ON dlLY HIDROGEN. QQ 



On the Difoxidation of Iron. 



The fimpleft truths of chemiftry are not always thofe which The , <i m P left 

 ' J J truths of che- 



are the molt eafily mown in public teaching. For example, m ]({ T y notal- 



nothing can be more evident to the mod numerous auditory ws »ys eafy to be 

 ., L . ,. . . , . •"'•»*.-•*■ manifefted in a 



than that, m the tube experiment, the iron carries with it an i e a ure , 



overcharge of oxigen, becaufe every one of the fpeclators can 

 fatisfy him felf by his eyes, and acquire an abfolute conviction 

 of that which is intended to be mown ; but when amidft the Instance. Dif- 

 connexion of ideas and proofs, we come to thofe which relate oxidationofiron 

 to the difoxidation of this metal, we mull quit facls and re- 

 place them by fuppoiitions, becaufe it is not poffible to exe- 

 cute them with facility in public. In fadt, it is impoffible 

 either to apply a degree of heat in a few inflants to the oxide 

 of iron, fumcient to deoxidate it, nor can it even be eafily 

 reduced by melting. But by the following procefs this diffi- 

 culty is partly overcome. 



Heat for an hour a mixture of one ounce of iron ore of Eafy procefs for 

 Eiba, and two gros of charcoal, in a fmall coated glafs retort, < his 'deoxidatioa 

 at the bottom of which the clay has been left of the thicknefs . re * h t , 

 of two inches. Place it immediately on the grate of the fur- in a glafs retort 

 nace, and its neck will then projeft from the furnace by the wich chaicoal * 

 door of the fire-place. Clofe it with fragments of bricks and 

 earth, which will keep the retort in its fituation. If the neck 

 be not long enough to reach into the pneumatic-trough, which 

 ,in this cafe ought to be a fallad-difti or a foup-plate covered 

 with a plate of lead perforated, add to it another which muft 

 be luted with paper and ftarch. 



Having done this, cover with the ufual precautions > the 

 grate and the retort with charcoal. It receives from this dif- 

 pofition a much more intenfe heat than if it had been placed 

 on the bars. The carbonic acid and carbonated oxide are 

 then obtained with the greateft facility. 



When the retort is cold, its belly will be found to be nearly State of the 

 filled with pure iron of a fpongy appearance^ which acquires reducediroa * 

 the metallic brilliancy by friction with any polifhed fubftance. 

 This mafs is broken with difficulty, and notwithstanding the 

 feparation of its parts, they will be all found to be foldered 

 together. On heating it dexteroufly by the blow-pipe, it burns 

 with fparkling. The magnet attracts the whole of it. Part 

 of it may be ufed to give hidrogen with fulphuric acid, in 



H 2 fhort 



