This gas, which was discovered by Rayleigh and Ramsay in atmospheric

nitrogen, was named _argon_[1] by them, and upon the supposition of its

being an element, they gave it the symbol A. But its true chemical nature

is not yet fully known, for not only has no compound of it been yet

obtained, but it has not even been brought into any reaction. From all

that is known about it at the present time, we may conclude with the

discoverers that argon belongs to those gases which are permanent

constituents of the atmosphere, and that it is a new element. The latter

statement, however, requires confirmation. We shall presently see,

however, that the negative chemical character of argon (its incapacity to

react with any substance), and the small amount of it present in the

atmosphere (about 1-1/4 per cent. by volume in the nitrogen of air, and

consequently about 1 per cent. by volume in air), as well as the recent

date of its discovery (1894) and the difficulty of its preparation, are

quite sufficient reasons for the incompleteness of the existing knowledge

respecting this element. But since, so far as is yet known, we are

dealing with a normal constituent of the atmosphere[1 bis], the existing

data, notwithstanding their insufficiently definite nature, should find a

place even in such an elementary work as the present, all the more as the

names of Rayleigh, Ramsay, Crookes and Olszewsky, who have worked upon

argon, are among the highest in our science, and their researches among

the most difficult.[2] These researches, moreover, were directed straight

to the goal, which was only partly reached owing to the unusual

properties of argon itself.

[1] From the Greek [Greek: Argon]--inert.

[1 bis] In Note 16 bis, Chapter V., I mentioned that, judging from the

specific gravity of argon, it might possibly be polymerised

nitrogen, N_{3}, bearing the same relationship to nitrogen, N_{2},

that ozone, O_{3}, bears to ordinary oxygen. If this idea were

confirmed, still one would not imagine that argon was formed from

the atmospheric nitrogen by those reactions by which it was

obtained by Rayleigh and Ramsay, but rather that it arises from the

nitrogen of the atmosphere under natural conditions. Although this

proposition is not quite destroyed by the more recent results,

still it is contradicted by the fact that the ratio of the specific

heats of argon was found to be 1·66, which, as far as is now known,

could not be the case for a gas containing 3 atoms in its molecule,

since such gases (_see_ Chapter XIV., Note 7) give the ratio

approximately 1·3 (for example, CO_{2}). In abstaining from further

conclusions, for they must inevitably be purely conjectural, I

consider it advisable to suggest that in conducting further

researches upon argon it might be well to subject it to as high a

temperature as possible. And the possibility of nitrogen

polymerising is all the more admissible from the fact that the

aggregation of its atoms in the molecule is not at all unlikely,

and that polymerised nitrogen, judging from many examples, might be

inert if the polymerisation were accompanied by the evolution of

heat. In the following footnotes I frequently return to this

hypothesis, not only because I have not yet met any facts

definitely contradictory to it, but also because the chief

properties of argon agree with it to a certain extent.

[2] The chief difficulty in investigating argon lies in the fact that

its preparation requires the employment of a large quantity of air,

which has to be treated with a number of different reagents, whose

perfect purity (especially that of magnesium) will always be

doubtful, and argon has not yet been transferred to a substance in

which it could be easily purified. Perhaps the considerable

solubility of argon in water (or in other suitable liquids, which

have not apparently yet been tried) may give the means of doing so,

and it may be possible, by collecting the air expelled from boiling

water, to obtain a richer source of argon than ordinary air.

When it became known (Chapter V., Note 4 bis) that the nitrogen

obtained from air (by removing the oxygen, moisture and CO_{2}, by

various reagents) has a greater density than that obtained from the

various (oxygen, hydrogen and metallic) compounds of nitrogen, it was a

plausible explanation that the latter contained an admixture of hydrogen,

or of some other light gas lowering the density of the mixture. But such

an assumption is refuted not only by the fact that the nitrogen obtained

from its various compounds (after purification) has always the same

density (although the supposed impurities mixed with it should vary), but

also by Rayleigh and Ramsay's experiment of artificially adding hydrogen

to nitrogen, and then passing the mixture over red-hot oxide of copper,

when it was found that the nitrogen regained its original density, _i.e._

that the whole of the hydrogen was removed by this treatment. Therefore

the difference in the density of the two varieties of nitrogen had to be

explained by the presence of a heavier gas in admixture with the nitrogen

obtained from the atmosphere. This hypothesis was confirmed by the fact

that Rayleigh and Ramsay having obtained purified nitrogen (by removing

the O_{2}, CO_{2}, and H_{2}O), both from ordinary air and from air which

had been previously subjected to atmolysis, that is which had been passed

through porous tubes (of burnt clay, _e.g._ pipe-stem), surrounded by a

rarefied space, and so deprived of its lighter constituents (chiefly

nitrogen), found that the nitrogen from the air which had been subjected

to atmolysis was heavier than that obtained from air which had not been

so treated. This experiment showed that the nitrogen of air contains an

admixture of a gas which, being heavier than nitrogen itself,[3] diffuses

more slowly than nitrogen through the porous material. It remained,

therefore, to separate this impurity from the nitrogen. To do this

Rayleigh and Ramsay adopted two methods, converting the nitrogen into

solid and liquid substances, either by absorbing the nitrogen by heated

magnesium (Chapter V., Note 6, and Chapter XIV., Note 14), with the

formation of nitride of magnesium, or else by converting it into nitric

acid by the action of electric sparks or the presence of an excess of air

and alkali, as in Cavendish's method.[3 bis] In both cases the nitrogen

entered into reaction, while the heavier gas mixed with it remained

inert, and was thus able to be isolated. That is, the argon could be

separated by these means from the excess of atmospheric nitrogen

accompanying it.[4] As an illustration we will describe how argon was

obtained from the atmospheric nitrogen by means of magnesium.[5] To begin

with, it was discovered that when atmospheric nitrogen was passed through

a tube containing metallic magnesium heated to redness, its specific

gravity rose to 14·88. As this showed that part of the gas was absorbed

by the magnesium, a mercury gasometer filled with atmospheric nitrogen

was taken, and the gas drawn over soda-lime, P_{2}O_{5}, heated

magnesium[6] and then through tubes containing red-hot copper oxide,

soda-lime and phosphoric anhydride to a second mercury gasometer. Every

time the gas was repassed through the tubes, it decreased in volume and

increased in density. After repeating this for ten days 1,500 c.c. of gas

were reduced to 200 cc., and the density increased to 16·1 (if that of

H_{2} = 1 and N_{2} = 14). Further treatment of the remainder brought the

density up to 19·09. After adding a small quantity of oxygen and

repassing the gas through the apparatus, the density rose to 20·0. To

obtain argon by this process Ramsay and Rayleigh (employing a mercury air

pump and mercury gasometers) once treated about 150 litres of atmospheric

nitrogen. On another occasion they treated 7,925 c.c. of air by the

oxidation method and obtained 65 c.c. of argon, which corresponds to 0·82

per cent. The density of the argon obtained by this means was nearly

19·7, while that obtained by the magnesium method varied between 19·09

and 20·38.

[3] It might also be supposed that this heavy gas is separated by the

copper when the latter absorbs the oxygen of the air; but such a

supposition is not only improbable in itself, but does not agree

with the fact that nitrogen may be obtained from air by absorbing

the oxygen by various other substances in solution (for instance,

by the lower oxides of the metals, like FeO) besides red-hot

copper, and that the nitrogen obtained is always just as heavy.

Besides which, nitrogen is also set free from its oxides by copper,

and the nitrogen thus obtained is lighter. Therefore it is not the

copper which produces the heavy gas--_i.e._ argon.

[3 bis] It is worthy of note that Cavendish obtained a small residue of

gas in converting nitrogen into nitric acid; but he paid no

attention to it, although probably he had in his hands the very

argon recently discovered.

[4] When in these experiments, instead of atmospheric nitrogen the gas

obtained from its compound was taken, an inert residue of a heavy

gas, having the properties of argon, was also remarked, but its

amount was very small. Rayleigh and Ramsay ascribe the formation of

this residue to the fact that the gas in these experiments was

collected over water, and a portion of the dissolved argon in it

might have passed into the nitrogen. As the authors of this

supposition did not prove it by any special experiments, it forms a

weak point in their classical research. If it be admitted that

argon is N_{3}, the fact of its being obtained from the nitrogen of

compounds might be explained by the polymerisation of a portion of

the nitrogen in the act of reaction, although it is impossible to

refute Rayleigh and Ramsay's hypothesis of its being evolved from

the water employed in the manipulation of the gases. Three thousand

volumes of nitrogen extracted from its compounds gave about three

volumes of argon, while thirty volumes were yielded by the same

amount of atmospheric nitrogen.

[5] The preparation of argon by the conversion of nitrogen into nitric

acid is complicated by the necessity of adding a large proportion

of oxygen and alkali, of passing an electric discharge through the

mixture for a long period, and then removing the remaining oxygen.

All this was repeatedly done by the authors, but this method is far

more complex, both in practice and theory, than the preparation of

argon by means of magnesium. From 100 volumes of air subjected to

conversion into HNO_{3}, 0·76 volume of argon were obtained after

absorbing the excess of oxygen.

[6] In these and the following experiments the magnesium was placed in

an ordinary hard glass tube, and heated in a gas furnace to a

temperature almost sufficient to soften the glass. The current of

gas must be very slow (a tube containing a small quantity of

sulphuric acid served as a meter), as otherwise the heat evolved in

the formation of the Mg_{3}N_{2} (Chapter XIV., Note 14) will melt

the tube.

Thus the first positive and very important fact respecting argon is that

its specific gravity is nearly 20--that is, that it is 20 times heavier

than hydrogen, while nitrogen is only 14 times and oxygen 16 times

heavier than hydrogen. This explains the difference observed by Rayleigh

between the densities of nitrogen obtained from its compounds and from

the atmosphere (Chapter V., Note 4 bis). At 0° and 760 mm. a litre of the

former gas weighs 1·2505 grm., while a litre of the latter weighs 1·2572,

or taking H = 1, the density of the first = 13·916, and of the latter =

13·991. If the density of argon be taken as 20, it is contained in

atmospheric nitrogen to the extent of about 1·23 per cent. by volume,

whilst air contains about 0·97 per cent. by volume.

