FREEZING, 
ether flrength will freeze at fo high a temperature. From 
this eee however, we muft be underftood to except 
very diluteacid, fuch as to be almoft entirely water. This 
acidulous oe "freezes with a leis degree of cold, and is fe- 
parated into two portions, m rt freezing 
>and afterwards the moft acid part. s be 
the — re pel of the acids. ‘The tempera- 
pai at which v acids freeze have been afcertained 
by fir Charles Bla sae as ouailen 
he fulphuric ae was of the 
ac 
1.454. To oa parts of water b 
certain weights of the above acids, at i: temperatures at 
which the pees froze were obferve 
: Sulphuric acid. 
Water Acid. Freezing point. 
100 10 24+ 
100 + 20 12°.5 
100 25 7°05 
‘Nitric acid. 
Water “Acid. Freezing point. 
100 + ite) . 22° 
_ + 20 10°.5 
a 7. 
Tt appea allo from fir mses oe s ig hele 
that various Seals diffolved in water co ute to lower the 
“freezing point ; and that the ie of vm are fale | is in pro- 
i i ye: arts of water, by weight, 
were added parts of the diffe oe falts as under, andthe 
fens points af the folutions found 
Names of falts. Pr soon Freezing point. . 
Common falt = = 25 4° 
Sal ammoniae - - 20 8° 
Rochelle falt - +50 ar 
Sulphate of magni oo 7 25°.5 
Nitre - “1265 26". 
alee of iron - re 6 28°. 
phate of zinc 33-3 28°% 
. Thefe noe may be cooled ies their re{pective 
freezing points, the fame as. ipiel: and the contact of ic 
ratures. For other ee fee CoNnGELATION, 
boa na a 
ee ae anges of tem- 
perature in the stmofphere allow. anriees a tempera- 
.ture is e seria by chemical u of -c tae 3 
more "properly, by jo “folution of on one body in 
diffolved in r, ice or fnow diffolved in 
nitric and muriatic acids, reduce — temperate of the 
mixtures a great: number , caufe -is, the 
mixture has a larger sa oe hea or would be derived 
from blending the two capacitie ‘the ingredients, and 
takinig a mean ; but this fubject will be agri more pro-- 
perly under the heads of Catoric,. Heat, 
ahrenheit feems ] have Lie the firit Ce made ul 
number s direGted to this point. ‘The z 
experimen 
of e 
of his thermometrical ‘feale is derived from the cold which 
a mixture of equal parts of fnow-and common falt produces; 
a. his 32°, or freezing ag is the sr la a of a mix- 
of ice or {now and water. .Mr. Walker of Oxford has 
profecuted this an. farther than any: 6 = 
i 
-initance, and eafily recovered for further ufe, and isn 
rofive, 
Sulphate of ome - 
cid = - 
The 'refults of his experience are given in two papers in the 
sce aca Pranfaétions for 1795 an 
obje& he ha 
filver without a natural cold. - He fucee eded fo faras ae 
freeze it even 
Fourcroy, Vauquelin ee uyton, gave memoirs on the 
effects of frigorific mixtures in the 2gth volume of the fame 
work, which contains many faés de eferving attention. 
Lowitz’s great improvement was in the introdudtion of 
muriate of lime, an article which unites almoft all the de 
firable properties of an ingredient in 
produces ‘the greateft degree of cold, is cheap in the firft 
ot cors 
eans of this article and fnow, or pounded ice, 
es of mercury have been frozen. In 
1793 Lowitz froze ralbs. of mercury at Peterfburgh ; and 
in 1799 Mr. W. H. Pepys of London, affifted by fome je 
lofophical ccirigaben froze 56lbs. of mercury; 
count of which may be saci in the 3d vol. of the Philo- 
Merc ae - freezing affumes the cryf- 
ntracts in its dimenfions, according to 
Mr. Cavendifh ad of its sen but according to Mr. 
Biddle, it amounts “to sth of the volume. 
The follov mite gives the moft complete and accurate 
lift of aes mixtures aud their effects, that we = haves 
| are the ae aie ef Mr. Walker’s experience. 
ym 
very darge quantiti 
fophical Ma acecwee 
talline form, and co 
Table of Freezing Mixtures. 
Thermometer finks 
{ From 50° to 10°. 
ixture 
Muriate of ammonia - 5 parts 
5 
16 
5 parts 
3 
Water - z - 
i of ammonia - 
Nitr . From so0° to 4° 
Sulphate of foda - 8 eee ead 
Water 16 
ate oe snot ? : part From eae 
Nitrate of ammonia - 1 part 
Carbonate of foda ss - —Ss ‘From 50° to — 7°. 
_ oe - - « J : 
Sulphate of foda - 3 parts , 6 
iluted nitric acid - 2 From 50° to — 3 - 
aiaed of foda 6 parts 
Muriate of ammonia - 4 
Nutr - . From 50° to — 10%. 
Diluted nitric acid - oe 
Ste aay of foda - 6 parts 
Nitrate of ammonia - 5: From 50° to ~ 14% 
Diluted nitric. acid - 4 
Phofphate of foda_- 
Diluted nitric acid = - 
Eade of aden « g parts 
eof. am - 6 : 
Diluted nitric aan - 4 
From 50° ta — 12°. 
pene go’ to — 21% 
es 50° to — rome 
8 parts 
5 
Sulphate 
Musiatic.a 
