Letrs anp BLaxe—Estimation of Oxygen in Solution. 465 
(Titrations by bichromate 1 c.c. = 1 ¢.c. oxygen at N. T. P.1 
Blank experiment required, : ; - &OO G0, 
Oxygen determination required, . : eee On 8s 
1:80 ,, 
Dissolved oxygen, per litre, found by Permanganate, 5°35 c.c. 
Fa 33 of » by Bichromate,. 5-41 ,, 
Dittmar’s result at 20° C., 5°31 ,, 
Sea Water from Belfast Lough, filtered and saturated with air at 
- 20°8°O.—(‘Titrations by permanganate 1 cc. = 1 ce. oxygen at 
INE TP.) 
Blank experiment required, : ; 5, G8) C0, 
Oxygen determination required, . : 5 | BRED. 
1:84 ,, 
(Titrations by bichromate 1 cc. = 1 ce. oxygen at N. T. P.) 
Blank experiment required, : : 5 880 Ce: 
Oxygen determination required, . : 5 AO 5 
AO 
Gasometric Analysis. 
200 c.c. of the water gave— Equivalent to, per litre— 
OO, . QB Cie. 6 5 j : . 45:15 ce. 
OW aa IRODRE Gi Ne eer en amen on Omer 
NPE ISOM Loa, (NU Bll eae Rh OO akge: 
Total, 12°04 ,, 60-20 ,, 
Dissolved oxygen, per litre, by new process (permanganate), 5°58 c.c. 
” ” ” ” 9 (bichromate), 5 Bell WP 
ce - 55 by gasometric analysis, . 1 jon lO 
Sewage Effluent from Belfast experimental “ Bacteria Beds” after 
double contact.—(Titrations by permanganate | cc. = 1 cc. oxygen 
at IN. ‘I P.) 
Blank experiment required, : : . 4°42 cc. 
Oxygen determination required, . : 2. 420004) 