When argon had been isolated the question naturally arose, was it a new

homogeneous substance having definite properties or was it a mixture of

gases? The former may now be positively asserted, namely, that argon is a

peculiar gas previously unknown to chemistry. Such a conviction is in the

first place established by the fact that argon has a greater number of

negative properties, a smaller capacity for reaction, than any other

simple or compound body known. The most inert gas known is nitrogen, but

argon far exceeds it in this respect. Thus nitrogen is absorbed at a red

heat by many metals, with the formation of nitrides, while argon, as is

seen in the mode of its preparation and by direct experiment, does not

possess this property. Nitrogen, under the action of electric sparks,

combines with hydrogen in the presence of acids and with oxygen in the

presence of alkalis, while argon is unable to do so, as is seen from the

method of separation from nitrogen. Rayleigh and Ramsay also proved that

argon is unable to react with chlorine (dry or moist) either directly or

under the action of an electric discharge, or with phosphorus or sulphur,

at a red heat. Sodium, potassium, and tellurium may be distilled in an

atmosphere of argon without change. Fused caustic soda, incandescent

soda-lime, molten nitre, red-hot peroxide of sodium, and the

polysulphides of calcium and sodium also do not react with argon.

Platinum black does not absorb it, and spongy platinum is unable to

excite its reaction with oxygen or chlorine. Aqua regia, bromine water,

and a mixture of hydrochloric acid and KMnO_{4} were also without action

upon argon. Besides which it is evident from the method of its

preparation that it is not acted upon by red-hot oxide of copper. All

these facts exclude any possibility of argon containing any already known

body, and prove it to be the most inert of all the gases known. But

besides these negative points, the independency of argon is confirmed by

four observed positive properties possessed by it, which are:--

1. The spectrum of argon observed by Crookes under a low pressure (in

Geissler-Plücker tubes) distinguishes it from other gases.[7] It was

proved by this means that the argon obtained by means of magnesium is

identical with that which remains after the conversion of the atmospheric

nitrogen into nitric acid. Like nitrogen, argon presents two spectra

produced at different potentials of the induced current, one being

orange-red, the other steel-blue; the latter is obtained under a higher

degree of rarefaction and with a battery of Leyden jars. Both the spectra

of argon (in contradistinction to those of nitrogen) are distinguished by

clearly defined lines.[8] The red (ordinary) spectrum of argon has two

particularly brilliant and characteristic red lines (not far from the

bright red line of lithium, on the opposite side to the orange band)

having wave-lengths 705·64 and 696·56 (_see_ Vol. I., p. 565). Between

these bright lines there are in addition lines with wave lengths 603·8,

565·1, 561·0, 555·7, 518·58, 516·5, 450·95, 420·10, 415·95 and 394·85.

Altogether 80 lines have been observed in this spectrum and 119 in the

blue spectrum, of which 26 are common to both spectra.[9]

[7] The greatest brilliancy of the spectrum of argon is obtained at a

tension of 3 mm., while for nitrogen it is about 75 mm. (Crookes).

In Chapter V., Note 16 bis, it is said that the same blue line

observed in the spectrum of argon is also observed in the spectrum

of nitrogen. This is a mistake, since there is no coincidence

between the blue lines of the argon and nitrogen spectra. However,

we may add that for nitrogen the following moderately bright lines

are known of wave-lengths 585, 574, 544, 516, 457, 442, 436, and

426, which are repeated in the spectra (red and blue) of argon,

judging by Crookes' researches (1895); but it is naturally

impossible to assert that there is perfect identity until some

special comparative work has been done in this subject, which is

very desirable, and more especially for the bluish-violet portion

of the spectrum, more particularly between the lines 442-436, as

these lines are distinguished by their brilliancy in both the argon

and nitrogen spectra. The above-mentioned supposition of argon

being polymerised nitrogen (N_{3}), formed from nitrogen (N_{2}),

with the evolution of heat, might find some support should it be

found after careful comparison that even a limited number of

spectral lines coincided.

[8] At first the spectrum of argon exhibits the nitrogen lines, but

after a certain time these lines disappear (under the influence of

the platinum, and also of Al and Mg, but with the latter the

spectrum of hydrogen appears) and leave a pure argon spectrum. It

does not appear clear to me whether a polymerisation here takes

place or a simple absorption. Perhaps the elucidation of this

question would prove important in the history of argon. It would be

desirable to know, for instance, whether the volume of argon

changes when it is first subjected to the action of the electric

discharge.

[9] Crookes supposes that argon contains a mixture of two gases, but as

he gives no reasons for this, beyond certain peculiarities of a

spectroscopic character, we will not consider this hypothesis

further.

2. According to Rayleigh and Ramsay the solubility of argon in water is

approximately 4 volumes in 100 volumes of water at 13°. Thus argon is

nearly 2-1/2 times more soluble than nitrogen, and its solubility

approaches that of oxygen. Direct experiment proves that nitrogen

obtained from air from boiled water is heavier than that obtained

straight from the atmosphere. This again is an indirect proof of the

presence of argon in air.

3. The ratio _k_ of the two specific heats (at a constant pressure and

at a constant volume) of argon was determined by Rayleigh and Ramsay by

the method of the velocity of sound (_see_ Chapter XIV., Note 7 and

Chapter VII., Note 26) and was found to be nearly 1·66, that is greater

than for those gases whose molecules contain two atoms (for instance, CO,

H_{2}, N_{2}, air, &c., for which _k_ is nearly 1·4) or those whose

molecules contain three atoms (for instance, CO_{2}, N_{2}O, &c., for

which _k_ is about 1·3), but closely approximate to the ratio of the

specific heats of mercury vapour (Kundt and Warburg, _k_ = 1·67). And as

the molecule of mercury vapour contains one atom, so it may be said that

argon is a simple gaseous body whose molecule contains one atom.[10] A

compound body should give a smaller ratio. The experiments upon the

liquefaction of argon, which we shall presently describe, speak against

the supposition that argon is a mixture of two gases. The importance of

the results in question makes one wish that the determinations of the

ratio of the specific heats (and other physical properties) might be

confirmed with all possible accuracy.[11] If we admit, as we are obliged

to do for the present, that argon is a new element, its density shows

that its atomic weight must be nearly 40, that is, near to that of K = 39

and Ca = 40, which does not correspond to the existing data respecting

the periodicity of the properties of the elements in dependence upon

their atomic weights, for there is no reason on the basis of existing

data for admitting any intermediate elements between Cl = 35·5 and K =

39, and all the positions above potassium in the periodic system are

occupied. This renders it very desirable that the velocity of sound in

argon should be re-determined.[12]

[10] This portion of Rayleigh and Ramsay's researches deserves

particular attention as, so far, no gaseous substance is known

whose molecule contains but one atom. Were it not for the above

determinations, it might be thought that argon, having a density

20, has a complex molecule, and may be a compound or polymerised

body, for instance, N_{3} or NX_{_n_}, or in general X_{_n_}; but

as the matter stands, it can only be said that either (1) argon is

a new, peculiar, and quite unusual elementary substance, since

there is no reason for assuming it to contain two simple gases, or

(2) the magnitude, _k_ (the ratio of the specific heats) does not

only depend upon the number of atoms contained in the molecules,

but also upon the store of internal energy (internal motion of the

atoms in the molecule). Should the latter be admitted, it would

follow that the molecules of very active gaseous elements would

correspond to a smaller _k_ than those of other gases having an

equal number of atoms in their molecule. Such a gas is chlorine,

for which _k_ = 1·33 (Chapter XIV., Note 7). For gases having a

small chemical energy, on the contrary, a larger magnitude would

be expected for _k_. I think these questions might be partially

settled by determining _k_ for ozone (O_{3}) and sulphur (S_{6})

(at about 500°). In other words, I would suggest, though only

provisionally, that the magnitude, _k_ = 1·6, obtained for argon

might prove to agree with the hypothesis that argon is N_{3},

formed from N_{2} with the evolution of heat or loss of energy.

Here argon gives rise to questions of primary importance, and it

is to be hoped that further research will throw some light upon

them. In making these remarks, I only wish to clear the road for

further progress in the study of argon, and of the questions

depending on it. I may also remark that if argon is N_{3} formed

with the evolution of heat, its conversion into nitrogen, N_{2},

and into nitride compounds (for instance, boron nitride or nitride

of titanium) might only take place at a very high temperature.

[11] Without having the slightest reason for doubting the accuracy of

Rayleigh and Ramsay's determinations, I think it necessary to say

that as yet (February 1895) I am only acquainted with the short

memoir of the above chemists in the 'Proceedings of the Royal

Society,' which does not give any description of the methods

employed and results obtained, while at the end (in the general

conclusions) the authors themselves express some doubt as to the

simple nature of argon. Moreover, it seems to me that (Note 10)

there must be a dependence of _k_ upon the chemical energy.

Besides which, it is not clear what density of the gas Rayleigh

and Ramsay took in determining _k_. (If argon be N_{3}, its

density would be near to 21.) Hence I permit myself to express

some doubt as to whether the molecule of argon contains but one

atom.

[12] If it should be found that _k_ for argon is less than 1·4, or that

_k_ is dependent upon the chemical energy, it would be possible to

admit that the molecule of argon contains not one, but several

atoms--for instance, either N_{3} (then the density would be 21,

which is near to the observed density) or X_{6}, if X stand for an

element with an atomic weight near to 6·7. No elements are known

between H = 1 and Li = 7, but perhaps they may exist. The

hypothesis A = 40 does not admit argon into the periodic system.

If the molecule of argon be taken as A_{2}--_i.e._ the atomic

weight as A = 20--argon apparently finds a place in Group VIII.,

between F = 19 and Na = 23; but such a position could only be

justified by the consideration that elements of small atomic

weight belong to the category of typical elements which offer many

peculiarities in their properties, as is seen on comparing N with

the other elements of Group V., or O with those of Group VI. Apart

from this there appears to me to be little probability, in the

light of the periodic law, in the position of an inert substance

like argon in Group VIII., between such active elements as

fluorine and sodium, as the representatives of this group by their

atomic weights and also by their properties show distinct

transitions from the elements of the last groups of the uneven

series to the elements of the first groups of the even series--for

instance,

Group VI. VII. VIII. I. II.

Cr Mn Fe, Co, Ni Cu Zn

While if we place argon in a similar manner,

VI. VII. VIII. I. II.

O = 16 F = 19 A = 20 Na = 23 Mg = 24

although from a numerical point of view there is a similar

sequence to the above, still from a chemical and physical point of

view the result is quite different, as there is no such

resemblance between the properties of O, F and Na, Mg, as between

Cr, Mn, and Cu, Zn. I repeat that only the typical character of

the elements with small atomic weights can justify the atomic

weight A = 20, and the placing of argon in Group VIII. amongst the

typical elements; then N, O, F, A are a series of gases.

