When holidays roll around, I like to poke around for a connection with the natural world, and I found some interesting stuff about The Declaration of Independence. This most revered American document kicked off our nation’s quest to rule itself, which we celebrate on the 4th of July, Independence Day.

Were I to ask what tree derived material was used to create this famous document, a lot of folks would think it’s the paper, which is a good guess but wrong. Early drafts of the document were likely written on paper made of hemp or flax fiber mixed with recycled cotton cloth fibers, which was the standard paper of the day. For important documents like the Declaration, they used the more expensive parchment paper, which is specially treated animal skin, sheep most likely. It’s very durable and had been in use for centuries.

So, the only thing left is the ink, and that’s it. The ink used to write the Declaration was called Oak Gall Ink, made with an acid obtained from oak galls. These are ball-like structures growing on oak leaves, and you may have seen them on oak leaves or other tree species. They are caused by an insect called the gall wasp. The female wasp lays an egg in leaf buds in the spring, which hatches a worm-like larvae. It feeds on the leaf bud and injects a secretion that causes the bud to modify its growth and grow a ball of spongy material around the larvae. The resulting gall protects the larvae until it metamorphs into an adult. The gall is very high is tannic acid, which was collected from the forest and processed into a liquid that was mixed with iron sulfate to create a dark purplish-black ink. A binder called gum arabic was added to the ink, which is also a tree derived product from the sap of acacia trees growing in northeast Africa. This ink goes way back in time and was used during the early Roman Empire, and many drawings by Leonardo da Vinci were done using oak gall ink.

The combination of oak gall ink on parchment created a very durable document. The parchment was tough and holds up well over time. The ink was water resistant and would adhere to the parchment so well that it could not be erased except by scraping a thin layer off the writing surface. This durability turned out to be crucial or we wouldn’t have the original document on display in Washington DC, where it is now protected in a titanium case filled with argon gas to reduce deterioration. But back in the day the original document was simply rolled up and carried around in a saddlebag by the Continental Congress and shown to whoever wanted to see it. Later it ended up on the wall of the patent office and hung there for 30 years near a bright window. It faded but endured until somebody recognized it was an important document and started protecting it. The original Bill of Rights and Constitution were also written using parchment and gall ink.

One other piece of trivia I picked up is that there is something written on the back of the Declaration of Independence: "Original Declaration of Independence, dated 4th July 1776" written at the bottom of the document, upside down. Have a great 4th and remember your freedom’s not free.