400 Dr. W. D. Halliburton. On Muscle Plasma. [June 16, 



prepared from the nitrate. The hydrogen was in each ease prepared 

 "by electrolysis. The water produced was free from any acid reaction, 

 and no trace of the oxides of nitrogen could be detected. 



XIX. " On Muscle Plasma." By W. D. Halliburton, M.D., 

 B.Sc, Assistant Professor of Physiology, University College, 

 London. Communicated by Prof. E. A. Schafer, F.R.S. 

 (From the Physiological Laboratory, University College, 

 London.) Received May 24, 1887. 



The facts described by Kiihne relating to the properties of the 

 muscle plasma of cold-blooded animals are true in great measure for 

 that of mammals. 



Admixture of muscle plasma with solutions of neutral salts prevents 

 the coagulation of the latter. Dilution of such salted muscle plasma 

 brings about coagulation ; this occurs most readily at 37 — 40° C. 

 Saline extracts of rigid muscle differ from salted muscle plasma in 

 being acid, but resemble it very closely in the way in which myosin 

 can be made to separate from it ; myosin in fact undergoes a recoagu- 

 lation. This is not a simple precipitation ; it is first a jellying through 

 the liquid ; the clot subsequently contracts, squeezing out a colourless 

 fluid or salted muscle serum. This does not take place at 0° C. ; it 

 occurs most readily at the temperature of the body, and is hastened 

 by the addition of a ferment prepared from muscle in the same way 

 as Schmidt's ferment is prepared from blood. The ferment is not 

 identical with fibrin ferment, as it does not hasten the coagulation of 

 salted blood plasma ; nor does the fibrin ferment hasten the coagula- 

 tion of muscle plasma. The recoagulation of myosin is also accom- 

 panied by the formation of lactic acid. 



The proteids of muscle plasma are — ■ 



1. Paramyosinogen, which is coagulated by heat at 47° C. 



2. Myosinogen,* which is coagulated at 56° C. 



3. Myoglobulin, which differs chiefly from serum globulin in its 

 coagulation temperature (63° C). 



4. Albumin, which is apparently identical with serum albumin x, 

 coagulating at 73° C. 



5. Myo-albumose ; this has the properties of deutero-albumose, and 

 is identical with, or closely connected to, the myosin ferment. 



The first two proteids in the above list go to form the clot of 

 myosin ; paramyosinogen is, however, not essential for coagulation ; 

 the three last remain in the muscle serum. 



* It is on the presence of this proteid that the power of fresli muscle juice to 

 hasten the coagulation of blood plasma depends. 



