Letter from SS-Oberführer Viktor Brack to Reichsführer-SS Himmler, June 23, 1942 (Documents on the Holocaust - Edited by Y. Arad, Y. Gutman, A. Margaliot, NY, Ktav Pub. House in Association with Yad-Vashem, 1981, p. 272):

Honorable Mr. Reichsführer!

On instruction from Reichsleiter Bouhler I placed a part of my men at the disposal of Brigadeführer Globocnik some considerable time ago for his special task. Following a further request from him, I have now made available more personnel. On this occasion Brigadeführer Globocnik pressed the view that the whole action against the Jews should be carried out as quickly as it is in any way possible, so that we will not some day be stuck in the middle should any kind of difficulty make it necessary to stop the action. you yourself, Mr. Reichsführer, expressed the view to me at an earlier time that one must work as fast as possible, if only for reasons of concealment. Both views are more than justified according to my own experience, and basically they produce the same results. Nevertheless I beg to be permitted to present the following consideration of my own in this connection:

According to my impression there are at least 2-3 million men and women well fit for work among the approx. 10 million European Jews. In consideration of the exceptional difficulties posed for us by the question of labor, I am of the opinion that these 2-3 million should in any case be taken out and kept alive. Of course this can only be done if they are in the same time rendered incapable of reproduction. I reported to you about a year ago that persons under my instruction have completed the necessary experiments for this purpose. I wish to bring up these facts again. The type of sterilization which is normally carried out on persons with genetic disease is out of the question in this case, as it takes too much time and is expensive. Castration by means of X-rays, however, is not only relatively cheap, but can be carried out on many thousands in a very short time. I believe that it has become unimportant at the present time whether those affected will then in the course of a few weeks or months realize by the effects that they are castrated.

In the event, Mr. Reichsführer, that you decide to choose these means in the interest of maintaining labor-material, Reichsleiter Bouhler will be ready to provide the doctors and other personnel needed to carry out this work. He also instructed me to inform you that I should then order the required equipment as quickly as possible.

Letter from Dr. Pokorny to Reichsführer-SS Himmler, October 1941 (Nazi Conspiracy and Aggression - Washington, U.S Govt. Print. Off., 1946, Supp. A, p. 1279):

Prompted by the thought that the enemy must not only be conquered but exterminated, I feel obliged to submit the following to you as the Reich Plenipotentiary for the Consolidation of German Folkdom:

Dr. Madous is publishing the results of his research into sterilization by medicaments (I enclose both works). In reading this article, I was struck by the enormous importance of this medicament in the present struggle of our people. Should it be possible to produce as soon as possible, as a result of this research, a medicament which, after a comparatively brief period, would cause an unnoticed sterilization in individuals, we would have in our disposal a new and very effective weapon. The thought alone that the 3 million Bolsheviks now in German captivity could be sterilized, so that they would be available for work but precluded from propagation, opens up the most far-reaching perspectives.

Letter from SS-Oberführer Gund to Reichsführer-SS Himmler, August 24, 1942 (Trials of War Criminals Before the Nuernberg Military Tribunals - Washington, U.S Govt. Print. Off., 1949-1953, Vol. I, p. 717):

At the orders of Gauleiter Dr. Jury, his staff have hitherto busied themselves especially with the problems of population, racial policy, and antisocial elements. Since the prevention of reproduction by the congenitally unfit and racially inferior belongs to the duties of our National Socialist racial and demographic policy, the present director of the District Office for Racial Policy, Gauhauptstellenleiter Dr. Fehringer, has examined the question of sterilization and found that the methods so far available, castration and sterilization, are not sufficient in themselves to meet expectations. Consequently, the obvious question occurred to him whether impotence and sterility in could not be produced in men and women by the administration of medicine or injections....

The director of my race policy office points out that the necessary research and human experiments could be undertaken by an appropriately selected medical staff, basing their work on the Madaus animal experiments in cooperation with the pharmacological institute of the Faculty of Medicine of Vienna, on the persons of of the inmates of the Gypsy (Roma) (Roma) camp of Lackenbach in Lower Danube.

Letter from Reichsführer-SS Himmler to SS-Oberführer Brack, August 11, 1942 (Trials of War Criminals Before the Nuernberg Military Tribunals - Washington, U.S Govt. Print. Off., 1949-1953, Vol. I, p. 722):

Dear Brack,

It is only today that I have the opportunity of acknowledging the receipt of your letter of June 23. I am positively interested in seeing the sterilization by X-rays tried out at least once in one camp in a series of experiments.

