I have a box full of old medium format B&W negatives from the 1950's. They all appear to be 'Kodak Safety Film' marked. Many of them appear to have a metallic silver sheen on the emulsion side. When I try to scan them on my Epson 4990 I have difficulties. If the emulsion side is face up the image is completely washed out (I imagine because most of the light from the hood is being reflected away). If I try to scan them face down I get better results but still the image looks worse than if I just held the negative up to the light and looked through it with my naked eye. Can anyone recommend a good way of solving this problem? Can the negatives be treated chemically (refixed? washed? etc)? I'm curious to know the chemistry that causes this problem in the first place. Were they not properly fixed when they were developed? Thank you!