What is storm glass?

The inventor of this interesting object was Robert Fitzroy, considered the first meteorologist in history. It was developed during a scientific expedition with Charles Darwin and was generally used by 19th century sailors.
It is a sealed glass container filled with a mixture of liquids that takes on different shapes depending on the weather conditions, which makes it possible to predict the weather in the short term.
The main components of the mixture are distilled water and ethanol, but it also contains small volumes of potassium nitrate, ammonium chloride and camphor.
The working principle of the apparatus is based on the fact that changes in atmospheric pressure and air temperature cause changes in the solubility of the liquid inside the glass. Thus, the inside of the storm glass may be with or without flakes, small crystallites or filamentary structures depending on the atmospheric conditions.

How does the storm glass behave depending on changes in the weather?

1st If the weather is good, the compound substance will remain at the bottom and the liquid will be transparent.
2nd Before it rains, the substance will gradually rise and the liquid will remain transparent, with small particles moving within it.
3rd Before a storm or strong wind the substance will rise partially to the top and take on the appearance of a plume. Generally, the warning will precede the change in the weather by twenty-four hours.
4th In winter, the substance will normally rise quite high; - in snowy or frosty weather it will be white, with small moving stars.
5th In summer, in hot, dry weather, the substance will be very low.
6th To know in which direction the wind will blow or the storm will arrive, it is necessary to observe that the substance sticks to the wall of the tube, opposite to the direction from which the squall or wind is coming.