“They Put it In our Teeth”

Now that the burden of my daily blogs is gone (via AG) I can talk about what’s really important, and that ain’t me! Many times in our rush for riches we don’t stop to think what part of this could be bad for us. I needed physical therapy, for instance, after working really hard for half a year on three non-fiction projects. Two were second edition, but still required a lot of attention. And the third was data-intense copper project. People think those manuals are easy to put together? They’re not.

This topic jumped out at me, as topics tend to do, while working on the first draft of “A Cartwright Ride through Virginia City History.” You’ve heard of Quicksilver, perhaps? It’s a cool word, but it doesn’t mean getting rich fast. Nor am I talking about a fictional Marvel hero.  Or a 1986 movie with Kevin Bacon.

No, in this case, and it took me a while to find this, is it’s a process utilizing mercury:

Mercury used to be highly regarded, for reasons both mystical and practical. Among the substances we deal with in our lives, mercury is pretty odd and amazing. The Latin name “hydrargyrum,” from which its chemical symbol Hg comes, means water-silver. English speakers used to call it quicksilver, or living silver. The medieval alchemists felt that mercury must have a mighty mojo, some excess of spirit that could be tamed for their great work of turning base metal into gold.

Mercury as we know it today fuels our thermometers. But did you know they also used to put it in your teeth? No, wait – they still do:

As a practical matter, mercury does some very useful things. It dissolves other metals in it to make instant alloys or amalgams. A gold or silver amalgam made with mercury is an excellent material for filling tooth cavities, hardening rapidly and wearing well. (Dental authorities do not consider this a hazard to patients.)

Heaven knows if it is — or isn’t. Dentists still use this amalgam in fillings, even while the use is debatable. Some claim it could lead to Alzheimers. But most say the amount of mercury in a filling is just too small.

The question I’m going to try to answer here is whether the silver miners in Virginia City showed any signs of quicksilver poisoning, when the use of mercury was discontinued, and what might be lingering effects to the environment.

Photo here is from my visit to the area in 1993.

These miners used mercury in the milling process — tons of the liquid metal in the process of ore reduction. They added mercury to the pulverized ore. They threw drew it off together with the gold and silver. The next step involved cooking away the mercury, which vaporized. They did try to recapture the mercury for re-use but lost most of it.

The amount of quicksilver used by mills working the Comstock ores alone averages 800 flasks,  of 76.5 pounds each or 61,2000 pounds per month. This amount … of quicksilver had to go somewhere, and counting backwards for ten years shows 7,344,000 pounds that have gone somewhere — either up the flue or down the flume.

Mercury is poisonous and can be deadly when inhaled. A question Ronald James, one of my sources, asked is how many had been affected? The symptoms at toxic levels caused hair loss, tremors, hallucinations, insanity and death.

The first effects of mercury were noted in the hat industry, of all places, because they used quicksilver in the making of felt. Remember “The Mad Hatter?” Lewis Carroll’s character went mad because of mercury. I doubt you’ll see that in the Disney version, though.

James was unable to share any data about the effects mercury had on the miners. Let’s see if we can update that. Here’s a report on the beginnings of mining in the 1850s in California. By the mid-1850s, in areas with sufficient surface water, hydraulic mining was the most cost-effective method to recover large amounts of gold.

Vast gravel deposits from ancestral rivers within the Sierra Nevada contained large quantities of placer gold, derived from the weathering of gold-quartz veins. Gold mining evolved from hydraulic mining of unconsolidated placer deposits in the early days of the Gold Rush, to underground mining of hardrock deposits, and finally to large-scale dredging of low-grade gravel deposits, which in many areas included the tailings from upstream hydraulic mines.

As mining progress into deeper gravels, the constant innovation to remove the gold and silver did not allow for “years of research” into safety measures. They built tunnels to discharge placer tailings to adjacent waterways. “Gold particles were recovered by mechanical settling in troughs (riffles) within the sluices and by chemical reaction with liquid mercury to form gold-mercury amalgam.”

The result was highly contaminated sediments; in 30 years, more than 1.5 billion “cubic yards of gold-bearing placer gravels were processed by hydraulic mining in California’s northern Sierra Nevada region.”As noted at this website, the high density of mercury allowed gold and gold-mercury amalgam to sink while sand and gravel passed over the mercury and through the sluice. 

This site does not tell us about any impact on the miners; it went on to say that mercury could still be consumed in the fish you catch in the area.

