ak on Crist ai from. pat ornia, ~ 105 
ed form of six-sided tablés, but; they are the result of 
‘ind of modification, and are*tiot macles. Dufrénoy 
lave each given a figire of a very perfect example 
tion as fig. 
e by inequalities, while the primary faces P, are perfectly smooth 
_ and brilliant.+ 
ome of the unmodified macles, as shown in different positions 
bs fig. 1, a, b, c, are very enon I ee the edges between ee, 
“Uniting the two segments of the ahedron, being well defined. 
ron with emarginated edges. Dafeétioy has described a macle 
of gold quite similar to fig. 1, and it may be seen figured in the 
volume of elegant and copious crystallographic illustrations which 
accompany his treatise.§ It came from Matto-Grosso, in Brazil, 
and is in the collection of the School of Saag: Paris. It differs 
from the example here described, in ex 5 
figure, but oouniite the octahedron as the 
primar ary form of gold, I have, besides con- 
forming his lettering to the notation of Phil- 
lips, made primary planes of ak aoe 
he Bites only as secondaries of the 
uld be observed that as ney ‘ll of these crystals show 
he effects of more or less abraded action, it is often difficult to 
* Fig 7 576, plate 144, of Dufrénoy’s, and fig. 3, plate 47, of Levy's Atlas of Plates, 
+ In the Taruer collection there is a a single macle ¢ rystal — ering almost exactly 
ee aan has figured it in his Atlas, plate 4, fig. 4 
{ Th i group prepress the figures as magnified to about twice their natural size, 
3 Atlae plate 145, fig. 581 
Srconp Serms, Vol. X, No. 28. —July, 1850. 14 
“fig Naa have besif brought. feomn Brazil hind Siberia: Shey had the. 
a Solid angles a, as lettered by Dufrénoy. Further ex- - 
amination “However, proved them to be the same macled combina-. 
