“Our investigation, however, was somewhat hampered by the fact that the condition in question is rare out of tropical countries, and that in our hospital wards we had not, at that time, any example of it.  So serious was this obstacle, that it seemed that we must leave other men more favourably situated to reap the benefit of our work and enjoy the credit of our discovery, but a curious chance gave us exactly what we were in search of, at the instant when we were about to despair.  It was Yorke-Bannerman who came to me in my laboratory one day to tell me that he had in his private practice the very condition of which we were in search.

“‘The patient,’ said he, ‘is my uncle, Admiral Scott Prideaux.’

“‘Your uncle!’ I cried, in amazement.  ’But how came he to develop such a condition?’

“’His last commission in the Navy was spent upon the Malabar Coast, where the disease is endemic.  There can be do doubt that it has been latent in his system ever since, and that the irritability of temper and indecision of character, of which his family have so often had to complain, were really among the symptoms of his complaint.’

“I examined the Admiral in consultation with my colleague, and I confirmed his diagnosis.  But, to my surprise, Yorke-Bannerman showed the most invincible and reprehensible objection to experiment upon his relative.  In vain I assured him that he must place his duty to science high above all other considerations.  It was only after great pressure that I could persuade him to add an infinitesimal portion of aconitine to his prescriptions.  The drug was a deadly one, he said, and the toxic dose was still to be determined.  He could not push it in the case of a relative who trusted himself to his care.  I tried to shake him in what I regarded as his absurd squeamishness—­but in vain.

“But I had another resource.  Bannerman’s prescriptions were made up by a fellow named Barclay, who had been dispenser at Nathaniel’s and afterwards set up as a chemist in Sackville Street.  This man was absolutely in my power.  I had discovered him at Nathaniel’s in dishonest practices, and I held evidence which would have sent him to gaol.  I held this over him now, and I made him, unknown to Bannerman, increase the doses of aconitine in the medicine until they were sufficient for my experimental purposes.  I will not enter into figures, but suffice it that Bannerman was giving more than ten times what he imagined.

“You know the sequel.  I was called in, and suddenly found that I had Bannerman in my power.  There had been a very keen rivalry between us in science.  He was the only man in England whose career might impinge upon mine.  I had this supreme chance of putting him out of my way.  He could not deny that he had been giving his uncle aconitine.  I could prove that his uncle had died of aconitine.  He could not himself account for the facts—­he was absolutely in my power.  I did not wish him to be condemned, Maisie.  I only hoped that he would leave the court discredited and ruined.  I give you my word that my evidence would have saved him from the scaffold.”