Rodolfo Amedeo Lanciani.

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center of the compass-needle that the S. end of needle was de-
flected 10° E. If the same end is deflected W. then the marked
end is a N. pola

JEx. 24. Experiments with tube of 1-08 in. diam. is given
under column A ; those with tube of 1*31 in. diam. under col-
umn B. Tangent galvanometer in all the experiments was at
80°. Tube and core placed 7i inches W. of needla

Marked end of tube placed in S. pole of helix and A B

withdniwn (as descibed above). Repeated 6 times S. 17° 18' E. S. 21° 40'E.

Introduced tube again and withdrew ** 17 30" "21 40 "

•* *• " •« " "17 30 •* "21 40 "

Core placed W. of needle «♦ 33 '* " 18 •*

Core slowly and steadily introduced into tube so that

S. end of core was in S. end of tube ; then tube and

core introduced into helix E. and withdrawn 6

times "16 2 " "20 18 "

Introduced and withdrew tube and core again "16 13 " "20 18 "

•« " »* " " •* " «• 16 16 " "20 18 "

*• »* " »* *» »* »* *• 16 16 ** "20 18 "

While tube remained in position W. of compass the

core was slowly withdrawn from the tube. Tube

now alone deflected "17 40 " "21 38 "

Core now alone deflected " 60 " " lOW.

Eeferring to Expts. A and B it is seen that when the tubes
were magnetized alone as fully as can be by the current (of T.
Q. 80°) through the helix, they deflect the needle in Exp. A
V 15' more and in Exp. B 1° 22' more than when the tubes
with enclosed cores acted together on the needle after having
been magnetized in exactly the same circumstances ; also, that
when the tubes, remaining undisturbed in their position, W. of
the needle, had the cores withdrawn, the needle was deflected
1° 25' more in Exp. A and 1*^ 20' more in Exp. B than when the
tubes with enclosed cores both acted upon the needla

In the break-circuit experiments the effects are more compli-
cated by reason of the instantaneous and intense extra-current
in the helix which causes a sudden inductive action on the tube
and core, and thus other actions are introduced which are foreign
to the object of the investigation. I have therefore only given
examples of the make-circuit experiments, though the others
showed even a greater difference between the action of the tube



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A. M. Mayer — Researches in Electro-Magnetism. 107

alone and the tube and core together ; this difference amounting
in some experiments to 5^.

After the results of the above experiments, it occurred to
me to investigate the action of a heltx introditced into the tube,
and to ascertain if a magnetism could be given to the tube the
reverse of that which is induced when the helix surrounds it
The former experiments show that the tube can give a reversed
magnetism to an enclosed core, and we will now see that a
helix can effect a reverse magnetism on a surrounding tube.

The first Expts. were made with opposing helices, one being
helix E with the 400 wire core, the other a tube of soft iron 9
in. long, 1'8 in. external diam. and '12 thick, around which was
wrapped a helix of one layer of 148 turns of ^V ^^^^ wire» ^^^
in its interior fitted a helix also of one layer 148 turns of the
same wire wrapped upon a cylinder of wood. This last I will
call the inner helix, the other the outer helix.

Hx. 25. The inner helix was placed in the circuit (near the
battery, far removed from the compass) and the compass was so

? laced that its needle stood at 0^ when cii'cuit was open or closed,
'he inner helix was now placed inside the tube and the current
passed through helix E and the outside helix ; and also through
the inside helix in a direction the same as the current in the
outer helix ; and the needle was noted. The current was now
reversed in the inner helix and needle again noted ; but as the
opposing helices were 8 fl. apart, and the current not strong, no
eSect (after allowance made for direct action of inner helix on
needle) was obtained from the action of the inner current

jEbs. 26. I then devised the following experiment The op-
posing helix E with 400 wire-core was removed and the compass-
needle brought to 0° by the action of the earth*s magnetism.
The iron tube was then placed 1 foot W. of center of needle with
its S. pole toward the compass. The deflection produced by its
magnetism was S. 4^ 40' E. The inner helix was now placed
in the position W. of the compass previously occupied by the
tube and the current passed so that its S. pole was opposed to
the needle ; the deflection was S. 8° 13' E. I now placed the
helix in the tube and both 1 ft. W. of needle and passed current
so that S. end of helix was in S. end of tubea The deflection
produced was S. 4° 50' E.

