An interesting part of the rubber processing would include the use of formic acid for firming up latex to form the more solid rubber sheets. Formic acid usually came in big glass bottles and I believe that there was little control of this dangerous acid until many women started to drink it to commit suicide!! There were tons of stories involving the drinking of formic acid. There were lots of stories involving men and women having fights using formic acid as well. These were fodder for good novels !!
And as the rubber industry almost came to a standstill during the Communist Insurgency in the 70's the formic acid bottles disappeared from our social scene. Today not many people would even remember these beautiful transparent bottles.
Lucas Johnny (from Sibu) had the foresight of collecting a few while he was a civil servant with RTM. He has been using these lovely bottles for bottled fern garden.
Here he is explaining to Honey Bee who is admiring the fern garden in a bottle.
Lucas Johnny's fern garden in a bottle on exhibit in Pustaka Miri recently!!
P/s The Sibu Fuzhou Cultural Heritage Gallery also exhibits one such formic bottle.