It appears to me simpler to assume that argon contains N_{3},

especially as argon is present in nitrogen and accompanies it,

and, as a matter of fact, none of the observed properties of argon

are contradictory to this hypothesis.

These observations were written by me in the beginning of February

1895, and on the 29th of that month I received a letter, dated

February 25, from Professor Ramsay informing me that 'the periodic

classification entirely corresponds to its (argon's) atomic

weight, and that it even gives a fresh proof of the periodic law,'

judging from the researches of my English friends. But in what

these researches consisted, and how the above agreement between

the atomic weight of argon and the periodic system was arrived at,

is not referred to in the letter, and we remain in expectation of

a first publication of the work of Lord Rayleigh and Professor

Ramsey. [For more complete information see papers read before the

Royal Society, January 31, 1895, February 13, March 10, and May

21, 1896, and a paper published in the Chemical Society's

Transactions, 1895, p. 684. For abstracts of these and other

papers on argon and helium, and correspondence, see 'Nature,' 1895

and 1896.

4. Argon was liquefied by Professor Olszewsky, who is well known for

his classical researches upon liquefied gases. These researches have an

especial interest since they show that argon exhibits a perfect constancy

in its properties in the liquid and critical states, which almost[13]

disposes of the supposition that it contains a mixture of two or more

unknown gases. As the first experiments showed, argon remains a gas under

a pressure of 100 atmospheres and at a temperature of -90°; this

indicated that its critical temperature was probably below this

temperature, as was indeed found to be the case when the temperature was

lowered to -128°·6[14] by means of liquid ethylene. At this temperature

argon easily liquefies to a colourless liquid under 38 atmospheres. The

meniscus begins to disappear at between -119°·8 and -121°·6, mean -121°

at a pressure of 50·6 atmospheres. The vapour tension of liquid argon at

-128°·6, is 38·0 atmospheres, at -187° it is one atmosphere, and at

-189°·6 it solidifies to a colourless substance like ice. The specific

gravity of liquid argon at about -187° is nearly 1·5, which is far above

that of other liquefied gases of very low absolute boiling point.

The discovery of argon is one of the most remarkable chemical

acquisitions of recent times, and we trust that Lord Rayleigh and

Professor Ramsay, who made this wonderful discovery, will further

elucidate the true nature of argon, as this should widen the fundamental

principles of chemistry, to which the chemists of Great Britain have from

early times made such valuable contributions. It would be premature now

to give any definite opinions upon so new a subject. Only one thing can

be said; argon is so inert that its rôle in nature cannot be

considerable, notwithstanding its presence in the atmosphere. But as the

atmosphere itself plays such a vast part in the life of the surface of

the earth, every addition to our knowledge of its composition must

directly or indirectly react upon the sum total of our knowledge of

nature.

[13] There only remains the very remote possibility that argon consists

of a mixture of two gases having very nearly the same properties.

[14] The following data, given by Olszewsky, supplement the data given

in Chapter II., Note 29, upon liquefied gases.

(_tc_) (_pc_) _t_ _t__{1} _s_

N_{2} -146° 35 -194°·4 -214° 0·885

CO -139°·5 35·5 -190° -207 ?

A -121° 50·6 -187° -189°·6 1·5

O_{2} -118°·8 50·8 -182°·7 ? 1·124

NO -93°·5 71·2 -153°·6 -167° ?

CH_{4} -81°·8 54·9 -164° -158°·8 0·415

where _tc_ is the absolute (critical) boiling point, _pc_ the

pressure (critical) in atmospheres corresponding to it, _t_ the

boiling point (under a pressure of 760 mm.), _t_{1}_ the melting

point, and _s_ the specific gravity in a liquid state at _t_.

The above shows that argon in its properties in a liquid state

stands near to oxygen (as it also does in its solubility), but

that all the temperatures relating to it (_tc_, _t_, and _t_{1}_)

are higher than for nitrogen. This fully answers, not only to the

higher density of argon, but also to the hypothesis that it

contains N_{3}. And as the boiling point of argon differs from

that of nitrogen and oxygen by less than 10°, and its amount is

small, it is easy to understand how Dewar (1894), who tried to

separate it from liquid air and nitrogen by fractional

distillation, was unable to do so. The first and last portions

were identical, and nitrogen from air showed no difference in its

liquefaction from that obtained from its compounds, or from that

which had been passed through a tube containing incandescent

magnesium. Still, it is not quite clear why both kinds of

nitrogen, after being passed over the magnesium in Dewar's

experiments, exhibited an almost similar alteration in their

properties, independent of the appearance of a small quantity of

hydrogen in them.

_Concluding Remarks_ (March 31, 1895).--The 'Comptes rendus' of

the Paris Academy of Sciences of March 18, 1895, contains a memoir

by Berthelot upon the reaction of argon with the vapour of benzene

under the action of a silent discharge. In his experiments,

Berthelot succeeded in treating 83 per cent. of the argon taken

for the purpose, and supplied to him by Ramsay (37 c.c. in all).

The composition of the product could not be determined owing to

the small amount obtained, but in its outward appearance it quite

resembled the product formed under similar conditions by nitrogen.

This observation of the famous French chemist to some extent

supports the supposition that argon is a polymerised variety of

nitrogen whose molecule contains N_{3}, while ordinary nitrogen

contains N_{2}. Should this supposition be eventually verified,

the interest in argon will not only not lessen, but become

greater. For this, however, we must wait for further observations

and detailed experimental data from Rayleigh and Ramsay.

The latest information obtained by me from London is that

Professor Ramsay, by treating cleveite (containing PbO, UO_{3},

Y_{2}O_{3}, &c.) with sulphuric acid, obtained argon, and, judging

by the spectrum, helium also. The accumulation of similar data

may, after detailed and diversified research, considerably

increase the stock of chemical knowledge which, constantly

widening, cannot be exhaustively treated in these 'Principles of

Chemistry,' although very probably furnishing fresh proof of the

'periodicity of the elements.'

* * * * *

INDEX OF AUTHORITIES

Abasheff, i. 75

Abel, ii. 56, 326, 410

Acheson, ii. 107

Adie, ii. 186

Alexéeff, i. 75, 94

Alluard, i. 458

Amagat, i. 132, 135, 140

Amat, ii. 171

Ammermüller, i. 504

Ampère, i. 309

Andréeff, i. 251

Andrews, i. 136, 203

Angeli, i. 266

Ansdell, i. 451

Arfvedson, i. 575

Arrhenius, i. 89, 92, 389

Aschoff, ii. 313

Askenasy, i. 508

Aubel, ii. 45

Aubin, i. 238

Avdéeff, i. 618; ii. 484

Avogadro, i. 309

Babo, v., i. 93, 200, 203

Bach, i. 394

Bachmetieff, ii. 31

Baeyer, v., i. 507

Bagouski, i. 384

Bailey, i. 449; ii. 29

Baker, i. 318, 403

Balard, i. 480, 494, 495, 505

Ball, ii. 414

Bannoff, i. 506

Barfoed, ii. 53

Baroni, i. 331

Barreswill, ii. 282

Baudrimont, ii. 35

Baumé, i. 193

Baumgauer, ii. 20

Baumhauer, i. 495

Bayer, ii. 76, 159

Bazaroff, i. 409; ii. 24, 68, 486

Becher, i. 17

Becker, i. 16

Beckmann, i. 91, 496; ii. 156

Becquerel, i. 228; ii. 97, 220

Beilby, i. 71

Beilstein, i. 373; ii. 188

Beketoff, i. 120, 122, 124, 146, 403, 459, 466, 534, 541, 574, 577;

