PHARMACY. 
Distilled acetous acid, in its effects on 
the animal economy, does not differ from 
vinegar, and as it is less pleasant to the 
taste, it is only used for pharmaceutical 
preparations. 
Class II. Alkalina. Alkai.ines, 
The following are the chief preparations 
under this head : 
Carbonas potass®, carbonate of potash, 
prepared kali, mild vegetable alkali, salt of 
tartar. 
Potassa, pure kali, caustic vegetable al- 
kali. 
Potassa cum calce, lime witli pure kali, 
mild caustic, 
Aqua potass®, Edin. aq. kali puri, Eond. 
■water of potash, caustic ley. 
Acetis potass®, Edin. acetite of potash, 
acetated kali, Loud. 
Sulphas potass®, Edin. sulphate of pot- 
ash, vitriolated tartar, vitriolated kali, Lond. 
Sulphas potass® c. suli)hure, Edin. sul- 
phate of potash with sulphur, sal polychrest, 
Lond. 
Sulphuretum potass®, Edin. sulphuret of 
potash, liver of sulpluu-. 
Tartris potass®, tartrite of potash, Edin. 
soluble tartar, tartarised kali, Lond, 
Carbonas sod-®, carbonate ofsoda, Edin. 
prepared natrqn, Lond. 
Phosphas sod®, Edin. phosphate of soda. 
Murias sod®, muriate of soda, sea salt. 
Sulphas sod®, Edin. sulphate of soda, 
natron vitriolatum, Lond. Glauber’s salt. 
Tartris sod®, Edin, tartrite of sod®, na- 
tron tartarisatum, Lond. Rochelle salt. 
Alcohol ammoniatum, Edin. ammoniated 
alcohol, spirit of ammonia, Lond. 
Carbonas ammoni®, Edin. carbonate of 
ammonia, prepared ammonia. Loud. 
Aqua carbonatis ammoni®, Edin, water 
of carbonate of ammonia. 
Aqua acetitis ammoni®, Edin. water of 
acetite of ammonia, spirit of mindere- 
sus. 
Hydro sulphuretum ammoni®, hydro sul- 
plmret of ammonia. 
Liquor volutilis cornu cervi, sal et oleum, 
Lond. spirit oil, and salt of hartshorn. 
Class III. Terrena. Earths, and 
Earthy Salts. 
The following are the preparations chiefly 
in use : 
Murias baryt®, muriate of baryte, Edin. 
Aqua calcis, lime water, Edin. Lond, 
Dubl. 
Carbonas calcis prsparatus, prepared 
chalk, Lond. carbonate of lime, Edin. 
Phosphas calcis, Edin. phosphate of 
lime, burnt hartshorn, Lond. 
Carbonas magnesi®, Edin. magnesia alba, 
Lond. Dubl. carbonate of magnesia. 
Phosphas calcis, Edin. magnesia usta, 
Lond. burnt or calcined magnesia. 
Sulphas alumin® exsiccatus, Edin. dried 
sulphate of alumine, burnt alum, Lond. 
In the Dublin process for making mag- 
nesia there is a mutual decomposition of 
the two salts employed. The potash unites 
itself to the sulphuric acid, while the car- 
bonic acid combines with the magnesia. 
The large quantity of water used is neces- 
sary for the solution of the sulphate of 
potash formed ; and the boiling is indispen- 
sably requisite for the expulsion of a por- 
tion of the carbonic acid, which retains a 
part of the magnesia in solution. Sulphate of 
potash may be obtained from the liquor 
which passes through the filter, by evapo- 
ration. This is not pure, however, but 
mixed with undecomposed carbonate of 
potash j for one hundred parts of crystal- 
lized carbonate of potash are sufficient for 
the decomposition of one hundred and 
twenty-five parts of sulphate of magnesia ; 
and hs the carbonate of potash of com- 
merce contains a larger proportion of al- 
kali than the crystallized carbonate, a still 
less proportion should be used. From these 
quantities about forty-five parts of carbo- 
nate of magnesia are obtained. 
The ablutions should be made with very 
pure water; for nicer purposes distilled 
water may be used, and soft water is in 
every case necessary. Hard water for this 
process is peculiarly inadmissible, as the 
principle in waters, giving the property 
called hardness, is generally a salt of lime, 
which decomposes the carbonate of mag- 
nesia, by compound affinity, giving rise to 
carbonate of lime, while the magnesia 
unites itself to the acid of the calcareous 
salt, by which the quantity of the carbo, 
irate is not only lessened, but is rendered 
impure by the admixture of carbonate of 
lime. Another source of impurity is the 
silica which the sub-carbonate of potash 
generally contains. It is most easily got 
rid of by exposing the alkaline solution to 
the air for several days before it is used. 
In proportion as it becomes saturated with 
carbonic acid, the silica is precipitated, and 
may be separated by filtration. 
The carbonate of magnesia thus prepar- 
ed is a very light, white, opaque substance, 
