HEMP HUKDS AS PAPER-MAKING MATERIAL. 25 



Nos. 143 and 144 are satisfactory in these respects, the other sam- 

 ples being more or less thickly specked with shives. The general 

 character and tests of these papers correspond very closely with 

 Ko. 1 machine-finish printing paper, according to the specifications 

 of the United States Government Printing Office, which call for a 

 sheet not exceeding 0.0035 inch in thickness, strength not less than 

 12 points, free from unbleached or ground wood pulp, and ash not 

 over 10 per cent. The strength factor of such papers is about 0.28. 

 The ash should not be over 10 per cent for this grade of paper, but 

 in spite of the larger amount used the physical tests are sufficiently 

 high. It is to be noted that the physical tests of samples Nos. 138 

 to 142, inclusive, are higher than in Nos. 143 and 144, in which 23 

 per cent of soda poplar was used, which shows clearly that hemp- 

 hurd stock imparts strength and folding endurance to a greater 

 extent than does soda-poplar stock. From these preliminary tests it 

 would be concluded, therefore, that hemp-hurd stock acts similarly 

 to soda-poplar stock, but will produce a somewhat harsher and 

 stronger sheet and one of higher folding endurance. Undoubtedly, 

 there is more dirt in the samples than would be tolerated by the 

 trade, but this was to be expected, since in this preUminary work the 

 raw material was sieved by hand screens instead of by automatic 

 machines which would sieve more thoroughly. 



CONCLUSIONS. 



There appears to 5e little doubt that under the present system of 

 forest use and consumption the present supply can not withstand 

 the demands placed upon it. By the time improved methods of 

 forestry have established an equilibrium between production and 

 consumption, the price of pulp wood may be such that a knowledge 

 of other available raw materials may be imperative. 



Semicommercial paper-making tests were conducted, therefore, on 

 hemp hurds, in cooperation with a paper manufacturer. After 

 several trials, under conditions of treatment and manufacture which 

 are regarded as favorable in comparison with those used with pulp 

 wood, paper was produced which received very favorable comment 

 both from investigators and from the trade and which according to 

 official tests would be classed as a No. 1 machine-finish printing 

 paper. 



