The Light Within (1918)

Dr. Laurel Carlisle marries wealthy Clinton Durand so she will have the money to finance her important experiments in bacteriology in order to find a cure for anthrax--even though she doesn't love Durand and is actually in love with her colleague Dr. Leslie. Durand turns out to be a violent brute who mistreats Laurel and her son Donald. Matters come to a head when Donald dies of pneumonia while on a trip with Durand, and Laurel blames him for it. Complications ensue.