324 PROF. HARRISON AND MR. JUKES-BROWNE ON [Aug. 1 895, 



Dr. Brazier's analysis is only 4*22, the total amount of these in- 

 gredients in the ooze as a whole is 13*58, and when corrected for 

 adherent sea-salts, it would be 14*23 per cent. From this we may 

 infer that the siliceous ingredients in the finer part of the ooze 

 would amount to 24*24 per cent. 



We thus obtain a good idea of the composition of the finer part 

 of the sample, and it is interesting to observe that it shows an 

 approach to that of the coarser parts of some ' Red Clays.' Thus 

 a Red Clay from Station 5, analysed after its finer part had been 

 washed away, contained 61 per cent, of carbonate of lime, and 34 

 per cent, of siliceous matter. Arranging the ingredients of the finer 

 part of the Globigerina-ooze, calculated differentially in the manner 

 above indicated, and placing them side by side with those of the 

 washed Red Clay, we have : — 



Finer part Coarser part 

 of Globigerina- of 



ooze. Red Clay. 



Water and organic matter 214 2*60 



Carbonate of lime 73*51 61*01 



Phosphate of lime *20 209 



Residual sulphate of lime — "29 



Silica and silicates 24-24 34*01 



10009 100*00 



This tends to show that the materials of Red Clay are universally 

 distributed over the ocean-floor, and are only masked by the cal- 

 careous ingredients of the Globigerina-ooze — a conclusion which is 

 quite in harmony with Dr. Murray's view of the origin of Red 

 Clay. 1 



There is no doubt that the Red Clay from Station 5 contained a 

 larger amount of calcareous matter than usual, but that the coarser 

 parts of other Red Clays bear the same relation to the finer parts is 

 shown by two other analyses of such clays from which the finer 

 part had been washed away. One of these gave 36*80 per cent, 

 and the other 38*13 percent, of calcium carbonate (see ' Challenger' 

 Reports, Deep-Sea Deposits, p. 198), amounts which are very high 

 when we remember that the average amount of calcium carbonate 

 in red clays from between 2000 and 3000 fathoms is only 7'77 per 

 cent. {op. cit. p. 193). 



Returning to our analysis of the Globigerina-ooze from Station 224, 

 it is satisfactory to find that it agrees very closely with the estimate 

 of its composition made by Dr. Murray himself on p. 108 of the 

 Report. In this and other similar analyses Dr. Murray states that 

 the amount of calcium carbonate was ascertained by actual quanti- 

 tative analysis from the total amount of carbon monoxide present ; 

 but the amount of siliceous residue was estimated by subtracting 

 the weight of the calcium carbonate from 100. It is evident, there- 

 fore, that the amounts entered under the head of fine washings 



1 Compare Klement's analyses of the portions of these oozes that are insoluble 

 in dilute acid, ' Challenger' Reports, Deep-Sea Deposits, pp. 220 & 221. 