From above it is seen that when tube and inner helix act
together on the needle the deflection is only 10' greater than
when the tube acts alone, although the helix acting alone causes
a deflection of 3° 13'. The neutralization of such a quantity of
magnetism can only be accounted for by the fact that the great-
er part of the magnetism of the tube was reversed by the action
of the heliacal current on the inner surface of the tube.

Ex. 27. To obtain directly a reversed magnetism by the



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208 A. M. Mayer — Besearches in Electro-Magnetism.

action of the (mtside of the heUx the following experiments were
made. Several wires 9 in. lone and ,V ii^ch diam. were heated
in a cupel furnace to bright redness and slowly cooled ; one end
of each wire was then marked A wire was then taken and
placed with its marked end 2*75 in. W. of the center of the
compass-needle and the deflection produced was S. 18' K, show-
ing that the marked end was a feeble S. pole. A current was
now passed through the inner helix ana the wire laid upon
it so that its marked or S. end was upon the S. pole of the helix,
after remaining here for a few moments it was conveyed to the
compass and placed, as before, with its marked end 2*75 in. W.
of the center of the needla The deflection was now S. 28' W.,
showing that the magnetism of the wire had been reversed and
that a wire placed on the (mtside of a helix has given to it a
magnetism tne reverse of that given when it is placed inside.

Sx. 28. Twelve wires were now placed witn their marked
ends 8^5 in. W. of the needle, and the deflection being S. 8' K
showed that their marked ends had a slight S. magnetism. They
were now removed and placed with their marked ends on the N.
pole of the helix at equal distances from each other around the
helix, through which a current was passing ; they were then re-
moved from the helix before the current was broken and again
placed in their former position 8 "25 W. of the compass-needle.
The deflection was now S. 55' K, showing that their marked
ends were of south magnetism. They were again placed on the
helix with their marked ends on its o. pole and removed, as be-
fore ; they now deflected the needle S. 20' W., showing that their
marked ends were now N., their magnetism having been reversed.

Mc. 29. The inner helix alone was placed 1 foot W. of needle
and the current passed so that its S. pole was opposed to the
needle. Deflection S. 8° 80' E. T. G. 20°. Reveraed current
Deflection 8° 15' W. By holding a bar of soft iron in the line
of the dip and passing the wires over its end I succeeded in ren-
dering them without action on the helix when put in the place
of the helix in the above experiment The twelve wires were
then tied aroimd the helix equidistant from each other and sepa-
rated about "2 inch. The current was then passed so that the S.
pole of the helix was opposed to the needle. Deflection S. 2° 40'
k. Reversed the current Deflection S. 2° 80' W. We therefore
have in the 1st experiment 50' less and in the 2d 45' less action
on the needle when the wires are around the helix than when they
are away. These results correspond to the above experiments
on the tube, the helix giving the wire a polarity the reverse of
its own.

Beccaria, Coulomb and Faraday have, by their well known
experiments, proved that frictional electricity when at rest only
exists on or just within the outer surfaces of bodies, and Prof



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A. M. Mayer — Beaeairckes in Medro-Magnetiam. 209

Joseph Henry, by many experiments, has shown that this is also
true when the same species of electricity, of high tension, is in
motion. The following beautiful experiment, so conclusive in
its evidence, appears so little known, that I will here give it as
stated by that philosopher. " A copper wire, of the size usually
employed for rmging door bells, passed through the axis of an
iron tube, or a piece of gas pipe, about three feet long. The
middle of this wire was surrounded with silk, and coiled into a
magnetizing spiral, into which a large sewing needle was insert-
ed. The wire was supported in the middle of the tube by pass-
ing it through a cork at each end, covered with tin-foil, so as to
form a good metallic connection between the copper and the
iron. On the outside of the tube and opposite each other were
placed two other magnetizing spirals, their ends soldered to the
iron. When these two spirals were also furnished with needles,
and a discharge fix>m a teyden jar sent through the apparatus,
as if to pass along the wire, the needle' inside of the iron tube
was found to exhibit no signs of magnetism, while those on the
outside presented strong polarity. This result conclusively
shows that, notwithstanding the interior copper wire of this com-
pound conductor was composed of a matenal which oflfered less
resistance to the passage of the charge than the iron of which
the outer portion was lormed, yet when it arrived at the tin-foil
covering of the cork, it diverged to the siu&ce of the tube, and
still further diverged into the iron wire forming the outer spi-
rals. We must not conclude, however, fix)m iQis experiment,
that the electricity actually passes on the outside of the tuba
On the contrary, we must infer from the following fact that it
passes just within the surface. If the iron be coated with a
thin coating of sealing wax, the latter will not be disturbed
when a moderate discharge is passed through it, though with a
large discharge in proportion to the conducting power of the
rod, the outward pressure may become so great as to throw off
the stratum of sealing wax."

