424 SIR JOHN LESLIE.
be revolted by absurd conclusions in other matters. Thus, even in physics,' he adds, ' mathematicians have been led to acquiesce in conclusions which appear ludicrous to men of different habits.' Something of the same kind was observ- able in the mind of this distinguished mathematician, for such also he was. He was apt, too, to run into some startling hypothesis, from an unwarrantable ap- plication of mathematical principles to subjects altogether foreign to them; as when he finds an analogy between circulating decimals, and the lengthened cy- cles of the seasons. In all his writings, with the exception, perhaps, of his last considerable performance, the discourse prefixed to the seventh edition of the Encyclopaedia Britannica, even in the sober field of pure mathematics, there is a constant straining after ' thoughts that breathe and words that burn,' and a love of abstract, and figurative, and novel modes of expression, which has ex- posed them to just criticism, by impartial judges, and to some puny fault-finding, by others, more willing to carp at defects than to point out the merits which redeem them . But when even severe criticism has said its worst, it must be al- lowed, that genius has struck its captivating impress, deep and wide over all his works. His more airy speculations may be thrown aside or condemned; but his exquisite instruments, and his original and beautiful experimental combinations, will ever attest the fruitfulness of his mind, and continue to act as helps to far- ther discovery. We have already alluded to the extent and excursiveness of his reading. It is rare, indeed, to find a man of so much invention, and who him- self valued the inventive above all the other powers, possessing so vast a store of learned and curious information. His reading extended to every nook and corner, however obscure, that books have touched upon. He was a lover, too, and that in no ordinary degree, of what is commonly called anecdote. Though he did not shine in mixed society, and was latterly unfitted by a considerable degree of deafness for enjoying it, his conversation, when seated with one or two, was highly entertaining. It had no wit, little repartee, and no fine turns of any kind, but it had a strongly-original and racy cast, and was replete with striking remarks and curious information.
" He had faults, no doubt, as all * of woman born' have : he had preju- dices, of which it would have been better to be rid; he was not over chari- table in his views of human virtue; and he was not quite so ready, on all occa- sions, to do that justice to kindred merit as was to be expected in so ardent a worshipper of genius. But his faults were far more than compensated by his many good qualities by his constant equanimity, his cheerfulness, his simplicity of character, almost infantine, his straightforwardness, his perfect freedom from affectation, and, above all, his unconquerable good nature. 3 He was, indeed, one of the most placable of human beings; and if, as has been thought, he generally had a steady eye, in his worldly course, to his own interest, it cannot be denied that he was, notwithstanding, a warm and good friend, and a relation on whose affectionate assistance a firm reliance could ever be placed.
" There is one other matter which, in justice to the illustrious dead, we can- not pass over in silence; we mean the permanent service rendered to the class of Natural Philosophy by the late Sir John Leslie in the collection of by far the
8 The person of Sir John Leslie was, in later life, far from gainly. He was short and cor- pulent with a florid face, and somewhat unsightly projection of the front teeth, and tottered considerably in walking. He was, moreover, very slovenly in his mode of dressing a pecu- liarity the more curious, as it was accompanied by no inconsiderable share of self-respect, and an anxiety to be thought young and engaging. The mixture of great intellectual powers with the humbler weaknesses of human nature, can seldom have been more strik- ingly exemplified than in his case ; though it is evident that, as his weaknesses were very much those to which unmarried men in advanced life are supposed to be most pe- culiarly liable, they might have probably been obviated in a great measure, if he had happened to spend his life in the more fortunate condition of matrimony.