80 REPORT—1840. 
same as upon chlorate of potassa. The chlorine and oxygen set free 
are in’a state of mixture, and every 4 atoms of chlorate yield 3 of ni- 
trate and 1 of hyperchlorate. The hyperchlorate of soda is a very 
soluble salt, and crystallizes in small rhombs. It is readily decomposed 
by heat, but is unacted upon by hydrochloric acid. It deliquesces by 
exposure to the air. The action of nitric acid on an iodate is very 
different from that on a chlorate, and is well illustrated in the case of 
iodate of potassa. When iodate of potassa is boiled for some time 
with a large excess of nitric acid, it is decomposed into potassa and 
iodic acid; the potassa combines with its proportionate quantity of 
nitric acid, forming the nitrate, and the iodic acid is deposited from 
the solution in minute, hard, and transparent crystals. If the acid so- 
lution of nitre, containing the iodic acid, be then evaporated, a re- 
action takes place; the iodic acid decomposes half of the nitre, sets 
free its nitric acid, and combines with the potassa, forming the binio- 
date. This change is completed when the mixture is dry, and if the 
heat be then withdrawn a definite mixture of biniodate and nitrate is 
obtained. If the heat be continued, a still further change occurs, the 
iodic acid expels the whole of the nitric acid, which is evolved as 
nitrous acid, and oxygen and neutral iodate of potassa remain. By 
adding a fresh portion of nitric acid to this iodate, the same changes 
may be produced by a proper regulation of the temperature. By act- 
ing upon iodate cf soda with nitric acid, Prof. Penny has obtained a 
biniodate of soda, and by adding a considerable excess of iodic acid to 
a solution of iodate of soda he has found a teriodate of soda. Both of 
these salts are anhydrous. The biniodate of potassa contains 1 atom 
of water. He also finds that crystals of iodate of soda contain differ- 
ent quantities of water, according to the strength of the solution from 
which they have deposited. From a hot and strong solution this salt 
crystallizes in acicular tufts, and these crystals contain 2 atoms of 
water. Ifthe solution be rather weak, long four-sided prisms are ob- 
tained, and these contain 6 atoms of water. If a solution of iodate of 
soda be evaporated spontaneously, large irregular prisms deposit, and 
these contain 10 atoms of water. They effloresce rapidly by exposure 
to the air, and lose in this way 8 atoms of water. The action of nitric 
acid upon bromate of potassa was next examined, and was found to 
differ remarkably from the actions of this acid on the chlorate and 
iodate. Neither hyperbromate nor bibromate is produced, but merely 
nitrate of potassa. ‘The nitric acid sets free the whole of the bromic 
acid, and this, at the moment-of its liberation, is resolved into its ele- 
ments, bromine and oxygen. In conclusion, the author remarks that 
the action of nitric acid on these three classes of salts affords a ready 
method of distinguishing them from one another. 
On a New Salt obtained from Iodine and Caustie Soda. By Professor — 
Frep. Penny. 
While examining the action of iodine on carbonate of soda a salt 
was obtained, which crystallized in regular six-sided prisms, and which 
