SCIENCE OF COMMON THINGS. 113 



Can animals foretell changes in the weather ? 



7*1(3 Is it probable that some animals and insects are able to foretell 

 changes in the weather before man can perceive any indications of the same ? 



Of this fact there appears to be no doubt. Some 

 varieties of the land-snail only make their appearance 

 'before a rain. Some other varieties of land crustaceous 

 animals change their color and appearance twenty-four 

 hours before a rain. 



7*17* What curious fact has been noticed in respect to the leaves of. trt 

 indicating changes in the iveather ? 



For a light, short rain, some' trees have been observed 

 to incline their leaves, so as to retain water / but for a 

 long rain, they are so doubled as to conduct the water 

 away. 



7*18 What fact has also been noticed respecting the changes in springs 

 previous to a rain ? 



The water of springs has been observed to rise and 

 flow out in greater volume previous to a rain. 



Most, if not all, of the popular proverbs respecting changes in the wea- 

 ther, the influence of the moon, of frosts, auroras, and the like, when 

 tested by observation, will be found to be unsupported by facts, and 

 unworthy of the slightest credence. 



7*19 Why will there be no rain if the air be very cold f 



Because it is so muck condensed that it has already 

 parted with as much moisture as it can spare. 



7*2O Have heat and cold any effect on the barometer f 



No, not of themselves ; but as cold weather is gene- 

 rally either dry or rough, with northerly winds, the 

 mercury generally rises in cold weather ; and as warm 

 weather is often moist, or accompanied by southerly 

 winds, which bring vapor with them, therefore the mer- 

 cury often sinks in warm weather. 



