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.
Is Ritalin Effective for Adult ADHD? Methylphenidate was the first drug to be used in the treatment of ADHD, originally to treat children in the 1960âs. Since its discovery, methylphenidate has been used to treat ADHD in both children and adults for many years.