This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
This, though not an officinal preparation, is based upon sound principles, and has been found practically useful. in all probability it is the first compound formed, when iodine is taken with, or immediately after, amylaceous food. it is well known that there is a strong disposition, between starch and free iodine, to unite and form a blue compound, insoluble in cold water. This compound is very bland, and almost free from the irritating properties of iodine; and, when taken into the stomach, readily gives up the iodine to the chemical influences there exerted upon it, by which it becomes soluble, and enters the circulation without difficulty. This is proved by the discovery of iodine in the urine, within a short period after it has been thus administered.