Here's a new video showing exactly how to make colored and flavored rock candy or sugar crystals. These are easy crystals to grow, plus you can eat them or use them as swizzle sticks for drinks.

Rock Candy Resources

Basic Sugar Crystal Recipe
Colored & Flavored Rock Candy
Fix Problems Growing Rock Candy
Video - Tips for Growing Rock Candy Crystals
Rock Candy Photo Gallery

You've heard of saturated fats in the context of foods, but do you know what it means for a fat to be saturated? It simply means the fat molecule is fully saturated with hydrogen atoms, so that there are no double bonds between the carbon atoms.

Examples of Saturated Fats

Saturated fats tend to be waxes or greasy solids. Animal fats and some plant fats contain saturated fats and saturated fatty acids. Saturated fats are found in meat, eggs, dairy, coconut oil, cocoa butter and nuts. A saturated fat is made from a triglyceride bonded to saturated fatty acids. Examples of saturated fatty acids include butyric acid in butter, stearic acid (shown) in meat in cocoa butter and palmitic acid in palm oil and cashews. Most fats contain a mixture of fatty acids. For example, you'll find palmitic acid, stearic acid, myristic acid, lauric acid and butyric acid in butter.

January 27^th marks the passing of David M. Cowie. Cowie was a medical researcher who was instrumental to the addition of iodine in table salt in the United States. Cowie was investigating the high incidents of goiter in the United States Great Lakes and Pacific Northwest areas. Goiter is a swelling of a thyroid gland in the neck and was recognized as a national health problem during the draft preceding World War I. Several young men were disqualified from service because of the condition.

The main reason for the development of goiter is the lack of iodine in a person's diet. The amount of iodine necessary to ward off these effects was very small and finding an effective means to administer iodine to people was needed. Cowie was aware of a Swiss process of adding sodium iodide to table salt (sodium chloride) and managed to convince Michigan salt producers to include minute quantities of sodium iodide to their salt for consumption locally. This type of salt was identified by the label "contains .01 per cent sodium iodide". In less than a year, the Morton Salt Company was distributing iodized salt nationally.

The incidents of goiter were greatly reduced by this dietary addition. Over time, other effects of dietary iodine deficiency were found. The most notable were deficiencies in pregnant women and infants. Iodine was shown to be vital to the development of the brain and the lack can cause lowered intellectual capacity or cretinism.

David Cowie's contribution to public health has helped diminish medical problems that were once a serious problem in the United States. Find out what else occurred on this day in science history.

You can make nitrous oxide or laughing gas quite easily in the lab or at home. However, there are reasons why you might want to forego the preparation unless you have chem lab experience.

What Is Nitrous Oxide or Laughing Gas?

Nitrous oxide (N₂O) is also known as laughing gas. It is a colorless sweet-smelling and sweet-tasting gas that is used in dentistry and surgery because inhaling the gas produces analgesic and anesthetic effects. The gas is also used to produce the engine output of automotive vehicles and as an oxidizer in rocketry. Nitrous oxide gets the name "laughing gas" because inhaling it produces euphoria.

How to Make Nitrous Oxide or Laughing Gas

Joseph Priestley first synthesized nitrous oxide in 1772 by collecting the gas produced from sprinkling nitric acid over iron filings, however, nitrous oxide usually is produced using Humphry Davy's method of gently heating ammonium nitrate to decompose it into nitrous oxide and water vapor:

NH₄NO₃ (s) → 2 H₂O (g) + N₂O (g)

The key here is gently heating the ammonium nitrate to between 170°C and 240°C, because higher temperatures may cause the ammonium nitrate to detonate. People have been doing this without incident for over 150 years, so they key is to be careful. Next, the hot gases are cooled to condense the water. The best way to do this is using a pneumatic trough, which involves a tube leading from the ammonium nitrate container that bubbles the gases up through water into a collection jar. This removes the water from the reaction as well as smoke from impurities in the ammonium nitrate. The gas in the collection jar is your nitrous oxide or laughing gas, plus lesser amounts of other nitrogen oxides, including nitric oxide or nitrogen monoxide. Nitric oxide is oxidized to nitrous oxide upon exposure to oxygen, although acid and base treatments are used to remove impurities for commercial-scale production of nitrous oxide.

Diagram of Nitrous Oxide Preparation

More Details on Nitrous Oxide Preparation