalialbuminats und Acid 

 albumins. Dissertation, Dorpat, 1882. n A. Rosenberg, Dissertat., Dorpat, 1883 



