The morning star and Catholic messenger. [volume] (New Orleans [La.]) 1868-1881, 1868-06-21
noarma STAR, AND CATHOLIC MESSENGER.
NEW ORLEANS. SUNDAY. JUNE 81. 1868
SCIENTIFIC AND MECHANICAL.

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SCIENTIFIC AND MECHANICAL.
To SHORTEN THE PROCESS OF DYE!NG.--
By previously oxidizing the oil used in the
beginning of the process. the time re-
Uuired for diving calico and wooden cloths
with madden is materially shortened.
This NAV be done by heating the oil to
about two hundred degrees with a soiuti ION
Of chlorate of potash, and very gradually
adding oxalic acid, boiling the mixture for
several hours.
To KEEP NAILS FROM RUsTING.-A BEL
cian has made a discovery which may be of
some utility. 1t is that the rustlng OF nails
employed to fasten the branches of fruit
trees to walls can be prevented by driving
into the wall, in contact with the nan, a
small piece of zinc. In giving an account
of his discovery to the Agricultural Society
of Client. he exhibited nails which had
been eight years in walls, in contact with a
niece Of zinc, and which were not ut all
rusty.
New METHOD OF MAKING WHITE LEAD.
The following process has been announced
as furnishing a result equal to that by the
old Dutch mode, and in considerably less
time. The metallic lead is first granulated,
and then placed in n barrel OF beech or
hornbeam wood (not Oal) with one-fourth
of it's weight of pure water. THe barrel Is
made to rotate about thirty or forty times
IN IL minute, d u tAI poSSAAAS
through Mt the same time. After the lapse
of several hours the lead will all be oxidized.
EFFECTS OF LIGHT ON V1TAL1TY.-In
remarkable paper addressed to the French
Academy of Sciences, DIR. Dubrunfaut ex-
amines the effects of light on vegetable and
animal life. The researches of NM. CRATIC
let, Cloz, and Cailletet have in great mea-
sure proved that the red rays of the lumin-
GUS spectre are those to which the impor-
tant physiological function exercised by the
sun on plants is to be exclusively attributed.
The leaves in this case act as analyzers OF
white light; they reject the green rays,
which constitute the physical complement
hues under which the organs of vegetation
are seen by us may he explained. If plants
were exposed to green illumination only,
that would be tantamount to their being in
the dark But this kind of light, which the
vegetable kingdom refuses to absorb, is pre-
cisely that which is coveted by the animal
one.
MINIATURE VoLCANo.-Among~ the nu-
merous experiments which may be made
with Ruhmkroff's machine, there is re-
markable one, which may be described as
follows: A quantity of flour of sulphur is
mixed with a small proportion Of iron fill
ings, or better still, with iron reduced by
hydrogen, in which case it is in quite an
impalpable state zinc and copper filings
may also be added in small quantities. The
mixture, which must be as complete as pos
sible, is then thrown on pane Of glass, or
on dry brick, SO as to form q heap two or
three oentimetres high, and much longer
than it is broad. If the ends of the wires
of RuhmbrOff's machine be now inserted
into the heap, so as to be two or three cen
timetres' distance from each other, and the
current made to pass through, violent ex-
plosion of the mass takes place, a sort of
crater is formed, whence magnificent
sheaves of fire will he seen to issue, much
resembling the bouquet OF fireworks, and
like it displaying different colors. 1t is in
reality n miniature volcano, with subterra-
mean noises and election of boiling lava.
CHIMNEY Pors-Mr. Mechi raises the
Question whether chimney pots are not %na
blew off the chimney pot of my dining room
without my knowing it. We were much
surprised at the greatly increased draught,
and consequent brightness of the fire. On
looking round after the storm missed the
chimney pot, and consequently removed
other chimney pots with a like advantage.
On reflection and calculation, l soon satisfied
my mind that it is great mistake, having
a large chimney for the escape Of the smoke
and heated air, to contract it's opening, and
thus neutralize the larger space. 1t is like
cutting a wide canal, or placing large drain
structing its exit by narrow and dimin-
ished opening. The narrowest portion OF
the chimney should be near the fire, where
the rarefaction of the air is more intense
and its upward passage most rapid, and the
chimney should rather increase than dimin-
ish in size upward. AS the heated air rises
it loses some of its brightness. We should
then not hear so much of smoky chimneys
and dull fires. Makers of railway engines
have found this out, and now they make
the engine chimneys funnel-shaped or bell
mouthed."
PREVENTION OF SMoKE.-A correspondent
writes: "The theory of the prevention of
smoke is very simple. 1t is only necessary
to secure the burning of the gases, instead
chimney; and, in every invention which
has yet been brought forward, the object
sought to be achieved is the passage of the
nroducts of the newly supplied coal over