This is a quote from the first chapter of later editions of The American by Henry James. In context it reads like this:
'His eye was of a clear, cold grey, and save for the abundant droop of his moustache, he spoke, as to cheek and chin, of the joy of the matutinal steel. He had the flat jaw and the firm, dry neck which are frequent in the American type;'
Click here to see this section quoted in a book by S.B. Liljegren entitled American and European in the Works of Henry James (p.6).
Interestingly, in the earlier editions of the novel (which was first published in 1877), the language is much simpler; the equivalent section reads like this:
'His eye was of a clear, cold gray, and save for a rather abundant mustache, he was clean-shaved. He had the flat jaw and sinewy neck which are frequent in the American type.
Click here to see the orginal version in an e-book of The American (1877 edition) on p.2.
Matutinal means related to the morning or occurring in the morning.