Before you buy materials, choose the location for your built-in cabinet and cut the hole. Then you can adjust the dimensions if your wall studs arenât exactly 14-1/2 in. apart. Remember, your walls are full of pipes, wires and ducts, so you need to do a little detective work to find a good spot.
Vitamin A Elmer V. McCollum and M. Davis discovered vitamin A during 19121914. In 1913, Yale researchers, Thomas Osborne and Lafayette Mendel discovered that butter contained a fat-soluble nutrient soon known as vitamin A. Vitamin A was first synthesized in 1947.
In the 1920s, scientists believed that only two vitamins existed. One was fat-soluble, which means it could dissolve in oil or fat. This vitamin the scientists called Vitamin A. The other vitamin was water-soluble; it could dissolve only in water. This, they called Vitamin B. The fat-soluble vitamins were given letters of their own.But some substances that were given letter names were later found not to be vitamins at all, and were renamed with a word. For instance, there was once a substance called Vitamin H, but itâs now called biotin.hatâs why we have a Vitamin A, B, C, D, E, and K, but no vitamins for the letters F, G, H, and I. But then scientists began to discover other vitamins. The first was a water-soluble vitamin, so it was named B2.