116 Chittenden and Cummins — Nature and Chemical 



solution we have mainly employed two methods, either dilution with 

 a large volume of distilled water, or dialysis of the ammonium 

 chloride solution until the salt is entirely removed. In this latter 

 process, we have often observed that the sepai'ation of myosin 

 partakes more of the nature of a coagulation than of an ordinary 

 precipitation. A moderately strong ammonium chloride solution 

 of myosin, on being placed in a parchment bag and suspended in 

 running watei", will ordinarily at the end of two or three days be 

 converted into a semi-solid, jelly-like mass, which later on contracts 

 more or less, but still shows all the characters of a genuine clot. 

 In fact, we are inclined, with Halliburton, to consider this a genuine 

 re-coagulation rather than a j^recipitation. We are inclined, how- 

 ever, to believe that separation of myosin by dialysis is hardly as 

 satisfactory in the preparation of small quantities, as precipitation by 

 water, since on dialysis the jellying of the myosin naturally tends to 

 enclose some of the salt and also any other proteids possibly present 

 in the solution, while by precipitation with water the myosin is floc- 

 culent, easily washed and thus more surely freed from both salt and 

 albumin. 



Myosin A, from ox muscle. 



The first sample of myosin was prepared from a freshly killed ox. 

 The finely chopped muscle from the thigh was freed, so far as possi- 

 ble, from all traces of blood and soluble albumin by long soaking 

 and frequent kneading with water. The water was frequently 

 changed and kept thoroughly thymolized so as to prevent any ap- 

 proach to putrefaction. When the washings failed to give any tur- 

 bidity by heat, or by acetic acid and potassium ferrocyanide, the 

 washed tissue was placed in 10 litres of a 15 per cent, solution of am- 

 monium chloride for extraction of the myosin. The resultant opales- 

 cent fluid was filtered through paper and the myosin precipitated 

 by saturation with sodium chloride. The precipitate was quickly 

 strained off, dried somewhat between folds of filter paper, dissolved 

 in a small amount of water and reprecipitated by treatment of the 

 fluid witli a large volume of water. The precipitate so obtained 

 was washed with water until the washings gave no reaction for 

 chlorides, when it was treated with weak alcohol and finally with 

 95 per cent, and absolute alcohol, and ether. 



When partially dried, it was ground tine and further dried at 110° 

 C. until of constant weight, for analysis. 



Its composition is shown in the accompanying table. 



