By the taste.
NOTE.
For writing by the taste, it will be necessary to immerse an equal number of the pegs or beads in weak solutions of alum, aloes, common salt, or any other liquid whose taste is sufficiently pungent or aromatic, to be distinguished when dry, on applying the tongue to them for that purpose.
No. XLII.
By the touch.
By these three senses, as perfectly, distinctly, and unconfusedly, yea, as readily as by the sight.
NOTE.
This object may be readily attained by the use of raised moveable types and the heavy pressure of an iron pen or mallet.
A mode of corresponding by the touch has been suggested by M. Haüy, and by this means the blind have been fully instructed, not only in the rudiments of language, but also in the liberal arts and sciences. M. Haüy's method of preparing the books, &c., which is simple and easy of attainment, is as follows: when the types have been arranged and fixed, a page of very strong paper is moistened, so as to be capable of receiving and retaining impressions, and laid upon the types; and then by the operation of a press or hammer, frequently repeated over the surface, the impression of the type is made to rise on the opposite side of the paper; and it continues, when dry, not only "obvious to the sight," but to the touch, and is not easily effaced. On the upper side of the paper, the letters appear in their proper position; and by their sensible elevation above the common surface, the blind may easily read them with their fingers. For epistolary correspondence it will be necessary to moisten the paper and use a metal pen.
No. XLIII.
How to vary each of these, so that ten thousand may know them, and yet keep the understanding part from any but their correspondent.