TO PROFESSOR LEWIS CAMPBELL.

                                                                           11 Scroope Terrace,
                                                                  Cambridge, 5th January 1878.

     It is more than a month that I have had your letter lying by me. I am glad you like Chrystal. His departure is a great   loss to the laboratory, as it is difficult to find any one to take up heavy work. W. D. Niven (brother of the  competitor) is going in for a heavy piece of work on conduction of heat in gases. I am no judge of Greek plays, but I think that your success in choruses is fully equal to that in dialogue, considering the greater difficulty,   not only in the interpretation, but in guessing the kind of effect, musical, rhythmical, rhetorical, poetical, and
     pictorial, which was aimed at in the delivery of the chorus.

     We have all been conversing on the telephone. Garnett recognized the voice of a man who called by chance. But   the phonograph will preserve to posterity the voices of our best speakers and singers. See Nature of Jan. 3d.