"[Uniforms] The Dark History of Indigo" Topic

-Slavery's Other Cash Crop.

No comment on the accuracy, but interesting commentary nonetheless…
and if a chemical process wasn't discovered, accidentally, until 40 years AFTER the period, what magical powers did the Prussians have to make their own blues?
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The Dark History of Indigo, Slavery's Other Cash Crop

See also :

Research into French Blue(s)
TMP link

The White Uniforms of the French Army, 1806-1807
TMP link

regards
d

Let's remember Prussian Blue is so called after its place if discovery not its putative shade.

Prussian blue was not indigo, it was ferric ferrocyanide, first synthesized in Berlin in 1706 and became the coat color of the Prussian infantry and artillery soon thereafter.

Having grown an indigo bush and made dye from it, I can say it truly is a labor-intensive chore. Just boiling down an 8-quart pot took almost a day, and only yielded a quarter-sized piece of indigo (I still haven't dyed anything with it.) And before you go off to grow indigo, be warned that it can become an invasive pest plant in your landscape… :-p

Interesting – did not realize it was so much work!

From a 2013 blog post of mine:

link

which digressed into the fascinating history of Prussian Blue (wikiopedia article linl below).

link

In short, the color was first produced accidentally circa 1706 (the chemist was trying to make a red pigment, but impurities in the reagents produced a blue product instead!). As it turned out to be light fast (relatively stable to light exposure), and much less expensive than the only other blue pigment useful for painting blue (made of a fine suspension of crushed blue stone imported from Afghanistan), its commercial value was readily appreciated, and it became widely used first in art, and then for creating dark blue clothing… the dunkelblau of the Prussian uniforms was created using Prussian Blue (the pigment is insoluble, but is used as a fine solid suspended as as a colloid). The chemistry of the (inorganic)compound turns out to be quite complex but also very fascinating (see the wiki article for those with an interest in Chemistry – like myself!), including at its heart both Ferrous and Ferric states of Iron cations complexed to six cyanide groups each. Indeed, when the Cyanide group was finally isolated( from Prussian Blue preparation)s, the very name given to it was a Latinized version of the Greek word for "blue". We use that term extensively in Medicine as well – a patient who is "turning blue" (due to lack of oxygen and thus excessive amounts of the purplish deoxy-hemoglobin as opposed to the bright red oxygenated version) is said to be "cyanotic". Many of us with color computer printers will also be familiar with the term "cyan" applied to the blue pigment in our cartridges. Prussian Blue is also the traditional blue color used in "blueprints". There's another interesting and shorter reference to the history and chemistry of the compound here as well:

link

It is also useful for treating certain kinds of heavy metal exposures, as well as a histo-chemical stain for iron stores on Bone Marrow biopsy and other tissue specimens.

"Fascinating!"

Peter

>>Prussian blue was not indigo,
Nobody suggested it was…

>> it was ferric ferrocyanide, first synthesized in Berlin in 1706
OK, so the blatently incorrect 'encyclopaedia of everything' needs a damn good thrashing then! Go to it!
Like I said, I wasn't vouching for accuracy…

Thanks for the additions Peter, I think your blog was patched in the links I provided too.
>>(made of a fine suspension of crushed blue stone imported from Afghanistan),

So there's still a hint of colonialism in that story too. Wonder how dirt from there ended up in Prussia~ friendly Turks?
BTW- what is the source of the Bedouins/ Berber shades?

regards d*

So there's still a hint of colonialism in that story too. Wonder how dirt from there ended up in Prussia~ friendly Turks?
BTW- what is the source of the Bedouins/ Berber shades?

You are misreading. The Afghanistani blue stone was not Prussian blue, but rather the other non-indigo source of blue dye prior to 1706.

Anybody could make Prussian blue, once the process was out, but it cost about 30% more than indigo to dye the equivalent amount of fabric. On the other hand, indigo caused damage to the fabric dyed with it. You could get at best two years out of an indigo dyed coat, while a Prussian blue coat was good for three or more years. Frederick the Great's miserly father seems to have been the only monarch smart enough to do the math.

I have found no source which states that Berlin blue (Prussian blue) was used for dying the Prussian uniforms.

Gisela Krause, Altpreussische Militärbekleidungswirtschaft, states (p. 21) that throughout the 18th century probably only indigo was used, instead of the cheaper but less durable woad (isatis tinctoria).

G__

and much less expensive than the only other blue pigment useful for painting blue (made of a fine suspension of crushed blue stone imported from Afghanistan),

You are misreading. The Afghanistani blue stone was not Prussian blue, but rather the other non-indigo source of blue dye prior to 1706.

You are right, my speed reading of your comprehensive one paragraph answer was insufficient. I apologise.

So what is its name? As I still don't see that mentioned.

cheers |-)
d