NOTES AND COMMENTS 511 



hemlock bark, doubling the value of the latter and saving around 

 $1,000,000 annually. The use of this bark for the manufacture of 

 paper products, increasing at the same time the tannin extraction, 

 gives promise of successful commercial application. A new method of 

 cooking wood by the sulphate process, giving larger yields of greater 

 strength, in shorter time, with less consumption of chemicals than 

 the standard method, has been developed and patented. Loss of 

 chemicals by cooking unbarked chips of yellow pine was investigated, 

 also white and black liquors in the sulphate process were analyzed. 

 An increased yield of 9 per cent in soda pulp, due to introduction of 

 moisture during the cooking period, and the same modification in the 

 kraft process gave excellent results. Darker colored papers, such as 

 are made from tamarack, were found not to produce practically and 

 difiference in eye fatigue compared with that from spruce. 



As regards utilization of sawmill waste for paper pulp, particu- 

 larly of hemlock, an extension of its use is foreshadowed. 



A chemical analysis of American woods has been begun and com- 

 pleted for a number of species, promising the development of the pro- 

 duction of many valuable organic compounds. It was also found that 

 spruce wood contains 61 per cent cellulose, as against a maximum of 45 

 per cent recovered in the yield of pulp. Attem{)ts to increase the pulp 

 yield are encouraging. 



In the manufacture of ethyl alcohol a yield of 20 gallons was ob- 

 tained per ton of dry wood, all conifers giving excellent yields, but the 

 yields from hardwoods being considerably lower. It is estimated that 

 a properly designed plant of 2,500 or 3,000 gallons, located where suffi- 

 cient waste is available, can make ethyl alcohol, at a cost of 14 to 20 

 cents per gallon. 



A method of purifying turpentine secured in the production of 

 kraft pulp from longleaf pine has been developed. 



A field experiment on the width of chipping in the turpentine 

 orchard, with one-fourth-inch streak once a week and with a one-half- 

 inch streak twice a week, averaged about 20 per cent less from the 

 narrower chipping than from the standard, but double chipping pro- 

 duced about 20 per cent greater yield than the standard, indicating 

 the possibility of greatly increasing the yield of turpentine and rosin. 

 The new annual growth rings, formed after the trees were chipped, 

 show that the cell formation began earlier and produced more normal 



