If you would like a natural way to fall asleep, I would say to try some chamomile tea. It's my favorite tea and it'll send you right to sleep. But if you want medicine for you ensomnia, you should talk to a doctor.

The atomic mass for Sulfur is 32.065. If not known "ask.com" is a very reliable source, which all sorts of answers can be found.

Nicotine is a short acting drug, that doesn't stay in the system for very long. It will exit the body in about a day but the affects are relevant after the nicotine is gone.