1887.] Mr A. Dickie on Chemical Analyses of Sea Water. 423 
I proceeded as follows : — After determining the other components, 
I weighed the bottle and all that remained of the sea water, filtered 
the water through a tared filter paper (which was then dried at 
100° C. and weighed), and then weighed bottle again, the difference 
of course being weight of water filtered. I found that, whilst there 
was generally about a kilogramme of water filtered, the weight of 
suspended matter never amounted to more than 8 mgrms., and was 
sometimes not more than 1J mgrms., and, as the probable error in 
weighing would amount to a not inconsiderable portion of this small 
weight, I considered that the importance of the result obtained was 
not worth the time and labour employed in the getting of it, which 
was sometimes considerable. 
Appended is a table of results. 
The first six columns of this table explain themselves. Column 
A gives the chlorine in grms. per kilo. ; column B gives the sul- 
phuric acid (S0 3 ) in grms. per kilo.; C and D are the alkalinity 
columns ; C gives the amount of C0 2 present as normal carbonate 
in mgrms. per litre; and D the amount in mgrms. per 100 mgrms. 
of total salts. In this latter, as I did not estimate the total salts, I 
have calculated from the chlorine, using the number 55*43 as equi- 
valent to 100 parts total salts, that being the number which Dr 
Dittmar establishes in his “ Challenger ” memoir. Column E gives 
the ratios existing in the different samples between the chlorine and 
the sulphuric acid ; i.e., the weight of S0 3 per unit of chlorine. 
On glancing over the chlorines ascertained in the “ Challenger ” 
work, we find that in no sample was the chlorine less than 18 grms. 
per kilo., that the largest number of samples gives quantities between 
19 and 20 grms. per kilo., and that the sample having greatest 
amount contained 20*64 grms. per kilo. In above table we find 
that the largest amount of chlorine is contained in Ho. 2619 = 
18*946 grms. per kilo., a sample taken’ in the channel south of 
Sanda ; and the least in Ho. 1423 = 1*1692 grms. per kilo., a 
Lochfyne sample. But though the difference between these two 
figures is considerable, the general variation in the quantity of chlo- 
rine is not so great, for we find that out of the eighty -nine samples 
only eight (all of them surface samples) contain less than 16 grms. 
per kilo., and only five less than 14 grms. per kilo. 
The difference in salinity between surface and bottom water is 
