Vol. XXII. No. 9.] 



POPULAE SCIENCE I^EWS. 



131 



5. The breccia, a second cave-earth of much 

 higher antiquity. 



In examining these deposits, it was necessary, for 

 reasons already indicated, to proceed in a manner 

 so careful and systematic, that it should be impos- 

 sible even for scientific men to doubt the facts that 

 should be recorded. 



Not to weary the reader with details, let him 

 imagine a datum line drawn from near the en- 

 trance to the back of the cave. Parallel lines to 

 this, one foot apart, are drawn all over the cave. 

 At right angles to these, other lines are drawn, till 

 the whole cavern is divided into sections, each one 

 foot square. The explorers examine each deposit 

 according to these sections; beginning, of course, 

 with the uppermost, the black mould. A section 

 is first carefully examined in silu by candle or 

 lamp light. It is then taken out, and brought to 

 the entrance, and examined in the daylight. Every 

 object that is not limestone is picked out and put 

 into a box, into which nothing else is put. These 

 boxes are taken to Mr. Pengelly's house each day. 

 The specimens are washed, and the box numbered 

 and labelled; the same number being put on every 

 specimen belonging to that particular box. Then 

 they proceed to the stalagmite, cutting it out in 

 sections, break it up to see what is in it, and put 

 any fossil that is found, into another box. ' Each 

 deposit is taken out in the same manner; so that, 

 in examining any specimen to-day, not only is it 

 known in which deposit it occurred, but also the 

 exact spot in the cavern where it was found, the 

 distance from the entrance, the parallel line, and 

 the level. This work was continued uninterrupt- 

 edly for years, and many thousands of boxes of 

 specimens have accumulated. 



And now let us see what was found in the differ- 

 ent deposits. In the uppermost deposit, the black 

 mould, they found pieces of slate cut into various 

 shapes, whetstones, pieces of smelted copper, and 

 various kinds of combs made of bone. Some of 

 the combs were rudely made, others were beauti 

 fully ornamented. Mr. Pengelly said he thouj?.lit 

 he could distinguish which belonged to the "mis- 

 sus," and which to the servant-maid. They found 

 also flakes of flint, spindle-whorls, amber beads, 

 hazelnuts, and charred wood. The bones and teeth 

 of man were found with those of the following 

 animals: pig, dog, badger, brown bear, ox, red 

 deer, sheep, goat, hare, rabbit, water-rat, seal, birds, 

 and fish ; also the shells of snails, limpets, whelks, 

 oy.sters, cockles, mussels, cuttle-fish, etc. 



It will be seen that this list does not contain the 

 names of any extinct animals. None were found 

 in the black mould, which is therefore to be re- 

 garded as a modern deposit, covering a period of 

 at least two thousand years, perhaps longer. The 

 human remains might have belonged to Romans 

 or ancient Britons, or races earlier than any which 

 history makes mention of. 



It will be evident that what is in the stalagmite 

 is older than any thing in this black mould. In 

 the first or uppermost stalagmite were found bones 

 and teeth of the following animals, some of which 

 belonged to races now extinct: rhinoceros, elephant, 

 bear, hyena, fox, horse, and man. Flakes and 

 cores of flint were found also, with stones of vari- 

 ous kinds, shells of cockles and cuttle-fish, and 

 charcoal and the impressions of ferns. 



In the black band which we have said occurred 

 in one part of the cavern were found three hun- 

 dred and sixty-six flint tools, flakes, and cores, a 

 bone awl, a bone harpoon, a bone needle having 

 a well-formed eye, burnt bones, and remains of 

 bear, hyena, rhinoceros, and other animals. 



In the next deposit below, the cave-earth, were 

 found stones which had come from distant places, as 

 granite from Dartmoor, whetstones, hammer-stones, 



flint tools and flakes, a bone pin, two bone har- 

 poons, burnt bones, charcoal, and bones and teeth 

 of various animals, such as the wildcat, the cave 

 hyena, the cave lion, several varieties of fox, glut- 

 ton, badger, cave bear, reindeer, grizzly bear, wild 

 bull, bison, beaver, the mammoth, and others. 



We have referred to the doubt that was cast on 

 Mr. MoEnery's alleged discovery of Machairodus 

 in Kent's Cavern. These excavations had gone on 

 more than seven years, and no other remains of 

 that animal had been found, although hundreds of 

 thousands of bones and teeth of other animals had 

 been dug out. The doubters were confirmed. But 

 it is dangerous to trust to negative evidence. A 

 tooth was at last discovered which undoubtedly 

 belonged to that animal. 



In the lower crystalline stalagmite the only ani- 

 mal remains that were found were those of the bear. 

 In the breccia, the lower cave-earth, an immense 

 number of bones and teeth were found, all of them 

 being those of the bear. Here also several flint 

 implements were found. 



And now as to the time required for the for- 

 mation of these various deposits, in the lowest of 

 which human implements have been found. Any 

 thing like even an approximate estimate of the 

 immense periods required would be impossible. 

 At least two thousand years must be allowed, 

 probably a much longer period was required for 

 the formation of the black mould. Then we get to 

 the still older stalagmite formed by the deposit of 

 one molecule of limestone after another from the 

 dropping water. This process could go on no 

 faster than the rain that fell on the hill could 

 percolate through the ground, disisolve the lime- 

 stone at the roof of the cave, and carry it in drops 

 to the floor. How small a portion of limestone 

 could be carried in each falling drop of water! 

