7 
du Nagana.’ They obtained their best results by using sodium 
arseniate subcutaneously; with this drug they were able to bring 
about a quick disappearance of the parasites from the blood. The 
lives of the animals were prolonged, but a permanent cure was not 
effected. These observers also used Sodium cacodylate, Sublimate 
of Mercury, various salts of Silver, but without effect. 
They were also led to try the effects of injecting human serum Serum 
into ngana-infected rats and mice ; they were led to do so as man 
was not susceptible to ngana. A marked improvement followed the 
injection of human serum ; the duration of the disease was prolonged, 
but a real cure could not be effected. 
E. J. Moore, in a paper upon the beneficial effects of Sodium 
arseniate employed hypodermically in tsetse-fiy disease, and published 
in the Lancet, Vol. II, 1904, records the most marked beneficial effects 
with large doses, and states that he would also recommend it for 
humans. 
Chichester, who collaborated with him in a letter which he sent to 
Sir Patrick Manson dated May 5th, 1904, and published in the Lancet 
under the title of ‘ Arsenic in the treatment of Trypanosomiasis in 
Cattle in Nigeria,’ says that ‘he used Arsenic hypodermically and 
produced most wonderful effects.’ He adds that the experiment is 
not over, but says that ‘ I do not think it wise to wait longer. I tell 
you what I have found, and you may perhaps think it wise to ask 
others to try the same treatment, especially in those parts where it 
seems a scourge to human beings.’ 
Thomas, in 1903, whilst at the MacGill University, in Canada, 
repeated some of the experiments upon the action of Arsenic on 
ngana-infected animals, and on joining the Liverpool School of 
Tropical Medicine, in August of the same year, immediately started 
extensive investigations upon the action of drugs upon trypano¬ 
somiasis. Amongst them he used Sodium arseniate, and with this 
drug his results were similar to those of Laveran. ‘ Many of the rats 
either died from the disease, were killed by the drug, or succumbed 
to an extensive ulceration around the site of injection.’ Thomas’s 
own words, taken from his paper entitled ‘ Some experiments in the 
treatment of trypanosomiasis’ {British Medical Journal, May 27, 
1905) were: ‘ Arsenic in the treatment of trypanosomiasis in animals 
seems rather to mitigate the disease, to cause the parasite to 
