Royal Society. 233 
sent to each other the combining bodies in opposite states 
of electricity. 
2. To counteract combination; or, if formed, to subvert 
it: all that is necessary is to induce a similar state of electri- 
city in the bodies ; or, which is the same thing, to give one 
a state contrary to that which it naturally possesses. 
The latter of these positions Mr. Davy says he has proved 
by experiment. : 
In contradiction to these consequences deduced from the 
hypothesis, I shall produce instances in which, 
1. Bodies in opposite states of electricity shall not 
combine when present to each other. 
2. Bodies in similar states shall combine with as much 
force as if in different states. 
And I shall show that Mr. Davy’s experiment does~ not 
prove its object. 
Were the former position of the above consequences true, 
we should be in possession of an easy method of forming 
combinations at present believed to be impracticable, as’ in 
the same manner substances have been. decompounded 
which never yielded to other means. Thus we should pro- 
duce all the salts formed by silica with acids; we should 
unite gold and platina with nitric acid: nay, ifthere be not 
that specific attraction attributable.to the ultimate particles 
of heterogeneous matter only, we should combine iron with 
iron, or potash with potash : and these similar substances 
held together by different states of electricity should, when 
placed: in the Voltaic circuit, arrange themselves, observing 
the law of other compounds, according to their respective 
attractions. : E 
The well established law, that affinity exerts its influence 
at insensille distances only, ought not to be trues since 
electricity to exert its attraction does not require an insensi- 
ble distance. On this account we should also produce 
all compounds by a mixture of its dry ingredients in fine 
powder; at least when forced to approach by strong pres- 
sure. 
[To be continued ] 
XLI. Proceedings of Learned Societies, 
ROYAL SOCIETY. . 
March Ist and this ats President in the chair. A 
Ester by Mr. Knight was read, detailing experiments on 
© manner in which plants shoot forth their radicles. In 
a former 
