418 Sir Humphry Davy on the relations of 
minute globules, owing, as was proved by tests, to the for- 
mation and oxidation of potassium which had combined with 
the mercury, and which, as is evident from Mr. Herschei/s 
researches, had given to that part of the globule in which it 
had combined its high electro-positive qualities. When the 
connexion was again made, the same series of constant and 
violent motions took place ; the elongated and negative ex- 
tremities of every globule moving towards the positive sur- 
faces, and undergoing continual oscillations ; but on pouring 
a small quantity of muriatic acid into the water, so as to make 
it slightly acid, these phenomena ceased ; the masses of mer- 
cury resumed their spherical form, hydrogen was given off 
from the negative surfaces, and all motion and agitation were 
at an end. The energy of the acid in this case being negative, 
may be considered as neutralizing the power of the potas- 
sium by its immediate contact, and as destroying all the 
phenomena of attraction by the positive pole. 
In the numerous experiments that I made in 1806, on the 
transfer of acids to the positive pole and of alkalies to the 
negative pole, there were similar instances in which masses 
of acid or alkaline matters, by exerting their own peculiar 
energies, prevented the accumulation of the antagonist ele- 
ments at their points of rest, so as to destroy, or materially 
weaken, their power of motion or transport. For instance, 
in attempting to transfer baryta from the positive to the 
negative pole, the negative pole being plunged in sulphuric 
acid, or sulphuric acid to the positive pole, the negative 
being plunged in a solution of baryta, the re-agents were 
neutralized, and formed insoluble precipitates at the point of 
