NEW METHOD OF niErARING IODIC ACID. 
49 
ART. X— NEW METHOD OF PREPARING IODIC ACID. 
By Lewis Thompson, Esq. 
Put one atom or 126 grains of iodine, into a proper bottle, 
with 24 ounces of water, and pass chlorine previously washed 
in cold water through the mixture, until it shall have become 
colourless; set the solution aside for an hour, then heat it to 
212° Fah. to disengage the uncombined chlorine, and add 2i 
atoms or 295 grains of recently precipitated oxide of silver, 
boil the whole for ten minutes, filter and evaporate carefully 
to dryness. The product is pure anhydrous iodic acid. 
Mr. Thompson concludes, from the above process, that 
there is no such acid as the chloriodic, the acid so called being 
in fact merely a chloride of iodine, which when dissolved is 
converted into muriatic and iodic acid and a variable quantity 
of iodine. He has never been able to unite chlorine and iodine 
in the proportions necessary to form these acids without the 
intervention of water, and an excess of iodine, but he believes 
it may be effected in a sufficiently reduced temperature. In 
one experiment, 50 grains of iodine were combined with 41.5 
cubic inches or about 30 grains of chlorine; the substance thus 
formed, when put into a large quantity of water and exposed 
for some days to the sunshine, deposited 8 grains of iodine, 
and became of a pale yellow colour. Mr. Thompson is con- 
vinced that the muriatic and iodic acids exist ready formed 
in the solution, not only from the taste and smell, but be- 
cause he obtained free muriatic acid from it by distillation, 
although, when this was continued until the solution became 
a good deal concentrated, these acids reacted on one another 
producing chlorine and iodine. 
The iodate of ammonia, he states to be a highly crystalline 
granular powder, possessing but little solubility; it is prepared 
by saturating the solution of the muriatic and iodic acids with 
ammonia, when it falls down leaving the muriate in solution. 
He finds that the iodic acid is decomposed by sulpho-cyanic 
VOL. III. NO. I. 7 
