The history of water filters can be traced to the earliest civilisations with written records. Water filters have been used throughout history to improve the safety and aesthetics of water intended to be used for drinking or bathing. In modern times, they are also widely used in industry and commerce. The history of water filtration is closely linked with the broader history of improvements in public health. Antiquity Ancient India and Egypt Ancient Sanskrit and Egyptian writings document practices that were followed to keep water pure for drinking. The Sushruta Samhita (3rd or 4th century CE) specified various methods, including: boiling and heating under the sun. The text also recommends filtering water through sand and coarse gravel. Images in Egyptian tombs, dating from the 15th to 13th century BCE depict the use of various water treatment devices. Greece Hippocrates conducted his own experiments in water purification. His theory of the four humors of the body led him to believe that the maintenance of good health required that the four humors be kept in balance. He recommended that feverish patients immerse themselves in a bath of cool water, which would help realign the temperature and harmony of the four humors. Hippocrates believed that water had to be clean and pure and he designed a crude water filter to “purify” the water he used for his patients. Later known as the “Hippocratic sleeve,” this filter was a cloth bag through which water could be poured after being boiled. Various methods for masking bad water were used: Diophanes of Nicaea of the first century BC advised putting macerated laurel into rainwater, Paxamus proposed that bruised coral or pounded barley, in a bag, be immersed in bad tasting water. and the eighth century Arabian alchemist, Gerber, described various stills for purifying water that used wick siphons — to transfer water from one vessel to another. Modern history Sir Francis Bacon in his famous compilation "A Natural History of Ten Centuries" 1627 (Baker & Taras, 1981) discussed desalination and began the first scientific experimentation into water filtration. He believed that if seawater was allowed to percolate through the sand, it would be purified of salt. He thought that sand particles would obstruct the passage of salt in the water. Although his hypothesis was proven incorrect, it marked the beginning of a new interest in the field. An experiment of sand filtration was illustrated by the