St. Landry democrat., 1883-04-14

Telephoning by underground caoies
has been pronounced impractlcable TOT
that such cables must necessarily each
contain a considerable number OF con-
Quoting wires and the induction pre-
vents speech. By means of special
arrangement of the circuits, Messrs.
FELTON, and Guilleaume, Of Mulheim on
the Rhine, claim to have overcome the
effects Of induction in these cables.
Their system was lately tried on line
thirty miles long, and proved SO
effectual that speech was transmitted
without trace Of foreign sound through
one wire while neighboring wire OF
the cable was in constant use.
A very faulty lightning conductor
may sometimes protect building.
Mons. Hirn tells Of such a case which
lately occurred at Colmar. A thin iron
rod about twenty feet long had a
conicaI brass point screwed on the top,
and was collected below, by means OF
a series of pieces Of thin wire having
terminal eyes with block of iron about
twenty inches long in the ground. Dur
ling violent thunder storm lightning
melted the brass point, but the current
seems to have nowhere left the conduc-
tor. Mons. Hirm insists that the mere
fact of a lightning discharge on the
point of a conductor is proof OF very
imperfect construction as, during
more than forty years OF observation,
he has never seen lightning strike one
| of the forty or fifty lightning rods OF
| the factories of Logelback, although
| he has found that currents are almost
constantly passing through the rods IN
| in the presence Of thunder storms.
| Mons. Perreaux has constructed an ap-
paratus for microscopic measurements
which is capable Of measuring one
115OOth part of a millimetre. The instru-
ment is SO delicate that it can only be
used at certain hours of the night when
the jar of passing vehicles has ceased.
Those not familiar with the metric sys-
TEN will Get a better idea of the minute
measuring powers of this apparatus
| when it is considered that a millimetre
] is only about one twenty fifth OF our
inch.
i A new form Of phosporus-termed
white phosphorus-has been discovered
| by Prof. Remsen, of the John Hopkins
University.
/ The name "commensals," meaning
eaters at the same table, has been ap-
4 piled by naturalists to creatures OF dlf-
ferent kind which live together but do
! not prey on each other. a newly re-
j corded case Of commensalism is that
of a curious lizard called tuatara-
found in the Chicken Islands, near New
i IZealand-and certain species OF petrol.
/. In burrow usually dug by the tuatara,
i both lizard and bird build their sep
arate nests, and live in apparent bar
| mony. They mutually profit by this in
i timacy, as the lizard yaliantly defends
i the entrance to the burroW while de-
q pending upon its companion for a large
part of its food. It is well known that
1 the underground home of the North
American prairie dog is often shared
by the rattlesnake and the burrowing
! owl; and arabbit-like yiscacha has a
messmate III a little burroWing owl, in
8 South America. Commensalism is,
however, very rare among the higher
animals. A few examples have been
recorded among insects; but the phe-
|. . nomenon is much more frequently OBJ
served among marine animals, many
of the weaker creatures Of the sea ow-
ing their existence to the food or pro-
lection bestowed by their powerful al
lies.
2 Koch's discovery Of the true nature oi
! tubercular consumption has naturally
raised the hope that some means may
. be found to destroy in the system the
organisms producing the disease. Mons
! De Korab has recently described to the
Paris Academy of Sciences an interest
ing experiment bearing on the subject
Tubercular matter from a guinea pig
was placed in ten tubes under favor
able conditions for development. Into
q three Of the tubes helenine was intro
duced. At the end of a week the mat
ter acted upon by the helenine had lost
it's infective powor, while that in th'
! other tubes still readily produced tn
bercnlosis.
II Aluminium, a blush white metal pos
sing valuable properties, constitutes