In 1765, the Reverend Dr. Chandler received a letter from Dr. Finley, President of the College in that province, relating the same experiment. It was read at the Royal Society, Nov. 21, of that year, but not printed in the Transactions; perhaps because it was thought too strange to be true, and some ridicule might be apprehended if any member should attempt to repeat it in order to ascertain or refute it. The following is a copy of that account.
"A worthy gentleman, who lives at a few miles distance, informed me that in a certain small cove of a mill-pond, near his house, he was surprized to see the surface of the water blaze like inflamed spirits. I soon after went to the place, and made the experiment with the same success. The bottom of the creek was muddy, and when stirred up, so as to cause a considerable curl on the surface, and a lighted candle held within two or three inches of it, the whole surface was in a blaze, as instantly as the vapour of warm inflammable spirits, and continued, when strongly agitated, for the space of several seconds. It was at first imagined to be peculiar to that place; but upon trial it was soon found, that such a bottom in other places exhibited the same phenomenon. The discovery was accidentally made by one belonging to the mill."
I have tried the experiment twice here in England, but without success. The first was in a slow running water with a muddy bottom. The second in a stagnant water at the bottom of a deep ditch. Being some time employed in stirring this water, I ascribed an intermitting fever, which seized me a few days after, to my breathing too much of that foul air which I stirred up from the bottom, and which I could not avoid while I stooped in endeavouring to kindle it.--The discoveries you have lately made of the manner in which inflammable air is in some cases produced, may throw light on this experiment, and explain its succeeding in some cases, and not in others. With the highest esteem and respect,
_Extract of a Letter from_ Mr. HENRY _of_ Manchester.
It is with great pleasure I hear of your intended publication _on air_, and I beg leave to communicate to you an experiment or two which I lately made.
Dr. Percival had tried, without effect, to dissolve lead in water impregnated with fixed air. I however thought it probable, that the experiment might succeed with nitrous air. Into a quantity of water impregnated with it, I put several pieces of sheet-lead, and suffered them, after agitation, to continue immersed about two hours. A few drops of vol. tincture of sulphur changed the water to a deep orange colour, but not so deep as when the same tincture was added to a glass of the same water, into which one drop of a solution of sugar of lead had been instilled. The precipitates of both in the morning, were exactly of the same kind; and the water in which the lead had been infused all night, being again tried by the same test, gave signs of a still stronger saturnine impregnation--Whether the nitrous air acts as an acid on the lead, or in the same manner that fixed air dissolves iron, I do not pretend to determine. Syrup of violets added to the nitrous water became of a pale red, but on standing about an hour, grew of a turbid brown cast.