Remove old yellow glue from wooden floor that has consistency of cement
The best thing is to try a little bit in an inconspicuous area of the floor to see if it works before doing the rest of the floor.

I just finished cleaning up my floors- I had carpet pad glue all over the floor. For me, two things worked: mineral spirits, and Wil-Bond.

Keep in mind that your surface may be different, your glue may be different. It's also possible that the glue will pull up the protective coating on the wood, or even some of the wood itself. In that case, you may need to re-stain and/or re-surface the wood.