The two co-existing pounds originally adjusted in relation to the specific gravities of wheat and spring-water, are now the sole remains and representatives of a fanciful theory spun in the middle ages; and the first question that occurs is, whether the pound troy, having served its purpose, might not be done away with, and the pound avoirdupois ascertained by reference to a cubic inch of distilled water. We were told forty years ago, that for the introduction of a uniform and scientific system, we must wait for the spread of education in the community; and we feel somewhat ashamed now to find that the members of the medical profession, which is understood to be one of the most highly-educated bodies, offer the most formidable opposition to reformation in this respect. 'The testimony, however,' says Mr Taylor, 'of many individuals of the medical profession, especially the younger portion, and certainly that of the retailers and dispensers of drugs, tends entirely to shew the practicability of a beneficial and convenient change. With all these, there appears no more serious difficulty to encounter than that involved in altered editions of their usual dispensatories, or books of reference'--an amount of trouble and expense, we should say, not greater, certainly, in proportion to the position of the parties concerned, than that which was forced on the poor chandlers and milkwomen by the act of 1826. Then, to adapt the avoirdupois pound to the further objects in view, it must be reconstructed as to its divisional parts. In order to this, it is not necessary that the nomenclature should be changed, or that our poor people should be puzzled with the _decas_, and _hexas_, and _millias_ which has formed the greatest practical difficulty in the decimal system of France. It is proposed simply to divide the pound avoirdupois into 10,000 parts instead of 7000, and to employ names at present in use for the minor denominations; but if it be thought incongruous to retain the term _grain_, which had reference to the weight of wheat or barley, _minim_ might be substituted. Then the multiples of the pound, which have hitherto been so various, are to be decimally graduated--as, stones of 10 lbs., cwts. of 10 stone (or, literally, 100 lbs.), and tons of 10 cwt. The decimal measures below the gallon would correspond of course with the weights, as it is decided by the act, that a gallon is to contain ten pounds of water. The measures above gallons, it is proposed to call firkins and butts.