ii. 87, 102, 289, 429

Bender, i. 476

Benedict, ii. 65

Berglund, ii. 229

Bergman, i. 27, 435; ii. 100

Berlin, i. 95

Bernouilli, i. 81

Bernthsen, ii. 228

Bert, i. 86, 153

Bertheim, ii. 337

Berthelot, i. 171, 173, 189, 199, 229, 230, 258, 264, 266, 267, 272,

83, 289, 351, 372, 393, 394, 405, 415, 424, 438, 457, 463, 502,

506, 507, 518, 529, 537, 582; ii. 23, 57, 207, 209, 251, 253, 259,

345, 367

Berthier, ii. 8

Berthollet, i. 27, 31, 105, 433, 434, 459, 470, 502, 609

Berzelius, i. 131, 148, 194, 255, 379; ii. 8, 100, 102, 147, 148,

219, 281, 300, 485

Besson, i. 288; ii. 67, 70, 105, 179

Beudant, ii. 7, 8

Bineau, i. 100, 271, 452, 504; ii. 239

Binget, i. 75

Blaese, ii. 188

Blagden, i. 91, 428

Blake, ii. 30

Blitz, ii. 184

Blomstrand, ii. 299

Boerwald, ii. 279

Böttger, i. 595

Bogorodsky, i. 574

Boilleau, i. 415

Boisbaudran, L. de, i. 97, 102, 572, 600; ii. 6, 26, 90, 82, 284, 483

Bornemann, i. 509

Botkin, ii. 30

Bouchardat, ii. 45

Boullay, ii. 55

Bourdiakoff, i. 584, 617

Boussingault, i. 131, 157, 233, 235, 525, 615

Boyle, i. 124

Brand, ii. 150

Brandau, i. 481

Brandes, i. 72

Bravais, i. 233

Brauner, i. 490, 491; ii. 26, 59, 94, 96, 97, 134, 144, 194, 271, 483

Brewster, i. 569

Brigham, ii. 193

Brodie, i. 212, 351, 405; ii. 252

Brooke, ii. 357

Brown, i. 81, 88

Brugellmann, i. 616

Brunn, ii. 182, 189

Bruyn, i. 262

Brühl, i. 263, 337

Brunner, i. 124, 146, 263; ii. 230, 309, 534

Buchner, i. 615

Buckton, ii. 143

Buff, ii. 103

Bunge, i. 288

Bunsen, i. 43, 69, 78, 117, 180, 465, 568, 575, 576, 577; ii. 27, 289

Bussy, i. 75, 594, 619

Butleroff, i. 143

Bystrom, i. 585

Cagniard de Latour, i. 135, 345

Cahours, ii. 143, 173

Cailletet, i. 132, 138; ii. 45

Calderon, i. 596

Callender, i. 134

Calvert, i. 484; ii. 45

Cannizzaro, i. 584, 587

Carey-Lea, ii. 420, 424, 425, 432

Carius, i. 69, 481

Carnelley, i. 483, 515, 555; ii. 22, 29, 30, 31, 64, 143, 486

Carnot, ii. 294, 361

Caron, i. 595, 604, 610; ii. 336

Carrara, i. 213

Cass, ii. 85

Castner, i. 431, 535, 541

Cavazzi, ii. 160, 172, 182

Cavendish, i. 113, 125, 228; ii. 493

Chabrié, i. 229

Chappuis, i. 50, 199, 205, 264

Chapuy, i. 59

Cheltzoff, i. 393, 457, 582; ii. 41, 247

Cherikoff, ii. 102

Chertel, ii. 245

Chevillot, ii. 311

Chevreul, i. 530

Chigeffsky, ii. 62

Christomanos, i. 511

Chroustchoff, i. 353, 444; ii. 122

Chydenius, ii. 148, 485

Ciamician, i. 565, 573; ii. 486

Clark, i. 26

Classen, ii. 146

Clausius, i. 81, 93, 140, 142, 212, 309, 491

Clement, i. 494

Clève, ii. 26, 94, 97, 484

Cloez, i. 207, 246, 377

Clowes, i. 242

Collendar, i. 134

Comaille, i. 596

Comb, ii. 81

Connell, i. 508

Coppet, i. 91, 428, 601

Corenwinder, i. 501

Cornu, i. 565

Courtois, i. 494

Cracow, ii. 380

Crafts, i. 380 ; ii. 80, 83

Cremers, ii. 100

Croissier, i. 251

Crompton, i. 247

Crookes, i. 229, 617; ii. 20, 91, 96, 440, 491

Crum, ii. 79, 311

Cundall, i. 611

Curtius, i. 258, 265

Dahl, ii. 59

Dalton, i. 29, 78, 81, 109, 206, 271, 322

Dana, ii. 8

Davies, i. 484

Davy, i. 37, 114, 195, 255, 364, 460, 463, 484, 489, 494, 533, 541,

594, 604, 617

Deacon, i. 599

Debray, i. 609; ii. 45, 122, 291, 293, 384, 385

De Chancourtois, ii. 20, 26

De Forcrand, ii. 106, 211

De Haën, ii. 189

De Heen, i. 140

Delafontaine, ii. 97, 148, 198

De la Rive, i. 198; ii. 226

Del-Rio, ii. 197

De Saussure, i. 235, 240

De Schulten, ii. 48

Deville, St.-Claire, i. 4, 36, 118, 143, 179, 180, 227, 239, 280, 281,

301, 320, 392, 393, 399, 459, 467, 476, 477, 500, 534, 595, 608, 609;

