IStf 



fappofed to be 

 insufficient for 



vetfons ft 4 tc»i. 



©xlgen abound* 

 no !efs in the 

 air over feas, 

 deferts, and 

 frozen regions, 

 as in places 

 where vegeta- 

 tion and the folar 

 influence pre- 

 dominate the 

 moil. 



CAUSBS BY WHICH THK OXlGtN 



tally unfit for refpiration or combuftion, fo that the- oxigen gas 

 formed in the day would not only be confumed in the night by 

 thefe proceffes, but a deleterious gas added to theatmofphere. 

 But fuppofing the quantity of this latter to be fo fmall as to 

 produce no effe6t, yet it muft be admitted, that while the fun 

 is under the horizon, none of the former can be produced ; 

 indeed it is only by the direft influence of the folar rays on 

 living vegetables that it is evolved at all. How many circum- 

 ftances then under the temporary deprivation of light, muft 

 concur to obftrucl the evolution of this falufary fluid from ve- 

 getation. The inhabitants of countries where fogs or clouds 

 obftruft the folar rays for weeks, nay months together, muft be 

 indebted for life to the winds wafting oxigen gas from regions 

 far diftant from their own, where a perpetual fpring and cloud- 

 lefs fikies prevail. In the depth of winter, when half the world 

 lies buried under ice and fnow, and vegetation fuffers a tem- 

 porary fufpenfion, every living creature in thefe climates muft 

 be indebted to the fame friendly winds and regions for health 

 and life. 



Thofe portions of the furface of the globe which furnifh 

 oxigen gas from vegetation, are not only fubject to moft of the 

 perpetual interruptions already mentioned, but make but a 

 fmall part when compared with the whole. The vaft tracls 

 of ocean can afford nothing for the prefervation of animated 

 beings more than the fandy defect bounded only by the horizon, 

 or the eternally frozen regions of either pole, and the blafts of 

 the north would carry deftruclion to all at leaft who inhabit 

 near the artic circle. It would be only in the torrid zone 

 where we could expe<5l to find, in fufficient quantity, that life 

 fupporting fluid, which, unfortunately for the common received 

 opinion, is as abundant in the midft of London at all times, as 

 at Nova Zembla, or on the line. As nature, ever uniform, 

 makes the moft ample provifinn for carrying on her operations 

 throughout her works, it cannot be ferioufly maintained that 

 (lie would truft a bufinefs of fo much importance as the pre- 

 fervation of animal life, to means fo precarious as clear or 

 cloudy weather, or the viciflitudes of the feafons. The quan- 

 tity of oxigen gas contained in the atmofphere is found to be 

 nearly the lame at all times and in all places, whether in the 

 depth of winter or middle of fmnrner, whether on land or on 

 water, whether in the crouched city or remote hamlet, but if 



the 



