Though all true cast iron is brittle, in the sense that it is not usefully malleable, i.e.
Economics, therefore, under modern conditions, is not only a subject which may usefully occupy the attention of a leisured class of scientific men.
Religious denomination, another of the general subjects suggested, is of considerably more importance in some countries than in others, and the same may be said of nationality, which is often usefully supplemented by the return of mother-tongue.
Other works which may usefully be consulted are the Journals of John Woolman, Stephen Grellet and Elizabeth Fry; also The First Publishers of Truth, a reprint of contemporary accounts of the rise of Quakerism in various districts.
That it does not involve anxiety or excitement, that it is comparatively inert and compatible with the entire absence of the sensuous element - it is generally and usefully distinguished from passion.