86 EFFECT OF VARIED INTENSITY PART i. 



also stratified leads to the conclusion that the ordinary 

 discharge of the voltaic battery, under every condition, 

 is not continuous but intermittent, that it consists of a 

 series of pulsations or vibrations of greater or less ve- 

 locity, according to the resistance in the chemical or 

 metallic elements of the battery or the conducting media 

 through which the discharge passes. 



Caustic potash absorbs the carbonic acid gas by 

 degrees, and at last so completely exhausts a vacuum 

 tube that electricity cannot be conducted. Air is a 

 non-conductor, and an electric discharge that will not 

 pass through an inch of air, will pass through more than 

 30 or 40 inches cf attenuated gas. 



It has already been mentioned that the stratified 

 discharge can be obtained by a single discharge of the 

 primary current of an inductive coil, however long may 

 be the vacuum tube through which the discharge is 

 passed. If no addition be made to the battery and no 

 alteration be made in the arrangement of the coil so as 

 to increase or diminish the intensity of the discharge, 

 the stratifications will always present the same appear- 

 ance and form, occupying the same spaces and positions 

 in the vacuum tube ; but if any change be made so as 

 to alter the intensity, then a corresponding alteration 

 will appear in the discharge, the strise assuming a dif- 

 ferent shape, and the bright and dark divisions occupying 

 different positions. 



In order to try what effect a change of intensity 

 would produce, three separate insulated voltaic batteries, 

 in which the exciting liquid was brine, formed an elec- 

 tric circuit which was completed by two long wires. It 

 was so arranged that the discharge of one, two, or all the 

 three batteries could be separately employed. In order 

 to vary the resistance at pleasure, two tubes 18 indies 

 long containing distilled water and connected at their 

 base were introduced into the circuit. By varying the 



