On the 7th the time was spent in excursions and carousing until the illumination of the castle began. I never saw an illumination of the ruins which could compare in beauty with that of the 7th. The night was favorable for fireworks, until finally they were rivaled by the moon, numerous boats trimmed with colored lanterns passed along the river, there were fire-wheels on the bridge, water fireworks on the river, and the quiet was disturbed alternately by the rockets and music, and when the names of the Grand Duke and Duchess, crowned with brilliant fire, appeared over the water, there was an involuntary outburst of enthusiasm. If the old Elector and Electoress could have been present at the closing entertainment of the jubilee, on the evening of the 8th, they would have rejoiced to see the new life brought to the ruins by their successor.—Illustrirte Zeitung.
MANUFACTURE OF LEATHER IN RUSSIA.
From this extensive paper it appears that the matters chiefly used in tanning are the bark of the oak, containing from 6.04 to 4.37 per cent. of tannin according to the season, that of willows, of the elm, and the birch. The leaves of the arbutus, employed in the governments of Kasan, Viatka, and Perm, contain about 16 per cent. of tannin, while the root of wild sorrel (Rumex acetosella) contains 12 per cent. For removing the hair from hides, a lye made from wood ashes is still employed. The softening of the leather is effected by means of the excrement of dogs, which acts on the leather by means of the biliary acid present, which forms with soda a kind of soap. After tanning, white Russia leather is coated with a mixture of tar and seal oil. Black Russia leather is dyed with alum, extract of sanders, and ferrous sulphate. Horse hides are tanned to a great extent for sole leather.—M. Ryloff.
IMPURITIES IN PHOTOGRAPHIC CHEMICALS, AND TESTS FOR SAME.
[Table referred to in a paper read before the Birmingham Photographic Society by G.M. JONES, M.P.S.]
| SUBSTANCE. | IMPURITIES POSSIBLY PRESENT. | TESTS. |
|---|---|---|
| Ammonia, NH3 Molec. Wt. 17 | Carbonic acid | Renders lime-water milky. |
| Dissolved solid matter | Residue left on evaporation. | |
| Chlorides | After acidulating with nitric acid, it gives a precipitate with silver nitrate, which after washing is readily soluble in ammonia and reprecipitated by nitric acid. | |
| Sulphates | After acidulating with nitric acid, it gives a precipitate with barium nitrate. | |
| Lime | A white precipitate with oxalate of ammonium. | |
| Lead is often present, derived from the action upon flint glass bottles | Black precipitate with sulphureted hydrogen. | |
| Nitric acid, H, NO3 Molec. Wt. 63 | Traces of sulphuric acid | After dilution it gives a precipitate with barium nitrate. |
| Chlorides | After dilution it gives a precipitate with silver nitrate. | |
| Peroxide of nitrogen | The acid is yellow. | |
| Iodine may be present if the acid be prepared from sodium nitrate. | After dilution and cooling it gives a blue color with starch, paste, or mucilage. | |
| Hydrochloric acid, HCl Molec. Wt. 36.5 | Free chlorine | Liberates iodine from solution of potassium iodide. See also "Chlorides," nitric acid. |
| Sulphuric acid | As above for nitric acid. | |
| Perchloride of iron | Yellow color. Brown precipitate with ammonia added till it smells slightly. | |
| Sulphuric acid, H2SO4 Molec. Wt. 98 | Bisulphate of potassium | Residue on evaporation. |
| Sulphate of lead | Milkiness on dilution. May be completely freed from lead by diluting with three or four times as much water, and allowing to settle. | |
| Acetic acid (glacial), H C2H3O2 Molec. Wt. 60 | Water | Does not solidify when cooled to 17° C. (53º F.) |
| Sulphurous and hydrochloric acids | White precipitates with silver nitrate. | |
| Aldehyde, or volatile tarry matter | Blackens in the light after adding silver nitrate. | |
| Organic sulphuric acid | Smell of garlic. | |
