Hot alum-water is a recent suggestion as an insecticide. It will destroy red and black ants, cockroachea, spiders, chinch bugs, and all the crawling pests which infest our homes. Take two pounds of alum and dissolve it in three or four quarts of boiling water ; let it stand on the fire till the alum disappears ; then apply it with a brush, while nearly boilinghot, to every joint and crevice in your closets, bedsteads, pantry-shelves and the like. Brush the crevices in the floor of the skirting, or mop-boards, if you suspect they harbor verniin. If in whitewashing a ceiling plenty of alum is added to the lime, it will also serve to keep insects at a distance. Cockroaches will flee the paint which has been washed in cool alum water. Sugar barrels and boxes can be treed froin ants by drawing a wide chalk mark just around the edge of the top of them. The mark must be unbroken or they will creep in, but a contiuuous chalk line half an inch in width will set their depredations at naught. Powdered alum or borax will keep the chinchbug at a respectable distance, and travelers should always carry a package of it in their hand-bags, to scatter over and under their pillo vrs; in places where they have reason to suspect the presence of such bed-fellows. - Germantown 2'elegraph - - -- - --h- - An experiment recently made in Washington demonstrated, in a curious instance, the effect of heat and cold in expanding and contracting metal. A plumb line was fixed to the colossal statue surmounting the iron dome of the National Capitol. As the morning sun upon the east side of the dome heated the iron and caused an expansión it was thrown westward four and-a-half-inches. In the afternoon, when the sun upon the west side heated and expanded that part, the statue inclined to the east a similar distance. Strange Effect tjpon Asts. - It is said that corrosive sublímate sprinkled across the paths of ants in dry weather has a most surprising effect. As Roon as one of the ants touches the white powder, it commences to run about wildly, and to attack any other ant it comes across. In a couple of hours, round balls of ants will be found biting each other, and numerous individuals will be seen bitten completely in two, while others have lost 8ome of their legs or antenna). News of the commotion is carried to the formicarium, and huge fellows, measuring three quarters of an inch in length, that only come out of the nest during a migration or an attack on the nest of one of the working columns, are 6oen sailing down with a deterinined air, as if they would soon right matters. As soon, however, as they have touched the sublímate, all the stateliness leaves them ; they rush about; their legs are seized hold of by some of the smaller ants already affected by the poison ; and they themselves begin to bite, and in a short tiuie become the center of fresh balls of rabid ants. The sublímate can only be used effectively in . dry weather. A letter from New York city to the Chicago Journal gives a gloomy account of the real estáte trado in that city and vicinity. Mauy dealers whohavebought pasture lots near the city for a sinall price per acre, divided into building lots at a large price per lot, fastened a romantic name upon the ruarsh, and called upon the world to purchase and enrich them, have been disappointed, and they are enpoored instead. This kind of hothouse prosperity in the suburbs has been overdone, and the end, for these operators, is at hand. But they fiud some consolation in the fact that the old proprietors in the city are equally affected ; even as one gentleman, who, in order to raise gome needy ready cash last week was obliged to sell a building on Broadway and accepted $100,000 less than he was offered for it three years ago. One thing is certaiu, as the correspondent says, real estáte lias advanced in price in New York unnaturally fast during ten years past and prices are now too high, by all odds. It stands to reason that the reaction must come, sooner or later. It is beginning to come now. The Brooklyn Argus is of opinión that a kind word " will always go farther than a flat-iron or a potato-inasher."