470 



NATURE 



\_March 17, 1881 



mode of growth ; the angles of crystalloids are also probably 

 somewhat variable. The crystalloids being chiefly regular and 

 rhombohedral form?, some are compounds containing metals — 

 chiefly magnesium, calcium, barium — others are free from metals. 

 The grow th is connected in a definite manner with the crystal- 

 line form ; the forms of the reg\ilar crystalloids remain unchanged, 

 while the rhombohedral crystallo ds undergo changes in their 

 angles, the maximum growth being in the dii-ection of the 

 principal axis. The growth and solutiility of the crystalloids are 

 not equal throughout ; they increase from without inwards, so 

 that in dilute reagents the growth or the solution begins in the 

 middle. The crystalloids are also frequently distinguished, like 

 starch granules, by layers of unequal growth. 



Herr Ballo states in Berliner Berichte that if camphor be 

 heated with a quantity of spirit of wine, containing from 36 to 

 65 per cent, ethylic alcohol, such that some of the camphor 

 remains undissolved, fusion of the camphor occurs on the surface 

 of the alcohol, and the melted camphor either floats on the surface 

 of the alcoholic solution, or sinks to the bottom according to 

 the specific gravity of; the liquid. 



In reference to the observations of Hautefeuille and Chappuis 

 regarding " periiitric acid," recently mentioned in these Notes, 

 the following details may be of interest. If a per.'ectly dry 

 mixture of oxygen and nitrogen is ozonised, and the aLsor| tion 

 spectrum of a layer about two metres long of this mixture is 

 observed, certain fine dark lines are noticed in the red, orange, 

 and green, in addition to the characteristic absorption bands of 

 ozone. These lines are not exhibited by nitrogen, nitrous 

 anhydride, nitrogen tetroxide, or nitric anhydride, when sub- 

 mitted to the action of the electric discharge. If the gas which 

 exhibits- the new lines be conducted through water, the water 

 acquires an acid reaction, and the ozone bands alone remain in 

 the spectrum. If the gas be heated to redness the spectrum of 

 nitrogen tetroxide appears. If the gas be allowed to remain at 

 ordinary temperatures the new lines gradually fade away ; after 

 tw enty-four to forty-eight hours they have entirely disappeared ; 

 the spectrum of nitrogen tetroxide becomes gradually more 

 prominent, and reaches a maximum after a few days. The same 

 lines are noticeable in the absorption-spectrum of the gas pro- 

 duced by the action of the electric discharge on a mixture of 

 nitrogen tetroxide and oxygen. The authors conclude that the 

 newly-observed lines are due to the presence of an oxide of 

 nitrogen containing relatively more oxygen than N2O5, .'.(■. to 

 the anhydride of " pernitric ncid." 



METEOROLOGICAL NOTES 



In a paper on the "Marche des Isotherms au Printemps dans 

 le Nord de I'Europe," Prof. Hildebrandsson of Up; ala Meteoro- 

 logical Observatory has struck out a fresh line of inquiry and 

 produced results at once of great scientific and practical value. 

 in a series of five maps he shows the advances with season 

 northwards over North- Western Europe of the isotherms of 

 32°'°, 37°'4> 42°'8. 48°'2, and 53°-6 respectively, the isotherms 

 being thus 5°'4 (or 3°-o C.) apart. On January 15 the isotherm 

 of 32°o proceeds along the south coasts of the Black Sea and 

 thence westwards to near Lyons, from which point it strikes 

 northwards, passing into the North Sea at Groningen, and skirts 

 the west of Norway as far as Christiansund. The progress 

 northvi'ards and eastu ards of this isotherm at the subsequent fort- 

 nightly epochs is extremely instructive, the advance northwards 

 over the plains of Kussia being manifoldly more rapid than its ad- 

 vance over the south-west of Norway. By May i the mean tem- 

 perature of the whole of North-Western Europe has risen above 

 32°'o except a small portion from the North Cape to the W hile 

 Sea. In the height of jummer the isotherm of 53°'6 (12 C.) 

 reaches its northern limit, and then includes the whole of Europe 

 except a thin slice of Norway from Vardd to the Lofoden Isle-;. 

 Since on April 15 this isotherm skirts the southern shorts of the 

 Black Sea, its advance northwards is much more rapid than that 

 of 32°'0. Specially instructive is it to note the influence of the 

 various seas ai.d mountain systems on the seasonal advance of 

 the different isotherms. An interesting table is given showing 

 the time taken by various natural phenomena to advance a 

 degree of latitude northwards ^along the shores of the Baltic. 