ii. 48, 80, 83, 85, 102, 147, 156, 198, 289, 309, 321, 352, 373, 374,

429

De Vries, i. 62, 64, 429

Dewar, i. 3, 5, 135, 139, 163, 297, 563, 565, 569, 585; ii. 176, 220

Dick, ii. 414

Dingwall, i. 486

Ditte, i. 72, 403, 430, 457, 509, 539, 618; ii. 64, 65, 85, 189, 249

Dittmar, i. 100, 452; ii. 240

Divers, i. 274, 294; ii. 54

Dixon, i. 171

Döbereiner, i. 145

Dokouchaeff, i. 344

Donny, i. 534

Dossios, i. 502

Draper, i. 465

Drawe, ii. 161

Drebbel, i. 294

Dulong, i. 131, 148, 437

Dumas, i. 28, 131, 148, 150, 233, 302, 320, 379, 471, 476, 584, 586,

604; ii. 22, 37, 62, 101, 156, 420

Dumont, ii. 197

Ebelmann, ii. 65

Eder, i. 566

Edron, ii. 95

Edwards, ii. 311

Egoreff, i. 569

Eissler, i. 553

Elbers, ii. 221

Emich, i. 286, 287

Emilianoff, ii. 126

Engel, i. 457; ii. 130, 132, 189, 206

Engelhardt, i. 530

Eötvös, i. 333

Erdmann, i. 150

Ernst, i. 399

Eroféeff, i. 352

Esson, ii. 314

Étard, i. 72, 516, 615; ii. 288, 335, 356

Ettinger, i. 53, 312

Famintzin, i. 611

Faraday, i. 134, 177, 296, 385, 463, 464

Favorsky, i. 373

Favre, i. 120, 172, 267, 582; ii. 83, 259, 284, 380

Fick, i. 62

Fisher, ii. 424

Fizeau, ii. 31, 429

Flavitzky, i. 21

Fleitmann, ii. 170

Foerster, ii. 375, 389

Forchhammer, ii. 311

Fordos, ii. 257

Fortmann, ii. 230, 366

Fourcroy, i. 114

Fowler, i. 449

Frank, ii. 88

Franke, ii. 311, 313

Frankel, ii. 294

Frankenheim, ii. 7

Frankland, i. 178, 357, 486; ii. 16, 143

Fraunhofer, i. 563

Frémy, i. 228, 489, 492; ii. 74, 131, 133, 142, 229, 290, 359

Freyer, i. 171, 488

Friedheim, ii. 197, 294

Friedel, i. 353, 472; ii. 80, 83, 103, 122

Friedrich, i. 49; ii. 144

Fritzsche, i. 94, 285, 600, 612; ii. 125, 218, 280, 341

Fromherz, ii. 313

Fürst, i. 484

Galileo, i. 7

Garni, i. 582

Garzarolli-Thurnlackh, i. 481

Gattermann, i. 596; ii. 102, 104

Gautier, i. 585

Gavaloffsky, i. 160

Gay-Lussac, i. 40, 61, 71, 93, 170, 302, 307, 406, 412, 460, 463, 464,

467, 500, 506, 508, 511, 515, 534, 539; ii. 8, 56, 256

Geber, i. 17

Gélis, ii. 257

Genth, ii. 359

Georgi, ii. 197

Georgiewics, ii. 64

Gerberts, i. 528

Gerhardt, i. 196, 309, 357, 388

Gerlach, i. 525

Gernez, i. 97; ii. 205

Geuther, i. 281, 283, 285; ii. 176

Gibbs, i. 140, 464; ii. 293, 410

Girault, i. 498

Gladstone, i. 337, 438, 573; ii. 213

Glatzel, ii. 213, 289, 309

Glauber, i. 17, 26, 193, 432

Glinka, i. 607

Goldberg, i. 93

Gooch, i. 484

Gore, i. 489, 492, 493

Graham, i. 62, 63, 98, 143, 155, 388, 429, 518, 601; ii. 77, 114, 131,

163, 170, 296, 307

Granger, ii. 157, 410

Grassi, i. 88

Green, ii. 310

Greshoff, i. 403

Griffiths, i. 135

Grimaldi, i. 537

Groth, ii. 10

Grouven, i. 615

Grove, i. 118, 119

Grünwald, i. 573

Grützner, ii. 296

Guckelberger, ii. 84

Guibourt, ii. 53

Guldberg, i. 439, 464

Güntz, i. 575; ii. 430

Gustavson, i. 443, 444, 472, 505, 547; ii. 29, 175

Guthrie, i. 99, 428, 601

Guy, i. 136

Habermann, ii. 210

Hagebach, i. 573

Hagen, i. 337

Haitinger, i. 593

Hammerl, i. 613

Hanisch, ii. 233

Hannay, i. 352; ii. 135

Harcourt, ii. 314

Hargreaves, i. 515

Harris, ii. 52

Hartley, i. 573; ii. 486

Hartog, ii. 268

Hasselberg, i. 566

Haüy, ii. 7

Haughton, ii. 20

Häussermann, i. 483

Hautefeuille, i. 199, 205, 264, 409, 414, 476, 477, 501, 538; ii. 102,

122, 379

Hayter, ii. 175

Hemilian, i. 132

Hempel, i. 59, 524

Henkoff, i. 530

Henneberg, ii. 170

Henning, ii. 3

Henry, i. 78, 81

Hérard, ii. 191

Hermann, ii. 8, 47, 197

Hermes, i. 529

Hertz, ii. 156

Hess, i. 178, 588

Heycock, i. 537; ii. 128, 448

Hillebrand, ii. 26, 93, 94, 484

Hintze, ii. 10

Hirtzel, ii. 55

Hittorf, ii. 155

Hodgkinson, ii. 432

Höglund, ii. 94

Hofmann, i. 302; ii. 146, 218, 447

Holtzmann, i. 505

Hoppé-Seyler, i. 611

Horstmann, i. 408

Houzeau, i. 202

Hughes, ii. 212

Hugo, ii. 21

Humboldt, i. 170

Humbly, i. 493; ii. 311

Hutchinson, i. 491

Huth, ii. 20

Huyghens, i. 569

Ikeda, ii. 152

Ilosva, i. 202

Inostrantzeff, i. 345; ii. 4

Isambert, i. 250, 257, 408; ii. 41

Ittner, i. 412

Janssen, i. 569

Jawein, ii. 170

Jay, i. 258

Jeannel, i. 104

Joannis, i. 251, 255, 405, 537, 559

Jörgensen, i. 498; ii. 359, 361, 376

Johnson, ii. 45

Jolly, i. 233

Joly, ii. 384, 385

Kamensky, ii. 414

Kammerer, i. 286, 462, 509; ii. 297

Kane, ii. 57

Kapoustin, i. 403

Karsten, i. 427, 428, 541, 599

Kassner, i. 158

Kayander, i. 133, 384; ii. 46

Keiser, i. 150

Kekulé, i. 358, 369, 507; ii. 294

Keyser, ii. 33

Khichinsky, i. 440

Kimmins, i. 510

Kirchhoff, i. 567

Kirmann, ii. 268

Kirpicheff, i. 132

Kjeldahl, i. 249; ii. 249

Klaproth, ii. 7, 145, 147, 301

Kleiber, i. 570

Klimenko, i. 465

Klobb, ii. 357

Klodt, i. 426

Knopp, ii. 338

Knox, i. 489

Kobb, ii. 125

Kobell, ii. 197

Koch, i. 44

Kohlrausch, i. 245, 525

Kolbe, i. 506

Kolotoff, i. 263

Konovaloff, i. 39, 65, 90, 93, 100, 140, 142, 172, 322; ii. 235, 268

Kopp, i. 586, 587, 612; ii. 3, 37

Koucheroff, i. 373

Kouriloff, i. 209, 247, 274; ii. 41

Kournakoff, i. 393; ii. 294, 365, 396

Kraevitch, i. 133, 134

Kraft, i. 65, 88, 537

Krafts, i. 393

Kreisler, i. 233

Kremers, i. 87, 443; ii. 244, 427

Kreider, i. 484

Krönig, i. 81

Krüger, ii. 282, 284

Krüss, ii. 355, 442, 447, 486

Kubierschky, ii. 213

Kühlmann, i. 608

Kuhnheim, i. 612

Kundt, i. 328, 589; ii. 496

Kvasnik, ii. 57

Kynaston, i. 522

Lachinoff, i. 116, 457; ii. 410

Ladenburg, ii, 103

Lamy, ii. 91

Landolt, i. 7, 337

Lang, i. 399

Langer, i. 226, 459, 462

Langlois, i. 570 ; ii. 257

Latchinoff (_see_ Lachinoff), i. 103, 352

Laurent, i. 28, 196, 388, 471, 526; ii. 7, 9, 10, 117, 292

Laurie, i. 106; ii. 32, 442, 486

Lavenig, i. 140

Lavoisier, i. 7, 29, 49, 114, 131, 155, 379, 459

Leblanc, ii. 8

Le Chatelier, i. 158, 172, 350, 393, 399, 585, 588, 611; ii. 51, 65,

420

Le Duc, i. 131, 170

Lémery, i. 125

Lemoine, i. 501; ii. 155

Lerch, i. 405

Leroy, i. 285

Lesc[oe]ur, i. 103

Leton, ii. 425

Levy, ii. 102

Lewes, i. 371

Lewy, i. 232

Lidoff, ii. 209

Liebig, i. 195, 388, 495, 527; ii. 56

Linder, ii. 223

Liés-Bodart, i. 604, 612

Lisenko, i. 373

Liveing, i. 563, 569

Lockyer, i. 565, 569

Loew, ii. 376

Löwel, i. 525, 600; ii. 45, 284, 286

Loewig, i. 528; ii. 77

Loewitz, i. 96

Lossen, i. 262

Louget, i. 489

Louguinine, i. 360

Louise, ii. 81

Lovel, i. 515; ii. 338

Lubavin, i. 593

Lubbert, ii. 85, 170

Ludwig, i. 463

Luedeking, ii. 194

Luff, ii. 321

Lunge, ii. 244, 246

Lüpke, ii. 157

Lvoff, i. 358

Maack, i. 596

Mac Cobb, i. 612

Mac Laurin, i. 553

McLeod, ii. 180

Magnus, i. 93, 510

Mailfert, i. 199

Malaguti, i. 437; ii. 300

Mallard, i. 172, 393, 588; ii. 4

Mallet, i. 493

Maquenne, i. 349, 620, 621

Marchand, i. 150

Marchetti, ii. 288

Maresca, i. 534

Marguerite, ii. 292

Marignac, i. 198, 233, 428, 430, 453, 454, 518, 525, 600, 601; ii. 6,

9, 95, 101, 194, 197, 198, 199, 234, 239, 241, 244, 292, 293, 295,

357, 440, 486

Markleffsky, i. 273

Markovnikoff, i. 373

Maroffsky, ii. 138

Marshall, ii. 253, 365

Matigon, i. 258, 266

Maumené, i. 258

Maxwell, i. 81

Mayow, i. 17

Mendeléeff, i. 99, 132, 133, 136, 141, 275, 321, 357, 373, 377, 406,

426, 427, 428, 506, 587, 596; ii. 27, 33, 93, 94

Menschutkin, i. 171

Mente, ii. 270

Mermé, i. 462

Merz, i. 505

Meselan, i. 463

Metzner, ii. 189

Metchikoff, i. 44

Meusnier, i. 114

Meyer (Lothar), i. 226, 321, 403; ii. 21, 24, 26, 29, 33, 486

Meyer (Victor), i. 135, 171, 294, 303, 320, 427, 459, 462, 467, 488,

506, 508, 558; ii. 43, 48, 52, 80, 129, 184

Meyerhoffer, ii. 410

Miasnikoff, i. 372

Michaelis, ii. 175

Michel, i. 65, 88

Millon, i. 481, 484, 508

Mills, ii. 20

Mitchell, i. 156

Mitscherlich, i. 428, 527; ii. 1, 5, 8, 156, 184, 311, 313

Moissan, i. 202, 349, 353, 490, 564, 585, 621; ii. 66, 67, 70, 88, 100,

107, 147, 174, 196, 289, 295, 309, 311, 313, 321

Mond, i. 129, 400, 405; ii. 345, 367

Monge, i. 114

Monnier, i. 611

Montemartini, i. 279

Moraht, ii. 384

Moreau, ii. 298

Morel, i. 549

Mosander, ii. 97

Mühlhäuser, ii. 66, 107

Muir, ii. 193

Mulder, i. 515

Müller-Erzbach, i. 103

Müller, i. 427; ii. 425

Munster, ii. 443

Müntz, i. 238, 241, 420, 553

Muthmann, ii. 273

Mylius, ii. 375, 389

Naschold, i. 483

Nasini, i. 496; ii. 156

Natanson, i. 282, 409

Natterer, i. 132, 135, 141, 385

Naumann, i. 399, 408

Nernst, i. 62, 148; ii. 3, 50

Nensky, i. 245

Neville, i. 537; ii. 128, 448

Newlands, ii. 21, 26

Newth, i. 505

Newton, i. 7, 29

Nicklès, ii. 10

Nikolukin, i. 491; ii. 144

Nilson, i. 618; ii. 26, 37, 80, 83, 91, 94, 95, 271, 378, 483

Nordenskiöld, i. 241

Norton, i. 76; ii. 94

Nuricsán, ii. 264

Odling, ii. 52

Offer, i. 99

Ogier, i. 321, 509; ii. 159, 182

Olszewski, i. 139, 569; ii. 491, 497

Oppenheim, i. 506

Ordway, ii. 80

Osmond, ii. 326

Ossovetsky, ii. 137

Ostwald, i. 89, 92, 389, 441, 443

Oumoff, i. 62

Pallard, i. 491; ii. 83

Panfeloff, i. 603

Paracelsus, i. 17, 125, 129, 379

Parkinson, i. 596,

Pashkoffsky, i. 595

Pasteur, i. 44, 241, 242

Paterno, i. 496; ii. 156

Pattison Muir, i. 436

Pebal, i. 315, 484

Péchard, ii. 282, 294, 296, 297

Pekatoros, i. 465

Peligot, ii. 299, 301

Pelopidas, ii. 22, 481

Pelouze, i. 463, 464, 480, 610; ii. 229

Penfield, i. 545; ii. 370

Perkin, i. 558; ii. 244

Perman, i. 537

Personne, i. 75, 506, 537

Petit, i. 584, 586

Petrieff, i. 440

Pettenkofer, ii. 22

Pettersson, i. 618, 619; ii. 37, 80, 83, 91, 197, 484

Pfaundler, i. 445; ii. 241, 430

Pfeiffer, i. 64

Pfordten, V. der, ii. 420

Phipson, i. 596; ii. 59

Piccini, ii. 23, 146, 197, 288, 298

Pici, ii. 57

Pickering, i. 88, 91, 99, 104, 106, 272, 333, 452, 517, 525, 529, 613;

