Chap. 3.] Ufe of tie Green Slime In Water. 1$ 



air copioufly ; after this it was removed into a dark 

 room, and from that time the production of air en- 

 tirely ceafed. When placed again in the fun, it afforded 

 no air till about ten days after, when it had more green 

 matter, the former plants being probably all dead ; 

 and no air could be produced till new ones were 

 formed. 



From various experiments it appeared, that different 

 animal and vegetable putrefcent fubftances afforded 

 a very copious pabulum for this green vegetable mat- 

 ter, which produced fo freely the vital air; whence 

 the philofophic author of this difcovery is led to the 

 following conclufions c It is impoffible,' fays he, c not 

 to obferve from thele experiments the admirable pro- 

 vifion in nature, to prevent or leffen the fatal effects 

 of putrefaction, t fpecially in hot countries, where the 

 rays of the fun are mod direct, and the heat moil in- 

 tenfe. Animal and vegetable fubftances, by limply 

 putrefying, would neceffarily taint great maifes of air, 

 and render it unfit for refpiration, did not the fame 

 fubftances, putrefying in water, fupply a moft abundant 

 pabulum for this wonderful vegetable fubftance, the 

 feeds of which feem to exift throughout the atmofphere. 

 By thefe means, inftead of the atmofphere being cor- 

 rupted, a large quantity of the pureft air is continually 

 thrown into it. By the fame means alfo, ftagnant wa- 

 ters are rendered much lefs offenfive and unwholfome 

 than they would otherwife be. That froth which we 

 obferve on the furface of fuch waters, and which is 

 apt to excite difguft, generally confifts of the pureft. 

 vital air, fupplied by aquatic plints. When the fun 

 fhines, this air may be obferved to iflue from them. 

 Even when animal and vegetable lubftances putrefy 

 in air, as they have generally fome moidnre in them, 

 various other vegetable productions* in the fon 