Barlow and Harris have made experiments which show that
magnetism is also a surface action ; and in Exp. 11 of this pa-
per we saw that when the surface of a wire-core was diminished
Dv compressing the bundle the magnetism diminished with it
To show that this diminution of force was not, in major part,
owing to the increased repulsion produced between the oars
when brought nearer together, the following experiments were
made.

JSx. 80. About 200 Vt iiich wires were pressed together as
tightly as could be by binding them in a Dundle with silken
cord, and the deflection they caused in the needle, when mag-
netized in the helix, was noted ; they were now taken apart and
bound as tightly as before around a wooden cylinder about 1



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210 A, M, Mayer — Reiearches in Electro- Magnetism.

inch in diameter ; and being magnetized again in the helix with
the same strength of current, tne bundle caused a fer greater
deflection in the needle than when it acted without the central
wooden cylinder. I consider this experiment as very conclu-
sive of the surface action of magnetism, for in the two measures
we used one and the same mass of metal, subjected to exactly
the same magnetizing influence, and only differing in the extent
of exterior surfaces existing during the two experiments. That
the increase of force with the surface was not owing to a change
of distance of the wires from the interior surface of the helix is
conclusively shown in the next section.

But there are differences to be made between these analogous
phenomena of frictional electricity and of magnetism ; in mag-
netism a considerable thickness of metal is required to develope
this action at the surface ; so that (Ex. 18) a tube must have a
thickness of about } of its diameter to equal a solid cylinder of
the same length and diameter, both being, when compared,
"saturated" with magnetism; also, it appears (Ex. 26) that
a magnetic action can be effected on tne interior surface of
a tube, while no similar action can be obtained with frictional
electricity.

Experiments to determine whether a change ofposiUm of a bar in
the interior of a helix causes a change in the intensity of its magnet-
ization, — Theory indicates that no change in the degree of mag-
netization will follow a change of position of a bar in the inte-
rior of a helix, and the following experiments conclusively
prove the truth of this deduction.

Ex, 81. In the interior of helix E resting on the bottom of
the opening was placed a cylinder of soft iron "88 inch diam.
and 9 in& long. Opposed to this helix was helix W, (in the
same circuit) with the 400 wire-core. Needle was brought to
such a position that it stood at 0° when the circuit was open or
closed. T. G. 44i^

Ex. 82. The axis of the iron cylinder was now made to co-
incide with the axis of the helix. Current passed. Needle still
at 0°. T. G. 44i°. Thus showing that the change of position
makes no difference in the intensity of the magnetization.

Experiments on the comparative magnetisdng effects of a helix
and of a combination of spirals, formed of similar wire, and con-
taining the same number of turns, arranged in a length equal to
that of the helix. — According to the theory of Ampere the cur-
rents which encircle a magnetized iron bar or a steel magnet
are in planes at right angles to the axis of the bars ; and it
seemed to me interesting to determine with this sensitive appa-
ratus what difference, if any, existed between the magnetizmg
effects of a helix whose turns were inclined in the successive
layers alternately in opposite and equal angles with the axis,



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A. J£ Mayer — Researches in Mectro-Magneiism. 211

and the eflfects of a combination of spirals composed of an equal
number of turns of wire as the helix and existing in the same
length.

Fifty spirals, each composed of 14 ft 8*06 ins. of j\ inch wire
in 20 turns, were made by a process to be described in a sub-
sequent communication. These spirals were placed vertically
in a frame at equal distances from each other so that they form-
ed a cylinder 9 ins. in length, 8*9 ins. in exterior diameter and
with a cylindrical axial opening of 1*68 ina The turns of the
spirals were carefully insulatea from each other by saturating
tne covering of the wires with melted parafina

A helix was constructed of the same wire, wrapped in 20
layers, each layer consisting of 50 turns. The wire in each
laver was wrapped parallel with two lengths of twine so that the
50 turns in a layer occupied a length of exactlv 9 ins. This
gave a " pitch " to the turns of the helix of 18 ins. and the
mnermost turns of the helix formed an angle of V 57''25, and
the outside turns formed an angle of 50' '5 with the axis of the
helix, alternately to the right and to the left, as it was wrapped.
Each layer of turns of wire and twine was carefully saturated
with melted parafine of a high temperature, so that the copper
was seen through the saturated covering after the parafine had
solidified.

