Good morning, readers, this is Maria Grace and I’m coming to you, once again, from the depths of the research rabbit hole. I’m sure you’re so surprised to find me here again.

Not.

Ok, seriously, I was quietly minding my own business, researching for the next book. Characters were writing letters and in need of blue ink to do so. But was it possible in 1815 or would I be stuck with boring black ink?

Turns out colored inks were a thing. You can read about them here.

And so were other things. Things like coloring changing ink! No joke! Here’s the recipe, straight from the 1810 source.

197. To Write different colours upon the same Paper with the Juice of Violets .
WITH a camel hair pencil dipt in any acid , such as diluted spirit of vitriol , run over part of the paper , and when it is dry write upon it with a pen dipped in the juice of violets , and the writing will immediately turn to a fine red . If you write with pure violet juice ; you have a violet blue . By running the other part of the paper over with a hair pencil dipped in any alkaline salt , as salt of wormwood dissolved in water , and writing upon the same , when dry , with violet juice , you have a very fine green . Writing upon tincture of steel with violet juice , you have a black . If you write with the juice of violets , and rub on one part of the writing spirit of vitriol , and on the other spirit of hạrtshorn , or salt of wormwood dis . solved , you have red and green . The writing held to the fire becomes yellow .

~Manual of Useful Knowledge

A Quick Glossary

salt of wormwood, potassium carbonate; alkali used in production of soap and wine

spirit of hạrtshorn: aqueous ammonia solution

Spirit of vitriol: dilute sulfuric acid

tincture of steel: An alcoholic solution of iron chloride.

Who’d a thought, right?

References

Pybus, William. A Manual of Useful Knowledge.  Printed for the author by William Rawson: London 1810.

Writing with Violets: Parlour Chemistry c. 1800. Her Reputation for Accomplishment.  April 24, 2015. Accessed 3/4/2023. https://herreputationforaccomplishment.wordpress.com/2015/04/24/writing-with-violets-parlour-chemistry-c-1800/

Find more on inks here.

Find more on the art of writing here.