Cadmium is dangerous if you breath it or eat it. This is the most important thing to remember. You can safely work with it by being careful and cover your reactions, work in under good fume control and practice good hygiene. In a beaker, place the contacts to no more than one third the volume of the beaker. Add equal amounts of whatever concentration of nitric acid you have and distilled water 50/50 to one half the volume of the beaker. Let the reaction take place without heat until the reaction slows down and then place the beaker on medium heat to finish the reaction. Be patient. Allow the solution to completely finish the reaction. There are one of two reasons the reaction stops, either the acid is depleted or the silver has been dissolved. turn off the heat and allow everything to cool completely. Decant the solution into a clean beaker. examine the solids left behind. If there is solid metals, rinse with distilled water and add this to the next batch. If there is no metal left, use the solution to dissolve more silver until the acid is depleted or you can neutralize the excess acid and proceed from there. If there are tungsten/silver points in the mix, a yellow powder of tungsten oxide will form. It's a pain to filter so I suggest you let the solution settle completely and draw the clear solution off from the top down.
