《天工开物·下篇·五金》
凡用金箔黏贴的物件，如果日后破旧不用，可以刮下来用火烧，金质就留在灰里。
凡金箔粘物，他日敝弃之时，刮削火化，其金仍藏灰内。
If an object with gold foil attached to it becomes old and unusable in the future, it can be scraped off and burnt in a fire, and the gold will be left in the ash.