Mc 88. The helix and combination of spirals were placed 8
feet apart and an uninsulated 400 wire-core placed in eacL The
compass was placed midway between them and the needle
brought to 0°. The current was now passed so that the N. pole
of the cores faced the compass. The S. end of the needle was
slightly deflected toward the helix, showing that the core of
this was somewhat stronger than that of the spirala

The greater strength of the helix could not be attributed to
the excess of wire it contained over the spirals, for this only
amounted to about 2 inches ; thinking that tne intense inductive
action of the spirals on each other might have some influence,
the following experiments were mada

JSx, 84. Jrlaced the needle between helix and spirals so that
it stood at 0° when the circuit was open or closed. Then I in-
troduced between the spirals 49 copper discs having central
openings a little smaller than those of tne spirala This arrange-
ment, as Prof. Joseph Henry has shown, so eflfectually cut of
the mutual inductive action of the spirals that, on passing a
current through them and breaking a mercury contact, the spark
of the '* extra-current " was (on account of the greater resistance
of the spirals) less than when only the circuit of the battery-
wires was similarly broken. With the exception of the inter-
posed copper discs things remained as in Exp. 88. Current
passed. IN eedle remain^ at 0°. Showing that the inductive



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212 A. M. Mayer — Besearchea in Electro-Magnetism.

action had no influence on the intensity of the magnetizing
effect I am therefore of the opinion that the increa^ effect
of the helix was due to superior insulation.

JSJx. 81. The combination of 50 spirals was separated into
two, each containing 25 spirala Between the spirals of one
combination were introduced the 25 spirals of the other, so that
every alternate spiral belonged to the same combination. If
the current is now passed through one of the combinations and
the two terminal wires of the other combination joined, Faradaj
has shown, that the " extra-current " in the first combination is
entirely given up to second. The spirals thus arranged, with
the terminals of the interposed spirals separated, were placed
opposite the helix E, and distant 8 feet, and Ihe needle so
placed between them that it stood at 0° when the circuit was
open or closed. On connecting the terminals of the interposed
spirals and passing the current, the needle remained at 0°. Thus
conclusively showing that in a combinaMon of spirals or in a
helix the inditctive action of the vrire on itself or of adjoining spirals
or turns on each other has no effect on the power of their magneti-
zation and therefore no ^ect on the intensity of the current passing
through them,

I do not remember ever having seen a solution of this ques-
tion, and these experiments have given it under conditions of a
very strong inductive action, and with a very delicate apparatus
for detecting any effect which might have been producei The
result is one wmch has an important theoretic oearing on dy-
namical inductive action, but I reserve for another communi-
cation my views on that point

In bringing this research to a conclusion I think I may safely
say that these results and experiments have shown the delicacy
and precision of this method of comparing and measuring the
electro-magnetic forces ; and at a future time I propose using it
to solve the problems which relate to the variation of the inten-
sities of cores with their diameters and with their surfaces, and
to examine the varying magnetizing effects of helices of different
lengths, diameters, ana number of turns of wire, and traversed
by currents of various intensities.

Some of the above experiments, which relate to the inverse
polarity given to cores placed inside of magnetized tubes and
wires placed outside of helices, are very suggestive as to an ex-

Elanation of diamagnetism, but I reserve for the present the
ypothetical notions which they have originated in reference to
tnose phenomena.
South Bethlehem, Pa., June 2, 1870.



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Meissner^s Beaearches upon Meetnzed Oxygen. 218



Art. XXL — Abstract of the Second Series of Professor Meissner^s

Researches upon Electrized Oxygen;* by George R Barker.

