1772.
October.
these to hasten away from them. Desirous of enquiring into the cause of this astonishing phænomenon, we procured a bucket full of the illumined sea-water. The most accurate attention to it proved, that innumerable minute sparks, of a round shape, communicated this luminous appearance to the water, and moved about in it with great briskness and velocity. After the water had been standing for a little while, the number of sparks seemed to decrease; but on being stirred again, the whole became as luminous as before. Again, as the water gradually subsided the sparks were observed to move in directions contrary to the undulations of the water, which they did not before, whilst the agitation was more violent, and seemed to carry them along with its own motions. We suspended the bucket, to prevent its being too much affected by the motion of the ship; the bright objects by this means betrayed more and more a voluntary motion, independent of the agitation of the water caused by our hands, or by the rolling of the vessel. The luminous appearance always gradually subsided, but on the least agitation of the water, the sparkling was renewed, in proportion as the motion was encreased. As I stirred the water with my hand, one of the luminous sparks adhered to my finger. We examined it by the common magnifier of Mr. Ramsden's improved microscope, and found it to be globular, transparent like a gelatinous substance, and somewhat brownish:by
