THE MUSCLE- ALBUMINS. 369 



offered evidence which goes to show that, after all, the process may 

 be a physical one, as the muscle-albumins, according to his experi- 

 ments, take no part in the process, viz., there is no coagulation of 

 the muscle-albumins. 



Other Albumins. Besides myosin and myogen, which latter was 

 formerly termed myoainogen, muscle-plasma was also supposed to 

 contain traces of serum-albumin, myoglobulin, and myo-albumose. 

 v. Fiirth, however, has shown that any trace of serum-albumin that 

 may be found is referable to the presence of small amounts of lymph 

 or blood that have not been removed by washing, and that if this is 

 done with special care no serum-albumin can be demonstrated. 

 Halliburton's myoglobulin he regards as identical with myogen, 

 while the existence of a myo-albumose in muscle-plasma has been 

 disproved by more recent investigations. That substances belong- 

 ing to the albumoses may be found in muscle-tissue after death, 

 when syntonin also is found, is, of course, likely, but in the living 

 tissue their presence can hardly be expected under normal condi- 

 tions. 



Myoproteid is a substance which v. Fiirth obtained from the 

 muscle-plasma of fish. Of its chemical nature nothing further is 

 known than the fact that it apparently does not belong to the com- 

 monly recognized classes of albumins. 



Nucleoproteids are not found in the muscle-plasma, but can be iso- 

 lated from the muscle-tissue as a whole or from the insoluble material 

 which remains in the filter-press after separation from the plasma. 

 Their amount is small, and in accordance with the slight degree to 

 which the nuclei enter into the structural composition of the muscle- 

 cell. Larger amounts are obtained from embryonic muscle, where 

 cellular reproduction is, of course, more active. From the tissue of 

 an adult dog Pekelharing obtained about 0.37 per cent. These 

 bodies must be regarded as the material from which the xan thin- 

 bases that can always be demonstrated in the muscle-tissue are de- 

 rived. These will be considered in detail later. 



Phospho-carnic Acid. Some years ago Siegfrid announced that 

 after removing the phosphates from extracts of muscle-tissue, 

 and treating with ferric chloride, under the application of heat, a 

 phosphorus-containing iron compound is obtained, which is insolu- 

 ble in water, but easily soluble in solutions of the alkalies. This 

 substance he regards as the iron salt of an organic acid, which he 

 terms phosphor-carnic acid ; the salt he speaks of as carniferrin. 

 On decomposition with barium hydrate he obtained the barium salt 

 of a crystallizable acid carnic acid, to which he gives the formula 

 C 1? H 15 N 3 O 5 . In addition, phosphoric acid, carbonic acid, paralactic 

 acid, succinic acid, and a substance which apparently belongs to the 

 carbohydrate group are found. 



Panella has recently pointed out that phospho-carnic acid occurs in 

 much larger amounts in the muscles of rabbits than in those of dogs ; 

 that the amount diminishes after death in proportion to the appear- 

 24 



