A. B. R. Belmont. * * * * * PHOTOGRAPHIC NOTES AND QUERIES. _Economical Way of Iodizing Paper._--The extravagant price of the salt called iodide of potassium has led me to experiments as to whether paper could not be iodized in another form; and having been successful, I offer the process to the readers of "N. & Q." Having verified it three times, I can safely say that it is quite as effectual as using the above salt. The first solution to be made, is a saturated solution of iodine. Put about sixty grains of iodine (the quantity is not of importance) into an ounce bottle, and add proof spirits of wine; set it near the fire "on the hob;" and when it is nearly boiling, agitate, and it will soon become a concentrated essence: take now a bottle of clear glass, called a quart bottle, and put in it about two ounces of what is called carbonate of potash (nothing more than purified pearlash); fill up with water to within an inch of the neck, and agitate; when it is dissolved, add any of the other approved sensitives, in discretionable doses, such as fluoride or bromide of potassa, ammoniac salt, or common salt--it may have about sixty grains of the latter; and when all are dissolved, add the iodine. This is added by degrees, and shaken; and when it is a pale yellow, it may be considered to be ready for iodizing: from some experiments, I am led to believe that a greater quantity of iodine may, if necessary, be added, only the colour should not be dark. And should the operator reach this point, a few drops of solution of cyanide of potassium may be added, until the pale colour returns. Bromine water I believe may be added, but that I have not used hitherto, and therefore cannot answer for its effects. The paper then having its usual wash of nitrate of silver, is then floated on the solution about one minute, and the accustomed process gone through as described by most photographers. It is only disposed to require a pretty strong solution of silver, say thirty grains to the ounce of water. This I attribute to the potash being in a little more caustic condition than when recrystallised with iodine. And the only difference in the above formula between the two states is, that the iodine in the medical preparation is incorporated by means of iron filings with the water, which I only interpret into being a cheaper method; which makes its high price the more scandalous, and I hope this method will save photographers from the imposition: the price of a quart of iodide of potassium would be about six shillings, by the above about ten-pence. And I can safely say, it is quite as effectual: theoretically, it appears to be better, because iodine is exceedingly difficult to preserve after being dissolved and recrystallised. And much of it is lost in the preparing iodized paper: as, for instance, the usual way generally requires floating on free iodine at the last; and with the