IOWA ACADEMY OF SCIENCES. 
157 
chloric acid, and whatever the concentration hydrogen is 
given off and the acid is reduced as in the case of the 
action of the acid on zinc. 
For the following experiments the ordinary aluminium 
wire of commerce was used. An attempt was made to 
compare, as in the case of zinc, the action of the dilute acid 
on an excess of the metal with the action of an excess of 
the strong acid. In the former case, however, the metal 
dissolved as indicated by the loss of weight was always too 
small by about 5 per cent to account for the hydrogen set 
free and the chloric acid reduced. Determinations of the 
actual amounts of metal in solution and in the residue 
showed that in very dilute acid the metal becomes coated 
with a layer of oxide, which accounts for the above men- 
tioned discrepancy. The ratio of the metal which re- 
placed hydrogen to that which reduced the more dilute 
acid was found to be about 1 to 7, while in the experi- 
ments with the 2 N. acid below the ratio was about 1 to 5. 
In the following experiments the aluminium was com- 
pletely dissolved in 2 N. acid, the hydrogen was collected 
and reduced to normal conditions and the HC1 was titrated 
in the usual way. 
Al. DISSOLVED. H. COLLECTED. HCl. FOUND. Al . TO H . Al . TO HCl . 
(1) .2435 47.8 .1363 .03876 .2027 
(2) .2637 55.4 .1386 .04487 .2210 
In each experiment there was an insoluble residue of 0.7 
milligram. 
Action of Chloric Acid on Iron. 
The treatises of Graham-Otto and hammer quote appar- 
ently from a very old but undesignated work, that zinc and 
iron dissolve in chloric acid with the evolution of hydrogen. 
Schiff* in his correspondence states that Pellagri found that 
iron reduces chlorates, and Tommasi f partially reduced 
copper chlorate with iron. There seem to be no other 
references to the action of iron on either free chloric acid 
or its salts. 
Contrary to the statement mentioned iron dissolves 
readily in dilute or strong chloric acid without the evolution 
* Berichte, 8, 1356. 
td. c.) 
