Permanent Staining with Iodine Vapor

Sections of cooked rice have been stained with iodine vapor, and the method has given greater permanency than any heretofore reported. The method, which permits the use of a counter-stain, has been applied also to starches, starch pastes, uncooked rice flour, and cooked rice flour. The resulting color is of moderate intensity, so that structure is revealed and the birefringence of ungelatinized starch is not impaired. Preparations made more than a year ago have retained their characteristic blue or lavender color.