On Sun, 18 Jan 2004 06:39:37 GMT, Bob Ingraham
wrote:

snip

I'm curious about something: I don't know where I first learned about the
sulphuric-acid content of the gum if C57 and C58, but it's not mentioned in
Scott! Not, at least, in my elderly (1986) edition. Is it mentioned in newer
editions? I did find mention of it on Linn's "Refresher Course" web page at
http://www.linns.com/howto/refresher/gum_20030217/refreshercourse.asp.

Page 28A of my 2002 Scott Volume 3 states that Germany B68 has highly
acidic gum. The stamp is valued with gum removed.

Page 126 of same edition states that "The note concerning gum after
No. B28 also applies to Nos. C57-C58."

Page 121 speaks about the Ostropa sheet (B68), gum and that collectors
prefer to remove it because of the acidity.

Tracy Barber