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the obstacle may be produced by the vacuum being so
high that the atoms of gas present are too few to form a
continuous procession. {Why a high vacuum should be
non-condu6ive does not clearly appear, but the fad itself
is beyond doubt ; it is probably conneded with the in-
ability of eledrified atoms to leave the poles.) Or again,
the obstacle may be a phosphorescent body like yttria. In
this case the negatively charged atoms deliver up iheir
charge of eledricity to the yttna, which is so constituted —
perhaps a'ter the manner of a Hertz resonator — that its
atoms charge and discharge, vibrating about 550 billion

* Inauirural Address delivered January zstb. xSqi.
i Roy, Soc, Froc., zlvii , 526.

times in a second, and producing waves in the ether of
the length, approximately, of 574 ten-millionths of a
millimetre, and occasioning in the eye the effed of citron

We are not under the necessity of supposing that this
number of hydrogen atoms are driven against the yttria
in the second, although even at a high vacuum there are
quite enough atoms left in the bulb to keep up such a
supply. All that is needed is that a succession of shocks,
not necessarily rhythmical, may strike the yttria at fre-
quencies which will set up such a number of vibrations,
just as a series of slow impads on a gong causes it to emit
sound waves of much greater freouency.

In a low vacuum only very few atoms can run the
gauntlet among the crowd of inrushing atoms, and those
few which succeed in reaching the yttria arrive with much
reduced velocity, and so faint is the phosphorescence they
set up that it is completely obscured* by the brighter
phosphorescence of the, residual gas. As the vacuum
becomes higher, more and more atoms find their
way across, and their speed being at the same time
accelerated, the phosphorescence becomes intensified.

At a good vacuum most of the atoms hit the yttria, their
velocity is increased, and the rhythmical excitation
reaches its maximum.

The Dark Spaa tn Mercury Vapour.

In applying the eledrolytic hypothesis, I have used for
illustration's sake the gaseous residue of hydrogen, which
is known as a diatomic gas. I have found, however, the
phenomena of the dark space, &c., to occur in the vapour
of mercury, which is a monatomic sas. This important
result induced me to patiently investigate this subjed, and
the result of one experiment is before you (Fig. 29). The
tube is furnished with aluminium terminals, and is so
arranged that the indudion spark can be kept passing
during exhaustion to drive off occluded gases. When at
the highest attainable vacuum, the tube is filled with pure
mercury by simply raising a reservoir. On applying heat
the entire contents of the tube are boiled away and pass
down the fall tubes of the pump, exhaustion going on at
the same time. When the whole of the mercury has thus
been boiled away in vacuo, except a little condensed at
the upper part of the tube, the results on passing the spark
are as followed :— When the tube is cold the indudion
current refuses to pass ; on gently heating with a gas*
burner the current passes and the dark space is distindly
visible. Continuing the heat so as to volatilise the drops
of mercury condensed on the sides, the whole tube be-
comes filled with a green phosphorescent light, the dark
space gees smaller and smaller, and ultimately the nega-
tive pole becomes coveted with a luminous glow. On
allowing the tube to cool the same phenomena ensue in
inveise order. The luminous halo expands, showing the
dark space between it and the pole, and this dark space
gradually grows larger as the tube becomes cooler. ' The
mercury again condenses on the side of the tube, the
green phosphorescence grows paler and paler, until at
last the indudion spark from the large coil refuses to

At first sight this result appears fatal to the eledrolytic
hypothesis, fur if the molecule of meicury contains only
one atom how can we talk of its separation into positive
and negative atoms by the eledric stress? It must be
remembered, however, that we are as yet ignorant of the
absolute mass of the atom of any element. All that can
be said is that a molecule of free hydrogen becomes halved
in combining chemically with certain other elements,
whilst a molecule o( free mercury does not suffer division
on yielding any known compound of mercury: the physi-
cal atoms in the one behave as two separate groups, and
those in the other as one undivided group. It has been
agreed by chemists, for simplicity's sake and for facili-

* This faint phosphorescence at a low vacuum can be rendered
visible by the elearical phoepboroscope described in my leAnre at the
Royal Institution in 16^7.

Digitized by


^SKJStfiT**} Electricity in Transitu: from Plenum to Vacuum. 113

Fio 29.

Fio. 30.

Digitized by


Electricity in Transitu : front Plenum to Vacuum.

