Tuesday, March 10, 2020

When Photography Required Chemistry

By Suzanne Norquist

Photography in the late 1800s fascinates me. Fancy chemical bottles, glass plates, and wooden box cameras with dark cloth draped over the back. Nothing like the digital camera on my phone.

In 1839, the daguerreotype was introduced to the public. It was a process that created highly detailed photographs on silver-plated sheets of copper. Only one copy could be made at a time, so each is an original.

By the 1860s, the wet plate process was the primary form of photography. A negative could be created on a glass plate, and multiple images produced from that negative. A less expensive alternative. And who doesn’t want copies for their friends?

It is the word “wet” in the wet plate process that created challenges. As long as the chemicals on the glass plates remained damp, they were photosensitive. Once dried, they were useless. A photography outing in the mountains required a portable darkroom, which is like a small laboratory.

A review of the list of materials carried by one photographer in 1870 on an expedition highlights the challenges.

Cameras were not one-size-fits-all. A larger photograph required a bigger camera. And, as you might imagine, these cameras were big.

The next item on the list is a dark tent.

No ordinary tent would do. If any light filtered through the fabric, it would ruin the picture. A lamp behind an orange curtain or a kerosene safety lamp (with orange glass) provided illumination for working. Some photographers used specially designed wagons or carts as portable darkrooms. An assistant might come along to set up the tent and lay out the equipment.

The negative image was captured on glass plates.

Rottenstone was an abrasive material used with the flannel to clean the glass. Imagine traveling in a wagon with all that glass! The photographer might also take along a glass plate cleaning vice as shown in the photograph below.

The glass had to be treated with chemicals before it was used to take a picture.

Colloid is a syrupy substance that sticks the silver nitrate (the light-sensitive material) to the glass. Alcohol was used to dilute it. The photographer held the clean glass plate flat on his fingertips and poured some colloid on it. Then he gently tipped it from side to side to “flow” it over the plate and completely cover it.

That is only the first use of the chemicals. See what I mean about photography requiring chemistry? Next, the plate would be placed in a silver nitrate bath for several minutes. 

Today, these chemicals would come with a warning label, and the nitric acid would only be opened under a fume hood. Yikes!

The process of coating the plate usually took about five minutes. It was then placed in the camera and exposed to light when the photographer removed the lens cover.

Once the plate had been exposed, the photographer returned to the lab—Dark Tent—to develop the negative, using the following materials.

The developer and fixer were each poured into trays. Then the glass would be dipped in the developer, and the image would appear. That must have seemed like magic. Next, the plate would be moved to the tray of fixer to stop the developing process.

Then, the negative was sealed and protected with varnish.

The negative could be transported and used to create a photograph on specially treated paper.

The whole process usually took about half an hour. It could be done in 15 minutes if pressed. And that is just for one picture.

And all of this says nothing about the long exposure time required for the picture or the need for good lighting.

Wet plate photography faded into history with the invention of a dry film by George Eastman in 1888. He ended an era with the slogan, “You press the button, we do the rest.”

But, what fun is just pressing a button?


Suzanne Norquist is the author of two novellas, “A Song for Rose” in A Bouquet of Brides Collection and “Mending Sarah’s Heart” in the Thimbles and Threads Collection. Everything fascinates her. She has worked as a chemist, professor, financial analyst, and even earned a doctorate in economics. Research feeds her curiosity, and she shares the adventure with her readers. She lives in New Mexico with her mining engineer husband and has two grown children. When not writing, she explores the mountains, hikes, and attends kickboxing class.

She authors a blog entitled, Ponderings of a BBQ Ph.D.

“Mending Sarah’s Heart” in the Thimbles and Threads Collection

Four historical romances celebrating the arts of sewing and quilting.

Mending Sarah’s Heart by Suzanne Norquist

Rockledge, Colorado, 1884

Sarah seeks a quiet life as a seamstress. She doesn’t need anyone, especially her dead husband’s partner. If only the Emporium of Fashion would stop stealing her customers, and the local hoodlums would leave her sons alone. When she rejects her husband’s share of the mine, his partner Jack seeks to serve her through other means. But will his efforts only push her further away?

For a Free Preview, click here: http://a.co/1ZtSRkK


  1. Wow, what a process! Amazing that we went from that to just clicking a button! Thanks for posting.

  2. We have a friend that does Silver/tint photography---and it's really amazing...the depth the photos have, eventhough digital is so 'Idiot-proof' now. Great article!

    1. Interesting. I watched some videos of people who do it now. It is an art form.

  3. Amazing research on your part. Photography has come a long way and has become idiot-proof for folks like me.