of pulsations or waves, which rise up so that their crest may be one, two, or three-tenths of an inch above the general surface of the water. These variations in height are marked by a series of curved grooves or ripple lines on the sides of the camphor, which gradually changes its dull translucent appearance for a bright transparent one, showing that the water has penetrated it. In the meantime an incision is made in the camphor, which goes on increasing as successive films are detached, until at last the stick is cut through, and the submerged piece commences a series of gyrations on its own account.

If lycopodium powder be faintly dusted over the surface, the camphor currents and pulsations may on a fine day be seen together. If two sticks of camphor be lowered into the same surface of water, the interference of the currents will be shown by the motions of the powder.

As in the case of small fragments of camphor rotating rapidly on the surface of water, the rotations are stopped if the water be touched with a fatty oil, so these pulsations are immediately arrested if the water be touched with a drop of any substance which spreads into a film, and arrests evaporation. The point of a pin dipped into olive oil and brought into contact with the water, at once arrested the lycopodium currents, a second contact stopped the pulsations. So also, if a body be added to the water that satisfies its adhesion, or, in other words, stops the solution, the pulsations are arrested. Thus a drop of oil of camphor will stop the pulsation by depriving the water of the power of dissolving camphor; a drop of olive oil will stop the pulsations by preventing the water from evaporating; but a drop of oil of bitter almonds, which speedily evaporates, will allow the pulsations to go on again very soon after it has been added. Turpentine, oil of cajeput, kreosote, etc., stop the pulsations; but ether, alcohol, benzole, naphtha, bisulphide of carbon, caustic potash, and sal-ammoniac, allow them to go on freely. A bit of sponge tied to the end of a glass rod, if dipped in ether and held near the camphor, will hold up the wave of water against the camphor for some time. A drop of benzole does not stop the pulsations, but it makes them less rapid. The pulsations will go on in a solution of caustic potash and in one of sal-ammoniac, and I have no doubt that the action of acids, etc., on rotating camphor as described in my first "Experimental Essay," will have a similar action on the camphor pulsations.

In your notice of my book you say that I do "not seem by any means to have exhausted the curious subject of the Storm Glass." I had reserved this subject for a separate essay, a copy of which I hope to have the pleasure of sending you shortly.

With respect to the motion of camphor towards the light

you do not seem to have apprehended me fully, or I may not have expressed myself clearly. My theory is that light has nothing to do with the deposit of camphor, of vapours, or of crystals of saline solutions on the most illuminated side of the glass vessels that contain them, but that such deposits are formed by condensation on the coldest side of the vessel, which may or may not be the most illuminated side. If a number of bottles containing a little camphor, naphthaline, iodine, water, turpentine, etc., be placed in the window, the deposits will be formed generally on the side nearest the light, because that side is generally the coldest; but if the sun be shining on the window, the side nearest the light will be the hottest, and the deposit will go to the back of the bottle, or to the coldest side. If the bottle be equally heated in every part, and equally cooled, no deposit will be formed except at the bottom of the vessel, unless the cooling be sufficiently rapid and great to condense the elastic vapour as it subsides. We shall then have a deposit equally all round the glass, and this is the more likely to happen with a thin one, because glass being a bad conductor of heat, a thick narrow glass is not so likely to cool unequally; it does not, in fact, present a cold side and a warmer side, unless under favourable circumstances. For instance, a thick barometer tube containing a charge of camphor was left in one corner of a warm room, it was afterwards exposed to the cold of winter, and when next examined it was found to have a deposit equally all round. It will, of course, be understood that under all ordinary circumstances a bottle containing camphor, etc., is filled with the vapour of that substance at all ordinary temperatures. A certain depression of temperature is required to cause a deposit, as in the case of dew, and unless the temperature be sufficiently depressed there will be no deposit. In vacuum, the camphor deposit may be formed in a few minutes, as in Dr. Draper's experiments, and it was to get rid of the cumbersome machinery of air-pump, and air-pump receivers, that I made use of the more sensitive crude camphor, which forms a good deposit if a little of it be placed at the bottom of an ordinary corked vial. So sensitive is this vapour of crude camphor that it will revive marks, and small impurities in the bottle, the presence of which was not suspected. The minute invisible filaments left by the duster used in wiping out the bottle, become visible in a few minutes after the bottle has received its charge of crude camphor, and exposed in the window in consequence of becoming coated with that substance condensed upon them.

KING'S COLLEGE, London, 15th June, 1863.

NOTES ON THE MOLE.

BY THE REV. J. G. WOOD, M.A., F.L.S.

A FEW days ago, a deputation of young friends brought me a fine specimen of the common mole, which they had captured in Belvedere Park. The creature had evidently contrived to get upon a patch of hard ground-the gravel comes to the surface in this locality-and before it could make its way below the stony ground, it was pounced upon and secured. The little captive was not in the least injured, and I transferred him to a rather large box, which I placed in the garden.

He ran about the box with great agility, thrusting his long and flexible snout into every crevice, and paying especial attention to the corners, in each of which he scratched perseveringly for some minutes. Seeming at last to make up his mind that he could not escape, he screwed himself into a corner, poked his muzzle into the darkest recess, and remained motionless as if dead. I then quietly introduced a few spadefulls of earth into the box, and scattered a little of the fresh soil under the creature's nostrils. New life seemed to be infused into the mole by the contact of the earth, and, Antæus-like, he inspired fresh vigour from the touch of mother Tellus.

