No, this is not the case. Obviously the sections were covered in emulsion
initially to deposit silver grains (duh), and the emulsion was initially
uniform after the fixation, but then disintegrated when I washed in water,
ethanols, etc. The essential point is that I can't see the silver grains when
the tissue remains covered with emulsion. Also, the emulsion is NOT
transparent there. The slide is perfectly clean between the sections. Thanks
for your help.