THE GENERAL BLEACHER.
Provide some strong chloride of lime, soak in it strips of printed cotton; take them out, dry them, and you will find them very white, but very rotten, slitting and dropping into holes upon the slightest touch.
The dazzling whiteness of paper is caused by bleaching it with chloride of lime. Thus, if you write on printing paper with common ink, it will fade, because the chloride will destroy the colouring matter of writing ink. It will not, however, change printing ink, as that owes its blackness to charcoal, which is a singularly permanent substance. Blot over a printed page with common writing ink, wash it with chloride of lime, when the blots will disappear, and leave the printing unchanged.