egyptian hieroglyphics

till yesterday, my idea of egyptian hieroglyphics
was that they were semigraphic in nature.. i.e.
the characters in the script represented a concept
or a word as a whole .
I was reading "The Code Book" (a history of
cryptography) and found this notion wrong.
It seems everyone believed so untill Thomas Young
(yeah !! u r right ! the double slit experiment guy from
Optics) discovered that the egyptian script is phoenetic.
But it seems Young was so fascinated by the existing idea
of it being a semigraphic script that he rejected his own
discovery as a faulty one. Later one linguist (I forgot his name)
took up where Young left and proved that egyptian script was
phoentic in nature by using a ancient tablet that had same
inscrption in egyptian and then in greek.