REACTIONS OF FIXATIVES WITH PROTEINS. I 



35 



The table shows that ahhough picric acid, mercuric chloride, 

 and chromium trioxide are coagulants of both albumin and nucleo- 

 protein, yet these two proteins are not always coagulated by the 



TABLE 2 



The reactions of fixatives ivith nucleoprotein solution.^^ 



(See Appendix, p. 317.) 



same substances. Thus acetic acid, a non-coagulant of albumin, is 

 a precipitant of nucleoproteins, a fact that must be correlated with 

 its almost invariable inclusion in fixatives for chromosomes. 

 Conversely, ethanol coagulates albumin but not nucleoprotein. 

 Potassium dichromate coagulates neither. 



When gelatine/albumin gels are acted upon by fixatives, they 

 generally either shrink or swell. The results of a series of 



