Researches in the Theory and Calculus of Operations. 285 



and similar rotation. Wind a thread in this manner spirally 

 around a cylinder : it offers to the looker on, at one end a 

 righthand, at the other end a lefthand twist, the course at 

 the latter end being from the righthand upwards over to 

 the left. Suppose the cylinder divided perpendicular to its 

 length, then united by turning end for end, and the terminal 

 turns of the spiral fashioned into a circle, we have the dis- 

 tinguishing types of a right- and a lefthancled crystal. 



Recurring to the example of the leyclen phial, partially 

 coated inside and outside with tinfoil. The inside is charged 

 with positive electricity, which inductively develops negative 

 electricity in the outer coating. The glass is neither a simple 

 element nor an alloy of the metals silicon and sodium (in 

 manner as brass is an alloy of copper and zinc, and is a con- 

 ductor of electricity), but is compound, a silicate of sodium, 

 and therefore a non-conductor, for the reason that every 

 aroused atomic force in it, of whatever relative magnitude, 

 answers by a negative semiatomic force of silicic acid against 

 a positive semiatomic force of sodium; so that the same 

 kind of electric force cannot pass through the glass, but the 

 opposite kind is developed, and called inductive. 



Stepping to the atlantic or submarine cable telegraph, 

 the wires correspond to the interior coating of the leyden 

 jar; the nonconducting guttapercha covering replaces the 

 glass of the jar; while the mixed aqueous matters of the 

 ocean take place of the exterior member of the electro-che- 

 mic system, and indeed contributes inductively to enhance 

 the strength of the original charge of the wire. 



23. Another stride, it is hoped, will approach the for- 

 mation of a theory of the origin of terrestrial magnetism 

 (the Earth is a magnet, Hansen, Gauss, Delarive, Airy, 

 &c). Of all the cosmotical metallic elements, iron is cer- 

 tainly the most plentiful : it abounds among the contents 

 of the superficial crust of the earth, combined or mixed 

 with other elements or substances; is also found in nearly 



