Syphilis mercury-containing treatment

Mercury (Hg) Mercury is a silvery white liquid metal. Because of its high density, mercury is used in sphygmomanometers. It is also found in some thermometers. Before its toxic nature was fully understood, mercury compounds had been used in medical applications ranging from treatment of syphilis to constipation. Mercury alloys well with many other metals, and alloys containing mercury are known as amalgams. 

Greco-Arabic classics, insisted on the value of experimentation (including the use of animal tests), and developed the idea that minerals and chemicals could have medicinal applications (iatrochemistry). His use of mercury preparations in the treatment of syphilis led to accusations of poisoning, to which Paracelsus replied by writing the Third Defense. It contains the following important statement ... 

The use of mercury in the treatment of diseases such as syphilis, psoriasis, and congestive heart failure began more than two centuries ago. Although mercury s medicinal use has tapered off in recent years, mercury compounds such as thimerosal and phenylmercuric nitrate still have a limited use in human and veterinary medicines to prevent bacterial growth in injection solutions (e.g. vaccines), antiseptics, and skin ointments. The United States Food and Drug Administration [1] estimates that approximately 200 human and veterinary drug products marketed in the U.S. contain mercury as an active or inactive ingredient. 

We now know that thallium is extremely toxic and should be handled with great care. In the first 50 years after its discovery, however, thallium was found to be an effective treatment for syphilis, gonorrhea, gout, dysentery, and tuberculosis. Someone should have taken a clue from the location of this element between lead and mercury in the periodic table. Its use as a medicine had many unpleasant—not to mention toxic—side effects such as alopecia, the loss of hair. Later, thallium compounds such as the colorless and odorless TI2SO4 (note that this compound contains thallium in the +1 ojddation state) was used as a rat poison and ant killer, but these and similar uses have been prohibited in many countries due to the high toxicity of thallium. 

---