I

In the first series of Dr. Meissner's researches upon oxygen,
published in 1868 — ^an abstract of which, by Professor John-
son, appeared in this Journal, volume xxxvii, page 825, and
volume xxxviii, page 18 — ^he arrived at the remarkable con-
clusion, that oxygen, under the influence of electrical tension,
was converted not only into ozone, but also into another modi-
fication which always appeared simultaneously, and which form-
ed, when brought into contact with watery vapor, especially
after the absorption of the ozone, a peculiar dense mist This
second modification of oxygen Meissner identified Vith Schon-
bein's antozone. So remarkable were these results, and so im-
portant their bearing, if true, not only upon our theories of
ozone itself, but also upon the philosophy of chemistry, that
Meissner desired to repeat his experim'ents, studying particu-
larly the character of tne antozone-mist and the effects of elec-
trical tension upon the volume of the oxygen submitted to the
discharge. The results of these experiments constitute the pa-
per now referred to.

I.

Section I is devoted to "Electrized Oxygen." The experi-
ment which is to be critically investigated is thus described :
" Oxygen is submitted to the action of electricity in a Siemens^s
or von Babo's apparatus, is then passed into a receiver contain-
ing a concentral^ solution of potassium iodid, in which the-
ozone is completely absorbed, and finally through water con-
tained in a second receiver ; the gas as it issues from the water,
forms above it a thick white mist, which also appears in a less
degree over the solution of potassium iodid, but which is den-
ser, the less concentrated the solution and the more favorable
the ozonizing conditions." To prove that this mist consists
solely of electrized oxvgen and water, Meissner proposes to
show : — 1st, that no other ^as but oxygen is in any way con-
cerned in the production of the phenomenon ; particularly no
nitrogen, chlonne, hydrogen, or carbonic acid, zd, that for the
production of the result, the presence of aqueous vapor in the
electrizing tube is not necessary. And 8d, that the potassixim
iodid solution used for the absorption of the ozone, has nothing
whatever to do with the appearance of the phenomenon, farther
than is implied in effecting the removal of the ozone fix)m the
current of electrized oxygen.

* Neue Untereuchunffen Uber den elektrisirten SaueretofEl Yon Dr. G. Keiss-
ner. Mit zwei lithograpnirten Tafeln. Aus.dem vierzehnten Bande der Abhand-
lungen der Kdnigliohen GteseUflohaft der WlBsensohaften zu Gottingexi. 4to, pp.
no. Odttingen, 1869.



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214 Meismer^s Researches upon Electrized Oxygen.

The apparatus used to establish the first point, consists of
two pieces, the first of which is intended for tne production of
chemically pure oxygen, the second for the electrization of this
oxygen, ana its subsequent analysis. We have sp»ce here for
only a general description of these marvellously accurate speci-
mens of Geissler*s glass-work, referring those specially interest-
ed to the original plates. The oxygen is evolved by electroly-
sis fi'om acidulated water contained m a U tube, and then pass-
es through a second U tube filled with bits of glass moistened
with sulphuric acid, then through a straight tube filled with
oxydizea copper-turnings to which heat can be applied, then
through a second U tube containing glass and sulpnuric acid,
and finally through a horizontal tuoe a foot in length, contain-
ing anhydrous phosphoric acid : being collected, after passing
an ingeniously-constructed mercury-valve, in a receiver over
mercury. All these tubes are joined, either by fusion or by the
most carefully ground joints. By means of the heated copper
oxyd, the hydrogen, wnich, by diffusion or mechanically, may
be mixed with the oxygen, — as well as the ozone produced by
the electrolysis, and the vapor of hydrogen peroxyd — ^if any
there be — are destroyed. Tne entire apparatus is nrst washed
out with several liters of pure oxygen chemically prepared, then
with 15 liters of the electrolytic oxygen ; after which tne oxygen,
being assumed pure, is collected. The second piece of appara-
tus was made in duplicate ; one has a tube filled with sulpnuric
acid between the receiver and the electrizing tube ; the other
has a tube filled with anhydrous phosphoric acid in this posi-
tion. Moreover, in the former, Siemens's tube, in the latter
von Babo*s, is used for the electrization. With these excep-
tions they are alike; a description of one suffices. The gas
passes fix)m the receiver throu^ the tube filled with the anhy-
drous phosphoric acid, to fi:ee it fi:om any traces of moisture it
may have acquired in the receiver, then into the electrizing
tube, thence into two small flask-shaped receivers, the first con-
taining potassium-iodid solution, the other water — and then to



Online LibraryRodolfo Amedeo LancianiThe American journal of science and arts → online text (page 77 of 109)