The new science of chemotherapy, which has achieved brilliant success in the attack on certain spirochetal infections, offers a fertile field for research in connection with other parasites. It is possible to produce, new chemical compounds which will possess affinities for cocci, bacilli, fungi, etc. In order to pursue fruitful research along these lines, it is desirable that the parasiticide properties of old and known medicaments be investigated and classified.
Modern medicine employs the experimental method in the development of new remedies for infectious diseases in contrast with the empiric method that characterized the prelaboratory period in medicine. There are two lines of approach in investigative work of this character. One is chemically to modify a drug or compound of clinical value in a certain infection and test the various modifications until an enhanced parasiticidal value is obtained. Starting with atoxyl, which possessed trypanocidal power and a perceptible influence in