102 Proceedings of Royal Society of Edinburgh. [sess. 
very tedious and doubtful as to results, we devised and adopted tbe 
following process, which was found to answer exceedingly well. 
Pure potash was added to a measured and carefully filtered portion 
of the sea water, and the precipitate formed removed by filtration 
through filter-paper, from which any traces of ammonia (generally 
present in filter-paper) had been removed by washing with pure 
potash water, the clear filtrate was then Xesslerised in the usual 
manner. We found that by adopting this plan we had a speedy 
and accurate means of determining between the actual ammoniacal 
salts and the nitrogenous matter, both of which are as a rule present 
i n sea water according to the proportion it carries of living or dead 
organisms. 
Exp. IX. (p. 89) seems to prove in a conclusive manner that the 
addition of pure potash to a fluid containing albuminoids alone does 
not at once give rise to the production of saline ammonia. 
Table I. Showing the Average Composition of Sea Water Salts 
Chloride of sodium, 
(Dittmar). 
. 77758 
77-758 
Chloride of magnesium, . 10*878') 
| 
Sulphate of ,, 
. 4-737 
V 15-832 
Bromide of ,, 
•217 v 
1 
Sulphate of potash, 
. 2-465 
2-465 
Carbonate of lime, 
•345 1 
|- 3-945 
Sulphate of ,, 
. 3-600 J 
100-000 
100-000 
Table II. Showing the Composition of Sea Water (Dittmar). 
Analyses of Sea Water in 10,270 parts, or 1 litre, density 4 S 15 . 56 . 
Water, 9897 ‘073 
Chloride of sodium, . . . 289 -980 
Chloride of magnesium, . . 40 '568 
Sulphate of magnesia, . . 17 '665 
Bromide of magnesium, . . 0"809 
Sulphate of lime, . . . 13‘425 
Sulphate of potash, . . . 9 '193 
Carbonate of lime, ... 1 '287 
10,270*000 
