REACTIONS OF FIXATIVES WITH PROTEINS. I 43 



and gels by coagulant fixatives would have very deleterious effects 

 in microtechnique. So long, however, as the network is a very fine 

 one, the effect is not wholly damaging, for the spaces produced by 

 coagulation give access to embedding media, especially paraffin, 

 that would otherwise be unable to enter. It is a striking fact that 

 the great majority of the familiar fixative mixtures contain a 

 coagulant (see p. 148). 



