Hard, Putty-like Material Inside A Bottle

[Flasks]

If your bottle is truly a keeper, and has the age you suspect, leave that accumulated "what-ever" alone as it is part of that bottles history. The picture I've included is a "crude oil" sample bottle with contents that was sent to a laboratory circa early 1860's to find out the ratio of paraffin to various other flammables within this oil as it came from the well. My point is, that rarely are these sample bottles found, let alone to find one with contents which have solidified as has the oil in the bottle pictured.....that makes this bottle unique. Knowing "what" the stuck contents are has more significance to me that guessing what might have that bottle might have contained...get my point? At one time about 150 years ago that dark oil would have been the consistency similar to cooking oil but hard a dried clay today.