It’s apparent that the human costs of working with metals tends to be hidden. I work with copper artifacts — oh, not directly handling them, most of the time. But I learned that Henry Hamilton, in his days of the early 1900s, handled more copper artifacts than maybe anyone else in the world. He likely handled them without gloves and likely even while eating. He died of an unknown ailment in his late ‘50s. Could it have been arsenic poisoning? My hunch is probably. But his great collection of them are on display in the lower level of the Wisconsin Historical Society in Madison, so at least he left a legacy, right?

Even back then the miners knew about foul odors. Ventilators were added to the top of the stamping buildings to encourage the escape of steam, gas, mercury vapors, and other foul airs. There was one instance noted that a man, who brought home a quantity of amalgam, left it burning on the stove while he ran errands. He came back to find his baby dead and his wife and German lodger rendered insensible. Had they known these kinds of dangers existed at the time, this would not have happened.

We all know today that these things can be poisonous but have we learned to care?

Here’s a current report from Indonesia, because, you know, some places are quite behind the times:

“Fahrul’s been working with mercury for many years, and he’s showing the typical symptoms of mercury intoxication,” says Bose-O’Reilly, a German medic who began studying the impact of mercury on Indonesians’ health a decade ago. “He also has a tremor and a co-ordination problem.”

Small scale miners supply 15% of the world’s gold today — using old methods of mining. “I often have a headache, and I am weak. I have a bitter taste in my mouth.”

I suspect that upgrading to different mining methods takes money they don’t have.

Here’s another current report:

There are tiny flecks of gold deep inside Montaña d’Oro that miners extracted using liquid mercury to dissolve the gold from the dirt. Miners then heat the mixture of gold and elemental mercury, which evaporates the liquid mercury so the gold can be recovered. As a result of heating the elemental mercury, invisible, toxic mercury vapor is released in vast quantities into the air, poisoning everyone nearby, including babies and dogs.

There is a cool photo of quicksilver on this page.  But there’s nothing cool about quicksilver, except in your thermometer. I haven’t been able to find the date when they stopped the quicksilver process in Virginia City, but it sounds like it was used until mining came to an end there in the 1880s.

Carson River is a superfund site, on the list of the nation’s worst toxic waste sites.

Here in the U.S., mercury is no longer added to industrial scale gold mining. Mercury had been added to the gold because it would make the gold stick, as an amalgamate, and then the mercury would be burned off, leaving the gold behind. Unfortunately, mercury is also in the ore of gold that is being mined.

“Often where there are very large gold deposits in ore, there are also large mercury deposits, which is the case in Nevada. This is not the case for other US gold mining regions, such as Colorado.”

Today they can significantly reduce the amount of mercury released in the air by adding controls to the process that captures the mercury. You can imagine this process to be costly and beyond the reach of the small miners in other countries, who are still sending amounts of mercury into the air.

The Food and Drug Administration says that too much mercury can cause:




memory problems


pathologic shyness


I know a lot of people with tremors. But all of these, in themselves, are not necessarily anything that we’d attribute to being poisoned. Pathological shyness? So it’s not a surprise that miners did not note anything unusual in their working environment. Today small amounts come in the fish we eat.

But what does large amounts of mercury do to the fish themselves? Studies on mercury’s effects on wildlife overall has been on-going since the 1970s.  Here’s just one paragraph from a website you might want to look at more closely:

In the earliest studies of these sub-lethal effects in the 1970s, Heinz reported that captive mallards fed mercury-laced food laid fewer eggs than control ducks and laid them outside the nest. Also, their ducklings didn’t respond well to their calls. Numerous examples have accumulated since. Fish form loose, sloppy schools and are slow to respond to a simulated predator. Several bird species sing different songs. Loons lay smaller eggs, and they incubate their nests, forage, and feed their chicks less. Salamanders are sluggish and less responsive to prey, Hopkins and colleagues found. Egret chicks are similarly lethargic and unmotivated to hunt.

Sub-lethal means effects don’t cause death but obviously makes life less productive for all living things. It’s a cost of progress, right? And who can argue with progress, no matter how depressed it makes us. We need that next great smart phone. Uh-uh. We don’t. We don’t need AI either. The problem with progress is what I call “ease of living.” All living things seek it. More on that in a future article.

So many very real things in nature are not meant to be tampered with. We may never learn the full costs of this lesson. Not if we continue to believe the benefits outweigh the costs — you know, the “side effects.”



 James, Ronald M. The Roar and the Silence: a History of Virginia City and the Comstock Lode,

(Reno: University of Nevada Press, 1998), 135-136.

 James, 136.


 Crouch, Gregory. The Bonanza King: John Mackay and the Battle over the Greatest Riches in the American West (Scribner: Kindle Edition, 2018), 178. 












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