Here's a breakdown of the story: upstanding scientist does research on the dark side of man's nature, and creates a potion that transforms him into a bad guy. What happens next? Read the book. Seriously. It isn't that long, and it's good. Look into it.
This silent version stars John Barrymore. His transformation from upright scientist-gentleman to ugly hedonist was remarkable. I wasn't sure it was the same actor. But here's where my biases come into play: I don't like silent films. When I started watching it, I didn't realize it was that old. There is a 1931 version that I understand is very good.
I watched the unimproved public domain version and found it rather tedious. The music track was terrible and never matched the action on screen. I turned the volume down almost all the way. Ten minutes shorter would have been ten minutes better. I don't think a fully restored copy with a new score wouldn't have made the difference for me. I should have skipped this one. AMRU 2.
Still interested? Watch it here.