in the spring furrowed, and roots planted in drills twenty inches apart, and covered with loose earth, two inches deep, the planter walking upon the drill and treading it firmly.  The proper time to procure roots is when the herb is a year old, when from six to eight square rods of ordinary mint will yield a sufficient quantity of roots to plant an acre, and the crop from which the roots are taken will not be deteriorated, but rather benefited by their extraction.  As soon as the herb makes its appearance it requires a light dressing with a hoe, care being taken not to disturb the young shoots, many of which have scarcely made their appearance above the ground.  In the course of a week or two the crop requires a more thorough dressing, and at this stage of growth the cultivator may be used with advantage, followed by the hoe, carefully eradicating weeds and grass from the drills, and giving the herb a light dressing of earth.  Another dressing a week or two later is all the crop requires.

The two following years no labor is bestowed upon the crop, though it is sometimes benefited by ploughing over the whole surface, very shallow, in the autumn of the second year, and harrowing lightly the following spring, which frequently renews the vigor of the plant and increases the product.

The mint should be cut as soon as it is in full bloom, and the lower leaves become sere; the first crop will not be fit to cut as early as the two succeeding ones.  It is then to be hayed and put in cock, and is then ready for distillation.

I have consulted many mint growers, who have cultivated it for a series of years, in regard to the average yield per acre, and have arrived at the following estimate, which I think is low, provided the land is suitable, and is properly cultivated.  I estimate the average yield per acre for the first year at 18 lbs.; the second year at 14 lbs.; and the third year at 8 lbs.—­making the product for three years 40 lbs., which I think will not materially vary from the actual result, though growers aver they have raised from 30 to 40 lbs. per acre the first season.

Several years since, the only method of extracting the oil then known was by distilling the herb in a copper kettle, or boiler, and condensing in the usual manner; a slow and tedious process, by which about 12 or 15 pounds of oil could be separated in a day.  But recently steam, that powerful agent, which has wrought such immense changes in our social and national economy, has been applied to this subject with its usual attendant success.  The present method consists in the use of a common steam-boiler, of the capacity of from 100 to 150 gallons, from which the steam is conveyed by conductors into large wooden air-tight tubs, of 200 gallons capacity, containing the dried herb; from which it is conveyed, charged with the volatile principle of the plant, into a water-vat, containing the condenser.