( S14* ) 
Art. III . — On the Use of the Thermometer in Distillation^ as 
an AlJcohometer By M. F. Groening. 
M.P . Groentng in Copenhagen, in the course of using an 
apparatus for distilling, invented by himself, made the following 
interesting and useful discovery of the use of the thermometer 
in distillation, as an alkohometer. 
At first he used the thermometer merely for comparing the 
temperature of the interior of the rectifier, with that of the wa- 
ter placed about it. 
After many experiments made with this view, he observed, 
without variation, that the thermometer always rose to a certain 
point, for example 65° Reaumur, before the first drop of the 
distilled liquor appeared ; and, likewise, that it remained at that 
point till about half the fluid in the retort was evaporated, but 
then, by degrees, at first slowly, afterwards more rapidly, rose 
to 8° R. 
This discovery led him to the conclusion, that the phenome- 
non could only depend on the different temperatures of the spi- 
rituous and watery vapours. The former, which comes over 
first, has, as is well known, a lower temperature than the latter, 
which follows after the spirit has been extracted, and thus the 
thermometer is affected by each in succession. 
To reap more benefit from this discovery, at each change of 
the thermometer, he tried the distilled liquor with the alkoho- 
meter, by which means he obtained the following very interest- 
ing result : that as long as the thermometer remained at a cer- 
tain point, the liquor which came over was of ah uniform 
strength, but when the thermometer rose, the liquor grew 
weaker and weaker, till at last mere water came over, namely, 
when the instrument had attained the height of 80° Reamur. 
The following table, constructed from many corresponding 
results, will serve to convey a clearer idea of what has been 
said. 
In a vessel of the capacity of 30 pots (rather more than a 
quart English to each pot), were placed £5 pots of brandy, of 
* We have been indebted for this account of M. Groening’s Alkohometer to 
W. Co Trevelyan, Es^. who translated it from the original Danish.— En. 
