THE HORMONES IN HUMAN REPRODUCTION 



postage stamp. To compare an unknown preparation with 

 this, it must be tested on rabbits under standard conditions. 



Progesterone is soluble in oils and fats as well as in fat 

 solvents like ether, and therefore it is generally injected hypo- 

 dermically in a bland vegetable oil, such as sesame oil. It is 

 ineffective when given by mouth, as shown by extensive trials 

 on rabbits. Recently some of the drug manufacturers have put 

 out another substance, a progestin of slightly different chem- 

 ical structure, which is reported to give progestational pro- 

 liferation in rabbits when given by mouth. Its usefulness in 

 human patients is now being established (Appendix II, 

 note 5). 



A failure and what it taught. Willard Allen and I had a 

 queer experience with our first extracts, from which we learned 

 something important, so that the story is not only amusing 

 but useful. The beginning of this tale is that when we started 

 we followed (as I said before) a hint from the work of Ed- 

 mund Herrmann, who had obviously produced progestational 

 proliferation in a few of his experiments without knowing it. 

 He had used very young rabbits, roughly 8 weeks old. They 

 react more readily than adults to the estrogen which was the 

 chief ingredient of his extracts. Since we wanted to follow his 

 methods closely at first, we used infant rabbits too, and with 

 them our first successes were obtained. In the spring of 1929 

 we were all ready to report the first steps in print. The paper 

 was being written, when it occurred to me that our directions 

 for extracting the hormone ought to be tried out by a none- 

 too-good chemist, just to make sure they were foolproof. We 

 did not want others to think our work could not be repeated, 

 just because our directions were not clear. It was agreed that 

 I was a bad enough chemist for the test : if I could make the 

 extract all by myself, then anybody could. So Allen went on 

 his vacation and I went back to our extractors and vacuum 

 stills. In a week I had a batch ready; to my horror it was 

 ineffectual. I made another batch; it, too, was worthless. I 



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