 But we have five feet to account for, and twelve 

 feet in the lower stalagmite. A curious fact ena- 

 bles us to give a sort of rough guess at the length 

 of time required. In one part of the cave there 

 is a huge boss of stalagmite rising up from the 

 floor, the process going on in this one spot faster 

 than elsewhere. Tliis bo.ss, or pillar, of stalag- 

 mite bears an inscription: " Robert Hedges of 

 Ireland, February 20th, 1088." This inscription 

 was described by the secretary of the Torquay 

 Natural History Society in 1825. His description 

 is good till now. I'he inscription is covered by a 

 thin film of stalagmite about the twentieth of an 

 inch thick. It has required, therefore, two hun- 

 dred years to deposit a film of stalagmite one-twen- 

 tieth of an inch in thickness. At this rate, which 

 is much more rapid than that at which the whole 

 has formed, it would retjuire two hundred and forty 

 thousand years to deposit five feet of stalagmite. 



This calculation cannot, of course, be supposed 

 to be even approximately correct. It only serves 

 to show what long periods of time are indicated by 

 this one instance in which human observation has 

 been able in a rough way to measure the slow 

 processes of nature. Then, under this stalagmite 

 is the cave-earth; and lower still is the second 

 stalagmite, much thicker and many long ages older 

 than that above; and below all these, and older 

 than all, is the breccia, a second cave earth; and 

 in this oldest of all the cave deposits, human im- 

 plements have been found. 



The researches in Kent's Cavern helped consid- 

 erably to revolutionize men's opinions as to the 

 antiquity of the human race. How great that an- 

 tiquity is, it is impcssible to afiirm; but we know 

 enough to warrant the belief that man has lived 

 on the earth during ages so vast, that, compared 

 with them, the historic period is but an insignifi- 

 cant portion of time. 



6 Allston Place, Boston, Mass. 



SOAP-BUBBLES. 



Soap-bubbles fill the same happy position as do 

 those charming books in which Lewis Carroll 

 describes the adventures of Alice, in that they 

 serve equally to delight the young and to attract 

 the old. Clerk-Maxwell has mentioned the fact 

 that on an Etruscan vase in the Louvre are seen the 

 figures of children amusing themselves with 

 bubbles, while to-day the same subject is being 

 forced on the attention of the world by a strange 

 development of modern enterprise. On the other 

 hand, the bubble has occupied the minds of scien- 

 tific men of all times. Professors Reinold and 

 RUcker have employed the soap-film in investiga- 

 tions which tend to throw more light on the molecu- 

 lar constitution of bodies. The latest experiments 

 with bubbles, which were shown by Mr. C. V. 

 Boys to the Physical Society and at the Royal 

 Society conversazione, depend upon no property 

 which is not well known, and, unlike those referred 

 to above, are not intended to increase our scien- 

 tific knowledge; and yet no one would have 

 ventured to predict that bubl)les would submit to 

 the treatment described in the paper, or would have 

 expected such simple means to produce such 

 beautiful results. 



The first property of the soap-film turned to 

 account, is that strange reluctance of two bubbles 

 to touch one another. Just as a bubble may be 

 danced on the sleeve of a serge coat, or even 

 embraced, without wetting the sleeve, or being 

 broken, so can two bubbles be pressed together 

 until they are materially deformed without really 

 touching one another at all. One bubble may be 

 blown inside another, and if the heavy drops which 

 accumulate at the bottom are removed, the inner 

 one may be detached and rolled about within the 

 outer one; or the outer one, held by two mois- 

 tened rings of wire, may be pulled out so as to 

 squeeze the inner one into an oval form, or may 

 even be swung round and round, and yet the inner 

 one remains free and independent, and when the 

 outer is broken it floats gently away. If the inner 

 one is colored with the fluorescent material uranine, 

 it shines with a green light, while the outer one 

 remains clear as at first, showing that there is no 

 mixture and no contact. 



When the inner bubble is blown with coal-gas, 

 it rests against the upper side of the outer one, 

 pulling it more and more out of shape as its size 

 increases. It can even be made to tear the outer 

 one off the ring to which it was attached, after 

 which the two bubbles rise in the air, one inside the 

 other. The outer bubble may be held by a light 

 ring of thin wire, to which thread and paper are 

 attached, and then, when an inner bubble of coal- 

 gas is blown, it will carry up the outer bubble, 

 ring, paper, and all ; and yet, in spite of this 

 weight pressing them together, the inner bubble 

 refuses to tpuch the outer one. If a little gas is let 

 into the outer of two bubbles, the inner one will 

 remain suspended, like Mahomet's cofiin. 



Diffusion of gas though a soap-film is shown by 

 lowering a bell-jar of coal-gas over a bubble in 

 which a second one is floating.. By degrees the 

 gas penetrates the outer bubble, until the inner 

 one, insufliciently buoyed up, gently sinks down. 



The heavy and inflammable vapor of ether is made 

 use of to show the rapidity with which the vapor 

 of a liquid which will mix with the soap solution, 

 will penetrate through the walls of a bubble. A 

 large inverted bell- jar has some ether poured into it, 

 after which bubbles blown with air in the usual 

 way may be dropped into the jar, when they will 

 float upon the vapor. They are then taken out 

 and carried to a flame, when a blaze of light shows 

 that the inflammable vapor has penetrated through 



