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This Day in Science History - February 10 - Saccharine Discovery

2010-02-10T00:05:36Z

February 10^th is Ira Remsen's birthday. Remsen was an American chemist and educator who brought many German chemical techniques to America and founded the chemistry department at Johns Hopkins University. He also founded the American Chemical Journal and acted as its editor for 35 years.

He is most known for the actions of one of his researchers, Constantin Fahlberg. Fahlberg apparently does not wash his hands after working with chemicals all day. During dinner one day, he noticed his dinner roll tasted extra sweet. He asked his wife if she did anything special with the rolls, but her roll was not sweet at all. He figured the sweetness was caused by something left on his hands from the lab.

He had been working on coal tar derivatives and spent the next day tasting his work. Ramsen and Fahlberg identified the sweetness was caused by an oxidation of o-toluenesulfonamide. Fahlberg quickly recognized the economic potential of a new sweetener and patented the discovery as 'saccharine' and claimed the discovery as his own. This caused a rift between the two chemists that lasted a lifetime.

I would still recommend washing your hands before dinner after a hard day in a chemistry lab, even if you miss out on important discoveries because of it. Find out what else occurred on this day in science history.

This Day in Science History - February 10 - Saccharine Discovery originally appeared on About.com Chemistry on Wednesday, February 10th, 2010 at 00:05:36.

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Hydrogen Peroxide Shelf Life

2010-02-09T11:23:38Z

If you've ever poured hydrogen peroxide solution onto a cut and didn't experience the expected fizz, it's likely your bottle of hydrogen peroxide has become a bottle of plain water. The 3% hydrogen peroxide solution you can buy for use as a disinfectant typically has a shelf life of at least a year if the bottle is unopened, but only lasts 30-45 days once the seal has been broken. As soon as you expose the peroxide solution to air, it starts to react to form water. Also, if you contaminate the bottle (e.g., by dipping a swab or finger into the bottle), you can expect the effectiveness of the remaining liquid to be compromised.

So, if you have a bottle of hydrogen peroxide that has been sitting in your medicine cabinet for a few years, it would be a good idea to replace it. If you've opened the bottle at any point, its activity is long-gone. If you feel like testing the solution. Solvay Chemicals describes a test you can perform to assess the remaining activity.

Hydrogen Peroxide Shelf Life originally appeared on About.com Chemistry on Tuesday, February 9th, 2010 at 11:23:38.

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This Day in Science History - February 9 - US Weather Bureau

2010-02-09T00:05:34Z

February 9^th is the birthday of the United States Weather Bureau. Professor Lapham of Milwaukee was instrumental in raising awareness for a need for the government to pay attention to weather. He frequently forwarded clippings of newspaper articles outlining the deaths of sailors due to severe Great Lake storms. Congress passed the legislation and President Ulysses S. Grant established the Bureau in 1870. The official name for this agency was "The Division of Telegrams and Reports for the Benefit of Commerce". The agency granted the Secretary of War to maintain meteorological observations and data and to warn citizens of approaching storms. The task was assigned to the War Department because it was believed military discipline would allow the "greatest promptness, regularity, and accuracy" needed to maintain the service. Every day, personnel from the Signal Service Corps would report weather information to Washington DC.

The Weather Bureau would evolve over time to become the National Weather Service under the administration of the National Oceanic and Atmospheric Administration. Find out what else occurred on this day in science history.

This Day in Science History - February 9 - US Weather Bureau originally appeared on About.com Chemistry on Tuesday, February 9th, 2010 at 00:05:34.

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Duct Tape (or Duck Tape) Triboluminescence

2010-02-08T17:38:01Z

Here's an extremely simple science project you can try. All you need is duct or duck tape. It doesn't matter which name you call it, but your results seem to depend partially on the brand you use: Henkel™ works well.

What You Do

Tear off two strips of tape. Stick the pieces together with the sticky sides facing each other, leaving enough tape so that you can pull the strips apart. Turn out the lights. Give your eyes a minute or two to adjust to the dark. Pull the strips of tape apart.

What Happened

Did you see the blue line where the tape separated? (NurdRage has a video if you'd like to see what to expect.) This is triboluminescence, which is a type of luminescence triggered by mechanical energy or electrical energy from an action such as friction. You can get the same effect from other types of tape as well. A good one to try is transparent Scotch™ tape.

