When equal weights of alcohol and sulphuric acid are mixed Sect. III. together without the application of any heat, about one-half of the sulphuric acid is converted into sulphovinic, which (as has been explained in a preceding part of this volume) is a compound of

2 atoms sulphuric acid,

1 atom tetarto-carbo-hydrogen.

When this mixture is distilled ether is formed, and passes over
into the receiver, while the sulphovinic acid disappears. It
would appear from this that the ether originates from the tetarto-
carbo-hydrogen in the sulphovinic acid. This substance, in order
to be converted into ether, requires only to quit the sulphuric
acid with which it was previously combined, and to unite with
an atom of water in its stead. The action of heat seems to
produce this effect in consequence of the great difference
between the volatility of sulphuric acid and aqueous vapour.
The sulphuric acid thus set at liberty acts upon a new portion
of the alcohol, doubtless converting it into sulphovinic acid,
which the heat afterwards decomposes. That this view of the
subject is correct, seems proved by the direct experiments of
Mr. Hennell, who mixed a portion of sulphovinate of potash
with the quantity of sulphuric acid requisite to saturate the pot-
ash, and distilling the mixture, a quantity of ether was obtained.
In preparing ether the ebullition is continued till white
vapours make their appearance, and the smell of sulphurous
acid is perceived. The receiver must then be changed, for no
more ether will be formed unless more alcohol be added to the
acid mixture. If we still continue the heat after changing the
receiver, sulphurous acid is produced abundantly, and a yel-
lowish liquid comes over quite different from ether. If we mix
it with a sufficient quantity of liquid potash, to saturate the
sulphurous acid which it contains, and then apply heat enough
to drive off the little ether which it may contain, what is called
the sweet oil of wine will remain floating on the surface of the
watery liquid. This liquid may be obtained in greater abun-
dance by distilling a mixture of equal volumes of alcohol and
sulphuric acid, and purifying the product by agitating it with
a weak solution of carbonate of potash. Thus obtained it has
a yellow colour, a fragrant smell, a bitterish and pungent taste,
and a specific gravity of 1.060. It does not mix with ether,
but combines with alcohol, and it produces no change on vege-
table blues. Mr. Hennell has shown by satisfactory experi-
ments that oil of wine is a compound of

Olefant gas is an elastic fluid, tetarto-carbo-hydrogen a liquid or solid body: elefant gas is a compound of

* Ann. de Chim, et de Prys, xxxvi. 294.

2 atoms carbon,

2 atoms hydrogen.

While tetarto-carbo-hydrogen is a compound of

4 atoms carbon,

4 atoms hydrogen.

The effect produced by the sulphuric acid on the alcohol is to
separate the olefiant gas from the water with which it was
before in combination. And it is not unlikely that the strong
affinity of sulphuric acid for water may contribute to this effect.
One portion of the sulphuric acid may combine with the olefiant
gas, and another with the water. But the olefiant gas when
thus united to the acid undergoes a farther modification: two
atoms of it are combined together to constitute one atom of
tetarto-carbo-hydrogen. How this new combination takes place
cannot at present be explained, as we have no exact notions
upon what the many different modifications of carbo-hydrogen
at present known depend. But it appears from the experi-
ments of Mr. Hennell that we can extract either ether or alco-
hol at pleasure from sulphovinic acid. When dry sulphovinate
of potash was mixed with the quantity of sulphuric acid neces-
sary to saturate the potash, ether was obtained; but when the
salt, previously dissolved in water, was mixed with the same
quantity of sulphuric acid, and distilled, alcohol was obtained.
In the former case the combination consisted of an atom of
water and an atom of tetarto-carbo-hydrogen, in the latter of an
atom of water and an atom of olefiant
gas. It appears from
this that water and heat have a tendency to convert tetarto-
carbo-hydrogen to olefiant gas.

We cannot easily explain the cause of the oil of wine being formed when the alcohol is greatly diminished. The charry matter formed seems to act upon the sulphuric acid. It probably contains a quantity of tetarto-carbo-hydrogen, which unites with the sulphovinic acid, and converts it into oil of wine.

