Editing Fritz Haber (section)

==World War I==
Haber greeted World War I with enthusiasm, joining 92 other German intellectuals in signing the ''[[Manifesto of the Ninety-Three]]'' in October 1914.<ref name=ED>{{cite book|last1=Grundmann|first1=Siegfried|title=The Einstein Dossiers: Science and Politics – Einstein's Berlin Period with an Appendix on Einstein's FBI File (translated by A. Hentschel)|date=2005|publisher=Springer|location=Berlin|isbn=978-3-540-31104-1|url=https://books.google.com/books?id=1bxYPMHPhGcC|language=en|access-date=30 April 2021|archive-date=23 February 2024|archive-url=https://web.archive.org/web/20240223090221/https://books.google.com/books?id=1bxYPMHPhGcC|url-status=live}}</ref> Haber played a major role in the development of the non-ballistic use of [[Chemical weapons in World War I|chemical warfare in World War I]], in spite of the proscription of their use in shells by the [[Hague Conventions of 1899 and 1907|Hague Convention of 1907]] (to which Germany was a signatory). He was promoted to the rank of captain and made head of the Chemistry Section in the Ministry of War soon after the war began.<ref name=Stoltzenberg />{{rp|133}} In addition to leading the teams developing [[chlorine#Use as a weapon|chlorine gas]] and other deadly gases for use in [[trench warfare]],<ref name="Gross">{{cite journal|last1=Gross|first1=Daniel A.|title=Chemical Warfare: From the European Battlefield to the American Laboratory|journal=Distillations|date=Spring 2015|volume=1|issue=1|pages=16–23|url=https://www.sciencehistory.org/distillations/magazine/chemical-warfare-from-the-european-battlefield-to-the-american-laboratory|access-date=20 March 2018|archive-date=22 December 2019|archive-url=https://web.archive.org/web/20191222061955/https://www.sciencehistory.org/distillations/magazine/chemical-warfare-from-the-european-battlefield-to-the-american-laboratory|url-status=live}}</ref> Haber was on hand personally when it was first released by the German military at the [[Second Battle of Ypres]] (22 April to 25 May 1915) in [[Belgium]].<ref name=Stoltzenberg />{{rp|138}} The team Haber assembled consisted of more than 150 scientists and 1,300 technical personnel.<ref>{{Cite journal |last=Witschi |first=Hanspeter |date=1 May 2000 |title=Fritz Haber: 1868–1934 |journal=Toxicological Sciences |volume=55 |issue=1 |pages=1–2 |doi=10.1093/toxsci/55.1.1 |pmid=10788553 |issn=1096-6080|doi-access=free }}</ref> Haber also helped to develop [[WWI gas mask|gas mask]]s with [[adsorption|adsorbent]] filters which could protect against such weapons.

A special troop was formed for gas warfare (Pioneer Regiments 35 and 36) under the command of Otto Peterson, with Haber and Friedrich Kerschbaum as advisors. Haber actively recruited physicists, chemists, and other scientists to be transferred to the unit. Future Nobel laureates [[James Franck]], [[Gustav Hertz]], and [[Otto Hahn]] served as [[Poison gas in World War I|gas troops]] in Haber's unit.<ref name=Stoltzenberg />{{rp|136–138}} In 1914 and 1915, before the Second Battle of Ypres, Haber's unit investigated reports that the French had deployed [[Turpinite]], a supposed chemical weapon, against German soldiers.<ref name="Richter 2014">{{cite book | last=Richter | first=D. | title=Chemical Soldiers: British Gas Warfare in World War I | publisher=Pen & Sword Books Limited | year=2014 | isbn=978-1-78346-173-8 | url=https://books.google.com/books?id=wAbangEACAAJ | page=6 | access-date=30 April 2021 | archive-date=23 February 2024 | archive-url=https://web.archive.org/web/20240223090222/https://books.google.com/books?id=wAbangEACAAJ | url-status=live }}</ref>

Gas warfare in World War I was, in a sense, the war of the chemists, with Haber pitted against French Nobel laureate chemist [[Victor Grignard]]. Regarding war and peace, Haber once said "during peace time a scientist belongs to the world, but during war time he belongs to his country". This was an example of the ethical dilemmas facing chemists at that 
time.<ref name=Novak>{{cite book|last1=Novak|first1=Igor|title=Science : a many-splendored thing|url=https://archive.org/details/sciencemanysplen00nova|url-access=limited|date=2011|publisher=World Scientific|location=Singapore|isbn=978-9814304740|pages=247–316|doi=10.1142/9789814304757_0004|chapter=Science and History}}</ref><ref>{{Cite book |url= |title=Medical Aspects of Chemical Warfare |date=2008 |publisher=Government Printing Office |pages=15 |language=en}}</ref>

