Materials Needed:
1. Large double-bed sheet 91" x 108."
2. Eight clear glasses of water.
3. Plastic "drop" cloth to catch any water.
4. Blackboard and chalk. (Hold a glass of water while talking.)
WATER is extremely important to health. One does not have to travel very far to realize the great advantage that comes in combating disease because of the growth of public health practices of pure water supply and of sewage disposal systems. Several diseases have practically been eliminated since pure water supplies have been regulated by laws.
Regularly bathing the body temple is part of preventive medicine. The external use of hot and cold water on the body often relieves pain, and prevents infection and skin diseases. The external use of water is one of God's most important remedies.
The internal use of water is essential to life. It is now known that under ordinary circumstances we cannot rely on thirst as an adequate indicator that we are drinking enough water to supply our needs. Hikers will be interested to know that research confirms that it is all right, in fact essential, to drink a lot of water on hikes in order to get the best performance from the wonderful human machine God created. Exhaustion occurs more quickly when we are dehydrated.
There are many facts that could be discussed about the distribution of water in the body, but to night we are going to demonstrate only one. (Draw diagram of kidney on board or have a model prepared.)
The body's blood-purification system includes the kidneys, which filter the blood under pres sure, something like when you make cottage cheese by putting the boiled-milk curd and whey into a cloth and squeezing it to remove the thinner liquid. Two of the body's high-speed cleansing organs are the kidneys. Each one has more than a million (write in figures on blackboard) tiny filters called glomeruli. The heart forcefully pumps the blood through the system and to the kidneys; in this way, the blood stream is cleansed under pres sure. The kidneys weigh about five ounces each, and, together, they are as big as the heart.
Remember, each day we lose about three glasses of water in perspiration. Four hundred gallons of fluid recycle through the kidneys per day to purify the blood, and only 0.1 percent of this is passed out. Water is drawn out of the blood to make digestive juices. Our average intake of water in food is about one glass with every 600 calories. The total length of the tiny tubes through which the clean fluid is reabsorbed is about forty-five miles.
These tubes have a surface area that is about sixty square feet. So the absorptive area of the kidneys is about the size of a double-bed sheet. (Unfold and have someone help you hold up the sheet.)
We have eight glasses of water here. First, we are going to try to wash this sheet, which represents the absorptive area of the kidneys, in one glass of water. (You may bunch up the sheet and pour the water over slowly, then hold the sheet up again.)
Well, we didn't drink enough today. Let's try another glass. (Pour another glass.) Now we are getting it a little wet, but we can't do a very good job of washing with this amount of water. (Keep pouring as long as you wish. It is recommended that this demonstration be rehearsed before the public meeting. Be sure to spread a plastic "drop" cloth, which you can buy at a paint store, on the floor before pouring.)
Remember Ellen White says, "In health and in sickness, pure water is one of Heaven's choicest blessings. . . . Drunk freely, it helps to supply the necessities of the system, and assists nature to resist disease." --Counsels on Diet and Foods, p. 419.
