“On January 2 I went to Mrs. Hart’s house and saw her body; have heard the evidence of Mr. Champneys, and should say that death was caused by prussic or oxalic acid; do not know of any other poisons that would produce death so rapidly; was present at Mr. Cooper’s experiments; have heard and perfectly agree with his evidence; oxalic acid must have been detected if present; I am quite of opinion that prussic acid was present in the stomach, and have no doubt about it; have heard the evidence of the witness Howard, the symptoms she describes (of supposed former attempt) are precisely those of prussic acid. That acid acts uniformly upon all animal subjects, and destroys life in the same way in all cases. Have tried experiments on dogs, and have seen cats and dogs poisoned by that acid. On the 18th February I made an experiment on two dogs. Five hours after feeding them I gave one of them half an ounce and the other one drachm of Scheele’s acid, administered it at 7 p.m., and exactly in ten seconds after receiving the smaller dose the dog fell as if dead, and the other in half the time; _I opened their bodies eighteen hours after and could not discover any odour_; I smelt the mouth of the dog and could not detect it then, nor at any other time; I opened the stomach of the dog, which smelt intensely of sour beer, the acid having been administered in beer. I attributed the absence of smell to the admixture of Guinness’s stout; I should have expected on opening Mrs. Hart’s body to have discovered the cause of death.” _By the Court._—“I examined the brain; it was perfectly healthy; death did not arise from apoplexy.” _By Serjeant Byles._—“Less than a grain of pure prussic acid would be sufficient to produce death.” _Cross-examined_ by _Mr. Kelly_:—