364 CHANGES IN MUSCLE DURING ACTIVITY. [BOOK I. 



When cyanhydrin is boiled with caustic potash, the potassium salt of 

 ethylene-lactic acid is obtained ; thus : 



CH 2 .CN CET.COOK 



+NH 



CH 2 .OH CH 2 .OH 



Cyanhydrin. Potassium Potassium ethylene- Ammonia, 



hydrate. lactate. 



2. Changes in the proportion of Water. 



According to Ranke 1 the amount of solid matter in muscles 

 undergoes diminution when muscles are tetanized, so that there 

 appears to be a relative increase of water. Further, according to this 

 author, the proportion of water in muscle is inversely proportional to 

 its power of doiag work. 



3. Changes in the water and alcohol extractives. 



It was first shewn by Helmholtz 2 that when muscles are tetanized 

 they yield a smaller quantity of matters soluble in water (water- 

 extractives}, but a larger quantity of alcohol-extractives than before. 

 This has been fully confirmed by Ranke 3 . 



Heidenhain and his pupils Nigetiet and Hefner 4 have more 

 recently shewn that as the resistance which an active muscle has to 

 overcome increases, the amount of the alcoholic extract increases and 

 that of the aqueous extract decreases. 



4. Changes in the Proteids. 



The total nitrogen of resting and tetanized muscle was found by 

 Ranke to be the same (about 14*4 p. c.). Ranke 5 fancied that he had 

 made out that the preparation of proteids removable by water 

 diminishes in the tetanized muscle. We may fairly say that no 

 trustworthy experimental results exist to prove that the proteids 

 of muscle undergo changes during activity. 



5. Changes in the amounts of Creatin. 



According to Sarokin 6 the amount of creatin in muscle is the same 

 whether it be in a state of rest or activity ; according to this author 

 a large production of creatinine occurs, however, during tetanus. 



1 Eanke, Tetanus, Chap. n. p. 63 ("Der Wassergehalt des Muskels"). 



2 Helmholtz, "Ueber den Stoffverbrauch bei der Muskelaction." Arch. f. Anat. u. 

 Phys. 1845, p. 72. 



' 3 Eanke, Tetanus, p. 141. 



4 Heidenhain, Nigetiet und Hefner. " Versuche iiber die Abhangigkeit des Stoffum- 

 satzes in den thatigen Muskeln von ihrer Spannung." Pfliiger's Archiv, Vol. in. (1870) 

 p. 574. 



5 Eanke, Tetanus, p. 119. See also Nawrocki, Centralblatt, 1866, p. 385. 



6 Sarokin, Virchow's Archiv, Vol. xxvui. 



