380. The bare ends of the two wires leading to your electric
lamp should never be allowed to touch each other.

CHAPTER NINE

MINGLING OF MOLECULES

SECTION 41. _Solutions and emulsions._

How does soap make your hands clean?

Why will gasoline take a grease spot out of your clothes?

If we were to go back to our convenient imaginary switchboard to turn
off another law, we should find near the heat switches, and not far
from the chemistry ones, a switch labeled SOLUTION. Suppose we turned
it off:

The fishes in the sea are among the first creatures to be surprised
by our action. For instantly all the salt in the ocean drops to the
bottom like so much sand, and most salt-water fishes soon perish in
the fresh water.

If some one is about to drink a cup of tea and has sweetened it just
to his taste, you can imagine his amazement when, bringing it to his
lips, he finds himself drinking tasteless, white, milky water. Down
in the bottom of the cup is a sediment of sugar, like so much fine
gravel, with a brownish dust of tea covering it.

To see whether or not the trouble is with the sugar itself, he may
take some sugar out of the bowl and taste it,--it is just like white
sand. Wondering what has happened, and whether he or the sugar is
at fault, he reaches for the vinegar cruet. The vinegar is no longer
clear, but is a colorless liquid with tiny specks of brown floating
about in it. Tasting it, he thinks it must be dusty water. Salt,
pepper, mustard, onions, or anything he eats, is absolutely tasteless,
although some of the things _smell_ as strong as ever.

To tell the truth, I doubt if the man has a chance to do all of this
experimenting. For the salt in his blood turns to solid hard grains,
and the dissolved food in the blood turns to dustlike particles. His
blood flows through him, a muddy stream of sterile water. The cells of
his body get no food, and even before they miss the food, most of the
cells shrivel to drops of muddy water. The whole man collapses.

Plants are as badly off. The life-giving sap turns to water with
specks of the one-time nourishment floating uselessly through it. Most
plant cells, like the cells in the man, turn to water, with fibers
and dust flecks making it cloudy. Within a few seconds there is not
a living thing left in the world, and the saltless waves dash up on a
barren shore.

Probably we had better let the SOLUTION switch alone, after all.
Instead, her