The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1866-04-03
NOTES ON SCIENCE.
PRODUCTION OF HEAT By rn1gr1o

bestowed upon the production of heat by
friction, the cxperiments being the same as
those conducted by our American philosopher,
Count RumfOrd, more than fifty years ago.
Rumtord constructed hollow cylinder of iron,
into which he fitted a solid plunger, which was
caused to press against the bottom of the cylin-
der. The cylinder was placed in a box con-
tanning water at sixty degrees Fahrenheit, and
was turned by horsepower. Two hours and
thirty minutes after the friction had commenced
the water boiled. In the present French eX-
pertinent copper cylinder and plunger are
used, and the proposition is made to warm rail
road carriages by the hot water produced by
attaching the plunger to the wheels, and placing
the copper globe under the car. It is claimed
that the additional fuel required to get up the
extra steam, in order to overcome the friction
and produce cheat, is not so great as would be
necessary If the cars were warmed in the usual
way.
Nothing is said about setting the passengers
teeth on edge by having TINS noise carried on
under their feet.
clear elucidation of the science of the sub
iect Is given in Professor Tyndall's "Heat Con-
sidered as a Mode of Notion published by the
Appletons Experiments in the direction of pro-
ducing heat by friction arc not likely to succeed
as economical investments.
NEW EXPLOSIVE COMPOUNDS.
New explosive compounds are diligently
sought for and every nitro-compound is made
the subject OF experiment, after sending the first
intrepid explorer to an untimely grave. The
most recent substance is nitro glycerlne, SOME
times called NObei's blasting OIL. The French
chemist Chevreul first announced to the Acade.
my OF Sciences IN Paris, In paper dated July 8,
1918, the discovery Of the compound nature of
the fats. Previous to that time fat had been re.
garded as an unmiXed organic substance.
CheyrUCl proved lt to be composed of several
salts called stearine, margarine, and oleine.
Stearine, for example, was shown to be a combi-
nation of steaIic acid and the oxide OF the sweet
principle Of Oil called glyCeryle; in other words,
steaTine is the steaTate of the oxide of glvceryle
If pOl1ld he poIlpd tho Of crlu
This glycerine, which is at the base of many
fatty bodies, is by some scientific men called an
alcohol, and it has recently found numerous ap-.
plications in the arts.
Nitro-glycerine was first prepared by Sombrero
about twenty years ago in the laboratory of Pc
louise, in Paris. Its enormous explosive force
was discovered at the same time, but the danger
attending its preparation deferred Investigators
from entering the field of research, until Mr..
Alfred Nobel had the intrepdity to introduce it
on large scale to the public as q substitute for
blasting powder or gun cotton.
Nliro-glycerine is pale yellow oily liquid of
l'G specific gravity, insoluble in water. II does
not explode by direct flame, and when exploded
by fuse or conclusion leaves no residue. 1t
eXplodes with great rapidity and force, and the
disCoverer claims that ii can be kept an indef-
mite time without decomposition, A few drops
on an anvil detonatGs under the blow of q ham
mer, but the explosion is not communicated be-
yond the drop which receives the blow, and
repeated blows are required to detonate the
whole quantity. 1t can be heated to 2l2 degrees
Fahrenheit without igniting, but eXplodes at
about $50 degrees Fahrenheit. 1t is poisonous,
producing violent but usually only temporary
headaches.
The freezing point is very nearly the same as
that OF water-and some authorities assert that
it soldlfes at forty degrees Fahrenheit. One
hundred parts OF nltro-glycerine, when burned,
produce 20 parts water, 50 parts carbonic acId,
3'5 parts oxygen, 1876 nitrogen.
One volume of the oil produces incombustion.
554 volumes of hydrogen, Ago volumes carbonc
acid SO volumes oxygen. 236 volumes nitrogen.
One volume thus suddenly expands to nearly one
thousand three hundred times its original space,
producing an irresistible dIsruptive force. As
the expansive force is greater than that OF gun
powder, smaller holes and fewer charges will be
required. The oil is simply poured into the drill
holes, and water-tight safetytuse attached and
the hole stopped with sand or water. 1t is often
poured through water into the holes, and as it
does not, like elycerine, mix with water, being
heavy, IL sinks to the bottom and the Water above
serves as plug. II the blasting oil be frozen it
must be handled with care, as an engineer in
Germany found to his cost when trying TO break
up some frozen pieces with his pick, 1t could
be frozen in tin cases OF proper size, and intro
duced in the same manner that gun-cotton is.
The question whether nitro-glycerne under
goes spontaneous decomposition or not is by no
means settled. 1t is WE'LL known that gun.
cotton, if not properly washed, and if exposed
even to ditfused light, undergoes spontaneous
decomposition, and as a recent instance of
spontaneous explosion in Greenwich street was
attributed to n'tro-glycerine, 1t may be worth
while to be cautious about storing quantities of
the oil in cities until the matter is sufficiently
investigated,
USES OF GLYCERINE.
The uses of glycerine are daily extending, and
as IT is now commercial article as easily OBJ
tanned as alcohol, there is one appicationwhich
ought to become popularity known. This is the
property it possesses Of dssolving out the
| odoriferous principle of flowers. The leaYes OF
roses OF hyacinth, iasmini geranlum, etc, are
| to be put into a stoppered bottle, and glycerne
left in contact with them Tor three or four weeks.
| All OF the perfume will be extracted, and as the
| glycerine will mix readily with water, scented
| wash can be prepared for the hands, as well as
| an extract made for use in the preparation OF
| pertumery. If the glycerine be LETT in contact
| with red pepper balls, it will extract principle
| very strengthening to the hair and less dan
| gerous than the preparation of cantharides now
| often used. We could fill n column with an
| account OF the uses of glycerine which have
| sprung up within ten years, and may recur to
| the subject again.
MAGNESIUM.
The metal magnesium is now extensively
| manufactured in this country and Europe. AS
we have large quantities of the native carbonate
| in New Jersey and Pennsylvania we ought TO bC
| able to compete with England in this article
| Various methods are used in It's production
GOO parts of chloride magnesium, 100 parts fuseC
| chloride of sodium (or better, mixture OF
| parts chloride OF sodium and 6 parts chloride O
| potassium), 100 parts pure pulverized huorspaT
| are to be intimately mixed, and to the mass 10
| parts sodium IN fragments added, and the mix
| ture projected into hot crucibe and covered
| After the first energetic decomposition ha
| passed, the fused mass must be stirred. Th
magnesium will be gathered in globules, an
can easily be separated from the slag; It
! afterwards purified by downward disHllatioE