milk glass as well as other canning jar lid liners were used to prevent the
taste of zinc from entering the canned food.  Boyd's patent I believe was
sometime in the early 1860s.  As I am at home I'm not sure of the exact
date.  The 5 does not reflect the size of the jar as most manufacturers made
the same size opening for different sized jars.  This not to say that there
are not different size lid liners...there are as well as a variety of jar
closures.  There are books devoted to canning jars, in fact there is a real
good series "The Red Books" used by collectors which are very helpful.  As
far as the use of PORCELAIN, I have seen it on milk glass that could almost
pass for porcelain and I've seen it on milk glass that this is almost
transparent with a dash of white...go figure.  Good luck in your search

Bill Liebeknecht
Hunter Research Inc.
Trenton, NJ
-----Original Message-----
From: Jim Ambrosino <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: Wednesday, September 29, 1999 4:47 PM
Subject: Milk glass CONFUSION!!!!!!!


>Our lab has come across a milk glass lid liner artifact that bears the
>inscrption "BOYD'S GENUINE PORCELAIN LINED CAP " around the edge, and in
>the center there is a "5." We are trying to figure out why something
>that is obviously milk glass is labeled as porcelain.  Can anyone help
>us with the identification of this inscription?
>
>Thanks,
>Laura Benson