1 14

tating chemical calculations, to reduce the units to the
lowest term, consistent with the avoidance of fradions ;
we therefore say that the atoms in a molecule of free
hydrogen ad in chemistry as two separate groups, each of
a minimum relative weight of i, whilst those m a mole-
cule of free mercury ad as one undivided group of the
relative weight 200. But to what number ofatoms the i
and 200 correspond respedively no chemist knows.

To show how intimately chemistry and eledricity inter-
lock, I may here remark that one of the latest theories
in chemistry renders such a division of the molecule into
groups of eledro- positive and eledro-negative atoms
necessary for a consistent explanation of the genesis of
the elements. This is so important that I may be excused
for digressing a little into this development of theoretical

Gtnesis of the Elements,

It is now generally acknowledged that there are several
ranks in the elemental hierarchy, and that besides the
well-defined groups of chemical elements, there are under-
lying sub-groups. To these sub-groups has been given
the name of meta-elements. The original genesis of atoms
assumes the adion of two forms of energy working in time
and space — one operating uniformly in accordance with a
continuous fall of temperature, and the other having
periodic cycles of ebb and swell, and intimately conneded
with the enerey of eledricity (Fig. 30). The centre of
this creative force in its journey through space scattered
seeds or sub-atoms that ultimately coalesced into the
groupings known as chemical elements. At this genetic
stage the new born particles vibrating in all diredions and
with all velocities, the faster moving ones would still over-
take the laggards, the slower would obstrud the quicker,
and we should have groups formed in different parts of
space. The constituents of each group whose form of energy
governing atomic weight was not in accord with the mean
rate of the bulk of the components of that group, would
work to the outside and be thrown off to find other groups
with which they were more in harmony. In time a con-
dition of stability would be established, and we should
have our present series of chemical elements each with a
definite atomic weight — definite on account of its being
the average weight of an enormous number of sub-atoms
or meta-elements, each very near to the mean. The
atomic weight of mercury, for instance, is called 200, but
the atom of mercury, as we know it, is assumed to be
made up of an enormous number of sub-atoms, each of
which may vary slightly round the mean number 200 as a

We are sometimes asked why, if the elements have
been evolved, we never see one of them transformed, or
in process of transformation, into another ? The question
is as futile as the cavil that in the organic world we never
see a horse metamorphosed into a cow. Before copper,
e,g., can be transmuted into gold it would have to be car-
ried back to a simpler and more primitive state of matter,
and then, so to speak, £hunted onto the track which leads
to gold.

This atomic scheme postulates a to and fro motion of a
form of energy governing the eledrical state of the atom.
It is found that those elements generated as they approach
the central position are eledro-positive, and those on the
retreat from this position are eledro- negative. Moreover
the degree of positiveness or negativeness depends on the
distance of the element from the central line; hence
calling the atom in the mean position eledrically neutral,
those sub-atoms which are on one side of the meam will
be charged with positive eledricity, and those on the other
side of the mean position will be charged with negative
eledricity, the whole atom being neutral.

This is not a mere hypothesis, but may take the rank
of a theory. It has been experimentally verified as far as
possible with so baffling an enigma. Long-continued
research in the laboratory has shown that in matter which
has responded to every test of an element, there are
minute shades of difference which have admitted of

f Chbiiical Nbws,
I March 6, 2891.

seledion and resolution into meta-elements, having
exadly the properties required by theory. The earth
yttria, which has been of such value in these eledrical
researches as a test of negatively excited atoms, is of 00
less interest in chemistry, having been the first body in
which the existence of this sub-group of meta-elements
was demonstrated.


I frankly admit I have by no means exhausted the sub-
jed which daily and nightly fills my thoughts. I have
ardently sought for fads on which to base my theory. I
have struggled with problems which must be conquered
before we can arrive at exad conclusions — conclusions
which, so far as inorganic Nature is concerned, can only
be reached by the harmonious interfusion — not confusion
—of our present twin sciences, eledricity and chemistry.
Of this interfusion I have just endeavoured to give you a
foretaste. In elaborating the higher physics, tne study of
eledrical phenomena must take a large, perhaps the
largest, share.

We have invaded regions once unknown, but a formid-
able amount of hard work remains to be completed. As
we proceed we may look to eledricity not only to aid, as
it already does, our sense of hearing, but to sharpen and
develop other powers of perception.

Science has emerged from its childish days. It has shed
many delusions and impostures. It has discarded magic,
alchemy, and astrology. And certain pseudo-applications
of eledricity, with which the present Institution is little
concerned, in their turn will pass into oblivion.

