THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[April 13, 1872. 
824 
to be evolved, leave an alkaline residue, which re¬ 
quires for neutralization 100 cubic centimetres of 
the volumetric solution of oxalic acid.] 
KNaC 4 H 4 0 6 4H 2 0 represents a molecule of the 
salt weighing 282; on ignition it gives a molecule of 
sodic potassic carbonate, KNaCO s , weighing 122. 
A twentieth of that quantity, 14T, taken in grams, 
would therefore leave OT grams of the alkaline car¬ 
bonate, a quantity which exactly neutralizes 100 
cubic centimetres of the standard solution of oxalic 
acid. 
Sodas Acetas, NaCH 3 0 2 3 H 2 0.— A salt pre¬ 
pared by neutralizing pyroligneous acid with car¬ 
bonate of sodium, and purified b}^ heating the diy 
salt and subsequently recrystallizing. 
Sodas Arsenias, Na 2 HAs0 4 , ?H 2 0.— [See 
Acidum Arseniosum.] 
Sodas Bicarbonas, NaHC0 3 .—This compound 
is manufactured in large quantity by exposing soda 
crystals to the action of carbonic acid gas. As the 
bicarbonate is formed, the water of crystallization 
drains away, saturated with carbonate of sodium, 
and the white pulverulent substance which finally 
remains has only to be rinsed with a little pure 
water and dried. The Pharmacopoeia employs a 
mixture of carbonate and dried carbonate of sodium, 
in order that the salt may not become too wet on 
exposure to the action of the gas. 
Na 2 C0 3 + H 2 0 + C0 2 
= NaHC b 3 + NaHC 0 3 . 
[§ A solution of the salt in cold water gives a 
white, and not a coloured precipitate, (mercuric oxi- 
cliloride), with solution of percliloride of mercury.] 
This test is intended to show the absence of the disodic 
carbonate, but is somewhat uncertain in its action. 
Soda: Carbonas, Na 2 C 0 3 .10H 2 O.— [§ Ob¬ 
tained from the ashes of marine plants, or produced 
by chemical decomposition from chloride of sodium.] 
The whole of the “ soda ” used in this country is 
from the latter source. The salt is mixed in muffle¬ 
like furnaces, with an equivalent of sulphuric acid, 
and the hydrochloric acid, which is expelled by a 
gradually increased temperature, is condensed by 
passing it through water. The decomposition which 
occurs, may be represented as passing through two 
cfq ffPQ * - - 
I. NaCl + NaCl -f H o S0 4 
= NaCl + HC1 + NaH S0 4 . 
II. NaCl + NaHS0 4 = HC1 + Na 2 S0 4 . 
The sulphate of sodium which is thus obtained, 
and is called salt-cake, is next mixed with small 
coal and carbonate of calcium, and roasted till in¬ 
flammable gases ceases to be evolved. By this ope¬ 
ration the sulphate is deoxidized by the combustible 
matters of the coal, and the sulphide of sodium which 
is formed effects a double decomposition with the car¬ 
bonate of calcium:— 
Na 2 S0 4 + C 4 + CaC0 3 
= CaS + 4CO + Na 2 C0 3 . 
A certain amount of the carbonate of calcium is 
simultaneously converted into oxide by loss of C 0 2 , 
so that, on lixiviating the “ black ash ” with tepid 
water, the resulting solution contains not only car¬ 
bonate, but hydrate of sodium. The sulphide of 
calcium is left in the insoluble residue. 
To obtain crystals the liquor is evaporated down, 
and the salt which separates, calcined and recrystal¬ 
lized. The caustic soda is recovered by evaporating 
the crude liquor from black ash till the crystallizable 
salts are all deposited, then continuing the evapora¬ 
tion with addition of a small quantity of nitrate of 
sodium, which destro} T s the cyanides and sulphides 
present. The concentrated liquor is then run into 
sheet-iron casks, where it solidifies. Carbonate of 
soda of commerce is generally called simply “ soda 
it occurs in large efflorescent, strongly alkaline 
crystals. [§ By heat it undergoes aqueous fusion, 
and then dries up, losing sixty-three per cent, of its 
weight.] The residual dry salt constitutes Soda. 
Carbonas Exsiccata, B. P. Dry carbonate of sodium 
for analytical purposes is obtained in a purer state 
by heating the bicarbonate. 
Soda Citro-Tartras Effervescens. —A mixture 
of bicarbonate of soda and tartaric and citric acids 
when subjected to a gentle heat readily aggregates 
from the liquefaction of the acids. A certain vari¬ 
able amount of C0 2 is then expelled, but the greater 
part of the carbonate remains undecomposed, the re¬ 
action being completed only when the preparation is 
dissolved in water. 
{To be continued.) 
THE SO-CALLED AFRICAN SAFFRON. 
BY PROFESSOR JOHN M. MAISCH. 
Nearly a year ago, my friend A. E. Ebert sent me 
a sample of what had been offered in Chicago under 
the name of African saffron, and was in the hands 
of an agent of a New York house. I also procured 
from Breithaupt and Wilson, New York, a sample 
under the same name, and found the Chicago and 
New York so-called African saffron alike, namely, to 
be the florets of Carthamus tinctorius, Cir., the well- 
known safflower or dyers’ saffron, but more broken 
than what we usually see under this name and that 
of American saffron; it is likewise more discoloured. 
This plant is originally indigenous to the East Indies, 
but is very extensively cultivated in Western Asia, 
Southern Europe, and Northern Africa, particularly 
Egypt. Whether this so-called African saffron was 
really imported from Africa or not, I have no means 
to ascertain; but it is not improbable that, with the 
staple drugs regularly shipped from Alexandria, 
Egypt, this lot of Carthamus may have likewise 
been exported in consequence of the failing supply 
from Europe and other places. 
Through the kindness of Messrs. M‘Kesson and 
Robbins, New York, I obtained three samples of so- 
called African saffron, two of which likewise proved 
to be Carthamus ; one of these samples was on hand 
in New York, and offered at $3.50 per pound; the 
other, the better quality as far as could be judged 
from the small samples, was, previous to its arrival, 
offered at 75 cents per pound. 
The third of these samples, representing thirty 
pounds, held in London, England, and for which 
offers were solicited, was not Carthamus; it consists 
of the corollas of a plant probably belonging to the 
Natural Order <S 'crophulariacece, which in their dried 
condition are of a dirty greenish-brown colour: they 
are about one inch long, the tube being about one- 
tentli inch in diameter, and three-quarter inch in 
length, inflated in the throat and smooth, the limb 
somewhat bilabiate, one sterile stamen, with the 
filament nearly free, the fertile stamens didynamous. 
Infused in cold water, they impart an intense yellow 
