64 ON THE APPLICATION OF ALFA OR ESPARTO 



bleach. Chlorides cause it to take the colour of walnut wood, and acid 

 baths, after the chlorides, leave the fibre in the form of greenish grey 

 matter, only fit for the manufacture of papier bulle. I do not speak of 

 processes -which will produce white pulp at great cost, by means of reagents 

 and time ; they are, or at least have been, commercially impracticable. 

 Those who have not commenced by the elimination of the yellow and 

 red dyes, have treated alfa with corrosive leys or chlorides equally 

 destructive ; they have been able to get white pulp, but the waste or the 

 cost has been represented by startling figures ; it is quite otherwise, in 

 following the rational method of bleaching, by the successive elimination 

 of the two colouring matters. 



According to my experiments, the normal waste is made up as fol- 

 lows : — 



Yellow colouring matter 12 



Red colouring matter 6 



Gum resins 7 



Salts constituting the ashes of alfa . 1-5 



Fibre suitable for paper " . 735 



100 



The theoretic loss of 26 - 5, it is true, can only be estimated, according 

 to the care and discernment exercised in the use of the chemical agents 

 and in the washing manipulations. It is as well, however, to know the 

 exact limit to which perfection may attain. 



The analysis of the ashes determines the quantities of the caustic 

 agents necessary for the washing of the plant. 



I obtained from 100 kilog. of alfa an ash weighing 1'41. From this 

 ash I extracted :— 



SSoda 0-110 

 Sulphuric acid . . 0-090 

 Hydrochloric acid . 0.030 



2. By washing in aqua ( Lime 0-200 



regia the residue left < Sulphuric acid . . 0.285 



bv the water. ( Oxide of iron Fe 2Q- 3 0-045 



^ftS&Ufc Oxide of iron . . 0-324 

 by the aqua regia. ( Slllca 0326 



1-410 



There are also in 100 kilog. of alfa 1-510 of incorporated silicious 

 and ferruginous salts, plus 7 kilog. of gum ; in all 8-510 of matter to be 

 got rid of, in order to free the fibre. Admitting that the silicates require 

 a quantity of alkali, thrice their weight, to make them soluble ; that 

 the resin, to become soap, requires weight for weight of caustic soda, 

 100 kilog, of the plant must, in theory, be treated with 2'250 of alkali, 

 and 7 kilog. of caustic earth. 



In practice, the degree of temperature, and of pressure at which 

 the boilings are made, must be considered, in order to increase or 



