76 ni General Notes. (January, 
SAMARSKITE FROM CaANADA.—Mr. G. C. Hoffman has found 
irregular fragments of samarskite in Berthier county, Canada. 
The mineral is massive, has a sub-metallic lustre, brownish-black ~ 
color, grayish-brown streak, hardness of about 6, fusing between — 
4 and 4.5, and specific gravity of 4.947. Its composition, accord- — 
ing to an analysis given in the Amer. Jour. Science, Dec., 1882, 
is as follows: e 
Cb,0,,Ta,0, SnO, YO CeO UO, MnO FO 
55-41 10 14.34 4.78 10.75 51 4 
CaO _ MgO K,O Na,O F H,O 
5.38- Il -39 23 (trace) 2.21 
Tue Cryotire Group oF Minerats.—J. Brandl has investigated 
the chemical composition of the minerals of the Cryolite grou 
and derives several new formula. Pachnolite is shown to ha 
the composition, AIF;, CaF, NaF. Thomsenolite, often c 
founded with pachnolite, differs from it in composition by com 
taining one molecule of water. New formule are also assign 
Al,(F,OH)s The rare mineral, Fluellite, has probably the for- 
mula, AIF, + H,O. Bi 
HEATING APPARATUS FOR THE Microscope.—Thoulet descri 
in the Bulletin de la Société Mineralogie de France, a new meth 
of heating objects upon the stage of the microscope. He 
constructed a small “stove,” or chamber, to rest upon the sta 
and to contain the object and the thermometer. It consists of. 
glass tube fitting into a copper cylinder which rests upon a © 
of copper, furnished with lateral prolongations, whic can 
heated by a gas jet. The whole is insulated by resting upon 
disk of cork. The temperature of the chamber can be raised ‘ 
heating the prolongations, of copper and lowered by introd 
a current of fresh air through a small tube fixed in the side. 
exact measurements can be taken with this simple apparatu 
well adapted for determining the temperature of the disap 
ance of bubbles in liquid inclusions, for studying the form 
of crystals at various temperatures, or for other micro-che 
investigations. 
MINERALOGICAL Notrs.—Descloiseaux has described som 
nute crystals which occur in Pegmatite near Nantes, France, í 
which probably are new. They are transparent, rectangular 
bles, less than a millimeter in length, which become white but ¢@ 
not fuse when heated, and are insoluble in acids. They are pror 
ably composed of a silicate of alumina, iron and lime, and af 
identical with some similar crystals previously described by 4 
trand from another locality in the same region ard 
just published a paper upon the action of heat upon cryst 
