Geology and Mineralogy. 241 
valley and township of Keene. He adopts for the 4 which 
Hunt showed to consist of feldspar identical with or r Labra- 
dorite along with hypersthene or a related augitic or hordblenaie 
minera (and more or less of iulageeting or menaccanite), the name 
norite, and uses the yi hypersthenic igen hornblendic norite, 
pyroxenic norite, for varieties. He giv s the specific gravities of 
orty-four varieties of 1 siotkean; which vary from 2°67 to 3°459, the 
_ proportion of the feldspar to the amphibolic species and menacanite 
determining it. The labradorite, from — norite forming the mass 
of Mount Marcy afforded him on analysis 
SiO, AlO, FeO, FeO CaO MgO Na,O K,O H,O TiO, 
5447 26-45 1°30 0°66 10°80 0°69 437 0°92 0°53 undet.=100°19 
giving the qanvel rapeat ratio for the pr vlone ss, POPMlON ess and 
Silica, 1°13: 3: 6°83. Another analysis was ma a waxy felsitic 
variety, from the same place, which afforded ven Poe the same 
resu 
Pricos Leeds gives also an analysis of a doleryte from the 
5 Sie and others of the pyroxenic portion of the Mount Marcy 
rite also gives the characters afforded by thin slices of 
Seas of the rocks, 
On a new method of determining hs species of TLRS 
contained in rocks, by Dr. J. 5za86, Professor of Mineralogy and 
Geology in the eee of Budapest, Hugs ty. 88 pp. 8vo; 
: lammenreaetionen,” This method, to the elaboration of which 
he has devoted four years of study and experiment, is based, first, 
eter atiatios of the degree of "fusibility, and, 
secondly, u e degree of coloration of t 
under certain omnes ns, Eos which the Saccuatd of sodium and 
the methods employed in ih the different experiments reference 
potereiams (observed with cobalt glass), is note r removal 
rom the flame the extent of fusion and character of the fused mass 
te observed. bh same assay is then introduced a ete time 
ty 
