8 
apparently disappear from the animal’s blood, and to prolong the life 
of the animal. Unfortunately the usual history is that if treatment 
be discontinued, even after a prolonged course of the drug, the animal, 
after a varying length of time, once more exhibits the symptoms, and 
finally succumbs to the disease. Undoubtedly some of the more 
resistant animals do recover.’ Thomas then quotes the view of 
Laveran and Mesnil (Trypanosomes et Trypanosomiases) that 
Arsenic kills the parasites which are free in the blood, but that when 
once the drug is eliminated or fixed in the tissues, the surviving 
parasites commence to multiply and the organisms once more 
reappear in the peripheral circulation unless another injection of 
Arsenic be given. On the administration of a second dose the 
parasites disappear only to reappear, and even though treatment be 
kept up, the majority of the animals succumb either from the disease 
or from the toxic effects of the drug. Some of the animals, such as 
rats and dogs, have been cured. Laveran also records the extensive 
necrosis and the pain which is apt to follow the administration of 
Arsenious acid. 
Thomas and Breinl, in a paper upon ‘ Trypanosomiasis 
and Sleeping Sickness,’ published as Memoir XVI, 1905, of 
the Liverpool School of Tropical Medicine, report fully upon the 
treatment. Sodium arseniate was found the most useful form of 
Arsenic, but the usual disadvantages soon appeared and they stopped 
It. Ihe sum total, therefore, of results obtained with Arsenic or its 
salts, dating from the early observation of Livingstone, through the 
elaborate experiments of Bruce and Lingard. to the more recent 
experimental observations of Laveran. Mesnil. Thomas, and Thomas 
and Breml was such as to encourage hope of a successful treatment ■ 
here was no doubt that the disease was modified, the life of many of 
he animals was prolonged, and some of the animals were cmed 
expenments showed equally well the disadvantages of the drug 
.uch as the recrudescence of the disease on stopping the druir and 
The employment of T'"" ^y it. . 
the Aniline colours -t-HRLICH and Shiga at about this: /. n . . 
' Farbentherateutische VersucATle f T " 
the Berliner klin.sche Wochlnschrift 
the Benzopurpurin group in the ourmg matters belonging to 
group m the treatment of trypanosomiasis; they 
