254 PHYSIOLOGICAL CHEMISTRY. 



sulphate until each 100 cc. of the liquid holds 94 grms. of the salt 

 in solution. The rnyosin which now separates is filtered, dissolved 

 in water by aid of the retained salt, precipitated by diluting with 

 water, and, when necessary, purified by redissolving in dilute-salt 

 solution and precipitating with water. 



The older and perhaps the usual method of preparation consists, 

 according to DANILEWSKY, in extracting the muscle with a 5-10$ 

 ammonium-chloride solution, precipitating the myosin from the 

 filtrate by strongly diluting with water, redissolving the precipitate 

 in ammonium-chloride solution, and the myosin obtained from this 

 solution is either reprecipitated by diluting with water or by remov- 

 ing the salt by dialysis. 



As the coagulation of the blood-plasma is considered by most 

 investigators as an enzymotic process, so certain observations seem 

 to show that the coagulation of the muscle-plasma is an analogous 

 process. From muscles which had been kept for a long time in 

 alcohol HALLIBURTON obtained, by extracting the mass with 

 water, a soluble substance contaminated with albumose which, 

 although not identical with fibrin ferment, had the property 

 of accelerating the coagulation of the muscle-plasma. This sub- 

 stance was called by him " myosin-ferment." 



As in the blood-plasma we have a mother-substance of fibrin, 

 fibrinogen, so also it is considered that in the muscle-plasma we 

 have a mother-substance of myosin, myosinogen. This body has not 

 thus far been isolated with certainty. HALLIBURTON' found that 

 a solution of purified myosin in dilute-salt solution (5$ MgS0 4 ), 

 and sufficiently diluted with water, coagulates after a certain 

 time, and at the same time becomes acid and a typical myosin-clot 

 separates. This coagulation, which is accelerated by warming or 

 by the addition of myosin-ferment, is, according to HALLIBURTON, 

 a process analogous to the coagulation of the muscle-plasma. Ac- 

 cording to this same investigator, myosin when dissolved in water 

 by the aid of a neutral salt is reconverted into myosinogen, while 

 after diluting with water myosin is again produced from the 

 myosinogen. These observations may, however, be explained in 

 other ways. In these cases the separation of the myosin is evi- 

 dently closely connected with the liquid becoming acid, while the 

 separation of myosin from the muscle-plasma, at least from the 

 muscle-plasma of the frog, is independent of this acidity, for it may 



