HdeL/BR 
The Royal Institution, 
21,Albemarle Street, 
LONDONjW.I. 
15th April 1952 
Dr. Richard Schultes, 
Agricultural Division, _ 
Embassy of the U.S.A. 
Bogota, 
Colombia, South America. 
Dear Sir, 
In conjunction with the Medical Research 
Council of the U.K. I am engaged on a project to 
find a chemical substance which will render women 
temporarily sterile if taken by mouth. 
We have started our work on Caladium and will 
shortly be testing a number of other plants, from 
various parts of the world, that are said to have 
these properties. Ultimately we hope to isolate 
and synthesise the active principles involved. We 
are anxious to make a survey of all such plants 
from any part of the world that were used by 
primitive tribes for this purpose in years gone by. 
Owing to your Ethno-Botanical interests I am 
now approaching you in the hope that you can give 
the names of some plants which grow in your 
territory having these properties, and perhaps 
help in obtaining some dried material for our 
work. 20-25 lbs. of the dried plants would be the 
mini mun i with which we could do the tests. 
Naturally I would be glad to repay the cost 
of collecting and mailing the above and in any case 
greatly look forward to having your views by/ 
P.T.O. 
