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MORE COPPER SULPHATE EXPERIMENTS
with Dr. Joe Schwarczs
Director McGill Office for Chemistry and Society
From his column in The Montreal Gazette

You can imagine that an album entitled “Copper Sulphate Crystals,” recorded by “Man in Formaldehyde” would capture my attention. What could this be all about? Was some eccentric musical genius inspired by an experiment gone awry in a chemistry lab? I had to find out, especially since I’ve always had a fondness for those beautiful blue crystals. I’ve admired them many times in the lab, but I’ve never had the chance to listen to them.

Actually, just about the only experiment I remember performing in high school involved copper sulphate. I remember attaching the leads from a battery to two graphite pencils immersed in a copper sulphate solution and watching in amazement as the pencil tips became coated with metallic copper. The copper ions in solution had picked up electrons from the battery and deposited as copper atoms on the graphite. But I remember something else as well. I remember Mr. Cook warning us to take care with copper sulphate because it could be toxic if misused. That was somewhat of a revelation because I remembered that as a youngster I used to grow pretty crystals by hanging a thread into a solution of copper sulfate. I didn’t recall that the chemistry set I used came with any such warnings. Of course, that may have been because I never read the instructions. Neither did I realize at the time that these crystals had a fascinating history going back all the way to the ancient alchemists.

Copper sulphate occurs in nature, with "chalcanthite" being a particularly attractive form of the mineral. I'm not surprised that the alchemists found its blue luster alluring. Unlike most minerals, chalcanthite is quite soluble in water, a property that lends itself to experimentation. Somewhere along the line an alchemist discovered that immersing a piece of iron in a solution of copper sulphate resulted in a dramatic effect. The iron seemed to have turned to gold! Of course that is not what happened. The copper ions had stolen electrons from the iron and had deposited on its surface as metallic copper. One wonders how many "clients" were taken in by this “transmutation.”

Copper sulphate induced folly was not limited to the alchemists. In 1891, Dr. Varlot, a French surgeon developed a way of copper plating a corpse for preservation. The body was dipped into silver nitrate, and then placed into an evacuated chamber where it was exposed to vapors of phosphorus which reduced the silver ions to metallic silver. Then came immersion in a copper sulphate solution. Since silver, like iron, can donate electrons to copper ions, Varlot was soon gazing at a body electroplated with copper. Why did he engage in this bizarre practice? It seems the good doctor had some ideas about preserving bodies for later resuscitation. Pretty unlikely, especially after having been exposed to such large amounts of copper sulphate. Like Mr. Cook told us, the stuff really can be toxic. That’s why it is used as a fungicide on grapes, as an algaecide in swimming pools and is thrown into pig manure pits to deal with the bacteria that produce those noxious smells.

All of this doesn’t mean that we should not allow students to carry out experiments with copper sulphate. But those experiments have to be prefaced with the appropriate warnings. Unfortunately, though, such warnings are sometimes taken the wrong way. And that is just what seems to have happened in a high school in Sylvan Lake, Alberta. Many of you may have read about this story a couple of weeks ago when newspapers, including this one, carried an account under the headline: "Girls plead guilty to "high school crap" that killed classmate." Now, I know that there is a lot of "crap" that goes on in high schools, but I didn't think any of it was lethal. The story described how three girls who had taken a dislike to a classmate decided to have some fun at her expense by stealing some copper sulphate from the school lab and mixing it into a "slushie" they had purchased at a convenience store. I’m not sure why they chose copper sulphate, but a good guess would be that they recalled some sort of warning from the teacher when they were using it in an experiment. The victim consumed the beverage and got sick. So did two of the pranksters who sipped a little of the slushie to convince the suspicious victim that there was nothing wrong with it. Somehow four other girls also drank from the spiked beverage and experienced a variety of symptoms which included vomiting, shaking, headaches and a burning sensation in the mouth. They were treated at a hospital and released. That's right. Nobody died! The sensationalist headline was written by some overzealous copywriter who had not read the whole story.

I'm not saying it couldn't have happened. Copper sulphate can be deadly but chances are that any significant ingestion would trigger vomiting, leading to most of the dose being expelled. That is just what happened in the Alberta school. Of course the three culprits didn't know that this would happen and were charged with attempted murder. This was recently plea-bargained down to "administering a noxious substance with the intent to endanger life, theft of copper sulphate, and criminal negligence." The potential penalty here is less severe but the girls could still be looking at jail time. We will find out what the judge's ruling is about that in November. They should of course be punished, but so should the headline writer who wrote the crap about the "high school crap" that killed a classmate.

Now back to my “Man in Formaldehyde” recording. I had to hear what this “Copper Sulphate Crystals” piece was all about. I downloaded a little excerpt from the web (legally) and began to listen with some trepidation. After all, some of this modern stuff that passes for music is pretty lethal. What a pleasant surprise! It seemed to be some sort of mix of guitar and computer generated tunes that were melodious and pleasant. What it has to do with copper sulphate, I have no idea. And I don’t know what the other tracks sound like either. But I will. Of course I sent for the CD. How could I not want to listen to “Birds in Magnetic Milk?”.