CHEMICAL SCIENCE. 



225 



analyzing a specimen of copper to which, when in a state of fusion, 

 some phosphorus had been added, it was found that it contained a con- 

 siderable quantity of phosphorus, and also a large portion of iron de- 

 derived from an iron rod employed in stirring the mixture at each 

 addition of the phosphorus. The copper employed was of the " best 

 selected " ; it appeared to be harder than copper treated with arsenic. 

 The details of the analysis of 116.76 grains gave this result: phos- 

 phorus, 0.93 ; iron, 1.99. A second analysis gave ; copper, 95.72 ; 

 iron, 2.41 ; phosphorus, 2.41 ; total, 100.54. It has long been stated 

 that a very small quantity of phosphorus renders copper extremely 

 hard, but such an alloy as that formed by Dr. Percy had not been 

 previously formed. It is a remarkable fact, that the presence of so 

 large a quantity of phosphorus and iron should so little affect the 

 tenacity and malleability of the copper. 



In remarking on this paper, Capt. James said that the rapidity with 

 which copper sheathing sometimes decays is surprising ; sometimes 

 it decays completely in five months, and, on the other hand, some of 

 the old copper has lasted for forty years. To determine the cause of 

 this difference he had made a series of experiments on all the copper 

 used at the dock-yard at Woolwich. By steeping these different cop- 

 pers in salt water for nine months, a series of actions set in, which, by 

 subsequent weighing, were accurately determined. The following 

 table exhibits the results of these experiments : 



Loss per sq. Loss per sq. 



in. Grains. in. Grains. 



1.40 Dock-yard copper, No. 1 , 1.66 



1.10 " " " 2, 3.00 



" " " 3, 2.48 



" " 4, 2.33 



Electrotype copper, 

 Selected copper, 

 Copper containing phos- 

 phorus, 



Muntz's metal, . . . 



0.00 

 0.95 



a 



It may be well to add, that the specimens were wholly immersed in 

 the water. 



DIFFERENT CHEMICAL CONDITIONS OF THE WATER AT THE SUR- 

 FACE OF THE OCEAN, AND AT THE BOTTOM, ON SOUNDINGS. 



DR. A. A. HAYES, of Boston, has for some years been engaged in 

 making chemical observations on sea-water, and has now collected 

 evidence from different sources, sufficient to convince him that in gen- 

 eral the chemical agencies exerted at the surface of the ocean are the 

 opposite of those observed in operation at the bottom, on soundings. 

 The method pursued has been that of carefully analyzing the results 

 of corrosions of metals at the surface and at the bottom, as produced 

 after exposures of months and years. It has been thus proved, that 

 the oxygen dissolved from the air and other sources at the surface 

 gives rise to corrosions which are generally oxides, sometimes oxides 

 and chlorides. At the bottom, however, in depths less than 80 feet, 

 or perhaps at much greater depths, a uniformity of effect has been 

 observed, resulting in the production of sulphurets of the metals. 



One interesting instance is thus stated. The Spanish ship San 