Letter from Blankenburg to Reichsführer-SS Himmler, April 29, 1944 (Trials of War Criminals Before the Nuernberg Military Tribunals - Washington, U.S Govt. Print. Off., 1949-1953, Vol. I, 723):

By order of Reichsleiter Bouhler I submit to you as an enclosure a work of Dr. Horst Schumann on the influence of X-rays on human genital glands.

Previously you have asked Oberführer Brack to perform this work, and you supported it by providing the adequate material in the concentration camp Auschwitz. I point especially to the second part of this work, which shows that by those means castration of males is almost impossible or requires an effort which does not pay. As I have convinced myself, operative castration requires not more than 6 to 7 minutes, and therefore can be performed more reliably and quicker than castration by X-rays.

Soon I will be able to submit a continuation of this work to you.

Letter from SS-Obersturmbannführer Brandt to Prof. Clauberg, July 10, 1942 (Trials of War Criminals Before the Nuernberg Military Tribunals - Washington, U.S Govt. Print. Off., 1949-1953, Vol. I, p. 729):

Today the Reich Leader SS charged me with transmitting to you his wish that you go to Ravensbrueck after you have had another talk with SS-Obergruppenführer Pohl and the camp physician of the women's concentration camp Ravensbrueck, in order to perform the sterilization of Jewesses according to your method....

Thorough experiments should be conducted to investigate the effect of the sterilization largely in a way that you find out after a certain time, which you would have to fix, perhaps by X-rays, what kind of changes have taken place. In some cases a practical experiment might be arranged by locking up a Jewess and a Jew together for a certain period and then seeing what results are achieved.

Memorandum of SS-Obersturmbannführer Brandt on discussion between Himmler, Gebhart, Gluecks, and Clauberg concerning sterilization experiments conducted on Jewesses (Trials of War Criminals Before the Nuernberg Military Tribunals - Washington, U.S Govt. Print. Off., 1949-1953, Vol. I, p. 728):

Führer Headquarters, July 1942

On 7 July 1942 a discussion took place between the Reich Leader SS, SS-Brigadeführer Professor Dr. Gebhart, SS-Brigadeführer Gluecks, and SS-Brigadeführer Clauberg, Koenigshette. The topic of the discussion was the sterilization of Jewesses. The Reich Leader SS has promised Brigadeführer Professor Clauberg that Auschwitz concentration camp will be at his disposal for his experiments on human beings and animals. By means of some fundamental experiments, a method should be found which would lead to sterilization of persons without their knowledge. The Reich Leader SS wanted to get another report as soon as the result of these experiments was known, so that the sterilization of Jewesses could then be carried out in actuality.

It should also be examined, preferably in cooperation with Professor Dr. Hohlfelder, an X-ray specialist in Germany, what way sterilization of men could be achieved by X-ray treatment.

The Reich Leader SS called the special attention of all gentlemen present to the fact that the matter involved was most secret and should be discussed only with the officers in charge and that the persons present at the experiments had to pledge secrecy.

Letter from Professor Clauberg to Himmler, June 7, 1943, on his research concerning sterilization of women (Trials of War Criminals Before the Nuernberg Military Tribunals - Washington, U.S Govt. Print. Off., 1949-1953, Vol 1, p. 730):

Dear Reich Leader,

Today I am fulfilling my obligation to report to you from time to time about the state of my research work....

The method I contrived to achieve the sterilization of the female organism without operation is as good as perfected. It can be performed by a single injection made through the entrance of the uterus in the course of the customary gynecological examination known to every physician. If I say that the method is "as good as perfected" this means:

1. Still to be worked out are only minor improvements of the method.

2. Already today it could be put to practical use in the course of our regular eugenic sterilization and could thus replace the operation.

As to the question which you, Reich Leader, asked me almost a one year ago, i.e., how much time would probably be required to sterilize 1,000 women by using this method. Today I can answer you with regard to the future as follows:

If my researches continue to have the same results as up to now - and there is no reason to doubt that - then the moment is not far off when I can say:

"One adequately trained physician in one adequately equipped place, with perhaps 10 assistants (the number of assistants in conformity with the speed desired) will most likely be able to deal with several hundred, if not even 1,000 per day."

Sources: Shamash

Nazi Medical Experiments: Sterilization Memoranda