To sum up, the probabilities are against sleeping sickness, but with our insufficient knowledge, we cannot definitely exclude it." "You think that it may really be sleeping sickness ?" "No; personally I do not entertain that theory for a moment.

But I am considering the evidence apart from our opinions on the subject.

We have to accept it as a conceivable hypothesis that it may be sleeping sickness because we cannot positively prove that it is not.

That is all.
But when we come to the hypothesis of morphine poisoning, the case is different.

The symptoms agree with those of morphine poisoning in every respect.