would have a regular meeting ground.  This was the famous x Club, a name singularly appropriate on the principle of lucus a non lucendo to a club of nine members who never proceeded to the election of a tenth.  Opinions as to the name and constitution of the little society being no less numerous than the members—­indeed more so—­“we finally accepted the happy suggestion of our mathematicians to call it the x Club; and the proposal of some genius among us that we should have no rules, save the unwritten law not to have any, was carried by acclamation.”

Huxley first propounded the scheme to his most intimate friends, Joseph Dalton Hooker, then Assistant Director of Kew, and John Tyndall, Professor of Natural Philosophy at the Royal Institution.  George Busk, the anatomist, afterwards President of the College of Surgeons, was another whose friendship dated from soon after the return of the Rattlesnake to England.  Herbert Spencer, the philosopher, and Sir John Lubbock, banker and naturalist, were friends of nearly as long standing.  Edward Frankland, Professor of Chemistry at the Royal Institution, and Thomas Archer Hirst, Professor of Physics and Pure Mathematics at University College, London, afterwards Director of Naval Studies at the Royal Naval College, Greenwich, entered the circle as special friends of Tyndall’s.  William Spottiswoode, Queen’s Printer and mathematician, was the ninth member, elected by the rest at the first meeting.

Between them they could have managed to contribute most of the articles to a scientific Encyclopaedia:  six were Presidents of the British Association; three were Associates of the Institute of France; and from among them the Royal Society chose a Secretary, a Foreign Secretary, a Treasurer, and three successive Presidents.  Meeting though they did for the sake of friendship and good fellowship, it was inevitable that they should discuss the burning questions of the scientific world freely from varied points of view, and, being all animated by similar ideas of the high function of science and of the great Society, the chief representative of science to which all but one of them belonged, they incidentally exercised a strong influence on the progress of scientific organization.

The first meeting took place on November 3, 1864; nearly nineteen years passed before the circle was broken by the death of Spottiswoode.  Proposals were made to fill the gap with a new friend, but, as the raison d’etre of the club had been simply the personal attachment of the original nine, the project fell through.  Finally, after Hirst’s death in 1892, when five out of the remaining six were living away from London and for the most part in uncertain health, it became more and more difficult to arrange a meeting, and the club quietly lapsed after nearly twenty-eight years of existence.

Guests were often entertained at the x dinners, men of science or letters of almost every nationality—­a delightful and quite informal mode of personal intercourse.  In the summer, also, the x often made a week-end expedition into the country or up the river, in which the wives of the married members took part, the formula for the invitation being x’s + yv’s.