ORGANIC LIFE. 



lightnings that illuminate whole clouds, which 

 seem to open up at once ; lightning in the form 

 of fire-balls(=»"). If the two first of these 

 scarcely last for the y^i^ of a second, the glob- 

 ular kind of lightning, on the contrary, moves 

 much more slowly, and continues visible for 

 several seconds. Occasionally — and late ob- 

 servations confirm the description of the phe- 

 nomenon already given by Nicholson and Bec- 

 caria — single clouds show themselves high 

 above the horizon, which, without audible thun- 

 der, without any appearance of a storm, con- 

 tinue steadily luminous for a long time both in 

 the interior and around the edges : hail-stones, 

 drops of rain, and flakes of snow, have also 

 been observed, which were luminous as they 

 fell, without any precursory thunder-storm. 



In the geographical distribution of storms, 

 the coasts of Peru, in which it never thunders 

 or lightens, present the most remarkable con- 

 trast with all the rest of the tropical zones be- 

 sides, in which at certain seasons of the year, 

 four or five hours after the culmination of the 

 sun, thunder-storms occur almost every day. 

 From the concurring testimony of northern nav- 

 igators — Scoresby, Parry, Ross, Franklin— 

 which has been collected by Arago, it is im- 

 possible to doubt that in high northern latitudes, 

 such as the parallels from 70° to 75°, electrical 

 explosions are extremely rare(^^"). 



The meteorological portion of our Delinea- 

 tion of Nature, which we here conclude, shows 

 that all the processes— absorption of light, ev- 

 olution of heat, alteration of elasticity, hygro- 

 metrical state and electrical tension, which the 

 immeasurable atmospheric ocean presents, are 

 so intimately connected, that each individual 

 meteorological process is simultaneously modi- 

 fied by any one, or by all the others. These 

 varied disturbances, which involuntarily re- 

 inind us of those that the nearer and particu- 

 larly the smaller of the heavenly bodies, the 

 satellites, comets, and shooting stars, experi- 

 ence in their course through space, render the 

 interpretation of the complex meteorological 

 processes difficult ; they circumscribe,, and, for 

 the most part, make impossible, the prediction 

 of atmospherical changes, which for horticul- 

 ture and agriculture, for navigation and the en- 

 joyment and pleasure of existence, would be 

 so important. Those who place the value of 

 meteorology not in a knowledge of the subject 

 itself, but in such problematical prognostica- 

 tions, are penetrated with the belief that this 

 portion of natural science, on account of which 

 so many journeys have been made into remote 

 mountainous countries of the globe, cannot 

 boast of any advance for centuries. The con- 

 fidence which they refuse to natural philoso- 

 phers, they yield to the changes of the moon, 

 and to certain famous days in the calendar. 



" Great departures from the usual distribu- 

 tion of mean temperature seldom occur locally ; 

 they are, for the most part, relatively shared 

 in by extensive districts of country. The 

 amount of departure is a maximum at one par- 

 ticular spot, from which it diminishes to the 

 confines around. If these confines be exceed- 

 ed, great variations in the opposite sense are 

 forthwith discovered. Like constitutions of 

 the weather are more frequently observed from 



South to North than from West to East. The 

 maximum cold of the end of 1829, (when I con- 

 cluded my Siberian travels), occurred at Berlin, 

 whilst North America enjoyed an unusual mild- 

 ness of season. It is an entirely arbitrary as- 

 sumption to suppose that a hot summer follows 

 a cold winter, or that a mild winter succeeds a 

 cool summer'X^^'). The states of the weather in 

 neighbouring lands — two corn and wine-grow- 

 ing countries, for example, often so varied and 

 so opposite, produce the most beneficial eflfects 

 in equalizing the prices of agricultural produce 

 i-n each. It has been well observed, that the 

 barometer alone informs us of what is going on 

 in respect of alterations in the pressure of the 

 w'hole of the strata of air above the place of 

 observation, even to the extreme limits of our 

 atmosphere, whilst the thermometer and hy- 

 grometer only report upon the local tempera- 

 ture and moistness of the lower stratum in con- 

 tact with the surface. We only conclude as to 

 the thermometrical and hygroscopical modifica- 

 tions of the upper strata, where immediate ob- 

 servations made on mountains or in aerostatic 

 journeys are wanting, from hypothetical com- 

 binations, so that the barometer may likewise 

 come to serve both as a thermometer and hy- 

 grometer. Important changes in the state of 

 the weather are not owing to any merely local 

 cause at the place of observation itself; they 

 are usually consequences of a condition which 

 has begun, through perturbation in the equilibri- 

 um of the currents of air, at a vast distance, 

 and, for the major part, not at the surface of 

 the earth, but in the highest regions : bringing 

 hither cold or warm, dry or moist air, impair- 

 ing or increasing the transparency of the at- 

 mosphere, changing the piled masses of cumu- 

 lus-clouds into the light and feathery cirrus. 

 Inaccessibility of phenomena thus allying it- 

 self to multiplicity and complexity of perturba- 

 tions, it has always appeared to me, that me- 

 teorology must seek her welfare and her roots 

 in the torrid zone ; in that favoured region 

 where the same winds always blow, where the 

 ebb and flow of the atmospheric pressure, the 

 course of hydrometeors, and the occurrence of 

 electrical explosions, are periodically and reg- 

 ularly recurrent. 



Having now passed through the entire circuit 

 of the inorganic life of the earth, and delinea- 

 ted our planet with a few leading touches, in 

 its configuration, its internal heat, its electro- 

 magnetical charge, its luminous processes at 

 either pole, and its internal or volcanic reac- 

 tion upon the solid and variously compounded 

 crusts ; having, finally, considered the phenom- 

 ena of its double outer covering, the ocean and 

 the atmosphere, our Picture of Nature, accord- 

 ing to the older ideas of Physical Geography, 

 might be held as finished. But when the phil- 

 osophic view essays to reach a higher point, 

 the delineation would seem to want its attract- 

 ive features, did it not at the same time pre- 

 sent the sphere of Org.\nic Life in the numer- 

 ous grades of its typical developments. The 

 idea of animation is so closely connected with 

 the idea of the existence of the impelling, cease- 

 lessly active, decompounding, compounding, 

 and fashioning natural forces, which inhere in 

 the terrestrial ball, that in the popular Mythus 



