How can you test for human blood?

My husband and I were cleaning out our attic and there was a really old trunk up there, it was so big we had to break it into pieces to remove it. The trunk had a big lock on it, and was clearly built in the attic. I took one of the pieces of wood to put plants on in the window upstairs, and when a little water overflowed onto the wood i wiped it up and discovered that it reeks like death. I wonder if the former occupants of this house killed someone in that trunk or hid a body in that trunk up in the attic. Our house is over one hundred years old and the trunk may be that old too. Is there a way to test this wood to see if it is indeed infused with dead person?