126 DEPOSITS OF PHOSPHATE OF LIME. [bull. 46. 
[V. Analysis of Aves guano, by Volcker.} 
Water - 2.39 
Organic matter and water of combination 7. 93 
Lime 39.48 
Magnesia 1. 17 
Phosphoric acid 41. 34 
Sulphuric acid 4.57 
Insoluble siliceous matter 2. 28 
99. 16 
Containing nitrogen 0. 139 
[VI. Analyses of Navassa phosphate.] 
Bret- 
Gilbert. Schneider. 
Water 3.01 3.54 
Organic matter and water of combination 7.17 4.64 
Lime 40.19 38.35 
Magnesia 1.72 
Sequioxideof iron ) 3.40 
Alumina S 6.50 
Potash 0.34 
Soda 0.32 
Phosphoric acid 33.28 35.60 
Sulphuric acid 0. 19 
Chlorine 0.08 
Carbonic acid 2.15 2.58 
Silica 1.34 
Sand 2.53 1.31 
100. 00 99. 91 
[VII. Analysis of Kaza Island phosphate, by Dr. H. Gilbert. 1 
Water 1.92 
Neutral phosphate of lime 58. 78 
Bone phosphate of lime 18. 86 
Tribasic phosphate of magnesia 3. 32 
Sulphate of lime _ 8. 26 
Oxide of iron 0. 99 
Silicic acid 3. 38 
Organic matter 4. 81 
100. 32 
BONE BEDS. 
These deposits include beds which are composed largely of bones. 1 
They occur principally as cave and lacustrine deposits. 
CAVE DEPOSITS. 
Caverns have always been the places of refuge and the sepulchers uf 
many kinds of animals, and sometimes bones have collected in them in 
sufficient quantities to form beds many feet thick. Such deposits are 
x The phosphate beds of South Carolina and other similar deposits do not belong 
under this heading, for, though many bones occur in them, they are few compared 
with the accompanying phosphatic nodules. 
(600) 
