The Crow.--Illustration.

The Praying Mantis and its Allies.--Illustration.

May Flies.--2 illustrations.

II. TECHNOLOGY.--A Quick Way to Ascertain the Focus
of a Lens.--1 diagram.

The History of the Pianoforte. By A.J.
HIPKINS.--Different parts of a pianoforte and
their uses.--Inventor of the instrument and his
"action."--First German piano-maker.--Square
pianos.--Pianos of Broadwood, Backers, Stodart,
and Erard.--Introduction of metal tubes, plates,
bars, and frames.--Improvements of Meyer, the
Steinways, Chickerings, and others.--Upright
pianos.--Several figures.

III. MEDICINE AND HYGIENE.--The Poisonous Properties of
Nitrate of Silver and a Recent Case of Poisoning
with the Same. By H. A. MOTT, Jr.

Tubercle Bacilli in Sputa.

Malaria. By Dr. JAMES H. SALISBURY.--VIII. Local
observations.--Effect of the sun on ague
plants.--Investigations into the cause of
ague.--Notes on marsh miasm.--Analysis of malari a