Amalgam Removal in 1916

Alfred Stock (1876-1946) was a famous German inorganic chemist[1] who is still recognized as a pioneer in his specialty. (The German Chemical Society awards an Alfred Stock Memorial Prize for inorganic chemistry, Stock was himself the victim of a chronic intoxication by mercury vapour, which was not uncommon (though poorly recognized) among chemists at that time. He became deeply involved in this problem, and wrote some 50 papers on various aspects of mercury during the years 1926-1943, many of which are still well worth reading for their amazingly modern educational content, insightful observations, and important experimental results[1].

During his illness Stock consulted Louis Lewin (1850-1929), a world-famous toxicologist whose textbook, "Gifte und Vergiftungen" is still in print, more than 70 years after his death(!). Below I am quoting from the 1962 edition[2]:

"From amalgam fillings, especially copper amalgam, the metal may be released into the oral cavity, or may in some form or other reach the dental cavity, and be absorbed by the circulation, giving rise to a chronic intoxication. Apart from local oral lesions, this manifests itself in a great variety of disturbances of bodily organs, particularly as a loss of normal functions of the brain and nervous system. Such disturbances are not always due to an increased sensitivity to mercury. Ever since the beginning of this century I have not only taught this in my lectures, but I have drawn the consequences of this knowledge when amalgam-bearing people came to me with obscure symptoms of nervous illness. I then always recommended the removal of such fillings, which resulted in improvements, even in professors [footnote: I informed Prof. Stock about these things, and he regained his health]."

This is how Stock's eyes were opened to the dental amalgam problem in 1923-24[3]. In 1926 he started what has later been called "The Second Amalgam War", which was a medical debate largely confined to Germany and lasting with decreasing intensity until 1939. Stock of course had no medical background, and it is truly remarkable how he managed to bring this problem to the forefront in a country which was then scientifically at the height of its power, not least in medicine[4,5]. But this is already outside the scope of my note.

Professor Erich Rudolf Jaensch (1883-1940), "Ordinarius" in psychology at the University of Marburg gave Stock the detailed story of his own "amalgam illness" in a written account from which Stock was permitted to quote[5].

Jaensch was 15 when he received his first amalgam fillings, and he then gradually developed nervous complaints which were diagnosed as "hypochondriac neurasthenia". Physically he still appeared to be in good health, but this changed in 1909, after his dentist had made some kind of bridge construction connecting the largish amalgam fillings in his molars, an apparently rather unnecessary intervention which may have involved the introduction of other metal alloys in addition to amalgam (no details quoted). After some time Jaensch developed chronic diarrhoea, which during the years 1912-1916 resulted in at least ten evacuations a day. This led to weight loss, severe pain in various parts of the body, sleep disturbance, stomatitis, asthmatic symptoms, anxiety, and gradually Jaensch became more or less bedridden and incapable of intellectual work.

The idea that his severe illness might have to do with his 24 large amalgams did not occur to Jaensch until 1916. He contacted a certain Professor Sommer who agreed to investigate this apparently remote possibility, and the urinary level of mercury was found to be raised. Prof. Sommer's written conclusions about a causal connection were however met with total denial by a series of dentists, who were convinced that the safety of amalgam was a matter of scientific fact. Amalgam removal was consequently regarded as unnecessary, and no dentist would undertake such an operation until a Prof. Binswanger (who may have been one of three possible psychiatrists B.) expressly asked a dentist friend of his to help Jaensch. At first his symptoms increased during the removal procedure, but later, when suction was applied in order to remove amalgam dust and vapours, this problem did not occur again. As soon as the removal was complete, his diarrhoea improved considerably, and this was followed by a slow recovery from all of his symptoms. The amalgam restorations were replaced by gold.

When Stock published those extracts from Jaensch's history, the follow-up time was already ten years, and recovery was apparently complete. His academic career confirmed this. Jaensch's work is cited in several places (along with that of his brother Walter) in Oswald Bumke's monumental handbook of psychiatry[6].

Jaensch can be followed further in a book by Weinreich[7]. It turns out that he became a relatively early academic champion of Nazi ideology. The point to be made here is however that he was all but down and out for several years up to 1916, but then fully regained his health after amalgam removal. It may be taken as a sign of his continued vitality that he published a book as late as 1937[8]. The follow-up time was thus more than 20 years without relapse. Jaensch died in 1940 at a relatively young age, and I have not found any information about the cause of his death.


  1. Wiberg E: Alfred Stock 1876-1946. [Biography with 274 references to Stock's work.] Chem Berichte 1950, 83:19-76.
  2. My translation from page 255 of the 5th edition published by Karl F. Haug, Ulm/Donau, 1962; the current 6th edition is from 1992.
  3. Stock A: Die Gefährlichkeit des Quecksilberdampfes. Z angew Chemie 1926, 39:461-68.
  4. Stock A: Die Gefährlichkeit des Quecksilbers und der Amalgam-Zahnfüllungen. Med Klin 1928, 24:1114-17, 1154-58.
  5. Stock A: Die Gefährlichkeit des Quecksilberdampfes und der Amalgame. Med Klin 1926, 22: 1209-12, 1250-52. Also in: Z angew Chemie 1926, 39:984-89. I have not made a complete and verbatim translation of Stock's extracts from Jaensch's report.
  6. Bumke O (ed.): Handbuch der Geisteskrankheiten. Berlin, Springer, 11 volumes published 1928-32.
  7. Weinreich M: Hitler's Professors: The Part of Scholarship in Germany's Crimes Against the Jewish People. New Haven and London, Yale, 1999.
  8. Jaensch E R: Jugendanthropologie und Neuformung des Menschentums. Leipzig, Barth, 1937. Cited in [7].

Per Dalen