AuG. 19, 1923 MOREY: MELTING-POINT DETERMINATIONS 327 
a series of quenches and of heating-curves were run on a sample of 
sodium metasilicate containing a slight excess of SiOo, analysis giving 
a ratio of SiO. to Na,O of 1.007. Heating curves were made with a 
nn 
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BV 
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800 23498 ps) ESSA 23508 
BY | 
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(06444 a 
600 
AV 
500 
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oe tee 
900 
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300 2347 AUTEN Me Oe eee 
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Fig. 1. Curves obtained on heating a charge of sodium metasilicate at various rates 
bare platinum-platinrhodium thermocouple. The charge was contained 
in a thimble crucible of platinum, 1 cm. in diameter and 2 cm. deep, 
