© Michel Fingerhut 1996/7

Pitch Bloch:
Zyklon B
Text published as an appendix to «A Paper Eichmann »
Translated by Jeffrey Mehlman
in Assassins of Memory (NY: Columbia University Press 1992),
English translation © 1992 Columbia University Press
Reproduction interdite sauf pour usage personnel - No reproduction except for personal use only

We are very grateful to Pierre Vidal-Naquet and his american publisher, Columbia University Press, for allowing us to make this text available here.
Ask those around you. I did, including a number of more or less young Jews and even orphans of deportees. Practically half of them had never heard of Zyklon B; others recalled the name in connection with the gas chambers (they had seen Holocaust on television or had read the relevant articles in Le Monde), but none knew exactly what kind of product it was.

Let them look it up in the dictionary, then: neither Cyclon nor Zyklon are to be found in Le petit Larousse illustré (1979 edition), Le petit Quillet-Flammarion (1963 edition), or even in the three-volume Larousse (1965 edition) or the twenty-volume Encyclopaedia Universalis (1968-1975 edition).

This, of course, makes the task of those who would like to deny that gas chambers existed in the Nazi concentration camps far easier. A Paul Rassinier can pinpoint "contradictions": "an insecticide: no gas had then been planned for exterminating"(!) and further on: "Zyklon B appears in the form of blue granules from which the gas emanates"; or: "This famous gas which has, until now, been presented to us 'in tablets from which the gas emanated upon contact with the air,' 'upon contact with water vapor,' in fact existed in the form of bottles filled with a highly volatile liquid."[1]

A Robert Faurisson is free to wax ironic on "gas crystals,"[2] or to insist repeatedly on the fact that Zyklon B adheres to surfaces and is difficult to ventilate, etc.[3]

The following note will attempt to clarify matters by explaining, among other things, the indispensable chemical terms.

I first thought it necessary to research the definition of Zyklon B in a classic work of industrial chemistry, which was published in Germany in 1954.[4]

Hydrocyanic (or prussic) acid is a powerful poison for the blood of all higher animals. The DL(50) [lethal dose in 50 percent of cases] for human beings is as high as 1 milligram per kilogram of body weight. In Germany, the most common application of hydrocyanic acid is Zyklon B, a mixture of liquid hydrocyanic acid with chloride and bromide derivatives as catalytic agents and silica as a support.
There follows a chart of the principal properties of several gases and vapors used as insecticides, in which the following may be read: "Blausaure -- Formel HC -- Kp 25,6 C -- Dichte (Luft=1) 0,93," that is: "Hydrocyanic acid -- (Chemical) formula HCN -- Boiling point 25.6° Centigrade -- Density (Air=1) 0.93."

It will thus be seen that:

R. Faurisson's principal "technical" arguments in support of his thesis of the nonexistence of gas chambers in the deportation camps are:[6]
  1. It is impossible to fit 2,000 persons in an enclosure of 210 cubic meters (or 236.78 cubic meters according to the documents).
  2. Working crews intervened without gas masks.
  3. In order to insert Zyklon B from outside, the SS guards would have had to ask their future victims to kindly open the windows, and then to close them carefully.
  4. It would have been impossible to enter the gas chamber to remove corpses without having first ventilated them.
  5. Finally, since Hydrocyanic acid is an inflammable explosive, it could not be used in proximity to a stove.
Now it happens that one of the first written documents that I had the opportunity to read about the gas chambers --it was in Switzerland in 1944, where I was privileged enough to begin my studies in chemistry-- was a rather precise description of the gassing process and of the precautions taken after gassing (ventilation, etc.). I believe it useful at this juncture to quote it almost in extenso :[7]
« At the end of February 1943, at Birkenau, the new gassing installation and its modern crematorium, whose construction had just been completed, were inaugurated.... [There follows a description of the A crematoria and the B preparation hall.]
« From there, a door and a few steps led to the gas chamber, which was narrow and very long, and was situated at a slightly lower level. The walls of the chamber were covered with curtains, producing the illusion of an immense shower room. Three windows opened on the flat roof, and could be hermetically closed from without. Rails ran across the hall leading to the oven chamber.
« Here is how the "operations" took place:
« The unfortunates were brought into Hall B and told that they were to take a shower and that they were to undress in the room in which they were. To persuade them that they were actually being taken to the showers, two men dressed in white gave each of them a piece of soap and a towel. Then they were pushed into the gas chamber. About two thousand persons could fit, but each disposed of no more space than was necessary to remain standing. To get such a mass into the room, there were repeated gun shots in order to force those who' were already inside to squeeze still closer. When everyone had entered, the heavy door was bolted. There were a few minutes of waiting, probably for the temperature in the chamber to reach a certain degree; then SS guards, wearing gas masks, climbed onto the roof, opened the windows, and threw in the contents of several tin cans: a preparation in powder form. The cans were marked "Zyklon" (insecticide); they were manufactured in Hamburg. The contents were probably a cyanide compound, which turned into a gas at a certain temperature. In three minutes all the inhabitants of the room were killed. Until now, upon reopening the gas chamber, there has never been a single body showing any sign of life, something which, on the contrary, occurred quite frequently at Birkenwald because of the primitive methods used there. The room was thus opened and ventilated, and the Sonderkommando began transporting corpses on flat carts towards ovens, where they were burned. »
I will not say that I was not "shocked" at reading this, but it was at a human level and not for reasons of technical plausibility. On rereading it today, I find it, on the one hand, remarkably consistent with the characteristics of Zyklon B mentioned above and, on the other, virtually a "reply" to Faurisson's arguments: people squeezed together; SS guards wore gas masks; the windows were on the roof and could be hermetically closed from without; the room was ventilated before the Sonderkommando entered; and the gas chamber was separated from the incinerating ovens since carts on rails were used to join the two.

