Slate pencils were made from a slightly softer type of slate than the writing slate. When it was scraped across the surface, little pieces of the pencil were grated off, leaving a white mark. This meant that pencils were quickly worn to a stump. As they wore down, they were easily lost between floor boards or slipped into a pocket and then lost in the playground. Slates and pencils were used in Victorian schools until the mid-twentieth century, despite concerns about hygiene. Children would often suck the end of their pencil, spreading colds and infection around the classroom. In fact, in England, a School Medical Officer succeeded in cultivating the diphtheria bacillus from the slate pencils belonging to a class