212 THE SCIENTIFIC PAPERS OF 



" cold-short," or brittle at ordinary temperatures. It is owing to 

 the presence of these impurities in nearly all British irons, that 

 the highest qualities of tool steel are still made entirely from 

 Swedish or other charcoal-iron of high quality, produced from the 

 purest ores. If phosphorus exists in steel in quantities exceeding 

 O'l per cent., its presence is indicated on breaking the sample, by 

 peculiarly bright and distinct faces of crystallisation on the fractured 

 surface, but the steel admits of being forged and welded, and 

 though somewhat brittle when cold, it is remarkable for hardness. 

 It would, therefore, not be safe to maintain that phosphorus in 

 small quantities is objectionable in steel under all circumstances. 

 Steel containing above 0'2 per cent, of sulphur breaks under the 

 hammer at a low red heat, and is, therefore, only applicable to the 

 production of steel castings : for this purpose the presence of a 

 small amount of sulphur is unquestionably a positive advantage, 

 imparting increased fluidity to the molten metal and toughness 

 to the casting when cold. This effect is so well understood in 

 Sweden as regards cast-iron, that in casting ordnance sulphur 

 is added to the metal. 



MANGANESE. Manganese possesses the remarkable property of 

 counteracting to a great extent the effect of sulphur (or red- 

 shortness) in steel. Its application for this purpose is due to 

 Josiah Marshall Heath (1839), and must be classed among, the 

 most important discoveries in modern times ; for it is only in 

 consequence of the addition of manganese (in the form of oxide, 

 mixed with carbon) to the steel melted in pots, that the Sheffield 

 melters have been enabled to use English puddled iron for the 

 commoner qualities of steel in place of the purer and more costly 

 Swedish iron ; and again it is only in consequence of the addition 

 (by Mushet) of manganese in the form of ferro-manganese or 

 spwgeleisen to the liquid bath produced in the Bessemer converter 

 that the better qualities of English pig-iron have been made avail- 

 able for the production of malleable Bessemer metal. It is dis- 

 tressing to think that the author of this invaluable discovery was 

 deprived of the fruits of his labour by an unjust combination 

 among the manufacturers chiefly benefited by him, who contested 

 the validity of Heath's patents upon trivial grounds, relying for 

 their success upon their financial power to crush his unquestion- 

 able claims. The specific chemical action of manganese has never 



