A HISTORY OF SCIENCE 



shock that nearly " knocked their teeth out," as the 

 professor tells it. 



LUDOLFF'S EXPERIMENT WITH THE ELECTRIC SPARK 



But Bose was only one of several German scientists 

 who were making elaborate experiments. While Bose 

 was constructing and experimenting with his huge 

 machine, another German, Christian Friedrich Ludolff , 

 demonstrated that electric sparks are actual fire a 

 fact long suspected but hitherto unproved. Ludolff's 

 discovery, as it chanced, was made in the lecture-hall 

 of the reorganized Academy of Sciences at Berlin, 

 before an audience of scientists and great personages, 

 at the opening lecture in 1 744. 



In the course of this lecture on electricity, during 

 which some of the well-known manifestations of elec- 

 tricity were being shown, it occurred to Ludolff to 

 attempt to ignite some inflammable fluid by projecting 

 an electric spark upon its surface with a glass rod. 

 This idea was suggested to him while performing the 

 familiar experiment of producing a spark on the surface 

 of a bowl of water by touching it with a charged glass 

 rod. He announced to his audience the experiment 

 he was about to attempt, and having warmed a spoon- 

 ful of sulphuric ether, he touched its surface with the 

 glass rod, causing it to burst into flame. This experi- 

 ment left no room for doubt that the electric spark 

 was actual fire. 



As soon as this experiment of Ludolff's was made 

 known to Bose, he immediately claimed that he had 

 previously made similar demonstrations on various 

 inflammable substances, both liquid and solid; and it 



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