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results, reduced to a uniform basis of comparison, with
oxygen » x6 as starting-point of the system. No decimal
places representing large uncertainties are used. When
values vary, with eaual probability on both sides, so far
as our present knowledge goes, as in the case of cadmium
(XI 1*8 and zia'2), the mean value is given in the Table.

The names of elements occurring in pharmacopceial,
medicinal, chemicals, are printed in italics.

Name. Symbol. Atomic weight.

Aluminum Al 27*

Antimony Sb 120-

Arsenic As 76*

Barium Ba 137*

Bismuth Bi 2089

Boron B 11-

Bromine Br 79*95

Cadmium Cd X12*

Caesium Cs 132*9

Calcium Ca 40*

Carbon C 12*

Cerium Ce 140*2

Chlorine CI 8545

Chromiunp Cr 52*1

Cobalt Co 59*

^Columbium Cb 94*

Copper Cu 68*4

fDidymium Di >43*3

Erbium Er 1663

Fluorine F 19*

Gallium Ga 69* .

Germanium Ge 72*3

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W^iST""} Electrictiy in Transitu

Name. Symbol* At^ic wdcbt.

tOlucinnm Ol 9*

Oold An 197-8

Hydrogm H 1-007

Indiam In 1137

IMns / 12685

Iridiam •• Ir I93*z

Iron F$ 66*

Lanthanom •• •• »• La 138*2

L$ad Ph 90695

Lithium Li 7*02

Magn4sium Mgr 24*8

Mangan$s$ Mn 55*

Mtrcury Hg 200-

Molybdenum Mo 96*

Nickel Ni 58*7

Niirogin N 14*08

Osmium 0% 191*7

lOxygin O 16*

Palladium Pd zo6-6

Phosphorus P 81*

Platinum Pt 195*

Potassium K 8911

Rhodium .. Rh 103*5

Rubidium .. Rb 85*5

Ruthenium. • Ru ioz*6

Samarium Sm 150*

Scandium.. • Sc 44*

Selenium Se 79*

SiUam Si 28*4

SilviT Ag 107 92

Sodium Na 2805

Strontium . • Sr 87*6

Sulphur 5 8206

Tantalum Ta 182*6

Tellurium Te 125*

Terbium Tb 159*5

Thallium Tl 204*18

Thoriom Th 232*6

Tin •• Sn 119*

Titanium Ti 48-

Tungaten W 184*

Uranium U 239*6

Vanadium V 51*4

Ytterbium Yb 173-

Yttrium Yt 89*1

Zinc .. Zn 65*8

Zirconium • • Zt 90*6

* Haa priority orer niobium.

t Now split into neo- aod prateo-didyminm.

t Haa onority orer beryllium.

f Standard, or baiia of the ayttera.



from Plenum to Vacuum.



77



Reaearches on Aliaarin Oil. — M. Scheurer-Kettner.^
The author arrives at the followmg conclusions: — The
oil for red tones is formed of sulphoricinoleic acid, a
compound which is definite and permanent at the or-
dinary temperature. It ia accompanied by polyriclnic
acids, the condensation of which extends as fiar as to
di-ricinic acids. The molecular weights, which the author
has found by Raoult*s method, emplo^ring the substance
dissolved in acetic acid, indicate a mixture of mono- and
di-ricinic acids. The sulpho-fatty compound is hydrated,
and is stable in the hydrous state. It looses its water of
hydntioA completely at about Z20 and becomes insoluble.
It ia fieeohred into hydrated sulphuric acid and an oily
add. From the tindorial point of viewt the author has
cecognised an interesting fad : — That the sulphonic com-
pound ^ives shades inclining to a yellow, whilst the
polymerised fatty acids give a carmine shade verging more
towards a blue* — Comptss Rsndus, Vol caii.. No. 3.

On Siaing Paper according to the Moat Recent
Pradical Experienee.— Dr. E. Muth {DingUr's youm.),
—A very full account of the preparation and application
of the sixes used by paper-makers, those especially in
which resin soaps play a leading part. —if onii. Stft.



