We wish that the persons, wishing the Daguerreian Journal would furnish us with their names--("no questions asked") and they can have a copy forwarded,--thereby our _honest_ subscribers would receive their Journal regularly. We do know that we put the Journal in the Post Office--but we don't know _why_ so many of our subscribers do not receive them. There is no doubt but that our Journal is valuable, and should be in the hands of all, yet it is with us as with most brother editors, we are unable to furnish copies gratuitously. * * * * * AMMONIA. Ammonia should be a perfectly colorless liquid; when concentrated its specific gravity should be 0·9. It must have a pure ammonial odor, and must volatilize without any residue. It must not become troubled when mixed with alcohol, or lime water, otherwise it contains carbonate of ammonia. Neither must it for the same reason, become troubled when tested with a solution of chloride of barium; this is the best test for carbonate of ammonia. Care is to be taken to observe the action of the test on its first addition, for after the mixture has been exposed to the air for a few minutes, a troubling necessarily ensues, because the ammonia abstracts carbonic acid from the atmosphere. When super-saturated with nitric acid, and tested with a solution of _nitrate of silver_, it must give no white precipitate; otherwise it contains sal-ammoniac. It must give no precipitate with a solution of chloride of barium, otherwise it contains sulphuric acid, in which case, the precipitate will be invisible in nitric acid. It must give no precipitate with a solution of oxalic acid or superoxalate of potash; otherwise it contains lime. When saturated with nitric acid and tested with a solution of yellow prussiate of potash, it must give no precipitate; otherwise it contains copper. When mixed with its weight of oil of vitriol, it must not become brown or black; otherwise it contains empyreumatic oil. As it is quite difficult to obtain ammonia entirely free from carbonate of ammonia, or to preserve it in that state, the employment of ammonia containing a small portion of the carbonate is admissible in the practice of the Daguerreotype. * * * * * An Army of Subscribers.--It is computed that the regular subscribers to the _New York Sun_, standing side by side, and each occupying eighteen inches space, would form a line _seventeen miles, fourteen rods, and three yards long_. Standing with arms extended, and occupying six feet each, they would reach _sixty-eight miles, fifty-eight rods and one yard_, &c. &c.--_Sun._