I am myself doing very well this year, rather light work, etc., but still troubled with bad sleep so as to advance very slowly with private study and writing. However, few days without a line at least. I found to my surprise and pleasure that Robertson was willing to print my chapter on Space in "Mind," even though it should run through all four numbers of the year.[85] So I sent it to him. Most of it was written six or even seven years ago. To tell the truth, I am _off_ of Space now, and can probably carry my little private ingenuity concerning it no farther than I have already done in this essay; and fearing that some evil fiend might put it into Helmholtz's mind to correct all his errors and tell the full truth in the new edition of his "Optics," I felt it was high time that what I had written should see the light and not be lost. It is dry stuff to read, and I hardly dare to recommend it to you; but if you do read it, there is no one whose favorable opinion I should more rejoice to hear; for, as you know, you seem to me, of all writers on Space, the one who, on the whole, has thought out the subject most _philosophically_. Of course, the experimental patience, and skill and freshness of observation of the Helmholtzes and Herings are altogether admirable, and perhaps at bottom _worth_ more than philosophic ability. Space is really a direfully difficult subject! The third dimension bothers me very much still. I have this very day corrected the proofs of an essay on the Perception of Time,[86] which I will send you when it shall appear in the "Journal of Speculative Philosophy" for October last. (The number of "July, 1886" is not yet out!) I rather enjoyed the writing of it. I have just begun a chapter on "Discrimination and Comparison," subjects which have been long stumbling-blocks in my path. Yesterday it seemed to me that I could perhaps do nothing better than just translate 6 and 7 of the first _Abschnitt_ of your "Tonpsychologie," which is worth more than everything else put together which has been written on the subject. But I will stumble on and try to give it a more personal form. I shall, however, borrow largely from you.... Have you seen [Edmund] Gurney's two bulky tomes, "Phantasms of the Living," an amazingly patient and thorough piece of work? I should not at all wonder if it were the beginning of a new department of natural history. But even if not, it is an important chapter in the statistics of _Völkerpsychologie_, and I think Gurney worthy of the highest praise for his devotion to this unfashionable work. He is not the kind of stuff which the ordinary pachydermatous fanatic and mystic is made of.... _To Henry P. Bowditch._ [Post-card] CAMBRIDGE, _Mar. 26_ [1887].