444 
have expected that he would have fthewn 
us, either that the falt imported into Ame- 
tica from other countries, was procured 
from other and pier fources, or that the 
Chefhire falt, exported from Liverpool, 
contained a larger proportion of thele 
earrhy impurities, than the falt received 
from other quarters. Can the author be 
fo igridrant of the fubje& about which he 
Wiites,'as not to know that falt is pro- 
cured in the lafge way from zo diher 
fources than fea-water, brine-{prings, and 
rock-falt, (or, in fome countries, from in- 
Jand falt lakes, which partake of the na- 
ture of the former fources,) and that the 
Portugal and Mediterranean falt is ob- 
tained by flow evaporatin of fea-water 
alone; whilft the Chefhire-falt is procur- 
ed fiom native brine-fprings and rock- 
falt? In his eagernefs to vilify the falt of 
Britifh manufaéture, he has, with fingular 
inconfiftency, incluced all kinds of {alt in 
the fame indifcriminate cenfure 3. for, 
fince all the fources of manutaétured fale 
contain ‘thefe impurities, and fince the 
author aftributes to thefe impurities an 
imperfection in the power of preferving 
animal.flefh, the fair inference would be, 
not that Liverpoo] falt’ alone muft be 
weak and impure, but that every kind of 
falt is unfit for the prefervation of animal 
food in hot climates, aid is theiefure ‘a 
moft pernicious article of import.” : 
But had the author given himfelf the 
trouble of examining into the compenent 
parts of Chethire falt, he would have dil- 
covered that this very falt, which he fta‘es 
to be neceffarily {o impure, is aldol ex- 
tirely free from thofe earthy falis, which he 
fiat.s to be ‘contained’ in the’ various 
fources whénce* muriate of foda is ex- 
tracted ; and he would have Jearnt, that 
even the rock-falt found in England con- 
fits of pure muriate of foda, combined 
with a certain proportion of argillaceous 
earth,* ‘with fearcely any other eartby ‘or 
faline adm:xture.’: The argillaceous earth, 
being perfectly infolublé in’ water, is com- 
pletely feparated whenthe rock-fal: ‘is dif 
folved ; and if any earthy matter be found 
mixed with the falt afterwards miad:, it. 
can be derived only from the water by 
which the folution is formed. In the na- 
tural brine {prings, which owe their ori- 
* In fixing the duty upon rock-falt to be 
ufed in refineries, Government allows fixty- 
five pounds of rock-falt to the buthel, in- 
ftead of fifty-fix pounds, -as in. wiiitte-falt ; 
this being confidered as the average proper- 
tion of argillaceous-earth mixed with the ~ 
sock-talt, * 
Ox the Manufaédture and Quality of Chefbire Salt. {June 1, 
gin to the waters of the furface finding 
their way through the fuperincumbent 
earth toa ftratum of rock-falt, and dif- 
folving a certain portion of this, (greater 
or lefs as it is more or lefs expofed to their 
aétion,) thé brine contains fearcely any 
more earthy matter than the water did 
previous to its a€tion on the falt, or no 
more than the water of f{prings or rivers. 
It is certainly only by experiment that 
the relative purity of the different falts; 
and of ‘the different’ fources from which 
they are procured, can be afcertained.— 
Such experiments we have, and the fol- 
lowing are their refults : ¢ 
Firft, with regard to the comparative 
purity of the fources whence the different 
kinds of falt are obtained 3 the bay-falt 
is procured entirely from fea-water, and 
the Chefhire falt trom the brine-fprings 
and rock-falt in that part of England.— 
The rock-falt, as we fhall prefently thew, 
contains few other foluble parts than pure 
muriate of foda, and therefore the proper 
fubjeécts for comparifon are’ the Cheshire: 
brine and fea-water. Hh hil Non ns carl 
To our jngenious countryman, Mr, 
William “Henry, whofe chemical know- 
ledge and accuracy’ of refearch are well 
known, we are indebted for ari examina- 
tion of the brine’ from the fprings at 
Northwich. ; debit i 
Examining it by re-agents, he found : 
1. That muriate of barytes gave a 
white precipitate. 5 
z. That there was a precipitation on 
the addition of oxalic-acid/ °° * 
3. That with pruffiate of potafh there 
was no immediate change, but after fome 
hours the brine acquired a blue tinge. 
* 4, That all the alkalies, fixed and vo. 
latile, threw down an abundant white 
precipitate. . “i 
‘ ‘The firft and fecond experiments indi- 
cate fulphate of lime, and ‘the third, ah 
inconfiderable quantity of iron. 
‘All the earths were precipitated from 
two-quarts of brine, by carbonate of pot- 
ath. This precipitate, wafhed and dried, 
weighed two’ hundred grains, and con- 
fitted of a mixture of carbonate of lime 
and carbonate of magnefia, principally the 
former. The muriate of foda in the fame 
quanti'y of brine was 2002, 256 grains.° 
Hence it appears, that ‘a wine-pint of 
the ‘orine contains § oz. 64 gr. or 24.64 
grains, of muriate of foda, together with a 
quantity of earthy falts, which are to be 
coniidered as impurities, and of which the 
mere earthy part, brought tothe ftate ot a 
carbonate, amounts to 50 grains. 
On the other hand, we have an analyfis 
of 
