NOTES 737 



such an extent that a critical condition exists in the newsprint business, 

 at least of Canada, and warning has been sent out that users of sulphur, 

 like fertilizer manufacturers, may have to be limited to 60 per cent of 

 their normal supplies to reserve its use for explosives. The new method 

 of recovering sulphur from smelter gases is known as the Thiogen 

 process. It can produce sulphur at $12 to $13 and less, while the price 

 for the last ten years has averaged $19 to $20. 



The wet Thiogen process is based on the fact that when an alkaline- 

 earth sulphide, as calcium or barium sulphide, either in divided water 

 suspension or in solution, is added to a solution of sulphur dioxide 

 a reaction takes place. The sulphur dioxide must first be removed 

 from the gases by absorption in water or mother liquor. This is ac- 

 complished by an absorption tower, after the gases have been cooled 

 and cleared of dust and fume. To this is added the sulphide solution, 

 and the precipitate containing the sulphite, thiosulphite, and sulphur is 

 settled, and the mother liquor returned to the absorption tower. The 

 settled precipitate is filtered and dried. The elemental sulphur and 

 one-half the sulphur from the thiosulphite is distilled and the sulphur 

 vapors are condensed. 



Upon recommendation by the Canadian Advisory Council for Scien- 

 tific and Industrial Research, instigated by the Commission of Conser- 

 vation, 100 square miles of the Petawaw^a military reservation, On- 

 tario, an artillery training camp, has been set aside by the militia de- 

 partment as a forest experiment station in co-operation with the Do- 

 minion Forestry Branch, to be available, however, for military purposes 

 so far as needed. Petawawa is situated in a typical white-pine district, 

 and, though almost completely logged at an earlier date, there is now a 

 fine stand of young forest growth and a limited amount of larger ma- 

 terial. The Forestry Branch will supervise the cutting of fuel, etc., for 

 the camp, observing and regulating the cutting operations for purposes 

 of silvicultural practice in the region. A preliminary survey of the area 

 is being made, a type map prepared, and detailed studies of volume, 

 growth, and reproduction undertaken. 



A purchase of 54.672 acres of land for National Forests in the White 

 Mountains, Southern Appalachians, and Arkansas has recently been 

 approved by the National Forest Reservation Commission. These lands 

 solidify the Government holdings, carrying out the Commission's policy 

 to consider only lands tending to block in with those previously ap- 



