405 



2000 one-inch sparks were required to produce a deviation of 

 forty degrees, while, in an experiment with a minute pair of 

 zinc and platinum plates, the zinc not weighing more than the 

 head of a pin, and probably not the thousandth part of a grain 

 dissolved during the action of an acid on it, the needle, never- 

 theless, whirled round the circle twice. Thus, a chemical ac- 

 tion, almost inconceivably small, produced an effect eighteen 

 times greater than 2000 sparks of electricity from a powerful 

 plate-machine. The inference drawn was, that the agents 

 could not be the same in both. 



In furtherance of the objects above detailed. Professor 

 Faraday has made experiments to determine the quantity of 

 electricity associated with the particles or atoms of matter; from 

 which it may be calculated, that to decompose a single grain 

 weight of water, 800,000 discharges of an electric battery, each 

 discharge consisting of 300 one-inch sparks, would be required; 

 which Faraday conceives is equal to a powerful flash of light- 

 ning : and he estimates that the electricity, that is the affinity, 

 which maintains the oxygen and hydrogen of the grain of water 

 in combination, is of the same amount. Thus, according to 

 him, there is the electricity of a flash of lightning in every 

 grain or drop of water, that is, if the electricity of a drop of 

 water could be collected in one spark, it would be 454545 

 miles in length. 



But Faraday neglected to compare his results with those 

 of MM. Pacts Van Troostwick and Deiman, and also with 

 those of Dr. Pearson. These philosophers, who made expe- 

 riments with the greatest care, represent the matter very diffe- 

 rently. Many calculations were entered into, which proved 

 that, according to the experiments of the Dutch chemists, the 

 quantity of electricity necessary to decompose a grain of water 

 is thirty-eight times less than Faraday's estimate, and, accord- 

 ing to those of Pearson, forty-two times less. The vast diffe- 

 rence of Faraday's estimate leads to some suspicions of the uni- 

 versality of the law as laid down by that philosopher, namely, 



