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picrico un composto giallo arancio, il quale si distingue dal corrispondente composto 

 dell' etilnaftalina già al colore, ma meglio al punto di fusione, fondendo a 139°; mentre 

 il picrato di etilnaftalina fonde a 98°; inoltre esso dà con un eccesso di bromo un 

 prodotto cristallizzato C 12 H 9 Br 3 fondente sopra 228°, mentre nelle stesse circostanze 

 r etilnaftalina dà un composto isomero fondente a 127°. 



« La dimetilnaftalina ottenuta dal sig. Moro si dimostrò identica all' idrocar- 

 buro proveniente dal nostro fenol, tanto per i caratteri fisici quanto per i suoi de- 

 rivati coll'acido picrico e col bromo ». 



Il Segretario Blaserna presenta la seguente Nota del sig. G. B. Jenkins, F. R. A. S. 

 intitolata: Onthe connection between meteorological phenomena and the tinte of the 

 arrivai of the earth at perihelion. 



« From an examination of the time at which the earth arrived at perihelion 

 during the last 50 years, I found that in the year 1847 this event happened 1 day 

 0 hour 0 minute {l d 0' 1 0"') of January, and I took that date as a starting-point. 



« Whenever the earth arrived at perihelion before that time I reckoned it as 

 early or minus so many hours, and I marked off those hours on a perpendicular to 

 a line passing through the point which represents i d 0" 0'" of January, 1847. Again 

 whenever the earth arrived at perihelion after that time I reckoned it as late or plus 

 so many hours, and I marked off those hours on a perpendicular on the other side 

 of the horizontal line. Continuing this for some time I observed on joining the 

 points, thàt a geometrical figure of much symmetry presented itself periodically every 

 8 years, each figure being in detail a little different from the others. 



« When I could gather no further information on the perihelion from the 

 Nautical Almanac I ceased to tabulate, having represented graphically the perihe- 

 lion of the earth for the years comprised between 1834 and 1883. However, I saw 

 that in the period between 1828 and 1884 (having calculated the perihelion for the 

 other years), a cycle of 28 years could be found; that, starting from the year 1856, 

 the four years before and the four after ranged themselves in pairs of remarkable 

 symmetry; and that the three series of 8 preceding, taken in succession, had a c<m- 

 siderable resemblance to the three series of 8 following. 



« In meteorology there is a tendency to cold periods on an average every 8 years, 

 as in 1829, 1837, 1845, 1855, 1861, 1870, 1878. Besides, there is a heat-wave on 

 an average every 11 or 12 years. 



« In the accompanying chart I bave endeavoured to show that there is a con- 

 nexion between the different times of arrivai of the earth at perihelion and the tem- 

 perature of the atmosphere. At the foot of the chart I bave given the temperature 

 of the corresponding years, and it is worthy of notice that from the year 1828 to 1880 

 there are seven sudden changes of temperature which appear to correspond to the 

 seven sudden changes in the time of arrivai of the earth at perihelion. 



« Between the years 1830 and 1879 there are seven periods of cold, having a 

 mean interval of eight years between them. 



« It may also be remavked that as the extremes of beat and ccld are near each 



