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Author Question: By 11 or 12 months of age, children of English-speaking parents cannot discriminate speech sounds ... (Read 42 times) |
It is believed that the Incas used anesthesia. Evidence supports the theory that shamans chewed cocoa leaves and drilled holes into the heads of patients (letting evil spirits escape), spitting into the wounds they made. The mixture of cocaine, saliva, and resin numbed the site enough to allow hours of drilling.
The most dangerous mercury compound, dimethyl mercury, is so toxic that even a few microliters spilled on the skin can cause death. Mercury has been shown to accumulate in higher amounts in the following types of fish than other types: swordfish, shark, mackerel, tilefish, crab, and tuna.
When Gabriel Fahrenheit invented the first mercury thermometer, he called "zero degrees" the lowest temperature he was able to attain with a mixture of ice and salt. For the upper point of his scale, he used 96°, which he measured as normal human body temperature (we know it to be 98.6° today because of more accurate thermometers).
Congestive heart failure is a serious disorder that carries a reduced life expectancy. Heart failure is usually a chronic illness, and it may worsen with infection or other physical stressors.
In ancient Rome, many of the richer people in the population had lead-induced gout. The reason for this is unclear. Lead poisoning has also been linked to madness.