Did you know?
Your skin wrinkles if you stay in the bathtub a long time because the outermost layer of skin (which consists of dead keratin) swells when it absorbs water. It is tightly attached to the skin below it, so it compensates for the increased area by wrinkling. This happens to the hands and feet because they have the thickest layer of dead keratin cells.
Did you know?
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.
Did you know?
In most cases, kidneys can recover from almost complete loss of function, such as in acute kidney (renal) failure.
Did you know?
Tobacco depletes the body of vitamins A, C, and E, which can result in any of the following: dry hair, dry skin, dry eyes, poor growth, night blindness, abscesses, insomnia, fatigue, reproductive system problems, sinusitis, pneumonia, frequent respiratory problems, skin disorders, weight loss, rickets, osteomalacia, nervousness, muscle spasms, leg cramps, extremity numbness, bone malformations, decayed teeth, difficulty in walking, irritability, restlessness, profuse sweating, increased uric acid (gout), joint damage, damaged red blood cells, destruction of nerves, infertility, miscarriage, and many types of cancer.
Dentition, as illustrated in Knight's Sketches in Natural History
Early History of the Universe
Earth scientists have devised a scheme to divide the planet’s natural history into distinct time ...
Recent history of biochemistry shown by the introduction of new techniques. (part 2)
Obliquity "Tilt of Earth on its axis"
The evolutionary history of the globin gene superfamily