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tongs with the fragment of severed neck being withdrawn, 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 
