300 



Miscellaneous Intelligence. 



The organic matter was partly soluble in hydrochloric acid, and partly 

 in potash. A cursory examination of it seemed to indicate that it con u 

 sisted chiefly of humus and the acids of the crenic group. 



From this analysis I thought myself justified in announcing that the 

 lime and magnesia in the compound under consideration are combined 

 with the phosphoric acid so as to form a tribasic salt, in which one atom 

 of water substitutes one atom of alkaline earth, according to the formula 

 2MO, HO, POs. A subsequent examination and recalculation of my re- 

 sults has convinced me that the announcement was somewhat premature, 

 and that the analysis would not fully bear the construction put upon it. 

 I have, however, never changed the opinion then advanced, as the dis- 

 crepancies are slight and easily accounted for. 



The statement of my views led to further investigation. Among oth- 

 ers, Dr. Campbell Morflt examined the substance, and came to a different 

 conclusion from that at which I had arrived. Drs. Higgins and Bickell y 

 Chief and Assistant State Chemists of Maryland, shortly after published 

 a paper in which they agreed with me in the main. Their analysis was 

 more elaborate than mine, and comprised two distinct examinations; one 

 of the white, polished crust, the other of the body of the rock. Without 

 going into minutiae, I will simply state that they found the exterior layer 

 to contain phosphates of lime and magnesia, of the formula 3 MO POs, 

 while, in the body of the rock, the salts were composed, as I had previ- 

 ously announce 1. They also ascertained that in the outer layer the sul- 

 phuric acid was combined with soda, while in the body of the rock it was 

 united to lime. 



6. On the Monks Island Guano ; by Dr. A. A. Hayes (Proc. Boston 

 Soc. Nat. Hist., v, 349). — Dr. Hayes first describes the general characters 

 of the hardened guano, mentioning its rounded nodular surface, its hard- 

 ness as above that of fluor, and its specific gravity as averaging 2*440. 

 He states that the arenaceous variety consists of grains about as large 

 as mustard seed, and that this granular structure is entirely lost as it 

 passes into the solidified guano, which forms a crust or layer over it. 

 The two kinds differ not very much in composition. After giving the 

 results of analyses and pointing out the existence of a very large per- 

 centage of bone, phosphate of lime, and magnesia, he argues that the 

 guano has been formed mainly from fish-bones. With regard to the 

 change in consolidation he observes. 



" Recurring to the composition of guano-rock, we see that the propor- 

 tion of organic salts and other organic matter, is much larger than exists 

 in the guano from which it is derived. The physical characters of the 

 rock are modified by the presence of these compounds, but the most re- 

 markable change is that from a granular to a compact solid. This 

 change could be effected by infiltration, as takes place from calcareous 

 waters ; but as the rock guano is above the mass producing the soluble 

 organic salts, it is necessary to consider another condition. 



" When water holding saline matter in solution evaporates from the 

 surface of the earth, pure water alone escapes, while the saline and col- 

 ored organic compounds remain at or near the surface. In accordance 

 with this law, the saline matters which can be dissolved, and the colored 

 matters which can be suspended, in water, rise to the surface, and so 

 long as capillarity can act, they are deposited in the porous parts, grad- 



