118 On Freezing of Alcohol. 
Moreover, two other instances have occurred within 
my knowledge, of a similar nature; in one of which, 
it was asserted by two French chemists of the first ce- 
Iebrity, (Messrs. Fourcroy and Vauquelin,) that they had 
produced an incalculable degree of cold, and had frozen 
spirit of wine, by means of muriate of lime and snow. 
Now it happened that at that time a paper of mine had 
been recently published in the Philosophical Transac- 
tions, in which I had demonstrated the extreme limit of 
cold which could be produced by the means above men- 
tioned, and had prosecuted the subject considerably further, 
by having resort to other means, and which degree of cold 
was still measured by a spirit of wine thermometer. The 
other was an experiment of M. Van Mons, in which it was 
asserted, that by means of the combined powers of muriate 
of hme and caustic potash, a cald of —87° had been pro- 
duced. I made several attempts, with the atmost attention 
and patience, to repeat this experiment, but without suc- 
cess. It is proper to add that each of these has passed 
away, and has been no more heard of, 
I beg leave to mention these circumstances, merely as 
an apology, or rather as a reason why I shall continue ta 
mark or notice —91° as the greatest degree of cold yet 
known, until various circumstances, apparently to me of 
an unsatisfactory nature in the present instance, shall have 
been removed. 
The circumstances I allude to, as requiring further elu- 
cidation, in order to remove from my mind all doubt, are 
these : First, it is asserted that this new method, with which 
ve are not made acquainted, possesses the power, in the 
author’s opinion, of producing an unlimited degree of gold. 
Secondly, it is vaguely stated, that the a/cohol froz Ze, as Wag 
believed, at —110°, without noticing any intermediate de- 
gree Baciled ly reached before congelati ion took place, and 
that the apparent irregularity in the temperature, at the 
time of freezing, was ‘attributed to the contraction of the 
alcohol; whereas it is well known that water, and mix- 
tures of spirit and water, as far as experiments had gone 
before, expan id or dilaie, that is, occupy a larger space than 
before, on freezing. 
Thirdly, from the description given of the alcohol, when 
frozen; viz. that it separated into three strata; the upper- 
most of which is said to be of an oily nature, and supposed 
to be that which communicates the flavour to alcohol; the 
lowerniost, presumed to be the alcohol, consisting of a liquid 
neatly tasteless; and a middle stratum, of which we have 
no account whatever. If 
