304. 
On the Oxidation of Ammonia in Sea Water. 
By 
G. P. Darnell-Smith, B.Sce., F.C.S8. 
Wuisr working at the Laboratory this summer on the function 
of iodine in Algs, it was suggested to me by the Director that I 
should study the influence of Algee on the ammonia in sea water. 
I here tender my thanks to Mr. E. J. Bles for his kind advice and 
assistance, 
Before commencing experiments with Alge the effect of keeping 
sea water in the light and in the dark was tried. Neither daylight 
nor darkness appears to have any effect on the amount of ammonia 
in the water. Thus— 
Sea water containing : . ‘002 grm. NH, per 100 litres, 
After standing in the dark twenty- 
four hours contained . "0025 Be - 
After standing in the dark fone 
eight hours contained : ay gUO2 2, if 
Sea water containing ? ‘001 3 2 
After standing in the eke el 
hours contained : ‘001 = - 
After standing in the lhght pean 
hours sontamied , ; ~a0OL 3 gs 
After a few days, however, whether standing in daylight or dark- 
ness, ammonia is produced by the decomposition of organic matter. 
In order to test the efficiency of Algze in oxidising the ammonia, 
sea water which had been in an inverted bell-jar seven days, with 
a fair quantity of Ulva, moderately illuminated, was analysed. 
It contained ; ; . ‘0376 erm. NH, per 100 litres. 
After being placed in the window 
twenty-four hours it contained . ‘010 
After being placed in the window 
forty-eight hours it contamed . ‘009 
