Assertion: lead pencil's lead | /r/AtLocation | earthen vessels
Facets:
value: over sharp vinegar
type: OTHER
Source sentences:
text: Lead is placed in earthen vessels over sharp vinegar, and after it has acquired some thickness of a sort of rust, which it commonly does in about ten days, they open the vessels and scrape it off, as it were, in a sort of foulness; they then place the lead over vinegar again, repeating over and over again the same method of scraping it till it has wholly dissolved.