Which two drugs, now illegal, were common ingredients in many 19th century patent medicines that advertised cures from many common maladies?

Cocaine, Opium and its chemical derivative morphine.

Explanation:

Many of the drugs that are illegal now were legal in 19 the century. Various substances such as lead and mercury were also used in medicine.

Cocaine and Opium were two drugs that were sold in both England and USA. Cocaine was widely used in Toothache drops, it was popular and didn't require any prescription in USA, druggists could easily sell it to the general public.

Medical practitioners in 18th century still followed the theory of " four humor" that was developed by Roman physician Galen. According to this theory, the body was made up of four humors and imbalance in any humor could cause illness, the illness was believed to be cured by restoring balance of humor, the medicines of 19th century intended to do this.