480 STUDIES IN GENERAL PHYSIOLOGY 



IX. SUMMARY OF RESULTS 



1. The addition of small amounts of a very dilute acid 

 or alkali brings about a great increase in weight (absorption 

 of water?) in a muscle contained in a physiological sodium 

 chloride solution. 



2. For the inorganic acids, HNO 3 , HC1, H 2 SO 4 , 

 KaHSO 4 , NaHSO 4 (in a high degree of dilution) this increase 

 in weight is solely a function of the number of hydrogen ions 

 contained in the unit of volume of the physiological salt 

 solution. Solutions of these different acids which contain 

 the same number of H ions in the unit of volume bring 

 about a quantitatively equal increase in weight. 



3. This simple relation does not hold for organic acids 

 (acetic acid, lactic acid, malic acid). In these the effect of 

 the anion or of the undissociated molecules makes itself felt. 



4. For the bases LiOH, NaOH, KOH, Sr(OH) 2 , Ba(OH) 2 , 

 this increase in weight is solely a function of the number of 

 hydroxyl ions contained in the unit of volume of the 

 physiological salt solution. Dilute solutions of these differ- 

 ent bases which contain an equal number of hydroxyl ions 

 in the unit of volume bring about an equal increase in 

 weight. 



5. If the muscle is introduced into various solutions of 

 NaCl the osmotic pressure of which is higher or lower than 

 that of the muscle, it is found that the change in the weight 

 of the muscle is not proportional to the difference between 

 the osmotic pressure in the muscle and that of the surround- 

 ing solution; in hypisotonic solutions the muscle increases 

 in weight more rapidly; in hyperisotonic solutions it 

 decreases in weight more slowly than corresponds to the 

 differences in osmotic pressure. 



6. The validity of Van 't Hoff's theory of osmotic pres- 

 sure for these processes is proved by the fact that solutions 

 of LiCl, KC1, RbCl, CsCl, MgCl 2 , CaCl 3 , SrCl 2 , and BaCl 2 



