134 Chronicles of Science. [Jan., 



silica, some phosphorus and sulphur. The carbon is hardly at all 

 removed. The appearance of the iron after the process is that of 

 refined metal. The cost of the process is nil, as the iron contained 

 in the haematite is reduced, and adheres as cast-iron to the bottom 

 of the iron in the mould. There is no sand or coke-dust used, and 

 the refined iron goes clean into the puddling-furnace. The yield in 

 puddling is that of refined iron, about 21 cwt. to the ton of puddled 

 bars. The puddlers like to have one or two pigs of white iron 

 with the metal so refined, as they say it works more liquory, show- 

 ing that when the silicon remaining is only - 200 or 0*300 per cent, 

 the charge does not possess the necessary fluidity. The puddling 

 furnace keeps longer in repair, no other fettling is used than hammer- 

 slag, and the former allowance of shearings to make scrap-balls has 

 been discontinued. The men do more regular work, and, like the 

 refined iron, the yields are larger. The puddled iron is of an im- 

 proved quality, and much liked in the rail mills. A second process 

 is the same in every respect as the first, only that J-ths by weight, 

 and half by bulk, of nitrate of soda is mixed with the haematite ore, 

 which is formed into a paste and applied in the same way. With 

 this mixture the ebullition is greater, the flame is of a yellowish 

 colour, showing the ignition of some of the soda. The cinder is 

 thrown up and out of the iron, over which it forms a crust, which 

 can be separated when cold. The iron has a cellular and honey- 

 combed fracture, like metal much overblown. The scoriae contain 

 sulphur, phosphorus, silica, and soda. The iron works drier and 

 cleaner, and to a better yield than that made by the first process, 

 but should have about one-third of grey pig added to make a very 

 clean and tough iron. The only cost of the process is the nitrate 

 of soda, which in the proportion named comes to about 4s. a ton at 

 its present high price. 



11. PHYSICS. 



Light. — The Eev. Father Secchi has published an account of the 

 spectrum of the planet Neptune ; he first refers briefly to his former 

 observations of the spectrum exhibited by Uranus, and then states 

 that the spectrum of Neptune consists chiefly of three lines, or 

 bands, placed near the green line, and that its light is entirely 

 devoid of red ; this is confirmed by the colour exhibited by the 

 planet when seen through a telescope, which is a sea-green. 



M. Bontemps, the managing director of the celebrated crystal 

 glass works of Choisy-le-Eoi, states, in his observations on the 

 colouration of glass under the influence of direct sunlight, that 

 he was led to the following results : — Within three months after 



