Lesson19 The Dead Sea
Throughout history people all over the world have gone to special places where mineral-rich hot springs flow from beneath the earth@s surface. Countries with much volcanic activity such as Japan have many such hot springs and have established over time many customs related to taking baths in these special waters. But many other countries especially in Europe also have centuries-old traditions associated with visiting springs to cure certain types of illnesses.
One of such oldest places in the world is located in present-day Jordan and Israel. Actually, it is not a spring, but rather a sea, the Dead Sea. The ancient Greek philosopher Aristotle wrote about the wonders of the Dead Sea 2500 years ago. It is also said that the Egyptian Queen Cleopatra used water from the Dead Sea to keep her skin beautiful.
The Dead Sea, which has a 33 percent concentration of salts and minerals, is located at the lowest point on Earth, 390 meters below sea level. Because of this unique location, certain atmospheric, thermal, chemical and optical characteristics are found which occur nowhere else in the world. Of course, no fish can live in the Dead Sea, but no one can drown there either. The high concentration of salt allows a person to float on the surface of the water and read a newspaper without getting it wet.

concentration 浓度
optical 光学的

死海
从古至今，世界各地的人们都去那些能从地下流出一些富含矿物质的温泉的特别的地方。火山活动频繁的国家如日本，有许多这样的温泉，并且长期以来形成了许多与在这些特殊水中沐浴有关的习俗。但很多其他国家，尤其是在欧洲，人们也到泉水中治疗某些疾病，这是有了上百年历史的古老传统。
世界上这种最古老的地方之一就位于今天的约旦和以色列。实际上，它不是温泉，更应说是个海：死海。两千五百年前，古希腊哲学家亚里士多德就写下了有关死海奇迹的记述。据说埃及女王克利奥帕特拉用死海的水保持皮肤的美丽。
死海中盐和矿物质的浓度是百分之三十三，它位于世界上的最低点：低于海平面三百九十米。由于这种独特的地理位置，这里有世界上其他地方找不到的某些大气、热、化学和光学的特征。当然，死海里没有鱼，但人在那里不会溺水。高浓度的盐能让人能浮在海面阅读报纸而不会把报纸打湿。