The bottle collection

The colour of old bottles intrigues me. I have a few and we have a good few in the ringing chamber. Historically, black was originally thought to be the most effective colour, but you could not see the substance inside. Blue became a more popular colour as it provided protection and you could see inside. Dark green and purple were also used for these reasons.
The most chemically inactive glass was red. This was not widely used to make bottles because it was expensive to produce. To make glass red, gold needed to be added to the molten glass. This is what makes it both expensive to produce and very stable. Gold is still added to produce red glass today.
In the mid 1900s amber became the most common glass used for preparations. It provides protection from light and was not expensive to produce. Before that, the most common colours used for glass bottles were blue and green. Blue was used into the 1900s due to its appeal to the eye, even though it was expensive.
There was a connection between the colours used and the contents of the bottle. Blue was the original colour used for poison bottles. Green became more common in the mid 1800s. Blue bottles were also used for syrup. They were designed with a wide-brimmed, loose-fitting stopper that would not become sticky but still keep out the dust. Tin and plastic caps were used later.
Blue was also used for essential oils that needed to be kept from the light and air that would affect their quality and fragrance. Green bottles shared similar contents to blue. Their contents were more likely to be dangerous containing poisons and acid.
If you look carefully you might just see the old Bovril bottle.