622 General Notes. [June, 
Descloiseaux announced in his “ Manuel de Mineralogie,” tephro- 
ite and chrysolite are isomorphous. | 
Pyrosmatite. — Alex. Gorgen! communicates an analysis of 
pyrosmalite from Dannemora which is of considerable interest in 
that it shows a close analogy in composition with a silicate of 
manganese from Adervielle, Hautes Pyrenees, described by Ber- 
trand under the name of Friedelite. 
The oxygen ratios of the two minerals are as follows: 
SiO, MnO FeO CaO MgO Cl Fe 4H,0 
ne ad 
Pyrosmalite 18.24 11.56 0.84 7.60 
Friedelite 18.37 11.42 0.80 8.53 
Both minerals are remarkable for the energy with which they 
retain their chlorine and water. Both are hydrated chlorosili- 
cates, and present chemically the same analogy as Berti d e 
shown to exist between their crystalline form and their opti 
properties. An 
HaypenitE.—H. N. Morse and W.S. Bayley’ have reëxamined 
the variety of chabazite known as haydenite, found in the om, 
quarries near Baltimore. Cleaveland named the species p ia 
but its independence as a separate species was doubted er ' 
in 1839, showed it to be, as he supposed, monoclinic. ‘hat the 
afterwards showed Levy to be in error, 
i in 
mineral was rhombohedral, occurring -deatical, although the 
Anae Spee EE i = 
chabazite. ; lyses): 
- The composition, as now ascertained, is (mean of two analyse 
SiO, AlO, FeO, CaO MgO. BO KO Bega 
49:24 18.07 0.84 5.16 0,86 1.47 ay at3 ike mag: 
By regarding the iron as in the ferrous condition ee 
nesium and barium, replacing calcium, the analys ; 
with the recorded analysis of chabazite and "e a tedi id 
formula for that mineral. Haydenite is thus un ue 
respects identical with chabazite. é 
BOTANY.’ 
| 
i 
s CELL E 
F THE GERM q 
AN OBSERVATION OF THE eames 2 he bè on the oth 1 
g 
oF EQUISETUM ARVENSE.—The spores Wert ~: seem 
April. For some reason, for a time growth did not 4 
and they were neglected until the last of J rae amale, the lat : 
they had developed large prothallia, both matea — 
1 Bull. Soc. Min. de France, 1884, p. 58. ye 
-2 Amer. Chem. Journal, March, 1884. 
3 Edited by Pror. C. E. Bessey, Ames, Lowa. 