I will add that this report by two young Slovakian Jews who had escaped from Birkenau[8] was published in Geneva in 1944. It was, that is, neither "a late addition," nor "composed under the surveillance of Polish jailers," nor Çvague and brief," nor "miraculously rediscovered" --as Faurisson claims of all the testimony with which he is confronted.[9] It strikes me, on the contrary, as astonishingly precise and written without passion by individuals from whom, at the time, a certain lack of composure might have been forgiven.

Let us examine now a bit more closely other "scientific" affirmations by R. Faurisson. I shall take only two examples:

  1. Concerning corpses transformed into soap during World War I, he writes:[10] "This absurd legend (ask any anatomist, chemist, or specialist about it) was taken up anew, but without great success, concerning the Second World War." I shall not debate the truth or falsity of this "legend"[11] in this forum, but I fail to see its "absurdity." Since soap is regularly prepared from beef or mutton fat and from pork lard,[12] why not from other higher animals?
  2. On the subject of gas emanating from Hydrocyanic salts upon contact with water, he writes:[13]"For the first time in the history of chemistry, a salt added to water gave off a gas." Without being "historians of chemistry," many readers, I take it, know (and may even have seen) how a commonplace acetylene generator works, in which calcium carbide (a "salt" and a solid) is decomposed by water and produces a gaseous form of acetylene.[14]
In conclusion, I would like to refer to an incident which unfortunately occurred quite recently in Switzerland:[15] on the night of May 15, 1980, there were a number of graves covered with swastikas and graffiti, one of which read: "Mehr Zyklon B fur Juden (More Zyklon B for the Jews)." Its author must not yet have read the works of R. Faurisson.

Pitch Bloch, Ph. D.
Chemical Engineer
Federal Polytechnical School of Zurich


  1. Rassinier, Ulysse trahi, pp. 111,155.
  2. Robert Faurisson, "Le problème des chambres a gaz," Défense de l'Occident, June 1978; also in Vérité p. 86.
  3. Ibid., p.88, as well as articles in Le Monde on December 29,1978 (in Vérité, pp. 104-105), on January 16, 1979 (pp. 110-111), and on March 29, 1979 (p. 112), and an interview with Faurisson in Storia Illustrata (August 1979; pp. 175-176,203-204).
  4. K. Winnacker and E. Weingaertner, Chemische TechnologieOrganische Technologie II (Munich: Carl Hanser Verlag, 1954), pp. 1005-1006.
  5. Institut National de Recherche et de Sécurité, "Acide cyanhydrique: Fiche Toxicologique No. 4" (revised ea., April 1969).
  6. Vérité pp. 88, 104-105, 110-111, 174-177, 203-204, 319-321.
  7. L'Extermination des Juifs en Pologne V-X: depositions by eyewitnesses; Third Series: "Les Camps d'extermination" (Geneva: C.J.M., 1944), pp. 59-60.
  8. They have subsequently been identified as R. Vrba and F. Wetzler; cf. G. Wellers, Mythomanie, pp. 14-15.
  9. Vérité, pp. 87, 110, 175.
  10. Ibid., p. 202, n. 1.
  11. To my knowledge, this was indeed a myth [P. V.-N.].
  12. Winnacker and Weingaertner Chemische Technologie, p. 276
  13. Vérité, p. 312.
  14. CaC2 + H2 -> C2H2 + Ca (OH)2; see, for instance, G. Champetier, La Grande Industrie chimique organique, coll. "Que sais-je?," no. 436 (Paris: P.U.F., 1950), p. 65.
  15. Jüdische Rundschau Maccabi 23 (June 5, 1980):5.

(Table of Contents)


Server / Server © Michel Fingerhut 1996-2001 - document mis à jour le 09/11/1998 à 19h32m52s.
Pour écrire au serveur (PAS à l'auteur)/To write to the server (NOT to the author): MESSAGE