ii. 241, 245, 246, 247

Pictet, i. 81, 129, 137; ii. 31, 241

Picton, ii. 223

Pierre, i. 452, 495; ii. 226, 485

Pierson, i. 93

Pigeon, ii. 377

Pionchon, i. 585

Pistor, i. 399

Plantamour, ii. 5

Plaset, ii. 289

Plessy, ii. 257

Plücker, i. 572

Poggiale, i. 427

Poiseuille, i. 355

Poleck, ii. 296

Poluta, ii. 30

Popp, ii. 232

Potilitzin, i. 96, 97, 98, 445, 486, 499, 502, 509, 612; ii. 29, 357

Pott, ii. 100

Poulenc, ii. 174, 289

Prange, ii. 422

Prelinger, ii. 310

Priestley, i. 17, 154, 159, 297, 379, 402

Pringsheim, i. 465

Prost, i. 98, 486

Prout, i. 31; ii. 439

Puchot, i. 452

Pullinger, ii. 389

Quincke, i. 427, 495

Rammelsberg, i. 430, 510, 525; ii. 26, 161, 485

Ramsay, i. 133, 140, 141, 232, 247, 333, 495, 496, 581; ii. 128, 491

Rantsheff, ii. 20

Raoult, i. 91, 274, 330, 331, 332, 429

Rascher, ii. 85

Raschig, i. 263; ii. 229

Rathke, i. 399

Ray, i. 17

Rayleigh, i. 226, 232, 491

Rebs, ii. 213, 217

Recoura, i. 332; ii. 289

Regnault, i. 40, 53, 54, 90, 93, 131, 133, 297, 443, 495, 584, 587,

588; ii. 50, 208, 238

Reich, ii. 91

Reiset, i. 238

Remsen, ii. 335

Retgers, ii. 157, 158, 180

Reychler, ii. 65

Reynolds, i. 581

Richards, i. 526, 585; ii. 32, 432

Riche, i. 509; ii. 127, 292

Richter, i. 193, 194; ii. 91

Ridberg, ii. 21, 24, 486

Riddle, i. 135

Rideal, ii. 297

Roberts-Austen, ii. 486

Robinson, i. 515

Rodger, ii. 213, 263

Rodwell, i. 17

Roebuck, i. 294

Röggs, ii. 119

Rohrer, ii. 343

Roozeboom, i. 106, 452, 453, 464, 496, 506, 511, 599, 613; ii. 3, 226,

341, 410

Roscoe, i. 80, 100, 101, 379, 452, 463, 485, 486, 568, 572; ii. 26,

194, 196, 197, 297, 303, 485

Rose, i. 436, 437, 518, 525, 608, 612; ii. 8, 230, 235, 248, 281, 363,

428, 485

Rosenberg, ii. 351

Rossetti, i. 428

Rouart, Le, ii. 86

Rousseau, i. 354; ii. 337, 366, 378

Roux, ii. 81

Rudberg, ii. 136

Rücker, i. 142

Rüdorff, i. 91, 428, 598, 601

Rybalkin, i. 455

Sabanéeff, i. 371

Sabatier, i. 284; ii. 66

Saint Edmé, ii. 335

Saint Gilles, i. 431

Sakurai, i. 331

Salzer, ii. 161

Sarasin, ii. 122

Sarrau, i. 140, 142

Saunders, ii. 189

Scharples, i. 576

Scheele, i. 155, 161, 412, 459, 462, 608; ii. 100, 150, 291

Scheffer, i. 453

Scheibler, ii. 292, 296

Scherer, ii. 8

Schiaparelli, ii. 318

Schidloffsky, i. 238

Schiloff, i. 212

Schlamp, i. 332

Schiff, i. 430, 588; ii. 106, 267

Schloesing, i. 238, 239, 240, 553, 610

Schmidt, i. 539

Schneider, i. 89

Schöne, i. 208, 209, 211, 394, 617; ii. 15, 72, 219, 251, 488

Schönebein, i. 198, 202, 208, 212, 509; ii. 228, 463

Schottländer, ii. 447

Schröder, i. 75

Schroederer, ii. 366

Schrötter, ii. 153, 284

Schützenberger, i. 511, 579; ii. 102, 107, 228, 367, 389

Schuliachenko, i. 608

Schuller, ii. 180

Schultz, i. 518; ii. 273

Schulze, i. 98; ii. 215

Schuster, i. 572

Schwicker, ii. 227, 230

Scott, i. 405, 537, 558

Sechenoff, i. 80, 86

Seelheim, ii. 379

Sefström, ii. 197

Selivanoff, i. 476, 507, 508

Senderens, i. 284

Serullas, i. 485

Setterberg, i. 576

Seubert, ii. 27, 83, 343, 442

Sewitsch, i. 372

Shaffgotsch, i. 555

Shapleigh, ii. 95

Shenstone, i. 611

Shields, i. 333

Shishkoff, i. 276; ii. 56

Silberman, i. 120, 172; ii. 259

Sims, ii. 268

Skraup, ii. 346

Smith, i. 271

Smithson, ii. 100

Snyders, ii. 100

Sokoloff, ii. 85, 122

Solet, i. 509

Sonstadt, ii. 443

Sorby, i. 88

Soret, i. 66, 202, 203, 427

Spring, i. 38, 98, 434, 486; ii. 45, 50, 133, 223, 258, 288, 314, 423,

427

Stadion, i. 485

Stahl, i. 16

Stas, i. 7, 233, 379, 428, 498, 581; ii. 420, 434, 485

Staudenmaier, ii. 168

Stcherbakoff, i. 97, 428, 458, 601

Stohmann, i. 359, 360, 396

Stokes, i. 355

Stortenbeker, i. 511

Stromeyer, ii. 47

Struvé, i. 208, 612

Tait, i. 203

Tammann, i. 91, 148; ii. 170, 247

Tanatar, i. 511

Tchitchérin, ii. 21

Terreil, ii. 313

Than, i. 317

Thénard, i. 207, 229, 460, 464, 534, 539; ii. 251

Thillot, ii. 170

Thilorier, i. 385

Thomsen, i. 111, 120, 124, 131, 173, 189, 267, 359, 389, 396, 441, 453,

466, 472, 494, 502, 515, 529, 555, 582; ii. 9, 32, 50, 55, 105, 165,

208, 224, 264, 368, 370, 438, 442

Thorpe, i. 142, 285, 445, 493; ii. 27, 160, 173, 213, 259, 263, 268,

301, 313, 442, 486

Thoune, i. 294, 295

Tiemman, i. 213

Tilden, i. 516

Timeraséeff, i. 170

Timoféeff, i. 78

Tessié du Motay, i. 158

Tissandier, i. 78

Titherley, i. 539

Tivoli, ii. 183

Tomassi, ii. 339

Topsöe, i. 506

Tourbaba, i. 88; ii. 247

Trapp, i. 511

Traubé, i. 312, 611; ii. 270

Troost, i. 64, 274, 281, 320, 409, 414, 500, 538; ii. 80, 83, 102, 147,

156, 254, 379

Tscherbacheff, i. 577

Tutton, i. 543; ii. 160, 174, 412

Umoff, i. 429

Unverdorben, ii. 280

Urlaub, ii. 301

Valentine, i. 17

Van der Heyd, i. 599

Van der Plaats, i. 496; ii. 438

Van der Waals, i. 82, 140

Van Deventer, i. 599

Van Helmont, i. 379

Van Marum, i. 198

Van't Hoff, i. 64, 65, 331, 599; ii. 3

Vare, ii. 55

Vauquelin, i. 114, 619; ii. 7

Veeren, i. 612; ii. 45

Veley, i. 279

Verneuille, ii. 225

Vernon, ii. 151

Vèzes, ii. 391

Viard, ii. 285

Vignon, ii. 126, 131

Villard, i. 106, 296, 297

Villiers, ii. 259

Violette, i. 342, 345

Violle, i. 301

Vogt, i. 611

Volkovitch, ii. 201

Voskresensky, i. 345

Waage, i. 439

Wachter, i. 508

Wagner, i. 357

Wahl, ii. 310

Walden, ii. 57

Walker, ii. 143

Walmer, i. 573

Walter, ii. 256

Walters, ii. 234

Wanklyn, i. 100, 539

Warburg, i. 589; ii. 496

Warder, i. 450

Warren, ii. 102

Watson, i. 527; ii. 169

Watts, i. 526

Weber, i. 280, 583; ii. 83, 129, 131, 186, 230, 233, 234, 249

Weith, i. 502

Weitz, ii. 57

Welch, ii. 425

Weller, ii. 146

Wells, i. 477, 545; ii. 57, 370

Welsbach, ii. 96, 97

Weltzien, i. 204, 595

Wenzel, i. 193

Weruboff (_see_ Wyruboff), ii. 4

Weselski, i. 507

Weyl, i. 255

Wheeler, i. 545

Wichelhaus, ii. 179

Wiedemann, i. 439, 588

Wilhelmj, ii. 315

Willgerodt, i. 508; ii. 29

Williamson, ii. 268

Wilm, ii. 376, 388

Winkler, i. 78, 79, 577, 594, 621; ii. 25, 30, 66, 97, 102, 124, 125,

147, 234, 246, 355, 483

Wischin, ii. 384

Wislicenus, i. 267, 294

Witt, ii. 3

Wöhler, i. 410, 619; ii. 85, 103, 107, 146, 285, 289, 420, 425

Wollaston, i. 8

Wreden, i. 507

Wright, ii. 321

Wroblewski, i. 79, 80, 106, 139, 387; ii. 226

Wülfing, ii. 119

Wülner, i. 91, 572

Würtz, i. 301, 476; ii. 171, 173, 213, 267

Wyruboff, ii. 4, 9

Young, i. 134, 136, 140, 141, 247, 495, 496

Zaboudsky, i. 354

Zaencheffsky, i. 140

Zimmermann, ii. 26, 303, 355, 485

Zinin, i. 276

Zörensen, i. 284

Zorn, i. 295

* * * * *

SUBJECT INDEX

Acid, acetic sp. gr. of solutions of, i. 59

-- arsenic, ii. 181

-- bismuthic, ii. 190

-- boric, ii. 64

-- carbamic, i. 408

-- chamber, i. 294

-- chloric, i. 482

-- chloroplatino-phosphorous, ii. 390

-- chlorosulphonic, ii. 268

-- chlorous, i. 481

-- chromic, i. 208; ii. 282

-- chromo-sulphuric, ii. 288

-- cyanic, i. 409

-- cyanuric, i. 409

-- dithionic, ii. 256

-- ferric, ii. 344

-- fluoboric, ii. 69

-- graphitic, i. 351

-- hydriodic, i. 501, 503, 505, 506

-- hydroborofluoric, ii. 69

-- hydrobromic, i. 80, 503, 505, 506

-- hydrochloric, i. 448, 451, 453

-- hydrocyanic, i. 406, 411

-- hydroferrocyanic, ii. 348

-- hydrofluoric, i. 49

-- hydrofluosilic, ii. 106

-- hydroplatinocyanic, ii. 386

-- hydrosulphurous, ii. 228

-- hydroruthenocyanic, ii. 388

-- hypochlorous, i. 479, 481

-- hyponitrous, i. 265, 294

-- hypophosphoric, ii. 161

-- hypophosphorous, ii. 172

-- iodic, i. 100, 508

-- isethionic, ii. 250

-- metantimonic, ii. 188

-- metaphosphoric, ii. 162, 169

-- metastannic, ii. 131

-- molybdic, ii. 292

-- nitric, i. 268, 272

-- Nordhausen, ii. 233

-- orthophosphoric, ii. 162

-- osmic, ii. 384

-- pentathionic, ii. 257

-- percarbonic, i. 394

-- perchloric, i. 484

-- periodic, i. 510

-- permanganic, ii. 313

-- permolybdic, ii. 297

-- pernitric, i. 264

-- persulphuric, ii. 251

-- pertungstic, ii. 297

-- phosphamic, ii. 179

-- phosphamolybdic, ii. 293

-- phosphorous, ii. 171

-- polysilicic, ii. 117

-- pyrophosphoric, ii. 169

-- pyrosulphuric, ii. 234

-- silenic, ii. 272

-- silicotungstic, ii. 295

-- stannic, ii. 130

-- sulphonic, ii. 249

-- sulphuric, i. 76, 77, 89, 111, 290, 294; ii. 235, 238, 241

-- telluric, ii. 272

-- tetrathionic, ii. 257

-- thiocarbonic, ii. 263

-- thiocyanic, ii. 263

-- thionic, ii. 255

-- thiosulphuric, ii. 230

-- trithionic, ii. 257

-- tungstic, ii. 292, 294

-- vanadic, ii. 196

Acids, i. 185

-- avidity of, i. 389, 442

-- basicity of, i. 387

-- complex, i. 197; ii. 293

-- fuming, i. 102

-- organic, i. 394, 396, 405

Acetylene, i. 372

Actinium, ii. 59

Affinity, chemical, i. 26, 389

Air, i. 131, 231, 233

Alchemy, i. 14

Alcohol, i. 53, 88

Alkali, metals, i. 558, 577

-- waste, ii. 204

Alkalis, i. 186

Allotropism, i. 207

Alloys, i. 537; ii. 128

Alumina, ii. 75

Aluminium, ii. 70, 85

-- bromide, ii. 84

-- bronze, ii. 88

-- carbide, ii. 88

-- chloride, ii. 80, 83

-- double chlorides, ii. 84

-- fluoride, ii. 83

-- hydroxide, ii. 75

-- iodide, ii. 85

-- nitrate, ii. 80

-- sulphate, ii. 82

Alums, ii. 5, 82, 343

Alunite, ii. 80

Amalgams, ii. 58

Amides, i. 258, 406

Amidogen, i. 258

-- hydrate, i. 258

Amines, i. 416

Ammonia, i. 229, 246

-- of crystallisation, i. 257

-- heat of solution of, i. 74

-- in air, i. 240

-- liquefaction of, i. 250

-- salts, i. 254

-- soda process, i. 524

-- solutions of, i. 80, 252

Ammonium, i. 254

-- amalgam, i. 255

-- bicarbonate, i. 527

-- carbamate, i. 407, 408

-- carbonate, i. 407

-- cobalt salts, ii. 359

-- dichromate, ii. 279

-- molybdate, ii. 292

-- nitrate, i. 273, 274

-- nitrite, i. 284

-- phosphates, ii. 167

-- sulphate, ii. 269

-- sulphide, ii. 218

Analogy of elements, i. 573, 578

Anthracite, i. 345

Antimoniuretted hydrogen, ii. 189

Antimony, ii. 186

-- chlorides, ii. 189

-- oxides, ii. 187, 188

-- sulphides, ii. 221

Aqua Regia, i. 467

Aqueous radicle, i. 213

Argon, i. 226, 232; App. III.

