76 



NA TURE 



\^Nov. 25, i< 



an opporlunity of seeing the latest forms of the uistruments in 

 Japan. 



No one knows better than Prof. Milne that the horizontal 

 pendulum seismograph is not obsolete. He adopted it himself 

 soon after I introduced it, and he has used it freely in his own 

 investigations. His letter will be understood to mean that 

 since I left Japan in 1SS3 there has been a new departure in 

 seismometric methods which has made my apparatus fall out of 

 date. There has been nothing of the kind. Can Mr. Milne 

 point to any methods involving novel features of importance, 

 and say what their novel features are ? It would be odd for 

 instruments to become obsolete when they answer their purpose 

 very well, and when there is nothing better to take their place. 



J. A. EwiNG 



University College, Dundee, November 13 



Ozone Papers in Towns 



I TAKE the opportunity of mentioning that I have experi- 

 mented with Moffatt's ozone papers in London for the past 

 month, and find that on exposing the papers already previously 

 coloured they all become bleached to their original white. They 

 were previously exposed to the air at Brighton and Hastings, on 

 the sea-coast, and were then coloured, and afterwards preserved 

 closely shut up for trial in the mephitic air of towns. 



Some more stained papers were also received from Cheltenham, 

 which also became blanched on open-air exposure in London, 

 though as highly stained as S degrees. They were not washed 

 by rain, but kept dry in the usual cage in the open air and out 

 of the sun ; and they were of various shades of colour, from 

 2 to 8, as already marked on them. I should like to know or 

 ask for opinion as to the chemical changes that had taken place, 

 and if these had been due to an antozone causing a recomposition 

 of the ingredients (starch and iodide potassium) to their original 

 constitution. It may be likely, therefore, that in Moffatt's 

 papers, coloured previously, we may have the means of testing 

 the impure condition of the air of any locality by exposing them 

 in it for a few hours. 



Other papers had already been prepared for testing the 

 sulphurous impregnation of the town air, as by compounds 

 of lead, tin, &c. ; but, though they became stained in the 

 laboratory, yet they failed on trial in the open air. As to 

 the influence of the wind, the quickest effect seemed to be pro- 

 duced by easterly winds, while those from the south-westerly 

 direction were slower in .action on the papers ; but this, I think, 

 may be merely due to the air from the east in London blowing 

 first over a greater expanse of city, carrying with it adulterating 

 emanations. W. J. Black 



London, November 



The Similarities in the Physical Geography of the 

 Great Oceans 



In the abstract of my paper read at the Royal Geographical 

 Society on the 8th inst., which was published in Nature of 

 Nov. 1 1, there is a statement (p. 34) that the weight of the column 

 of water between 20 fathoms and 70 fathoms from the surface 

 under the westerly equatorial current is only 8S per cent, of the 

 weight of the same column under the easterly counter equatorial 

 current.^ I regret that a serious arithmetical error occurs in the 

 calculations on which this statement was founded. There is no 

 such considerable difference of weight in the two columns of 

 water. _, J. Y. Buchanan 



Edinburgh, November 22 



Lung Sick 



Dr. E. J. DuNGATE, with compliments to the Editor of 

 Nature, begs to inclose him a letter which he h.as just received 

 from Prof. Smets, of Hasselt. It refers to the letter on "lung 

 sick," which appeared in Nature for November 11 (p. 29), and 

 contains most important evidence on the subject. Dr. Dungate 

 is sure, from the genial tone of the letter, that the Editor of 

 Nature is at liberty to publish it, if he desires. 



6, Marchmont Road, Edinburgh, November 17 



Hasselt {Belgique), le 14 Novembye, 1 886 

 Monsieur Dungate,— J'ai lu votre demande dans la 



Nature du 11 Novembre. 



L'inoculation preventive de la pleuropneumonie exsudative 



a commence a Hasselt, et la methode, suivie deja chez les 



Zoulous, a ete preconisee, en premier lieu, par un medecin de 

 Hasselt, M. le Dr. Willems. Je vous communiquerai, avec 

 plaisir, ses travaux si vous les desirez. 



