SECOND REPORT-1882. 
466 
Perchloric acid. —The perchloric acid of Yon Stadion has 
been studied by Serullas and Mitscherlich, the latter of whom 
has shown it to be isomorphous with the permanganic. Serul¬ 
las has shown that the perchlorate of potash may be prepared 
in any quantity by fusing the chlorate and driving off oxygen 
as long as muriatic acid causes a yellow stain when dropped 
on the salt. From an ounce of chlorate heated in a retort till 
four bottles of oxygen gas were given off, Liebig obtained 
three drams and a half of perchlorate; what remains in the 
retort is a mixture of chloride and perchlorate. This is dis¬ 
solved in hot water and allowed to cool, when the perchlorate, 
which is difficultly soluble, is deposited. From this salt the acid 
is obtained by means of fluo-silicic acid. Serullas suggests 
that the insolubility of the salt of potash may render this acid 
useful in separating that alkali from soda. 
Iodic acid. —Iodic acid has also received considerable atten¬ 
tion. Mr. Connell* has established the fact, that iodine may be 
acidified directly by digestion with nitric acid over a spirit lamp 
in a large flask, and washing down the iodine as it condenses on 
the sides of the flask. The process has been repeated by Du- 
flos f, who, from half an ounce of iodine and two ounces and 
a half of concentrated acid, after an hour and a half boiling, 
obtained five drams and a half of iodic acid. This acid from 
its weight must obviously have contained 'water. 
Mr. Connell does not find, after repeated trials, that bro¬ 
mine undergoes any oxidation by a similar treatment with nitric 
acid. 
The process recommended by Liebig is to precipitate the 
iodate of soda by chloride of barium; to every nine parts of the 
precipitate, well washed and dried, to add two of sulphuric 
acid diluted with ten or twelve of water, to boil half an hour, 
filter, evaporate to a sirupy consistence, and expose it to the 
air for several days. Regular transparent crystals are obtained 
to the last drop. 
Test for chlorine in bromides. —M. Caillot 1 proposes the 
chromate of potash as a test for the presence of chlorine in the 
bromides. This salt decomposes the bichloride , but has no 
action on solutions of the bibromide of mercury. The bromide 
to be tested, therefore, is decomposed by a salt of mercury, and 
brought into the state of bibromide of mercury, as, for exam¬ 
ple, by subliming it with sulphate of mercury mixed with a little 
peroxide of manganese,—is dissolved in water and tested with a 
* Jameson 's Journal, 1831, p. 72. 
f Neues Jahrbuch der Chemie, ii. p. 496. 
X Journal de Pharmacie , March 1830. 
