The most curious statement by Heaviside on Ampère is in his paper "The Mutual Action of a Pair of Rational Current-Elements " ( The Electrician , Dec. 28, 1888 (written: 25 Nov. 1888), p. 230 = Electrical Papers (vol. 2), p. 501); Heaviside ends the paper with:
It has been stated, on no less authority than that of the great Maxwell[ Treatise §528], that Ampère's law of force between a pair of current-elements is the cardinal formula of electrodynamics. If so, should we not be always using it? Do we ever use it? Did Maxwell, in his treatise? Surely there is some mistake. I do not in the least mean to rob Ampère of the credit of being the father of electrodynamics; I would only transfer the name of cardinal formula to another due to him, expressing the mechanical force on an element of a conductor supporting current in any magnetic field; the vector product of current and induction. There is something real about it; it is not like his force between a pair of unclosed elements; it is fundamental; and, as everybody knows, it is in continual use, either actually or virtually (through electromotive force) both by theorists and practicians.
cf. "Why is one of Maxwell's equations named after Ampère? Who first named it after Ampère?"
Duhem's Electric Theories of J. Clerk Maxwell ch. 9. Conclusion cites:
O. Heaviside . On the Electromagnetic Wave-Surface (Philosophical Magazine, 5th series vol. XIX, p. 397; 1885.— Heaviside ’s Electrical Papers, vol. II, p. 8 [DjVu p. 29]).— On Electromagnetic Waves, Especially in Relation to the Vorticity of the Impressed Forces and the Forced Vibrations of Electromagnetic Systems (Philosophical Magazine, 5th series, vol. XXV, p. 130; 1888.—Electrical Papers, vol. II, p. 375 [DjVu p. 397]).
Heaviside coined the term "permittivity". He explains it and related terms in his Electrical Papers (vol. 2) pp. 124-5, § "Nomenclature Scheme":
To explain the word "permittance" that I used in the last Section, I may remark that in stating my views in 1885 in several communications to this journal on the subject of a systematic and convenient electrical nomenclature based upon the explicit recognition of the three fluxes, conduction-current, magnetic induction, and electric displacement, proposing several new words, some of which have found partial acceptance, I remarked upon the unadaptable character of the word "capacity." It must be the capacity of something or other, as of permitting displacement. I did not then go further in connection with the flux displacement than to use "elastance," for the reciprocal of electrostatic capacity. The following shows the scheme so far as it is at present developed:
