Then the wizard cast a wizzy spell and mumbled several very learned words in the wizardese language over the glass dog. Whereupon the little animal first wagged its tail from side to side, then winked his left eye knowingly, and at last began barking in a most frightful manner—that is, when you stop to consider the noise came from a pink glass dog. There is something almost astonishing in the magic arts of wizards; unless, of course, you know how to do the things yourself, when you are not expected to be surprised at them.