46 
ALCOHOL. 
is decomposed, being partly converted into 
water and partly into aether. Now it is evi- 
dent that the alcohol could not have been 
converted into water unless it had contained 
oxygen. 
Y\ hen alcohol, in the state of vapour, is 
made to pass through a red hot porcelain 
tube, it is decomposed completely. Carbu-. 
reted hydrogen gas and carbonic acid gas are 
disengaged; water passes into the receiver, 
and on its inner surface are deposited a 
number of small brilliant crystals, which 
Yauquelin ascertained to be a concrete vola- 
tile oil. The inside of the volatile tube is 
coated with charcoal in the state of a line 
black. This experiment was lirst made by 
Priestley ; but it was afterwards repeated with 
more care, and the nature of the products 
ascertained by the Dutch chemists. 
Alcohol has a strong affinity for water, and 
is miscible with it in every proportion. The 
specilic gravity varies according to the pro- 
portion of the two liquids combined ; but, as 
happens in almost all combinations, the ’spe- 
cific gravity is always greater than the mean 
of the two liquids; consequently there is a 
mutual penetration : and as this penetration 
or condensation varies also with the propor- 
tions, it is evident that the specific gravity of 
different mixtures of alcohol and water can 
only be ascertained by experiment. As the 
spiritous liquors of commerce are merely 
mixtures of alcohol and water in different 
proportions, and as their strength can only be 
ascertained with precision by means of their 
specific gravity, it becomes a point of Very 
great importance to determine with precision 
the proportion of alcohol contained in a spirit 
of a given specific gravity : and as the specific 
gravity varies with the temperature, it is ne- 
• cessary to make an allowance for that like- 
wise. 
The importance of this object, both for 
the purposes of revenue and commerce, in- 
duced the British government to employ Sir 
Charles Rlagden to institute a very minute 
and accurate series of experiments. An ac- 
count of these was published by Blagden in 
the Philosophical Transactions for 1790 ; and 
a set of tables, exhibiting the result of them, 
was drawn up by Mr. Gilpin, who had per- 
formed the experiments, and published in 
the Philosophical Transactions for 1794. 
The following little table, constructed from 
Dr. Thomson’s experiments, wall enable the 
reader to ascertain the proportion of real al- 
cohol and water in mixtures. Suppose alco- 
hol at 0.800 to be pure; then alcohol of 
0.813 is composed of 100 alcohol -j- 2 water. 
'0.818 100 4-4 
0.825 100 + 7.53 or 
93 + 7. 
Alcohol has no action upon sulphur while 
solid ; but when these two bodies are brought 
together both in the state of vapour, they 
combine and form a reddish sulphuret, which 
exhales the odour of sulphurated hydrogen 
gas. This compound contains about 60 parts 
of alcohol and one part of sulphur. The sul- 
phur is precipitated by water. Alcohol dis- 
solves also a little phosphorus when assisted 
by heat. This phosphorized alcohol exhales 
the odour of phosphurated hydrogen gas. 
When a little of it is dropt into a glass of 
water, a flame instantly makes its appear- 
ance, and weaves beautifully on the surface 
of the water. This phenomenon, which is 
occasioned by the emission of a little phos- 
phurated hydrogen gas, can only be observed 
when the experiment is performed in a dark 
room. 
Alcohol has no action upon charcoal, hy- 
drogen gas, azotic gas, the metals, nor upon 
any of the metallic oxides. 
Alcohol dissolves the fixed alkalies very 
readily, and forms with them a reddish co- 
loured acrid solution. It is from this solu- 
tion only that these alkalies can be obtained 
in a state of purity. When heat is applied 
to it, the alcohol is partly decomposed; but 
the nature of the products has not been ac- 
curately ascertained. Ammonia also com- 
bines with alcohol with the assistance of heat : 
but at a temperature somewhat below the 
boiling point of alcohol, the ammonia flies off 
in the state of gas, carrying with it, however, 
a little alcohol in solution. 
None of the earths are acted upon by al- 
cohol. It absorbs about iis own weight of 
nitrous gas, which cannot afterwards be ex- 
pelled by heat. 
