THE 
AMERICAN 
JOURNAL OF SCIENCE, &c. 
Anr. I.—QContributions to Electricity and Magiatem: On 
Electro-Dynamie Induction ; by Josepn Henry, Professor of 
Natural Philosophy in the College of New Jersey, Princeton. 
Read November 2, 1838.* ig 
INTRODUCTION, 
1. Since my investigations in in reference to the influence of a 
spiral conductor, in increasing the intensity of a galvanic current, 
were submitted to the Society, the valuable paper of Dr. Faraday, 
on the same subject, has been published, and also various modifi- 
cations of the principle have been made by Sturgeon, Masson, 
Page and others, to increase the effects. The spiral conductor 
has likewise been applied by Cav. Antonori to produce a spark by 
the action of a thermo-electrical pile ; and Mr. Watkins has sue- 
ceeded in exhibiting all the phenomena of hydro-electricity by 
the same means. Although the principle has been much exten- 
ded by the researches of Dr. Faraday, yet I am happy to state that 
the results obtained by this distinguished philosopher are not at 
Variance with those given in my paper. 
2. I now offer to the Society a new series of investi in 
the same line, which I hope may also be considered of sufficient 
importance to merit a place in the Transactions. 
3. The primary object of these investigations was to discover, 
if possible, inductive actions i in common electricity analogous to 
ni ile 
rom the Transactions 
From of the American Philosophical Society, Vol. 6. N. S. 
Vol. xxxviu, No. 2.—Jan. ~March, 1840. 27 
