B. _Fowl, hail, nail, sail, tail, soul; _in Anglo-Saxon_, fugel, haegel, naegel, segel, taegel, sawel._ --These words are by the best grammarians considered as derivatives. Now, with these words I can not do what was done with the word _strength_, I can not take from them the part which I look upon as the derivational addition, and after that leave an independent word. _Strength_ - _th_ is a true word; _fowl_ or _fugel_ - _l_ is no true word. If I believe these latter words to be derivations at all, I do it because I find in words like _handle_, &c., the _-l_ as a derivational addition. Yet, as the fact of a word being sometimes used as a derivational addition does not preclude it from being at other times a part of the root, the evidence that the words in question are not simple, but derived, is not cogent. In other words, it is evidence of the second degree. II. _According to the effect._--The syllable _-en_ in the word _whiten_ changes the noun _white_ into a verb. This is its effect. We may so classify as to arrange combinations like _-en_ (whose effect is to give the idea of the verb) in one order; whilst combinations like _th_ (whose effect is, as in the word _strength_, to give the idea of abstraction) form another order. III. _According to the form._--Sometimes the derivational {369} element is a vowel (as the _-ie_ in _doggie_); sometimes a consonant combined: in other words, a syllable (as the _-en_ in _whiten_); sometimes a change of vowel without any addition (as the _i_ in _tip_, compared with _top_); sometimes a change of consonant without any addition (as the _z_ in _prize_, compared with _price_; sometimes it is a change of _accent_, like _a s['u]rvey_, compared with _to surv['e]y_. To classify derivations in this manner is to classify them according to their form. For the detail of the derivative forms, see Deutsche Grammatik, ii. 89-405. IV. _According to the historical origin of the derivational elements._--For this see the Chapter upon Hybridism. V. _According to the number of the derivational elements._--In _fisher_, as compared with _fish_, there is but one derivational affix. In _fishery_, as compared with _fish_, the number of derivational elements is two. s. 427. The list (taken from Walker) of words alluded to in p. 293, is as follows:-- _Nouns._ _Verbs._