How the throng go thoughtlessly onward. Do they ever think--think what a sirocco blast from the valley of the Upas tree, is sweeping over this city? Do mothers ever inquire, ever think whether it is possible for their sons to escape the contagion of such company as they keep in the great evening promenade of this mighty Babylon? Have New York mothers no feeling of fear for their sons? or has "the pestilence that walketh in darkness," obtained such strength that this is overcome? or has the plague spot grown so familiar to their eyes that they no longer seek to wash it out? If they have given up their sons, if they have surrendered the great street to the almost exclusive occupancy, at night, of painted harlots; have they also given up their daughters, surrendered them to the wiles of the seducer? do they let them go out without fear, even in company with their male friends, to be jostled upon the side-walks by midnight ramblers, and seated at the same table, at some of the great "saloons," side by side with those who win to kill, whose trade is death, whose life is gilded misery, though enticing as the siren's song? Have they forgotten that we are all creatures of surrounding circumstances, subject to like influences, and liable to the same disease as those who breathe the same atmosphere, and if that is impure, those who breathe it may become so? Even now, while I write, the "New York Daily Tribune," gives this "Item" to its readers:-- "MYSTERIOUS DISAPPEARANCE.--On Sunday evening last, between six and seven o'clock, Miss G. C---- left her father in Spring street, near Broadway, to go to her brother-in-law's (Mr. B----), No. -- Spring street, since which time nothing has been heard of her, and it is feared that she has been dealt foully with. She is seventeen years of age, good-looking and rather tall; dark complexion, and dark eyes; lisps somewhat when in conversation. She was dressed in plaid, light and dark stripe; Talma cape; straw bonnet, trimmed with white outside, and green and white inside. Her disappearance has caused the deepest affliction to her family, and any information that can be given will be gratefully received by her aged parent, No.--Spring street." "It is feared that she has been foully dealt with." Yes, and it ought to be feared that "good-looking, rather tall" young girls, are foully dealt with in the streets of this city, every night in the week. It is feared she is not the first girl of seventeen, whose "mysterious disappearance has caused the deepest affliction to her family."