232 BIOLOGICAL PROBLEMS 



rags were allowed to ferment, and were then boiled in 

 an infusion of wood ashes. The resulting pulp, after 

 being anchored in streams of running water to wash 

 out the alkali, was beaten by hand till it reached the 

 proper degree of maceration. The rectified pulp was 

 then diluted with water in vats, and taken up in 

 sieves, so that the water drained away, whilst the 

 fibres, under skilful manipulation, settled down to 

 form the web of paper. Sheet by sheet the paper was 

 pressed between felt, and hung up to dry. Such 

 methods sufficed for many centuries, and, so far as the 

 quality of the product is concerned, still hold their 

 own. With lapse of time, and the natural growth of 

 population, paper came to be produced in increasing 

 quantities, beating by hand was replaced by an auto- 

 matic machine termed the Hollander, but the great 

 impulse came through the invention of the paper- 

 making machine associated with the name of Four- 

 drinier, by means of which the pulp was run on to a 

 travelling fine-wire web, so that it could be treated 

 by a continuous process without breaking bulk. 



The spread of the reading habit, stimulated by 

 compulsory education, and exploited by editors and 

 publishers, created a demand for paper which could 

 not be met by the conversion of rags alone. So far 

 as this country is concerned the increased demand 

 was met in the sixties of last century by utilizing 

 straw, which in due course was displaced by esparto 

 grass (Stipa tenacissima) from North Africa and 

 Spain. By the nineties the manufacture of pulp from 

 wood, and especially the wood of conifers, had become 

 general. 



The esparto industry is in effect a speciality of the 

 British paper-maker, who for many years has imported 

 some 200,000 tons of the dried grass. 



On the continent of Europe straw largely takes its 



