152 Royal Society : — 



2. When the bars, thus charged, lay on the plane transverse to 

 the dip, they lost about one-fifth of their magnetism in one or two 

 days, and lost very little afterwards. 



3. When the charge of magnetism is smaller than the maximum, 

 the diminution in a day or two is nearly in the same proportion as 

 for the maximum. 



4. The effect of violence on the bars, when lying on the plane 

 transverse to the dip, is not in all cases to destroy the magnetism 

 completely, sometimes it increases the magnetism. 



o. The Cold-Rolled Iron receives (under similar violence) or parts 

 with (under similar violence) a greater amount of magnetism than 

 the Hot-Rolled Iron, in the proportion of 6 to 5. 



6. There is some reason to think that the Hot-Rolled Iron has a 

 greater tendency to retain its primitive magnetism than the Cold- 

 Rolled Iron has. 



7. There is some reason to think that, when lying tranquil, the 

 Hot-Rolled Iron loses a larger portion of its magnetism than the 

 Cold-Rolled Iron loses in the same time. 



" On the Analvtical Theory of the Conic." By Arthur Cayle}', 

 Esq., F.R.S. 



May 22. — Major-General Sabine, President, in the Chair. 



The following communication was read : — 



" On the Constitution of Sea-water, at different Depths, and in 

 different Latitudes." By George Forchhammer, Ph.D., Professor 

 of Mineralogy in the University of Copenhagen. 



Professor Forchhammer was present at the Meeting, and, by request 

 of the President, gave a statement of the principal results of his re- 

 searches. He first, how r ever, took occasion to express his great 

 satisfaction in being allowed the opportunity of personally and grate- 

 fully acknowledging the liberality with which men of science in this 

 country had entered into his views and supplied him with specimens 

 requisite for carrying on his inquiries ; and he particularly mentioned 

 the name of a late distinguished Fellow of this Society, Sir James 

 Clark Ross, who had kindly furnished various samples of sea- water 

 procured in his Antarctic voyage. 



The number of elements hitherto found in sea-water the author 

 stated to be thirty-one, viz. Oxygen, Hydrogen, Azote in ammonia, 

 Carbon in carbonic acid, Chlorine, Bromine, Iodine in fuci, Fluorine 

 in combination w T ith calcium, Sidphur as sulphuric acid, Phosphorus 

 as phosphoric acid, Silicium as silica, Boron as boracic acid, discovered 

 bv the author both in sea-water and in sea- weeds, Silver in the Po- 

 cillopora alcicomis, Copper very frequent both in animals and plants 

 of the sea, Lead very frequent in marine organisms, Zinc principally 

 in sea-plants, Cobalt and Nickel in sea-plants, Iron, Manganese, Alu- 

 minium, Magnesium, Calcium, Strontium and Barium, the latter two 

 as sulphates in fucoid plants, Sodium, Potassium. These twenty- 

 seven elements the author himself had ascertained to occur in sea- 

 water ; the presence of the next four elements, viz. Lithium, Ccesium, 

 Itubidium, and Arsenic > has been shown by other chemists. 



