Sign Up for a Free Account

This is an image preview.
Start a Free Account
to view the full image.

  • Nearly 3,000 illustrations, including video clips of neurologic disorders.

  • Every article is reviewed by our esteemed Editorial Board for accuracy and currency.

  • Full spectrum of neurology in 1,200 comprehensive articles.

German chemist Justus von Liebig

German chemist Justus Freiherr von Liebig (1803-1873) circa 1866. Liebig discovered tyrosine in 1846. (Courtesy of the U.S. National Library of Medicine. Public domain.)