1002 
adhering to the clay. Such adhering connate salts of course can no more 
be expected to occur in the samples of fossil deep-sea clay. The quantity 
of this adhering salt is not inconsiderable and amounts to 3.61 °/,, 
as shown by Harrison and Wi.iiAms') in material of the Challenger. 
The constituents of this salt are NaCl, MgCl,, CaSO,, and a trace 
of phosphate... Moreover Brazier has not determined the alkalis in 
the samples of the Challenger, so that the figures assigned by him 
to SiO, and other substances are too high. To meet this deticiency 
in our knowledge of the chemical composition of the recent red 
deep-sea clay, Harrison and Wirrrams®) have made a new analysis 
of the typical red deep-sea clay collected by the Challenger determining 
the percentage of the alkalis and mentioning separately the quantity and 
the composition of the adhering sea salt. Leaving out the adhering 
salt the analysis of the sample of deep-sea clay, examined by Har- 
RISON and Winiiams would come to this: 
SiO, 56.12 
Al;O; 16.30 
Ber, 10.94 
MnO, ACG 
CaO 1.65 
MgO 1.43 
K,O 1.95 
Nar. Bot 
H,O 6.92 whilst heating 
an natter ey ALI 
100.3 at 100° 
Now we are enabled to compare the above analysis of recent red 
clay with those of the fossil deep-sea clay, as soon as in both the amount 
of water, escaping below and above 100°, has been taken into 
account in the same way. Doing so it is desirable not to take into 
account the water which escapes on heating to 100°, because this 
was done neither in the analyses of the miocene deep-sea clay of 
Barbados, nor in the most recent analyses of recent red deep-sea clay 
made by G. Srrigur and discussed by CLARKE *). 
The analysis referred to, of the cretaceous deep-sea clay of Noil 
Tobee, recalculated in this way runs: 
1) J. B. Harrison and A. J. JuKEs BROWNE. Lit. 6 p. 315. 
Dj ‘Rei. 6 py 31 5<and 321. 
5) F. M. CraRkKE. Ref. 4, p. 785. 
