THE CURE FOR ALL DISEASES
tect as little as 100 fg/ml (femtograms per milliliter). A milliliter
is about as big as a pea, and a femtogram is
1/1,000,000,000,000,000th (10-15) of a gram!
- Rinse the glass cup measure with filtered water and put one
 half teaspoon of table salt in it. Fill to one cup, stirring with
 a plastic spoon. What concentration is this? A teaspoon is
 about 5 grams, a cup is about 230 ml (milliliters), therefore
 the starting concentration is about 2½ (2.5) gm per 230 ml,
 or .01 gm/ml (we will discuss the amount of error later).
- Label one clean plastic spoon “water” and use it to put nine
 spoonfuls of filtered water in a clean glass bottle. Use
 another plastic spoon to transfer one spoonful of the .01
 gm/ml salt solution in the cup measure to the glass bottle,
 stir, then discard the spoon. The glass bottle now has a 1 in
 10 dilution, and its concentration is one tenth the original,
 or .001 gm/ml.
- Use the “water” spoon to put nine spoonfuls of filtered
 water in bottle #2. Use a new spoon to transfer a spoonful
 of salt solution from bottle #1 to bottle #2 and stir briefly
 (never shake). Label bottle #2 “.0001 gm/ml”.
- Repeat with remaining bottles. Bottle #13 would therefore
 be labeled “.000000000000001 gm/ml.” This is 10-15
 gm/ml, or 1 femtogram/ml.
- Do the skin test with water from bottle #13 as in Lesson
 Five. If you can detect this, you are one hundred times as
 sensitive as an ELISA assay (and you should make a bottle
 #14 and continue if you are curious how good your
 sensitivity can get). If you can not, try to detect water from
 bottle #12 (ten times as sensitive as ELISA). Continue until
 you reach a bottle you can detect.
Calculate the error for your experiment by assuming you
could be off by as much as 10% when measuring the salt and
