Several American missionaries have resided at Kolingsoo, and without doubt will, at no distant period, succeed in winning the attention and good-will of many of the inhabitants of Amoy. A boundless field has at length been opened for missionary enterprise in the benighted empire of China; for, although it cannot be said that the country has been made completely accessible to the foreigner, still the hostility of the government has been materially modified. It rests with the Christian nations to profit _as Christians_, by the opportunities which cannot fail to offer. Among a people so fond of reading and _thinking_, and so given to study and inquiry as the Chinese generally are, the best possible results are to be expected from the judicious teaching of Christianity, and, above all, of Christian _practices_. If China is really to be opened, it is to be effected by missionary enterprise cautiously and judiciously, and, above all, not too hastily applied. The most valuable of all aids to these undertakings, is that of medical knowledge, which may be considered as almost indispensable to the proper character of a missionary in China. The relief of bodily suffering (above all, in a country where the medical art is so low as it is in China) softens the feelings of our nature, and paves the way for kinder influences over the mind itself. It will open the family mansion of the most secluded and prejudiced Chinese, when words or doctrines _first_ propounded would meet an unwilling or perhaps a hostile listener. Religious teaching and the practice of the healing art, the comfort of the suffering mind, and the solace of the tortured body, must go hand in hand in effecting the good work of "opening" China. Why is it that the Americans have taken precedence of the English in this great and glorious work, since the commencement of the war in particular? For many years, a talented medical missionary, Dr. Parker, has dispensed his double blessing upon the Chinese at Canton, and can testify the gratitude of the people, from the highest to the lowest, and the readiness with which they have accepted his counsel and his teaching in both capacities. At Macao, Hong-Kong, Kolingsoo, and Chusan, the Americans have alike preceded us. There is, however, one great and fatal error to be avoided; and that is, the rivalry of religious sects among each other, and the attempt to gain followers at the expense of each other's tenets. It was this want of unanimity which in some measure produced the decline of the influence of Roman-catholic missionaries in China.