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
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, here are a couple of experiments
that will help to make clear what happens when anything dissolves to make a solution.
HOW PRECIOUS STONES ARE FORMED
. Colored glass is made by dissolving coloring matter in the glass
while it is molten. Rubies, sapphires, emeralds, topazes, and amethysts were colored in the same way, but by
nature. When the part of the earth where they are found was hot enough to melt stone, the liquid ruby or
sapphire or emerald, or whatever the stone was to be, happened to be near some coloring matter that dissolved
in it and gave it color.
Several of these stones are made of exactly the same kind of material, but different
kinds of coloring matter dissolved in them when they were melted.
Many articles are much used chiefly because they are good emulsifiers or good solvents (dissolve things well).
Soap is a first-rate emulsifier; water is the best solvent in the world; but it will not dissolve oil and gummy
things sufficiently to be of use when we want them dissolved. Turpentine, alcohol, and gasoline find one of
their chief uses as solvents for gums and oils.
Almost all cleaning is simply a process of dissolving or
emulsifying the dirt you want to get rid of, and washing it away with the liquid. Do not forget that heat helps to dissolve most things.