270 FRAGMENTS OF SCIENCE. 



the honesty to expose, the weakness of the evidence 

 adduced in its support. 



And here observe how these discoveries tally with 

 the common practices of life. Heat kills the bacteria, 

 cold numbs them. When my housekeeper has pheas- 

 ants in charge which she wishes to keep sweet, but 

 which threaten to give way, she partially cooks the 

 birds, kills the infant bacteria, and thus postpones the 

 evil day. By boiling her milk she also extends its 

 period of sweetness. Some weeks ago in the Alps I 

 made a few experiments on the influence of cold upon 

 ants. Though the sun was strong, patches of snow 

 still maintained themselves on the mountain slopes. 

 The ants were found in the warm grass and on the 

 warm rocks adjacent. Transferred to the snow the 

 rapidity of their paralysis was surprising. In a few 

 seconds a vigorous ant, after a few languid struggles, 

 would wholly lose its power of locomotion and lie prac- 

 tically dead upon the snow. Transferred to the warm 

 rock, it would revive, to be again smitten with death- 

 like numbness when transferred to the snow. What is 

 true of the ant is especially true of our bacteria. Their 

 active life is suspended by cold, and with it their 

 power of producing or continuing putrefaction. This 

 is the whole philosophy of the preservation of meat by 

 cold. The fishmonger, for example, when he sur- 

 rounds his very assailable wares by lumps of ice, stays 

 the process of putrefaction by reducing to numbness 

 and inaction the organisms which produce it, and in 

 the absence of which his fish would remain sweet and 

 sound. It is the astonishing activity into which these 

 bacteria are pushed by warmth that renders a single 

 summer's day sometimes so disastrous to the great 

 butchers of London and Glasgow. The bodies of 