There is no occasion to be disheartened at the apparent
slow pace of elemental discovery. The desponding declare
that if Roger Bacon could re-visit ** the glimpses of the
moon" he would shake his head to think we have got no
further, that we are still in a haxe as to the evolution of
atoms. As for myself I hold the firm convidion that
unflagging research will be rewarded by an insight into
natural mysteries such as now can scarcely be conceived.
Difficulties, said a keen old statesman, are things to be
overcome, and to my thinking Science should disdain the
notion of Finality. There is no stopping half way, and
we are resistlessly driven to ceaseless inquiry by the spirit
** that impels all thinking things, all objeds of all thought,
and rolls through all things.*'


(Continueil from p. xox).

If the phosphoric anhydride corresponding to the free
phosphoric acid is deduded from the 35*8 per cent PaOj
found, we have 29*2 per cent PaOs corresponding to the
51*8 per cent of the undecomposed monocalciom phos-

In this case the determination of the free phosphoric
acid and the monocalcium phosphate by titration with
uranium acetate are not accurate, and the results are only
approximations, as, by boiling the acid liquid (the solution
of uranium acetate used having been as usual acidulated),
a small part of the pyrophosphate is converted into ortho-

According to theory the phosphoric acid is present in
the solution in the following form : —

Per cent Pound.

PtO«. Per ceot P,0«.
CaH4(P04)a*HaO .. .. 28*3 29*20

HJPO4.. ,, , 7*0 C'6o

3CaHaPa07'2HaO .. .. 703 694




* From the Zeitschri/t Anal. Chemie.

Digitized by



March 6, 1891. |

London Water Supply.


By the decomposition of half the original monocalctum
phocphate during the drying there have been formed : —
Per cent.

&P& :: :: :: ":if ) i-iub.ep.rt.



The resoltfi above indicated give an interesting ex-
planation of the processes during the desiccation of mono-
calcium phosphate in a quite new diredion. Birnbaum
certainly recognised the normal calcium pyrophosphate
and free phosphoric acid, but he nowhere mentions having
found metaphosphate and monocalcium pyrophosphate.
He considers that the decomposition takes place as
follows :—

2[CaH4(P04)a+HaO] = CaaPa07-f-aH,P04+3HaO.

The decomposition cannot take place in this manner,
since by the continued adion of the temperature mono-
calcium pyrophosphate is formed from pyrophosphate and
free phosphoric acid.

S. Drewsen, who examined the transformations of
superphosphates at higher temperatures, does not mention
the formation of normal calcium pyrophosphate and
metaphosphate. He merely observed that a considerable
quantity of monocalcium pyrophosphate is formed even
at Ioo^ But this phenomenon, as I will show below, is
occasioned by other fadors, and not merely by tempera-
ture. He suggests, therefore, that the aqueous solution of
superphosphates on analysis should be boiled with nitric
acid, as we cannot know if the superphosphate in question
has been artificially dried at a high temperature. From
the tabular conspedus in which he summarises the results
of his experiments, it is seen that the quantity of the
phosphoric acid soluble in water remained unaltered even
m drying the superphosphates at 300**, for if the aqueous
solution of such a dried superphosphate was boiled in
nitric acid, the same quantity of phosphoric was found
as in the original sample. Drewsen does not, indeed,
mention the composition of the superphosphates which
be examined, but it is evident from his memoir that he
means the soluble phosphoric acid which appears in
superphosphates as monocalcium phosphate. He is thus
in a serious error, for his results cannot be applied to
superphosphates, which contain the soluble phosphoric
acid chiefly in the state of monocalcium phosphate.

The author repeated the experiments with superphos-
phates whith contained 18 per cent of soluble phosphoric
acid (17 per cent as monocalcium phosphate and i per
cent as free phosphoric acid), and on drying for four hours
at I20% he observed great losses of soluble phosphoric
acid. Slightly different results are reached if free phos-
phoric acid is found in the superphosphates in addition to
monocalcium phosphate. Drewsen's results may be ex-
plained on the supposition that he operated upon super-
phosphates containing at least 80 per cent soluble phos-
phoric acid in the state of free acid. At high tempera-
tures the free phosphoric acid, or that liberated by
decomposition, reads upon the normal calcium pyrophos-
phate so as to form monocalcium pyrophosphate :—

The author has proved this readion. Chemically pure
calcium pyrophosphate (CaaPa07+4HaO) was prepared
from calcium chloride and sodium pyrophosphate.

The analysis showed : —


Pa05 42*85 per cent. 43*56 per cent.

