KEPORT ON THE DEEP-SEA DEPOSITS. 
221 
added in successive small quantities, while the substance was stirred continually, care being 
taken to have but a very feeble acid reaction during the operation. In this way there 
was obtained, after complete elimination of the carbonates and phosphates, an impalpable 
residue presenting a deep brown colour, similar to a Red Clay when wet and yellowish 
brown when dry. The physical characters resemble those of an impure argillaceous sub- 
stance coloured by iron ; before the blow-pipe it melts into a black vesicular glass, like 
ferruginous felspathic mud. These two residues from the Globigerina Ooze of Stations 
224 and 338 were then analysed, with the following results : — 
a 
.S 'S 
o 
’•P 
d 
m 
CD ci 
No. 
SiOj 
AI 2 O 3 
FejOs 
M11O2 
CaO 
MgO 
K 2 O 
Na^O 
H.n 
Ba 
P2O5 
Total. 
224 
1850 
57 
64-16 
15-13 
8-19 
tr. 
1-66 
1-79 
1-01 
0-90 
7-10 
tr. 
tr. 
99-94 
338 
1990 
59 
50-47 
18-01 
12-75 
3-00 
1-71 
2-44 
1-11 
1-05 
10-93 
tr. 
tr. 
101-47 
These two analyses of residues of Globigerina Ooze show, as might be expected, 
remembering the variability of the deposits, considerable dilferences in all the substances 
estimated. It may be held, however, that these two residues, from the point of view of 
their constitution, present a very close analogy with the Red Clay of greater depths. 
In short, according to the percentages of water, alumina, and silicic acid, there must 
exist in the Globigerina Oozes an argillaceous matter coloured by oxides of iron and 
manganese, and mixed with this clay alkaline and other silicates, as shown by microscopic 
examination. The composition of this residue is, in fact, similar to a Red Clay. The 
materials have the same origin in both cases, — the inorganic portion of a Globigerina 
Ooze being, indeed, analogous to a Red Clay. 
This conclusion receives further confirmation from the following analysis (No. 59 a) 
of the portion of the residue soluble in hydrochloric acid, the results of which show 
the presence of argillaceous and ferruginous matter in these calcareous deposits. The 
Globigerina Ooze at Station 338 was submitted to the action of boiling hydrochloric acid 
and a certain quantity of silica, alumina, iron, and manganese was dissolved. After this 
operation there remained 2 ’21 grms, of insoluble residue, and the amount dissolved and 
re-precipitated by ammonia represented 0‘0487 grm. of silica, 0’0404 grm. of alumina, and 
0‘0917 grm, of peroxide of iron. 
SiOz . . . . . 26'94 per cent. 
ALA 22-34 „ 
FeA ..... 50-72 „ 
100-00 
The atomic relations of the silica and alumina are here those in which these two 
