My dear Barrett,—­I am always glad when a man I like and respect treats me as a friend.  I am advised by other friends also not to waste more time on Dr. C. [Carpenter], and I do not think I shall answer him again, except perhaps to keep him to certain points, as in my letter in the last Nature.  In a proof of his new edition of “Lectures” I see he challenges me to produce a person who can detect by light or sensation when an electro-magnet is made and unmade.  The Association of Spiritualists are going to experiment, as Dr. C. offers to pay L30 if it succeeds.  Should you have an opportunity of trying with any persons, and can find one who sees or feels the influence strongly, it might be worth while to send him to London, as nothing would tend to lower Dr. C. in public estimation on this subject more than his being forced to acknowledge that what he has for more than thirty years declared to be purely subjective is after all an objective phenomenon.

I never had anything to do with showing or sending a medium to Huxley.  He must refer to his seance a few months ago with Mrs. Kane and Mrs. Jencken (along with Carpenter and Tyndall), when ... nothing but raps occurred....—­Yours very faithfully,

ALFRED R. WALLACE.

* * * * *

The British Association met in Dublin in 1878, and Prof.  Barrett asked Wallace to stay with him at Kingstown, or, if he preferred being nearer the meetings, with a friend in Dublin.  Earlier in the year Mr. Huggins, afterwards Sir W. Huggins, O.M. and President of the Royal Society, had sent Prof.  Barrett a very beautifully executed drawing of the knots tied in an endless cord during the remarkable sittings Prof.  Zoellner had with the medium Slade.  Sir W. Huggins invited Prof.  Barrett to come and see him at his observatory at Tulse Hill, near London, and there he met Wallace and discussed the whole matter.  It may not be generally known that so careful and accurate an observer as Sir W. Huggins was convinced of the genuineness of the phenomena he had witnessed with Lord Dunraven and others through the medium D.D.  Home.  He informed Prof.  Barrett of this himself.

TO PROF.  BARRETT

Waldron Edge, Duppas Hill, Croydon.  June 27, 1873.

My dear Barrett,—­The receipt of a British Association circular reminds me of your kind invitation to stay with you or your friend at Dublin, and as you may be wishing soon to make your arrangements I write at once to let you know that, much to my regret, I shall not be able to come to Dublin this year.  Since I met you at Mr. Huggins’s I have done nothing myself in Spiritual investigations, but have been exceedingly interested in the knot-tying experiment of Prof.  Zoellner and the weight-varying experiments of the Spiritualists’ Association.  I do not see what flaw can be found in either of them....—­Yours very faithfully,