“I have no idea how much Prussian blue I obtained from the first experiment, as it was made in a hurry. (_The bottle of dark blue liquid was here shown again._) I thought the obtaining evidence of its presence sufficient. I got more Prussian blue in the second experiment than in the first, and more in the third experiment than the second. I have not calculated the total amount of Prussian blue in the bottle.” _As to the contents of the stomach_: “There was undigested flesh and a pulpy mass of which I could make nothing, and some portion of apple, but no pips either partially digested or undigested with the apple. I am not prepared to say that the pips of this apple contained more prussic acid than others. There is a great difference between bitter and sweet apples—_the bitter contain a great deal of prussic acid, the sweet, I believe, none_.”[14] _As to prussic acid being in many substances_: “Strictly speaking, I don’t think it exists in any substance, not even in bitter almonds. I mean in a free state; it is so extremely volatile that it cannot possibly exist unless in combination with some other substance. It is my opinion that prussic acid is a ‘product,’ and not an ‘educt’—that is to say, in consequence of its great volatility it cannot exist unless in combination with some other substance; you liberate it by combination and change. The elements of it exist in a great many substances. These elements, on taking new arrangements, may produce prussic acid. Therefore I feel that it is always a ‘product,’ and that it does not exist in any substance in a free state, because if it did it would be continually evaporating from that substance.” _Question._—“Are not the substances which are already known to contain the elements of prussic acid, and from which it can be obtained, very numerous?” _Answer._—“They are very numerous certainly, because all those compounds which contain carbon, nitrogen, oxygen, and hydrogen, may, in my opinion, by new changes be made to produce prussic acid. All animal substances of any kind contain those elements, in which are contained the elements of prussic acid. I agree, as far as I know, with Christison, that the distilled seeds of bitter almonds, and pomaceous seeds, yield prussic acid by distillation.” _Question._—“Is it not found, from time to time, by accident or experiment, to exist in organic and other matters?” _Answer._—“I believe it is. I was the first person to discover it in fulminating silver, and perhaps also in apple-pips, from recent experiments. I am not aware of it ever having been produced by mere organic changes in the stomach. If the apple-pips on which I operated had been macerated, I cannot say that I should have obtained more Prussian blue. I know it is the habit to macerate bitter almonds, but I also know that without maceration they have sometimes yielded more prussic acid than with maceration.”