94 



THE ATMOSPHERE. 



presents a greater mass of organic life than is 

 perhaps to be found collected together in any 

 other portion of the earth's surface. Charles 

 Darwin observes with justice, in the interest- 

 ing Journal of his extensive sea-voyage, that 

 our woods on shore do not harbour so many 

 animals as the woody regions of the ocean, 

 where the sea-weed groves, rooted to the bot- 

 tom of the shallows, or the fuci detached by 

 waves and currents, supported by air-cells and 

 swimming free, unfold their delicate arms and 

 branches. The use of the microscope increases 



^ still farther, and in the most remarkable man- 



ner, the impression of the universal life of the 

 ocean, the astounding assurance that here sen- 

 sibility is everywhere diffused and active. In 

 depths that surpass the height of our most lofty 

 mountains, every one of the several superposed 

 strata of waters, is animated with its own Poly- 

 gastric worms, Cyclidia, and Ophrydia. Here 

 swarm, turning each wave into luminous foam, 

 and attracted to the surface by particular weath- 

 er-influences, the innumerable host of small 

 light-flashing Mammaria from the Orders of the 

 Acalephee, Crustacea, Peridinia, and Nereides 

 moving in circles. 



The abundance of these small animals, and 

 of the animal matter which their rapid destruc- 

 tion supplies, is so immeasurable, that the sea- 

 water at large becomes a nutritious fltiid for 

 much larger creatures. If this exuberance of 

 living forms, these myriads of dissimilar Mi- 

 croscopical, and yet in j)art extremely perfect 



^ organisms, engage and pleasantly excite the 



** fancy, this is appealed to in a more earnest, I 



might say a more solemn manner, by the sense 

 of the Limitless and the Immeasurable, w^hich 

 every sea-voyage presents to our contempla- 

 tion. He who is awakened to a spiritual self- 

 activity, and who delights to build up a world 

 within himself, fills the amphitheatre of the 

 boundless ocean with the lofty image of the 



♦■* Infinite and the Endless. His eye is fixed 



especially by the far horizon, where indefinite- 

 ly and as in mist, the ocean and the air meet 

 bounding one another, in which the stars set and 

 rise anew before the eyes of the beholder. .But 

 still, with the eternal play of this interchanging 

 scene, as everywhere else with human happi- 

 ness, there comes the breath of sadness, of un- 

 gratified longing, to mix itself with the joy. 



A peculiar predilection for the sea, grateful 

 remembrances of the impressions which the 

 mobile element between the tropics, in the 

 peace and silence of the night, or roused and 

 at war with the natural forces, has left upon 

 my mind, could alone have induced me to speak 

 of the individual enjoyment of the prospect, be- 

 fore referring to the beneficial influence which 

 contact with the ocean has had on the devel- 

 opment of the intelligence and character of va- 

 rious nations ; on the multiplication by its 

 means of the bonds that ought to embrace the 

 whole of the human family ; on the possibility 

 it has afforded of attaining to a knowledge of 

 the- configuration qf the earth and its parts ; 

 lastly, on the improvement it has led to in as- 

 tronomy, and in the mathematical and natural 

 sciences at large. A portion of this influence 

 was originally confined to the waters and the 

 shores of the south-western parts of Asia ; but 

 from the 16th century onwards it has extended 



far and wide, and even attained to nations that 

 live in the interior of continents remote from 

 the sea. Since Christopher Columbus was 

 " sent forth to unchain the ocean"("*) (for so 

 was he addressed in a dream by an unknown 

 voice whilst he lay on a sick-bed by the river 

 Belem), man, too, mentally more free, has ven- 

 tured with greater boldness into unknown re- 

 gions. 



The second and most external and univer- 

 sally diffused of the coverings of our globe, the 

 Atmosphere, on whose depths, or shoals, which 

 are lofty table-lands and mountains, we live, 

 present six classes of natural phenomena, con- 

 nected in the most intimate manner with one 

 another ; these are : chemical composition ; 

 alterations in the transparency, polarization, 

 and colour ; in the density or pressure ; in the 

 temperature, humidity, and electricity. If in 

 its oxygen the air contains the first element of 

 physical animal life, another excellence, it 

 might almost be said of a higher order, must be 

 indicated in its constitution. The air is the 

 " carrier of sound," and so also the bearer of 

 speech, the means of communicating ideas, of 

 maintaining social intercourse among men. The 

 earth, robbed of its atmosphere, like the moon, 

 presents itself to the imagination as a desert 

 brooded over by silence. 



The relations of the substances which be- 

 long to the strata of the atmosphere that are 

 accessible to us, have, since the beginning of 

 the 19th century, been made the object of re- 

 searches, in which Gay Lussac and I took an 

 active part ; it is but very recently, however, 

 through the admirable labours of Dumas and 

 Boussingault, that the chemical analysis of the 

 atmosphere, pursued in new and trustworthy 

 ways, has been advanced to a high degree of 

 perfection. From this analysis dry air appears 

 to contain per volume 28-8 oxygen, and 79-2 

 azote ; besides from 2 to 5 ten thousands of 

 carbonic acid, a still smaller quantity of carbu- 

 retted hydrogen(3*5), and from the important 

 experiments of Saussure and Liebig, traces of 

 ammoniacal vapours(3"), which may supply 

 plants with their azotized constituents. That 

 the quantity of oxygen may vary in a trifling 

 but still appreciable degree according to season, 

 situation of a place — upon the sea or in the in- 

 terior of a continent — has been rendered prob- 

 able by some observations of Lewy. It is con- 

 ceivable that changes in the quantity of oxygen 

 held in solution by water, induced by micro- 

 scopical animal organisms, may be followed by 

 changes in the strata of air that lie in immedi- 

 ate contact with its surface(^*^). The air col- 

 lected by Martins on the Faulhorn at a height 

 of 8226 feet, did not contain more oxygen than 

 the air of ParisC^^s). 



The admixture of carbonate of ammonia in 

 the atmosphere may probably be held as older 

 than the existence of organic beings on the sur- 

 face of the earth. The sources of the carbon- 

 ic acid of the atmosphere are extremely nu- 

 merous(3*'). We may here mention the res- 

 piration of animals, which receive the carbon 

 they exhale from the vegetable food they con- 

 sume, as vegetables themselves derive it from 

 the atmosphere ; the interior of the earth in 

 the country of extinct volcanoes and thermal 



