FEBRUARY 22, 18S4.] 
date she was in about latitude 17° north, longitude 
125° west. The captain’s wife, Mrs. Davis, described 
the phenomena to me as extremely brilliant. 
S. E. BIsHoP. 
Honolulu, Jan. 30. 
The Philadelphia biological institute. 
The proposition of Professor Allen of the Univer- 
sity of Pennsylvania for the establishment of an in- 
stitution for the education of both sexes in biological 
science, is one that he, and many others like minded, 
have long hoped to see established in Philadelphia. 
Indeed, it was somewhat expected, when the large 
building-fund that enabled the Academy of natural 
sciences to put up its present elegant quarters was 
asked for, and generously subscribed to principally by 
the manufacturers of Philadelphia, that something 
of the kind Professor Allen asks for would be the 
result. The writer was principal of the school of 
design for women at the time the successful effort 
was being made for a new building for the academy; 
and well does he remember the promises that were 
then made as temptations to contributors. It may 
be that ‘the representative members of the academy’ 
think that the quite limited extent of the ‘ educa- 
tional’ plans that they have been pursuing is a fulfil- 
ment of the promises then made; and perhaps they 
are, as they understood it at the time. Yet dolI feel 
quite certain, that if the gentlemen who so generously 
helped the academy then, and before that time, also 
were told that the controlling parties of the acade- 
my were to refuse to put the building and what there 
is therein to the use of extended scientific education, 
it would be to most of them, if not to all, a surprise. 
I do not mean to say that the academy people have 
refused to do so; but it looks, trom your ‘ Comment 
and criticism,’ as if something of that kind had been 
done. My long and intimate experience with ‘repre- 
sentative members’ of public educational institutions 
has impressed my mind strongly with the idea that 
those gentlemen fail to draw distinction enough be- 
tween themselves and the schools they represent; 
and, being placed there to manage and direct, they 
too often seek to carry out their own ways, rather 
than consider broadly the full purpose, scope, and 
public usefulness, of the institutions under their care, 
egg should ever be rule, amongst evolutionists at 
east. 
The Academy of natural sciences in Philadelphia 
would be a grand central body, magnificently pre- 
pared as a starting-point for biological education; and 
it would be a pity indeed, if the generous citizens of 
my old city should be put to the expense of another 
distinct building, and its professors to the trouble and 
expense of getting together another collection, per- 
haps to be placed within a few hundred yards or feet 
of the present academy. Would it not be more than 
a mere pity? T. W. BRAIDWOOD. 
Cassiterite from King’s Mountain, North Caro- 
lina. 
Mr. Robert Claywell, a student at the high school 
at King’s Mountain station, on the line between 
Cleveland and Gaston counties, found in the street 
of the village a piece of mineral, which he sent me 
for determination. The mineral turned out to be 
massive cassiterite, the first found in this state. 
Ascertaining that there was a considerable amount 
of it scattered through the surface-soil there, I vis- 
ited the locality, and instituted some explorations. 
My expectations were more than verified when I 
found pieces of cassiterite from the size of an egg to 
the finest sand, loose and sticking in quartz, scattered 
SCIENCE. 
“Q17 
over the surface in a belt beginning about the centre 
of the village, and extending southward a mile or 
more. Several shafts were sunk, and trenches dug, 
which finally exposed a main vein and several smaller 
veins of quartz and quartzite, bearing the tinstone. 
The veins are nearly vertical; direction of outcrop, 
north-east with the rocks of the country. The wall- 
rock is a mica schist, which is broken down from 
both sides of the vein at places farther than has been 
dug. The chief accompanying minerals are tourma- 
line, titanic iron, mica, and, less abundant, zirkon 
and rutile. At points the tinstone is disseminated 
abundantly through the vein-rock: at other points 
little is found. Itis mostly in small grains mingled 
with the other minerals, tourmaline chiefly. Changes 
of temperature have broken it out of the surface- 
rock; and washing the soil yields a black sand, which 
is composed of the dark-colored minerals mentioned. 
The cassiterite is mostly massive or semi-crystal- 
lized. I have noticed the forms P, Px, wP, and 
oPo in only afew specimens. Hardness, 6.5 to 7; 
specific gravity, 6.6 to 6.9; color, generally dark brown, 
but varying from black to almost colorless; composi- 
tion, mostly an impure cassiterite, with 50 % to 60 % 
of tin, some specimens running as low as 46 %, others, 
light-colored ones, as high as 74.4% The other in- 
gredients are silica and oxide of iron. So far, I have 
not detected any sulphur or arsenic. 
According to Dr. Emmons, the village of King’s 
Mountain is near the dividing-line between the Lau- 
rentian granite and the Huronian slates. To the 
east of the village the rocks are micaceous and slaty 
quartzites, taleose slates, and bluish crystalline lime- 
stone. A few miles west are the hornblende slates, 
gneiss, ete. 
The only remark on tin which I find in writings on 
North Carolina mineralogy is the following from Dr. 
Genth (‘ Mineralogy of North Carolina’): ‘*No tin 
ore has been found in North Carolina as yet; traces 
of this metal have been found in the tungstates of 
Cabarrus county, and in a micaceous slate (Huro- 
nian) in Gaston county, associated with garnet and 
columnar topaz’’ (the Italics and parenthesis are 
mine). The observation is very interesting in the 
light of the recent discoveries. Have we not here at 
King’s Mountain, at or near the juncture of. these 
slates and the older gneiss and granite, a concentra- 
tion of this diffused tin? 
CHARLES W. DABNEY, jun. 
N.C. experiment-station, Feb 14, 1884. 
Behavior of Dolomedes tenebrosus. 
Last August I obtained a large female specimen of 
Dolomedes tenebrosus. It measured over four inches 
from the tips of the first pair of legs to the fourth 
pair. It was taken in a swamp, and confined in a tin 
can, where it remained a day or two before it came 
into my possession. Upon opening the can, I found 
it apparently half dead with fright. It had deposited 
its eggs without attempting to make a cocoon. The 
appearance of the eggs indicated that it had ex- 
truded them prematurely. They were mixed with an 
abundance of mucilaginous substance, which soon - 
hardened, and held the eggs firmly together and fast 
to the can. I now put it in a cage, where it soon 
recovered from its fright. The cage was two by three 
feet, the top covered with glass, and the bottom 
uncovered, so that it might have the fresh earth and 
plants to run among. 
I also put the can in the cage; but a colony of 
small ants (Crematogaster lineolatus) soon found 
the eggs, and carried them all to their own domin- 
ions. It was amusing to see them work and struggle 
