Ask scientists of a certain age about their childhood memories, and odds are they'll start yarning about the stink bombs and gunpowder they concocted with their chemistry sets. Dangerous? Yes, but fun.
"Admittedly, I have blown some things up in my time," said William L Whittaker, 64, a robotics professor at Carnegie Mellon University who unearthed his first chemistry set, an AC Gilbert, in a junkyard around age 8. By 16, he was dabbling in advanced explosives. "There's no question that I burned some skin off my face," he recalled.
Under today's Christmas tree, girls and boys will unwrap science toys of a very different ilk: slime-making kits and perfume labs, vials of a fluff-making polymer called Insta-Snow, "no-chem" chemistry sets (chemical free!), plus a dazzling array of modern telescopes, microscopes and DIY volcanoes. Nothing in these gifts will set the curtains on fire.
"Basically, you have to be able to eat everything in the science kit," said Jim Becker, president of SmartLab Toys, who recalled learning the names of chemicals from his childhood chemistry set, which contained substances that have long since been banned from toys.
Some scientists lament the passing of the trial-and-error days that inspired so many careers. "Science kits are a lot less open-ended these days," said Kimberly Gerson, a science blogger who lives outside Toronto. "Everything is packaged. It's either 'yes' or 'no.' If you don't get the right result, you've done it wrong and you're out of chemicals."
Others, though, say the new crop of science toys - even with their cartoonish packaging and heavy emphasis on neon goo - actually represent progress. More entertaining, educational and accessible than earlier products, which relied heavily on a child's inner motivation, these toys may actually help democratise the learning of science and introduce children to scientific methods and concepts at an earlier age.
"I grew up in the 1960s, and a lot of the chemistry sets were kind of boring," said William Gurstelle, a science and technology writer. "You'd go through the book, and at the end of the experiment you'd get some light precipitate at the bottom of the beaker. Maybe at most it changes colour or something."