1887 .] Mr A. Dickie on Chemical Analyses of Sea Water. 427 
very marked. In every instance the amount of chlorine is greater 
in bottom than in surface samples taken at the same spot. It is 
also curious to note that, where three samples have been taken (a 
surface, a bottom, and one from some intermediate depth), the 
chlorine in the latter is always greater than in the surface, and less 
than in the bottom samples, leaving one to infer that the chlorine 
in estuary water, at least, increases steadily from surface to bottom. 
I may here state that in five cases were surface, intermediate, and 
bottom samples collected, and in every one of these the above rule 
holds good. 
The alkalinity was determined in 250 c.c. of the water, by means 
of titration with ~ normal acid and alkali. The mean over all the 
i _ 
samples for alkalinity, in terms of 100 parts total salts, or, in other 
words, the weight of C0 2 present as normal carbonates, expressed 
in terms of 100 parts total salts, or of 55 ‘43 parts chlorines, is as 
T482 is to 100. The mean alkalinity of the forty-one surface 
samples is T5, and of the thirty-nine bottom samples T470. 
In the “Challenger” water the mean over all was *1520, that of 
fifteen surface waters T492, and that of sixty-three bottom waters 
•1540. 
The sulphuric acid was determined in about 50 grms., strictly in 
accordance with the method described by Dr Dittmar in his “ Chal- 
lenger ” memoir. These results are shown in columns B and E of 
the table, B giving the sulphuric acid (S0 3 ) per kilo., which, of 
course, varied with the quantity of chlorine ; and E the quantity 
expressed in mgrms. per mgrm. of chlorine. In the latter column 
the results, except in three cases, are fairly constant. In the three 
exceptional cases, which are enclosed in brackets, it is noticeable 
that the amount of chlorine is remarkably small, and, of course, in 
the analysis the amount of BaS0 4 to be weighed would he corre- 
spondingly small, so I suppose the lowness of the results arises from 
the probable error in weighing, which, of course, in a calculation 
of this kind is multiplied up enormously. The average quantity of 
sulphuric acid (S0 3 ), in terms of the grammes of chlorine, is T175 ; 
whilst in the “Challenger” water it was T1576, a somewhat lower 
figure. 
