A discovery in the same mounds which interests scientific men even more than this, or than anything else has done for a long time, is the finding in these mounds of quantities of meteoric iron. It was said by Hildreth ("Archaeologia Americana," i., 1820, page 163) that traces of iron-work had been found in a mound at Marietta, Ohio; but a re-examination of the specimens preserved at Worcester showed that they were of oxidized copper. The present discovery was therefore the first of its kind, and excited so much interest that chemists and mineralogists have been called into council with the archaeologists on the subject. This is the only kind of crude iron that is malleable; and that the people who built the mounds, or any other of the native races of the United States, had any knowledge of working iron-ore, yet remains to be shown. Some of the iron was in its original shape,--unworked nodules; a part in solid bars, etc.; but much of it had been treated like silver,--that is, hammered into sheets and used in thin plates as an ornamental covering for ear-rings and pendants. The mixture of nickel in this meteoric iron has not only preserved it, but caused a polished surface to gleam white, as though plated with silver, while tarnishing less easily than that metal. No doubt it was among the most highly prized of all the treasures of those old days, and nothing more precious than this could have been offered as a sacrifice, when, with lavish hand, pearls and silver and gold, weapons and tools, household furniture and products of the chase and the farm, were heaped upon the funeral pyre or contributed to the sacrificial flame. In materials illustrating the life and crafts of the Indians during the last century and at present, this museum is not yet so well supplied as some others,--that at Washington, for example, which has been constituted the depository for the collections of scores of government expeditions into the West and North. Nevertheless, some things of great value and completeness in this way are already owned. Thus, in the South American room may be seen a series of specimens illustrating the whole operation of pottery-making among the Caribs of British Guiana. This was obtained several years ago by Professor H. A. Ward, who bought the entire stock of materials of a woman of that tribe whom he found at work. These consisted of a mass of clay ready for the potter, a number of vessels ready for the fire, others which had been burned, and several ornamented in colors. The gourd scrapers of several shapes, with which she smoothed the vessels, small, smooth stones used in polishing the raw colors, and other appurtenances, are included, together with toy vessels which the woman hastily pinched into shape and gave to her children as playthings to amuse them while she worked, the forms of which help to explain many similar articles found in ancient graves.