Your doctor may need to change the doses of your medications or monitor you carefully for side effects. ... Metformin side effects can also affect other parts of the body. It can leave a metallic taste in the mouth, cause heartburn or headache, flushing of the skin, nail changes or muscle pain. More serious metformin side effects include chest pain or rash. ...
Early String Theory. The first attempt to construct a physical model of an atom was made by William Thomson (later elevated to Lord Kelvin) in 1867. The most striking property of the atom was its permanence.
In the first decade of the 20th century, Einstein produced the theory of the conversion of mass into energy, E=mC(2), which was confirmed by laboratory observations. A new theory of the atom was devised by the English physicist Rutherford in 1913.