language consists of a series of words that are but slightly
differentiated parts of speech following each other in the order
suggested in the mind of the speaker without absolute laws of
arrangement, as its sentences are not completely integrated. The
sentence necessitates parts of speech, and parts of speech are
possible only when a language has reached that stage where sentences
are logically constructed. The words of an Indian tongue, being
synthetic or undifferentiated parts of speech, are in this respect
strictly analogous to the gesture elements which enter into a sign
language. The study of the latter is therefore valuable for comparison
with the words of the former. The one language throws much light upon
the other, and neither can be studied to the best advantage without a
knowledge of the other.

Some special resemblances between the language of signs and the
character of the oral languages found on this continent may be
mentioned. Dr. J. HAMMOND TRUMBULL remarks of the composition of their
words that they were "so constructed as to be thoroughly self-defining
and immediately intelligible to the hearer." In another connection the
remark is further enforced: "Indeed, it is a requirement of the Indian
languages that every word shall be so framed as to admit of immediate
resolution to its significant elements by the hearer. It must be
thoroughly _self-defining_, for (as Max Mueller has expressed it) 'it
requires tradition, society, and literature to maintain words which
can no longer be analyzed at once.'... In the ever-shifting state of
a nomadic society no debased coin can be tolerated in language, no
obscure legend accepted on trust. The metal must be pure and the
legend distinct."

Indian languages, like those of higher development, sometimes
exhibit changes of form by the permutation of vowels, but often an
incorporated particle, whether suffix, affix, or infix, shows the
etymology which often, also, exhibits the same objective conception
that would be executed in gesture. There are, for instance, different
forms for standing, sitting, lying, falling, &c., and for standing,
sitting, lying on or falling from the same level or a higher or lower
level. This resembles the pictorial conception and execution of signs.

Major J.W. POWELL, with particular reference to the disadvantages of
the multiplied inflections in Indian languages, alike with the Greek
and Latin, when the speaker is compelled, in the choice