SCIENTIFIC SUMMARY. 
325 
the meteoric rocks belong to the lowest beds of the earth. Some are 
eruptive rocks of basic character consisting of anorthite and augite, like 
certain lavas from Iceland; others are oli vinous rocks, like lherzolite, to 
which the meteorites containing magnesia — those, in fact, of the ordinary 
type — belong. The presence of olivinous rocks accompanying the platinum 
of the Urals, and the presence of nickel in the iron combined with 
platinum, have confirmed these relations, which are of interest to both the 
geologist and the astronomer. It was expected that among the aluminous 
and magnesian rocks some might be found in which iron should begin to 
make its appearance, and this gap has now been filled. In the Greenland beds 
layers of lignite are found associated with the basalt, and this may have 
furnished the material which has reduced the iron to the metallic state. — 
(Compt. rend, lxxxvii. 911.) 
Fairfield County Minerals. — G. J. Brush and E. S. Dana have published 
a second paper on the minerals of Fairfield County, Connecticut, in the 
“ American Journal of Science,” May, 1879. In the present paper they 
describe a new mineral which they name fairfieldite. It occurs in massive 
crystalline aggregates, rarely in distinct crystals. It has a hardness 3*5, and 
the specific gravity 3*25, a subadamantine lustre, and is white or of a pale 
straw colour. The streak is white and the substance itself transparent. It 
occurs in small particles in fillowite (described beyond) and in masses of 
some size immediately associated with eosphorite, triplcidite, and dickinsonite. 
The crystals belong to the triclinic system. The analyses closely accorded 
with the numbers : 
Phosphoric acid . 
. 39-30 
Iron protoxide 
. 6-64 
Manganese protoxide 
. 13-10 
Lime 
. 30-99 
Water 
. 9-97 
100-00 
which correspond with the formula 3R0,P 2 0 5 ,H 2 0, where R = Ca : Mn + Fe 
= 2:1, and the ratio of Mn : Fe is also 2: 1. Fillowite occurs in granular 
crystalline masses which are not unfrequently penetrated by distinct pris- 
matic crystals of triploidite, and sometimes enclose particles of fairfieldite. 
Reddingite is very commonly associated with fillowite, and in many cases it 
is not easy to distinguish the two minerals. The hardness is 4*5, and the 
specific gravity 3-41-45. The lustre is subresinous to greasy ; the colour 
generally wax-yellow, also yellowish to reddish-brown, with a red or green 
tinge, and rarely almost colourless. The crystals have a marked rhombo- 
hedral aspect ; the measurements, however, point to a monoclinic form, and 
that this is the true explanation was proved by the subsequent optical 
examination. The results of the analyses of this mineral nearly accord 
with the numbers given below : 
Phosphoric acid .... 
. 40-19 
Iron protoxide .... 
, 6-80 
Manganese protoxide 
. 40-19 
Lime 
. 5-28 
Soda 
. 5-84 
Water 
. 1-70 
100-00 
