86 WRITINGS OF JOSEPH HENRY. [1835 



partially discharging itself through its own liquid, and the 

 intensity at the poles does not increase with a short interrup- 

 tion of the current. 



There is also considerable loss on account of imperfect in- 

 sulation even in the case of low intensity, and when the poles 

 are connected by a perfect conductor. In one experiment 

 with an arrangement of five pairs, and the poles united by 

 a conductor composed of thirty strands of copper bell-wire, 

 each forty feet long, the loss was found to be at least one- 

 seventh, as measured by the quantity of zinc surface re- 

 quired to be immersed in order to produce the same mag- 

 netic effect. I would infer from this that the most perfect 

 of all Dr. Hare's ingenious galvanic arrangements is that in 

 which the elements dip into separate glass vessels, as this 

 combines perfect insulation with the power of instantaneous 

 immersion. 



A variety of experiments have been made during the past 

 year with this instrument on several points of Galvanism 

 and Electro-magnetism, which will be communicated to the 

 Society as soon as my engagements will permit me to repeat 

 and arrange them for publicatiop « 



