I gave up looking for a description of these with the term weather
glass. Now it seems they are posted all over the bloody place:

http://chemistry.about.com/od/weirds.../a/fitzroy.htm
http://en.wikipedia.org/wiki/Storm_glass


From Wikipedia:

A storm glass is a type of weather-forecasting device, composed of a
sealed glass container, filled with liquid, that allows the user to
forecast the weather by observing the appearance of the liquid in the
glass.

The liquid within the glass is a mixture of several ingredients, most
commonly distilled water, ethanol, potassium nitrate, ammonium
chloride, and camphor. This specific mixture was developed by Admiral
Robert FitzRoy and used on his voyage with Charles Darwin on the HMS
Beagle.

During the historic voyage, FitzRoy carefully documented how the storm
glass would predict the weather:

* If the liquid in the glass is clear, the weather will be bright
and clear.
* If the liquid is cloudy, the weather will be cloudy as well,
perhaps with precipitation.
* If there are small dots in the liquid, humid or foggy weather
can be expected.
* A cloudy glass with small stars indicates thunderstorms.
* If the liquid contains small stars on sunny winter days, then
snow is coming.
* If there are large flakes throughout the liquid, it will be
overcast in temperate seasons or snowy in the winter.
* If there are crystals at the bottom, this indicates frost.
* If there are threads near the top, it will be windy.

Obviously if the following text were true then merely treating the
apparatus to heat and pressure would verify it:

"A storm glass works on the premise that temperature and pressure
affect solubility, sometimes resulting in clear liquid; other times
causing precipitants to form."

"However, the method by which this works is not fully understood.

Although it is well-established that temperature affects solubility,
some studies have simultaneously observed several different storm
glasses forming similar crystal patterns at different temperatures.

In addition, sealed glasses are not exposed to atmospheric pressure
changes and do not react to the pressure variations associated with
weather systems."

Thus requiring:

"Some people have proposed that surface interactions between the glass
wall of the storm glass and the liquid contents account for the
crystals. Explanations sometimes include effects of electricity or
quantum tunnelling across the glass."

The article doesn't detail whether or not the thing actually works. If
it does I suspect the cause to be the same as that which affects the
fluid in the joints of arthritics and other similarly afflicted
empaths.

I came across the description years ago - the early 1990's perhaps in
a decidedly fungal and damp copy of Whittaker's Almanac dated to the
turn of the 19th century, 1880's -90's.

At the time I was having success with some decidedly damp and fungal
home brewed beer or wine or mixture (I forget.) The sediment had a
remarkable ability to follow the weather.

And why shouldn't it? We take for granted that milk goes off in
certain weather conditions far more easily than in others. And this
process is far more occult than mere temperature would allow.

Here is how to make one:
"Here are instructions for constructing a storm glass, described by
Pete Borrows in response to a question posted on NewScientist.com,
attributed to a letter published in the June 1997 School Science
Review.

Ingredients for Storm Glass

* 2.5 g potassium nitrate
* 2.5 g ammonium chloride
* 33 mL distilled water
* 40 mL ethanol
* 10 g camphor

Dissolve the potassium nitrate and ammonium chloride in the water; add
the ethanol; add the camphor. Place in corked test tube."

http://chemistry.about.com/od/weirds.../a/fitzroy.htm

The author goes on:

"Mark Ford, who has been making storm glasses for years, e-mailed me
to add that man-made camphor, while very pure, does contain borneol as
a by-product of the manufacturing process. His experience is that the
synthetic camphor doesn't work as well as natural camphor, perhaps
because of the borneol."

I doubt it is the impurity, a little impurity seems implicit in the
ingredients given above. What is true about manufactured organics is
that they display no significant optical polarity.

Natural organic chains on the other hand seem to be a product of the
left hand of god.

(The molecular structure of the amino acids used to make protein in
all living things is left handed. This indicates either a preference
expressed by the designer of all living things or the hemisphere in
which primordial soup was most successfully struck by lightning.)

On Oct 5, 1:16 am, Weatherlawyer wrote:

I doubt it is the impurity, a little impurity seems implicit in the
ingredients given above. What is true about manufactured organics is
that they display no significant optical polarity.

Natural organic chains on the other hand seem to be a product of the
left hand of god.

Nice pictures he
http://www.owltechs.com.au/

Nice prices too. I somehow doubt the efficacy of Chinese alternatives -
which country though famous for cheap goods is also famous for poor
quality control. So basically how do you test that the camphor used is
actually natural camphor?

And is camphor the only wax that displays these properties?

On Oct 5, 1:16 am, Weatherlawyer wrote:

http://chemistry.about.com/od/weirds.../a/fitzroy.htm

"Mark Ford, who has been making storm glasses for years, e-mailed me
to add that man-made camphor, while very pure, does contain borneol as
a by-product of the manufacturing process. His experience is that the
synthetic camphor doesn't work as well as natural camphor, perhaps
because of the borneol."

I doubt it is the impurity, a little impurity seems implicit in the
ingredients given above. What is true about manufactured organics is
that they display no significant optical polarity.

Natural organic chains on the other hand seem to be a product of the
left hand of god.

(The molecular structure of the amino acids used to make protein in
all living things is left handed. This indicates either a preference
expressed by the designer of all living things or the hemisphere in
which primordial soup was most successfully struck by lightning.)

From Wikipedia:

The specific rotation of a chemical compound [ ] is defined as the
observed angle of optical rotation when plane-polarized light is
passed through a sample with a path length of 1 decimeter and a sample
concentration of 1 gram per 1 deciliter.

The specific rotation of a pure material is an intrinsic property of
that material at a given wavelength and temperature. Values should
always be accompanied by the temperature at which the measurement was
performed and the solvent in which the material was dissolved. Often
the temperature is not specified; in these cases it is assumed to be
room temperature.

The formal unit for specific rotation values is deg cm² g-1 but
scientific literature uses just degrees. A negative value means
levorotatory rotation and a positive value means dextrorotatory
rotation. Some examples:

* Sucrose +66.47°
* cholesterol 31.5°
* Camphor +44.26°
* Penicillin V +223°
http://en.wikipedia.org/wiki/Specific_rotation

I wonder if I can make a cheap version with a drop of gin and some
sugar? Or is the angle of rotation a priority? And does the substance
forming the crystals have to be insoluble in one of the mixtures?