416 Dr. Genth’s Contributions to Mineralogy. 
far as the 141 foot level, where it gradually disappeared. At its 
widest place it was two feet in thickness and consisted of a very 
friable quartz with mica, supposed staurotide or partschine (Shep- 
ard) (?), automolite, Harrisite, Cantonite, pyrites, ete. At th 
ore-stratum of the Canton mine or a similar one should be devel- 
oped where the atmospheric influences have been favorable to 
such changes. 
arrisite has very much the appearance of a dark variety of 
galena, though it is always darker than the darkest, which I 
have ever seen. It occurs both in broadly foliated and granular 
masses, which show a perfect cleavage even to the smallest ste i 
ments. Between the cleavage planes, which are often tarnishe 
we frequently find a coating of clay. 
It has lost its compactness and has become friable. Sp. Gr. 
{at 20° Cels.) =5°485. H.=3—3°5. : 
The material for the analyses was treated with chlorhydric acid, 
washed and dried over sulphuric acid, in order to obtain it in 4 
state of perfect purity. I found: 
I. Il. 
Sulphur, - ae 90'648 20°647 p.c. 
Selenium, - not determined. 0047 
Silver, - : : 0-207 O164 * 
Copper, - - - - 7'7-298* T7758 
Lead, - s ; - 0-056 0-060 
Tron, é . 2 0°442 0°359 
Insoluble, - - - 0272 o667 
98-923 99°702- 
The eminent cleavage of this pseudomorph in the form of the 
original mineral has for a long time perplexed and pie me in 
, but the 
on 
my a 
and those at the Canton mine, the more have I become:convia 
ave 
rd of minerals that have an eminent cleavage. This ca 
m to change from a single one to an aggregate of innumerable 
| ytials by agencies, such as heat, pressure, ete., which woul 
