Talk:Hermann Kolbe

Creation of Acetic Acid

Can anyone find a source for the method for Kolbe's creation of acetic acid from carbon disulphide? It isn't available in primary searches, which suggests to me that it might have been an inefficient method and could have been discarded by chemists in the long run. Which would also explain its absence from the main article of acetic acid. But being a milestone in organic chemistry, it at least deserves a mention on this page.DM224b (talk) 11:34, 22 April 2018 (UTC)

The Kolbe synthesis was indirect. In 1844, Kolbe published a paper describing the chlorination of carbon disulfide to yield carbon tetrachloride. He also described passing the carbon tetrachloride through a hot reduction tube, isolating tetrachloroethylene from the reaction mixture. A third oxidizing reaction yielded trichloroacetic acid. In a second paper of 1845 he noted that trichloroacetic acid was already known to be reducible to acetic acid; therefore, he claimed success in transforming carbon disulfide (an inorganic compound) into acetic acid (an organic compound), even though he had not actually performed that last step. Following this feat, he predicted a glorious future of organic synthesis. The references are Kolbe, "Notiz ueber einige gepaarte Verbindungen der Chlorkohlenstoffe," Annalen der Pharmacie und Chemie, 49 (1844), 339-41, and Kolbe, "Beitraege our Kenntniss der gepaarten Verbindungen," ibid., 54 (1845), 145-188. For a discussion of these matters, see my (Alan Rocke's) book, The Quiet Revolution: Hermann Kolbe and the Science of Organic Chemistry (University of California Press, 1993), pp. 58-60.Ajrocke (talk) 17:31, 22 April 2018 (UTC)

Kolbe and vitalism

Two comments on the first sentence in the section Work: "At that time, some believed that organic compounds could be created only by living organisms."

1. By the normal rules of English, "At that time" should mean the last time mentioned which is 1876, when vitalism was long dead. The context implies that the intended meaning is rather the next time mentioned, about 1843-45.

2. There is an apparent contradiction with the article on Wohler which suggests that his urea synthesis killed off belief in vitalism immediately. A more accurate history is found in Wohler synthesis which explains that Wohler convinced few at the time, and that vitalist belief persisted until Kolbe's work.

I suggest that the sentence above be modified to something like: "As late as the 1840s, many chemists believed the doctrine of vitalism that organic compounds could be created only by living organisms. This belief persisted despite the Wohler synthesis of urea in 1828 which was considered an anomaly.

Other opinions please before I edit the article? Dirac66 (talk) 03:36, 14 December 2007 (UTC)

Dirac66, you are quite right about the misleading phrase "at that time," for the time intended to be indicated, as you suggest, is indeed the earlier date. An appropriate edit by you to clarify this passage would be great. Your second point raises an interesting set of issues. If one looks at the current state of research in the history of chemistry, neither of your assertions appear to be statements that historians of science would agree with -- that Woehler killed off vitalism at a stroke, OR that he convinced few at the time. (See, for example, P. Ramberg, "The Death of Vitalism and the Birth of Organic Chemistry," Ambix, 47 (2000), 170-95.) Rather, Woehler's 1828 synthesis of urea appears to have been just one event along a continuum, in which vitalism gradually was abandoned. For instance, if you look at the private correspondence between Woehler, Berzelius, and Liebig, none of them appeared to have much sympathy for transcendental chemical vitalism even before 1828; on the other hand, one can find some convinced vitalists (mostly non-chemists!) long after 1850. Considering all this, I would suggest modifying your suggested sentence to something like the following: "As late as the 1840s, and despite Friedrich Woehler's synthesis of urea in 1828, some chemists still believed in the doctrine of vitalism, according to which a special life-force was necessary to create organic compounds." This may also call for some appropriate re-editing of the Woehler article! Ajrocke (talk) 14:03, 14 December 2007 (UTC)

Thank you for your help. I accept your point about a gradual abandonment of vitalism, and I realize now that there was no "magic moment" when everyone saw the light simultaneously. Your phrasing seems better given the facts so I will insert it into the article.

I will just change the spelling of Wöhler for consistency with his article, and suppose that your "oe" was a gentle hint to remember the umlaut.

As for the Wöhler article, the phrase "Until 1828, it was believed ..." certainly suggests that he killed off vitalism at a stroke, and should be modified. As the historian, perhaps you could consider the most appropriate change. Dirac66 (talk) 02:21, 16 December 2007 (UTC)

Requests for references

Asking for references should be held moderate and appropriate. bkb (talk) 08:59, 28 July 2016 (UTC)