with enlarged illustrations of the same, and a graphic
account of the entire subject.--7 illustrations. 11452

The Modern Theory of Light.--By Prof. OLIVER LODGE.--An
abstract of a lecture by the eminent investigator and
expositor of Prof. Hertz's experiments, giving a brief review
of the present aspect of this absorbing question. 11459

VIII. PHYSIOLOGY.--Heat in Man.--Experiments recently made by Dr.
Loewy on the heat of the human system.--Described and
commented on by Prof. ZUNTZ. 11461

IX. SANITATION.--On Purification of Air by Ozone--with an Account
of a New Method.--By Dr. B. W. RICHARDSON.--A very important
subject treated in full, giving the past attempts in the
utilization of ozone and a method now available. 11460

X. TECHNOLOGY.--Alkali Manufactories.--Present aspect of the
Leblanc process and the new process for the recovery of
sulphur from its waste. 11457

Dried Wine Grapes.--The preparation of the above wine on a
large scale in California, with full details of the process
adopted. 11461

The Production of Ammonia from Coal.--By LUDWIG MOND.--A
valuable review of this important industry, with actual
working results obtained in carrying out a retort process.--2
illustrations. 11454