and urates of ammonia, lime, and magnesia. Exterior por- tion, phospb. of lime and triple phosphate. Friable. 11''' by 9'''.
2604. Spheroidal. Skeleton made up of ox. of lime, and there are found interspersed ur. ac. and ur. of lime, and phosph. of lime, with triple phosph. The latter two form the soft exterior. Original length, 1" 6 W , and breadth 1'' 2'''.
2605. Oblong, oval, rugged stone. Composed of alternate layers of ur. ac., urates of ammonia, lime, and soda, and ox. of lime. Phosph. of lime also intermixed. Exterior shows signs of deep chemical erosion. 2'' by 1'' 4''' .
2606. Oval, compact. Pinkish tinge in places. Ox. of lime, and ur. ac., and urates of ammonia and lime. Between the loosely joined laminae is phosph. of lime. Exterior quite dark, in part of an olive tint and scaling. 1'' 8''' by 1'' 3'''.
2607. Oblong ; very irregular. Central portion, ox. of lime, ur. ac. and ur. of ammonia. About this is a deposit of phosphate of lime and triple phosphate. 2''' 3''' by 1'' 3'''.
2608. Section of a large calculus from the human subject. No history of the case. Analysis and description by Dr. J. C. White : " Large, irregularly pyriform ; originally oval, but changed in shape by the subsequent deposition near one end of an amorphous mass, which finally was covered in by the general layers. Nucleus and body composed of a mixture of ur. of ammonia, ox. of lime, triple phosph. of ammonia and magnesia, and carb. and phosph. of lime. A narrow ring of ox. of lime separates the large unstrati- fied nucleus from the outer layers. Externally, except a portion of the smaller end, the surface is covered by a de- posit of large, white, rounded, prismatic crystals, resem- bling somewhat those of ox. of lime occasionally found in the same situation, but softer and efflorescent. Color of exposed and cut surfaces, pale, brownish-yellow. Strati- fication not very compact." Length of section, 2'' 9''' ; breadth, 2''. 1860.
Dr. T. H. Gibby, of Nashua, N. H.
