Miscellaneous. Dok 
_ Delvauxite.* —This mineral, when free from hygroscopic moisture, 
has the formula Fe,PO,, aq. + Fe.H303, which demands 16°31 p. c. 
H,O: experiment gave 16:9 p.c. -Delvauxite dried at 100° has the 
formula Fe,PO, + Fe,H,03, which demands 10:46 p. ec. HO: ex- 
periment gave 10:97 p.c. ‘The delvauxite analysed was from Liége, 
Belgium, and contained no calcium compounds. 
Dufresnite—This mineral when perfectly pure has the formula 
Fe,PO, + Fe,H303, which requires 10°46 p. c. H,O: experiment 
gave 10°55. In fact air-dried dufresnite has the same composition as 
delvauxite dried at 100°. : 
Prasine.—Pseudomalachite or prasine generally contains some 
malachite, together with other impurities ; when due allowance is 
made for these intruding compounds its formula, like that of phos- 
phochalcite, is Cuz;PO, + 83CuHO  Dihydrite (and perhaps ehlite 
also) has the formula Cu;PO, + 2CuHO, while the composition of 
libethenite (and possibly of pseudolibethenite and tagilite also) would 
seem to be represented by the expression Cu,PO, + CuHO. 
Calaite—The formula assigned to turquoise has scarcely been 
sufficiently supported by analysis. Mr. Church analysed a blue 
specimen from Nichabour, Persia, and after deduction of 10-47 per 
cent. of hydrated phosphate of copper (CuzPO,, aq.) and 4°89 per 
cent. of hydrated ferroso-manganous phosphate (3(FeMn),PO,, aq.), 
the analytical results closely correspond to those required by the 
formula Al,PO,+ Al,H,03. 
A New Minera or OrGanic Oricin.t—Tasmanite.—In the 
Tasmanian Court of the International Exhibition of 1862, a ‘resini- 
ferous shale’ was exhibited by the Dysodile Company. On exa- 
mination and analysis, the combustible matter of this shale proved to 
be different from the true dysodile both in physical and chemical 
characters. It occurs in discs (:03 inch in diam.) disposed in planes 
parallel to the laminations of the shale; these discs are translucent, 
reddish-brown : lustre resinous, and fracture conchoidal. The density 
of the mineral is about 1:18; its hardness 2. The mineral, to which 
Mr. Church gives the name Tasmanite, is unaffected by alkalies 
and most solvents of organic resinoids: its chief chemical charac- 
teristic is the large amount of sulphur in organic combination which 
it contains. Numerous analyses of tasmanite gave these results as 
a mean— 
Carbon . p : - (2°88 
Hydrogen . : ; ~ + 9°56 
Sulphur. : ; . 4:90 
Ash(a). : : se SpA 12-24 
Making due deductions for the ash of the specimens, these numbers 
correspond to the following corrected percentages :— 
* In this and the four following notices Gerhardt’s notation is adopted: — 
C1016) S39. 
f+ Phil. Mag., Dec. 1864. 
