$ 
"ee oe 
1883. ] Mineralogy. 1059 
“ SULFURAIRES.”—M. Plauchud, having shown that the presence 
of hydrogen sulphide in water containing vegetable matter is 
due to the action of some species of conferve, which have the 
power of reducing sulphates to sulphides, formulates the theory 
that many of our natural mineral sulphides are due to the 
reducing action of this class of alge. He sealed some of these 
algæ, which he designates “sulfuraires,” between plates of gyp- 
Sum, and after some months found granules of sulphur. Several 
other observers have noticed this chemical activity of certain 
alge, and have shown that this action occurs only when the 
plants are alive. 
€nstatite. Rose and Rammelsberg also analyzed the chladnite, 
the latter stating that no feldspar was present. 
Quite recently Dr. M. E. Wadsworth has examined the same 
meteorite and come to the conclusion that there is no such min- 
eral as chladnite, and that it is an aggregate of enstatite, feldspar 
and augite ; with traces of other minerals. The microscope 
clearly reveals the compound nature of the supposed mineral, 
Which has a granitic structure and is a rock belonging to the 
gabbro variety of basalts. 
That such diverse conclusions should thus be reached by the 
most able investigators seems indeed most strange. The conclu- 
Sion of Dr. Wadsworth, undoubtedly the correct one, clearly 
