vocab sizes

[cbmvax!uunet!violet.berkeley.edu!chalmers (John H. Chalmers Jr.)]

Can anyone help me with the following questions and/or
furnish me with references: What languages have the 
largest vocabularies, what are the sizes, how are
vocabulary sizes measured (spoken words, literary sources,
official dictionaries, etc.), and how reliable are the
measures? 
	From what I had read, English was thought to have in
excess of 500,000 words and Classical Arabic was second
with about 350 K. Recently, a friend told me that English
is now thought to have about 1.5 M words, Russian nearly 1 M
and French about 500 K.  She also stated that the vocabulary
sizes of all speakers of natural languages are measured in the 
100's of thousands of words.  Even including transparent compounds,
derivatives and inflected forms, these numbers seem up to an
order of magnitude larger than the estimates I have seen in the 
older literature from my college days.   Is my knowledge 
out of date?