In order to proceed regularly with this subject, it appears that our reasonings may be employed concerning things, or the objects in nature, and on terms which are not the immediate representatives of natural phenomena, but as they have been denominated general or abstract; and which are intended to be the verbal representatives of multitudes of objects arbitrarily classed, or of opinions comprised under such term. That reason is not an inherent, peculiar, and independent faculty of the human mind, receives a strong confirmation from considering, that it cannot be voluntarily exerted on subjects of discussion, but requires, as the indispensable condition of its operation, the basis of knowledge, which is to be understood to mean, the result of observation and experiment: for the mere employment of language, on a subject with which we are unacquainted, is but idle prating and a lavishment of words. To reason, is to adapt our means, that is, our knowledge, for the attainment of the end or object proposed: it is the estimate or admeasurement of these means. If, for example, a military commander intended effectually to bombard a city;--such being the object proposed, he would immediately proceed to estimate, admeasure, or calculate his means to produce the effect, and his success would depend on the knowledge he possessed of the nature and properties of the materials employed: he must calculate the distance, elevation, proportionate quantity of powder, and the time the fuzee should burn previously to the explosion of the shell; with various other necessary circumstances. This is an example of a very pure process of reasoning as applied to things, and accords with the definition that has been attempted. If it were necessary to multiply instances of the reasoning on things, perhaps the construction of a thermometer would be a well-adapted illustration; and it would likewise exhibit that which I am very anxious to impress, namely, the very gradual manner in which knowledge, by the operation of reasoning has been applied to the purposes of utility. That many substances, and particularly metallic bodies, augmented in magnitude by being heated, or, as we now term it, expanded by heat, was known many centuries ago, and was a fact of hourly occurrence to the artificers in metals. A similar increment of bulk was also observed in fluids; and it was likewise known, that their dimensions contracted as they cooled. This fact appeared to obtain so generally, that it became an aphorism, that bodies expanded by heat and contracted by cold. Of the precise gradations of heat they were, however, ignorant. Most of the senses became tests, although they were inaccurate criteria. The sight conveyed some distinctive marks; so that when some metallic bodies were heated to a high degree, they were observed to become red, and as the heat was increased, they were rendered white. By the touch, a variety of