Stubborn bossy Jack Russel?

We have an older mixed terrier that my 4 year old jack russel has been terrorizing for the last 2 years or so. When he was a puppy the older dog was mean to him now it the other way around. Every time the poor old guy moves the young one will run up to the side of him and growl and nip him occasionally. Almost every time I scold him and make him sit down. I have pecked him with a newspaper before too, but these only work temporarily. What might i be doing wrong and what do i need to do?