362 



PHYSIOLOGICAL CHEMISTRY 



Besides this salt we have present chlorides and salts of sodium, calcium, 

 magnesium, and iron. Sulphates are present in traces. 



Mendel and Saiki have made some interesting observations upon the 

 chemical composition of non-striated or smooth (involuntary) mammalian 

 muscle, such as the urinary bladder and the muscular coat of the stom- 

 ach of the pig. Hypoxanthine was found to be the predominant purine 

 base present. Creatine and paralactic acid were also isolated. These 

 investigators were unable to demonstrate, definitely, the presence of 

 glycogen in the non-striated muscles studied, but state that "the 

 tissues possess the property of transforming glycogen in the char- 



FIG. 116. XANTHINE. 

 After the drawings of Horbaczewski, as represented in Neubauer and Vogel. 



(Ogden.) 



acteristic enzymatic way." The most important part of their in- 

 vestigation consists in a rather complete analysis of the inorganic 

 constituents of these muscles. A notable difference in the relative 

 distribution of the various inorganic constituents was observed, a 

 difference which, according to the authors, "can be accounted for in 

 part only by an admixture of lymph." The comparative composition 

 of the inorganic portion of striated and non-striated muscle and of blood 

 serum for comparison is shown in the following table: 



An interesting comparative study of the ash of the smooth muscle of 



