170
Total period of observation-One year.
Result. Both animals are alive and well at the present time.
Conclusions:-
The conclusion to be drawn from these experiments is that the incarceration for months of monkeys in rooms presumably infected with the so-called Beri-beri virus, failed to induce the occurrence of the disease in them. We were unable to confirm the results of HAMILTON WRIGHT.
B.--FEEDING EXPERIMENTS.
After the publication by HAMILTON WRIGHT of his observations on the nature of Beri-beri and his theory of a definite primary lesion in the disease, feeding experiments were resorted to as a possible means of inducing infection. Again, as certain observers, as PEKELHARING and WINKLER, GERRARD and others, claim to have found micro-cocci, etc., in the blood stream of Beri-beri patients, feeding animals with the blood of such cases seemed to afford the best opportunity for a successful mode of conveyance of Beri-beri from man to animal. By this method the organisms said to be present in the blood would reach that part of the gut, namely, the gastro duodenal mucosa, alleged to be the site of primary Beri-beri infection, and in susceptible animals set up the disease. It seemed to us that by resorting to such experiments, the question as to the presence of a definite primary lesion in Beri-beri, and our hopes of obtaining positive evidence of the transmission of the disease to monkeys by this method were strengthened by the publication of WRIGHT dealing with natural infection in monkeys incarcerated in presumably infected prison cells.
As already noted under a separate paragraph our results as regards natural infection of monkeys are directly opposed to those of HAMILTON WRIGHT. In every instance a negative observation was made. At the same time our experiments regarding natural infection might have been unsuccessful for other unknown adverse circumstances, so that the prosecution of other methods of experimentation in monkeys would decide definitely whether these animals (or indeed any animal) can suffer from Beri-beri naturally, or can be infected artificially by simple or drastic methods of incorporation of Beri-beri infected tissues.
The following feeding experiments on monkeys were undertaken :-
Experiment No. I.
Animal-One monkey.
Nature of experiment :-
Feeding with freshly drawn defibrinated venous blood of acute
Dropsical Beri-beri patients.
The blood was obtained under sterile conditions from one of the veins in front of the elbow joint, defibrinated, and imme- diately poured down the animal's throat.
Quantities of blood varying from 40-50 c.c. were administered for a dose. Several doses of the same quantity were given. The animal was fed with blood from different cases of Beri-beri.
The experiment was commenced on the 11th October, 1904. For some days previous, the animal was kept under observation and during this period shewed no signs of disease. The teinperature was normal. During the whole period of observation, the temperature of the animal was taken twice daily per rectum. Its food consisted of bananas, nuts and rice. The condition of the animal was also tested daily, particularly in regard to emaciation, motor and sensory disturbances, knee-jerks and the presence of epigastric tenderness and diarrhoea.