Chapter II: TECHNOLOGY AND CHEMISTRY.--Drawing Room Photography

A New Method of Preparing Photographic Gelatine Emulsion by
Precipitation of the Bromide of Silver. By FRANZ STOLZE.

Taylor's Freezing Microtome.--1 figure.

Vincent's Chloride of Methyl Ice Machine. 10 figures.--
Longitudinal and transverse sections of freezer.--Half plan of
freezer.--Longitudinal and vertical sections and plan of pump.--
Details.--Vertical section of the liquefier.

Carbonic Acid in the Air. By M. DUMAS.

Influence of Aqueous Vapor on the Explosion of Carbonic Oxide
and Oxygen. By HAROLD B. DIXON.

Composition of Beers Made Partly from New Grain.