Arsenic, ii. 179

-- anhydride, ii. 181

-- sulphides, ii. 221

-- tribromide, ii. 181

-- trichloride, ii. 180

-- trifluoride, ii. 181

Arsenious anhydride, ii. 184

-- oxychloride, ii. 180

Arsenites, ii. 185

Arseniuretted hydrogen, ii. 182

Astrakhanite, i. 59

Atmolysis, i. 156

Atomic theory, i. 216

-- volumes, ii. 33

-- weights, i. 21

Atoms and molecules, i. 322

Barium, i. 614, 617

-- chlorate, i. 483

-- chloride, i. 615

-- hydroxide, i. 616

-- metatungstate, ii. 295

-- nitrate, i. 615

-- oxide, i. 616

-- peroxide, i. 157, 160, 209, 617

-- sulphate, i. 614, 615

Bauxite, ii. 76

Benzalazine, i. 258

Berthollet's doctrine, i. 433

Beryllium, i. 618

-- atomic weight of, i. 325, 618

-- chloride, i. 584

-- oxide, i. 619

Binary theory, i. 195

Bismuth, ii. 189

-- nitrates, ii. 192

-- oxides, ii. 190, 191

Blast furnace, ii. 324

Bleaching, i. 469

-- powder, i. 162, 477

Boiling point, absolute, i. 130

Borates, ii. 63

Borax, ii. 61

Boric anhydride, ii. 64

Boron, ii. 60, 66

-- chloride, ii. 69

-- fluoride, ii. 67, 68

-- iodide, ii. 70

-- nitride, i. 227; ii. 67

-- oxide, ii. 60

-- specific heat of, i. 585

-- sulphide, ii. 62

Bromides, ii. 32

Bromine, i. 494

Bronze, ii. 127

Butyl alcohol, solubility of, i. 75

Cadmium, ii. 47

-- iodide, ii. 48

-- oxide, ii. 48

-- sulphide, ii. 47

Cæsium, i. 576

Calcium, i. 590, 604

-- carbonate, i. 592, 608, 609, 610

-- chloride, i. 237, 612

-- -- crystallohydrates of, i. 613

-- fluoride, i. 491

-- hypochlorite, i. 162

-- iodide, i. 604

-- peroxide, i. 607

-- phosphate, ii. 167

-- sulphate, i. 611

-- sulphide, ii. 220

Calomel, ii. 54

Carbamide, i. 409

Carbides, i. 349, 353

Carbon, i. 338

-- bisulphide, ii. 258

-- molecule of, i. 354

-- oxysulphide, ii. 264

-- tetrachloride, i. 473

Carbonic anhydride, i. 379

-- -- assimilation of by plants, i. 393

-- -- dissociation of, i. 392, 393, 399

-- -- in air, i. 238, 242

-- -- liquid, i. 385

-- -- solutions of, i. 80, 86

-- -- specific heat of, i. 393

Carbonic oxide, i. 396

-- -- and nickel, i. 405

Carborundum, ii. 107

Carboxyl, i. 395

Carnallite, i. 421, 544, 560

Catalytic phenomena, i. 211

Caustic potash, i. 550

-- soda, i. 529

Cements, ii. 122

Cerite metals, ii. 93

Cerium, ii. 93

Chamber crystals, i. 290; ii. 230

Charcoal, i. 343

Chemical change, rate of, ii. 314

-- transformations, i. 3

Chloranhydrides, i. 468; ii. 174, 175, 177

Chlorates, i. 482

Chlorides, i. 455, 466; ii. 31

Chlorine, i. 463

-- compounds, heat of formation of, i. 44

-- crystallohydrates of, i. 464

-- oxides, i. 479

-- preparation of, i. 460

-- solubility of, i. 463

Chloroform, i. 473

Chlorophosphamide, ii. 179

Chloryl compounds, i. 476

Chrome alum, ii. 283

Chromic acid, i. 208

-- anhydride, ii. 280

-- oxide, ii. 284, 285

Chromium, ii. 276, 289

-- chlorides, ii. 285

-- fluorides, ii. 280, 289

Chromyl chloride, ii. 281

Chryseone, ii. 108

Clay, ii. 70

Coal, i. 345

Cobalt, ii. 353

-- dioxide, ii. 366

-- fluoride, ii. 358

Cobaltamine salts, ii. 359

Cobaltic oxide, ii. 362

Cobalto-amine, ii. 359

Cobaltous hydroxide, ii. 358

Cohesion of liquids, i. 52

Coke, i. 345

Collodion cotton, i. 275

Colloids, i. 63; ii. 77, 423

Combination, chemical, i. 3

Combining weights, i. 21; ii. 439

Combustion, imperfect, i. 341

-- heat of, i. 172, 176, 399, 400

Compounds, definite and indefinite, i. 31

-- types of, ii. 10

Compressibility of solutions, i. 88

Conductivity, electro-molecular, i. 389

Contact reactions, i. 163, 290

Copper, ii. 400

-- carbonate, ii. 411

-- complex salts of, ii. 412

-- nitrate, ii. 411

-- nitride, ii. 409

-- sulphate, ii. 413

Corundum, ii. 75

Critical points, i. 141

Cryohydrates, i. 99

Cryoscopic investigations of solutions, i. 90, 332

Crystals, i. 51

Crystalline form, ii. 7

Crystallo-hydrates, i. 102

Crystalloids, i. 63

Cupellation, ii. 417

Cyanides, i. 406

Cyanogen, i. 406, 414

-- chloride, ii. 176

Decomposition, chemical, i. 4

Deliquescence, i. 104

Delta metal, ii. 414

Desiccator, i. 58

Detonating gas, i. 115, 170, 173

Depression of freezing point of solutions, i. 90, 92, 330

Dialysis, i. 63; ii. 114

Diamond, i. 350, 353

Didymium, ii. 93

Diffusion, rate of, i. 63

Dimorphism, i. 610, ii. 178

Disinfectants, i. 245

Disodium orthophosphate, ii. 166

Dissociation, i. 36, 282, 608

Distillation, dry, i. 4, 247, 342

Dust, atmospheric, i. 241

Efflorescence, i. 103

Ekacadmium, ii. 59

Ekasilicon, ii. 25

Electro-chemical theory, i. 195

Electric energy and thermal units, i. 582

Electrolysis, i. 116

Elements, i. 20

-- grouping of, ii. 1

-- typical, ii. 19

Emulsions, i. 98

Energy, chemical, i. 29

Equations, chemical, i. 278

Equivalents, law of, i. 194

Equivalent weights, i. 581

Ethane, i. 366

Ether, critical points of, i. 141

Ethylene, i. 370

Ethyl silicates, i. 104

Euchlorine, i. 484

Eudiometer, i. 169

Expansion, linear, of elements, ii. 31

Explosion, rate of transmission of, i. 171

Explosives, i. 275, 276

Felspar, ii. 122

Fermentation, i. 242

Ferric chloride, i. 558; ii. 340

-- hydrates, ii. 339

-- nitrate, ii. 340

-- orthophosphate, ii. 342

-- oxide, ii. 339

Ferrous chloride, ii. 335

-- sulphate, ii. 335

-- -- solubility of, i. 72

-- sulphide, ii. 210

Flame, i. 177, 179

Fluoborates, ii. 69

Fluorides, i. 491, 493

Fluorine, i. 203, 489

Fluorspar, i. 491

Formula, chemical, i. 151, 326

Freezing mixtures, i. 76

Fuel, calorific capacity of, i. 360

Furnace, electrical, i. 352

Fusco-cobaltic salts, ii. 360

Gadolinite metals, ii. 93

Gallium, ii. 88, 90

Gas, illuminating, i. 361

-- producers, i. 397

Gases, absorption of, i. 348

-- diffusion of, i. 83

-- expansion of, i. 133

-- liquefaction of, i. 134, 135, 137

-- measurement of, i. 78, 300

-- solution of, i. 68, 78, 86

-- theory of, i. 81, 83, 140

Germanium, ii. 26, 124

-- chloride, ii. 125

-- oxide, ii. 125

Glass, i. 123

-- soluble, ii. 110

Glauber's salt, i. 517

Glycols, ii. 117

Gold, ii. 442

-- alloys, i. 446, 447

-- chlorides, ii. 448, 450

-- colloid, ii. 447

-- cyanide, ii. 450

-- extraction of, ii. 444, 445

-- fulminating, ii. 450

-- oxides, ii. 448

-- refining, ii. 446

Graduators, i. 424

Graphite, i. 350, 351

Gros' salt, ii. 393

Guignet's green, ii. 285

Gunpowder, i. 557

Gypsum, i. 593, 611

Halogens, i. 445, 487, 499

Halogen compounds, heat of formation of, i. 494, 502; ii. 32

-- -- boiling-points of, i. 502

Hausmannite, ii. 10

Helium, i. 570; ii. 498

Hemimorphism, ii. 9

Homeomorphism, ii. 8

Homologous compounds, i. 358

Humus, i. 344

Hydrates, i. 109, 185

Hydrazine, i. 258

Hydrides, i. 621; ii. 23

Hydrocarbons, i. 355, 359

Hydrogen, i. 123, 129, 130, 142, 143, 146

-- pentasulphide, ii. 217

-- peroxide, i. 207, 312

Hydrosols, i. 98

Hydroxyl, i. 192, 213

Hydroxylamine, i. 262

Hypochlorites, i. 481

Hyponitrites, i. 294

Imides, i. 258

Indium, ii. 27, 37, 88, 97

Iodates, i. 509

Iodides, ii. 32

-- of nitrogen, i. 507

