40. SLATER, E. C. and K. W. CLELAND. 1953. The effect of tonicity of the medium on the respiratory and phosphorylative activity of heart-muscle sarcosomes. Biochem. J. 53: 557-567. 41. SPECTOR, W. G. 1953. Electrolyte flux in isolated mitochondria. Proc. Roy. Soc. B. 141: 268-279. 42. STANBURY, S. W. and G. H. MUDGE, 1953. Potassium metabolism of liver mitochondria. Proc. Soc. Exp. Biol. Med. 8...