Classicly

In dealing with a subject so old and yet so new, I can do little more than suggest explanations of phenomena. I do not venture to assert them. Those suggestions are submitted to the reader to induce him to think and as subjects for further examination and discussion rather than as dogmatic assumptions of ascertained truths.

The facts and phenomena reported are vouched for so far as my own means of ascertaining their truth[ enable me; but causes and conclusions can of necessity be little more than conjecture until a much larger collection of the facts be made. To the gathering of such facts I hope this little book may stimulate many observers. I shall deem the communication of them a valuable contribution to science, and a favour to myself.