June 2, 1887] 



NATURE 



10: 



pressure, and a short description of how this has been 

 done may not be uninteresting. 



In order to determine the boihng-points, about 15 cubic 

 centimetres of the hquid were obtained as above, gently 

 freed from pressure, and communication with the air 

 estabhshed by opening the vah'e //. Marsh gas, nitric 

 oxide, and oxygen behaved under these circumstances 

 perfectly quietly, evaporating only from the surface, 

 necessitating shaking of the apparatus to prevent super- 

 heating ; while in the case of carbon monoxide and 

 nitrogen the evaporation proceeded with gentle ebullition. 

 It required 5 to 15 minutes for the liquid to escape com- 

 pletely out of the apparatus, affording ample time to take 

 the boiling-point with a hydrogen thermometer. A list 

 of the boiling-points obtained is given in the table. It is 

 satisfactory that VVroblewski has completely confirmed 

 the accuracy of Olszewski's temperatures by thermo- 

 electric measurements, and he asserts that a hydrogen 

 .thermometer affords correct indications as far as — 193°, 

 but the latter gentleman proves that the error must be 

 very small, as all the boiling-points are above —220", the 

 critical temperature of hydrogen, and he shows that 

 oxygen and nitrogen thermometers are not influenced by 

 an error exceeding 1" even at several degrees below their 

 critical points. From an inspection of the critical points 

 given in the table we can at once see why the earliest 

 attempts to liquefy these gases so utterly failed, for no 

 amount of pressure would liquefy nitrogen for instance, 

 unless its temperature could be at the same time reduced 

 to —146", a temperature not procurable by the means 

 known to the earlier experimenters. 



For the purpose of the density-determinations the inner 

 tube within the liquefaction tube was calibrated, the 

 thermometer removed, and the hole in the stopper 

 closed with glass rod and sealing-wax. About 15 c c. 

 of the liquefied gas were obtained as before, freed gra- 

 dually from pressure, and, as soon as all the liquid in the 

 interspace had evaporated, the height of the liquid 

 ■column left under atmospheric pressure was read off. 

 At the moment of reading off the valve h was connected 

 by a caoutchouc tube with the aspirator r, and when the 

 gas was completely volatilized, water was run out until 

 the levels in the tube and respirator were again equalized. 

 The volu ne of water received in the measuring-flask was 

 of course equal to that of the gas formed by evaporation 

 of the known volume cf liquid, and, after applying cer- 

 tain corrections dependent upon the nature of the 

 apparatus, was reduced to 0° and 760 mm. As the 

 pressures under which the densities of marsh gas, oxygen, 

 iand nitrogen were determined were nearly identical, the 

 numbers obtained are strictly comparable. 



i Boiling- 



p 'int. 



' ° C. 



Marsh gas - 164 



Oxygen - 181-4 



Nitrogen - 194 '4 

 Carbon 



Density. 



Melting- Critical 

 point. p. int. 



o o xaxa. 



0-4I5 at - 164 and 736 



^ -Ii8'8 i'i24at - i8i'4and 743 



146 0-885 at - i94-4and 741 



214 



monoxide r '9° " 207 -139-5 

 Nitric oxide - 153-6 - 935 



It is a subject for sincere congratulation that these 

 dangerous experiments should have been so far free from 

 accident, but this immunity was not to last ad infinitum, 

 for, just as the last experiment with nitrogen was in pro- 

 gress, the liquefaction tube suddenly flew to pieces and so 

 deranged the apparatus that the densities of carbon 

 mono.xide and nitric oxide could not be determined. 



These researches, taken in conjunction with those of 

 Victor Meyer on the dissociation of the molecule of 

 iodine, and of Lockyer, Liveing and Dewar, and other 

 workers on the effect of high temperature generally in 

 simplifying the structure of molecules, have assisted, and 

 will in the future assist us still more, in arriving at much 



more accurate views respecting the ultimate structure of 

 matter itself. On the assumption that the molecule of 

 iodine consists of two atoms, which, according to the view 

 now becoming more and more accepted by thinkers on 

 this subject, may themselves consist of aggregations of a 

 still simpler substance— aggregations which, at tempera- 

 tures obtainable in the laboratory, we have not been able 

 to break up — the classical experiments of Victor Meyer 

 have shown that at a temperature of about 1500'' C. the 

 molecules are dissociated into single atoms, that is to say, 

 the intensity of the heat-vibrations is so great that the 

 attraction between the two atoms in the molecule is over- 

 come, and they are torn asunder. At still higher tem- 

 peratures there is a possibility that the atom itself could 

 be resolved into something simpler still. 



Reasoning on the same lines, there is great probability 

 that even hydrogen, oxygen, and other more permanent 

 gases could, by a sufficiently high temperature, be resolved 

 first into single atoms and then into something simpler 

 still. Now, taking the opposite extreme, on reducing the 

 temperature sufficiently to liquefy and even to solidify 

 these gases, we ought to find that as the atoms in the 

 molecule are allowed to approach more closely, and conse- 

 quently to attract each other more strongly (according to 

 the law of inverse squares), the difficulty of breaking up 

 the molecule into its constituent atoms is more and more 

 increased. This, in the case of liquefied oxygen, has been 

 directly proved to be the case by a series of very beautiful 

 experiments performed by Prof. Dewar, who has shown 

 that liquefied oxygen at — i6o°C. has not the slightest 

 chemical action upon, among other substances, the 

 alkali metals and phosphorus, which in ordinary air or 

 oxygen are rapidly converted to oxides. Chemical action, 

 if such there had been, would have shown that the force 

 of the attraction of atoms of phosphorus or potassium for 

 those of oxygen exceeded that of the atoms of oxygen 

 for each other ; but the result proved that at this low 

 temperature the force (whatever force may mean) exerted 

 between the atoms of the molecule of oxygen was greater 

 than that between the atoms of potassium and oxygen. 

 What the possibilities are as we approach absolute zero 

 form an interesting subject for the " scientific use of the 

 imagination," but, reasoning from analogous phenomena 

 of polymerization, of which organic chemistry furnishes 

 so many examples, and from the antilogous effect of high 

 temperature, we have some reason to suppose that the 

 condensation will continue until molecules more complex 

 than those consisting of the ordinary two atoms are built 

 up. However this may be, the main result of these im- 

 portant experiments has certainly been to show in the 

 clearest possible light how completely the state of matter 

 depends upon the temperature under which it exists. 



A. E. TUTTON- 



A RECENT JAPANESE EARTHQUAKE. 



PROFESSOR SEKIYA, of the Imperial University, 

 Tokio, has lately sent to this country a remarkably 

 interesting and complete record of earthquake motion 

 obtained by him during a severe shock which occurred at 

 6.52 p.m. on January 15 of this year. The most important 

 portion of the record is shown in Fig. i, reduced to a little 

 more than one-third of the original size. The motion is 

 recorded (by means of the writer's horizontal pendulum 

 and vertical motion seismographs) in three rectangular 

 components — two horizontal and one vertical — on a plate 

 of smoked glass which is caused to revolve uniformly by 

 clockwork. The plate is started by an electric seismo- 

 scope at the beginning of the disturbance, and for one or 

 two seconds its motion is consequently slower than the 

 uniform rate it afterwards attains. On this occasion the 

 plate made one revolution in 126 seconds, and the hori- 



