Composition of the Myosiyi of Muscle Tissue. 127 



muscle tissue. In fact, microscopic examination showed that 15 per 

 cent, solutions of this salt generally cause destruction of the muscle 

 fibres, while weaker solutions of the ammonium salt, as 5 per cent., 

 extract the myosin equally well, without injuring the structural 

 elements in the least. 



Thinking that possibly a purer myosin might be obtained by the 

 use of a weaker salt solution, several kilos, of thoroughly washed 

 muscle tissue were rubbed up with an excess of 5 per cent, ammo- 

 nium chloride and kept in contact with it for 48 hours. From the 

 filtered solution, myosin was separated by addition of a large volume 

 of water and the product washed and dried for analysis (G'). 



The tissue remaining after extraction as described, was treated 

 with a fresh 5 per cent, solution of ammonium chloride, and from 

 this fluid a second precipitate of myosin was obtained by addition of 

 water. This also was washed and dried for analysis (Gr"). 



The residue of tissue still i-emaining was then extracted with a 15 

 per cent, solution of ammonium chloride. The extract so obtained 

 gave a flocculent precipitate on saturation with sodium chloride, and 

 a coagulum appeared on boiling the solution, but no precipitate could 

 be obtained on addition of a large volume of water. It is thus evi- 

 dent that there was an almost complete extraction of myosin by the 5 

 per cent, solution of the ammonium salt. 



On precipitating the small amount of myosin present in the 15 per 

 cent, ammonium chloride solution by saturation of the fluid with 

 salt, a clear filtrate was obtained which gave a turbidity on boiling 

 and also on addition of acetic acid and potassium ferrocyanide, thus 

 showing the presence of a small amount of soluble albumin. 



The composition of the two myosins, as seen from the accompany- 

 ing tables, does not differ at all from that of other preparations. 



Myosin H., from muscle of sheep. 



In this preparation, the thoroughly washed and chopped muscle 

 was pai'tially extracted with a 5 per cent, ammonium chloride solu- 

 tion, and the myosin separated by addition of water. It was then 

 washed and dried for analysis (H^). 



The residue of tissue was extracted with a 15 per cent, solution of 

 ammonium chloride and the myosin separated from this solution, 

 likewise, by addition of water (H"). 



