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night blindness

(Encyclopedia)night blindness, inability to see normally in subdued light. It is usually a result of vitamin A deficiency. The rod cells, one of two light-sensitive areas of the retina of the eye, are impaired in t...

C, letter of the alphabet

(Encyclopedia)C, third letter of the alphabet. In position and form, but not in meaning, it corresponds to Greek gamma (see G). In English it is pronounced variously, e.g., in can, cent, church, and loch. In musica...

lanthanum

(Encyclopedia)lanthanum lănˈthənəm [key] [Gr.,=to lie hidden], metallic chemical element; symbol La; at. no. 57; at. wt. 138.90547; m.p. about 920℃; b.p. about 3,460℃; sp. gr. 6.19 at 25℃; valence +3. Lan...

antenna

(Encyclopedia)antenna ăntĕnˈə [key], in electronics, system of wires or other conductors used to transmit or receive radio or other electromagnetic waves (see radio); sometimes called an aerial. The idea of usi...

nitrogen

(Encyclopedia)nitrogen nīˈtrəjən [key], gaseous chemical element; symbol N; at. no. 7; interval in which at. wt. ranges 14.00643–14.00728; m.p. −209.86℃; b.p. −195.8℃; density 1.25 grams per liter at ...

Jensen, Johannes Vilhelm

(Encyclopedia)Jensen, Johannes Vilhelm yōhänˈəs vĭlˈhĕlm yĕnˈsən [key], 1873–1950, Danish writer. As a young man he studied medicine; his interest in biology and anthropology is obvious throughout his w...

dharma

(Encyclopedia)dharma därˈmə [key]. In Hinduism, dharma is the doctrine of the religious and moral rights and duties of each individual; it generally refers to religious duty, but may also mean social order, righ...

consent

(Encyclopedia)consent, in law, active acquiescence or silent compliance by a person legally capable of consenting (see age of consent). It may be evidenced by words or acts or by silence when silence implies concur...

Scheele, Karl Wilhelm

(Encyclopedia)Scheele, Karl Wilhelm kärl vĭlˈhĕlm shāˈlə [key], 1742–86, Swedish chemist, b. Stralsund. He is known as the discoverer of many chemical substances. He was a pharmacist in Stockholm, in Uppsa...

pentathlon

(Encyclopedia)pentathlon pĕntăthˈlən [key], composite athletic event. In ancient Greece it comprised leaping, foot racing, wrestling, discus throwing, and casting the javelin. The modern pentathlon, an Olympic ...