This section is from the book "A Practitioner's Handbook Of Materia Medica And Therapeutics", by Thos. S. Blair. Also available from Amazon: A Practitioner's handbook of Materia Medica and Therapeutics.
Spongia Tosta. Roasted Turkish Sponge. Early in the nineteenth century Girtanner used burnt sponge in the treatment of venereal ulcers of the throat. This contains iodine, bromine, potash, magnesia, and lime salts, and in our books of not many years ago was highly commended. After a time it fell into disuse in regular medicine, but the homeopaths make a strong tincture of it, which they quite unnecessarily dilute and use in croup, throat affections, difficult breathing. and many glandular affections in the 2x and 3X.
Adequate personal experience with the tincture leads me to say that it is probably the best form in which to give small doses of iodine. Its action is similar to the iodized lime so aggressively pushed by the alkaloidal enthusiasts as a remedy in certain types of croup. It is a good remedy, and so also is tincture of burnt sponge. Recently, some of the throat specialists have revived the use of burnt sponge. In doses of 5 to 30 drops of the tincture a pretty prompt manifestation of the effects of iodine can be secured and with very little irritation, and I am inclined to think that the total medicinal content of burnt sponge, as naturally associated, is less irritating and more useful than the separated iodine in the treatment of glandular and throat troubles. This tincture is of very similar composition to the analyses given of the inorganic salts and bases in cod-liver oil, and I have used it to iodize nutritive oils, such as olive oil and peanut oil, and have had very good therapeutic results from them.