should not be made until the stem has attained the height it ought to
have.--_From the French_.


_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