FROM



ELECTRICITY

iN TRANSITU:
PLENUM TO VACUUM.*



By WILLIAM CROOKBS, F.R.S.,

President of the Inatitation of Bledrical Bngineera.

(Continued from p. 70).

Radiant MatUr.
By means of this tube (Fig. 9), I am able to show that
a stream of uUra-gaseous particles, or Radiant Mattert
does not carrv a current of eledricity, but consists of a
succession of negatively eledrified molecules whose
eledrostatic repulsion overbalances their eledro-magnetic
attradion, probably because their speed along the tube ia
less than the velocity of light. The tube has two negative
terminals, a, a', close together at one end, enabling me to
send along the tube two parallel streams of radiant
matter, rendered visible by impinging them through holes
in a mica diaphragm on a screen of phosphorescent sub-
stance. It is exhausted to a pressure of 0*1 m.m. I con-
ned one of the negative poles, a, with the indudion coil
and the luminous stream darts along the tube from c to o
parallel with the axis. I now conned the other nega*
tive pole, giving a second parallel stream of radiant
matter. If these streams are in the nature of wires carrying
a current they will attrad each other, but if they are simplY
two streams of eledrified molecules they will repel each
other. As soon as the second stream is started you see
the first stream Jump away in the diredion c, a, showing
strong repulsion, proving that they do not ad like current
carriers, but merely like similarly eledrified bodies. It is.
however, probable that were the velocity of the streame
of molecules greater than that of light, they would behave
difiierently, and attrad each other, like condndors carrying
a current.

To ascertain the eledrical state of the residual mole-
cules in a highly exhausted tube such as you have just
seen, I introduced an idle pole or exploring eledrode be-
tween the positive and negative eledrodes in such a
manner that the molecular stream might play upon it.
The intention was to ascertain whether the molecules on
collision with an obstacle gave off any of their eledrical
charge. In this experiment (Fig. zo, P.>«o*oooi m.m.| or
0*13 M.f ) it was found that an idle pole, c, placed in the
dired line between the positive and the negative poles,
A, B, receiving in consequence the full impad of the mole«
cules shot from the negative pole, manifested a strong
positivi charge. In a variety of other experiments made
to decide this question, the eledricity obtained was alwajrs
found positive on testing with the gold leaf or Lippman*s
eledrometer, and when the idle pole was conneded to
earth through a galvanometer a current passed as if this
pole were the copper element of a copper-zinc cell, indi-
cating leakage of a current to earth, the idle pole being
positive. If, instead of sending this current to earth, the
wire was conneded to the negative pole of the tube, a
much more powerful current passed in the same diredion.

Ths Edison Effset.
An exadly parallel experiment has been made by Mr.
Edison, Mr. Preece, F.R.S , and Prof. Fleming, nting, in-
stead of a vacuum tube, an incandescent lamp. They
found that from an idle pole placed between the ends of
the filament the eledricity always flowed as if the pole
were the zinc element of a copper-zinc cell ; having re-
peated their experiments I entirely corroborate them. I
get a powerful current in one diredion from an idle pole
placed between the limbs of an incandescent carbon fila-
ment, and one in the opposite diredion from an idle pole
in an highly exhausted vacuum tube. This discrepancy



* Inaogufal Addreu delivered Janoary zstb, 1891.

t M. » one-millionth of an atmosphere.
1,000,000 M. « 760 m.m.

M « one atmoephere.



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78



Electricity in Transitu : from Plenum to Vacuum.



i Cbbmical Ntwt,
1 Feb. 13,1891.



Fio. 9. — P. « o'l m.m.



Fio. 10. — P. a 0*0001 m.m., or 0*13 M.



Fio. II.— P, -• 0*001 m.m., or 1*3 M.



WIS extremely puzzling, and I tested, with a similar resalt,
very many experimental tube» made in different wajrt.
The elearicity obtained from an idle pole placed between
the positive and negative terminals in a highly exfaansted
tube was always strongly positivt, and it is only recently
that continued experiment has cleared the matter up.

