The mistresses of American families, whether they like it or not, have the duties of missionaries imposed upon them by that class from which our supply of domestic servants is drawn. They may as well accept the position cheerfully, and, as one raw, untrained hand after another passes through their family, and is instructed by them in the mysteries of good housekeeping, comfort themselves with the reflection that they are doing something to form good wives and mothers for the Republic. The complaints made of Irish girls are numerous and loud; the failings of green Erin, alas! are but too open and manifest; yet, in arrest of judgment, let us move this consideration: let us imagine our own daughters between the ages of sixteen and twenty-four, untaught and inexperienced in domestic affairs as they commonly are, shipped to a foreign shore to seek service in families. It may be questioned whether as a whole they would do much better. The girls that fill our families and do our house-work are often of the age of our own daughters, standing for themselves, without mothers to guide them, in a foreign country, not only bravely supporting themselves, but sending home in every ship remittances to impoverished friends left behind. If our daughters did as much for us, should we not be proud of their energy and heroism? When we go into the houses of our country, we find a majority of well-kept, well-ordered, and even elegant establishments where the only hands employed are those of the daughters of Erin. True, American women have been their instructors, and many a weary hour of care have they had in the discharge of this office; but the result on the whole is beautiful and good, and the end of it, doubtless, will be peace. In speaking of the office of the American mistress as being a missionary one, we are far from recommending any controversial interference with the religious faith of our servants. It is far better to incite them to be good Christians in their own way than to run the risk of shaking their faith in all religion by pointing out to them the errors of that in which they have been educated. The general purity of life and propriety of demeanor of so many thousands of undefended young girls cast yearly upon our shores, with no home but their church, and no shield but their religion, are a sufficient proof that this religion exerts an influence over them not to be lightly trifled with. But there is a real unity even in opposite Christian forms; and the Roman Catholic servant and the Protestant mistress, if alike possessed by the spirit of Christ, and striving to conform to the Golden Rule, cannot help being one in heart, though one go to mass and the other to meeting.