The studies of Morgenroth and his collaborators have shown that a number of quinin derivations manifest considerable curative powers against trypanosomes, spirochetes and pneumococci, and that this power reaches its maximum in the substance known as ethylhydrocuprein.
Although this drug is very successful in curing mice affected with pneumococcus septicemia, Engwer and also one of us (H.) have been unable to obtain any striking series of cures in guinea-pigs and rabbits with experimental lobar pneumonia, even with the lowest dose (60,000 pairs per cubic millimeter) which is certainly fatal.
This drug has been used with a certain amount of success in clinical pneumonia by Linné and Vetlesen and also locally in cases of pneumococcus keratitis by Ginsberg. Giemsa and Izar have found it a specific in the treatment of stubborn estivo-autumnal malaria cases which have withstood the action of quinin.
Further extension of clinical observation with this drug in other