224 CHEMISTRY OF THE PROTEIDS . CHAP. 



are the protanrins, which possess, however, a different constitution. 

 Both histones and protamins form salts with nucleic acid, which in 

 some cases are called nucleo-proteids. 



Albumoses contain acid as well as basic substances, and react as a 

 rule slightly alkaline. 



Siegfried's peptones are strong acids. On being dissociated with 

 acids they liberate the strong base kyrin (see p. 200). 



Special attention is drawn to the fact that any albumin or its 

 derivative maintains its amphoteric character (see p. 208), however 

 acid or however basic it may be, although of course either the acid or 

 the basic character will predominate. 



III. THE INDIVIDUAL SALTS 



The chlorides, nitrates, and sulphates of all albumins are much 

 more soluble in water than are the pure albumins ; they are also 

 soluble in fairly, strong alcohol, and differ in this respect from neutral 

 albumins. According to Paal, 1 peptone -chlorides are soluble in 

 absolute methyl alcohol, and in mixtures of methyl alcohol and glacial 

 acetic acid. According to Morner, 2 the crystalline serum -albumin, 

 prepared by Krieger's method, 3 is the sulphate, while the crystalline 

 egg-albumin of Hopkins and Pinkus 4 is the acetate. That gastric 

 digestion gives rise to chlorides of the albumoses and peptones has 

 already been mentioned. The salts of albumins with phosphotungstic 

 acid and other alkaloidal reagents are insoluble, for which reason these 

 reagents are used as precipitating agents. The peptone-phosphotung- 

 states are soluble in alcohol according to Cremer. 5 The metaphosphates 

 described by Lorenz 6 and Fuld 7 show distinct hydrolysis, and they 

 have already been mentioned in connection with the nucleo-proteids. 



The salts which albumins form with ammonia, with fixed alkalies, 

 and with the alkaline earths, are still more important, because 

 the acid albumins, nucleo-albumins, mucins, etc., occur in nature 

 as such readily soluble salts. According to Friedrich Miiller, 8 normal 

 mucin is an alkali salt of mucin, while, according to Hammarsten, 9 



1 C. Paal, Bericht. d. deutschen chem. Ges. 25. II. 1202 (1892). 



2 K. A. H. Morner, Zeitschr. f. physiol. Chem. 34. 207 (1901). 



3 H. Krieger, Strassiburger, Dissertat. 1899. 



4 F. G. Hopkins and S. N. Pinkus, Journ. of Physiology, 23. 130 (1898). 



5 M. Cremer, Miinchener Ges. f. Morphol. u. Physiol. 1898, fasciculus III. 



6 R. Lorenz, Pfluger's Arch. f. d. gesamte Physiol. 47. 189 (1890). 



7 E. Fuld, Hofmeisters Beitrage, 2. 155 (1902). 



8 Fr. Miiller, Schleim der Respirationsorgane ; Sitzungsber. d. Ges. z. Bef. d. ges. 

 Naturwissensch. zu Marburg, 1896, p. 53. 



9 0. Hammarsten, Kgl. Gesellsch. d. Wissensch. zu Upsala, 1877, Reprint. 





