ts must be made. On this
work he is now engaged. One noteworthy result of his researches is the
opinion that orchestral instruments should be made on different
principles from those used in solos. The reason for this is, that
certain over tones should predominate in orchestral instruments in
order to give them their due expression in the midst of graver sounds.
These exaggerated peculiarities will unfit them to be played alone. If
the learned Professor's views are carried out, a theatre or opera
manager will be obliged to own the instruments of his orchestra, and
perhaps to have different sets for different musical works!

THE NITROGEN OF PLANTS.

The direct source of the nitrogen contained in plants is an unsolved
mystery, though the ultimate source of much of it must be the
atmosphere. A wheat crop gave on unmanured land from 15.9 to 25.2
pounds of nitrogen, per acre, yearly, but the amount found in the
rainwater of the same district was only from 6.23 to 8.58 pounds per
acre. Singular to say, the use of a fertilizer, called a "complex
mineral manure" in the reports, added only about two pounds of nitrogen
per acre. But the case is altered when potassic manure is used, and
especially when applied to land bearing beans. Such a crop gains 13-1/2
pounds of nitrogen by the addition of saltpetre, or 28 per cent. A
similar result was obtained with clover--a leguminous crop. A potassic
fertilizer increased the yield of nitrogen one-third. One of the
anomalies observed in the study of plant growth is that a good crop
instead of exhausting the soil seems to improve it. The better the
crop, and the more nitrogen removed, the better will the succeeding
crop be. Thus clover removes a much larger amount of nitrogen than
wheat, the quantity being on unmanured land, say 30.5 pounds per acre
for clover and 20.7 pounds for wheat, and yet the wheat crop is
improved if clover is occasionally interpolated or a fair rotation of
crops kept up. In 1874 barley succeeding barley gave 39.1 pounds of
nitrogen, while barley following clover gave 69.4 pounds of nitrogen
withdrawn from an acre of soil. These amounts take no account of the
nitrogen carried off by the drainage of the soil, which analysis of
drainwater proves to be considerable. The source of all this nitrogen
is undoubtedly the atmosphere, but the mode of conveying it into the
soil is unknown.

IMPORTANT PREHISTORIC DISCOVERIES.

Few persons are aware of the wea