I've been Christmas shopping for my two kids (ages 4 and 2 1/2) and have seen plenty of things that they'll be getting when they're older. Like chemistry sets - although the ones they sell now (standard chemist's complaint coming) are wimpy and underpowered.

But there are ways of fixing that. When I was around 9 years old, I was given a chemistry set augmented through the efforts of my father, who rounded up some more interesting chemicals then the ones provided. For example, there was a 100 gram cardboard container of copper (II) sulfate, whose deep blue crystals I was immediately taken with. (I haven't had to use that compound in several years now, but every time I see it in the lab I recognize an old friend, unchanged.)

There was some sodium potassium tartrate, which meant, years later, that I was probably the only first-year chemistry student at my college who knew what "Rochelle salt" was. I still use that one once in a while, too, to complex out aluminum from a reduction - since it doesn't have a distinctive color, though, I have to remind myself every so often that I'm using a compound that I've known since I was ten. Dishing out its rod-shaped crystals is more of a reminder than the solution can be.

Rochelle salt is pretty innocuous. But my father had bought some potassium permanganate, which is a rather high oxidation state for a kid to have on his shelf. You can get in some actual trouble with permanganate, since it would just as soon slide down to the mud of manganese dioxide and ditch plenty of energy along the way. I was always amazed by its color, the very definition of purple as it dissolved in water. (If you left the solutions standing around, though, they would find a way to turn back into muck.) As I experimented with it, I came across several mixtures that gave it room to run, sometimes violently, with plenty of heat and fizz.

Some of those involved elemental sulfur, so I'm sure I got some whiffs of sulfur dioxide and other odd gases along the way. I used plenty of that stuff in a research project at my former company, but its smell induced no Proustian recollections - getting a good dose of it was more like standing in a steaming extraterrestrial swamp. What takes me back immediately, though, is powdered sulfur itself. Every time I come across it, I think "Now that smells like a chemistry lab!"

I didn't have any of the things that I use more often now - no hexane, no ethyl acetate or any of the other dozen solvents under my fume hood. The only organic solvent I had was some carbon tetrachloride, for a butterfly kill jar, and I never used it with the rest of the chemicals, since I knew that the salts wouldn't dissolve in it. Certainly I had no air-sensitive reagents, and probably a good thing, too. (I was impressed to read in Oliver Sacks's Uncle Tungsten that he had actually prepared things like phosphine as a boy - that's something I'd think twice about handling even now.)

Actually, my ten-year-old self would have been a bit puzzled by a career choice in organic chemistry, as opposed to inorganic (although the news that I was a working scientist would have gone over well.) I had my father's college copy of the CRC Handbook, from back in the days when it really was a handbook, and I used to skip over the organic chemical tables and the half-breed organometallics. Those sections of the book had to wait a few years to become intelligible to me (like the tables of integrals - what an odd feeling it was to leaf through those after taking calculus and suddenly finding myself able to read them.)

That handbook is up on a shelf in this room as I write, over my left shoulder. And my two children are asleep down the hall. A few years from now, we'll all sit down together.