precipitin: an antibody that causes precipitation when it unites with its antigen
antibody: any of a large variety of proteins normally present in the body or produced in response to an antigen which it neutralizes, thus producing an immune response
saxe-coburg-gotha: the name of the royal family that ruled Great Britain from 1901-1917; the name was changed to Windsor in 1917 in response to anti-German feelings in World War I