ELECTIVE ATTRACTION. 
out one, till they are reduced to thirteen, 
■who, together with two more, of whom each 
party shall nominate one, and who are 
called the nominees, shall be a select com- 
mittee for determining such controverted 
election, 10 and 11 Geo. III. c. 16 and 42. 
See Parliament. 
Election, is a term frequently used in 
mathematics, to signify the several different 
ways of taking any number of things pro- 
posed, either separately, or as combined in 
pairs, in threes, in fonrs, &c. ; not as to the 
order, but only as to the number and va- 
riety of them. Thus, of the things a, h, e, d, 
&c. the elections of 
One thing 'i f (a) 1 = 2' — 1 
Two things ^ are <a,b, db) 3 = 2^ — 1 
Three things ) i (a, b,c, ab, ac, be, abc') 7 = 2’ — 1 
And generally of any number n, all the 
elections are 2" — 1 ; that is, one less than 
the power of 2, whose exponent is n ; the 
number of single things to be chosen either 
separately, or in combinations : thus, when 
n=12, the answer is 2‘’ — 1=4096 — 1= 
4095. 
ELECTIVE attraction. The attractions 
which take place in the chemical operations 
of art and nature, are, for the most part, 
effected under circumstances of such com- 
plexity, that it is extremely difficult to de- 
duce the general laws by which they are 
governed, or even the particular habitudes 
of the bodies so acted upon. In general 
it appears to us, from the facts, that some 
among the bodies upon which we make our 
experiments are attracted by each other, 
and enter into combination, while others 
seem to have no disposition to form this 
union, (see Chemistry) and from this prin- 
cipal observation the attractions of chemis- 
try have been called elective attraction, or 
elective affinities. See Attraction. 
The phenomena of attraction, as distin- 
guished under the heads of simple elective 
attraction, and double or more complex 
elective attraction, have been sketched 
under our article Chemistry. It is clear, 
tliat no results of this nature can be 
foretold, or indicated, unless the order and 
energy of the powers of bodies upon each 
other be first known. Geoffroy, in his ta- 
ble of simple elective attractions, first led 
the way in this research ; and he was fol- 
lowed by Bergman, who greatly improved 
both tlie tables and the method of philoso- 
phising, in his treatise on the elective at- 
tractions ; and, lastly, that most perspicu- 
ous chemist, Berthollet, has pursued the 
subject to a much greater extent, in his 
“ Statique Chimique,” of which we have 
an indifferent translation by Lambert. 
We have, at the article last quoted, made 
mention of the variations in results of com- 
bination arising from the proportion of the 
principles, the influence of solvents, of co- 
hesion, of elasticity, of efflorescence, and 
from the compounded nature of the principles 
themselves, the state of saturation, the effect 
of heat, &c. These variable considerations 
must necessarily render all tables of the ef- 
fects of attraction inapplicable, excepting 
with allowances; but they may nevertheless 
be considered as exhibiting very valuable 
summaries of facts. A like uncertainty must 
be considered as belonging to all numerical 
or other inferences, of the relative energies 
of the elective attractions ; for determining 
which, it must be confessed, our means are 
far irom being adequate, even if we were 
fully acquainted with the disturbances to 
which it is probable they are subject from 
the Galvanic action. See Galvanism. 
Tables I. to VI. contain in substance the 
two tables of Attractiones Electivae Sim- 
plices, placed at the end of Bergman’s 
treatise upon elective attractions, with such 
corrections and additions as subsequent dis- 
coveries have rendered necessary. These 
tables require no other explanation, than 
that the substances enumerated are consi- 
dered to be simple, as far as relates to the 
facts exhibited in these sketches. The or- 
der of position denotes that the higher any 
substance stands in any column, the stronger 
is its elective attraction to the substance at 
the head of that column. The under part 
of each table exhibits the attractions in the 
dry way, and must be considered as en- 
tirely distinct from the upper part. 
