458 
THE VOYAGE OF H.M.S. CHALLENGER. 
Wo seo that in both our specimens 7n=p as in Abich’s pumices ; but while our “quasi” is just a little too 
basic for the A-set, our purilied pumice is far too acid for set B even. The excess of base in our quasi- 
pumice might bo explained by the presence in it of Anorthite,^ which according to Tschermak always ac- 
companies albite as a normal admixture. Going -by Abich’s determinations our quasi-pumice would appear 
to stand closer to what he calls pumice than our undoubtedly genuine pumice does. 
^ j Q |2SiOo ; i.e., 4(RO or R§0) for 2SiOj. • 
84. Glauconite. — Station 164b. 
Lat. 34° 13' S., long. 151° 38' E., 410 fathoms (Sipdez). 
I. 0'4544 grm. of substance, fused with the carbonates of soda and potash, gave 0’0311 grm. of water, 0'2573 
gmi. of silica, 0'0770 grm. of peroxide of iron, 0'0570'grm. of alumina, trace of manganese, 0'0077 
grm. of lime, and 0‘0315 grm. of pyrophosphate of magnesia = 0‘01 135 grm. of magnesia. 
II. 0’3519 grm. of substance, treated with hydrofluoric and sulphuric acids, gave 0'0199 grm. of the chlorides 
of potash and soda, 0'0456 grm. of chloroplatinate of potash, corresponding to 0‘0139 grm. of chloride 
of potash = 0 ‘00889 grm. of potash, and 0‘0060 grm. of chloride of soda = 0‘00318 grm. of soda. 
III. 0‘1483 grm. of substance, treated with hydrofluoric and sulphuric acids, required for oxidation 0‘3 c.c. 
permanganate of potash (1 c.c. permanganate of potash = 0‘0058355 grm. of protoxide of iron), corre- 
sponding to 0‘0175 grm. of protoxide of iron. 
Silica, .......... 56-62 
Peroxide of iron, ......... 15‘63 
Alumina, .......... 12‘54 
Proto.xide of iron, . . . . . . . . . 1‘18 
Lime, . . . . . . . . . . . 1‘69 
Magnesia, . . . . . . . . . . 2‘49 
Potash, . . . . . . . . . . 2‘52 
Soda, ........... 0-90 
Water, . . . . . . . . . . 6‘84 
Manganese, .......... trace 
100-41 
Note. — T his substance contained about 65 per cent, of white, pale grey, and some yellow casts, 20 per cent, pale green casts, 
and 11 per cent of dark green casts, together with 14 per cent, of mineral particles and siliceous organisms (J. M.). 
85. Glauconite. — Station 164n. 
Lat. 34“ 13' S., long. 151° 38' E., 410 fathoms (Sipocz). 
I. 0-6340 grm. of substance, fused witli the carbonates of soda and potash, gave 0‘0352 grm. of water, 0-3299 
grm. of silica, 0-1664 grm. of jieroxide of iron, 0‘0566 grm. of alumina, trace of manganese, 0 0080 
grm. of lime, and 0 055 grm. of pyrophosphate of magnesia = 0-019856 grm. of magnesia. 
II. 0‘5320 grm. of substance, treated with hydrofluoric and sulphuric acids, gave 0 0380 grm. of the chlorides 
of potash and so<la, 01 164 grm. of chloroplatinate of potash, corresponding to 0 0355 grm. of chloride 
of potash ■■ 0-02243 grm. of jiotash, and 0 0025 grm. of chloride of soda = 0‘00133 grm. of soda. 
III. 0 2633 grm. of substance, treated with hydrofluoric and sulphuric acids, required for oxidation 0-75 c.c. 
permanganate of potash (1 c.c. permanganate of pota.sh = 0‘0058355 grm. of jirotoxide of iron), corre- 
sponding to 0-004376 grm. of protoxide of iron. 
