Fact or Mint-myth?

[Spartancrest]

From a book I just purchased.  "Tsuba: Japanese Sword Guards from the Ota Collection"
Publisher International Christian University, Hachiro Yuasa Memorial Museum, Length 43 pages " written in 1997.  It only has 65 tsuba in it and most are sukashi, written in both Japanese and English but it also has some details I had never heard of - it relates that:- 

 

"SHINCHU [brass]: alloy of copper with lead and zinc. Also called "yellow copper"(odo) due to its color. Since very little zinc was mined and no technique for its production was known in Japan, old Chinese coins were melted down to provide the material to make brass." 

 

Remembering this is a book specifically on Tsuba - Melting coins to make tosogu?  - Must have been 'money' in it! 

Where then did they get enough Chinese coinage to meet the demand? Would it not have been cheaper to import zinc from China or brass scrap rather than coins?

Fact or a myth?

[Bugyotsuji]

Although there is much interesting stuff there that I cannot answer, cheap Chinese 'cash' coinage flowed back and forth between China and Japan for centuries. There were even periods where Japan was not particularly minting her own coins. I can imagine that broken or corrupt coins were also regularly collected and taken out of circulation, to be melted down and remade into this, that or the other.

[IBot]

If I remember my chemistry from the very distant past, obtaing metallic zinc was a tricky job since it is volatile. In fact, metallic zinc was not identified until about 1750. When making brass it was more usual to add a zinc ore ( usuall an ore called calamine) to the copper since much of the zinc would be lost if added as metal. 

Ian Bottomley

[ROKUJURO]

Dale,

I think I remember a post by Ford Hallam about this subject where he mentioned that SHINCHU was almost as valuable as gold in these times.

The advantage of SHINCHU over gold was probably that it could take on an interesting colourful patina which gold can not. 

[rkg]

13 hours ago, Spartancrest said:

From a book I just purchased.  "Tsuba: Japanese Sword Guards from the Ota Collection"
Publisher International Christian University, Hachiro Yuasa Memorial Museum, Length 43 pages " written in 1997.  It only has 65 tsuba in it and most are sukashi, written in both Japanese and English but it also has some details I had never heard of - it relates that:- 

 

"SHINCHU [brass]: alloy of copper with lead and zinc. Also called "yellow copper"(odo) due to its color. Since very little zinc was mined and no technique for its production was known in Japan, old Chinese coins were melted down to provide the material to make brass." 

 

Remembering this is a book specifically on Tsuba - Melting coins to make tosogu?  - Must have been 'money' in it! 

Where then did they get enough Chinese coinage to meet the demand? Would it not have been cheaper to import zinc from China or brass scrap rather than coins?

Fact or a myth?

Yeah, about that...  years ago Ford took an xrf gun to a bunch of sinchu inlay/sinchu pieces, and found that the percentage of zinc was pretty consistent ~30% or so if I recall correctly (Ford can hopefully comment or reprint his results).  You need an alloy of zinc somewhere in that range (or higher) to make the brass malleable enough to inlay work.  The big problem with this whole melt theory is that the Chinese brass has a range that is mostly lower than that (though they seemed to have some brass in that range), and... it turns out that as noted earlier, a fair percentage of the zinc flashes off when you melt the brass and... you end up with too little zinc in the resulting melt to be useful for inlay work.  So something else was going on. Either the inlay material is all newer, dating from when they could get spelted brass (European), they were importing brass from somewhere in Asia just for this inlay work, somebody was bringing in zinc to mix in to get the alloy percentage up in coin or other melt, or some other explanation.  The Indians seemed to be making zinc quite early, and I have been told there is apparently some research out of Japan claiming they were getting zinc (either as the calamine or as actual alloy of some kind) to do this (though YMMV on that - I could never locate the paper though quite a few Japanese collectors told me it was out of one of the many universities in Kyoto).

Probably somebody could do an isotope analysis on old fittings/compare them to "known" sources and see where the component materials actually came from, but...

 

This was too big to link, but here's an analysis of the metal composition of Chinese coins:
http://www.rkgphotos.com/facebook_stuff/RP 152 Metall Analysis Chinese coins-Prelims-Appendix.pdf

And I'll attach a paper about zinc in china in the 14-1500s for your reading pleasure.  I'd attach more, but the papers aren't small...

 

Best,

rkg

(Richard George)

Zinc in the Ming and early Qing.pdf

[Bugyotsuji]

FromJ Wiki, where they say that shinchu was long thought to have become available only from the Edo Period, but now it seems from written records that it was widely used from 12th century Heian in Japan. From an extract about 亜鉛 Aen, zinc.

亜鉛 - Wikipedia

従来、日本では真鍮は江戸時代になって普及したと考えられていた。しかし、12世紀の平安時代、鳥羽上皇の皇后、美福門院が高野山に奉納した「紺紙金字一切経」に、真鍮が大量に使われていることが判明し、すでにこの時代には日本でも真鍮が使われていたようである。

[Rivkin]

I think the issue is that for a variety of reasons (i.e. different Ph.D. thesis give different explanations) production of soft metals was scarce in early Muromachi Japan, the imports were quite common and absolutely all coinage was imported.

Such coins were later outlawed when Hideyoshi was shifting country to a centralized trade system, all melted down to make whatever was made out of bronze at the time. But their metal content is extremely varied and dirty, so you can't just get any decent shinchu or other alloys from them as is.

[Bugyotsuji]

Just for illustration of varying Shinchū qualities in Kan-ei-tsū-hō (and Ho-ei-tsu-ho) cash coins of the Edo Period. 

PS The upside-down one bottom left does not attract to a magnet.

 

 

[Rivkin]

Copper coins were always towards the bottom of the metal quality in East Asia. More often than not the government monopoly mattered more than the content; 18th century Japanese copper coins are magnetic (i.e. iron based).

[mecox]

But in 1600's-1800's many "copper' coins were made from Cu alloys, but were also made from copper, also iron/Fe-alloy, so depends on period and location, and they were cast. 

[Bugyotsuji]

Yes, from about 1740 onwards many were minted in iron, but 'copper' (some dark red, others bright yellow) coin issues also continued in perhaps equal numbers right to the end of Edo.

 

By the way, use of Chinese coinage was only banned in Japan from Kanbun 10 (1670) onwards.

[Spartancrest]

2 hours ago, Bugyotsuji said:

use of Chinese coinage was only banned in Japan from Kanbun 10 (1670) onwards.

So do we take from this that the melting of Chinese coinage only occurred for a short span from 1670 onwards - till the available stock was used up? Say ten years at most?

If the Chinese coinage was still in circulation up to 1670 you would assume it still had monetary value and would thereby be uneconomic to melt it down before that date. If this "speculation" on my part is right, then the use of melted coinage to obtain brass was for a very short time span. Logical?

[Bugyotsuji]

Well, as I mentioned above, I think the culling of faded or broken coins would have continued down the centuries, perhaps even poured into the mixture for making Buddhist figures, bells, gun locks and barrels etc.

Oh, and the odd tsuba, of course! 

(I tried to include a couple of such coins in the shot above.)

 

It is possible that remaining Chinese coins after 1670 were melted down; if the authorities felt confident that they could mint enough to supply the whole of Japan, perhaps that is where they all went at that time. (Or were they also gathered up and sold back in China by clever merchants?)

[Dave R]

I remember reading on one site, that was specifically about Edo period coin production, that Chinese Cash were twice the value of the Japanese coins, which makes sense, as they were an internationally accepted currency rather like Dollars.

 So where did they go after 1670, back to China!