THE PHYSICO-CHEMICAL BASIS OF STRIATED 

 MUSCLE CONTRACTIONi 



2. Surface tension 



WILLIAM N. BERG 



(WITH PLATE l) 



If the physico-chemical basis of muscle contraction is ever to be 

 understood or explained, it is almost certain that it will be brought 

 about thru speculation and experiment of a quantitative, rather 

 than of a qualitative nature. The mere Statement that muscle con- 

 traction is caused by surface tension, or thru osmotic action, etc., 

 unless accompanied by quantitative data of an experimental or 

 theoretical nature, can add little toward the Solution of the problem 

 of the transformation of energy by muscle. It is, perhaps, regret- 

 able that so many of the " theories of muscle contraction " which 

 have appeared in the recent literature belong to the qualitative class. 

 Occasionally someone attempts to treat the subject quantitatively. 

 From this point of view the works of Bernstein,^ and of Zuntz^ 

 are particularly meritorious, even if the problem has not yet been 

 solved by them. 



Among the latest qualitative contributions to the theory of 

 muscle contraction, is that of Strietman and Fischer.^ They studied 

 the contraction and relaxation of catgut strings immersed in various 

 Solutions. By attaching the strings to the usual arrangement of 

 iever and recording drum, they found that when a catgut string is 

 immersed in water or physiological salt Solution, even for some 

 time, no changes in length take place (p. 66). But if the string be 

 immersed in Solutions of hydrochloric or lactic acids (w/8o to 



^ Berg, W. N. : Biochemical Bulletin, 1912, i, 535. 

 ^ Bernstein, J. : Arch. f. d. ges. Physiol., 1901, 85, 271-312. 

 ^Zuntz, N. : Die Kraftleistung des Tierkörpers. Festrede; Berlin, 1908. 

 * Strietman, W. H., and Fischer, M. H. : Ztschr. f. Chemie und Industrie der 

 Kolloide, 19 12, 10, 65-77. 



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