Chemotherapy is the treatment of disease by specifically targeting the disease with certain drugs. Chemotherapy is commonly linked with the treatment of cancer where powerful drugs are used that have severe unwanted side affects. Chemotherapy was coined by Paul Ehrlich who made the greatest contribution to the science. He tried to create a disinfectant that could kill the targeted organism without damaging healthy tissue. In 1903, he invented the dye trypan red the first drug to show signs of combating trypanosome in mice. His greatest achievement was a drug that was effective in combating the disease syphilis. Chemotherapy treatment is now used to treat malignant cancer cells, breast and prostate cancer, leukemia and lymphatic cancer, and some progress has been made in fighting Hodgkin\'s disease. While some chemotherapy treatments treat what it is supposed to some treatments kill healthy cells that hinder infection while also killing malignant cells. Chemotherapy treatments are also being developed for the treatment of mental diseases too.