A year and a half ago, an article about cycads at the University of Giessen brought to my attention the University’s most famous member, about whom Wikipedia says:

“In the 1820s, the organic chemist Justus Liebig discovered silver fulminate (Ag-CNO) and Friedrich Wöhler discovered silver cyanate (Ag-OCN). The fact that these substances have the same chemical composition led to an acrid dispute, which was not resolved until Jöns Jakob Berzelius came up with the concept of isomers.”

However, Liebig was no stranger to scientific controversy.  I wondered if the disagreement with Wöhler left him fulminating!”

And that’s where I thought things stayed. 

However, recently I started reading The Case of the Poisonous Socks: Tales from Chemistry, by William H. Brock, and found this: 

CHAPTER 17: Liebig and Wöhler: Creating a Path through the Dark Province of Organic Nature

Liebig first met Wöhler at Frankfurt in the winter of 1828. There they “ironed out” their previous difference of opinion over the apparently identical composition of Wöhler’s silver cyanate and Liebig’s silver fulminate. They agreed (as Gay-Lussac had already suggested) that the two acids and their silver salts were remarkable examples of different modes of combination among the elements carbon, hydrogen oxygen and nitrogen.  In 1830, Berzelius coined the word isomerism to describe the remarkable phenomenon whereby organic compounds with very different chemical and physical properties were composed from the same elements in identical proportions but in some unknown different physical arrangement.

So, puzzlement.  A bit of searching, and I then found

Justus von Liebig, Student and Teacher, by Ralph E. Oesper, Journal of Chemical Education, 1927, vol 4, No 12, pp 1461–1476.

The relevant part is this:

Liebig loved a good discussion, was merciless in his criticism of errors hallowed by tradition or founded on faulty experimentation.  In his zeal he often overshot his mark but was always willing to acknowledge his mistakes.  “I never care if others pluck out feathers which I intended to drop at the next moulting season; only those who cannot grow new plumage need worry about such happenings.” Though his criticisms engendered many enmities, he was always impersonal in such discussions, and he stoically regarded such hard feelings as the inevitable heritage of one holding strong convictions.  He once said of Dumas: “He is not a small character, but a man who has had to lay out his out his own road.  Consequently, it has occasionally been necessary for him to poke certain people in the ribs, and naturally they have not found this pleasant.” He once to Mohr: “With me, it is never a question of persons; I consider only the matter at hand.  I try to reach a definite objective and if you cannot see my goal, it is your fault, not mine.”

On the other hand, Liebig was a distinctly social being.  The students were always welcome to his hospitality, especially on Sunday afternoons when his garden was a favorite gathering place for faculty and students.  He loved to dominate the conversation, but he had little patience with long faculty discussions or gossip.  Academic administrative offices had no charms for him; he was never dean or rector.  He was a good whist player, and it was distinctly understood that cards and conversation are incompatible.  Liebig’s friendships were lasting and sincere and a perusal of his correspondence reveals the innate lovableness of his character.  His relations with Wöhler formed one of the most beautiful chapters in the history of chemistry.  Germinating in a controversy over the fateful fulminates, it grew into mutual admiration, flowered into an abiding friendship whose fruits were an inestimable boon to chemistry.  Begun in 1829, it lasted to Liebig’s death in 1873, and practically all of their letters to each other have been preserved.  Wöhler sent more than 600 to Liebig and received about as many in reply.  On December 31, 1871, Liebig wrote “I cannot let the year run out without giving you a sign that I am still in existence and to send you and yours my best wishes for the coming year.  We will not be able to exchange such greetings much longer, but when we have passed away and returned to dust, the ties which united us in life will still bind us together in the memories of men as a rare example of two men who loyally worked and strove in the same field, and yet remained the best of friends with never a trace of jealousy or envy.”

There is so much more that could be said about Liebig.  My fellow Brits should remember, every time we use an Oxo cube, that this is an invention of his.  Bovril comes from a later, rival company.

However, regarding the character of Liebig in correspondence and in person, I am reminded of what St Paul wrote in his second letter to the Corinthians:

For they say, “His letters are weighty and strong, but his bodily presence is weak, and his speech of no account.”  Let such a person understand that what we say by letter when absent, we do when present.

Suggested exam question: Compare and Contrast?