Around mid-century, Mendeleev began to develop the table of elements which helped in the discovery of new elements. In the last decade of the century, the discovery of radium by Marie and Pierre Curie, and the electron by Becquerel as well as observation of radioactivity in the laboratory, challenged Dalton's theory.
Medications Used to Treat ADHD. Stimulant medications commonly prescribed for attention deficit disorder include methylphenidate (Ritalin, Concerta, Metadate, Methylin) and certain amphetamines (Dexedrine, Dextrostat, Adderall). Methylphenidate is a short acting drug, and in older forms, had to be taken multiple times a day.
A: Brand name Ritalin (methylphenidate) is manufactured by Novartis Pharmaceuticals Corporation. Ritalin is a stimulant medication that affects the central nervous system. It is used to treat attention deficit hyperactivity disorder (ADHD), attention deficit disorder (ADD), and narcolepsy.Ritalin helps to increase attention and control symptoms such as hyperactivity and impulsiveness.he Food and Drug Administration (FDA) first licensed methylphenidate hydrochloride in 1955 for treating what was formerly known as hyperactivity, attention-deficit disorder or ADD. The drug was commonly prescribed in the 1990s when the diagnosis of ADHD became better known and accepted.