the eyesight.--The invention of Dr George J. Bull.--3
illustrations. 9908

X. SANITATION AND HYGIENE--The Sanitation of Towns--By J. GORDON,
C.E.--A presidential address before the Leicester meeting of
the Society of Municipal and Sanitary Engineers and Surveyors
of England. 9909

XI. TECHNOLOGY--A New Monster Revolving Black Ash Furnace and the
Work Done with It--By WATSON SMITH--The great furnace of the
Widnes Alkali Company described, with results and features of
its working--4 illustrations. 9900

Apparatus Used for Making Alcohol for Hospital Use during the
Civil War between the States--By CHARLES K. GALLAGHER--A curiosity
of war times described and illustrated.--1 illustration. 9900

Confederate Apparatus for Manufacturing Saltpeter for Ammunition
--By CHARLES K. GALLAGHER--Primitive process for extracting
saltpeter from earth and other material--1 illustration. 9900

Electrolysis and Refining of Sugar--A method of bleaching sugar
said to be due to ozone produced by electric currents acting on
the solution--1 illustration. 9903

Improvements in the Manufacture of Portland Cement--By FREDERICK
RANSOME, A.I.C.E.--An important paper recently read before the
British Association, giving the last and most advanced methods
of manufacture. 9901