276 ANNUAL OF SCIENTIFIC DISCOVERY. 



G10 err. from the hull gave -075 gr., and from the cabin -072 gr., a very slight 

 difference indeed. 



It will be observed that the amount of silver in the above specimens of 

 fresh metal is very high, and it is probable that most of these are merely 

 the re-rolling of masses of metal melted down from the old sheathing, and 

 have derived the greater part of their silver from the sea on former occasions. 

 It is well known that the copper used in the manufacture of yellow metal is 

 very pure, containing 2 or 3 dwts. of silver per ton, frequently not so much, 

 and silver is very seldom associated with the other constituent, zinc. 



To arrive at more certain results, Mr. Fhld has granulated some very 

 pure copper, and reserving a portion in glass, has suspended the remainder 

 (about ten ounces), in a wooden box perforated on all sides, a few feet under 

 the surface of the Pacific Ocean. When occasion offers, the box is towed by 

 a line at the stern of a vessel which is trading up and down the coast of 

 Chili. The result of this experiment, when obtained, is to be forwarded to 

 the London Chemical Society. 



M. Piesse, of London, as the result of experiment, ascribes the beautiful 

 blue color of the Mediterranean Sea to an ammoneacal salt of copper, and 

 the greenness of other seas to chloride of copper. His experiments were 

 performed between the ports of Marseilles, on the French Mediterranean 

 coast, and Nice, in Sardinia. A bag of nails and scrap-iron was suspended 

 at the side of the steamer which plies between these places, and af;cr the first 

 voyage (about twelve hours), copper was indicated to be present on the iron. 

 Four separate voyages, however, were made before the bag of iron was 

 removed to the laboratory ; then the quantity of copper was found to be so 

 great that much surprise was shown that the presence of this metal had not 

 been previously discovered, especially when the action of sea-water on 

 ship's bottoms has long been known. 



ON SOME PHENOMENA IN CONNECTION WITH MOLTEN SUBSTANCES. 



Mr. J. Kasmyth, in introducing a paper on the above subject, to the atten- 

 tion of the British Association, stated that his object in so doing was to direct 

 the attention of scientific men to a class of phenomena which although in 

 their main features may be familiar to practical men, yet appeared to have 

 escaped the attention of those who were more engaged in scientific re- 

 search. The great fact which he desired to call attention to is comprised iu 

 the following general proposition, namely, that all substances in a molten 

 condition are specifically heavier than the same substances in an unmoltcn 

 state. Hitherto water has been supposed to be a singular and special excep- 

 tion to the ordinary law, namely, that as substances were elevated in 

 temperature they became specifically lighter, that is to say, water at temper- 

 ature 32 dcg., on being heated, docs, on its progress towards temperature 

 40 deg., become more dense and specifically heavier until it reaches 40 dcg., 

 after which, if we continue to elevate the temperature, its density progres- 

 sively decreases. From the facts which Mr. Nasmyth brought forward, it 

 appears that water is not a special and singular exception in this respect, but 



