34 
The results will be found in the table at the end. 
9.—MINoR CONSTITUENTS OF THE WATER. 
These consist of Iron, Bromine, Ammonia, Nitrites, and 
Nitrates. 
None of these were estimated, though attempts were at 
first made to do so, as they are present in such small 
quantities that larger volumes of water than I had at my 
disposal were found to be necessary for their determination. 
Iron.—Attempts were made to estimate this colouri- 
metrically with ammonium sulphocyanide and a standard 
solution of iron alum, but it was found almost impossible 
owing to the extreme paleness of the tint. 
Brourne.—No attempt to estimate this was made, but 
using the figures given by Dittmar in the Challenger report, 
the total Halogen (mot ‘ Chlorine’) may be obtained by 
multiplying the chlorine values given in this paper by 
1:001681. 
AMMONIA. 
This appears to be absent, or very nearly so, 
as Nessler’s solution produced no visible colouration. 
Nirrires.—These do appear to be present to some trifling 
extent, especially at inshore stations. Their determination 
was attempted colourimetrically by means of a solution of 
metaphenylenediamine sulphate, but the tint obtained, 
though visible, was so faint that no further trials were 
made. 
Nirrates.-—No attempts to estimate these were made. 
It is to ‘be regretted that Jack of time and apparatus 
prevented me from estimating the magnesium, alkalies, 