My camera was not sufficiently sensitive to take a photo of this effect, but you may be able to capture tape triboluminescence if you have high-speed capability.

More Triboluminescence Examples | Candy Spark-in-the-Dark

Duct Tape (or Duck Tape) Triboluminescence originally appeared on About.com Chemistry on Monday, February 8th, 2010 at 17:38:01.

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Nitrogen Facts

2010-02-08T09:37:09Z

You breathe oxygen, yet air is mostly nitrogen. You need nitrogen to live and encounter it in the foods you eat and in many common chemicals. Here are some quick facts about this element. You can find detailed information about nitrogen on the nitrogen facts page.

Nitrogen is odorless, tasteless, and colorless.
Nitrogen gas (N₂) makes up 78.1% of the volume of the Earth's air.
Nitrogen is a nonmetal.
Nitrogen gas is relatively inert, but soil bacteria can 'fix' nitrogen into a form that plants and animals can use to make amino acids and proteins.
The French chemist Antoine Laurent Lavoisier named nitrogen azote, meaning without life.
Nitrogen was sometimes referred to as 'burnt' or 'dephlogisticated' air, since air that no longer contains oxygen is almost all nitrogen. The other gases in air are present in much lower concentrations.
Nitrogen compounds are found in foods, fertilizers, poisons, and explosives. Your body is 3% nitrogen by weight.
Nitrogen is responsible for the orange-red, blue-green, blue-violet, and deep violet colors of the aurora.
One way to prepare nitrogen gas is by liquefaction and fractional distillation from the atmosphere.
Nitrogen has a valence of 3 or 5.

Photo: Nitrogen in a gas discharge tube glows blue-violet. This color is commonly seen when air is ionized by lightning. (Jurii, Creative Commons)

Nitrogen Facts originally appeared on About.com Chemistry on Monday, February 8th, 2010 at 09:37:09.

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This Day in Science History - February 8 - Dmitri Mendeleev

2010-02-08T00:05:51Z

February 8^th is Dmitri Mendeleev's birthday. Most people associate Mendeleev the first accepted periodic table of the elements. His table ordered the elements by increasing atomic weight where columns of elements had similar chemical properties and is the immediate forerunner of the modern periodic table.

Mendeleev was also the man responsible for making Russia "metric". As Director of Russia's Bureau of Weights and Measures, he was instrumental in bringing the metric system to Russia.

In his personal life, he was famous for his "grooming". Mendeleev was widely known for his long hair and wild beard. He would only cut his hair or trim his beard once a year. He had one minor scandal where he was labeled a bigamist for a legal technicality for not waiting the required seven years after a divorce before marrying his second wife.

Find more about Mendeleev and what else occurred on this day in science history.

This Day in Science History - February 8 - Dmitri Mendeleev originally appeared on About.com Chemistry on Monday, February 8th, 2010 at 00:05:51.

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Scientists Freeze Water by Heating It

2010-02-07T20:16:04Z

According to the RSC, Israeli scientists have managed to freeze water by heating it. How was this achieved? They used supercooled water, which is just waiting for a stimulus to cause it to freeze, and put it on a lithium tantalate substrate, which was warmed from -17°C to -7°C. The water froze as the temperature was raised, but the reason is probably that the ionic charge on lithium tantalate changes from positive to negative as the material is warmed. Thus, it would appear electrification plays a role in the nucleation of ice crystals. The reason for this is not entirely clear, but the research may offer clues about how water freezes in cumulus clouds.

Scientists Freeze Water by Heating It originally appeared on About.com Chemistry on Sunday, February 7th, 2010 at 20:16:04.

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This Day in Science History - February 7 - Periodic Table and Law of Octaves

2010-02-07T00:05:02Z

February 7, 1863 was the day John Newlands published what would be known as "The Law of Octaves". Newlands discovered if he ordered the known elements by increasing atomic weights, the chemical properties of the elements would be similar for every eighth group. Since the pattern seemed to follow the same pattern as the piano's octaves, he called his periodic law the "Law of Octaves"

The reception Newlands received after publishing this discovery was met with severe criticism. His ideas were labeled 'useless' and 'arbitrary' and caused him to give up his work on organizing the elements. In the next decade, two other chemists published periodic laws based on atomic weights. Mendeleev and Meyer both independently identified their versions of the Law of Octaves and showed Newlands' ideas were neither 'arbitrary' no 'useless'. The periodic table would follow the increasing atomic weights until the discovery of atomic numbers by Henry Moseley in 1914 and the current periodic table was born.

