SPONTANEOUS GENERATION. 307 



tubes, containing clear infusions of turnip, hay, beef, 

 and mutton, in iron bottles, and subjected them to 

 air-pressures varying from ten to twenty-seven atmo- 

 spheres pressures, it is needless to say, far more than 

 sufficient to tear a preserved meat tin to shreds. After 

 ten days these infusions were taken from their bottles 

 rotten with putrefaction and teeming with life. Thus 

 collapses an hypothesis which had no rational foundation, 

 and which could never have seen the light had the 

 slightest attempt been made to verify it. 



Our fifty-four vacuous and pellucid flasks also declare 

 against the heterogenist. We expose them to a warm 

 Alpine sun by day, and at night we suspend them in a 

 warm kitchen. Four of them have been accidentally 

 broken ; but at the end of a month we find the fifty 

 remaining ones as clear as at the commencement. 

 There is no sign of putrefaction or of life in any of 

 them. We divide these flasks into two groups of 

 twenty-three and twenty-seven respectively (an accident 

 of counting rendered the division uneven). The ques- 

 tion now is whether the admission of air can liberate 

 any generative energy in the infusions. Our next 

 experiment will answer this question and something 

 more. We carry the flasks to a hayloft, and there, 

 with a pair of steel pliers, snip off the sealed ends of 

 the group of three-and-twenty. Each snipping off is 

 of course followed by an inrush of air. We now carry 

 our twenty-seven flasks, our pliers, and a spirit-lamp, 

 to a ledge overlooking the Aletsch glacier, about 200 

 feet above the hayloft, from which ledge the mountain 

 falls almost precipitously to the north-east for about a 

 thousand feet. A gentle wind blows towards us from 

 the north-east that is, across the crests and snow-fields 

 of the Oberland mountains. We are therefore bathed 

 by air which must have been for a good while out of 



