22 ORGANIC ALKALIES AND IODIDE OF POTASSIUM. 
same properties as the first product, weighing three grains, 
which, added to that, made fifty-seven grains. 
From these results hv is quite apparent that a perfect 
decomposition of the sulphate of quinia and a part of the 
iodide of potassium took place, resulting in an hydriodate of 
quinia and sulphate of potassa. The excess of iodide of 
potassium in the solution is found requisite for the 
success of the process, as a perfect decomposition of the 
sulphate of quinia did not take place when only the 
quantity indicated by the equivalents were used. 
In further proof of the formation of the hydriodate of 
quinia, it was treated with acidulous sulphuric ether and 
exposed, to favor evaporation, when iodine was set free 
and deposited on the upper part of the vessel, and a fioc- 
culent precipitate of the sulphate of quinia appeared in 
the ether. It is decomposed by the strong and dilute 
mineral acids setting the iodine free, as shown by the starch 
test. Similar combinations were formed by means of the 
sulphates of morphia and veratria. The former is in very 
delicate, white, feathery crystals, and the latter in transpa- 
rent yellowish scales. All of these salts are [affected by 
exposure to the direct rays of the sun, the iodine being 
slowly evolved. 
The composition of the hydriodate of quinia may be in- 
ferred, from what has been said, to be a dihydriodate. 
Thus, sixty grains of sulphate of quinia, being about the 
one-seventh of its equivalent, would require one-seventh of 
an equivalent of iodide of potassium, or about twenty-four 
grains, to enable the hydriodic acid to replace the sulphuric. 
As no free potassa or quinia was found in the solution, 
it follows that the whole of the potassium and sulphuric 
acid must have left their original combinations, yielding 
twelve grains, or about one-seventh of an equivalent of 
sulphate of potassa; the hydriodic acid and quinia pre- 
