1858.] SENATE— No. 4. 205 



which at 16 cents per pound, is worth $1.36; 2l pounds phosphoric 

 acid at 2 cents per pound, is 4^ cents ; together, $1.41. This multi- 

 plied b}' 20 gives $28.20 as the value per ton. If the English prices 

 are adopted, viz., 12 cents for ammonia and 3 cents for phosphoric 

 acid, we have $21.80 as the value per ton. The market price, you 

 say, is $25. Therefore, next to Peruvian guano, this is a substance 

 which, if its composition proves uniform, is most nearly worth what it 

 costs. 



k 



Yale A^jalytical Laboratory, March 16, 1857. 



Dr. E. Sanborn, of Andover, presented an ingenious con- 

 trivance, to illustrate the influence of magnetism and electricity 

 in the material world, and with it the following 



STATEMENT: 



This arrangement of magnetic needles, with the accompanying 

 lode-stone or magnetic iron ore, is presented for a place in your exhi- 

 bition, to invite from farmers, philosophers, and all original thinkers, 

 more general attention to some of the subtle agencies and latent 

 principles of action which exist in nature. Examine, for instance, 

 the powerful chain of attraction between the j)ositive and negative 

 poles of magnetism, or rather magnetism itself and electricity, and 

 the corresponding but no less powerful lever of repulsion which 

 exists between the usually termed positive and positive, and negative 

 and negative qualities. If even one individual is hereby prompted 

 to deeper thought and investigation into the beauty, simplicity and 

 similarity of laws by which the All-wise Artificer controls his won- 

 drous works, and manifests His all-harmonizing and reproducing 

 influences in mineral, vegetable and animal worlds, my object will 

 be accomplished. 



The needles, you will please to observe, are equally balanced, and 

 so arranged as to revolve Avithin the circle and sphere of each other's 

 attraction and repulsion. To make the illustration the more life- 

 like, and suggestive to seekers for truth, of the analogy which may 

 exist between the laws of mind and matter, and account for phenom- 

 ena which sometimes occur in social relations, each point or pole of 

 each needle is made to represent its corresponding sexual distinction. 

 The positive or magnetic ones are distinguished by male, and the 

 others by female attire. In revolving, each coldly repels each, or its 

 similar; that is, positive repels positive, and negative repels negative, 

 and as ardently seeks and attracts each its opposite. The positive seeks 



