270 Proceedings of the Royal Society of Edinburgh. [Sess. 
A. General analysis by Mr Steiger. 
B. Portion soluble in water. 
C. Analysis reduced to standard form by rejecting soluble salts, calcium 
carbonate, and hygroscopic water, and recalculation of the remainder to 
100 per cent. 
Molybdenum and zirconium were not detected. Nickel, cobalt, lead, 
zinc, and arsenic, which were reported in the red clay, were not looked for. 
Apart from these trivial omissions, the red and terrigenous clays are fairly 
comparable. The red clay is lower in silica and alumina, but higher in 
iron than the muds, and other minor differences appear. The high 
manganese of the red clay may be correlated with the abundance of 
manganese nodules in the greater oceanic depths. 
{Issued separately October 2, 1907 .) 
