be skeptical

References in classic literature ?
And the wandering visitor might be skeptical about all the swindles, but he could not be skeptical about these, for the worker bore the evidence of them about on his own person-- generally he had only to hold out his hand.
Now Mbonga and Rabba Kega might not take much stock in their own magic, and they might even be skeptical as to the magic of another; but there was always a chance of SOMETHING being in it, especially if it were not their own.