O. A. Derby—Santa Catharina Meteorite. 35 
not troubled as in that rock, and the opacity is, in this case, 
evidently due to vitrification of the margins of the grain, and 
not to decomposition as in the case of the granitic rock. 
n order to verify the idea that was at once suggested, that 
this porphyritic rock was the result of the partial fusion of the 
granitoid, [ attempted to reproduce the peculiarities it presents. 
ing quartz to represent the infusible element and labra- 
9 
oe 
& 
Scraps of iron turnings and fragments of magnetic pyrites. 
After an incomplete fusion, the characters above mentioned - 
were found to be very satisfactorily reproduced. The principal 
differences noted were that the glass was clearer and that those 
grains of feldspar which escaped complete vitrification were, for 
the most part, more troubled, many of them becoming quite 
opaque and with an abundant development of microlites. 
It appears therefore that this meteorite presents a mixture of 
metallic and siliceous elements combined in a way that has not 
hitherto been noticed, and that the stony portion also presents 
@ hew type of structure in which olivine and plagioclase are the 
predominant elements. The partial vitrification of the ston 
portion seems to afford unequivocal evidence of the meteoric 
_ Origin of the mass. The presence of silicates, in part fusible, 
which would form a crust of low conducting power about the 
iron will enable us to account satisfactorily for the low mag- 
hetism of portionsof the mass noted by Lawrence Smith and 
Becquerel,* which led them to infer that the iron had crystallized 
elow a red heat, a fact which it would be difficult to reconcile 
With the ineandescence of meteorites, if the mass had been 
composed exclusively of metal. It ma be reasonably inferred 
that different portions of the mass will be found to vary in 
magnetic properties. It is hoped that material for investiga- 
tng this and other questions may be obtained in a visit whic 
esting meteorite. 
The observations here presented suggest the suspicion that 
and it is hoped that an opportunity may shortly be afforded for 
> eammabitie 3 the famous Bemdego meteorite which, judging 
0 . 
Pected to have belonged to it. Both mention masses of quartz 
tom ded in the iron which are most probably of olivine. — 
* Comptes Rendus, vol. xciii, p. 794, 1881. This Journal, March, 1882. 
