There was nothing difficult about this. The stock would have been prepared from Monday’s delivery of shin of beef. It was my father’s habit always to keep a pan of stock simmering on the hob. By Thursday morning there would probably be just sufficient left to cook his evening meal, after which he would boil up the new supply of shin for the rest of the week.
Now, in what form would the poison have been added? Not in the solid form, for my father would have noticed the presence of fungi in his stock. But a teacupful of poisonous liquid might easily have been poured in at any moment. I was, therefore, brought back to my previous idea that Lathom had managed to procure the Amanita muscaria and decoct the poison during my father’s absence from the hut.
But how I was ever to prove this, I did not know. I had plenty of evidence of motive and opportunity, but nothing that could put the crime beyond any reasonable doubt in the minds of twelve good and true jury-members. And besides, I was by no means satisfied of Lathom’s ability to identify Amanita muscaria with certainty. Was there no easier and more reliable method by which he might have obtained the stuff? Was it possible, for instance, to buy muscarine? If so, and if one could trace the sale to Lathom, there would be genuine evidence of criminal intent. For what innocent reason could an artist require muscarine?
The difficulties of the thing stared me in the face. Even if muscarine was procurable commercially (which I thought very unlikely, for, so far as I know, it has no medicinal use), it was impossible for me, as a private individual, to broadcast an investigation among all the chemists in the country. Only the police could do that, and I could not set the police to work without producing the very evidence which was the object of the search. There were not only chemists—there were all the research laboratories too. The thing seemed hopeless.