CHAP. x. | CONTINUITY OF THE CHALK. 5d 
These figures appear to show (1) that intermediate waters are 
more free from organic contamination than either surface- or 
bottom-waters, as might be expected from the comparative 
absence of animal life in these waters ; (2) that the total absence 
of organic matter is least frequent in bottom-waters, and most 
frequent in intermediate waters, surface-waters occupying a 
middle place in this respect; and (3) that there is not much 
difference between bottom- and surface-waters, either in the 
total quantity of organic contamination or in the relative pro- 
portions of the “decomposed” and “easily decomposable” 
organic matter. 
It may be worth notice that when the bottom-water from 
great depths was muddy, tests made before and after filtration 
showed that some of the organic matter was removed by this 
operation. 
APPENDIX B. 
Results of the Analyses of Eight Sanuples of Sea-Water col- 
lected during the Third Cruise of the ‘Porcupine’ By Dr. 
FRANKLAND, F.R.S. 
Royat CoLiecEe oF CHEMISTRY, 
November 15th, 1869. 
DEAR Dr. CARPENTER,—Herewith I enclose results of analyses 
of the samples of sea-water collected during your recent cruise 
in the ‘ Porcupine.’ 
I shall not attempt to draw any general conclusions from these 
results; your own intimate knowledge of the circumstances 
under which the different samples were collected will enable you 
to do this much better than I. 
There is, however, one point which is highly remarkable, and 
to which I would draw your attention ; it is the large amount of 
very highly nitrogenized organic matter contained in most of 
