354 
MISCELLANY. 
The following are my experiments : 
I dissolved twenty-four parts of neutral hydriodate of potassa, and 
twenty of bisulphate of quinia, each separately, in eight parts of distilled 
water. The solutions having been filtered, I added, drop by drop, that 
of the hydriodate into the liquid containing the sulphate. The mixture, 
after its penetration, acquired a pale yellow tint, which continued during 
some minutes, when the liquid became coloured, and a saffron yellow colour 
was developed ; by minutely observing these changes, I perceived that 
at this moment decomposition took place, and a red powder was deposit- 
ed, similar to that of the carbonate of peroxide of iron. The liquid from 
which the precipitate was separated, became limpid and devoid of bitter- 
ness. I collected the precipitate obtained, and, after having placed it 
upon a filter, I washed it promptly with distilled water, so as to deprive 
it of every particle of sulphate of potassa, which by chance might have 
remained with it; and I dried it in the shade, upon a cloth covered with 
leaves of bibulous paper. 
Explanations of the phenomena, which take place in the decomposition and 
analysis of the compound resulting. 
The first direct action, is that of the sulphuric acid combined with the 
quinia; it acts upon the potassa, and sets the iodine free. This, uniting 
with a portion of quinia, gives origin to iodide of quinia and sulphate of 
potassa; but as the acid in the sulphate is in excess, this decomposes a 
portion of hydriodate still untouched, separates the hydriodic acid, which, 
by combining with the remaining quinia, forms a sub-hydriodate, which 
is precipitated, intermixed with iodide. 
The theory accords with the analysis of the precipitate, the composi- 
tion of which I present. 
Hydriodic acid, 30 
Quinia, 50 
Iodine, 20 
100 
Physico-chemical properties of the compound.. 
The taste of this substance is acrid and bitter. It is little soluble in 
distilled water at the ordinary temperature, but at 60'=' R. it dissolves 
completely, and after some time is decomposed, losing its colour, and 
developing the odour of iodine. The same decomposition takes place 
when the compound is dissolved in water at the ordinary temperature, 
but it then requires more time, and the assistance of the atmosphere. It 
is very soluble in alcohol at 40°, but, by its solution, loses its red colour* 
and takes that of a pale yellow. Diluted sulphuric acid, dropped into 
