Practical Leather Chemistry: A Handbook of Laboratory Notes and Methods for the Use of Students and Works' ChemistsC. Lockwood and son, 1920 - 207 pages |
Common terms and phrases
acetic acid added alcohol alkali allowed to stand ammonia ammonium bark basin beaker bichromate boiling boric acid brown ppt c.cs calculated carbonate cent chloride chrome chromic acid Coll colour conical flask containing cooled crucible cubic centimetre detannised determined dilute HCl dissolved distilled water dried drops estimated evaporated to dryness excess extract fatty acids filter paper filtrate gallic acid give heated hide powder hide substance ignited insoluble iron Leather Chem Leather Trades Chem liquid liquor magnesium method methyl orange mixture moisture NaOH nitrogen NOTES NOTES CHAPTER orange as indicator oxidised permanganate petrol ether phenol phenol phthalein phthalein as indicator pipetted potassium precipitate quantity residue salt sample saponified soap sodium soln specific gravity steam oven sulphate sulphide sulphuric acid Sumach tannin tannin solution tanning materials temperature titrated total soluble matter tube turbidity unsaponifiable volume washed water bath weighed yell Yell.-brown Yell.-white ΙΟ
Popular passages
Page 123 - ... hours, so as to extract the maximum of tannin. Any remaining solubles in the material must be neglected, or reported separately as "difficultly soluble
Page 123 - Sumach and myrobalans extracts should be dissolved at a lower temperature. Solid extracts shall be dissolved by stirring in a beaker with successive quantities of boiling water, the dissolved portions being poured into a litre flask, and the undissolved being allowed to settle and treated with further portions of boiling water. After the whole of the soluble matter is dissolved the solution is treated similarly to that of a liquid extract. Solid tanning materials, previously ground till they will...
Page 126 - In the case of tans it must be clearly stated in the report whether the calculation is on the sample with moisture as received, or upon some arbitrarily...
Page 122 - The total solubles must be determined by the evaporation of a measured quantity of the solution previously filtered till optically clear both by reflected and transmitted light ; that is, a bright object such as an electric light filament must be distinctly visible through at least 5 cm. thickness, and a layer of 1 cm. deep in a beaker, placed in a good light on black glass or black glazed paper, must appear dark and free from opalescence when viewed from above. Any necessary mode of filtration...
Page 125 - The moisture in the air-dried powder is estimated and the quantity equal to 6.5 grm. actual dry hide powder is calculated, which will be practically constant if the powder be kept in an air-tight vessel. Any multiple of this quantity is taken according to the number of analyses to be made and wetted again with approximately 10 times its weight of distilled water.
Page 125 - This solution is added to the powder and the whole churned slowly for i hour. In laboratories where analyses are continually being made it is more convenient to use a 10% stock solution, made by dissolving 100 grm.
Page 122 - ... cm. deep in a beaker, placed in a good light on black glass or black glazed paper, must appear dark and free from opalescence when viewed from above. Any necessary mode of filtration may be employed, but if such filtration causes any appreciable loss when applied to a clear solution, a correction must be determined and applied as described in paragraph 6.
Page 126 - IX. All evaporation shall be rapidly conducted at steam temperature in shallow flat-bottomed basins of not less than 6.5 cm. diameter, to apparent dryness, and shall be subsequently dried between...
Page 126 - The analysis of used liquors and spent tans shall be made by the same methods as are employed for fresh tanning materials, the liquors or infusions being diluted, or concentrated by boiling in...
Page 123 - Liquid extracts shall be weighed in a basin or beaker and washed with boiling distilled water into a litre flask, filled up to the mark with boiling water, and well mixed and rapidly cooled to a temperature...