Some of the contradidory results are due to the exhaus-
tion not being identical in all cases. In my vacuum tubes
the diredions of current between the idle pole and the
earth changes from negative to positive as the exhaustion
rises higher. Testing the current when exhaustion is
proceeding, there is a point rtsched when tht galvano-



meter defledion— hitherto negative— becomes nil, aboWing
that the potential at this point is eero. At this stage the
passage of a few more drops of mercury down the pump
tube renders the current positive. This changa occurs sil
a pressure of about a m.m.

After this point is reached, when the indudion current
is passed throush the tube, the walla rapidly become
pontively eledrined, probably by the fridion of the
•molecular stream against the glass, and this eledrification
extends over the surface of any objed placed inside the
tube. I will show you how this eledrification of the inner
walls of the tube ads on the molecular stream at higb



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^Jh!uJ55^} Electricity in Transitu : from Plenum to Vacuum. 79



Fio. 12.— P. ai o'oooi m.m., or 0*13 M.



Fio 13a.— P. - O'OOOI tn.m., or o'i3 M.



Fio. 136. — P. « 0*0001 m.in., or 0*13 M.



Fio. 13c.— P. a o'oooz m.m., or 0*13 M.



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8o



Vapour Density of Ammonium Chloride.



I Feb. 13, 1891.



Ttcua. In thit tube, Fiff. iz (P.ao*ooz m.m., or 1*3 M.)f
are fixed to ezadly ■imilar phosphorescent screens, c and
D ; at one end of each is a mica gate, b, b', with a nega-
tive pole, A, a', facinff it. One of the screens, c, is in the
cylindrical part of Uie tube and close to the walls ; the
other, D, is in the spherical portion, and therefore far re-
moved from the walls. On passing the current the screen
D in the globe shows a narrow sharp streak of phosphor-
escence, proving that here the molecules are free to follow
their normal course straight from the negative pole. In
the cylindrical part of the tube, however, so great is the
attraftion of tne walls that the molecular stream is
widened out sufficiently to make the whole surface of the
screen, c, glow with phosphorescent light.

If an idle pole, c, c. Fig. za (P.so'oooz m.m., or 0*13
M.),proteded all but the point by a thick coating of glass,
is brought into the centre of the molecular stream in front
of the negative pole A, and the whole of the inside and
outside of the tube walls are coated with metal, d, d, and
** earthed," so as to carry away the positive eledricity as
rapidly as possible, then it is seen that the molecules
leaving the negative pole and striking upon the idle pole
c on their journey along the tube carry a negative charge,
and communicate negative eledricity to the idle pole.

This tube is of interest since it is the one in which I
was first able to perceive how in my earlier results I
always obtained a positive charge from an idle pole placed
in the direA stream from the negative pole. Having got
so far, it was easy to devise a form of apparatus that com-
lately verified the theory, and at the same time threw
considerably more light upon the subjed. Fig. Z3, a, 6, c,
is such a tube, and in this model I have endeavoured to
show the eledrical state of it at a high vacuum by marking
a number of -f and - signs. The exhaustion has been
carried to o'oooz m.m.,or 0*13 M., and you see that in
the neighbourhood of the positive pole, and extending
almost to the negative, the tube is strongly eledrified with
positive eledricity, the negative atoms shooting out from
the negative pole in a rapidly diminishing cone. If an
idle pole is placed in the position shown at Fig. Z3 a, the
impads of positive and negative molecules are about
equal, and no decided current will pass from it, through
the galvanometer, to earth. This is the neutral point.
Bot if we imagine the idle pole to be as at Fig. Z3 6, then
the positively eledrified molecules greatly preponderate
over the negative molecules, and positive eledricity is
shown. If the idle pole is now shifted as shown at
Fig. 13 «, the negative molecules preponderate, and the
pdfe will give negative eledricity.

