ON THE ELECTRICAL CHARGE OF PROTEIN. 153 



freshly cut frog's muscles into salt solutions of various 

 kinds and measured the current of rest, he found that 

 the effects of the different salts in this regard arrange 

 themselves into a table similar to that given above for 

 the precipitation of electropositive protein. The sign 

 indicating a precipitation corresponds with a reversal 

 in the current of rest, while that indicating a solution 

 with the normal current of rest. 



The electrical behavior of proteins is of importance to 

 the histologist also for a proper understanding of the 

 important cellular reactions which take place in fixation 

 and staining. In spite of the fact that all the different 

 portions of the cell are exposed to the same action of 

 the fixing-agent, be this an indifferent substance, such as 

 alcohol, or one imposing a positive charge, such as a 

 solution of an acid or a heavy metal, the separate con- 

 stituents of the cell react differently toward acid and 

 basic dyes. Through the investigations of BILTZ in par- 

 ticular, the identity of the process of dyeing and colloidal 

 reactions seems to be well established, so that we may 

 assume that different portions of a cell may show different 

 electrical states when exposed to the same external con- 

 ditions. We will carry this discussion no further, but 

 will only draw attention to an observation which is 

 intimately connected with our own. E. MAYR (Graz) 

 has studied under BETHE'S direction the influence of 

 salts upon the fixation and precipitation of nervous tissue- 

 These studies have shown that the effects of ions upon the 

 preservation and staining qualities of nerve fibres arrange 

 themselves in a way similar to the table given on page 147 

 for the precipitation of electronegative protein, while the 

 order of the ions is just the reverse and corresponds, in 



