Paul Sengupta wrote:

So "mineral spirits" is the same?

Nope. Completely different smell. It's used primarily here to thin oil-based
house paints and for cleaning stuff. It's an oilier substance than naptha,
which makes naptha better for cleaning applications that must be oil free. So
I used turpentine for oil painting (back when I did such things), I use mineral
spirits for paintbrush cleanup and cleanup of car and aircraft parts, and naptha
to clean items I'm preparing to paint.

I haven't found much on how they're made or what the chemical differences are,
but I did find a medical dictionary which lists them as different substances
and prescribes different treatments for cases of poisoning. That site is
http://www.nlm.nih.gov/medlineplus/ency

As others have pointed out, mineral spirits is also called "Stoddard's Solvent".

George Patterson
Some people think they hear a call to the priesthood when what they really
hear is a tiny voice whispering "It's indoor work with no heavy lifting".