On the Pho/phorefcence of the Luciole. ‘oy 
and the fame difpofition in the matrix, as thofe of the red 
lead, and which are only a combination of the oxyd of 
chrome and the oxyd of lead. It is probable that thefe 
combinations originally exifted in the ftate of the chromate 
of lead, and that at leneth a portion of oxygen taken away 
by caufes with which we are unacquainted, made them pafs 
to that of oxyd, and converted the red into green, 
xVt: Experiments and Ob/ervations on the Phofphorefcence 
of the Luciole, Lampyris Italica. By Dr. Carrapori. 
From the Annales de Chimie. 
‘Tues winged infe&ts, which. during the calm nights 
of {pring fly about in the air, where they appear like {parks 
of fire, that attract the curiofity of children and afford them 
amufement, cannot fail in a more particular manner to. ex- 
cite the curiofity of the philofopher. 
It adheres in long or thort cryttals in the fiffures of quartz, as well as on the 
edges of the ore, which is a fandy kind of ftone. It has very frequently, 
and wherever the {pace has permitted, the fame fize and the fame prifmatic 
form, with four flat facets, having two extremities irregularly blunted. It 
is found alfo in fa! irregular twifted pyramids, attached to a quartz like 
fmall rubies. When well. ground with water, it gives a beautiful fub- 
ftance of a dark yellow colour, which may be employed in miniature paint- 
ing. In all the experiments made on this lead ore in the laboratories of 
Ekaterimbourg, a fmall grain of filver has always been obtained. It is 
difficult at prefent to procure the ‘quantity neceffary ‘for extenfive experie 
ments, as the workmen cannot labour where this lead ore 1s found, for 
want of good air. There are found in the mixed matrices of quartz, where 
this rare and curious mineral is formed, {mall cryftals pointed at both ends, 
and of the colour of fulphur, They refemble native fulphur, and they 
are confidered as fuch by the miners; but they do not burn in the fire, and 
do not flath when applied to a flame, like the lead ore. They may confift 
perhaps of metallic fpar, but it is difficult to procure the quantity neceflary 
for experiments. Thefe finall cryftallifations are found both on the quartz 
and the fand-ftone.” Epir. 
6 The 
