49 
roughly equal proportions. The normal weathering of such material 
would give rise to large quantities of sulphuric acid and sulphates. 
PHYSICAL PROPERTIES. 
The specimens from the Harbour View Lease consist of prac- 
tically pure mineral in irregular masses from a few grammes to % 
kilo in weight. They are bright ochre yellow to brownish yellow in 
colour, dull in lustre, porous, and at times more or less cellular. 
They vary in coherence from very friable to moderately tough. In 
one specimen the mineral encloses a small vein of quartz. 
An examination of the powder under the microscope discloses 
the fact that this is wholly in transparent crystalline grains, of 
which many are perfect crystals, varying in diameter from 3 to 5 /x. 
The crystals are disc-like, with a thickness equal on the average to 
one-third of the diameter. Many possess a small turbid core, the 
exact cause of which was not determinable. By pressing some of 
the powder, mounted in cedar oil, between cover-glass and slip, a 
number of crystals were flattened against the glass. In the more 
perfect crystals the outlines of upper and lower basal planes were 
then seen to be equilateral triangles in alternating position. As 
the crystals in this position proved to be singly refracting, the crys- 
tal system is evidently rhombohedral, and the form the combination 
of rhombohedron with two truncating basal planes. The refractive 
index was high, birefringence strong. 
The specific gravity was determined by immersing several small 
fragments (previously washed in small quantities of distilled water, 
alcohol, and ether, vide infra.) in methylene iodide of density 3.32 
and gradually diluting this with measured quantities of a mixture 
of xylol and methylene iodide of density about 1*5. The sinking 
point was noted as compared with that of test minerals whose speci- 
fic gravity had been determined with great care. By thus interpolat- 
ing between spodumene of density 3 14 and rubellite of density 
3.01, the Kundip mineral was shown to have a density of 3-11 at 
29° C. 
The melting point was indeterminate owing to the mineral dis- 
sociating at a low temperature. 
CHEMICAL PROPERTIES. 
Preliminary experiments proved, as was expected with such 
porous material, that about one per cent, of water-soluble salts de- 
posited by the saline ground water {vide supra) were present. These 
were chiefly common salt and epsom salts. Further it was proved 
that Natrojarosite itself was apparently entirely unaffected even by 
long continued contact with boiling water. For analysis, therefore, 
a seemingly pure fragment of mineral was selected, broken to pass 
a 20-mesh sieve and washed rapidly with a few small lots of cold, 
distilled water to remove all associated salts, then in succession with 