Iodine, i. 320, 321, 496, 497, 498

-- chlorides of, i. 511

Iodosobenzol, i. 508

Iridious oxide, ii. 382

Iridium, ii. 382

Iron, i. 585; ii. 317, 322

-- and carbonic oxide, ii. 345

-- cast, ii. 325

-- nitride, ii. 346

-- ores, ii. 319

-- sulphate, ii. 335

Isethionic acid, ii. 250

Isomorphism, i. 203, 368; ii. 1, 4, 8

Kaolin, ii. 70

Lakes, ii. 77

Lanthanum, ii. 93

Laughing gas, ii. 297

Law of Avogadro-Gerhardt, i. 309

-- -- Berthollet, i. 445

-- -- Boyle and Mariotte, i. 132

-- -- combining weights, i. 221

-- -- Dulong and Petit, i. 584

-- -- equivalents, i. 194

-- -- even numbers, i. 357

-- -- Gay Lussac, i. 133, 304, 307

-- -- Guldberg and Waage, i. 441

-- -- Henry and Dalton, i. 78

-- -- indestructibility of matter, i. 6

-- -- Kirchoff, i. 568

-- -- limits, i. 357

-- -- maximum work, i. 120

-- -- multiple proportions, i. 109, 214

-- -- partial pressures, i. 82

-- -- periodic, ii. 17

-- -- phases, ii. 410

-- -- reversed spectra, i. 568

-- -- specific heats, i. 584

-- -- substitution, i. 260, 365

-- -- volumes, i. 304

Lead, ii. 134

-- acetate, ii. 137

-- carbonate, ii. 140

-- chloride, ii. 139

-- chromate, ii. 136, 279

-- dioxide, ii. 142

-- nitrate, ii. 139

-- oxide, ii. 137

-- red, ii. 142

-- salts of, i. 491

-- tetrachloride, ii. 144

-- tetrafluoride, ii. 144

-- white, ii. 140

Leucone, ii. 107

Levigation, ii. 72

Light, chemical action of, i. 465

Lime, i. 605

Liquids, boiling points of, i. 135

Lithium, i. 574

-- carbonate, i. 575

Litharge, ii. 137

Litmus, i. 185

Lixiviation, methodical, i. 521

Luteocobaltic salts, ii. 359

Magnus' salt, ii. 392

Magnesia, i. 597

Magnesium, i. 590, 594

-- carbonate, i. 592, 602

-- chloride, i. 602

-- crystallohydrates of, i. 601

-- double salts of, i. 597

-- nitride, i. 595

-- silicide, ii. 102

-- sulphate, i. 600

Manganese, ii. 303

-- nitrides, ii. 310

-- oxides, ii. 306, 307, 308, 313

-- peroxide, i. 159; ii. 305

-- sulphate, ii. 307

Mass, influence of, i. 32, 436

Matches, ii. 154

Matter, primary, ii. 440

-- transmutability of, i. 14

Mercury, ii. 48

-- ammonia compounds, ii. 57

-- basic salts of, ii. 54

-- chlorides, ii. 52, 53, 54

-- compounds, heat of formation, ii. 50

-- cyanide, ii. 55

-- fulminating, ii. 56

-- iodide, ii. 55

-- nitrates, ii. 51

-- nitrides, ii. 56

-- oxides, ii. 53

-- sulphate, ii. 57

-- sulphides, ii. 221

Metalepsis, i. 28, 471

Metalloids, i. 23

Metals, i. 23

-- of alkaline earths, i. 64, 590, 591

-- of alkalis, i. 543

-- displacement of, ii. 427

Methane, i. 360

Moisture, determination of, in gases, i. 40

-- influence upon reaction, i. 403

Molecular volumes, ii. 37

-- weight and boiling point, i. 331

-- -- -- coefficient of refraction, i. 336

-- -- -- latent heat, i. 329

-- -- -- specific gravity of solutions, i. 335

-- -- -- surface tension, i. 334

Molecules, i. 319, 322

Molybdates, ii. 292

Molybdenum, ii. 290

-- anhydride, ii. 291

-- fluo-compounds, ii. 298

-- sulphides, ii. 297

Monophosphamide, ii. 178

Monosodium orthophosphate, ii. 167

Morphotropy, ii. 10

Naphtha, i. 373, 377

Nascent state, i. 33, 145, 146

Neodymium, ii. 97

Nickel, ii. 353

-- alloys, ii. 367

-- and carbonic oxide, ii. 367

-- fluoride, ii. 358

-- hydroxide, ii. 358

-- oxide, ii. 365

-- sulphate, i. 97; ii. 359

-- tetra-carboxyl, ii. 367

Niobium, i. 199; ii. 194, 198

Nitrates, i. 273

Nitres, i. 268, 555

Nitric anhydride, i. 280

-- oxide, i. 286

Nitrides, i. 227, 258, 620

Nitriles, i. 406

Nitrites, i. 284

Nitro-cellulose, i. 275

Nitro-compounds, i. 274

Nitrogen, i. 223, 225, 475

-- chloride, i. 476

-- iodide, i. 507

-- oxides of, i. 267, 280, 284, 294, 295

-- sulphide, ii. 270

Nitro-prussides, ii. 351

Nitroso-compounds, i. 288

Nitrosulphates, ii. 229

Nitrosyl chloride, ii. 176

Norwegium, ii. 59

Occlusion, i. 143

Olefiant gas, i. 370

Organo-metallic compounds, i. 356

Osmium, ii. 372, 382, 384

Osmotic pressure, i. 64

Osmuridium, ii. 383

Oxamide, i. 406

Oxidation, i. 16

Oxides, i. 183; ii. 36

Oxycobaltamine salts, ii. 359

Oxygen, i. 152, 157, 158, 163

-- compounds, heat of formation of, i. 120, 466

Ozone, i. 198, 229

Palladium, ii. 369

-- hydride, i. 143; ii. 380

Palladous chloride, ii. 379

-- iodide, ii. 379

Paracyanogen, i. 414

Paramorphism, ii. 9

Parasulphatammon, ii. 269

Peat, i. 344

Peligot's salt, ii. 281

Percentage composition, i. 326

Perchloric anhydride, ii. 282

Periodates, i. 510

Permanganic anhydride, ii. 313

Permolybdates, ii. 297

Peroxide, chloric, i. 484

Peroxides, i. 159; ii. 15, 23

Perstannic oxide, ii. 133

Persulphates, ii. 253

Petroleum, i. 373

Phenol, solubility of, i. 75

Phlogiston, i. 17

Phosgene gas, ii. 175

Phospham, ii. 178

Phosphides, ii. 157

Phosphine, ii. 158, 160

Phosphonium iodide, ii. 159

Phosphoric anhydride, ii. 161

Phosphorous anhydride, ii. 160

Phosphorus, ii. 149

-- ammonium compounds, ii. 178

-- chlorides, ii. 174

-- fluorides, ii. 173

-- iodides, i. 505, 506; ii. 172

-- oxychlorides, ii. 175

-- sulphides, ii. 213

-- sulphochloride, ii. 213

-- thermo-chemical data for, ii. 153

Phosphuretted hydrogen, ii. 158, 160

Photography, ii. 431

Photo-salts, ii. 432

Plants, chemical reactions in, i. 547

-- and nitrogen, i. 230

Platinic chloride, ii. 377

-- hydroxide, ii. 379

Platino-ammonium compounds, ii. 391

-- chlorides, i. 467; ii. 378

-- cyanides, ii. 386

-- nitrites, ii. 390

-- sulphites, ii. 390

Platinous chloride, ii. 379

Platinum, ii. 376

-- alloys, ii. 373

-- black, ii. 376

-- metals, ii. 369, 375

-- oxide, ii. 378

Poly-haloid salts, i. 545

Polymerism, i. 207, 367

Polysulphides, ii. 217

Potassium, i. 544, 558

-- aurate, ii. 449

-- bromide, i. 550

-- carbonate, i. 549

-- chlorate, i. 161, 482

-- chloride, i. 72, 543

-- chromate, ii. 280

-- cyanide, i. 412, 551

-- dichromate, ii. 278

-- ferricyanide, ii. 346

-- ferrocyanide, i. 346, 412

-- hydrosulphide, ii. 219

-- hydroxide, i. 548

-- iodide, i. 550

-- manganate, ii. 310

-- nitrate, i. 553

-- oxides, i. 559

-- permanganate, ii. 311

-- stannate, ii. 133

-- sulphate, i. 72, 549

-- sulphide, ii. 219

-- telluride, ii. 274

Praseocobaltic salts, ii. 361

Praseodidymium, ii. 97

Proteid substances, i. 224

Prout's hypothesis, ii. 439

Prussian blue, i. 419; ii. 349

Purpureocobaltic salts, ii. 361

Purpureotetramine salts, ii. 361

Pyrocollodion, i. 275

Pyronaphtha, i. 375

Pyrosulphuryl chloride, i. 321; ii. 235

Reactions, chemical, i. 3

-- -- conditions for, i. 34

-- -- contact, i. 39

-- -- endothermal, i. 30

-- -- exothermal, i. 30

-- -- limit of, i. 437

-- -- rate of, ii. 152

Recalescence, ii. 333

Reduction, i. 16

Refraction equivalent, i. 336

Regenerative furnaces, i. 398

Reiset's salts, ii. 394

Respiration, i. 152, 154, 387

Rhodium, ii. 381

Rock salt, i. 421

Roseocobaltic salts, ii. 360

Rosetetramine salts, ii. 361

Rubidium, i. 576

Ruthenium, ii. 372, 382, 384

The Principles of Chemistry, Volume II · 第 13 / 14 章