176 Miscellanea. 
treatment at present than they received when their loss could be 
supplied from the market at the low rate which anciently prevailed ; 
a fact acknowledged by every native slave-owner. This scarcity, 
greater value, and increased comfort are all the results of our 
blockade; and thus the blessing of British humanity is daily felt 
by the captive in the remotest corner of Brazil. 
[This paper was of very great length, and contained numerous 
descriptions of mines and scenery ; it was illustrated by an extensive 
and beautiful suite of gold specimens on the table.] 
On THE Minerats oF THE AurRiFERoUS DistRIcTs OF WICKLOW. 
By Wittiam Mattert, Esa. 
[Edinburgh New Philosophical Journal, January 1851.] 
THE circumstances attending the original discovery of native 
gold in the beds of some of the streams in the county of Wicklow 
have been already often detailed, and will, therefore, need but a 
brief repetition. The source of the auriferous streams is the moun- 
tain Croghan Kinshela, whose summit forms a portion of the bound- 
ary between the counties of Wicklow and Wexford. The stream 
from which most of the gold has been obtained rises on the north- 
east side of this mountain, and then flowing down one of the glens 
with which that part of the country is intersected in almost every 
direction, joins the Aughrim River, a little above the confluence of 
the latter stream with the Avonmore. It receives several smaller 
Streams at different parts of its course, in all of which some gold 
appears to have been found, though in general in such small quan- 
tity as not to repay the cost of its extraction. 
Although this part of the country, since it has been known to be 
auriferous, has been an object of some attraction to mineralogists, 
but little attention seems to have been directed to the other minerals 
which are to be found accompanying the gold in the alluvial deposits. 
These, however, are interesting, not only from their number and 
variety, but also from the occurrence amongst them of some of the 
rarer species, which do not appear to have been noticed in any other 
locality in Ireland. The following minerals were obtained from a 
considerable mass of sand and gravel taken from various parts of the 
bed of the principal stream :—Gold, platina, tinstone, magnetic 
oxide of iron, micaceous iron, red iron ochre, hydrous peroxide of 
iron, common clay ironstone, iron pyrites, titaniferous iron, wolfram, 
oxide of manganese, copper pyrites, galena, sulphuret of molybde- 
num, sapphire, topaz, zircon, garnet (two varieties), quartz, prase, 
augite, chlorite, felspar, mica. 
The author has since observed, in addition to those here men- 
tioned, arsenical iron, in small fragments, and also spinelle. The 
latter occurs in very small grains along with the second variety of 
garnet, from which it is readily distinguished by its peculiar purplish- 
red colour. 
