Electro-Magnetic Experiments. 333 



The artificial magnets which were made by the Abbe Lenoble 

 were celebrated in their time. The largest weighed nine pounds two 

 ounces, and supported one hundred and five pounds French poids de 

 Marc. 



Galileo, in his younger days, applied himself much to the making 

 of magnets ; and Castelli, his pupil, speaks of one which weighed 

 only six ounces, and supported fifteen pounds. 



Mr. Park says* that one of the Emperors of China presented to 

 Toao V. king of Portugal, who reigned from 1750 to 1777, a large 

 natural magnet carrying two hundred pounds. 



Our countryman Dr. Ingenhouss, made very small artificial mag- 

 nets, carrying about a hundred times their own weight. 



Professor AUamand of Leyden had a magnet, supporting from 

 eighty to one hundred and twenty pounds. It is now in the collec- 

 tion of the Rotterdam Society of Arts and Sciences. 



Coulomb made artificial magnets, weighing ten kilogrammes or 

 twenty pounds, and supporting fifty kilogrammes or one hundred 

 pounds. 



A certain Keilius or Keil, a German doctor, made, it is said, mag- 

 nets of extraordinary power, supporting in some cases two hundred 

 and fifty pounds. A horse-shoe magnet of this man weighed, it is 

 asserted, six pounds, and supported seventy pounds. 



It appears from this that the magnet v^^hich I made by galvanic 

 force was inferior only to that of the Teylerian Museum, that of the 

 Emperor of China, and to that one which Dr. Keilius is said to have 

 made. 



Before the discovery of Dr. Oerstedt, it was a matter of doubt among 

 natural philosophers, whether any magnetism could be produced by 

 galvanism. Now, magnets nearly equal to the largest in existence 

 are produced instantaneously by the mere application of galvanic 

 power. 



When Dr. Oerstedt first published his brilliant discovery, it was 

 observed by some that the new facts which were then daily brought 

 to light, added very little to the stock of our knowledge. It was said 

 that these facts were unconnected vv'ith each other, and with any oth- 

 ers previously known. I am very far from approving these views; 

 and I am much more inclined to believe that the series of new facts 

 discovered within the last years, clearly points out a more intimate 

 connection between phenomena which formerly were held to be en- 



Park's Chemical Catechism, p. 405. 



