ix THE MUSCLE-ALBUMINS 389 



and which had redissolved in salt-solutions. It constitutes about 80 

 per cent of the muscle-albumin, and is more readily prepared than 

 is paramyosinogen. In certain respects it resembles globulin, as 

 v. Fiirth has pointed out, for it is precipitated by acids and by 

 being diluted with water or by dialysis ; but it differs from the 

 globulins in being only partially precipitated by dialysis and in being 

 fairly soluble in pure water, with a neutral reaction. By mineral 

 acids it is precipitated, but it dissolves with great ease if an excess 

 of acid be employed. As has been known since the time of Liebig, it 

 is especially readily converted into acid-albumin. It is precipitated by 

 acetic acid only in the presence of neutral salts, as otherwise it is 

 transformed at once into acid-albumin. On the other hand, myo- 

 sinogen is also precipitated by alkalies and by ammonia if salts are 

 present, and resembles in this respect the basic histones. Myo- 

 sinogen is precipitated by sodium chloride and magnesium sulphate 

 only if the solutions are quite saturated, the precipitation being even 

 then not complete according to v. Fiirth. The precipitation-limits for 

 ammonium sulphate are 3*6 and 5*2; a certain portion is, however, 

 only precipitated by saturated solutions. 



Myosinogen does not become rapidly insoluble after precipitation. 

 as does paramyosinogen, and it is denaturalised so very slowly by 

 alcohol that v. Fiirth employed alcohol for obtaining it in a pure 

 state. It is precipitated by the salts of the heavy metals only in the 

 presence of neutral salts. 



The coagulation-temperature of unchanged myosinogen is unani- 

 mously given at 56, but it is very difficult to bring about a com- 

 plete coagulation, particularly in solutions poor in salts, because 

 myosinogen is very apt to be partially converted into acid-albumin 

 and thereby to escape coagulation. 



On standing, myosinogen -solutions are apt to become changed 

 analogously to paramyosinogen-solutions. There is formed a coagulum 

 of myogen-fibrin. During the transition from myosinogen to myogen- 

 fibrin v. Fiirth has noticed a state during which the coagulation- 

 temperature falls to 40. This transition-product of myogen he calls 

 * soluble myogen-fibrin.' 



g ; According to Kiihne and Halliburton muscle-albumins are supposed 

 to coagulate completely >pr nearly so, whether they are left in situ 

 or whether they are pressed out of the muscle, and it is also believed 

 that they may be extracted completely from muscle in rigor mortis by 

 10 per cent sodium-chloride solutions or 15 per cent ammonia. 



v. Fiirth, on the other hand, is of the opinion that the coagulated 

 albumins are quite insoluble, and that the salt-soluble fraction is Hallibur- 



