at temperatures of 600°and above, the activity of the catalyst decreased much more rapidly than at the optimum temperature 575°. Very little difference in activity or life of the two catalysts reported in this paper was noted. Several other catalysts of different ratios of chromium and nickel were prepared; they also showed very little difference in activity. With space velocity ratio of 4:1 of hydrogen sulfide to ethylbenzene, only low yields (~5%) of thianaphthene were obtained.Preliminary results with other alkylbenzenes indicate that the reaction may be general, however, the yields do not appear to be as good as in the case of ethylbenzene.Acknowledgment.-The authors are verymuch indebted to the Research Corporation for a Frederick Gardner Cottrell grant-in-aid which supported this research. Summary Thianaphthene has been prepared in 18.5% conversion from hydrogen sulfide and ethylbenzene using a chromia on alumina catalyst at 575°. Claremont, Calif.