good faith--and I cordially sympathise with any one who is so charged unjustly. Such cases have seemed to me almost the only ones for which it is worth while entering into controversy.”... “These polemics of the scientific world are very unfortunate things; they form the great stain to which the beautiful edifice of scientific truth is subject. _Are they inevitable?_” Controversy whether in religion or science was to him alike detestable. He took no part in politics. A letter to Tyndall (see “Faraday as a Discoverer,” p. 39), written after the latter had told him of a rather heated discussion at the British Association meeting in 1855, speaks of his own efforts at forbearance. He says:-- These great meetings, of which I think very well altogether, advance science chiefly by bringing scientific men together and making them to know and be friends with each other; and I am sorry when that is not the effect in every part of their course.... The real truth never fails ultimately to appear.... It is better to be blind to the results of partisanship, and quick to see good will. One has more happiness in oneself in endeavouring to follow the things that make for peace. You can hardly imagine how often I have been heated in private when opposed, as I have thought unjustly and superciliously, and yet I have striven, and succeeded I hope, in keeping down replies of the like kind. And I know I have never lost by it. [Sidenote: HATRED OF CONTROVERSY.] During the years when he was examining the apparatus of rival inventors for lighthouse illumination, he could calmly hear them described as Mr. So-and-So’s electric lights, all the while knowing that it was his own discovery of magneto-electric induction which had made the mechanical production of electric light possible. Yet he fired up if anyone dared to revive the priority dispute between Davy and Stephenson as to the invention of the safety lamp. “Disgraceful subject,” was his own comment. In his dispute with Snow Harris as to the design of lightning rods, in which, as it is now known, Snow Harris was right; in his dispute with Airy over the curved lines of force; in his minor difficulties over Hare’s pile and Becquerel’s magnetic observations, none could either assert his own position with more simple dignity, nor admit with greater frankness the rights of his rival. To Hare he wrote:-- You must excuse me, however, for several reasons from answering it [Hare’s letter] at any length; the first is my distaste for controversy, which is so great that I would on no account our correspondence should acquire that character. I have often seen it do great harm, and yet remember few cases in natural knowledge where it has helped much either to pull down error or advance truth. Criticism, on the other hand, is of much value.