NATURAL HISTORY OF COMMERCE. 



NATURAL HISTORY OF COMMERCE. 



CHAi-Ti.i: xil. 



N ATI' UK AND MAM AB AOINT8 OH OIIANOK. 



i-y of Koriner Chapter* Contrast of Old and New World* M to 

 riuM.Ml OOBdWoM CkolOfftal Eridauce of Chaujfo of Climato 

 and Fr<Kluce-VurUtion of Orbit-Man ulct to thcw Law* - 

 Their Harmony illuctratod. 



U'l: luivo now traced the relation thnnij/lmuL tho earth, 

 ( 1) between geological OOnditioni ami mineral produce; 

 (_') between c'liinato and soil mi tin- one h:iml, and or- 

 ganic produce on the other. Wo have soon how contour, 

 .il relief, ami other physical facts modify climate 

 il, and c(insfi|iicnily animal and vegetable produce. 

 Wo have also been led to observe that a study of tho 

 geology of any region is auxiliary to a knowledge of its 

 llora and fauna. 



The threat mountain ridge of tho New World presents 

 no barrior between tho equator and the polos, as the 

 Himalayas and their adjuncts offer in the Old World. 

 The dispersion of plants and animals is therefore limited 

 by more elastic conditions, and tho separation of zones 

 is marked by less decided linos. Tho tropical waters 

 of tho Caribbean Sea divide America into a northern 

 and southern continent, closely corresponding; each 

 division being related to the other by bands of analogous 

 climate and produce, which are but portions of bands 

 similarly crossing the Old World, and encircling the 

 earth. 



There is abundant geological evidence to prove that 

 the zones of tho earth nave been subject to cliauge both 

 in climate and produce. The agents of change have 

 been Nature and man. Tho great plains of America are 

 geologically recent. Coal-beds are found in the Arctic 

 regions, the fossil flora of which, composed of a pre- 

 ponderance of conifera, indicates a climate corresponding 

 to that of mid-Europe, and proving that, in tno long 

 cycles of the earth's physical history and its successive 

 oscillations, the poles whose frosts we often call eternal 

 have aforetime and more than once borne excess of heat. 



The vibrations of tho earth in reference to its axis, 

 slow though they be, are persistent; and although 

 intervals of thousands of years are required to make 

 perceptible comparisons, yet the equilibrium of our planet 

 goes through a long period of unresting change. At tho 

 present time the Arctic coasts are rising and the bed of 

 the Pacific is sinking, in obedience, it is believed, to the 

 law requiring the centre of gravity of the earth's mass to 

 be maintained by the mobility of the ocean. The nature 

 of the changes thus brought about may be illustrated by 

 a supposition easy to comprehend. If the relation be- 

 tween America and the Atlantic were gradually to alter 

 so that the sea-level rose 300 feet, tho llanos of tho 

 Orinoco would be covered. If it were 1,100 the sea 

 would wash the base of the Andes, and only leave those 

 mountains and the highland of Venezuela, the Guianas, 

 and Brazil above the waves. 



Man finds work ever ready to his hand. By diligent 

 labour, guided by intelligence, he can modify the minor 

 aspects of Nature, and obtain from her bounty an in- 

 definite increase of enjoyment. He cannot alter the 

 past or arrest the future, but he may shape the issues 

 of both to his advantage. What are the limits of our 

 power, and how may we best use it to promote well- 

 being P Such aro tho inquiries which tho course of 

 study we have pursued should aid us to answer. 



Nothing more beautifully shows the harmony of natural 

 laws than tho modifications of tho forms of life by the 

 change of conditions. We fell a forest, and the timid 

 browsers lose their shelter and food and disappear ; the 

 wild beast is deprived of its covert and prey, and 

 no more; even bo birds migrate to districts whore insects 

 and berries abound. We cultivate a plain, and the 



120 y-f- 



grub of the cockchafer begin* it* havoc with tho corn 



root H, and the earthworm its system of under 'tillage, 



till, attracted l.y 'Mir prevalence, the familiar form* of 



I* are Men, and the balance of vegetable) 



M restored. The sparrow wan unknown 



-ia but century; but the rapid program of corn 



cult uro, the sign of 



this bird to unread over the empire, eren M far a* 

 Cartridges, again, whose food i* found in tho 

 of England and Franco, have recognised the 

 high husbandry of Scotland, and are met with at Inver- 

 ness, the limit .,f Mriiish wheat growth. Food, therefore, 

 ia seen to be tho link between the flora and fauna of the 

 climatic /.ones. 



Many illu.st rations n.i/lit be submitted of the offset* 

 of human agency in modifying the aspect* of Nature. 

 sometimes intentionally arranged, sometimes otherwise. 

 Mr. Gricrson, at a meeting of the British Association, 

 read a paper referring to the destruction of planta- 

 tions at Drumlanrig, in Dumfriesshire, by the voles, 

 commonly called rats, which aro the \n-*t of Sweden, 

 They appear to bo migratory in their habiu, and 

 occasionally increase in myriads. From the recent 

 slaughter of rapacious birds, such as owls, hawks, and 

 eagles, which Nature has appointed to bound the un- 

 limited fecundity of tho rodentia, the voles found a sale 

 field for action. They principally destroyed the young 

 oak and ash, gnawing a ring of berk near the root* and 

 beneath tho grass ; tho trees being unable to resist such 

 attacks until after at least twelve years' growth. 



By our acquaintance with the facing of a floral region 

 wo are able to judge when and where we can with profit 

 introduce or transfer the plants of one country to 

 another, even to another hemisphere. Thus it is that 

 we have spread tho useful food plants, fruits, fibres, 

 and timbers, or strewn our colonies with wild flowers. 

 associated with tho thoughts of home. 



The vegetable kingdom is full of striking examples, 

 The fruits of Europe, mostly of Asiatic origin, were 

 removed westward in the same zone, and subsequently 

 to the New World. The diffusion is carried still further 

 into the zones of tho southern hemisphere. The vino 

 now flourishes in South Africa and Australia. Grains, 

 either tropical or northern, have gone with man into 

 every habitable clime. Maize has enlarged its area in 

 tho three continents of tho East, and rice has spread 

 almost as widely in the West. Wo owe to Chili the 

 potato, which has lightened existence to extra millions of 

 mankind. Tho pine-apple was a native of the Bahamar. 

 and Bermudas, but is now plentiful round the Mediterra- 

 nean. Tobacco, unknown till the sixteenth century, belU 

 both sides of tho equator far beyond tho tropics. Cloves 

 and pepper are acclimated in each of the Indies, though 

 native only to the East. Coflee, also an indigene of Arabia 

 or Abyssinia, has sped througnout the tropical zone. 

 Thus, also, with the fauna, we nave aided Nature in tho 

 distribution of her productions, enriching each zono 

 with the representative species of its corresponding 

 zone. Tho wild horses and cattlo of Sc.uth America 

 seem destined to exterminate tho native llama. The 

 English sheep in Australia have driven the kangaroo 

 inland, and threaten its extinction. The effect of intro- 

 ducing our domestic animals into other countries has 

 been to increase our resources for food and clothing, to 

 add to wealth, and to tho duration of human life. 



Nature has arranged the climatic zones in a manner 

 whose simplicity and unity of working fill our minds 

 \\iiii an exalted pleasure. Oceans come between the 

 continents, and obstruct tho passage of certain forma 

 of life; yet many thousands of miles distant the con- 

 ditions of UMH..J ape only modified, and we meet, not 

 tho same species, but representative ones, whether of 

 animals or plants. The auhimU of the Old World, both 



