212 THE DEPTHS OF THE SEA. [cHapP. X. 
the samples, as shown of the determinations of organic 
carbon and organic nitrogen, and the proportion of organic 
carbon to organic nitrogen. For the purposes of comparison, I 
have appended the results of analyses of Thames-water and ot 
the water of Loch Katrine, the former representing probably 
about a fair average of the proportion of organic nitrogen 
reaching the sea in the rivers of this country, but being pre- 
sumably considerably greater than that contributed by rivers in 
other parts of the world. If this be so, it follows either that 
soluble nitrogenous organic matter is being generated from inor- 
ganic materials in the sea, or that this matter is undergoing con- 
centration by the evaporation of the ocean,—the rivers and 
streams continually furnishing additional quantities whilst the 
water evaporated takes none away. 
The amounts of carbonate of lime given in the table are 
obtained by adding the number 3 (representing the solubility 
of carbonate of lime in pure water) to the temporary hardness 
which denotes the carbonate of lime thrown down on boiling. 
As the determination of temporary hardness in water containing 
so much saline matter is not very accurate, the numbers in the 
columns headed ‘Temporary Hardness’ and ‘ Carbonate of Lime’ 
must only be regarded as rough approximations to the truth ; 
moreover, a small proportion of carbonate of magnesia is mixed 
with the carbonate of lime and estimated with it. 
In all their peculiar features these analytical results agree 
with those which I have previously obtained from numerous 
samples of sea-water collected by myself off Worthing and 
Hastings. 
Yours very truly, 
E. FRANKLAND. 
