SPONTANEOUS GENERATION. 573 



place, and in this way we fill our little flask to about four- 

 fifths of its volume. This description is typical; we may 

 thus fill a thousand flasks with a thousand different infu- 

 sions. 



I now ask my friend to notice a trough made of sheet 

 copper, with two rows of handy little Bunsen burners 

 underneath it. This trough, or bath, is nearly filled with 

 oil; a piece of thin plank constitutes a kind of lid for the 

 oil-bath. The wood is perforated with circular apertures 

 wide enough to allow our small flask to pass through and 

 plunge itself in the oil, which has been heated, say, to 250 

 degrees Fahr. Clasped all round by the hot liquid, the 

 infusion in the flask rises to its boiling point, which is not 

 sensibly over 212 degrees Fahr. Steam issues from the 

 open neck of the flask, and the boiling is continued for 

 five minutes. With a pair of small brass tongs, an assistant 

 now seizes the neck near its junction with the flask, and 

 partially lifts the latter out of the oil. The steam does 

 not cease to issue, but its violence is abated. With a 

 second pair of tongs held in one hand, the neck of the 

 flask is seized close to its open end, while with the other 

 hand a Bunsen's flame or an ordinary spirit flame is brought 

 under the middle of the neck. The glass reddens, whitens, 

 softens, and as it is gently drawn out the neck diminishes 

 in diameter, until the canal is completely blocked up. The 

 tongs with the fragment of severed neck being withdrawn, 

 the flask, with its contents' diminished by evaporation, is 

 lifted from the oil-bath perfectly sealed hermetically. 



Sixty such flasks filled, boiled, and sealed in the manner 

 described, and containing strong infusions of beef, mutton, 

 turnip, and cucumber, are carefully packed in sawdust, 

 and transported to the Alps. Thither, to an elevation of 

 about 7,000 feet above the sea, I invite my co-inquirer to 

 accompany me. It is the month of July, and the weather 

 is favorable to putrefaction. We open our box at the Bel- 

 Alp, and count out fifty-four flasks, with their liquids as 

 clear as filtered drinking water. In six flasks, however, 

 the infusion is found muddy. We closely examine these, 

 and discover that every one of them has had its fragile end 

 broken off in the transit from London. Air has entered 

 the flasks, and the observed muddiness is the result. My 

 colleague knows as well as I do what this means. Examined 

 with a pocket-lens, or even with a microscope of insufficient 



