‘? 
f 
al 
THE DISCOVERY OF ALCOHOL. 99 
The operators of the Middle Ages finished by finding 
out that they could more rapidly conduét distillation by 
cooling the cap and the pipe which led to the final recep- 
tacle. To this end, they first placed around the cap a’ 
bucket filled with cold water. This facilitated condensa- 
tion bnt caused a portion of the liquified vapour to fall 
back intothe boiler. A fresh improvement which PORTA 
describes, consisted in bending the pipe between the cap 
and the receiver so as to give it the form of a serpent 
(anguineos flexus). ‘Thus came into existence our 
“worm” and it was surrounded with cold water con- 
tained in a wooden vessel. The modern alembic was 
thence constructed. Nevertheless the use of the worm 
spread but slowly, and the invention was regarded by 
the writers of the 18th century as of recent origin. 
Such is the successive progress made in the middle 
ages in the construction of apparatus for the distillation 
of liquids. . 
Let us here observe that in the present article, the word 
distillation is understood in the modern sense of 
evaporation followed by condensation of liquids: but 
with many of the authors of the middle ages it had a 
wider meaning. In faét, the word in a literal sense, 
Signifies flowing drop by drop, and is also applied to 
filtration and indeed to any refinement or purification. 
The word ‘ distil’ even in modern language is sometimes 
used in this sense. 
Nor is this all—it comprised formerly in the Greco- 
Egyptian ages two distinét operations, namely, the con- 
densation of moist vapours such as water, alcohol, 
and essences; and the condensation of dry vapour ina 
solid form, such as metallic oxides, sulphur and metallic 
N2 
