960 Brush and Dana—the Spodumene of Branchville, Conn., 
we have given the name eucryptite ; and the other “ cymato- 
lite, an aggregate of albite and muscovite. We have also 
tinct pseudomorphs, hee the form of the etc mene. The 
mica, taken independently of its constant associate the albite, 
plays only a secondary part. In addition there are other pseu- 
domorphs, of composite character, consisting, as Mr. Julien has 
well expressed it, ‘of vein granite.” 
We will first give the physical and chemical characters of 
the various minerals (including the two aggregates) taken sep- 
arately, and then go on to describe more minutely the way in 
which they are associated together. 
I. PRopUCTS OF THE ALTERATION. 
1, £ Spodumene. 
The substance which we have, for convenience, called f 
umene, since we do not regard it as deserving an inde- 
sink spodumene, described above, and the outer portion was 
this mineral (similar to fig. 5). The line of demarcation was 
perfectly sharp, so that the purity of the material analyzed 
— be ceectanaate: The results of the analysis are as 
) 
No. 1, G@.===2°649. L Il. Mean. Ratio. 
iO. 61-35 61°42 61°38 1023 4 
AlO, 26-26 25°74 26-00 — 
Fe,0s 0-24 0-24 0-24 002 t eat: 
% 3°63 3°59 3°61 ee . 
Na,O 8°32 8°25 8-29 134 t — 
; tr tr tr 
Ignition 0°46 0°46 0°46 
100-26 99°70 99-98 
The second portion analyzed was from a fragment ot a fag 
and entirely altered crystal ; its dimensions were 9 by 8 by 24 
inches. It consisted mostly of cymatolite, and the # spodu- 
