In reviewing the works of missionaries, we have repeatedly dwelt on the opportunities of scientific usefulness which are open to the messengers of the Gospel in every part of the world. We are not afraid of the common objection that missionaries ought to devote their whole time and powers to the one purpose for which they are sent out and paid by our societies. Missionaries cannot always be engaged in teaching, preaching, converting, and baptising the heathen. A missionary, like every other human creature, ought to have his leisure hours; and if those leisure hours are devoted to scientific pursuits, to the study of the languages or the literature of the people among whom he lives, to a careful description of the scenery and antiquities of the country, the manners, laws, and customs of its inhabitants, their legends, their national poetry, or popular stories, or, again, to the cultivation of any branch of natural science, he may rest assured that he is not neglecting the sacred trust which he accepted, but is only bracing and invigorating his mind, and keeping it from that stagnation which is the inevitable result of a too monotonous employment. The staff of missionaries which is spread over the whole globe supplies the most perfect machinery that could be devised for the collection of all kinds of scientific knowledge. They ought to be the pioneers of science. They should not only take out--they should also bring something home; and there is nothing more likely to increase and strengthen the support on which our missionary societies depend, nothing more sure to raise the intellectual standard of the men selected for missionary labour, than a formal recognition of this additional duty. There may be exceptional cases where missionaries are wanted for constant toil among natives ready to be instructed, and anxious to be received as members of a Christian community. But, as a general rule, the missionary abroad has more leisure than a clergyman at home, and time sits heavy on the hands of many whose congregations consist of no more than ten or twenty souls. It is hardly necessary to argue this point, when we can appeal to so many facts. The most successful missionaries have been exactly those whose names are remembered with gratitude, not only by the natives among whom they laboured, but also by the savants of Europe; and the labours of the Jesuit missionaries in India and China, of the Baptist missionaries at Serampore, of Gogerly and Spence Hardy in Ceylon, of Caldwell in Tinnevelly, of Wilson in Bombay, of Moffat, Krapf, and last, but not least, of Livingstone, will live not only in the journals of our academies, but likewise in the annals of the missionary Church. [Footnote 92: 'The Chinese Classics;' with a Translation, Critical and Exegetical Notes. By James Legge, D.D., of the London Missionary Society. Hong Kong, 1861.]