CaO 34'92 .» 3435 t»

HaO 21-26 „ 2209



A mixture of 2 grms. pjrrophosphate and 1*202 grms.
phosphoric acid was dried for ten hours in a platinum
capsule at 200^ The monocalcium pyrophosphate
formed was placed in a litre flask which was nlled with
water up to the mark. After shaking for an hour, the
solution became slightly turbid, and contained free phos-
phoric acid only in traces. There was found in the solu-
tion monocalcium pyrophosphate (without heating with
nitric acid) and 4 per cent of phosphoric acid ; after the
solution had been heated with nitric acid, there were
found 56*08 per cent of phosphoric acid by the molyb-
denum method. In our case there was first formed
monocalcium phosphate, which afterwards loses water
and passes into monocalcium pyrophosphate.

If we dry monocalcium phosphate at 150® for longer
than an hour, we do not find the quantity of free phos-
phoric acid which corresponds to the monocalcium
phosphate taken. This phenomenon led to the thought
that the decomposition is different. On examinmg
the aqueous solution, there was found a large quantity
of monocalcium pyrophosphate. The author proved by
a number of experiments that not merely the tempera-
ture reached, but the time during which the desiccation
is prolonged at 150% a higher has great influence on the
formation of monocalcium pyrophosphate.
(To be continned).

Report on thb Composition and Quality of Daily
Samples of the .Water Supplied to London
for the Month Ending January 31ST, 1891.


Professor of Chemistry at the Uoiversitv of Oxford ;

and C.MBYMOTT TIDY, M.S., F.C.S., Barrister-at.L^w,

(Professor of Chemistrr and of Forensic Medicine at the London

Hospital; Medical Officer of Health for Islington.

To General A. Db Courcy Scott, R.A.,
Water Examiner, Metropolis Water Act, 187 1.

London, Febraary 7th, 1891.
Sir, — We submit herewith the results of our analyses
of the 142 samples of water colleded by us during the past
month, at the several places and on the several days indi-
cated, from the mains of the seven London Water Com*
panics taking their supply from the Thames and Lea.

In Table f. we have recorded the analyses in detail of
samples, one taken daily, from January ist to January
31st inclusive. The purity of the water, in resped to
organic matter, has been determined by the Oxygen and
Combustion processes ; and the results of our analyses by
these methods are stated in Columns XIV. to XVIIL

We have recorded in Table IL the tint of the several
samples of water, as determined by the colour-meter
described in a previous report.

In Table IIL we have recorded the oxygen required to
oxidise the organic matter in all the samples submitted
to analysis.

Of the Z42 samples examined, 131 were found to be
clear, bright, and well filtered, i being recorded as ** very
slightly turbid," and 10 as ** slightly turbid.**

As a consequence of the impra^icability, during the
prolongation of the frost, of obtaining samples of water
from some of the standpipes, the record of analytical re-
sults included in this Report is more defedive than in any
that we have hitherto made. Samples of water were
occasionally still met with manifesting the evanescent
smoky taste spoken of and considered in our previous
Report for December ; but the analytical results obtained
during the first three weeks of the month of January, and
ecorded in our present Report, continued to be, except fi>r
two instances occurring of alight turbidity, entirely

Digitized by



Chemical Society^s jubilee.


I March 6, iSgx.

eatisfadory. With the breaking up of the long frost,
however, a distin A deterioration became noticeable in the
charader of the water supplied by several of the Thames
companies ; but only in a single sample, taken on January
30th, was the organic matter present— and that inferred
to be of a non-animal origin — at all excessive.

Owing to the almost complete want of samples of the
Southwark and Vauxhall Company*s water during the
early part of the month, the mean results of the examina-
tion of this Company's supply recorded in the Tables are,
in fad, rather means for the least satisfadoiy week of the
month than for the entire month ; whereby they are ex-
posed, in some particulars, to an unduly unfavourable
comparison with the mean results recorded in the ease of
the other Thames companies* supplies.
We are. Sir,

Your obedient Servants,

William Crookks.

William Odlino.

C. Mbymott Tidy.



Ftbruary 24th,

(Continued from p. 105).

Edward Frankland, D.C.L., LL.D., F.R.S.,
President, 1871 — 1873.

1. EudiomtUr and CalibraUon TabU,—ln this eudio-
meier ethyl was first analysed. —yoKm. Ch»m, Hoc, 1850,
p. 263.

(Exhibited by the Science and Art Department, South

2. Isolation of the Organic RadicUst and Conception of
their Hydrides as a C/ass.— Ethyl butane ; ethylic hydride
ethane.— joNm. Chem, Soc, 1850, p. 263.

