CHEMICAL BASIS OF THE ANIMAL BODY. 15 



specimen taken at the same time will give hardly any precipitate on 

 leutralisation. Some time later, the interval depending on the pro- 

 )ortion of the acid to the albumin, on temperature, and on other 

 sircumstances, the coagulation will be less, and the neutralisation 

 >recipitate will be considerable. Still later the coagulation will be 

 bbsent, and the whole of the proteid will be thrown down on neutrali- 

 ;ation. 



The conversion of the native albumins in solution into acid-albumin by dilute 

 icids is facilitated by heating to temperatures below those at which the albumins 

 espectively coagulate 1 . The conversion is extremely rapid if a strong acid is added 

 o a concentrated solution of the proteid, thus when a little glacial acetic acid is 

 tirred into undiluted white of egg the whole solidifies into a yellow transparent 

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

 Ibumin is placed in a ring-dialyser and floated on dilute acids (1 2 p. c.) 2 . 



Globulins are more readily converted into acid-albumin than are the 

 lative albumins. Coagulated proteids or fibrin require for their con- 

 ^ersion the application of the acids, preferably hydrochloric, in a 

 :oncentrated form, the products thus obtained being practically 

 ndistinguishable from the products of the action of dilute acids on the 

 nore readily convertible proteids. As obtained by the action of acids 

 >n the various proteids the products exhibit certain not very marked 

 lifferences, which however indicate that each proteid yields its own 

 pecial acid-albumin. The researches of Morner 3 have shewn that, 

 :ontrary to earlier views 4 , acid-albumins differ distinctly from the 

 Jkali-albumins. These differences may be more appropriately con- 

 idered after the preparation and properties of the latter have been 

 lescribed. 



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

 :0 50 for several hours with 1 2 p.c. hydrochloric acid. The 

 olution is now filtered, carefully neutralised, the precipitate collected 

 >n a filter and washed with distilled water. 



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

 ,cid to white of egg which has been chopped with scissors and strained 

 hrough muslin. A jelly is thus formed which can be dissolved in warm 

 pater, and from this solution the acid-albumin can be precipitated by 

 Leutralisation and washed as before. 



1 Eollett, Sitzb. d. Wien Akad. Bd. LXXXIV. (1881), S. 332. Heynsius, Pfliiger's 

 Irch. Bd. xi. (1875), S. 624. 



2 Johnson, Jl. Chem. Soc. 1874, p. 734. Ber. d. deutsch. chem. Gesell. 874, S. 

 ;26. Kollett, loc. cit. 



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

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

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



4 Soyka, Pfliiger's Arch. Bd. xn. (1876), S. 347. 



