7. as if there was nothing between them. For, by this reciprocal reference of numbers, one may turn, as one leaf, all those that are between the two, even as if they were pasted together. You have an example of this in the third and tenth pages.
Every time I put a number at the bottom of a page, I put it also into the index; but when I put only a V. I make no addition in the index; the reason whereof is plain.
If the head is a monosyllable, and begins with a vowel, that vowel is at the same time both the first letter of the word, and the characteristic vowel. Therefore I write the word Ars in A a, and Os in O o.
You may see by what I have said, that one is to begin to write each class of words on the backside of a page. It may happen, upon that account, that the backside of all the pages may be full, and yet there may remain several pages, on the right hand, which are empty. Now if you have a mind to fill your book, you may assign these right sides, which are wholly blank, to new classes.
If any one imagines that these hundred classes are not sufficient to comprehend all sorts of subjects without confusion, he may follow the same method, and yet augment the number to five hundred, in adding a vowel. But having experienced both the one and the other method, I prefer the first; and usage will convince those, who shall try it, how well it will serve the purpose aimed at; especially if one has a book for each science, upon which one makes collections, or at least two for the two heads, to which one may refer all our knowledge, viz. moral philosophy, and natural.
You may add a third, which may be called the knowledge of signs, which relates to the use of words, and is of much more extent than mere criticism.
V.
