324 MYOSIN. MUSCLE SERUM. [BOOK I. 



into water furnishes at once pure myosin, and resembles muscle 

 plasma in all respects, except in not coagulating spontaneously. 



Coagulation When gradually heated a solution of myosin begins 



of myosin. to be turbid at 55 C., and deposits flakes of proteid 



matter at 60 C., which consists of a coagulated product which 

 resembles other proteids coagulated by heat. 



Powdered common salt, added in excess, precipitates myosin from 

 its solutions in common salt. 



Myosin, like fibrin, decomposes peroxide of hydrogen. 

 Myosin- Liebig 1 shewed that when muscle is placed in dilute 



Syntonin. hydrochloric acid containing 1 part of acid in 1000, the 



proteid natter is in great part dissolved, to be precipitated when the 

 solution is neutralized. Liebig believed that the body dissolved in 

 the acid was a special body, muscle-fibrin ; it is now known, however, 

 that the solution merely contains acid-albumin or syntonin. differing 

 in no respect from acid-albumin obtained from other proteids. It 

 has been suggested that the ease with which it is converted into 

 syntonin, under the influence of dilute hydrochloric acid, specially 

 distinguishes myosin ; it is probable that the rapid formation of acid- 

 albumin is due to the fact that muscle always contains a trace of pepsin. 

 The facility with which a solution of acid-albumin can 

 Characters ^ obtained from muscle, causes us to examine in this place 

 f S B tonin n *^ e reac ^ ons f suc h a solution in greater detail than was 

 thought advisable in Chapter I. 



To prepare acid-albumin from muscle this tissue is finely divided and 

 then placed in a large quantity of dilute hydrochloric acid (1 part of HC1, 

 1000 parts of water). The solution is after some hours filtered. On 

 neutralizing, gelatinous flakes are obtained, which are collected on a filter 

 and washed. These contain in 100 parts : C, 54-06 H, 7'2S ; N, 16-05 ; 

 S, Ml; O, 21-50. 



Acid solutions of syntonin are not coagulated by heat; they are 

 precipitated by sodium chloride, ammonium chloride, calcium chloride, 

 sodium sulphate and magnesium sulphate. 



Syntonin is soluble in a solution of sodium carbonate of 1 p. c., and the 

 solution is not coagulated by heat. It is soluble in cold solution of lime 

 \vater, and the solution does not coagulate when boiled ; it froths when shaken. 



Muscle Serum. 



Following the analogy of the blood, we may designate, by the 

 name of muscle serum, the liquid which remains after the separation 

 of the spontaneously coagulating substance from the muscle plasma. 

 The muscle serum from which myosin has separated at a low tem- 

 perature has a neutral or faintly alkaline reaction. Kept at the 

 ordinary temperature of our dwelling-rooms it acquires an acid re- 

 action, in consequence of the development within it of sarcolactic acid. 



Proteids of Muscle serum contains three proteids in solution : 



the muscle 1. A proteid body which coagulates when the 



Berum. muscle serum is cautiously heated (if needs be after 



1 Liebig, Ann. d. Chem. u. Pharm. Vol. LXXIII. pp. 125129. 





