Many more questions were put to the doctor, after which his colleague, Dr. Lynes, was called, and corroborated the police surgeon's evidence. He, too, was utterly unable to ascribe any fatal cause. The tattoo marks had puzzled him, but he suggested that the man and woman might be husband and wife, and that in a freak of caprice, to which women of some temperaments are subject, she had caused the device on her husband's arm to be copied upon her own. Opinions were, however, divided as to whether the pair were husband and wife. For my own part I did not regard his theory as a sound one. "You did not overlook the contents of the stomach, of course?" the Coroner exclaimed. "No, we sent them in sealed bottles to Dr. Marston, the analyst of the Home Office." "And have we his report?" inquired the Coroner. "Dr. Marston is here himself, sir. He has come to give evidence," Patterson answered from the back of the room, while at the same time an old grey-haired gentleman in gold-rimmed spectacles rose, and walking forward took the oath. "You received from the previous witnesses two bottles?" suggested the Coroner. "Will you please tell us the result of your analysis?" "I tested carefully with group reagents for every known poison, and also for ptomaine," he said, "but all the solvents--alcohol, benzol, naphtha, ammonia and so forth--failed. I tested for the alkaloids, such as strychnine, digitalin, and cantharidin, and used hydrochloric acid to find either silver, mercury or lead, and also ammonia in an endeavour to trace tin, cadmium or arsenic. To none of the known groups does the poison--if poison there be--belong. Therefore I have been utterly unable to arrive at any definite conclusion." "Is there no direct trace of any poison?" "None," was the answer. "Yet from the result of certain group reagents it would appear that death was due to the virulence of some azotic substance." "You cannot, we take it, decide what that substance was?" "Unfortunately, no," the renowned analyst answered, apparently annoyed at having to thus publicly acknowledge his failure. "The state of the stomach of either person was not such as might cause death. Indeed, there was only a secondary and most faint trace of the unknown substance to which I have referred." "Then, to put it quite plainly," said the Coroner, "it is your opinion that they were poisoned?" "I can scarcely go so far as that," the witness responded. "All I can say in evidence is that I found a slight trace of some deleterious substance which all tests refused to clearly reveal. Whether it were an actual poison which resulted in death I hesitate to say, as the result of my analysis is not sufficiently clear to warrant any direct allegation." "Do you suggest that this substance, whatever it was, must have been baneful and injurious to the human system?"