The History & Science of Iron Gall Ink

Name:

Date:

Objectives

After successfully completing this lab, you will be able to:

• Summarize the importance of ink through human history and how the most common types were produced. • Understand how the biology and chemistry of oak galls made them perfect for making ink. • Identify oak galls in the wild and describe how they participate in their ecosystem. • Prepare and process their own iron gall ink and quill pen.

Materials

• Gall & distilled water solution, left in the sun for 3 days • Iron sulfate, powdered • Gum Arabic, powdered • Cheesecloth • Pitcher or bowl with easy-pour lip • Quill feather or hollow stick/reed • Watercolor paper • X-acto knife or scalpel • Jar or vial with airtight lid

Pre-Lab Questions

1. List some ways that people use ink in their everyday lives:

2. What is the main advantage of using ink versus a lead (graphite) pencil?

Background Information: Ink, Galls, and the Declaration of Independence

Some of the earliest evidence for humans producing and using inks for writing come from areas of China and Egypt, between 4,000 and 5,000 years ago. These first inks were made using ingredients from plants, animals, and minerals such as graphite, which we still use in pencils today. Soon the most common inks were mostly made of soot (carbon) collected from burning fuel or bones and mixing them with water and glues. However, these inks had one major problem: they were not permanent. It was easy to smudge or remove marks made with carbon inks, much like how we can erase our pencil marks today. As human civilization developed, important information like laws and historical records needed to be written down and protected from tampering. A new, indelible (permanent) ink was needed.

That new ink was finally invented approximately 1,600 years ago by a combination of biology and chemistry. The ink was produced by mixing a strange growth found on oak trees called “gallnuts” with a mining byproduct called “copperas” or “vitriol” by early Europeans. The “gallnuts”, which we now just call “galls,” are actually caused by many species of small wasps who lay their eggs in the tissue of oak trees. The wasps create the galls by secreting hormones designed to instruct the tree to grow a protective layer of tissue (the gall) around the developing larvae, while the larvae feed on sugars and starches provided by the tree until they mature into adults and chew their way out of the gall. This is an example of a parasitic relationship, but luckily the trees are not normally damaged by the gall wasps. Galls are full of tannic acids, or tannins, which act as protection from fungal infections, a major threat to the developing wasp larvae.

“Copperas” and “vitriol” were both names for a chemical compound that we now call iron sulfate. The chemical formula for iron sulfate is:

FeSO4

This means that each iron sulfate molecule has one iron (Fe) atom, one sulfur (S) atom, and four oxygen (O) atoms. Today, we still use iron sulfate to treat iron-deficiency anemia, a condition in which a person does not have enough iron in their blood to help their red blood cells carry oxygen around the body.

When tannic acids and iron sulfate are combined, a water-soluble ink is created. Solubility is important for ink, because it enables the ink to sink into the paper it is used on. When the ink is exposed to air, the iron begins to oxidize and darken on the page. Oxidation is when atoms lose electrons, and is also how iron can turn to rust if left out in the open. The oxidized iron is no longer water-soluble, meaning that it cannot easily be removed from the page. Finally, a permanent ink!

From the Middle Ages until the 20th century, iron gall ink was the most common ink used in most parts of the world. Millions of books, records, pieces of art and music, and important historical documents were written in iron gall ink, including the Declaration of Independence! There’s only one downside: iron gall ink is acidic and will gradually eat away at the paper it is written on. Historians and museum curators continue to work on new ways to protect these important documents from the very ink they were written with. Iron gall ink is still used today by those who want to understand how our ancestors made and used a product as commonplace (and crucial) as ink. Let’s make some!

Procedures

In this lab, we will be making our own iron gall ink as a class. At the same time, you will begin the process of making your own ink at home and you will be given the supplies to finish the process. We will also be demonstrating how to cut our own quill pens from feathers.

1. The lab instructor will have a gall solution already prepared. This solution is made by pounding 80 grams of oak galls and adding them to 300 milliliters of distilled water. The solution is then covered and left in the sun for three days, which allows for microorganisms to ferment glucose into gallic acid. The more gallic acid (a tannic acid), the darker the ink will be.

2. To begin making your own gall solution, take 20 grams of oak galls and place them into a ziploc bag. With a rubber mallet, pound the galls into small pieces. Add the pounded galls into a jar and add 75 milliliters of distilled water. Set the jar aside for you to bring home later.

3. The lab instructor will weigh out 50 grams of iron sulfate and 25 grams of gum Arabic. The gum Arabic is a dried tree sap that thickens the ink.

4. Take note of the color of the gall solution before the other ingredients are added by dipping a popsicle into it. Then add the 50 g of iron sulfate and stir until all the iron sulfate has dissolved.

5. Take note of any color change. Add in the 25 g of gum Arabic and stir until dissolved.

6. Once everything has been mixed in, strain the solution by carefully pouring it over several layers of cheesecloth into a wide bowl or pitcher. Squeeze as much liquid out of what is left in the cheesecloth as possible. Make sure to be wearing gloves!

7. Transfer your ink into a container with an airtight lid. If the ink is too runny, more gum Arabic can be added. If it’s too thick, add more distilled water.

Congratulations! You have made your own iron gall ink in almost the exact same way people have been making it for centuries. When you use your ink, you may notice that it starts off a lighter color and then darkens over time. This is because the iron can take a little while to oxidize and reach its full color.

The lab instructor will now show you how to cut your own quill pen from a turkey feather. A step-by- step guide will also be given to you as a separate handout. Always be sure to work slowly and carefully when cutting your quills. Have fun!

Post-Lab Questions:

8. Which is easier: writing with a modern pen or a quill pen & ink?

9. Can you imagine having to make your own ink every time you wanted to write something down (like people had to do for hundreds of years)? How much time do you think modern pens and pencils save you every day?

10. Do you think it is still worth the effort to make our own ink and pens? Why or why not?