Fowler's Solution is a potassium arsenic solution that was prescribed as a general tonic from about 1786 to 1936. The carcinogenic nature of arsenic compounds caused numerous disastrous side effects including Cancer and Cirrhosis. Some say Charles Darwin used it often.
Fowler's solution, also known as "Liquor Potassii Arenitis," Kali Arsenicosum, or Kali arseniatum, is a 1% solution of potassium arsenite, KH2AsO3. A Dr. Fowler of Stafford, England proposed its use in 1786 as a substitute for a patented medicine, "tasteless ague drop." It was prescribed in the United States until the late 1950s for a range of ailments including malaria, chorea, and syphilis.
Documented side effects of treatment with Fowler's solution include: