(23) J. H. S. says, in answer to J. H. B.'s query as to a parrot pulling out his feathers: Take a knife and scrape the inside edge of the bill, and the feathers will slip from the bill without coming out. This is done for feather-eating hens; no doubt it will answer for a parrot as well. (24) S. R. S. says: I have some dentists' pellet gold. I alloyed it with brass and silver. I melted it several times, but it was so very brittle that I could not work it. I then added a $2½ gold coin, and fused, all together, but it was as brittle as before. I then fused it and dropped in lumps of pure saltpeter, but it is still as brittle as before. I fused the gold on a lump of charcoal with an alcohol blowpipe. Please tell me how to work it. A. You fail to state the proportions of your alloy. There may be an excess of zinc and copper, or the fusion may not have been complete. Place it, together with several small pieces of rosin and a little borax or carbonate of soda, in a small blacklead crucible, and heat to very bright redness over a good fire. If this does not obviate the difficulty, fuse the alloy with about three times its weight of nitrate of potassa (saltpeter), and treat the mass when cold with dilute sulphuric acid. Pour off the acid solution and fuse the alloy, together with any silver sulphate adhering to it and a little carbonate of soda. Any silver contained in the acid solution may be recovered by adding a little salt or muriatic acid, and fusing the precipitated chloride of silver with carbonate of soda. (25) N. S. asks: 1. Can water be decomposed into its constituents (oxygen and hydrogen) with any considerable rapidity, and in large quantities, by electricity? A. Yes; providing a large magneto-electric machine be used. 2. What is the best and cheapest method of generating hydrogen in large quantities? A. The action of iron or zinc scraps on diluted oil of vitriol is among the best. A considerable volume of pure hydrogen may also be obtained with facility by passing superheated steam through a large iron tube filled with scrap iron heated to bright redness. (26) G. S. D. W. asks: Is there any process by which an engraving can be transferred either to stone or wood, where the printing ink can be made to show up as black as in the original after the transfer has been made? A. We know of no satisfactory method whereby this may be accomplished directly. By means of the chromate of gelatin photographic process, such transfers may be made without great difficulty.