The limited amount of the _data_ must be borne in mind. As has been
stated, no vocabularies beyond those of the four works enumerated
were used. Had the comparison been more extended, the evidence of
the Tibetan affinities of the languages under notice would have been
stronger. That this would have been the case has since been proved.
In 1849, just before the publication of my Varieties of Man, I found
from my friend Mr. Norris that, upon _grammatical_ grounds, he had
come to the same conclusion. A reference to the, then, recently
published contributions of Rosen satisfied me that this was the case.
The following is an abstract of his exposition of the structure of (1)
the Iron, and (2) the Circassian.
(1)