(_b_) _Crust._ Portion Chloride of Silver 19·98 soluble in Protoxide of Copper } ammonia-water. (Black Oxide) } 0·56 Chlorine 0·15 Copper 0·13 Sulphuric Acid traces Carbonic Acid } Water } 1·15 ------ 21·97 (_c_) _Crust._ Portion Gold 0·05 insoluble in Silver 1·36 ammonia-water. Protoxide of Copper } (Black Oxide) } 0·09 Carbonate of Lime 1·36 Silica } Peroxide of Iron } 0·30 Alumina } ------ 3·16 ----- 99·79 ----- The composition per cent. of the metal, exclusive of the crust, as calculated from the above analysis, is given underneath; but it certainly cannot be inferred that the original metal had the exact composition shown in that analysis, because some of the ingredients may not have been carried away during corrosion in the same relative proportions in which they were present in the original alloy. COMPOSITION PER CENT. Silver 95·59 Gold 0·30 Copper 3·23 Lead 0·44 Iron 0·12 ----- 99·68 ----- A portion of the crust when heated in a glass tube gave off water, and the glass was stained yellow. A portion of the crust treated with dilute hydrochloric acid effervesced, the acid became pale blue, and was found to contain copper and lime. The crust was examined under the microscope, but no trace of crystalline structure could be detected. A qualitative examination was made of a portion of the inner crust, from which it appeared that its composition was similar to that of the outer crust. * * * * * IV.--PORTION OF A BRONZE SWORD. (No. 546.) The weight of the specimen, inclusive of the incrustation, was 585 grains; it was about 1½ inch in length, and varied from about 5-8ths to 7-8ths of an inch in thickness. A sketch of a section of the specimen is annexed. [Illustration: No. 546. Piece of a Bronze Sword. Sepulchre IV. Dimensions stated in fractions of an inch.] The whole of the specimen was coated with an irregular layer or layers of matter, varying in chemical and physical characters and in thickness. In the centre, where the crust was removed, the solid metal varied from about 4-8ths to 5-8ths of an inch in thickness. [Sidenote: DR. PERCY'S ANALYSIS.]