MKTAI.S. 



ty of fine iron-ores, either raw or pre- 

 : -in tin- proportimi of oao cwt. of ore to 



,-\\t. iif nn-t.-il may In- added (luring the 



-. It i- claimed that iron thus treated 

 will puddle into wrought <>r malleaMe iron in 



mo than is usually consumed in puddling, 

 with a sasiiig of fuel. The fluxes M-parate from 

 |g iron tin; deleterious ingredients, such as 

 sulphur, silica, phosphorus, and arseim-, an<l 

 th-' pniportioii of tluxes must be regulated 

 according to the impurities in the iron. 



nxitiii of Cast Iron. A series of experi- 

 ments instituted byF. Grace Calvert,of Manches- 



ul.uid. have established the fact that cost 

 iron, under eertain conditions, undergoes a loss 

 of st reii^rt li or cohesion without a corresponding 

 change- of volume or size. The phenomenon 

 ditl'ers from superficial rusting; it affects the 

 whole body of the iron. Cast-iron cubes, each 

 one centimetre in dimension, were immersed 

 by him in faintly acidulated water, and, after 

 three months of this exposure,. the cubes were 

 found to be so soft externally, that a knife- 

 hlado could penetrate them three or four milli- 

 metres deep. Dilute acetic acid accomplished 

 this iv.-ult better than either sulphuric or hy- 

 drochloric acid. The longer the exposure, the 

 more thorough was the rotteuing of the iron. 

 At the end of several years it was found that 

 the pure iron in the cuhe, immersed in acetic 

 acid, had decreased from 95.413 to 79.960, the 

 phosphorus from 0.132 to 0.059, the sulphur 

 from 0.179 to 0.096, while the amount of 

 carbon had increased from 2.90 to 11.07, the 

 nitrogen from 0.79 to 2.59, the silicon from 

 0.478 to 0.607. Poor iron, exposed to the action 

 of sea-water, is gradually deteriorated, though 

 much more slowly than in the experiments 

 mentioned. Mr. Calvert's researches confirm 

 those previously made by Mallet, showing that 

 the corrosion of cast iron depends upon its want 

 of homogcneousness of surface, density, or hard- 

 ness, or the imperfect combination of the carbon 

 with the iron. Good white iron is said to 

 rc-i-: corro-ion better than any other variety. 



Manufacture of Steel. Some improvements 

 in preparing cast steel have been proposed by 

 M. Victor Gallet, of France. He takes iron 

 which has been submitted to one rolling opera- 

 tion only, and coats it with a paste made by 

 mixing water with the following ingredients: 

 Limestone (carbonate of lime), 37 parts; vege- 

 table mould or clay, 13 parts; carbonate of 

 potash, 10 to 20 parts; oxide of manganese, 

 8 parts; iv-in, 3 parts; soot, 10 parts; wood 

 charcoal, 40 parts; common salt, 1 to 3 parts. 

 The iron coated with this composition is melted 

 in a crucible, and the result is cast steel. In 

 order to prepare steel by cementation, the same 

 composition is employed in a dry state, and the 

 M is then conducted as usually practised 

 in cementation. The (piantity of cement neces- 

 sary to coat the iron varies from two to seven 

 per cent, .if the weight of the iron. The re- 

 action of the substances is supposed by the 

 inventor to be about as follows : Electric cur- 



nut-; complete reduction of the manganese 

 with tin- sti-rl; the reduction of injurious ruat- 

 ,iid of the alkaline metals with the 'ab- 

 S'lrln-nts and metalloids; the disengagement and 

 elimination of azotic gases, since calcined pot- 

 ash, reduced in the pn-eiico of steel and char- 

 coal at a given moment, coml/mes with ni- 

 i to form cyanides of potassium and of 

 calcium. 



Analysis of Blister Steel. David Forbes 

 contributes to the Chemical News (Vol. XVI., 

 No. 404) an account of an analysis of blister 

 steel, converted in Sheffield from bar-iron of 

 Swedish manufacture. The determinations 

 seem to have been made with the utmost care, 

 and resulted as follows : 



Carbon combined 0.627 



Carbon graphitic 0.102 



Silicon 0.080 



Phosphorus 0.000 



Sulphur 0.005 



Manganese 0.120 



Iron... 99.116 



100.000 



Native Hydrate of Iron. An analysis of the 

 ferric hydrate, known as limonite, obtained at 

 the iron mines of Salisbury, Conn., has showed 

 it to be an oxide of iron containing not far 

 from five per cent, of water a number of speci- 

 mens yielding very uniform results and a com- 

 plete analysis proved the mineral to be a ferric 

 hydrate with the formula Fe a H, identical with 

 the turgite of Hermann, and with Breithanpt's 

 hydro-Jiematite, as analyzed by Fritzsche. The 

 physical characters are so nearly those of ordi- 

 nary anhydrous hematite that it is difficult to 

 distinguish the species without having recourse 

 to an estimation of the loss on ignition. The 

 turgite yields an abundance of water when 

 heated in the closed tube, and it decrepitates 

 in a remarkable manner. Hardness, about 5.5. 

 G. = 4.14. For analysis the mineral was care- 

 fully dried over sulphuric acid until of constant 

 weight, and this desiccated mineral was then 

 heated for several hours in an air-bath of 100 

 0., without showing any further diminution of 

 weight. The amount of hygroscopic moisture 

 abstracted from the air- dried mineral, by treat- 

 ment in the desiccator, was 1.40 per cent. 



The analytical results are thus stated: 



Other determinations of water on different 

 specimens gave 5.02 and 5.09 per cent (Amer- 

 ican Journal of Science, September.) 



Ti/nystcn Steel ly Bessemer 1 * Process. Cap- 

 tain J. Le Guer has recently made experimenst 



