The reign of law is a phrase comprehensive enough to embrace many points of minor import; and among those assigned to its sway the prevalent habit of right-handedness has been recognised as one of too familiar experience to seem to stand in need of further explanation. It has been accepted as the normal usage and law of action common to the whole race; and so no more in need of any special reason for its existence than any other function of the hand. Nevertheless it has not wholly eluded investigation; nor is it surprising that the exceptional but strongly marked deviations from the normal law should have attracted the notice of thoughtful observers to the question of right-handedness as a curious and unsolved problem. A philosophic speculator of the seventeenth century, the famous old Norwich physician, Sir Thomas Browne, reverts characteristically to the mystic fancies of the Talmud for guidance, as he turns to the question in its simplest aspect, and quaintly ignores the existence of its foundation. With his strong bent towards Platonic mysticism, this question, like other and higher speculations with which he dallied, presented itself in relation to what may well be called “first principles,” as an undetermined problem. “Whether,” says he in his _Religio Medici_, “Eve was framed out of the left side of Adam, I dispute not, because I stand not yet assured which is the right side of a man, or whether there be any such distinction in nature.” That there is a right side in man is a postulate not likely to be seriously disputed; but whether there is such a distinction in nature remains still unsettled two centuries and a half after the inquiry was thus started. The same question was forced on the attention of an eminent philosophic speculator of our own day, under circumstances that involved a practical realisation of its significance. Towards the close of a long life in which Thomas Carlyle had unceasingly plied his busy pen, the dexterous right hand, that had unflaggingly toiled for upwards of threescore years in the service of his fellow-men, was suddenly paralysed. The period of life was all too late for him to turn with any hope of success to the unaccustomed and untrained left hand; and more than one entry in his journal refers to the irreparable loss. But one curious embodiment of the reflections suggested by this privation is thus recorded by him upwards of a year after experience had familiarised him with all that the loss involved: “Curious to consider the institution of the Right hand among universal mankind; probably the very oldest human institution that exists, indispensable to all human co-operation whatsoever. He that has seen three mowers, one of whom is left-handed, trying to work together, and how impossible it is, has witnessed the simplest form of an impossibility, which but for the distinction of a ‘right hand,’ would have pervaded all human things. Have often thought of all that,--never