cotton yarn or not?

[olg]

I have a large ball of yarn that was given to me. I think it is cotton. How can I tell if it is cotton or not? 

[Avon Lady]

Take a match or a lighter to one end.  If it starts burning, it is cotton.  If it melts, it is acrylic.

[Granny Square]

Burning is the best test, but don't forget other natural fiber like wool & linen burns, too.  And blends can give funky results.  Google 'fiber burn test' for more info, this is one result.

http://www.threadsmagazine.com/item/31497/how-to-identify-fabrics-with-a-burn-test

[Katieallen311815]

sometimes wool smells  different than acrylic too, to the sensitive noses that is.....

[olg]

My question was accidentally answered today. I went into a yarn shop to pick up some mercerized cotton thread and there was a skein of yarn just exactly like the ball I had been given, and the label read cotton. So, if I can get up my nerve to do my first swap, I have the cotton yarn on hand for the dishcloth.