As the exhaustion proceeds, the positive charge in the
tube increases, and the neutral point approaches closer to
the negative pole, and at a point just short of non-conduc-
tion so greatl3r does the (wsitive eledrification pre-
ponderate that it is almost impossible to get negative
eledricity from the idle pole, unless it adually touches the
negative pole. This tube is before you, and I will now
proceed to show the change in diredion of current by
moving the idle pole.

I have not succeeded in getting the ** Edison '* current
in incandescent lamps to change in diredion at even the
highest degree of exhaustion which my pump will produce.
The subjed requires further investigation, and like other
residual phenomena these discrepancies promise a rich
harvest of future discoveries to the experimental
philosopher, just as the waste produds of the chemist have
often proved the source of new and valuable bodies.

(To be continaed).



New Process of Bleaching.— This process depends
on the decolourising adion of certain produds of the dis-
tillation of bituminous shales upon all fibrous matters
with which they are boiled. The quantity of oil used per
ton varies from 4*5 to 9 litres, according to the quality of
the material.— AfoMifmr ScUnUfiqui^ iv., Part i.



PROCEEDINGS OF SOCIETIES.

CHEMICAL SOCIETY.
Ordinary Meetings yanuary 15^%, 1891.

Dr. W. J. Russell, F.R.S., in the Chair.

Cbrtificatbs were read for the first time in favour of
Messrs. Henry Austin Appleton, zg. South Street,
Middlesbro' ; John Charles Aydans, 44, Crescent Road,
Plumstead, S.E. ; Clayton Beadle, Beadonwell, Belvedere,
Kent; Thomas Byrne, Olenville, Dundrum, co. Dublin;
Arthur Cole, B.A., Holmleigh, Charles Street, Berk-
hamsted ; Reginald Lorn Marshall, 25, Lancaster Park,
Richmond ; Tom Kirke Rose, 9, Royal Mint, E. ; R.
Greig Smith, Springwells, New Street, Musselburgh ;
Howard C. Suci6, Breeze House, Higher Broughton,
Manchester ; Matthew Carrington Sykes, Sykesnorst,
Bamsley, Yorks; W. Will, Ph.D., i, Beethoven Strasse,
Berlin, N.W.
The following papers were read :—

X. *• Magn$tU Rotation:' By W. Ostwald.

The magnetic rotation of organic compounds, according
to Perkin, is an additive fundion of their composition and
equal to the sum of the rotations of the components, but
this is not the case with the rotation of inorganic com-
pounds, which is usually found greater than that cal-
culated on such an assumption. In the case of hydrogen
chloride, for instance, the calculated value is about 2*18,
and as a matter of fad the value obtained for hydrogen
chloride dissolved in an organic solvent, isoamyl oxide, is
2*24, but when dissolved in water tne value found is from
4*05 to 4*42, increasing with the dilution. The author
points out that these exceptional values are only obtained
m the case of eledrolytes, and that they must therefore
be referred to a fundamental difference existing between
the constitution of eledrolytes and that of non-condudors.
That such a difference exists has been already deduced
from other considerations, and has led Arrhenius to the
formulation of the theory of eledrolytic dissociation. The
author claims that the fads established with regard to
magnetic rotation are in perfed accordance with this
theory, and that any exceptional values in the magnetic
rotations of eledrolytes are due to the occurrence of
eledrolytic dissociation.

Discussion.

Mr. Pickering said that in Professor Ostwald's attempt
to appropriate Dr. Perkin*s results on the magnetic rota-
tion of solutions of eledrolytes in support of the dissocia-
tion theory, no attempt was made to explain what connec-
tion should exist between the magnetic rotation and the sup-
posed dissociation into ions, but it was boldly stated that
if, as in the case of hydrogen chloride, the magnetic rota-
tion and dissociation both increased with dilution, the result
proved the truth of the dissociation theory, while equal
support to this latter theory was afforded if, as in the
case of sulphuric acid, dilution diminished the rotation
and increased the dissociation ; and the most astonishing
part of the argument appeared to be that the nearly
double magnetic rotations obtained in some cases should
be brought forward as a proof of dissociation, when the
observations were made on solutions so strong that the
dissociation theory represents them as containing hardly
any dissociated substance at all. Surely the natural con-
clusion to draw from such a doubling when it occurs in
the absence of dissociation would be that it could not be
explained by dissociation.

