This procedure at that time was a common practice, and indeed we have statements from Mary Ann Cotton’s neighbours when she lived in West Auckland, that they themselves used such mixtures. The fact that she used the mixture is not in question, however the facts of the case hinged on the fact that she poisoned her family members with it. However as we know, exhumations took place and the corpses were found to contain amounts of arsenic, as to how it was deposited in their organs is a matter which we will address later. Firstly we must concentrate on the prosecutions evidence which was that Mary Ann purchased the arsenic and the proof that she purchased the arsenic was evidence of her intentions to wilfully poison her family. But I ask the question, what proof of purchase did the prosecution have, because as we know the search of Mary Ann Cotton’s house on the 18th of July 1872 produced no evidence to confirm she had any in her possession. All of the kitchen’s utensils and dishes, pots and pan’s were thoroughly analysed, according to the police and no traces of arsenic were found in any of the items. Professor Scattergood said in his evidence that if such items were used to contain arsenic, then washing of the utensils would not satisfactorily remove its presence. His words if used as a measure of competence, appear to support Mary Ann’s case. Could she use the arsenic in her utensils such as a teapot or cup and thoroughly wash away those traces, quite clearly Scattergood inadvertently suggested that it was totally impossible. To overcome this dilemma the prosecution switched tack and had to present hard evidence that Mary Ann Cotton was seen to actually purchase the arsenic, which would further strengthen their case, without that evidence that part of the prosecution would fail. It was here that the prosecution found a witness to strengthen their claim, enter Thomas Detchon, who gave his evidence as follows to the Durham Assizes. Thomas Detchon: I am an assistant chemist to Mr. William Owen of Newcastle-on-Tyne. I remember a woman 4 years ago coming to my masters shop between 2.pm-3pm on January 21st of 1869 and asking for three-penny’s worth of soft-soap and arsenic. She gave her name as Mary Ann Booth, and that is the person who I see in the prisoners dock. Detchon also said that he had seen Mary Ann Cotton in Durham Prison whilst she was on remand and had picked her out from a group of twelve women prisoners. I must say I find this to be fascinating as Mary Ann told her relatives that she never did or was ordered to attend an identity parade or similar parade. Durham Jail and officials made no mention of that fact and a search of the Home Office records also shows that no evidence of that identity parade ever took place? Detchon further said that the woman who bought the soft-soap and arsenic wanted it to kill bugs on beds and linen. “I told her that I could not sell her the mixture because she needed a witness, but I could sell her an alternative mixture called “bug specific” which we make without needing a witness. She said that she would rather have the other and again I said not without a witness.”
