. Journal. mperatureof formation over a very wide range of temperature :in the other class of cases there was no freezing point at all,nor even a long range of solidification, because the singset as a viscous fluid or glass and did not solidifvin the ordinary sense at all. In these latter eases, thetrue freezing point could be found by resorting to veryslow cooling, possibly aided by inoculation of suitable?crystals. That ordinary slags, by slow cooling, or even [repeated heating and cooling, could undergo changes of the nature of crystallisation coidd be well observed in thepuddling cinder en
. Journal. mperatureof formation over a very wide range of temperature :in the other class of cases there was no freezing point at all,nor even a long range of solidification, because the singset as a viscous fluid or glass and did not solidifvin the ordinary sense at all. In these latter eases, thetrue freezing point could be found by resorting to veryslow cooling, possibly aided by inoculation of suitable?crystals. That ordinary slags, by slow cooling, or even [repeated heating and cooling, could undergo changes of the nature of crystallisation coidd be well observed in thepuddling cinder enclosed in ordinary wrought these slag enclosures appeared practicallystructureless under the microscope ; but recently, whileexamining a specimen of wrought iron which had beenused as a furnace tool and thus repeatedlv heated andcooled, Mrs. Rosenhain had foimd slag enclosures whichshowed a marked dendritic crystallisation, illustrated inthe accompanying photomicrograph, magnified 100 times ;. this was undoubtedly a fine example of crystallisation in aslag at temperatures far below its melting Turners contention that what was wanted wasthe knowledge of the temperature required to producea given degree of fluidity in a slag, recalled some experi-ments which had been published within the last two years,upon the melting points of certain glasses; theglasses were used in the form of rods, and drops wereallowed to form and drop off on exposure to known tem-peratures ; this recalled the German definition of a liquidas tropfbar fliissig, and apparently the temperature atwhich drops could form was a definite function of thesubstance used, aud did not vary with the size of rod, & some such method might lead to definite resultsin the case of slags. Mr. 0. F. Hudson said that although the cooling termwas a matter of very great interest, he did not see howthey could expect to get any very definite or startlingresidts from slag, because slag consi
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectchemist, bookyear1882
