136 Proceedings of Royal Society of Edinburgh. [sess. 
was then added, and the mixture boiled and filtered, and the pre- 
cipitate washed. The precipitate was dissolved in hydrochloric 
acid,- and ferric hydrate precipitated with pure caustic potash in a 
platinum basin. It was then diluted and filtered, ignited and 
weighed. To the filtrate ammonium chloride was added, and the 
solution boiled till ammonia ceased to come off. The precipitate 
was filtered, ignited to A1 2 0 3 , and weighed. 
In the Fe 2 0 3 the variations are not great. The minimum, 3 ’45 
per cent., is on the Balearic Bank, and the maximum, 6 ’64, in the 
deep water near the African shore. In this neighbourhood all the 
muds have large amounts of Fe 2 0 3 and small amounts of A1 2 0 3 , 
except No. 35, where the amount of Fe 2 0 3 is small and that of 
A1 2 0 3 very large — in fact, the maximum (12 ’3 per cent.). It is 
remarkable that at No. 41 we find the maximum of Fe 2 0 3 (6 ’64 per 
cent.), and the minimum of A1 2 0 3 (1*3 per cent.). The deep water 
between Africa and the Balearic Islands covers muds comparatively 
rich both in A1 2 0 3 and Fe 2 0 3 ; on the Balearic Bank the amounts 
are small, and in the Gulf of Lyons moderate. 
Table Ya. — Determination of Fe 2 0 3 and A1 2 0 3 in Hydrochloric 
Acid Solution of Table V. 
No. of 
Sample. 
Weight of 
Sample taken 
(grammes). 
Weight of 
Fe 2 0 3 
(grammes), 
Per cent, of 
Fe 2 0 3 . 
Weight of 
A1 2 0 3 
(grammes). 
Per cent, of 
A1 2 0 3 . 
a 
b 
c=100 - 
a 
d 
C* | 
. ii ! 
i 
■ ... 
31 
1-4796 
0-0826 
5-58 
0-0203 
1-37 
32 
1-8465 
0-0991 
5-37 
0-0415 
2-45 
35 
1*1713 
0-0452 
3-86 
0-1441 
12-30 
36 
1 -5547 
0-0956 
6-17 
0-0538 
3-46 
39 
1-1890 
0-0788 
6-54 
0-0460 
3-87 
41 
1-7195 
0-1060 
6-64 
0-0224 
1-30 
43 
1-9403 
0-1235 
6-22 
0-1864 
9-60 
45 
1-3528 
0-0720 
4-23 
0-1389 
10-27 
46 
1-5053 
0-0732 
4-86 
0-1645 
10-93 
64 
1-1908 
0-0505 
4-24 
0 0302 
2-54 
65 
1-3671 
0-0472 
3-45 
0-0292 
2-04 
86 
1-7149 
0-1073 
6-26 
0-0920 
4-26 
87 
1-4539 
0-0783 
5-39 
0-1212 
8-34 
88 
1-7470 
0-0763 
4-37 
0-0680 
3-89 
89 
1-6682 
0-0726 
4-42 
0-0765 
4-58 
Table YI. Estimation of FeO and Fe 2 0 3 . — A weighed quantity 
of the substance was placed in a 200 c.c. flask and the flask filled 
