ELE 
jority. And the sheriff returns the whole, 
together with the writ for the county, and 
the names of the knights elected thereupon, 
to the clerk of the crown in chancery, before 
the day of meeting, if it is a new parliament; 
or within fourteen days after the election, it 
it is an occasional vacancy; and this under 
the penalty of 500/. It the sheriff does not 
return such knights only as are duly elected, 
he forfeits by stat. II. Y I. 100/. and the re- 
turning officer of a borough, for a like false 
return 40/. and by the late statutes they are 
liable to an action at the suit ot the party 
duly elected, and to pay double damages, 
and the like remedy shall be against an officer 
making a double return. 1 Black 180. 
If two or more sets of electors make each 
a return of a different member (which is called 
a double election), that return only which 
the returning officer to whom the sheriff’s 
precept w as directed, lias signed and sealed, 
is good; and the members by him returned 
shall sit until displaced on petition. Sim. 
184. 
On petition to the house of commons, 
complaining of an undue election, forty-nine 
members shall be chosen by ballot, out of 
whom each party shall alternately strike out 
one, till they are reduced to thirteen, who, 
together with two more, of whom each party 
shall nominate one, shall be a select com- 
mittee for determining such controverted 
election. 10 and 11 Gto. III. c. 16. 
Election, in numbers, is with regard 
to combinations, the different ways of taking 
any number of quantities given: thus, the 
quantities a b c may be taken different ways, 
as a b c, or a b, a c, and a, b, c. 
ELECTIVE attraction; in chemistry. 
The union of heterogeneous substances is 
effected in many instances by elective at- 
traction, i. e. a substance quits another with 
which it was before combined, to unite w ith 
a third, to which it is then said to have a 
superior affinity. Thus, when potass is 
added to sulphat of magnesia, in water, the 
sulphuric acid seizes the potass by its su- 
perior affinity, and the magnesia is precipi- 
tated. "This is simple affinity: but if the 
potass is added in union with carbonic acid, 
the latter will seize the magnesia at the mo- 
ment of its disengagement, forming carbonat 
of magnesia ; and the sulphuric acid having 
combined with the potass, forming sulphate 
of potass, we have a case of double affinity. 
When several bodies are mixed, decompo- 
sitions and new combinations often take 
place, which would not have been produced 
had the bodies been presented in a separate 
state. If for instance, into a solution of sul- 
phat of ammonia here is poured nitric acid, 
no decomposition is produced, because the 
sulphuric acid lias a stronger affinity for am- 
monia than nitric acid has. But it nitrat of 
potass is poured in, we obtain by evaporation 
two new bodies, sulphat of potass and nitrat 
of ammonia. Such cases of decomposition 
were called by Bergman cases of double 
elective attraction ; a name which is exceed- 
ingly proper when there are only four bodies 
concerned. But asthere are often more than 
four, it is necessary, as Mr. Morveau observ- 
ed, to employ some more comprehensive 
term. Tne phrase compound affinity may 
be employed with propriety, comprehending 
under the term all cases where more than' 
three bodies are present, and produce com- 
Vol. I. 
E L E 
binations which would not have been formed 
without their united action. In these cases ; 
the affinity of all the various bodies for each 
other acts ; and the resulting combination 
has been supposed to be produced by the 
action of those affinities w hich are strongest. 
The manner in which these combinations 
and decompositions take place, was thus ex- 
plained by Dr. Black. Let the affinity be- 
tween potass and sulphuric acid be — - 62 ; 
that between nitric acid and ammonia = 38 ; 
that between the same acid and potass = 50 ; 
and that between the sulphuric acid and am- 
monia = 46. Now 7 , let us suppose that all 
these forces are placed so as to draw the ends 
of two cylinders crossing one another, and 
lixed in the middle in tins manner : 
l’otass. Nitric acid. 
50 
It is evident, that as 62 and 38 =100 are 
greater than 50 -f- 46 = 96, they would over- 
come the other forces and siiut the cylinders. 
Just so the affinity between ammonia and 
nitric acid, together with that between sul- 
phuric acid and potass, overcomes the af- 
linity between ammonia and sulphuric acid, 
and that between nitric acid and potass, and 
produces new 7 combinations. 
