228 C. F. GAUSS ON THE GENERAL THEORY OF 



to be such as has hitherto been obtained at a very few only; 

 they should be cleared from the effect of irregular changes ; 

 they should be all for the same epoch. It will probably be long 

 before such demands are satisfied. 



Next to this the chief desideratum is to obtain complete ob- 

 servations (i. e. including all three elements) from points in those 

 large parts of the earth's surface where such observations are 

 still wholly wanting. Every new station Avill have for the gene- 

 ral theory an importance proportionate in great measure to its 

 distance from those we already possess. 



After a sufficient interval of time shall have elapsed, the ele- 

 ments may be determined afresh for a second epoch, and their 

 secular changes may be thence deduced. Manifestly it will be 

 essential for this purpose to reject altogether the present measure 

 of the intensities, and to substitute for it an absolute measure. 



In the course of the present century these alterations wiU no 

 longer appear uniform, and the examination of the course and 

 progress of the elements will offer to men of science inexhaust- 

 ible materials for research. 



35. 



Conclusions as to interesting points of theory may also be ex- 

 pected in future. 



In our theory it is assumed that every determinate magnet- 

 ized particle of the earth contains precisely equal quantities of 

 positive and negative fluid. Supposing the magnetic fluids to 

 have no reality, but to be merely a fictitious substitute for gal- 

 vanic currents in the smallest particles of the earth, this equahty 

 is necessarily part of the substitution ; but if we attribute to the 

 magnetic fluids an actual existence, there might Mithout ab- 

 surdity be a doubt as to the perfect equality of the quantities of 

 the two fluids. 



In regard to detached magnetic bodies (natural or artificial 

 magnets), the question as to whether they do or do not contain 

 a sensible excess of either magnetic fluid might easily be decided 

 by very exact and delicate experiments. 



In case of the existence of any such excess in a body of this 

 nature, a plumb-line to which it should be attached should de- 

 viate from the true vertical position in the direction of the mag- 

 netic meridian. 



If experiments of this kind, made with a great number of 



