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SELECTED ARTICLES. 
tion is essentially of the same nature, but the sur-oxidation of 
the iron takes place slowly on account of the sugar which 
Griffith has introduced into his formula, relying certainly 
upon the obstacle it would present to the absorption of 
oxygen. 
In a formula very similar to the preceding, other practi- 
tioners have substituted the bicarbonate for the carbonate of 
potassa; there result, in consequence, marked changes in the 
nature of the medicine. When two solutions are mixed, one 
of sulphate of iron, the other of bicarbonate of potassa, a pre- 
cipitate is obtained, similar to that which is furnished by the 
simple carbonate, but it is less abundant; the nature of the 
supernatant liquid is entirely different; it contains protoxide 
of iron in abundance, doubtless in the state of double carbo- 
nate. 
An analogous action is produced when a pillular mass pre- 
pared with the same ingredients is dissolved in water; but 
these pills like the others, soon experience the destructive 
effects of the atmosphere, they are hardly made before a 
greenish tint announces a change, and very soon an ochreous 
color pervades the whole mass. We have examined a mass 
which has been left for five days under the form of a cake, 
a line thick, and have found that the protoxide of iron had 
entirely disappeared; with water, a colorless solution was af- 
forded which contained but small quantities of iron. 
A more successful administration of carbonate of iron results 
from the solution of this salt by carbonic acid, either in the na- 
tural or artificial mineral waters; the last, in consequence of the 
great excess of acid with which they are charged, more com- 
pletely secure the solution of the carbonate; but those who are 
well acquainted with these kinds of preparations, know also with 
what difficulty the iron is prevented from oxidation, and have 
witnessed its transformation into a peroxide; the carbonic acid 
can no longer hold it in solution, it precipitates in reddish 
flocculi. This effect is inevitable, when the bottles have been 
uncorked and the atmospheric air has had access. 
Next in order comes the formula published two years since 
