452 Experiments on the Combination of Acetic Acid 
1 think that if the oil has only absorbed this time 30 parts of 
aci‘] in place of 45, it is owing probably to the acid having be- 
come more aqueous, and therefore less fit for mixing with the 
oil. Of the 100 parts of acetic acid employed for this experi- 
ment, there were six parts which could not combine with the oil. 
This remnant of the acid had acquired a yellow colour: its taste 
was still very acid, and its odour indicated that it contained much 
oil. In fact, when a drop of this acid was put in water, it fell 
to the bottom, and the oil separated and mounted to the sur- 
face. 
In this experiment, the acetic acid and oil formed two com- 
pounds of unequal proportions; one in which there was an ex- 
cess of oil, the other in which there was more acid than oil. It 
appears from this experiment, that 100 parts of oil of lavender 
can absorb 56 parts of acetic acid ; but as the portion of vinegar 
which remains, holds in solution a certain quantity of oil not 
easy to be estimated, it may be concluded that 50 parts of vine- 
gar will saturate 100 of oil, that is to say, one portion of acid 
for two portions of oil. 
Exp. 3.—To know if water could separate acetic acid from 
oil, 50 parts of the compound richest in oil, and 55 parts of 
water, were well shaken together for a long time. It was then 
found that the bulk of the oil was reduced to 35, while that of 
the water had been augmented 15: the oil however was still 
acid ; in fact, it contained three parts of acetic acid. 
Twenty parts of the same compound were shaken with S80 parts 
of water; the oil on settling had lost eight, and the water was 
augmented in the same proportion. In this experiment, the 
water had abstracted from the oil the whole of the acid which 
it contained, and had absorbed also a little oil, since the 20 parts 
of the compound contained but 7°2 of acid, and there was a loss 
of 8. 
When the acetic acid is pure, the oil can absorb it entirely ; 
but if it contains a portion of water, were it only 5 per cent., a 
part will remain which the oil cannot seize upon ; so that the 
part of the acetic acid which does not combine with the oil, 
contains necessarily a greater quantity of water than vinegar 
previous to the operation. 
This property which vinegar possesses, of combining with vo- 
latile oil, ought, not to cause any surprise, for it is well known 
with what facility this acid imbibes the odours of plants. 
Effects nearly similar are,produced when camphor is dissolved 
in nitric acid, and also in acetic acid ; that is to say, the cam- 
phor seizes on the pure part of the acids, and leaves another 
watery portion which was previously combined with the whole 
of 
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