| Citric acid, H3C6 H5O7H2O Molec. Wt. 210 | Tartaric acid | Strong solution of potassium. Acetate added to a strong solution of the acid will deposit whitecrystalline bitartrate. |
| Pyrogallic acid, (C6H3)HO3 Molec. Wt. 126 | Metagallic acid | Black residue, insoluble in water. |
| Silver nitrate, AgNO3 Molec. Wt. 170 | Free nitric acid | Reddens litmus paper. (Neutral silver nitrate does not affect litmus.) |
| Potassium carbonate, K2CO3 Molec. Wt. 138 | Chlorides and sulphates | Same as for ammonia. |
| Potassium iodide, KI Molec. Wt. 166 | Potassium carbonate | A strong solution is alkaline to test paper. |
| Sulphates and chlorides | Same as for ammonia. | |
| Potassium iodate | A pretty strong solution becomes yellow from liberation of iodine on addition of dilute sulphuric acid or, better, a strong solution of citric acid. | |
| Potassium bromide, KBr Molec. Wt. 119 | Similar to potassium iodide | See potassium iodide. |
| Sodium carbonate, Na2CO3 Molec. Wt. 106 | Chlorides and sulphates | Same as for ammonia. |
| Sodium chloride, NaCl Molec. Wt. 58.5 | Chloride of calcium Chloride of magnesium | Oxalate of ammonium (afteraddition of a little acetic acid) gives a milkiness, or precipitate, indicating calcium; filter this out and add ammonia,chloride of ammonium, and phosphate of sodium (clear solutions). A precipitate indicates magnesium. Both the abovecause dampness in wet weather. |
| Sodium sulphate | As for "sulphates" in ammonia. | |
| Potassium cyanide, KCN Molec. Wt. 65, and hydrate, KHO Molec. Wt. 56 | Potassium carbonate nearly always present | Effervescence with dilute acids, giving off a gas carbonic anhydride, which renders lime-water turbid. |
| Kaolin | Chalk | Effervescence with dilute acids. |
| Water, H2O Molec. Wt. 18 | Sulphates and chlorides | Same as for ammonia. |
| Calcium carbonate, temporary hardness | Deposited by boiling. Test as for calcium chloride. See sodium chloride. | |
| Ammonia, almost always present in distilled and rain water | Brown coloration, or precipitate with Nessler's reagent. | |
| Gelatine | Alum | Ash, sometimes as much as ten per cent. |
| Fatty matter | Separated by precipitation with alcohol. Dissolved out by ether or benzine, and left as a residueon evaporation of the solvent. | |
| Ammonium bromide (NH4)Br Molec. Wt. 98 | Potassium bromide or other non-volatile bodies | Leaves a residue when heated. |
| Ammonium chloride | Same as for chlorides in ammonia. | |
| Pyrogallic acid | Powdered glass | Left behind on solution. |
| Potassium iodide | Potassium bromide | The crystals of bromide are usually more transparent than those of iodide, but no reliance can be placed on this. |
| Silver nitrate | Potassium nitrate, sometimes present in the fused sticks—not in the crystals | Will not yield the full quantity of chloride on precipitation with HCl. Gives a purple color to flame. |
| Sulphuric acid | When vended as pure, it invariably contains a trace of iron. Common acid is also liable to contain arsenic, selenium, thalium, and many other substances. | No easy test can be given, as the substances are so numerous some of them volatile, and most require separation from the acid before detection. |
| Organic matter, as a piece of straw in a carboy of acid | Gives a brown color to the acid. | |
| Hydrochloric acid | Arsenic | Marsh's test. |
| Some yellow samples contain no iron, but an organic salt, and give an alkaline ash on ignition of the residue after evaporation | Reinsh's test; a small piece of copper foil becomes coated on boiling in dilute acid. | |
| Calcium chloride | Calcium hydrate | The clear filtered solution made with distilled water is alkalineto test paper, and gives a precipitate on breathing into it through a tube. |
| Pure (?) chemicals generally | Broken glass, bits of straw, wood, paper, etc. | These impurities either float or sink on solution, and may easily be seen. |
G.M. JONES, M.P.S.