Part 10

“Yes,” I agreed, “and having regard to the importance of the footprints, I think it would be wise to get a photograph of them.”

“Oh, the police will see to that,” said Foxton. “Besides, we haven’t got a camera, unless you thought of using that little toy snapshotter of yours.”

As Foxton was no photographer I did not trouble to explain that my camera, though small, had been specially made for scientific purposes.

“Any photograph is better than none,” I said, and with this I opened the tripod and set it over one of the most distinct of the footprints, screwed the camera to the goose-neck, carefully framed the footprint in the finder and adjusted the focus, finally making the exposure by means of an Antinous release. This process I repeated four times, twice on a right footprint and twice on a left.

“Well,” Foxton remarked, “with all those photographs the police ought to be able to pick up the scent.”

“Yes, they’ve got something to go on; but they’ll have to catch their hare before they can cook him. He won’t be walking about barefooted, you know.”

“No. It’s a poor clue in that respect. And now we may as well be off as we’ve seen all there is to see. I think we won’t have much to say to Mrs. Beddingfield. This is a police case, and the less I’m mixed up in it the better it will be for my practice.”

I was faintly amused at Foxton’s caution when considered by the light of his utterances at the breakfast table. Apparently his appetite for mystery and romance was easily satisfied. But that was no affair of mine. I waited on the doorstep while he said a few--probably evasive--words to the landlady and then, as we started off together in the direction of the police station, I began to turn over in my mind the salient features of the case. For some time we walked on in silence, and must have been pursuing a parallel train of thought for, when he at length spoke, he almost put my reflections into words.

“You know, Jervis,” said he, “there ought to be a clue in those footprints. I realize that you can’t tell how many toes a man has by looking at his booted feet. But those unusual footprints ought to give an expert a hint as to what sort of man to look for. Don’t they convey any hint to you?”

I felt that Foxton was right; that if my brilliant colleague, Thorndyke, had been in my place, he would have extracted from those footprints some leading fact that would have given the police a start along some definite line of inquiry; and that belief, coupled with Foxton’s challenge, put me on my mettle.

“They offer no particular suggestions to me at this moment,” said I, “but I think that, if we consider them systematically, we may be able to draw some useful deductions.”

“Very well,” said Foxton, “then let us consider them systematically. Fire away. I should like to hear how you work these things out.”

Foxton’s frankly spectatorial attitude was a little disconcerting, especially as it seemed to commit me to a result that I was by no means confident of attaining. I therefore began a little diffidently.

“We are assuming that both the feet that made those prints were from some cause devoid of little toes. That assumption--which is almost certainly correct--we treat as a fact, and, taking it as our starting point, the first step in the inquiry is to find some explanation of it. Now there are three possibilities, and only three: deformity, injury and disease. The toes may have been absent from birth, they may have been lost as a result of mechanical injury, or they may have been lost by disease. Let us take those possibilities in order.

“Deformity we exclude since such a malformation is unknown to us.

“Mechanical injury seems to be excluded by the fact that the two little toes are on opposite sides of the body and could not conceivably be affected by any violence which left the intervening feet uninjured. This seems to narrow the possibilities down to disease; and the question that arises is, What diseases are there which might result in the loss of both little toes?”

I looked inquiringly at Foxton, but he merely nodded encouragingly. His rôle was that of listener.

“Well,” I pursued, “the loss of both toes seems to exclude local disease, just as it excluded local injury; and as to general diseases, I can think only of three which might produce this condition--Raynaud’s disease, ergotism, and frost-bite.”

“You don’t call frost-bite a general disease, do you?” objected Foxton.

“For our present purpose, I do. The effects are local, but the cause--low external temperature--affects the whole body and is a general cause. Well, now, taking the diseases in order, I think we can exclude Raynaud’s disease. It does, it is true, occasionally cause the fingers or toes to die and drop off, and the little toes would be especially liable to be affected as being most remote from the heart. But in such a severe case the other toes would be affected. They would be shrivelled and tapered, whereas, if you remember, the toes of these feet were quite plump and full, to judge by the large impressions they made. So I think we may safely reject Raynaud’s disease. There remain ergotism and frost-bite; and the choice between them is just a question of relative frequency. Frost-bite is more common; therefore frost-bite is more probable.”

“Do they tend equally to affect the little toes?” asked Foxton.

“As a matter of probability, yes. The poison of ergot acting from within, and intense cold acting from without, contract the small blood-vessels and arrest the circulation. The feet, being the most distant parts of the body from the heart, are the first to feel the effects; and the little toes, which are the most distant parts of the feet, are the most susceptible of all.”

Foxton reflected awhile, and then remarked:

“This is all very well, Jervis, but I don’t see that you are much forrarder. This man has lost both his little toes, and on your showing, the probabilities are that the loss was due either to chronic ergot poisoning or to frost-bite, with a balance of probability in favour of frost-bite. That’s all. No proof, no verification. Just the law of probability applied to a particular case, which is always unsatisfactory. He may have lost his toes in some totally different way. But even if the probabilities work out correctly, I don’t see what use your conclusions would be to the police. They wouldn’t tell them what sort of man to look for.”

There was a good deal of truth in Foxton’s objection. A man who has suffered from ergotism or frost-bite is not externally different from any other man. Still, we had not exhausted the case, as I ventured to point out.

“Don’t be premature, Foxton,” said I. “Let us pursue our argument a little farther. We have established a probability that this unknown man has suffered either from ergotism or frost-bite. That, as you say, is of no use by itself; but supposing we can show that these conditions tend to affect a particular class of persons, we shall have established a fact that will indicate a line of investigation. And I think we can. Let us take the case of ergotism first.

“Now how is chronic ergot poisoning caused? Not by the medicinal use of the drug, but by the consumption of the diseased rye in which ergot occurs. It is therefore peculiar to countries in which rye is used extensively as food. Those countries, broadly speaking, are the countries of North Eastern Europe, and especially Russia and Poland.

“Then take the case of frost-bite. Obviously the most likely person to get frost-bitten is the inhabitant of a country with a cold climate. The most rigorous climates inhabited by white people are North America and North Eastern Europe, especially Russia and Poland. So you see, the areas associated with ergotism and frost-bite overlap to some extent. In fact they do more than overlap; for a person even slightly affected by ergot would be specially liable to frost-bite, owing to the impaired circulation. The conclusion is that, racially, in both ergotism and frost-bite, the balance of probability is in favour of a Russian, a Pole, or a Scandinavian.