586 



ALBUMIN AND CONDUCTIVITY 



EXPERIMENTAL. 



The crj^stalline egg albumin used in these experiments was prepared 

 according to the method described by Hopkins,^ and recrystallized 

 twice. It was dialyzed until practically free from inorganic salts. 

 The percentage of albumin was determined by drying to constant 

 weight. The hydrogen ion concentration was determined by a gas 

 chain and the conductivity by a Kohlrausch bridge at 25°. Duplicate 

 observations were made in every case. The albumin was brought to 

 the various hydrogen ion concentrations by the addition of NaOH or 

 HCl. 



The first experiment (Table I) was performed with pure albumin 

 solutions varying from 1.1 to 8.3 per cent. The conductivity of these 



TABLE I. 

 Conductivity of Pure Albumin Solutions. 



solutions was determined at pH 3.1, 5.3, and 7.3. The results are 

 plotted in Fig. 1, with the concentrations of albumin as abscissae and 

 the specific conductivities X 10"* as ordinates. The curves are reduced 

 to the same scale and plotted at equal intervals above each other. 

 The increase of conductivity with each increment of albumin appar- 

 ently follows a straight line curve in each instance. The quantitative 

 relations at the various hydrogen ion concentrations are similar to 

 those found in the gelatin solutions. 



In a second experiment (Table II) gradually increasing amounts of 

 albumin were added to a 0.6 per cent NaCl solution. Observations 



« Hopkins, F. G., /. Physiol, 1899-1900, xxv, 306. 



