Nevertheless, the fact that most signs are capable of logical explanation does not mean that they are self-explanatory. Indeed nearly all have become conventional, and each must be learned separately before it can be rightly used.
Signs which make the heart the seat of the mind are,
I think, older than those which give the place of honor to the brain.
THE MANUAL ALPHABET
Although not at all Indian, it is exceedingly helpful to know the single-hand alphabet as given in the cut on [page li]
; partly because it must sometimes be used for giving proper names and also because it saves time in describing hand positions. For example, we say “position A or B” instead of describing each hand all over again for each new sign.
THE NUMERALS
Fingers and numbers are nearly synonymous the world round when making signs, manual or written, hence the universality of the decimal system. The Indian Code, the Popular Code, and the Deaf Code are nearly alike in this, but in most points of difference the Indian is best.
To prevent mistakes in certain cases preface the number with the sign of numbers or arithmetic.