Cords In Glass (Part 1) - Part 2 (553) - Part 3 (613) - Part 4 (668)

Cords (inclusions) are detected by their physical differences from the parent glass. Extensive studies demonstrated conclusively that cords invariably differ chemically from their parent glass, and that it is these chemical differences that cause the more apparent physical ones. This article is primarily a revision of a comprehensive report by the author, written in 1947 at the close of an extensive research program on cords at the Preston Laboratories. An extensive reference list is cited.