266 PHYSIOLOGICAL CHEMISTRY. 



by them that during rest glycogen is formed from the sugar, and 

 also that in activity other bodies besides sugar are transformed in 

 the muscles. 



The faintly alkaline or amphoteric reaction of the inactive 

 muscles is changed during activity to an acid reaction (DuBois- 

 KEYMOKD and others), and the acid reaction to a certain point 

 increases with the work (HEIDENHAIN). The quickly-contracting 

 pale muscles produce, according to GLEISS, more acid during ac- 

 tivity than the more slowly-contracting red muscles. The acid 

 reaction appearing during activity was formerly considered due to 

 the formation of lactic acid, a view which has been contradicted by 

 ASTASCHEWSKY, PFLUGER and WARREN", who found less lactic acid 

 in the tetanized muscle than when at rest. According to the 

 recent and more carefully conducted investigations of MARCUSE, 

 which have since been confirmed by WERTHER, there is no doubt 

 that free lactic acid is actually produced in the muscle during 

 activity. According to WEYL and ZEITLER, the active muscle con- 

 tains a larger amount of phosphoric acid (formed at least in part 

 from the decomposition of lecithin) than the resting muscle; and 

 the acid reaction of the active muscle may, therefore, in part be 

 due to the acid phosphate. 



The amount of albumin in the removed muscles is, according to 

 KANKE and NAWROCKI, decreased by work. The correctness of 

 this statement is, however, disputed by other investigators. Also 

 the older statements in regard to the nitrogenized extractive bodies 

 of the muscle in rest and inactivity are uncertain. According to the 

 recent researches of MOKARI, the total quantity of creatin and 

 creatinin is increased by work ; and indeed by an excess of muscular 

 activity, the amount of creatinin is especially augmented. The 

 creatinin is formed essentially from the creatin. In excessive 

 activity MOKARI also found xantho-creatinin in the muscle, and 

 the quantity was one tenth of that of the creatinin. The quantity 

 of xanthin bodies is, according to MOUARI, decreased under the 

 influence of work. It seems to have been positively shown that the 

 active muscle contains a smaller quantity of bodies soluble in 

 water and a larger quantity of bodies soluble in alcohol than the 

 resting muscle (HELMHOLTZ). 



An attempt has been made to solve the question relative to the 



