318 Dr. Wollaston on the Discovery of Palladium. 
to undertake a comparative examination, from whose well 
known skill in chemical inquiries, as well as peculiar knowledge 
of the subject, we have every reason to expect a complete ana- 
lysis of this ore. 
§ II. Hyacinths. 
Among those bodies which may be separated from the ore 
of platina, in consequence of their less specific gravity, by a 
current of water or of air, there may be discerned a small 
proportion of red crystals so minute, that 100 of the largest I 
could collect weighed scarcely of a grain. The quantity 
which I possess is consequently too small for chemical analysis ; 
but their physical properties are such as correspond in every 
respect with those of the hyacinth. I was first led to compare 
them with that stone by their specific gravity, which I con- 
jectured to be considerable from their accompanying other 
substances, that appear to have been collected together solely 
by reason of their superior weight. 
Like the hyacinth, these crystals lose their colour imme- 
diately and entirely when heated ; they also agree with it in 
their hardness, which is barely sufficient to scratch quartz, but 
is decidedly inferior to that of the topaz. 
The principal varieties of their form may be very well un- 
derstood by description. 
1st. In its most simple state the crystal may be considered 
as a rectangular prism terminated by a quadrilateral obtuse 
pyramid, the sides of which sometimes arise direct from the 
sides of the prism ; but, 
adly. The position of the pyramid is generally such that its 
sides arise from the angles of the prism. In this case the sides 
of the prism are hexagons. 