Haber was a patriotic German who was proud of his service during World War I, for which he was decorated. He was even given the rank of [[captain (land)|captain]] by the [[Kaiser]], which Haber had been denied 25 years earlier during his compulsory military service.<ref name="Coffey2008">{{cite book|author=Coffey, Patrick|title=Cathedrals of Science: The Personalities and Rivalries That Made Modern Chemistry|url=https://books.google.com/books?id=UQt6glJEiGsC&pg=PA102|date=29 August 2008|publisher=Oxford University Press|isbn=978-0-19-971746-0|pages=102–|access-date=15 June 2017|archive-date=20 July 2023|archive-url=https://web.archive.org/web/20230720090111/https://books.google.com/books?id=UQt6glJEiGsC&pg=PA102|url-status=live}}</ref>

In his studies of the effects of poison gas, Haber noted that exposure to a low concentration of a poisonous gas for a long time often had the same effect (death) as exposure to a high concentration for a short time. He formulated a simple mathematical relationship between the gas concentration and the necessary exposure time. This relationship became known as [[Haber's rule]].<ref name="GadKaplan1990">{{cite book|author1=Gad, Shayne C.|author2=Kaplan, Harold L.|title=Combustion Toxicology|url=https://books.google.com/books?id=088qMHudhRoC&pg=PA99|date=2 October 1990|publisher=CRC Press|isbn=978-1-4398-0532-9|pages=99–|access-date=15 June 2017|archive-date=20 July 2023|archive-url=https://web.archive.org/web/20230720090111/https://books.google.com/books?id=088qMHudhRoC&pg=PA99|url-status=live}}</ref><ref name="SalemKatz2014">{{cite book|author1=Salem, Harry|author2=Katz, Sidney A.|title=Inhalation Toxicology, Third Edition|url=https://books.google.com/books?id=pWULBAAAQBAJ&pg=PA130|date=2014|publisher=CRC Press|isbn=978-1-4665-5273-9|pages=130–|access-date=15 June 2017|archive-date=20 July 2023|archive-url=https://web.archive.org/web/20230720090612/https://books.google.com/books?id=pWULBAAAQBAJ&pg=PA130|url-status=live}}</ref>

Haber defended gas warfare against accusations that it was inhumane, saying that death was death, by whatever means it was inflicted and referred to history: "The disapproval that the knight had for the man with the firearm is repeated in the soldier who shoots with steel bullets towards the man who confronts him with chemical weapons. [...] The gas weapons are not at all more cruel than the flying iron pieces; on the contrary, the fraction of fatal gas diseases is comparatively smaller, the mutilations are missing".<ref name="Haber 1924 p.50">{{cite book | last=Haber | first=Fritz | title=Die Chemie im Kriege; fünf Vorträge (1920–1923) über Giftgas, Sprengstoff und Kunstdünger im Ersten Weltkrieg | publisher=Comino Verlag | publication-place=Berlin | year=2020 | isbn=978-3-945831-26-7 | oclc=1136163177 | language=de | page=50}}</ref>

Haber received much criticism for his involvement in the development of chemical weapons in pre-World War II Germany, both from contemporaries, especially [[Albert Einstein]], and from modern-day scientists.<ref name="Shapin">{{cite journal|last1=Shapin|first1=Steven|title=Tod aus Luft|journal=London Review of Books|date=26 January 2006|volume=28|issue=2|pages=7–8|url=https://www.lrb.co.uk/v28/n02/steven-shapin/tod-aus-luft|access-date=18 April 2017|archive-date=20 June 2019|archive-url=https://web.archive.org/web/20190620141723/https://www.lrb.co.uk/v28/n02/steven-shapin/tod-aus-luft|url-status=live}}</ref><ref name="Genius">{{cite book|last1=Charles|first1=Daniel|title=Between genius and genocide : the tragedy of Fritz Haber, father of chemical warfare|date=2006|publisher=Pimlico|location=London|isbn=978-1844130924}}</ref>