Vintage/Antique Ginger Jar/ Pot (?) Made For Van Alphen, Leiden Netherlands

I saw this in a local thrift shop earlier this year and gave $1.75 for it. Stands about 4 inches high. I don't know what was actually kept in it, but it is called a ginger jar for lack of a better description. The Van Alphen company in Leiden no longer exists and there is no information to find about it.

After months of searching, tonight I finally found one of these pots for sale on the local internet site Marktplaats. First one I've seen, so they must be somewhat rare. No other ones listed anywhere else. The one there has no lid and a crack in it. People are still putting bids on it. Mine has its lid and no cracks.

I am hoping my Dutch CW friends might know the real use of this pot. The material seems to be glazed white earthenware rather than porcelain, as the pot is heavy and dense.

See below for the hotlink.

Thanks for any help!