The first ever toothbrush design, used by ancient Babylonians and Egyptians, dates back to 3500 BC. The primitive toothbrush, known as a 鈥渃hew stick鈥�, was a thin twig with a frayed end. The modern...
When we write the old-fashioned way, with ink on paper, we rarely think of the pen鈥檚 ingredients. For hundreds of years聽gall ink聽was used to produce documents such as Shakespeare鈥檚 will and the U.S...
The green in American paper bills is chromium oxide, a refined version of chromite, a naturally occurring ore in the Earth鈥檚 crust. This ore is also the source of chromium metal which is produced...
