The minute parasites which cause Malta, yellow, and malarial fever, and other infections, are no doubt best dealt with by excluding them from access to the human body when that is possible. But once they have effected a lodgment and commenced to multiply in the blood or tissues, it is still possible to get at them by means of drugs, which poison them without injuring their human victim. Thus quinine has been of enormous service in checking the ravages of the malaria parasite, and really in Great Britain has exterminated “ague,” which is the English name for malaria. Many experiments have been made during the last two years, with the view of finding some drug which will, in like manner, destroy the trypanosomes which have established themselves in the blood and lymph-passages of the human body, and are slowly killing their victim with sleeping sickness. An arsenic compound, “atoxyl,” has been found effective when injected into the patient’s body, and according to Dr. Koch, who returned last year from Uganda, he has found nothing better than this treatment, discovered by Dr. Thomas and Dr. Breinl, of the Liverpool School of Tropical Medicine, three years ago. Dr. Plimmer and Dr. Thomson, who have been experimenting in London for the Royal Society, have found a drug which is more effective than atoxyl in destroying certain trypanosomes which attack rats, and is now being tried in the treatment of sleeping sickness. This is the tartrate of sodium and antimony--a salt corresponding to the well-known tartar emetic, with this difference, that it contains sodium instead of potassium. It seems that this sodium variety of tartar emetic is very destructive to trypanosomes in the blood and lymph, and has no injurious effect of a lowering nature, such as occurs when the potassium salt is used. As the antimony drug is far cheaper than atoxyl, it will be possible to apply it freely to horses and cattle suffering from “nagana” and “surra,” which are diseases due to trypanosomes of a special kind. Two white men who had become infected by the trypanosome of sleeping sickness in West Africa have been treated with the new drug in London, and the parasites have completely disappeared from their blood in consequence, though it remains to be seen whether a permanent cure has been effected. One cannot imagine a situation of more thrilling interest than that existing in the nursing home where those two victims were given a strong hope of escape from what seemed to be certain death, whilst the fate of thousands of African natives, similarly infected, was hanging in the balance! After six months from the date of treatment the report is satisfactory. The parasites have not yet re-appeared (July, 1908) in the two patients treated in November. 14. _Tsetse-Flies and Disease_