3. Digester used in the production of organo-metallic
compounds, and for chemical readions under heat and
pressure.— yoMm. Chem. Soc, 1850, p. 297.

4. Organo-metallic Compounds, — Zinc ethyl, ZnEta ,
stannic ethodimethide, SnEt^Mea.

5. The First Regenerative Gas Burner, — An intermediate
glass (bVoken) caused the air to pass close to the inner-
most glass before it reached the flame.—'* Ure*s Didion-
ary," vol. ii., p. 562. 1854- , ^ ...

6. Artificial Human Afi/^.— Prepared by the partial
removal of casein from, ana addition of, milk-sugar to
cow*s milk. — Manchester Guardian, Dec, 1854.

7. SubsHtutionof*ll%*for Civ in Organic Compounds, —
Cupiic diniuocthylate —

— PAt/. Trans,, 1856, p. 59.

8. Influence of Atmospheric Pressure on the Rate and
Light of Combustion, - Th^ six candles burnt tor one
hour on the summit of Mont Blanc. — Journ, Chem, Soc,
i86z, p. 168.

9. Organo boron Compounds, — Boric ethide, BEtj. —
youm. Chem, Soc, 1862, p. 363.

10. Source of Muscular Power.^Thompaon*% apparatus
used in the aetermination of the potential energy in
various articles of food.— PAi/. Mag,, 1866, Series 4, vol.
xzii., p. 182. , . ^ « .

(Exhibited by the Science and Art Department, South

11. Simple Apparatus for Oas Analysis.^youm, Chem,
Soc, 1868, p. 109. ^ . . ^ „ ,

12. Apparatus Used for the Combustion of Hydrogen
and Carbonic Oxide under Great Pressure. — Proc, Roy.
Soc, 1868, p. 419.

13. Thermometric Observations in the Alps,—B\tick box

in which water was boiled by the unconcentrated Ban's
rays at Davos, Dec. 22nd, 1873. The plain thermonaeter
in the box rose to 221* F. — Proc Roy, Soc, 1874, p. 317.

14. Self-registering Maximum Solar Thermometer. —
This is essentially a differential air thermometer, one
bulb of which is blackened and exposed in vacuo to the
solar rays upon a white ground, the other bulb is freely
exposed to the air beneath the shade of a white arch.
The difference in temperature is read off upon an arbitrary
scale attached to the capillary limb of the inverted siphon,
the maximum height attained by the mercury in this limb
being registered in the usual manner. — Proc. Roy. Soc.,
1882, p. 331.

Dr. Frankland and Dr. Kolbb.

15. Transformation of Cyanogen (CN) itito Oxafyi
(CO Ho). — Caproic acid from AyCy. — ** Mem. Chem.
Soc.,'* iii., 1847, P* 386.

16. Polymerisation of Bthylk Cyanide. — Kyanetbine
N3(CEt)3.— yowrfi. Chem. Soc, 1848, p. 69.

Dr. Frankland and Mr. Duppa.

17. Organo- mercury Compounds. — Mercuric amylide,
HgAya. — youm. Chem, Soc, 1863, p. 420.

18. Transformation of the Acetic into the Acrylic Series

of Acids, —

f CRi"Rt
Ethylcrotonic acid ^ ^

Cupric ethylcrotonate

-youm, Chem, Soc, 1865, p.
19. Synthesis of Esters,—



CO (CnO,)
^ CEf'Et

Ethylic diethacetoacetate
Ethylic diethacetate






—youm. Chem. Soc, 1865, p. 395.

20. Synthesis of Ketones, —

Diethylated acetone j qq^^

—youm, Chem, Soc, 1865, p. 401.

21. Synthesis of Acids of the Acetic Series. —

Ethacetic (butyric) acidj^Q^*

obtained by the successive a^ion of sodium and ethyKc
iodide on ethylic acetate.—yotirfi. Chem, Soc, 1865, p.


22. Synthesis of Acids of the Lactic Series. —

Ethylic diethoxalatej^^^lJJ®

Diamyloxalic acidj^^g^^
—Phil, Trans,, 1866, p. 37.

Dr. Frankland and Dr. Armstrong.

23. Eudiometer for the Determination of Nitrogen in
Nitrates and Nitrites,— your n, Chem, Soc, 1867, p. 102.

24. Analysis of Potable ^a^^r.— Tube charged for com-
bustion of water-residue. — Journ. Chem, Soc, 1868, p. 77.

(Exhibited by Dr. Franldand).

Sir Frbdbrick Abbl, K.C.B., D.C.L., D.Sc., F.R.S.,

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