circumgyration

The word which is now going out of my mouth causes pulsations or waves in the air, and these, though invisible to human eyes, expand in every direction until they have passed around the whole globe, and produced a change in the whole atmosphere; nor will a single circumgyration complete the effect; but the sentence which I am now uttering shall alter the whole atmosphere through all future time.

In the vertigo from circumgyration the irritative motions of vision are increased; which is evinced from the pleasure that children receive on being rocked in a cradle, or by swinging on a rope.

But this rolling of the eyes, after revolving till we become vertiginous, cannot cause the apparent circumgyration of objects, in a direction contrary to that in which we have been revolving, for the following reasons.

To these movements of the eyes, of which he supposes the observer to be inconscious, Dr. Wells ascribes the apparent circumgyration of objects on ceasing to revolve.

Secondly, though there is an audible vertigo, as is known by the battement, or undulations of sound in the ears, which many vertiginous people experience; and though there is also a tangible vertigo, as when a blind person turns round, as mentioned above; yet as this circumgyration of objects is an hallucination or deception of the sense of sight, we are to look for the cause of our appearing to move forward, when we stop with our eyes closed after gyration, to some affection of this sense.