SECTION IV. OF ACID ETHERS.

The ethers, which I distinguish by the appellation acid, not because they possess acid properties, but because they contain an acid as one of their constituents, are twelve in number, and naturally divide themselves into two sets, namely: those that contain a hydracid or chlorine as a constituent, and those which contain an oxygen acid. The first set comprehends 4 ethers, namely: muriatic ether, chloric ether, hydrobromic ether, and hydriodic ether. The second set consists of 8 ethers, namely:

Sect. IV.

iceno eilen, benzoic ether, formic ather, and malic ether.

fistilling mixtures of alcohol,

a constituent. Somertion of sulphuric acid to

by adding the term ether and which exists in it as

by Mr. Basse. Keep a

in a state of

bent

into a tubulated retort, to ube, plunging into a Woolfe's of alcohol as strong as possible. the retort, in small quantities at a time, 10 parts of the entrated sulphuric acid, allowing the commen aiz to from the bottle containing the alcohol; then distil in a siri lath fill the muriatic acid comes over, keeping the alecke ottle as cool as possible during the process. The alcohol, thus saturated with acid, is put into a retort, and one-half of it distilled over. Agitate this portion with an alkaline lev, and then decant of the ether which swims on the surface: it usually amounts to 21 parts. *

Very little was known of the properties of muriatic ether, till Gehlen published a dissertation on the subject in 1804.† He employed two processes: 1. the action of the fuming liquor of Libavius on alcohol; 2. the process of Basse detailed above. Both of them furnished ether, the peculiar properties of which he has described with accuracy. Thenard published three dissertations on it in 1807.; pointed out the simplest process for

Jour. de Chim. iv, 86.
Mem. d'Arcueil, i. 115, 140, 337.

+ Gehlen's Jour. ii. 206.

obtaining it, examined the effect of chlorides on alcohol, described the properties of muriatic ether in detail, and made a set of experiments to ascertain its constituents. To the dissertations of these two chemists we are indebted for all that we know of this very remarkable substance.

Sect. VI.

The process recommended by Thenard for procuring this Formation. ether is the following: Equal bulks of muriatic acid and alcohol, both as strong as possible, are put into a retort, of such a size as not much more than to hold the mixture. A few grains of sand should be put into the retort, to prevent the violent boiling which might otherwise take place. From the beak of the retort a tube passes into a glass jar, twice the size of the retort, and furnished with three mouths. This jar should be half filled with water, of the temperature of about 70°. Into the second mouth a straight tube of safety is luted, and into the third a tube, which passes into a water trough to receive the gas. When heat is applied, the mixture soon emits bubbles. There passes into the receiver alcohol with acid and water: but the whole of the ether makes its escape in the state of gas, and must be received in proper vessels. From 500 grammes of acid and the same bulk of alcohol, between 20 and 30 litres of ethereal gas are obtained. Or, in round numbers, a mixture of acid and alcohol, weighing about 30 ounces troy, will yield between 1220 and 1830 cubic inches of ethereal gas.

This gas is colourless, it has a strong ethereal smell, and a Properties. sweetish taste. It produces no change on the infusion of litmus, the syrup of violets, or lime water. Its specific gravity is 2-219, that of air being 1. At the temperature of 64° water dissolves its own bulk of this gas.

When exposed to a cold of 52°, it loses its aërial form and becomes liquid ether. It may be procured abundantly in that state by passing it into a dry glass jar surrounded with ice. Muriatic ether, in its liquid state, is colourless like water, very liquid, has no action on vegetable blues, and has the same smell and taste as in the gaseous state. At the temperature of 41°, Thenard found it of the specific gravity 0-874.* It is much more volatile than alcohol, or even sulphuric ether, assuming the gaseous state when not hotter than 64°. None of the usual tests indicate the presence of any muriatic acid. It does not affect vegetable blues, nor give out acid when agitated with an

Basse obtained it of the specific gravity 0·820, and Gehlen of 0.845. Here we must consider weight as a mark of purity. Hence it is obvious that the muriatic ether of the German chemists was less pure than Thenard's.