May 29, 1891.] 



SCIENCE. 



301 



ordinary game. Let us place them in a little box, shake them, 

 and throw them on the table. We will assume that they had 

 fallen so that each cube exhibited the number three on its upper 

 face; of course, a rare chance. Now it can be mathematically 

 shown after how many throws those six numbers are likely to re- 

 appear according to the law of chance. It is possible that they 

 may turn up already with the next throw ; on the other hand, we 

 may have to cast those dice ten thousand times. Both cases are 

 improbable: the probability lies in a certain number. If, instead 

 of six dice, we were to take seven, the critical number is, of course, 

 so much further removed, viz : it would be necessary to throw 

 oftener to get the seven threes, and so the number of casts in- 

 creases with every additional cube, till we finally obtain enormous 

 figures. But no matter how many dice, the threes must turn up, 

 if we can throw them long enough, and if, in the case of a thou- 

 sand dice, it were to take a million years, the threes must appear 

 and reappear again and again after proportionate intervals. 



Supposing now, that, instead of dice, we were to take a glass 

 filled with sand. There are, let us assume, twenty thousand sand 

 grains in the glass. Each particular grain occupies a certain posi- 

 tion, which is bound to differ from that of aU the rest of the sand 

 grains : this the reader will douhtless admit. We shake the glass ; 

 the positions are altered, the order of arrangement is disturbed. 

 We shake it again; the sand grains are now in a totally different 

 position. We continue shaking the glass, and the time must coooe 

 when each individual grain again occupies the exact position 

 which it occupied when we originally started. It is a mathemati- 

 cal necessity, which all will admit who know anything of the cal- 

 culus of permutations. The twenty thousand sand grains may be 

 looked upon as so many dice, which are bound to fall precisely as 

 they once fell if we can throw them sufficiently often. 



Now, I have strong grounds for assuming that my body is com- 

 posed of atoms, or groups of atoms, of a limited number of ele- 

 mentary substances, or of one elementary substance, if all matter 

 has been evolved from one primary element. The number of 

 these atoms may be ever so great, it has nothing whatever to do 

 with the inevitable result. I know also that all other bodies are 

 composed of such atoms, or groups of atoms (molecules); not only 

 those of the human species, animals, and plants, but of inorganic 

 substances, rocks, metals, fluids, gases; in short, of every thing 

 which exists in, upon, or above the ground in the atmosphere. I 

 know, furthermore, that the atoms of even the hardest and seem- 

 ingly most enduring substances, such as agate and diamond, are 

 in a state of continual vibration ; that nothing can permanently 

 retain" its form; that the entire universe always has been, is 

 now, and always will be, in a state of metaphorphosis or continual 

 change. 



The time must arrive when the atoms or molecules which are 

 now united in my body, after countless transformations and wan- 

 derings through all kinds of bodies, substances, or intermediary 

 stages, will once more unite in the same manner; in other words, 

 the time will arrive when my life, like that of every other indi- 

 vidual, will repeat itself. Yes, repeat itself, and not merely once, 

 but an infinite number of times. 



And more than this, if one of my readers should imagine that 

 the atoms or molecules which now constitute his body, are thus 

 associated for the first time, I can only admire his simplicity. 

 There is nothing new under the sun. Those molecules were united 

 in this manner before, and before this again, and 100,000,000 times 

 previously, as far as our imagination can carry us back into the 

 abysmal night of the aaons of the past. In other words, each of 

 my readers has been, ages ago, what he is now, has lived and gone 

 through all this before, has felt and experienced what he now 

 feels and experiences, down to the minutest details, has opened 

 his Journal of the Franklin Institute billions of years ago and read 

 the same lines ; not once, but an endless number of times. The 

 recollection, of course, is lost. Life and mind itself, conscious- 

 ness, or " soul," is only a product of matter, and if the same sub- 

 stances reunite in the same manner, the same phenomena must 

 inevitably recur. 



