Blue Mass is 33% mercury. It was used to treat syphillis,
tuberculosis, constipation, tootache, parasitic infestations
and the "pains of childbirth".
3 grains of Blue Mass per pill in this 1890s bottle amounts
to 65mg of mercury. The World Health Organization currently
recommends that mercury exposure in food be no more than 2
micrograms per kg of body weight per week.
So people who took one pill per day of this Upjohn Blue Mass
would have a mercury level 2000 times higher than today's