1829 .] 
Additional Notice on Cooling Wines. 
303 
The salts employed in producing artificial cold, are saltpetre (shora), sal-ammoniac 
(noskadth), and Glauber’s salt : the latter may be obtained by solution and crys- 
tallisation from the native salt called C,hara nun. 
To produce the greatest effect, the proportions are, to 16 parts of water, five parts 
of saltpetre, five parts of salamtnoniac, and six parts of Glauber’s salt. The salts 
should be finely pounded and quite dry. 
At the temperature of 80”, saltpetre and sal-ammoniac will each, singly, produce 
acold of about 25 degrees, when dissolved in water to saturation; that is to say, water 
at80° will be lowered to 55° by saturating it with either of them. Attlie same tem- 
perature, Glauber's salt will give a cold of 20 degrees. But it must not be supposed 
that the combination of the three salts will produce 25 -f- 25 -f- 20 or "0 degrees of 
cold. The reason of this is, that when water has dissolved a certain quantity of 
one salt, it cannot dissolve as much of a second, or a third salt, as it would do of 
each singly. The greatest degree of cold which can be produced by the three salts 
in combination is about 50 degrees, that is, water at 80° will be lowered in its tem- 
perature to 29°, or three degrees below the freezing point. A much less degree of 
cold, however, is sufficient for every useful purpose. One part of saltpetre, and one 
part of sal-ammoniac, to three parts or measures of water, will produce a cooling 
mixture of 40 degrees ; and throe quarts of this cooling mixture, in a pewter vessel, 
cased with wood, will cool a quart bottle of water or rvine, much beyond what any 
abd&r can effect with saltpetre alone ; and as cold as claret, for example, can be 
made, without destroying the flavour of the wine. The wines which can bear the 
greatest degree of cooling, are champaignc and hock ; and these may be cooled 
down to the freezing point, by the most powerful mixture above mentioned. 
Saltpetre and sal-ammoniac compose the best cooling powder, as they can be re- 
covered by evaporation. But the cheapest mixture is that of saltpetre, and Glauber’s 
salt. We shall presently explain how the latter is to be obtained. The experiment 
to be mentioned in the sequel, was made with the refuse of saltpetre from the Com- 
pany’s refining works at Isliera, which costs three rupees per maund, and with 
Glauber's salt. 
Into a tub, lined with sheet lead, and capable of containing 10 or 12 gallons, four 
gallons of water were poured, at the temperature of 78° ; to this were added seven 
seers of Glauber’s salt, when the water fell to 60*. Seven seers of dry saltpetre in a 
state of powder, were then put in, when the temperature of the mixture became 43*. 
This mixture was capable of cooling five or six bottles of wine ; but the object of the 
experiment being to ascertain in what time a bottle of water placed in a cooling 
mixture, attains its maximum of cold, or how long it may be kept in that state, 
in a proper vessel, such ns above desciibed, only one bottle of water, with a 
thermometer placed in it, was put unto the tub, and examined every quarter of an 
hour, for several hours in succession. It may he proper to mention that the tub 
had a lid fixed to it, to exclude communication with the external air. 
After the first quarter of an ho 
2d quarter, 
3d do. 
4th do. 
5th do. 
6th do. 
7th do. 
From the above, it will be obse 
from 78° to 45° ; and remained stationary at that point for more than two hours. At 
the end of five hours it had risen 10 degrees, viz. from 45° to 55°, and even then 
was 23 degrees colder than what it was at the commencement of the experiment. 
Another experiment was made at the same time in another tub, by keeping the 
coolin'' mixture in a constant state of agitation by means of a churn ; but the only 
effected this, was to bring the water in the bottle to its maximum of cold in a quarter 
of an hour, instead of half an hour, by bringing fresh portions of the cooling mixture 
constantly in contact with it. It is obvious that the same effect will beproduced, whe- 
ther the cooling mixture be driven round the bottle of wine, or the bottle of wine be 
driven about in the cooling mixture, as the abdars do in the Ids : but many peo- 
ple believe that wine is spoiled by too much agitation or shaking. The plan, therefore, 
of agitating the cooling mixture, instead of the wine, has the advantage of cooling the 
wine without disturbing it. But in fact, if the cooling mixture be 35 or 40 degrees 
colder than the fluid to he cooled, no agitation is necessary. It is sufficient to allow 
the bottle to remain in the cooling vessel for an hour. 
45 
8th do. 
45 
45 
9th do. 
46 
45 
10th do. 
46 
45 
11th do. 
47 . 
45 
12th do. 
47 
45 
that in half anhour the water was 
cooled down 