Let the molecules which now constitute my body undergo 

 ever so many metamorphoses, let them even — which, of course, 

 is very improbable — once fill a bung-hole, let them be scattered 



about in all manner of forms and conditions, in close contact or 

 millions of mUes apart; they must come together again, may the 

 thought please or distress me, — this is the iron logic of modem 

 dynamics. 



A JOURNEY IN COSTA RICA. 



At the February meeting of the Geographical Society of Paris 

 (reported in the Proceedings of the Royal Geographical Society, 

 London) a letter was read from M. H. Pittier, head of the Physico- 

 Geographical Institute of Costa Rica. His route lay through 

 country not previously explored from a scientific point of view. 

 At a distance of several leagues from the capital, the traveller en- 

 tered the region of oaks, which he hardly quitted for a whole 

 week. The whole of the district known under the name of Can- 

 delaria, which, at the time of OElrsted's visit, was well wooded and 

 rich in interesting plants, has become denuded of vegetation 

 through the carelessness of the inhabitants, and is to-day partly 

 covered with a poor kind of turf, over which are scattered clumps 

 of the fragrant bushes of the " tuete " {Vernonia braehiata). Be- 

 yond the Rio Tarrazu the character of the country changes, and 

 the road ascends in a zigzag line the mountain slopes, covered 

 with forests of virgin oaks. On the summit of the Cordillera the 

 "Paramo del Abejonal," the vast prairie which occupies the ridge 

 of the mountain is crossed, and then a rapid descent was made to 

 San Marcos. From the latter place to the valley of the Rio Gen- 

 eral is a journey of five days, across the great mountain of Buena 

 Vista, the geographical importance of which has, according to M. 

 Pittier, been overlooked, owing to insufficient exploration. Al- 

 though inferior in height to the peaks of Irazu and Turialba, Buena 

 Vista presents more sudden changes of climate and a greater va- 

 riety of vegetation. The summits are almost continuously swept 

 by a keen, strong wind, which condenses thick mists. Sleet falls 

 frequently, and a white frost forms when the nights are clear. 

 The immense forests, which clothe its flanks up to a great altitude, 

 are formed almost exclusively of oaks, among which the most 

 frequent varieties are the Weinmannia glabra and the Drymis 

 Winteri. The vegetation of the upper region, above the forests, 

 is alpine in character, but the bamboos were found growing beside 

 representatives of an evidently northern flora. At one point, 

 clearly defined formations of columnar basalt were noted. This, 

 with other indications, led the traveller to the conclusion that the 

 whole of the Cerro de Buena Vista is of eruptive origin, although 

 no traces of former volcanoes were descovered. The mountain is 

 important from a hydrographical point of view. The head waters 

 of the Rio Reventazin occupy the greater part of its northern 

 slope; on the west it feeds the Rios Parrita Grande, Naranjo, 

 Savegre, and Baru; while the various branches of the Rio Gen- 

 eral take their origin from its southern flank. M. Pittier in- 

 tended to cross the immense forest-covered plains extending on 

 the left bank of the Rio General as far as the Indian villages of 

 Terrata and Boruca, and to return to San Jose at the end of 

 February. He states that the maps of all this part of Costa Rica 

 are very faulty. 



HIGH WINDS AND BAROMETRIC PRESSURE. 



The relation of high winds to barometric pressure, from obser- 

 vations carried out at the Ben Nevis Observatory, was the subject 

 of a paper from Dr. Alexander Buchan, at a meeting of the Royal 

 Society of Edinburgh on March 3, 1891, an abstract of which is 

 given in the Scottish Geographical Magazine for May. This was 

 a question. Dr. Buchan said, which had been much discussed in 

 recent years, — some meteorologists maintaining that the influence 

 of high winds was to depress the barometer, others that it was to 

 raise the barometer, and several others, again, that it had practi- 

 cally no effect whatever. In the discussion of the Ben Nevis ob- 

 servations, particularly from the time that hourly observations 

 began to be obtained from the low-level observatory at Fort WU- 

 liam, in July last, the first question that appeared to him calling 

 for thorough investigation was this question of the relation of the 

 winds to the readings of the barometer, inasmuch as, till this re- 

 lation be approximately determined, the proper discussion of 



