40 DDT— Killer of Killers 



must go to the factory where it is being manufactured or 

 formulated. 



But what is DDT? To you it is a killer of insea life. 

 To the chemist, it is a compound of carbon, hydrogen, and 

 chlorine, represented by the following structural formula. 



and bearing the name dichloro-diphenyl-trichloroethane. It 

 is easy to see from the jaw-breaking length of this chemical 

 name that a drastic abbreviation was necessary. An official 

 of the British Ministry of Supply got tired of writing this 

 long chemical name, and early in 1943 earned the gratitude 

 of many suffering stenographers by substituting the simple 

 letters DDT. And DDT it has been ever since. 



Pure DDT, as designated by the above formula, is a 

 white, crystalline powder with a weak, fruit-like odor, and 

 having a melting point of 107-108 °C. The commercial 

 product, however, melts as low as 88°C., due to the presence 

 of so-called isomers, that is, compounds having the same 

 number of carbon, hydrogen, and chlorine atoms as shown 

 in the above formula but arranged in a slightly different man- 

 ner. These isomers don't harm the product, for they also 

 possess insecticidal properties. 



If you should be interested in making some DDT, you 

 could follow the instructions which appear in a 1942 British 

 Patent issued to J. R. Geigy, A. G. : 



"225 parts of chlorobenzene are mixed v/ith 147 parts 

 of chloral or the corresponding amount of chloral hydrate 