The mole traversed the box with wonderful rapidity, pushing his way through the loose soil, entering and re-entering the heap, and in a few moments had scattered the earth tolerably evenly over the box. Every now and then the whole skin gave a quick convulsive shake, which had the effect of throwing the loose earth from the fur. This peculiar shake, or twitch, was really a curious sight. At one moment the mole was grubbing away, hardly to be distinguished from the surrounding soil, so completely was the fur covered with the dusty particles; suddenly a spasmodic shudder passed through the body, and in a moment the moving dust-heap had vanished, and in its place was manifest the soft, velvet coat of the mole.

The creature was unremitting in his attempts to escape from the box. After satisfying himself that he really could not burrow through a deal-board-a lesson which was not learned until after many attempts and as many failures-the creature tried to scramble over the sides, and stood perseveringly on his hind legs, scraping pertinaciously at the smooth wood, and ever and anon slipping sideways, and coming on his fore-feet.

The mobility of the long snout is really astonishing. The animal moves quickly about with an uncertain kind of gait, now to one side and now to the other, popping the nose here and there so rapidly that the eye can hardly follow its movements.

The senses of sight and smell seem to be practically obso

lete. I placed a worm upon the track of the mole, and though his nose came within the tenth of an inch of the worm, he did not seem to be aware of the presence of his prey. I tried this experiment eight or nine times in succession, and always with the same result; but if the nose or either foot happened to come in contact with the annelid, the mole flew round in a moment, flung himself upon the prey, shook the worm backwards and forwards with his paws, passed his snout rapidly over it, bit it here and there, and scratched it about until he got one end of it into his mouth; either end answered his purpose equally well.

He then began to eat it in a most voracious manner, arching his back, sinking his head between his shoulders, keeping his fore-feet close on either side of his mouth, and using them with great dexterity, just as a Chinese uses his chopsticks, cramming the writhing annelid into his jaws as fast as it was eaten. The crunching sound of his teeth making their way through the tough skin of the worm was audible at a distance of two yards, and a sort of fury seemed to actuate the animal; it ate as if savage with hunger, and as fast as I could supply it with worms, so fast did it devour them.

One worm was of huge dimensions, and the mole could make nothing of it for a long time. He trampled over it many times, passing the worm underneath his body from his fore to his hind feet in a very peculiar manner, scuffling it, as it were, backwards and forwards. He bit it in twenty places, left it, came back again, got each end successively into his mouth, and rejected them both, and altogether behaved in a manner that could not have been pleasant to the worm. All this time the mole was full of excitement and fiery activity.

At last, he seized the worm about an inch from the head, held it fast with his jaws, and with his feet pulled it asunder. He then dropped the severed piece, searched for its head, found it, and crunched it up. He then scrabbled about until he came upon the rest of the worm, and pouncing upon it, like a cat on a mouse, he pulled off another piece, ate it, and so proceeded until he had finished the worm in detachments. Whenever he swallowed the last morsel of the worm, he used to potter about the same spot for some little time, trying it over and over with his nose, and ever and anon returning to it. I fancy that this precaution is taken for the purpose of securing any fragments of the worm which may have been bitten off, worms being sometimes very brittle.

The creature had now disposed of six worms, some of moderate size, and one three times as long as the mole itself. He seemed as hungry as ever, so I set to work and dug up a fresh supply. I could still hear the animal scraping about the box,

and my cat heard the noise also, and became very uneasy, trying to lift up the lid of the box, and catch the inhabitant.

After reducing pussy to reason, and making him understand that moles were not mice, I proceeded to give the animal a second supply of worms. He was just as furious about them as he had been with the former batch, and ate them as rapidly as before; inclusive of the time occupied in digging up the worms, fourteen were eaten in thirteen minutes. The second batch consisted of ten worms, all rather large, and these were as quickly devoured.

Ι

Wishing to know whether he would eat the common Julus millipede, I put a fire one on his track. As soon as he felt its writhing form touch his feet, he pounced on it as he had done with the worms, and scrambled it under his nose. As soon, however, as the sensitive snout touched the millipede, the mole threw up his head, and with one of his fore-paws chuckedthere is no other word that expresses the action-the julus on one side, flinging it about two or three inches away.

I tried this experiment several times, and always found that the mole flung the julus away in the same manner. There was something inexpressibly ludicrous in the change of manner that came over the animal whenever he found that he had seized a julus instead of a worm, and the contemptuous air with which the millipede was tossed aside was most absurd.

About 8 P.M. I resumed the fork and spade for the purpose of procuring the mole's supper. Having heard from popular report that a twelve hours' fast would kill a mole, I determined to afford the creature a bountiful supply of food late in the evening, and then to give him his breakfast about 5.30 or 6 A.M. next morning.

So I dug perseveringly until I had captured a large handful of worms, and about 9 P.M. I put them into the box. As the mole went backwards and forwards, he happened to touch one of the worms, and immediately flew at it. While trying to get its head into his mouth, he came upon the whole mass of worms, and flung himself upon them in a perfect delirium of excitement. He kicked them backwards and forwards under his body, he trampled over them, he pulled them about, and seemed so overjoyed at his treasure that he could not settle upon any one individual. At last, however, he caught one of the worms, and began to crunch it, the rest uncoiling their many folds, making their escape in all directions, and burrowing into the loose mould.

Thinking that the animal was now well supplied for the night, some two dozen worms having been put into the box, I shut him up with an easy conscience.

Now, it so happened that on the following morning the rain