62 



NA TURE 



[May 17, 1894 



xsthesiometric tests. He found that on the latter forearm the 

 one so long unmovabi;, when the two points of a pair of 

 diriders or compasse'. toucV.ing the skin at a given locality, were 

 separated by as much as fifty-five millimetres, ihey were felt as 

 one instead of two ; while on the right forearm they only had 

 to be about twenty millimetres apart in order to be perceived as 

 two. On the back of the left arm, at a different localiiy from 

 that jast mentioned, it was found that even when the two points 

 of the dividers were seventy-five and eighty millimetres apart, 

 they were felt as one ; while at a corresponding locality on the 

 right arm the skin was so sensitive that points but 17 mm. 

 apart conld be felt as two. It should be mentioned that the 

 subject was pi^clically ambidextroas before meeting with the 

 accident which led to the casing of his arm in plaster. Prof 

 Krohn thinks, therefore, that the s.nsitivily of the skin over the 

 injured forearm wis lost simply because that member was for so 

 long a time immovable. He points out that this has an impor- 

 tant bearing upon the principle that "the localising power is 

 delicate in proportion as the skin covers a movable part of the 

 body." 



An ".\tlas of the French Lakes" has been in progress 

 since 1SS6, under the auspices of the Ministry of Public 

 Works in France. It is now completed, and published in ten 

 sheets, with coloured contour-maps of the French lakes, 

 great and small. Lake Geneva, partly done by Swiss sur- 

 veyors, is drawn to scale 1/50,000, Lake d'Annecy to scale 

 1/20,000, and the others i/io,ooo. Several results of general 

 interest are obtained — for eximple, the regular .-pheric.il shape 

 of old crater lakes in the Auvergnc district, the shallowness and 

 irregularity of lakes at the outflow of a glacier, such as Lake 

 Sylans in the .\in Department ; again, the fiUing-up of lakes 

 at the inflow of the river, typically shown by Like Brenets, 

 io the course of the River Doubs. The work has been accom- \ 

 plished by M. Andre Delebecque, Civil Engineer of Bridges 

 and Roads, assisted by his collea'^ues M.M. Garcin and 

 Magnin. The day has yet to come when our Government 

 will authorise a similar speciil work on British lakes. 



So little is known about the origin of many infectious diseases 

 ibat an article by Dr. Keser, in the Meaiial .l/i7<;a2/«,r for May, 

 will be read with interest. The chief reason why the matter is 

 in obscurity is that the descriptions of diseases found in the 

 works of early writers do not atTord the necessary means of 

 identification. .\ noteworlhy exception to this, however, is 

 Thucydides' narrative of the plague of .\lhen5. The author 

 gives a graphic account of an acute well-marked epidemic I 

 disease which invaded Athens in the ye.ir 450 B.C., appearing I 

 unexpeclenly amongst healthy people, and destroying the lives 

 of many thousand inhabitants during the three years that it i 

 lasted. It has been supposed by some that the disease was 

 smallpox, while others have considered it to have been a | 

 malignant form of scarlatina or lyplius. A careful review of the 

 factj and evidence, however, leads Dr. Keser to believe that the 

 plague of Athens was probably a variety of the true Orienlal 

 planar, characterised chiefly by a varioliform exanthem wiih 

 redness and lividity of the skin, by ulcers, and by ihe absence i 

 or rarity of buboes. The connecting links between this form of \ 

 the plague and the typical P.sUs ingvinaria still remains a 

 matter of conjecture. 



