4 AMERICAN ARCHEOLOGY. 



geneous throughout; while in others there are layers of clay, 

 mould, sand, and stone, varying in thickness and mode of distri- 

 bution. By sinking a shaft from the centre of the apex, or by 

 cutting a ditch on a level with the ground, from the circumference 

 toward the centre, the structure will be revealed. 



6. Contents. — The contents of earthworks and other ancient 

 structures vary with the purpose which they were designed to sub- 

 serve, with the locality, and, in the case of burial mounds, with the 

 social standing of those interred within them. The greatest diver- 

 sity of contents is found in the mounds of the Mississippi Valley, 

 which, indeed, have been named burial, sacrificial, domiciliary, and 

 defensive mounds, according to the end which they seem to have 

 served. The most desirable objects among the contents of these 

 mounds and other earthworks are the human remains. In order to 

 preserve the crania and bones, as well as bone implements or other 

 friable objects, they should be covered with boiled oil, or with a 

 weak solution of warm white glue. When this has dried sufiiciently, 

 the process may be repeated until the tissue is completely hardened. 

 Small fragments may be immersed in the liquid at once. Where 

 it is practicable to save crania and other fragile objects entire, the 

 glue may be applied before they are removed from the earth. Dr. 

 Otis, of the Army Medical Museum, has succeeded in taking out a 

 block of earth containing the skull, and by repeated washings and 

 application of the glue has saved some very frail specimens. The 

 Societe d'Anthropologie de Paris has issued two pamphlets of in- 

 structions, indispensable to collectors of human remains, viz., " In- 

 structions Craniologiques et Craniometriques " and " Instructions 

 Gfinerales pour les recherches Anthropologiques." With regard to 

 the nucleus and to aboriginal relics contained therein, the explorer 

 should examine every object in the position where first discovered, 

 with reference to the original level of the ground, to the structure 

 of the tumulus, and to the objects buried with it. He should dis- 

 regard no object however insignificant it may seem, and record 



