Medicine Rust?

TomBell · June 4, 2023

Hello again,

Since my post on this forum last year seeking help with the translation of a mei, my katana has been examined by two highly respected authorities. One found the blade to be genuine and "attributed to "高田守次 Takada Moritsugu - he worked in 豊後国 Bungo no kuni during the 大永 Daiei period (1521-1528)". This quote is from second person who translated the opinion for me. The other believes the blade is a mumei. His opinion is based on the corrosion pattern on the Nakago "a large portion of the rust on the omote is all pock marked with small pin holes. This is caused by using chemicals to make a forced rust. This is called medicine rust." My question: Is there a corrosion pattern that is definitive of this practice or process? I hope my inclusion of a photo of the Nakago will help.

Larason2 · June 4, 2023

I wouldn't trust the person who tells you a sword with a signature on the nakago is "mumei." They clearly don't know what that word means. As for medicine rust, you should tell him that when steel rusts, it makes small pock marks.

Brian · June 4, 2023

Mumei means unsigned. So that is not an option. I'm guessing the guy means machi okuri (moving the machi upwards) which is likely true. The blade was likely "moved upwards" and the newer patina was originally blade.
It's possible, doesn't change much. The question is whether the mei was added later or not, and that I can't tell.

Geraint · June 4, 2023

Dear Tom.

While doing a bit of digging I came across your post in another forum where the NTHK paper is illustrated, I think you can take that as pretty definitive, especially as the sword has a mei. It is unlikely that NTHK would paper a blade that had such issues as your second authority described so perhaps not someone to rely on too much in the future.

By the way, NTHK certificates usually come with a work sheet, did you get one of those?

Enjoy the sword.

All the best.

TomBell · June 4, 2023

Thank you all.

The second authority also had this to say regarding alteration of the original blade: "Your sword is an ubu sword just reworked to make it look older. If it was suriage then the temper would go back into the nakago. It actually stops with a downward turn about ¾” after the ha machi.....Then the signature was added Moritsugu below a hole lower on the blade. This is all done to make a mumei sword easier to sell. It is a fake. Natural rust will always be smooth."

If the original mei was lost by suriage might the second smith have added a new mei in sosho using the original smith's name to preserve the attribution but signaling that this is a new mei?

I had committed to having the sword polished but this controversy makes me wonder if it is worth it.

NTHK_Worksheet.pdf

drbvac · June 4, 2023

With the worksheet from the NTHK I am not sure why you are putting much credence in the "second authority". Considering he stated the sword was mumei, that would be the end of my paying any attention to him at all! Is he interested perhaps in purchasing the blade from you ?

Bruce Pennington · June 4, 2023

Maybe overkill, but let me summarize the second guy:

He thinks the original blade was mumei. It has since been cut down, mei then added, chemicals then applied to make the nakago look older.

I agree with the rest of the guys - I would think the NTHK guys would recognize a gimei and faked rust. I'd go with the first guy and have your blade polished.

Ed Harbulak · June 4, 2023

The NTHK worksheet ATTRIBUTES the blade to Takada Moritsugu, they don't say it's signed Takada Moritsugu. They do mention there is another inscription, but that isn't translated. With so many questions, I'd certainly think twice before spending money to get it polished, just my opinion. The two characters on the nakago might be Moritsugu in script writing and if indeed they are,that would explain why the worksheet indicates the mei is Moritsugu. Then perhaps the attribution gives more details as to which Moritsugu. Still lots of questions. The nakago does look ubu and machi ocuri , but then the question becomes did Moritsugu sign in script with two characters? Still, the blade is papered by the NTHK.

Edited June 4, 2023 by Ed Harbulak

SteveM · June 4, 2023

The paper says the signature is "Moritsugu" and their attribution of Takada Moritsugu is affirming the signature.

The bit after the signature (on the paper) is "大永" which is repeated at the bottom, indicating the approximate era.

PNSSHOGUN · June 5, 2023

Not to say the NTHK are faultless but they are made up of a panel of very experienced and accomplished experts. Weigh that up against the person giving you their opinion from the hip.

TomBell · June 6, 2023

To return to my original question, I was skeptical of the identification of medicine rust based on pinholes and the statement that "Natural rust will always be smooth". After examining the image of a rusted wakizashi, which has a nearly identical corrosion texture to that on my nakago, I feel certain that the expert's opinion is in error. Based on the opinions above and this comparison, I am relieved. Finding a polisher has been a challenge.