Editing 1891 in science (section)

==Physiology and medicine==
* Julius Ludwig August Koch begins publication of ''[https://archive.org/details/diepsychopathis00kochgoog Die psychopathischen Minderwertigkeiten]'' in [[Ravensburg]], introducing the concept of [[psychopathology]].<ref>{{cite journal|author-link=Jon Ronson|first=Jon|last=Ronson|title=How to spot a psychopath|journal=[[Guardian Weekend]]|date=2011-05-21|page=31}}</ref>
* [[Arnold Pick]] first uses the term ''[[dementia praecox]]'' in this form.<ref>{{cite journal|title=Ueber primäre chronische Demenz (so. Dementia praecox) im jugendlichen Alter|journal=Prager medicinische Wochenschrift|volume=16|pages=312–15|year=1891}}</ref>
* [[Heinrich Wilhelm Gottfried von Waldeyer-Hartz]] names the [[neuron]].<ref>{{cite journal|first=H. W. G.|last=von Waldeyer-Hartz|title=Ueber einige neuere Forschungen im Gebiete der Anatomie des Centralnervensystems|journal=Deutsche medicinische Wochenschrift|location=Berlin|year=1891|volume=17|pages=1213–1356}}</ref>
* [[Myxedema]] is first treated successfully, by [[George Redmayne Murray]] using thyroid extract.
* The earliest recorded attempt at hip replacement is carried out by [[Themistocles Gluck]] in [[Berlin]], using [[ivory]] to replace the [[femoral head]].<ref>{{cite journal|last1=Gomez|first1=Pablo F.|last2=Morcuende|first2=Jose A.|title=Early attempts at hip arthroplasty, 1700s to 1950s|pmc=1888777 |journal=Iowa Orthopaedic Journal|volume=25|pages=25–9|year=2005|pmid=16089067}}</ref>
* Viennese pathologist [[Hans Chiari]] describes a form of [[Chiari malformation]].