Indeed, it is not to be doubted that man's temperament is capable of being corrected, of being modified, of being changed, by causes as physical as the matter of which it is constituted. We are all in some measure capable of forming our own temperament: a man of a sanguine constitution, by taking less juicy nourishment, by abating its quantity, by abstaining from strong liquor, &c. may achieve the correction of the nature, the quality, the quantity, the tendency, the motion of the fluids, which predominate in his machine. A bilious man, or one who is melancholy, may, by the aid of certain remedies, diminish the mass of this bilious fluid; he may correct the blemish of his humours, by the assistance of exercise; he may dissipate his gloom, by the gaiety which results from increased motion. An European transplanted into Hindostan, will, by degrees, become quite a different man in his humours, in his ideas, in his temperament, in his character. Although but few experiments have been made with a view to learn what constitutes the temperament of man, there are still enough if he would but deign to make use of them--if he would vouchsafe to apply to useful purposes the little experience he has gleaned. It would appear, speaking generally, that the igneous principle which chemists designate under the name of _phlogiston_, or inflammable matter, is that which in man yields him the most active life, furnishes him with the greatest energy, affords the greatest mobility to his frame, supplies the greatest spring to his organs, gives the greatest elasticity to his fibres, the greatest tension to his nerves, the greatest rapidity to his fluids. From these causes, which are entirely material, commonly result the dispositions or faculties called sensibility, wit, imagination, genius, vivacity, &c. which give the tone to the passions, to the will, to the moral actions of man. In this sense, it is with great justice we apply the expressions, 'warmth of soul,' 'ardency of imagination,' 'fire of genius,' &c.