Borax

Borax was a substance that was considered to be of some importance on 19th century Earth. In fact, a slogan from the era even proclaimed that "Borax is king".

A poster advertising 20 mule team package borax and borax soap was on display in San Francisco in 1893. It showed a small child holding up a package of Borax, with the 20 mule team behind it. 

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 * , the man behind promoting Borax and the 20 mule team
 * , the man behind promoting Borax and the 20 mule team