"And it's all black where it is not disturbed. As soon as the yacht's prow rushes through, everything is flashing out with phosphorescent light, and you can see myriads of tiny stars gliding away." "Yes, beautiful," said Sir John. "Grand," cried the doctor. "And Mr Bartlett here says it is nothing compared to what he has seen off Java and the other islands. Look now! it's just as if the sea as deep down as we can pierce was full of tiny stars. Oh, here's the pail." The sailor had returned, and way was made for him to drop the bucket at the end of a rope down into one of the brightest parts, and bring it up full of the phosphorescent water. Just then the doctor gave Sir John a dig in the ribs with his elbow, as much as to say, "Now, who's right?" While mentally agreeing that his friend was, Sir John moved out of the way, so as not to receive another poke. Then followed rather a learned discourse from the doctor on the peculiarities of the wonderful little creatures which swarmed in the bucket, whose contents in the light seemed to be so much clear sea-water, but which in the darkness flamed with light as soon as it was disturbed by a hand being passed quickly through. "Why, it makes my hand tingle and smart just slightly," said Jack. "Oh yes," said the mate. "If you bathe in a sea like this you can feel quite an irritation of the skin, while the large jelly-fish sting like a nettle." "Then are these jelly-fish?" "Yes, almost invisible ones," replied the doctor. "But it seems so strange. Why is it?" said Jack. "Well, we know that fish prey upon these things wholesale, and my theory is that the tiny things have the stinging power as a defence by day, and the ability to light up to make the fish think they will burn their mouths at night and leave them alone. Sounds absurd, eh? But I believe that's it." Jack spent an hour having bucketfuls of water drawn up from the spots where the luminous cold fire seemed to burn most fiercely, the mate and Edward, called in to assist, entering into the business with the greatest of enthusiasm, and helping, after Sir John and the doctor had gone, in another way, fetching tumblers and a glass globe from the steward, Edward having to carry these well-filled into the cabin, where, chuckling to himself, the doctor brought out his small microscope, and using a tiny water-trough designed for the purpose, proceeded to examine these little wonders of the world. Gibraltar was reached a couple of days later, and a very brief stay made, Jack contenting himself with watching the huge mass of rock with his binocular. Then away over the rather rough sea, with a favourable wind, they ran for Naples, where it grew calmer, and at night the slow from the summit of the burning mountain was seen reflected on the clouds, while by day these clouds could be seen to be of smoke. On again for the Canal, and the doctor confided to Sir John his belief that he was a little anxious now.