1 Always handhold both the stone and the tool that you are sharpening. 2  Sharpening rigs are not necessary for this task. 3  In fact, they can cause problems. 4  Artificial stones can be used with water or oil.ips & Warnings. 1  Always handhold both the stone and the tool that you are sharpening. 2  Artificial stones can be used with water or oil. 3  Stones that are mined from natural quarries need special care when being used.
The cell was first discovered by Robert Hooke in 1665 using a microscope. The first cell theory is credited to the work of Theodor Schwann and Matthias Jakob Schleiden in the 1830s.his discovery is largely attributed to Robert Hooke, and began the scientific study of cells, also known as cell biology. Over a century later, many debates about cells began amongst scientists. Most of these debates involved the nature of cellular regeneration, and the idea of cells as a fundamental unit of life.
He advanced the design of the simple microscope. The compound microscope was invented 40 years before Anton van Leeuwenhoek was born. He used a simple one lens microscope. More: Anton van Leeuwenhoek, (October 24, 1632 -- August 26, 1723) is known as the Father of Microbiology.