Help understanding part of Taisho era sentence - もうちかねまじく


My edition of こゝろ by 夏目漱石 includes an addendum written by his son about his
memories of his father. In the part recounting his funeral, he uses the
following sentence, which I can't make sense of grammatically (especially the
bolded part):

> また小さい私がでんぐり返し **もうちかねまじく** 驚かされた坊さんの喝という怖がるべき大声を忘れられない。




Do you know how [～かねない](https://jlptsensei.com/learn-japanese-
grammar/%E3%81%8B%E3%81%AD%E3%81%AA%E3%81%84-kanenai-meaning/) and
[～かねる](https://jlptsensei.com/learn-japanese-
grammar/%E3%81%8B%E3%81%AD%E3%82%8B-%E3%81%8B%E3%81%AD%E3%81%BE%E3%81%99-kaneru-
kanemasu-meaning/) work? かねる is a verb that literally means something like "to
find it impossible/difficult" or "rather not". With this in mind, the phrase
in question can be parsed like this:

  * **でんぐり返し** : "roll (on a floor)"
  * **も** : "even" (∼すら)
  * **うち** : "to do (でんぐり返し)" (this 打つ is a verb collocated with でんぐり返し; see [this](https://myokoym.net/aozorasearch/search?word=%E3%81%A7%E3%82%93%E3%81%90%E3%82%8A%E8%BF%94%E3%81%97))
  * **かね** : continuative form of かねる
  * **まじく** : "in a way that (something) seems unlikely/impossible" (continuative/adverbial form of [まじ](https://classicaljapanese.wordpress.com/2015/03/18/maji/), which is an auxiliary for negative inference)

Put together, でんぐり返しもうちかねまじく literally means "in a way that even avoiding
doing a roll seemed impossible". The ordinary way to say this in modern
Japanese would be ひっくり返らずにはいられない(だろうという)ほど驚かされた (or more simply
ひっくり返りそうなくらい驚かされた). So he was so surprised at the voice that he almost
tumbled.




Do you know how [～かねない](https://jlptsensei.com/learn-japanese-
grammar/%E3%81%8B%E3%81%AD%E3%81%AA%E3%81%84-kanenai-meaning/) and
[～かねる](https://jlptsensei.com/learn-japanese-
grammar/%E3%81%8B%E3%81%AD%E3%82%8B-%E3%81%8B%E3%81%AD%E3%81%BE%E3%81%99-kaneru-
kanemasu-meaning/) work? かねる is a verb that literally means something like "to
find it impossible/difficult" or "rather not". With this in mind, the phrase
in question can be parsed like this:

  * **でんぐり返し** : "roll (on a floor)"
  * **も** : "even" (∼すら)
  * **うち** : "to do (でんぐり返し)" (this 打つ is a verb collocated with でんぐり返し; see [this](https://myokoym.net/aozorasearch/search?word=%E3%81%A7%E3%82%93%E3%81%90%E3%82%8A%E8%BF%94%E3%81%97))
  * **かね** : continuative form of かねる
  * **まじく** : "in a way that (something) seems unlikely/impossible" (continuative/adverbial form of [まじ](https://classicaljapanese.wordpress.com/2015/03/18/maji/), which is an auxiliary for negative inference)

Put together, でんぐり返しもうちかねまじく literally means "in a way that even avoiding
doing a roll seemed impossible". The ordinary way to say this in modern
Japanese would be ひっくり返らずにはいられない(だろうという)ほど驚かされた (or more simply
ひっくり返りそうなくらい驚かされた). So he was so surprised at the voice that he almost
tumbled.

