120 THE ORIGIN OF CEEATIOIT. 



on the earth, astronomers and physicists show, that an impor- 

 tant portion of the earth's heat supply is derived from the stars. 

 A statement just as absurd as the other. 



Porta denied that the moon and stars had anything to do 

 with dew. He discovered that dew was sometimes deposited 

 on the inside of glass panes ; and again, that a glass hell placed 

 over a plant in cold weather, was more copiously covered with 

 dew within than without. He thought his observations justified 

 him in looking on dew as condensed not from vapour as 

 Aristotle thought, and as is now believed by the scientific 

 world generally but from the air itself. This, although not 

 entirely correct, was a remarkable discovery, and had it been 

 believed in then and worked up to, a great deal of blundering 

 might have been avoided, and our knowledge of meteorology 

 would have been much further advanced than it is. 



Dew was generally supposed to fall, and people still continue 

 to speak of its falling, but Porta's experiment showed that it 

 rose from the earth, that it was an exhalation from the ground 

 and from plants. In making observations to establish this view, 

 Muschenbrook found that dew forms much more readily on some 

 substances than others. This was supposed to be damaging to 

 Porta's theory, for dew neither seemed to fall, nor to rise, but to 

 be caTised in a great measure by the nature of the substance on 

 which it was found deposited. Had this circumstance only 

 been searched into more minutely, it would have shown still 

 more conclusively that Porta was right, and greater discoveries 

 might have resulted from it. Yet it is always the way of the 

 world, we are often on the eve of wonderful discoveries, by 

 great minds who are ahead of their day and generation, but 

 which are foiled by the stupidity of those for whose benefit they 



