Manning now concentrates all his energies toward this end. Obviously, all the deductions of Messrs. Lecocq and Sherlock Holmes would be futile. But through shrewd questioning of the servants in the house he ascertains that the husband was taken violently ill after supper and that no guests were present at the meal.
An analysis of the sediment in the husband's coffee cup establishes the presence of arsenic. It must be inferred that the wife's cup contained none of the poison, for she developed no symptoms of poisoning after the meal.
The servants declare that the wife invariably made the after-dinner coffee in a percolator that stood on the sideboard. On the night in question, she had boiled the coffee, but none of the servants had seen her draw it from the percolator or serve it in the cups. But all of them assert that for a year or more it had been the wife's custom to do the serving, so it is a fair inference that the husband did not leave his seat at the table to help himself to coffee, on the occasion of his fatal illness. No one but the wife being in the room with him, and it having been ascertained that she purchased the arsenic, hers was the exclusive opportunity to drop it into the cup--and the evidence against her is complete.
A case of this nature is not established by the deductive methods of a Lecocq, but by the patient labor of a score or a half score of detectives intelligently guided by their chief. The druggist who sold the poison was found after a canvas of perhaps three or four hundred apothecaries. The domestic strife in the victim's home was disclosed to the police by relatives of the husband, whose interests naturally conflicted with those of the wife. Other evidence was furnished reluctantly by the servants, and, through the collective efforts of all the detectives, the woman's crime has been reconstructed in a way calculated to convince the ordinary juror.
It was because Detective-Lieutenant Britz was endowed with a rare combination of talents that enabled him to direct the work of others, even while participating actively in the physical search for evidence, that he ranked as the foremost detective of the Central Office. Had he been merely a shrewd, capable, resourceful investigator, he could never have attained to his present eminence.