I've real doubts. So, silver in some areas of the print are
immune to the presence of the selenium atom. And what
could be the reason for that?
I prefer to believe that the highlight silver IS 'toned'
along with the rest of the print's silver. Due to the very
fine character of that highlight silver the 'toning' is less
noticeable. Dan
This is fairly easy to test. Take a few prints, and selenium tone for a variety of times, then bleach with a standard Ferri/Br bleach.
Here are a couple of examples I have just tried. These are using two test prints from a previous session, photographed with one of those computerised imagey things with a lens on the front.
I tend to use a moderately strong toner, and in this case it was selenium stock (Fotospeed), diluted 1+9. Bleach was 2.5% ferri (10% stock, diluted 1+3), with approx 8g of potassium bromide added to 800ml of working solution. The prints were made on Ilford MGIV RC, developed in Beer's #5.
The first image is the untoned print; the second is the straight toned print (in this case 3 minutes in the toner described); the third was toned for one minute, then bleached for ten minutes; and the fourth was toned for three minutes, and bleached for ten minutes.
As you can see, the one minute toned print has lost pretty much all of the highlight detail, and a lot of the shadow silver has been removed as well. With selenium toning for three minutes, the shadows and the midtones are holding up much better, but the highlights have still gone. I think given five to six minutes in this concentration of selenium toner, even the highlights would be immune to the bleaching.
So, whatever the mechanism underlying the action of selenium toner, the highlights definitely appear to tone last.
(Apologies for some of the wierd reflections on some of the shots!

)