My partner started a chemical fire at my studio which got me thinking about the chemicals I use. The fire was so very weird - NO flame or smoke for about 8 hours, just a slow invisible burning - a chemical fire.  There were bush fires that day, so I assumed the smell was from the bush.  Where did it originate?  Amazingly from my pickling solution.  I never would have dreamt just how dangerous and toxic even this 'mild' solution I use daily, is.  Not something they teach you in jewelry courses. I have always poured my used pickling solution into a big dead pot plant outside and my partner put out his cigarette in the pot plant.  That simple.  So I thought I would begin writing  something about other jewelry processes  I use AND know about, in the event it might help someone out there not make the same mistake. Let's start with nitric acid.  Why?  because every time I use nitric, I still am both totally paranoid of it and totally fascinated by it.  So please check out my article Engraving with Nitric Acid.