Water is absolutely essential to every single form of life; not limited to the fishes. Every living cell – plants and animals alike – depend on this substance.
More than half of the human body is made up of water. Much the same is true of other living things. Without water to drink, human beings would die in a very short time.
The reason every living thing needs a certain amount of water is because the cells, the basic units that make up living things, have water molecules in them. Without water these basic units would be very different and of no use to life as we know it.
In the course of a day, an adult human being takes in about two quarts of water as fluids, and one quart in what we call solid foods, such as fruit, vegetables, bread, and meat. These solid foods are not really dry, since they are thirty to ninety per cent water.
Besides these three quarts that enter the body from outside, about ten quarts of water pass back and forth within the body between the various organ systems.
There are about five quarts of blood in the vessels of the body and three quarts of this is water. This always remains unchanged. No matter how much water you drink you cannot dilute the blood.