Alexandria gazette. [volume] (Alexandria, D.C.) 1834-1974, 1872-08-27
ALEXA. GAZETTE & VIRGINIA ADVERTISER.


duced into this country from abroad along WIN
foreign seeds, slips and plants. He says :
''It would seem as if every grain brought its
bane," and while according much credit to the
Agricultural Department at Washington tor
its importation of valuable seeds, slips and
plants. he deplores that want OF care or skill
which has resulted in the introduction of the
eggs and larvae of foreign insect-pests which
are so troublesome to the husbandman and SO
destructive of crops.
Everybody has heard of the Hessian fly,
which was introduced into this country In l776
in the provender of the Hessian soldiers, and
has proved much more formidable enemy
than the troops that brought 1t. Professor
Lockwood refers to several of the new pests
that have been introduced He detected one
in 1870 in New jersey which is very destruc.
tive to cabbages. 1t was small green cater
pillar, which be describes as the Pleres rapee,
or cabbage caterpillar of Europe. The parent
was pretty butterfly, mainly white, with
black spots on the wings. 1t first appeared on
this continent at Quebec, and made its noX-
iouS power felt in the destruction OF the cab,
bages to the amount of many thousands of
dollars in that neighborhood. 1t then invad-
ed northern New England, and in 1869, was
found in the gardens within few miles OF
New York. It next appeared at Philadelphia,
then at Baltimore, and last June, made It's ap-
pearauce at Washington. The Professor says:
This terrible little beauty is thus betting the
land with scourge
He describes new grasshopper which has
appeared on the grounds OF the Agricultural
Department at Washington. He says: Its
Jaws are remarkably strong and sharp,
and when the insect is handled incau.
tiously it bites so severely as to draw blood:
1t is of light pea green color, the labrum and
clypeus being bright yellow and the mandbes
let black 1t has cone or horn on the top OF
the head A pair were hatched from the
Larvae in the greenhouse. 1t is supposed to
have been imported in the egg state with some
plants from South America or the West In
dies AS it comes from a tropical climate 1t is
supposed that it will not spread in his climate.
a new earth worm has also appeared In the
lighthouses of the Agricultural Department.
1t is much larger than the common ange-worm
and has multiplied in the hot houses Of the De-
partment to such an extent as to have become
a real pest. 1t is believed to have been intro
duced from Japan in the earth with the plants
imported 10 the expedition under Commodore
Perry. 1t breeds with great rapldlty.
Professor Lockwood does not describe any IN
sect thus imported along with seeds and plants
that has become generally destructive. Such
as he refers to with (the exception OF the cab
bage caterpillar) are thus far confined to the
green houses and hot houses of the Depart
ment. But iu process of time. unless, great
care is practiced, some of these little pests may
be introduced, which will commit terrible havoc
with our crops.-Rrl,mond Wing
TIE Color OF THE SEA.-The rich blue
color often seen in masses of water is to be ac'
counted for by the action of the suspended par
tclcs in the fluid on the light traverslng it. 10
understand how the color may vary 1t IS neces.
sary to recall tor a moment the composition OF
sunlight When such light is passed through
a triangular column of glass or optical prism 1t
is broken up into the seven prsmatlc coorS'
Wis, red, orange, yellow, green blue, indigo,
and violet.
When the light falls on water of sufficient
depth it is also decomposed or broken up the
red rays of light are absorbed near the surface
of the water and disappear, while the other
colored rays pass to greater depth one after
the other being lost in their proper order, VIZ;
red, orange, yellow, green, blue, indigo, uotll
at last there is complete extinction OF hight II
the water is free from solid particles
The presence of minute particles, howev er,
causes part of the light to be reflected, and
according as this reflected light has come from
various depths so will its color vary, Ii, tor
example, the particles are large and freely re-
fleet from moderate depth, while they pre-
vent reflection from greater depth, the color
will be green, while if they are minute and the ne
reflection is from great depth, the color Will
be blue.
In the experimental examination of this sub
icct Professor Tyndall reports that while max
ing trip in the steamer Urgent he caused his
assistant to cast white plate attached to
cord into the water from the forward part OF
the vessel, while he marked its color when it
reached his post of observation at the stern
In every instance the plate appeared OF green
color although the water was OF deep blue
The plate had thus tar reflected the hight from
moderate depth and showed the tint OF hight
reflected from this DEPTH while the indigo tint
of the remainder of the water represented the
color reflected from minute particles at great
depths. -SuiJmcr'S for September
A FISH WITH Four HANps.-Mr. Foord,
member of the Australian Eclipse Expedition,
recently described before the Royal Society a
most extraordinary creature, which was dredged
up from the bottom of the sea near the northern
shores of Australia Mr.. Foord says: inc
BODY was that of a fish, but wonderful to relate,
it had in the place of fins four legs, terminated
by what you might call hands, by means OF
which it made its way rapidly over the cora
reef. When placed on the skyght of the steam
er, the fish stood up on its four legs sght 10
behold! 1t was small and something hike
lizard, but with the body of fish The lana
animals of Australia are notorious tor their Pc
cular forms and structure, but according 10 tne
above they are even less nondescrpt than those
inhabitiug the Australian seas MI. w hlte mem
Der of the same expedition, tells strange tales
about rats. 1.-The little island upon which we
pitched our tents, he says, was oyerrum with
them and what was most extraordinary, they
We're of every color from black to yelloWW' and :,
some tortoise sh I'll. .-"S Scientific Miscellany,