Preservation of Potatoes.
Potatoes at the depth of one foot in the ground, produce shoots near the end of spring; at the depth of two feet they appear in the middle of summer; at three feet they are very short, and never come to the surface; and between three and five feet they cease to vegetate. In consequence of observing these effects several parcels of potatoes were buried in a garden at the depth of three and a half feet, and were not removed. until after an interval of one or two years. They were then found without, any shoots, and possessing their original freshness, firmness, goodness, and taste. From the French.
Leeches.
It is well known that atmospheric changes have a remarkable influence upon leeches. In 1825, M. Derheim, of St. Omer, ascribes the almost sudden death of them at the approach of, or during storms, to the coagulation of the blood of these creatures, caused by the impression of the atmospheric electricity.—From the French.
Carpenter's Microscope.
Mr. Carpenter's achromatic solar microscope has now a white circular area of nine feet in diameter, to receive the images of the objects upon, some of which are magnified to the enormous size of upwards of eight feet in length!
Mr. Carpenter's lucernal microscopes are now arranged in a kind of temple, placed in the middle of a room, and illuminated by the light of one powerful Argand lamp, so as to be independent of all natural light; thus, in all seasons, even in cloudy weather, the objects are as brilliantly displayed as they could be last year when the sun shone.—Gill's Repository.
Beet Root Sugar.
There are now in France upwards of one hundred manufactories of beet root sugar, from which were produced last year upwards of 5,000 tons of sugar, worth 60 l. per ton, or 300,000 l.; the profit of which is estimated at 15 l. an acre; but, says one of the manufacturers, the process may be so far improved, that sugar will be made in France from the beet root at 30 l. per ton, which will increase the profit to 24 l. an acre. A writer in the Quarterly Journal of Agriculture observes that "it is difficult to conceive that one half of the sugar consumed in Great Britain, or in all Europe, will not, in a few years, be home-made beet root sugar."