42 PHYSIOLOGY [BoT. Absts., Vol. X, 



258. LoEB, Jacques. Ion series and the physical properties of proteins. 1. Jour. Gen. 

 Physiol. 3: 85-106. 1920. — The writer has conducted experiments to determine whether the 

 effects of acids and alkalies on proteins (gelatin and egg albumin) as measured by viscosity 

 and osmotic pressure can be explained on the basis of ion series or on a purely chemical basis. 

 The data all indicate that differences previously obtained by other workers and explained as 

 due to differences in ion series are probably due to the fact that rather large and equivalent 

 quantities of acids and alkalies were used rather than low concentrations having the same 

 Ph values. When solutions of protein with the acids HCl, HBr, HNO3, acetic, mono- 

 chloracetic, also di- and trichloracetic, succinic, tartaric, citric, and phosphoric were used 

 at the same Ph values and with the same concentrations of originally isoelectric protein there 

 were no differences between the acids in their effects on the osmotic pressure and viscosity of 

 gelatin and on the osmotic pressure of crystalline egg albumin. These protein acid salts all 

 behaved as if the anions were monovalent. H2SO4 formed protein salts with dibasic anion and 

 these salts have osmotic pressures and viscosities of only one-half or less that of the protein 

 salts with monovalent anion (protein chloride) at the same Ph values and with the same 

 concentration of originally isoelectric gelatin, while oxalic acid behaves as if most of the 

 anions were monovalent but a few divalent. It was also found that the osmotic pressures 

 and viscosities of the solutions of Li, Na, K, and NH4 salts of proteins are the same at the same 

 Pii values. Ca(0H)2 and Ba(0H)2 form salts with proteins in which the cations are dibasic, 

 and the osmotic pressures and viscosities of their salts are only one-half or less than half 

 those of salts with monovalent cations at the same Ph values. — Otis F. Curtis. 



259. LoEB, Jacques. Ion series and the physical properties of proteins. II. Jour. Gen. 

 Physiol. 3: 247-269. 1920. — This paper gives additional evidence (see preceding abstract) 

 that the physical properties of proteins, especially hydration, viscosity, and osmotic pressure, 

 are determined by the purely chemical forces of primary valency and not by the ion series 

 of Hofmeister. The relative solubilities of gelatin solutions in alcohol mixtures are in a simi- 

 lar sense independent of ion series. Conductivity measurements of solutions of gelatin 

 salts do not show a definite relation between the physical properties of proteins and changes 

 in degree of ionization. — Otis F. Curtis. 



280. LoEB, Jacques. Ion series and the physical properties of proteins. III. The actions 

 of salts in low concentration. Jour. Gen. Physiol. 3: 391-414. 1921. (See also the 2 pre- 

 ceding abstracts.) — Ions with sign of charge opposite to that of a protein ion diminish the 

 swelling, osmotic pressure, and viscosity of the protein solution, while ions with the same sign 

 of charge as the protein ion, excepting H and OH ions, seem to have no effect on the phenomena 

 mentioned so long as the concentration of the electrolytes does not exceed about J\I/16. The 

 relative depressing effects of different ions on the physical properties are functions of the 

 valency and of the sign of charge of the ions ; and those ions of the same sign of charge and of the 

 same valency have practically the same depressing effects on gelatin solutions of the same 

 Ph. The depressing effect increases rapidly with an increase in valencj\ The Hofmeister 

 ion series is explained as an error due to a failure to recognize the influence of the addition 

 of various salts on the hydrogen ion concentration of the solution. — Otis F. Curtis. 



261. LoEB, Jacques. The colloidal behavior of proteins. Jour. Gen. Physiol. 3 : 557-564. 

 1921. — The writer has applied the Donan equilibrium, — which supposes that one of the ions 

 in solution can not move through a membrane while another may, — to the colloidal behavior 

 of proteins showing that curves presenting potential differences (P.D.) as a function of the 

 hydrogen ion concentration resemble those for osmotic pressure, and that these P.D. and, 

 therefore, the physical properties of protein solutions, can be predicted from the differences 

 between the Ph of the solutions inside and outside of the membrane on the basis of the Nernst 



ip/TT /-I 



formula E = In -— if it is assumed that the P.D. are due to differences in the hvdrogen 



nF Ci 



ion concentrations on the 2 sides of the membrane. — Otis F. Curtis. 



