I took my foldscope on a recent trip to China and collected air samples of the smog by letting a slide sit on an outdoor table for an hour or by carrying it with me as I walked around.  This was so much fun and so easy to travel with that I am taking my foldscope with me on all my trips now.  It makes a great conversation starter!

Here are some more of my China air samples.  Each slide I made had about 10-15 of these black gobs in different sizes.  FYI to be fair I also checked my air in the U.S. and there are no black things in the air where I live.