Phosphate

Phosphate is a chemical compound that contains phosphorus
and oxygen. It is necessary to the growth of plants and
animals, and has extensive use as fertilizers. Phosphates
are also used in the manufacture of detergents. In these
products, phosphates help remove dirt and soften hard
water. 
There are large amounts of natural phosphates. They occur
in phosphate rocks, mostly combined with the elements
calcium and magnesium. They also occur in the remains of
animals(bone ash) and of plants (vegetable mold). 
Phosphate rock is the chief source of fertilizers
containing phosphates. A soluble fertilizer known as
superphosphate acts much more quickly than the pulverized
rock. It is made by crushing the phosphate rock and
treating it with sulfuric acid. 
Phosphorous is a chemical element that man, animals, and
plants need for normal growth. Phosphorus is also used in
the manufacture of many industrial products, such as plant
fertilizers. Plants absorb phosphorus compounds from the
soil, and human beings and animals eat the plants and other
foods containing phosphorus. Foods that are rich in
phosphorus include egg yolks, milk, fish, and peas. In the
human body, phosphorus compounds are found chiefly in the
bones, brain, and nerves. 

Phosphorus was discovered in 1609 by the German alchemist
Hennig Brand. 

Bibliography:
 
Adams, Melinda. Environmental Science. Redwood City, Ca.:
The Benjamin/Cummings Publishing Company, Inc., 1991.