7 FEBRUARY 1891, Page 29

Air - Analysis : a Practical Treatise on the Examination of Air.

With an Appendix on " Illuminating Gas." By J. Alfred Wank- lyn and W. J. Cooper. (Kogan Paul and Co.)—This small book deals more particularly with the analysis of air for sanitary pur- poses. The apparatus used is that of Hempel, and by its use the old method recommended by Priestly for measuring the oxygen in air by oxide of nitrogen is restored. The error due to the solution of oxygen in water is done away with ; it can hardly be said to exist. It would have been better if results had boon obtained for small quantities of carbonic oxide in the air of factories. Nevertheless, this book is certainly the simplest and best written on the subject.