16 PROTEIDS. 



consisting of acid-albumin. A similar jelly is formed, only gradually, 

 if the albumin is placed in a ring-dialyser and floated on dilute acids 

 (1-2 p. c.) 1 



Globulins are more readily converted into acid-albumin than 

 are the native albumins. Coagulated proteids or fibrin require 

 for their conversion the application of the acids, preferably hydro- 

 chloric, in a concentrated form, the products thus obtained being 

 practically indistinguishable from the products of the action of 

 dilute acids on the more readily convertible proteids. As ob- 

 tained -by the action of acids on the various proteids the products 

 exhibit certain not very marked differences, which however in- 

 dicate that each proteid yields its own special acid-albumin. The 

 researches of Morner 2 have shewn that, contrary to earlier views, 3 

 acid-albumins differ distinctly from the alkali-albumins. These 

 differences may be more appropriately considered after the prep- 

 aration and properties of the latter have been described. 



Preparation 1. Serum or diluted white of egg is digested at 

 40 50 for several hours with 1 2 p.c. hydrochloric acid. The 

 solution is now filtered, carefully neutralised, the precipitate col- 

 lected on a filter and washed with distilled water. 



2. Acid-albumin may be rapidly prepared by adding glacial 

 acetic acid to white of egg which has been chopped with scissors 

 and strained through muslin. A jelly is thus formed which can 

 be dissolved in warm water, and from this solution the acid-albu- 

 min can be precipitated by neutralisation and washed as before. 



2. Syntonin. 



Although this substance is merely the acid-albumin which re- 

 sults from the action of acids on the globulin (myosin) contained 

 in muscles, and in its more obvious properties^is at first sight 

 identical with other acid-albumins, it merits a short and separate 

 description, not only on account of its historical interest in the 

 chemistry of muscles, but also because recent work has shewn it 

 to be distinctly different from the similar products of the action of 

 acids on other proteids, and its properties and reactions have been 

 more fully studied than those of any other form of acid-albumin. 



Liebig, unacquainted with the existence of myosin in the dead 

 muscle, was the first to prepare it by the action of dilute (! p.c.) hy- 

 drochloric acid on the nmscle substance, 4 and he regarded it as the 



1 Johuson, Jl. Chem. Soc. 1874, p. 734. Ber. d. deutsch. chem. Gesell. 1874, S. 826. 

 Rollett, loc. cit. 



2 The original is in Swedish, but is fully abstracted in Maly's Jahresbericht, Bd. 

 vn. (1877), S. 9, and is also published in extenso in Pfliiger's Arch. Bd. xvn. (1878), 

 S. 468. A convenient resume is given on p. 541. 



8 Soyka, Pfluger's Arch. Bd. xii. (1876), S. 347. 

 4 Annalen d. Chem. n. Pharm. Bd. 73 (1850), S. 125. 