It has been supposed that in all cases of 
compound affinity, there are two kinds ot 
affinities to be considered: 1st. Those af- 
finities which tend to preserve the old com- 
pound, these Mr. Kirwan has called quiescent 
affinities; and those which tend to destroy 
them, w hich he has called divellent affinities. 
Thus, in the instance above given, the 
affinity between ammonia and sulphuric acid, 
and that between nitric acid and potass, are 
quiescent affinities, which endeavour to pre- 
serve the old compound; and it they are 
strongest, it is evident that no new compound 
can take place. On the contrary, the affinity 
between potass and sulphuric acid, and that 
between nitric acid and ammonia, are divel- 
lent affinities ; and as they are in this case 
strongest, they actually destroy the former 
combinations and form new ones. 
It has been supposed that when two of 
those salts which mutually decompose each 
other are mixed together,’ the decomposition 
instantly takes place in consequence of the 
force ot" affinities alone, independant of the 
proportions of the ingredients. 
Thus when sulphat of potass and nitrat of 
lime are mixed together, it was supposed 
that the sulphuric acid, if present in sufficient 
quantity, combines with the whole of the 
lime, and disengages the nitric acid and the 
potass, which also combine till the least 
abundant of the two is saturated. But if 
this w 7 as the case, some of the four ingredients 
must be left disengaged, as the proportions 
of the ingredients of the salts formed by the 
four ingredients are not such as to saturate 
4 F 
ELE SQ3 
each other. According to Mr. Kirwnn's ex- 
periments, the proportions ot ac id and al- 
kali in the four follow ing salts are as under : 
Sulphat of potass | i' 0 i a ss 121.48 
c , . . , r S Ac id too 
Sulphat of lime ' j il);e 70 
, , , ( Acid 100 
Nitrat ot potass | p otass 117 . 7 
\ Acid 100 
| Lime 55.7 
Nitrat of lime 
Now 7 let sulphat of potass and nitrat of 
lime be mixed together ; h t the quantity of 
sulphat of potass be such, that the acid con- 
tained in it amounts to 100 ; and let a more 
than sufficient quantity of nitrat ot lime he 
added, to saturate the sulphuric acid with 
lime. It is evident that for that purpose 70 
of lime must be present; and the quantity 
of nitric acid combined with these 70 must 
be 123.8. This quantity would require for 
saturation 145.7 of potass, but there are only 
121.48 in the mixture; consequently there 
ought to exist in the mixture, after the mutual 
decomposition of the salt-, a quantity of nitric 
acid in a slate of liberty. But the fact is^ 
that no such excess of acid exists in the mix- 
ture. T his is a sufficient proof that the de- 
composition does not take place in the man- 
ner that has been supposed. It may be said, 
ii.deed, that the composition ot these salts 
may not be sufficiently known to warrant 
reasoning from it. Brit be tiie proportion 
of the ingredients what it may, still if the 
decomposition" v.as absolute, as has been 
supposed, when mixed in any proportion 
whatever, except in one, some of the ingredi- 
ents ought to remain disengaged: but as this 
does not happen either in this case or in any 
other, we have a right to conclude that the 
decomposition is not what it has been con- 
sidered. 
. 2 . When two saline solutions are mixed 
together, either no apparent change takes 
place, or a precipitate is formed. Let us 
consider each of these cases. 
When no precipitation takes place, the 
two salts no doubt combine together, and 
form a compound consisting of the two acids 
and their bases ; and the degree of saturation 
must be the same as before mixture, because 
the proportions and the affinities must con- 
tinue the same. Hence the reason that in 
these cases there are never any indications 
of any one of the ingredients being disengaged 
from the others. Hence also the reason 
that when two salts are dissolved in water, 
they increase the solubility of each other, 
their mutual affinity serving as an additional 
counterbalance to the cohesion of each. 
Thus Vauquelin has shewn that saturated so- 
lutions of sulphat of lime, alum, and sulphat 
of potass, are' capable of dissolving a greater 
proportion of common salt than pure water 
is. 
3. When two salts may be mixed together 
without any precipitation taking place, it is 
a proof that all the salts capable of being 
formed by the component parts of each are 
soluble. ’ Hence the alkaline salts very rare- 
ly occasion a precipitate when mixed to- 
gether, nor the earthy salts when the acid 
combined in each is such as to form soluble 
salts w'ith all the earthy bases, as nitric acid, 
muriatic acid. On the other hand, when a 
precipitation lakes place, some two of the in- 
