1 In the mercury barometer, atmospheric pressure balances a column of mercury, the height of which can be precisely measured. 2  Of the many different varieties of mercury barometers, most variations arise from different techniques for measuring the height of the mercury column.
Recognizing the Symptoms of an HIV Rash. 1  1. Check for a rash that is red, slightly raised, and very itchy. 2  2. Note if the rash appears on your shoulders, chest, face, upper body, and hands. 3  3. Pay attention to other symptoms that may occur when you have HIV rash.  4. Be aware of the causes of HIV rash.
As the immune system worsens, a variety of complications start to take over. For many people, the first early symptoms of HIV infection are large lymph nodes or swollen glands that may be enlarged for more than three months. Other symptoms often experienced months to years before the onset of AIDS include: Lack of energy.