A few weeks ago, I smelled a horrible sulfury acidic smell coming from outside. I live in a forest area, a short ways from hundreds of acres of BLM land, quite a nice neighborhood - mostly all 5 acre parcels, all owner occupied.
The smell was quite bad outside. I called the local cop shop (it was about 9 at night) and when I described it, the lady cop said someone must be cooking meth not too far away. They use the sulfur from match heads in some way.
Most likely battery acid,as in car battery.That is what I have heard meth cookers use.
Cat pee. If you're ever in the woods and smell a strong odor of cat pee, turn around and run like hell.
Funny thing is, I don't think any components of meth are illegal. So much for legalizing it makes everything all better and the problem goes away.