Sulphuric acid, nitric acid, and oxymuri- 
atic acid, decompose alcohol; but all the 
other acids are soluble in it, except the me- 
tallic acids, phosphoric acid, and perhaps 
also prussic acid. 
Alcohol is capable of dissolving a great 
many saline bodies. A considerable number 
of these, with the quantities soluble, is exhi- 
bited in the following tables: 
1. Substances dissolved in large quantities. 
Names of the substances. 
Tem- 
pera- 
ture. 
240 parts of 
alcohol dis- 
solve 
Oxysulphat of iron . . . 
* 
Nitrat of cobalt 
54.5 
240 parts 
copper .... 
54.5 
240 
alumina .... 
54.5 
240 
lime 
300 
magnesia . . . 
180.5 
694 
Muriat of zinc 
54.5 
240 
alumina . . . 
54.5 
240 
magnesia . . . 
180.5 
1313 
iron 
180.5 
240 
copper. . . . 
180.5 
240 
Acetat of lead 
113 
copper .... 
Nitrat of zinc decomposed 
iron decomposed 
bismuth decomposed 
2. Substances dissolved in small quantities. 
Names of the substances. 
240 parts of al- 
cohol, at the 
boiling tem- 
perature, dis- 
solve 
Muriat of lime 
Nitrat of ammonia 
Oxymuriat of mercury . . . 
Succinic acid 
Acetat of soda 
Nitrat of silver 
Refined sugar 
Boracic acid 
Nitrat of soda 
Acetat of copper 
Muriat of ammonia ....'. 
Arseniat of potass 
Superoxalat of potass .... 
240 parts 
214 
212 
177 
112 
100 
59 
48 
23 
18 
17 
9 
7 
Names of the substances. 
240 parts of al- 
cohol, at the 
boiling tem- 
perature, dis- 
solve 
N drat of potass 
5 
Muriat of potass 
5 
Arseniat ot soda 
4 
White oxide of arsenic . . . 
3 
Tartrat of potass 
1 
Nitrat of lead 
Carbonat of ammonia .... 
3. Substances insoluble in alcohol. 
Sugar of milk 
Sulphat of potass 
Borax 
soda 
Tartar 
magnesia 
Alum 
Sulphite of soda 
Sulphat of ammonia 
Tartrile of soda and 
lime 
potass 
barytes 
Nitrat of mercury 
iron 
Muriat of lead 
copper 
silver 
siiver 
Common salt 
mercury 
Carbonat of potass 
zinc 
soda 
These experiments were made chiefly by 
Macquer and Wenzel. The alcohol* em- 
ployed by Macquer was of the specific gra- 
vity 0.84b. Wenzel does not give the den- 
sity of his alcohol; but as he compares it 
with that of Macquer, we may suppose it 
nearly of the same strength. As the solubi- 
lity of salts depends upon the strength of the 
alcohol employed, the experiments of these 
chemists must be considered as defective, 
because they have confined themselves to 
one particular density. This defect is in 
part supplied by the following very valuable 
table of Mr. Kirwan’s, constructed from iris 
own experiments. 
Solubility of salts in 100 parts of alcohol of 
different densities. 
Salts. 
Alcohol of 
0.900 
0.872 
0.848 
0.834 
0.817 
Sulphat of soda 
0 . 
0 . 
0 . 
0 . 
0 . 
Sulphat of mag- 
> 
nesia 
1. 
1. 
0 . 
0 . 
0 . 
N itrat of potass 
2.76 
1. 
\ 
0 . 
0 , 
Nitrat of soda 
10.5 
6. 
0.38 
0 . 
Muriat of potass 
4.62 
1.66 
0.38 
0 . 
Muriat of soda 
5.8 
3.67 
0.5 
Muriat of am- 
monia 
6.5 
4,75 
1.5 
Muriat of mag- 
nesia, dried 
at 120° 
21.25 
23.75 
36.25 
50. 
Muriat of bary- 
tes 
I. 
0.29 
0.185 
0.09 
Ditto crystal- 
lized 
1.56 
0.43 
0.32 
0.06 
Acetat of lime 
2.4 
4.12 
4.75 
4.88 
