Letter: Letters: E before i

From P. M. HEMMING

David Bradley’s remark about ‘icosa’ (Letters, 7 May) ignores the fact
that the form ‘eicusa’ does exist in Chemistry, while the spelling ei is
used side by side with i and is even preferred sometimes.

The confusion of forms arises from the one-time custom of obtaining
bits of words from ancient Greek via Latin. The Latin rule, when assimilating
Greek words, was to drop the e from ei. Hence icosa as in icosahedron. But
eicosa also exists: witness eicosalexaenoic acid. Other examples are chiromancy
and its alternative cheiromancy, while kaleidoscope and Deimos are standard.

Deriving direct from Greek is coming back into fashion. I myself have
seen stoicheiometry.

P. M. Hemming London