I let loose on twitter when the bastard word "publically" slipped through a couple of competent hands last night.
This spelling for publicly was first used in the 1920s, according to this dictionary of etymology. And the correct spelling, publicly, dates from the 1560s.
Curiously, another word of this kind is in common use in the health field. That may explain why health writers do not question the use of publically. This is "chronically". I've been uneasy ever since I came across it - surely the correct word should be chronicly? Like publically, it looks ugly on paper. Well chronicly looks no more right than does publically. And it seems chronically was enshrined into UK law in 1970. But search on-line etymology and you will find neither word.
There also appears to be a difference in pronunciation. You would say chronic-uh-ly but you would not say public-uh-ly. So perhaps it's a case of English spelling following the pronunciation, not the grammar.
The dictionary to which I referred suggests the reason is that all adverbs of this kind, except publicly, are spelt with the "-ally" ending. I wonder if this is right. I can think of the word "musically". But it is a different word from publicly. Music is a noun, musical the adjective and musically the adverb. Public is an adjective as is chronic.
Perhaps the solution is the one I learnt in the days when I wrote bad schoolboy English. Avoid adverbs and use nouns where possible. A patient has a chronic illness rather than being chronically ill. You make a public statement rather than making a statement publicly. You give a plastic smile, you don't smile plastically (the word exists).
As this is the internet it is possible to find a list of all words that supposedly end in "-ically". Here it is. You can see the problem. Most are indeed bastard words - unpleasant and unnecessary. Some derive from adjectives ending in "-ical" - such as analytical and physical - and on the whole they grate on the tongue less than those derived from "-ic" words.
Can anyone produce a good and useful word ending in "-ically" and derived from an "-ic" adjective?