248 Olservations and Experiments concerning 
T can also produce instances of bodies neutral * with re- 
gard to attraction, which combine with the most intense 
force. Potassium has an amazing attraction for oxygen 3 
their combination is quick, and the heat and light intense, 
The result of al! such powerfully energetic attractions is a 
compound which is neutral as to other bodies. Such a 
body is also waters. Here then are two neutral bodies; and 
yet so powerful is their affinity for each other, that in or- 
dinary processes we never obtain potash free from water. 
Mr. Davy seems to place great reliance on the fact that 
a copper wire which is naturally positive, when made 
negative, will not be acted on by nitrous acid, whieh 1s na- 
turally negative. ‘This however proves nothing ; ; for it does 
not follow that it is electric repulsion which | prevents the 
combination: and if it did follow, it would be far from 
proving that combination is ‘caused by electric attraction. 
Having now given examples, in which combination 
ought to “take’ place, and does not, as well as instances in 
which combination does take place, and ought not; I shall 
proceed to some general remarks. 
There are, I think, a variety of facts inexplicable by the 
agency of electricty, which are easily accounted for if at- 
tributed to afinity: for instance, the various attractions 
coexisting in certain salts. Let the example of super- 
phosphaie of potash be selected, the component principles 
of which have been already nneritioned. Positive phos- 
phorus unites to negative oxygen, forming phosphorous acid; 
and this must be supposed to be still positive, as it unites 
with another dase of negative oxygen, forming phosphoric 
acid, Positive potassium combines with negative oxygen, 
forming potash : this being positive has a attraction to 
the negative phosphoric acid: they combine, and form phos- 
phate of potash; which must be still positive, as it has an- 
other attraction to 4n excess of acid : this additional dose en- 
ters into union, and at Jength there is formed super-phosphate 
of potash, which has also an attraction to water, forming 
* « Similar.effects may be conceived to occur in the case of oxygen and 
hydrogen, which form water, a body apparently nevtral in electrical energy 
to most other substances: and we may reasonably conclude that there ia the 
same exaltation of power in all cases of combustion. In general, when the 
different energies are strong and in ‘perfect equilibrium, the combination 
ought to be quack, the heat and light anfense, and the new compound in the 
neutral state. Thiswould seem to be the case in the instance just quoted, 
and in the circumstances of the union of che strong alkalies and acids. But 
when one energy is feeble and the other strong; all the effects must be less 
vivid; and the compound, instead of being neutral, ought to exhibit the ex- 
cess of the strenger energy.”—Davy’s Bukerian Lecture, Phil. Trans, 
the 
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