.... (1742-86), a Swedish pharmacist and chemist. It is generally believed that Scheele was the first to isolate oxygen, but that Priestley, who independently achieved the isolation of oxygen somewhat later, was the first to publicly announce his findings. The interpretation of the findings of Priestley and the resultant clarification of the nature of oxygen as an element was accomplished by the French scientist Antoine-Laurent LAVOISIER (1743-94). Lavoisier's experimental work, which extended and improved upon Priestley's experiments, was principally responsible for the understandi .....

.... and health care. The U.S. Public Health Service estimates that in 1993, the lifetime cost of treating a person with AIDS from infection to death is approximately $119,000. Outpatient care, including medication, visits to doctors, home health aids, and long-term care, accounted for approximately 32 percent of the total cost. Persons exposed to may have difficulty in obtaining adequate health-insurance coverage. Yearly AZT expenses can average approximately $6,000, although in 1989 the drug's maker did offer to distribute AZT freely to -infected children. The yearly expense for .....

.... the hydroelectric is because their countries don’t have enough concentrated water to create enough energy to generate electricity. (World Book vol. 14, 586) Nuclear power plants generate only about eleven percent of the world’s electricity. There are around 316 nuclear power plants in the world that create 213,000 megawatts of electricity. (INFOPEDIA) Radioactive, or nuclear, waste is the by-product of nuclear fission. Fission occurs when atoms’ nucleus’ split and cause a nuclear reaction. (General Information) When a free neutron split .....

.... during an epileptic seizure; another from brain hemorrhage. Other dogs, before death, became feverish and anemic, lost their appetites, and had hemorrhages. The experimenters compared their results to those experiments conducted at the University of Utah and the Argonne National Laboratory in which beagles were injected with Strontium 90. They concluded that the dose needed to produce “early death” in fifty percent of the sample group differed from test to test because the dogs injected with Strontium 90 retain more of the radioactive substance than dogs forced to inhal .....

.... cleanup program was developed in 1980. The EPA then evacuated Times Beach, Montana for dangerous levels of dioxin in soil, which was then criticized for its heavyhandedness and arrogance. Charges of mismanagement and undue political influence caused the head of the EPA to resign in '83. "The deputy director resigns because of charges of making a 'hit list' of employees to be hired, fired, or promoted because of political leanings. The former head of the toxic waste cleanup is found guilty of perjury and obstructing congressional inquiry. A regulation requiring treatm .....

.... method. The concentrated beams of sunlight are collected in a device called a solar furnace, which acts on the same principles as a large magnifying glass. The solar furnace takes the sunlight from a large area and by the use of lenses and mirrors can focus the light into a very small area. Very elaborate solar furnaces have machines that angle the mirrors and lenses to the sun all day. This system can provide sizeable amounts of electricity and create extremely high temperatures of over 6000 degrees Fahrenheit. Solar energy generators are very clean, little waste is e .....

.... is the birth control pill? The combined oral contraceptive pill (the pill) is a reversable, hormonal method of birth control. The pill consists of a mixture of two synthetic hormones similar to oestrogen and progesterone, the woman’s natural hormones which regulate the menstrual cycle. The pill is on of the most popular methods of birth control. How does it work? The pill basically prevents ovulation, therefore, the ovaries can’t release a mature egg. Without an egg for the sperm to fertilize , a woman cannot get pregnant . The hormones also increase cervical muc .....

.... reducing stress, relaxing, uplifting, sedating or stimulating, restoring both physical and emotional well-being. Although Aromatherapy is consider to be a new and alternative foram of medicine in the western world, however it has been practiced for thousands of years in the eastern world. A lot of interest in Aromatherapy stems from its use as an 'alternative medicine' or even a 'complementary medicine'. It is certainly true that before pharmaceutical companies brought a vast array of modern drugs to the market, people had to make do with many 'home remedies' - often herbal r .....