CHAPTER IV

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Columbian Dental Congress--Opinions on Tin Foil--Reasons for Using--Manufacture in United States--Number and Weight of Foil--Cohesion--Good Qualities of Tin Foil--Temporary Teeth-- Thermal Changes--Calcification--Chalky Teeth 27

## CHAPTER V .

Discoloration of Tin--Decomposition of Food--Sulfids--Oxids-- Galvanic, Therapeutic, and Chemical Action 40

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