Comment
　Thermograph shows the first heating and cooling cycle of DSC run.In the heating process：at 122℃　S melting　→　at 239℃　Sn melting　→　SnS formation（255-340℃）. In the cooling process：at 212℃　Sn solidfication. Sulfidation reaction of Sn seems to proceed gradually and slowly even at high temperatures.
The enthalpy of formation
　Main product is the orthorhombic SnS. Its lattice constants are a=4.335Å,b=11.204Å,c=3.980Å. Other impurity phases are hexagonal SnS2 and Sn2S3.