vin THE ACID- AND ALKALI-ALBUMINS 337 



HC1 in a few minutes that its coagulation by heat is not an easy 

 matter. This acid-albumin prepared from muscle has received the 

 special name ' syntonin,' but by some workers the term syntonin is 

 also used, without exception, for all acid-albumins. Egg-albumin is 

 much more difficult to convert into acid-albumin than is muscle- 

 albumin, and yet, according to Goldschmidt, 1 i normal HC1 will form 

 in one hour a demonstrable amount of acid-albumin, and even a 

 weaker acid may perhaps do so. Serum-albumin is still more resistant 

 to the action of acids : 0*25 per cent HC1 and 2 per cent acetic acid 

 'have no action whatever at room -temperature, while at 40 acid- 

 albumin is formed to a slight extent in 1 4 days ; even 2 per cent HC1 

 converts serum-albumin only very slowly at room-temperature. In all 

 these experiments we have to remember, as was pointed out by Danilew- 

 sky, 2 that native albumin is a base, and that in neutralising a part of 

 the acid it makes the latter to that extent ineffective. Many of 

 the differences which have been described as existing between certain 

 albumins and certain strengths of acid may be explained in this way. 



The transformation of albumin into acid -albumin is enormously 

 hastened, especially at body-temperature, if the acid is assisted by 

 the ferment pepsin. Under these conditions acid-albumin is not only 

 formed much more quickly, but it is also very quickly transformed 

 into albumoses, peptones, and peptids. According to Umber, 3 the 

 relative resistance of different albumins to pepsin + hydrochloric acid 

 is quite different from that shown to hydrochloric acid alone ; but in 

 this case anti-ferments play perhaps a part (Cohnheim). The author 

 holds with Umber that the pepsin attacks the albumin-molecule in 

 quite a different way than does the acid. (See also index.) 



The natural albumins are changed by alkalies even more readily 

 than by acids, in consequence of which, as a rule, alkali-albuminates 

 are formed more quickly, at a lower temperature, and with feebler 

 concentrations of alkalies than are the corresponding acid-albumins. 

 Alkali-albuminates are formed at once, if albumins are heated to 

 their coagulation -temperature, but even at room -temperature the 

 greater part of serum-albumin is converted into alkali-albuminate in 

 2J hours if it is acted upon by 0'2 per cent sodium hydrate, according 

 to Johannsson. A 2 per cent NaOH solution quickly disintegrates 

 serum-albumins in a remarkable way, according to Maas. 4 According 

 to Zoth 5 and Dieudonne, 6 serum-albumin becomes partially converted 



1 F. Goldsclimidt, Sduren und Eiiveiss. Dissertation, Strassburg, 1898. 



2 A. Danilewsky, Zeitschr. f. physiol. Chem. 5. 158 (1881). 



3 F. Umber, ibid. 25. 258 (1898). 4 0. Maas, ibid. 30. 61 (1900). 



5 0. Zoth, Sitzungsber. der Wiener Akad., Math.-nat. KL, Abteil. III. 10O. 140 (1891). 



6 Dieudonne, Verli. d. Phys.-med. Ges. zu Wurzb. Munch, med. Wochens. 1903, p. 43. 



Z 



