Jan. 31, 1889] 



NATURE 



25 



The area within which this earthquake was most per- 

 ceptible is tolerably well defined by that of the geological 

 features here described. It is rudely elliptical in shape, 

 about fifteen or twenty miles along the longer, and from 

 five to seven across the shorter axis. Outside these 

 limits, the shock, though in some places distinctly felt, 

 seems to have rapidly lost force, so that at Linlithgow, 

 about ten miles away, it was hardly perceptible. The 

 effects by which the passage of the seismic wave made 

 itself sensible were of the usual kind. For the most part 

 all that was noticed was a tremor or quivering movement 

 of the ground or houses, accompanied with the rattling of 

 any loose objects. I was myself awake, and about to rise, 

 when I was aware of a peculiar grinding noise and the 

 jangling of all the crockery and glasses on the wash-hand- 

 stand. It seemed as if some heavy load had been dis- 

 charged from a waggon on the ground immediately outside 

 the house. But as the position of the house on the out- 

 skirts of the southern suburbs of the city made this 

 impossible, I was at a loss to conjecture the cause of the 

 disturbance. I thought of an earthquake, but found that 

 no other inmate of the house had noticed anything peculiar. 

 In the course of the day, however, accounts came from all 

 parts of the district affected, which put the real nature of 

 the event beyond any doubt. The undulation of the ground 

 was experienced by many observers, and the general 

 impression was that the wave moved from west to east, 

 or from south-west to north-east. Some who were not 

 yet astir felt first one end of the bed and then the other 

 depressed and raised. To others who were already on foot 

 the ground seemed to sink away from their feet and to 

 rise upward again. Chairs appeared to slide forward and 

 backward. Pictures, lamps, and other hanging objects 

 were set swinging. In one recorded case, an eight-day 

 clock, which had been standing at the time, and of which 

 the pendulum swings in an east and west line, was made 

 to go. On the other hand, the parish clock of Currie was 

 stopped at the moment of shock. One boy is said to 

 have been pitched out of bed, and was found immediately 

 afterwards with a hammer in his hand ready to attack 

 someone whom he supposed to be concealed under the 

 bed. Numbers of witnesses spoke of the feeling of giddi- 

 ness or nausea that so frequently accompanies earth- 

 movements. Dogs barked or howled to mark their 

 sympathy in the general alarm. No damage of any kind, 

 however, seems to have been done, unless under that 

 name be included the dislodgment of a portion of the 

 plaster from the ceiling of a church at Portobello. 



The most violent motion appears to have been felt 

 along the north-west base of the Pentland Hills and thence 

 in a north-easterly direction through the northern parts of 

 Edinburgh. There can be little doubt that the source of 

 the shock lay somewhere along the line of these hills. 

 We may plausibly connect it with the failure of support, 

 and consequent fall, of some part of the rocks along one 

 of the main lines of fault that define the chain of the 

 Pentlands. 



The greater frequency of earthquakes in the winter 

 half of the year has often been remarked upon. It is 

 certainly during that season that they most generally occur 

 in Scotland. With regard to the shock of last week, we 

 find that a strong gale had been blowing for some time, 

 and that the barometer had fallen four-tenths of an 

 inch between Thursday and Friday. The position of the 

 moon, according to some seismologists, conduces to the 

 determination of those disturbances of the terrestrial crust 

 that give rise to earthquakes. With regard to the dis- 

 turbance of the 1 8th instant it is noticeable that full 

 moon happened the previous morning, when there was a 

 lunar eclipse. It is about the time of new moon and the 

 first quarter that the chief earthquake-maxima are said to 

 take place. 



A. G. 



DECOMPOSITION OF NICKEL AND COBALT. 



/^HEMISTS have recently heard with great interest that Dr. 

 Kriiss, of Munich, a well known and trusted worker, has 

 succeeded in " decomposing " nickel and cobalt. Judging from 

 the accounts which thus far have reached us, it would appear 

 that his discovery consists in finding that cobalt and nickel 

 contain about 3 per cent, of a new element which is common to 

 both as ordinarily prepared. By the removal of this hithertO' 

 unrecc^nized " impurity," the properties of the cobalt and 

 nickel salts are slightly modified as to colour, &c. It is to be 

 expected that the discovery will serve to explain the discrepan- 

 cies which are to be noted among the various determinations 

 of the atomic weight of nickel and cobalt. We give the 

 following details from a short note upon the subject in the 

 Chemiker Zeitung of January 27 : — 



Dr. Kriiss, in conjunction with Herr Schmidt, read a 

 paper at the meeting of the Munich Chemical Society of 

 January 11, upon the results of their attempted redetermination 

 of the atomic weights of these two metals. Clemens Zimmer- 

 mann, as the outcome of a determination made some years 

 ago, found the atomic weight of cobalt S8'74, and that of nickel 

 58 •56. The method followed by Kriiss and Schmidt was a 

 revival of the older process of Winkler, and consisted in deter- 

 mining the relative equivalents of gold and nickel, and of gold and 

 cobalt. Such a method ought now to be very much more trust- 

 worthy, on account of the recent exceptionally accurate determin- 

 ations of the atomic weight of gold made simultaneously by Dr. 

 Kriiss himself, and by Prof. Thorpe and Mr. Laurie in this 

 country. The process simply consisted in precipitating the gold 

 from a neutral solution of gold chloride or sodium gold chloride 

 by weighed quantities of metallic nickel or cobalt, chlorides of 

 the two latter metals passing into solution. The results, how- 

 ever, were not what were expected, and differed among them- 

 selves to a remarkable extent. It was found impossible to 

 precipitate the equivalent in gold of the nickel or cobalt 

 employed, owing to the inverse effects of polarization, small 

 quantities of metallic nickel or cobalt being reprecipitated, and 

 thus mixed with the finely divided gold. In order to determine the 

 amount of metal which had been dissolved, the precipitate was 

 weighed, dissolved in aqua regia, and the gold reprecipitated by 

 sulphurous acid. The weight of gold thus obtained, deducted 

 from the weight of the whole precipitate, of course gave that of 

 the admixed nickel or cobalt. Even after making this correction, 

 the method afforded such surprisingly untrustworthy values that it 

 became necessary to seek for the disturbing cause. On washing 

 the reprecipitated gold, it was noticed that the red colour of the 

 filtrate due to chloride of cobalt gradually paled, and eventually 

 took a greenish tint. On evaporating a quantity to dryness and ig- 

 niting in a platinum dish, the small residue obtained was found to 

 dissolve in warm concentrated hydrochloric acid forming a beauti- 

 ful green solution. On cooling, the liquid again became almost 

 colourless, and gave a white precipitate of hydrate on addition 

 of ammonia, which on ignition gave a white oxide ; and a brownish- 

 black precipitate of sulphide with ammonium sulphide. A 

 number of other reactions also show that the compounds of this 

 metal, which was itself obtained as a black powder by reduction 

 of the oxide with charcoal, are not to be identified with those ol 

 any known element. The most interesting fact, however, is that 

 the washings from the gold obtained in the nickel determinations 

 gave precisely the same indications ; the same residue on ignition, 

 a green solution on treatment with warm hydrochloric acid, 

 and the same hydrate and oxide. Several other methods 

 were also described in the memoir, which we hope shortly to see 

 published, by which this same common ingredient could be ex- 

 tracted from both nickel and cobalt. It is very interesting that 

 Dr. Kriiss has also obtained a green double chloride of the 



