The object for this study was to determine the conditions of stability for tin artifacts and to check for tin disease (tin pest, * 2Zinnpset*1). Many samples of corroded tin alloys were examined. They originated from 300-year-old sarchophagi (from the Grand Duchy of Hessia) and bowls. Optical methods, x-ray powder diffractometry, and energy dispersive analysis were used on microsamples to determine the crystalline phases of corrosion. The formation conditions of the corrosion products were related to Eh-pH (Pourbaix) diagrams. The authors concluded that the corrosion products had formed in the transitional area of the Eh-pH diagrams, centered around Eh +O.6 and pH 5. Tin pest was detected in only one sample. -- AATA