How China declared war on Germany in WW1?

Hello,

Does any one know what was the reason and the excuse for China to declare war on Germany in WW1?

I have read that the excuse was the faked story about german “corpse factories”. British accused Germans in making soap out of dead bodies. This allegation lasted from yearly 1917 till 1925. Any one has more info and sources?
A bit more on the “corpse factories” can be found in the book by Philip Knightley: “The first casualty”. And here is the extract on-line: http://www.nizkor.org/ftp.py?camps/stutthof/soap.03

But what was also the real reason? What was the China’s aim?

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