In the study of the utlizatiom of the dry distillat'on oils, such as the wood turpentine and the bark oil, we obtained the favonrable frothing ag nts. Our frothing agents were prepared as follows these dry distillation oils were treatel by 10% Japanese acid clay, then distilled, and the camphor was added. When the products, prepared in this method, were used in selective flotation of zinc and lead ores, we found that their frothing powers could stand comparison with G. N. S. No.5 and Takasago Frothing Agent No.9.
The writers still desire to continue this research.