STRUCTURE AND NATURE OF TROOSTITE 



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Fig. 5 — Mag. 3500X. Fig. 5 is of a small but well developed nodule showing 

 four fan-shaped grains about a nucleus of growth. Some excess constituent has 

 appeared but only the very early stages in the process of stratification to pearlite 

 are visible. It is apparent, however, that the nodule is not composed of a solid so- 

 lution. The nodule is about eight ten-thousandths of an inch in diameter. 