On a essaye, a diverses reprises, a Hasselt, les inoculations au 

 fanon, a la poitrine, etc. ; elles ont eu des consequences mortelles. 



Je crois que cette pratique permettait au microbe d'envahir 

 rapidement les poumons, et d'etouffer le bceuf. Mais quand on 

 pratique l'inoculation a la queue, le microbe a passe par les 

 divers stades de son existence, et est deja a son declin avant 

 d'arriver au poumon. II est possible aussi que le microbe, que 

 je crois fortement aerobic, a ete attenue dans sa virulence par 

 suite de son passage dans des organes oil I'oxygene est plus 

 rare 



Plusieurs fois, neanmoins, l'inoculation est encore mortelle, en 

 moyenne I cas sur 100 inoculations a Hasselt. 



La perte de la queue est due, a mon avis, a ce que Ton fait 

 usage d'un virus impur, obtenu empiriquement, sans culture. 

 La gangrene, qui emporte une partie de la queue, pent etre 

 causee par un autre organisme inocule simultanement avec le 

 microbe de la maladie. Car, parfois, plusieurs betes inoculees 

 en meme .temps, avec le meme virus, ne perdent pas la partie 

 infcrieure de la queue, tandis que d'autres fois cet accident est 

 frequent. On previent partiellement cet accident en faisant des 

 incisions longitudinales dans I'engorgement qui se produit. 



Agreez, Monsieur Dungate, I'expression de ma consideration 

 distinguee et de mon entier devouement. 



Dr. Gerard Smets, 

 Professeur a Hasselt (Belgique) 



Meteor 



Passing along Kensington Gore yesterday at 7.20 p.m., I 

 saw the finest meteor I have ever seen in my life. It descended 

 from near the zenith perpendicularly through the constellation 

 of the Great Bear. It was much larger than any planet. About 

 half-way on its downward course it gave out a second meteor of 

 a red colour, being itself of a pale yellow. The atmosphere 

 was rather foggy at the time, but I could see the stars through 

 the mist. It was, no doubt, the same meteor as is mentioned 

 in to-day's Times as having been seen at Reading. 



P. L. Sclater 



3, Hanover Square, London, W., November 18 



The Origin of Species 



Mr. Catchpool, writing in Nature (vol. xxxiv. p. 617) 

 on this subject, s.ays : — " If B is separated from A by 

 being nearly infertile, and C from B in the same way, C 

 is likely to be still more infertile with A." This is quite a 

 mistake. Suppose B to be the cat species, and A and C two 

 varieties of dogs ; A and C are quite fertile with each other, 

 and infertile with B. 



It is certain that mutual infertility is not caused by mere 

 visible unlikeness. The horse and the ass, which do not pro- 

 duce fertile offspring, are much less visibly unlike than many 

 of the varieties of dogs or of pigeons, which are mutually quite 

 fertile. 



May not mutual infertility be a result of long-continued 

 separation, quite independently of any unlikeness arising? I 

 do not know whether this conjecture is supported by any obser- 

 vations on the mutual relations of kindred species or varieties in 

 lands separated by oceans. Joseph John Murphy 



Belfast, November 8 



Mr. Murphy has mistaken my meaning, which I will try to 

 make clear by an example. Suppose one brood of an ancient 

 species of Gallinoe to h.ave exhibited, as a sport, a partial infer- 

 tility with the rest of the species, while the birds composing the 

 brood remained abundantly fertile among themselves. Suppose 

 the main body of that species to have become, by natural selec- 

 tion, our pheasants, while the isolated brood became the 

 ancestors of our grouse. Suppose one brood of these grouse to 

 have become partially infertile with the main body of grouse, 

 and to have been the ancestors of our red grouse, while the main 

 body of the grouse became, by natural selection, our black 

 grouse. If, as I believe, variation does not produce or increase 

 infertility, the black grouse will still be only partially infertile 

 with the pheasant, and the red only partially infertile with the 

 black grouse ; but it seems probable, prima facie, that the 

 second spontaneous infertility would remove the red grouse 



