IOWA ACADEMY OF SCIENCES. 
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be traced, that had apparently come down from treatise to 
treatise to the present time. It seemed, therefore, desirable 
to attempt to make some contribution to the subject, and if 
possible to clear up some contradictions and doubtful points, 
and this seemed the more desirable since chloric acid is one 
of the few strong oxidizing acids, which can be obtained 
in the free state easily and in pure condition, and which is 
fairly stable. 
So far as known to me scarcely any attempt has been 
made to study quantitatively the action of chloric acid on 
metals. It is a highly dissociated acid and it is also a 
strong oxidizing agent. As might be expected, its action 
on metals may take one or both of two courses. It may 
dissolve some metals with the liberation of hydrogen in 
about the same way as hydrochloric acid, and with very 
little oxidizing action ; again, it may act purely as an oxidiz- 
ing agent. The course depends upon the nature of the 
metal in any case and the concentration of the acid. 
Contrary to statements that have been made I do not find 
any metal that dissolves in chloric acid without the reduc- 
tion of at least a small portion of the acid. On the other 
hand, there are several metals that simply disappear in the 
acid and that rapidly and at ordinary temperature, without 
the evolution of any gas whatever. Among these are 
cadmium, copper and iron. 
Most of the chloric acid in the market is far from pure, 
and I have been able to obtain only one sample pure 
enough for use in this work. It was secured from Eimer 
and Amend, and it contained no sulphuric acid, barium or 
free chlorine, and only a trace of hydrochloric acid. This 
supply was some time ago exhausted and the delay in 
importing an additional supply has occasioned in some 
measure the incompleteness of this paper. The acid as 
received show T ed by titration that it contained 211.7 HCIO 3 
per liter, or almost exactly the amount corresponding to 
2.5 normal acid. 
It was very desirable in some of these experiments to 
hasten the action of the acid by heat. Since it is stated in 
the literature that chloric acid in water solution decom- 
