544 THE AIR AND LIFE. 



l)ital wards, whilst at 7,()()() meters above the sea and at a distance 

 from land noDe at all are found. These flgnres will sufficiently indi- 

 cate how dangerous an agent air may be under certain circumstances 

 and how it transmits death. 



As we have seen, air carries at once both life and death. Each one 

 of its elements is indispensable to life, and each one is a death-dealing 

 agent according to conditions and doses. That element which appears 

 to be the best supporter of life becomes at times a dangerous poison ; 

 while the element that is apparently useless and most noxious is shown 

 by analysis to be one of the essential foundations of life. The con- 

 clusion must be that not one of them could disappear or change its 

 condition without at once turning the earth into a naked and barren 

 globe, deprived of all animate life. 



On closer examination another fact is disclosed to us. In the very 

 felicitous words of J. B. Dumas, all living beings are nothing but con- 

 densed air. The i)lants owe their existence to air, and animals could 

 not exist without plants. The elements of plants are themselves air, 

 and as animals depend on plants, the connection is close, intimate, 

 and direct; man is condensed air. And since throughout the centuries 

 during which human-kind has existed, that same air has done nothing 

 but pass without intermission through the bodies of our ancestors, 

 forming a part of them for a time and then becoming disengaged, onr 

 present body is composed of the same elements as was that of onr fore- 

 fathers. Our substance is the same as theirs. And that substance 

 which is also that of the plants of yore, is incessantly moving through 

 space in a ceaseless tide. To day or to-morrow, a flower or a fruit, it 

 will unite at one time with the sluggish organism of a moUusk, at 

 another with the brain of a Descartes, a Pascal, a Joan of Arc, or a 

 Shakesi^eare. It never stoi)s; its cycle, of which no human eye ever 

 saw the beginning and no human mind can imagine the end, seems to 

 be intinite; alternating from life to death, as old as the world and, 

 withal, eternally young, it wonld, if it only were conscious, have ex- 

 hausted all the joy and all the grief that life can afford and experienced 

 all the emotions, the most imble and the basest. 



The air that lately gently fanned our faces is the sum total of all 

 life that has been, it is a myriad of lives ; it is those who preceded us ; it 

 is the dear dead for whom we mourn; it is now a part of ourselves, to- 

 morrow it will proceed on its way, going through incessant meta- 

 morphoses, passing from one organism to another without choice or 

 favor, until the time comes when our i)lanet shall die and the sub- 

 stance of all that was life shall return to the cold eartli, a gigantic 

 grave that will revolve in silence and desolation through the unfath- 

 omable depths of the darkened heavens. 



And then? Science returns no answer. In the book of nature which 

 is spread before us and which we eagerly scan for a key to the future, 

 two i)ages are missing, the two very pages that we care most for, the 

 lirst and the last. 



