A CURE FOR GOITRE.

Otago Daily Times, Issue 19702, 1 February 1926, Page 10

A CURE FOR GOITRE.

lODINE DISTRIBUTION. NEW ZEALAND SOILS AND WATER. A paper on the distribution of iodine in the soils and natural waters of Now Zealand with comments on its geological role was delivered by Mr C. L. Carter and Professor Benson. The paper recorded the results of geological and chemical interest arising from the researches on the relation between the distribution of iodine and the prevalence of goitre undertaken in conjunction with Professor Hercus. It appeared probable that iodine was primarily derived from igneous rocks and was concentrated in the more acid plutonio rooks which were richest in volatile constituents, and in basic plutonio and volcanic rocka in which it was presumably combined in the mineral apatite. It was thus found in the waters given of! by crystallising acid volcanic rocks, but not in the acid volcanic rocks themselves which had lost their volatile constitutents. _ It was found aboundantly in the soils of basic rocks. The iodine was set free by the weathering of the rocks, and was carried from them by the rivers draining into the sea. Soils which were of a gritty or sandy nature had little power of retaining iodine, but those which contained colloidal or clayey matter, largely hydrous compounds of iron or of aluminium, could absorb and" retain the iodine. There was thus some variation in the amount of iodine in the soils derived from the same type of rock, according to the amount of leaching that the soils hud suffered. Plants, however, might also absorb the iodine in the soil-water, and on decomposing to humus the iodine, now in organio combination, might be added to that in the soil, but in a form that was not soluble and so not removed by leaching —a further cause for* the irregularity in the amount of idoino in the soils derived from any one type of rock. Moreover, marine organisms, and especially seaweeds, absorbed the iodine from the sea water, and their decayed remains were entombed in the sea silts—and the marine fosiliferous sediments were therefore sometimes rich in iodine. The spring waters draining from them contained proportionately to their content of chlorine 500 times as much lodine as did sea water. Again, however, the presence of iodine retaining oolloids in tno soil was important in determining the amount of iodine that it might contain. Sandstones and limestones and unfosiliforous rocka contained little iodine. Gravels on high terraces that had become somewhat weathered might often contain more soluble iodines than similar rocks on low, frequently flooded areas in which the soluble salts could not accumulate.