The judicious use of an ordinary female syringe, with cold water alone, or a weak solution of white vitriol or other stringent in cold water, immediately after coition, will in most cases prevent conception. The syringe must be a large one, if made of metal, and should be filled several times, and its contents injected as far up as possible. The India-rubber syringe has of late years nearly superseded metal ones, and is beautifully adapted to the business of preventing conception. By the use of this article a female may inject as much fluid as she pleases, through an elastic tube, quite as far up into her person as is necessary. The mixture should be prepared beforehand, and, with the syringe, kept by her bed-side, as success often depends upon promptness in using it. If used immediately, with a weak solution, as hereinafter stated, there is very little danger but that a woman may keep herself safe from child-bearing as long as she pleases. Solutions of Alum, Sulphate of Zinc, Chloride of Zinc, Sulphate of Iron, &c., will kill the animalculæ of the Semen, if injected with sufficient force and profuseness. If the woman rises _instantly_ and performs the duty, she will probably be successful. If solutions are used in preference to pure cold water, it is better to use water at last as a rinsing process. The use of the syringe, so far from injuring the female, keeps the part clean and healthy, and tends to promote general good health. In commencing this practice, you should first accustom yourself to the use of cold water by degrees. Use but little at first, and let it not be too cold. Increase the quantity and the coldness gradually, until at last the feeling will be refreshing and agreeable. India-rubber syringes can be purchased at almost any respectable drug-store in New York, at from two to three dollars. We can furnish the best article to our customers for three dollars. It is an instrument that every family should keep in the house to be used in case of sickness, if for no other purpose. Either of the following lotions may be used, as we have explained, in preventing conception. Sulphate of Iron is the favorite article which our quack doctors recommend. They usually charge five dollars for an ounce paper of it, including directions for use; whereas the cost in New York, at a drug-store, is less than fifty cents a pound. LOTIONS.—1. Dissolve half an ounce, or more, of pulverized Alum in two quarts of rain-water. If you can get Sulphate of Zinc, put in that with the Alum, in equal quantities, say a quarter of an ounce each. 2. Two drams (quarter of an ounce) Sulphate of Zinc in two quarts of soft water. Or, one-third of an ounce will perhaps do better, if used alone. 3. Chloride of Zinc, (liquid,) half a fluid ounce to two quarts of water. You can buy an ounce phial full, and use half at a time, or a two or four ounce phial, and use in proportion. If you prefer to make the lotion stronger, it will do no harm.