429 
of specimens from two of its three localities, as seen in the following 
list, which contains all the analyses I have been able to find : — 
BOs. 
CaO. 
HO. 
NaO. 
KO. 
SOs. 
NaCl. Sand. 
Peru, 
4611 
18-89 
35-00 
Hayes* 
Tuscany, . 
51-135 
20-85 
26-25 
Bechi* 
Peru, 
49-50 
15-90 
25-80 
8-8 
Ulext 
Peru, 
49-50 
17-70 
26-00 
8-8 
„ t 
33 • 
45-46 
14-32 
8-22 
0-51 
1-10 
2-65 0-32 Dick* 
33 • 
43-70 
1311 
35-67 
6-67 
0-83 
Ramm.t 
3! • 
47-25 
15-98 
25-46 
9-88 
0-45 
0-98 Anderson§ 
Nova Scotia, 
, 41-97 
13-95 
34-39 
8-36 
1-29 
MgO 0-04 H. How* 
„ 
44-10 
14-20 
34-49 
7*21 
33 
In the account of the analysis by Anderson, the quantities of soda 
and sulphuric acid, as given above, are reversed ; from the conclu- 
sion drawn by the author, this is evidently a typographical error. 
As regards the amount of water present, no mention is made, in 
any case but my own, as to the temperature at which the substance 
was dried ; in my analysis the mineral was air-dried. The soda, it 
will be observed, is a constant ingredient, in pretty uniform amount, 
in all but the first two analyses ; and in my, examination as stated 
at the time, the mineral was washed, for the second analysis, with 
cold water till all sulphuric acid was removed. 
From the preceding data the following formulae have been de- 
duced : — 
CaO 2 B0 3 + 6 HO . 
NaO 2 B0 3 + 2 CaO, 3 BO. + 10 HO. 
NaO 2 BO3 + 2 CaO, 3 B0 3 + 15 HO. 
NaO 2 BO3 + 2 (CaO 2 B0 3 ) + 18 HO. 
Hayes ; 
Ulex ; 
H. How ; 
Rammelsberg ; 
all referring to a mineral found in rounded masses, consisting of in- 
terwoven fibres, opaque, snow-white, and of a silky lustre. 
The mineral to which I would now draw attention was found in 
the same quarry as the preceding, at a distance of about 100 yards, 
and at about 20 feet lower level, and also associated with glauber- 
salt, which, it is worthy of notice, is generally met with here, accord- 
ing to the quarrymen, in narrow seams at the line of junction of the 
“hard plaster” (anhydrite) with the “ soft plaster” (gypsum). I 
detected it in the form of an opaque white substance without lustre, 
* Dana’s Min., 4th ed., p. 394. 
t Liebig und Kopp’s Jahrb. 1849, p. 780. 
X Silliman, Sept. 1856, 3d Supt. to Dana’s Min., p. 6. 
§ Proc. Phil. Soc. Glasgow, Feb. 1853. 
