(1)      Carbon tetrachloride a chemical compound created when carbon disulfide is treated with chlorine is a colorless and inflammable liquid that is used extensively in industry today. This broad use of carbon tetrachloride in industry is because of its efficacy as a solvent, a refrigerant, and a propellant.

(2)      Despite its widespread use in industry, carbon tetrachloride has been banned for home use. In the past, carbon tetrachloride was a common ingredient in cleaning compounds that were used throughout the home. However, it was found to be extremely hazardous: When heated, it turns into a poisonous gas that can cause severe maladies and may even prove deadly if it is inhaled. Because of this dangerous characteristic, the United States revoked permission for the home use of carbon tetrachloride in 1970. The United States has taken similar action with various other chemical compounds.

(1)      The words to "The Star-Spangled Banner," the national anthem of the United States, were created by Francis Scott Key, lawyer by trade and poet at heart. For these memorable words to have been written in the manner that they were, required both his training as a lawyer and his poetic soul.

(2)      At the time of the War of 1812 against the British, Key had a successful law practice in Washington, D.C. During a series of attacks by the British in 1814, the British occupied Washington, D.C., burned public buildings, including the White House, withdrew from Washington, and sailed up the Chesapeake Bay to attack Baltimore. As the British were withdrawing from Washington, they arrested local physician Dr. William Beanes and forced him to accompany them.

(3)      Some friends of Beanes' visited the lawyer Key and asked him to try to negotiate for Dr. Beanes' release from the British. Key, accompanied by a U.S. government official for prisoners of war, sailed out to the British fleet on Chesapeake Bay. Key was able to negotiate a promise from the British to release the doctor. However, since their attack on Baltimore was imminent, the British decided to detain the Americans on board until after the attack so that they would not have the chance to get word back to the American forces about the British plan to attack.

(4)      All through the night of September 13, the British navy bombarded one of the American forts guarding Baltimore, Fort McHenry. In the first light of dawn, Key, standing on the deck of a British warship, was overcome with emotion at the sight of the U.S. flag with its stars and stripes still flying over the fort. On seeing the flag, he was inspired to write the poem that begins "Oh, say can you see by the dawn's early light...." This quickly written poem was immediately printed on handbills and widely circulated.

(5)      Key only wrote the words to "The Star-Spangled Banner." Key did not write the music, nor did anyone else write music specifically to accompany Key's poem. Ironically, the music to today's "The Star-Spangled Banner" was an old English drinking song that far preceded the words that Key wrote. Later, after Key's poem had achieved prominence, it was set to a well-known song that had actually originated in the country of the enemy, and eventually Key's words, set to the tune of a British drinking song, became the national anthem of the United States.

(1)      Another type of lizard, Jackson's chameleon is a remarkable model of adaptability, one whose ability to adjust to varying environments exceeds that of other members of its species. True to the reputation of the species, Jackson's chameleon is a master of camouflage. Special skin cells called chromatophores enable the chameleon to change the pigment in its skin rapidly and escape detection. While the lizard is stalking its prey, it moves very slowly, in a deliberate rocking gait so as to appear to be a part of a branch moved by a gentle breeze. Jackson's chameleon also has the ability to change the shape of its body. By elongating itself, it can look like a twig; by squeezing its sides laterally, it can appear flattened like a leaf. These camouflaging techniques also help the chameleon to escape detection from predators.

(2)      The color change that is characteristic of all chameleons is not solely for the purpose of camouflage. Jackson's chameleon, like all lizards, is an ectotherm that depends on the sun to maintain its body temperature. By changing to a darker color in the morning hours, it can absorb more heat. Once it has reached its optimal body temperature of 77 degrees Fahrenheit (25 degrees Celsius), it changes to a paler hue. Through color change, the chameleon can also communicate its mood to other members of the species. A color change may signal a warning to stay away or an invitation to draw closer.

(3)      Jackson's chameleon has further exemplified its adaptive nature in a way that surpasses other chameleons in its noteworthy migration to a new home: it has become a well-established resident of the Hawaiian Islands even though it is indigenous to the highland rain forests of Kenya and Tanzania. As the story goes, back in 1972 a pet shop owner on the island of Oahu imported several dozen Jackson's chameleons to be sold as pets. When the shipment arrived, the reptiles were emaciated and dehydrated, so the pet shop owner released the lizards into his lush garden, assuming that he could recapture them after they had revived. The chameleons escaped and spread throughout the island, where they thrived in the moist, well-planted tropical flora. Relishing the habitat of secondary growth forest, agricultural areas, and even residential gardens, the chameleon found a ready-made home in its adopted environment.

(4)      Jackson's chameleons continued their unsolicited migration to other islands in the chain as the popular lizards were captured by hikers and other visitors to the island, who took them home and released them in their gardens. This is now a truly ubiquitous lizard; that is, it is now commonplace on all the major Hawaiian Islands.