ON SUPERACID AND SUBACID SALTS.' 169 



there is but one mode of union. If they unite in the pro* 

 portion of two to one, the two particles will naturally arrange 

 themselvtrs at opposite poles of that to which they unite. 

 If there be three, they might be arranged with regularity, at 

 the angles of an equilateral triangle in a great circle sur- 

 rounding the single spherule ; but in this arragement, for 

 want of similar matter at the poles of this circle, the equi- 

 librium would be unstable, and would be liable to be de- 

 ranged by the slightest force of adjacent combinations ; but 

 when the number of one set of particles exceeds in the pro- 

 portion of four to one, then, on the contrary, a stable equi- 

 librium may again take place, if the four particles are situate 

 at the angles of the four equilateral triangles composing a 

 regular tetrahedron. 



But as this geometrical arrangement of the primary ele- This merely 

 meats of matter is altogether conjectural, and must rely for ^1'°' ^^'^'cu • 

 its confirmation or rejection upon future inquiry, I am de- 

 sirous, that it should not be confounded with the results of 

 the facts and observations related above, which ai-e suffi- 

 ciently distinct and satisfactory with respect to the existence 

 of the law of simple multiples. It is perhaps too much to 

 hope, that the geometrical arrangement of primary particles 

 will ever be perfectly known; since even admitting that a 

 very small number of these atoms combining together would 

 have a tendency to arrange themselves in the manner I have 

 imagined; yet, until it is ascertained how small a jjroportion 

 the primary particles themselves bear to the interval between 

 them, it may be supposed, that surrounding combinations, 

 although themselves analogous, miglit disturb that arrange- 

 ment, and in this case, the effect of such interference must 

 also be taken into the account, before any theory of chemi- 

 cal combination can be rendered complete. 



III. 



