53 



When soda is used, tlie woods employed are usually softer, of mel- 

 lower fiber, and without much strength. The process is similar to that of 

 sulphite, except that in place of sulphurous acid a solution of caustic soda 

 is used iu the digestors. There are various other methods by which at- 

 tempts have been made to separate the wood fibers, most interesting of 

 which perhaps is Kellner's electrical process, in which the wood, boiling 

 in a solution, commonly salt, is subjected to electrical discharges. The 

 value of this px'ocess has not been ascertained, however. Of all the 

 chemical methods in use tlie sulphite method is by far the cheapest and 

 most satisfactory. 



Characteristics and Advantages of Wood-Fibered Paper. 



Ground wood with an admixture of from 10-2.5 per cent, of the 

 chemical tiber is used for newspaper stock, wrapping paper, and for manj' 

 of the lower grades of book, magazine and writing papers. For the very 

 best grades of paper, whether for printing or writing, an admixture 

 of sulphite with rag pulp is neces-'sary. For permanent records the author 

 is of the opinion that only rag pulp, and that of the best quality, should 

 be used. It is true that in from 15 to 20 years the "wood pulp" books, 

 papers, etc., will be greatly deteriorated and that for permanence some 

 other substance must be used. A writer in a recent number of the "Out- 

 look" suggests that publishing houses should print a special edition of 

 each publication on a special <iuality of durable paper, suitably resistant 

 both to chemical and mechanical wear and tear and thus preserve them 

 for posterity. Whether or not the people of our country are careless in 

 this matter, the fact remains that papers made from wood pulp and 

 especially mechanical fiber, are perishable, and that within a very short 

 time. Notwithstanding the great desirability for permanent copies of all 

 our good publications, the larger majority of printed matter will continue 

 to be discai'ded after the first reading — newspapers entirely so and 

 magazines and even books to a large degree at least at the end of six 

 months or a year. It is quite probable that the same prodigality would 

 exist if our papers were made of the scarcer rag pulp, but wood pulp is 

 not only cheaper than pulp made from rags, but it takes impressions 

 better, wears out type less and decreases the possibility of spreading 

 contagious diseases. 