2. **ThsVapour Density of Ammonium ChloriiU:* By
Frank Pullingbr, B.A., B.Sc., and J. A. Oardnbr, B.A*

The authors have made experiments atvarioua tem*
peratures on the vapour density of ammoniom chloride.
The apparatus used was that of Vidor Mejrer. In view
of the iml-known resnha of Worts concemmg the vapour

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OMBMICAL NfWt, I

Feb. 13, 1891. I



New Modification of Phosphorus.



81



density of photphonis pentachloride, it was decided to
▼apourise the ammoninm chloride into an atmosphere of
ammonia— one of the produds of dissociation. In the
first instance the experiments were conduced at a
moderate red heat, and the salt was vapoarised into air.
The mean result of five experiments was 0*926 ; the
calcalated value for complete dissociatiou is 0*921 .

At Z040* C. (the temperature of boiling zinc), Deville
and Troost, using Dumas*s method, found the vapour
density to be I'ooo.

Boiling sulphur was next used, giving a temperature of
448"* C. The salt was first vapourised into air. The
values found were 0*983 and 0*932. The air was then
displaced by ammonia, and the values obtained were
o*939f 0*994, and 1*009.

At a temperature of 360" C. (that of boiling anthracene),
the relative density in an atmosphere of air was 0*944,
while in an atmosphere of ammonia it was z*za8 and
z*i4i.

It is evident that in this latter case the ammonium
chloride was not wholly dissociated.

It was found impossible to vapourise the salt into
ammonia at 300" C. m a bath of boiling a-naphthylamioe.
In one case, o*oijr5 grm. of ammonium chloride was
heated for forty minutes, but the loss in weight during
that time was only 0*0045 grm., and the volume of am-
monia expelled from the apparatus was only o'pz c.c. In
another experiment, 0*0037 grm. was taken, and the loss
during forty minutes was o*oo2Z grm., no gas being ex-
pelled The vapourisation into air, however, goes on
with comparative rapidity at this temperature, and the
values found were 0*982, 0*986, and 0*985. The time
taken for expulsion of the air was ten to twelve minutes.

At a temperature of 354* C, Deville and Troost, using
a bath of mercury vapour, found that the vapour dehsity
was Z'oz. The authors propose to continue their experi-
ments at temperatures between sj&* and 360".

3. •* ChloriHotid PhiHylhydroMims." By J. T. Hbwxtt,
B^., B.Sc.
The author describes the following compounds : —

OrthochlorophinylhydraMiHi, ClC6H4*NH*NHa, and its
hydrochloride.



FaraeHlorophinylHydrasiHi parabanate, —
CsOjNaHaaCdH^NaCl-OHa.

Diparachhrophgnyluna, CO(NH*C6H4Cl)a.

The compounds formed by interadion of aldeh^ds or
ketones and orthochlorophenylhydrazine, according to
the author, are very unstable.

4. •* A N4W Modification of Phosphorus.," By H. M.
VxRNON, Scholar of Merton College, Oxford.

Observations on the rate of rise of temperature of phos*
phorus and other experiments have led the author to the
conclusion that one or other of two different modifications
of phosphorus may result when fused phosphorus solidi-
fies ; the new variety is formed when the phosphorus is
cooled below its solidifying point and then solidified, and
has an undefined melting-point ; the ordinary variety of
well-defined melting-point being formed when solidinca-
tion of the phosphorus sets in diredly the point of solidifi-
cation is reached without the temperature sinking below
this point. From examination of crystals under the
microscope, the author considers that the new variety
crystallises in rhombic prisms, the ordinary crystallising
in odahedral ; he summarises the properties of the two
modifications in the following table :— •



Oftabfldral variety. Rhombic variety.

