“You’d better watch out …” I sang, as I skipped upstairs with more than just the capture of Father Christmas in mind.

Wet, heavy flakes were falling straight down towards the earth, no two alike as they plummeted past the lighted window of my laboratory—yet all of them members of the same family.

In the case of snowflakes, the family’s name is H₂O, known to the uninitiated as water.

Like all matter, water can exist in three states: At normal temperatures it’s a liquid. Heated to 212 degrees Fahrenheit, it becomes a gas; cooled below 32 degrees, it crystallizes and becomes ice.

Of the three, ice was my favorite state: Water, when frozen, was classified as a mineral—a mineral whose crystalline form, in an iceberg, for instance, was capable of mimicking a diamond as big as the Queen Elizabeth.

But add a bit of heat and poof!—you’re a liquid again, able to run easily, with only the assistance of gravity, into the most secret of places. Just thinking of some of the subterranean spots in which water has been makes my stomach tickle!

Then, raise the temperature enough, and Ali-kazam! you’re a gas—and suddenly you can fly.

If that’s not magic, I don’t know what is!

Hyponitric acid, for instance, is absolutely fascinating: At –4 degrees Fahrenheit, it takes the form of colorless prismatic crystals; warm it up to just 7 degrees and it becomes a clear liquid. At 30 degrees the liquid turns yellow and then orange, until at 82 degrees, it boils and becomes a brownish-red vapor: all within a range of no more than 86 degrees!

Stupendous, when you stop to think about it.

But getting back to my old friend water, the thing of it is this: No matter how hot or how cold, no matter its state, its form, its qualities, or its color, each molecule of water still consists of no more than a single oxygen atom bonded to two sister atoms of hydrogen. It takes all three of them to make a blinding blizzard—or a thunderstorm, for that matter … or a puffy white cloud in a summer sky.