Sil. There may be some confusion about use of the word gum. In common
parlance gum and glue are synonymous, so gelatine-based adhesives count as
gum. The old carpenters glue was cows foot gelatin. I believe such glues are
still used in making violins and other musical instruments because you can
soften and release the bond by gentle heating when its necessary to take
them apart in order to repair cracks etc. George