Part 1 of Essay
is a mineral that occurs naturally in almost all foods and water supplies. The ion comes from the element fluorine. Fluorine, the 13th most abundant element in the earth's crust, is never encountered in its free state in nature. It exists only in combination with other elements as a compound. is effective in preventing ....

Part 2 of Essay
.... is the adjustment of the amount of the beneficial trace element fluoride found in water to provide for the proper protection of teeth. Fluoridation has been widely utilized in this country since 1945. It does not involve adding anything to the water that is not already there, since virtually all sources of drinking water in the United States contain some fluoride. Fluoridation is a form of nutritional supplementation that is not unlike the addition of vitamins to milk, breads and fruit drinks; iodine to table sal ....