Has the word “manal” (instead of “manual”) ever actually been used? If so, how?

Question

Recently, I've been going through checking how many Latin words ending in -alis have corresponding English words ending in -al. It seems there was a Latin word mānālis meaning "flowing" (as well as a separate word meaning "of or belonging to the Manes"). So I looked up "manal" in OneLook Dictionary Search and found that there are three dictionaries that have an entry for "manal".

But oddly, the definitions they give are unrelated to the Latin "flowing" word. Instead, the English word "manal" is supposed to have a meaning related to hands (evidently based on the Latin word manus, which is a u-stem noun, and the base of the much more common adjective manual).

Because of the apparently irregular derivation, I'm feeling a bit suspicious about this word and I'm wondering if it ever had any significant use. It's not in the Oxford English Dictionary. The three OneLook-indexed dictionaries that have an entry are:

• Wiktionary (entry created October 2006‎): no examples are given of actual use

• The Phrontistery: it's just in a list. The Phrontistery FAQ says

  With very few exceptions, every word in the International House of Logorrhea and every word in all of the glossaries is a real English word found in at least one major English dictionary. There are a couple of dummy words included to thwart those who would copy my site in toto, but these will be obvious if you find them.

  It doesn't appear to be an obvious dummy word.

• Wordnik, which references the Wiktionary entry mentioned above as well as an entry in The Century Dictionary and Cyclopedia. None of the examples in the sidebar seem to be legitimate: they are all misspellings of the noun "manual" or proper names or transliterations of non-English words.

Answer 1

There seems to be more information in the supplement to The Century Dictionary and Cyclopedia Volume XII (published 1910). This may be the source of the Wordnik and Phrontistery entries.

It says

manal (mā´nal), a. [L. man(us), hand + al¹.] Of or pertaining to the manus or hand.—Manal formula, in zoöl., a statement of the distance between the distal ends of the second to fifth metacarpals of a bat, measured when the wing is extended as in flight.

(p. 766)

A search through Google Books for "manal formula" turned up an interesting footnote from the person who coined the expression:

¹I proposed the term manal formula for the widths of the spaces between the metacarpal bones at the distal ends when the wing is extended—as compared with the length of the forearm—in 1890. (See Proc. Amer. Philisoph. Soc. xxvii, Jan 23rd.) This formula has been found by me to be of value in distinguishing species in a group in which many of the best characters are not found on the periphery. It has been suggested to me that this term should be "manual" instead of "manal". I avoided the term "manual" since the significance uniformly attached to this adjective forbad in my judgment its employment in this new connection, and that it was permissible to slightly modify the spelling of the word. If, however, such a course be found inadmissable the word "pteral" may be substituted.

("Description of a new species of Vampyrops", by Harrison Allen, in Proceedings of the Academy of the Natural Sciences of Philadelphia, 1891, p. 400)

I did not find any books that used the term that were more recently published than the 1910 Cyclopedia entry quoted at the start of this post. Allen's alternative suggestion of pteral formula doesn't seem to have done any better: the most recent document in Google Books using that term seems to be from 1898. This makes me wonder a bit if people came up with a third, perhaps less obscurely derived term for the concept, or if the concept itself was not found to be useful enough to have a special name dedicated to it—but the right person to answer that question would probably be a bat specialist rather than a lexicographer. I am now satisfied that manal did indeed have an (apparently brief) period of time when it was used "for real" as a word.