 The flowering of plants takes 4 '3 days in advancing over a degree 

 of latitude in April, 2-3 d.ays in May, r5 days in June, and 0-5 

 days in July; the ripening"- of fruits generally 1-5 days; and 

 the fall of forest leaves 2'j days. Hence the phenomena are 



propagated with the greatest rapidity when the jitemperature 

 approaches and reaches the annual maximum. 



Some months ago Miss Ormerod made a present to meteoro- 

 logists of some value in her book entitled "The Cobham 

 Joumah," which gives an appreciative, well-written, and in some 

 respects novel and ingenious account of the meteorological and 

 phenological observations made by the late Miss Caroline 

 Molesworth at Cobham, from 1825 to 1850. For each of the 

 years complete tables are given of temperature, rainfall, and 

 wind, which include also a comparative table for temperature 

 and rain for Chiswick, taken from Glaisher's discussion of the 

 Chiswick meteorological observations from 1826-69. Along 

 with these tables are printed fuU notes setting forth the main 

 features of ihe weather of each month, the month being divided 

 into more or few er sections, according to the number of types of 

 weather which prevailed ; and a detailed account of the accom- 

 panying phenomena of vegetation and animal life. In the 

 general summary appended to the work the bearings of weather 

 on plant and animal life are more specially dealt with, and a 

 valuable table is given showing the dates of the flowering of 

 plants, the leafing of trees, the ripening of fruits, and the arrival 

 of birds. What is much to be admired in the work is 'the 

 modesty, conscientiousness, and earnestness everywhere manifest, 

 and these qualities of the scientific worker, it may be added, 

 equally characterise the admirably plarined and worked scheme of 

 Observations of Injurious Insects the author is now conducting 

 so successfully. 



At the General Meeting of the Scottish Meteorological Society 

 held on Friday last, Mr. Buchan read a paper on the atmo- 

 spheric pressure of the British Islands, based on the observations 

 of the last twenty-four years at about 300 stations. The mean 

 pressure of these Islands taken as a whole is very nearly 

 29*900 inches, this isobar crossing the country from Galway to 

 Newcastle. From this it rises southwards to 29'983 inches in 

 the Channel Ishs, and falls northward to 29*780 inches at North 

 Unst in the extreme north of Shetland, there being thus a 

 difference of ab.ut two-tenths of an inch of mean pressure 

 between the extreme south and north. As regards individual 

 stations the annual monthly maximum is attained in May, to the 

 north of a line drawn from the mouth of the Shannon to the 

 Wash, and thence round to Colchester, and the excess of this 

 month's pressure is the greater as we advance north-westwards 

 to the Hebrides ; it is greatest in July over the extreme south of 

 Ireland and the extreme south-west of England ; but elsewhere 

 the highest monthly mean is in June. The maximum in May 

 over the whole of the northern portion of these Islands is con- 

 nected with the maximum during the same month over arctic 

 and sub-arctic North Atlantic, and regions adjoining, and the 

 maximum in July over the southwest is connected with the high 

 pressure which obtains in this month over the Atlantic between 

 Africa and the United .States. The July pressure of the south-east 

 of England is lowered from its proximity to the Continent, where 

 pressure falls to the uiinimum in July. The mean monthly mini- 

 mum occurs in January everyv\ here to the north of a line from 

 Galway to Berwick ; in March to the east of a line from Hull to 

 Osboine ; and in October over the rest of England and Ireland, 

 which thus includes the larger portion of the British Islands. 

 Of these depressions in the annual march of the pressure, by far 

 the largest is the January one, which in the Outer Hebrides falls 

 to o'oSo inch below the mean of any other month. It is there 

 accordingly where the great diminution of pressure in the north 

 of the Atlantic during the winter month is most felt. The 

 greatest difference between the extreme north and south, amount- 

 ing to nearly o"400 inch, takes place in January, and it is in this 

 month when the isobars lie most uniformly from w est-south-west 

 to east-north-east, thus giving the gradient for the south-westerly 

 winds which prevail in this season. The least variation occurs 

 in May, the extremes being 30*002 inches in Scilly in the south, 

 and 29'9o6 inches at North Unst in the north, being thus only a 

 fourth part of the difference which obtains in January. The 

 greatest divergei.ce from parallelism among the isobars occurs in 

 July, where the arrangement somewhat resembles a fan with the 

 hand part in the west of Ireland, and the lines opening out to 

 their greatest extent in the east of Great Britain — adisposition of 

 the lines due to the position of Great Britain between the high 

 presmre which at this season overspreads the Atlantic to the 

 south-west, and the low pressure which is so characteristic a 

 feature of the meteorology of the old Continent in summer. 



The temperature of January last was of a character sufficiently 

 striking and unusual as to call for a permanent recoid in ou 



