ON THE ACTION OF NITRIC ACID, ETC. 
225 
The salt may also be procured, by pouring a saturated solu- 
tion of iodide of sodium, on crystals of iodate of soda, and set- 
ting them aside for some days. The crystals will be dissolved 
and replaced by crystals of the new salt. The following for- 
mula is deduced from the results of Professor Penny's 
analysis: Na 5 I 5 12 + 38HO ; or regarding it as a com- 
pound of iodate and iodide, it may be thus represented 
3NaI+ 2Na I+3SHO. 
ART. XL VIII.— ON THE ACTION OF NITRIC ACID ON THE 
CHLORATES, IODATES, AND BROMATES OFPOTASSA AND 
SODA. By Professor Frederick Penny. 
In order to examine the action of nitric acid upon chlorate 
of potassa, a known weight of the salt was mixed in a retort 
with a measured quantity of the acid, and the mixture heat- 
ed on a sand bath ; as soon as it became warm, chlorine and 
oxygen were evolved in a state of mixture, and not of combi- 
nation, and the chlorate slowly disappeared. The solution 
was then evaporated to dryness, and the saline residue was 
found to be a mixture of hyperchlorate and nitrate of potassa, 
in the proportion of three equivalents of the latter to one of 
the former. Professor Penny expresses the reaction that 
occurs, as follows: 
4 (K + Cl + 0«) and 3{N + 5 ) = (K + Cl + 8 ) and 
3(K+N + 6 ) and Cl 3 +0 13 . 
The action of nitric acid on chlorate of potassa differs, then, 
from the action of sulphuric acid on the same salt. With 
nitric acid the salt is decomposed tranquilly, and the chlo- 
rine and oxygen are liberated uncombined; whereas, with 
sulphuric acid these gasses are evolved in a state of combina- 
tion, forming that dangerous explosive compound, chlorous 
VOL. VII — no. in. 29 
