442 



NEW ENGLAND FARMER. 



Oct. 



deleterious gases which are constantly escaping 

 from the surface of the earth. Thus plants may 

 be regarded as an indispensable link or chain in that 

 circle of connected mediums, through ■which the 

 oxygen that has become fixed and consolidated in 

 the bones of animals, and in the mineral substances 

 of the earth, is absorbed and again distributed into 

 the atmosphere. 



There is reason to believe that there is not on 

 the surface of the earth, a plant that does not ab- 

 sorb from the atmosphere something which is inju- 

 rious to animal life, or that does not give out some- 

 thing that is needful to it. Plants live on substances 

 wtich animals reject, either by breathing or by ex- 

 cretion. As the constant exhalations which ascend 

 into the atmosphere from the smoke of millions of 

 fires, and from the decomposition of millions of ani- 

 mal and vegetable substances, would soon render it 

 unfit for the respiration of animals, were these ex- 

 halations not absorbed by something provided in 

 the economy of nature for this purpose. Plants are 

 Tindoubtedly the chief agents in this work of puri- 

 fication and renovation. 



It is not certain that the leaves of the higher or- 

 dfeJs of vegetation absorb any of these deleterious 

 gases except ammonia and carbonic acid. But with 

 every quantity of smoke that issues from a chim- 

 ney', comes hydrogen as well as carbonic acid gas, 

 Putrifying substances give out sulphurated hydro- 

 gen. A great variety of gases, injurious to animal 

 life from thousands of different substances, are con 

 stantly emanating into the atmosphere. What 

 provision has Nature made for the absorption of all 

 these deleterious gases ? We can give only a con- 

 jectural answer, because we know nothing by exper- 

 iment. But reasoning from analogy, we have rea 

 son to believe, that as the higher tribes of vegeta 

 tion absorb ammonia and carbonic acid, the inferior 

 tribes of plants are the instruments in the hands of 

 Nature for the absorption of other gases, which are 

 exhaled into the atmosphere ; and that by the in- 

 strumentality of these millions of agents, the whole 

 atmosphere is kept in a constant state of purity. 



To assist in this great work, Nature has caused 

 the atmosphere to be constantly circulating over 

 the globe, following one current from the poles to 

 the equator, and in another from the equator to the 

 poles. This constant circulation causes every part 

 of it to be exposed successively to all these influ- 

 ences. As the currents pass over the surface of 

 the earth, every plant, from the tall tree to the 

 minutest lichen that lives upon the surface of a 

 rock, takes up its infinitessimal share of the spoil 

 it contains, and the deleterious gases are finally re- 

 turned again to the earth, in a state in which they 

 may be subservient to some important end in the 

 ^and economy of nature. 



It is, therefore, highly probable, that the exis- 

 (j^ce of every tribe of plants is indispensable to 



the purity of the atmosphere, and that the mossy 

 clothing and lichenous incrustations of the rocks 

 and fences are each subserving an important pur- 

 pose. The most effectual means which we can use, 

 therefore, to preserve the atmosphere in a state of 

 purity, is to multiply the abundance of vegetation. 

 The majority of pestilences and epidemics are oc- 

 casioned by the impurities arising from decaying 

 vegetable and animal substances. 



In new settlements, the quantity of decomposing 

 substances is greater in proportion to the growing 

 vegetation than in old settlements which are not too 

 dense. The new land which has been cleansed and 

 plowed, exhales an immense quantity of pestilen- 

 tial matter which has long been confined by the in- 

 bedding of the forests. In winter, when these ex- 

 halations are confined by frost and snow, and in 

 spring and early summer when vegetation is active, 

 the climate is healthy. But in the latter part of 

 summer, until frosts arrive, the absorbent powers 

 of vegetation are much less active, and do not take 

 up the noxious exhalations as fast as they are min- 

 gled with the atmosphere. Hence the fevers of 

 the latter summer and early autumn. When frosts 

 arrive the equilibrium of the climate is distributed ; 

 brisk currents of wind ensue, and assist in carrying 

 off these pestilential gases, and the health of the 

 country is restored. 



Should the time ever arrive when the dispropor- 

 tion between animal and vegetable life is so greatly 

 increased over the whole earth, that tbe amount of 

 vegetation is not sufficient to perform its work, ex- 

 tensive epidemics must ensue, which will carry off 

 the surplus of animals, including the human race : 

 and this depopulation of the earth must continue, 

 until the balance is restored. Hence there is no 

 danger of the coming of that crisis which people 

 have sometimes imagined might occur at some in- 

 definite period of the future, when the earth would 

 be so greatly overstocked with human beings that 

 its whole surface would resemble a tract which is 

 now covered by a city and its suburbs. Such a cri- 

 sis can ne%'er occur, since epidemics would carry off 

 the surplus population as soon as it exceeded 

 the bounds wisely assigned it by Nature and Prov- 

 idence. 



Let us thank Heaven who has ordained all things 

 with so much wisdom, that every excess is reduced 

 by some agent established for this purpose. And 

 let us thank Him for that benevolence which has 

 so regulated the productions of the earth, that the 

 trees and herbs and flowers, that please us by their 

 beauty and nourish us by their produce, are also 

 the means by which the atmosphere itself is pre- 

 served in a constant state of purity. It is the duty 

 of all to work in accordance with this wisdom, and 

 when we are engaged in the destruction of the 

 groves, which are the most important agents in thia 

 work of renovation, we ought to use means for imr 