Has a definite melting-point Has no well-defined melt-
at 44*3^ ing-point ; melta at about

Relative densitv at 13*, z*8z77. Relative density at 13*,

Has a considerably greater z '8272

latent heat of fusion than

rhombic variety.
Solidifying point, 43'8^ Solidifying point, 43*8*.

Discussion.

Mr. PiCEBRiNO thought that Mr. Vernon's eonclasiooa
must be accepted at present with great reserve. A diller-
ence of i" in the melting-points, especially where one of
these melting-points was undefined, might easily be
accounted for by the presence of dissolved matter, acci-
dental impurity, produds o( oxidation, or some of the oil
used to cover the molten phosphorus. Mr. Vernon's
curves seem to prove conclusively that this was the case,
for that portion which represented the temperature of the
substance while it was melting was very much curved,
instead of being horisontal as it would be if the phos-
phorus had been pure. The small difference in the
densities— o'oz — was equally unsatisfaAory, and even if
any conclusion could be drawn from a superficial exami-
nation of the crystals under the microscope, it would be
invalidated by the fad that the specimens examined had
both been disaolved in, and re-crystallised from, benzene,
for, since fusion had been shown to render the two sup-
posed varieties identical, it was more than probable that
dissolution would do the same. It was noticeable that
although the two modifications were supposed to be ob-
tained by cooling fused phosphorus, yet the fused phos-
phorus solidified in each case at the same temperature, a
temperature which was not identical with the melting-
points of either of the supposed varieties.

Mr. TuTTON concurred with Mr. Pickering in con-
sidering that such an important conclusion as to the
existence of a new variety of phosphorus was not justified
by the data brought forward. It is well known that
phosphorus is a substance which exhibits the property of
superfusion in a high degree, and the thermal disturbance
caused by the sudden solidification of a superfused mass
would be likely to influence the results of a determination
of melting-point made after solidification under such
circumstances. In the speaker's own experiments on the
fusion of phosphorous oxide, which also exhibits super-
fusion in a very marked manner, a determination of
melting-point after such solidification from a state of
superfusion frequently yielded values differing sometimes
by a whole degree from the true melting-point of the sub-
stance. It is not at all surprising that a difference of a
degree should have been observed by Mr. Vernon, but
this fad in itself could scarcely be said to furnish proof of
the existence of two modifications. The speaker also
took exception to the arbitrary manner in which, from a
microscopical examination of which absolutely no details
are given, it was concluded that the supposed new
modification crystallised in rhombic prisms. Remem-
bering that man^ really isotropic substances frequently
exhibit polarisation colours, owing to their deposition
probably in a slight state of strain, it would not be sur-
prising if regular crystals of phosphorus were to exhibit
polarisation. It is certainly necessary to have at least
data concerning the mode of extindion of the crystals
and their behaviour in convergent light before any con-
clusion can be arrived at as regards their crystalline
system.

Means of Recognising the Kind of Siae Used in
Paper. — W. Herzberg. — Resin-size is evenly distributed
in the entire mass of the sheet of paper. Animal size
forms two layers entirely separated from each other by
the body of the paper. Hence, if the paper is well rubbed
and bruised, any charaders traced upon it penetrate
through if an animal size has been used.-'if on. SetnUifiqus.

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82



The Fellowship of the Chemical Society.



Feb. 13, 1891.



CORRESPONDENCE.



THE FELLOWSHIP OF THE CHEMICAL
SOCIETY.

To th( Editor of the Chemical News.
Sir,— We mre instruded to ask you to allow the following
faifts to be inade known through your columns to the
Fellows of the Chemical Society.

As stated in a former letter, after having carefully con-
sidered the suggestions and large number of letters for-
warded to us in response to our circular, the following
letter was sent by our Committee to the Council of the
Chemical Society : —

[Copy.]

4, Lombard Court,
Oa. 31, 1890.

Gentlemen, — We are requested, and therefore beg to
call your attention to the enclosed circular relating to the



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