156 REPORT OF THE HARVARD AFRICAN EXPEDITION 
trail or in the forest. The risk of sleeping in or inhabiting even for a few hours 
resthouses in some districts which have been occupied by the natives must 
be pointed out, and also the precautions to be taken when they must be oc- 
cupied. Every case of illness must be carefully examined and treated. In cases 
of fever the blood must be carefully examined and proper and complete 
treatment carried out. Every case of diarrhoea must be investigated micro- 
scopically and promptly treated according to the diagnosis. The porters must 
be quartered and separated from the camp of the white people, and protected 
from rain at night, and arrangements must be made for their food and fire 
wood. Every case of disease among them must be investigated and treated. 
Only healthy men in good physical condition must be allowed to undertake the 
march. 
Owing largely, no doubt, to the intelligent cooperation of my seven col- 
leagues in the exercise of these and other hygienic precautions, there was not 
a case of dysentery or diarrhoea or of serious illness among them. Attacks 
of fever, never requiring the patient to be in bed for more than several days 
at a time, were the only illnesses experienced by any of us, and all came out 
of Africa in good physical condition. 
Although in the light of certain recent experimental work upon malarial 
infection that bears on the prophylactic use of quinine, it seems that drug 
may not sometimes actually prevent primary infection with sporozoites of mala- 
ria, the great value in the use of quinine as a practical prophylactic to prevent 
serious malarial paroxysms and invalidism in men on expeditions in infected 
localities is, in the author’s opinion, unquestionable. Fifteen grains of quinine 
taken on two successive days of the week (our custom on this Expedition) will 
not always prevent primary malarial infection, but when infection does result, 
the paroxysms are usually mild. Apparently the only disadvantage of moment 
in such prophylactic use of quinine is that it makes diagnosis difficult, for it is 
almost impossible to find malarial parasites in the blood of a man who is tak- 
ing thirty grains of the drug a week. On the Expedition any case that was 
diagnosed as malaria as well as the cases in which parasites were actually found 
in the blood, was treated with from thirty to forty-five grains of quinine dur- 
ing four or five days, and then with fifteen grains daily for from six to eight 
weeks. In one instance a relapse with malarial paroxysms and parasites in 
the blood of the tertian variety occurred in one of the members of the Expe- 
dition a year and a half after his return to this country. The probable explana- 
tion is that, owing to the unpleasant effects of the quinine, it was difficult to 
persuade the patient after his return to the United States to pursue a six weeks’ 
course of continued treatment with the drug. 
In respect to the prophylactic use of quinine, the investigations of James, 
Nicol and Shute ' are of interest. After having demonstrated that the injec- 
tion into man of sporozoites obtained from infected mosquitoes produced in- 
fection, they performed the following experiment: two mosquitoes infected 
with Plasmodium vivax were placed in a 1-5000 solution of quinine bisulphate 
1 James, Nicol and Shute: Trans. Royal Soc. Trop. Med. and Hyg. (1927), XXI, 233. 
