462 Scientific Proceedings, Royal Dublin Society. 
Dissolved oxygen per litre,. 7:27 c.c. found (A). 
” ” ”? e206 ”? 29 (B). 
Roscoe & Lunt’s results at 
>) 99 99 : 7°20 oe) . 5 fo) 4 
distilled water at 13°5°C. 
Mean difference, 0:065 _ ,, 
Distilled Water, with one per cent. of foul Sewage added; the 
mixture being then thoroughly aerated at 15°C.—(Titrations by 
permanganate 1 c.c. = 0-1 c.c. oxygen at N. T. P.) 
Blank experiment required, ; : 5 Well Ce: 
Oxygen determination required, . : . 144 ,, 
Difference, i BROT 
Dissolved oxygen = 2°87 c.c. 
Dissolved oxygen per litre, 7:13 c.c. found. 
Roscoe & Lunt’s results for); 
a * : O98" 57) aistilled areron tsa! 
Difference, . O17 ,, 
The next determinations were made with the view of testing 
the results of the new process against those obtained by gasometric 
analysis. For the latter purpose the excellent and reliable ap- 
paratus devised by Dr. W. E. Adeney was employed, slightly 
modified by the authors. In this apparatus a measured volume 
of the water is boiled in vacuo with dilute sulphuric acid, and the 
evolved gases analysed at constant volume. 
Belfast Water supply from Main.—Titrations by permanganate 
vere, — Oulerce) oxygen at IN. Te.) 
A. Blank experiment required, : : 5 BO) GG." 
Oxygen determination required, . : Soren 
128, 
B. Blank experiment required, : : = i Sicxe. 
Oxygen determination required, . ‘ 5) WG coy ee 
19°3 ,, 
Dissolved oxygen = 1°98 c.c. 
1 Adeney, Roy. Dublin Soc. Trans., 5 (series 2), 1895, p. 547. 
® The same ferrous sulphate solution was employed as in experiments 1 and 2, bus 
a period of three weeks had elapsed since those determinations. 
