764 General Notes. : [Aug j 
probably merely a monoclinic twin, whose twinning plane is thè 
clinopinacoid. Since Rammelsberg has shown that the orthe | 
rhombic mesolite (galactite) is probably natrolite, and since this 
mineral is found only in orthorhombic crystals, there has as ye 
been no proof given to show that either of the three minerals 
mentioned crystallizes in more than one system.——A. Becker’ 
has analyzed a/stonite and darytocalcite from Alston Moor, it 
order to decide as to whether Groth’s view in regard to tht 
- composition of these substances is well founded. Both mit 
galle, in Canton Uri, Switzerland, are found oolitic masses Cot 
posed of a brown or green substance in little elliptical and lete 
ticular grains cemented together by carbonate of lime. These 
little grains are themselves made up of scaly magnetite and 3 1 
to analysis, with the following result : 
SiO, - Al,O, FeO MgO H,O 
ae 19.97 37-5! 4.39 12.90 
in the obtuse angle 8 eee ont, he verti 
l rhs optical angle Wv. and is inclined 5° 54’ to the i 
action # = 1.9465 and y = 1.9285.——The ferri 
* Mineralchemie, ii., Aufl, 2, p. 6 tae t Krist, SE 
: : See aes bid -2 3- . PS eea +" ' 
3 C. Schmidt, ib., xi. p. 597. 7 3° 4 Zeits, f, Kryst, xii P- 25 
