An Index to the chemical patents issued by the United States Patent Office during the year 1852. Prepared for the SCIENTIFIC AMERICAN by Dr. D. Breed, solicitor of patents, Washington, D. C. Continued from the SCIENTIFIC AMERICAN of November 21, 1857 : Archil—Prepared by treating lichen roccel-lus with volatile alkali, urine and lime water, in certain proportions: Leon Garosson, June 15, 1852. Acid—Sulphuric ; concentrating of, in leaden vessels to GQ Baume, at a temperature below the boiling point: Carl Hinrichs, September 7. Baryta and Strontia—Production of sulphur and sulphuric acid from sulphuretted hydrogen evolved in process of manufacturing carbonates : Charles Lennig, March 16. Beer—Concentrated material for ; gum, starch, sugar, c. from evaporated infusion of grain : Franz G. Rietsch, February 3. Beer—Use of corn boiled to a jelly, into which malt or rye is then mashed : Frederick Seits, January 20. Butter—Preserved by use of iodide of potash : Louis De Corn, August 3, Cement—Hydrate of lime and pulverized resin mixed with cold water : B. S. Welsh, May 18. Enamel—For brick and iron; mixture of glass, lime, (hydrate or sulphate,) salt, oxyd of iron and water : Dunn and Howes, September 7. Gutta Percha—Heating to 285 to 430 Fah., then vulcanizing by a hyposulphite alone, or with metallic sulphurets, whiting or magnesia : John Rider, June 1. Gas—Refrigerated b y air. Apparatus : Robert Foulis, October 12. Gas—Feeding into heated retort, charged with tituminous coal, either oil, coal tar, resin, asphaltum, or other bituminous or carbonaceous matter, in a fluid state, separately or mixed : Henry W. Adams, August 10. Gas—Use of mixture of wood and fat for generating: Danre, Nichols and Lopez, December 8. France, September 27, 1851. 'India Rubber—Juice or milk of tree treated with common salt, to preserve : F. Bronner, September 7. Iron and Steel—Use of calcined borax and carbonate of ammonia in welding; certain proportions : Boyd C. Leavitt, July 27. Ivory—Placed at certain angle to bleach in sunlight: Ulysses Pratt, January 6. Antedated'July 6, 1851. Oil—Obtaining paraffine and paraffine oil from bituminous coal: James Young, March 23. England, October 7, 1850. Oil—Mixture of camphene, benzole, carbonate of potash and glycerine with whale oil: William H. Mason, May 25. Paints—Treatment of magnesian minerals with mineral acids, for preparing pigments : Heman S. Lucas, November 23. Paint—Watery solution of sulphate mixed with oil paints: Washington F. Davis, August 17. Powder—For blasting; chlorate of potash and prussiate of potash: Edward Callow, February 17. England, August 6, 1850. Soap—Use of ammonia (or carbonate ammonia) with kaolin, or other aluminous earth ; composition of: William McCord, July 27. Soda—Chromate ; from ore heated with salt, chloride of potash, or hydrate of lime; jet of steam to expel iron as sesque-chloride; then treat with muriatic acid : John Swindells, December 21. England, November 14, 1850. Soda—Carbonate; sulphate, heated with carbonaceous-.-materials, and treated with water, carbonic acid, evaporation, c.: Henry Pemberton, October 19. Sugar—Use of aluminate of lime with phosphate of alumina, or of lime and phosphoric acid, for clarifying: Oxland and Oxland, July 6. England, May 15, 1851. Zinc—Metallic; impalpable powder prepared by cooling agency of steam : Henry W. Adams, July 28.