ETHER 
the vegetable proximate principles, as the 
essential oils, camphor, and resins. It is 
also, as has already been remarked, the 
most powerful solvent of caoutchouc. 
In medicine it is employed as a diffusible 
stimulant. 
Nitric ether. The action of nitric acid 
on alcohol is so violent, that the formation 
of nitric ether is extremely difficult, and 
requires considerable precaution. One part 
of the acid may be added gradually to three 
parts of alcohol without any risk ; and after 
standing for some days, to allow of their 
reciprocal action, heat may be applied, 
When a portion of nitric ether that lias been 
formed distils over, with a quantity of un- 
changed alcohol. A preparation of this kind 
has been long known in pharmacy, under 
the name of sweet spirit of nitre. But when 
the proportion of acid is increased the ac- 
tion becomes very violent; a quantity of 
aerial fluid is suddenly formed, and disen- 
gaged at each addition; and it requires 
particular arrangements to admit of so much 
acid being added as is sufficient to convert 
the whole of the alcohol into ether. 
The method proposed by Navier is, to 
put into a strong earthenware bottle twelve 
parts of alcohol, and immerse it in water or 
ice ; eight parts of nitrous acid are to be ad- 
ded in successive portions, mixing them by 
agitation at each addition ; the bottle is well 
corked, and tied over, and is put in a cool 
place. At the end of six days the cork is to 
be perforated, to allow a quantity of gaseous 
fluid that has been formed, and is retained 
by compression, to escape. The bottle is 
then uncorked, the liquid poured into a 
funnel, and the acid liquor beneath allowed 
to run off from the ether which swims 
above. , 
An ingenious method, somewhat similar, 
but less hazardous, was employed by Dr. 
Black. He first poured into a strong flint 
glass bottle six ounces of alcohol ; then, by 
a funnel, the tube of which reached to the 
bottom of the bottle, he poured in two 
ounces of water gently, so that it did not 
mix with the alcohol, but raised it above it ; 
and, lastly, he poured in four ounces of ni- 
trous acid in the same manner, so that the 
small column of water was interposed be- 
tween it and the alcohol. The phial was set 
aside for some time in a cool place : the water 
attracted the alcohol at the one surface, 
the acid at the other, and thus brought them 
very gradually together, so as to admit of 
their reciprocal action without violence. 
At the end of a few months they were com- 
pletely mixed, and nitric ether formed, 
which floated above, was withdrawn and 
rectified by distillation. 
The theory of the formation of nitric 
ether is as obscure as that of sulphuric 
ether. It is ascertained, however, that 
even from the commencement of the pro- 
cess the acid is decomposed ; nitric oxide 
gas is disengaged ; and Pelletier found that 
the decomposition was complete, nitric 
acid not being discoverable, either in the 
liquor which passed over, dr in the resi- 
duum. 
It is also proved, that in the formation of 
nitric ether the alcohol suffers decomposi- 
tion, as in the residual liquor oxalic and 
acetic acids are formed. There is no de- 
position, however, of carbonaceous matter, 
as there is in the formation of sulphuric 
ether, the residual liquor being quite trans- 
parent, and of a light colour. It appears to 
follow, therefore, from these facts, that in 
the formation of nitric ether part of the 
elements of the alcohol combine with oxy- 
gen from the nitric acid, and form oxalic 
and acetic acids ; carbonic acid gas too is 
formed and disengaged, as Pelletier found, 
in considerable quantity, and much of the 
nitric acid mixed with nitric oxide and ni- 
trogen gases. (Mfmoires de Chimie, tom. i. 
p. 138.) 
It is difficult, however, to determine in 
what manner these facts are to be combin- 
ed, so as to give with precision the theory 
of the formation of nitric ether : nor is it 
very apparent, whether any of the elements 
of the nitric acid enter into its composition, 
or whether they are entirely disengaged 
during the process. It might be supposed, 
that it must contain more carbon than sul- 
phuric ether, as none is deposited during its 
formation; but we are not certain what 
quantity is carried off in the state of carbo- 
nic acid. 
Nitric ether has some resemblance in its 
properties to sulphuric ether. Like it, it is 
light and volatile, and has been said, when 
highly rectified, to have these qualities even 
in a higher degree than sulphuric ether. It 
is also inflammable, burns with an enlarged 
flame, and is said to deposit more charcoal. 
It is soluble in water and in alcohol. Its 
odour is strong, though scarcely so agree- 
able as that of sulphuric ether ; in the state, 
however, of what lias been named dulcified 
spirit of nitre, it is more fragrant. Its co- 
lour is usually yellow ; but this, as well pro- 
bably as some of its other qualities, appears 
rather to be owing to the presence of ffi- 