The April numlnrrof Das /f*//^/- contains an article on sun- 

 ipon and weather, by P. Polis, based on sixty-four yeais' 

 observaiions at Aix-laChapclle (i8jo 93). The author h-is 

 tabulated VVoICi relative sun spot numbers, together with the 

 yearly, winter, and summer mean temperature values, the 

 number of thunderstorms and annual rainfall, and has aUo 

 repre enied the values graphically. The curves show that down 

 to the year 187S the summer and annual mean temperatures 

 NO. 1281. VOL. 50] 



decrease with greater sun-spot frequency, and that an increase 

 of summer and yearly temperature occurs with a decrease of 

 sun-spots. The winter temperature curve also agrees generally 

 wiih the other two. From the year 1S7S the temperature 

 curves are reversed, a decrease of sun-spots corresponding with 

 a fall of temperature, and vice vcrs^i. The rainfall curve is 

 irregular, but it appears, contrary to results obtained elsewhere, 

 to take exactly an opposite course to that of the sun-spots. The 

 number of thunderstorms increases generally with a decrease 

 of sun-spots, and vice versti. 



For some years past. Prof. Klossovsky, Director of the 

 Meteorological Observatory of Odessa, has been actively 

 engaged in collecting and discussing observations bearing on 

 the climate of south-west Russia, and the observers co- 

 operating with him amounted in 1892 to 1900 in number. \ 

 valuable paper on the clim-ite of Odessa has recently been pub- 

 lished (in Russian), from which it appears that the mcin annual 

 rainfall for 1866-92 was about 17 inches ; the wettest month 

 during this period was June 1SS6. in which the rainfall was 6 6 

 inches, while in September 1S92 no rain fell. The annual 

 mean temperature was 50°'2; the maximum was 95'4, and 

 the minimum - lS°S, giving an annual range of 114° '2. 

 Several papers have also been published, bearing upon the 

 agriculture of the district, including phenological observations, 

 and also the occurrence of sandstorms, which are frequent 

 that part of Russia. 



A RF.CEST number of the Comptes Rendiis corAiXm a paper by 

 \ M. R. Swyngedauw, on the ratio of the currents produced by 

 the discharge of a condenser in two circuits placed in parallel, 

 one containing a spark-gap and the other self-induction. The 

 apparatus employed by the author consists of a battery of two 

 Leyden jars charged by a lloltz machine. The conductorwhich 

 ' joins the coatings of these jars contains (i) a spark gap I, ; (2^ 

 a coil T which is traversed by the whole discharge Qt ; (3) two 

 branch circuits, one containing a coil D exactly similar to T, the 

 other containing .1 spaik-gaj) 1.^. The two coils T and D are 

 identical, and can be placed either simultaneously or separately 

 on the cross-bar of a Wiedemann-d'.Vrsonval galvanometer. 

 Thus, by placing first the coil T and then D on the galv,ino- 

 metcr, the total quantity of electricity discharged, or the fr.icii 

 which passes through the branch circuit contaming the coil, l 1 

 be measureJ. The author finds that if the sparking distance I 

 is left constant, that the quantity of electricity passing throiu : 

 the branch circuit containing the coil increases continuously 

 the spark interval !._. is increased. When the spark interval 

 passes a certain limiting value, the q.iantlly of electricity p.is^i 

 through the branch coil is greater than that passing through il 

 coil T. This anomalous increase might be considered tobeili; 

 to a dissymmetry in the spark-gap L, so that oscillatory curren 

 set up in the branch circuits would pass one way but not il 

 other. The author finds, however, that if this spark-gap 

 changed, or the direction of the discharge changed, the incre a 

 is still observable. 



An elaboration of the presidential address delivered by Dr 

 D. Chrislison in November 1892, before the Uot.inical Socic 

 of Edinburgh, has just been published in the Society's I'lvia 

 ings (vol. XIX. part 3). The subject of the address was ili 

 actual size of the largest trees of species, native or \ong 

 naturalised, in Britain, particularly in Scotland, with a dis- 

 cussion of the question of their probable age. At the end nf 

 the paper Dr. Chrislison dispels a few pleasing illusions with 

 regard to some historic trees. It is chielly the oak, among tree 

 that has been associated with historic deeds, and perhaps mm 

 has acquired such fame as the lioscobcl oak, reputed to hav 

 concealed Charles II. after the battle of Worcester in 1651 

 Dr. Cbristisonsays that an inscription which was placed against 



