How can you tell an original???

I have a painting. It is framed. The frame looks to be VERY old. The painting is called "Child in white" by Pierre Auguste Renoir. The original was painted in 1883. The frame looks like it could be that old! Is there a way I can tell without taking it to an antique appraiser? Do I have to take it out of the frame to tell? Best answer to the most helpful.