~*~ 
pepe emi ee et. df 
Dr. Genth’s Contributions to Mineralogy. 417 
table from each other. ’ Before their conversion into the new 
‘mineral we have to consider such masses not as one individual, 
but as made up by the close juxtaposition of a great number of 
single individuals, each of which had been altered separately 
from the others, and which after their alteration had not the 
power to unite again into a single one. 
in the galena, is further to be remarked, both in the Harrisite 
and Cantonite. 
if we bear in mind 
an observa : or 
ms Phe sulphid of lead, throws down sulphid of copper, when 
a 
cies, I am not prepared to sa , but from the experiments of Mit- 
scherlich and G. tnd H. Rhee, that by fusion of sulphur and cop- 
Per or copper-glance, a monometric subsulphid of copper can be 
obtained, it is not improbable that under favorable circumstances 
it may also be found in nature. _ | | 
3. Cantonite (Pratt), a pseudomorph of Covelline after Galena. : 
Mr. N. A. Pratt announces (Am. Jour. Sci., xxii, 449) as a 
Rew species, which he calls Cantonite, a very rare and eh | 
Mg pseudomorph of covelline after galena, or rather oe i 
Msite, the latter having been the intermediate result of oe 
OMposition. He ises in his announcement to give in the 
-hext number of sha: Am. Jour. of Sci. a full description of it, 
= having failed to do so in the numbers for 
January and March 
57, I do not hesitate to give the results of my investigations. 
SECOND SERIES, VOL. XXIII, NO. 69.—MAY, 1857. 
33 
