Deborah Blum

And the containers were filthy, and the ladles were filthy.

And adding to that problem, dairymen, ever eager to make a profit, would thin the milk with water.

And so one of the common practices for this, basically you'd mix water with milk until the milk turned kind of bluish, and then you would recolor the milk white with either chalk or plaster of Paris so it looked like normal milk.

And finally, the preservative formaldehyde had become the number one preserver of bodies during the Civil War.

And the American dairymen, in their inventive way, said, wow, if this really works so well to preserve rotting bodies, what could it do for dairy products?

And two things happened.

One, the formaldehyde killed the bacteria, hands down.

The other was that formaldehyde, it's apparently fairly sweet.

So when you mix the formaldehyde into the milk, it covered up the taste of the rot.

And so dairymen then embraced this.

And you had dairymen who would kind of go to themselves.

Well, if a little formaldehyde does the job, a lot would do it even better.

And some of these guys would actually advertise.

They would have advertised saying, you know, buy our special milk.

You can leave it on the counter for three weeks.

But the problem was that often when that happened, the levels of formaldehyde were really toxic.

They didn't have to tell the consumers.

There's no requirement to label.

They usually didn't acknowledge that it was formaldehyde.

The formaldehyde formulas had names like Rosaline and Preservaline and Icing and sort of benign names.