272 Davenport—Chemical Investigation on some 
too hard to be cut by a drill; after the first annealing an inter- 
esting change showed itself in the fracture; a whitish surface 
extended in about ,; of an inch on all sides, surrounding a 
dark core of dull black color; the line of change from the light 
to the dark was quite distinct, and the whole was easily cut by 
a drill. A portion of this white outside layer was filed off and 
the carbon determined to be present only in traces, while 
analyses II. and V. show the presence of a considerable amount 
of carbon, when a sample of the entire cross section was taken. 
The black core was noticeably smaller in the case of casting 
No. 2 than in casting No. 1, which accounts for the small 
amount of total carbon in analysis V. After the second anneal- 
events only a reduced, that which remains is by the 
an — slow cooling changed in its state of 
he tas carbon; for where the iron before annealing is white 
and very hard, after annealing it shows.a dark fracture and 18 
technically called, gave a dirty green color to the solution and 
ess of the iron owing to the p 
amount of silicon, phosphorus or sulphur; but it also must 
