“My dear fellow, I know you well. I know the military neatness which characterises you. You shave every morning, and in this season you shave by the sunlight; but since your shaving is less and less complete as we get farther back on the left side, until it becomes positively slovenly as we get round the angle of the jaw, it is surely very clear that that side is less illuminated than the other. I could not imagine a man of your habits looking at himself in an equal light and being satisfied with such a result. I only quote this as a trivial example of observation and inference. Therein lies my métier , and it is just possible that it may be of some service in the investigation which lies before us. There are one or two minor points which were brought out in the inquest, and which are worth considering.”

“What are they?”