Find out what else occurred on this day in science history.

This Day in Science History - February 7 - Periodic Table and Law of Octaves originally appeared on About.com Chemistry on Sunday, February 7th, 2010 at 00:05:02.

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This Day in Science History - February 6 - Joseph Priestley

2010-02-06T00:05:31Z

February 6^th marks the passing of Joseph Priestley. Priestley was an English theologian and natural philosopher who is best known with this experimental works with gases or "airs". He was the first to identify several gases including the element oxygen. This discovery helped answer the old question: Why do things burn? The prevailing theory of the time held there was a substance present in all things called phlogiston. Things would burn until they become saturated with phlogiston and any fire would go out. Priestley's found his new air greatly increased the process of burning and called it "dephlogisticated air" since it appeared to contain no phlogiston. Even though his discovery seemed to support the phlogiston theory, it was one of the key elements to launch Lavoisier's chemical reaction theories that started the Chemical revolution of the 19^th Century.

Priestley began his work with gases with a ready supply of phlogistated air, or carbon dioxide. He obtained near limitless supplies from a brewery near his ministry. One of the most notable achievements from this was a process to easily create carbonated water. Enjoy a carbonated beverage in honor of Priestley and find out what else occurred on this day in science history.

This Day in Science History - February 6 - Joseph Priestley originally appeared on About.com Chemistry on Saturday, February 6th, 2010 at 00:05:31.

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Make Your Own Shampoo

2010-02-05T09:33:05Z

There are a lot of reasons why you might want to make your own shampoo from scratch. The big two probably are wanting to avoid the chemicals in commercial shampoos and just simply wanting to make shampoo yourself. Back in ye olden days, shampoo was soap, except with additional moisturizers so that it didn't strip the natural oils from your scalp and hair. Although a shampoo can be solid, it is easier to use if there is enough water to make a gel or liquid. Shampoos tend to be acidic because if the pH gets too high (alkaline) the sulfur bridges in the hair keratin can break, damaging your hair. This recipe for making your own gentle shampoo is chemically a liquid soap, except vegetable-based (many soaps use animal fat) and with alcohol and glycerine added during the process. Make it in a well-ventilated room or outdoors and be sure to read all of the safety precautions on the ingredients.

Shampoo Ingredients

2 lb 10 oz olive oil
1 lb 7 oz of solid-type vegetable shortening
1 lb coconut oil
10-1/4 oz lye (sodium hydroxide)
2 pints water
1-1/2 oz glycerine (glycerol)
1/2 oz alcohol (I'd use vodka or other food-quality ethanol and call it close enough. Do not use methanol.)
1-1/2 oz castor oil
essential oils (optional), such as peppermint, rosemary, lavender, for fragrance and therapeutic properties

Let's Make Shampoo!

In a large pan, mix together the olive oil, shortening, and coconut oil.
In a well-ventilated area, preferably wearing gloves and eye protection in case of accidents, mix the lye and water. Use a glass or enameled container. This is an exothermic reaction, so heat will be produced.
Warm the oils to 95°F-98°F and allow the lye solution to cool to the same temperature. One of the easiest ways to accomplish this is to set both containers into a large sink or pan full of water that is at the correct temperature.
When both mixtures are at the proper temperature, stir the lye solution into the oils. The mixture will turn opaque and may darken.
When the mixture has a creamy texture, stir in the glycerine, alcohol, castor oil, and any fragrance oils or colorants.
You have a couple of options here. You can pour the shampoo into soap molds and allow it to harden. To use this shampoo, either lather it with your hands and work it into your hair or else shave flakes into hot water to liquefy it.
The other option is to make liquid shampoo, which involves adding more water to your shampoo mixture and bottling it.

You may have noticed that many shampoos are pearlescent. You can make your homemade shampoo glittery by adding glycol distearate, which is a natural wax derived from stearic acid. The tiny wax particles reflect light, causing the effect.

Make Your Own Shampoo originally appeared on About.com Chemistry on Friday, February 5th, 2010 at 09:33:05.

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